EPA/S30-SW-91-065C
PB92-124783
Mining Sites on the National Priorities List
NPL Site Summary Reports
U.S. Environmental Protection Agency
Office of Solid Waste
June 21, 1991
FINAL DRAFT
Volume ffl
Prepared by :
Science Applications International Corporation
Environmental and Health Sciences Group
7600-A Leesburg Pike
Falls Church, Virginia 22043
REPRODUCED BY
U.S. DEPARTMENT OF COMMERCE
NATIONAL TECHNICAL
INFORMATION SERVICE
SPRINGFIELD. VA 22161
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/530-SH-91-Q65C
3.
PB92-124783
4. Title and Subtitle
MINING SITES ON THE NATIONAL PIRORITIES LIST: NPL SITE SUMMARY REPORTS
(FINAL DRAFT) VOLUME III: KERR-MC6EE CHEMICAL CORP. TO ORMET CORPORATION
5. Report Date
JUNE 21. 1991
6.
7. Author(s)
V. HOUSEHAN/OSH
8. Performing Organization Rept. No
9. Performing Organization Name and Address
U.S. EPA
Office of Solid Waste
401 M. Street SH
Washington. DC 20460
10. Project/Task/Work Unit No.
11. Contract(C) or Grant(6) No.
(C)
(G)
12. Sponsoring Organization Name and Address
SAIC
ENVIRONMENTAL & HEALTH SCIENCES GROUP
7600-A LEESBURG PIKE
FALLS CHURCH. Vft 22043
13. Type of Report & Period Covered
SUMMARY REPORT
14.
15. Supplementary Notes
16. Abstract (Limit: 200 words)
Volune III of the Mining Sites on the National Priorities List contains the following NPL Site Summary Reports: Kerr-
McGee Chemical Corp. (Soda Springs Plant), Lincoln Park, Martin Marietta Reduction Facility, Midvale Slag (Valley
Materials Slag), Hllltown Reservoir Sediments, MOfttsanto Chemical Company, MOnticello Mill Site, Monticello Vicinity
Properties, Mouat Industries, and Ormet Corporation.
17. Document Analysis a. Descriptors
b. Identifiers/Open-Ended Terms
c. COSATI Field/Group
18. Availability Statement
RELEASE UNLIMITED
(See ANSI-Z39.18)
19. Security Class (This Report)
UNCLASSIFIED
20. Security Class (This Page)
UNCLASSIFIED
OPT!
(For
21. No. of Pages
Ml
22. ' Price
0
ONAL FORM 272 (4-77)
inerly NTIS-35)
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SENT BY:SQIC IJPSTE REGS DEPT ; 2- 3-92 12:25PM ; 7038214775-j 321 6199;« 3
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
WASHINGTON. O.C. 20460
OFFICE OF
8OLIO WASTE AMD EMERGENCY HESPON9E
Appendices of these reports include excerpted
pages from documents referenced in the text of
the reports, and as a result, page numbers in
the appendices are not necessarily consecutive.
In addition, since many of the references are
3rd or 4th generation copies, some pages may
not be legible, but are the best available.
Printed on Rtcycied Papw
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Mining Waste NPL Site Summary Report
Kerr McGee Chemical Corporation
Soda Springs, Idaho
U.S. Environmental Protection Agency
Office of Solid Waste
June 21, 1991
FINAL DRAFT
Prepared by:
Science Applications International Corporation
Environmental and Health Sciences Group
7600-A Leesburg Pike
Falls Church, Virginia 22043
I!
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Volume Ill
Kerr-McGee Chemical Corp. (Soda Springs Plant)
Lincoln Park
Martin Marietta Reduction Facility
Midvale Slag (Valley Materials Slag)
Milltown Reservoir Sediments
Monsanto Chemical Company
Monticello Mill Site
Monticello Vicinity Properties
Mouat Industries
Orinet Corporation
Mining Sites on the National Priorities List
NFL Site Summary Reports
TABLE OF CONTENTS
Soda Springs, ID
Cannon City, CO
The Dalles, OR
Salt Lake Co., UT
Militown, MT
Soda Springs, ID
San Juan, Co., UT
San Juan, Co., UT
Columbus, MT
Hannibal, OH
111
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.Iv
DISCLAIMER AND ACKNOWLEDGEMENTS
The mention of company or product names is not to be considered an
endorsement of the U.S. Government or by the U.S. Environmental
Protection Agency (EPA). This document was prepared by Science
Applications International Corporation (SAIC) in partial fulfillment of
EPA Contract Number 68-W0-0025, Work Assignment Number 20.
A previous draft of this report was reviewed by Christine Psyk of
EPA Region X [ (206) 553-6519], whose comments have been
incorporated into the report.
0
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Mining Waste NPL Site Summary Report
KERR MCGEE CHEMICAL CORPORATION
SODA SPRINGS, IDAHO
INTRODUCTION
This Site Summary Report for the Kerr McGee Chemical Corporation is one of a series of reports on
mining sites on the National Priorities List (NPL). The reports have been prepared to support EPA’s
mining program activities. In general, these reports summarize types of environmental damages and
associated mining waste management practices at sites on (or proposed for) the NPL as of February
11, 1991 (56 Federal Register 5598). This summary report is based on information obtained from
EPA files and reports and on a review of the summary by the EPA Region X Remedial Project
Manager for the site, Christine Psyk.
SITE OVERVIEW
The Kerr McGee Chemical Corporation, a vanadium pentoxide production facility, is an active site
located approximately 2 miles north of Soda Springs, Idaho (population 3,000). The 158-acre site is
accessed via State Highway 34, and is situated in a rural valley, near the western base of the Aspen
Range (see Figure 1).
The Kerr McGee facility produces vanadium pentoxide from ferrous-phosphate solid residuals
obtained from the Monsanto Chemical Corporation elemental phosphorus plant. Monsanto is located
directly across State Highway 34 from Kerr McGee. The Kerr McGee plant also produces small
amounts of ammonium metavanadate (AMy). Vanadium pentoxide is used primarily by the
petroleum refining industry as a catalyst for organic reactions and in sulfuric acid production. AMV
is used in the production of maleic anhydride and adipic acid (Reference 1, pages 2, 10, and 11).
Maleic anhydride and adipic acid are used in the production of polyester.
On behalf of EPA, Ecology and Environment inspected the site in 1988. As a result of the Site
Inspection, 14 ground-water samples, 1 surface-water sample, and 9 waste-pond samples were
collected from the site and surrounding areas. The results of the Site Inspection showed that
hazardous substances were being stored in ons lie waste ponds (Reference 1, Abstract). Leached
calcine tailings, magnesium ammonium phosphate (MAP) residuals, solvent extraction raffinate, and
scrubber residuals are among the wastes stored in these ponds (Reference 1, page 11).
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Kerr McGee Chemical Corporation
Figure 1
U.A.P.
Ponds
0 150 300 450
scsi. (uI
600
oIogy & environment.
flO470204 west. 5Iis moOZ3
brown by: 0. p Dots: Duc. 1! J!!L
SITE NAP
KERR MCGEE CHEMICAL CORPORATION
Sodo Springs. ID
FIGURE 1. SITE MAP
LEGEND
- u - -
—..—-..— Co. Ib *
.____--. 0iviro d
Pow ’
— . — (Iltuont flow
2
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Mining Waste NPL Site Summary Report
The Site Inspection also determined that the shallow aquifer is contaminated with hazardous
constituents released by the Kerr McGee facility. The degradation of ground-water quality
downgradient of the site may adversely impact irrigation and industrial water-supply sources
(Reference 1, Abstract). The sampling completed by Environment and Ecology revealed that the
concentrations of arsenic, copper, nickel, potassium, silver, sodium, vanadium, chloride, phosphate,
and sulfate in ground water collected from monitoring wells significantly exceeded background
concentrations (Reference 1, pages 27 and 29).
Topography in the area of the site inhibits contaminant migration via surface water (Reference 2,
Cover Sheet). The closest surface water to the Kerr McGee site is Soda Creek, located 2.5 miles to
the west. There are no registered surface-water intakes within 3 miles of the site, although Soda
Creek is used for irrigation and stock water in other areas (Reference 1, pages 7 and 47).
To date, a Health Assessment has not been completed. In addition, costs for removal/rernediation
actions have not been estimated (Reference 3, page 2). According to EPA Region X, EPA signed an
Administrative Order for a Remedial Investigation/Feasibility Study on September 20, 1990.
OPERATING HISTORY
The Kerr McGee Chemical Corporation purchased the site property from Vernal Hopkins of Soda
Springs, Idaho, in 1963. A vanadium pentoxide production facility was constructed on the property,
and has operated since that time. The facility has not been used for any other industrial purpose
(Reference 1, page 1).
The Kerr McGee facility produces vanadium pentoxide and small quantities of AMV. Vanadium
pentoxide is used in the petroleum refining industry as a catalyst of organic polymers and in sulfuric
acid production. AMV is used in producing maleic anhydride and adipic acid. Raw ore that is
utilized at the facility is ferro-phosphorous. The ore is obtained from Monsanto’s elemental
phosphorous plant (Reference 1, pages 10 and 11).
Ferro-phosphorous ore is crushed and mixed with limestone rock and then roasted. The ferro-
phosphorous ore and limestone rock conversion process produces sodium vanadate (vanadium salt).
Vanadium is recovered from sodium vanadate by solvent extraction and direct precipitation. AMV is
produced after purification during the solvent extraction and precipitation processes. Some AMV is
washed, dried, and marketed, but the majority is decomposed at a regulated temperature to form
granular and flaked vanadium pentoxide. Production wastes have been stored in onsite waste disposal
ponds (Reference 1, page 11).
3
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Kerr McGee Chemical Corporation
Leached calcine tailings, MAP residuals, solvent extraction raffinate, and scrubber residuals are the
four major wastestreams generated by the Kerr McGee facility. All of these wastes are contained in
onsite surface impoundments that are lined with 10 feet of clay (see Figure 1). According to Kerr
McGee records, hazardous feedstock materials stored onsite include anhydrous ammonia (20 tons),
sulfuric acid (36 tons), sodium hydroxide (2,000 pounds), ferrous sulfate (40,000 pounds), potassium
hydroxide (4,000 pounds), and vanadium products produced at the facility (66,000 pounds)
(Reference 1, page ii).
Leached Calcine Tailings
Leached calcine tailings originate from the preparation of sodium vanadate leach solution. The
tailings are the first major impurity removed in the plant process. The tailings are slurried through a
pipe and stored in two separate 1-acre evaporation ponds east of the facility (Reference 1, pages 13
and 14).
Magnesium Ammonium Phosuhate Residuals
MAP is a by-product of phosphorous and calcine removal from the first precipitation stage of solids
containing slight amounts of vanadium (vanadium cake). The MAP residuals are slurried to two
MAP Ponds located on the northern edge of the site (Reference 1, page 13).
Solvent Extraction Raffinate
Solvent extraction raffinate is a liquid residual produced from the vanadium purifying process. The
extraction raffinate wastestream, mixed with residuals from the limestone scrubbers, is piped to two
Settling Ponds located east of the Solvent Extraction (SX) Pond. From the Settling Ponds, the liquid
fraction is pumped into the SX Pond. The SX Pond is the final impoundment for the raffinate
discharge, and has an approximate total area of 60,000 square feet (Reference 1, pages 11 and 13).
Scrubber Residuals
Scrubber residuals are produced from the two major scrubbing systems within the facility. Limestone
scrubbers in the sizing and physical ore-preparation section of the plant generate limey tails, which
are mixed with the raffinate stream and piped to the Settling Ponds. Roaster scrubbers produce tails
from the emissions from high-temperature heating of the raw ferro-phosphorous ore (Reference 1,
4
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Mining Waste NPL Site Summary Report
page 14). The Roaster Scrubber Pond, basically triangular in shape, has an area of approximately
75,000 square feet.
Other Potential Sources
The waste oil generated at the facility is spread on roads for dust control. Prior to 1980, waste
solvents generated at the facility were mixed and disposed with the waste oil. Since 1980, waste
solvents have been removed from the facility for recycling by a contractor (Reference 1,
page 15).
SITE CHARACTERIZATION
The site is located in the Bear River Basin of southeast Idaho. The basin is characterized by broad,
flat valleys with base elevations near 6,000 feet above sea level, and northwest-trending mountain
ranges with relief above the valleys of 1,000 to 1,500 feet. Soda Creek, the main drainage system in
the site area, has its headwaters near Five Mile Meadows, at an elevation of approximately 6,000 feet
(Reference 1, page 5).
The structure and geology of the site are characteristic of the Basin and Range physiographic
province, and are reflected in the high-angle normal faults which have created a series of valleys
bounded by isolated mountain ranges. These ranges are composed of pre-Tertiary and Tertiary rocks.
The valley floors are mantled by Quaternary/Tertiary volcanic rocks and recent sediments. Tertiary
and/or Quaternary basalt flows cover a majority of the valley floors (Reference 1, pages 5 and 6).
Bedrock at the site is a series of highly fractured basalt flows that range in total thickness from 16 to
greater than 250 feet. The basalt is overlain by from 2 to 19 feet of recent sediments, much of them
alluvial in origin. The western border of the Kerr McGee site is traversed by a locally north-south
trending, high-angle normal fault. A local subsidiary fault that trends east-west intersects the north-
south trending fault near the southwest corner of the site (Reference 1, pages 6 and 7).
Ground Water
The highly fractured basalt bedrock is the most productive aquifer in the vicinity of the site, yielding
greater than 1,000 gallons of water per minute, and is a major source of ground water in the area. In
the site area, depth to ground water in the basalt ranges from 20 to 38 feet below ground surface.
Variable amounts of ground water are also found in the overlying alluvial deposits, although this
5
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Kerr McGee Chemical Corporation
water is used primarily to supply domestic and stock wells. The direction of ground-water movement
in the Soda Creek Basin is generally to the west-southwest. This pattern is locally affected by the
normal faults that exist in the area. The faults serve as conduits for the movement of ground water,
and cause local changes in the vertical and/or horizontal patterns of flow. The most productive zones
in the basalt occur in the porous materials between basalt flows (Reference 1, pages 6 and 7).
Ground water in the vicinity of the Kerr McGee site is used for domestic and public drinking
supplies, irrigation, and industrial purposes. There are 22 registered domestic wells within 3 miles of
the site that serve approximately 84 individuals. There are also four industrial production wells on
(and near) the site (three at Monsanto, one at Kerr McGee). Previously, approximately 400
employees were provided with drinking water from the Monsanto wells and 80 from the Kerr McGee
well; now, they are served by the City water system. Water that is distributed by the Soda Springs
Water Department is obtained from two natural springs, one northeast of the site and another
south/southeast. This system serves over 3,000 people. Ground water drawn from seven wells
located within 3 miles of the site is used to irrigate approximately 4,698 acres (Reference 1,
page 9).
Ground water is considered to be the most likely pathway for contaminant migration from the Kerr
McGee site (Reference 2). Analyses provided in the Site Inspection Report indicated that arsenic,
copper, nickel, potassium, silver, sodium, vanadium, chloride, phosphate, and sulfate are potentially
being released to shallow ground water from the waste ponds at the facility. Each of these
constituents was detected in monitoring wells located downgradient of the waste ponds at
concentrations greater than 10 times the concentration in the background well. Table 1 summarizes
these data. Vanadium, chloride, sulfate, and sodium appear to be the constituents most widely
distributed in ground water (Reference 1, pages 27 and 29). The Site Inspection Report specifically
implicates the Scrubber and SX Ponds as sources of this contamination (Reference 1, pages 46 and
47).
In 1988, it was concluded that neither the domestic drinking wells nor the municipal water supply
appeared to be affected by contaminants attributable to the Kerr McGee site. However, contaminants
from the site that have been detected in the onsite and offsite monitoring wells have the potential to
migrate downgradient over time, due to the fractured nature of underlying basalt flows. This
potential for contamination is evident in the high concentrations of contaminants reported in the
samples from the nine monitoring wells (Reference I, page 47).
6
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TABLE I. SUMMARY OF SIGNIFICANTLY ELEVATED CONTAMINANT CONCENTRATIONS
IN MONITORING WELL SAMPLES (in mg/I)
r
(I , )
C ,)
C
9
3
9
.
-J
Contaminant
MW
#7
(Background)
MW
#2
MW
#3
MW
#4
MW
#5
MW
#6
MW
#8
NW
#9
Monsanto
#12
Monsanto
#33
Arsenic
<0.001
0.031
0.019
0.025
Copper
0.028
0.32
Nickel
0.007
0.156
0.134
Potassium
2.40
82.9
37.1
34.2
_________
Silver
0.0004
0.005
Sodium
9.00
3,482
184
1,397
165
955
405
387
Vanadium
0.055
19.1
1.88
8.50
0.640
4.90
2.72
1.00
0.465
Chloride
6.00
2,880
252
1,190
272
1,690
334
333
Phosphate
0.430
31.2
8.8
5.4
Sulfate
34.1
7,070
2,840
I ,060
780
769
TOTAL’
10
3
8
3
7
0
4
4
1
‘Number of analytes detected at concentrations greater than or equal to concentrations observed in background well (MW #7).
Source: Reference I, Table 12
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Kerr McGee Chemical Corporation
Surface Water
Should a spill or leak from the Kerr McGee Waste Ponds occur, surface migration of contaminated
wastewater would be a potential hazard. Soda Creek, the surface water nearest to the site, would
likely not be directly affected by surface migration of contaminants due (primarily) to local
topographic features as it is 2.5 miles from the site (Reference I, page 47).
Waste Ponds
Data provided by Kerr McGee for the liquid fraction of samples from the East Calcine Tailings Pond
are shown in Table 2 below.
TABLE 2. CALCINE TAILINGS POND
Substance
Concentration (mg/I)
Vanadium
370.0
Arsenic
0.01
Cadmium
0.01
Chromium
0.026
Lead
0.076
The Site Inspection data indicated that concentrations of chromium and vanadium in the Calcine
Tailings Pond were of concern. In addition, the Site Inspection Report provided the results of the
analysis of samples of the solid and liquid portions of the Calcine Tailings Pond. These data are
presented in Tables 3 and 4 (Reference 1, pages 14. 32, 33, 45, and 46).
Analyses of samples of the solid and liquid portions of the SX Pond that were performed in
conjunction with the Site Inspection are provided in Tables 3 and 4. Concentrations of arsenic,
cadmium, and vanadium in the SX Pond were of concern (Reference 1, pages 11, 13, 32, 33, and
46).
Extraction Procedure (EP) Toxicity analysis provided by Kerr McGee for the Scrubber Pond solids
did not exceed EP Toxicity criteria for hazardous waste. The results of the analyses of samples
collected from the Scrubber Pond during the Site Inspection are reported in Tables 3 and 4. Of
concern were concentrations of arsenic, lead, and vanadium in the Scrubber Ponds (Reference 1,
pages 14, 32, 33, and 46).
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Mining Waste NPL Site Summary Report
The Site Inspection Report also provided the results of organics analyses performed on a sample
collected from the Settling Pond. These results are presented in Table 5. The Report stated that
organic constituents of concern in the Settling Pond included phenanthrene, naphthalene, and 2-
methylnaphthalene (Reference 1, pages 35 and 46).
ENVIRONMENTAL DAMAGES AND RISKS
Initially, the Kerr McGee facility was identified by EPA Region X as requiring a preliminary
assessment screening. Subsequently, Ecology and Environment conducted a Site Inspection for EPA
to assess waste-disposal activity at the Kerr McGee facility. This Report was intended to identify the
existence and nature of potentially hazardous waste contamination alleged in a 1985 Preliminary
Assessment completed by the Idaho Hazardous Materials Bureau (Reference 1, page 1).
Ground water is the most likely pathway for contaminant migration from the Kerr McGee site.
Although the private and municipal drinking-water wells have not yet been affected, contaminants
have been detected in offsite monitoring wells. Ground-water contamination from the facility is
evidenced by the sampling data gathered by Environment and Ecology during the inspection in July
and August 1987.
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Kerr McGee Chemical Corporation
TABLE 3. SUMMARY OF INORGANIC ELEMENTS AND ANIONS DETECTED
IN SOLID FRACTION WASTE POND SAMPLES
Elenienti
Compound
MAP Solids
(mg/kg)
Tailings Solids
(mg/kg)
SX Pond Solids
(mg/kg)
Scrub Solids
(mg/kg)
Aluminum
5.639.O
4.470 0
11.980 0
2.938 0
Antimony
U
U
U
05
Arsenic
11
03
5.3
2.6
Barium
41.0
290
750
65.0
Beryllium
0.41
0.10
1.19
049
Cadmium
0.76
0 07
4.17
5 2
Calcium
5,240.0
130,400
46.300 0
85.900 0
Chromium
56.9
2.1100
1,6270
2.2040
Cobalt
5.0
155
148
11 5
Copper
525.0
2,228 0
691 0
2,986.0
Iron
5,255.0
27.770 0
22,380 0
35,810.0
Lead
3.0
U
100
1120
Magnesium
114,700.0
1.8840
7.1500
2,3020
Manganese
98.0
862 0
234 0
179 0
Mercury
U
U
035
13
Nickel
520
2,126 0
4990
4680
Potassium
6,460.0
626.0
4.680 0
924 0
Selenium
U
U
U
4 3
Silver
2 94
34 6
61 0
25.9
Sodium
719 0
2 1.220 0
7,780.0
3.135 0
Thallium
U
U
03
05
Vanadium
660.0
3,660 0
2,620 0
3,940 0
Zinc
25.0
25 0
130 0
54 3
Chloride
82.7
208 0
4,060 0
2,210.0
Fluoride
162.0
378 0
302.0
368.0
Phosphate
111,160.0
84,6300
19.360 0
15.7400
Sulfate
64.3
204 0
25,260 0
698 0
U - Undetected at detection limits presented in Appendix C
Source’ Reference 1, Table 14
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Mining Waste NPL Site Summary Report
TABLE 4. SUMMARY OF INORGANIC ELEMENTS AND ANIONS DETECTED
IN LIQUID FRACTION WASTE POND SAMPLES
Element/
Compound
MAP Water
(mg/I)
Tailings Water
(mg/I)
SX Pond Water
(mg/I)
Scrubber Pond
Water (mg/I)
Aluminum
1.09
0 650
0.590
0 66
Antimony
U
U
U
U
Arsenic
0 032
0 005
0.394
U
Barium
U
U
U
U
Beryllium
U
U
0.001
U
Cadmium
0 0022
0 0004
0 0065
0 052
Calcium
35.6
130
2670
2120
Chromium
0.032
0 030
0 012
0 862
Cobalt
0.001
0 009
0 050
0.009
Copper
0.365
0 298
0 845
22.3
Iron
1.485
1462
0311
2.54
Lead
U
U
0049
0.026
Magnesium
176.0
16 8
332.9
51.5
Manganese
0.043
0.088
0 187
0 132
Mercury
U
U
U
U
Nickel
0 038
0 205
0.097
0.283
Potassium
14.0
7 7
1,148.0
25 1
Selenium
0.006
0 006
0.097
0.012
Silver
0.0115
00229
00381
0188
Sodium
146.0
508.0
9,480.0
1,178.0
Thallium
U
U
U
U
Vanadium
70.4
56 1
64.8
9.24
Zinc
0.024
0 012
0.061
0 085
Chloride
126.0
376 0
8,950 0
2,430.0
Fluoride
0 20
0 44
I 4
1.9
Phosphate
61.5
662
2100
436
Sulfate
88 4
146 0
20,400 0
146 0
U - Undetected at detection hmits presented in Appendix C
SourceS Reference 1, Table 15
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Kerr McGee Chemical Corporation
TABLE 5. SUMMARY OF ORGANIC COMPOUNDS DETECTED IN SOLID FRACTION
SAMPLES FROM THE SCRUBBER AND SETFLING PONDS
I Concentration (mg/kg)
Compound
ScrUbb f Pond
Settling Pond
Acetone
0.263’
U
Chioromethane
U
0001
Total Xylenes
U
0.256
Ethylbenzene
U
0 024
Tolucne
U
0.024
Benzo(a)pyrenc
U
0 240
Dibenzo(a,h)anthracene
U
0 320
Phenanthrene
U
430
Napthalene
U
2.50
2-Methylnaphthalene
U
18.0
Pyrene
U
0250
Benzo(g,h,i)perylene
U
0 350
Indeno(1.2,3-cd)pyrene
U
0.310
Benzo(b)fluoranthcne
U
0 230
Benzo(k)fluoranthcne
U
0 230
U - Undetected at detection broils presented in Appendix C
‘Acetone is a common . oratory solvent and is likely present an this sample as a result of laboratory contamination or field decontamination
residuals.
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Mining Waste NPL Site Summary Report
In addition, according to EPA Region X, there have been two reported spills from the Kerr McGee
Waste Ponds. The first was in 1981 when the SX Pond dike failed; the other was in 1989 from the
Settling Pond. Surface migration of contaminated wascewater is a potential hazard, but migration of
wastewater to Soda Creek, the nearest, permanent surface waler to the site, is unlikely due
to local topography and distance from the site. Waste Pond solids may be a source of potential,
direct-contact exposure to onsite workers or trespassers. Air monitoring was not conducted,
“although local air quality may be affected by continuing emissions from the Kerr McGee facility”
(Reference 1, pages 27, 47, and 48).
Targets at the highest potential risk from ground-water contamination include users of nearby
production and irrigation wells. Croplands near the site that are irrigated with water from the
production wells located on the Monsanto property are potential targets for releases from the Kerr
McGee facility. As previously mentioned, the nçarest domestic drinking-water and municipal-water
supply sources are located upgradient from the site (Reference 1, page 48).
REMEDIAL ACTIONS AND COSTS
Remedial action alternatives have not yet been investigated, so potential costs for remedial action have
not been estimated.
CURRENT STATUS
The site continues to operate as a vanadium pentoxide production facility. According to EPA Region
X, EPA signed an Administrative Order for an Remedial Investigation/Feasibility Study on September
20, 1990. Field work is underway.
13
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Kerr McGee Chemical Corporation
REFERENCES
I. Final Site Inspection Report for Kerr McGee Chemical Corporation, Soda Springs, Idaho;
Ecology and Environment; April 1988.
2. Hazard Ranking System Score Sheet and Documentation for the Kerr McGee Chemical
Corporation, Lynn Guilford, EPA; May 11, 1988.
3. Riegel’s Handbook of Industrial Chemistry, (edited by James A. Kent) Seventh Edition; Van
Nostrand Reinhold Company, N.Y.; 1974.
14
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Mining Waste NPL Site Summary Report
BIBLIOGRAPHY
Downey, F. Kent (Kerr McGee Chemical Corporation). Letter and Attachments to Jeffrey Whidden,
Ecology and Environment. April 21, 1987.
Ecology and Environment. Field Notes From Site Investigation, Kerr McGee Chemical Corporation,
TDD F1O-8702-04. March 1987.
Ecology and Environment. Field Notes From Site Investigation, Kerr McGee Chemical Corporation,
TDD F1O-8702-04. July 1987.
Ecology and Environment. Final Site Inspection Report for Kerr McGee Chemical Corporation, Soda
Springs, Idaho. April 1988.
Gilford, Lynn (EPA). Hazard Ranking System Score Sheet and Documentation for the Kerr McGee
Chemical Corporation. May 11, 1988.
Kirk, R.E. and P.F. Othmer. Encyclopedia of Chemical Technology, Third Edition, Volume 23,
Wiley-Interscience Publications. 1983.
State of Idaho, Department of Water Resources. Water Rights Abstract, Soda Springs, Idaho Area.
March 15, 1987.
State of Idaho, Department of Water Resources. Well Logs, Soda Springs, Idaho Area. March 15,
1987.
15
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Kerr McGee Chemical Corporation Mining Waste NPL Site Summary Report
Reference 1
Excerpts From Final Site Inspection Report for Kerr McGee Chemical Corporation,
Soda Springs, Idaho; Ecology and Environment; April 1988
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FINAL SITE INSPECTION R.EPORT FOR
KERR MCGEE CHEMICAL CORPORATION
SODA SPRINGS, IDAHO
TDD F1O-8702-04
Report Prepared by: Ecology and Environment, Inc.
Date: April 1988
Submitted to: J.E. Osborn, Regional Project Officer
Field Operations and Technical Support Branch
U.S. Environmental Protection Agency
Region X
Seattle, Washington
-------
LESTRAC !
Under Environsental Protection Agency (EPA) Technical Directive
Docunent (TDD) P10—8702-04, a file r.vi.v and sit, inspection va con-
ducted at the Karr McGee e.ica1 Corporation plant in Soda Springs,
Idaho, to evaluate the facility’s status vi thin the Agency’ s Une o1-
led Hazardous Vasts Site Progras. As a result of this inspection, four.”
teen ground vacer saaples, one surface vater sssple, and am, vasts pond
sa.plea vere coU.ctsd f roe the site and surrounding areas. The uaplss
vera analyzed for EPA Target Cospound List (TCL) caspoimda and four
anions (chloride, fluoride, phosphate, and sulfate) to detsriin. the
presenc. and concentrations of these eonpounda in local ground vater,
surface vater, and the on—sits vests ponds. In addition, a g.ophysi
survey vas conducted at the site to d.tsrein. the potential presence of
coacalinant pl’— — cing fre. the vests panda. The .ssapling strat-
s van designed to dst.ratne the potential effects of the sit. on hit .ii
health or environ.,ntal quality of the surrounding ares.
The results of the sits inspection indicate that hazardous sub-
stances are being stored in the on—site vast, ponds. Saspling results
fran this investigation and past studies indicate contaninacion of the
ik tl v aquifer vith heavy ..tals and anions in the vicinity of the SI
and scrubber ponds. The inspection concluded that releases fre. the
facility are esuting a general decrease 0 f ground vater qn l Icy dovu-
gradient of the site that say adversely affect irrigation and industrial
vater supply sources. -
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1• 0 WrRO0UC I0N
The Kerr McGee Cheeical Corporation plant, near Soda Springs,
Idaho, is an active facility that has been identified by the Region I
Envi ronsen tal Protection Agency (EPA) free preliainary assessaen t
screening as requiring additional infornation to accurately profile the
and extent of past vaste disposal activity at the site. Ecology
and Environment, Inc. (E&E) yes requested by the EPA under Contract
No. 68-01—7347, and Technical Directive Document (TDD) No. P10-8702-04
to conduct a Site Inspection (SI) of th. property. The SI v ia intended
to evaluate the existence and nature of potential hazardous vaste con-
taaination alleged in a Preliminary Asssss.ent coeple ted by the Idaho
!azardeus Materials Bureau in 1963.
An EPA Site Inspection (SI) represents the last phase of a three—
step process desigued to identify and rank actual or potential public
health and enviroii ,ntal threats associated vith a particular site rela-
tive to other sites across the nation. The SI specifically is intended
to gather sufficient data, suppl..ental to that gathered during Site
Discovery and Preliminary Assessment activities, to prioritize sites for
additional york and guide decision sahara in ascertaining the leap. of
such york.. The SI is not intended to provide complete environmental
characterization of a site.
The Kerr McGee e.ical Corporation facility processes vanadium
pentoxide. £ number of vaste strew are generated in the plant pro-
cesses, and are stored in on-cite vests disposal ponds. EPA has raised
concerns over the potential for off—site .igration of these vastes,
vhich say contain hazardous substances.
This document is a cospilation of data gathered for and during the
investigation of the Kerr McGee Chical Corporation site. Inior.ation
pertaining to the ovuership, history, enviroumental setting, and opera-
tions of th. site are included in this report, as an, data generated
during field sampling and site characterization activities. Information
collected during the inspection is mrized on EPA Porn 2070-13 in
Appendix A.
2.0 0V!I10P A 0R ST0&T
The Kerr McGee sical Corporation (Kerr NcG.s) purchased the site
property from Vernal !opk.tas of Soda Springs, Idaho in 1943, and built a
vanadium pentexide production facility on the property vbich has oper-
ated since that ties. The property has not been used for any other
industrial purposes. Kerr McGee’ s corporate offices are located at 123
Robert S. Kerr Avenue, Okiahoen City, Oklahoma.
33’
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3.0 LOCATION
The facility is located approximately two miles north of Soda
Springs, Idaho, in Sections 27, 28, 32 and 33, Township 8 South, Range
42 East of the Boise Meridian (Figure 1) (1). The site is accessed via
State Highway 34, north of Soda Springs.
4.0 SITE DESCRIPTION AND SURROUNDING AREA
The facility manufactures vanadium pentoxide from ferrous-phosphate
solid residuals acquired from the nearby Monsanto Chemical Corporation
plant. Vanadium pentoxide is used primarily by the petroleum refining
industry as a catalyst for organic reactions (2). Liquid and solid
wastes from the facility are disposed of in on—site surface impoundments
(ponds) (Figure 2).
The 138 acre site is situate _in a broad rural valley, near the
western base of the Aspen Range. Lsiguificant agricultural crops in the
area include wheat and hay. A nuiber of other large industrial com-
plexes are located in the valley, including the Monsanto Chemical Cor-
poration plant (elemental. phosphorous production), directly across State
Highway 34 from Kerr McGee, and the Mu Vest Industries facility (phos—
phori , acid production) , located approximately four miles to the north
(1).J
— The largest population center in the site area is the City of Soda
springs, with an approximate population of 3,000. Population demo-
graphics within a three—mile radius of the facility are sttm rized in
Table 1.
TABLE 1
POPULATION DEMOGRAPKICS (1., 3)
Radial Distance Demographical. Description
On—Site Drinking Vater Veils: 1
Number of Employees: 80
1 Mile Residents: approx. 23
Buildings: 44
2 Miles Residents: approx. 650
Buildings: 200
3 Miles Residents: approx. 3,000
Buildings: 800
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4 AND SURBOUNDDIG ARIA
nufactures vanadlue pentozide from ferrous-phosphate
ired from the nwby Nonsant. Chemical Corporation
toxide is used primarily by the petroisu. refining
at for organic reactions (2). !.iquid and solid
.l.ity are disposed of in on—sits surface iapowid.ents
its is si tuat.4..in a broad rural valley, near the
Aspen Rang.. LSlsnificaat agricultural crops in the
and hay. A nuiber of other large industrial cc.-
in the valley, including the Koasanto Chemical Car-
i.ental phosphorous production), directly across State
.r McGee, and the N s a Vest Industries facility (phos..
tion) , located approximately four silos to the north
apulation center in the site ax.. is the City of Soda
ipproximat. population .f 3,000. Population d=
thrse a ll. radius of the facility are s”’ised in
fuLl 2
POPUUTZOU * uJ3 (1. 3)
Distance Dsgraphical Description
e Drinking Vatsr Vsl.lsi 1
Nosber of Raployeess 80
sags Ph7Iiogx phj
‘ixed by flO thy. t.
ave created a series
L. t this charact. _
a th. area range
•ouplea
ivs I(jla Neadovs Is
e gapes Rang, to the
rocks. Zn
‘I Tertj . ‘olcanic
rftagy saadsto . 5 ,
and
Included L i this
lined loca]1 y and
tiaxy rocks Yield
of the Aspen
‘s.d in the
Lieatoeni, tuUa...
mation yislda
tic and stock
of the ‘alley
cone LUuvjel
dark gray in
35 local vents,
?isceous. Tb.
in 30 £.ee near
hiehoess in the
.5 of fault
Located approximately eve
:tions 27, 28, 32 and 33,
leridian (Figure 1) (2).
th of Soda Springs.
miles north of Soda
Tovnship 8 South, Range
The site is accessed via
of sau Idh .
flit ‘all. 75 vIth baa,
ort e,e treading
1,000 to 1,3 feet.
:o th. east of the site.
area, has lt head..
6,0Q
ervoj near Soda
Lea
Residents,
Buildingis
Rasidents:
Buildiagis
Residents a
Buildings a
approx. 23
‘ 4
approx. 630
200
approx. 3,000
800
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5.0 TOPOGRAPHY AND DRAINAGE
The site is located in the Bear River Basin of southeast Idaho.
The Bear River Basin is characterized by broad, flat valleys with base
elevations near 6,000 feet above sea level, and northwest trending
mountain ranges vith relief above the valleys of 1,000 to 1,500 feet.
One such mountain range, the Aspen Range, rises to the east of the site.
Soda Creek, the main drainage system in the site area, has its head—
vaters near Five Mile Meadows, at an elevation of approximately 6,000
feet. The creek flows south to the Alexander Reservoir near Soda
Springs (Figure 1) (1).
6.0 GEOLOGY/HYDROLOGY
6.1 Regional Geology/Hydrology
Southeastern Idaho is part of the Basin and Range physiographic
province. The Basin and Range province is characterized by northvest—
southeast trending high—angle normal faults which have created a series
of valleys bounded by isolated mountain ranges (3).
The structure and geology of the site area reflect this character-
istic pattern of the Basin and Range. Geologic units in the area range
in age from pre—Tertiary to Quaternary, and have a complex structural
history. The broad structural valley that contains Five Mile Meadows is
bounded by the Chesterfield Range to the vest and the Aspen Range to the
east. These ranges are composed of pre—Tertiary and Tertiary rocks. In
contrast, the valley floors are mantled by Quaternary/ Tertiary volcanic
rocks and recent sediments.
The Aspen Range is composed dominantly of pre—Tertiary sandstones,
conglomerates, limestones, doloinites, cherts, shales, and quartzites.
These units have been extensively folded and faulted. Included in this
sequence is the Permian Phosphoria Formation that is mined locally and
used in manufacturing phosphate products. The pre—Tertiary rocks yield
variable amounts of water to wells along the foothills of the Aspen
Range.
Tertiary rocks of the Salt Lake Formation are exposed mainly in the
Chesterfield Range. This unit consists of freshwater limestones, tuffa—
ceous sandstones, and conglomerates. The Salt Lake Formation yields
varying amounts of water that is used locally for domestic and stock
wells (4).
Tertiary and/or Quaternary basalt flows cover most of the valley
floors in the area. Locally the basalt is covered by recent alluvial
sediments, and/or soil. The basalt flows are generally dark gray in
color with a vesicular texture. The flows originated from local vents,
and near these source areas the flows are rubbly and scoriaceous. The
total thickness of the flov sequence varies from less than 50 feet near
the margins vhere they contact older rocks to a maximum thickness in the
valley center estimated to be as much 1,000 feet. A series of fault
.1;)
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scalps trending vest-of-north exist vithth the valley north of Soda
SpringS. The scarps are mazked by extensive zones of fractured, rubbly
basalt (3).
. The basalt flovs are a major source of ground vater in the area.
The most productive aquifers are zones betveen flovs vhere the rubb].y
flay—tops are porous.
A system of springs have precipitated large deposits of Quaternary
age travertine or tufa in the area around Soda Springs. The vhite to
buff colored deposits of calcium carbonate are rich in iron and mangan-
ese. Righ concentrations of these minerals in so.. local spring vaters
make the vater undesirable for domestic use. The tufa beds are lo fly
interbedded vith the basalt flovs (4).
Recent sediments mantle much of the land surface at lover eleva-
tions in the Soda Springs area. These generally unconsolidated silts,
sands, and gravels represent deposition along stream channels, as veil
as slop.vaah and landslid, deposits. The recent sediments include ter-
race and bench deposits from former vater levels of Bear Lake, vbich is
located approximately sev miles south of th . site area at the head of
the Bear River.. Former levels of the lake stood as much as 30 feet
above the present lak, elevation. The alluvial material yields variable
amounts of vater that is utilized primarily by domestic and stock veils
(4).
, The direction .f ground vater movement in the Soda Creek Basin is
( generally to the vest—southvest. This pattern is locally affected by
normal faults that exist in the area (4) • The faults serve as conduits
for the movement of ground vater, and cause local changes in the verti-
cal and/or horizontal patterns of flay.
The most important sources of recharge to aquifers in the area are
via infiltration of precipitation, and by seepage from strea.. near the
valley sides. An additional source of recharg. to the basalt aquifer is
via leakage fro. the Blackfoot Reservoir.
Construction of the llackfoot Reservoir had a dramatic affect on
the vater table in the Soda Creek Basin. After construction of the res-
ervoir in 1910, the Five Nile Meadovs area, located four miles to the
north, yes transformed from productive cropland to unproductive marsh-
land. In addition, the discharge of Soda Creek, vhich drains the cen-
tral portion of the basin, reportedly doubled (4).
6.2 Site Geolosy/!ydrology
The site is located at the southern margin of the Blackfoot Lava
Field. Bedrock beneath the site is basalt of Tertiary and/er Quaternazy
age. In th. site area, the basalt is overlain by tvo to 19 feet of re-
cent sediments. Logs of six veils on site and tea veils vithin 1.3
miles of the Kerr NeGee site indicate that the total thickness of the
basalt in the site area ranges from 16 to greater than 2. 0 feet. The
basalt is generally thinnest near the base of the Aspen Range, and in-
3Co
-------
j thickness tO the vest toward the center of the basin. Along
crsa ,. .g the Aspen Range east of the site, the bedrock is pre—
Limestone, with local deposits of Quat.rnay Travertine.
. basalt unit is composed of a series of flows separated by in-
CUf 1 OV zones of cinders, weathered and broken basalt., clay, silt,
travertine. The individual basalt flows rang. fro. five to 92
in thickness. The inter—flow zones rang. in thickness from two to
20 feet.
The vestern margin of the Kerr McGee site is trsnsv.rs.d by a lo-
cally north—south trending, high—angle normal fault (Figure 3). This
fault extends from approximately seven miles south of the site to three
miles north of the site, and is part of the regionally extensiv, north—
vest trending fault system (3).
A local subsidiary fault, trending approximately east-vest, inter-
sects the north—south trending fault near the southwest corner of the
site (figure 3). Both of the faults on site are traceable on the sur-
face by their topographic expression. The faults are marked by scarps
with relief of 15—20 feet, and by areas of broken basalt cobble. and
cinders.
The highly fractured basalt unit is the .ost productive aquifer in
the site area. Veils completed in the basalt generally yield greater
than 1,000 gallons per minute. The depth to water in the unconfined
basalt aquifer beneath the site ranges from 20 feet belov ground surface
at MV $2, to 38 feet belov ground surface at MV 03.
Test veils completed to depths as great as 230 feet baby ground
surface vest of the site have identified two zones within the basalt
aquifer (6). An upper basalt zone exists to a depth of approximately
tOO feet, and baby the upper zone, from 100 to 230 (and greater) feet,
is a ‘lover basalt zone. Both zones consist of a series of individual
flows separated by aquitards. Tests show that the upper and lover zones
act as distinct aquifers, and that there is probably Little vertical
sovemsi’ t between the two zones (6).
Veils in the foothills east of the site draw water from pr.—
Tertiary sediments. The depth of vatsr in these veils ranges from 17 to
63 feet below ground surface.
7.0 VAT USB
7.1 Surface Vater
The closest surface water to the Kerr NcGe sits is Soda Creek,
Located 2.3 miles to the vest (figure 1). There are no registered sur-
face water intakes within three miles of the site, although Soda Creek
is used for irrigation end stock water in other areas. Approximately
4,200 acres of land are irrigated with waste water fro. the Monsanto
Chemical Company plant. The water, obtained f roe industrial production
veils, is disebarged to Soda Creek and is later diverted for irrigation.
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Soda Creek flovs into Alexander Reservoir. located near Soda Springs.
Alexander Reservoir is used prisarily for recreation and hydroelectric
pover generation (1., 7, 8).
7.2 Ground Vater
Ground vatsr in the Kerr McGee site area is used for do.eatic and
public drinking supplies, irrigation, and industrial purposes. Private
and public dr( ng vatsr supplies vithin three cues of the site serve
a population of .pproxieately 3,364. In addition, ground vater dravo
fros veils vithin three cues of the site is used to irrigate approxi—
.atsiy 4,698 acres (8, 9).
The City of Soda Springs Vater Departaent distributes veter to all
residences vithin th. city Units. This vater is obtained fro. tvo
natural springs (Torastion and Ledge Creek Springs) located north of the
city. Porastion Springs and Ledge Creek Springs, both aasia.d to be
hydrologically upgrsdient of the Kerr McGee site, serve a total popula ..
tion of approxiastsly 3,000 (10).
There are 22 registered do.es tic veils vithin three .11.. of the
site, serving an estisated. pdpulation of 84 p.rzons. Total depthz of
the does . tic veils range betveen 19 feet and 400. feet belay ground sur-
face. Four industrial production yells exist on sad near the Kerr McGee
site. The Monsanto ..ical Co.psny uses three production veils vhich
serve approxiastely 400 e.picy.ea vith drinking vater (11). Approxi-
astely 80 e.plnyeea coniun. vater free the production ,.ll (910) located
at the Kerr McGee facility (12).
Seven registered veils located vi thin three cues of the sits are
used for irrigation (including the Monsanto industrial veils). Approxi-
astely 4,698 total acres are irrigated. Table 2 r ’izea ground vater
use vi thin three ails, of the Kerr McGee sits.
4
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TaBLE 2
.0tBID VITU USE
Approximate
Number of Population
Type of V.11 VelLi Use Depth Served
Domestic Veils 22 Drinking Ranges: 84
19’ to 400’
Industrial 4 Industrial Ranges: 480
Supply Veils and 200’ to 230’
Drinking
Municipal 2 Drinking Surface 3,000
Supply — Intake
Natural Springs __________
Total Drinking Vater
Population Served Vithin Three Miles: 3,564
Irrigation Veils 7 Crop Uuknovu 4,698
Irrigation acres
1 Sources: 9, 10, 11, 12.
8.0 CLIXATE
Southeastern Idaho has a seal-arid clint. that is characterized by
hot su.rs end cold viaters. Mean monthly teaperaturas in the area
rang. from 16.3’? in January to 63’? in July (4). £ National Veather
Service vather station is located four miles north of the Kerr McGee
sire in the tova of Coeds. The veather station reports approximately 19
inches of precipitation u 1ty, vith June having the highest monthly
precipitation (2.15 inches) and July having the lovest monthly precipi-
tation (0.71 inches). Average annual lake evaporation in th. area ii 35
inches per year, yielding a net precipitation deficit of sinus 16 inches
annually (7). The one—year 24—hour maxisun rainfall for Soda Springs is
1.06 inches (13). Saov usually remains on the ground in the site area
fm. early November through April.
910 0V VZEV 0? SITE 0P ATI0NS
The Kerr McGee Soda Springs Plant produces vanadium pentoxide
(V,0 ), and small amounts of amooniun setavanadate (AXV). Vanadium pen-
toiide is used primarily by the petroleum refining industry as a cata—
-------
iyst of organic polymers, and in suljurjc aciCproduction. £MV is used
in the production of majeic anhydrid. and adipec acid (2). The ray or.
utilized at the facility is fer o—phosphorous, vhich is obtained as a
byproduct f ro. the nearby Monsanto Chemical Corporation elemental phos-
phorous plant.
Figure 4 is a generalized diagram of Kerr McGee plant processes.
Terre—phosphorous ore is crushed and mixed vi th limes tone rock of by
magnesium content to combine vith the excess phosphorous formed during
the roasting (conversion) process. Vanadium is recovered from a result-
ing concentrated sodium vanadate (vanadium salt) solution by tvo mt.—
grated circuits: solvent extraction sad direct precipitation. Vsahea
and filtrates from the we systems are recycled for further vanadium
recovery. Aonium .etavanadate (NE 4 VO ) is produced after purification
during the solvent extraction and preciktatioa processes. Some AIIV is
vashed, dried, and marketed in that form, although the majority of the
AI(V is decomposed at a regulated temperature to form granular and flaked
.vanadium pentoxide (2, 14). £ number of vaste str . ar. produced at
different stages during the production process, and are discussed in
Section 10.0.
10 ;O CIAE&.CT ZSTI 07 P0T ITZAZ. C0!IWWIANT S0I S
The Kerr McG.. facility generates four major vaste str vhich
includei leached calcine tailings, magnesium aoniu. phosphate (MAP)
residusi., solvent extraction raffinate, and scrubber resid” . These
vastss are contained in on-site surface impoundments that are reportedly
lined vith 10 feet of clay (15). Additional vastes generated at the
facility include vaste oil and solvents. According to the Kerr McG.e
records, hazardous feedstock materials stored on sit. include: ashy-
drous aoaia (20 tons), sulfuric acid (36 tons), sodium hydroxide
(2,000 pounds), ferrous sulfate (40,000 pounds), potassium hydroxide
(4,000 pounds), and vanadium products produced at the facility (66,000
pounds) (14).
10.1 Solvent Extraction Raffinate
Solvent extraction raffinate is a liquid residual originating from
the solvent extraction circuit (vanadium purifying process) (see Figure
4). Kerr KeG.. has provided Extraction Procedure Toxicity (U Toxicity)
data for undiluted raffinate discharges, vhich are presented in Table 3
(14). None of the U Toxicity analyses performed for Kerr KeG.. on the
raffinate vaste strea. exceeds £7 Toxicity criteria for hazardous vasts.
qo
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TABLE 3
SU)Q(ARY OP PREVIOUS RAFPVIATE_DIS AP £MLTrIC&L DATA
(EP TOfliiij)
Undiluted Raffinate Discharge EP Toxicity Mixisus
Metal Concentvatiou (ag/i) Concentration (ag/i)
Arsenic 0.01 5.0
Barius < 1.0 100.0
Cadsius < 0.02 1.0
Chro.i ua < 0.1 5.0
Lead 0.3 5.0
Mercury < 0.005 0.2
Selenius < 0.01 1.0
Silver 0.3 3.0
The extraction raffinate stress is sized vith residuals frol the
li.eston. serubbers, and piped to tvo settling ponds located east of the
$2 (solvent extraction) pond. The discharged vests is shoved to circu-
late through the settling ponds, and the liquid fraction is piped into
the 52 Pond. The settling ponds are organized in series (flay is f roe
the north pond to the south pond), and both are approxitsly 230 feet
by 30 feet in size. The SZ Pond is the final ispoundeout for the raf—
fLoats discharge, end is approxisetely 600 feet by 100 feet in size (see
Figure 2).
10.2 Masnesius Aonius Phosphate Residuals
Magnestu. aoniu. phosphate (MAP) is a byproduct øf phosphorous
and calcine re.ovsl free the first precipitation stags of vanadius cake
(solids containing trace venadius) (see Figure 4). No analytical data
for this vaste stress or for the MAP Ponds contents have been provided
by Kerr McGee. The MAP residual., are slurried te the tvo MAP Ponds
located on the northern edge of the site (see Figure 2). At the tie, of
the £62 sits inspection, the ponds contained little vater (tvo to four
inches deep).
10.3 Leached Calctne Tailings
Leached ealcine tailings originate fre. th. preparation of sodius
vanadate leach solution. The tailings represent the first najor ispur-
i ty renoved in the plant process. No analytical data is available for
the cosposition of the cal.cine tailings vests stress, although Kerr
McGee provided data for aqueous sasples collected free the tailings dis-
posal pond. Selected parasetsrs fre. these data ar. presented in Table
4 (14).
L1
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TABLE 4
STJ)O ART OF PREVIOUS EAST AL fl TAILDIGS POND
AQUEOUS Fa crION ANALYTICAL RESULTS
Substance
Arsenic
Concentration (total)
0.01 mg/i
Cadmium
0.01 mg/i
Chromium
0.026 mg/i
Lead
0.076 mg/i
Vanadium
370 mg/i
The tailings are stored in two separate ponds located on the east
end of the site, and cover approximately one acre each (see Figure 2).
The tailings are siurried through a pipe from the plant to the ponds,
where the vater is alloyed to evaporate. At the time of the E&E site
inspection, Kerr NcGee vas excavating the northern— ost calcine tailings
pond (no longer in use), and were planning to sell the tailings for fer-
tilizer base.
10.4 Scrubber Residuals
Scrubber residuals are produced from two major scrubbing systems
within the facility. The limestone scrubbers, located in the sizing and
physical ore preparation segment of the plant, generate limey tails
which are mixed with the raffinate stream, and deposited in the settling
ponds as discussed in Section 10.1. The Roaster scrubbers produce tails
from emissions that originate from high temperature heating of raw
ferro—phosphorous ore. The roaster scrubber pond (scrubber pond) is
located in the southeast corner of the site (see Figure 2). No analyti-
cal data for the roaster scrubber waste stream are available, although
Kerr McGee provided EP Toxicity results for solids samples collected
from the scrubber pond (Table 5) (14). None of the EP Toxicity analyses
performed for Kerr McGee on the scrubber pond solids exceeded EP Toxic-
ity criteria for hazardous vaste.
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TABLE 3
SU QIá&T 0? PREVIOUS ROaST S UB3U POND SOLIDS
ANAL ICAL DAT,& (El T0fl iz I TEOD)
Scrubber Pond Solids
EP Toxicity Sample El Toxicity Maximum
Metal Concentration (mg/i) Concentration (mg/i)
Arsenic 0.01 3.0
Barium 1.0 100.0
Cadmium 0.02 1.0
Chromium 0.1 3.0
Lead 0.3 3.0
Mercury 0.003 0.2
Selenium 0.01. 1.0
Silver 0.1. 3.0
10.3 Other Potential Sources -
Viate oil generated at the facility is spread on roads for dust
control. Until approximately 10 years ago, vaste solvents generated at
the facility vera mixed and disposed vith the vuste oil. Currently all
vaste solvents are removed from the facility for recycling by a contrac-
tor (Safety Kleeu) (12).
11.0 PREVIOUS IVESTTG&TIVE STORY
The Kerr McGee site vms visited by Caribou County B.alth Department
personnel in Jun. 1981. So .. surface impoundments (ponds) vera sampled
as part of the inspection. Analyses .t the samples using El Toxicity
methods shoved trace elements at concentrations belov El Toxicity cri-
teria for hazardous vsste (16?.
£ Preliminary Assessment. (PA) of the site vms conducted by the
Idaho Eazardous Materials Bureau in 1983. Th PA vms primarily a file
r.viev and literature search. Periodic sampling of on—site surface im-
poundments via recoemended to ensur. non-hazardous levels of El Toxicity
parameters in the vaste ponds (16).
Kerr McGee has performed in—house site investigation activities on
this site in the past. The scope, results, and conclusion. of the york
vera not available for inclusion in this report.
-------
McGee site inspection are presented in Appendix C. Quality Assurance
Memoranda are included in Appendix D. Field Sample documentation is
s”— -rized in Appendix B.
13.1 Ground later Samples
A total of 15 ground vatsr samples vera collected as part of the
sit. inspection; nine from on-site monitoring veils, tvo from off—sit.
monitoring veils, one from the on—site.production veil, one from an up—
gradient domestic veil, and tvo from nearby springs vhich serve as part
of the Soda Springs municipal supply system. Veil sample data sheets
vere completed for all veils sampled, and are included in Appendix F.
13.1.1 Monitoring Veils
Ho organic compounds vere detected in MV $4 or MV $6 at Levels
significantly (i.e., greater than 10 times) above those found in the
quality control blank samples.
Table 11 s”rizes inorganic elements and anions detected in the
11 monitoring veils. A total. of. nineteen TCL inorganic elements and all
four anions vere detected in it least one- of the monitoring veils.
Seven inorganic elements and three anions vere detected at significantly
higher concentrations (greater than 10 times) in -o itoring veils
located dovngradient of the on-site vaste ponds than La Background Veil
$7. Table 12 s’ rizes the concentrations of these analytes in the
background veil (MV 07) and the dovugradient .ani taring veils.
Results presented in Table 12 indicate that ten analytes are
potentially being released to the environment from vaste ponds at the
facility. Veils MV 02, MV 04, and MV $6 appear to be the most signi-
ficantly impacted in ter of the number and concentrations of analytes
detected. In addition, vanadium, chloride, sulfate, and sodium appear
to be the most videly distributed constituents detected in ground vater
across the site. Each of these four analytes vere ala, detected in the
monitoring veils sampled on the Monsanto Chemical Company’s property.
Although vater from the monitoring veils is not used for drinking
purposes, hydraulic connections to deeper vater bearing zones (basalt
fractures and joints) ax. likaly and comparisons to Federal Drinking
Vater Standards may be applicable (6). Iron v . a detected above Federal
Secondary Drinking Vatex Standards in all of the monitoring veils except
MV $8, MV $9, and Hr’mnto $12. These values may reflect generally .1.—
vated iron levels in the site vicinity (7). It should also be noted
that all of the Kerr McGee monitoring veils had steel casings, vhich
likely inflated the values. Manganese, chloride and sulfate vere also
detected at concentrations above Secondary Drinking Vater Standards in
many of the monitoring veils (Table 1]).
13.1.2 Drinking and Industrial Supply Sources
t4o organic compounds vere detected in the drinking or industrial
supply source samples at levels significantly above those found in the
quality control samples.
-------
TABLE 12
SIBSIUBT OP SI 1IflC*IIfLT ELEVATED )IITANINAIft
EI INTUTUNlS IN NONITOSIIW VELL SAISPLIS
(mg/i)
1W 17
Contaminant (Background) 1W 02 1W 13 1W 14 1W IS 1W 06 1W 06 MV 19 Monsanto 112 Monsanto 133
Arsenic (0.001 0.031 0.019 0.025
Copper 0.028 0.321
NickeL 0.007 0.156 0.134
Potassium 2.40 82.9 37.1 34.2
Silver 0.0004 0.005
Sodium 9.00 3.482 184 1.397 165 955 405 387
Vanadium 0.055 19.1 1.88 8.50 0.640 4.90 2.72 1.00 0.465
Ch lorids 6.00 2,880 252 1,190 272 1,690 334 333
Phosphate 0.430 31.2 8.8 5,4
Sulfate 34.1 7,070 2,840 1,060 780 769
Totala 10 3 8 3 7 0 4 4
* - number of analytes detected at concentrations greater than or equal to concentrations observed in background
veil (NV •7).
-------
TABLE 14
SU)OIAIY OP INORGANIC EL ITS AND ANIONS
DETEC1’ IN SOLID FRACTION VASTZ POND SAMPLES
El.ment/ HAP Solids Tailing! Solids SI Pond Solids Scrub Solids
Compound (mg/kg) (mg/kg) (mg/kg) (mg/kg)
Aluminum 5639.0 4,470.0 11,980.0 2,938.0
Antimony U U U 0.5
Arsenic 1.1 0.3 3.3 2.6
Barium 41.0 29.0 75.0 65.0
B.rylltu* 0.41 0.10 1.19 0.49
Cadmium 0.76 0.07 4.17 5.2
Calcium 3,240.0 130,400.0 46,300.0 83,900.0
chromium 56.9 2,110.0 1,627.0 2,204.0
Cobalt 5.0 13.3 14.8 11.5
Copper 523.0 2,228.0 691.0 2,986.0
Iron 5,235.0 27,770.0 22,380.0 33,810.0
Lead 3.0 .11 10.0 112.0
Magnesium 114,700.0 1,884.0 7,130.0 2,302.0
Manganese 98.0 862.0 234.0 179.0
Mercury U U 0.35 1.3
Nickel 32.0 2,126.0 499.0 468.0
Potassium 6,460.0 626.0 4,680.0 924.0
Seledium U U U 4.3
Silver 2.94 34.6 61.0 23.9
Sodium 719.0 21,220.0 7,780.0 3,135.0
Thallium U U 0.3 0.3
Vanadium 660.0 3,660.0 2,620.0 3,940.0
Zinc 23.0 23.0 130.0 34.3
Chloride 82.7 208.0 4,060.0 2,210.0
Fluoride 162.0 378.0 302.0 368.0
Phosphate 111,160.0 84,630.0 19,360.0 13,740.0
Suliate 64.3 204.0 23,260.0 698.0
U - Undetected at detection Limits present.d in Appendix C.
q(o
-------
TABLE 1.5
SUI0 ARY OF INORCANIC z rrs AND ANIONS
orrzcr D I LIQUID FRACTION VASTE POND SAIIPLES
Scrubber
El.ment/ MAP Water Tailings Water SX Pond Water Pond Water
Compowtd (mg/i) (mg/i) (mg/i) (mg/i)
Aluminum 1.09 0.630 0.390 0.66
Antimony U U U U
Arsenic 0.032 0.003 0.394 U
Barium U U U U
Beryllium U U 0.001 U
Cadmium 0.0022 0.0004 0.0063 0.052
Calcium 35.6 13.0 267.0 212.0
chromium 0.032 0.030 0.012 0.862
Cobalt 0.001 0.009 0.030 0.009
Copper 0.363 0.298 0.843 22.3
1.483 1.462 0.311 2.54
Lead U. U 0.049 0.026
Nagmosium 176.0 16.8 332.9 51.3
Mangmnese 0.043 0.088 0.187 0.132
Mercury U U U U
Nickal 0.038 0.205 0.097 0.283
Potassium 14.0 7.7 1,148.0 23.1
Selenium 0.006 0.006 0.097 0.012
Silver 0.0113 0.0229 0.0381 0.188
Sodium 146.0 508.0 9,480.0 1,178.0
Tk.ltium U U U U
Vanadium 70.4 56.1 64.8 9.24
Zinc 0.024 0.012 0.061 0.085
chloride 126.0 376.0 8,930.0 2,430.0
Fluoride 0.20 0.44 1.4 1.9
Phosphate 61.3 66.2 210.0 43.6
Sulfate 88.4 146.0 20,400.0 146.0
U — Undetected at detection limits presented in Appendix C.
-------
Table 15 strn ,rizes inorganic elements and anions detected in the
Scrubber Pond liquid fraction sample. Seventeen TCL inorganic elements
and four anions vere detected in the sample. In comparison vith other
waste pond samples, relatively high concentrations of cadmium, chromium,
copper, iron, nickel, silver, zinc and fluoride were observed in the
liquid fraction sample.
13.2.5 Settling Pond
Table 16 s” —rizes organic compounds detected in the Settling Pond
solid fraction sample. The sample vas not submitted for TCL inorganic
analyses. Fourteen TCL organic compounds were detected in the sample.
Four of the compounds detected are volatile organica, and the remaining
ten compounds are semi—volatile organics. Three organic compounds were
detected in the parts—p.r—million concentration range, including Phen-
anthren. (4.30 mg/kg), Naphthalene (2.50 mg/kg), and 2—Methy].naphthalene
(18.0 mg/kg).
13.3 QA/OC Samples
A transport blank and a transfer blank were prepared for quality
control purposes during th. site inspection. Table 17 gt rj 5 g TCL
elements and compounds detected in. the blanks. Ace ton. was detected in
a number of the field samples (Appendix C) but vms discounted because of
its presence in both of the quality control blanks.
13.4 Field Parameters Samples
La discussed in Section 12.3, field parameters samples vere col-
lected and monitored for stabilization during veil purging. Table 18
s. —. rizes field parameters results of the final readings recorded
before veil sampling, and from the v ia te ponds.
13.3 L X Survey Results
Figures 7 through 1.3 illustrate terrain conductivity contours de-
rived from the EN survey results. £ background grid, located north of
the site, and an upgradient grid, located north of the SI Pond vers sur-
veyed to define the natural conductance of underlying materials at the
sits. The background values were used to determine the significance of
readings obtained dovngradient of the vaste ponds. Table 19 suamazises
the background ranges for different depth readings obtained vi th the
LX 31. and the LX 34-3.
Comparison of background values presented in Table 19, and values
obtained dovngradient of the waste ponds (Figures 7 through 13) indicate
the presence of two major anomalies to the south of the site. One anom-
aly (SI anomaly) is located south of the SI Pond, and the second anomaly
(SF anomaly) is located south of the Scrubber Pond (Figures 7, 8, 9, 10,
11, 12, 13). The anomalies vary in magnitude and size according to the
exploration depth and dipol. orientation utilized during the LX survey.
&j b
-------
Potential interferences vi th the geophysical survey include changes
in depth to ground vater, topographic variations, changes in clay or
lithologic contents, and cultural (ht _sade) features. None of these
potential interferences yen judged to be affecting the data collected
during the LX survey. Therefore, the detected anomalies are attributed
to electrolytic solutions and/or aetallic elements in the subsurface or
ground vater.
Generally, the U anomaly is apparent in the vertical dipole orien-
tation and alsost non—existent in the horizontal orientation. The LX
dat& suggests that the SI anomaly represents vertical and horizontal
movement of contaminants along tvo intersecting normal faults vhich are
discussed in Section 6.2. The shape and magnitude of the S I anomaly
increased as the exploration depth in the vertical dipole orientation
yes increased from 13 to 60 meters. Retveea depths of 13 and 30 meters,
the SI anomaly increased significantly in both size and magnitude, vhich
indicates possible horizontal migration of contaminants along a basalt
interflov zone. The values of highest magnitude vers obtained at the 60
meter depth, vhich indicates possible vertical migration of contaminants
through joints or faults.
The SP anomaly Is apparent in both of the dipole orientations, al-
though the lagnitude of values vere greater in the vertical orientation.
Generally, the SP anomaly increased in magnitude and siz, from 7.3 to 30
meters and decreased in magnitude and size from 30 to 60 meters (Figures
8 through 23). The I data suggests that the SP anomaly represents
horizontal migration of contaminants along basalt interflov zones be—
tveen 13 and 30 meters depth. Vertical movement of contaminants belov
30 meters is not apparent from the data.
Comparing the tvo anomalies, information suggests that the SI and
SP anomalies should behave similarly, yet the contour patterns surround-
ing the ponds have significant differences. These differences are be..
lieved to be related to the existence of faults near the SI Pond that do
not extend eastvard to the Scrubber Pond area. Enovu faulting south and
vest of the SI Pond (Figure 3) is likely causing vertical displacement
of Ii thologic zones in the subsurface. La a consequence of the fault-
ing, basalt interf3ov zones may be offset against less permeable basalt
units, causing contaminant migration fro. the SI Pond to mov , horizon-
tally and vertically along th. fault lines. Th. fault.. appear to con-
centrate the contamination. vbicb is indicated by the concentration of
contour lines along th. fault lines (Figures 12 and 14). Conversely,
con taminants migrating from the Scrubber Pond could become more diluted
as they move south along an interflov zone, and are likely not affected
by the subsidiary east—vest trending fault near the SI Pond.
14.0 SWIXART *1W C02I USI0NS
14.1 Vaste Pond Constituents
The solid fraction vests pond sample data reveals the presence of
hazardous substances In the en—site vests ponds. Potential inorganic
contaminant concentrations of concern detected in the vests ponds
-------
include: arsenic in the SX and Scrubber Ponds; cadejum in the SX Pond,
chromium in the Calcine Tailings Pond, lead in the Scrubber Pond, and
vanadium in the SX, Calcine Tailings, and Scrubber Ponds (Table 14).
Additionally, potential organic contaminant concentrations of concern
detected in the Settling Pond include: phenanthr,ne, naphthalene, and
2—Nethy]naphthalene (Table 16).
Liquid fraction vaste pond sample data supplied by Kerr McGee are
generally similar to those derived during the EU site inspection. Vhen
compared vith data provided by Ksrr—McGee, analytical results of the SI
indicate significant variances in arsenic concentrations for the SX Pond
liquid, and lead concentrations for the Scrubber Pond.
14.2 Ground Vatar Quality
Concentrations of TCL inorganic elements and four selected anions
in the on-site monitoring veils indicate a release from the site to
local shailov ground vater. Significantly higher concentrations of ten
inorganic contaminants detected in dovugradient monitoring yells as com-
pared vi th the background yell sampl. results support this conclusion
(Table 12). Tvo distinct anomalies detected during the I survey pro-
vide additional evidence of ground vater contamination near the site.
The anomalies are east evident dovngradient of the U and Scrubber Ponds
(Figures 944). Table 20 presents correlations betveen the SZ Pond
liquid and solid fraction constituents and contaminants detected in
dovugradient monitoring veils (MV 02 and MV 04) at levels significantly
higher than background. The table illustrates that elevated contaminant
concentrations detected in MV *2 and MV *4, located dovngradient of the
SX Pond, may be attributed to vaates stored in the SZ Pond.
TABLE 20
swoi*a or oi a m xc&i ru
iv coa’w irr i ria csss m MV 02 A1 MV *4
SX Pond U Pond
Background Solids Liquid MV 02 MV *4
MV *7 (mg/i) (mg/kg) (mg/i) (mg/i) (mg/l)
Arsenic (0.0O1)U 5.30 0.394 0.031 0.01.9
Copper 0.028 691 0.845 0.321 —
Nickel 0.007 499 0.097 0.136 0.134
Potassium 2.40 4,680 1,148 82.9 37.1
Silver 0.0004 61.0 0.038 0.003 —
Sodium 9.00 7,780 9,480 3,482 1,397
Vanadium 0.053 2,620 64.8 19.1 8.30
Chloride 6.00 4,060 8,930 2,880 1,190
Phosphate 0.430 19,360 210 31.2 8.8
Sulfate 34.1 23,260 20,400 7,070 2,840
U — Undetected at listed detection limit.
-------
The LX survey data suggest that potential contaminant migration
from the SX Pond is being affected by a local, normal, fault. Cons.-
quently, contaminant concentrations may be increased along the fault
lines, vhich vould not be reflected in the monitoring veil, results.
Table 21. presents correlations betveen the Scrubber Pond liquid and
solid fraction constituents and contaminants detected in a dovngradient
monitoring veil (MV *6) at levels significantly higher than background.
The table illustrates that elevated contaminant concentrations detected
in MV 06 may be attributed to vastes stored in the Scrubber Pond.
TABLE 21
suioiaaz or s’ ”i iim UI u 1T3 az sI arxcIII’rLT
.IVA COWTAI MIIT N 5XX0NS D I MV 06
Background Scrubber Pond Scrubber Pond
Contaminant MV 07 (mg/i) Solids (mg/kg) Liquid (mg/i) MV 06 (mg/i)
Arsenic (0.001 W 2.60 (0.001) 11 0.023
Nickel 0.007 468 0.283 -
Potassium 2.40 924 23.1 34.2
Sodium 9.00 3,133 1,178 933
Vanadium 0.053 3,940 9.24 4.90
Chloride 6.00 2,210 2,430 1,690
Phosphate 0.430 1.5,740 43.6 5.4
Sulfate 34.1 . 698 146 1,060
U — Undetected at Listed detection limit.
None of the domestic drinking vater veils or municipal vater supply
sources appear t. be affected by contaminants attributable to the kerr
McGee site. Elevated levels of iron and .ngamese in some of the vater
sources is most likely the result of ambient eo”ditions in the sit.
vicinity. ifovever, contaminants attributable te the Kerr McGee sit.,
found in samples collected from on— and off—mite monitoring veils, have
th. potential to migrate dovngradient over tim. due to the fractured
nature of underlying basalt flays.
1.4.3 Overviev of Potential Migration Patkvays and Targets
Ground vater is the most likely p.thvay for contaminant migration
from the Kerr McGee site. An observed release to ground vater is evi-
denced by sample data and supported by the LX survey. Spills and leaks
from the Kerr McGee vaste ponds have reportedly not occurred in the
past, although surface migration of contaminated vastevater is a poten-
tial hazard. Soda Creek, the nearest permanent surface vater to the
site, vould likely not be directly affected by surface migration of con-
taminants due primarily to topographic features in the site area. V&ste
pond solids may be a source of potential direct contact exposure to on-
-------
450 100
ipp. bieta sad. i fast
*
ecology & environment, Inc.
Job: FI0- 1702—04 West. ts 0033
Drown b 0. P. 0ats D.c. $4, 1557
FIGURE 2
SITE: MAP
KERR MCGEE CHEMICAL CORPORATION
rlv,nq Ifl
Lkn.stons
Stodipi.
I Pond
L (cover.d
PhmIEJ n\ I Talhiga
I Tolkigs
Pond
(cov.r.d)
LEGEND
o I Fsiic.
C.. ii
— - - — Pow.iIbis
— ) ‘ — Ifflusni low
a
-------
site yorkers or trespassers. Air eonitoring vu riot conducted during
the £&Z site inveitigation, although local air quality say be affected
by continuing eaissions free the Kerr McGee facility.
The targets at the highest potential risk free ground vater contas—
inatiori free the site include users of nearby production and irrigation
veils. The nearest douestic drinking vater veils and eunicipal vater
supply sources are all located upgradient free the site. Crop lands in
the area that are irrigated vith vater dravn free production veils on
the Monsanto Chuica.i Coepany property are also potential targets for
c Ieuea free the Kerr McGee facility.
-------
13.2.4 Scrubber Pond
Table 16 s rizss TCZ. organic compounds detected in the solid
fraction sampl. collected f roe the Scrubber Pond. Of the 127 TCL or-
ganic compounds, only acetone yes detected in the sample at a concen-
tration of 0.263 mg/kg. Acetone, a comeon laboratory solvent, is likely
present in the sample as a result of laboratory contamination, or as the
result of field decontamination of sampling equipment.
tAIZIl 16
swe aT or o ic iirowmS ii .- w m
SOLID flLCTIO1I SWLES FROIS T
s u’ u im SE L G icims
Concentration (mg/kg)
Compound Scrubber Pond Settling Pond
Acetone 0.263* U
Chioromethan . U 0.001
Total Zylenes U 0.236
Ethy lb.nxen. U 0.024
Toluene U 0.024
Benzo(a)pyren. U 0.240
Dibenzo(a,h)authrac .ne U 0.320
Ph,i’ threne U 4.30
Nap thal .ne U 2.30
2 -Nethylnaphthalene U 18.0
Pyren. U 0.230
Benso(g,h,i)perylene U 0.330
Indeno(l,2,3 —cd)pyren. U 0.310
Benzo(b)fluormnthen. U 0.230
Benzo(k)fluoranthees U 0.230
U — Undetected at detection limits presented in Appendix C.
* — Acetone is a eo— ii laboratory solvent and is likely present in this
sample as a result of laboratory contamination or field
decontamination residu*l..
Table 14 s rizes inorganic elements and anions detected in the
Scrubber Pond solid fraction sample. All tventy—three TCL inorgmaics
and four anions vets detected in the sample. As compared vith other
vaste pond samples, the Scrubber Pond sample contained relatively higher
concentrations of antimony, beryllium, cadmium, chromium, copper, iron,
lead, mercury, selenium, thallium, and vanadium.
-------
Kerr McGee Chemical Corporation Mining Waste NPL Site Summary Report
Reference 2
Excerpts From Hazard Ranking System Score Sheet and Documentation for the
Kerr McGee Chemical Corporation, Lynn Guiltord, EPA;
May 11, 1988
-------
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-------
Kerr McGee Chemical Corporation Mining Waste NPL Site Summary Report
Reference 3
Excerpts From Riegel’s Handbook of Industrial Chemistry, (edited by James A. Kent)
Seventh Edition; Van Nostrand Reinhold Company, N.Y.; 1974
4,0
-------
Riegel ‘s
Handbook of
Industrial Chemistry
SEVENTH EDITION
Edited by
James A. Kent
Colleg. of Engin ring
Michigan 7.d noIogicaI Univertity
Houghton. Michigan
VAN_NOSTRAND REINHOLD COMPANY
NIW Uk CINcIJIlSATI ATLANTA S ” SAN FRANCISCO
-------
Van No.rmnd 1’o14 Company Ra o aI Of8as:
Nuw York ( wi r 1tlMIL fjfl’
Van Nosiroad Reinhold Company Intsmadonii Oqflms:
L ” n Toronto Mnibo
CopyntO 1974 by Litton Educational PuM4 4 . .
Lãbrory of Coiwi... CataIc Card Numbs,: 731479$
iSBN: 0-442-24347.2
*11 n iu . ...a ...4 . Certom portions of thu work copyn tt C 1962
by Utica Edimadanil PubIi.M , Inc. No part of thin work
coisiud by the copynte borsun may be rsprodumd or med many
form or by any m _gmpiMt, alecironsa, or m ’ ’ ’ . arciuding
phot e .#ini, tscordla$. mpm , or informanco storops and ratnomi
. ,.i —mthoiu wuttan permmaoa of the p usk T .
Menufastorud in ibs United Stems of Amanna
Publnbsd by Van Nisirind Remuiold Cornpsay
133 Wisi 30th Strum, New York, N.Y. 10020
P’ hsd omulteasoirdy I. Cana by Via Nostrand Renshold Ltd.
15 14 13 12 11 10 9 $ 7 6 $
Llbmoy of Cows. Catein in Pnb° ’a Dam
Riqel, EaR Raymond. 1882—1963
Riugal. of .usmal —‘-I ’ .
Flr,t-Sth ad. puNIth d under tidu: laduroed
dtamiauy; 6th sd a 1962 under tide: Rapi’s
industrial rksmrsuy. __
Includes bibilcçuphical nf.jsii ...
1. Oumuavy, T. K!i f I L Kent, liaise A.. 1922-
ad. 11. TIde. 111. flds: Handbook of indusmal
17145.134 1974 660 73-1479*
131W 0442-24347-2
-------
ao RIEGILS HANDSOOk OF INDUSTRIAl. CHEMISTRY
C l i i
Cl 2 ’
The diversity of chemicals used during cur-
ing and the complexity of the curing reactions
explain why those who use epoxies (in con-
trast to many other plastics) frequently have
an independent chemical laboratory directed
by a competent industrial chemist or chemical
en neer.
PoIyesse?’L Ii the plastics industry the term
polyesters has a far narrower connotation
than is implied chemically. In the plastics
field a polyester is ordinarily the bus renn
consisting of a liquid unsaturated polyester
plus a vinyt-type monomer; this liquid mix-
ture is capable of reacting to form infusible
crosslinked solids under the influence of cata-
lysts and/or heat. Such polyesters (in the
strict chemical sence) as ethylene glycol.
terephthalic acid polycondensates for textiles
(Chapter 11) and alkyds for paints (Chapter
22) are not polyesters in the plastics indusuy.
One of the largest uses of polyesters is in
fibers for textiles and automobile tires. How-
ever, this uss will not be discussed in this
chapter. In the “plastics” industry unsatu-
rated polyesters, also called polyester resins,
are used primarily in ripd laminates, mold-
ings, or castings and are almost always rein.
forced with glass cloth or glass fibers. They
were developed during World War II and were
first used very successfully in self-sealing gas
tanks containing a rubber liner. When pierced
by a bullet, metal tanks splay or “flower” and
prevent the rubber tank liner from swelling
shut and closing the hole. Polyester laminates
HC —CM
,.C\/C
do not splay and therefore allow the rubber
liner to close the hole. When reinforced wuji
glasa, their high flexural strength is OuEstan4.
ing, approaching that of metals. The rnajo
markets are the automotive and marine indus
tries. Pam now being molded include fender
extensions, rocker panels, and roofs. In hous.
ing, the use of polyesters in modular bath.
rooms has become sigiuficant. ApproximateLy
770 million pounds of polyester resins are ex-
pected to be produced in the Usuted States in
1970.
Maleic anhydride is the principal Unsatu.
rated dibasic acid used in the polyester. al-
though fumanc acid is also used in lmute4
OH
=1O
HC — CX
C —O
HO
Music anhydr . F uminc acid
amounts. Uniquely among ordinary unsatu-
rated monomers, the double bond in maleic
anhydride, Its acid, its esters, and similar
aØ-carboxyl.substituted olefins will not tin.
dergo homogeneous polymerization even at
high temperatures but will copolymerize
rapidly with a wide variety of vinyl mono-
mers at even faster rates than these monomers
will homopolymerize. It is because of this
peculiar property of maleic anhydride that
polyesters are prepared by first making (at the
necessarily high temperatures) a linear low-
viscosity gel-free polyester containing several
double bonds per molecule and then mixing
this unsaturated polyester with a vinyl type
monomer, usually styrene, which, under the
influence of catalysts and/or heat, will cross.
link the polyester molecules to form a rigid
infusible polymer.
The difunctional alcohol ethylene glycol is
frequently used for the coreactant. but it is
supplemented with propylene glycol. diethyl.
ene glycol, or dipropylene glycol to decrease
the tendency for the liquid resin to crystallize
and to increase the flexibility of the cured
resin.
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-------
SYNTHITIC agTIca 2 51
To promote compatibility with the styress
monomer used to croedink th. polyester.
phthsIIC anhydside is incorporated into the
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dride imparts some flexibility to the cured
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of its long flexible aliphatic carbon chain, is
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polyester by the manufacturer of th. poly-
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saturated poup. are macted and optimura
strength is achieved, an excees of stysene must
be used (30-40 per cent is th. average) be.
cause the styrene monomer will polymerize
not only with an active maleic r dfr l but also
with an active styrene radical; rusleic radicals,
however, wlU react only with stysene mono-
mer. Low temperatures favor the music-
styrene reaction while high temperatures favor
the styrenestyron. reaction, accounting for
the advantages frequently found In rnulal low
temperature cures.
Beides styrens , many other vinyl mono-
roots may be used to develop spe ui y u,.i .
tos, 14, triallyl cyanurate to promot. heat
reantance, dully phthalate to reduce volatility
during cine, acaylic acid ester to promote
flexibility iii lntssnel plasticization and to
impart ip d westherability.
In addition to the dthmctfonaj acids and
alcohols, monofuactional acids and alcohols
may be added in ainell amounts to limit poly-
ester mnIeeulir weight. Allyl alcohol has been
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c roeslial
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promote hardneu, rigidity, strength, and brit-
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chains impart flexibility and seine impact
strength. Larger polyester molecules promote
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definite upper limit which is reached at a
moderate molecular weight. The above brief
picture Illustrates how complicated and varied
the formulation of polyesters can be. As an
example” the preparation of a particular
polyester might be carried out in a jacketed
stainless steel reaction vessel equipped with
an agitator, and a roflux condenser followed
by a total condenser. The charge is 5 moLes of
malslc anhydride, 3 moles of phthalic anhy-
drid., 4 moles of ethylene glycol. and 4 moles
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to 37 5’C until an acid number of 60-65 is
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sphere. The inert puip p5 (CO , or N 2 ) is
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Mining Waste NPL Site Summary Report
Lincoln Park Site
Canon City, Colorado
U.S. Environmental Protection Agency
Office of Solid Waste
June 21, 1991
FINAL DRAFT
Prepared by:
Science Applications International Corporation
Environmental and Health Sciences Group
7600-A Leesburg Pike
Falls Church, Virginia 22043
‘.1 ’
-------
DISCLAIMER AND ACKNOWLEDGEMENTS
The mention of company or product names is not to be considered an
endorsement by the U.S. Government or by the U.S. Environmental
Protection Agency (EPA). This document was prepared by Science
Applications International Corporation (SAIC) in partial fulfillment of
EPA Contract Number 68-W0-0025, Work Assignment Number 20.
A previous draft of this report was reviewed by Gene Taylor of EPA
Region VIII [ (303) 293-16401, a former Remedial Project Manager for
the site, whose comments have been incorporated into the report. The
new Remedial Project Manager is Denise Link [ (303) 294-71461.
-------
Mining Waste NPL Site Summary Report
LINCOLN PARK SITE
CANON CITY, COLORADO
INTRODUCTION
This Site Summary Report for the Lincoln Park Site (Cotter Uranium Mill) is one of a series of
reports on mining sites on the National Priorities List (NPL). The reports have been prepared to
support EPA’s mining program activities. In general, these reports summarize types of environmental
damages and associated mining waste management practices at sites on (or proposed for) the NPL as
of February 11, 1991 (56 Federal Register 5598). This summary report is based on information
obtained from EPA files and reports and on a review of the summary by the former EPA Region VIII
Remedial Project Manager for the site, Gene Taylor.
SITE OVERVIEW
The Cotter Corporation Mill, located near Lincoln Park in Fremont County, Colorado, is an inactive
facility that processed uranium ore into yellow cake from 1958 to 1986. The Cotter Corporation is a
4ubsidiary of Commonwealth Edison Company of Chicago (Reference 1, page 1-1). The Mill ceased
operations in 1986. The site covers approximately 1.4 square miles in south central Colorado and
consists of two inactive mills, a partially reclaimed tailings pond disposal area, and an inactive tailings
pond disposal area (Reference 1, page 1-3; also see Figure 1).
Sources of contamination include the uranium ore stockpile, tailings, and raffinate; contaminated soils
and ground water; leaks from the old tailings ponds; and suspected leaks from the new impoundment
area. Contaminants include radium, nickel, molybdenum, cobalt, copper, arsenic, zinc, lead, and
cadmium (Reference 1, pages 1-8 and 1-10).
The Cotter site is located south and almost adjacent to the semirural area of Lincoln Park and 3.5
miles south of Canon City (Reference 1, page 1-1). The site is located in a topographic bowl known
as “Wolf Park Basin.” Offsite ground-water contamination from the Cotter site was first noted in the
Lincoln Park area in 1968 (Reference 1, page 1-9). Prior to a 1988 State-ordered clean-up, a number
of residences used water from wells on their property, either in addition to their Canon City tap water
or as their sole supply. Homes in the impacted area are presently supplied with Canon City water
(Reference 3). Most land around the Mill is used for grazing livestock and as a wildlife habitat
(Reference 1, page 7-1).
1
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2
Lincoln Park Site
EXPLANA11ON
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1 )
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Mining Waste NPL Site Summary Report
In 1971, a Soil Conservation Service (SCS) flood control dam was built in Sand Creek, about 4,000
feet north of the main tailings impoundment, to mitigate the effects of storm-generated floods. Prior
to the dam’s construction, storm water runoff from the Mill site flowed down Sand Creek to Lincoln
Park and eventually into the Arkansas River. This runoff and contaminated ground water from
springs and seeps in the Sand Creek channel are now impounded and isolated from Lincoln Park and
the Arkansas River. Since 1979, Cotter Corporation has been withdrawing contaminated, impounded
water and pumping it to the primary impoundment, which is lined (Reference 1, page 1-7). As part
of the 1988 State clean-up, a cut-off barrier was established at the site of the dam to prevent ground-
water flow beneath the dam. Presently, all surface and ground water is prevented from moving off
Mill property. This water is collected and pumped into a lined pond. In addition, there are concerns
related to wind dispersion of tailings that has caused soil contamination onsite and offsite (Reference
2, page 4).
From 1958 to 1968, the U.S. Atomic Energy Commission (AEC) was the regulatory body responsible
for oversight of the Cotter Corporation facility. In 1968, the Colorado Department of Health
assumed regulatory authority through an agreement with the Federal government (Reference 2, page
5). A Remedial Investigation at the site was conducted for the Colorado Attorney General by
Geotrans Inc. in 1986 (Reference 1). A natural resource damage claim lawsuit by the State has
resulted in a February 18, 1988, Consent Decree and associated Remedial Action Plan, between the
State of Colorado and Cotter Corporation. The Remedial Action Plan was developed to assess and
effectively mitigate any impacts to human health and the environment attributable to the Mill facility.
The site remediation could cost from $18 to 20 million, although no formal estimates have been
made.
OPERATING HISTORY
Uranium milling began at the Cotter site in 1958. The first mill operated until 1979 using an alkali
process (Reference 1, page 1-3). An acid leach mill process began in 1979, but has been inactive
since 1986.
During the milling process, molybdenum and vanadium were recovered as by-products during
uranium concentrate production (Reference 2, page 1). During the period of alkali milling (prior to
1979), 10 ponds were used for storage of process liquid and fresh water, for the disposal of tailings,
and for storage of fresh water. These ponds are unlined except for Pond 2 (lined in 1972); Pond 3
(lined in 1981); and Pond 10 (lined in 1976) (Reference 2, page 2).
3
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Uncoin Park Site
In December 1979, when the acid milling process began, a double-lined impoundment was installed
with drains above the synthetic membrane and below the clay layer and synthetic membrane. Tailings
from this acid leach process and water collected from ground-water interceptors are stored in this
impoundment. It consists of two sections: (1) a 91-acre primary impoundment for the storage of acid
leach mill wastes; and (2) a 44-acre secondary impoundment (Reference 1, page 1-5). During the
period between April 1981 to August 1983, the contents of Ponds 1, 2,4, 5, 6, and 8 (2.2 million
cubic yards of tailings) were moved to a double-lined secondary impoundment (Reference 1, pages 1-
7 and 1-8; Reference 2, page 46). Ponds 9 and 10 were removed in 1978 during construction of the
secondary impoundment (Reference 1, page 3-7).
Reagents used in the milling process included sulfuric acid, ammonia, ammonium sulfate, kerosene,
tertiary amines, sodium and calcium salts, potassium permanganate, zinc sulfate, and organic
flocculents (Reference 1, page 3-5).
The Mill occasionally processed custom ores such as waste raffinate from other mills and precipitates
or slags from other processes (Reference 1, page 3-4). In one instance, Polychiorinated Biphenyl
(PCB)-contaminated ore was processed, which contaminated some of the plant areas.
Trichloroethylene was used to extract the PCBs from the contaminated soils. This issue was being
investigated by EPA at the time the Remedial Investigation was prepared in 1986 (Reference 1, pages
3-4 and 3-5).
A catalyst plant on the Mill site was operated briefly in 1978 and 1979 to recover metal values from
spent catalyst material. Spent sulfuric acid catalyst material is currently stockpiled north of the old
Mill (Reference 2, pages 4 and 5).
SITE CHARACTERIZATION
The State of Colorado conducted a Remedial Investigation in 1986 to determine the environmental
characteristics and the type and extent of contamination. The Mill was active at the time. The
potential sources of contamination at the time included the uranium ore stockpile; leakage from the
old tailings areas; the soils and rocks beneath the old tailings ponds; and suspected leakage from the
new impoundment. Potential exposure pathways are wind dispersion of contaminants; onsite and
offsite soils; onsite ground water in a shallow and a deep path; offsite ground water in a shallow path;
and onsite surface water. Contaminants of concern have been identified as uranium, radium,
molybdenum, nickel, cobalt, copper, arsenic, zinc, lead, and cadmium (Reference 1, pages 1-10 and
3-2).
4
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Mining Waste NPL Site Summary Report
Soils
According to a study conducted in 1981, the soils and rocks in the 65-acre old tailings ponds area are
contaminated with uranium, molybdenum, radium-226, and heavy metals (Reference 1, page 1-8). In
addition, particulates have contaminated onsite and offsite soils (Reference 2, pages 173 and 174).
Soils in the upper horizons contain the highest levels of uranium, molybdenum, and heavy metals.
Sampling in 1981 showed nickel levels as high as 3,700 milligrams per kilogram (mg/kg), arsenic at
62 mg/kg, and molybdenum at 720 mg/kg in the sediments of Pond 8. Mean values of lead, nickel,
arsenic, and uranium oxide were 45.2, 59.9, 7.02, and 15.9 mg/kg, respectively. Extractable
molybdenum was 15.9 mg/kg, and gross alpha and radium-226 were 7.92 and 2.27 pico Curies per
gram, respectively (Reference 1, page 3-12).
Onsite investigations began in 1988, following entry of the Consent Decree by the court.
Investigations included a calibrated gamma scintillometer survey and a soil sample survey. Soil
samples were analyzed for radium-226 and molybdenum. (Data relating to these investigations are
not included in the references.) Investigations of soils adjacent to the facility are currently underway.
This includes examining existing data on contaminated offsite soils, and if necessary, conducting a -
supplemental soil survey (Reference 2, page 189).
Air transport represents the major mechanism by which contaminated onsite material is deposited to
offsite soils (Reference 1, page 4-1). Potential sources of wind-dispersed particulates include the
main and secondary impoundments; old tailings pond area; ore stockpile and ore handling areas; and
the yellowcake dryer. In 1985, soils were sampled along the primary wind vectors, and the
concentration of contaminants was plotted as a function of distance from the center of the Mill site.
These studies showed a significant correlation between distance from the site and the concentrations of
molybdenum, cobalt, nickel, radionuclides, gross alpha, and strontium. According to the study, these
contaminants were contributed by Cotter Corporation. There was also a correlation shown between
the concentrations of copper, arsenic, zinc, lead, and cadmium and distance from the Mill. However,
due to their spatial distribution, it is believed that this second group of contaminants was contributed
by two sources, Cotter Corporation and an old smelter (Reference 1, pages 4-20 through 4-25).
Ground Water (Shallow Path
Shallow ground-water contamination beneath the tailing ponds is a major problem. In the old tailings
area, contamination is present at depths of 100 to 150 feet below the water table. Further
5
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Lincoln Park Site
downgradient, near the Sand Creek dam, contaminants are present in the upper 20 to 30 feet of the
saturated zone beneath the water table (Reference 1, page 5-29).
There is evidence to support the concept that a shallow pathway has been the major pathway for
contaminant transport by ground water. Data show that, prior to the construction of the barrier
during the 1988 clean-up, a shallow pathway existed from the Mill area, along Sand Creek where the
dam was constructed, and into Lincoln Park. Contaminated ground water seeped through the dam’s
foundation (Reference 1, pages 1-11 and 5-31; Reference 2, page 3). DeWeese Dye Ditch, which is
used for irrigation, is located along this pathway. During irrigation season, leakage from the ditch
diluted shallow ground water and limited further degradation of ground-water quality beneath Lincoln
Park (Reference 1, page 5-32). Maps of uranium and molybdenum concentrations in shallow ground
water show a contaminant plume in Lincoln Park. The plume from the Cotter Corporation into
Lincoln Park shows high contaminant concentrations, but it was not mapped (Reference 1, pages 5-32
and 5-33).
Ground-water data (in 1978) showed uranium concentrations of 20 to 50 milligrams per liter (mg/i)
around the old ponds area. Uranium concentrations near the dam at the same time were 2 to 3.5 mg/I
(Reference 1, page 5-85). According to EPA Region VIII, seepage from the old tailings area is now
largely controlled. Sampling at 58 to 99 feet detected a 4- to 20-mg/I range for uranium in 1979 and
2.5 mg/I in 1985; measurements taken in 1986 showed the concentration had increased to 17.5 mg/I.
Another well (at 30 to 60 feet) showed uranium concentrations of about 7 mg/l in 1980 and 5.8 mg/I
in 1985; molybdenum concentrations were 18.3 mg/I in 1980 and 9.4 mg/I in 1985 (Reference 1,
pages 3-19 through 3-21).
In addition, there are suggestions that the liner in the primary impoundment may be leaking
(Reference 1, page 3-26). This is evidenced by increased levels of water near the impoundment and
an increase of uranium and molybdenum concentrations from the leachate in the underdrains
(Reference 1, page 3-27).
Contaminants of concern in Lincoln Park ground water include uranium, molybdenum, selenium, and
nitrates. Concentrations of these contaminants are much higher in the Mill area than in Lincoln Park;
the Mill area also shows contamination with cadmium and lead (Reference 1, page 5-126).
Ground Water (Deep Path )
The tailings impoundment area is located close to a deep shaft (1,084 feet deep) at the abandoned
Wolf Park Coal Mine (Reference 2, page 106). There is a potential for deep ground-water
6
_7’.
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Mining Waste NPL Site Summary Report
contamination beneath (and beyond) the area. Samples of water in the Wolf Park mine shaft obtained
prior to 1978 showed uranium concentrations of 30 to 50 mg/I. The mine shaft was filled in 1978, so
there is currently no sampling access. The potential contaminant pathway is from the mine shaft into
the saturated mine workings, along unmined coals and sandstones into Lincoln Park. However, this
path is not well documented and no evidence of uranium migration along the deep ground-water
pathway and into Lincoln Park is presented, although this pathway remains of concern (Reference 1,
pages 5-13, 5-53, and 5-54).
Surface Water
The Mill area is drained by Sand Creek, which discharges to the Arkansas River. Another five
intermittent streams lie within 2 miles of the site (Reference 1, page 6-5). There are four surface-
water pathways for salutes from the site to enter the environment: (1) erosion and transport of
previously deposited windblown material down ephemeral watersheds; (2) transport of contaminated
water and sediments down the lower Sand Creek watershed below the dam; (3) ground-water accrual
through the bed sediments in the Arkansas River; and (4) transport by surface water through the
outlet works of the dam when storms larger than the 10-year event occur (Reference 1, pages 6-12
and 6-13).
Storm-water runoff plays a significant role in secondary transport of wind-blown contaminants
deposited onsite and off’site. Storm water transports these contaminants to drainage channels which
eventually reach the Arkansas River (Reference 1, pages 6-5 and 6- 15). The specific pollutants of
concern that can be transported by this pathway are copper, arsenic, cobalt, molybdenum, nickel, --
silver, and radionuclides (including gross alpha and beta, radium-226, and thorium-230) (Reference 1,
pages 6-13, 6-16, 6-22, and 6-30).
The Mill has a drainage system to collect onsite runoff and remove it from Sand Creek drainage.
However, significant levels of contaminants continue to leave the site or contaminate offsite areas by
transport in the intermitted stream near the Mill. The contaminants are apparently the result of wind-
blown material or previously contaminated soils/sediments in the drainages (Reference 1, page 6-15).
As of the date of the Remedial Investigation (1986),.Cotter data (described as “limited” and
“insufficient to document ... potential problems in the aquatic ecosystem”) did not indicate major
changes in Arkansas River quality (Reference 1, pages 6-15 through 6- 17). State data from 1985
indicate that components of the tailings and raffinate are present in the Arkansas River (Reference 1,
page 6-22).
7
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Lincoln Park Site
ENVIRONMENTAL DAMAGES AND RISKS
The AEC was the regulatory agency responsible for oversight of the facility from 1958 to 1968.
Between 1959 and 1966, the site was cited 18 times for failing to track radioactive releases. The
State of Colorado Department of Health assumed regulatory oversight in 1968 and cited Cotter
Corporation 82 times for various violations under the Nuclear Regulatory Commission regulatory
process between 1968 and 1984. Among the state citations were exceedance of ‘As Low As
Reasonably Achievable” particulate emissions, discharge and releases from tailings discharge pipes,
and poor recordkeeping on control of offsite surface-water contamination (Reference 1, page 1-9).
Contaminated ground water at the site is transported downgradient into the Lincoln Park area.
Ground-water contamination was first noted in Lincoln Park in 1968. Concentrations of molybdenum
in Lincoln Park ground water were in the range of 24 to 60 mg/I (compared to a background level of
about 0.005 mg/I). These levels were described as injurious to cattle and unsuitable for irrigation of
crops used for cattle feed (Reference 1, pages 1-9 and 1-11). A contaminant plume of uranium and
molybdenum extends from the Cotter site (in the shallow pathway along the Sand Creek drainage)
into Lincoln Park and eventually to the Arkansas River. Concentrations of molybdenum and uranium
at the Mill site from 1981 to 1984 ranged up to 231 and 116 mg/I, respectively, in Lincoln Park.
Concentrations in Lincoln Park ranged up to 0.92 and 13.2 mg/I (Reference 1, pages 5-36 and 5-37).
Maximum concentrations in Lincoln Park of lead and selenium, as well as gross alpha and beta,
exceeded Maximum Contaminant Levels for drinking water (Reference 1, page 5-40).
Wind transport of contaminants has been observed since 1958. Emissions of radionuclides and
hazardous metals have been measured through air and soil sampling (Reference 1, page 1-14).
Offsite soil concentrations of metals are at (or above) a level of concern for agriculture use, cattle
grazing, and wildlife. In particular, soil concentrations were above critical values for molybdenum,
cobalt, nickel, arsenic, copper, zinc, and cadmium (Reference 1, page 4-28). In general, it was
found that contamination decreased with distance from the Cotter site (Reference 1, pages 4-20
through 4-28). Contaminated offsite soils are, in turn, entrained in surface flow, and contaminants
are transported in the intermitted streams to the Arkansas River (Reference 1, pages 4-28, 6-13, and
6-15).
Offsite vegetation samples were also shown to be contaminated, with levels exceeding levels toxic to
plants and/or animals of molybdenum, zinc, and cadmium (Reference 1, page 4-33).
8
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Mining Waste NPL Site Summary Report
REMEDIAL ACTIONS AND COSTS
The 1988 Remedial Action Plan calls for complex and comprehensive actions to remedy onsite and
offsite contamination. Major components of the Remedial Action Plan, and their current status,
include:
• Main and Secondary Imooundments - A well system has been constructed and will operate to
collect leakage from the new impoundments and intercept ground-water flow from the old
tailings area to the area beneath the new impoundments (until the flushing described below is
complete). The well system may be changed/upgraded for the “production” flushing system
described below (Reference 2, pages 36 through 45).
• Secondary impoundment - The secondary impoundment has been modified to manage water (by
evaporation) on the site, and minimize air transport of particulates from the impoundment
(Reference 2, pages 46 through 50).
• Water Distribution Pond - A lined surge pond has been constructed to control water from the
SCS hydrologic barrier, withdrawal wells, flushing extraction wells, and/or site runoff
(Reference 2, pages 51 through 54).
• Neutralization of Main Impoundment - An evaluation of the impacts of the acid tailings (the pH
was about 2.3) on the liner, and an evaluation of the technical feasibility of neutralizing the
acid tailings, have been undertaken. The Remedial Action Plan requires that, to the extent
necessary and feasible, any degradation of the clay liner be mitigated/minimized (Reference 2,
pages 55 through 60).
• Old Tailines Pond Area - Areas where flushing will be conducted have been identified and a
1-year pilot program to conduct ground-water flushing (including injection) and surface soil
removal has been undertaken. After the pilot program has been completed and evaluated, a
“production” injection and flushing program to minimize/mitigate sources of ground-water
contamination in the area will be undertaken (Reference 2, pages 61 through 78).
• Hydroloeic Barrier at SCS Dam - A hydrologic barrier has been constructed and a water
withdrawal system on the upstream side of the dam on Sand Creek is operational. Withdrawn
water is pumped to the main impoundment or the water distribution pond (Reference 2, pages
79 through 96).
• Northwest and Northeast Shallow Ground-water Pathways - A program (including the design
and construction of a well field) to determine the existence of hydrologic divides in certain
places has been implemented and water quality is being monitored. If necessary, these
pathways of shallow ground-water flow will be minimized/mitigated (Reference 2, pages 97
through 105).
• Wolf Park Mine Shaft - The potential for the mine shaft (by means of constructing and
operating a monitoring well) to serve as a deep ground-water pathway for contaminants is
9
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Lincoln Park Site
currently being investigated through a monitoring program. If monitoring indicates that it is
necessary, steps will be taken (by grouting or an appropriate equivalent) to minimize/mitigate
the shaft as a pathway (Reference 2, pages 102 through 113).
• SCS Dam to DeWeese Dye Ditch - By means of an excavated trench, water is being injected
into the shallow ground water in the Sand Creek channel below the dam to flush contaminants.
The water is not being collected; rather, the system relies on dilution to reduce contaminant
concentrations (Reference 2, pages 114 through 119).
• Lincoln Park Water Use - A study (including sampling) to determine the extent of ground-
water use by Lincoln Park residents has been conducted and three previously unconnected
residents have been connected to the Canon City water supply (future residents may be
connected as necessary). In addition, the Health Department will develop guidelines for the
use of ground water for irrigation and stock watering; if necessary, an alternative water supply
will be provided (Reference 2, pages 120 through 128).
• Ground-water Monitoring and Compliance - The Lincoln Park monitoring wells (there are two
wells) have been installed. A “compliance point” well system, to assess compliance with 40
Code of Federal Regulations (CFR) Part 192, will be installed at closure. These wells will
allow an assessment of the effectiveness of all ground-water remediation actions. Objectives
for the Lincoln Park wells have been set at 0.035 mg/I uranium (the National Academy of
Sciences’ recommended drinking water level) and 0.1 mg/i molybdenum (EPA’s adjusted
average daily intake value). Objectives for the 40 CFR Part 192 compliance point, to be met
near the toe of the main impoundment and along the downgradient boundary of the old tailings
pond area, are the levels established under 40 CFR Part 192, which incorporates and modifies
sections of 40 CFR Part 264, Subpart F (Reference 2, pages 129 through 154). To date, the
State of Colorado indicates that some improvement in molybdenum concentrations in Lincoln
Park have been recorded.
• Wind-dispersed TaiIin s/Contaminants - Existing and new air samplers are monitoring the wind
dispersion of particulates to evaluate the amount leaving the site, and to evaluate the
effectiveness of other remedial activities (Reference 2, pages 184 through 188). Air dispersion
is being mitigated/minimized from:
- The main impoundment, by means of water management and by covering the tailings
“beaches” (which form as water evaporates from the impoundment) with “clean” material
(Reference 2, pages 155 through 156).
- The old tailings ponds area, by revegetation or covering as appropriate (or by wetting the
areas if ongoing activities prevent revegetation or covering). Test plots for evaluating
potential revegetation success have been established (Reference 2, pages 157 through 161).
- Ore handling areas and stockpiles, by using clay pads (to prevent ground-water and surface-
water impacts) and, if necessary, by surface wetting (Reference 2, pages 162 through 164).
- Roads, by watering and/or by covering with gravel (Reference 2, pages 182 and 183).
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Mining Waste NPL Site Summary Report
• Onsite Soils - Efforts have been undertaken to revegetate onsite soils to minimize/mitigate air
dispersion of particulates. Soils containing elevated levels of radium-226 or molybdenum are
to be removed (to the main or secondary impoundment) and the affected areas revegetated
(Reference 2, pages 173 through 181).
• Off ite Soils - Extensive reviews of existing data and surveys (for radium-226 and
molybdenum) of adjacent offsite soils have been initiated. If necessary, some areas will be
fenced to prevent grazing; at closure, soils contaminated above certain levels with radium-226
or molybdenum will be removed (to the main or secondary impoundments) and disturbed areas
will be revegetated (Reference 2, pages 189 through 201).
• Lincoln Park Soils - A gamma scintillometer survey to identify contaminated soils in Lincoln
Park has been completed (Reference 2, pages 202 through 205).
• Willow Lakes - A program to sample water, sediment, and fish (for uranium, molybdenum,
and radium-226) in the Willow Lakes and feeder springs has been completed; EPA and the
State are currently reviewing the report (Reference 2, pages 206 through 208).
• Enhemeral Streams and Fremont Ditch - A survey of radium-226 concentrations in sediments
has been completed; if necessary, they will be removed to the main or secondary
impoundments (Reference 2, pages 209 through 214).
• Perennial Streams - A survey (for molybdenum and radium-226) in perennial segments of Sand
and Willow Creeks has been initiated; if necessary, they will be removed to the main or
secondary impoundments (Reference 2, pages 215 through 221).
• Pathway Mana2ement - A survey (for radium-226, molybdenum, and thorium-230) of soils in
defined drainage sub-basins is underway. If necessary, contaminated soils will be removed to
the impoundments, or appropriate “silt fences” will be constructed to filter and remove
sediment from runoff (Reference 2, pages 222 through 233).
• Arkansas River - A sampling program to assess impacts and measure the effectiveness of
Remedial Action Plan activities has been initiated. A report on the program is due in mid-
1991 (Reference 2, pages 234 through 237).
• Minnequa Reservoir and Pueblo Reservoir - An optional State-sponsored study of sediment
cores from these reservoirs is planned (Reference 2, pages 238 through 240). This study has
not been undertaken to date.
• Health Risk Assessment - A Health Assessment panel has been established to assess risk and
impacts attributable to mill-derived constituents in ground or surface water, soils and
sediments, inhalation of radon or dust, and fish and other food consumption. The Risk
Assessment will use data collected under several other Remedial Action Plan activities and is
due to be completed in late 1991 (Reference 2, pages 241 through 247).
11
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Uncoin Park Site
• Establish Background Data for Soils and Sediments - A sampling program has been designed
and begun to establish background concentrations of uranium, molybdenum, radium-226, and
thorium-230 in five reference sub-basins.
• Yellowcake Dryer - An assessment of current emission control technology was performed
(Reference 2, pages 169 through 172). According to the State, the study has been completed,
and steps are being taken to increase the efficiency of emission control devices. Once the
changes are made, an operational test of the dryer and emission control will be undertaken.
• Catalyst Pile - This calls for the removal and disposal (in an interim status or permitted
Resource Conservation and Recovery Act hazardous waste facility) of about 500 tons of
catalyst material (Reference 2, pages 166 through 168). According to the State, this material
was stored on the ore pads and became a “mixed” waste by virtue of mixture with radioactive
materials. Cotter has proposed onsite treatment; alternatively, it may be disposed of offsite.
CURRENT STATUS
See the preceding section for the current status of remedial activities. As of early 1991, the Cotter
Corporation was seeking renewal of its license to operate the Mill.
12
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Mining Waste NPL Site Summary Report
REFERENCES
1. Remedial Investigation, Cotter Corporation Uranium Mill Site; Prepared for the State of
Colorado, Department of Law, Office of the Attorney General, by GeoTrans, Inc., et al.;
February 1986.
2. Final Consent Decree and Remedial Action Plan, Cotter Uranium Mill Site, State of Colorado vs.
Cotter Corporation, Civil Action No. 83-C-2389; U.S. District Court for District of Colorado;
April 4, 1988.
3. Telephone Communication Concerning Lincoln Park Site; From John Vierow, SAIC, to Denise
Link, EPA Region VIII; May 13, 1991.
13
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Lincoln Park Site
BIBLIOGRAPHY
EPA Region VIII. Mining Information Collection Sheet. June 12, 1990.
Lamb, Laurie (SAIC). Telephone Communication Concerning Lincoln Park Site to Ed Cray
Colorado Department of Health. October 19, 1990.
McCarter, Sue (SAIC). Telephone Communication Concerning Lincoln Park Site to Gene Taylor,
EPA Region VIII. January 2, 1991.
McCarter, Sue (SAIC). Telephone Communication Concerning Lincoln Park Site to Gene Taylor,
EPA Region VIII. January 31, 1991.
State of Colorado Department of Law, Office of the Attorney General. Remedial Investigation
Report, Cotter Corporation Uranium Mill Site. February 1986.
U.S. District Court for District of Colorado. Final Consent Decree and Remedial Action Plan, Cotter
Uranium Mill Site, State of Colorado vs. Cotter Corporation, Civil Action No. 83-C-2389.
April 4, 1988.
Vierow, John (SAIC). Telephone Communication Concerning Lincoln Park Site to Denise Link,
EPA Region VIII. May 13, 1991.
14
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Lincoln Park Site Mining Waste NPL Site Summary Report
Reference 1
Excerpts From Remedial Investigation,
Cotter Corporation Uranium Mill Site;
Prepared for the State of Colorado, Department of Law,
ornce of the Attorney General, by GeoTrans, Inc., et al.;
February 1986
-------
IN’
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Preparsd For
THE STATE OF COLORADO DEPARTMENT OF LAW
OFFICE OF THE ATTORNEY GENERAL
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GEOTRA1* INC.
ROCKY MOUNTAiN CONSULTANTS, INC.
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1.0 INTRODUCTION
1.1 Site Background Information
The Cotter Corporation is a wholly-owned subsidiary of
Commonwealth Edison Company, Chicago, Illinois. The Cotter
Corporation is a mineral development company with offices in
Lakeweod, Colorado and operates a uranium mine (Schwartzwaldar
Mine) near Golden, Colorado and operates a processing mill
(Uranium, Molybdenum and Vanadium) near Canon City, Colorado.
The most recent data (Standard and Poors, 1983) indicate 450
employees in the mining and milling activities. The parent
company is an electrical utility serving Chicago and Northern
Illinois, having the highest nuclear componsnt in its fuel mix
in the utility industry.
The Cotter Corporation Canon City site is located in
Fr.mont County in the south-central part of Colorado,
approximately 96 miles south of Denver and approximately 36
miles northwest of Pueblo (Figure 1.1—1). Canon City lies
adjacent to the Arkansas River where the river begins its
transition from the Rocky Mountains to the Great Plains
physiographic provinces. The Cotter Corporation Uranium Mill
lies in a topographic bowl known as Wolf Park, some 2 miles
south of a semi—rural area named Lincoln Park and about 3.5
miles south of Canon City. The Cotter Corporation owns Section
16 and the southern three quarters of the eastern half of
Section 9, Tl93, R7OW, 6 Principal. Meridian, hereafter, referred
February 28, 1986 1-1 CR1
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to as “the site”. The site encompasses approximately 1.4 square
miles (830 acres) and contains an inactive mill, an active
a partially reclaimed tailings pond disposal area, and an active
tailings pond disposal area.
Milling activities at this sits began in July 1958. The
original mill used an alkali leach process and remained in
service from 1958 to the end of 1979. The acid mill began
production in 1979. Th. mill sites (current acid leach mil. and
abandoned alkali leach mill) are in the northwestern corner f
Section 16. Tailings impoundments or ponds used for waste
disposal activities cover most of the central areas of Section
16. Figure 1.1-2 shows the old mill and associated tailing
ponds; the photo was taken in Septamb.r 1975. The tailing ponds
were created using an upstream method of disposal and were
located in the western half of Section 16. “Upstream method”
tailing dam refers to a common method of emban3 ent
construction. The coarse fraction of the tailing is deposi. ed,
as a hydraulic fill, upstream of a smaller starter darn. Th .s
hydraulic filL forms a shell or beach which becomes the
downstream face of the emban1 ent. Control of seepage and
surface discharges is diffIcult as a result of the method 3f
deposition and typical high permeability of the shell mate .a .
The ponds were generally unlined except for pond 2 (. ed
July 1972), pond 3 (lined approximately . une 1981), and por. :
(Lined June 976). The effectiveness of these liners is
February 28, 1986
-------
unknown. The ponds were used for storage of various process
liquids and fresh water, and for disposal of tailing . and
raffinate.
In December 1979, the alkaline mill, was rep1ac d with an
acid leach mill, and the old upstream method tailing ponds (in
use from 1958 to 1980) were replaced by a full-height compacted
earth embanJ ent (Figure 1.1-3). The new impoundment was
segregated into a 91-acre primary impoundment for storage of the
acid leach mill, wastes and a 44—acre secondary impoundment,
originally planned to store wastes resulting from secondary
recovery of product from processing old tailings. The new
primary emban]ent lies approximately on the diagonal between
the northeastern and the southwestern corners of Sectioka 16.
The secondary impoundment lies upstream and southwat of the
primary impoundment. The capacity of the main and s ondary
impoundments is 2,283AP (3,683,000 Cu. yds.) and 1,045k?
(1,686,000 cu. yds.), respectively (License Renewal, Cotter
Corporation, 1984).
The new impoundments were provided with compacted soi ,, -.d
synthetic membrane linings with drains above and below the
lining. The underdrains were installed to reduce hydrostat
forces caused by seepage from the underlying strata on the
lining during construction and early phases of tailings
deposition in the impoundment. The overdrain system was
installed to dewater the tai tgs and to enhance settlezner:
February 28, :986
0 ’
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reclamation of the site. The plan to reprocess the alkali
circuit tailings was abandoned and the material contained within
the old ponds was mechanically transferred, using heavy earth—
moving equipment, to the new secondary impoundment di.iriiig the
period April 1981 to August 1983.
An event which changed surface water flow off the site was
the construction of the SCS Flood Control Dam completed in 1971
(Plate 1). Th. dam is located 4000 feet north of the main
tailings impoundment of Sand Creek. Prior to construction of
the dam, surface water from the mill site flowed down Sand Creek
unrestrained to the Arkansas River. The dam was built to
mitigate the effects of storm-generated floods. The outlet
works are at an elevation of approximately 5480 feet above Mean
Sea Level (MSL) and the spillway is at about 5510 feet MSL, 20
and 50 feet above the stream bed, respectively. Sin vi the
construction of the dam, runoff from the mill, has beeii so1ated
from Lincoln Park and the Arkansas River. The dam construction
resulted in the impoundment of contaminated water in the Sand
Creek channel. The source of this water is site runoff ar.d
contaminated ground water which emerged in springs and seeps a
various points along the channel. At one time a small dra
the dam’s outlet works allowed the flow of contaminated
impounded surface water into the Lincoln Park area. The dra
was subsequently plugged by Cotter. Cotter, since 1979, “ as
been withdrawing contaminated impounded water from the si , rface
pond at the dam and pumping it into the main impoundment.
Cotter has proposed to construct a compacted fill cutoff : e
February 28, 1986 :RI
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SCS dam, in conjunction with a gravel drain and sump, to reduce
the flow of contaminated ground water into tinco].n Park.
Hazardous materials used or generated at the site
include: uranium ore, tailings (solid waste material at the end
of the mill process containing radjortuclides, molybdenum and
unprocessed metals), raffinate (an aqueous solution of spent
reagents and residual material from the mill, process contain1J g
radionuclides and metals), metal-bearing catalysts processed for
molybdenum and vanadium, and natural earth materials and water
contaminated from previous disposal practices.
Ore is stockpiled at the northern end of the mill, site.
The ore is typically crushed to a nominal size at its saur e.
This results in significant amounts of fine material ausce;t le
to being transported offsite by wind (process known as aeoL.art
dispersion).
Tailings and raffinate are currently disposed in the
primary impoundment, which is leaking. When the tailings
impounded in the unlined ponds were removed to be isolated
the secondary impoundment, the contaminated material benea e
ponds remained. In excess of 65 acres of contaminated sc .s a:’.d
rock remains in the area previously occupied by the origi a.
disposal ponds. This material is a significant source of
contamination to both the air and ground water in the area.
‘ebruary 28, 1986 1-3
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The U.S. Atomic Energy Commission (AEC) was the regulatory
agency responsible for oversite of the Cotter facility from 1938
to 1968. There were six on—site inspections by the AEC
resulting in 18 citations in 1959, 1960, 1961, 1964 and 1966 for
the lack of, or inadequacy of, surveys to ascertain the
quantities of radioactive materials released to the air and
environs, i.e., th. unrestricted area in the vicinity of the
mill. In 1968, the State of Colorado Department of Health (CDH)
assumed regulatory authority by a mutual agreement with the
federal government. The State has conducted 13 inspections
resulting in 82 citations through 1984. Off-site ground water
contamination was identified in 1968 in the Lincoln Park area.
Th, concentrations of molybdenum in Lincoln Park were elevated
to approximate ranges of 24 mg/ I. to 60 mg/I. (background is
estimated at 0.005 mg/i) and were injurious to cattle and
unsuitable for irrigation of alfalfa and related leguminaceotis
crops to be used for cattle feed. Subsequent inspections to
1983 resulted in ma er citations on regulatory issues ranging
from not using reasonable care in limiting effluents during
operations to Limiting data required for a scientific evaluation
of site conditions. More specifically, Cotter was cited for
incomplete reports, exceedance of particulate emissions in
violation of ALARA (As Lou As Reasonably Achievable), poor
record keeping on control of surface water contamination
off-site, and discharge and releases from tailings discharge
pipes. At no time since 1968 was there an understanding between
the State and Cotter Corporation that established either the
extant of ground—water contamination from the site or the
February 28, 1986 R1
‘3’,,
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restoration alternatives.
1.2 Nature And Extent Of The Problem
The source of contaminants identified on the Cotter site
include substances containing radioactive and toxic metal
constituents. Th, contaminants include radium, nickel,
molybdenum, cobalt, copper, arsenic, zinc, lead and cadmium.
Becaus. this is an active facility, th. volume of source
contaminants is not constant. The inventory of ore is increased
or depleted depending upon the relative rates of delivery, ar.d
production at the mill. Th. accumulation of raffinate and
tailings waste occurs at rates dependent upon mill production.
Observed releases of radionuclides and metals at the site
include: spills and surface runoff; recharge of raffinate
contaminants leached from the old tailings into ground water;
leaking of the main impoundment; and aeolian (wind) dispersicn f
particulates from or. stockpiles, contaminated soils (old
tailings area) and old mill site, unstabilized tailings
(secondary impoundment), and point-source stack emissions (ye: w
cak. dryer).
Prier to construction of the SCS dam on Sand Creek,
surface water flows transported mill site contaminants to
offsita Locations. Although no surface water discharges ;ast
the SCS dam have been recorded to date, two significant
February 28, 1986 L—1O
-------
conditions exist. F.:st, contaminated ground water seeps
through the dam foundation and second, a major storm cou ].d
release contaminants through the outlet works. The pool at the
tipstream toe of the arn permits seepage of the contaminated
water beyond the northern ridge enclosing the site area. Threat
of a surface discharge results from the design of the darn. A
flood control dam is not intended to store water but rather to
attenuate the flood peaks. As such, an outlet works is designed
in this typ. of structure to release water after a given volume
is stored in the pool. This volume is approximately equal to
the runoff generated by the ten—year storm event. That is, the
event of a magnitude which is statistically expected to be
equalled or exceeded in any ten-year period, or have a
probability of one in ten that it would occur in a given year.
While it is evident that contaminant concentrations will be
diluted during extreme storm events, the total mass of
contaminants is not affected by dilution. Even without
consideration of the Sand Creek drainage, surface water runoff
has been a significant factor in the secondary transport of
aeolian contaminants lepesited off site. Storm events transport
released contaminants to the drainage channels off site, and
subsequently convey these contaminants downstream to the
Arkansas River (see Figures 1.2-1 and 1.2—2).
Contaminated ground water at the site is transported
gradient (to the north) into the Lincoln Park area. Genera :’,
two principal paths for the m .gration of contaminated gu
water exist, the “shallow path” and the “deep path”.
February 28, 1986
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Figure 1.2—3 illustrates thee. pathways. Water in the shallow
path travels through near-surface soils and bedrock. Cotter
Corporation concedes the existence of contaminant migration
the shallow pathway but contends that this is a single nar ou
plume. Available data indicate that,, probably are released r:a
ground-water paths outside this narrow plume. The “deep oath”
is particularly ill—defined from a single sampling well 339,
completed in the mine workings. Historical data obtained from
sampling the Wolf Park Mine shaft indicated high levels of
contaminants in the flooded mm. workings. How.vsr, recent data
from well 339, which may not be sampling the cam. hydrologic
zone, indicate greatly reduced concentrations of contaminants.
Aeolian transport of contaminants has been observed over
the past 23 years during regulatory inspections, by the
residents of Canon City/tincoin Park and the State’s (C!RC.A)
investigating team. Emissions of radionuclides and hazardous
metals have been measured through air and soil sampling both
historically and during these investigations.
Hazardous contaminants that have elevated ccncentra:.c s
specific to the Cotter facility both onsite and offsite re
summarized in Table 1.1—1. Thes. contaminants are found ..
the onsite and offsits ground water and soils, ephemeral ar.d
perennial stream sediments, and surface waters including
springs. This degradation of the environment threatens t e
quality of water supplies; drinking and irrigation water:
Febr 1ary 28, 1986
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2.0 SITE FEATURES INVESTIGATION
2.1. Demographics /
The cotter study area is located south of the Arkansas
River and changes southward from single and multi-family
residential development to rural single family residences with
acreage.. This area is typically small grazing parcels for
horses, cattle, dairy cows, and sheep. The specific subdivision
designations, distance from the project and populations are
summarized in Table 2.1-1 and identified on Plate 1. The
estimated population of the area, including Canon City, is 20,072
(1980 Census Data, Colorado Department of Commerce).
Further growth for the Lincoln Park, Brookeid., and Prospect
Heights area is not affected by limitations in the water supply.
These areas have access to Canon City water either through a
special district or a direct city water connection: however,
there remains a number of residences which continue to use wells
on their property. A complete water and sewer system for the
Lincoln Park area is limited by restrictions in the distribution
and collection system. The Canon City water district ssrves the
Cotter mill and has adequate capacity and water rights to serve
the Lincoln Park area north of the Cotter mill site with the
installation of larger supply lines and storage tanks. Further,
the Canon City sewer district does cover the northern half of
the Lincoln Park area and has approximately 1,500 connections
which represent nearly 90% of the population (Fremont County
February 28, 1986 2—1 CRt
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metals are also in the tailings and raffinate.
o Raffinate - The barren Liquid waste contains
dissolved adionticlides, metals and reagents from
old and new tailings at a pM ranging from less than
2 to more than 12. The raffinate currently in the
main impoundment has a pH of about 2.5.
Secondary Wastes are the result of releases to the environmer.t
from primary sources or earlier activities and include:
o On-site highly contaminated soils - soi.ls
underlying the old tailings areas.
o On-site highly contaminated ground water.
o On-site h .ghly contaminated surface runoff.
o Off—site contaminated soils and dra .nages from w d
blown contamination.
o Off—site surface water contaminat.on from w .nd :wn
contaminants.
o Off—site ground water contami.nation w.th raffi a:a
constituen:s in a rthking water su;py.
3.1.1 Stockpiled Ore
Although the ore s not a waste product per se, it s
Feb ary 28, 1986 3—2
-------
and cof finite (hydrated uranium silicat.). Associated with
minerals are minor amounts of iron, lead, copper and zinc
suif ides (chenoweth, 1980). There are little availabl, data
concerning the level of trace metals in the Schwartzwalder ore
that was delivered to Cotter. Most of the ore assays were
concerned with economically recoverable metals. Between July
1978 and November 1979, the molybdenum (Mo) concentration ranged
from 0.033 to 0.088% (Drauth, 1980).
The other main source of ore has been th. so called
“Western Slope” mines. Some of these mines are or were owned by
Cotter but most are owned by other individuals and companies. A
list of ore receipts from 1967 through 1969 contains over 40
separate mines. The principal ore minerals of the Colorado
Platsau are carnotite (potassium, uranium, and vanadium oxide),
coffinite, and roscoelite (aluminum and vanadium silicate).
Minor amounts of sulfide minerals, selenium, and arsenic are
also present.
The remaining source of raw material is a variety of
“custom oles”. These custom orss may actually be materials such
as waste raffinates from other mills and precipitates or slags
from other processes (L.sher, 1979). Very little data are
available concerning the level of trace metals in these custom
ores. A few analyses that are on file in the Colorado
Department of Health indicate that measurable quantities of
antimony, arsenic, cobalt, copper, lead, molybdenum, nickel,
February 28, 1986 3-4
00
-------
vanadium and zinc were frequently found. Some “custom ores”
were contaminated with other hazardous materials. For exam Le,
olych1orinated biphenyls (PC3) contaminated materials were
processed at the facility arid resulted i :ontamination of some
Cf the plant areas. :n order to dispose of ?C3—corttaminated
soils (1984), trichloroethylene (TCE) was .ised to extract the
PC3s from the soils. PC3 contamination was itvestigated y the
.3. Environmental Protection Agency (EPA). This issue is
unresolved and is still being reviewed by the EPA.
].2 Mill Process
The major chemical reagents used in the processing circu .t
include sulfuric acid, ammonia, * onium sulfate, kerosene, a
variety of tertiary amirtes, sodium arid ca .cium salts, potassi
per anganate, zinc sulfate and organic flocculertts.
Some of these regents are released to the environment,
though probably after being modified. !i; . concentrations f
sulfate in the ground water are attributa e to the sulfur c
acid used in the milling process. Analysis of soils beneath
Pond a contained high .evels of extracta .e titrate, der.ved
from the ammonia. The ground water has ct been analyzed
e .ther ammonium or ni.trate.
The sources of hazardous waste emiss :r.s in the mi
rocessing include emissions of fugit .ve th st from ore
February 23, 1986
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stockpiles, mii.ling and grinding operations, yellow cake dryer
stack, volatile emissions from hot liquid processes, and
emissions of radon gas. The stockpiled ore and yellow cake
dryer, if not operating at optimum efficiency, can be the
largest contributors to off-site radionuclide contamination (tS
NRC-GElS, 1980). This assumes a responsible tailing management
program. The contribution by aeoliart transport offsite from the
stockpiles to private and municipal property can be assessed
through a detailed air monitoring program of metals and
radionuclides. The time constraints of this investigation did
not allow the implementation - - a one year, 3 or 4 sample
location air particulate sampling program. This test program
could be implemented as a part of a license condition. The
present air monitoring is for compliance with CON radiation
emission standards. Future monitoring and analysis at old and
additional stations should include Cotter specific metals
(molybdenum, cobalt, nickel, arsenic, copper, cadmium, lead,
and zinc) until such time that source control has been ach .eved.
Second, the yellow cake dryer stack emission requires efficier.t
operation and an approved quality control check on the operat g
system, which includes monitoring. Compliance with CON and
federal radionuclide emissions is a part of the operating
.icense. All other emissions should meet CON air quality
standards.
3.3 Process Wastes
A discussion of the process wastes must include both : e
ebruary 28, 1986 36
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old (alkali leach) and the new (acid leach) mill. During
operation of the alkali leach mill (1958-1979) the liquid and
solid wastes were discharged into a series of 10 ponds. Ponds 9
and 10 were removed during construction of the secondary
impoundment in 1978. As part of an interim reclamation process
from 1981-1983, 6 of the remaining ponds were removed and
deposited in the lined secondary impoundment. The pond liquids
have either evaporated, were pumped into what is currently the
main impoundment, or seeped into the ground. Fugitive dust from
the old tailings in the secondary impoundment remain and the old
tailings area as a significant source of airborne contamination.
The impoundments were constructed in 1979 with a compacted clay
and hypalon liner and an overdrain system. The main and
secondary impoundments have a maximum surface area of 91 and 45
acres, respectively.
3.3.1 Old Tailings and Underlying Soils
The old tailings area contained primary waste until 1983
when removal of this material to the secondary impoundment was
completed. The leakage rate from the old tailings ponds is an
important parameter in site characterization, even though their
use has been discontinued. Using the data from a report by
Colbert and Klus1nan (1984) on concentrations of uranium and
other metals beneath Tailings Ponds 1, 2 and 6, an estimate of
30 tons of uranium presently beneath the old tailings ponds area
is derived. Other reports by Colbert and Kiusmart show similar
concentrations beneath other tailings ponds, so this number is
February 28, 1986 3—7 CR1
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soil column. A preliminary soils investigation (Table 3.3-2),
(CDX, 1981) revealed nickel levels as high as 3,700 mg/kg,
arsenic at 62 mg/kg, and molybd.num at 720 mg/kg in the
sediments in Pond 8. A follow—up survey reports mean values for
total lead, nickel, arsenic and uranium oxide were 45.2, 59.9,
7.02 and 15.9 mg/kg, respectively. Extractable (DTPA)
molybdenum was 15.9 mg/kg and th. gross alpha and Radium-226
were 7.92 and 2.27 pCi/g respectively.
Al ]. of the wastes from the new mill operation are
discharged into the main impoundment and the bulk of the liquid
waste is the raffinate. Further, Cotter is not neutralizing
their raffinat. to pM 4 as required by their 1979 license and as
stated in their 1984 Application for License Renewal. Runnels et
al. (1983) measured concentrations (in mg/l) for arsenic (3),
cadmium (1.3), cobalt (30), copper (27), lead (4.3), molybdenum
(1.6), nickel (2.0), vanadium (80) and zinc (36). Sampling of
the main impoundment in 7uly 1985 indicated concentrations (in
mg/i) of dissolved arsenic (12), cadmium (1.2), cobalt (4.8),
copper (33), lead (2.6), molybdenum (12), nickel (11), vanadium
(170), and zinc (83). The pM of this liquid is approximately
2.0 and th. salinity is high (66,000 mg/l TDS). This
environment is harsh and will .xpedit. the normally slow
weathering of residual minerals and release of soluble trace and
heavy metals.
February 28, 1986 3—12
o
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Table 3.3—2 Examples of Contaminant Migration With Depth
in soils Underlying Pond 8. Concentrations are in
meg/i for the past., mg/kg for available and total
extractions. (1981 — CDX Laboratory for T.A. Colbert)
Determination 0—lOcm(4”) 15—3Ocm(12”) 30—45(17”) 50-65(32”)
Paste
pH 7.3—7.8 7.0 7.3 7.4
Calcium 18—21 41 28 8.5
Magn.sium 11—13 9.9 11 5.2
Sodium 150—200 81 84 17
Potassium 0.32—0.36 0.56 0.16 0.05
Chloride (Ci_) 3.14 3.2 4.9 3.5
Sulfate (504 ) — 140—220 14 60 20
Bicarbonat.(HCQ3 ) 38—53 24 21 24
Carbonate (C03 ) <1 <1 <1 <1
Nitrate 60—230 480 390 103
(as N)
Avail able
Arsenic 2.2—3.0 .44 0.06 0.09
Cadmium 1.7—2.6 0.1 0.06 0.12
Copper 29—32 4.1 2.2 2.1
Iron 5.0—7.5 6.8 6.5 15.0
Manganese 15—27 69 65 2.4
Molybdenum 74—66 120 110 7.6
Nickel 76—83 80 2.6 2.8
Lead 26—30 2.2 1.6 3.7
Selenium 0.6—0.8 0.26 0.13 0.11.
Zinc 39—54 1.8 1.1 3.4
Total
Arsenic 44—62 9.9 4.9 11
Cadmium 5—7 1.0 2.0 2.0
Copper 83—106 19 15 12
Iron 28000—30000 30000 29000 31000
Manganese 380—410 530 480 250
Molybdenum 460—720 310 600 120
Nickel 2500—3700 270 52 73
Lead 130—190 34 28 37
Selenium 2.0—2.3 0.3 <0.1 1.9
Zinc 542—820 84 70 110
Uranium 0.0018—0.0045 0.0005 0.0001 0.0005
Radium—226 (pCi/g) 3.0+0.7 1.6+0.6 1.5+0.5 1.6-4.2
0.2
February 28, 1986 3—13
‘U
-------
(analyses from 701 Figure 3.4-1), in 1979 ranged from 90-100
mg/i; in 1985 the range was from 100—115 mg/i. Removal of the
Liguid and the tailings has not abated the source of
contamination. Other collection sites show similar results. At
sample collection site 703 uranium ranged from 5-25 mg/i in
1979, and now ranges from 35—40 mg/i. Molybdenum shows sim .ar
results, although the concentrations are higher.
The high values of uranium and molybdenum occurring in the
samples from the collection points 701, 702, and 703 are as yet
unexplained. Few analyses of raffinate from the alkaline leach
mill have been found. The levels of uranium and molybdenum in
those analyses were far below those observed in the coliecti.on
points 701, 702 and 703. The raffinates may have contained
higher levels of these contaminants than the limited data
indicate; more likely, evaporation or other mechanisms result
i.n an increase in concentration.
The contamination problem is not confined to the surface
water and shallow ground—water system. Well 303, samp1i g
waters at depths of 58-99 feet below ground surface, conta ed
.1—20 mq/]. of uranium in 1979. By 1985 this had decreased :
approximately 2.5 mg/i indicating that water guality of the
deeper waters may be improving. Recently, however, uran m
concentratIon had increased to 17.5 mg/i., reversing the trer .
Well 333, open at depths f 30—40 feet, contained
February 28, 1986
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concentrations of about 7 mg/i in December 1980. By March 1985,
this concentration had dropped to 5.8 mg/i; molybdenum decreased
from 18.3 mg/i to 9.4 mg/i over ths same time period.
In summary, major problems still exist for the shallow
ground water beneath the old tailings pond area. Concentrations
in the deeper ground water may be decreasing; unfortunately, the
monitoring points within the old tailings area are very limited
and the understanding of rate of change in concentration is
incomplete. Only one well samples the deeper ground-water
system in the 4 - ediate area of the old tailings. The major
source of contamination in the old tailings areas was the liquid
disposed or stored in the old tailings ponds. Removal of this
liquid has been a first step in rem.diating the ground water in
this area. However, seepage through the remaining contaminated
solids still occurs. Seepage from the contaminated sediments
underlying the old tailings ponds contains uranium at
concentrations equal to or greater than that in the raffinate
disposed of in the ponds.
3.4.2 Imboundments
Use of the new primary and secondary impoundments was
authorized by the Colorado Department of Health in 1979 to
improve the disposal practices of the Cotter mill. Construction
began in 1978 by removing soil and loose rock from beneath the
area to be covered by the impoundment and the necessary berm.
In the process of this excavation several springs were uncovered
February 28, 1986 3—21 CR1
-------
precipitation reactions are probably occurring. Whether this
precipitation and Liqui.d neutral.zation are occurring within the
liner or in the drains (where the raffinate is mixing with water
that has reacted with calcite) is unknown. If it is occurr:ng
due to mixing in the drains, permeability in the clay liner will
not be reduced.
Several lines of evidence indicate that the impoundment ..s
leaking today. Generically, synthetic membranes are known to
leak; see, for example, the papers on durability, and leakage
monitoring in the proceedings from the International Conference
on Geomembranes (1984). Cotter performed (through their
subcontractors) several experiments on the properties of Mypalon
after short-term exposure to various chemical agents. In a
short time frame few problems were noted. It is known that
Mypalon exposed to ultraviolet light (UV) loses its strength
properties. The random fill cover placed upon the Hypalon should
protect the Hypalon from UV exposure, but slumping of this
random fill cover throughout much of the impoundment area has
exposed the Mypalon.
next, the information available clearly indicates that the
Mypalon liner used in the impoundments at the Cotter Cororat n
Mill site is leaking. This conclusion is supported by:
1) Cotter Corporation memoranda documenting damage to
the Mypalon Liner discovered over the years caused y
rocks in the natural cover and underlying foundat.cn
February 28, 1986
-------
material, and reports of numerous seam failurss during
construction that required repair. Those holes that
have been discovered have been repaired.
2) Photographs of impoundment construction illustrating
the presence of rocks (up to boulder size 12”) in
the natural cover material placed over the Mypalon and
the use of heavy earth—moving equipment.
3) An increase in water levels near th. impoundment,
indicating recharge of water to the ground-water
system.
4) Geophysical data that document a zone of higher
electrical conductivity of either water or rock near
the impoundment.
5) Uranium and molybdenum data from the underdrains that
document an increase in contaminant concentrations in
water beneath the liners of the impoundment.
It is apparent that the heavy equipment, as well as the
weight of the natural cover layer itself, pushed rocks into and
through the Hypalon liner. Any foreign material present in the
cover could also tear, puncture, or rip the Hypalon with
pressure supplied by heavy equipment.
A continuing history of breaches (tears, rips, holes,
separations, fabric failures) in the impoundment’s Hypalon 1ir er
February 28, 1986 3—27
ggL)
-------
4.0 AI :NvESTIGAT:oMs
Air transport represents the major mechanism by which
contaminated on-site particu .ate :naterials are deposited on the
off-site terrestrial .andscape and within alluvial water
drainages. These transported materials contain a number of
heavy metal and radiological contaminants.
4.1 Site Wind Distributions
The climatology of tile site and therefore the transport
mechanism is influenced by the immediate surrounding terrain.
See Section 2.4 for a review of the site climatology.
The data used for determining wind distributions are 1982
data (Loureiro, 1984) from the Cotter mill site facility. e
meteorological facility is located at the Cotter mill site
(Plate 1). Figure 4.1-1 shows that the predominant wind
directions are from the west-northwest and west with a secor.dary
peak out of th. east-southeast. The wind distribution is
bimodal being either westerly or east-southeast in direct n.
The scuthsrly winds would be exected to be diminished due :
the orographic features on and near tile Cotter site, espec: -7
the high ridge just south of the facility.
n order to assess the extent of contaminant movemer.:
tile environment in the areas surrounding tile Cotter faci. ..:y
February 28, .986
-------
the higher wind speeds were evaluated to determine when the
tailings and other f.igitive materials would be transported
off-site by the wind. Figures 4.1-2 through 4.1-4 show wind
rose distributions containing only data for those winds of
greater than 10, 15.5, and 21.5 mph, respectively. One should
be careful in reviewing and compar ng these figures since the
scale varies between the var ous presentations.
These data show a dominance of west-northwest winds from
the facility, which would indicate that blowing tailings and
other fugitive em .ssions would be transported to the
east—southeast of the mill site.
4.2 Air Quality
The sources of materials for air transport are discussed n
Section 3.0. Specifically, they include contaminated res dua
earth materials in the area of the old tailings ponds, ta . gs
relocated from the old ponds that reside in the secondary
impoundment, and stockpiled ore. All these sources are
relatively unprotected from wind erosion. Large amounts of
blowing fine—grained material nave been observed both in
past and on recent ocoasions. The analysis presented .n
3.3—2 indicate with depth the degree of metal contaminat .on :f
some of the residuals from the alkaline mill. During
this material was ground so that 80% passed a 200 mesh s eve
(<0.13 mm). This material currently lies within the seco da :
February 28, 1986 4—3
,I J
-------
from the site.
iigh—volume filter data concerning the air trar.s ort of
heavy metals off-sLte have riot seen comprehensively oollec:ed.
? owever, the sint .lar nature of the air transport of heavy - etals
suggests that they too have been transported by air off the
Cotter property. This content on is further supported by
analytical data measured for soils collected along east and west
transact lines originating from the Cotter property (Sect.on
4.3).
4.3 Aeolian Soil Contamination
As a preliminary assessment of aeo.ian soil contaminat.on,
soils ware sampled along the primary wind vectors. Figure
4.1—2 shows the distribution of wind directions for ‘,e1oc - s
greater than 10 miles per hour. This velocity is oonside:ed the
minimum that would result in significant transport of
particu.lates. The wind rose shows that the dominant direc:orts
of strong (>10 mph) winds are from the west-northwest and :om
the east-southeast.
4.3.1 Soil and Vegetation Sampling 1ethods
A reconnaissance was conducted on July 11, 1985. Sam;.e
sites were selected along each of two approximately linear
transects oeginni.ng near the eastern and western boundar: s
the Cotter property. Additional sample sites were esta5
February 28, :986
-------
within Lincoln Park in garder.s reported to have been irrigated
by contaminated ground water and in cont .guous areas irrigated
w .th water from other sources.
Sample sites were des .gnated using four character alpha-
numeric code. The first letter of the code (C) designates the
Cotter site. The second letter designates either transect
direction (E — ESE direction; W - WNW direction). Numeric
suffixes increase in magnitude with increasing distance from the
Cotter site.
The location of each sample was marked on 1:24000 scale
aerial photos. Locations were transferred to identical scale
USGS topographic maps as presented in Plate 2. At each sample
site, a wooden stake with the alpha-numeric site code was placed
at the southwestern corner of a 20 m (meter) by 20 m (meter)
area. Random numbers, generated prior to sample site
establishment, were used to determine three locations for both
soil and vegetation sampling wLthin each site. Two random
numbers were used to designate each soi . and each vegetat .cn
sample location.
Soil Sampling : Six (6) distinct soi. samples were
obtained at sample sites along the east and west transects.
Samples of two depths (0-5 cm and 5—15 cm) were obtained at eact
of 3 replicate locations. At each sample location a pit was
excavated to a depth of about 25 cm. Zxcavated material was
February 28, 1986
“1
-------
placed on a plastic tarp to aid in backfilling pits and to
minimize disturbance to the site. At the onset of the sampling
effort, soils were dry.
One side of each pit was cut back a distance of 2-5 cm
using a clean stainless steal digger to remove material which
may have been contaminated whil, digging the pit. Soil was
removed progressively from the surface down in order to avoid
contamination for subtending layers with overlying materials.
The digger was washed in a laboratory grade soap solution and
triple rinsed with deionized water between each use.
Depth increments (0-5 cm and 5—15 cm) were measured from
the soil surface. Samples were obtained by cutting an area of
each depth increment onto a clean plastic dustpan. Care was
exercised in order to obtain a sample with equal portions of the
entire depth increment. The 5—15 cm increment was sampled first
to reduce the potential of cross-contamination between
increments.
The sample wa, split between the State’s consultant and
Cotter representative, in the field. The soil sample was
labeled and double bagged. Plastic implements (dustpans and
spatulas) were washed in laboratory grade soap solution, rinsed
in a nitric acid solution and triple rinsed in deionized water
between each use. Thi. procedure was repeated for the 0—5 cm
depth increment. Soil samples wer. transported directly from
February 28, 1986 4—17
-------
the field to the analytical laboratory for subsequent
preparation and analyses.
Vegetation Sampling : Six (6) vegetation samples were
collected at every sample site on the ESE and WNW transects.
Three (3) rsplicates of each of the two (2) plant species were
collected. Plant species selected were rabbitbrush
( Chrysothamnus nauseosus ) and three—awn ( Aristida longiseta) .
Sampling was repeated at site CEO2 after a heavy rainstorm in
order that prs— and pest—rain contaminant concentrations could
be compared. Four (4) samples, including two (2) replicates of
each two (2) species were taken from each of the Anderson and
Procerione gardens. Plant species selected were dandelion
( Taraxacum officinale ) and red radishes ( Raphanus sitirus ) from
the Andersen garden (AVO1) near well CGOO6 and dandelion and
white radishes from the Procorione garden (PVO1) near well
CGOO4. Two (2) samples of dandelions were taken from both the
Andersen pasture (APO1) and the Procorione lawn (PRO].).
Sample locations at sample sites along the ESE and WNW
transects were selected randomly within a 400 square meter area
at each sample site. Vegetation samples were taken from the
closest plants of the desired species to the randomly selected
points. Plants were sampled until adequate plant material was
obtained.
Sampling procedures used pruners and garden shears.
February 28, 1986 4—18
I1&
-------
Sampling i.mplements were washed before each sampling using a
Laboratory grade soap solution and a triple rinse with dei.on ed
water. Disposable rubber gloves were worn at all times and
changed after each separate sample was taken.
Dandelion and three—awn plants were harvested as close to
the ground level as possible without including litter from .asz
year’s growth. Rabbitbrush branch tips were harvested to
include only the present year’s growth. Radishes were harves:e
whole. ? fter harvesting, the plants were spl .t between Cotter
and the stats. The state samples were stored on ice until
processing was complete.
At the laboratory, samples were removed from the ice thests
and placed in plastic tubs which had been washed rt a laboratory
grade soap solution, rinsed in a nitric acid solutLon and ::
rinsed with eioniied water. Three-awn samples were cut :
segments approximately two inches long in order to fit n:o : e
tubs. Samples were oven dried (50°C) and then crushed to
<2mm size particles.
4.3.2 Analysis of 3oi.ls ata
:n order to test the hypothesis that soils contam a::
or ginated from the ll site, the concentration of each
contaminant was plotted as a function of distance from the
center of the transect (approx mately the center of the s :e
February 28, 1986
-------
Separate regression equations were developed for the eastern
transect (stations C!01 through CE05) and ti’e western transec
(stations CWO1 through CWO4). The regression equations were
then tested for statistical significance. The equations were
determined to be significant when alpha (probability of Type :
error) was less than or equal to 0.05. The regression equations
for ten metals and gross alpha are presented in Table 4.3-1.
The transect regression curves have been grouped based upon the
significance levels and the contaminant concentrations at the
farthest sample sites. This analysis allowed the grouping of
the contaminants present into five sets (Figures 4.3-1 through
4.3-5). All soils analysis was based upon a total digestion of
the material passing a 100 mesh sieve.
Figure 4.3-1 contains data for metals molybdenum, cobalt,
and nickel, and Figure 4.3-2 the data for radionuclides, gross
alpha, and strontium. These metals and radionuclides have
statistically significant correlations between the distance ar.d
concentration in both directions with the far sample sites be g
approximately equal. This identifies the source of the
contaminants at the Cotter site (between CWO1 and CEOl).
also indicates no other detectable sources along the two
transects.
Figure 4.3—3 contains data for the metals copper and
arsenic. These metals have statistically significant
February 28, 1986 4—20
iI%
-------
TABLE 4.3—1.
THE REGRESSION EQUATIONS FOR THE EAST-WEST SOIL TRANSECTS AT
THE COTTER SITE. EQUATIONS ARE IN THE FORM OF Y - EdDjgt
WHERE I - CONCENTRATION mg/kg.
2 (2)
ELEMENT TRANSECT a b r SIG LEVEL
Cd West 4.55 —.208 .32 .14
Cd East 6.8 —.512 .43 .04
Co West 10.19 —.897 .73 .006
Co East 6.41 —.434 .4 .05
Cu West 9.62 —.637 .69 .0].
Cu East 7.6 —.403 .51 .02
Pb West 5.8 —.080 .04 .62
Pb East 9.1 —.474 .41 .04
Mo West 20.02 —2.163 .92 .002
Mo East 11.18 —1.030 .62 .007
Ni West 12.92 —1.155 .72 .007
Ni East 9.6 —.737 .54 .0 ].
Zn West 8.98 —.225 .41 .08
Zn East 11.31 —.538 .54 .01
As(].) West 15.7 —.001]. .03
As(1) East 18 —.00135 .92
Be West 0.72 —.14 .02
Be East 2.32 —.331 0
Cr West 2.86 —.033 0
Cr East 2.76 —.032 0
Gross Alpha West 13.4 -1.14 .90
Gross Alpha East 11.6 —.855 .55
Ra—226 East 18.9 —1.97
Ra—226 West 8.01 —.744
(1) NOTE: The As regression is the form y — a + b x.
(2) Significance levels not reported for parameters
without analysis of field replicates.
4—21
-------
Co
Ui 0-5 cm Soil Depth Co in 0-5 cm Soil Depth
—
; L
C— UT O taims ( ..* lAST —>
J
Ni in
0-5 cm Sod Depth Ni in 0-5 cm Soil Depth
—
- --•
<— W T flW su utiicS (?. ) lAST —)
Figure 4. 3 —I Plots for the east and west soil transcce at the
Cotter site for Mo, Co, and Ni.
.
€XPLANAT ON
I CRITICAi.. L(VCu. OR LEVELS WHICH TONIC
- — - I SYMPTOMS HAV( 8CEN RCPORTEO N PLANTS
Mo in 0-5 cm Soil Depth
Mo ‘0-5 cm Soil DePth
S
4—22
I ()
-------
Figure 4.3-2 Pldts for the east
Cotter site for gross aLpha
and west soi .L transeCts at the
and Sr.
Gross a in 0-5 cm Soil
S
•201 zao
Gross a in 0-5 cm Soil
hO
U
5
iii
S
S
0
a
‘Si
S
•0
10
60 S i
<— WEST Otatanc. (f.t)
.
I
I
10 50 15000
Distinc. ( fist) EAST — >
Sr in 0-5 cm Soil Depth
S. Ii
.
Sr in 0-5 cm Sod Depth
VS 7 5
S
I .
:1
II
hISS
40 40
IS IS
- WEST titi ,
S
1405
Olstsnc. (f•st) EAST —>
-
tSG O O
4—23
-------
.
.
-
L
:
.
-
* 30 . .
1 10
V
hi
10
U’
‘%% •
.
0
S
.
. -.
,
‘ * 100
Figure 4.33 Plots for the east and west soil transects at t e
Cotter site for As and Cu.
EXPLANATION
CRITICAL i(VEI. OR V(LS WHICH TOXIC
SYMPTOMS HAVE SEEN REPORTED IN PLANTS
4—24
As in 0-5 cm Soil Depth
As in 0-5 cm Soil Depth
. .
3
a
1-
<— WEST Olitinos (list)
S
• 10.S hiss
Dlstsncs (list) EAST —>
Cu in 0-5 cm Soil Depth
Cu in 0-5 cm Soil Depth
I
moss lass
<- WEST Olstisics (list)
au
Dlstancs (fist) EAST —>
-------
relationships between distance and concentration to the east and,
a strong, but not statistically significant, relationship : the
west. There were also higher concentrations at comparat.ve
distances along the western transect. These data indicate a
source (the Cotter site between CWO1 and CEOl) and a secor.dary
source (near the western transect). There is an abandoned
smelter near this transact.
The third, set of metals, zinc, lead, and cadmium,
illustrated on Figure 4.3—4, have statistically signifIcant
relationships to the east and a consistent and elevated
concentration to the west. These data indicate a source t the
west of site CEO ].. The high soil concentrations along the
western transect indicate that these metals have two sources
(smelter and Cotter Corporation).
A final set of metals, illustrated on Figure 4.3-5,
chromium and beryllium, are examples of materials which do ot
demonstrate any particular pattern and thus indicate either a
different source, or multiple source(s), or no source ot .er : a
natural occurrences.
The soil data are consistent with the air particulae :33
collected at the site beundar:es. Although only radioLog a .
arameters were measured on the air particulate samples ee
Section 4.2), the data do indicate that contaminants are a;: q
the site boundary and that during certain time periods ..
February 28, 1986 4—25
‘I
-------
ii
a I_
•1 5
.K.
S
.
“
I
Figure 4. 3-4 Plots for the east and west soil, transects at the
Cotter site for Zn, Pb, and Cd.
EXPLANATION
____ k CRITICAL LEVEL OR LEVELS WI4ICN TOXIC
- — - SYMPTOMS NAVE OCEN REPORTED IN PLANTS
Zn in 0-5 cm Soil Depth
Zn in 0-5 cm Soil Depth
.
—
1000
a
Si
5000 l Ist
<— WEST Olotsac. (fist)
I I I .
OIstsncs (fist) EAST —>
Pb in 0-5 cm Soil Depth
5000
( I .
Pb in 0-5 cm Soil Depth
5
£
5 5
nil.
m i ii ioi o
<— WEST Otstsnc. (fist)
S
5005 5 .05
Olitanco (fist) EAST —>
Cd In 0-5 cm Soil Depth
UI .
45 .5
.
Cd in 0-5 cm Soil Depth
10
II
ii
a
ii
1s
U
5005 list
(— WEST OI.tanc. (fist)
S
miii
OIst.ncs (fist) EAST —>
/‘ 4,
4-26
-------
Be in 0-5 cm Soil Depth Be in 0-5 cm Soil Depth
11.0 1.0
• • : ::
0.4 S 0.4
0.2 0.2
Q .Q 0.0
tS 0 0 0 10000 8000 S 0 5000 10000 15000
<— WEST Otstance (feet) O!otance (feet) EAST —>
Cr in 0-5 cm Soil Depth Cr in 0-5 cm Soil Depth
IS IS
Ii 10
S
14 g 14
S S I2 12
12 10
.
‘S S
5o0o 12000 8000 0 5000 10000 15000
<— wEST Oletonce (feet) O stanco (feet) EAST .->
Figure 4.3-5 Plots for the east and west soil transccts at the
Cotter sitc for Be and Cr. ‘
/
-
-------
1981), the western station had higher particulate contaminant
concentrations. The highest soil contaminant levels for the
radionuclides (i.e., gross alpha) were also along the western
transect. In addition, the ability to group the metals into
similar categories has allowed the targeting of certain metals
(Mo, Co, Ci, and radionuclides) to Cotter alone. Finally, the
data indicate that released contaminants, inferred from the air
quality data, are being deposited within the watersheds
surrounding the site.
The concentration of heavy metals and radionuclides in the
soils along the two transects sampled indicate contaminant
release from the Cotter site. The.. concentrations at several
sample locations are at or above a concern level for the uses of
these soils for agriculture, cattle grazing or wildlife uses
(Table 4.3—2 through 4.3-5 and Figure. 4.3-1 through 4.3-5).
Soil concentration. above critical values were detected for
molybdenum, cobalt, nickel, arsenic, copper, zinc and cadmium.
At the present time, the arsal extent of injury (for soils,
vegetation, and wildlife) as a result of off site contamination
due to air transport from Cotter cannot be quantified.
4.3.3 Analysis of Vegetation Data
Concentrations of heavy metals in rabbitbrush were below
instrument detection at many sites. This limited the
opportunities to perform statistical analysis of concentrati.o
February 28, 1986 4—28
Fr
-------
and distance relationships. Metal concentrations were
constantly higher in three—awn plants sampled from the same
locations.
Levels of concern for toxicity in plants or to grazing
animals (Tables 4.3—2 and 4.3—5; see Table 4.3—5) were exceeded
by several samples for both transects. Levels of Mo in a range
resulting in toxic symptoms in livestock were detected in
rabbitbrush at CWO1 (16 mg/kg) and CWO2 (6.9 mg/kg), and in
three—awn at CEO ]., CEO2, CEO3, CWO1 and CWO2 (26, 16.5, 8.1, 78
and 12.4 mg/kg, respectively). Levels of Mo at which some
plants exhibit toxic symptoms were found in rabbitbrush at CWO1,
and in three-awn at CWO1 and CWO2. Zinc levels in rabbitbrush
from CEO3 (101 mg/kg) were in a range at which toxic symptoms
occur in some plants. Levels of cadmium at CEO3 (1.6 mg/kg)
exceed levels (greater than 0.5 mg/kg in Table 4.3-5) toxic to
animals with long-term consumption. Samples from stations AVO1,
PVO1, APO1, and PRO]. (gardens) were not analyzed.
The relationships between natural log concentration of
metals in three—awn plants and the natural log distance from the
Cotter tailings pond were not significant along the east
transect. The absence of stron 5 relationships may be the result
of there being only three sample sites (containing enough
three—awn to sample) along this transect. Relationships between
log concentration and log distance along the west transect were
significant at the 0.05 level for nickel and highly significant
February 28, 1986 4—33 CR1
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5.0 HYDROGEOLOGIC INVESTIGATION
5.]. tntrothiceion
From the time the Cotter alkaline—leach uranium miii
started discharging tailings and waste liquids in 1958, unt.1.
the main impoundment was finished in 1979, waste products were
(with few exceptions) disposed to unlined ponds. Contam at .or
of tile ground water became apparent, in the mid to late six .es.
Removal of liquid and solid wastes from the old tailings area to
tile main or secondary impoundments in the early eighties marked
the beginning of control of sources of ground-water
contaminants. Removal of contaminated ground water downgrad .ent
of tils old tailings area began at about the sam. time. -
Subsequently, Cotter has proposed construction of a hydrologic
cutoff barrier at the SCS dam, with collection and evaporation
of intercepted ground and surface water.
Ground-water problems still persist. Although the grcu d-
water removal program has caused apparent improvement of wa:er
quality in part of Lincoln Park, tile water is still corttam-
mated. In the mill area, there is no evidence of improvement
of water quality. Until the ground water in the mi..l is
remediated, ground—water interception and removal programs iust
continue; their effectiveness must also be improved.
Section 5.3 of tile Remedial Investigation report sun tar :es
tile current :< ow1edge of the ground—water system at the s.:e a
February 28, :986 3—1
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overlapping, and in places reported direct connections between
mines, the presence of large quantities of water in the mines,
and the close proximity of the old and current Cotter tailings
impoundments to the deep shaft of the Wolf Park Mine all
combine to provide the potential for contamination of ground
water at depth beneath the area and make the interpretation of
the possible pathways for contaminant migration complex.
5.3 Ground Water
Since the Cotter Uranium Mill began operatilns in
approximately 1958, disposal of raffinates, other waste liquids,
and solid tailing material has been to either a series of
ponds in what is called the old tailing area, or to a lined
impoundment completed in 1979. All ponds in the old tailir.g
area were originally unlined; later, three were provided with
synthetic liners.
In addition to the waste products from the uranium mill g
process, contaminants from other activtties may also be preser.:.
For example, materials contaminated with polychiorinated
biphenyls (PC3s) were processed at the facility and resu.ted :t
contamination of some of the plant areas. In order :o d.s;ose
of PC3—contaainated soils, trichloroethylene (TCE) was used :
remove the PC3s from the soils. Both PC3 and TCE are pr or y
toxic pollutants. Evidence of contamination of soils or gr:ur.d
water from these organics has not been collected and the ex:er.:
of any problem is unknown. This situation has been inves:.;i:ed
February 28, 1986 —L3
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by the U.S. Environmental. Protection Agency.
The following sections will deal w .th contaminants
resulting only from the milling process. These contaminants
include metals such as molybdenum, selenium, nickel and cobalt.
Radionuclides such as uranium, radium, thorium and polonium flave
also been released to the environment. The milling process uses
various reagents such as sodium salts, sulfuric acid, and
arthydrous ammonia. Ammonia is naturally converted to nitrate
through oxidation.
Since the time that contamination of ground water became
known, arguments have persisted over the role of a shallow path
and a deep path for ground—water flow from the mill to the
contaminated area beneath Lincoln Park. The data clearly shcw
that a shallow pathway from the mill around the Sand Creek
drainage is involved in the transport of contaminants from the
mill to :.incoln Park. The data for the deep pathway are not
very numerous and the deep pathway is believed to be j.ess
important than the shallow one. Nonetheless, ev.dence does
exist for contamination of a deep ground-water system beneath
the mill area. The fate of contaminants n this system s
unknown.
Data on the ground-water systems are available from se’:e i .
sources and are used in the following discussions. The ;rea:e :
amount of data has been collected by Cotter Corporat on 3S ; “
Feb iary 28, 1986 5—14
30
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of their monitoring program and provides the bulk of the
evidence presented below (this information is on file at the
Colorado Department of Health). Another set of data was
collected for the State of Colorado as part of its remedial
investigation and feasibility studies of the Cotter mill site
and Lincoln Park area (see Appendices Al-A5). These studies
included sampling of ground water at several wells in Lincoln
Park, electromagnetic and resistivity surveys around the Cotter
mill area, water—level measurements collected near the mill
area, and sampling of various sites near the mill. Ground-water
flow and transport modeling was also performed to better
understand hydrologic conditions in Wolf and Lincoln Parks.
Existing data on the ground-water hydrology of the Cotter
mill area and Lincoln Park do not provide a complete
understanding of the hydrologic controls on ground—water
movement. By far the bulk of the data consists of chemical
analyses of water in the mill area and beneath Lincoln Park.
These data, although valuable, are insufficient for providing
complete information of the geochemistry of the waters and
interactions with the solid materials in the aquifer.
Permeability data have been collected for a few specific areas
primarily through the use of small-scale injection tests. These
data also are valuable but are incomplete. Very few multiple
well pumping tests have been performed; these tests are
generally preferred for aquifer characterization. Water—level
data are available from wells comprising Cottsrs monitoring
network.
February 28, 1986 5—15
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In spite of deficiencies in the existing data base, data
are sufficient to estimate the geographic extent of
contamination throughout the mill area and beneath Lincoln Park,
and to develop an understanding of the geologic and hydrologic
controls on the transport of these contaminants through the
ground—water system. For final design of remediation
techniques, additional data will be required on hydrologic
properties within the mill area itself, the old tailings
disposal area, the new impoundment area, and the area between the
mill and disposal areas and the SCS dam.
5.3.1 Permeability
The ability of a material to transmit water is termed the
permeability of the material. Permeability is generally not the
same in all directions and varies spatially. For example, in
sedimentary rock such as sandstones and shales, water moves much
more easily parallel to the bedding than perpendicular to the
bedding. The permeability of the rocks is therefore greater
parallel to bedding. This is an example of the rock’s
permeability being anisotropic; it varies with change in
direction. Spatial variations refer to the rocks heterogeneity.
Hydraulic conductivity is a term that incorporates permeability,
as well as certain properties of the fluid.
Water will move from one area to another based in part on
the difference in potential energy possessed by water in the t o
areas. In the absence of variable density, the elevation to
February 28, 1986 5—16
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but the extent of this focused flow is not known. The general
lack of hydraulic-head data both northwest and especially
southeast of the gap makes interpretation difficult.
The Cotter Corporation has proposed building a hydrologic
barrier on the upstream side of the SCS dam to cut off flow that
is presently passing beneath the dam into the Lincoln Park area.
One of their assumptions is that the vast majority of flow from
the mill area passes beneath the SCS dam on its way to Lincoln
Park. This assumption may not be ]ustified. It should be noted
that most of the data points used to justify the assumption are
located along Sand Creek. The available data away from Sand
Creek does not constrain the interpreted width of the plume to
just along Sand Creek. The hydraulic—head data can be used to
evaluate some of the assumptions made by Cotter. f what is
proposed is indeed accurate, the hydraulic-head contour lines
should (1) vee upgradient along Sand Creek in the vicinity
of the SCS dam and (2) be closer together beneath the ridge.
EvLdence of both exists. However, the increase .n gradient
beneath the ridge is only slight, indicating that the rocks
beneath the ridg, are only slightly less permeab.e than the
rocks beneath th. site. And the development of a iee i.s also
sl.ght, indicating that the concentration of ground-water flow
is also slight.
Within the section occupied by the mill and the disposal
area (Section 16), the situation is complicated by several
ebruary 28, 1986 5—26
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It is appropriate to now comment on the distribution of
contaminants in the shallow ground-water System. Although data
are somewhat sparse beneath the old tailings area, contaminants
are present to depths of perhaps 100 to 150 feet below the water
table in the old tailings area. However, further dovngradient
in the vicinity of the SCS dam, contaminants are typically
present in the upper 20 to 30 feet of the saturated zone beneath
the water table. Relative to the water table there is an upward
component of flow contrary to what the water—level information
would predict. Recall, however, that the rocks in this area are
layered sedimentary rocks and th.r.for. should be expected to be
anisotrepic in their permeability properties, and that water
will tend to move parallel to bedding. A more complex form of
the Darcy equation incorporates the anisotropy of the rocks, and
us.. hydraulic gradient that is a vector sum of the horizontal
and vertical components. When the flow directions are
calculated correctly it becomes apparent that the bedding
plan.., which rise to the south, have an impact on the directiort
of flow in a vertical sense, and bring the contaminants closer to
the surface.
Well 339 (the deep well toward the left of the diagram) was
drilled to intercept the Canon Wolf Park mine beneath the site.
The water level in this usil indicates that the hydraulic head
at depth is approximately 100 feet lover than it is near the
surface. This difference in hydraulic head would cause water to
move downward toward the old mine workings, especially in either
an open mine shaft where the permeability is much greater than
February 28, 1986 5—29
/3 ”
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5.3.3 Water Quality and Geochemistry
5.3.3.1 Spatial 7ariability Of tranjuut And Molybdenum
As would be expected, contaminant c3ncentratjons are
generally highest close to the source (old tailings pond and
impoundments), and decrease dovngradient from it, through the
mechanisms of dilution, mixing, and geochem .cal retardation.
The best documented oath is from the mill area, along Sand
Creek, into Lincoln Park.
Shallow ground water in the old tail.ngs area contains
uranium at concentrations of 10 to 100 ag/i. Deeper ground
waters are less contaminated today, although tn the past
contaminant levels were higher. For example, well 303 (58 to 99
foot sampling interval) produced water with uranium concen-
trations ranging from 4 to 20 mg/i four or five years ago:
concer.trations decreased to approximately 2.5 n early 1983, bt t
have recently risen, perhaps in response to a change in sanpL g
technique.
Most, but not all, of the contaminants appear to be o”: .q
down Sand Creek through the gap where the Soi Conservat :n
Service constructed a dam. Th.s path .s ortant because
the presence of alluvial materials in the drainage that are c:e
permeable than nearby sandstones and shales. cranium conce-
trations near the dam are approximately : to 5 mg/i, proba y
because of dilution by water moving upwards parallel to
February 28, 1986 5—3.
-------
d .ition by inflltrat.ng surface water .rt Sand Creek, or because
retardation in the old tai.lings area and w .thin Section 9 s .cws
the movement of uranium.
After the corttam .nated water passes beneath the darn, and
perhaps beneath the ridges east and west of the dam, it
continues on to Lincoln Park. During irrigation season,
di:ution is caused by leakage from the DeWeese Dye ditch. The
ditch has had a signi.ficant ro in limiting ther degradation
of water quality beneath Lincoln Park. Lini. f the ditch t
prevent seepage losses would decrease the amount of dilut on and
have unfortunate consequences on the ground-water quality.
Measurements of flow made by GeoTrans/RXC (August 16, 1 35)
in the DeWeese Dye ditch yielded an approximate leakage rate f
360 gpm/mi. The flow measurements were made at three stations
along the ditch. The stations were roughly centered at the
ditch’s intersection with Sand Creek, with station *1 and
station $3 approximately one mile apart. 3ecause irrigation
ocours for about six months of each year, the annualized .eakage
rate is about 180 gpm/mi.
Other shallow pathways may exist, although not of t e sa e
importance as the pathway along Sand Creek. •ells 135, 33,
342 (almost due north of the mill) have ha .
-------
recently. An electromagnetic geophysical survey (which is
sensitive to changes in electrical, conductivity of rocks ar d
water) performed during July 1985, suggested the
possibility of a contaminant pathway near these ‘Jells (See
Section 5.3.6). An abandoned pipeline may run through this
area, affecting geophysical. readings. The pipeline itself would
e distinguishable by the survey; the signature of shallow pipes
.s significantly different from that of deeper contaminant
plumes. iewever, leakage from the pipe may have affected the
survey. Nonetheless, the elevated uranium concentrations in the
wells suggest another shallow pathway beneath the gap west of
Sand Creek.
Similarly, east of the SCS dam is another possible shal.ow
pathway. Again, the electromagnetic survey detected an area
with h gher electrical conductance than to the west.
From data collected by GeoTrans/RNC and Cotter Corporat:on
.n July 1985, contour maps of iranium and molybdenum concen-
:rat ons were drawn for the shallow ground-water system in
:.ncoln Park (Figures 5.3—4 and 5.3-5). These data were
su lemented with July 1984 data collected y Cotter
corporation. The contour lines were not extended south f : e
SCS dam onto the Cotter mill site (1) because of the high ‘ es
present there in the shallow ground—water system, and (2) so
that concentration values for r.derdrains, deep wells and :
main impoundment could be shown without confusing the reader.
February 28, 1986 5—33
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The concentrations on Cotter Corporation’s property for
uranium and molybdenum are important because they are several
orders of magnitude above drinking water guidelines proposed by
National Academy of Sciences and being considered by EPA
for uranium (0.035 mg/i) and molybdenum (0.05 mg/i). In
particular, note the high concentrations (Table 5.3—1)
recorded at intercept trenches 701, 703, and 714; the main
impoundment underdrain 712; at wells 303, 333, 312 and 313; and
lastly, wells 330 and 331 at the SCS Dam (see Appendix AS).
In Lincoln Park, well 138 has uranium and molybdenum
concentrations of 0.92 and 13.2 mg/l, respectively.
Evident from Figures 5.3-4 and 5.3-5 is a contaminant
plume of uranium and molybdenum that emanates from Cotter
Corporation’s property and extends into Lincoln Park, and
eventually to the Arkansas River. The maps show the plume to be
wider at the scs dam than those maps produced by Wahler and
Associates (1978). Wells have not been drilled to determine the
true extent of the plume where it passes beneath the ridge north
of the mill.
Where possible, wells of unknown construction, large open
intervals, and great depth were omitted in construction of the
maps. Each of these factors contribute to a water sample being
collected out of the plume’s domain or becoming diluted by
uncontaminated water, thus providing inaccurate information on
concentrations within the plume. However, well 141, which has a
February 28, 1986 5—36 CR1
I 3c6
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Table 5.3-1
Concentrations of Uranium and Molybdenum at Selected
Sites, 1984—85.
Site
701
703
714
712
303
333
312
313
330
331
U ( mg/i )
71—116
36—42
3.4—4.3
6.6—10.0
2.3—3.8
4.0—6.4
3.6—5.8
4.3—6.1
3.8—5.2
2.5—3.6
Mo ( mg I 1 )
220—231
140—169——
10.2—16.8
20. 1—42
15.9—25.
8.0—16.1
19.6—40.0
28. 1—39 .8
17.1—20.5
15.7—25.4
February 28, 1986
5—37
CR’
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Table 5.3—2
Comparison of Maximum Contaminant Levels (MCL, from The Safe
Drinking Water Act of 1974) with Selected Samples Extending from
the Cotter Hill Area to Lincoln Park; blanks indicate no
concentrations exceeding the MCL.
Parameter (MCL)
Gross Gross
Location Cd Pb Se Alpha Beta
( 0.01 mg/i) (0.05 mg/i) (0.01 mg/i) (15 pCi/i) (50 pCi/i )
701 .228 62000 32000
702 .148 No readings
703 0.06 0.16 .336 32000 14200
303 .163 3500 2100
710 <0.05 .20 . 5—.8 550 360
712 .043 .5—.8 3300 1800
312 0.1—0.15 4000 1900
714 .7—1.7 4800 1400
715 .04—.1 No readings
716 <.05—.1 1190 610
SCSDAM
330 .18—.75 3100 1400
DeWEESEDYEDITCH
138 .017 340 260
139 .015 158 338
140 0.62 .013 173 378
123 .012 41
119 120
117 100 53
120 - 20
122 0.16 58•
124 64
114 18
NW DIRECTION
344 .068 85
340 .077 No readings
338 .061 27
337 .066 27
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metals to the water. Mowever, inless the water chemistry
changes radically, concentrations should not significantly
.ncrease.
Geochemical calculations performed from an analys3.s of a
.uted raffinate from the old tailings pond indicate that
:arnotite (a uranium ore) may have prec:p .tated beneath the ol
:a.l ngs area. During experiments run y Runnells et a!.
.983), a yellowish precipitate that they suspected to be
arrtotite formed.
Both sorption and ion exchange reactions are readily
reversible. When concentrations in the water begin to decline.
sorbed or exchanged ions in storage on the solid surface will e
released back to the water. Dissolution reactions are general.y
much slower but do occur, and their effect may be noted during
remediation. Again, the net effect of this release of
:ontaminants from the soils to the ground water is to require
:onger period of time for remediation.
um.rous Speciation calculations were performed as part
these studies. While these calculations :ontain many of the
rob].ems associated with evaluation of geochemical environments,
such as variability and Lack of data, they do provide a usefu
::ol for hypothesizing about the geochemical environment.
:!owever, geochemical reactions are many and complex, and
generally insufficiently known or metals present n trace
ebruary 28, 1986 —52
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quantities. The use of this tool, for making predictions is
limited. Data presently unavailable, but deemed important,
include concentrations and forms of radionuclides and metals in
the solid phase, information on their release rates, and
information on types of geochemical environments that will.
(1) either enhance or (2) retard the release.
5.3.4 Evidence for Deep-Path Contamination
For many years there have been concerns expressed about the
existence of the deep flow path and the possible transport of
raffinates from the Cotter mill, area into Lincoln Park through a
deep flow path. Evidence for the existenc. of the deep flow
path includes a series of water samples collected from the old
Wolf Park mine shaft that contained elevated levels of uranium.
For a number of years uranium levels were less than 5-10 mg/i;
(although approximately two orders of magnitude above
background). However, in approximately 1976 or 1977, after a
hiatus of sampling of several years, water samples contained
uranium concentrations of 30 to 50 mg/i. When the mine shaft
was filled in 1978, access to this sampling site ended. The
proposed flow path from the mill area was down the abandoned
mine shaft, into the saturated mine workings, out the mine
workings into coals, and along coals and sandstones into the
Lincoln Park area. Wells have bean drilled into the same coal
seams mined in the Wolf Park Mine and have not found evidence of
uranium contamination. In addition, well 339 was drilled back
into the workings of the old mine and has shown low levels of
February 28, 1986 5-53
1 q )
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contaminants. No evidence of uranium contamination elsewhere
that can be specifically attributed to the deep path exists.
In spite of all the data discussed above, concern persists
over the existence of a deep path and contamination of the
ground-water system, via the Wolf Park Mine shaft. The mine is
completed in the Verme o Formation, which has been shown to be
of low permeability. Contaminants in the ground-water system
would probably not move quickly along this path into Lincoln
Park. The shallow path is the more critical path, however,
hydrologic data do exist which indicate that continuing
contamination of the deeper flow system is of concern.
Hydraulic-head measurements in wells 339 and 324 indicate
there is a head difference of about 62 feet between the mine and
the moderately deep ground-water system. Well 324 was completed
at a dspth of 200 to 350 feet, while well 339 was completed in
the mine workings (1054 feet). The gradient calculated from
these measurements is about 0.06. The mine shaft was filled
with a gravel, the hydraulic conductivity of which is estimated
to be between 0.04 and 0.16 centimeters per second from
grain—size analysis. The mine shaft has dimensions of 13 by 17
feet. The rssultant estimate of flow of water down the mine
shaft through the permeable gravels is on the order of ten to
thirty. gallons per minute.
Observations by Washburne in 1908 indicate that most of t e
February 28, 1986 5—54
\U )
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C ntaminar.t rans ort zo Sim . .ate Present Conditions
To simulate present cond : ons, transLent contaminant-
transport simulaticr.s were perf rmed for 20 years after t i
operations began in :953. Steady-state velocities were used
from the flow simulat.cn of c:r.ditions in 1958. 3oundary
conditions were specified as described in Section 5.3.5.2.2.
Calibration of the transport cdel was performed as descr bed
below by adjusting boundary cor.ditions, and aquifer proper:es
as appropriate.
The ground-water-quality data during 1978 showed elevated
uranium concentrations in the range of 20 to 50 mg/i around the
old ponds area. Therefore, the source should be at a
concentration of at Least 50 mg/i. At the same time, near the
SCS dam, the uranium concentrations were .n the range of 2 :c
3.5 mg/i. To simu’ate the obseried concentrations in 1973, an
adequate understanding is :equ.:ed of the contaminant trans o:t
processes involved. he transport processes sLmulated were
advection, dispersion and :e:ardat.on (adsorption). t s
expected that these processes adequately represent
contaminant transport to a .d n the avalua: .on of remed .a...
a.ternat .ves. Other geocnem :a. processes ay play an c: a :
role n transformation of u:ar. um scecies, but are not
considered n the c:n:am nar.:-::ansport s muations.
The transport of uran m :y advect on is dependent or.
1eicc tias specified to the :de1 from the steady-state f:w
ebruary 28, :986
qLf
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.3 An area 3f high : nductivity was found at the southeastern end
of line 6, near ZPA well 6. Chemical data from this well
support the hypothesis that this anomaly was caused by
contaminated ground water.
1.4 One other conductivity anomaly was discovered on line
:e is possible that this anomaly was caused by shallow seeca e
from the main imooundment.
1.5 En general, the resistivity sounding data support and are
consistent with the conductivity data.
5.5 Summary
The disposal of raffinate from the alkaline process mill,
and from a smaller acid process mill, in unlined ponds has
created a zone of contaminated ground water extending from the
old tailings pond area northward into Lincoln Park.
contaminants of concern in Lincoln Park include uranium,
mo.ybdenum, selenium, and nitrate. Within the mill area,
concentrations of these, and other contaminants are much h ne:.
levated concentrations of the above contaminants, plus cad :_i
ar.d lead are present.
The so Ils and rock beneath the o :a l ngs area cor.:3:
hn concentrations of uranium, molybdenum, and many metals.
Ehe uranium and molybdenum are the most easily removable ner
cy natural or enhanced fushing. Cr.fortunately, natural
flushing is too slow to be effective as a remediation meas :
n the time period since the ponds were removed, concentra:
/
Fecr’..iary 28, 1986 5—.26
-------
in the old tailings area have not declined, but have risen
slightly. Leakage from the impoundments is providing a
continuing source of contamination.
of the contaminants enter Lincoln Park by passing
:eneath the SCS dam in Sand Creek. owever, chemical data a-.d
geophysical survey indicate that contaminants may aLso
enter Lincoln Park by other pathways along the northwest and
northeast pathways.
The Jolf Park mine shaft s believed to be a pathway c:
contaminants to enter the underlying ‘lermejo Formation.
irectjon of travel after entering the mine is unknown:
%onitorLng well. )39 (completed in the :nine) has shown low
2.evels of contaminants. Flow within the iermejo is probably
slow, and the effects of this contaminant pathway will probao.y
not be known for many years.
The modeling of Lincoln Park and the mill area nf
of the concepts developed by previous nvestigat ons.
Cal bration of the model has prov:ded es: mates o
Luxes that differ from previous est.mates. For example, :e
rate of leakage for the DeWeese ye ditch, and from rri;a ::n
n Lincoln Park are probably lass then previously thought. e
Leakage rate from the old tailings ponds was probably greate:
:nan prev ously estimated. The modeling indicates that
:cncentraticns n L nco1n Park are, :n average, not char.q -:
Fecr. ary 23, 1936
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5.L.2 Arkansas River :ibuzar es
x inte ttent streams :ie withln two miles of the Coz:er
n :: and are tributary to the Arkansas River (see Figure 6.1-3).
The 1l area i.e drained by Sand Creek which ultimately
:scharges .nto the Arkansas River. Other drainages i.n the mill
3:ea include: Wolf Park Creek, Forked Gulch, Willow Creek, Fawn
o1.ow and Chandler Creek. The eastern fork of Grape Creek Lies
:n the western edge of the study area. Only Sand, Grape and
Chandler Creeks are named on the tSGS Canon City topograph:c
map: the other streams are referred to here by the names gi,en
them by Hershey—Wooderson Associates (1977). A summary of these
drainages and their basin areas is given in Table 6.1-2.
There are insufficient data available for these drainages to
characterize their chemistry.
Sand Creek is the major drainage feature in the V
the Cotter mill site. The headwaters of Sand Creek are
approximately 2.3 miles southwest of the mill site on the
eastern flank of Dawson Mountain in the San Isabel Nat or.aL
Forest. Two major tributaries pass through the hcgback r ;e
ostream of the mill site, Qass on either side f the old
tailings ponds and join about one-quarter (1/4) mile dcwrst:ea
:ont the mill site. Near the m l, the eastern trthutary s
zeen obliterated by construct cn of the impoundments. The :: <
:ontinues .n a northerly di:ec:.on .in:.L it is .inpounded
Soi. Conservati.on Service SCS am C-3, approximately : .e- i
L/2) mile downstream from the site. The creek con:-- --
Fecruary 28, .986
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major ions and selected trace elements) s requ .red, for
example, to adequately compare waters from different aquifers,
to model solution—mineral equilibria or to quantitatively def e
environmental impacts from the Cotter facility. Most of the
water—quality data at the Cotter site pertains to ground waters
in response to the contaminant migration problem under part of
Lincoln Park (discussed by Wahier c Associates, 1978).
.l.4 Pathways
Surface Water Pathways
Evidence for present day surface—water pathways indicates
that salutes from Cotter enter the environment as follows:
1. Erosion and transport of previously deposited,
windblown material (Section 4.3) down the ephemeral
watersheds: these and Wolf Park and Forked Gulch
drainages to the vest of the site and Willow Creek,
Fawn Mallow and Chandler Creek drainages to the east.
2. Transport of contam r.ated water and sediments cw :
lower Sand Creek watershed (below the 3CS dam)
- 3. Ground—water accruaL through the bed sediments
Arkansas iver (above ar.d below the mouth of Sar.d
Creek).
February 23, 1986
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4. Transport by surface water through the outlet works f
the SCS dam, when st rms larger than the 10-year event
occur.
The intermittent streams surrounding the site play an
important role in the transport of off-site windblown
contaminants downstream to the Arkansas River. Comparison of
storm event water quality data for two sites art upper Sand Creek
( Table 6.1-3) indicates that contaminants leave the mill site
during storm events and that wind-blown contaminants wash into
intermittent streams off-site. Site 328 is on Sand Creek ori.y
about about 0.3 north of the new mill. Site 531 is upstream
on the creek, about 1 ) from the plant and relatively isolated
from it by the hogback to the south of the mill.
Water samples from both sites exhibit a range of meta
concentrations between storm events which probably depend on
runoff volumes; however, the site closest to the mill S23 n s
the Largest variation. Comparing means, site 328 has a :an:
concentration of 2.23 mg/i wn :n is 22 times the mean for
ostream site 531 and 63 t mes the .035 mg/i uranium gue e
(SNARL— Suggested No Adverse ?.esponse .evel) reported y
Nat ona1 Academy of Science A ) in 1983 for drinking a:e:.
Similarly, molybdenum is 34 times higher near the plant,
selenium at least 14 times hi ner, radium 43 times higher,
thorium 33 times higher near :ne plant. With a mean
concentration of 3.06 mg/I, mcybdenum at site 528 is a c :
february 28, 1986
-------
: mes the molybdenum guideline for drinking water of o.os mg / i.
(GCA, L983). The new Cotter i1l has a concrete drain system
designed to collect on-site surface runoff and remove it from
the Sand Creek Drainage, so it appears that the high contaminant
levels at site 528 may be due to windblown material or
eviously contaminated soils/sediments. In view of the above
data, and because all stream drainages near the mill contain
. er:nittent streams, it appears that significant .evels f
on:antinants leave the Cotter property or off—site areas n
surface wash during storms. Storm event data should be
collected on other drainages .n the area besides Sand Creek;
these include: Forked Gulch, Wolf Park, Fawn Hollow, Chandler
Creek and a segment of eastern Grape Creek.
Off-site surface water contaminants will ultimately reac .
the Arkansas River although they may be retained for vary: g
per ods in soils, sediments and alluvial waters. Surface water
interactions with ground water and vegetation serve as
additional modes of transport via other pathways.
The ma ority of the data :ollected by Cotter nas oeen :
resolution appropriate for .i:ensing requirements for the :e
as opposed to the finer resol.ition required for impact a a.ys: .
As a result, very little emphasis has been placed on surface
water contamination of the Arkansas River in terms of
identifying potential impacts. The monitoring program has
neglected important oomponents of the aquatic ecosystem h::.
?ebruary 23, :986
/S?)
-------
are necessary to detect sublethal impacts and/or bioaccumulatjon
(i.e., sediments, algae, macroinvertebrates). This is
especially important because of the dynamic nature of water
chemistry and the upstream sources of certain metals. While the
upper Arkansas River may be characterized as contaminated by
metals from Leadville, natural processes which regulate
dissolved metals tend to restore water quality to more
acceptable conditions in the region above Canon City. A more
comprehensive collection and analysis of data upstream and
downstream may require several years to characterize the impact
on the Arkansas River.
The net surface water movement of lead, arsenic, cobalt,
cadmium, copper, nickel, selenium, molybdenum, uranium,
radium—226 and thorium-230, as well as the migration of
integrating parameters (gross alpha, gross beta), will be
controlled by the concerted action of physical, chemical and
biological processes including chemical precipitation/dissolutiofl,
adsorption/desorption, speciation, ion exchange and
bioconcentration/bicaccumulation. The ultimate fate and impacts
are likewise dependent upon the net effect of these processes.
6.1.5 Previous Monitoring of Water Resources
In the initial review of available Cotter data concerning
contaminant concentrations in soils, watersheds and in the ma;or
river system, the Arkansas River, it was found that a less than
comprehensive approach was taken to monitoring the potential
February 28, 1986 6—16
-------
adverse effects of the mill operation. ata concerni.r.g the
migration of contaminants off-site, the transport ther.cmer a
governing contaminant movement through the environment, the
f :es (temporary and semi—perrnanent) and potential :m acts were
essentially non—existent. A limited effort has been made :
monitor the Arkansas River above and below the site for grass
changes in water quality parameters. This monitoring :s
.r.sufficient to document diffuse and dynami.c Loadings and the
potential problems in the aquatic ecosystem.
Water samples collected by Cotter Corporation in the
Arkansas R ver do not indicate major thanges in water qual :ty
from Grape Creek (Location 302) to Fourmi.e Bridge (Location
304). The reasons for this apparent lack of significant change
are as follows:
1) The analytical detection limits are insuffic en: f:r
detecting the contaminants at environmentally
significant levels. For example, lead, cadmium nd
molybdenum are rarely found in surface waters at
than 5 ugh, 5 ug/l and 50 ug/l, respectively. :5
important to note that due to the variety 3f :eac::: s
that control the chemical behavior of :ontamina :s
solution (adsorption, precipitation, dissolut :or..
biological uptake, et:.), a low :oncentrat cn : a:a:
column contaminants :es ot nd’cate that there s
been no loading or no : .ury to the aqua::: svs: -.
) he contam nan :s of :n:eres: at the C: er s::e
Feoruary 23, 936
-------
deter ine the concentrations in water, sed.Lmextts and in as ar.y
tro hic levels as ossible ( orstner and Whittman 1981; ER:,
:933) and deter u .ne the funct ona1 responses of the ecosyste t3
elevated contaminant concentrat ons (Medine et al., 1980).
Fo1low ng the recent sampLing (JuLy - August, 1985) of
soils, watersheds and compartments (water, sediments,
macroinvertebrates) of the Arkansas River, the State’s C!RC.A
consultants have collected data and assembled an integrated
picture of the movement of contaminants from the Cotter site :
the Arkansas River. The data indicates that components of : e
raffinate and tailings are present in the Arkansas River. he
first part of this complex picture was described in Section .
which documented the off-site air transport of contaminants
the site to surrounding soils. ifl this section, the contir. ed
movement of these contaminants are traced and alternative
pathways are examined. The analysis continues with the
contaminants which were found :0 be Cotter-specific
(radionuciides, Cc, Mo, Ii), those due to both the Cotter 3 d
the smelter (Cu, As) and those primari.y related to the s e.:
(Cd, Zn and Pb) . :t is o :ed :nat Cotter’s waste also cor.:i:
n, Pb and Cd, but these re :resent.y beir.g re.eased to : e
west in lesser degrees than sine:er-related contamination.
Ground—water contamination in the Sand Creek alluvium and
contamination to the east by n, Pb and Cd are still related
Cotter emissions.
[ RIFOdUCUd horn
I b..t avUdthIi copy. -_____
ebr.iary 23, 1986 5—22
-------
Stream sediments were obtained with a 2.3 nch diamece.
pLast c core. Replicate sample locations were selected v
deL .neating a 60—foot section along the length of the char. e:.
Three random numbers were generated and were used to deter e
the distance from the end of the station to the replicate
Locations.
Sediment samples were div .ded and sieved. The fract.:
passing the 100 mesh sieve was digested and analyzed for te:a.s
as described in the Quality Assurance Prc)ect Plan. Sample
stations are located on Plate 2 .
6.3 Sediments in ! hemeral Drainages
Because most of the drainages which surround the Cotter
s.te flow in their upper reaches only during storm events,
char.nel sediment samples were collected. :n general, the
drainage channels contained lower levels when compared t: : e
soil transect sites. However, several drainages near the ::: r
s te contained sediments which were contaminated with
cotter—specific metals and rad .onuclides. This indicates
ephemeral surface—water transport of the prev ously depcs:: :
a.: contaminants.
Fecruary 28, 1986 5—30
, Lf
-------
7.3 3IOTZC NVESTGAT:ONS
Selected biotic components of the ecosystems were studied
for both the terrestrial and aquatic environments as part of
t u..s investigat .on. :n addition, a limited amount of data was
available from studies sponsored by Cotter Corporation.
Sampling and analysis of vegetation near the :nill were d scussed
in Section 4.4, Summary of Air Znvestigat ons, SQL ].
Contamination and Vegetation. The study was an attempt to
correlate 3011 contamination with plant uptake. It was not a
detailed study of the terrestrial vegetation in the study area.
7.]. Terrestrial
Most of the land surrounding the mill supports native
vegetation used primarily for grazing of livestock and w l l.fe.
This vegetation and associated annual communities consists of
two basic types: pinyon—juxu.per woodland and plains grass.ar d.
.:. 1 Flora
The pinyon- un ;er woodlar.d is domi a:ad y smaLL
pine and s ngle—seed uniper trees. Other shrub spec es
complete the plant canopy. The understory is sparse and
consists mostly of grass species such as blue grama and f3-
grass.
ebruary 23, :986
-------
Lincoln Park Site Mining Waste NPL Site Summary Report
Reference 2
Excerpts From Final Consent Decree and Remedial Action Plan,
Cotter Uranium Mill Site, State of Colorado vs. Cotter Corporation,
Civil Action No. 83-C-2389; U.S. District Court for District of Colorado;
April 4, 1988
A
-------
APPENDIX A
COTTER URANIUM MILL SITE
REMEDIAL ACTION PLAN
C0?T1R—O 150969
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TA8LZ OF CONTENTS
PAGE
IN’I’RODt7CTION . . . . . . . . . . • . . • . • • . • • • • • • • • • • • • 1
2 REGIONAL SETTING AND SITE FEATURES ... 6
2 . 1 Demographics . . . . . . . . . . . . . . . . . . . . 6
2.2 t.and Use 7
2 . 3 GeoLog ! . . . . . . . . . . . . .
2.4 Soils •1 . 10
2 . 5 Cl .mato1ogy . . . . . . . . . . . 11
2 . 6 Ground Water . . . . . . . . . . . . . . . . . . . . . 1 1.
2 . 7 Surface Water . . . . . . . . . . . . . . . . . . . . . . . . . . .
2.8 Terrestrial Ecosystem 15
2.8.1 Vegetation 15
2.8.2 Fauna 17
2.9AquaticEcosystem .... 18
3 SCOPE OF P.E DIAL ACTION PLAN ...... 20
3.1 General RAP Provisions ..... . 21
3.1.1 RAP Annual. Report S...... 21.
3.1.2 RAP Liqui.d Disposal Capaci.ty ........... 21
3.1.3 Surface Water Releases 22
3 . 2 Definitions . . . . . . 22
3.2.1 Well Design 22
3.2.1.1 Class A Wells 22
3.2.l ..2C lassBWel ls 23
3.2.L.3Piszometers......... 23
3.2.1.4 Well, and Piezometer Surveying .. 23
3.2.2 Quality Assurance/Quality Control 24
3.2.3 Soils and Sediment Analysis ............ 26
3.2.4 Background Data Set for Soils and
Sediments . . . . . . . . . . . . . . . . . 26
3.2.5 Background Mean for Soils and
Sediments . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 3
—3 .—
COTTIR01 5097 °
-------
S PAGE
3.2.6 Background Range for Soils and
Sediments . 33
3 . 2 . 7 Steady State . . . . . . . . . . . . . . . . 34
4 MAIN AND SECONDARY IMPOT.TNDZCNTS .................. 36
4.1. Description of Operations and
Relevant Envirorun.ntal Conditions .. 36
4.2RemedialActivities........... 36
4.3 Requisite Assessments and Engineering
Activities . . . . . . . . . . . . . . . . . . . . 40
4 . 4 Schedule . . . . . . . . . . . . . . . . . . . . . 4 3
5 SECOMDARYINPOUNDMENT............ 46
5.1 Description of Operations and Relevant
EnvironmentalConditions.......... . 46
5.2Rernedi.alActl.v lt les.............. 46
5.3 Requisite Assessinenti and Engineering
Activities 43
5 . 4 Sck edule . . . . . . . . . . . . . . . . 4 9
6 WATER DISTRIBUTION POND .. 51
6.1 Description of Operations and Relevant
Environmental Conditions ....... 51.
6.2RsmedLa1Activ .t .es........... 51
6.3 Requisite Assessments and Engineering
Activities ...................... .... 52
6.4 Schedule .................................. .. . 53
7 NEUTRALIZATION OF THE PRIMARY I1IPOUNDMENT ........ 55
7.1 Description of Operations and Relevant
EnvironasntalConditions......... 55
7.2ReIned1.alActi.v3.t .es......... 5
COTTfl—0 150971
-------
PAGE
7.3 Requisite Assessments and Engineering
Activities . . I • I • • I I I 56
7.4 Schedule •• I. 58
8 OLD TAILINGS PONDS AREA . . . . . . . . . . . . . . . . 61
8.3. Description of Operations and Relevant
Environmental Conditions ................... 61
8.2Remedi.a lActi.vi.ties... 61
8.3 Requisite Assessments and Engineering
Activities 71
8.4 Schedule 75
9 THE HYDROLOGIC BAMIER AT THE SOIL CONSERVATION
SERVICE (SCS) DAM . . . . . . . . . . . . . . . . . . . . . . . . 79
9.]. Description of Operations and Relevant
EnvironmentalConditions ... 79
9.2Remed .alAct1vLt1.e5;......................... 79
9.3 Requisite Assessments and Engineering
Activities 89
9.4 Schedule 92
10 NORTHWEST AND NORTHEAST SHALLOW GROUND WATER
PATH JA1S e.......I... .se.sI .s.•.ISSIII . . .s 97
10.1 Description of Operations and Relevant
Environmental Conditions .................. 97
10.2 Remedial Acti.vities .................. 97
3.0.3 Requisite Assessments and Engineering
Activities 10].
3.0.4 Schedule •........................ .....I . ..II 103
1 ,3. WOLF PARK MINE SHAFT . . . . . . . 106
11.1 Description of Operations and Relevant
Environmental Conditions .................. 106
—iii—
COTTIRO 150972
-------
PAG £
11.2 Remedial Activity . 106
11.3 Requisite Assessments and Engineering
Activities • • • • • • • • • • . . . . . . . . . . . . . . .
12. . 4 Schedule . . 12.0
12 SOIL CONSERVATION SERVICE (SCS) DAM TO THE DEWEESE
DYE DITCH . . . . . . 114
12.1 Description of Operations and Relevant
Environmenta lConditiens....... 114
12.2 Remedial Activities 114
12.2. lFlushingActivities..... 114
12.2.2Testi.ngAct .vi.ti.es ........ . 11
12.3 Requisite Assessments and Engineering
Activities . 2.16
12.3.1F1ush .ngActLv1t .es 116
12.3.2 Testing Activiti .es 117
12.4schedu ls 118
12.4.1 Flushing Activities 113
12.4.2TestingAct .vLt .es ..... 119
13 LINCOLN PARK WATER USE 120
13.1 Description of Operations and Relevant
Environmental Conditions ......... 120
S
13.2 Remedial Activities 120
1.3.3 Requisite Assessment and Engineering
Activities •. . . . . . . . . . . . . . . . . . . . . 125
13.4 Scheduls 127
14 GROUND WATER COMPLIANCE 129
14.2. Description of Operations and Relevant
Environmental Condit .ons 129
14.1.1. Objectives .. 129
14.1.2 Cotter Site Ground Water Protection. 129
COTTU0 150973
I’ ,”
-------
PAGE
14.1.3 Lincoln Park Ground Water Quality
Objectives . . . . . . . . . . . . . . . . . . . . . . . 129
14.1.4 Testl.ngandAnalysj .s .......... 130
14.1.4. lTransjtTjme... 130
14.1.4.2 Lincoln Park Compliance
Testing . . . . . . . . . . 133
14.1.5 40 C.F.R. 192, Subpart D Compliance 134
14.2Reinedia lkctjvjtjes...,..,.................. 142
14.3 Requisite Assessments and Submittals ... 143
14 • 4 Schedule . . . . . . . . . 145
15 GROUNDWATERMONITORING...S............. 147
15.1 Remedial Activities 147
15.2 Requisite Assessments and Engineering
Ac iv ties . . . 153
15.3 Schedule •1• •Is •.... 153
16 MAI” INPO”’ DMENT -
‘Gel . . . . . . . . . . . . . . . . . • . . .
16.1. Description of Operations and Relevant
Environ enta1 Conditions ....
16.2 Remedial Activities
16.3 Requisite Assessments and Engineering
Activities . . . . . . . . . . . . . . . . . . . . . . . 155
16.4 Schedule 156
17 OLD TAILINGS PONDS AREA •......... 157
17.1. Description of Operations and Relevant
Environmental Conditions ........ 157
17.2RsmedialActivities 157
17.3 Requisite Assessments and Engineering -
Activities 1
17.4 Schedule 160
CO? R_o15og? 4
-------
18 ORE MANDLING AND ORE STOCKPILES .. 162
18.1 DescriptiOn of Operations and Relevant
Environmsnta lConditions....... 162
28.2Remed2.alActl .vl.tles................ 162
18.3 Requisite Assessments and Engineering
Activities •............................... 163
18.4 Schedule •.S.... . . .S...S.S.. .......S......... 164
19 CATALYST PILE . . . . . . 166
19.1 Description of Operations and Relevant
Environmental Conditions .................. 166
L9.2Remed .alActj.vi.ties.................... 166
19.3 Requisite Assessments and Engineering
Activities . . 167
19.4 Schedule . 163
20 YELL.OWCAP DRYER 169
20.2. Description of Operations and Relevant
EnvironmentalConditions.................. 169
20.2Remedi.alAct 2 .vLtl.es................ 169
20.3 Requisite Assessments and Engineering
A i ities 169
2’ Scedle 11 ’
4, — .. ..... I.... • a
21 ON—SITE $011.8 . . . . . . . . . . . . . . . . . . . . . . 173
21.1. Description of Operations and Relevant
Environmental Conditions 173
23..2RejnsdialActivities......................... 17)
22.3 Requisits Assessments and Engineering
Activities •..•........•.••.•.••••••••• 176
2 a 1 1
C.ae U . s .C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . —
-vi -
COfTU—0 150975
-------
PAGE
22 ROADS ••• . .s••••••••s••• ....S.. ...S....... sI... 182
22.1 Description of Operations and Relevant
Environmental Conditions •................. 182
22.2 Rentedi .alAct .vi.ti.es ............... 182
22.3 Requisite Assessments and Engineering
Activities ••••••.••.......... 182
22.4 Schedule . . . S S • • S • I I S S • S • S I • I S I I 5 5 5 • 183
23 AIR MONITORING 184
23.1. Description of Operations and Relevant
Environmental Conditions 184
23.2 Remedial Activities 184
23.3 Requisite Assessments and Engineering
Activities ....................... 186
23 .4 Schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187
24 SITE ADJACENT SOIL. ........ ...... 189
24.1. Description of Operations and Relevant
EnvironmentalConditions....... 189
24.2Remedi.alAct .vi.ti .es........... . 189
24.3 Requisite Assessments and Engineering
Activities . 193
24.4 Schedule .......... . 198
25 LINCOLN PARIC SOILS .... 202
25.1. Description of Operations and Relevant
EnvironmentalConditioris.......... 202
25.2RsmsdialActivities... ........ 202
25.3 Requisite Assessments and Engineering
Activities ................•.....•••..... 203
25.4 Schedule •1• 1•5• .S •I.SS... .... . . . • •.. . 204
-vii —
CO?T11O 160976
-------
PAGE
26 WILLOW IJ..XES . 206
26.]. Description of Operations and Relevant
Enviren entalconditjons......... .... 206
26.2Remed .alAct .vit .es .. 206
26.3 Requisite Assessu ents and Engineering
Activities . . . . . . . . . . . . 207
A eh 4 1
. . . . . . . . . . . . . . . . . . cw a
27 EPHEMERAL STREAMS AND FREMONT DITCH .............. 209.
27.1 Description of Operations and Relevant
Environmental Conditions 209
27.2RemedialActivities 209
27.3 Requisite Assessments and Engineering
Activities . . . . . . . . . . . . . . . . . . . . . . . . 21.1
27.4 Schedule 213
28 PERENNIAL STREAMS 215
28.1 Description of Operations and Relevant
Environmenta lConditions ............ 215
28.2 Reutedia3. Activities 2:5
28.3 Requisite Assessments and Engineering
Activities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213
28 . 4 Schedule . . . . . 220
29 PATH IA1 !4AtJAGEMENI . . . . 2 2 2
29.1 Description of Operations and Relevant
ErmvironmentalConditiorms......... 222
29.2RemsdialActLvltles ....... 222
29.3 Requisite Assessments and Engineering
Activities 228
29 • 4 Schedule . . . . . . . . . • . . . . . . . . • . . 2 2 —
—viii —
COTTZR—0150 977
-------
S PAGE
30 APJCANSAS RIVER .. . 234
30.1 Description of Operations and Relevant
EnvironmentalConditions.................. 234
30.2 Remedi.alActi.v3 .tjes ......................... 234
30.3 Requisite Assessments and Engineering
Activities . . . . . . . . . . . . . . . . . . . . 235
30 . 4 Schedule . . . . 2 6
31 MINNEQUA RESERVOIR AND PUEBLO RESERVOIR 233
31.1. Description of Operations and Observed
Impacts . . . . . . . . . . . . . . . . . 2 3 3
31.2 Remedl.alkct3.vLtl.es ..
31.3 Requisite Assessments and Engineering
Activities . . . . . . . . . . . . . . . . . 243
3 1 . 4 Schedule . . . . . . 2 40
32 HEALTHRISKASSESSMENT 24.
32.1 Description of Operations and Observed
Impacts 24
32.2 Remedia lActivities 24.
32.3 Requisite Assessments and Engineering
Activities . . . . . . . . . . . . . . . . . . . . . . 2 . 3
32.4 Schedule 245
- ix-
COTTU—0150 978
-------
LIST OF FICtTRES
Figure Title Follows Page
1—1 Mill. I.ocation Map...... ........ ••...... 1
1—2 RAP Activity Map 1
3—1 ClassAWs l lDesign....... ..... 22
4-1 Conceptual Representation of Withdrawal
Well and Piezometer Configuration Which
Would be Acceptable to the State 38
10-1 Northwest/Northeast Pathway Monitoring
Program... . . . •...• . •......... . . . . . . .93
11—1 Wolf Park Mine Shaft Location 106
13—1 Lincoln Park Water Use Survey Area 121
14—1 Compliance Point Wells Area... 136
15—1 Well Mon .tori.ng Locat .ons
23-1 Present and Proposed Air Monitoring
Locations. . . . . . 184
cOTTIR015 0979
170
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LIST OF TABL!S
Table Title Follows Page
1 .-I. Ground Water Quality in the Old
Tailings Ponds Area. . . . . . . . . . . . . . . . . . . . . . . . .3
1—2 Chemical Analysis of Cotter Alkaline
Tailings. . . . 4
15-1 Ground water Monitoring Program 148
-xi-
COTTfl—0150980
‘I
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1 INTRODUCTION
Cotter Corporation (Cotter) is a uranium mining
and milling company which owns and operates a uranium-vanadium
mill near Canon City, Colorado. The Canon City mill facility
produces uranium concentrate and recovers molybdenum and
vanadium as by products. The Cotter Canon City mill site is
located in Fremont County in the south—central part of
Colorado, approximately 96 miles south of Denver and
approximately 36 miles northwest of Pueblo (see Figure 1-1).
The Cotter mill site lies in a topographic bowl
known as the Wolf Park basin and is about 3.5 miles south of
Canon City and 2 miles south of Lincoln Park, a semi-rural
area. Cotter owns Section 16 and the southern three quarters
of the eastern half of Section 9, Township 19 South, Range 70
West, 6th Principal Meridian. This area will be referred to
as “the site” or “the mill site” or “the Facility” in the
remainder of this document. The site includes approximately
1.4 square miles (880 acres) and contains an inactive mill, an
active mill, a partially reclaimed tailings pond disposal
area, and an active tailings pond disposal area. The two
mills are located in’ the northwest corner of Section 16.
Currently active tailings impoundments and ponds formerly used
for tailings disposal cover most of the central area of
Section 16. (See Figure 1—2.)
—1—
CO?Tfl—0150981
-------
The original mill, now inactive, used an alkaline
leach process and was in service from July 1958, when milling
operations bEgan at the site, until December of 1979.
Tailings from the old alkaline leach mill were disposed in ten
unlined and lined tailings ponds. Thes. old tailings ponds
were unlined except for pond 2 (lined July 1972), pond 3
(lined approximately June 1981), and pond 10 (lined June
1976). Pond 7 was used for the storage of fresh water. The
remaining nine ponds were used for storage of various process
liquids and for disposal of tailings (liquid (raffinate) and
solid waste material produced by the mill process). During
the period April 198]. to August 1983, the tailings contained
in the old tailing ponds, together with some of the underlying
soils and other materials, were removed and transferred to the
secondary impoundment using conventional earthinoving
equipment.
Surface water runoff from the site, which occurred
prior to the construction of the Soil Conservation Service
Flood Control Dam (SCS Dam), represented a pathway for the
potential transport of mill derived materials off-site.
Surface water flow of f the sits was changed when the SCS Dam
was completed in 1971. Located approximately 4000 feet north
of the main tailings impoundment on the site, the dam was
built to mitigate the effects of storm-generated floods. 3y
impounding site runoff and springs and seeps, the dam has
—2—
C0TU —O 150982
-------
isolated surface water on the site from Lincoln Park.
Hydrologic and water quality data indicate a shallow ground
water pathway beneath the SCS Dam, allowing ground water to
migrate from the site to Lincoln Park. The State suspects
that other shallow ground water pathways to the northeast and
northwest of the SCS Dam may exist.
In September 1979, an acid leach mill commenced
operation. All tailings from the mill have been disposed cf
in the new impoundment. The new impoundment is divided into a
91-acre main impoundment, currently used for storage of the
acid leach mill tailings and water collected from ground water
interception facilities, and a 44—acre secondary impoundment.
These new impoundments ware constructed with compacted earthen
em an)cnents, compacted clay and synthetic membrane linings,
and drains below the clay and membrane liners to reduce
hydrostatic uplift. The drains above the membrane liner are
intended for us. in dewatering the impoundments at mill
closure. This Remedial Action Plan (RAP) provides for the
construction of facilities designed to collect leakage, if
any, from the main and secondary impoundments.
Mill derived constituents found in uranium
tailings generated at the site have been released to ground
water on site and are present in Lincoln Park, and released to
soils on site and certain offsite locations. Data presented
in Table 1-1 are representative of ground water quality in the
—3—
COrTfl—01 50983
jl’/
-------
TABLE 1-i.
Ground Water Quality in the Old Tailings Ponds Area
Average Concentration
Constituent In 1986 ( g/1 )
Uranium 97.7
Mo lybd.nua 214
Vanadium cO.OSO
Selenium 0.30
Chloride 848
Sulfate 17,400
Carbonate <10
COTTER—O 150984
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Old Tailings Ponds Area. Tailings material from the site is
dispersed by the wind. Values shown in Table 1-2 are
representative of the composition of tailings particulates.
Wind dispersed tailings material may be a source of surface
water impact in drainages adjacent to the site.
The yelloucake dryer, part of the acid leach mill,
performs a roasting operation to dry and decompose
precipitated ammonium diuranate. Emission controls are
currently in place on the yellowcake dryer discharge gases
stack. Emissions from the yellowca3ce dryer stack contain
uranium which can be dispersed by wind. This RAP requires
that emission controls on the yellowcaka dryer stack be Best
Available Technology (SAT).
Ore on the site is presently stockpiled
approximately 800 to 1000 feet northeast of the mill. Ore .s
moved from the stockpile area to the ore handling area, wh .:h
is immediately north of the mill, and is then placed in the
ore hopper of the mill. The maximum ore inventory permit:e
by the radioactive materials license is 200,000 tons. The
major economic constituent of ore processed at the Cotter l .
is uranium. Ore particulates are dispersed from the site by
the wind.
A catalyst plant on the mill site was operated
briefly in 1978 and in 1979 to recover metal values from spent
—4—
COTTU 0 150985
I . ) ’
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- TABLK 1-2
Chemical Analysis of Cotter Alkaline Tailings
S
ParticleSize As Cu Ni Mo Se f !
>10 mIcrons
(64.9lZ) 0.0053 0.011 0.005 <0.01 0.0006 0.04 0.0023 0.021 0.011 0.022
5-10 microns
(4.25Z) 0.011 0.026 0.011 <0.01 0.0011 0.08 0.00085 0.063 0.021 0.044
<5 mIcrons
(30.84Z) 0.0204 0.043 0.020 0.01 0.0011 0.10 0.00093 0.190 0.038 0.060
TOTAL 0.0102 0.022 0.0098 <0.01 0.0008 0.06 0.00047 0.075 0.020 0.035
Values are expressed as percent by veight.
As — Arsenic; Cu — Copper; NI Nickel; Mo - Molybdenum; Se — Selenium; P — Plorine; Hg Mercury;
Pb Lead; U - Uranium; Zn - Zinc
Rad lu.-226 ThorIum—230 -
Analysis of
Samples Not 0
Segregated By
Particle Size 0.001229 0.002009
Values are expressed as micro curles per gram.
•.1
0
U
C—
C-
-------
catalyst material. Spent sulfuric acid catalyst material
currently is stockpiled on the site north of the old mill.
From 1958 to 1968, the U.S. Atomic Energy
Commission (AEC) was the regulatory agency responsible for
oversight of the Cotter facility. On February 1, 1968, the
Colorado Department of Health assumed regulatory authority
through an agreement with the federal government. Cotter’s
Colorado Radioactive Materials License expired on August 17,
1984. A license renewal application was submitted on March
30, 1984. The previous license is currently in effect under a
regulatory timely renewal extension.
The State of Colorado (State) and Cotter have
developed the Remedial Action Plan contained in this document
in order to assess and effectively mitigate any impacts
attributable to the mill facility to health, welfare and the
environment.
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CO?TU—O 150987
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2 REGIONAL SETTING AND SITE FEATURES
2.1 Demopraohics
The land us. from Canon city south to the Cotter
site changes from single and multi family residential
development to rural single family residences. This southern
area typically consists of small grazing parcels for
livestock. Canon City, located approximately 3.5 miles north
of the Cotter mill, site, has a population of 13,037 (1980
Census Data, Colorado Dept. of Commerce). Lincoln Park, a
semi—rural area located between the mill site and the Arkansas
River, is an unincorporated community with a population of
3,426 (1980 Census Data, Colorado Dept. of Commerce). Small-
scale agricultural activities in the Lincoln Park area include
growing fruits and vegetables. Livestock in the area include
horses, beef and ‘dairy cattle, sheep, and chickens.
The Canon City water district serves the Cotter
mill and the Lincoln Park area. The majority of residences in
Lincoln Park currently use the Canon City water supply for
drinking water purposes through a direct connection; however,
a number of residences use water from wells on their property
either in addition to their Canon City water tap or as thei:
sole supply. Some residences still us• well water for stock
watering and/or irrigation. The Lincoln Park water use survey
(see Section 13) will be conducted to further determine the
extent of ground water us. by Lincoln Park residents.
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COTTU—0150988
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2.2 Land Use
The Cotter site is near the center of a “bowl-
like 1 geomorphic feature known as the Wolf Park Basin and is
drained by Sand Creek, an intermittent, northward flowing
stream that rises in the Wet Mountains and empties into the
Arkansas River on the northeastern side of Lincoln Park.
Canon City lies adjacent to the northern bank of the Arkansas
River. The river begins its transition from the Rocky
Mountains to the Great Plains physiographic provinces in the
Canon City area. One of Colorado’s major drainages, the
Arkansas River from Leadvill .e to Pueblo lies in a high-
altitude, intermountain basin that consists of several
structurally formed, alluvium—filled sub-basins joined by the
Arkansas River and i s tributaries. The Cotter mill site i.s
located within one of these intermediate sub—basins.
A majority of the area surrounding the mill site
and the site itself are above the 100 year flood plain of the
Arkansas River (1982 Canon City Fringe Area Land Use Plan).
Soil characteristics are generally favorable for development;
however, geologic hazards such as slope failure, rock falls,
swelling soils, and debris fans discourage further dsvelopmertt
in some arsas south of the present Lincein Park area.
The zoning for Lincoln Park is predominantly
agricultural with single-family residences and some small
rural businesses. Land use patterns described in the 1982
—7—
COTTZR—0150989
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Canon City Fringe Area Land Use Plan include residential
development for an area approximately 2.5 miles northwest of
the Cotter site, and commercial and industrial development
west and northwest of the Cotter site. The land immediately
north, east and south of the mill site will be open range used
for pasture and grazing.
2.3 Geoloav
The site is located on the axis of the Chandler
syncline, a doubly—plunging, asymmetric fold with a steeply
dipping northeastern flank. Dips on the west and south range
from vertical to about 45 degrees northwest, while bedrock on
the northeastern side dips southwest at 5 to 12 degrees.
Bedrock units of importance at the site include the Poison
Canyon Formation, Raton Formation, and the Vermejo Formation.
An outcrop of resistant sandstones of the Raton Formation
defines the synciine in the sits area and forms an acute
hogback ridge. This hogback ridge encloses Wolf Park, a
topographic and structural basin.
Alluvium and terracs deposits of varying
thicknesses overlie bedrock at the sits. Beneath the alluvium
and outcropping in and around the site is the Poison Canyon
Formation. Consisting of interbeddsd and interfingered layers
of shale, siltston., sandstone, and conglomerate, this is the
uppermost bedrock unit at the sits. Fractures in the upper
part of the Poison Canyon Formation are one of the major
—8—
COTTU—016099O
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pathways ofground water flow in the vicinity of the mill.
Beneath the Poison Canyon Formation lies the Raton Formation.
Underlying the Raton Formation are the coal-
bearing silty sandstones and shal.s of the Vermejo Formation.
The Vermejo Formation is exposed at th. land surface or
underlies alluvial and terrace deposits in the area from the
ridge adjacent to the SCS Dam northward to within a mile of
the Arkansas River. The Vermejo Formation contains the seven
coal seams that were mined. Approximately 60 percent of
Section 16, including the area on which the mill is located,
is underlain by the abandoned Wolf Park coal mine.
The Wolf Park Mine, in operation for over 25
years, was notable for a shaft sunk to a depth of
approximately 1,084 feet. Mill derived constituents have beer
measured in water in the mine shaft.
Beneath the.Vermejo Formation lies the Trinidad
Sandstone. In the Lincoln Park area, the Trinidad Sandstone
is typically overlain by alluvium. Available information
indicates that ground water does not occur in significant
quantities in this formation in the site area. Continuing
toward the Arkansas River, the low-permeability Pierre Shale
becomes the surfacs bedrock. The Pierre is the bottom of the
shallow ground water system in the Lincoln Park area.
Underlying formations are riot considered to have significant
effects on the ground water system near the site.
—9—
COTTfl—0150991
I( i
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2.4 Soils
Generally, the terrace deposits overlying the
Poison Canyon Formation consist of sand, gravel, cobbles and
boulders. These deposits range from 0 to 60 feet in thickness
southwest of the SCS Dam. Northeast of the SCS Darn, alluvial
deposits of the Arkansas River’ (approximately 80 feet thick)
intrude and abut against a 120—foot thick gravel terrace.
These terrace and alluvial deposits provide the majority of
well water in Lincoln Park.
Natural undisturbed soils on the site are located
near the site boundaries. Undisturbed soils lie principally
along the southern and eastern boundaries of Section 16 and
the eastern, western, and northern boundaries in Section 9,
Township 19 South, Range 70 West. The undisturbed soils are
described as the Pojoque Variant-Sedillo Complex, the
Louviers-Travesilla Complex and the Travesilla-Rock Outcrop
Complex. Smaller areas of Kim Loam and Fort Collins Loam also
exist on the periphery of th. disturbed area.
Most of the site soils are described as disturbed
or reclaimed borrow areas. Stockpiles of graded earth and
borrow materials, estimated at 2.8 million cubic yards by
cotter, are maintained on the sits for future use and final
reclamation.
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COTTU—O 150992
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2.5 Climatoloav
The climatology of the site is influenced by the
immediate surrounding terrain. The summers are hot with an
veraga daily maximum of 89.5 degrees Fahrenheit (F) in July
and a record maximum temperature of 101F. The winters are
relatively mild with an average daily minimum of 22.5’F in
January and a record minimum temperature of -24’F. The mean
annual precipitation for Canon City is 12.34 inches; most of
the rain occurs from April through August (Colorado Climate
Center, C.S.U.). Most of the summer precipitation is
associated with local convective storms, and, accordingly, the
precipitation during this portion of the year is quite
variable.
The predominant wind directions are from the west-
northwest and west with a secondary peak out of the east-
southeast. The wind distribution is bimodal, being either
westerly or east—southeast in direction. The southerly winds
would be expected to be diminished due to the orographic
U
features on and near the Cotter site, especially the high
ridg, just south of th. facility. Existing data show a
dominance of west-northwest winds at the facility.
2.6 Ground Water
Ground water impacted by the mill, site has bean
detected in Lincoln Park. One principal ground water flow
path has been demonstrated to exist from the mill site to
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c0?TU ’° 18O993
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Lincoln Park (“shallow path). Water in this shallow path
travels through near-surface soils and bedrock. A significant
data base exists identifying the shallow pathway from the mill
along the Sand Creek drainage.
The geologic units underlying the mill site and
environs include (beginning with the uppermost unit) the
Poison Canyon Formation, on the mill site; the Raton
Formation, at the SCS Darn: and the Vermejo and Trinidad
Sandstones, and the Pierre Shale in Lincoln Park. In
addition, alluvial sands and gravels may overlie all of these
units at different areas. On the mill site, fracture flow is
the significant ground water pathway. In Lincoln Park, flow
through the alluvium is more significant than flow through the
sandstones or the shale. The hydraulic head relationships
indicate that ground water flows from the mill site to springs
in Lincoln Park which flow to the Arkansas River.
The shallow ground water flow is down Sand Creek
through the gap in the Raton Formation ridge, where the SCS
Dam is located on the north side of the site. Alluvial
materials in the Sand Creek drainage ars mere permeable than
nearby sandstones and shale.. The Stats suspects that
additional pathways to the northeast and northwest of the
shallow pathway described above may exist. Construction of
various ground water remediation facilities at and near the
mill site, and implementation of monitoring programs to
—12—
COTTU—0150994
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control and further define shallow ground water pathways are
included in the RAP.
The State also suspects that a deep pathway for
ground water flow from the mill site may exist. Ground water
may flow down the abandoned Wolf Park mine shaft. A series of
water samples collected from the old Wolf Park mine shaft
contained mill derived constituents. Access to that sampling
site ended when the mine shaft was plugged with bentortite clay
and then backfilled in 1978. Monitoring activities will be
conducted to determine the effectiveness of this clay plug and
remediation steps will, be taken, if necessary (See Section
11)
2.7 Surface Water
The Arkansas River, one of the few perennial
surface water bodies in tPte site area, begins near the
Continental Divide and flows approximately 120 miles before
reaching Canon City. Downstream of Canon City, water from the
the Arkansas River is diverted into the Minneque Reservoirs
and the river flows through the Pueblo Reservoir. Stream flow
typically remains relatively stabl. at about 200 to 400 cubic
feet per second (ofa) during the fall and winter months,
begins to increase in March, peaks in June, and then rapidly
declines during the summer. Averag, annual streamf low is
approximately 71.5 cfs. Streamf low is affected by
transmountain diversions, storage reservoirs, municipal arid
—13—
COTTER.. 0150995
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agricultural diversions, and their associated return flows.
six intermittent streams lie within two miles of the Cotter
mill, and are tributary to the Arkansas River. Thi mill site
lies within the Sand Creek drainage. Sand Creek is the major
drainage of the mill site and flows into the Arkansas River.
Other drainages in the area which are tributary to the
Arkansas River include: Wolf Park Creek, Forked Gulch, Willow
Creek, Fawn Hollow, and Chandler Creek.
Th, sit. facilities and tailing ponds are along,
and in part occupy, the course of Sand Creek. Sand Creak’s
estimated total drainage basin is 5.63 square miles (3,600
acres). The Sand Creek drainage area consists of three
topographic regimes:
l) Headwaters — characterized by steeply
sloping mountainous terrain, sharply defined stream channels,
and small amounts of ground water recharge. The headwaters
extend from the upper reaches of the watershed to the hogback
ridge upstream of the sits:
(2) Wolf Park Basin — which has flatter
terrain and broader stream channels, is primarily considered
to be a ground water recharge area although some ground water
flow from springs in the vicinity of the SCS Darn occurs. The
Wolf Park Basin includes the area from the hogback ridge
located upstream of the site north to the SCS Dam; and
—14—
COTTII—0150996
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(3) Arkansas River Alluvial Plain - which has
gently sloping terrain, may discharge or recharge ground water
depending upon the relative water table elevation, and
includes the area from the SCS Darn to the confluence of Sand
Creek and the Arkansas River.
Drainage patterns of th. mill sits area were
modified when the SCS Darn was built in 1971-1972 to control
flooding on the lower reaches of Sand Creek. The dam is
located 4000 feet north of the main and secondary
impoundments. Since the construction of the SCS Dam in 1971,
surface runoff from the site has been isolated from Lincoln
Park and impounded in the pool behind the SCS Darn. The lower
outlet works from the darn were closed in 1978. Presently
there is no overflow from the dam, and, since 1979, Cotter has
been withdrawing the impounded water and pumping it into the
main impoundment on the site.
Remediation activities include actions to manage
surface runoff, and to monitor air quality and surface runoff.
(See Sections 15, 18 and 23.)
2.8 Terrestrial Ecosystem
2.8.1. !i i ign
Most of the land surrounding the mill. supports
native vegetation and is used primarily for livestock and
wildlife grazing. This vegetation consists of two basic
types: pirzyon-juniper woodland and plains grassland.
—15—
COTTIR—0 150997
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The pinyon—juniper woodland is dominated by,smaij.
pinyon pine and single—seed juniper trees. Other shrub
species complete the plant canopy. The understory is sparse
and consists mostly of grass species such as blue grama and
buffalo grass.
The plains grassland is dominated by wheat
grasses, blue grama, red three—awn, and other short and mid-
grasses. Forb and shrub species include scarlet globemallow,
slimf lower scurfpsa, rabbitbrush, and yucca.
Agricultural land in the area consists of small
orchards, gardens, and pastures in Lincoln Park and Canon City
with some larger farms to the northeast along the Arkansas
River. The larger farms produce alfalfa, barley, hay, oats,
wheat, corn and apples. Pastures support stands of native
grasses and alfalfa which are fed to beef and dairy cattle.
Urban vegetation in Lincoln Park and Canon City
consists of lawns (both residential and at the golf course)
and ornamental trees, shrubs, and forts. Vacant lots,
roadsides, and other disturbed areas support weedy plant
species that are also found in disturbed areas of native
vegetation.
An investigation into the possibility for adverse
human health effects, including those from consumption of
fruits, vegetables, and livestock, will be conductsd (see
Section 32).
—16—
COTTRR —0150 998
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2.8.2 Fauna
Birds comprise the most diverse group of
vertebrates found in the area of the site and Lincoln Park.
Of the 430 species of birds recorded in Colorado, 104 species
are likely to use the area around the mill site while 295
species might use the areas around Lincoln Park and along the
Arkansas River. Duck, pheasant, and quail are all, hunted in
the area. Utilization of the area by birds is primarily a
function of habitat availability, the season of the year, food
supply, and disturbance levels.
Approximately 36 species of mammals are likely to
be found around the Cotter mill site with 46 species occurr .ng
in and around Lincoln Park. Mule and white—tailed deer, as
well, as several species of rabbit, are hunted in the area.
Habitat diversity in the Lincoln Park area probably allows fo ’
greater species diversity for both mammals and birds as
compared to the mill site.
Four species of amphibians may occur in the
vicinity of the mill site, while five may occur around Lincoln
Park. Seventeen reptil, species are thought to live near the
mill sits, and sixteen may be found in the Lincoln Park area.
A wide variety of invertebrate species inhabit the
Lincoln Park and sit. areas. This group includes insects,
spiders, earthworms, nematodes (parasitic worms), and others.
—17—
COTTZR—0160999
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These species provide an important food source for many
species of birds, mammals, reptiles, and amphibians.
Five species which are listed as threatened or
endangered by the U.S. Fish and Wildlife Service or by the
Colorado Department of Natural Resources may occur in Fremont
County, Colorado. Peregrine Falcon and Bald Eagle are of
particular significance because both may use land adjacent to
the Arkansas River as habitat.
2.9 Aauatic Ecosystem
The biotic portion of th. aquatic ecosystem
consists of three major groups of organisms. The groups are:
(1.) macroorganisms, including algae and bacteria, (2)
macroinvertebrates, and (3) fish. An inspection of the
seasonal dynamics of the alga. community indicates that
Chrysophytes are the dominant species except in late summer
when water temperatures exceed 2O C and Cyanophytes dominate.
During Late summer, a transition between the two groups result
in a peak abundance of Chiorophytes.
A total of 27 species of aquatic macro—
invertebrates have been identified above Canon City in the
Arkansas River. Simuliida. (blackflies) and Chironemidae
(midges) comprise the majority of the organisms with
Ephemeroptera (mayfli.s) the third most common group.
No quantitative fishery data are available on the
Arkansas River in the vicinity of the Cotter sits. A
—18—
COTTU—OlS 1000
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comparison of upstream and downstream data indicates that the
river reach near Canon City represents a transition between a
cold-water trout fishery and a warm-water fishery located
primarily at Pueblo Reservoir. It is probable that
representatives of both fisheries would be present near Canon
City.
The Minnaqua Reservoirs are a series of off-line
reservoirs created by diversion of Arkansas River water at the
Minnequa Darn into the Minnequa Canal. The water is used
primarily for water supply for CF&I Steel Co. in Pueblo,
Colorado.
—19—
COTTU—0151001
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3 SCOPE OF REMEDIAL ACTION PLAN
The scope of this Remedial Action Plan (RAP) is to
describe the purposes, standards and requirements of the
remedial activities. The remediation program addresses ground
water, surface media, and public health. Within each Section,
the specific activity descriptions include:
1. A brief description of the mill operations
and relevant environmental conditions.
2. A description of the remedial activity tasks
and purposes.
3. A description of the assessments and
engineering activities Cotter is required to perform and a
listing of requisite submittals to the State.
4. A schedule for implementation of the Remedial
Action Plan, subi ittals by Cotter to the State, and responses
to Cotter by the State.
The RAP as presented herein includes a description
of engineering and construction activities, requisite studies
and assessments, and procedures to be implemented by Cotter to
lead to the ultimate cleanup and remediation of the Cotter
site and other affected areas adjacent to and near the site.
Items that are not specifically addressed herein
include but are not limited to the following:
1. Mill operations and waste disposal;
2. Occupational exposure;
—20—
COTTU—0151002
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3. Mill decommissioning;
4. Site Reclamation;
5. Long-term monitoring, except as otherwise
stated, and maintenance:
6. Aspects of site water management plan.
Thes. items are to be addressed pursuant to all
applicable and relevant and appropriate law.
3.1 General RAP Provisions
3.1.1 RAP Annual Recort
Except as otherwise provided herein, for the
purpose of this RAP, one annual report shall be required. The
RAP Annual Report shall bs comprised of sections addressing
each of the remedial activities as specified in this RAP, and
shall be submitted by Cotter to the State by June 30 of each
year after the entry of the Consent Decree by the Court. As
specified in this RAP, the Annual Report shall include
information pertaining to RAP act .vities undertaken during the
preceding calendar year.
3.1.2 RAP Liauid Dis osal Ca acitv
Cotter shall not be •xcus•d from the performance
of the requirements of this RAP on the basis that it lacks
sufficient capacity on its site for the storage, treatment,
disposal or manag.msnt of liquid generated as a result of the
implementation of this RAP.
—21—
COTTER—0151003
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S
3.1.3 Surface Water Releases
Water produced by remedial activities shall not be
released to the surface unless approved by the State. The
basis for State approval shall be a demonstration that such
release shall meet the previsions of the Colorado Water
Quality Control Act and all regulations promulgated
thereunder; shall be compatible with Sections 24, 26, 27, and
29 of the RAP, and compatible with Section 30 of the RAP
during the term of the preliminary study described in
Paragraph 1 of Section 30.2; and shall not prevent the
achievement of the ground water quality objectives stated in
Section 14.1.3 of the RAP.
3.2 Definitions
3.2.1 Well Design
New monitoring wells shall be designed as
described below:
3.2.1.1 Class A Wells
Class A wells shall be constructed in accordance
with Figure 3—]. and shall includi:
1. A casing which is fully sealed from the
ground surface to the top of the monitored interval;
2. Inert casing material, such as epoxy resin
bonded fiberglass, which is neutral with respect to the
chemistry Cf the ground water;
—22—
CO?TtR—0151004
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3. Permanently installed, EPA approved, bladder
pump water sampling system;
4. A secure, locked welihead.
3.2.1.2 Class Wells
Class B wells, shall be cased with four (4) inch
internal diameter (ID) PVC pip., or equivalent pipe approved
by the State, which is slotted in the monitoring zone, gravel
packed, and the remainder of the borehole sealed with a cement
or bentonite grout. Class B wells shall be fitted with a
secure, locked welihead.
3.2.1.3 Pj.ezçmeters
Piezometers shall be cased with no smaller than
2-inch ID PVC pipe, or equivalent pipe approved by the State,
with an appropriate screened interval. The length of the
screened interval shall be recorded and reported to the State.
A sand or gravel pack shall be installed opposite the screen,
and the remainder of the borehole sealed with a cement or
bentonite grout. Piezometers shall be fitted with a secure
locked walihead.
3.2.1.4 Well and Piazometer Survevinc
Elevations of well or piezometer measuring points
shall be determined to the nearest 0.1. foot, except that where
hydraulic heads in piezometers are compared against each other
as a performance criterion, measuring point elevations shall
be determined to the nearest 0.01 foot. Surveying shall be
—23—
COTTU—0 181005
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conducted by a qualified surveyor within the first year of
installation, and, with respect to pieZometsrs compared
against each other as a performance criterion, measuring point
elevations shall be recertified by a qualified surveyor at
least every two years. Water level measurements shall be made
with either a chalked steel tape or with an electric probe.
If an electric probe is used, its length shall be calibrated
under hanging conditions at least annually and whenever any
maintenance or repair is performed which may affect the depth
measurement. Depth to water will, be measured and recorded to
the nearest 0.01 foot.
3.2.2 quality Assuranee/Oualitv Control
Quality Assurance/Quality Control (QA/QC) plans
describe procedures to be used and standards to be met in the
execution of the remedial activities in this document. Cotter
shall submit a QA/QC Plan, as required by the Requisite
Assessments and Engineering Activities and Schedule for each
remedial activity. The State shall review and act upon each
remedial activity QA/QC Plan in accordance with the schedule
for that particular rm.dial activity. If Cotter proposes a
modification to any QA/QC Plan, the State shall have ninety
(90) days following written notice of the proposed
modification to approve or disapprove such change.
The State shall have the right to the results of
any analysis conducted for the purposes of RAP implementation
—24—
COTTfl ”O 15 1OOS
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and the right of access to any retained sample material
collected in conjunction with RAP implementation so long as
the use of this sample material by the State does not deprive
Cotter of the material needed to comply with this RAP.
Each remedial activity QA/QC plan shall include,
specifically or by reference, as appropriate:
1. Description of, and rationale, as appropriate
for:
a. construction specifications;
b. material specifications;
c. sample procurement;
d. sample handling;
e. sample preparation;
f. data handling and reporting;
g. statistical treatments of analytical
results;
h. laboratory analysis;
i. limits of detection;
j. documentation of chain of custody of
samples:
k. blind, spiked, and duplicate samples,
including the total number and frequency
of each;
1. confidence levels for sources of error:
m. calibration and operation of equipment;
—25—
COTTU—O 15100?
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n. computer program documentation, if
applicable;
a. procedures for follow—up of anomalous
data.
2. Documentation of consideration and
incorporation of applicable guidelines and requirements for
sampling and analysis established by the U.S. Environmental
Protection Agency, the U.S. Nuclear Regulatory Commission, and
the Colorado Department of Health;
3. Proposed laboratory facility or facilities t
be used in analyzing samples, if applicable.
3.2.3 Soils and Sediment Analysis
Except for samples collected in accordance wit 1
Sections 21 (On—site Soils) and 24 (Site Site Adjacent Soi..Ls),
all soil and sediment samples shall be sieved with stainless
steel mesh. The less than 100 mesh fraction shall be analy:ed
after preparation with a nitric acid/perchloric acid
(HNO 3 /HC1O) digestion. Th. data shall be analyzed and
reported on an air dry weight basis.
3.2.4 Backaround Data Set for Sails and S.diinents
Unless specifically stated othsrwise, the
background data set for soils and sediments, which shall be
used in calculating background mean and background range, as
further defined below, shall be collected according to the
schedule in Paragraph 6 of this Section 3.2.4 and the
following criteria and requisite assessments. The “target
—26—
CO?Tfl—0151008
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e].eaents” are uranium, molybdenum, radium-226, and, as
specified in Section 29, thorium-230. These target elements
can be used to evaluate the remediation of soils and
sediments. If th. concentrations of these elements have been
reduced to standards specified in this RAP, then the
concentrations of other constituents originating at the site
also should have been reduced to acceptable levels.
Furthermore, with respect to Section 29, if a correlation can
be demonstrated to the State’s satisfaction that clean—up of
radium—226 and molybdenum to the required levels also reduces
thorium-230 to levels acceptable to the State, then Cotter
need only analyze for molybdenum and radium—226. However,
with respect to Section 29, if a correlation acceptable to the
State is not demonstrated, then thorium—230 must be analyzed
in conjunction with radium—226 and molybdenum.
1. Representatives of Cotter and the State sha .
jointly locate five (5) reference sub—basins by field
investigation. The five (5) sub—basins shall include:
a. approximately one hundred and fifty
(150) acres each;
b. geology, soils, vegetation (pirlyon and
juniper), and geomorphology similar to
the geology, soils, vegetation, and
geemorphelogy present on and adjacent t:
the mill site.
—27—
COTTU—016 1009
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2. Cotter shall prepare and submit to the State
a plan for the reference sub-basin sampling program. which
shall include:
a. Collection of samples in the top fifteen
(15) centimeter layer of surface soil
according to th. following:
i. samples shall be collected from
four (4) sites selected jointly
and randomly by Cotter and the
State within each reference sub—
basin:
ii. each sampl. shall be a composite
from five (5) randomly selected
locations within a 900 square
meter area (thirty (30) meters on
a side) centered on the selected
sampling site;
iii. where target element
concentrations in soil samples are
below the analytical detection
limit, a value equal to the
detection limit shall be used for
calculation purposes.
b. Collection of samples in the top fifteen
(15) centimeter layer of dry sediments
according to the following:
—28—
COTTU—0151010
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i. samples shall be collected from
four (4) sites selected jointly
and randomly by Cotter and the
State within each reference sub—
basin. Each sampl. site shall be
located at the Lowest point of the
sub—basin channel;
ii. each sample shall be a composite
from five (5) randomly selected
locations along a thirty (30)
meter channel segment;
iii. where target element
concentrations in dry sediment
samples are below th. analytical
detection limit, a value equal to
the detection limit shall be used
for calculation purposes.
c. Collection of wet sediment samples,
where available, according to the
following:
i. samples shall be collected from
four (4) sites selected jointly by
Cotter and th• Stats within each
reference sub—basin. Each sample
site shall be located at the
—29—
COT?ER—016101 1
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‘1
I
lowest point of th. sub-basin
channel.
ii. each sample shall be a composite
from five (5) randomly selected
locations along a thirty (30)
meter channel segment.
iii. wet sediment samples shall include
the top fifteen (15) centimeter
layer where possible;
iv. where target element
concentrations in wet sediment
samples are below the analytical
detection limit, a value equal to
the detection limit shall be used
for calculation purposes;
d. An alternat, method for establishing a
background data set for wet sedi’nents,
if wet .diwents are unavailable within
the referenc. sub—basins;
.. Gamma scintillometer surveys according
to the following:
i. a referenc. grid of nine hundred
(900) square meters (thirty (30)
• meters on a side), with
scintillometer readings at ten
-30- coTTU_.0151 ] 2
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(10) meter intervals, shall be
surveyed at each surface soil
sampling site. An equivalent
channel sampling segment area at
each dry sediment sampling site
with three (3) scintillometer
readings (center of channel and at
each side) at ten (10) meter
intervals;
ii. scintillometer readings from the
corners of each one hundred (100)
square meter grid shall be
averaged to produce a data point
for each reference grid (a total
of on. hundred and eighty (180)
data pou ts for soils and one
hundred and eighty (180) data
points for dry sediments);
f. Proposed analysis methods;
g. QA/QC Plan.
3. All background samples shall be analyzed for
uranium, molybd.num, radium—226 and thorium—230.
4. Means and standard deviations of the
background data set shall be calculated.
-31- COTTKR—0151 013
Q 0 q
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I-
,.1
()
5. Cotter shall submit a w”rittan final
implementation report on the reference sub-basin sampling
program, which shall include:
a. Summary of methods and procedures;
b. Location of all sampling sites;
C. Data collected;
d. Explanation of and response to
unexpected conditions;
a. Quality assurance and quality control
evaluation.
6. The activities for establishing the
background data set shall be performed according to the
following schedule:
a. Within thirty (30) days of the entry of
a Consent Decree by the Court, Cotter
and the State shall locate five (5)
reference sub—basins.
b. Cotter shall propose a plan and schedule
for the reference sub-basin sampling
program within ninety (90) days of the
selection of the reference sub-basins.
c. The State shall act upon the plan and
schedule within ninety (90) days.
d. Cotter shall initiate the reference
sub—basin sampling program in accordance
with the approved schedule.
—32—
COTTU—0151014
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a. Unless an alternative method is
necessary to conduct the wet sediment
sample collection, Cotter shall complete
the reference sub—basin sampling program
within two (2) years after
implementation of th. plan.
f. Cotter shall submit the final report on
the reference sub—basin sampling in
conjunction with the schedule set forth
in Paragraph 4 of Section 29.4 regarding
the sub—basin release soil studies
and/or installation of silt fences.
g. The Stats shall act upon the report
within sixty (60) days after its
receipt.
3.2.5 Backaround Mean for Soils and Sediments
Unless specifically stated otherwise, the
background mean concentrations of radium-226, uranium,
molybdenum and thorium—230, (i.e., the target elements), shall
be established from background data sets collected in
accordance with Section 3.2.4.
3.2.6 Background Ranae for Soils and Sediments
The background range for a given target element irt
any data set shall be the concentration range within two
standard deviations of the mean of the background data set.
—33—
COT?U—0151015
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If the mean of a given monitoring data set is net greater than
the background range, than th. monitoring data set is
considered to be within the background range. If the mean of
a given monitoring data set is greater than the background
range, then the monitoring data set is not considered to be
within the background range.
3.2.7 ea y S te
Analysis of a monitoring data set to determine
whether the concentration of a target element (i.e., uraniui ,
molybdenum, radium—226, and, if appropriate pursuant to
Section 29, thorium—230), is at steady state shall be
conducted using a linear regression performed on a plot of the
concentration of a target element over time. The slope of the
least—square linear regression line shall be tested to
determine if the slope is significantly different from zero
using a one—tailed t—test as described in Chapter One of
Applied Regression Analysis, second edition, by Norman Draper
and Harry Smith (Wiley, New York, 1981). The independent
variable shall be time, and the dependent variable shall be
the concentration of the particular target element. If the
one—tail•d t-t.st det.rmines that the slope is significantly
different from zero at the ninety—five (95) percent confidence
level, a significant trend is occurring. If no significant
trend is occurring, a steady state condition exists or has
been achieved for that particular target element at the
—34—
cOTTU0151 6
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sampling location. If the data suggest clear seasonal trends,
these trends shall be considered in the data analysis.
Where there is more than one data point available
in any month, the arithmetic average of those values will be
used for that month.
—35-
CO’fTIR—0151017
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4 MAIN AND SECONDARY IMPOtJNDZ. NTS
4.]. Descri tion of O eratjprts and Relevant
Environmental Conditions
From 1958 to 1979, mi i i tailings were disposed in
a series of unlined and lined ponds. In 1978 construction of
a double—lined, double cell impoundment began. This new
impoundment includes an 18—inch thick layer of compacted clay
which serves as a liner and an overlying layer of a synthetic
membrane liner (Hypalon). The Hypalon was covered with a
random fill material. Construction of the new impoundment,
which was segregated into a 91-acre main impoundment and a
44-acre secondary impoundment, was completed in 1979. The
main impoundment has been used since September of 1979 for the
disposal of tailings from ongoing mill, operations and water
collected from current ground water interception facilities.
From April 198]. to August 1983, the tailings from the Old
Tailings Ponds Area was moved to the secondary impoundment
using conventional .arthaoving equipment.
The State suspects that the new impoundment may be
leaking, and, if so, is a continuing source of ground water
impact.
4.2 Remedial Activities
The purpos. of thes. remedial activities is to
collect leakage, if any, from the main and secondary
impoundments, to intercept, to the maximum extent reasonably
achievable, ground water flow moving from the Old Tailings
—36—
COflU—015 1018
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Pond Area to the area beneath the new impoundments, and in
conjunction with the other ground water remedial activities to
achieve the ground water quality objectives stated in Section
14.
Cotter shall perform the following remedial
activities:
1. Cotter shall design, construct and operate a
withdrawal well system along the toe of the outer emban)c ents
of the new impoundments. The line of withdrawal wells shall
extend to the east and southwest of the new impoundments to
points where the concentration of molybdenum in the withdrawal
wells drops below 1.0 mg/i. The screened interval of the
withdrawal wells shall be in the Poison Canyon Formation.
2. As an element of the withdrawal well systen
design plan, Cotter shall propose a piezometer configuration,
data to be collected, and a protocol for interpreting the data
to determine whether a ground water gradient towards the
withdrawal well system is being maintained in the Poison
Canyon Formation. The piezometers shall be placed at 200 foot
intervals unless a different interval is approved by the
State. The piezometer design and well operation shall be
sufficient to demonstrate that, to the maximum extent
reasonably achievabl•, a gradient exists to the withdrawal
wells at all locations between each pair of withdrawal wells.
M example of the typ. of conceptual design which would be
—37—
COTTU—O151Ol 9
-------
ac:epta ] .e to the Stats would include: the first line of
piezometsrs (Line A) would be placed midway between adjacent
withdrawal wells. A second line of piezometers (Line B) would
be constructed west or north Cf the first line, so that a line
drawn between two adjacent piezometers, one for each line, is
perpendicular to the first line (see Figure 4-1).
As an element of the construction report filed
after installation of the withdrawal well system, Cotter shall
review the protocol for interpreting the data proposed in the
design plan. Cotter shall incorporate any modifications
necessary in response to information obtained in the
construction of the withdrawal wells, and shall propose a
final protocol for determining whether ground water gradient
towards the withdrawal wells is being maintained in the Poison
Canyon Formation.
3. In the event that the monitoring data, as
interpreted by the protocol, indicate that the ground water
gradient towards the withdrawal wells is not being maintained,
Cotter shall notify the Stat., and then conduct an analysis to
determine whether a transient condition caused by, among other
things, unusual, precipitation, infiltration, etc., has changed
gradient conditions. If it is determined that a transient
condition does not exist, Cotter shall modify the withdrawal
well system pursuant to the schedule set forth in the
transient condition report. Cotter shall prepar. and submit
—38—
COTTU—0151O2O
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S
to the State a report describing the modification of the
withdrawal well system.
4. The withdrawal wells and piezometers located
adjacent to the main impoundment shall be operated and
maintained continuously until flushing of the Old Tailings
Pond Area is completed, the free—standing liquid has been
removed from the main impoundment, and the main impoundment
has been capped with clay. The withdrawal wells and
piezometers located adjacent to the secondary impoundment
shall be operated and maintained continuously until flushing
of the Old Tailings Pond Area is completed, and phased closure
of the secondary impoundment is underway. Cotter may apply
for an earlier termination of a particular withdrawal well.
The basis for this application shall be a demonstration that
the well has been operationally dry for a period of five (5)
consecutive calendar quarters. The State shall review and act
upon any such application within ninety (90) days of its
receipt.
5. The water pumped from the withdrawal wells
shall not be, unless approved by the State, (1) rein ected
into th. ground water downgradiant of the SCS hydrologic
barrier, or (2) released to the surface. The basis for State
approval of such use shall be a demonstration that such use or
release shall meet the requirements set forth in Section
3.1.3. Pursuant to appropriate restrictions, the water may be
—39-.
CO??fl_0 15102 1
-------
used in the mill, circuit, discharged to th. main or secondary
impoundment, used in the flushing of the Old Tailings Ponds
Area, or in the Section 9/16 hydraulic barrier, provided that
such use of the water shall not adversely impact the ability
to achieve ground water quality objectives stated in Section
14.
4.3 Reauisite Assessments and nathesrina Activities
Cotter shall prepare and submit to the State for
review and approval the following:
1. A plan for th. design, construction and
operation of the line of withdrawal wells, which shall
include:
a. Design drawings, including the protocol
designed for verifying that the ground
water gradient is toward the withdrawal
wells;
b. Construction specifications;
c. Quality Assurance/Quality Control
(QA/QC) plan;
d. Construction schedule;
e. Operations and maintenanca plan;
f. Proposed withdrawal rates;
g. Perasability data and calculations to
justify well, depth, well spacing and
pumping rates;
—40—
COTffl—0151022
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h. Disposal of withdrawn water;
2. A Final Construction Report, which shall
include:
a. As-built drawings;
b. Explanation of and response to
unexpected conditions and problems;
c. Quality assurance evaluations;
d. Proposed modifications to operation and
- maintenance plans, or protocol for
verifying that the gradient in the
Poison Canyon Formation is toward the
withdrawal wells.
3. An annual summary on the operation and
maintenance of the line of withdrawal wells, which shall
include:
a. Description of operations, including
rates of withdrawal;
b. Explanation of and response to
unexpected conditions and problems;
a. Monthly water level measurements;
d. Analysis to demonstrate that the line of
withdrawal wells is accomplishing the
purposes set forth in Section 4.2.
4. The transient condition analysis report, if
required, shall include:
—41—
COrrga-.0151023
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a. A proposed modification of the
withdrawal well system which will result
in the reestablishment of the gradient
towards the withdrawal walls. The
modification may be either a
modification in the operation of the
system or the construction of additional
facilities;
b. Analysis which indicates that the design
modification will, achieve the
reestablishment of the gradient towards
the withdrawal wells;
c. Construction specifications (if
required);
d. Quality Assurance/Quality Control Plan;
a. Construction or Implementation Schedule;
f. Operations and Maintenance Plan;
g. Proposed withdrawal rates.
5. Cotter shall submit to the State a final
construction report for any construction required under
Paragraph 4 of this section. Th. report shall include:
a. Aa’.bui],t drawings;
b. Explanation of and response to any
unexpected conditions and problems;
c. Quality assurance evaluation;
-42—
COlT! 1•-0 151024
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d. Proposed modifications of operations and
maintenance plan.
4.4 Schedule
cotter shall conduct these remedial activities
according to the following schedule:
1. Within ninety (90) days after the entry of a
Consent Decree by the Court, Cotter shall submit to the State
a plan for the design, construction and operation of the
withdrawal well system, which includes the piezotneter
monitoring program.
2. The State shall act upon the plan for the
design, construction and operation of the withdrawal well
system within ninety (90) days of its receipt.
3. cotter shall complete the construction and
start the operation of the withdrawal well system pursuant to
the approved schedule required by Paragraph 1 of Section 4.3,
but in no event later than September 30, 1989.
4. Cotter shall submit a written final
construction report to the State within one hundred twenty
(120) days of the completion of the construction of the
withdrawal well syitem.
5. The State shall act upon the final
construction report within one hundred twenty (120) days of
its receipt.
CO1TU—0151025
—43—
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6. Cotter shall submit, as part of the RAP
Annual Report specified in Section 3.1, a written annual
summary on the operation and maintenance of the withdrawal
well system described in Section 4.2.
7. The Stat, shall act upon the Annual Report on
the operation and maintenance of the withdrawal well system
within one hundred twenty (120) days of its receipt.
8. Cotter shall submit written notification to
the State pursuant to the requirements of Paragraph 3 of
Section 4.2 within thirty (30) days of the collection of the
water level data.
9. Cotter shall submit to the State the
transient conditions report required under Paragraph 4 of
Section 4.3 of the Plan within ninety (90) days of the
collection of the water level data.
10. The State shall act upon the transient
condition report within sixty (60) days of its receipt.
11. Cotter shall initiate any withdrawal well
system modification required tinder Paragraph 4 of Section 4.3
in accordance with th. approved schedul. in the withdrawal
well modification/transient condition report.
12. Cotter shall submit a final construction
report for any construction required under Paragraph 5 of
Section 4.3 within on. hundred twenty (120) days of its
completion.
—44—
COTTI 1—0151O 26
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13. The State shall act upon this report within
one hundred twenty (120) days of its receipt.
—45—
COTTU—0151027
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5 SECOND Y IMPOUNDMENT
5.1 Descri tion of O eratjons and Relevant
Environmental Conditions
From 1981. through 1983, approximately 2.2 million
cubic yards of tailings material was moved from the Old
Tailings Ponds Area to the double—lined secondary impoundment
using conventional earthmoving equipment.
In conjunction with th. main impoundment and water
distribution pond, the secondary impoundment will provide the
capability to manag. the accumulation of excess water, if any,
which results from the implementation of this RAP.
After raising the elevation of the Hypalon liner,
the secondary impoundment will receive liquid from the main
impoundment, water distribution pond, withdrawal well water,
pumpback water from the SCS hydrologic barrier and/or other
waters from the site for evaporation.
The secondary impoundment currently is a potential
source of wind dispersed particulates. Controlling exposure
of tailings in th. secondary impoundment is addressed in this
Section.
5.2 Remedial Activities
The purpose of this remedial activity is to
provide a m.ans to manag. the accumulation of liquid on the
mill site, to reduce, to the extent feasible, the hydrau1 .c
head in the main impoundment and, in conjunction with the
—46—
CO?TU—0151028
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other ground water remedial activities, to achieve the ground
water quality objectives stated in Section 14.
The purpose of these remedial activities also is
to effectively minimize and mitigate the secondary impoundment
as a potential source of wind dispersed particulates.
Cotter shall perform the following remedial
activities:
1. In conjunction with the SCS barrier
construction, Cotter shall construct an evaporation pond in
the secondary impoundment. An additional liner shall not be
required. The secondary impoundment shall be for evaporation
of liquids from the milling operation or from remediation
activities.
2. Prior to.construction of an evaporation pond
in the secondary impoundment, dust control shall be
accomplished by furrowing the surface of the secondary
impoundment.
3. Following construction of an evaporation pcnd
in the secondary impoundment, Cotter shall manage the
secondary impoundment to:
a. Maintain a nominal liquid depth of at
least one (1) foot over the entire
surface area of th. secondary
impoundment, with the exception of the
solid waste disposal area, which shall
—47 CO?Tfl—01510 39
U
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not be used for the disposal of
free—standing liquid. This condition
acknowledges that liquids may be present
in the solid waste disposal area as a
result of precipitation and infiltration
from th. evaporation pond. The solid
waste disposal area shall be dewatered,
as necessary, to avoid significant
liquid accumulation.
5. Reauisite Assessments and Encineering Activities
Cotter shall prepar. and submit to the State for
review and approval the following:
1. An interim plan to control dust by furrowing
the secondary impoundment.
2. A plan for an evaporation pond in the
existing secondary impoundment, which shall include:
a. Design drawings:
b. Construction specifications;
c. Soils data for soil borrow areas
describing the molybdenum, uranium and
radium—226 concentrations in those soils
that will be used as the foundation for
the increas, in the Mypalon elevation;
d. Operations and maintenance plan;
e. Construction schedule.
—48—
COTTRR—015103 0
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3. A written final construction report, which
shall include:
a. As-built drawings;
b. Explanation of and response to
unexpected conditions and problems;
C. Quality assurance evaluations.
4. A written annual summary on the
implementation of this remedial activity to effectively
minimize and mitigate the secondary impoundment as a potential
source of wind dispersed particulates, which shall include as
appropriate:
a. Summary description of results of
activities; and
b. Explanation of unexpected conditions and
responses to any problems which prevent
effective minimization and mi.tigation of
the secondary impoundment as a potential
source of wind dispersed particulates.
5.4 Schedule
Cotter shall conduct these remedial activities
according to the following schedule:
1. Cotter shall submit a plan for dust control
by furrowing the secondary impoundment to the State within
thirty (DO) days after the entry of the Consent Decree by the
Court.
—49—
COTTII—0151031
1
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2. The State shall act upon the plan within
thirty (30) days of receipt.
3. Cotter shall implement the approved plan
within thirty (30) days of receipt of State approval.
4. Within five (5) days after entry of a Consent
Decree by the Court, Cotter shall submit a design plan and
schedule for the construction of the secondary impoundment
evaporation pond.
5. The State shall act upon this design plan and
schedule within fifteen (15) days of its receipt.
6. Cotter shall construct the secondary
impoundment evaporation pond in conjunction with the
construction of the hydrologic barrier at the SCS Dam.
7. Cotter shall file a written final
construction report with the State within one hundred twenty
(120) days of the completion of the construction of the
secondary impcundin.nt evaporation pond.
8. The Stats shall act upon the final
construction rspørt within on. hundred twenty (120) days of
receipt.
9. Cotter shall submit, as part of the RAP
Annual Report specified in Section 3.1, a written annual
summary as described in Paragraph 4 of Section 5.3.
10. The Stats shall act upon the Annual Report
within one hundred twenty (120) days of its receipt.
—50—
I’) COTTU—0151O 32
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6 WATER DISTRIBUTION POND
6.]. Descri tiOfl of ODeratjons and Relevant
Environmental Conditions
A compacted clay and membrane-lined water
distribution pond will be constructed in the area formerly
occupied by Pond No. 7, which was a fire water pond. This
pond will function as a surge pond to control the inflows and
outflows of water from the SCS hydrologic barrier, withdrawal
wells, flushing extraction wells, and/or site runoff.
6.2 Remedial Activities
The purpose of this remedial activity is to
provide a means to manage the accumulation of liquid on the
mi ii. site, and in conjunction with the other ground water
remedial activities, to achieve the ground water quality
objectives stated in Section 14.
The water distribution pond will be built in
conjunction with the secondary impoundment evaporation pond.
This water distribution pond will provide surge capacity f3r
pumpback water from the SCS hydrologic barrier, withdrawal
wells and/or the flushing extraction wells prior to
distribution to the mill process, main impoundment, secondary
impoundment, or reus. in remedial activities on site pursuan
to appropriate restrictions.
Th. water distribution pond design incorporates a
double liner system consisting of twenty—four (24) inches of
compacted clay overlain by a membrane liner. The water
—51—
CO?TIR—0151033
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distribution pond shall be constructed pursuant to the
requirements of 40 C.F.R. 192.32(a) (1) inCorporating 40 C.F.R.
264.221 (as codified on January 3., 1983). The liner system
shall prevent any migration out of the pond into adjacent
soils, ground water or surface water during th. active life of
the facility and, after pond closure, the liner system shall
be removed. Post-closure soi.t clean—up shall be verified
p arsuant to Section 21.
6.3 Reauisite Assessments and Engineering Activities
Cotter shall prepare and submit to the State for
review and approval the following:
1. Cotter has submitted to the State the plan
for the water distribution pond, which includes:
a. Design drawings;
‘b. Construction specifications.
2. A schedule for construction of the water
distribution pond, which shall include:
a. Soils data for th. area underneath the
pond and soil borrow arsas describing
the molybdenum, uranium and radium-226
concentration of these soils that will
be used for the construction of the
water distribution pond;
b. Operations and maintenanc, plan;
c. QA/QC Plan.
—52—
COTTU—0151034
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3. A written final cor struction report, which
shall include:
a. As-built drawings;
b. Explanation of and respons. to
unexpected conditions and problems;
C. Quality assurance evaluations.
4. A written annual summary of activities
undertaken pursuant to the operations and maintenance plan
described in this section.
6.4 Schedule
Cotter shall conduct this remedial activity
according to the following schedule:
1. Cotter has filed with the Stats a design plan
for the construction of the water distribution pond.
2. Cotter shall s.thmit a schedule for
construction of the water distribution pond within ten (10)
days after th. entry of the Consent Decree by the Court.
3. The Stats shall act upon the schedule with .n
fifteen (15) day. after receipt of the schedule.
4. Cotter shall construct ths watsr distribution
pond in conjunction with the construction of the hydrologic
barrier at the SCS Darn.
5. Cotter shall file a written final
construction report with the State within one hundred twenty
—53—
COTTZR—0151035
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(120) days of the completion of th. construction of the water
distribution pond.
6. The Stats shall act upon the final
construction report within on. hundred twenty (120) days of
its receipt.
7. Cotter shall submit, as part of the RAP
Annual Report specifisd in Section 3.1, an annual activities
summary as required by Paragraph 4 of Section 6.3.
8. The State shall act upon the Annual Report
within one hundred twenty (120) days of its receipt.
—54—
COTTU015 1036
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7 NEUTRALIZATION OF THE PRIMARY IMPOUNDMENT
7.]. Descri tiOfl Of Operations and Relevant
Environmental Conditions
The Cotter Radioactive Materials License for the
mill requires that the pM of the liquids in the main
impoundment be adjusted to approximately 4.2. This
requirement is based upon the recommendation found in the
Supplement to Design Report, Cotter - Uranium-Vanadium
Tailings Impoundment, W.A. Wahier & Associates, January 1979.
The pH of the main impoundment is approximately 2.3.
7.2 Remedial Activities
The purpose of these remedial activities is: 1) to
evaluate impacts, if any, of the acid tailings upon the clay
liner; 2) to evaluate the technical feasibility of
neutralization of the main impoundment: 3) if necessary and
feasible, to effectively minimize and mitigate significant
degradation of the clay liner shown to be caused by the low pH
tailings; and 4) in conjunction with the other ground water
remedial activities to achieve the ground water quality
objectives stated in Section 14.
1. Cotter shall design and implement a plan to
evaluate impacts, if any, of the acid tailings on the clay
liner, including an analysis of the ability of the liner to
raise the pM of the liquids passing through it, the volume of
the liquid which could exhaust this ability to raise the pM of
—55—
COTTU—0151037
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the liquids, and changes in clay liner permeability that
reactions with the liquid might cause.
2. If necessary, on the basis of the report
described in Paragraph 2 of Section 7.3, Cotter shall design
and implement a plan to evaluate the technical feasibility of
neutralization of the liquids in the main impoundment.
3. If necessary and feasible, Cotter shall
design and implement a plan to effectively minimize and
mitigate significant degradation of the clay liner shown to be
caused by the low pH tailings.
7.3 Reauisite Assessments and Enaineerin Activities
Cotter shall prepare and submit to the State for
review and approval the following:
1. A plan to evaluate impacts, if any, of the
acid tailings, which shall include:
a. Description of proposed actions;
b. Quality Assurance/Quality Control
(QA/QC) Plan;
c. Schsdule;
2. A report of th. findings and conclusions of
the evaluation conducted pursuant to Paragraph 1. of Section
7.3.
3. If required by the State—approved findings of
the impact evaluation program descr bed in Paragraph 1 of
Section 7.2, a plan to evaluate the technical feasibility of
—56—
COffEl —0151 038
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main impoundment neutralization in order to prevent
significant degradation of the clay liner.
4. A report of the findings and conclusions of
the technical feasibility evaluation conducted pursuant to
Paragraph 3 of Section 7.3.
5. If necessary and feasible, a plan to
effectively minimize and mitigate significant degradation of
the clay liner shown to be caused by the low pM tailings,
which shall include:
a. Description of proposed actions;
b. Operations and maintenance plan;
C. QA/QC Plan;
d. Schedule,
6. If the plan described in Paragraph 5 of
Section 7.3 is implemented, a report on its implementatiort,
which shall include:
a. A report of th. results of the
implementation of the plan;
b. Explanation of and response to
unexpected conditions and problems;
c. Quality assurance evaluations.
7. As part of the RAP an Annual Report as
specified in Section 3.]., an annual summary, which shall
include:
a. Status of actions taken;
—57—
couu o t0 39
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b. pM of the liquids in the impeundments,
measured quarterly:
c. Quality assurance evaluations;
d. Explanation of and response to
unexpected conditions and problems.
7.4 Schedule
Cotter shall conduct these remedial activities
according to the following schedule:
1. Within sixty (60) days of the entry of a
Consent Decree by the Court, Cotter shall submit a plan to
evaluate impacts, if any, of the acid tailings.
2. The State shall act upon the proposed inpact
evaluation plan within thirty (30) days of its receipt.
3. Pursuant to the approved schedule set forth
in the impact evaluation plan, Cotter shall complete the
impact evaluation plan and submit its findings and conclusiorts
as to whether neutralization is necessary to effectively
minimize and mitigate significant degradation of the clay
liner.
4. The State shall act upon the findings and
conclusions of the impact evaluation plan within sixty (60)
days of its receipt.
5. If required, based on the State—approved
findings and conclusions of the impact evaluation report,
Cotter shall submit a plan to evaluate the technical
—58—
COTTIlO 151040
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feasibility of neutralization of the liquids in the main
impoundment within sixty (60) days of the State’s action
pursuant to Paragraph 4 above.
6. The State shall act upon the proposed plaii to
evaluate the technical feasibility of main impoundment
neutralization within sixty (60) days of its receipt.
7. Pursuant to the approved schedule in the
technical feasibility evaluation plan, Cotter shall complete
the technical feasibility evaluation plan and submit its
findings and conclusions, and, if impoundment neutralization
is necessary and feasible, submit a plan to effectively
minimize and mitigate significant degradation of the clay
liner shown to be caused by the low pH tailings.
8. The State shall act upon this plan within
sixty (60) days of its receipt.
9. If a plan is submitted pursuant to
Paragraph 7 of this Section 7.4, Cotter shall complete the
implementation of the plan pursuant to the approved schedule
set forth in the plan described in Paragraph 5 in Section 7.3.
10. If the plan described in Paragraph 5 of
Section 7.3 is implemented, Cotter shall submit an
implementation report pursuant to Paragraph 6 of Section 7]
within sixty (60) days of its completion.
11. The State shall act upon the implementation
report within sixty (60) days of its receipt.
COTru—0151041
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12. Cotter shall submit as part of the RAP Annual
Report specified in Section 3.1, the written annual summary
specified in Paragraph 7 of Section 7.3.
13. The Stat. shall act upon the Annual Report
within one hundred twenty (120) days of its receipt.
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COTTU—0151042
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8 OLD TAILINGS PONDS AREA
8.1 Descrthtiort of O erations and Relevant
Environmental Conditions
During the operation of the old alkaline leach
mi i i (1958-1979) tailings were discharged into seven of ten
ponds. Tailings from the catalyst plant were placed in a
separate pond. Seven of the ten ponds were unlined. In 1978,
during construction of the secondary impoundment, ponds 9 and
10 were removed, and this new impoundment was constructed over
the location formerly occupied by those ponds. The tailings
from the six remaining ponds were removed during 1981-1983,
and were deposited in the secondary impoundment. One
remaining pond is lined and is used for the storage of mill
site runoff. Old pond 7 is unlined, is presently not in use,
but was used to store water for fire control.
During the time the old ponds were used for
tailings disposal, liquids from the tailings entered the
underlying soil and ground water. This ground water flows
from the Old Tailings Ponds Area to the SCS Dam and then
continues into Lincoln Park.
8.2 Rem.dial Activities
The purpes. of these remedial activities is to
identify the area where flushing will, be conducted, to conduct
a ground water flushing and surface soil removal program to
effectively minimize and mitigate the Old Tailings Ponds Area
as a source of ground water impact, and in conjunction with
—61—
COT?KR—015 1043
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other ground water remedial activities to achieve the ground
water quality objectives stated in Section 14.
Cotter shall perform the following remedial
activities:
1. Cotter shall design and conduct an initial
evaluation of the Old Tailings Ponds Area for the purpose of
selecting and designing effective injection and extraction
ground water flushing technologies to test on a pilot scale.
The initial evaluation shall include the following:
a. Appropriate core and water quality
samples shall be collected from areas
upgradient of the SCS Darn and, in
conjunction with other data, used to
determine the chemical char4cteri zati.or
of uranium and molybdenum within the
soils and ground water and in order to
id.ntify the zone in the Old Tailings
Ponds Area to be flushed;
b. Appropriate studies and analyses shall
be performed, including a study of water
chemistry modification to reasonably
maximize the dissolution and desorpt .cn
of molybdenum and uranium, to permit the
design and implementation of an
effective pilot test flushing program.
-62 coTTfl—015 1044
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c. Prepare a written report describing the
findings and conclusions of the initial
evaluation and setting forth the plan
for a pilot study for an injection and
extraction ground water flushing
program.
2. Cotter shall design and conduct a pilot study
for an injection and extraction ground water flushing progra!t.
The pilot study shall include the following:
a. The pilot study shall be operational for
approximately one (1) year;
b. The pilot study shall include the
development of a ground water model of
the Old Tailings Ponds Area to predict
and evaluate the performance of the
ground water flushing program. Thi.s
model shall include the effects of
injection and withdrawal well
geomstries, well depths, psrmsabilit1.es.
porosity, geochemistry, and other
relevant properties of the ground water
flushing program. It shall also prov e
for mass balanc. calculations.
c. The pilot study shall also include t e
development of a ground water flow and
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COTTU—0151045
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transport model of the mill area and
Lincoln Park for use in predicting
uranium and molybdenum concentrations at
the Lincoln Park Monitoring Well. The
model shall include the effects of
variable ground-water velocity,
hydrodynamic dispersion, chemical
retardation and mixing. Current
hydrologic data, as supplemented by data
collected pursuant to this RAP, are
sufficient as input parameters for this
model. The model shall be developed
using two— or three—dimensional
analytical or numerical techniques
capable of providing resolution on a
scale that is sufficiently fine to
accurately characterize the area using
standard modeling practice. The
geographic coverage of the model shall
extend from the hogback south of the
mill, to the outcrops of Pierre Shale in
north central Lincoln Park.
d. The pilot study shall be performed to
allow the testing of design concepts to
achieve the ground water quality
-64- COTTIR’015 46
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objectives stated in Section 14 within
sixteen (16) years of the commencement
of the production flushing program.
a. The pilot study shall include a plan to
test techniques for modification of the
injection water or a substantially
equivalent water management system to
reasonably maximize dissolution and
desorption of molybdenum and uranium;
f. The upper two (2) feet of soil from the
area of old ponds 1, 2 and 6 shall be
removed prior to the start of pilot
scale operations and disposed in the
main and/or secondary impoundment;
g. Written i onth1y reports and a final
report stating the findings and
conclusions of the pilot study and
setting forth the plan for a production
scale injection and extraction ground
water flushing program.
3. Cotter shall design, construct, and operate a
production injection and extraction ground water flushing
program. The production flushing program shall include the
following:
—65—
COTTU—0151047
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a. An additional six (6) feet of soil. shall
be removed from the entire Old Tailings
Ponds Area at the time of mill, closure
and used as the lower strata of the
tailings cover in conjunction with final
reclamation of the main impoundment.
The tailings cover shall meet all
applicable requirements, including the
requirements of Criteria 1, 4 and 6 of
Part III, Schedule E, of the Colorado
Radiation Control Regulations, pursuant
to an approved final reclamation plan
(which is not part of this RAP):
b. Following the cessation of ground water
remedial activities and the intercept .or
of ground water at the SCS hydrologic
barrier (as. Section 9), mean annual
concentration of total dissolved solids
(TDS) in the Lincoln Park monitoring
well shall not exceed 400 mg/i or 1.25
times the average TDS concentration,
whichever is least restrictive, for the
period 1985 and 1986 at well 123 (the
mean concentration at well. 123 during
this period was 567 mg/i);
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COTTER—015104 8
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c. The design of the production scale
flushing program shall provide for water
treatment or a substantially equivalent
water management system to reasonably
maximize the dissolution and desorption
of mo lybd.num and uranium;
d. An array of injection and withdrawal
wells or trenches designed to flush
water through the area identified
pursuant to Paragraph 1, Section 8.2 at
a rate sufficient to meet remediation
goals within sixteen (16) years of the
commencement of the production flushing
program. The amount of water in)ected
shall be less than the amount of water
removed. Th. flushing system shall be
designed to allow flushing to continue
throughout the year.
e. The design, construction, and operation,
at approximately the common boundary of
Sections 9 and 16, of the 9/16 hydraulic
barrier, created by injecting water of a
quality which is approved by the State
and is compatible with the objectives of
this remedial activity into a line of
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cOTT!R015l 049
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injection wells, to attain and maintain
a ground water hydraulic gradient for
flow from this barrier back to the Old
Tailings Ponds Area. The existence of
this gradient shall be verified by
piezometers. The flushing of the area
in the southeast quarter of Section 9,
north of the hydraulic barrier, will.
result from or be in conjunction with
the construction and operation of the
9/16 hydraulic barrier. An example of
the type of conceptual design which
would be acceptable to the State would
include two lines of piezemeters: the
piezometers in the first line (Line C)
to be drilled at a spacing of 200 feet,
or greater spacing as the State may
approve, such that each piezometer shall.
be drilled midway between two adjacent
injection wells; the second line of
piezometsrs (Line D) to be drilled south
of Line C such that the line drawn
between each pair of piezometers (one in
each line) shall be perpendicular to
Line C; the hydraulic head in each of
—68—
COTTU01 61060
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the piezometers in Line C to be
maintained a minimum 0.2 feet higher
than the adjacent piezemeter in Line D.
The piezom.ter design and well operation
shall be sufficient to demonstrate that,
to the maximum extent reasonably
achievable, a gradient exists away from
the 9/16 hydraulic barrier at all
locations.
f. Monitoring of concentrations of uranium
and molybdenum at the perimeter of the
Old Tailings Ponds Area shall be
conducted to detect movement of these
constituents away from the flushing
area. If such movement is detected,
operation of the flushing system shall
be modified to prevent further movement.
g. Modifications proposed by Cotter in, or
made in response to State action upon,
each Old Tailings Ponds Area Flushing
Annual Report shall be implemented
pursuant to an approved schedule.
h. The further development and updating of
the ground water models required by
Paragraph 2.b. and c. of Section 8.2.
—69—
- COT1’fl_01 51051
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4. The production flushing program shall
continue until either criterion a or b, below, is satisfied:
a. The Lincoln Park ground water quality
objectives are met in accordance with
the provisions of Sections 8, 9, 12 and
14.1.3; provided that:
i. Pursuant to the procedures set
forth in Section 9.2, Cotter may
make application for temporary
cessation of the production
flushing program and SCS
hydrologic barrier at any time
that the model described in
Paragraph 2.c. of Section 8.2
predicts that the Lincoln Park
ground water quality objectives
will be met. The Stat. shall
approve the initial application
absent disagreement with the model
prediction;
ii. Cotter shall then demonstrat. by
monitoring data, pursuant to
Section 12.2.2 and 14.1.3 that the
Lincoln Park ground water quality
objectives ar. met.
—70—
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iii. If the monitoring data demonstrate
that the Lincoln Park ground water
quality objectives are met, Cotter
may permanently cease operations
of the production flushing program
and SCS hydrologic barrier;
iv. If the monitoring data demonstrate
that the Lincoln Park ground water
quality objectives are not met,
Cotter shall resume operations of
the SCS hydrologic barrier, and,
unless an application for
permanent cessation pursuant to
Paragraph 4.b. of this Section
has been approved by the State,
operation of the production
flushing program; or
b. Technological limits have been met,
provided that Cotter applies for
permanent cessation of the production
flushing program when the reasonable
technological limits of that program
have been met and the State concurs.
8.3 Reauisite Assessments and Enainasrina Activities
Cotter shall prepare and submit to the State for
review and approval the following:
—71—
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1. Plan for initial evaluation which shall
include:
a. Description of actions required by
Paragraph 1 of Section 8.2;
b. Locations of test borings and tests to
be performed;
c. Proposed laboratory studiss of
geochemical controls and water chemistry
modification to reasonably maximize
dissolution and desorption of molybdenum
and uranium;
d. QA/QC Plan;
e. Schedule.
2. Plan for a pilot study of the injection and
extraction ground water flushing program, which shall include:
a. Findings and conclusions of the initial
evaluation;
b. Description of actions;
c. Design drawings;
d. Construction specifications;
e. Proposed concept for modeling the
performance of the ground water flushing
program and predicting its effectiveness
as predicted at the Lincoln Park
monitoring well;
—72—
COTTU—0151054
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f. Proposed water chemistry modifications;
g. QA/QC Plan;
h. Schedule.
3. Written monthly reports on the progress of
the pilot study, which shall include:
a. Water quality data;
b. Injection and extraction well pumping
rates;
c. Molybdenum dissolution and uranium
deserption efficiency;
d. Results of water chemistry
modifications.
4. Application to EPA for an Underground
Injection Control (UIC) permit, if required.
5. Plan for a production injection and
extraction ground water flushing program including the 9/16
hydraulic barrier, which shall include:
a. Findings and conclusions of the pilot
study;
b. Description of proposed actions;
c. Design drawings;
d. Construction specifications;
a. Proposed water chemistry modifications;
f. Ground water model(s) described in
Paragraphs 2.b. and c. of Section 8.2
coTTxR—0151055
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evaluate the performance of the ground
water flushing program in the Old
Tailings Ponds Area and to predict
compliance with the ground water quality
objectives stated in Section 14;
g. Operations and maintenance plan;
h. QA/QC Plan:
i. Schedule.
6. A written final construction report, which
shall include:
a. As-built drawings;
b. Explanation of and response to
unexpected conditions and problems;
c. Quality assurance evaluations;
d. If necessary, modification of the
operation and maintenance plan.
7. A written Old Tailings Ponds Area Flushing
Annual Report on the progress of the production injection and
extraction ground water flushing program, which shall include:
a. Assessment of chemical extraction
efficiency;
b. Assessment of water injection rates;
c. Assessment of water chemistry and
proposed water chemistry modifications,
if any;
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COTTU—015 1056
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d. Assessment of mass removal:
e. Assessment of other relevant aspects of
the program;
f. Proposed modifications to the program,
including for example, additional
injection or extraction wells and
alternative pumping rates to optimize
the effectiveness of the in—place and
xisting technology;
g. An update of the ground water model(s)
to include current data and information;
h. Using the updated ground water model(s),
art assessment of the actual program
performance compared to the performance
necessary to meet the ground water
quality objectives stated in Sect .on 14;
j. Quality assurance evaluations.
8.4 Schedule
Cotter shall design and conduct these remedial
activities according to the following schedule:
1. Within sixty (60) days of the entry of a
Consent Decree by the Court, Cotter shall submit a plan for
the initial evaluation;
2. The State shall act upon the plan for the
initial evaluation within sixty (60) days of its receipt;
CO?TU—0151057
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3. Within two hundred and seventy (270) days of
the approval by the State of the plan for the initial
evaluation, Cotter shall start and complete the initial
evaluation and shall submit to the State a written report
stating the findings and conclusions of th. initial evaluation
and a plan for a pilot study for an injection and extraction
ground water flushing program.
4. The State shall act upon th. plan for the
pilot study within ninety (90) days after its receipt.
5. Within sixty (60) days of the approval by the
State of the pilot study and the issuance of any required
permits, Cotter shall initiate the pilot study.
6. Cotter shall submit written monthly reports
to the State on the progress of the pilot study by the last
day of each month following the month for which the report s
written.
7. Cotter shall meet with the State, as
requested by the State, to review and discuss the progress of
the pilot study.
8. The pilot study shall be operational for
approximately one (1) year.
9. Within one hundred twenty (120) days of the
completion of the pilot study, Cotter shall submit to the
Stat. a written report stating the findings and conclusions of
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COTTKR—0151 05 8
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the pilot study and a plan for a production injection and
extraction ground water flushing program.
10. The State shall act upon the plan for the
production injection and extraction ground water flushing
program within ninety (90) days of its receipt.
11.. Following the issuanc. of any required
permits, Cotter shall undertake the construction and commence
operation of the production injection and extraction ground
water flushing program pursuant to the approved schedule.
12. cotter shall submit a final construction
report to the State within sixty (60) days of the completion
of the construction of the production injection and extraction
ground water flushing facilities.
13. The State shall act upon the final
construction report within sixty (60) days of its receipt.
14. Cotter shall submit the Old Tailings Ponds
Area Flushing Annual Report to the State on December 15 of
each year. This report shall cover activities performed
during the period of the previous October 1 through
September 30, and any proposed future modifications to the
program.
15. The State shall review the performance during
the period of the preVious October 1 through September 30 and
act upon each modification proposed in the O1d Tailings Ponds
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COTTIR—016 1069
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Area Flushing Annual Report within ninety (90) days of its
receipt.
16. Cotter shall submit a written respons. to the
State’s action on each Old Tailings Ponds Area Flushing Annual
Report for the production injection and extraction ground
water flushing program within sixty (60) days of tIie State’s
action, and implement approved modifications pursuant to an
approved schedule.
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9 THE HYDROLOGIC BARRIER AT THE
SOIL CONSERVATION SERVICE (SCS) DAM
9.1 Descri tiOrI of O erations and Relevant
Environmental Conditions
In 1972 a flood control dam was completed by the
Soil Conservation Service (SCS) on Sand Creek, approximately
0.8 miles north of the area occupied by the mill and the new
impoundments. Since the dam’s completion, surface runoff and
spring flow which emerges upgradient of the dam have been
impounded at the dam, and since 1979, the impounded water has
been pumped back to the main impoundment.
The pathway of the shallow ground water flow from
the mill site is to the north—northeast through a gap in the
ridge at the SCS Dam, then north into Lincoln Park. The
3round water emerges in springs which flew downstream to the
Arkansas River.
9.2 Remedial Activities
The purpose of these remedial activities is to
effectively mitigate the flow of mill-derived constituents in
the shallow ground water pathway and in conjunction with other
ground water remedial activities to achieve the ground water
quality objectives stated in Section 14.
Cotter shall perform the following remedial
activities:
1. Cotter shall construct, operate and maintain
a hydrologic barrier and water withdrawal system at the
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COTU2—O1&lO 6
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upstream side of the SCS Darn on Sand Creek. The following
criteria shall apply:
a. The SCS hydrologic barrier at the SCS
Darn shall be constructed according to
information and details provided in
Section 2 and 6.3, with associated
drawings A—i, A—2, 5—1, 8—2 and B-3 in
the “Engineering Report and Design
Specifications for Water and Waste
Management Plan - — Part ]. at Canon City
Mill, Frernont County, Colorado,” dated
Jun. 29, 1984, Volumes I and II
(Engineering Report), and the
Supplemental G.otechniça]. Investigation,
dated June, 1985, except as specifically
provided below:
b. Th. construction area shall be dewatered
during construction. Construction shall
be considered to have commenced when
either excavation or d.wat.ring begins.
Contractor dewatering equipment shall be
moniter.d to determin, pumping rates and
volumes necessary to dewater the
construction area. Thes. rates and
volumes shall be recorded so that
—80—
COTTU—0 151062
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subsurface flow rates can be estimated
and so that the dewatering pump back
system can be modified, if necessary;
c. The SCS hydrologic barrier shall be
founded in the shale layer described in
the Supplemental Geotechnical
Investigation report, dated June, 1985.
Upon completion of trench excavation,
any significant geological features that
require special treatment to provide the
intended cutoff contact shall be mapped
to a scale and level of detail approved
by the State. This together with the
foundation testing provided for in
Section 6.3.6 of the Engineering Repor:
shall be used to determine any needed
foundation treatment or additional
excavation requirements. Needed
foundation treatment or additional
excavation requirements shall be
undertaken based on a plan developed by
Cotter and approved by the State,
pursuant to subparagraphs 2. e. and 2. j.
of Section 9.4, prior to placement of
—81—
COTTU01 51 ° 53
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any drain or fill material in the
completed excavation.
d. The upgradient (southerly) trench wall
shall be cleaned to remove any condition
created by construction activity that
impedes ground water inflow into the
drain material.
a. The drain material shall be placed, with
prior concurrence of the State, against
the upstream trench wall. In those
locations where highly permeable zones
are encountered, the drain material
shall extend upward to the highly
permeable zones. Th. highly permeable
zones shall be determined, with State
approval, from field inspection.
f. All excavation area material shall be
assayed for radiu -226. The
concentrations of radium-226 shall be
averaged over areas not greater than 100
square meters and over a depth of not
more than 15 centimeters. If the
excavation area materials exceed the
background mean by more than 5 (five)
picocuries of radium—226 per gram, such
—82—
COTTIR—0151064
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material shall not be used for
construction, shall not be stockpiled in
a manner that represents a source of
windblown dust and shall not be mixed
with soils containing less than 5 (five)
picocuriss of radium-226 per gram above
ths background mean, and shall not be
removed off-site. Such soils shall be
handled in accordance with Section 21,
On—site Soils.
g. Materials from the Old Tailings Ponds
Area shall not be used for SCS
hydrologic barrier construction. All
clay and rar dom soils used as fill
material shall be assayed prior to use.
If the materials exceed background mean
by more than 5 (five) picoCuries of
radium—226 per gram, such materials
shall not be used for construction or
fill.
Li. Preliminary pump operating criteria
which would be acceptabl. to the State
are:
Pump Proposed Water
Oceration Level Elevatipn
1st Pump on 5,455
2nd Pump on 5,460
—83—
COTTIR—O15lO 65
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3rd Pump en 5,465
3rd Pump off 5,460
2nd Pump off 5,455
1st Pump off 5,450
These criteria shall be reviewed based
on the analysis conducted pursuant to
subparagraph j, below. These criteria
are intended to minimize hydraulic head
on the barrier to the extent practical.
j. If surface water elevations exceed 5,472
(feet above M.S.L.), and it is apparent
that the permanent pumpback system is
unable to effectively reduce the pool in
a timely manner, as jointly determined
by Cotter and the State, emergency
pumping shall be implemented to reduce
the surface water elevation to below
5,472.
j. Following barrier construction, Cotter
shall conduct sufficient testing to
optimize th. operation of the pumpback
system.
k. The ground water model required pursuant
to Paragraph 2.c. of Section 8.2 shall
be updated based on soil and substrate
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CO?TIR—0 151066
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conditions encountered during
construction of the SCS hydrologic
barrier.
1. Monitoring the SCS hydrologic barrier
shall includ, monthly water level
observations for wells 329, 330, 331,
714, 715, 716 and SCS barrier
piazometers for net less than one (1)
year after commencement of operation,
and semiannually thereafter. Post-
construction water level monitoring
shall include all wells, piezometer 7,
and those piezometers which remain after
construction. Additionally, two (2) new
piezo!neters shall be constructed near
the crest of the SCS Dam and its extre’e
right and left spiliways.
•1
m. The pumpback system to the main
impoundment or the water distribution
pond shall be constructed according t
Section 6.4 and drawings C-i, C-2, and
C-3 of the Engineering Report.
n. Quality control and quality assurance
shall be according to the Quality
Control Plan, dated August 30, 1985 ar.d
—85—
COTTIR—0151O 6 ?
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as modified and superseded pursuant to
paragraph 1(a) through 1(m) of Section
9.2. Additionally, the quality control
program shall conform to ‘Geotechnical
Quality Control: Low-Level Radioactive
Waste and Uranium Mill Tailings Disposal
Facilities,” NUREG/CR—3356. The
specific plan of action and
documentation procedures, including a
description of organizational structure,
methods and tests for evaluating
performance, and notification steps for
changes or corrective actions and
including reporting, recordkeeping, ar.d
storage, shall be revised as appropriate
whenever regulatory guidance req11irir g
such revisions is provided to Cotter by
the State. The quality control prograt
shall identify who has responsibility
for providing test and inspection
results to the State.
2. In the event of a request to temporarily
cease operations, the hydrologic barrier and water withdrawal
system shall continue in operation until Cotter submits and
—86—
COTTUO1 6 lO 6 B
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the State approves a request to temporarily cease these
activities as set forth below.
a. A request to temporarily cease barrier
operations may be made based upon a
projection that following cessation of
SCS hydrologic barrier operations the
ground water quality objectives stated
in Section 14.1.3 viii. be met. The
State shall approve the initial
application to temporarily cease
barrier operations absent disagreement
with the model prediction. A request to
temporarily cease operations shall be
made no more than annually.
•b. Operation of the SCS hydrologic barrier
and water withdrawal system shall
continue until such time that the State
preliminarily approves an initial
application to temporarily cease
operations.
c. Following preliminary approval by the
State of the initial application to
cease operations, Cotter shall
temporarily ceas. water withdrawal and
cause water from behind the barrier to
—87—
COTTU01 51 ° 69
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bypass the barrier. (See Section
12.2.2.) Monitoring shall occur as
provided in Section 14.1.4. If the
ground water quality objectives of
Section 14.1.3 are met pursuant to the
procedure sit forth in Section 14.1.4,
then the State shall make its
preliminary approval of the cessation of
operations final. If these ground water
quality objectives of Section 14.1.3 are
not met, then the operation of the SCS
hydrologic barrier and th. water
withdrawal system shall resume.
3. The SCS hydrologic barrier and water
withdrawal system shall continue in operation until either
criterion a or b below is satisfied:
a. The-Lincoln Park ground water quality
objectives are met in accordance with
th. provisions of Sections 8, 12 and
14.1.3 and Paragraph 2 of Section 9.2;
or
b. The mill has permanently closed and
decommissioning has begun and the
production flushing program has
—88— COTTU—0181070
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permanently ceased operation pursuant to
Paragraph 4 of Section 8.2.
4. The outlet works for the SCS Dam shall be
unblocked by Cotter in consultation with the Fremont County
Flood Conservancy District, after approval by the State to
permanently cease operation of the SCS hydrologic barrier and
the water withdrawal system.
9.3 Reauisite Assessments and Enaineerirto Activities
Cotter shall prepare arid submit to the State for
review and approval the following:
I.. Cotter has submitted to the State designs and
specifications for the SCS hydrologic barrier and water
withdrawal system.
2. A construction schedule, a protocol for
conducting the sampling required pursuant to Paragraphs l.f.
and l.g. of Section 9.2, arid a QA/QC plan for the construction
of the barrier.
3. If required by the State, revisions of the
proposed design for the SCS hydrologic barrier and water
withdrawal system described in the Engineering Report.
4. A report on the results of the testing of the
pumpback system operation criteria, which shall include:
a. Results of testing;
b. Explanation of and response to any
unexpected conditions or problems;
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COTTU—O15lO 7 l
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c. Proposed pumpback operating criteria.
5. A written final construction report, which
shall include:
a. As-built drawings;
b. Explanation of and response to
unexpected conditions and problems;
c. Quality assurance evaluations;
d. Plan for operation and maintenance:
a. Soils analysis conducted pursuant to
Paragraphs l.f. and l.g. of Section 9.2.
6. As a part of the RAP Annual Report specified
in Section 3.1, a written annual summary on the o aration and
maintenance of the SCS hydrologic barrier and water withdrawal
system, which shall include:
a. Monthly pumping rate;
b. Monthly pond storage data;
c. Quarterly water chemistry data;
d. Explanation of and respons. to
unexpected conditions and problems;
a. Quality assuranc, evaluations;
f. A discussion of the effectiveness of the
SCS hydrologic barrier;
g. Monitoring data required pursuant to
Paragraph 1.1. of Section 9.2.
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COTTU—01 5 l 072
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7. Written notice prior to any application to
temporarily cease operations, which shall include:
a. Date application will be filed;
b. Summary of basis for application.
8. Written application to temporarily cease
operations based on a prediction that the ground water quality
objectives as stated in Section 14.1.3 will be met, which
shall include:
a. The basis for the application to
temporarily cease operations;
b. All data that are relevant to a
cessation of operations;
c. A projection of the concentrations of
uranium and molybdenum at the Lincoln
Park Monitoring Well following cessat .o
of barrier operations using the updated
ground water model.
9. An application to permanently cease
operations after commencement of decommissioning and permanent
mill closure in th. case where th. model predicts that the
ground water quality objectives as stated in Section 14.1.3
will not be met shall be submitted at the same time and
consistent with th. application filed pursuant to Paragraph
4.b. of Section 8.2, which shall include:
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COTTER—0151073
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a. All data that are relevant to a
cessation of operation of the SCS
hydrologic barrier and water withdrawal
system;
b. A projection of the concentrations of
uranium and molybdenum at the Lincoln
Park Monitoring W•1l using the updated
mill area and Lincoln Park ground water
model(s) prepared pursuant to Paragraph
2.b. and c. of Section 9.2.
9.4 Schedule
Cotter shall design and conduct these remedial
activities according to the following schedule:
1. Cotter shall submit the information required
pursuant to Paragraph 2 of Section 9.3 not later than ten (10)
days after entry of the Consent Decree by the Court. The
State shall act upon the information submitted within fifteen
(15) days of its receipt.
2. SCS Hydrologic Barrier Construction
a. Within fifteen (15) days of the entry of
the Consent Decree by the Court, the
State shall review and act upon the
proposed plan for the SCS hydrologic
barrier and water withdrawal system as
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COTTIR—0151O 74
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previously submitted to the Colorado
Department of Health by Cotter.
b. If the review and action by the State
requires substantial changes in the
proposed design, then within one hundred
and twenty (120) days of the action of
the State, Cotter shall prepare and
submit a revised plan and schedule for
the SCS hydrologic barrier and water
withdrawal system.
c. The State shall act ipon the revised
plan end schedule within thirty (30)
dayi of receipt;
c i. Construction of the SCS hydrologic
barrier and withdrawal system shall be
conducted in accordance with the
approved schedule, and be completed not
later than November 1, 1988.
Construction will not be required to
commenc. during the months of August
through May.
.. During barrier construction, Cotter
shall verbally notify the State not Less
than three (3) working days prior to
COfTU—015l 075
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completion of trench excavation and
commencement of:
i. Grouting;
ii. Barrier material placement and
compaction;
iii. Drain material placement.
f. The State shall inspect on the date
specified in the verbal notice provided
pursuant to Subparagraph a of this
Paragraph.
g. Cotter shafl. submit the report on the
results of the pumpbaek operation
testing conducted pursuant to paragraph
l.J. of Section 9.2 within three hundred
sixty (360) days after the commencement
of water withdrawal operations.
h. The Stats shall act on the report within
sixty (60) days of its receipt.
i. Cotter shall construct the piezometers
required pursuant to Paragraph 1.1. of
Section 9.2 in accordance with the
construction schedul. approved pursuant
to Paragraph 2.d. of Section 9.4.
j. The State shall provide decisions
regarding the items listed in
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COTTU—Ol5lO? 6
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subparagraph e of this Paragraph, within
twenty—four (24) hours of the State’s
field inspection.
c. Cotter shall submit a final construction
report to the State within one hundred
twenty (120) days of the completion of
the construction of the SCS hydrologic
barrier and water withdrawal system.
1.. The State shall act upon the final
construction report within one hundred
twenty (120) days of its receipt.
3. Annual Report
a. Following completion of the construction
of the SCS hydrologic barrier, as part
of the RAP Annual Report specified in
Section 3.1, Cotter shall submit to the
Stats an annual summary of the operatior.
of the SCS hydrologic barrier and its
related pumpback system.
b. The State shall act upon the annual
report within one hundred twenty (120)
days of its receipt.
4. Application to terminate operation of the SCS
hydrologic barrier and water withdrawal system.
—95—
COTTU—0151077
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a. In the event of an application to
temporarily cease operation pursuant to
Sections 8.2 and 9.2, Cotter shall give
thirty (30) days written notice to the
State prior to submitting a written
application to temporarily cease
operation of the SCS hydrologic barrier
and water withdrawal system. The State
shall act upon the application within
one hundred and twenty (120) days of its
receipt.
b. In the event of a request to permanently
cease operations pursuant to Paragraph 3
in Section 9.2, Cotter shall submit an
application for permanent cessation of
operations as described in Paragraph 9
of Section 9.3. The State shall act
upon the application submitted by Cotter
within one hundred and twenty (120) days
of its receipt.
—96—
COTTU—O 151078
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- 10 NORTHWEST AND NORTHEAST SHALLOW GROUND WATER
PATHWA 5
10.1 Descriotion of O erations and Relevant
Environmental Conditions
The ina or pathway of th. shallow ground water flow
is to the north—northeast from the mill area through a gap in
the ridge at the SCS Darn into Lincoln Park. Th State
suspects that other shallow ground water pathways may exist.
One suspected pathway may be from the site to the northwest
and another may be from the site to the northeast.
10.2 Remedial Activities
The purpose of these remedial activities is to
deter ins the existence of hydrologic divides, if any, through
the west one—half of Section 9 and along the east section line
of Section 9, to monitor th. water quality in these locations,
based on these water quality data, to determine whether either
or both of these pathways of shallow ground water flow to the
northwest and northeast exist, if necessary, to effectively
minimize and mitigate these pathways as routes of shallow
ground water flow, and in conjunction with other ground water
remedial activities to achieve the ground water quality
objectives stated in Section 14. Continued monitoring and
possible rsm.diation of these areas is required because of the
potential for rsmediai. activities at other areas,
specifically, flushing in the Old Tailings Ponds Area, which
might affect the water quality in these locations.
—97—
COTTU—0 15 1079
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Cotter shall perform the following remedial
activities:
1. cotter shall design, and implement a well
monitoring plan to determine whether hydrologic divides exist
through the west 1/2 of Section 9 (northwest) and
approximately along th. east Section line of Section 9
(northeast).
The monitoring wells shall be drilled at the
locations indicated on Figure 10—1. The Class A well at or
near proposed well 009 shall be completed as two holes. One
hole (009) shall be completed to a depth of fifty (50) feet
and the other hole (014) shall be completed to a depth of one
hundred (100) feet. The Class A well (015) at or near present
well 342 shall be completed to a depth from five (5) feet
above the then existing water table to twenty (20) feet below
the then existing water tab]... The Class A well north of the
southeast (SE) corner of Section 9 shall be completed as two
holes. One hole (016) shall be completed to a depth from the
then existing water table to twenty-five (25) feet below the
then existing water table, and the other hole (017) shall e
complet .d to a depth from thirty—five (35) feet below the then
existing water table to sixty (60) feet below the then
existing water table. All siven (7) Class B walls shall be
completed to be open from the water table to a depth of thirty
(30) feet below the water table.
—98—
CO?Tfl—0151080
C
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Water quality and water levels shall be monitored
for a one-year monitoring period beginning ninety (90) days
after the wells are drilled to allow for stabilization of
water quality and water level condition, and monitored
according to Section 15.
2. Following a one year monitoring period,
Cotter shall analyze the accumulated data and report to the
State its conclusions as to whether either of the hydrologic
divides exist.
3. If a hydrologic divide is determined to exist
for the suspected northwest or northeast pathway, then Cotter
shall continue monitoring the newly installed Class A wells
and after the collection of a minimum of two years water
quality data, perform an analysis of water quality data
obtained from th. identified Class A wells along the
pathway(s) to determine if there is a steady state condition
or if there is a trend of increased molybdenum concentration.
Monitoring shall continue until Old Tailings Pond Area
flushing operations are complete. The protocol to determine
whether there is a steady state condition is that identified
in Section 3.2.7. The monitoring data to be used are the most
recent data for the concentration of molybdenum for each of
the identified Class A wells for a period not Less than two
(2) years and not mor. than five (5) years. This analysis
shall be performed annually by Cotter. Specifically, a total
—99—
COTTER—0151081
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of at least two years of data must be accumulated prior to
conducting the analysis, then the analysis shall be conducted
annually on the accumulated monitoring data until a total of
five years of data an, collected. Analyses conducted in
subsequent years must use only the most recent five years of
data. If a steady state condition does not exist and if there
is a statistically significant upward trend, as defined in
Section 3.2.7, of increasing molybdenum concentrations, then
Cotter shall conduct remediation as described in Paragraph 5,
below.
4. If a hydrologic divide is determined not to
exist for the suspected northwest or northeast pathway, then
Cotter shall perform a statistical analysis of the monitoring
data obtained from the Class A wells located along the
suspected pathway(s) to determine whether the concentrations
of molybdenum in any of the Class A wells (Figure 10—1) exceed
the background rang. of molybdenum. The comparison of the
monitoring data with the background range shall be performed
by use of the protocol identified in Section 3.2.6. The
background data shall be all of the data collected after July
1984 for the concentration of molybdenum at wells 325 and 337.
Th. monitoring data for each indicated Class A well shall be
the most recent data for the concentration of molybdenum in
each indicated Class A well for a period not less than one (1)
year and not more than two (2) years. Specifically, the
—100—
COTTU—O 151082
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analysis must be conducted on no lass than one year of
accumulated monitoring data and no more than two years of
accumulated monitoring data, thus subsequent analyses shall be
conducted using only the most recent two years of data. If
the statistical analysis indicates that the concentration of
molybdenum in the monitoring data in any of the indicated
Class A wells along the suspected pathway(s) exceeds the
background range of molybdenum, Cotter shall conduct further
remediation as described in Paragraph 5 of Section 10.2.
5. If Cotter is required to conduct remediation
pursuant to Paragraph 3 or 4 of this Section, Cotter shall
conduct additional appropriate investigations, and design and
submit a proposal and construction schedule for a remediation
program to effectively minimize and mitigate th. pathway(s) of
ground water flow.
10.3 Recuisite Assessitients and Enaineerina Activities
Cotter shall prepare and submit to the State for
review and approval the following:
1. A well monitoring plan, which shall include:
a. Design drawings;
b. Construction specifications;
C. QA/QC Plan;
d. Schedule..
2. A written report stating the findings and
conclusions regarding the existence of hydrologic divides,
which shall include:
—101—
COfTIl—01 5 1083
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a. As built drawings;
b. Explanation of and response to
unexpected conditions and problems;
c. Quality assurance evaluations:
d. Statistical analysis of data, including
statistical analysis of molybdenum
concentrations if a hydrologic divide
does not exist.
3. A written annual summary, which shall
include:
a. If a hydrologic d .vide(s) exists, the
monitoring and background data and
statistical analysis for a steady state
condition for the identified Class A
wells;
b. If a hydrologic divide(s) does not
exist, a statist2.cal comparison of the
monitor .ng and background data sets:
c. Explanation of and response to
unexpected conditions and problems;
d. Quality assurance evaluations;
e. Conclusions;
f. Description of remediation activities,
if any, as described in Paragraph 5 of
Section 10.2.
—102—
COT’IU—01510 84
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4. If Cotter is required to conduct remediation,
pursuant to Paragraph 3 or 4 of Section 10.2, Cotter shall
submit a report which shall include:
a. All data and analyses relevant to the
definition of the pathway;
b. Design drawings and construction
specifications for the proposed
rem.diat ion facilities;
c. Schedule for the construction and
operation of the proposed remediation
facilities:
d. QA/QC plan;
e. Operations and maintenance plan.
5. If Cotter is required to conduct remediation,
a written final construction report, which s ia11 include:
a. As-built drawings;
b. Explanation of and response to
unexpected conditions and problems;
c. Quality assuranc. evaluations;
4. If necessary, any modifications of the
operation and maintenance plan.
10.4 Schedule
Cotter shall conduct thea. remedial activities
according to the following schedule:
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COTTU—O 18 1085
(p
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.. Within sixty (60) days of the entry of the
Consent Decree by the Court, Cotter shall submit a well
monitoring plan.
2. The State shall act upon the well monitoring
plan within sixty (60) days of its receipt.
3. Cotter shall implement the well monitoring
plan pursuant to the approved schedule, but not later than two
hundred seventy (270) days after receiving approval from the
State.
4. Within sixty (60) days following one (1) year
of monitoring all of ths Class A and Class B wells at the
locations indicated in Paragraph 1. of Section 10.2, Cotter
shall submit a written report to the State on the findings and
conclusions regarding whether hydrologic divide(s) exist and
the statistical analysis of the molybdenum concentrations, if
the report concludes that a hydrologic divide does not exist.
5. The State shall act upon the report regarding
whether the hydrologic divides exist within sixty (60) days of
its receipt.
6. Cotter shall submit as part of the RAP Annual
Report specified in Section 3.1, a written annual summary as
described in Paragraph 3 of Section 10.3.
7. The Stats shall act upon the annual summary
within one hundred twenty (1.20) days of its receipt.
—104—
COTTEE—O 151088
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8. Wi€hin three hundred sixty (360) days of the
determination that remediation is required pursuant to
Paragraph 3 or 4 of Section 10.2, Cotter shall conduct
additional appropriate investigations, and design and submit a
proposal and construction schedule for a remediation program
to effectively minimize and mitigat. the pathway(s) of ground
water flow.
9. The State shall act upon th. migration
pathway plan within ninety (90) days of £ts receipt.
10. If permits ar. required, Cotter shall submit
the permit applications to the appropriate authorities at the
time Cotter submits the migration pathway plan to the State.
11. Cotter shall initiate the migration pathway
plan and start the necessary construction pursuant to the
approved schedule-.
12. Cotter shall submit a final construction
report to the Stat. within ninety (90) days of the completion
of the implementation of the migration pathway plan.
13. The State shall act upon the final
construction report within sixty (60) days of its receipt.
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12. WOLF PARK MINE SMAFT
11.1. Descri tion Of 0 aratioris and Relevant
Environmental Conditions
The Wolf Park coal mine last operated beneath
Section 16 in the early 1900’s. The mine included a shaft
approximately 1084 feet deep, and located as shown on
Figure 11—1.
1.1.2 Remedial Activity
The purpose of these remedial activities is to
investigate the Wolf Park Mine Shaft as a pathway of flow to
deep ground water, to effectively minimize and mitigate the
mine shaft as a pathway, if the pathway is determined to
exist, and, in conjunction with the other ground water
remedial activities, to achieve the ground water quality
objectives stated in Section 14.
Cotter shall perform the following remedial
activities:
1. Cotter shall install and maintain a well
(018) within twenty-five (25) feet of the mine shaft. The
well shall be located between the shaft and the Old Tailings
Ponds Area, unless Cotter demonstrates that an alternative
location is suitable and said location is acceptable to the
State. The well shall be completed to Class A wall standards
(see Section 3.2.1), and its sampling interval shall be
between one hundred and forty (140) feet and one hundred and
seventy (170) feet below the ground surface.
—106—
COTTfl—O 151088
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2. Water samples shall be collected from the
monitoring well once a month for one (1) year following the
completion of the installation of the wall. Water sample
collection shall commence ninety (90) days after wall
installation to allow for stabilization of water quality and
water level conditions in the well. The sampling shall be
completed prior to the start of th. flushing of the Old
Tailings Ponds Area in any location that has significant
potential to create changed chemical conditions in the mine
shaft or in the open interval of the well. Each water sample
shall be analyzed for molybdenum.
3. The data obtained shall be evaluated to
determine if the mean concentration of molybdenum exceeds the
background range. The background data shall be the
concentrations of molybdenum in existing well 324 after July
1984.
4. If the mean concentration of molybdenum in
the monitoring wall exceeds the background range of olybdenuzn
during the first year of monitoring, than Cotter shall design,
install and maintain a cement grout plug or an appropriate
equivalent. A plan for the plug shall be submitted to the
State for review and approval. The plug shall be designed to
effectively minimize and mitigate flow from the formation
above two hundred and forty (240) feet below the surface of
the ground to the lower portion of the mine shaft and may be
—107—
COTTU—0151089
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accomplished either by installing a low permeability plug in
the mine shaft at an approved location above two hundred and
forty (240) feet below the surface of the ground or by
grouting the rock surrounding the mine shaft in the interval
between one hundred and forty (140) feet and two hundred and
forty (240) feet below the surface of the ground.
5. If the concentration of molybdenum in the
monitoring well does not exceed the background range of
molybdenum, during the one (1) year monitoring period, then
monitoring of the wall or remedial action with respect to the
Wolf Park mine shaft shall continue on a quarterly basis unt .
the flushing program in the Old Tailings Ponds Area is
permanently terminated. If the molybdenum concentration in
the well exceeds the background range as determined in
Paragraph 3, above, Cotter shall submit a proposed remedj.at :r
program to minimize and mitigate the condition inducing the
increased concentration.
11.3 R. uisite Assessments and npinearina ActivitLes
Cotter shall submit to the State for review and
approval the following:
2.. Plan and schedule for construction of the
monitoring well, including appropriate QA/QC.
2. A written final construction report for the
monitoring well, which shall include:
a. As—built drawings;
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COITU—015l 090
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b. Explanation of and response to
unexpected conditions and problems;
c. Quality assurance evaluations;
d. Monitoring plan.
3. Monitoring results report, which shall
include:
a. The results of the sampling and analysLs
of the water samples of the new shaft
monitoring well and well 324;
b. An analysis of whether the levels of
molybdenum in the monitoring well exceed
the background range of molybdenum;
c. Quality assurance evaluations.
4. If a cement grout plug or equivalent is
required pursuant to Paragraph 4 of Section 11.2, then a
irritten remediation plan shall be submitted, which shall
include:
a. The design drawings and construct .cn
specifications for the plug or
equivalent;
b. A construction schedule for its
installation;
C. QA/QC Plan;
d. Maintenance plan.
—109—
COTTII—O151Og1
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5. If a cement grout plug or equivalent is
required pursuant to Paragraph 4 of Section 11.2, then a
written final construction report shall be submitted which
shall include:
a. As-built drawings:
b. Explanation of and response to any
unexpected conditions or problems.
6. If a rem.diation program is required pursuant
to Paragraph 5 of Section 11.2, then a written remediation
plan shall be submitted, which shall include:
a. Design drawings and construction
specifications;
b. Construction schedule;
c. QA/QC Plan;
d. Maintenance Plan.
7. If a remediation program is required pursuant
to Paragraph 5 of Section 11.2, then a written final
construction or implementation report shall be submitted whicii
shall include:
a. As-built drawings;
b. Explanation of and response to any
unexpected conditions or problems.
11.4 Schedule
Cotter shall design and conduct thee. remedial
activities according to the following schedule:
—110—
a COTTKI—0151092
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1. Within sixty (60) days of the entry of a
Consent Decree by the Court, Cotter shall submit the plan for
construction of the monitoring well for State review and
approval.
2. The State shall act upon the plan and
schedule within sixty (60) days of its receipt.
3. Cotter shall complete the installation of the
monitoring well in accordance with the approved schedule.
4. Within one hundred twenty (120) days of
installation of the monitoring well, Cotter shall submit a
final construction report.
5. The State shall act upon the final
construction report within one hundred twenty (120) days of
its receipt..
6. The well shall be monitored monthly for one
(1) year beginning ninety (90) days after its installation
and, if a plug or equivalent is not installed, quarterly
thereafter until the Old Tailings Ponds Area flushing program
is terminated.
7. Within sixty (60) days of the completion of
the first year of monitoring, Cotter shall submit a monitoring
results report. Th. results of any subsequent monitoring
shall be reported as part of the RAP Annual Report as
specified in Section 3.1.
—111—
r LI
COT?ER—0 15 1093
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8. The State shall act on the monitoring results
report of the first year of monitoring data within thirty (30)
days of receipt. The State shall act upon subsequent
monitoring .results reported in the RAP Annual Report within
one hundred twenty (120) days of the receipt of the annual
report.
9. If a cement grout plug or equivalent is
required pursuant to Section 11.2:
a. Cotter shall submit a plan and schedule
- for the cement grout plug or appropriate
equivalent within sixty (60) days of the
action by the State on the monitoring
results report:
b. The State shall act on the plan and
schedule for a cement grout plug or
equivalent within thirty (30) days of
its receipt:
c. Cotter shall complete construction of
the cement grout plug or equivalent
pursuant to th. schedule set forth in
the plan as approved:
d. Cotter shall submit to the State a final
construction report within thirty (30)
days of the completion of the
—112—
COTTU—0151O 94
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construction of the cement grout plug or
equivalent;
e. The State shall act upon the final
construction report within sixty (60)
days of its receipt.
10. If a remediation program is required pursuant
to Paragraph 5 of Section 11.2:
a. Cotter shall submit a remediation plan
and schedule within sixty (60) days of
submitting the RAP Annual Report.
b. The State shall act on the plan and
schedule for the remediation program
within sixty (60) days of its receipt.
c. Cotter shall complete the remediaticr
program pursuant to the approved
schedule.
d. Cotter shall submit to the State a final
constructi on report within thirty (30)
days of the completion of the
construction or implementation of the
rsmedi.atLon program.
e. The Stat. shall act upon th . final
construction report within sixty (60)
days of its receipt.
—113—
COTTU—0151095
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12 SOIL CONSERVATION SERVICE (SCS) DAM
TO THE DEWEESE DYE DITCH
12.1 Daccri tiOn of O erations and Relevant
Environmental Conditions
The major pathway of shallow ground water flow is
through a gap in the ridge at the SCS Dam. The ground water
flows along the Sand Creak channel to the DeWeasa Dye Ditch.
During the irrigation season th. ditch series as a source of
ground water dilution.
12.2 Remedial Activities
12.2.1 Flushing Activities
The purpose of these remedial activities is to
flush the ground water in the Sand Creek channel between the
SCS darn and the DeWeese Dy. Ditch so as, in conjunction with
other ground water remedial activities, to achieve the ground
water quality objectives stated in Section 14. In order to
accomplish this purpose, Cotter shall perform the following
remedial activities:
1. Cotter shall design and implement a plan to
flush the ground water along the Sand Creek channel from the
SCS Darn to the DeWsese Dye Ditch. Water, of a quality which
is approved by the State and is compatible with the goals of
this remedial activity shall be injected either by wells or by
a trench located in close proximity to th. downstream edge of
the SCS Dam. The rate of flushing shall be sufficient to
rais. the ground water in the Sand Creek channel from the SCS
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COTTU—0 15 1096
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Darn to the DeWeese Dye Ditch to an elevation at or above the
water level elevations existing prior to the start of the
purnpback operations at the SCS Dam in 1979, but the rate of
flushing is not required to be greater than one hundred (100)
gallons per minute (gprn). Thi Sand Creek channel flushing
program shall operate seasonally during that period of time
when the DeWeese Dye Ditch is delivering water.
2. The flushing program shall operate until the
ground water quality at the Lincoln Park Monitoring Well first
achieves the objectives stated in Section 14.1.3, but in no
event for less than one (1) year, or until the SCS hydrologic
barrier ceases operation pursuant to Paragraph 2 or 3 of
Section 9.2, whichever is earlier.
12.2.2 Testina Activities
The purpose of the testing activities is to
determine whether the Lincoln Park ground water quality
objectives can be satisfied after cessation of SCS hydrolog.c
barrier operations.
In order to accomplish this purpose, Cotter shall
perfor the following testing activities:
2.. In accordanc. the procedures specified in
Paragraph 2 of S.ction 9.2, Cotter shall cause the water
impounded upgradi.nt and upstream of the SCS hydrologic
barrier to be injected by well or trench downgradient of the
SCS Darn.
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COTTU-0 151097
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2. This injection procedurs shall be conducted
as an element of the compliance evaluation described in
Section 14.1.4.2.
12.3 Re.cuisite Assessments and Engineering Activities
12.3.1 Flushina Activities
Cotter shall prepare and submit to the State for
review and approval the following:
1. A plan to flush the ground water in the Sand
Creek channel from the SCS Dam to the DeWeese Dye Ditch, which
shall include:
a. Design drawings and construction
specifications;
b. QA/QC Plan;
c. Construction schedule and conceptual
operation schedule;
1. Operations and maintenance plan;
e. Permit applications, if required;
f. Water withdrawal quantity information
collected after the initiation of the
SCS hydrologic barrier and water
withdrawal system operations. (This
information will be incorporated into
design of the flushing proposal.)
2. A written final construction report, which
shall include:
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COTTU-0151098
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a. As-built drawings;
b. Explanation of and response to
unexpected conditions and problems;
c. Quality assurance evaluations;
d. Plan for operation and maintenance.
3. A written annual report, which shall include:
a. Description of operations, including
rate of flushing;
b. Explanation of and raspanse to
unexpected conditions and problems;
c. Quality assurance evaluations.
12.3.2 Testina Activities
Cotter shall prepare and submit to the State for
review and approval the following:
1. A plan to inject the water stored upstream
and upgradient of the SCS hydrologic barrier in the Sand Creek
channel downgradi.nt from the SCS Dam following State approval
of Cotter’s initial application to ceas. barrier operations
which shall include:
a. Design drawings and construction
specifications:
b. QA/QC Plan;
c. Construction schedule and conceptual
operat ion schedule;
d. Operations and maintenance plan;
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c L)
COTTIR—O 151099
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a. Permit appiications, if required.
2. A written final implementation report, which
shall include:
a. As-built drawings;
b. Explanation of and respons. to
unexpected conditions and problems;
c. Quality assurance evaluations;
d. Plan for operation and maintenance.
3. Th . Annual Report for this activity shall be
as described in Paragraph 3 of Section 12.3.1.
12.4 Schedule
12.4.1 Flushing Activities
Cotter shall design and conduct these remedial
activities according to the following schedule:
1.. Within one hundred and eighty (180) days
after the completion of construction of the SCS hydrologic
barrier and the start of the pumpback operations at the SCS
hydrologic barrier, Cotter shall submit to the State a plan to
f lush the ground water in the Sand Creek channel from the SCS
Darn to the DeWeess Dye Ditch.
2. The Stat. shall act upon the plan within
ninety (90) days after its receipt.
3. Cotter shall apply to EPA for an Underground
Injection Control (UIC) permit, if required, arid for any other
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COTTfl—0151100
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required permits to the appropriate State or federal agency
within ninety (90) days of approval of the plan by the State.
4. Construction activities shall be completed by
Cotter according to the approved construction schedule, and
the flushing system shall be operated seasonally during that
period of the year when the DeWeese Dye Ditch is delivering
water.
5. Cotter shall submit a final construction
report within one hundred twenty (120) days after the
completion of construction.
6. The State shall act upon the final
construction report within sixty (60) days of its receipt.
7. As a part of the RAP Annual Report specified
in Section 3.1, Cotter shall submit an annual activities
summary after entry of the Consent Decree and after the
completion of construction.
8. The State shall act upon the annual report
within one hundred twenty (120) days of its receipt.
12.4.2 Testing Activities
1. Cotter shall implement the provisions of
Section 12.2.2 pursuant to the Schedule sat forth in Paragraph
4 of Section 9.4.
2. The State shall act on the plan submitted
under Section 12.3.2 pursuant to the schedule set forth in
Paragraph 4 of Section 9.4.
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COTTU01 5 1101
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13 LINCOLN PARK WATER USE
13.1 Descri tion of O erations arid Relevant
Environmental Conditions
The major pathway of shallow ground water flow
from the mill northward into Lincoln Park is through the gap
in the hogback occupied by the SCS Darn. The Canon City
water district serves the Cotter mill and the Lincoln Park
area. The majority of residences in Lincoln Park currently
use the Canon City water supply for drinking water purposes
through a direct connection: a number of residences use water
from wells on their property either in addition to their Cancri
City water tap or as their sole supply. Some residences still
use well water for stock watering and/or irrigation.
13.2 Remedial Activities
The purpose of these remedial activities is t
further determin, the extent of ground water use by Lincoln
Park residents, to connect any unconnected drinking water
users in the Lincoln Park Water Use Survey Area to the Canon
city water supply pursuant to Paragraphs 4 and 7 of this
Section, in conjunction with the Health Risk Assessment (see
Section 32), to develop guidelines for the use of the ground
water for irrigation and stock watering, and, as appropriate.
to protect agricultural, ground water uses.
Cotter shall perform the following remedial
activities:
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COT?I*—0151102
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.. Cotter shall design and implement a water use
Survey for the Lincoln Park Water Use Survey Area, which is
shown on Figure 13-1. The survey shall be designed with the
participation of the State and the Health Risk Assessment
Panel and submitted to the Stat. for review and approval. The
State-approved survey shall be conducted by individual
personal interview, or other reasonable combination of
alternatives, including by way of example, telephone survey,
mail survey or use of data collected by the U.S. Geological
Survey and the Canon City Water Department of all of those
within the area of Lincoln Park Water Use Survey Area. The
State shall be given the opportunity to participate in each
interview.
Each location where well water is used or is
available for use, and the well has not been abandoned shall
be included in the survey. A well shall be considered
abandoned if the property is vacant, the well or pump is
inoperative, or the well, has been plugged.
The survey shall:
a. Determine the source(s) of water
availabl, to each location within the
survey area;
b. Determine the historic use of ground
water as of June 12, 1987, and current
us. of each source of ground water;
—121—
9, COTTU—0151103
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c. Collect a water sample of each source of
ground water;
d. Analyze each water sample for
concentrations of uranium and
molybdenum.
2. Following the survey, Cotter shall report the
survey and sample results to the State and the Health Risk
Assessment Panel, and on the basis of guidance from the State
and the Health Risk Assessment Panel propose a discussion with
each person from whose property a sample was collected.
3. Cotter shall design and implement a program
to disseminate relevant information obtained by the water use
survey, including water sample results, water uses, and
guidelines for water use. The program shall be designed with
the participation of the State and Health Risk Assessment
Panel. Following State approval, the program shall be
implemented with the participation of the State and the Health
Risk Assessment Panel.
4. Following the survey, Cotter shall offer each
residence in the survey area, which is not connected to the
Canon City water supply, a connection to the Canon City water
supply. Each connection shall be made at the sole expense of
Cotter.
5. On the basis of the survey and the Health
Risk Assessment, if it is determined by the State that the
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COffgR—0151 104
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ground water is not appropriat, for irrigation or stock
watering, Cotter shall offer each agricultural user of ground
water in the survey area who has a legal right to use that
ground water, an alternative water supply. This obligation
shall be limited to those agricultural water uses in
existence, or for which a water, land use or other relevant
application had been filed and was pending as of June 12,
1987. Each alternative water supply shall be supplied at the
sole expense of Cotter.
6. As approved by the State, Cotter shall pay
the incremental costs, if any, resulting from the replacement
of ground water suppliss, pursuant to Paragraph 4, 5 or 7 of
this Section and the implementation of the water use
recommendations of the Health Risk Assessment Panel. This
incremental cost obligation shall be in effect during the
period prior to the establishment of ACLa pursuant to Section
14 when uranium and molybdenum concsntrations exceed:
a. For residences, an annual average of
0.035 mg/I. and 0.1 mg/i, respectively,
as measur.d at the Lincoln Park
Monitoring Well: or
b. For agricultural us.. in existence, or
for which a water, land use or other
rel•vant application had b..n filed and
was pending as of June 12, 1987,
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COT?U—0151105
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guidelines for those uses as recommended
by the Health Risk Assessment Panel and
approved by the State for each
agricultural use well.
7. Cotter shall have a continuing obligation to
make future connections to the Canon City water supply when:
1) a proposed water user is entitled by all applicable laws to
install a well; 2) for a proposed drinking water well, when
the water quality in the Lincoln Park Monitoring Well exceeds
an annually averaged concentration of 0.035 mg/i or 0.1 mg/i
uranium and molybdenum, respectively; 3) for a proposed
agricultural use well, when the water quality in that well
exceeds the State—approved guidelines applicable to the
proposed use, as recommended by the Health Risk Assessment
Panel and approved by the State pursuant to Section 32; and,
4) when the proposed well is located within the Lincoln Park
Water Use Survey Area. This obligation is suspended when the
annually averaged uranium and molybdenum concentrations at the
Lincoln Park Monitoring Well a:. less than 0.035 mg/i and 0.1
mg/i, respectively. This obligation shall permanently cease
when it has been determined that the ground water quality
ob ectives at the Lincoln Park Monitoring Well have been met
pursuant to Section 14, or alternate concentration limits
(ACL’s) are established pursuant to Section 14.
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COTTU—0151106
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13.3 Recuisit. Assessment arid £riairi .eririp Activitig
Cotter shall submit to the State for review and
approval the following:
1. A plan for the Lincoln Park water use survey,
which shall include:
a. Complete list of locations to be
surveyed;
b. Proposed survey nethods;
C. QA/QC Plan for sampling and analysis;
d. Schedule;
•. Ground Water Use Survey questionnaire.
2. A written report of the results of the
survey, which shall include:
a. Locations surveyed;
b. Ground water uses:
c. water sampl. results;
d. Proposed ground water use standards;
•. Proposed guidelines for ground water
use.
3. A plan to dissuinat. the relevant
information obtained by the water use survey, which shall
include:
a. Information to be disseminated,
including ground water uses, water
—1 .25—
COTTU—O 151107
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sample results, relevant guidelines for
water use;
b. Methods for information dissemination;
c. Schedule.
4. A written annual summary en the replacement
of ground water supplies, which shall include:
a. Each location eligible, pursuant to
Paragraphs 4 and 5 of Section 13.2, to
have an alternative source of water;
b. Each such location offered a connection
to the Canon City water supply and/or an
alternative source of water;
c. The source of water for each water
supply provided and the date such supply
was made available;
d. The reason any eligible property was not
supplied with a connection to the Canon
City water supply and/or an alternat2.ve
source of water;
e. If applicable, the plan to pay
incremental costs incurred by use of a
connection to the Canon City water
supply and/or an alternative source of
water;
f. Schedule for future connection, if arty.
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COTTU—015l 108
3 0O
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13.4 Schedule
Cotter shall conduct these remedial, activities
according to the following schedule:
1. Within on. hundred fifty (150) days after the
entry of the Consent Decree by the Court, Cotter shall submit
to the State a design for a water use survey plan.
2. The State shall act upon the water use survey
plan within sixty (60) days of its receipt.
3. By no later than March 1, 1989, Cotter shall
complete the water use survey.
4. Within one hundred twenty (120) days of the
completion of the water use survey, Cotter shall submit a
written report to the State on the survey results, a plan for
information dissemination, anda schedule for water
connections, if any.
5. The State shall act upon the water—use survey
report, the plan for information dissemination and schedule
for any water connections within sixty (60) days of their
receipt.
6. Within sixty (60) days of the approval by the
State of the information diss.mination plan and schedule,
Cotter shall implement the plan.
7. Pursuant to the schedule set forth in
Paragraph 4 above, Cotter shall, as determined necessary by
—127—
CO?fU—0151109
f O
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the State, make or have made any necessary residential
Connections to the Canon City water supply.
8. Within sixty (60) days of the determination
made by the State pursuant to Paragraph 5 of Section 13.2,
Cotter shall submit a plan and schedule to replace, as
required by the State, any necessary ground water supplies
used for irrigation or stock watering with appropriate
alternative water supplies.
9. Within sixty (60) days of its receipt, the
State shall act upon the replacement plan and schedule.
10. Cotter shall implement the plan in accordance
with the approved schedule.
11. Any future residential connections to the
Canon City water supply and any future replacement of
irrigati.on or stock watering supplies shall be made or caused
to be made by Cotter according to an approved schedule for
these future activities.
12. Cotter shall submit as part of the RAP Annual
Report specified in Section 3.1, a written annual summary as
described in Paragraph 4 of Section 13.3.
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COTTIR—0 151 110
t
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14 GROUND WATER COMPLIANCE
14.1 Descri tion of Operations and Relevant
Environmental Conditions
14.1.1 Ob-iectives
This section describes how attainment of the
ground water quality objectives will be determined, anó now
alternate concentration limits (ACL’s) will be established.
14.1.2 Cotter Site Ground Water Protection
The methodology which will be employed includes
the use of ground water quality objectives to be measured at
two designated monitoring walls in Lincoln Park.
Concentration objectives have been established (see Section
14.1.3) for the two constituents of concern, uranium and
molybdenum. These concentration objectives have been
determined to be protective of human health, welfare, and
environment. These concentration objectives are predicted :
be technically feasible and as low as reasonably achievab .e.
14.1.3 Lincoln Park Ground Water quality Obiectives
The ground water quality objectives established
for uranium and molybdenum at the Lincoln Park Monitoring Well
(located pursuant to Paragraph 1 of Section 14.2) are not c e
than the average concentration of 0.035 mg/liter of urani n
and 0.1 mg/liter of molybdenum, calculated using the method
described below. The uranium objective is the same as the
drinking water recommendation for uranium by the National
Academy of Science and the molybdenum objective is the
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COTTIB0151U
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adjusted average daily intake (AADI) v lua proposed by the
U.S. Environmental Protection Agency.
14.1.4 Testina and Analysis
14.1.4.1 Transit lime
1. Temporary cessation of SCS hydrologic barrier
operation shall not occur until cessation of operations of
each of:
a. Flushing operations at the Old Tailings
Ponds Area;
b. The SCS Dam to DeWeese Dye Ditch
flushing operation.
With respect to the temporary cessation of SCS
hydrologic barrier operation described in Paragraph 2 of
Section 9.2, the transit time for ground water to flow from
behind the SCS Dam to Lincoln Park Monitoring Well shall be
determined by the following procedure.
2. Once the SCS hydrologic barrier operations
have ceased, a linear regression procedure as described in
Section 14.1.4.2 shall be used to determin, when there is no
longer a significant upward trend in the flux of both uranii.im
and molybdenum at the Lincoln Park Monitoring Well. A measure
of flux shall be calculated according to the following
procedure or other State approved procedure:
a. Cotter shall propose locations for two
to four piezometers approximately 300
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COTTU—0151112
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feet apart and each approximately 300
feet from the two wells comprising the
Lincoln Park Monitoring Well, so that
the piezometers and the Lincoln Park
Monitoring Well form an approximate
equilateral triangle. To the extent
possible, the piezoineters and the
Lincoln Park Monitoring Wall shall also
be located so that water levels in each
are not unduly affected by pu page of
nearby wells.
b. Following approval by the State, Cotter
shall drill the piezometers to a depth
great enough to penetrate to the Ver ie o
Formation, so that the depth to the
contact between the Verme o and
overlying alluvial deposits is known.
The wells shall then be plugged back t
th. contact. The piezometers shall be
constructed using casing slotted
throughou.t the alluvial material, except
that ths upper 5 feet of each well shall
be grouted. Locations of the wells
shall be determined by a qualified
surveyor, with th. elevation of the
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COTTIR—0151113
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measuring point determined to the
nearest one-hundredth of a foot.
c. At the same time that water samples are
collected from the Lincoln Park
Monitoring Well, Cotter shall also
measure depth to water in the Monitoring
Well and the piezometers. In the
Monitoring Well, depth to water shall be
measured prior to collecting the sample
or purging the well.
d. The hydraulic gradient at the time of
sampling shall be calculated from the
hydraulic heads (relative to sea level),
and the locations of the wells and
piezomsters.
e. The average saturated thickness in the
vicinity of the Lincoln Park Monitoring
Well shall be calculated by averaging
the saturated thickness of alluvial
materials (estimated by hydraulic head
minus elevation of the Vermejo—Alluviai.
contact) for each of the wells and
pi.zometers.
f. The measures of uranium and molybdenurn
flux shall be calculated by multiply.ng
—132—
COTTfl—0151114
3/0 t
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the concentration of each by the average
saturated thickness and the magnitude of
the hydraulic gradient.
14.1.4.2 Lincoln Park Cotn liance Testina
Compliance testing (i.e., comparison to numerical
objectives for uranium and molybdenum) shall be performed
using the data from each of the two wells comprising the
Lincoln Park Monitoring We].]. separately. The monthly data for
the most recent three—year period after the measures of flux
begin to increase shall be used in the statistical analysis.
When the slopes of both regression lines (time being the
independent variable and fluxes of uranium and molybdenum
being the dependent variables) are no longer greater than zero
(a one—tailed t:tsst at a 95 percent confidence level) at one
of the two wells comprising the Lincoln Park Monitoring Well,
the water from behind the SCS Dam shall be determined to have
reached the Lincoln Park Monitoring Well and comparison of
water quality against the objectives for uranium and
molybdenum shall be performed. Cencentrations of these
constituents measured in samples collected over the last 24
months of the three year period shall be averaged, and the
respective average compared against the numerical objective.
!n the event that the averages of both molybdenum and uraniunt
are equal to or less than the respective objectives in both of
the two wells comprising the L.Lncoln Park Monitoring Well,
—133—
COTTIR—0151115
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approval for permanent cessation of Old Tailings Ponds Area
flushing and SCS hydrologic barrier operations pursuant to
Sections 8.2 and 9.2, respectively, shall be given by the
State. In the event that either averag. is greater than its
respective objective, in either well, these remedial measures
shall be restarted, and the model which formed the basis for
granting temporary cessation of remedial activities shall be
corrected. Permanent cessation of the Old Tailings Pond Area
flushing and SCS hydrologic barrier operations shall occur
when either the ground water quality objectives of Section
14.1.3 are permanently achieved pursuant to the requirements
of Paragraph 4.a. of Section 8.2 and Paragraph 3.a. of Section
9.2 respectively, or with respect to the operation of the Old
Tailings Ponds Area flushing the reasonable technological
limits are met as described in Paragraph 4.b. of Section 8.2
and with respect to the operation of the SCS hydrologic
barrier the requirements of Paragraph 3.b. of Section 9.2 are
satisfied.
14.1.5 40 C.F.R. 192. Sub art D Com 1iance
The RAP described in this document is designed to
achievs applicabl, ground water protection requirements of 40
C.F.R. 3.92, Subpart 0, as it incorporates and modifies
specific sections of 40 C.F.R. 264, Subpart F.
Notwithstanding any other provision of this RAP, Cotter shai.
comply with 40 C.F.R. Part 192, Subpart D, as it incorporates
—13 4—
COfTIR—01511 16
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and modifies specific sections of 40 C.F.R. Part 264, Subpart
F, as described in this Section 14 and comply with Section
121, including, but not limited to, Section 121(d) (2) (B) (ii)
of CERCLA.
At the Cotter site, these requirements are
described below:
1. The pround water rotection standard is as
set forth in 40 C.F.R. 192.32 (a)(2) as it incorporates and
modifies 40 C.F.R. 264.92.
2. The list of hazardous constituents is
established in 40 C.F.R. 192.32 (a)(2)(i) which incorporates
and modifies 40 C.F.R. 264.93. 40 C.F.R. 192.32 (a) (2) (i)
adds uranium and molybdenum to the list of hazardous
constituents identified in Appendix VIII of 40 C.F.R. Part
261.
3. The concentration limits are provided in 40
C.P.R. 192.32 (a)(2)(ii) as it incorporates and modifies 40
C.F.R. 264.94. Table A of 40 C.F.R. 192, Subpart D, adds
concentration limits for combined radium-226 and -228 (5
pCi/i) and gross alpha—particle activity (excluding radon and
uranium) (15 pCi/i) to the concentration limits established n
40 C.F.R. 264.94, Tabl. 1. The concentration of a hazardous
constituent:
a. Must not exceed the background level of
that constituent in the ground water at
the time that limit is specified; or
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COTTfl—0151117
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b. For any of the constituents listed in
Table 2. of 40 C.F.R. 264.94 must not
exceed the respective value given in
that Table if the background level of
the constituent is below the value given
in Table 1; or
c. Must not exceed an
established by the
below.
4. The coint of coin liance is as set forth in 40
C.F.R. 264.95. Specifically, at the Cotter site the
compliance points shall be monitoring wells located in the
uppermost aquifer which is contained in the Quaterrtary Terrace
Deposits and the Poison Canyon Formation. The compliance
point wells shall be located along a vertical surface
hydraulically dewngradient of the main impoundment near the
toe of the impourtdinent and along the downgradient boundary of
the Old Tailings Ponds Area. Th. wells shall be located in
the area shown on Figure 14—1. The distribution of these
wells shall be proposed by Cotter. Their open interval shall
not exceed 30 f t in length and the vertical distribution of
monitored zones shall extend from the water table to the
unweathered surface of the Poison Canyon formation. These
wells shall be of a design, construction, and specific
location approved by the State.
alternate limit
State under item 7
CO1TTfl O 151118
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5. The comDliance osriod is th. period of time
during which the compliance standard applies. The compliance
period is as set forth in 40 C.F.R. 264.96.
6. The around water com liance monitorina
roaram is described in 40 C.F.R. 264.99 and 40 C.F.R. 264.100
(d).
7. The process for settina a1ter ative
concentration limits to be applied at compliance points is as
set forth in 40 C.F.R. 192.32(a) (2) (v) which incorporates 40
C.F.R. 264.94(b) and and as set forth Section 121 of
the Comprehensive Environmental Response, Compensation and
Liability Act of 1980 (CERCLA), as amended by the Superfund
Amendments and Reauthorization Act of 1986 (SARA).
a. In establishing ACL’s the following
factors will be considered:
i. Potential adverse effects n
ground water quality, considering:
a) The physical and chemical
characteristics of the waste in
th. regulated unit, including its
potential. for migration;
b) The hydrogeological
characteristics of the facility
and surrounding land;
—137—
COTTRP—0151 119
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C) The quantity of ground water
and the direction of ground water
flow;
d) The proximity and withdrawal
rates of ground water users;
e) The current and future uses of
ground water in the area;
f) The existing quality of ground
water, including other sources of
contamination and their cumulative
impact on the ground water
quality;
g) The potential for health risks
caused by human exposure to waste
constituents;
h) The potential darnage to
wildlife, crops, vegetation, and
physical structures caused by
exposure to waste constituents;
i) The persistence and permanence
of the potential adverse effects;
and
ii. Potential adverse effects on
hydraulically connected surface
water quality, considering:
—138—
COTTIR—O 151120
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a) The volum, and physical and
chemical characteristics of the
waste in the regulated unit;
b) The hydrogeologica].
characteristics of the facility
and surrounding land;
C) The quantity and quality of
ground water and the direction of
the ground water flow:
d) The patterns of rainfall in
the region;
e) The proximity of the regulated
unit to surface waters;
f) The current and future uses of
surface waters in the area and any
water quality standards
established for these surface
waters;
g) The existing quality of
surface water, including other
sources of contamination and
cumulative impact on surface water
quality;
h) The potential for health risks
caused by human exposure to waste
constituents;
—139—
COTTI 1—0151121
I ?
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i) The potential damage to
wildlife, crops, vegetation and
physical structures caused by
exposure to waste constituents;
and
j) The persistence and permanence
of the potential adverse effects.
b. An ACL shall be established through
either:
i. Considering the foregoing issues
(a.i.(a—i)) and (a.ii.(a—j)) and
the requirements of Section 121 of
CERCLA, as amended by SARA, an ACL
will be set at each compliance
point monitoring well, as
necessary, when the Lincoln Park
Monitoring Well. ground water
quality objectives as set forth in
Section 14.1.3 have been achieved,
and operation of the withdrawal
well system has ceased pursuant to
Paragraph 4 of Section 4.2. The
ACL for each compliance point well
shall be the constituent
concsntration in that compliance
—140—
COTTU—016 1122
jL/
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point well, as measured quarterly
over a two year period; or
ii. Considering the foregoing issues
(a.i.(a—i)) and a.ii.(a—j)) and
the requirements of Section 121 of
CERCL&, as amended by SARA, an ACL
will be set at each compliance
point well, as necessary, when the
Stats approves Cotter’s
application demonstrating that the
reasonable technological limits of
the remedial, activities have been
reached pursuant to Paragraph 4.b.
of Section 8.2, and operations of
the withdrawal well system has
ceased pursuant to Paragraph 4 of
Section 4.2. The ACL for each
compliance point well shall be the
constituent concentration in that
compliance point well as measured
quarterly ovsr a two year period.
8. The corrective action roaram required by 40
C.F.R. 192.33 as it incorporates 40 C.F.R. 264.100 for the
Cotter site is as set forth in the RAP, until the completion
of RAP ground water remedial. activities. If an exceedance of
—141—
COTTU—0151 123
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S
concentration limits occurs after RAP ground water remedial
activities are completed, a corrective action program pursuant
to 40 C.F.R. 192.33 shall be implemented.
14.2 Remedial Activities
The purpose of the remedial activities is to
establish the Lincoln Park Monitoring Well, to establish the
40 C.F.R. 192 Compliance Point Wells, and to assess the
effectiveness of the remedial ground water actions described
in Sections 4 through 13.
Cotter shall perform the following remedial
activities:
1. Cotter shall propose either two (2) existing
wells within the southwest one-quarter (SW 1/4) of the
southwest one—quarter (SW 1/4) of Section three (3) or two (2)
new wells within the same area or one existing wall and one
new well within the same area to be the Lix coln Park
Monitoring Well. The new wells shall be constructed to Class
A well specifications. The monitoring wells shall be located
downgradient from the DeWeese Dye Ditch in or near the Sand
Creek channel, and completed between depths of the estimated
water table at its highest, and 40 feet below the estimated
water tabl. at its highest, and shall be capable of being
pumped at 10 qpm for one hour, prior to installation of the
permanent pump.
—142—
COTTU0l 61124
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Cotter shall implement a plan for maintenance and
monitoring of the wells. If new wells are drilled to be the
Lincoln Park Monitoring Well, Cotter shall collect monthly
water samples from the monitoring wells. Each sample shall be
analyzed for the concentrations of uranium and molybdenum.
Cotter shall collect water samples monthly for analysis and
maintain the well until remedial activities have been
completed at the site pursuant to this RAP. Together, these
wells shall be designated, and collectively referred to
herein, as the “Lincoln Park Monitoring Well.”
2. Cotter shall install compliance monitoring
wells in the area described in Section 14.1.5, item 4 above.
These wells shall be constructed to Class A well
specifications (see Section 3.2.1) and the construction
requirements of 40 C.F.R. 264.97(c).
Wells shall also be installed or existing wells
designated which will satisfy the requirements of background
monitoring set forth in 40 C.F.R. 264.97(a) (1) and (g)(2).
14.3 Re uisita Assessments and Submittals
Cotter shall prepare and submit to the State for
review and approval ths following:
1. 1 proposal for existing monitoring wells
and/or new monitoring wells to be the Lincoln Park Monitoring
Well, which shall include:
a. The location of the wells;
—143—
COTTU—OlS 1125
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b. The well completion data of existing
wells if the use of existing wells is
proposed;
c. The design drawings arid construction
specifications for new wells;
d. QA/QC Plan;
a. •A plan for monitoring and maintenance.
2. A written final construction report for new
wells, which shall include:
a. As-built drawings;
b. Explanation of and response to
unexpected conditions and problems;
c. Summary of construction and quality
assurance evaluations;
3. As a part of the RAP Annual Report specified
in Section 3.1, a written annual summary of the analysis of
the water samples and the annual average of the analysis of
the water samples.
4. A plan for the on—site 40 C.F.R. 192
compliance point wells, which shall include:
a. The location of the wells;
b. The well completion data of an existing
well, if an existing well is proposed;
c. The design drawings and construction
specifications for new well(s); and
—144—
COTTU—015 1126
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d. The list of constituents to be measured
in those wells in accordance with 40
C.F.R. 264.99.
a. Identification of the background well(s)
as required by 40 C.F.R. 264.97.
14.4 Schedule
Cotter shall design and conduct these remedial
activities according to the following schedule:
1. Within sixty (60) days following the entry of
a Consent Decree by the Court, Cotter shall submit a plan for
the proposed Lincoln Park Monitoring Well.
2. The State shall act upon the proposal within
sixty (60) days of its receipt.
3. Cotter shall start and complete construction
of a new well within one hundred and eighty (180) days of the
approval by the State of the proposal.
4. Cotter shall submit a final construction
report to the State within on. hundred twenty (120) days after
the completion of new wells.
5. The State shall act upon the final
construction report for new wells within on. hundred twenty
(120) days of its receipt.
6. As a part of the RAP Annual Report required
pursuant to Section 3.1, Cotter shall submit to the State a
written annual summary of the analysis of water samples and
the annual average of the analysis of the water samples.
—1.4 5—
CO?TIl015h’ 2 ’
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7. Cotter shall submit a proposed plan,
including location, an installation schedule, arid a QA/QC Plan
for the compliance monitoring wells required pursuant to
Paragraph 4 of Section 14.3 to the State within one hundred
twenty (120) days of the completion of Old Tailings Ponds Area
soil removal pursuant to Paragraph 3.a. of Section 8.2.
8. The State shall act upon th. plan within
sixty (60) days of its receipt.
9. Cotter shall implement the approved plan and
start compliance monitoring as soon as possible pursuant to
the approved schedule set forth therein and in any event
within one (1) year of completion of Old Tailings Ponds Area
soil removal as provided in Paragraph 8 of Section 14.4.
10. The State shall act upon the proposal witlu.n
sixty (60) days of its receipt.
—14 6—
COTTER—O 15 1128
V
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15 GROUND WATER MONITORING
15.]. Remedial Activities
The pi.trpose of monitoring is to provide
information (1) on which to base decisions regarding changes
to remedial activities, (2) with which to verify if
performance criteria are being met, (3) with which to measure
the effectiveness of remediation, (4) with which to determi.ne
if regulatory requirements are being met, and (5) to meet
regulatory requirements pertaining to aonitoring7 specifical.y
to satisfy the ground water monitoring requirements of
Section 14.
Three classes of wells are required. Class A
wells shall be constructed in a manner to comply with the
specifications listed in Section 3.2.1.1. New Class B welts
shall be completed as described in Section 3.2.1.2. and new
piezometers shall be constructed as described in Section
3.2.1.3.
Cotter shall perform the following remedial
activities:
3.. Install and/or operate the monitoring wells
and pi.zometsrs listed in Table 15—1. Additional monitoring
wells may also be required under contingent actions, part of
proposals for other remedial actions, or regulatory
compliance. Proposals for their locations, construction, and
—147—
COTTER—0151129
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completion shall be inc1 ded in the pertinent planning
documents.
2. Upon approval by the State, Cotter shall
construct and complete the monitoring wells and piezometers
that do not currently exist as required by Table 15-1 and
pertinent planning documents.
3. Cotter shall sample the wells and piezometers
for the constituents listed in Table 15—1, at the intervals
specified in that Table. This monitoring program shall
supersede all previous ground water quality monitoring
requirements specified in Cotter’s radioactive materials
license. Approximate locations are shown on Figure 15—1.
Unless specified otherwise in this document, results of
measurements and analyses shall be presented annually to the
State as part of the RAP Annual Report specified in
Section 3.1.
—148—
COTTEI—0151130
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TABLE 15-].
GROUND WATER MONITORING PROGRAM
ON-SIT! MONITORING
a&b
(if flow permits)
(if flow permits)
313
Withdrawal
We].]. Piezometers
Sec. 9/16 piezometers
SCS berm piezometers
329
330
331
339
334
336
338
714
715
716
335
312
MONTNLY
A,C,F(lst year)
A,C,F(].st year)
A,C,F(lst year)
A,C,F(lst year)
A,C,F(lst year)
A, C, F
A,C ,F
Water Levels
Water Levels
Water Levels
Water Levels
Water Levels
A,P’(during flush)
A,F(during flush)
A,F(durthg flush)
QUARTERLY AN NTJAL
A,3,C,F
A,3,C,F
A, 3, C, F
A,3,C,F
A, 3,C,F
A, B,C,F
A,3,C, F
A, B,C, F
A,B,C, F
A, B,C,F
A, B,C, F
A, B,C,F
A, B,C, F
A, 8,C, F
A ,3,C, F
A, B,C, F
710
71].
712
001
002
003
004
005
701
703
333
A,F
A,F
A,F
A,C,F
A, C, F
A ,C,F
A,C,F
A, C, F
A,F
A,F
A,T
A,F
A,F
A,F
A,F
A,F(see note)
A,F(see note)
A,F
A,?
A,?
A, 8,C, F
A, B,C, F
A, B,C, F
A,3,C, F
A, B,C, F
, , ,—
I)
—1.49—
COTTU-01 51131
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TABLE 15-1 (CONTINUED)
GROUND WATER MONITORING PROGRAM
OFF-SITE MONITORING
MONTI!LY
119
137
138
139
140
141
143
144
006
007
008
010
011
114
122
129
130
Lincoln Park
Monitoring Well
A,C,F(lst year)
A,C,F(lst year)
A,C,F(lst year)
A,C,F(lst year)
A,C,F(lst year)
4.14 A,?
4.14
4.14,A,F
4.14
4.14
4.14
4.14
4.14,A,F
A,F
A,C,F
A,C,F
A,C,F
A,C,F
A, F
A,F
A,?
A,?
A,B,C, F
A, B, C, F
A,B,C,F
A, B,C, F
A,B,C,F
A, 8,C, F
A,B,C, F
A, B, C, F
A,B,C,F
A,B,C, F
A,B,C, F
A,B,C,F
A,B,C,F
, , p.
AF(during flush)
A,F(during flush)
OUARTERLY ANNUAL
U,Mo -
—150—
COTTU—0151 132
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TABLE 15-i. (CONTINUED)
GROUND WATER MONITORING PROGRAM
PATHWAY MONITORING
MONTHLY QUARTERLY ANNUAL
Northwest
O9 A,C,F(lst year) A,C,F
014 Mo, Water Levels A,C,F
325 U,Mo,F A,B,C,F
337 U,No,F A,B,C,F
015 Mo, Water Levels A,C,F
342 A,F A,B,C,F
Piezometers Water Levels
Northeast
016 Mo, Water Levels
017 Mo, Water Levels
Piezometers Water Levels
• Mine Shaft
018 Mo(for 1st year) Mo
324 Mo(fcr 1st year) Mo
SURFACE WATER
526 TJ,Mo,F
NOTES:
1. The proposal for the Old Tailings Ponds Area flushing
program will include provisions for monitoring the ground
water system around the perimeter of th. area being flushed.
This proposal shall include wells sufficient for detecting the
movement of water from the area being flushed.
2. Wells 312 and 313 will be sampled quarterly for the
parameters in lists A and F. This sampling shall continue
throughout a period of three years following successful
drilling, completion, and development of Class A wells 004 a
and 004 b. Wells 004 a and 004 b will be sampled according t
the schedul. indicated in the above table.
3. “During flush” refers to the flush described in Section
12.2.1.
—151—
COTTU0151133
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EXPLANATION OF DESIGNATORS
Des ignator Constituents
A Mo,U
B Al, Cd, Cu, Fe, Ni, Pb, Mn, V, Zn
C SO, HCO 3 , C0 3 , C l, NO 3 , NM, Na, Ca, K, Mg
F Temp, pH, SpC, DTW, Flow (Measured in the
Field); TDS, pH, SpC, Alkalinity (Measured in
the Lab)
4.14 U, Ra—226, Th—230, Pb—210, Po—210
—152—
COTTU—0151 134
3 o
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15.2 Recuisite Assessments and Engineering Activities
1. Cotter shall submit to the State a detailed
monitoring plan which includes an installation schedule for
new wells and piezometers.
2. Cotter shall submit to the State an
appropriate QA/QC Plan for this monitoring program.
3. Cotter shall submit a final construction
report for any new wells or piezometers constructed pursuant
to Section 15.1, including well, logs.
4. Cotter shall submit, unless otherwise
specified in this document, results of monitoring measurements
and analyses in the RAP Annual Report.
15.3 Schedule
1. Cotter shall submit a proposed detailed
monitoring plan, including installation schedule for new wells
and piezotneters, and a QA/QC Plan to the State within one
hundred twenty (120) days of entry of the Consent Decree by
the Court.
2. The State shall act on the plans within sixty
(60) days of receipt.
3. Cotter shall implement the approved plans
pursuant to th. approved schedule.
4. Cotter shall submit the final construction
within one hundred twenty (120) days of completing
construction of new wells and piezometers.
—153—
COTTU—O 151136
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5. The State shall act upon this report within
one hundred twenty (120) days.
6. Cotter shall submit the monitoring results
and analyses annually as part of the RAP Annual Report
specified in Section 3.1.
7. The State shall act upon the Annual Report
within one hundred twenty (120) days of its receipt.
—154—
COTTIR—015113’7
3;?
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16 MAIN IMPOUNDMENT
16.1 Descriotion of Ooerations and Relevant
Environmental Conditions
The main impoundment is a potential source of wind
dispersed tailings particulates. Controlling exposure of dry
tailings beaches in the main impoundment is addressed in this
Section.
16.2 Remedial Activities
The purpose of these remedial activities is to
effectively minimize and mitigate the main impoundment as a
source of wind dispersed particulates.
Cotter shall perform the following remedial
activities:
1. Cotter shall manage the main impoundment to:
a. Minimize the area of the tailings
beaches;
b. Control the drying of the ta .lings
beaches, as necessary, to minimize and
mitigat. particulate dispersion.
16.3 Reauisite Assessments and Eriaineerin Activities
Cotter shall prepare and submit to the State the
following:
1. A written annual summary on the
implementation of this remedial activity to effectively
minimize and mitigat. the main impoundment as a potential
—155—
COTTER—0151l 38
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source of wind dispersed particuiatss, which shall include, as
appropriate:
a. Summary description of results of
activities; and,
b. Explanation of unexpected conditions and
responses to any problems which prevent
effective minimization and mitigation of
the main impoundment as a potential
source of wind dispersed particulates.
16.4 Schedule
Cotter shall conduct these remedial activities
according to the followinq schedule:
1. Cotter shall implement this remedial activity
thirty (30) days after the enti y of the Consent Decree by the
Court.
2. Cotter shall submit, as part of the RAP
Annual Report specified in Section 3.1., a written annual
summary as described in Section 16.3.
3. The Stats shall act upon the Annual Report
within one hundred twenty (120) days of its receipt.
—156—
CO?TU0l 51 139
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17 OLD TAILINGS PONDS AREA
17.1 Descri tiorI of ODerations and Relevant
Environmental Condit ions
The Old Tailings Ponds Area is a potential source
of wind dispersed particulates. Controlling particulate
emissions from the Old Tailings Ponds Area is addressed in
this Section.
17.2 Remedial Activities
The purpose of these remedial activities is to
effectively minimize and mitigate the Old Tailings Ponds Area
as a potential source of wind dispersed particulates.
Cotter shall perform the following remedial
activities.
1. Cotter shall revegetate or cover, as
appropriate, the Old Tailings Ponds Area to effectively
minimize and mitigate particulate dispersion.
2. In those areas where the operation of the
production injection and extraction ground water flushing
program (see Section 8) prevents revegetation or in those
areas where the revegetation program is not successful, Cot:er
shall, as appropriate, apply either a surface cover, such as
gravel, surfactant, tactif jar or mulch, or wet the area t
effectively minimize and mitigate particulate dispersion.
17.3 Reauisita Assessments and Enaineerina Activit .es
Cotter shall prepare and si.thmit to the State f:r
review and approval the following:
—157—
co’r’ru—01 5114 °
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1. A plan to revegatate or cover the Old
Tailings Ponds Area, which shall include:
For areas to be revegetated:
a. Area to be revegetated:
b. Species to be planted;
c. Seeding and/or stocking rates:
d. Seed bed preparation;
e. Methods of planting;
f. Mulching and fertilizing specifications;
g. A monitoring and maintenance plan for
the vegetation;
h. Proposed revegetatiori success standards,
including criteria to be measured, such
as perc&nt of cover and rate of
production measurement methods, and
seasonal effectiveness;
i. Schedule.
For areas sub ect to alternate surface cover or
wetting:
a. Description and purpose of activiti.es;
b. Schedule;
c. Operations, inspection and maintenance
plan;
d. Discussion of reasons for use of
alternate surface cover or wetting
instead of revegetation;
—158—
COTTU—0151141
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2. A written report on the completion of the
plan required by Paragraph 1 of this Section, which shall
include:
a. Description of activities;
b. Explanation of and response to
unexpected conditions and problems;
c. Discussion of actual performance and a
comparison to the success standards.
3. A plan to recontour and to establish a
self-regenerating vegetation cover in the Old Tailings Ponds
Area at mill closure and site reclamation pursuant to the
approved final reclamation plan (which is not part of this
RAP), which shall include:
a. Description and purpose of activities;
b. QA/QC Plan for contouring operation;
c. Species to be planted;
d. Methods of planting;
e. Schedule;
f. Proposed revegetation success standards,
including criteria to be measured, such
as percent of cover and rate of
production and measurement methods.
4. A written annual activities su aary regarding
the plan required by Paragraph 1 of this Section, which shall
include:
—159—
COTTRR—O 151142
-------
a. Description and results of activities;
b. Explanation of and response to
unexpected conditions and problems;
c. Proposed modifications to the plan to
effectively minimize and mitigate the
Old Tailings Ponds Area as a potential
source of wind dispersed particulates.
5. A written final report on the implementation
and completion of the plan required by Paragraph 3 of this
Section, which shall include:
a. Description of activities and results;
b. Explanation of and response to
unexpected conditions and problems;
c. Quality ssurance and quality control
evaluation.
17.4 Schsdule
Cotter shall conduct these remedial, activities
according to the following schedule:
1. Within ninety (90) days of the entry of a
Consent Decree by the Court, Cotter shall submit a plan
pursuant to Paragraph 3. of Section 17.3.
2. The State shall act upon the plan within
ninety (90) days of receipt.
3. Cotter shall implement the approved plan
required by Paragraph 1 of Section 17.3 pursuant to the
—160—
coTfla015h 343
-------
approved schedule, but in any case no later than one (2.) year
after State approval.
4. cotter shall submit the written completion
report as required as Paragraph 2 of Section 17.3 within one
hundred twenty (120) days of completion of the plan.
5. The State shall act upon the written
completion report within sixty (60) days of its receipt.
6. Cotter shall submit, as part of the RAP
Annual Report specified in Section 3.1, a written annual
activities summary.
7. The State shall act upon the annual report
within one hundred twenty (120) days of its receipt.
8. As an element of site closure, Cotter shall
submit a plan purs3lant to Paragraph 3 of Section 17.3.
9. The State shall act upon the plan within
ninety (90) days of receipt.
10. Cotter shall implement the approved plan for
final recontouring and revegetating the Old Tailings Ponds
Area pursuant to thS approved schedule.
11. Cotter shall submit a written final report
pursuant to Paragraph 5 of Section 17.3 within one hundred
twenty (120) days of completion of final contouring arid
establishment of self-regenerating vegetation of the Old
Tailings Ponds Area.
12. The State shall act upon the written final
report within one hundred twenty (120) days after its rece .;t.
—161—
I , —
CoTTIl—0151144
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18 ORE HANDLING AND ORE STOCKPILES
18.1 Descri tiOfl of O erations and Relevant
Environmental Conditions
The uranium ore at the site is presently
stockpiled and handled in two areas. One, the ore handling
area, is immediately north of the mill and is used to feed the
ore hopper of the mill. The other is approximately 800 to
1000 feet northeast of the mill and is used to inventory or
stockpile ore received from the mines, prior to the ore’s
transport to the ore handling area. These stockpiles and
handling areas are potential sources of wind dispersed
particulates. Ore stockpiles are also a potential source of
ground and surface water impacts.
18.2 Remedial Activitie
The purpose of these remedial activities is to
effectively minimize and mitigate the uranium ore stockpi.les
and handling areas as potential sources of wind dispersed
particulates and potential ground water and surface water
impacts.
Cotter shall perform the following remedial
activities:
1. Cotter shall construct and maintain compacted
clay ore pads with runoff water control in accordance with the
proposed design of th. compacted clay pads, as previously
submitted by Cotter to the Colorado Department of Health as
part of its Engineering Report and Design Specifications f::
—162—
COTTER—0151145 (0
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Water and Waste Management Plan - Part 1 at Canon City Mill,
Fremont County, Colorado, ” dated June 29, 1984, Volumes I and
II. Ore stockpiles shall be maintained and ore handling shall
take place only in those areas where these ore pads are
constructed and maintained.
2. The ore stockpiles shall be sub:Ject to
surface wetting, as necessary, to effectively minimize and
mitigate them as a potential source of wind dispersed
particulates. The use of water for dust control will not
contaminate soils, ground water or surface water.
3. Ore handling areas shall not be used to
stockpile ore unless the stockpiles in the ore handling areas
are subject to wetting to effectively minimize and mitigate
them as a potential source of wind dispersed particulates.
4. The volume, area, and moisture content of the
ore in the ore handling process shall be managed to
effectively minimize and mitigate it as a potential source of
wind dispersed particulates.
18.3 Recuisite Assessments and £npinaerina Activities
Cotter shall prepare and submit to the State for
review and approval the fo].lowing:
1. A written final construction report, which
shall include:
a. Description of activities and results;
COTTU015ll 46
-------
b. Explanation of and response to
unexpected conditions and problems;
c. Quality assurance and quality control
evaluation;
d. Plan for management of these stockpiles
to minimize dust generation.
2. A written annual summary on the
implementation of the plan to effectively minimize and
mitigate the ore stockpiles and ore handling areas as
potential sources of wind dispersed particulates and potential
ground and surface water impacts, which shall include:
a. Description and results of activities,
if any;
b. Explanation of and response to
unexpected conditions and problems;
c. Proposed modifications to the plan ta
effectively minimize and mitigate the
uranium ore stockpiles and ore handling
areas as a potential source of wind
dispersed particulates and ground and
surfac. water impacts.
18.4
Cotter shall conduct these remedial activities
according to the following schedule:
—164—
COTTU—O 15 1147
-------
A
1. Cotter shall complete the construction of the
compacted clay pads arid conduct all ore handling activities ott
the clay pads within one (1) year after entry of a Consent
Decree by the Court.
2. Cotter shall. submit a written final
construction report within one hundred twenty (120) days after
completion of construction of the clay pads.
3. The State shall act upon the written final
construction report within one hundred twenty (120) days after
its receipt.
4. Cotter shall implement the remedial
activities required by Paragraphs 2, 3 and 4 of Section 18.2
within thirty (30) days of receipt of the State’s approval of
the final construction report.
5. Cotter shall submit, as part of the RAP
Annual Report specified in Section 3.1 a written annual
summary as described in Paragraph 2 of Section 18.3.
6. The State shall act upon the Annual Report
within one hundred twenty (120) days of its receipt.
COT TIR—O 151148
—165—
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19 CATALYST PILE
19.1 Descrthtiort of 0 erations and Relevant
Environmental Conditions
me catalyst pile is comprised of approximately
500 tons of material.
19.2 Remedial Activities
The purpose of these remedial activities is to
dispose of the catalyst material at a permitted or interim
status hazardous waste facility.
Cotter shall perform the following remedial
activities:
1. Cotter shall remove and dispose of the
catalyst material at a permitted or interim status hazardous
waste facility. Cotter shall document such removal in
accordance with applicable law.
2. Cotter shall remove the hypalon liner and
dispose of it at a permitted or interim status hazardous waste
facility or demonstrate that the hypalon liner is not a
characteristic hazardous waste.
3. Cotter shall verify catalyst removal by soil
sampling. Five soil samples collected from the area beneath
the Mypalon liner to a depth of three (3) inches shall be
composited into on. sample. Th. sample location shall be
randomly selected using a grid pattern comprised of ten (10)
squares. At least one sample shall be collected from an area
over]ain by catalyst. The composite sample shall be subjected
—166—
COT?IR—0151 149
-------
to the E.P. toxicity test procedure, as set forth in 40 C.F.R.
261.24, and analyzed only for cadmium. If this laboratory
test result exceeds 1.0 mg/i of cadmium, Cotter shall conduct
further sampling of this area pursuant to “Test Methods for
the Evaluation of Solid Waste, Physical/Chemical Methods”
(Publication No. SW—846), as codified in 40 C.F.R. 260.11,
dated July 1, 1986. The samples collected and analyzed
pursuant to the foregoing procedure shall be subjected to the
EP Toxicity test procedure and analyzed only for cadmium, and
these results shall be used to determin, the volume of soil
underlying the Hypalon liner requiring off-site disposal, if
any.
19.3 Recuisite Assessments and Engineering Activities
Cotter shall prepare and submit to the State f r
review and approval the following:
1. A plan for removal and disposal of the
catalyst material which shall include:
a. Description of activities;
b. Method of removal and disposal of the
material:
c. Schedule.
2. A written final report on the removal arid
disposal of the catalyst material and the results of testing
conducted pursuant to Paragraph 3 of Section 19.2, which sha .
include:
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COTTU—015 1150
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a. Description of activities and results;
b. Quantity of material removed and the
location of disposal;
c. Explanation of and response to
unexpected conditions and problems;
d. Test results, including quality
assurance and quality control
evaluations.
19.4 Schedule
Cotter shall conduct these remedial activities
according to the following schedule;
1. Cotter shall submit a proposed plan for the
removal and disposal of the ca4lyst to the State within sixty
(60) days of entry by the Court of the Consent Decree.
2. The State shall act upon the proposed plar%
within sixty (60) days of its receipt.
3. Cotter shall implement the disposal plan i
accordance with the approved schedule.
4. Cotter shall submit a written final report
within thirty (30) days of completion of removal and disposal
of the catalyst material and completion of the test descr.bed
in Paragraph 3 of Section 19.2.
5. The State shall act upon the final removal
report within sixty (60) days of its receipt.
• —168—
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20 IELLOWCAKE DRYER
20.1 Descri tion of O eratjoyis and Relevant
Environmental Conditions
The yallowcake dryer stack is a potential source
of wind dispersed particulates.
20.2 Remedial Activities
The purpose of these remedial activities is to
effectively minimize and mitigate the yeilowcaks dryer stack
as a potential source of wind dispersed particulates.
Cotter shall perform the following remedial
activities:
1. Cotter shall submit either a r port to
substantiate that current emission control technology is best
available technology or a proposal for application of best
available technology at the yellowcaka dryer stack.
2. The yellowcake dryer shall be operated in
accord with Colorado Radioactive Materials License 369—015 ar.d
the Colorado Rules and Regulations Pertaining to Radiation
Control.
20.3 Recuisite Assessments and Engineering Activities
Cotter shall prepare and submit to the State for
review and approval the following:
1. A report to substantiate that the technology
presently used on the yelloucake dryer is the best available,
which shall include:
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CO?7fl015U 52
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a. Description of available technology and
its effectiveness;
b. Description of technology presently used
and its effectiveness;
c. Discussion of methods to maximize
effectiveness of technology presently in
use.
2. As determined by the State, if the best
available technology is not in use, a plan to install, operate
and maintain the best available technology, which shall
include;
a. Description of available technology and
its effectiveness;
b. Description of technology to be used ar.d
its effectiveness;
C. QA/QC Plan;
d. Schedule;
e. Operations and maintenance plan.
3. A written final construction report if new
technology is installed, which shall include:
a. Accurat. as built drawings;
b. Explanation of and response to
unexpected conditions and problems;
c. Quality assurance and quality central
evaluations;
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COTThR—0151153
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d. Operations and maintenance plan.
4. A written annual summary, which shall
include:
a. Description and results of activities;
b. Explanation of and response to
unexpected conditions and problems;
c. Comparison of actual performance of the
yellowcake dryer to the best available
technology;
d. Quality assurance and quality control
evaluations;
e. Proposed xnodi.fi.cations to the plan to
effectively nu.nimize and mitigate the
yalloucake dryer as a potential source
of wind d spersed particulates.
20.4 Schedule
Cotter shall conduct these remedial activ.ties
according to the following schedule:
1. Cotter shall submi t the report, required by
Paragraph 1 of Section 20.3, within sixty (60) days after the
entry of a Consent Decree by the Court.
2. The State shall act upon the report required
by Paragraph 1 of Section 20.3, w thin sixty (60) days of its
receipt.
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COTTU—0151 154
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3. Cotter shall submit the plan required by
Paragraph 2 of Section 20.3 within sixty (60) days of the
entry of the Consent Decree by the Court, if a report pursuant
to Paragraph 1 of Section 20.3 is not submitted, or within
sixty (60) days of the State’s determination that the best
available technology is not in use, if a report pursuant to
Paragraph 1 of Section 20.3 is submitted.
4. The State shall act upon the plan within
sixty (60) days of its receipt.
5. Cotter shall implement the plan required by
Paragraph 2 of Section 20.3 pursuant to the approved schedule.
6. Cotter shall submit a written final
construction report within one hundred twenty (120) days of
completion of installation of best available technology, if
required pursuant to Paragraph 2 of Section 20.3.
7. The State shall act upon the written final
construction report within on. hundred twenty (120) days after
receipt.
8. Cotter shall su.bsit, as part of the RAP
Annual Report specified in Section 3.1, a written annual
summary as described in Section 20.3.
9. The State shall act upon the Annual Report
within on. hundred twenty (120) days after receipt.
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21 ON—SITE SOILS
21.1 Descri tion of Operations and Relevant
£nv .ronmental Conditions
Particulates are dispersed from the sources
identified in Sections 16, 17, 18 and 20 to soils both on arid
off the site. The on-site soils then serve as a potential
secondary source of wind dispersed particulates.
21.2 Remedial Activities
The purpose of these remedial activities is to
effectively minimize and mitigate the soils on the mill Site
as a potential secondary source of wind dispersed particulates
and to provide for soil cleanup at mill closure.
Cotter shall perform the fo1lowing remedial
activities:
1. Cotter shall revegetate all on—site soils,
with the exception of soils in areas where revegetatiori is
prevented by mill operations or by remedial activities
conducted in accord with this Remedial Action Plan or where
existing vegetation provides adequate cover as determined by
the standards developed in the revegetation plan required in
this Section, to effectively minimize and mitigate wind
dispersion.
2. In areas where revegetation is prevented by
mill operations, with the exception of roads (see Section 22),
and in areas where revegetation is prevented by remedial
activities conducted in accord with this Remedial Action Plan.
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COTT!R—0151l 58
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Cotter shall apply either a surface cover, such as gravel,
surfactants, tactifiers, or mulch, or wet the area to
effectively minimize and mitigate wind dispersion.
3. As an element of mill closure and site
reclamation, Cotter shall:
a. Conduct a calibrated gamma
scintillom.ter survey on a one hundred
(100) square meter grid in accord with
calibration and measurement procedures
consistent with the procedures of the
Colorado Department of Health;
b. Conduct a soil sample survey to confir i
the findings of the scintillometer
survey ih accord with a sampling
protocol utilizing the unbalanced
hierarchical analysis of variance
techniques, as specified in Sampling
Designs for Geochemical Baseline Studies
in the Colorado Oil Shale Region: A
Manual for Practical Application, U.S.
Department of Ensrgy, Jun. 1980
(D.O.E./EV/10298—2) or other analysis
approved by the Stat.. All soil samples
shall be analyzed for radiu —226, and
molybdenum, except for samples collected
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coT TIR—O 151157
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from the Old Tailings Ponds Area, which
shall be analyzed only for radium-226.
c. Based en the gamma scintillometer survey
and the soil sample survey, Cotter shall
remove all soil containing
concentrations of radium-226, averaged
over areas of 100 square meters, which
is greater than the background mean by
mere than:
i. five (5) picoCuries per gram
(pCi/g) averaged over the first
fifteen (15) centimeters (cm)
below th. surface, or
ii. fifteen (15) picoCuries per gram
(pCi/g) averaged over fifteen (15)
centimeter (cm) thick layers more
than fifteen (15) centimeters (cm)
below the surface.
d. Based en the soil sample survey, Cotter
shall remove all soil containing
concentrations of molybdenum, averaged
over areas of 100 square meters, which
is greater than th. background range by
more than fifteen (15) milligrams per
kilogram (mg/kg) averaged over the fi:s
—17 5—
COTTfl—0151]53
1 )
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fifteen (15) centimeters (cm) below the
surface. In the Old Tailings Ponds
Area, soil removal shall not be required
based upon the molybdenum
concentrations.
a. Dispose of all removed soil in the main
or secondary impoundments and establish
self regenerating vegetation cover in
all areas where soil removal has
eliminated the vegetation cover or
reduced the vegetation cover to below
the standards developed in the
rev.getation plan required in
Paragraph 1 of Sect on 21.3.
21.3 Reauisite Assessments and Kncjneerjr Activities
Cotter shall prepare and submit to the State for
review and approval th. following:
1. A plan to revegetate or cover the on—site
soils, which shall include:
For areas to be revegetated:
a. Species to be planted;
b. Seeding and/or stocking rates;
c. Seed bed preparation;
d. Methods of planting;
e. Mulching and fertilizing specifications;
—176—
COTTU—0151159 3
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f. A maintenance plan for the revegetatjon;
g. Proposed revegetation success standards,
including criteria to be measured, such
as percent of cover and rate of
production, measurement methods, and
seasonal effectiveness;
h. Schedule.
For areas subject to alternate surface cover
or wetting:
a. Description and purpose of activities;
b. Schedule;
c. Operations, inspection and maintenance
plan;
d. Discussion of reasons for use of
alternate surface cover or wetting
instead of revegetation.
2. A written report on the completion of the
plan required by Paragraph 3. of this Section, which shall
include:
a. Description of activities;
b. Explanation of and response to
unexpected conditions and problems;
c. Discussion of actual performance and a
comparison to the success standards.
—177—
COTTEØ0l 51160
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3. A plan to conduct the gamma scthtillometer
survey and soil sample survey and to remove and dispose of the
soil and to establish self—regenerating vegetation cover, as
required by Paragraph 3 of Section 21.2, which shall include:
a. For gamma scintillometer and soil sample
survey:
i. Description of methods and
procedures for gaa
scinti]lometer survey;
ii. Description of methods and
procedures for soil sample survey;
iii. Description of methods and
procedures to remove and dispose
of the soil;
iv. QA/QC plan.
b. For establishment of self—regeneratthg
vegetation cover:
Description and purposes of
activities;
ii. QA/QC Plan for contouring
operations, if necessary;
iii. Species to be planted;
iv. Seed bed preparation;
v. Methods of planting;
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collU—015116l
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vi. Proposed self-regenerating
vegetation Success standards,
including criteria to be measured,
such as percent of cover and rate
of production, and measurement
methods;
vii. Schedule.
4. A written annual activities summary regarding
the plan required by Paragraph 3. of this Section, which shall
include:
a. Description and results of activities;
b. Explanation of and response to
unexpected conditions and problems;
c. Proposedmodifications to th..plan to
effectively minimize and mitigate the
on—site soils as a potential secondary
source of wind dispersed particulates.
5. A written final report on the gamma
scintillom.ter survey, soil sample survey, and implementation
of the plan for soil removal and disposal and establishment of
self-regenerating vegetation cover as required by Paragraph 3
of Section 21.2, which shall include:
a. Description of activities;
b. Explanation of and rssponse to
unexpected conditions and problems;
—179—
COTTU—O 151162
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c. Topographic map with approximate grid
locations;
d. Values and ranges of meter readings;
e. Quantity of soil removed;
f. Quality assurance and quality control
evaluations.
21.4 Schedule
Cotter shall conduct thes. remedial activities
according to the following schedule:
3. Within ninety (90) days of the entry of a
Consent Decree by the Court, Cotter shall submit a plan
pursuant to Paragraph 1 in Section 21.3.
2. The State shall act upon the plan within
ninety (90) days of.receipt. -
3. Cotter shall implement the approved plan
required by Paragraph 1. of Section 21.3 pursuant to the
approved schedule, but in any case, no later than one (1) year
after State approval.
4. Cotter shall submit a written completion
report as required by Paragraph 2 of Section 23.3 within one
hundred twenty (120) days of completion of the plan.
5. Cotter shall submit, as part of the RAP
Annual Report specified in Section 3.1, a written annual
activities summary as described in Section 21.3.
—180—
COTTU—016 1163
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6. The State shall act upon the annual report
within one hundred and twenty (120) days of its receipt.
7. As an element of mill closure and site
reclamation, Cotter shall submit a plan for the gamma
scintillometer survey, soil sample survey, soil removal and
disposal and self-regenerating vegetation plan, as required by
Paragraph 3 of Section 21.3.
8. The State shall act upon the surveys, removal
plan, and self-regenerating vegetation plan within one hundred
and eighty (180) days of its receipt.
9. Cotter shall implement the surveys, removal
plan, and revegetation plan pursuant to the approved schedule.
10. Cotter shall submit a written final report
within sixty (60) days of completion of the gamma
scintillometer survey, soil sample survey, implementation of
soil removal and disposal, and establishment of
sel f-regenerating vegetation cover.
11. The State shall act upon the written final
report within one hundred and eighty (180) days after its
receipt.
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COTTI*0151l 64
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22 ROADS
22.1 D.scri tion of O erations and Relevant
Environmental Conditions
The roads on-site are a potential source of
windblown particulates.
22 .2 Remedial Activities
The purpose of these remedial activities is to
effectively minimize and mitigate the roads as a potential
source of windblown particulates.
Cotter shall water the roads with uncontaminated
water on the mill site as necessary to effectively minimize
and mitigate air dispersion.
22.3 Reanisite Assessments and En jneerjrt Activities
Cotter shall prepar. and submit to the State for
review and approval the following:
1. A plan for watering the roads on the mill
site, which shall include:
a. Description and purpose of activities;
b. Schedule.
2. A written annual activities summary on the
watering of th. roads to effectively minimize and mitigate air
dispersion, which shall include:
a. Description and results of activities;
b. Explanation of and response to
unexpected conditions and problems;
—182—
COTTfl—O 151165
( .2
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c. Proposed modifications to the plan to
continue to effectively minimize and
mitigat. the roads as a potential source
of wind dispersed particulates.
22.4 Schedule
1.. Cotter shall submit a plan for watering the
roads on—site within thirty (30) days of approval of the entry
of a Consent Decre. by the Court.
2. The Stat. shall act upon the plan within
thirty (30) days of receipt.
3. Cotter shall implement the plan for watering
the roads on—sit, pursuant to th. approved schedule.
4. Cotter shall submit, as part of the RAP
Annual Report specified in Section 3.1, a written annual
summary as described in Paragraph 2 of Section 22.3.
5. The State shall act upon the Annual Report
within one hundred and twenty (120) days of its receipt.
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COT!U—0151166
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23 AIR MONITORING
23.]. Descriotion of 0t srations and Re1eva t
Environmental Conditions
A number of potential sources of wind dispersed
particulates exist on the sit.. These potential sources
incLude the main and secondary impoundments, the Old Tailings
Ponds Area, the ore stockpile and or. handling area, and the
yelloucaks dryer. Remedial actions to mitigat. these areas as
potential sources of particulat.s are addrsssed in
Sections 16, 17, 18, 20, 2] and 22.
23.2 Remedial Activities
The purpos. of thee . remedial activities is to
monitor the wind dispersion of particulatss, to evaluate the
amount of particulat.s leaving the mill sits by the medium of
air, and to evaluate the effectiveness of other remedial
activities.
Cotter shall perform the following remedial
activities:
1. Continue to operate and maintain seven (7)
existing continuous air samplers at the locations shown on the
Figure 23—1.
2. Install, operate, and maintain two (2)
additional event—actuated air samplers at the locations shown
on Figure 23—1.
a. The east boundary event actuated air
sampler shall operate only witen the wind
—184—
COTTU—0151187
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direction is from between two hundred
and twenty-f ive (225) degrees
(southwest) and three hundred and
fifteen (315) degrees (northwest) and
the wind speed is four (4) miles per
hour or greater.
b. The vest boundary event actuated air
sampler shall operate only when the wind
direction is from between ninety (90)
degrees (east) and one hundred and
eighty (180) degrees (south) and the
wind speed is four (4) miles per hour or
greater.
C. The two ivent actuated air samplers
shall be equipped with recording devices
which will allow determination of
operating time and volume of air
sampled.
3. The event actuated air sampler filters shall
be analyzed for:
a. Uranium;
b. Thorium—230;
c. Radium—226;
d. Total suspended particulates using pre-
and post-sampling filter weights.
—185—
COT?U-O 151188
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4. The continuous air sampler filters shall be
analyzed in accordance with U.S. uc1ear Regulatory Commission
Regulatory Guide 4.14.
5. After three years of data collection, Cotter
shall submit a report evaluating the capability and usefulness
of the event—actuated air samplers to achieve the purposes set
forth in Section 23.2. Equipment adequacy shall be )udged on
the basis of data capture efficiency and suitability of air
quality data collected. Cotter shall propose modification of
the event-actuated sampling program, if necessary. Cotter
shall implement the State approved modification.
23.3 Remilsite ssisssments and Ertairteerina A tiyitjes
Cotter shall prepare and submit to the State for
review and approval the following:
1. A monitoring plan, which shall include:
a. Description of existing air samplers;
b. Design of and installation procedures
for event-actuated air samplers;
a. Schedule;
d. Operations and maintenance plan;
e. Monitoring schedule;
f. QA/QC Plan.
2. A written report on the installation of the
event-actuated air samplers, which shall include:
a. Description and results of activities;
—186—
COTTfl0151 169
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I
)
b. Explanation of and response to
unexpected conditions and problems;
c. Quality assurance and quality control
evaluations.
3. A written quarterly report on the results of
the monitoring program, which shall include:
a. Description and results of activities;
b. Explanation of and respons. to
unexpected conditions and problem.s;
c. Quality assuranc. and quality control
evaluations;
d. Monitoring results.
4. A report pursuant to Paragraph 5,
Section 23.2.
23.4 Schedule
Cotter shall conduct these remedial activities
according to the following schedule:
1. Cotter shall submit a proposed monitoring
plan to the State within one hundred twenty (2.20) days of
entry by the Court of the Consent Decree.
2. The State shall act upon the plan within
sixty (60) days of receipt.
3. Cotter shall implement the approved plan
pursuant to the approved schedule.
— 187—
COTTII—O 16 1170
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4. Cotter shall subsit an installation report to
the State within one hundred twenty (120) days of the
completion of installation activities.
5. The State shall act on the installation
report within one hundred twenty (120) days of receipt.
6 • Cotter shall submit quarterly reports to the
State within ninety (90) days from the end of each quarter.
7. The State shall act upon th. reports within
ninety (90) days or as appropriate.
8. Cotter shall submit the report required by
Paragraph 5 of Section 23.2 ninety (90) days after the
collection of three years of event—actuated air quality data.
9. The State shall act upon this report within
sixty (60) days of its receipt.
10. Cotter shall implement any modifications to
the event-actuated monitoring program within on. hundred
eighty (180) days of State approval.
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COTTU—O 151171
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24 SITE ADJACENT SOIL
24.1. Descrthtion of O erations and Relevant
Environmental Conditions
Particulates are dispersed from the sources
identified in the RAP to soils oft the site. Off-site land
use is described in Section 2.2.
24.2 Remedial Activities
The purpose of these remedial activities is to
effectively minimiz, and mitigate the off—site soils as a
potential secondary source of wind dispersed particulates and
of surfac. water sediment transport, to restrict access to
impacted soils, if any, and to reduce constituent
concentrations in soils to background rang..
Cotter shall psrform the following remedial
activities.
1. Cotter shall submit a report. The purposes
of this report are to det.rmine the adequacy of all existing
radium-226 soils data for use in determination of the location
of grazing restriction fences and to document the grazing uses
of adjacent lands. The Stat. shall review this report for its
adequacy to address soil data needs.
2. Cotter shall, if required by the State,
conduct a supplemental soils survey of the soils adjacent to
the mill site. The site adjacent soil survey area is defined
as beginning at the restricted area boundary and continuing
outward from that boundary until concentrations of radium-226
—189—
COTTfl—0151172
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are below five (5) picoCuries per gram (pCi/g) above
background range averaged ever the upper fifteen (15)
centimeters of soil. tf the existing soil, data do not result
in joint approval of the five (5) picoCurie per gram (pCi/g)
above background range boundary (ice), then Cotter shall
conduct this supplemental survey. The supplemental survey
shall include:
a. A calibrat.d gamma scintillometer survey
in accord with calibration and
measurement procedures consistent with
procedures of the Colorado Department of
Health;
b. Soil sampling, if necessary;
c. All soilsamples shall be analyzed for
radium—226.
3. Based on existing soil data presented in the
report on all existing soil data or on the results of the
supplemental site adjacent soil survey (see Paragraph 2 of
his Section), Cotter shall, except wher, established that
grazing does not occur, erect and maintain fences to prevent
grazing in all areas where the concentration of radium ’-226 is
greater than the background rang. by more than five (5)
picoCuries per gram (pCi/g) averaged over th. first fifteen
(15) centimeters (cm) below the surface.
—190—
COTTU—0151173
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4. As a part of mill closure and sit.
reclamation, Cotter shall:
a. Conduct a site closure soil survey ef
off site soils in areas contiguous to
the sits, which were net surveyed in
conjunction with the pathway management
program (see Section 29). The survey
shall include a soil calibrated gamma
scintillem.t.r survey en a on. hundred
(100) square meter grid in accord with
th. calibration and measurement
procedures consistent with the
procedures established by the Colorado
Department of Mealth.
b. Conduct a sits closure soil sample
survey to confirm the results of the
survey required in Paragraph 4.a. of
this Section in accord with a sampling
protocol utilizing the unbalanced
hierarchical analysis of variance
techniques, as specified in Sampling
Designs for Geochemical Baseline Studies
in the Colorado Oil Shale Region: A
Manual for Practical Application, U.S.
Department of Energy, Jun. 1980
—191—
COTTU—0151174
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(D.O.E./EV/10298—2), or other analysis
approved by the State. All, soil samples
shall be analyzed for radium-226 and
molybdenum.
c. Based on the gamma scintillometer
survey, as required in Paragraph 4.a. of
this Section, and the soil, sample
survey, as required in Paragraph 4.b. of
this Section, Cotter shall. remove all
soil with concentrations of radium—226
greater than the background rang. in the
soil averagsd over the first fifteen
(15) centimeters (cm) below the surface.
All removed soils shall be disposed in
the main and/or secondary impoundments.
Cotter may propos. an alternative
remedial method(s) to soil removal that
is as effective as soil removal.
d. Based on the soil sample survey, as
required in Paragraph 4.b. of this
Section, Cotter shall remove all soil
with concentrations of molybdenum
greater than the background range in the
soil averaged over the first fifteen
(15) centimeters (cm) below the surface.
—192—
COTTfl—O 151175
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AU, removed soils shall be disposed in
the main or secondary impoundments.
Cotter may propose an alternative
remedial method(s) to soil removal that
is as effective as soil removal.
e. Cotter shall perform a final soil survey
in all areas where soil has been removed
to confirm that radium—226 and
molybdenum levels have been reduced to
background range. The final soil survey
shall be conducted by calibrated gamma
scintillometer survey. Confirming soil
samples shall be collected and analyzed
for molybdenum and radium-226 from those
areas where gamma scintilloineter
readings exceed background range. The
criteria described in Paragraphs 4.c.
and d. shall be met.
f. Cotter shall develop a soil restoration
program, as necessary, to promote
r.growth of vegetation in disturbed
areas and to minimize increases in
erosion rates.
24.3 Recuisite Assessments and Knainearina Activities
Cotter shall prepare and submit to the State for
review and approval the following:
—193—
CO?Tfl—0151178
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1. Cotter shall submit a report of all existiri
radjum-226 soil data, which shall include:
a. All existing radium—226 soil data;
b. Methods of locating sampl. sites;
c. Methods of sampl. collection;
d. Methods of sample preparation;
a. Methods of analysis;
f. Criteria for rejection of a sample;
g. Information pertaining to , the grazing
uses of adjacent lands;
h. Evaluation of need for supplemental sit
adjacent soil survey.
2. A plan for a supplemental site adjacent soil
survey, if required, (see Paragraph 2 of Section 24.2) which
shall include:
a. Description of methods and procedures
for gamma scintillometer survey,
including calibration procedures:
b. Description of methods and procedures
for soil sample survey, if necessary;
C. QA/QC Plan;
d. Schedule.
3. A written report on the supplemental soil
survey, which shall include:
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cOflU—0151177
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a. su ilary of methods, procedures and
survey locations;
b. Analyses and survey results;
c. Topographic map with approximate grid
locations and sample locations with
results at each location;
d. Values and rang.. of meter readings;
e. Explanation of and response to
unexpected conditions;
f. Quality assurance and quality control
evaluations.
4. Pursuant to Paragraph 3 in Section 24.2, a
plan to erect fences to prevent grazing, which shall include:
a. Design drawings and construction
specifications;
b. Location of the fences;
C. QA/QC Plan;
d. Maintenance plan;
e. Schedule.
5. A written final construction report on the
erection of the fences to prevent grazing, which shall
include:
a. Accurate as-built drawings;
b. Explanation of and response to
unexpected conditions and problems;
—195—
COTUR-0151178
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c. Quality assurance and quality control
evaluations.
6. A written annual activities summary on the
maintenance of the fences to prevent grazing, which shall
include:
a. Description of activities;
b. Explanation of and response to
unexpected conditions and problems;
c. Documentation of grazing status on
adjacent lands.
7. A plan to conduct the sits closure gamma
scintillometer survey (see Paragraph 4.a. of Section 24.2),
the sits closure soil sampl. survey (see Paragraph 4.b of
Section 24.2), to remove and dispose of the soils (see
Paragraphs 4.c. and 4.d. of Section 24.2), to conduct the
final soil survey (see Paragraph 4.5. of Section 24.2) and, as
necessary, to conduct a soil restoration program (see
Paragraph 4.f. of Section 24.2) which shall include:
a. Description of methods and procedures
for site closure gamma scirttillometer
survey;
b. Description of methods and procedures
for site closure soil sample survey;
c. Description of methods and procedures
for the final soil survey;
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COTTIl—0161179
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d. D.scr±ption of methods and procedures to
remove and dispose of the soil, and, a
plan to rector, soils:
e. QA/QC Plan;
f. Schedule;
g. All existing molybdenum and radium-226
soil data in the area.
8. A written final implementation report on the
plan required in Paragraph 4 of Section 24.2, which shall
include:
a. Suary of methods and procedures and
survey locations;
b. Data collected;
c. Topographic map .with approximat. grid
locations and sample locations with
results at each location;
d. Values and ranges of meter readings;
e. Explanation of and response to
unexpected conditions;
f. Location and quantity of soil removed
and location and method of disposal,
and, any soil restoration activities;
q. Quality assurance and quality control
evaluations;
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h. All existing molybdenum and radium-226
soil data in the area.
24.4 Schedule
Cotter shall conduct these remedial activities
according to the following schedule:
1. Within ninety (90) days of th. entry of the
Consent Decree by the Court, Cotter shall submit the report
required by Paragraph 2. of Section 24.3.
2. The State shall act upon the report within
sixty (60) days of its receipt.
3. If required, pursuant to Section 24.2, Cotter
shall submit a plan for a supplemental soil survey of the site
adjacent area within ninety (90) days of action by the State
on the report required by Paragraph 1. of Section 24.2.
4. The State shall act upon the supplemental
soil survey plan within ninety (90) days of its receipt.
5. Cotter shall complete the supplemental soil
survey plan pursuant to the approved schedule.
6. Cotter shall submit a written report on the
supplemental soil survey, if required, within sixty (60) days
of completion of the supplemental survey and receipt of lab
results.
7. The State shall act upon thi report on the
supplemental soil survey within sixty (60) days after its
receipt.
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8. Cotter shall submit a written plan to
restrict grazing, if required, within sixty (60) days of the
determination of background range as defined in Section 3.2.4,
or within sixty (60) days of Stats approval of the
supplemental. soil survey report, if required, whichever is
later.
9. The Stats shall act upon the grazing
restriction plan within sixty (60) days of receipt.
10. Cotter shall complete the erection of fences
to restrict grazing pursuant to the approved schedule.
11. Cotter shall submit a written final
construction report on the erecti on of the fences to prevent
grazing within one hundred twenty (120) days after the
completion of the erection of the fences.
12. The State shall act upon the written final
construction report within one hundred twenty (120) days after
its receipt.
13. Cotter shall submit, as part of the RAP
Annual Report specified in Section 3.1, a written annual
sllmmkry as described in Paragraph 6 of Section 24.3.
14. The State shall act upon the Annual Report
within en. hundred and twenty (120) days after its receipt.
15. As an element of mill closur, and site
reclamation, Cotter shall submit to the State a proposed plan
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and schedule to conduct the soil surveys described in
Paragraphs 4.a. and b. of Section 24.2.
16. The State shall act upon the proposed plan
within ninety (90) days of it. receipt.
17. Cotter shall implement the plan pursuant to
th. approved schedule.
18. Cotter shall submit the results of the soils
surveys to the State within sixty (60) days of Cotter’s
receipt of the laboratory results.
19. The Stats shall act upon the results within
sixty (60) days of receipt.
20. Cotter shall submit to the State a proposed
plan and schedule to implement the remedial activities
described in Paragraphs 4.c., d., s. and f. of Section 24.2
within sixty (60)’ days of Stat. action upon the soil, survey
results.
21. The State shall act upon the proposed plan to
implement the remedial activities described in Paragraphs
4.c., d., s . and f. of Section 24.2 within sixty (60) days of
its receipt.
22. Cotter shall implement the approved plan
pursuant to the approved schedule.
23. Cotter shall submit a written final report
within sixty (60) days of the completion of all remedial
activities required in Paragraph 4 of Section 24.2.
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24. Tb. State shall act upon the written final
construction report within sixty (60) days after its receipt.
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COTTU—0151184
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25 LINCOLN PARK SOILS
25.]. Descriction øf O erations and Relevant
Environmental Conditions
Particulates are dispersed from the sources
identified in the remedial action plan to soils off the sit
25.2 Remedial Activities
The purpose of these remedial activities is to
conduct a gamma scintillometer survey in Lincoln Park and t
report the survey results to the Health Risk Assessment Pan
and the Colorado Department of Health for analysis.
Cotter shall perform the following remedial
activities:
1. Cotter shall conduct a gamma scintillometer
study in Lincoln Park, which shall include:
a. Scintilloaster measurements shall be
obtained in Lincoln Park in the area
bounded by Ninth Street to the west,
Park Avenue to the north, Pinon Avenue
to the south, and Willow Street to t e
east.
b. Scintillometer measurements shall be
collected at intervals corresponding t:
the intersections of the public roads i
Lincoln Park.
c. At each sampling location, one gamma
scintillometer measurement shall be
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COTTU—O 151185
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obtained no closer than three (3) meters
from the shoulder of the road but not
further than thirty (30) meters from the
center of the intersection of the public
roads.
d. The gamma scintillom.ter shall be
calibrated in accord with the
calibration and measurement procedures
consistent with the procedures of the
Colorado Department of Health.
25.3 Recuis it. Assessments and Enainearina Activities
Cotter shall prepare and submit to the State the
following:
1. A plan for a gamma scintillometer survey as
required in Paragraph 1 of Section 25.2, which shall include:
a. Description of methods and procedures
for the gamma scintillometer survey,
including calibration procedures;
b. QA/QC Plan;
c. Schedule.
2. A written report of the results of the gamma
scintillometer survey as required in Paragraph 1 of Section
25.2, which shall also be submitted to the Health Risk
Assessment Panel, and which shall include:
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CO??U—O 161188
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a. Summary of methods and procedures and
survey Locations;
b. Data collected;
c. Map of sample Locations with results at
each Location;
d. Explanation of and response to
unexpected conditions;
e. Quality assuranc. and quality control
evaluations;
f. Al ]. existing radium-226 soil, data in the
area.
25.4 Schadula
Cotter shall conduct these remedial activities
according to the following schidule:
1. Within ninety (90) days after the entry of
the Consent Decre. by the Court, Cotter shall submit a plan
for the soil gamma scintilloinetsr survey, as required by
Paragraph 1 of Section 25.2;
2. The State shall. act upon the soil gamma
icintillemst.r survey (see Paragraph 2. of Section 25.2) within
ninety (90) days of its receipt.
3. Cotter shall implement and complete the soil
gamma scintillometer survey pursuant to the approved schedule.
4. Within sixty (60) days of the completion of
the soil gamma scintillomater survey, Cotter shall submit a
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co!T2R O 161187
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written report of th. results of the soil gamma scintillometer
survey and any existing radium—226 soil data to the State and
the Health Risk Assessment Panel.
5. The State shall act upon the soil gamma
scintillometer survey within sixty (60) days of its receipt.
6. The Health Risk Assessment Panel shall
incorporate the results of the soil gamma survey into the
studies required by Section 32.
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COTTIlO 161 i88
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26 WILLOW LAKES
26.1 Dascrthtion of O erations and Relevant
Environmental Conditions
Mill-derived constituents are suspected to be
present in the lower portion of the Willow Creek drainage.
Several small ponds located in this drainage have ground water
as their sourc.. These pói%ds are used for fish stocking and
might be used for irrigation.
26.2 Remedial Activities
The purpos. of t iese remedial activities is to
survey the ground and surface water quality parameters, biota
and water uses in the Willow Lakes and feeder springs, and to
report the survey results to the Health Risk Assessment Panel
and the Colorado Department of Health for analysis.
Cotter shall perform the fällowing remedial
activities:
1. Cotter shall conduct a sampling program of
the watsr, sediment and fish in the Willow Lakes and feeder
springs. The sampling program shall include at least one
fish-stocking season. The sampling program shall include:
a. A number of water, sediment, and biota
samples from each pond;
b. Results of analysis for uranium,
molybdenum, and radium—226;
c. Documentation of the use of the Willow
Lakes;
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CO?Tfl—0151189
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d. Documentation of the management, of the
Willow Lakes, which shall include:
i. Fish stocking, feeding and
harvesting practices;
ii. Use of algicides;
iii. Management practices.
26.3 Reauisit. Assessments and Enaineerina Activities
Cotter shall prepar. and submit to the State for
review and approval the following:
1. A plan for a sampling program of the Willow
Lakes and feeder spring., which shall include:
a. Description of sampling;
b. QA/QC Plan;
c. Schedule.
2. A written report of the results of the
sampling program shall be submitted by Cotter to the State and
to the Health Risk Assessment Panel, and which shall include:
a. Results and data collected;
b. Explanation of and response to
unexpected conditions;
c. Quality assurance and quality control
evaluations.
26.4
Cotter shall conduct these remedial activities
according to the following schedule:
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1. Within one hundred and eighty (180) days
after the entry of the Consent Decree by tha Court, Cotter
shall submit a plan for a sampling program of the Willow Lakes
and feeder springs.
2. The State shall act upon the plan for the
sampling program within ninety (90) days after its receipt.
3. Cotter shall implement the sampling program
pursuant to the approved schedule.
4. Within sixty (60) days after the receipt of
the laboratory analytical results, Cotter shall submit to the
State of Colorado and Health Risk Assessment Panel a written
report of the results of the sampling program.
5. The Stats shall act upon the report of the
sampling program within sixty (60) days after its receipt.
6. The Health Risk Assessment Panel shall
incorporate results of th. sampling program into the studies
required by Section 32.
—2 08—
CO??U—0151191
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27 EPM PAL STRZAMS AND FREMONT DITCH
27.1 DescriDtiOfl of O erations and Relevant
Environmental Conditions
Mill-derived particulates dispersed by the wind
are deposited in off sit. soil. Thee. particulates are
available to migrat. down nearby ephemeral drainages as part
of sediment loading during storm events. These drainages
include Sand Creek and Willow Creeks. Sand Creek flows to the
Arkansas River above the intake of the Fremont Ditch.
Mill-derived constituents are suspected to be present in the
sediments in thes. drainages and the Fremont Ditch. Sediments
in these drainages are transported during storm events to the
Arkansas River.
27.2 Remedial Activities
The purpose of these remedial activities is to
survey the radium—226 concentrations in sediments in the
ephemeral segments of Sand Creek, Willow Creek and the Fremont
Ditch, and, if necessary, remove and properly dispose of the
sediments from the.. segments. The purpos. of sediment
removal is to reduce radium—226 concentrations to background
range.
Cotter shall perform the following remedial
activities:
1. Cotter shall conduct a survey of the dry
channel segments of Sand Creek, Willow Creek, and in the bed
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COTTfl—0151192
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conducted by calibrated gamma scintillomet.r survey.
Confirming sediment samples shall be collected and analyzed
for radjum-226 from those areas where gamma scintillometer
readings exceed background range. Th . sediment removal
criterion of this paragraph shall be met.
27.3 Reouisite Assessments and Engineering Activities
Cotter shall prepare and submit to the State for
review and approval the following:
1. A plan for a survey of the dry channel
segments of Sand Creek, Willow Creek, and the Frsmont Ditch,
which shall include:
a. Description of methods and procedures
for gamma scintillometer survey,
• including calibration procedures;
b. Description of methods and procedures
for supplemental sediment sample survey;
c. QA/QC Plan;
d. Schedule.
2. A written report of the results of the survey
of the dry channel segments of Sand Creek, Willow Creek, and
the Frement Ditch, which shall include:
a. summary of methods and procedures and
survey locations;
b. Data collected;
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COTTU—O 151194
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• a.
b.
C.
—2 12—
readings;
CO?URO 151195
c. Topographic sap with approximate grid
locations and sampl. locations with
results at each location;
d. Values and ranges of meter
•. Findings and conclusions:
f. Explanation of and response to
unexpected conditions and probisms;
g. Quality assurance and quality control
evaluations;
h. If necessary, a plan to remove and
dispose of the sediments, which shall
include:
i. Description of methods and
procedures to remove and dispose
of the sediments;
ii. QA/QC Plan;
iii. Schedule.
3. A written final report on the removal and
disposal of the sediments from the dry channel segments which
shall include:
Description of activities and results;
Quantity of material temoved;
Explanation of and response to
unexpected conditions and procedures;
3” 7
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d. Quality assurance and quality control
evaluations.
27.4 Schedule
Cotter shall conduct these remedial activities
according to the following schedule:
1. Within ninety (90) days after the entry of a
Consent Decre, by the Court, Cotter shall submit a plan for a
survey of the dry channel segments and Fr.mont Ditch.
2. The State shall act upon the plan for a
survey of the dry channel segments and Fremont Ditch within
ninety (90) days after its receipt.
3. Cotter shall implement and complete the
survey pursuant to the approved schedule. If the Fremont
Ditch is not dry during the period of implementation of the
survey, it shall be surveyed within sixty (60) days after it
is dry.
4. Cotter shall submit a written report of the
results of the survey within sixty (60) days of the
determination of background range (see Section 3.2.4).
5. The Stats shall act upon the report of the
results of the survey within sixty (60) days after its
receipt.
6. Cotter shall remove and dispose of the
sediments if necessary, pursuant to the approved schedule.
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coma—015U98
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7. within one hundred twenty (120) days after
completion of th. removal and disposal of the sediments,
Cotter ehall submit a written final report.
8. The State shall act upon the final report
within one hundred twenty (2.20) days after its receipt.
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COT7U—O 161197
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28 PERENNIAL STREAMS
28.1 Descriøtion of O erations and Relevant
Environmental Conditions
Mill—derived particulat.s dispersed by the wind
are deposited in off—sits soil. These particulat.s are
available to migrate down nearby drainages as part of sediment
loading during storm events. These drainages include Sand
Creek and Willow Creek. Sand Creek flows to the Arkansas
River above the intake of the Frsmont Ditch. Mill-derived
constituents are suspected to be present in the sediments in
these drainages and the Yr.mont Ditch. Sediments in these
drainages are transported during storm events to the Arkansas
River.
28.2 Remedial Activitiep
The purpose of these remedial activities is to
survey the molybdenum and radium—226 concentrations in
sediments in the perennial segments of Sand Creek and Willow
Creek, and, if necessary, to remove and properly dispose of
the sediments from those segments. The purpose of sediment
removal is to reduce molybdenum and radium—226 concentrations
to background range.
Cotter shall perform the following remsdial
activitiss:
1. As an element of mill closure and site
reclamation, Cotter shall conduct a survey of the sediments i.n
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COTTfl—0151198
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the perennial segments of Sand Crsek and Willow Creek. The
survey shall include:
a. Five (5) sediment sampiss at the head of
Sand Creek and five (5) sediment samples
at the head of Willow Creek:
b. Five (5) sediment samples at the
confluence of Sand Creek with the
Arkansas River and fivs (5) sediment
sample. at the confluence of Willow
Creek with the Arkansas River:
c. All sediment samples shall be obtained
at fifty (50) foot intervals along the
center of. each channel;
d. All seditent samples shall be obtained
within the first fifteen (15)
centimeters (cm) below the surface;
e. All sediment samples shall be analyzed
for radium-226 and molybdenum;
2. Based on the results of the survey of the
perennial segments, Cotter shall submit a sampling and
remediatien plan to investigate the extent of necessary
remediation for:
a. All sediments containing concentrations
of radium—226, averaged over areas of
100 square meters, which is greater than
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COTTU—015 1199
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the background mean by more than five
(5) picoCuries per gram (pCi/g) averaged
over the first fifteen (15) centimeters
(cm) below the surface, and
b. All, sediments containing concentrations
of molybdenum, averaged over areas of
3.00 square meters, which is greater than
the background range by more than five
(5) milligrams per kilogram (mg/kg)
averaged over th. first fifteen (15)
centimeters (cm) below the surface.
3. Based on the results of the perennial
sampling survey and sampling and remediation plan, Cotter
shall remove:
a. All sediments containing concentrations
of radium—226, averaged over areas of
100 square meters, which is greater than
the background mean by more than five
(5) picoCuries per gram (pCi/g) averaged
over the first fifteen (15) centimeters
(cm) below the surface, and
b. All sediments containing concentrations
of molybdenum, averaged over areas of
100 square meters, which is greater than
the background range b more than five
—217— -
COTTU—015 1200
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(5) milligrams per kilogram (mg/kg)
averaged over the first fifteen (15)
centimeters (cm) below the surface.
All removed sediments shall be disposed of in the
main or secondary impoundments. Sediment removal shall
continue until molybdenum and radium—226 concentrations are
reduced to background range. A verification program shall be
conducted by Cotter in accordance with a sampling protocol
approved by the State. All sediment samples shall be analyzed
for radium-226 and molybdenum.
28.3 Recuisite Assessments and Encinserina Activities
Cotter Corporation shall prepare and submit to the
State for review and approval the following:
1. A plan for a survey of the sediments in the
perennial segments of Sand Creek and Willow Creek, which shall
include:
a. Description of methods and procedures
for sediment sample survey;
b. QA/QC Plan;
c. Schedule.
2 • A written report of the results of the survey
of the perennial segments of Sand creek and Willow Creek,
which shall include:
a. Summary of methods, procedures, and
survey locations;
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COT’ffl—0151201
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b. Data collected;
c. Map of sample Locations with results at
each location;
d. Findings and conclusions;
e. Explanation of and response to
unexpected conditions and problems;
f. Quality aasurancs and quality control
evaluations;
g. A sampling and remediation plan to
investigate the extent of necessary
remediatien, which shall include:
i. Description of methods and
procedures for sediment sample
survey;
ii. QA/QC Plan;
iii. Schedule.
3. A written report of the results of the
sampling and reasdiatien plan, which shall include:
a. Summary of methods, procedures, and
survey locations;
b. Data collected:
c. Map of sample locations with results at
each location:
d. Findings and conclusions;
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CO!TIIOl 5 2 OZ
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e. Explanation of and response to
unexpected conditions and problems;
f. Quality assurance and quality control
evaluations;
g. A plan to remove and dispose of the
udia.nta which shall include:
i. Description of methods and
procedures to remove and dispose
of the sediments;
ii. QA/QC Plan:
iii. Schedu].;
iv. Verification protocol.
4. A written final report on the removal and
disposal of the sediments from the perennial segments, which
shall include:
a. Description of activities and results;
b. Quantity of material removed;
c. Explanation of and response to
unanticipated conditions and problems;
d. Quality assurance and quality control
evaluations.
28.4
Cotter shall conduct this . remedial activities
according to the following schedule:
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COTTU—0151203
3 ’ ?
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1. Cotter shall submit a plan for a survey of
the perennial segments of Sand Creek and Willow Creek one
hundred and twenty (120) days prior to mill closure and site
reclamation.
2. The State shall act upon the plan for a
survey of the perennial segments prior to mill closure and
site reclamation.
3. Cotter shall implement the approved survey of
the sediments in the perennial s.qments of Sand Creek and
Willow Creek as part of mill closure and sit. reclamation.
4. Cotter shall submit the report required by
Paragraph 2 of Section 28.3, including the verification
protocol, to the State within sixty (60) days of Cotter’s
receipt of the laboratory analysis results.
5. The State shall act upon this submittal
within sixty (60) days of receipt.
6. If necessary, Cotter shall implement the
approved sampling and remediation plan described in Paragraph
2.g. of Section 28.3 according to the approved schedule.
7. Cotter shall submit a final report describing
the results of the remedial activities to the State within
sixty (60) days of completion of the activities.
8. The Stats shall act on this submittal within
sixty (60) days of its receipt.
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COTTU—0151204
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29 PATHWAY MANAGEMENT
29.]. Dewri tion of ODerations and Relevant
Environmental Conditions
Mill-derived particulates dispersed by the wind
are deposited in off—site soils. These particulates are
available to migrate down nearby ephemeral drainages as part
of sediment loading during storm events. These drainages
include Sand Creek, Willow Creek, Forked Gulch, Wolf Park, and
Chandler Creek. Mill—derived constituents are suspected to be
present in the sediment in these drainages. Sediments in
these drainages are transported during storm events to the
Arkansas River.
29.2 Remedial Activities
The purpose of the.. remedial activities is to
effectively miniaizs and mitigate the potential transport of
soils and sediments in ephemeral drainage surface runoff
during storm events to the Arkansas River and to effectively
minimize and mitigate the concentrations of molybdenum,
radium—226 and, if appropriate, thorium-230 in these
drainages.
Cotter shall perform the following remedial
activities:
1. Cotter shall design and conduct a sub-basin
release soils study for each defined drainage sub—basin, the
approximate boundaries of which are indicated in Figure 1-2.
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COTfla—o151205
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A sub—basin release soils study shall
include:
a. A gamma scintillometer survey in
accordance with the calibration and
measurement procedures consistent with
the procedures of the Colorado
Department of Health.
b. A soil sampling program shall be
conducted by Cotter in accordanc. with a
sampling protocol approved by the State
which will, supplement the scintillometer
survey. All sediment samples shall be
analyzed for radium —226, molybdenum and,
thorium-230, except that the elimination
of thorium—230 analyses due to
correlation of thorium—230
concentrations with either the
molybdenum or radium—226 concentrations
shall, if appropriate, be permitted by
the State.
2. Within one (1) year following completion of
any sub-basin release soils study and the determination of
background range (see Section 3 • 2.6), any discovered areas of
soil concentrations above background range shall, at Cotter’s
discretion, either be removed or remediated by the
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COTTfl—0151206
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construction of a site-specific Silt fence by Cotter. The
mean concentration of radium-226, molybdenum and, if
appropriate pursuant to Paragraph l.b. of Section 29.2,
thoriun—230 in the soil samples over the first fifteen (15)
centimeters (cm) below the surface shall be used to determine
whether remediation to background range has been accomplished.
3. If Cotter elects to rem.diate any sub—basin
by construction and maintenance of a silt fence pursuant to
Paragraph 2 of this Section, then the following shall apply:
a. Each iilt pence shall be designed to
filter and remove transported sediment
from surface runoff:
b. Each silt fence shall be constructed and
operational pursuant to the approved
schedule set forth in the report
required by Paragraph 3 of Section 29.3;
c. Each silt fence shall be constructed of
commercially available filter material,
that has a minimum flow rating of four
hundred (400) gallons per minute (gpm);
d. Each silt fence shall be constructed in
accordance with the, manufacturer’s
specifications of the filter material,
if available, or specifications approved
—224—
COTTU—0151207
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by the Stats if ianufactursr’s
specifications are not available.
e. Except as described below, each silt
fence shall be installed in a sub-basin
not greater in area than 150 acres.
Silt fences can be sits—specifically
designed for areas greater than 150
acres when capable of passing runoff
attributable to at least a fifty—year
recurrenc. interval flow.
f. Each silt fence shall be designed to
prevent mechanical and/or structural
failure. Failure means physical
collapse, overtopping or underf low of
runoff, or any occurrence such that the
fence does not function to filter
sediment material.
q. If any silt fence experiences frequent
failure, it shall be redesigned to
prevent frequent mechanical and/or
structural failure and replaced.
Frequent failure means the failure of
any silt fence more than once p.r year
or three (3) or more sequential annual
failures. Structural design
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COTTU—0151208
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improvements shall not be required to
exceed the design requirements of a
rigid overtoppabi. structure;
h. Any silt fence that has experiencsd a
failur, shall be repaired or replaced
within ten (10) days of notice to or
3a owledge of Cotter of the failure;
The sediments retained by each silt
fence shall be removed and disposed of
in the main or secondary impoundment
when the depth of the sediments retained
by a silt fenc. exceeds a nominal depth
of one (1) foot.
j. Samples of the sediments retained by
each silt fence shall be collected and
analyzed for radium—226, molybdenum, and
thorium—230, except that analyses for
thorium—230 may be eliminated based on
the correlation developed in Paragraph
l.b of Section 29.2 and approved by the
State. Sediment sample collection and
analysis shall occur at intervals not
less than ninety (90) days, except that
at least one sample shall occur prior to
each time the sediments retained by a
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CO?TJR —0 151209
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silt fence are removed and disposed and
at least on. sampl. shall occur
annually.
k. A silt fence shall bs maintained until
removed, which may occur when either:
i. the mean concsntrations of
radium-226, molybdenum and, if
appropriate, pursuant to Paragraph
lb. of Section 29.2, thorium—230
in the monitoring data for a silt
fence location is not greater than
the background range of
radium—226, molybdenum or, if
appropriate pursuant to Paragraph
l.b. of Section 29.2, thcrium—230.
The monitoring data shall consist
of the data obtained in accordance
with Subparagraph j from four (4)
sequential representative samples
or;
ii. the monitoring data establishes
the existence of a steady stat.
condition. Th. existence of a
steady state condition shall be
determined, in accord with Secticn
—227 -
1_lol COTTU—0151210
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3.2.7, using a linear regression
on five (5) years of data obtained
in accord with Subparagraph j.
4. Cotter shall design and conduct a sub-basin
release soils study as described in Paragraph 1 of Section
29.2 prior to the removal of a silt fence, in accordance with
Paragraph 3.1. of Section 29.2.
29.3 Reauisite Aeseisments and Enaineerina Activities
Cotter shall prepare and submit to the State for
review and approval the following:
1. A plan for sub—basin release soil, studies,
which shall include:
a. A gaa scintillometer survey;
b. A soil sample survey to confirm the
results of the gamma scintilloineter
survey;
c. Survey procsdures and methodology;
d. Locations of sampling;
e. QA/QC Plan:
f. Schedule.
2. A written report on the results of the sub-
basin release soil studies, which shall include:
a. Topographic map with approximate grid
locations:
b. Values and ranges of meter readings;
—228—
COTTfl—0161211
s /a
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c. Locations of soil samples;
d. Results of laboratory analysis of soil
samples;
a. Quality assurance and quality control
evaluations.
3. A plan for the construction and maintenance
of the silt fences or soil rsmoval, as appropriate, which
shall include:
a. Location of each proposed silt fence or
soil. removal;
b. Design drawings and construction
specifications and materials:
c. QA/QC Plan:
d. Maintenance plan:
e. Sediment or soil removal and disposal
plan;
f. Sampling plan;
g. Schedule.
4• A written final report which shall include,
as appropriate:
a. Description of action taken:
b. As—built drawings;
C. Explanation of and response to
unexpected conditions and problems;
—229—
0 COTTU—0151212
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d. Quality assurance and quality control
evaluations;
a. Schedule.
5. A written annual activities summary as part
of the RAP Annual Report specified in Section 3.1, which shall
include:
a. Data collected;
b. Analysis of monitoring data and
background range for each silt fence;
c. Analysis of steady state condition for
each silt fence;
d. Description of maintenance activities
for each silt fence;
a. Description of failures and repairs and
• replacements for each silt fencs;
f. Description of removal and disposal of
retained sediments for each silt fence;
g. Explanation of and response to
unexpected conditions and problems;
h. Quality assurance arid quality control
evaluations.
6. A written proposal for the removal of any
silt fence, which shall include:
a. The basis for the removal of the silt
fence, in accord with Paragraph 3.k. of
Section 29.2;
—230—
COTTU—0151213
LJO ”
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b. A plan to remove any remaining areas of
soil containing mean concentrations of
radium—226, mo].ybdenum or, if
appropriate pursuant to Paragraph l.b.
of Section 29.2, thorium—230 so that
constituent concentrations are reduced
to background range, or a plan to
construct and maintain a silt fence for
any smaller drainage area upstream of
the silt fence proposed to be removed
where the mean concentrations data for
radium—226, molybdenum, or, if
appropriat. pursuant to Paragraph L.b.
of Section 29.2, thorium—230 are greater
than the background range for
radium—226, molybdenum, or, if
appropriate pursuant to Paragraph l.b.
of Section 29.2, thorium—230.
29.4 Schedule
Cotter shall conduct these remedial activities
accqrding €0 the foLlowing scheduls: -
i... Cotter shall submit a plan for the sub-basin
rel.ase soil studies within ninety (90) days after entry of
the Consent Decree by the Court.
—231—
C0T7fl O1 5 i 2 i 4
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2. The State shall act upon Cotter’s plan for
sub-basin release soil studies within ninety (90) days of
receipt.
3. Cotter shall implement the plan for sub—basin
soils studies in accordance with Paragraph 1. of Section 29.2
at a rate of two sub—basins per year until all sub-basins
identified in Figure 1-2 have been studied. Thes. studies
shall be completed pursuant to the approved schedule.
4. Cotter shall submit a written report on the
results of th. sub—basin release soil, studies within sixty
(60) days of the completion of the survey in each sub-basin
and the receipt of background data.
5. The State shall act upon the sub-basin
release soil study report within sixty (60) days of its
receipt.
6. Cotter shall—submit a plan nd schedule for
the construction and-maintenance of silt fences or for soil
removal uith&n..s,ixty (60) days of State action upon the sub-
basin release soil itudy report. -
— 7 • The State shall act upon the ‘plan and
schedule within sixty (60) days of its receipt.
8. - Cotter shall submit a writtsn final report
within one hundred twenty (120) days after the completion of
the construction of any silt fences.
—232—
COT?fl—O 151215
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9. The State shall act upon the final report
within thirty (30) days after its receipt.
o. Cotter shall submit as part of the RAP Annual
Report specified in Section 3.1 a written annual activities
su ary as described in Section 29.3.
11. The State shall act upon each annual report
within one hundred and twenty (120) day. of its receipt.
12. Cotter shall notify the State sixty (60) days
prior to removal of any silt fence.
13. The State shall act upon a written proposal
submitted by Cotter to remove a silt fence within thirty (30)
days of receipt.
—233—
COfTU O15l 2 l 6
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30 AR1 AN$AS RIVER
30.3. DLescri tion of 0 erations and Relevant
Environmental Conditions
Mill-derived particulates dispersed by the wind
are deposited in off—site soils. These particulates are
available to migrate down nearby ephemeral drainages as part
of sediment leading during storm events. RAP activities are
designed to minimize and mitigate such migration. Data
concerning the impacts of storm event sediment loadings on the
water quality are not available.
30.2 Remedial Activities
The purpose of this study is to evaluate the
adequacy of the on—going river monitoring program and its
ability to measure the effectiveness of RAP activities.
Cotter shall perform the foilpuing remedial
activities:
3.. Cotter shall design and conduct a preliminary
study to document the performance and effectiveness ef - -
remediation efforts-as they affect the Arkansas River and its
ephemeral and perennial surface water -tributaries in the
vicinity of the mill site. The overall reich of the Arkansas
River to b..monitoredihall be sufficient in length to monitor
spatial variability. The proposal shall identify the
constituents to be studied and shall address a study of stream
flows, water, quality, sediments, macroinvertebrates, and fish
populations. It is anticipated that the preliminary study
—234—
COTTU—0181217
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should, for example, examine seasonal events and should
contemplate an intensive sampling effort including three
replicated water samples over fifteen sample periods within a
five-day time frame, with sediment sampling coincident with
water sampling, and programm.d macroinv.rtsbrate collection.
2. Cotter shall initiate the preliminary study
coincident with the next spring runoff period following State
approval and continue it through the spring runoff period of
the following year.
3. Cotter shall modify its current monitoring
program of the Arkansas River based en the results of the
preliminary study.
30.3 Recuisit. Assessments and Enaineerina Activities
Cotter shall prepare and submit to the State for
review and approval the following:
. A an for this study which shall include;
a. Description of sampling efforts;
b. Descriptionof constituents to be
studied;
c. A/QC Plan:
d. Schedule.
2. A itten flinal report of the results of this
study which shall include:
a. Description of activities:
b. Data collected;
—235—
COTTU—0151218
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c. Findings and conclusions;
d. Quality assurancs and quality control
evaluation;
e. Explanation of and respons. to
unexpected conditions and problems.
3. A plan for modifying the ongoing performance
monitoring of the Arkansas River, if necessary, which shall
include:
a. Proposed modifications to the current
monitoring conducted in accordance with
the Radioactive Materials License;
b. Quality Assurance/Quality Control
(QA/QC) plan;
c. Schedule.
4. Annual activities summary of the performance
monitoring program, which shall include:
a. Data collected;
b. Quality assurance and quality control
evaluations.
30.4 S hdule
Cotter shall conduct these rsm.dial activities
according to the following sch.dul :
1. Within one hundred and eighty (180) days
after the entry of a Consent Decree, Cotter shall design and
submit a plan for this study to the State.
—236—
COTTU—015 12 19
q/ 0
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2. The State shall act upon said plan within one
hundred and twenty (120) days after its receipt.
3. cotter shall start this study coincident with
the start of spring runoff following approval of the plan.
4. Cotter shall continue the study through the
end of spring runoff of the year following the start of the
study.
5. Within one hundred and eighty (180) days
following the receipt by Cotter of all laboratory analysis,
Cotter shall submit a written final report of the results of
the study to the State and the Health Risk Assessment Panel,
including a proposal for any modification of the performance
monitoring program.
6. The State shall act upon the final report of
the results of the study within one hundred and twenty (120)
days after its receipt.
7. Cotter shall implement the approved ongoing
performance monitoring program within thirty (30) days of
receipt of State approval of the plan.
8. Cotter, as part of the RAP Annual Report
specified in Section 3.3., shall submit an annual s imm ry of
the performance monitoring program as described in Paragraph 4
of Section 30.3.
9. The State shall act upon th. annual summary
within one hundred twenty (2.20) days of its receipt.
—237—
COTTU—O 1 1220
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31. MINNEQUA RESERVOIR AND PUEBLO RESERVOIR
31.1 Descri tion of Oi .rat ions and Observed Im acts
The Arkansas Rivsr flows to the Minnequa and
Pueblo Reservoirs. Sediment material in the Arkansas River
settles out in the Ninnsqua and Pueblo Reservoirs.
31.2 Remedial Activities
The purpose of these remedial activities is to
define the existing concentrations of specified elements in
the sediments of the Minnequa Reservoir and the Pueblo
Reservoir.
The Stats may conduct or may have conducted, as
appropriate, a study of sediment cores of the Minnequa and
Pueblo Reservoirs. Cotter may observe sample collection
procedures, and will have acc.Is to split samples if
sufficient sampl volume is available. If conducted, the
study shall include:
a. Sediment core samples shall be collected
from each of the two rsservoirs.
b. The number of sediment core samples for
each location shall not be greater than
twelve (12);
c. Each sample shall consist of two
sediment cores; one sediment core shall
be maintained in an appropriate archive,
and the other sediment core shall be
—238—
comi—oiiiazi
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analyzed by an appropriate laboratory to
be agreed upon by the parties;
ci. Each sediment core to be analyzed shall
be divided into the following depth
segments:
i. Zero (0) to two (2) centimeters
(cm);
ii. Two (2) to five (5) csntimetsrs
(cm);
iii. Five (5) to ten (10) centimeters
(cm);
iv. Ten (10) to twenty (20)
centimeters (cm);
v. Twenty (20) to thirty (30)
centimeters (cm);
vi. Below thirty (30) centimeters
(cm).
e. Each sediment core segment shall be
analyzed only for radium—226, thorium-
230, molybdenum and nickel;
f. Th. results of each laboratory analysis
shall be subjected to a two-way analysi.s
of variance with blocking by location
and depth;
—23 9—
C0TTU—O 151222
-------
g. Contouring shall be used to further
establish the concentrations of
radium—226, thoriu -23O, molybdenum and
nickel;
h. Cotter may observe the collection of the
sediment cores.
31.3 Reaui it. Assessments and Knatheerina Activities
Pursuant to the analysis to be conducted as
described in Section 31.2, a written report shall be prepared
which shall include:
a. Description of activities;
b. Data collected;
c. Findings and conclusions;
d. Explanation of and response to
• unexpected conditions and probleins
e. Quality assurance and quality control
evaluations.
31.4 Schedule
The State shall provide a copy of the report of
the results of the study of the sediment cores of the !4innequa
and Pueblo Reservoirs to Cotter within thirty (30) days of the
completion of the report.
—240—
coflfl—0151223 14)11
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32 HEALTH RISK ASSESSMENT
32.1. Descrthtiofl of O erations and Observed Im acts
Mill. derived constituents are released into the
environment, and are present in the ground water, air and
soils. There ar. potential routes of exposure from the
environment to humans. The present data ar. insufficient to
determine if there is an effect en human health.
32.2 Remedial Activities
The purpose of these remedial activities is to
determine if the release of mill, derived constituents has an
effect on human health.
Cotter shall perform and the State shall be given
the opportunity to participate, as specified below, in the
following remedial activities:
1. Cotter shall have a health assessment panel
comprised of at least three (3) qualified and independent
persons with expertise in medicine, toxicology, epidemiology,
public health, or h” ’s health effects associated with
exposure to radionuclide. and metals to design and conduct a
comprehensive study to assess the human health risks and
impacts, if any, attributable to mill derived constituents.
The geographic boundaries shall include the off-site area in
the vicinity of the mill site, including Lincoln Park and
Canon city. The study shall include:
—241—
COfTII01 51224
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a. An assessment of human health risks and
impacts associated with:
i. Consumption of impacted ground
water;
ii. Consumption of impacted surface
water;
iii. Exposure to impacted soils and
sediments;
iv. Inhalation of radon gas or
impacted airborne dust;
v. Consumption of fish from impacted
• surfac. water bodies;
vi. Consumption of fruits and
Vegetables irrigated with impacted
water;
vii. Consumption of milk from cows that
have consumed impacted water;
viii. Consumption of meat from livestock
that have cOnsumed impacted water
or feed.
b. A multi dim.nsional risk ass•ssment
matrix using an estimate of human health
risk, considering, a. appropriate,
sensitive segments of the population, as
the dependent variable, and using hazard
—242—
COTTfl—0151225
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potential and mechanism of exposur. as
the independent variable;
c. Phases for problem definition, design of
methodology, completion of sampling and
methodology, generation of written
rsport and recommendation. for future
action;
d. The rsviev and integration of
appropriat, information, obtained as a
result of the remedial activities
conducted as described in this RAP.
e. Sampling.
32.3 Recuisits Assessments and Enain.erinc Activities
Cotter shall prepare, or for Paragraphs 2 and 3
have prepared by ‘the Health Risk Assessment Panel, and submi.t
to the Stat. for review and approval th. following:
1. A written proposal identifying the persons
who will design and conduct the health risk assessment, which
shall include:
a. Identity of each person:
b. Curriculum vitae of each person;
c. Experience in the design and conduct of
health risk assessment;
d. All relevant past experience;
—243—
COTTIlO16lZZS
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2. A plan for the design and implementation of a
study to assess the human health risks and impacts, which
shall include:
a. Description of activities and goals;
b. D.scription of procsdures and
msthodologi.s, including the proposed
nam. of a volunteer local Community
representative who will act as a liaison
between the panel and th. community for
the purposes of information exchange
between the.. two groups. (The minimum
qualifications of this volunteer local
community representative are: resident
in the area for no less than three (3)
years and medical doctor or Ph.D. in a
physical or biological science);
c. Consideration and integration of
appropriate information, as determined
by the panel, generated as a result of
the remedial activities being conducted
pursuant to this RAP and any relevant
reports or findings prepared by the
Agency for Toxic Substances and Disease
Registry (ATSDR).
—244—
COTTIl—0151227
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d. QA/QC Plan:
•. Schedule.
3. A written intsria report on the study to
assess human health risks and iapacts, which shall include:
a. Description of activities and rssults;
b. Recommendations for future action,
considering ATSDR’ s recommendation;
c. Quality assurance and quality control
evaluation;
d. Explanation of and response to
unexpected conditions and problems.
4. A written report stating findings and
conclusions of the Health Risk Assessment Panel regarding any
site-related reports submitted to th. panel by Cotter, the
State or the ATSDR, including reports of the ground water
survey (see Section 13), Lincoln Park soil survey (S .. Section
25), Willow Lakes study (see Section 26), and the Arkansas
River (see Section 30).
5. A written final report of th . results of the
study to assess h’am health risk.. and impacts, which shall
includ.:
a. Description of activities and results;
b. R.comm.ndations for future action,
considering ATSDR’ s recommendation;
—245—
COT?Il—0151333
1)
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c. Quality assurance and quality control
evaluation;
d. Explanation of and response to
unexpected conditions and problems.
32.4 Schedule
Cotter shall conduct these remedial activities
according to the following schedule:
1. Within sixty (60) days of the entry of the
Consent Decre, by the Court, Cotter shall submit a written
proposal identifying the persons who will design and conduct
the health risk assessment.
2. The State shall act upon the written proposal
within thirty (30) days after its receipt.
3. Within one hundred and twenty (120) days
after approval of th. written proposal, Cotter shall have the
health assessment panel prepare and Cotter shall submit a plan
for the design and implementation of a study to assess human
health risks and impacts, if any.
4. Th. Stat, shall act upon the plan within
ninety (90) days after its receipt.
5. Within one hundred and eighty (180) days of
the approval of th. plan, Cotter shall have the M.alth Risk
Assessment Panel impisment the plan and submit a written
interim report.
—246—
COfTfl015 1229
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and twenty (120) days of
the Health Risk Assessment
Risk Assessment Panel
Paragraph 4 of Section
6. The State shall act upon the interim report
within thirty (30) days of receipt.
7. Within one hundred
receipt of any reports submitted to
Panel, Cotter shall have the Health
submit a written report pursuant to
32.3 to the State.
8. The State shall act on the reports within
thirty (30) days of receipt.
9. Within one hundred and eighty (1.80) days
after the completion of the assessments, Cotter shall have the
Health Risk Assessment Panel prepare the final written report,
and Cotter shall submit it to the State.
10. The State shall act upon the final written
report within oni hundred twenty (1.20) days of its receipt.
—247—
C0T’fflO16 1230
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Linailn Park Site Mining Waste NPL Site Summary Report
Reference 3
Telephone Communication Concerning Lincoln Park Site;
From John Vierow, SAIC, to Denise Link, EPA Region VIII;
May 13, 1991
-------
I
.3
TELECOMMUNICATIONS
SUMMARY REPORT
SAIC Contact: John Vierow Date: 5/13/91 Time: 12:30 p.m.
Made Call — Received Call
Person(s) Contacted (Organization): Denise Link, EPA
Subject: NPL Site Summary Report for lincoln Park, Colorado
Summary: Ms. Link verified that residences near the site which used well water oresently are supplied
with Carson City water. She did not know lf ll residences were supplied with Canon City water, and
stated that the ground water near the site Is still contaminated.
-------
.319’
Mining Waste NPL Site Summary Report
Martin Marietta Reduction Facility
The Dalles, Oregon
U.S. Environmental Protection Agency
Office of Solid Waste
June 21, 1991
FINAL DRAFT
Prepared by:
Science Applications International Corporation
Environmental Health and Sciences Group
7600-A Leesburg Pike
Falls Church, Virginia 22043
-------
DISCLAIMER AND ACKNOWLEDGEMENTS
The mention of company or product names is not to be considered an
endorsement by the U.S. Government or by the U.S. Environmental
Protection Agency (EPA). This document was prepared by Science
Applications International Corporation (SAIC) in partial fulfillment of
EPA Contract Number 68-WO-0025, Work Assignment Number 20.
A previous draft of this report was reviewed by Mary Kay Voytilla of
EPA Region X [ (206) 553-2712], the Remedial Project Manager for
the site, whose comments have been incorporated into the report.
-------
Mining Waste NFL Site Summary Report
MARTIN MARI A REDUCTION FACILITY
THE DALLES, OREGON
INTRODUCTION
This Site Summary Report for the Martin Marietta Reduction Facility site is one of a series of reports
on mining sites on the National Priorities List (NPL). The reports have been prepared to support
EPA’s mining program activities. In general, these reports summarize types of environmental
damages and associated mining waste management practices at sites on (or proposed for) the NPL as
of February Ii, 1991 (56 Federal Re2ister 5598). This summary report is based on information
obtained from EPA files and reports, and on a review of the summary by the EPA Region X
Remedial Project Manager for the site, Mary Kay Voytilla.
SITE OVERVIEW
The Martin Marietta Reduction Facility (MMRF), a 350-acre site located in The Dalles, Wasco
County, Oregon, is an aluminum processing plant. The facility was first operated in 1958 and was
designed to produce approximately 90,000 tons per year of aluminum (by electrolysis of alumina
dissolved in molten cryolite) (Reference 2, page 3). The site contains several areas of significant
contamination resulting from past treatment, storage, and disposal of wastes associated with aluminum
production (see Figure 1).
A 15-acre landfill located near the aluminum reduction building contains approximately 200,000 cubic
yards (yd’) of waste and construction debris. Waste disposed of in the landfill include asbestos,
metallic wastes, and 5,000 tons of spent cathode-waste materials containing cyanide, Polynuclear
Aromatic Hydrocarbons (PAHs), and arsenic. Leachate released from the landfill prior to the
installation of a leachate-collection system has resulted in the contamination of the area aquifers.
In addition to the landfill, approximately 64,670 yd’ of cathode-waste material was deposited at the
unloading area and the old cathode-waste management area. Additionally, the MMRF has four
Scrubber Sludge Ponds (SSP-l through SSP-4), two of which have been covered with soil and
vegetation. The ponds cover 14.8 acres, and contain contaminated sludge and subsoil.
The primary contaminants of concern at the MMRF are Volatile Organic Compounds (VOCs),
including trichioroethylene (TCE) (from landfill leachate), PAHs; and inorganics, such as asbestos,
cyanides, arsenic, and other metals (Reference 1, Abstract; Reference 2, page 3).
1•
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Martin Marietta Reduction Facility
FIGURE 1. AREAS OF INVESTIGATION MARTIN MARIETTA REDUCTION FACILITY
N
0 500 1000
L
SCALE IN FEET
a
c r
CAThOOI WAfT1 Pt .I
OtflFAJ. .
$C UII( I
MCYCU
PONO
APP OIIMATt STUDY
A SA SOW4DMY
2
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Mining Waste NPL Site Summary Report
The area surrounding the site is primarily used for heavy industry and manufacturing, with less than
20 residences and businesses located in close proximity. Land not used for industrial/manufacturing!
residential purposes is leased for agricultural uses such as cattle grazing. Ground water is an
important source of water supply in The Dallas area for domestic, industrial, and agricultural
purposes (Reference I, pages 3 and 4; Reference 2, page 3). Ground water flows in an easterly
direction, towards the Columbia River (see Figure 1).
In the spring of 1983, cyanide compounds were detected in the ground water, which lead to the
proposal of the site for the NPL in October 1984. In 1987, the site was formally placed on the NPL
(Reference 1, page 7).
The Remedial Investigation and Feasibility Study were completed in June 1988, and EPA issued a
Record of Decision (ROD) in September of that year. The selected remedial action for this site
includes:
• Excavating the cathode-waste material, placing it into the existing landfill, and covering the
landfill with a Resource Conservation and Recovery Act (RCRA) cap (a multi-media cap
meeting RCRA performance standards)
• Placing a soil cover over the two remaining uncovered Scrubber Sludge Ponds (SSP-2 and
SSP-3)
• Plugging and abandoning nearby production wells and connecting ground-water users to the
City of The Dallas water supply
• Collecting and treating leachate generated from the landfill, the perched water east of River
Road and the Cathode-Waste Management Areas, and ground water in the Unloading Area
using an aqueous treatment system with onsite discharge into a recycling pond
• Implementing ground-water monitoring, and establishing a contingency plan to perform
additional recovery of ground water in the event of further contamination
• Implementing institutional controls such as deed restrictions and fencing (Reference 1, page
30).
The estimated present cost for this remedial action is approximately $6,707,400 with an annual
Operation and Maintenance (O&M) cost of $144,000 for years 1 through 5 and $55,600 for years 6
through 30 (Reference 1, Abstract).
‘1 3•
U ?
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Martin Marietta Reduction Facility
OPERATING HISTORY
Operations at the MMRF site began in 1958, when Harvey Aluminum, Inc., established an aluminum
processing facility with the capacity to produce 90,000 tons per year of aluminum from alumina. The
process takes place in a reduction cell, potlined with alumina insulation and carbon potlining. An
electrical current is sent through a solution of aluminum oxide dissolved in a bath of moten cryolite.
The aluminum and oxygen separate with aluminum forming on a cathodic surface.
Harvey Aluminum, Inc., became a wholly owned subsidiary of the Martin Marietta Corporation in
1970. Operations continued at the plant until it was closed in 1984. Legal tide to the property was
acquired by Martin Marietta Corporation in 1984. In 1986, Martin Marietta Corporation leased the
plant and adjacent property to Northwest Aluminum Company, which resumed primary aluminum
operations in 1987 (Reference 1, page 1; Reference 2, page 3; Reference 3, page 1-4). The Lined
Pond, Discharge Channel, and Recycle Pond were reactivated for plant operations. A detailed
chronology of MMRF operation is presented in Table 1 (Reference 2, Table 1).
During operation of the aluminum 1 ciity, waste constituents derived from alumina reduction were
stored, treated, and disposed of at the site. These waste constituents are derived from spent cathodes
and anodes utilized in the alumina reduction process and include refractory bricks, carbon bricks
(potliner), fabricated metal, remnant aluminum, and process bath (Reference 2, pages 3 and 4).
Waste-management practices at the site from 1958 to 1972 involved washing and temporarily storing
spent cathodes and shipping spent cathodes offsite via railroad. From 1972 to 1984, land disposal of
spent cathodes and other materials was conducted onsite (Reference 4, page 1).
The first scrubber system to control fluoride emissions began operation in 1958. This scrubber
system was replaced in the 1960’s, and a secondary scrubber was added to the system in 1969
(Reference 2, pages 3 and 4 and Table 1). These scrubbers generated air emission-control sludge that
contained elevated levels of fluoride, sulfate, and PAils. This waste was discharged to the SSPs, the
Recycle Pond, the New Lined Pond; it was also recycled into the pots (production) (Reference 2,
pages 3 and 4 and Figure 2).
As a result of releases from the waste-management units onsite, in September 1985, Martin Marietta
Corporation entered into a Consent Order with EPA to conduct an Remedial Investigation/Feasibility
Study (Reference 2, pages 3 and 4). Prior to initiating the Remedial Investigation, the following
interim remedial actions were performed at the site: (1) construction of a lined pond; (2) relocation
of the old cathode-waste pile to the new cathode-waste pad containing a leachate-collection system;
(3) fencing of the landfill to restrict access; and (4) construction of a landfill leachate-coltection
system consisting of perimeter ditches and a collection sump (Reference 2, page 4).
4
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Mining Waste NPL Site Summary Report
TABLE 1. CHRONOLOGICAL HISTORY OF MMRF OPERATIONS
Datsa
Ev t
1957- 1960
Plant construction debris placed in the Landfill. Paper and wood burned in the Landfill. Burning ceased after 1960. aa piper and wood
waste weie crushed and shipped to Wasco County Landfill.
1958
Process operations initiated by Harvey Aluminum, Inc Plant emiuiona collected in a wet pnmary-fluondc scrubber system (known as
the 01d Tower system) and di.chargcd to SSP-2 and SSP-3.
1960’.
Old Cathode-waste Pile started at noiihcast corner of the plant. Old Cathode-wash Area constructed cast of the plant and next to River
Road
1961 - 1971
Bricks separated from cathodes taken out of service and placed in the Landfill. Other cathode waste was shipped offsitc for processing
at Reynolds Aluminum.
1968
Bonn and Settling Basin added to the Old Cathode-wash Area. Martin Marietta Corporation purchased 41 percent of common stock of
Harvey Aluminum.
1969
Secondary acnibber added to existing scrubber system to enhance air emission controls. Mattin Marietta Corporation purchased an
additional 41 7 percent of common stock of Harvey, bringing the total stock purchased to 82 7 percent.
1972
Martin Marietta Corporation purchased the remaining 173 percent of common stock of Harvey Aluminum. Clarifier placed online
SSP-I use began. SSP-2 and SSP-3 use diicontinued except for use as a back-up when the clarifier was oftline.
1974
Recycle Pond constructed for use aa Scaling Basin for solids separation from secondary scrubber waler Old National Pollutant
Discharge Elimination System (NPDES) Discharge Channel removed (toni service.
1974 - 1984
Caathonae, Paste Plant, and plant operattona waste were deposited in the Landfill.
1976
SSP-4 was constructed and used to store dredged matenala from SSP-2. SSP-3, and the Recycle Pond.
1977
SSP-2 was dredged and the material was placed in SSP-4.
1978
A Dry Scrubber System was installed to replace the Electrostatic Precipitator.. A Wet Scrubber added downstream of the dry system as
a backup and to collect sulfur dioxide emissions, fluoride absorbed by activated alumina in the Dry Scrubber was recycled back to the
Reduction Cell. Solids from the Wet System were pumped to the SSP.
1979
SSPs and Old Cathode-wash Area were extended to the cast.
1980
A Lined pond was constructed in reduce the volume placed in the S5P. Mama Marietta Corporation study control of surface-water
flow arcund the Landfill. A Hard-pitch building was conatiucted.
July 1980
Piping from the Landfill to the Landfill Leachate-collectionSump was installed. A Suing pump was installed to eliminate discharges
from the Landfill under River Road.
1981
SSP-l and SSP .4 use was discontinued. The SSPa were capped.
1982
SSP-2 received runoff from SSP-3. The Dredged bottoms of the Lined Pond and the Recycle Pond were placed in SSP-3
1983
(spring)
Cyanide levels were above detection limits during routine sampling of Production Well 2. The well property subsequently was
abandoned.
1983
Leachate was detected migrating from the landfill under River Road to the Rock-line Quarry. Century West Engineering investigated
the Landfill for depth to bedrock and subsurface/surface runoff Surface cover was added to the Landfill to control surface drainage
towards the east, and drainag, ditches were conattucted to control runoff and runon (in the Surface Drainage Ditch and the Laa haw
Collection Ditch). A diversion berm also cosistiucted on the west side of the ditch to eliminate surface runoff.
5.
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Martin Marietta Reduction Facility
TABLE 1. CHRONOLOGICAL HISTORY OF MMRF OPERATIONS (Continued)
1983
Century West Engineering prepared a leachate-collection system design for the Landfill. EPA performed
hazardous waste ranking of MMRF. The State of Oregon Department of Environmental Quality listed
potliner (cathode) waste as hazardous. Martin Marietta Corporation built an approved waste pad to store
waste potliner (cathode). Old polliner cathode waste previously stored at the Old Cathode-waste Pile was
located to the permitted storage area.
1984
Martin Marietta Corporation acquired legal title to the property from Martin Marietta Aluirunum, Inc.
Martin Marlene Corporation constructed a leachare-collectioo system for the Landfill and constructed a New
Cathode-wage Pad. The remaining Old Cathode-wage Pile waste and 6 inches of sod was relocated to the
New Cathode-wage Pad. Area backfllled and graded with clean sod.
December 1984
Martin Marietta Aluminum, Inc., ceased production.
September 1985
Martin Marietta Corporation entered into a Consent Ceder with EPA Regina X. Requirements of the consent
order include the performance of a Remedial Investigation and Feaaibihty Study lbr the MMRF. This was
the first regulatory action enforced on the MMRF.
December 1985
Work plan for the Remedial Investigation/Feasibility Study prepared by Geraghty & Miller, Inc., for Martin
Marietta Corporation was submitted to the EPA. Camp. Dmassr & McKee, Inc., submitted a Community
Relationa Plan for the !vUt1RP to EPA.
February 1986
The Remedial Investigation/Feasibility Study Work Plan were modified.
March 1986
The Remedial lnvestigstion/Feuibility Study Work Plan was implemented by Gersghty & Miller, Inc.
April 1986
Fencing was installed to secure Landfill.
September 1986
Martin Marietta Corporation leased the MMRF to Northwest Aluminum Company under. 5-year lease/sale
agreement. Northwest Aluminum Company resumed primary aluminum operations. The Lined Pond, the
Discharge Channel, and the Recycle Pond were reactivated for plant operations.
November 1986
Results of initial Remedial Investigation data collection activities were summarized by Geraghty & Miller,
Inc.. in lntenm Report Remedial Investigation, MMRF. the Dilles, Oregon’ (submitted to EPA).
1987
Flows to the Duck Pond were diverted to the Discharge Channel.
January 1987
MMRF was designated as a Supe,fiind Site.
March 1987
Remedial Investigation/Feasibility Study Work Plan Addendum was submitted to EPA.
May 1987
Remedial Investigation/Feasibility Study Work Plan Addendum was modified.
June 1987
EPA approved the Remedial Investigation/Feasibility Study Work Plan Addendum. Field activities specified
in the addendum were initiated.
November 1987
Th. Preliminary Remedial Investigation was submitted to EPA.
March 1988
The Final Remedial Investigation was submitted to EPA.
April 1986
The Preliminary Feasibility Study was submitted to EPA.
June 1988
The Final Feasibility Study was submitted to EPA.
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Mining Waste NPL Site Summary Report
SITE CHARACTERIZATION
The MMRF site is located in The Dallas, Wasco County, Oregon, west of the Columbia River. The
site occupies approximately 350 acres within an 800-acre area zoned for heavy industry and
manufacturing. Approximately 110 acres of the site area are used for industrial purposes. MMRF is
bounded by the Mountain Fir wood-hauling and chip mill to the north; Weber Street to the
south; the Columbia River to the east; and the Union Pacific Railroad line and West Second Street to
the west (see Figure 1) (Reference 1, page 1; Reference 2, page 3; Reference 3, page
1-2).
Currently, there is little development along the Columbia River waterfront in the vicinity of MMRF,
although there are plans to use a tract between the River and the site for industrial development. The
rest of the 800-acre industry/manufacturing-zoned area around the site is light1 ’ vegetated or wooded.
MMRF land not used for industrial processes is leased for agricultural activities, such as cattle
grazing. Based on aerial photographs, less than 20 homes and small businesses were located in the
vicinity of MMRF as of 1988 (Reference 1, page 3; Reference 2, page 3; Reference 3, page 1-2).
The site topography is relatively level and is characterized by man-made and natural features such as
man-made ponds, the Landfill, drainage ditches, stream channels, road beds and filled areas
(Reference 2, page 6; Reference 3, page 1-42).
Described below are the major sources of contamination (disposal areas) followed by descriptions of
associated impacts on ground water, surface water, soil, and air.
Landfill and Associated Drainage Areas
The Landfill occupies approximately 15 acres immediately north of the alumina reduction building.
Wastes at the landfill were randomly deposited on the ground surface. Total waste volume is
estimated to be approximately 200,000 cubic yards (yd 3 ), and consists of the following types of
materials, which resulted from the aluminum production process and construction operations at
MMRF:
• Construction debris, including basalt fragments
• “Target wastes,” including spent cathode materials (an estimated 5,000 tons), refractory bricks.
off specification carbon fragments, pitch, coke, and cryolite
• Metallic wastes (e.g., buss bars and collector studs)
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Martin Marietta Reduction Facility
• Pallets, cans, rags, and empty drums.
Prior to the institution of asbestos-handling and disposal regulations, asbestos was deposited randomly
into the Landfill. Subsequent to these regulations, this material was disposed of in discrete areas of
the Landfill (Reference 1, page 10; Reference 2, page 12; Reference 3, page 1-87).
ft was estimated that 5,000 tons of spent-cathode materials are present in the landfill. These materials
contain high levels of carbon, sulfate, sodium, and fluoride plus minor amounts of cyanide. Cryolite,
which is composed of fluoride, sodium, and aluminum, was also found to be present in the Landfill.
Pitch and coke associated with the reduction process are present and contain elevated levels of PAHs
and low levels of arsenic (Reference 1, page 10; Reference 2, page 13).
Leachate generated by the landfill is contained by a leachate-collection system. Leachate generation is
seasonal and is directly related to precipitacions or snow melts. From 0 to 50,000 gallons per day
(gpd) leachate has been pumped from the landfill for treatment, with the peak flow occurring
generally in the early spring. Contaminant concentrations in the leachate also vary seasonally
(Reference 1, pages 12 and 13). In 1986 and 1987, leachate was found to contain the following
chemicals: trichlorethylene [ 8 milligrams per liter (mgIl)J, PAHs [ 0.010 to 0.206 micrograms per
liter ( g1I)], total cyanide (373 to 1,280 mg/I), free cyanide (34.2 to 77.2 mg/I), fluoride (5,400 to
8,000 mg/I), sodium (36,600 to 99,800 mg/i), sulfate (10,500 to 49,300 mg/I), and chloride (1,210 to
3,430 mg/I) (Reference 1, page 89).
Potliner Handling Area (Within Old Cathode Manacement Areas
Past cathode-waste management activities occurred near the northeast corner of the plant building and
included the Metal Pad Storage Area, the Bath Recovery Area, the Salvage Area, the Potliner
Handling Area, and the Old Cathode Waste Pile.
Scrubber Sludge Ponds
The SSPs, which are no longer in use, were used to settle particulates from wastewater generated in
the air pollution-control system. These ponds discharged accumulated water to the Columbia River
(Reference 1, page 12; Reference 2, page 17; Reference 3, page 1-108).
The lateral extent of the four SSPs is approximately 14.8 acres. The ponds were subsequently
covered with soil and vegetation to help prevent direct contact with the waste. According to the
Remedial Project Manager, SSP-2 and SSP-3 were capped with soil and revegetated during Phase 1
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Mining Waste NPL Site Summary Report
remedial action activities. Prevalent winds have scattered approximately 538 cubic yards of sludge
south of SSP-2 and SSP-3. The material in the SSPs can be divided into three categories: (1) soil
cover; (2) sludges; and (3) contaminated subsoils (Reference 1, page 12; Reference 2, page 17;
Reference 3, page 1-112).
As part of the sampling effort completed for the Remedial Investigation, the following contaminants
were detected in samples from the sludge ponds: fluoride [ 204 to 613 milligrams per kilogram
(mg/kg)), arsenic (below detection limit to 77 mg/kg), sodium (6,250 to 45,000 mg/kg), and PAHs
(1,940 to 8,570 mg/kg) (Reference 1, page 12; Reference 2, page 18).
Described below are the contaminated media and the related sources of contamination. All sampling
data are from the 1988 Remedial Investigation; sampling was conducted in 1986 and 1987.
Ground Water
The ground-water flow system in the vicinity of the site is complex, and includes four aquifers [ the S
Aquifer, the A Aquifer, the B Aquifer, and the Dalles Ground Water Reservoir (DGWR) Aquiferl.
The S Aquifer is a water-table aquifer that overlies a series of confined aquifers. The first confined
aquifer, A Aquifer, ranges from 100 to 150 feet below the ground surface, and is 5 to 45 feet thick.
The second confined aquifer, B Aquifer, ranges from 150 to 200 feet below ground surface, and is 30
to 50 feet thick. The B Aquifer is below the A Aquifer and is separated from it by low permeability
basalt (lava lobe). In areas where the lava lobe is absent, the aquifers combine to form a single
hydrogeological unit. A deep confined aquifer (greater than or equal to 220 feet below ground
surface), the DGWR Aquifer, exists below the B Aquifer and supplies regional ground water
(Reference 1, page 14; Reference 2, page 8; Reference 3, page 1-47). In addition to the S, A, B, and
DGWR Aquifers, an alluvial aquifer is present in the area north of the plant. The alluvial aquifer is
approximately 400 feet wide and at least 60 feet deep (Reference 2, page 8).
Perched water has been encountered in the permeable fill material at the Old Cathode-waste Pile,
Salvage Area, and Potliner Handling Area (see Figure 1). One source of the perched water is
precipitation; other potential sources include infiltration from the Landfill Ditch and North Ditch, and
leaks in below-grade water-distribution lines. Table 2 lists the hydrogeological units and their
characteristics (Reference 1, page 14; Reference 2, page 8 and Table 3; Reference 3, page 1-47).
The S Aquifer is believed to discharge into the Columbia River, and into the Alluvial Aquifer at the
point where the two aquifers intersect at the northern portion of the facility. The A Aquifer may be
recharged by the Alluvial Aquifer, the Columbia River, and the S aquifer. Discharge of ground
q 2 ?
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Martin Marietta Reduction Facility
water in the A Aquifer appears to be from the B Aquifer and regional water-supply wells. Ground-
water flow in the S Aquifer is generally east and northeast; ground-water flow in the Alluvial Aquifer
is expected to be east; ground-water flow in the A aquifer predominantly west; and ground-water flow
in the B aquifer is to the west and south (Reference 1, page 14; Reference 2, page 8; Reference 3,
page
1-48).
Ground water is an important source of water supply in The Dalles area for domestic, industrial, and
agricultural use. The primary aquifer in the area for those purposes is the DGWR. The alluvial
aquifer located in the Chenoweth Creek area is used by a nearby Animal Shelter (see Figure 1)
(Reference 1, page 4).
According to the Remedial Investigation, chemicals of concern identified in the ground water include
total and free cyanide, fluoride, sodium, and sulfate. The highest constituent concentrations are
present in the perched aquifer with progressively lower concentrations identified in the S. A, and B
Aquifers; concentrations in the DGWR Aquifer are well below health-based standards and are within
the range expected for background (Reference 1, page 16; Reference 2, page 18; Reference 3, page
1-116). Monitoring data from each contaminated Aquifer (perched water and Alluvial Aquifer, S
aquifer, A Aquifer, and B Aquifer) are described below.
W nd
Perched water samples, taken for the Remedial Investigation from the Old Cathode-waste Area
showed elevated concentrations of free cyanide (3.0 mg/I), fluoride (3,000 mg/I), and sodium (10,500
mg/I). Contaminants in wells sampled in the Alluvial Aquifer were found above detection limits but
below health-based standards (Reference 1, page 16; Reference 2, pages 18 and 19).
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Mining Waste NPL Site Summary Report
TABLE 2. SITE IIYDROGEOLOGY MMRF
Confined/
Unit
Characteristics
Thickness/Extent
Unconfined
Transmissivity
Perched-
Fill
Limited to areas where fill
Unconfined
Low
water Zone
overlies depressions in
bedrock
Alluvial
Alluvial Sand
Limited areal extent;
Unconfined
Moderate
Aquifer
and Gravel
approximately 60 ft. deep x
400 ft. wide x 3,000 ft. long
S Aquifer
Basalt
(Subaerial) and
Byron Interbed
Upper portion not present in
SE portion of site
(approximately 100 ft. thick)
Uncontined
Low
A Aquifer
Basalt
(Subaqueous)
Pinches out in southern
portion of site (5-45 ft. thick)
Confined
Moderate
B Aquifer
Basalt
(Subaqueous)
30 to 50 ft. thick
Confined
High
Quincy/Squ
Silistone
Approximately 20 ft. thick
NA
Confining Unit
aw Creek
Interbed
The DaIles
10 to 50 ft. thick
Confined
Very High
Ground-
Basalt
water
(Subaerial)
Reservoir
Source: Reference 2, Table 2
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Martin Marietta Reduction Facility
S Aouifer
Elevated chemical concentrations were identified in the S Aquifer at several locations during the 1986
and 1987 Remedial Investigation sampling effort, including:
• Near the Landfill and Old Cathode-waste Management Area - Fluoride concentrations ranged
from less than or equal to 1.0 to 4.7 mg/I. Free cyanide ranged from 0.09 to 0.136 mg/I,
and sodium ranged from 57.2 to 82.2 mg/I (Reference 1, page 16; Reference 2, page 19;
Reference 3, pages 1-61 and 1-117).
• Scrubber Sludge Ponds - Ground-water samples collected from this area contained fluoride (4.8
to 7.1 mg/I), sodium (246 to 658 mg/I), and sulfate (117 to 3,020 mg/I). Free cyanide was
below detection limits (Reference 1, page 16; Reference 2, page 19; Reference 3, pages 1-61
and 1-117).
• New Cathode Waste Area Near the Alumina Unloading Building - Samples of ground water
collected in this area contained free cyanide at a concentration of 0.215 mg/I. Sulfate was
found at concentrations up to 680 mg/I, and sodium up to 1,270 mg/I. Detectable fluoride
concentrations were as high as 57 mg/I (Reference 1, page 16; Reference 2, page 19;
Reference 3, page 1-61 and 1-117).
• Recycle Pond - Water samples collected from a well downgradient of the Recycle Pond had
concentrations of fluoride up to 5.5 mg/I, sodium up to 90.5 mg/I, and sulfate up to 871 mg/I
(Reference 1, page 16; Reference 2, page 19; Reference 3, pages 1-61 and 1-117).
In general, the constituents of concern in ground water at the site have primarily been identified in the
S Aquifer (the uppermost Aquifer). The S Aquifer is not currently used for water supply in the area,
because the S Aquifer is not very extensive and is of low productivity. It is not likely to be used in
the future as a water supply. Ground water in the S Aquifer is believed to discharge to the Columbia
River (Reference 1, pages 14, 16, and 19).
A Aquifer
The impacts of contaminated areas of the site on the A Aquifer water quality are less widespread, and
at lower concentrations, than those identified in the S Aquifer. The sampling for the Remedial
Investigation found that chemical contaminants present in the A Aquifer near the sludge ponds include
sodium (44.7 to 84.8 mg/I), sulfate (23 to 153 mg/I), and fluoride (less than or equal to 0.1 to 1.0
mg/I) (Reference 1, page 19; Reference 2, pages 19 and 20; Reference 3, page 1-117).
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Mining Waste NPL Site Summary Report
B Aquifer
Elevated constituent concentrations in the B Aquifer are confined to a location in the vicinity of the
Landfill and the Old Cathode-waste Management Area. Contamination of the B Aquifer, detected
during the Remedial Investigation sampling effort, consists of elevated levels of total cyanide (less
than or equal to 1.0 mg/I). Free cyanide and fluoride concentrations have been detected at less than
or equal to 0.10 mg/I and less than or equal to 1.4 mg/I, respectively (Reference 1, page 19;
Reference 2, page 20; Reference 3, page 1-118).
Surface Water and Sediment
The Columbia River and its tributaries act as the major surface-water resource in this area; a
Reservoir on Mill Creek is the principle water-supply source for the City of The Dalles. The
Columbia River and its Tributaries provide a habitat for important commercial and sport fisheries
with Salmon, Trout, Steel head, Walleye, and Bass among the many game fish common to the river.
Many of the Tributaries serve as hatcheries for the Salmonids (Reference 1, page 4; Reference 3,
page 1-53). Fluoride and sulfate both occur naturally in the Columbia River. Background
concentrations of fluoride are reported to range from 0.24 to 0.7 mg/I and background concentrations
of sulfate are likely to range from 15.9 to 34 mg/I (Reference 1, page 20).
Topography largely controls the direction of surface-water flow. In general, surface-water runoff
from active portions of the site is routed to the recycle pond. Leachate from the Landfill and Landfill
runoff are collected by a leachate-collection system, and are also routed to the runoff pond via a
discharge channel. Prior to the construction of this runoff-interception network, Landfill runoff
followed three primary drainage-discharge pathways, all of which aischarged into the Alluvial Aquifer
(Reference 1, page 2; Reference 2, page 7; Reference 3, pages 1-42 and 1-44).
Surface-water ponds at the MMR.F site include four scrubber sludge ponds, the Recycle Pond, the
Duck Pond, and the Lined Pond. The Recycle Pond serves as a collection point for runoff from the
Landfill, the Old Cathode-waste Management Area, and areas immediately south and west of the
alumina plant. The Recycle Pond discharges into the Columbia River under a NPDES permit.
According to the RemeØial Project Manager, the Recycle Pond and Lined Ponds are no longer in use
as part of the plant’s production operation. The Lined Pond was remediated during Phase 1 of
remedial action activities. The Recycle Pond is used to control surface-water runoff, but is not an
active part of the plant’s wastewater recycling system. The scrubber sludge ponds are no longer in
use, but intersect the water table and are saturated in proportion to the relative ground-water elevation
(Reference 1, page 2; Reference 2, page 7).
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Martin Marietta Reduction Facility
Chenoweth Creek (a tributary to the Columbia River - see Figure 1) was sampled in 1987 (during the
Remedial Investigation, and again, in the spring 1988. No impact was demonstrated on the
Chenoweth Creek sediment or surface water from any potential discharge from the site, and detected
levels were all below available aquatic-life criteria (Reference 2, page 20).
The Potliner Handling Area has been identified as the main area of.concern in terms of direct human
exposure to soils. Cyanide (total - 14 mg/kg, free - 4 mg/kg), fluoride (673 mg/kg), sodium (29,600
mg/kg) and PAHs (9,041 mg/kg) have been detected in samples from the Potliner Handling Area
(Reference 1, page 11; Reference 2, page 17).
Mr
Ambient air samples were collected upwind and downwind of active drilling and lest-pit sites during
the Remedial Investigation. Samples were analyzed for gaseous cyanide, particulate cyanide, and
coal-tar pitch volatiles/total dust. Only 1 upwind sample for coal-tar pitch volatiles exceeded
Occupational Safety and Health Administrations (OSHA’s) Permissible Exposure Level (PEL).
Similarly, only I coal-tar sample detected ionizable pollutants above the threshold, requiring Level C
protection (respirators) (Reference 2, pages 20 and 21).
Soil-sieve analyses and fugitive-particulate modeling were carried Out to assess fugitive dust from the
site. The results indicated that “the potential for significant risks from windblown dust were
minimal” (Reference 1, page 21).
ENVIRONMENTAL DAMAGES AND RISKS
Chemicals of potential concern were evaluated in a Risk Assessment, by first identifying the exposure
pathways by which human and environmental populations could be exposed under either current land
use or hypothetical, future land use of the site and surrounding areas. Risks associated with ground
water were assessed by comparing ground-water concentrations at points of potential exposure (both
onsite and offsite) to applicable regulations or health advisories (Reference 1, page 22).
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Mining Waste NPL Site Summary Report
Human Health Risks
According to the Risk Assessment, fluoride, sulfate, and cyanide, which are noncarcinogenic
chemicals of potential concern, are not expected to pose adverse health effects to humans under any
of the soil-related exposure scenarios (Reference 1, page 22; Reference 2, page 24).
Potentially unacceptable carcinogenic risks from exposure scenarios listed above are expected in
certain areas of the MMRF site. Listed below (in Table 3) are the areas of concern at the site, the
exposure pathways and media, and their associated estimated risk. The carcinogenic risks presented
here show a range that reflects both average- and high-exposure values for different scenarios that
were considered, including a residence and a worker scenario (Reference 1, page 23; Reference 2,
page 25; Reference 3, page 1-64).
TABLE 3. CARCINOGENIC RISKS ASSOCIATED WITH MMRF
Area or Concern
Estimated Carcinogenic Risk
Landfill and associated areas:
• Direct contact with PAHs in landfill soils
• Direct contact with PAHs in surface drainage ditch
sediments
lO to 10.2
1O to 10.2
Potliner Handling Area:
• Direct contact with PAHs in soils
10.’ to 10
Discharge Channel:
• Direct contact with PAHs in sediments
1O to lO
Scrubber Sludge Ponds:
• Direct contact with PAHs in pond sediments
IO to 102
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Martin Marietta Reduction Facility
Based on the human health risks identified above, and the potential for contaminant leaching to
ground water, remediation criteria for contaminated soils were established as follows (Reference I,
page 23):
• Arsenic - 65 mg/kg
• PAHs - 175 mg/kg
• Fluoride - 2,200 mg/kg.
According to the Remedial Investigation, of the exposures evaluated in the Risk Assessment, two
scenarios are of potential concern: (1) If the S Aquifer is used as a sole drinking-water source, water
consumption may cause adverse human health effects because fluoride concentrations in several wells
at the site exceeded drinking-water standards; (2) Hypothetical, future, onsite construction workers
and future out-door workers may be exposed through direct contact to soils containing arsenic and
PAHs in the Landfill, Landifil-runoff areas, Potliner Handling Area, and the scrubber sludge ponds
(Reference 2, page 29).
Ecological Effects
Pathways by which environmental receptors (flora and fauna) at, or near, the site could be potentially
exposed to site-derived chemical constituents were qualitatively evaluated due to the general lack of
data from which to evaluate such exposures. Potential exposure scenarios for environmental receptors
include:
• Ingestion (by wildlife) of fluoride in leachate-collection ditch water
• Ingestion (by wildlife) of cyanide and fluoride in Landfill ditch water (Reference 1, page 23;
Reference 2, page 25; Reference 3, page 1-79).
Of greatest concern is the effect on wildlife of drinking Landfill leachate-ditch water, which may
result in ‘adverse effects. The specific types of adverse effects were not provided (Reference 2,
page 29).
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Mining Waste NPL Site Summary Report
REMEDIAL ACTIONS AND COSTS
The remedial alternative selected by EPA is comprised of the following actions:
• Consolidate residue cathode-waste material and underlying fill material from Old Cathode-
waste Management Areas into the existing Landfill
• Consolidate cathode-waste material from the Unloading Area into the existing Landfill
• Cap the existing Landfill in place with a multi-media cap that meets RCRA performance
standards
• Place a soil cover over SSP-2 and SSP-3
• Plug and abandon nearby production wells, and connect users to the City of The Dalles water
supply system
• Collect and treat leachate generated from the Landfill and perched water east of River Road
and from the former Cathode-waste Management Areas
• Recover and treat contaminated ground water from the Unloading Area
• Conduct ground-water quality monitoring, and develop a contingency plan to perform
additional recovery of ground water in the event that further contamination is detected above
appropriate standards (Reference 1, page 41; Reference 3, page 5-20).
In addition, it was recommended that institutional controls such as deed restrictions and fencing be
implemented during (and after) remediation to assure that the proposed remedial action will protect
the public health and the environment during its execution and to ensure a similar level of protection
after the remedial actions have been completed (Reference I, page 41).
The capital cost for the selected remedy is approximately $5,728,400. The annual O&M costs for
years I through 5 is estimated to be $144,000. The annual O&M costs for years 6 through 30 is
estimated at $55,600. The total present worth value of this alternative is expected to be $6,707,400.
The total capital costs for implementing a ground-water contingency plan in the A Aquifer is
estimated at $277,000. The annual O&M costs for this plan would be S48,000. The total present
worth of this plan is estimated at $767,000.
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Martin Marietta Reduction Facility
The capital cost of implementing a ground-water contingency plan for the B Aquifer would be
$495,000. The annual costs for this plan would be $55,000. The total present worth of this plan is
estimated at $1,114,000 (Reference 1, page 33).
CURRENT STATUS
According to the Remedial Project Manager, remedial activities at the site were conducted in two
Phases. During Phase 1 (1989 and 1990) waste material from various waste-management units
around the site was ezcavated and consolidated into the Landfill, and a soil cap was placed over SSP-
2 and SSP-3. In March 1990, a Landfill test pad was built to test the permeability and other
engineering parameters of the clay cap t r the landfill. A 300,000-gallon storage tank was installed
to collect cyanide leachate wastes from the Landfill and perched water from the Cathode-waste Area
prior to treatment for the destruction of cyanide. In June 1990, a cyanide-destruction system was
installed to treat leachate from the Landfill and perched water from the site. The final cap and
collection system was completed in March 1991, during Phase 2 activities.
Perched water is being pumped out of the perched zone (i.e., the permeable-fill material in the Old
Cathode-waste Pile, the Salvage Area, and Potliner Handling Area) and is treated by the cyanide-
destruction system. Another action being taken toward remediation is to provide municipal water to
residents with contaminated private wells. Ground-water monitoring continues to determine if pump
and treat activities are necessary.
1 W
(I
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Mining Waste NPL Site Summary Report
REFERENCFS
1. Record of Decision for the Martin Marietta Superfund Site, The Dallas, Oregon, EPA/ROD/RiO-
88/017; EPA Region X; September 1988.
2. Remedial Investigation, Martin Marietta Reduction Facility, the Dallas, Oregon; Geraghty &
Miller, Inc.; June 1988.
3. Final Feasibility Study, Martin Marietta Reduction Facility, The Dallas, Oregon; Geraglny &
Miller, Inc.; June 1988.
4. Profile - Martin Marietta Reduction Facility, The Dalles, Oregon, Document No. 983-TS 1 -RT-
ERRS-i; Author Not Provided; June 15, 1987.
19.
LILI C\
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Martin Marietta Reduction Facility
BIBLIOGRAPHY
Author Not Provided. Profile - Martin Marietta Reduction Facility, The Dalles, Oregon, Document
No. 983-TSL-RT-ERHS-l. June 15, 1987.
Calaba, Gary (Oregon Department of Environmental Quality). Martin Marietta Aluminum Co.,
Hazard Ranking System Package. May 2, 1984.
EPA Region X. Record of Decision for the Martin Marietta Superfluid Site, The Dalles, Oregon,
EPA/ROD/R1O-88/017. September 1988.
Geraghty & Miller, Inc. Final Feasibility Study, Martin Marietta Reduction Facility, The Dalles,
Oregon. June 1988.
Geraghty & Miller, Inc. Remedial Investigation, Martin Marietta Reduction Facility, The Dalles,
Oregon. June 1988.
20.
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Martin Marietta Reduction Facility Mining Waste NPL Site Summary Report
Referesice 1
Excerpts From Record of Decision for the Martin Marietta
Superfund Site, The Dalles, Oregon, EPAIROD/R1O-88/017; EPA Region X;
September 1988
L4
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UnIC.a Siacea O 1 ceo( €PAIROOIIItO.e&OI7
Enw nsnarcaj P, t c on Eirsrgiv cy ‘d Seocenoe, •g68
Agency Remedial R.sp nse
SEPA Superfund
Record of Decision:
Martin Marietta, OR
— — — — ——. .—— — -——.—— ——.—,__ —— — —
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iartir Marietta, OR
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First Remedial. Action - Final
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SocniorinS Or aii.UtioA P44 ”e and Addr.aa
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401 M Street, S. l.
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14.
15. Su piun.ntary M t,i
i
II. Abstract (Limit: 200 words)
Tne 3 0—acre Martin larietta seduction Fac l: y (MIaF) s tC LS loca’ed :n e
asco County, Oregon. me site 1.L s dit .1:n a (1 à03ac area ed r ar ii :
.ndustrj and manufactur ng: land no used r r .ndusr:al proce.ses .s lea. e f.c
agricultural purposes. ess t an 20 n nes and ous aesse3 are located _n a: - -
site. Oround dater is an unportan sourre of wa er supply in Tie Dailes area f
domestic, industrial and agr cu1tura1 uses and fl3ws in an easterij d rect.:o , ar:
the Columoia River. From 1958 to 1970, Harvey Aluminum, Inc. operated a process:i
fac ilitj designed to produce amout 90,000 tons of aluminum a year. :4ar :.n :e
Corporation (MMC) acquired the facility in 1970 and con inued. a1u inum pro . .-z
operations until L9 4, when the plant vas snut down. In 1986, MMC leased e :‘
adjacent portions of tne property to 4ortnwes Aluminum Company, wn::n res e: aL -
operat ons in 1987. The :It4RF site cons a 3 of 23 areas of s gn f cant conai:.a -
result_ng from treatment, s orage, and d sposal practices a trle sire. A i3-a;:
landfill located near ne aluminum reduct on building con ains ap r3xima elJ O,.J3)
yd 3 of waste and p1an cons!ructl3n deoris. Leacha e emanating from tne 1an; Ll
operat ons prior to ne installation a leacnata collection sym nas resu1
con amination of tne area aqu .fer. Sgnifican iaste types in tne Landfill
(See APtacned Snee )
(7. Docum.. t Analysjs a. O..criptora
ecoru or decision
:1art n Marietta, OR
First Remedial Action — Final
Contaminated Media: deans, gw, soil
:
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PA/ROD/RlO—88/0 17
.artin Marietta, OR
First Remedial ctiOn - Final
15. ABSTVIC (continued)
asbestos, metallic wastes, and 5,000 tons of spent cathode waste materials con:ai. ’ .
c ani e. ?A s, and arsen .:. in addition e :andfi::, ap r :< ace1” 4 .’5 :
cathode waste material was deposited in areas referred to as the unloading area ar.d : .e
cathode waste management areas. nd scrubber sludge ponds, consisting of 4 surface
impoundments, two of which are covered with soil and vegetation, cover 14.8 acres and
contain contaminated sludge and subsoil. The primary contaminants of concern affectir.g
the soil, ground water, and debris are VOCs including TCE, organics including ? Hs.
inorganics including asbestos and cyanide, and metals including arsenic.
The selected remedial action for this site includes: excavation of the cathode was:e
material and placement into the existing landfill, and covering the landfill with a RC A
cap; placement of a soil cover over scrubber sludge ponds 2 and 3; pluggi. g a
abandonment of nearby production wells and connecting ground water u 3ors to t e City o
Dalles water supply system: collection and onsite treatrent e f eachate g ner :e f :r’
the landfill, the perched water east of River Road and tne car.hcae w.ise ma e:,en
areas, and the ground water in the unloading area us r.g an aq ec s a: t •s e
onsite discharge to a recycling pond; ground water monitoring; estab1isr.r ent f a
ccntingency plan to perforrn additional re o’:ery f g n iater in e e•;ent f_::
c ntaznination is detected; and inplementation of instit tiona1 controls. T1’.e es:i -a:
oresent worth cost for this remedial action is $6,707,400 with annual O&4 of S.44. )3
or years 1—5 and $55,600 for years 6—30.
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I. SITE DESCRIPIION AND 8ACX ROIJND
The Martin Marietta Reduction Facility (MMRF) sit, Is located in The
Dalles, wasco County, Oregon. west of the Columbia River and east of the
Union Picific Railroad line. The site occupies apDroitmat ,ly 350 acres
within an 300—acr, area zoned for heavy Industry and manufacturing. The
area of the sits used for industrial purposes encompasses apProximately
110 acres in sections 21.28.33 and parts of sections 20 and 29 in T.ZM,
R.13E.. Willamette Meridian. The MRF Is bounded near the Meuntiln FIr
wood hauling and chip mill on the north. Webber Street to the souti’i, the
Columbia River on the east, and the Union Pacific Railroad line and West
Second Street to the west.
The MMRF Is an aluminum processing facility designed to produce
approximately 90,000 tons per year of aluminum from alumina. Operations
were begun at the site by Harvey Aluminum, Inc., in 1958. That company
became a wholly owned subsidiary of Martin Marietta Corporation (MMC) in
1970. The MMRF continued operations until 1984, when the plant was shut
down and MNC acquired legal title to the property. In 1986, P414C leased
the plant and portions of property adjacent to the plant to Northwest
Aluminum Company, which resumed primary aluminum operations In 1987,
Ouring facility operation, waste constituents derived from alumina
reduction were stored, treated, and dispc ed of at the MMRF. During past
plant operations, waste c nst1tuents, principally fluoride, sodium.
sulfates, cyanide, and ;olynuclear aromatic hydrocarbons (PANs), vere
released to the environment.
Site Features
The MMRF is located within the semi—arid region of eastern Oregcn
where the climate is characterized by warm, dry suniners and cold,
relatively wet winters. At The Oalles. the mean annual temperature is
about 540F. July Is generally the warmest month with a mean maximum
temperature of 860F. The mean minimum temperature is 340F in January.
The area receives from 10 to 15 inches of precipitation annually with
a mean annual precipitation at The Dalles of 13.7 inches. Average annual
evaporation from shallow lakes in the area is approximately 40 inches.
Records from The Oalles indicate a cumulative moisture deficit of about 15
inches per year; that is, evaporation exceeds precipitation.
Wind velocity measured at an on—site meteorological station during the
months of Jun. and July 1987 showed maximum wind speeds of uo to 6Ovnfles
per hour (mph); gusts of up to 30 mph mere coninon. The highest wind
sceeds ar. associated wit’i northwest winds. typical MInd sPeeds rinçe
frcm S to 20 mph and trie re cminant wind ¶jirection Is fr:m the nort”we :
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Land—serface elevations at the MMRF range from about 100 ft nil at e
Columbia River to more than 155 ft ins.) at the Landfill. The top raoriy-f
the site has changed over time iue to filling of lo areas: In general
the site IS level with the exception of dIitinct man—made and natural
features. Thou features include: man—made ponds, the landfill, drainage
ditches. strum channels, and road beds. These site features are srtown in
Figure 1.
The topography at the MMRF largely Controls the direction of
surface—water flow, except where ,ian—made structures have been built
alter flow patterns. In general, surface—water runoff from active
portions of the site is routed to the recycle pond. Surface—water fl w
are shown In Figure 2.
Runoff from the landfill area i currently Intercepted by the leachate
collection system and the lan ftll ditch and then routed to the recycle
pond via the discharge hanne1. Prior to the construction of this
interception network, landfill runoff followed three primary drainage
pathways, all of which discharged to the alluvial aquifer. Those 1 ws
are now collected in the leachate collection system.
Surface ponds at the ‘4MRF Include thO four scrubber sludge ponds,
recycle pond, duck pond, and lined pond. The recycle pond se’ves as a
collection point for runoff from the landfill, the former cathoce was
management area, and areas to the Immediate south and west of the plant.
and it discharges to the Columb River in accordance with a National
Pollutant Qischarge Elimination System (NPOES) permit. The recycle and
lined ponds are currently in use. The scrubber sludge ponds are no longer
in use but Intersect ne water table and are saturated in proportion to
the relative groundwater elevation.
Surface—water runoff front the southwest part of the site flows to t e
south and east through a natural drainage channel prior to discharging to
the Columbia River. Surface—water drainage front the non—active part of
the MMRF (northwest of the landfill) discharges directly to Chenowet
Creek.
LitPtoloay/Giolo v . The surface soils at The Dalles are poorly
developed and In most places are non—existent. During construction and
operation of the MMRF, a large part of the native soils at the site were
covered with fill material.
Underlying the soils/fill at the site is rock of the Columbia iver
8asalt Group (CRBG). The rock strata at the site are generally flat lying
except in the north where the Cherioweth Fault transects the site. The
CRBG is overlain by Pleistocene Age alluvial deposits in the nortlern
2arts of the site.
Existing and Future Land arid roundwatef Use . The MMRF. as ot o
jrevtously, is located i:iifl 3C0 acres zorea f r e3vj Industry ar.
i anufact jri g. Orthwest uminum ii currently t e lar’est ir cus ry i
: i z rii. ’g area, picji—; :e’ .ris.
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A small trucking facility, plant recreation area, and a rodeo grounds
are located near the southern boundary of the industrial area. Th
northern part of the area contains the Mountain Fir facility and t o small
areas zoned as conmiunity facilities. Located within these CO T 5flunity
facilities are the wasco County Animal Shelter, Rocklin. (whith consists
primarily of a machine shop employing about four people), and an eiectr :
power substation. A gravel Pit owned by Munion Paving is also lOcated ‘.,
the northern part of this zoning area.
Currently, there i little develoomerit along the Columoia River
waterfront in the vicinity of the t$lRF, although there are plans to use a
tract between the site and the river for industrial development. The area
has been leveled, graded. and landscaped. A small barge ccmpany Is
located on the waterfront approximately 0.5 mile southeast of the ‘iMRF.
The remainder of the zoning area is lightly vegetated or wooded; i .lit4RF
land that is not used for industrial processes IS leased for agrlcult’jral
uses such as cattle grazing. Cattle grazing takes place primarily in t e
vegetated areas northeast of tne facility and in the area near the rodeo
grounds.
Interstate 84 separates the light and heavy industrial manufacturing
area r-c ,ii residential areas. Oirectly west of the Interstate and
a oroximat y one—third of a mile from the MMRF site are several areas
zoned for residential development. General coninercial sites, such as a
drive—in theater, are located in arid arOund these residential areas,
aoprexirnately two—thirds of a mile west of the MP4RF. Addit1 nal
residential areas zcned for single—family, multi—family, and mobile hc e
dwellings are located southwest of the site.
A gravel pit is operated within the quaternary gravels of the alluv’al
aquifer northeast of the MMRF. This operation is relatively small, aria
probably could not be expanded significantly owing to the limited extent
of the alluvium.
Nearby Residences . A strip of land zoned for light Industrial an:
manufacturing development Is located between the railroad tracks and
Interstate 84 directly west of the MMRF main building. In addition o
several small businesses, this’ area currently Includes a few resident’al
homes. These homes were in place prior to zoning, and upon new ownersn ’
or destruction of the hcmes, tne area will be used strictly fcr ligr.:
industrial and manufacturing development. Based on recent aerial
photographs, less than 20 homes and businesses are in the area west of :e
site.
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Natural ResoUrces . Croufldiiatl, 5 fl Ifllwobtaflt Source of water suc ly
ii The Oall.s area for domestic. lidustf al, md agricultural uses. The
primary aquifer in the area is the Oalles Groundwater Resevoir (OG R;
alluvial aquifer located in the Chenoweth Creek area Is used by the Animal
Shel tsr.
The C lu Ia River and its tributaries represent the major
surface watSr resources in the area, with an impoundment On Mill Creek
used as the principal source of dater supply for the C ty of The Oalles.
The Columbia River and its tributaries provide habitat for important
c:ii iiercial and sport fis’eries, with salnon, trcut, steel head, walleye.
and bass being among the many game fish ccmmon to the river. Many of t e
tributaries serve as hatcheries for the salmonotds.
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It. ENFURCENE 1’ S XMARY
In the spring of 1983. the presence of cyanide compounds were detected hi
the groundwater and the EPA ranked the facility for inclusion Oil the NPL.. The
site was Proposed for the NPL. in October 1984. In 1987 the Site was formally
placed on the NPI ,.
t C has been identified as a Potentially Resconsible Party for the site.
MMC entered into a C nser%c Order ‘cn PA ii Sepeemcer 1985 that direc: Mc
to perform an RI/FS for specific areas &t the ute that might have :een
Impacted during plant ocerations. The Final FS report was submitted In July,
1988. MI4C Is In compliance with the terms of the order.
Special Notice has not teen issued in this case to date.
III. CCt’INIJMIT( RELATIONS
Coimnunity concern about the Martin Marietta site has never appeared to Ce
widespread, although several sues and questions were raised. These three
Issues were raised by several community members:
• the concern over cyanide contamination;
• the Importance of trie aluminum reduction facility to the local economy; and
• concerns about ‘aricus airborne emissiorts frcnt the smelter.
The remedial nvest1gation addressed the concerns about cyanide.
concluding that there Is no significant cyanide contamination In grouncwater
beneath the site. The reduction facility was leased and reopened by NW
Aluminum, which has Improved their practices for handling the wastes •hlcn
earlier caused the contamination now beneath the site. Finally, as a result
of a lawsuit, Martin Marietta Installed new flouride emission c:nt l
equipment.
3udging from the fact that EPA received no written conmients on the
Feasibility Study despite 2 pub)ic meetings, 2 fact sheets, and several public
notices about the Feasibility Study and convuent period, EPA concludes that the
coimnunity’s concerns have been addressed and that they are relying on E and
OEQ to select an appropriate remedy. The selected remedy takes into account
the concerns mentioned above.
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IV. NATURE AND E(IENI O PRtJBLEM
Site Cbaracterizatio i
The site Coniists of a number of areas of contamination that have resute
from past practices at tne site. These areas are shown on Figure 1 arid
Include:
Land? i 1 1
Landfill Runoff Areas
Area A
Area •
Area C
Area 0
Former Cathode Waste management Areas
Metal Pad Storage Area
8ath Recovery Pad Area
Old Cathode Waste Pile Area
Salvage Area
Potitner Handling Area
Cathode Wash Area
Duck Pond
Lined Pond
Recycle Pond
Scrubber Sludge Ponds
SSp 1
S SP2
S SP 3
5SP4
Orainage Ditches
Surface Orainage Ditch
Loachate Collection Ditch
Landfill Ditch
North Ditch
River Road Ditch
River Road Curb
Discharge Channel
Drainage Ottch
Old NPDES Discharge Channel
Abandoned Scrubber Sludge Channel
gore detailed e cri tion of t o e areas øhere stgni? cant •:fl 3ffiIfl
as cetec e are ic. d :—e e: 5eC::n ‘:‘:‘e : a ic: —: - :
f reas rivesttga:ed’
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Waste Cbaractert atioo of Areas !nvesti ated
Landfill
Shown us Figure I, the landfill occupies approsilnately 15 acres just north
of the ii Ifl4 reduction building. Former drainage pathways from the landfill
area correspcnd to the landfill runoff areas.
wastes at the landfill were Diaced randomly on the ground surface and
piled to t e current configuration; total waste volume is estimated to be
about 200,000 cubic yards. Wastes present in the landfill as a result of trie
reduction process and construction operations Coflsistof: ConStruction debris
(primarily basalt fragments): ‘target wastes’ such as spent cathod, waste
materials, refractory briccs. off—specification carbon blocK. pitch, coke and
cryolite; and metallic wastes such as buss bars and collector studs, and
pallets, cans, rags, and empty drums. Prior to the regulation .f asbestos
disposal and handling practices, asbestos and materials containing asbestos
were disposed of in a random fashion within the landfill. Since regulation cf
these materials, MMRF disposed of asbestos in discret, areas of the landfifl
The following volumes have been estimated for the waste types in the landfill:
• Basalt Fragments 100,000 yds.
• Asbestos 300 yds.
• Metallic Wastes 500 yds.
• Target Wastes 59.200 yds.
Of the target wastes. it is estimated that 5.000 tons of spent cathode
waste materials are present In the landfill; these wastes contain high levels
of carbon, sulfate, socium, and fluoride in addition to minor amounts of
cyanide. Cryolite, which is composed of fluoride, sodium, and aluminum, Is
also present In the landfill. Pitch and coke associated with the continuous
anode in the r,ductton process are present In the landfill and contain
elevated levels of PASs and l w levels of arsenic.
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To confirm the composItion of the landfill, five test pIts ier
excavated. The materials observed ranged from fin, dust to very large asalt
boulders. Samples from the five test pits indicat, the presence of the
fol loving contaminants:
• EP Toxicity — Barium 0.234 g/L (one sample)
• Total cyanide 0.32 — 70 mg/kg
• Free cyanide 0.27 — 54 mg/kg
• Sodium ],400 — 82.200 mg/kg
• Fluoride 204 — 2.880 mg/kg
• PAHs 276 — 2,406 mg/kg
Former Cathode Waste Management Areas
Past cathode waste management activities were concentrated near the
northeast corner of the plant building. These areas Include the metal pad
storage area, the bath recovery area, the salvage area, the cathode wash area.
the potliner handling area and the old cathode waste pile. In addition to t e
perched water Identified In this area, the potliner handling area was
Identified as the main area of concern In terms of direct human exposure to
soils, and Is descrIbed in •‘ ore ,tiIl bil w. tn addition, thesi areas lere
Identified as potential sourceS of fluoride contamination to groundwater.
Potliner Handling Ar i . The potliner handling area (PHA) occupies
approxImately 0.9 acre. ;‘ st eas: of the reduction building (See Figure 1).
Thi PHA was used ur’1 :tle er1cC whifl waste cathode was crushed and loaded
onto railroad cars f r ff—sIt recycling. As a result of the crusriing
process, cathodic dust, pitch, and coke residuals have accumulated. Sampliflg
of the PHA Indicated tre presence of the following contaminants:
• Cyanide
— Total 14 mg/kg
— Free 4 mg/kg
• Fluoride 6 mg/kg
• Sodium 29,600 mg/kg
• PAI4S 9,041 mg/kg
— II—
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Scrubber Sludge Ponds
The scrubber sludge ponds (SSPI) consist of four surface impoundment 3
(numbered I through 4) located south ‘of the reduction buildings and f
River Road. The large surface aria and retention capacity of the SSPs allowed
for particulate settlement of slurry waters from the air p lluti n control
system prior to discharge of accumulated water to the Columbia River.
Collectively, the lateral extent of the SSPs Is approximately 14.8 acres.
SSPI and 55P4 have soil covers and established vegetation which currently
precludes direct contact with the wastes. SS?2 and 55P3 are not covered. e
material present In the SSPs can be divided into three categories: l SQ!l
cover. (2) sludges, and (3) contaminated ub oIls. The volumes for each SSP
by category are presented below:
• Cyanide
— Free
• Fluoride
• Arsenic
• Sodium
• VOCs
• PAI4
Surface Oral nage Ditches
Below detection limIt(BDL)
204 — 613 mg/kg
801 - 77 mg/kg
6,250 — 45.000 mg/kg
8 0L.
1,940 — 8,570 mg/kg
Leachate generated by the landfill is contained by
system that consists of the following ditches (Shown in
• Surface Drainage Ditch;
• Leachate Collection Ottch: and
• Landfill Ditch.
a leachate collectcn
Figure 2):
Sludge Subsoil
SSP 1
SSp2
SSP 3
SSP4’
7.970 63.730
6.820
‘3.600
4.640 17,660
2,760
14.500
6,200
Subtotal
71,700
9.580
58.100
28.500
In addition, prevalent winds have
of sludge south of SS?Z ano S 5P3.
Samples frcm the 5crJt er sludge
following contaminants:
TOTAL 167,880
scattered approximately 538 cubic yards
ponds indicate the presence of t e
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The generation of leachate is seasonally dependent and Its presence is
directly related to precipitation or snow melt. Available records of leachate
collected and pumped range from 0 to 50,000 gallons per day (gpd) with peak
flows occurring generally in the early spring. Concentrations of contaminants
in the landfill leachate also vary with season and are higher when leachate is
being developed.
The following compounds mere identified in the leachate collection ditch
Identified the presence of the following constituents:
• Volatile Organic Compounds
Trichioroethylene
• Cyanide
— Total
— Free
• Fluoride
• Sodium
• Sulfate
0.11 — 29
0.01 — 4.7
1,490 - 2.440
4,270 — 5,900
840 — 2,660
8 mg/I. (one saniple)
mg / I.
mgi I.
mg / I.
mg / I.
mg / L
Analyses of leachate samples from the
presence of the following constituents:
landfill ditch
Identified the
• PAHS (including Bls(Z-ethyl—
hexy l]Phthalate)
• Cyanide
— Total
— Free
• Fluoride
• Sodium
• Sulfate
• Chloride
0.01 — 206 ugh.
373 — 1,280
34.2 — 77.2
5,400 — 8.000
36.600 — 99,800
10,500 — 49.300
1,210 — 3.430
mg / L
mg/ L
mg/i.
mg / I.
mg / L
mg / I.
Sediments from the surface drainage ditch showed the following
contaminants:
Cyanide
— Free
c
0.62 — 3.6
mg/kg
Fluoride
189 — 519
mg/kg
Sodium
2.720 — 5.600
mg/kg
—l 3—
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Croundweter Charaetertzatioa
General ydroqeoIoqy
The groundwater flow system at the MMRF inCludes a water—table aquifer (S
aquifer) overlying a series of confined aquifers (A and B aquif r and
DG R). Figure 3. a site specific stratigrapriic column, shows the ver:tcaI
relationship bit .in the principle aquifers at the site. Zones of per l ed
dater near the surface of : ie 31d cithode waste pile and an alluvial ac. ier
are also present locally.
Distribution of Main Aquifers . The unconfinqd S aquifer is present wlthti
the relatively low permeaøi I I ty areas of the basalt south of the landfill
though a small area of S—Aquifer was also defined northeast of the landfill.
The S aquifer generally thins out toward the western portion of the facility.
The first confined aquifer (A aquifer) is within the upper pillow lava horizcn
of the subaqueous portion cf the Rosalta flow. The A aquifer ranges frcm 1CC
to 150 ft below the surface and t 5 to 45 feet in thickness. The B aquifer
is below the A aquifer and is locally separated from it by a low permeaDility
basalt (lava lobe). The lava lobe ii apparently absent north of the site due
to non—deposition. The S aquifer ranges from 150 to 200 ft below the surface
and is 30 to 50 ft in triIc ness. In areas whirl the lava lobe is absent, the
A and B aquifers cmoi ie o form a single Piydrogeologtc unit. A thick, lOw
permeability siltston a 1 ld sandstone unit forms the confining unit between he
8 aquifer and the underlying OGWR. The top of the OG 4R occurs at deotris
greater tflan 220 feet belcw the surface.
Localized Grcur aer n alluvial aquifer, aoproximatsly 400 ft wise and
at least 60 ft deec. i present in the area north of the plant. The geometry
of the alluvial aquifer is apparently controlled by the location of the trace
of the Chencweth Fault. Flow in the alluvial aquifer is expected to ta eas ,
toward the Columbt.a River.
Perched water has been Identified at the old cathod. waste pile, salvage
area, and potliner handling areas within the permeable fill material ‘at
exists above competent basalt. The saturated thickness of the percneo zone
varies, ranging from 0 to 3 ft during the RI. One source of the percrieo ‘ater
is precipitation; other potential sources include infiltration from the
landfill ditch and north ditctv, and leaks in below—grade water distrl utlon
lines.
Groundwater Flow . Groundwater flow in the S aquifer is generally t t e
east and nortniast; discharge from the S aquifer 5 believed to be into the
alluvial aquifer where it intersects the S—aquifer at the northern portion of
the facility, and to thi Columbia River. Groundwater flcw in the A aquifer Is
predominantly east to west. The A aquifer nay be recharged by the al vlaI
acuifer, the Columbia River. and the S aquifer; discharge aooears to ce
8 aquifer and regional’ acer—suoply wellS. Groundwater flew In tne B : .i er
is generally to the west and south; hydraulic gradients vary, cwe er.
ie endirIg on the hydrolcVc arid :L nolflg concitiOr% .
-l4-
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CNv ica1 Characterization of Groundwater
The cOnStituents of concern identified in the groundwater system I nCl udi
total and free cyanide, fluoride, sodium, and sulfate. The higne
constituent concentrations are present in the Perched water with orogressively
lower concentrations identified within the S. A, an 8 aquifers.
Concentrations of constituents In wells taoolng the OGiR are eI1 below healt,
based standards. Table 2 lists cotentlal AR,%Rs anø o: er he j :ase
standards for groundwater to be considered in selecting a remedy.
ocal1zed Groundwater . ?erc ed water samples from : e old cathode ast
pile show elevated concentrations of free cyanide (3.01 rng/L), fluoride (LOGO
mg/U, and sodIum (10.500 mg/L). No free cyanide or fluoride was detected in
samples from the well in the alluvial aquifer at the Animal Shelter. Qtrter
willS in the alluvial aquifer were above detection limits but below health
based standards.
S Aquifer . Elevated constituent concentrations were identified in the S
aquifer at several locations:
(1) Niar the landfill and former cathode waste management area . F1uori e
concentrations range frcm d.0 mg/L to 4.7 mg/L. Free cyanide -ançed
from <0.09 to 0.136 mg/L, and sodium ranged Prom 57.2 to 82.2 mgiL.
(2) Scrubber sludae conds . ThIs area Contains fluoride (4.8 o 7 1
mg/I .), cdium (246 to 6Ea mg/L), and sulfate (117 to 3.020 ng/’.).
Free cyanide is below detection limits.
(3) The new c : e aste area near the alumina unlcading building . Free
cyanide was fOund dt a concentration of 0.215 tng/L In uell MW—5S.
Sulfate is found at concentrations of up to 1.270 mg/I.. Grounawacer
samples Show detectable fluortde as high as 57 mg/i.
(4) Recycle pond . Samples from well 1414—31 downgradient of the por.d
indicate fluoride concentrations of 5.5 mg/L. sodium concentrations
of 90.5 mg/I.. and sulfate concentrations of 871 iig/L.
Figure 4 showS fluoride concentrations in the S Aquifer.
A aquifer . Groundwater quality Impacts in the A aquifer are less
widespread and at lower concentrations than those identified in the S
aquifer. The highest concentrations in the A aquifer exist east of trie
landfill and the former cathode waste management area. The highest readings
are reported for will MW—9A. but they are uspected to be an artifact of qell
con truct1on. The monitoring and contingency plan described in the se1ec ed
remedy will allow for a determination and appropriate action should iesa
c ncentrat1ons be found to be representative of groundwater C:nqitlons.
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TABLE 2
0TEMTIA1. ARA $ A)ID OTHEB CUIDAIICE TO BE CONS1D RFD
I 1&carbonate
Calcium
Ca rbon to
Cyanide (tree)
fluorides
Lead
Magnesium
SodIum
Sul tote
Zinc
4 mg/L (2 mulL) (C l
50 ugJL (20 ug I..)
220 ug/L (child) (d)
0 u (adult) (.3
(a Maximum Contaminant Levels are enforceable drinking water standards from 40 CFU 141.1).
Those levels are based on health, technical feasibility, and coat benefit analysis. Secondary
Maximum Contaminant Levels are shown in ( ) and or. goals for drinking water quality ba .d
on aesthetic considerations such as taste, odor or straining ability, 40 CVIt 143.3.
jbJ Final and proposed MCIGs (maximum contaminant level goals) are developed as part of the
process for developing final drinking water standards, (i.e., HCLs). under the Sate Water
Drinking Act. MCLGs are entirely health-based and ar. always less than or equal to the
proposed or final MCLs subsequently developed.
id Oregon Administration Rule 333-61
(&1 iit&alLh advisory by USEPA Office of Drinking Water for longer-term exposure, M rcli 1987;
Iiased on exposure to free cyanide.
ej HeaLth advisory by USEPA Ottice of Drinking Water for life time exposure for adults, March,
1 i8i; based on exposure to tree cyanide.
4 .stioflal Primary end secondary Drinking Water Hegulations. Federal kcqister bL: 11396-11412,
April l9ü6.
., s ij• ,.i iii re depeiid& iiL
r.d.ral
ISCL
Chemical (SNCL)
(a) Fe lerol MCI (bj Oregon NCL (c) Other
(250 aq/L )
(5 ag/L)
1.4—2.4 aqJL (91
a - a
250 mg/L
5 .q/L
400 .g/L (hi
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Contaminants are also present in the A aquifer near the Scrubber slud e
ponds. Sodium ranges from 44.7 to 84.8 tng/L. Sulfate from 23 to 153 mg/L an
fluoride from (0.1 to 1.0 it!g/L.
8 Aquifer . In the 8 aquifer, elevated constituent concentrations ar
chiefly confined to a single location: the landfill and ld cathode waste
management area. The highest readings are reported for wells MW —gB and ‘ W — 8 .
but they are suspected to e an artifact of well c nstructicn. rhe ntt rI g
and contingency plan described in me selected remedy will allow f3r a
determination and aooroorlame action snould these concentrations be F u’d t
be representative of ;rcur.cwa:er :nditIcns. n other .ells, eveIs f
cyanide range up to 1.0 tng/L. Free cyanide Concentrations are 0.10 iIgIL or
less and fluoride concentrations are less than 1.4 mg/i...
Establishment of ACLs in the 5 Aquifer
An ACI. is being proposed for those portions of the S Aquifer on the site
where concentrations of fluoride and sulfate exceed Oregon MCL’s, which are
considered the note stringent standard at this site. Proposed ACL.s are as
follows:
Fluoride — 9.7 mg/I
Sulfate — 3,020 mg/i
Criteria for Establishment of an ACL . Section 121 (d)(2)(8)(ii allcws
for tne establishment of an ACL .nere:
• There are knewn ro ected points of entry of the groundwater tht sur’Ice
water,
• there will be no staristicaily significant increase of such c nstituenms
at the point of entry, and
• the selected remedy Inctudi enforceable measures to preclude human
exposure prior to discharge to the surface—water.
Protected Points of E’ itry . In general, the constituents of concern i
groundwater at the site have been characterized as tO their vertlcai anø
horizontal extent. The constituents of concern have primarily been icentified
in the uppermost aquifer at the site (S—aquifer) which is not currently used
for water supply purposes in the area, is not really extensive. ano Is of low
productivity and thus not likely to be utilized In the future for ‘ater sucoly
purposes. Groundwater in th• S—aquifer f1ow toward, and discharges to t”.e
Columcia River which borders the MMRF site. The Columbia River I; eit—emely
deep ad3acent to the site, and there Is essentially no potential for uncerflcw
from the S—aquifer.
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The only surface—water potentially affected by groundwater which conta1n
elevated levels of fluoride or sulfate Is the Columbia River. The Columbia
River currently receives discharges from the MMRF via a single discharge point
regulated under a NPOES permit. The mass of fluoride currently discflarged
under the NPOES permit from the site is 123 POunds/day during the dry eascn
and :46 pounds/day during the wet season.
estimated tncrease i C:r’ce’itraticr, at e Point f Entry . Fl’jori e ar
sulfate are øotn naturali occurring in tne grounawarer ano surface —macer
environment. Background concentration of fluoride In the Columbia are
reported to range from 0.24 mg/L to 0.1 riTgIL. Background concentrations of
sulfate In surface water are likely to range from 15.9 mg/L to 34 ng/L.
The hydraulic cOnductivity of thi S—aquifer is aoproximately 2.1 ft/day;
the hydraulic gradient in ne S—aquifer Is estimated to be 0.05 ft/ft.
Assuming a cross sectional area of the S—aquifer which discharges into the
Columbia River from the MMRF of aooroximately 6000 ft long (based on the
length of thi facility) by SO ft deep (thickness of S—aquifer) gives and
estimated contact area of 300.000 sq ft. This assumed contact area (300.000
square ft of the S—aquifer Interfacing with the Columbia River) Is
significantly greater than the discharge area of the pc’tton of the aquifer
affected by site conditions. Groundwater discharge from the S—aquifer to t e
Columbia River is estimated to be 10 L/sec using this assumotion.
The Columbia River In the area of the MI4RF is very deep and flow is
c ntrol1ed by several :ams in : e area. The average flow In :he C3lumbIa
River is approximately 192,a20 cfs or 5.500 .000 L/sec. The 7—day, 10—jear Icy
flow of the Co1um ia River in the area of the site Is estimated to be 81.3C0
cfs.
Fluoride has been detected as high as 57 mgIL in groundwater at tne MRF;
however, as part of the final remedy for the site, any groundwater with a
concentration of greater than 9.7 mg/L will be remedlated. Based upon a
groundwater flux f 10 1./sec containing a worst case concentration of 9.7 i g/L
of fluoride, the mass flux f fluoride tO the Columbia River wOuld :e 97
mg/sec or 18.5 pounds per day. Under average flow conditions in tne Columola
River, the average surface—water concentrations as a result of site
groundwater discharge would, be approximately 1.76 X 10—5 mg/L. A
concentration increase of 1.6 x 10—4 mg/I.. is estimated assuming l w flow
conditions and a zone of mixing. For a maximum detected sulfate concentration
of 3,020 mg/L in S—aquifer groundwater, the concentration in the Coluniola
River would be 5.5 X 10—3 mg/I. under similar flow conditions.
These estimated concentrations of fluoride and sulfate as a resjlt of
groundwater discharges from the itte are several orders of magnitude ecw
acceptable concentrations, below oetec 4 ori limits and be 1 ow ac ;r:uro
concentrations. Therefore, ale ouqn a cefinable ieass, tt e otsciar;e f
fluoride and .sulfate to the Columbia River from on—site grouno a:!r
statistically insignificant (riot measurable).
‘ ares i • —a ” :: i . : a! ::r
stric crts i :e :e seec:eo e’ ::
installation of deMs :n—;.:e :—a: —a 4a:ar :..... i-—:.
20
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Coataminut Tr ms rt
In order to assess fugitive dust from the site, soil sieve analyses and
fugitive particulat. modeling was carried Out. The results of thI 5 modeling
indicated, that the potential for significant risks from windblown dust were
minimal.
Groundwater
Based on the hydrostratigraoriy of the site, the rinc pal route of concern
for contaminant lnigratiQn. to Chenoweth irrigation wells involves horizontal
migration from the landfill to the alluvial aquifer with subsequent downward
migration to the B aquifer, and from there to the DGWR. A mathematical model
wIS also developed to estimate the impacts on Chenoweth irrigation wells using
this scenario. Using that model and including conservative assumptions.
estimated concentrations of free cyanide at the wills were estimated as ‘own
below. These can be compared to the health advisories ShOwn In Table 2.
CONSTITUEMI CONCENTRATZON (mg/l)
Initial B—Aquifer Production Well
Free CM 0.051 0.012 0.003
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Risk Mses ment
posure Evaluation
ChemicalS of potential concern were evaluated in the risk assessrne’,t y
firit identifying the exposure pathways by which human and invironmental
populatiOnS could be exposed under either current land use Or hypothetical
future land use of the “I4RF and surr urvding areas. Mane pathways 1n cl ’r ’
human exposure to contaminated soils and dust were possible; therefore. for
eac , category of e ;csure cils (I e. . iri us:rtal — ;e’ eral :c:Jj:’:i
exposures. with and withOut cil disturbance at the s;:e), the expcs. ire
scenario selected for evaluation was that which would result in the highest
exposure, and therefore highest potential risk worst caso. Th1 resulted in
several exposure scenarios related to potential future uses of the site and
surrounding areas, by both future industrial and residential populations,
being evaluated. For each exposure scenario evaluated, an average case
(copulations exposed to average Site chemical concentrations at average
exposure frequencies, etc.) and a maximum exposure case (maximum reported
concentration was used with upper—bound exposure scenarios) were evaluated.
Risk from these exposures were characterized in several ways. 8ecau e
groundwater was the only exposure medium for which ARARs or health ad ’s r es
were available for all chemicals of potential concern, risks isscciate It
groundwater were assessed by comparing concentrations c chemicals Ii
groundwater at points of potential exposure (both n and 3ff site) to ARs or
health advisories, as has been creviously discussed. Such colirnarison ali.es
wire not available for all chemicals in other site exposure media (i.e.,
surface—water, and 5311); exposure of humans to these contaminated meola were
evaluated by quantitative risk assessment in which potential intakes
calculated for each potentially exposed population were combined with critical
toxicity values.
Risks from Mon Carcfnoqenic Compounds . The non—carcinogenic chemicals of
potential concern (e.g., fluoride and cyanide) are not expected to pose
adverse health effects to humans under any of the soil—related exposure
scenarios quantitatively evaluated: this conclus’3n i ased on cal:j a:
hazard indices which gere all several orders of nagnit..ce less than
hazard index is defined as the sum of the ratios of the daily intakes Cf
non—carcinogenic substances by potentially exposed individuals to the ir
corresponding relevant reference dose or allowable intake).
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Carcinogenic Ccmpound . Certain atlas of tile MP4R# were idliltified tn the
risk assessment as being associated with Potentially unecceptable carcinogenic
risk to humans under the exposure scenarios assumed. These areas are listeø
below with details of the exposures, media, and chemicals which have been
assoclatedvith this risk. The carcinogenic risks presented ShOw a range that
reflects both average exposure and high exposure values fOr di?ferenct
scenarios that were considered, Including a residence scenario and a .erker
scenario.
Estimated Carcinogenic qi
Landfill and associated areas:
direct contact with PAI4s in lQ — lO2
landfill soils;
direct contact with PAK5 lO— — 10—2
In surface drainage ditch sediments.
Potliner Handling Area:
direct contact with PAHs In soils. lO — 101
Discharge Channel:
direct contact with PAHs In sediments. l0— — 10—2
Scrubber Sludge Ponds:
direct contact with PAHs in pond sediments; i — — 10—2
olcgtcal Effects
Pathways by which environmental receptors (flora and fauna) at acic near
the t44RF could potentially be exposed to site—derived chemical const1 e ts
were generally qualitatively evaluated due to the general paucity of data ‘tn
which to evaluate such exposures. When sufficient data were availaole.
estimates of risks to biota were made based on exposure and tOxiC ti
estimates. Estimated ecological impacts included:
ingestion by wildlife of fluoride in leachate collection ditch øater, arid
ingestion by wildlife of cyanide and fluoride in landfill ditch water;
emediation Criteria
Based on the human health risks identified above and the potential f r
contaminant leaching to groundwater, remediation criteria for contaminated
soils were established as follows:
Arsenic 65 mg/kg
PAI4I — 175 mg/kg
Fluoride — 2.200 mg/kg
.i1
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V. ALTERNATIVES EVALUATION
Summary of Alternatives asid Evaluation Criteria
This section sunsaarizes the detailed evaluation of the final candidate
remedial action alternatives. First, alternatives are subject to a screer r .g
for com lI1flCe with the protecti ;efleSs and ARAR criteria. An additIonal
screening of cost effec ie”ess Is en one isure : e selec - — :j ‘
a cost effective one. ‘.cse : at ass tfle Screening are then evaLace
against all nine criteria arid an alternative I selected that best addresses
the combination of criteria. This alternative is considered to represent
treatment to the maximum extent practicable.
Alternatives were develooed by firit targeting areas for remediation based
on Identified public health and environmental concerns. These areas Included:
• Landfill,
Unloading Area.
• Farmer Cathode Waste Management Areas,
• Scrubber Sludge Ponds, and
• Groundwater
Table 3 shows the various remedial measures that were considered ‘:r ICI
of these target areas. Table 4 shows how these measures were comoir.e i :
the Final Candidate Alternatives.
The Final Candidate Alternatives. identif1 d briefly, are:
Alternative I — No Action Alternative (presented to provide a basaline for -
evaluating the other alternatives).
Alternative 2 — Consolidation and Asphalt/Soil Capping of Target Areas:
Limited Groundwater Treatment.
Alternative 3 — C3nsolidaticn and RCRA/Soll Capping of Target Areas,
Limited Groundwater Treatment.
Alternative 4 — :onsolidation and RCRA/Soil Caoping of Target Areas:
Hydraulic Barriers at Scrubber Sludge Ponds; Limited Groundwater Treat, ’teri:.
Alternative 5 — Full Consolidation and RCRA Capping of Tar;et Areas:
Limi ted Groundwater Treatment.
Alternative 6 — Fufl Consolidation into RCRA Landfill: Limited Gr:L’ wa er
Treatment.
Alternative 7 — Full ::rs lIdat1on and RCRA Capping of Target ‘eas.
Complete Gr.oundwater Ireatnent.
Alternative 8 — Full C:nsolidation into RC A Landfill: Comole:e
Groundwater Treatlrent.
Alternative 9 — C ris li aticn and RC AISoil aQpiriq f Target areas.
Stabilization of Scr ::er Sluc;e cnds: Cctnolete Grcijndwarer Trea —e’”
Alternative 11) — :,ce: :n ; i ::molece rcuno a:er Treac, enc
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AIter ative 3 EvaLuation
.medial AlternatIve 3 includes the following actions:
• Consolidation of the residual cathode waste material and underlying fill
material fYc. the Former Cathode Waste Management Areas into the existing
Landfill;
Consolidation of the cathode waste material frcm the Unloading Area Into
the existing Landfill:
• Capping the existing Landfill in place with a multi—media cap meeting
performance standaras;
• Placing a soil cover over Scrubber Sludge Ponds 2 and 3;
• Plug and abandon nearby production wells and connect users to the City cf
The Dalles water supply system:
• Collection and treatment of leachate generated from the Landfill and
perched water east of ‘iver Road and from the Former Cathode Waste
Management Areas;
• Recovery of groundwater from the Unloading Area;
• Institutional controls such as access and deed restrictions: and
• Groundwater quality monitoring and a contingency plan to recover aria tr at
additional grcun waeer If further contamination in the A or 3—aquifers Is
detected.
Short—Term Effectiveness
Implementation of Remedial Alternative 3 should reduce risks to the
ccnvnunlty and would pose minimal threats to on—cite construction workers. The
only potential risks to on—site workers would result frcni handling the waste
materials from the Unloading Area. Former Cathode waste Management Areas and
LLndflll during remedlation. Mowevir, the us. of dust controls, protective
clothing and respiratory protection and by implementing a health and safety
plan during remediation should greatly reduce the risks. Remedial Alternative
3 would take less than two years to implement upon Initiation of remedial
actions.
- 30-
411
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Overall Protection
Alternative 3 provides protection to the colirunity of The 0ille , on—site
workers and the environment. The risks at the MMRF would be reduced by
containing the waste, recovering groundwater and treating affected leac ,are
and perched water. Containment of the waste reduces the potential f r direct
contact with the waste as well as the generation of leachate and fugitIve dust
emissions. Recovery of groundwater and treatment of the leachate and :er ed
water greatly minimizes tne potential for off-site migration of contaminants.
Thus, Remedial Alternative 3 effectively mitigates tne e*posure patnways
Identified for the target remeøi&tion areas.
Cost
The capital cost of emedial AlternatIve 3 5 55.723,400. The annual C&M
costs for years 1 through S will be 5144,00. The annual O&I4 costs for years 6
through 30 viii be 555.600. The total present worth value of this alternative
using a discount rats of g , is $6,707,400.
The capital cost of implementing a groundwater contingency plan in the
A—aquifer would be $277,000. The annual O&M cost for this plan would be
$48,000. The total present worth of this plan using a discount rate f 3 Is
$767,000.
The capital cost of Implementing a ground water contingency plan in the 3-
aauifer would be $495,000. The annual O&M cost for this plan would be
S55.000. The total present worth of this plan using a discount rate of 3 ’L is
$1 , 11 4 .000.
(/7 ‘
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/I SELECTED ALTERNATIVE
De3criptio at Selected Remedy
The selected remedy is based on Alternative 3 and ccmprises the follcwing:
• Consolidate the residual cathode waste material and underlying i1l
material from the Former Cathode Waste anaqement Areas into t e
existing Landfill;
• Consolidate the cathode øaste material from the Unloading Area into
the existing Landfill:
• Cap the existing Landfill in place with a multi—media cap meet’ng
RCRA performance standards;
• Place a soil cover over Scrubber Sludge Ponds 2 and 3;
• Plug and abandon nearby production wells and connect users to the
City of The Dafles water supply system;
• Collect and treat leactiate generated frcm the Landfill and per e
water east of giver Road and from the Former Cathode Waste Mana;emenc
Areas;
• Recover’mnd treat contaminated groundwater from the Unloading area;
• Groundwater quality monitoring and a contingency plan to perform
additional recovery of groundwater in the event that further contamination I
detected above ARARs or health based standards.
Institutional controls such as deed restrictions and fencing will 3e
implemented during and after remediatlon. The purpose of these controls sill
be to assure that the remedial action will protect public health arid :e
environment during its execution, and to ensure a similar level of protec ci
after the remedial actions have been implemented.
Consolidation Into Landfill . The Lindfill and associated areas will te
consolidated to limit tne actual lateral extent of the cap. The UnloadIng
Area and Former Cathode Waste Management Areas will be excavated ccwrl to
competent basalt and consolidated into the existing Landfill. Leacnate will
be collected after capping the Landfill. Perched water, beneath trie Former
Cathode Waste Management Areas will be collected during excavation activitIes
and treated. This should be effective in collecting percned dater on coth
sides of River Road. However, temporary sumo(s) may be necessary to coliect
perched water east of River Road If the collecticn pumps in the Cathcds ias:e
management Areas are not effective. A oiI cover wi 11 e lacel over c a:er
Sludge Ponds 2 and 3. Groundwater controls will corts’ct of nsti :u : 1:ral
c ntrels and limited groundwater recovery. Oust :ontrols 4111 :e :‘ •:
during remediation to miiiiii:e f q ttve lust emi ion . Fencing ano ee
restrictions will oe utilized to m: ac:ess ard rever.: P.atjre se
4nere materials are managea cn— ; :e rij autor’Zed :er nrie’ cu : :
allowed entry to cne LiriOfflI mn S — ::er Siuc e after re eo,a::,
::molete.
-41-
I Rproduc.
I _ . !!! IvaI I. copy .
ui
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Martin Marietta Reduction Facility Mining Waste NPL Site Summary Report
Reference 2
Excerpts From Remedial Investigation, Martin Marietta
Reduction Facility, The Dalles, Oregon; Geraghty & Miller, Inc.;
June 1988
-------
SUMMARY
REMEDIAL INVESTIGATION
MARTIN MARIETTA REDUCTION FACILITY’
THE DALLES, OREGON
JUNE 1988
PREPARED FOR:
MARTIN MARIETTA CORPORATION
6801 ROCKLEDGE DRIVE
BETHESDA, MD 20817
PREPARED BY:
GERAGHTY & MILLER, INC.
14655 BEL-RED ROAD, SUITE 202
BELLEVUE,WA 98007
(206) 644-7226
LI
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U.
GERAGHTY & MiLLER. INC.
MNRF-RI SUMMARY
JUNE 30, 1988
2.0 SITE BACKGROUND
2.1 SITE LOCATION
The MMRF site is located in The Dalles, Wasco County, Oregon, west
of the Columbia River and east of the Union Pacific Railroad Road
(Figure 1). The MMRF occupies approximately 350 acres within an
800—acre area zoned for heavy industry and manufacturing. The area
of the site used for industrial purposes encompasses approximately
110 acres. The !‘ (RF is bounded near the Mountain Fir wood hauling
and chip mill on the north, Webber Street to the south, the
Columbia River on the east, and the Union Pacific Railroad line and
West Second Street to the west.
2.2 SITE HISTORY
The ! F is an aluminum processing facility designed to produce
approximately 90,000 tons per year of aluminum from alumina.
Operations began at the site in 1958 under the ownership of Harvey
Aluminum, Inc. Harvey Aluminum became a wholly owned subsidiary
of MNC in 1972. The MMRF continued operations under the name of
Martin Marietta Aluminum, Inc. until 1984, when the plant was shut
down and MMC acquired legal title to the property from Martin
Marietta Aluminum, Inc. In 1986, MNC leased the plant and portions
of property adjacent to the plant to Northwest Aluminum Company,
which resumed primary aluminum operations in 1987. A chronological
history of events and actions related to the aluminum plant
operations is provided in Table 1. Review of ) C’s files on the
MMRF indicate that the first and only necessary regulatory
enforcement action for the site occurred in September 1985 when MMC
signed a consent order with EPA to conduct the RI/FS.
During facility operation, waste constituents derived from alumina
reduction were stored, treated, and disposed of at the MMRF. These
waste constituents are derived from spent cathodes and anodes
utilized in the alumina reduction process and include refractory
bricks, carbon bricks (potliner), fabricated metal, remnant
aluminum and process bath (of which cryolite is a principal
constituent). The other primary process waste stream from the
facility is air emission control residuals. These residuals are
a result of air scrubber systems installed to control the emission
of fluoride; however, these scrubber wastes also contain elevated
3
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$CALI IIFUT ___________
FIGURE 1
SITE LOCATION MAP
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GERAGHTY & MILLER. INC.
TABLE 1
CHRONOLOGICAL HISTORY OF MMRF OPERATIONS
RI SUMMARY
MMRF, THE DALLES
Dates Event
1957 and Plant construction debns placed in the Landfifl. Paper and wood burned in the Landfill. Burning
through 1960 ceased after 1960 as paper and wood waste were crushed and shipped to Wasco County Landfifl.
1958 Process operations initiated by Harvey Aluminum, Inc. Plant emissions collected in a wet primary fluonde
scrubber system (known as the 014 Tower system) and discharged to Scrubber Sludge Ponds 2 and 3.
1960 ’s Primary Otd Tower system replaced with electrostatic precipilators. Collected emissions sent to
Scrubber Sludge Ponds 2 and 3.
1960 Old Cathode Waste P e started at northeast corner of the plant. Old Cathode Wash Area constructed
east of plant and next to River Road.
1961-1971 Bricks separated from cathodes taken out of service and placed in the Landfdl. Other cathode waste
shipped off-site for processing at Reynolds Aluminum.
1968 Berm and settling basin added to Old Cathode Wash Area.
Martin Marietta Corporation purchased 41% of common stodc of Harvey Aluminum.
1969 Secondary scrubber added to existing scrubber system to enhance air emission controls.
Martin Marietta Corporation purchased an additional 41.7% of common stock of Harvey bringing the total
stock purchased to 82.7%.
1972 Martin Manetta Corporation purchased the remaining 17.3% of corernon stock of Harvey Aluminum.
Clarifier placed on-line. Scrubber Sludge Pond I use began. Scrubber
Sludge Ponds 2 and 3 use discontinued except for use as a backup when clanliec was off4ine.
1974 Recyde Pond constructed for use as settling basin for solids separation from secondary scrubber water
Old NPDES Oischarge Channel removed from service.
1974-1984 Casthousa. Paste Plant, and plant operations waste deposited in the LandilU.
1976 Scrubber Sludge Pond 4 constructed and used to store dredged materials
from Scrubber Sludge Ponds 2 and 3. and the Recycle Pond.
1977 Scrubber Sludge Pond 2 dredged and material placed in Scrubber Sludge Pond 4.
1978 Dry Scrubber system lnstafled to replac. electrostatic precipilators. Wet saubber added downstream of
the dry system as a backup and to coilect sulfur dioxide emissions. Fluonde adsorbed by activated
alumina v i the dry satibbsr was recycled back to the reduction cell. Sofids from the wet system were
pumped to the Scrubber Sludge Ponds.
1979 Scrubber Sludge Ponds arid Old Cathode Wash Area extended to the east.
1980 Lined pond constructed to reduce volume placed In the Scrubber Sludge Ponds. Martin Marietta
Corporation studies control of surface water flow around the LandfiU. Hard Pitch Building constructed
July 1980 Piping from the LandfiU to the Landfifl leachate collection sump installed. Sump pump installed to efim:naie
disch tges from the Landfdl under River Road.
1981 Scrubber Sludge Ponds I and 4 use discontinued, ponds capped.
1982 Scrubber Sludge Pond 2 received runoff from Scrubber Sludge Pond 3. Dredged bottoms of Lined POnd
and Recyde Pond placed in Scrubber Sludge Pond 3.
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GERAGHTY & MILLER. INC.
TABLE 1 (CONT’D)
CHRONOLOGICAL HISTORY OF MMRF OPERATIONS
RI SUMMARY
MMRF, THE DALLES
Dates Event
Spring 1983 Cyanide levels above detection limits obseived dunng routine sampling of Production Well 2 Well
subsequently property abandoned.
1983 Leachate detected migrating from the t.andfili under Riv Road to the Rock.line Quarry. Century West
Ertgineenng investigated Landfill for depth to bedrock and subsurface/swiace runoff. Surface cover
added to Landfill to control surface drainage towards the east arid drainage ditches were constructed to
control runoff and runon (Surface Drainage Ditch and Leachate Collection Ditch). A diversion berm also
constructed on west side of ditch to ebminate surface runoff.
Century West Engineering prepared a leachate collection system design for Landfill. EPA performed
hazardous waste ranking of MMRF.
Stale of Oregon Department of Environmental Quality lists potfiner (cathode) waste as hazardous. Martin
Manetta Corporation builds an approved waste pad to store waste potliner (cathode). Old potlirier
cathode waste previously stored at the Old Cathode Wa8te Pile relocated to the permitted storage area.
1984 Martin Marietta Corporation acquired legal title to property from Martin Mailetta Aluminum, Inc. Martin
Marietta Corporation constructed a leachate collection system for the L.andfill and constructed a New
Cathode Waste Pad. Remaining Old Cathode Waste Pile waste and sia inches of soil relocated to the
New Cathode Waste Pad. kea backfilled and graded with clean sod.
December 1984 Martin Marietta Aluminum. Inc. ceases production.
September 1985 Martin Marietta Corporation enters into a consent order with Region X EPA. Requirements of the consent
order include the performance of a Remedial Investigation and Feasibdity Study (RI/FS) for the MMRF
This was the first regulatory action enforced on the MMRF.
December 1905 Work plan for the Rh/FS prepared by Geraghty & Miller. Inc. for Martin Manetta Corporation submitted to
the EPA. Camp. Dresser & McKee. Inc. submitted a community relations plan for the MMRF to the EPA
February 1986 RIIFS Work Plan modified.
March 1986 RIIFS Work Plan implemented by Geraghty & Mdler. Inc.
April 1986 Fencing instailed to samire Lantififl.
September 1986 Martin MarIetta Corporation leased the MMRF to Northwest Aluminum Company under a five year
lease/sale agreement. Northwest Aluminum Company resumed primary aluminum operations. Uned
Pond. Discharge Channel. and Recycle Pond were reactivated for plant operations.
November 1986 Results of initial RI data collection activilies summanzed by Gersghty & Miller. Inc. in intenm Repot1
Remedial Investigation. MMRF. The Dallas. Oregon submitted to EPA.
1987 Flows to the Duck Pond were diverted to the Discharge Channel.
January 1987 MMRF designated as a Supedund site.
March 1987 RIIFS Work Plan Addendum submitted to EPA.
May 1987 RIIFS Work Plan Addendum modified.
June 1987 EPA approved RIIFS Work Plan Addendum. Field activities specified In the addendum initiated.
November 1987 Preliminary RI submitted to EPA.
March 1988 Final RI submitted to EPA.
April 1988 PrelimInary FS submitted to EPA.
June 1988 Final FS submitted to EPA.
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GERAGHTY & MILLER. INC.
RF-RI SU AR
JUNE 30, 1988
levels of sulfate and PANs. The fate and disposition of these
waste streams are described in Figure 2.
Although waste management techniques such as installation of wet
and dry scrubbers were employed and all necessary environmental
operating permits were obtained, waste constituents (principally
fluoride, sodium, sulfates, cyanide, and polyriuclear aromatic
hydrocarbons) were released to the environment. As a result of
such releases, !C entered into a Consent Order with Region X of
the USEPA in September 1985 that directed t*tC to perform an RI/FS
for specific areas at the site that might have been impacted during
plant operations.
Prior to initiating the RI, a number of interim remedial actions
were performed at the ! 2IRF to mitigate the environmental effects
of plant activities. These include: construction of the lined
pond; relocation of the old cathode waste pile to the new cathode
waste pad containing a leachate collection system; fencing of the
landfill to restrict access (performed as an interim remedial
measure); and construction of a landfill leachate collection system
consisting of perimeter ditches and a collection sump.
2.3 OVERVIEW OF THE REMEDIAL INVESTIGATION
The RI for the site was initiated in March 1986. The areas
investigated during the RI are the:
o Landfill and Adjacent Areas
o Former Cathode Waste Management Area
o New Cathode Waste Pad
o Duck Pond
o Lined Pond
o Recycle Pond
o Scrubber Sludge Ponds
o Wastevater and Surface-Water Transport Ditches.
Details of the site and the areas of investigation are shown in
Figure 3. Table 2 summarizes the volumes of soil, sediment, waste,
or liquid estimated to be contained within these areas. In
addition, ground—water systems located beneath the facility were
investigated for impact from plant operations. Four aquifer
systems, designated the S, A, and B aquifers and the Dalles Ground-
water Reservoir (DGWR), have been identified at the RF. Perched
water at the old cathode waste pile, salvage area, cathode wash
area, and an alluvial aquifer of limited areal extent were also
evaluated during the RI.
4
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WGERAGHTY
4P’& MILLER, INC.
Wc:r Cosuvl:.ae:
NOTE:
CATHODE WASTE
MASS BALANCE ± 5%
(VOLUMES AND TONNAGE
ARE APPROXIMATE)
FIGURE 2
MAJOR PLANT
OPERATION WASTES
START-UP THROUGH
MMRF. THE DALLES. OREGC
R SITh*MRY
FROM
1984
qaO
43,000 TONS
22.000 TONS
OFFSrrE
RECYCLE
OLD CATHOOE
WASTE PILE
69.000 TONS
‘P
RCRA PAD
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C,
NPOES
I’ WGERAGHTY
AP& MiLLER, INC.
W.: r Consul:o,,s
FIGURE 3
AREAS OF INVESTIGATION
MMRF, THE OAU.ES. ORE CN
sup v, Y
N
0 50 1000
SCALE IN FEET
/*NIMAL
I
I
I
I
QUARRY)
OL CAThODE WAS 1 Plu
SALVAGE
AREA
POTUNER
IIANOUNG
AREA
r
2
(
-.3
RECYCLE
POND
APPROXIMATE STUDY
AREA BOUNDARY
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GERAGHTY & MILLER. INC.
Table 2. Sune ary of Volume Estimates
RI Sun nary
N2 RF , The Dalles
Es
Area of Investigation cubic
timated
Volume
yards
gallons
L ,andfi 11
Landfill Runoff Areas
Area A
Area B
Area C
Area D
Metal Pad Storage Area
Bath Recovery Pad Area
Old Cathode Waste Pile Area
Salvage Area
Potliner Mandling Area
Cathode Wash Area
Duck Pond
Lined Pond
Recycle Pond
Scrubber Sludge Ponds
sSP 1
SSP2
SSP3
SSP4
Wind Blown
Unloading Area
Ditches
Surface Drainage Ditch
Leachate Collection Ditch
Landfill Ditch
North Ditch
River Road Ditch
River Road Curb
Discharge Channel
Drainage Ditch
Old NPDES Discharge Channel
Abandon Scrubber Sludge Channel
Note: (1)
(2)
(3)
(4)
Seasonally at fected — not relevant
Estimated
Lined with concrete, unable to probe
Negligible
200,000
510
150
230
138
1,690
1,660
24,200
28,700
9.910
4,530
2,430
7,700
8,915
71,700
9,580
58,100
28,500
538
20&2)
1,240
(3)
2,050
610
200
(4)
1,100
920
(4’
(4)
4,000,000
8,000,000
(1)
soils underneath.
yQ ,
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GERAGHTY & MILLER. INC.
!2IRF-RI SU ARY
JUNE 30, 1988
The RI consisted of waste characterization at the landfill and
sampling of sediment, soil, air, surface water, and ground water
throughout the site to: characterize site conditions and the extent
and nature of constituents released to the environment; gather site
data necessary to evaluate potential remedial responses; and
determine the nature and extent of the risk posed to public health,
welfare, or the environment by the release of constituents at the
During this work, monitor wells were installed, several
previously constructed wells were replaced, aquifer tests were
conducted, and water-level measurements were made. New monitor
wells were installed on-site and off-site to enhance delineation
of the direction of ground-water movement and hydraulic
relationships among the aquifer systems. RI data-collection
activities included the following:
o Abandonment of 3 wells;
o Reconstruction of 16 pre-existing monitor wells;
o Installation of 41 new monitor wells;
o Completion of 66 borings;
o Completion of 15 test pits;
o Collection of 272 ft of rock core;
o Completion of 13 slug tests;
o Completion of 6 aquifer pumping tests;
o X—ray fluorescence analysis of 29 rock samples;
o Collection and analysis of 133 ground-water samples;
o Collection and analysis of 38 surface—water samples;
o Collection and analysis of 19 soil samples;
o Collection and analysis of 60 sediment samples;
o Collection and analysis of 22 waste samples;
o Collection and analysis of 446 air samples.
Subsequent to the RI, an electromagnetic resistivity (EM)
geophysical survey was run (approximately 500 stations) and test
pits (13) completed in areas underlain by fill material in order
to evaluate the extent of perched water at the site. In addition,
12 surface water, 12 sediment, 6 test pit, and 25 ground-water
samples were collected and analyzed. The results of these analyses
are presented in the RI Supplement (July 1988).
The types of constituents detected in source areas and ground-water
systems at the !*IRF were consistent with the types of materials
treated, stored, or disposed of at the site. Appendix A is a
summary of the quality assurance review and analytical data
obtained during the RI for ground water, soil, sediment, waste,
and surface-water samples.
5
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GERAGHTY & MILLER. INC.
RF-RI SUI*IARY
JUNE 30, 1988
3.0 PHYSICAL CHARACTERISTICS OF THE SITE
3.1 CLIMATE
The !ff1RF is located within the semi-arid region of eastern Oregon
where the climate is characterized by warm, dry summers and cold,
relatively wet winters. At The Dalles, the mean annual temperature
is about 54°F. July is generally the warmest month with a mean
maximum temperature of 86°F. The mean minimum temperature is 34°F
in January.
The area receives from 10 to 15 inches of precipitation annually
with a mean annual precipitation at The Dalles of 13.7 inches.
Average annual evaporation from shallow lakes in the area is
approximately 40 inches. Records from The Dalles indicate a
cumulative moisture deficit of about 15 inches per year; that is,
evaporation exceeds precipitation.
Wind velocity measured at an on-site meteorological station during
the months of June and December 1987 showed maximum wind speeds of
up to 60 miles per hour (mph); gusts of up to 30 mph were common.
The highest wind speeds are associated with northwest winds.
Typical wind speeds range from 5 to 20 mph and the predominant wind
direction is from the northwest. The on-site wind data are
consistent with the more complete long-term data collected at the
Dalles airport and verify the utility of the airport wind data for
use at the site in the RA.
3.2 TOPOGRAPHY
Land-surface elevations at the 1RF range from about 100 feet above
mean sea level (ft xnsl) at the Columbia River to more than 155 ft
msl at the Landfill. The topography of the site has changed over
time due to filling of low areas; in general, the site is level
with the exception of distinct man-made and natural features.
These features include: man-made ponds, the landfill, drainage
ditches, stream channels, and road beds.
6
Uq Lf
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GERAGHTY & MILLER. INC.
MNRF-RI SUNMARY
JUNE 30, 1988
3.3 SURFACE-WATER DRAINAGE AND PONDS
The topography at the * RF largely controls the direction of
surface-water flow, except where man-made structures have been
built to alter flow patterns. In general, surface—water runoff
from active portions of the site is routed to the recycle pond.
Runoff from the landfill area is currently intercepted by the
leachate collection system arid the landfill ditch and then routed
to the recycle pond via the discharge channel. Prior to the
construction of this interception network, it is believed that
landfill runoff followed three primary drainage pathways, all of
which discharged towards the alluvial aquifer.
The ponds at the MMRF include the four scrubber sludge ponds,
recycle pond, duck pond, and lined pond. The recycle pond is used
to recycle rectifier water and roof scrubber water and receives
runoff from the landfill, the former cathode waste management area
and areas to the immediate south and west of the plant. The
recycle pond discharges to the Columbia River in accordance with
a National Pollutant Discharge Elimination System (NPDES) permit.
The recycle and lined ponds are currently in use. The scrubber
sludge ponds are no longer in use but intersect the water table
and are saturated in proportion to the relative ground-water
elevation.
3.4 LITHOLOGY/GEOLOGY
The surface soils at The Dal].es are poorly developed and in most
places are non—existent. The four native soil groups known to be
present, are, in order of decreasing areal extent: (1) the Rock
Outcrop-Xeropsamments Complex, (2) the Hessian-Skyline Complex,
(3) the Van Horn Loam, and (4) the Quincy Loam Fine Sand. During
construction and operation of the !*IRF, a large part of the native
soils at the site were covered with fill material.
Underlying the soils/fill at the site is rock of the Columbia River
Basalt Group (CREG). The rock formations evaluated consist of the
following stratigraphic horizons (in order of increasing depth):
o Lob flow of Priest Rapids Member:
o Sedimentary (Byron) Interbed:
o Rosalia flow of Priest Rapids Member;
o Sedimentary (Quincy/Squaw Creek) Interbed; and
o Sentinel Gap flow of Frenchman Springs Member.
The rock strata at the site are generally flat lying except in the
north where the Chenoweth Fault transects the site. The CRBG is
7
Jq)
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GERAGHTY & MILLER. INC.
MMRF-RI SUMMARY
JUNE 30, 1988
overlain by Pleistocene age alluvial deposits in the northern parts
of the site. The geology of the site is presented schematically
in Figure 4.
3.5 HYDROGEOLOGY
The ground-water flow system at the MMRF includes a water-table
aquifer (S aquifer) overlying a series of confined aquifers (A and
B aquifers and DGWR). Zones of perched water and art alluvial
aquifer are present locally.
The unconfined S aquifer is present within the relatively low
permeability basalts of the Lola flow and the subaerial portion of
the Rosalia flow and the Byron Interbed. The first confined
aquifer (A aquifer) is within the upper pillow lava horizon of the
subaqueous portion of the Rosalia flow. The A aquifer ranges from
5 to 45 ft in thickness. The B aquifer is below the A aquifer
and is locally separated from it by a low permeability basalt (lava
lobe). The lava lobe is apparently absent north of the site due
to non—deposition. The B aquifer ranges from 30 to 50 ft in
thickness. In areas where the lava lobe is absent, the A and
B aquifers combine to form a single hydrogeologic unit. A thick,
low permeability siltstone and sandstone unit forms the confining
unit between the B aquifer and the underlying DGWR. The top of
the DGWR occurs within the permeable zones of the Sentinel Gap
flow, and the most permeable portion of the DGWR is within the
flow—breccia top of the Sand Hollow flow. Characteristics of the
various hydrogeologic units are described in Table 3.
Ground-water flow in the S aquifer is generally to the east and
northeast (as shown in Figure 5); discharge from the S aquifer is
believed to be into the A aquifer and the Columbia River.
Ground-water flow in the A aquifer is predominantly east to west.
The A aquifer may be recharged by the alluvial aquifer, the
Columbia River, and the S aquifer; discharge appears to be to the
B aquifer and regional water-supply wells. Depending on the
hydrologic and pumping conditions, ground—water flow in the
B aquifer is generally to the west and south and discharge appears
to be to the A aquifer, DGWR or regional water-supply wells.
An alluvial aquifer, approximately 400-ft wide and at least 60-ft
deep, is present in the area north of the plant within Pleistocene
age sand deposits. The geometry of the alluvial aquifer is
apparently controlled by the location of the trace of the Chenoweth
Fault. Flow in the alluvial aquifer is expected to be east, toward
the Columbia River; however, ground-water levels and gradients have
not been measured in the alluvial aquifer.
8
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PLEISTOCENE
BYRON INTERBED
4 GERAGHTY
r& MILLER, INC.
CHENOWETH
CREEK
FIGURE 4
SCHEMATIC
ILLUSTRATION
OF SITE GEOLOGY
MMRF. ThE DALLES. CI EGQN
r .‘. Iia..fl ,
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GERAGHTY & MILLER, INC
TABLE 3
SITE HYDROGEOLOGY
RI SUMMARY
MMRF. THE DALLES
UNIT CHARACTERISTiCS THICKNESSIEXTENT CONFINEDIUNCONFIHED TRANSMISSIVITY
Perched Water Zone Fill Umited to areas where fill overlies Unconfined Low
depressions In bedrock
Alluvial Aquifer Alluvial Sand Umited areal extant; approximately 60 Ii Unconlined Moderate
and Gravel deep X 400 It wide X 3000 ft long
S Aquifer Basalt (Subaerial) Upper portion not present in SE portion ci Unconlined Low
and Byron interbed silo. ApproxImately 100 ft thick.
A Aquller Basalt (Subaqueous) Pinches out in southern portion of site. Confined Moderate
5-45 ft thick.
B Aquifer Basalt (Subaqueous) 30-50 ft thick Conilned I-Ugh
Oulncy/Squaw Siilstone Approxlmalely 20 Il thick NA Confining Unit
Creek Interbed
The Dallas Ground- Basail (Subaerial) 10-50 ft thick Confined Very High
Water Reservoir
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GERAGHTY & MILLER. INC.
? 1RF-RI SU?*IARY
JUNE 30, 1988
4.0 NATURE A D EXTENT OF SITE-DERIVED CONSTITUENTS
The nature and extent of the site-derived constituents can be
defined from the RI results, including the RA conclusions and the
characteristics of the site and waste materials. Analytical data
obtained during the RI are used to ascertain the lateral and
vertical extent of the released constituents. Conditions are
further defined based on waste and site characteristics for the
areas of concern in order to evaluate potential exposure,
transport, and remediation of site materials. Finally, in the PA,
potentially impacted areas are assessed for points of exposure and
associated risks to human health, welfare, and the environment.
In order to perform the PA, chemical-specific standards for
constituents detected at the site are established.
4.1 SOIL. SEDIMENT AND SURFACE WATER: AREAS OF POTENTIAL CONCERN
Although a number of areas were investigated during the RI, the
following areas were identified as areas of potential concern
because of potential risk by human contact, ingestion by wildlife;
or risks associated with future impact to ground water presented
by the presence of constituents in soil, sediments or surface
water. The following areas were identified:
o Landfill and associated areas
— landfill soils
— landfill runoff area soils
- leachate collection ditch water
- landfill ditch water
— surface drainage ditch sediments
o Potliner Handling Area soils
o Scrubber Sludge Ponds sediments
o Discharge Channel sediments
o Lined Pond sediments
o Recycle Pond sediments
The Lined Pond, Discharge Channel, and Recycle Pond are currently
operating units. While these units are in operation they do ct
11
1 1 c ci
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GERAGHTY & MILLER. INC.
!RF-RI SUXMARY
JUNE 30, 1988
pose a risk; therefore they are not included in the discussion of
areas of concern.
4.1.1 Landfill
The landfill occupies approximately 15 acres just north of the
aluminum reduction building. Former drainage pathways from the
landfill area correspond to the landfill runoff areas. The
installation of the leachate collection ditch, which was gunite
lined, was designed to collect and control leachate. The leachate
collection ditch is effective in preventing surface runoff but is
less effective in capturing leachate following the contact between
surface soils/fill and the underlying basalt. MNRF installed an
interceptor trench in an effort to minimize the impact of
surface-water runon from the area west of the landfill.
Wastes at the landfill were placed randomly on the ground surface
and piled to the current configuration; total waste volume is
estimated to be about 200,000 cubic yards. Wastes present in the
landfill as a result of the reduction process and construction
operations consist of: construction debris (primarily basalt
fragments); spent cathode waste materials; refractory bricks;
off-specification carbon block, pitch, and coke; cryolite; metallic
materials such as buss bars arid collector studs; and pallets, cans,
rags, arid empty drums. Prior to the regulation of asbestos
disposal and handling practices, asbestos arid materials containing
asbestos were disposed of in a random fashion within the landfill.
Since regulation of these materials, (RF disposed of asbestos in
discrete areas of the landfill.
Waste materials within the landfill can be divided into four main
categories:
o Basalt fragments;
o Asbestos;
o Metallic wastes; and
o Target wastes.
Most of the waste appears to be basalt from construction
activities; particle sizes range from very fine silts to boulders
several feet in diameter. Although written records do not exist,
the volume of asbestos in the landfill is not anticipated to be
large quantity (less than 100 cubic yards). However, it is nc
possible to accurately estimate the volume of asbestos distribute.
throughout the landfill prior to controlled burial. Metail::
12
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GERAGHTY & MILLER. INC.
MNRF-RI SUMMARY
JUNE 30, 1988
wastes consist of buss bars, collector studs, and miscellaneous
drums, cans, etc. However, there does not appear to be a
significant quantity of metallic wastes. The target wastes consist
of the remaining materials, including: spent cathode waste,
refractory bricks, and off-specification carbon block, pitch, and
coke. The following volumes have been estimated for the waste types
in the landfill:
o Basalt Fragments 100,000 yds3
o Asbestos
- Buried 100 yds3
- Distributed 200 yds3
o Metallic Wastes 500 yds3
o Target Wastes 99,200 yds3
It is estimated that 5,000 tons of spent cathode waste materials
are present in the landfill; these wastes contain high levels of
carbon, sulfate, sodium, and fluoride in addition to minor amounts
of cyanide. Cryolite, which is composed of fluoride, sodium, and
aluminum, is also present in the landfill. Pitch and coke
associated with the anode in the reduction process are present in
the landfill and contain elevated levels of PAMS and low levels of
arsenic.
To confirm the composition of the landfill, five test pits were
excavated. The materials observed ranged from fine dust to very
large basalt boulders. Composite samples from the five test pits
indicate the presence of the following constituents:
o EP Toxicity Metals
- Barium
o Total cyanide
o Free cyanide
o Sodium
o Fluoride
o PAHs
4.1.1.1 Landfill Leachate : Leachate generated by the landfill
is contained by a leachate collection system that consists of the
following ditches:
o Surface Drainage Ditch;
0.234 mg/L (one sample)
0.32 — 70 mg/kg
BDL - 54 mg/kg
3,400 — 82,200 mg/kg
204 — 2,880 mg/kg
10.3 — 2,406 mg/kg
13
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GERAGHTY & MILLER. INC.
!* RF-RI SU 4AR
JUNE 30, 1988
o Leachate Collection Ditch; and
o Landfill Ditch.
The generation of leachate is seasonally dependent and its presence
is directly related to precipitation or snow melt. Available
records of leachate collected and pumped range from 0 to 50,000
gallons per day (gpd), with peak flows occurring generally in the
spring.
Analyses of leachate samples from the leachate collection ditch
identified the presence of the following constituents:
o Volatile Organic Compounds
— Trichloroethylerte 8 mg/L (one sample)
o Cyanide - Total 0.11 — 31 mg/L
- Free 0.25 - 4.7 mg/L
o Fluoride 1,490 - 2,440 mg/L
o Sodium 4,270 - 5,900 mg/L
o Sulfate 840 - 2,660 mg/L
Analyses of leachate samples from the landfill ditch identified
the presence of the following constituents:
o PAHs (including Bis(2 -ethyl—
hexyl)Phthalate) 0.020 — 0.206 mg/L
o Cyanide — Total 373 - 1,280 mg/L 1
— Free 34.2 — 77.2 ing/L
o Fluoride 5,400 - 8,000 xng/L
o Sodium 36,600 — 99,800 ing/L
o Sulfate 10,500 — 49,300 ing/L
o Chloride 645 — 3,430 mg/L
The surface drainage ditch was dry and leachate was not present
for sampling. The leachate collection ditch was gunite lined and
sediment samples were not available. Sediments from the surface
drainage ditcb and the landfill ditch were analyzed for the
following constituents:
o - Cyanide — Free BDE — 3.6 mg/kg (one sample)
o Fluoride 189 - 519 mg/kg
o Sodium 2,720 - 5,600 mg/kg
14
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GERAGHTY & MILLER. INC.
! ff1RF-RI SU 4ARY
JUNE 30, 1988
o Cyanide - Total 14 mg/kg
- Free 4 mg/kg
o Fluoride 673 mg/kg
o Sodium 29,600 mg/kg
o PAHs 9,041 mg/kg
These results are characteristic of cathode waste, coke, and pitch.
4.1.3 Scrubber S1udc e Ponds
The scrubber sludge ponds (SSPs) consist of four surface
impoundments (numbered 1 through 4) located south of the reduction
buildings and west of River Road. The original locations for the
SSPs were selected because the air emission slurry produced in the
aluminum reduction process could be discharged to the SSPs under
gravity conditions. The large surface area and retention capacity
of the SSPs allowed for particulate settlement and final discharge
of accumulated water to the Columbia River.
SSPl was diked and was used to receive chemical sludges resulting
from the lime precipitation of the air emission control waters for
fluoride removal. The primary salt formed during the precipitation
was calcium fluoride. SSP4 received dredgings from SSP2 and SSP3
and the recycle pond. Both SSP1 and SSP4 were removed from service
and covered in 1981.
Collectively, the lateral extent of the SSP5 is approximately 14.8
acres. SSP1 and SSP4 have soil covers and established vegetation
which currently precludes direct contact with the wastes. SSP2
and SSP3 are not covered. The material present in the SSPs can be
divided into three categories: (1) soil cover, (2) sludges, and
(3) contaminated subsoils. The volumes for each SSP by category
are presented below:
Pond Cover S1ud e Subsoil Subtotal
SSP1 .7,970 63,730 71,700
SSP2 — 6,820 2,760 9,580
SSP3 43,600 14,500 58,100
SSP4 4,640 17,660 6,200 28.500
TOTAL 167,880
In addition, prevalent winds have scattered approximately 538 cubic
yards of sludge south of SSP2 and SSP3.
17
•0
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GERAGHTY& MILLER. INC.
1RF-RI SUMMARY
JUNE 30, 1988
Samples were collected from pond and analytical results indicate
the presence of the following chemicals:
SSP1 a Cyanide - Free BDL
o Fluoride 204 - 407 mg/kg
o Arsenic BDL - 64 mg/kg
o Sodium 15,400 — 20,700 mg/kg
o VOCs BDL
o PARs 2,760 - 8,570 mg/kg
SSP2 0 Cyanide - Free BDL
o Fluoride 263 - 317 mg/kg
o Arsenic 34 - 71 mg/kg
o Sodium 14,500 — 17,700 mg/kg
o VOCs BDL
o PARs 1,940 - 7,180 mg/kg
SSP3 o Cyanide - Free BDL
o Fluoride 387 - 613 mg/kg
o Arsenic 66 - 77 mg/kg
o Sodium 18,400 — 45,000 mg/kg
o VOCs BDL
o PANs 3,950 - 8,360 mg/kg
SSP4 o Cyanide - Free BDL
o Fluoride 212 - 258 mg/kg
o Arsenic BDLI - 50 mg/kg
o Sodium 6,250 — 13,600 mg/kg
o VOCs BDL
o PANs 2,670 — 3,979 mg/kg
Surface water was not present in SSP2 when samples were collected
and therefore could not be analyzed.
4.2 GROUND WATER: AREAS OF POTENTIAL CONCERN
The constituents of concern identified in the ground-water system
include fluoride, free cyanide, sulfate, and sodium. The highest
constituent concentrations are present in the perched water with
progressively lower concentrations identified within the S, A, and
B aquifers. Concentrations of constituents in wells tapping the
DGWR are low and within the range expected for background. The
following discussion references analytical data from the summer of
1987 which represents data collected from the reconstructed wells.
18
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GERAGHTY & ! VIILLER. INC.
MMRF-RI SU? fl1ARY
JUNE 30, 1988
Perched water samples from the old cathode waste pile show elevated
concentrations of fluoride (3,000 mg/L), free cyanide (3.01 mg/L),
and sodium (10,500 ing/L). Samples from the well in the alluvial
aquifer at the Animal Shelter detected a sulfate concentration of
15 mg/L; no free cyanide or fluoride was detected.
Elevated constituent concentrations were identified
S aquifer at several locations:
in the
(1) Near the landfill and former cathode waste management area.
(2) Scrubber sludge ponds.
o Fluoride
o Free cyanide
o Sulfate
o Sodium
4.8 to 7.1 mg/L
BDL
10 to 3,020 mg/L
3.930 to 658 mg/L
o
Fluoride
57
mg/L
o
Free Cyanide
0.215
mg/L
o
Sulfate
680
mg/L
o
Sodium
1270
mg/L
(4) Recycle pond; MW-21S downgradient of the pond.
The distribution of fluoride and free cyanide in the S aquifer are
shown in Figures 6 and 7.
Ground—water quality impacts in the A aquifer are less widespread
and at lower concentrations than those identified in the S aquifer.
The highest concentrations in the A aquifer exist east of the
0
Fluoride
BDL
to
4.7
mg/L
o
Free cyanide
BDL to 0.136
mg/L
o
Sulfate
up
to
103
mg/L
o
Sodium
10.5 to
82.2
mg/L
(3) Upgradient of the new cathode waste area
unloading building (MW—5S).
near the alumina
o Fluoride
o Free Cyanide
o Sulfate
o Sodium
5.5 mg/L
BDL
871 mg/L
90.5 mg/L
- f
-------
LEGEND
o $
• S.A
• A,8
• S.A.B
• A,B.D
a a
S A
a PW
I PW (Abidond)
1.0 mgll. CONTOUR
A ’GERAGHTY
r& MILLER, INC.
IV.tEr Co.twl:Mgs
FLU
(S
FIGURE 6
ORIDE CONCENTRATION
AQUIFER) AUGUST 1987
MMRF, THE OAU.ES. OREGON
J1JMRV
N
0 500 1000
SCALE IN FEET
Mdu tOin Fu ,
as
NW-33
S
r
/
Recreation Arsa
$ o
-------
LEGENO
o S
• S,A
• A,B
• S.A,B
I A,B,D
o D
I RN
i PW (Ab.idon.d)
0.06 m 4. CONTOUR INTERVAL
d GERAGHTY
AV& MILLER, INC.
Wi,r Coøsith.ius
FREE
(S
\
)
FIGURE 7
CYANIDE CONCENTRATION
AQUIFER) AUGUST
MMRF, THE DALLES, OREGON
M4 R1
1987
N
o 500 1000
SCALE IN FEET
Moutit in Fir
a.
MW.33
S
r
/
• A
Rec? Otion Aria
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GERAGHTY & MILLER, INC.
1RF-RI SU ARY
JUNE 30, 1988
landfill and the former cathode waste management area. In this
area, free cyanide concentrations range from <0.010 to 0.132 mg/L;
sodium is found at 167 mg/L. In parts of the A aquifer, fluoride
concentrations exceed 1 mg/L.
Site—derived constituents are also present in the A aquifer near
the scrubber sludge ponds. Sodium ranges from 38.4 to 46.7 mg/L,
sulfate from 23 to 81 mg/L, and fluoride from <0.1 to 1.0 mg/L.
Free cyanide was not observed above the detection limit.
In the B aquifer, elevated constituent concentrations are chiefly
confined to a single location: the area near the landfill. The
highest readings are reported for wells MW-9B and MW—SB, but they
are suspected to be an artifact of well construction. Free cyanide
concentrations are 0.057 mg/L 1 or less and fluoride concentrations
are less than 20 1ng/L.
4.3 CHENOWETH CREEK SAMPLING
Three surface water samples were collected from Chenoweth Creek
during the RI. Detection limits for cyanide and fluoride in
Chenoweth Creek surface water samples were not sufficiently low
enough to allow for valid comparison with applicable EPA Ambient
Water-Quality Criteria and Health Advisories. Therefore, two
additional rounds of surface water and sediment samples were
collected from six sample locations in Chenoweth Creek during
Spring 1988. The samples were taken during and shortly after the
spring spawning period and double sample volumes were collected
and analyzed to achieve the required quantification limits.
Analytical results for these samples were evaluated to determine
if upstream and downstream results were significantly different,
and to determine if detected values exceed levels which may
adversely impact aquatic life. No impact has been demonstrated on
Chenoweth Creek sediment or surface water from any potential
discharge from I RF, and detected levels were all below available
aquatic life criteria.
4.4 AMBIENT AIR MONITORING
Ambient air samples were collected upwind and downwind of active
drilling and test pit sites during the investigation. Samples were
analyzed for gaseous cyanide, particulate cyanide, and coal tar
pitch volatiles/total dust. All samples collected were be1c
Occupational Safety and Health Administration (OSHA) Permissi 1e
20
O S
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GERAGHTY & MILLER. INC.
MMRF-RI SUMMARY
JUNE 30, 1988
Exposure Limits (PELS) with the exception of one upwind sample for
coal tar pitch volatiles.
Personnel/Health and Safety air-quality monitoring was also carried
out; no concentrations of ionizable pollutants were detected above
the threshold requiring Level C protection and all samples were
below OSHA PELs (except one sample for coal tar pitch volatiles).
In order to assess fugitive dust from the site, soil sieve analyses
and fugitive particulate modeling was carried out. The results of
this modeling are included in the Risk Assessment for the site.
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GERAGHTY & MILLER. INC.
MMRF-RI SUMMARY
JUNE 30, 1988
exposures, with and without soil disturbance at the site), the
exposure scenario selected for evaluation was that which would
result in the highest exposure, and therefore highest potential
risk (worst case). This resulted in several exposure scenarios
related to potential future uses of the site and surrounding areas,
by both future industrial and residential populations, being
evaluated.
Risks from these potential human exposures were characterized in
several ways. Because ground water was the only exposure medium
for which ARARS or other guidance (Health Advisories) were
available for all chemicals of potential concern, risks associated
with ground water were assessed by comparing concentrations of
chemicals in ground water at points of potential exposure (both on
and off site) to ARARs. Such comparison values were not available
for all chemicals in other site exposure media (i.e., surface
water, soil, and air); exposure of humans to these contaminated
media were evaluated by quantitative risk assessment in which
potential intakes calculated for each potentially exposed
population were combined with critical toxicity values to assess
risk.
Pathways by which environmental receptors (flora and fauna) at and
near the MMRF could potentially be exposed to site—derived chemical
constituents were generally qualitatively evaluated due to the
general paucity of data with which to evaluate such exposures.
When sufficient data were available, estimates of risks to biota
were made based on exposure and toxicity estimates. Because the
ditches and puddles of concern at the MMRF are smaller than other
sources of fresh water nearby, the potential impacts of the site
study areas on entire environmental populations is expected to be
small.
The noncarcinogenic chemicals of potential concern (e.g., fluoride,
sulfate, and cyanide) are not expected to pose adverse health
effects to humans under any of the soil—related exposure scenarios
quantitatively evaluated; this conclusion is based on calculated
hazard indices which were all several orders of magnitude less than
1 (the hazard index is defined as the sum of the ratios of the
daily intakes of noncarcinogenic substances by potentially exposed
individuals to their corresponding relevant reference dose or
intake). It should be noted, however, that fluoride and sulfate
concentrations in a few ground-water wells exceeded APARs.
24
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GERAGHTY & MILLER. INC.
F-RI SUMMARY
JUNE 30, 1988
5.3 RESULTS OF RISK ASSESSMENT
Certain areas of the MMRF were identified in the risk assessment
as being associated with potentially unacceptable carcinogenic risk
to humans under the exposure scenarios assumed and to potentially
have adverse health impacts on environmental receptors. These
areas are listed below with details of the exposures, media, and
chemicals which have been associated with this risk. Included in
this list are those areas which may also be potential sources of
chemical constituents in ground water.
o Landfill and associated areas:
- direct contact by humans with cPAHs in landfill soils;
- direct contact by humans with arsenic in landfill runoff
area soils;
— ingestion by wildlife of fluoride in leachate collection
ditch water;
- ingestion by wildlife of cyanide and fluoride in landfill
ditch water;
- direct contact by humans with cPAMs in surface drainage
ditch sediments.
o Potliner Handling Area:
- direct contact by humans with cPAHs in soils.
o Discharge Channel:
- direct contact by humans with cPAHs in sediments.
o Scrubber Sludge Ponds:
- direct contact by humans with cPAHs in pond sediments;
- sediments are potential source of fluoride in ground
water.
o Lined Pond:
- direct contact by humans with cPAHs in pond sediments.
o Recycle Pond:
- direct contact by humans with cPANs in pond sediments;
- sediments are potential source of fluoride in ground
water.
o Alumina Unloading Building Area (Upgradient of New Cathode
Waste Pad):
- buried cathodic waste material is a potential source of
fluoride in ground water.
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GERAGHTY & MILLER. INC.
1RF-RI SU 2 AR1
JUNE 30, 1988
inhalation of dust, and exposures to ground water and surface
water. Of the exposures evaluated in the risk assessment,
only the following are of potential concern: (1) use of the
S aquifer as a sole drinking—water resource may pose adverse
effects based on fluoride concentrations in several wells at
the site that exceeded ARAR5; (2) exposure of hypothetical
future on-site construction workers, and future workers who
work outdoors via direct contact with soils containing arsenic
and PAHs in the following areas: landfill, landfill runoff
areas, potliner handling area, and the scrubber sludge ponds.
In addition, concentrations of constituents in the landfill
leachate may result in adverse effects to wildlife drinking
this water.
All of the potential risks identified can be remedied with
currently available technologies; these remedial measures are fully
considered in the feasibility study. A number of control measures
have already been implemented by Martin Marietta to diminish or
eliminate the environmental effects of past plant activities.
These include construction of the lined pond; relocation of the old
cathode waste pile to a new lined cathode waste pad; fencing of the
landfill to restrict access (interim remedial measure taken during
the RI); construction of a leachate—collection system at the
landfill; and, construction of a concrete lined pad in the cathode
wash area.
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GERAGHTY & MILLER. INC.
Table 4. Chemical—specific ARPRs for Constituents of Concern
Detected in Ground Water or Perched Water
RI Sunmary
The Dalles
Federal MCL
(SMCr. 1 )
(mg/L)
Federal
MCLG
(mg/L)
Oregon MCL I
(SMCL)
(mg/L)
Other
(mg/LI)
Bicarbonate
—
—
—
——
Calcium
—
—
—
—
Carbonate
Cyanide (free)
Fluoride
Lead
—
—
4(2)
.050
—
—
—
.020
—
—
l.4—2.4 ’
—
——
.220 (child)
.770 (adu1t) t
—
—
Magnesium
Sodium
Sulfate
—
—
(250)
—
—
—
—
250
—
400
Zinc
(5)
—
5
—
(a) Maximum Contaminant Levels are enforceable drinking water standards from 40
CFR 141.11. These levels are based on health, technical feasibility, and
cost benefit analysis. Secondary Maximum Contaminant Levels are shown in
parentheses and are goals for drinking water quality based on aesthetic
considerations such as taste, odor, or staining ability, 40 CFR 143.3.
(b) Final and proposed MCLGs (maximum contaminant level goals) are developed as
part of the process for developing final drinking water standards, i.e.,
MCLs, under the Safe Drinking Water Act. MCLGs are entirely health—based
and are always less than or equal to the proposed or final MCLs subsequently
developed.
Cc) Oregon Administration Rule 333—61.
Cd) Health advisory by USEPA Office of Drinking Water for long—term exposure of
children, March 1987; based on exposure to free cyanide.
Ce) Health advisory by USEPA Office of Drinking Water for lifetime exposure for
adults, March 1987; based on exposure to free cyanide.
(f) National Primary and Secondary Drinking Water Regulations. Federal Register
51: 11396—11412, Ppril 1986.
(g) Temperature dependent.
(h) Guidance level proposed by USEPA Office of Drinking Water 50 FR 46936, 13
Nov. 1985.
I 5
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Martin Marietta Reduction Facility Mining Waste NPL Site Summary Report
Reference 3
Excerpts From Final Feasibility Study, Martin Marietta
Reduction Facility, The Dalles, Oregon; Geraghty & Miller, Inc.;
June 1988
/
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G&M Consulting Engineers, Inc.
FINAL FEASIBILITY STUDY
MARTIN MARIETTA REDUCTION FACILITY
THE DALLES, OREGON
Prepared for
MARTIN MARIETTA CORPORATION
Bethesda, Maryland
7une 1988
Prepared by
G&fl CONSULTING ENGINEERS, INC.’
14497 North Dale Mabry, Suite 200
Tampa, Florida 33618
(813) 968—2248
I1
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G&M Consulting Engineers. Inc
introduction. The remaining sections of the F’S deal with
utilization of site and waste specific information in order
to develop remedial alternatives for the site. The approach
used in Sections 2.0 through 7.0 to generate remedial
alternatives for the site consists of the following steps:
o Step 2. — Identification and screening of general
response actions and related remedial tech-
nologies for addressing site problems
including attainment of reinediation
criteria;
o Step 2 — Assembly and screening of area specific
remedial measures incorporating applicable
remedial technologies;
o Step 3 — Assembly of applicable remedial measures for
the target reinediation areas into remedial
alternatives;
o Step 4 — Detailed assessment of sitewide remedial
alternatives; and
o Step 5 — Summary and recommendation of sitewide rem-
edial alternative.
1.1 SITE BACKGROUND
1.1.1 Site Location
The MMRF site is located in The Dalles, Wasco County,
Oregon, west of the Columbia River and east of the Union
Pacific Railroad as shown in Figure 1—1. The 350 acre site
is situated within an 800—acre area zoned for industrial and
manufacturing facilities. The MMRF occupies approximately
110 acres for processing operations. The MMRF is bounded
near the Mountain Fir wood hauling and chip mill on the
1—2
6Ic
-------
north, Webber Street to the south, the Columbia River on the
east, and the Union Pacific Railroad line and West Second
Street to the west.
1.1.2 Site History
The MMRF is an aluminum processing facility designed to
produce approximately 90,000 tons per year of aluminum from
alumina. A facility plan is provided as Drawing A—i in
Appendix A. Operations began at the site in 1958 under the
ownership of Harvey Aluminum, Inc. Harvey Aluminum, Inc.
became a wholly—owned subsidiary of Martin Marietta
Corporation (MMC) in 1970. The MIIRF continued operations
under the name of Martin Marietta Aluminum, Inc. until 1984,
when the plant was shut down and MMC acquired legal title to
the property from Martin Marietta Aluminum, Inc. In 1986,
MMC leased the plant and portions of property adjacent to the
plant to Northwest Aluminum Company, which resumed primary
aluminum operations. A chronological history of events and
actions related to the aluminum plant operations is provided
in Table 1—1. Review of MMC’S files on the MMRF indicate
that the first and only regulatory enforcement action for the
site occurred in September 1985 when Martin Marrietta
Corporation signed the consent order with the EPA to conduct
the RI/FS.
During the 26 years of aluminum production, waste
constituents derived from the process were stored, treated,
arid disposed of at the MMRF. MMC performed a number of
1—4
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G&M Consulting EngIneers Inc.
direction at the site is from the northwest. Depending on
wind velocities and directions, use of dust suppressants may
be required to manage fugitive dust emissions.
1.1.4.2 Topograghy
A topographic map of the MNRF is provided on Drawing
A—i. The land surface elevations vary from approximately 100
feet above mean sea level (insi) at the Columbia River to more
than 155 msl at the Landfill. The topography of the site has
changed over time due to filling of low areas; in general,
the site is level with the exception of distinct man—made and
natural features. These features include: man—made ponds,
the Landfill, drainage ditches, stream channels, and road
beds.
1.1.4.3 Surface Water Drainage
The topography of the PIMRF largely controls the
direction of surface water flow except where man—made
structures have been constructed to alter flow patterns.
Drawing A—3 presents the site surface drainage patterns for
the MNRF. Surface water flows are generally directed towards
th oluiabia i(ive . The cwo major natural drainage features
in or near the MMRF are Chenoweth Creek and a shallow ravine
south of the reduction buildings in the area of the Scrubber
Sludge Ponds.
1—42
,. t
-------
• -
Surface water runoff from the Landfill is currently
intercepted by the ].eachate collection system and the
Landfill Ditch. The leachate collected by the Landfill Ditch
gravity drains to a surnp and is then pumped to the Discharge
Channel where it gravity drains to the Recycle Pond. Prior
to the construction of this interception network, runoff from
the Landfill followed three primary drainage pathways, all of
which discharged northeast of the Landfill.
The ponds at the MMRF include the four Scrubber Sludge
Ponds, Recycle Pond, Duck Pond, and Lined Pond. The Recycle
Pond serves as a collection point for runoff from the
Landfill, the Former Cathode Waste Management Areas, and
areas to the immediate south and west of the plant. Waters
collected by the Recycle Pond are recycled back to the
secondary roof scrubbers in the reduction buildings. Excess
flows are discharged to the Columbia River in accordance with
a National Pollutant Discharge Elimination System (NPDES)
permit. The Recycle Pond is currently in use.
The Lined Pond is used to manage air emission
particulates from the aluminum production process. The
p rticulat ar epc acuraced to prevent fugitive dust
emissions. As the name implies, the Lined Pond is a lined
unit constructed with a 45—millimeter scrim reinforced
hypalon liner. Like the Recycle Pond, the Lined Pond is also
currently in use.
1—44
-------
Uc,i I OnbUAUflg J U1 t1 £flC.
The Duck Pond received non—contact cooling waters front
cast house operations and a sump in the alumina unloading
building. Flows to the Duck Pond were diverted in 1986 to
the Discharge Channel, which flows to the Recycle Pond. The
Scrubber Sludge Ponds are no longer in use but intersect the
water table and are saturated in proportion to the relative
ground—water elevation.
Surface—water runoff from the southwest part of the site
flows to the south and east through a natural drainage
channel prior to discharging to the Columbia River.
Surface—water drainage from the non—active part of the MMRF
(northwest of the Landfill) discharges to Chenoweth Creek.
1.1.4.4 Lithology/Geology
The soil arid rock types at a waste management site
influence choices on the remedial methods to be used at the
site. Excavation depths would be limited by the basalt
underlying the study areas at the MMRF. The presence of the
basalt will preclude the construction of certain remedial
measures.
Tha sur ce soiLs in The Dailes region are poorly
developed and in most places are non—existent. Although
found in limited amounts, four native soil groups are known
to be present at the MMRF and in order of decreasing surface
extent are the: (1) Rock Outcrop—Xeropsamments Complex; (2)
Hessian—Skyline Complex; (3) Van Horn Loam; arid (4) Quiricy
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G&M Consulting Engineers, Inc.
1.1.4.5 Hydrogeology
Identification of the Aquifer Systems
The aquifer systems at the M?IRF include a water table
aquifer (S—aquifer) overlying a series of confined aquifers
(A— and B—aquifers and the DGWR). Zones of perched water and
an alluvial aquifer are also present locally.
The unconfined S—aquifer is present within the
relatively low permeability basalts of the Lob flow and the
subaerial portion of the Rosalia flow and Byron Interbed.
The first confined aquifer (A—aquifer) is within the upper
pillow lava horizon of the subaqueous portion of the Rosa].ia
Flow. The A—aquifer ranges from 5 to 45 feet in thickness.
The B—aquifer is below the A—aquifer and is locally separated
from it by low permeability basalt (lava lobe). The lava
lobe is apparently absent north of the site due to
non—deposition. The B—aquifer ranges from 30 to 45 feet in
thickness. In areas where the lava lobe is absent, the A—
and B—aquifers combine to form a single hydrogeologic unit.
A thick, low—permeability siltstone and sandstone unit forms
the confining unit between the B—aquifer and the underlying
DGWR. The top of the DGWR occurs within the permeable zones
of the Sentinel Gap flow, and the most permeable portion of
the DGWR is within the fbow—breccia top of the Sand Hollow
flow.
1—47
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G&M Consulting Engineers Inc.
Ground—water flow in the S—aquifer is generally to the
east and northeast. The S—aquifer at the site potentially
receives recharge from precipitation, perched water, the
Recycle Pond and from the Discharge Channel; discharge from
the S—aquifer is believed to be into the alluvial aquifer and
the Columbia River. Ground—water flow in the A—aquifer is
predominantly east to west. The A—aquifer is potentially
recharged by the alluvial aquifer, the Columbia River, and
the S—aquifer; discharge from the A—aquifer appears to be to
the B-aquifer and regional water—supply wells. Ground—water
flow in the B—aquifer is generally to the west and south;
hydraulic gradients vary, however,, depending on the
hydrologic and pumping conditions. The B—aquifer is
potentially recharged by the Columbia River, the A—aquifer
and the DGWR; discharge for the B—aquifer may be to regional
water supply wells, the DGWR or the A—aquifer. Ground—water
movement in the DGWR was not determined as part of the RI.
However, the DGWR is likely to be recharged by the Columbia
River and seasonally by the B—aquifer; discharge for the DGWR
is likely to regional water supply wells, lower aquifers or
the B—aquifer (seasonally).
An alluvial aquifer, approximately 400 feet wide and at
least 60 feet deep, is present in the area north of the plant
within Pleistocene age sand deposits. The geometry of the
alluvial aquifer is apparently controlled by the location of
the trace of the Chenoweth fault. Flow in the alluvial
1—48
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G&M Consulting Engineers Inc.
The Columbia River and its tributaries represent the
major surface water resources in the area, with the Mill
Creek Watershed as the principal source of water supply for
the city of The Dalles. The Columbia River and its
tributaries provide habitat for major commercial and sport
fisheries with salmon, sturgen, trout, steelhead, walleye,
and bass being among the many game fish common to the river.
Local tributaries to the Columbia River including Chenoweth
Creek may provide limited spawning grounds for the steelhead
and salmonoids when they are not seasonally dry.
Ground water is an important source of water supply in
The Dalles area for domestic, industrial, and agricultural
uses. The primary aquifer in the area is the DGWR; the
alluvial aquifer located in the Chenoweth Creek area is used
by the Animal Shelter.
A gravel pit is operated within the quaternary gravels
of the alluvial aquifer northeast of the MMRF. This
operation is relatively small, and probably could not be
expanded significantly owing to the limited extent of the
alluvium.
Future development around the MMRF appears to be focused
on the Port .of The Dalles located northeast of the site on
the Columbia River. The area for the proposed port has been
leveled, graded, and landscaped in preparation for future
industrial development. Currently, five people are estimated
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( &M (.onswtmg t .nwneers mc.
o The Scrubber Sludge Ponds — maximum fluoride
concentration detected is 7.1 mg/L;
o The Unloading Area — maximum fluoride concentration
detected is 57 rrtg/L;
o The Landfill/Former Cathode Waste Management Area —
maximum fluoride concentration detected is 4.7 mg/L;
and
o Recycle Pond — maximum fluoride concentration
detected is 5.5 mg/L.
Sulfate concentrations in the S—aquifer beneath the MMRF
range from <5.0 mg/L to 3020 mg/L. The following three areas
have sulfate concentrations in the S—aquifer above the State
of Oregon secondary contaminant level for sulfate in drinking
water of 250 mg/L based on the most recent data from the
MMRF.
o The Scrubber Sludge Ponds — maximum concentration
detected is 3,020 mg/L;
o The Recycle Pond — maximum concentration detected is
871 mg/L; and
o The Unloading Area — maximum concentration detected
is 680 mg/L.
Sulfates were not detected at concentrations above the state
secondary contaminant level in the A— and B—aquifers or The
Dalles Ground—Water Reservoir except for monitor well 18B,
which indicated a sulfate concentration of 271 mg/L.
1.2.1.3 Surface Water
The potential surface water exposures identified in the
baseline RA of concern at the MMRF were associated with
wildlife ingesting water in the Landfill Ditch and the
Leachate Collection Ditch. Remediation criteria in surfa
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health—based soil remediation criteria will be calculated for
those constituents of concern (arsenic and CPA}is) for
exposures involving direct contact with soils at the NMRF
site. Contaminant—specific soil remediation criteria for
fluoride will be calculated utilizing the approach applied by
EPA for deriving acceptable soil contaminant concentrations
based on drinking water standards.
Development of Health—based Soil Criteria
Health—based soil remediatiori criteria are concen-
trations of a chemical in soil which, under specified
exposure conditions, would not yield a dose of the chemical
in excess of an acceptable daily dose. Because the dose
received is dependent on the exposure conditions assumed
(such as frequency of exposure and quantity of soil
contacted) different soil criteria will be associated with
different exposure scenarios.
Soil remediation criteria for direct exposure pathways,
such as direct contact with soil, will be calculated for two
types of potential future land use of the MMRF: industrial
use and residential use. Criteria are developed using
reverse risk assessment techniques which combine scenario—
specific exposure parameters with an acceptable daily dose
(D’) of each chemical for the exposed population. The
constituents of concern in soil (arsenic and cPAHs) are both
carcinogens. Doses corresponding to excess risks of lO
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TABLE 1—13
Potential Risks Associated with Target Rernediation Areas
Feasibility Study: Martin Marietta Reduction Facility
Martin Marietta Corporation
The Dalles, Oregon
Target Remediation Potential Risks Associated with
Area Target Rerneaiation Area
Landfill and — Potential future generation of
Associated Areas leachate containing cyanide and
fluoride from wastes
— Potential direct contact by humans
with cPAHs in Landfill soils
— Potential ingestion by wildlife of
fluoride in Leachate Collection
Ditch water
— Potential ingestion by wildlife of
cyanide and fluoride in Landfill
Ditch water
— Potential direct contact by humans
with cPAHs in Surface Drainage
Ditch sediments
Former Cathode Waste — Potential future generation of
Management Areas leachate containing cyanide and
fluoride from cathode waste
residuals in the Old Cathode Waste
Pile, Salvage, Bath Recovery Pad
and Potliner Handling Areas
— Potential source of fluoride and
cyanide to perched water
— Potential direct contact by humans
with cPAHs in Potliner Handling
Area waste residuals
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G&M Consulting Engineers, Inc.
o Basalt Fragments 100,000 cy
o Asbestos
— Buried 100 cy
— Distributed 200 cy
o Metallic 500 c
o Target Wastes 99,200 cy
Appendix A of the RI presents information indicating that
54,381 tons of spent potliner material was shipped off—site
from the MMRF (owned and operated by Harvey Aluminum at the
time) from July, 1961 to November, 1971. Best estimates
based on conversations with Martin Marietta personnel
indicate that an additional 5,000 tons of spent potlirier
(approximately 10% of potliner material sent off—site) was
placed in the Landfill. The estimated 5,000 tons of spent
cathode waste material present in the Landfill contain high
levels of carbon, sulfate, sodium, and fluoride in addition
to minor amounts of cyanide. Cryolite, which is composed of
fluoride, sodium, and aluminum, is also present in the
Landfill. Pitch and coke associated with the continuous
anode in the reduction process are present in the Landfill
and contain elevated levels of PAHs and low levels of
arsenic.
To confirm the composition of the Landfill, five test
pits were excavated and their locations are displayed in
Figure 1—9. The materials observed ranged from fine dust to
very large basalt boulders. Composite samples from the five
test pits indicate the presence of the following constituents
of concern:
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o Cyanide
— Total 0.32 — 70 mg/kg
— Free 0.27 — 54 mg/kg
o Fluoride 204 — 2,880 mg/kg
o PPtHS 276 — 2,406 mg/kg
Leachate generated by the Landfill is contained by a
leachate collection system that Consists of the following
study areas:
o Surface Drainage Ditch;
o L.eachate Collection Ditch; and
o Landfill Ditch.
Figure 1—6 illustrates the location of the leachate
collection system.
The generation of leachate is seasonally dependent and
its presence is directly related to precipitation or snow
melt. The majority of the precipitation or snow melt occurs
from September through May. Available records of leachate
collected and pumped range from 0 to 50,000 gallons per day
(gpd) with peak flows occurring generally in the early
spring.
Analyses of leachate samples from the Leachate
Collection Ditch identified the presence of the following
constituents of concern:
o Cyanide
— Total 0.11 — 29 mg/L
— Free 0.0]. — 4.7 mg/I.
o Fluoride 1,490 — 2,440 mg/I.
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feet and is approximately 5 feet deep. This results in a
maximum volume of cathode waste material of approximately 200
cubic yards.
1.2.3.5 Scrubber sludge Ponds
The Scrubber Sludge Ponds (SSPs) consist of four surface
impoundments (numbered 1 through 4) located south of the
reduction buildings and west of River Road as illustrated in
Figure 1—18. The locations for the SSPs were selected
because the air emission slurry produced in the alumina
reduction process could be discharged to the SSPs under
gravity conditions. The large surface area and retention
capacity of the SSPs allowed for particulate settlement and
final discharge of accumulated water to the Columbia River.
Figure 1—19 illustrates the location of low areas prior to
construction of the SSP and indicated by early aerial photos.
The topographic differences between the plateau just to
the northwest of the SSPs to that east of 5SP2 is between 30
to 40 feet. The geologic information obtained through the
installation of ground—water monitor wells around the SSPS
revealed that the Byron Interbed outcrops along the face of
the ridge immediately adjacent to the SSP5. The approximate
location of the outcropping of the Byron Interbed is
illustrated on Figure 1—20. The Byron Interbed is a
permeable layer which is considered to be part of the uppe:
portion of the S—aquifer. The Byron Interbed .s not presen:
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to the east of the SSPs. The potentiometric contours for the
S—aquifer as illustrated in Figure 1—21 indicate that the
Byron Interbed is discharging to the SSPs and the saturation
of the scrubber sludges in SSP2 is a result of this surface
expression of the ground water.
The lateral extent of the SSP5 was confined by
topographic constraints including basalt outcroppings, a
ridge to the north of the SSPs and other local topographic
features. Figure 1—19 illustrates the general drainage
conditions prior to construction of the SSPs. Figure 1—22
displays the interim configuration of the SSPs during
operation prior to 1972 when MNRF began treating the air
emission control waters using chemical. precipitation and a
clarifier.
SSP1 was diked and was used to receive chemical sludges
resulting from the lime precipitation of the air emission
control waters for fluoride removal. The primary salt formed
during the precipitation was calcium fluoride. SSP4 received
dredgings from SSP2 and SSP3 and the Recycle Pond. Both SSP1
and SSP4 were removed from service and covered in 1981.
Collectively, the lateral extent of the SSPs is
approximately 14.8 acres. SSP1 and SSP4 have soil covers and
established vegetation which currently precludes direct
contact with the wastes. However, SS?2 and 5SP3 are not
currently covered. The material present in the SSPs can be
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1.2.3.6 Ground Water
The constituents of concern identified in the ground-
water systems are fluoride and sulfate. The highest
concentrations of fluoride are present in the perched water
with progressively lower concentrations identified within the
S—, A—, and B—aquifers. Concentrations of fluoride in wells
tapping the DGWR are low and within the range expected for
background. Sulfate concentrations exceeding the State of
Oregon secondary contaminant level of 250 mg/I.. were detected
in the S—aquifer in the vicinity of the Scrubber Sludge
Ponds, the Recycle Pond and the Unloading Area. The maximun
sulfate concentration detected in ground water was 3,020 mg/L
in the S—aquifer southeast of the Scrubber Sludge Ponds.
Sulfates were not detected at concentrations in excess of the
State secondary contaminant level in the A— or B—aquifers
with the expection of MW—18B which indicated a sulfate
concentration of 271 mg/L. Sulfates were also not detected
in The Dalles Ground—Water Reservoir above background levels.
Samples from the well in the alluvial aquifer at the
Animal Shelter include a total cyanide concentration of 0.023
mg/L, a fluoride concentration of <1.0 mg/L and a sulfate
concentration of 15 mg/L.. No free cyanide or fluoride was
detected in this sample. The remediation criteria is based
on free cyanide and because none was detected, there is nc
reason to retain the alluvial aquifer for furthe:
considerat2.on.
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Elevated constituent Concentrations were identified in
the S—aquifer at several locations:
(1) Near the Landfill and Former Cathode Waste
Management area . Fluoride concentrations
range from <1.0 r tq/L te .7 rra/L ‘ d frr
cyanide ranged from <0.01 to 0.136 mg/L.
(2) Scrubber Sludge Ponds . This area contains
fluoride (4.8 to 7.1 mg/L), sulfate (1,810 to
3,020 mg/L), free cyanide is below detection
limits and total cyanide is reported in only
one well (MW—18S) at 0.05 mg/L.
(3) unloading Area . Ground—water samples show
detectable fluoride at 57 mg/L at well MW—SS.
Sulfate was found at 680 mg/L and 1,130 mg/L.
(4) Recycle Pond . Samples from well MW—31
downgradient of the pond indicates a maximum
fluoride concentrations of 5.5 mg/L. and well
MW—21 indicates a maximum sulfate
concçntration of 871 mg/L.
Ground—water quality impacts in the A—aquifer are less
widespread and at lower concentrations than those ideritifiec
in the S—aquifer. Recent data indicates that none c. t- .
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G&M Consulting Engineers, Inc.
constituents of concern are present in excess of the sjtewjde
remediation criteria presented in Table 1—11 except for
fluoride at a concentration of 10.0 mg/L. in monitor well 9A.
It is suspected that the detection of this constituent in
monitor well 9A is an artifact of well construction.
Continued monitoring of this ell wil1 perfcrmed to yr -
this interpretation. Should the results . -if. -
additional actions will be conducted as discussed in Section
4.0.
In the B—aquifer, elevated constituent concentrations
are chiefly confined to monitor wells 9B and l8B near the
Landfill and Former Cathode Waste Management Areas and
Scrubber Sludge Ponds. Fluoride has been detected in monitor
well 9B at 20 mg/L and sulfate has been detected in monitor
well 18B at 27]. mg/L. It is suspected that the detection of
these constituents of concern are artifacts of well
construction. Continued monitoring of monitor wells 9B and
18B will be performed to verify this interpretation. Should
these results be verified, additional actions will be
conducted as discussed in Section 4.0.
1.3 OBIECTIVES OF REMEDIAL ACTION
The remedial action objectives for the MMRF are source
control and ground—water management for the protection of
human health, welfare and the environment from potential
impacts due to constituents introduced to the area by past
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for off—site migration of contaminants. Thus, Alternative 2
reduces the potential exposure pathways of concern identified
in the RA for each target remediation area.
Cost
The capital cost of Remedial Alternative 2 is
$4,111,500. The annual O&M costs for years 1 through 5 will
be $158,500. The annual O&M costs for years 6 through 30
will be $69,900. The total present worth of this alternative
using a discount rate of 8% is $5,252,300. The detailed
development of these costs is presented in Table 5—3.
5.2.3 Remedial Alternative 3: Containment with Complete
Removal and Ground—Water Controls
Remedial Alternative 3 includes the following actions:
o Consolidation of the residual cathode waste
material and underlying fill material from the
Former Cathode Waste Management Areas into the
existing Landfill;
o Consolidation of the cathode waste material from
the unloading Area into the existing Landfill;
o Capping the existing Landfill in place with a
multi—media cap meeting RCRA performance standards;
o Placing a soil cover over Scrubber Sludge Ponds 2
and 3;
o Plug and abandon nearby production wells and
connect users to the City of The Dalles water
supply system;
o Collection and treatment of leachate generated from
the Landfill and perched water east of River Road
and from the Former Cathode Waste Management Areas;
o Recovery of ground water from the Unloading Area;
5—20
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Martin Marietta Reduction Facility Mining Waste NFL Site Summary Report
Reference 4
Excerpts From Profile - Martin Marietta Reduction Facility, The Dalles, Oregon,
Document No. 983-TS1-RT-ERIIS-1; Author Not Provided; June 15, 1987
-------
)5C NO: 983-TSI-RT-ERHS , “ - -.
0C:DATE: ::‘o/15/87 ENTRY DATE: 06/24/87
SC—PRCFILE:M.MARIETTA REDUCTION FAC 1 57 f
LITY PROFILE
‘ Ir
PROFILE
MARTIN MARIETTA REDUCTION FACILITY
THE DALLES, OREGON
L)OCUMENT NO.: 983-TS1-RT-ERHS-1
A. SITE OPERATIONS
A.1 PRODUCTS — Aluminum metal from alumina (Al 2 0 3 ).
A.2 SITE OPERATION
A.3 PROCESSES
Products Process Time Period
Aluminum metal Hall—Heroult reduction 1958 — 1984
process: Electrolytic
reduction of alumina to
aluminum in molten
cryoli te (Na 3 A1F 6 )
Waste Management Practices :
Vashing and temporarily storing spend cathodes; 1958 — 1972
shipping spent cathodes off—site via railroad
Land disposal of spent cathodes and other 1972 — 1984
materials on—site
—1—
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.5V2.
Mining Waste NPL Site Summary Report
Midvale Slag (Valley Materials Slag)
Salt Lake County, Utah
U.S. Environmental Protection Agency
Office of Solid Waste
June21, 1991
FINAL DRAFT
Prepared by:
Science Applications International Corporation
Environmental and Health Sciences Group
7600-A Leesburg Pike
Falls Church, Virginia 22043
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DISCLAIMER AND ACKNOWLEDGEMENTS
The mention of company or product names is not to be considered an
endorsement by the U.S. Government or by the U.S. Environmental
Protection Agency (EPA). This document was prepared by Science
Applications Enternational Corporation (SAIC) in partial fulfillment of
EPA Contract Number 68-WO-0025, Work Assignment Number 20.
A previous draft of this report was reviewed by Eva Hoffman of EPA
Region VIII [ (303) 293-1534), the Remedial Project Manager for the
site, whose comments have been incorporated into the report.
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Mining Waste NPL Site Summary Report
MID VALE SLAG (VALLEY MATERIALS SLAG)
SALT LAKE COUNTY, UTAH
INTRODUCTION
This Site Summary Report for Midvale Slag was developed as one of a series of reports on mining
sites on the National Priorities List (NPL). The reports have been prepared to support EPA’s mining
program activities. In general, these reports summarize the types of environmental damages and
associated mining waste and materials management practices at sites on (or proposed for) the NPL as
of February 11, 1991 (56 Federal Register 5598). This summary report is based on information
obtained from EPA files and reports and on a review of the summary by the EPA Region VIII
Remedial Project Manager for this site, Eva Hoffman.
SITE OVERVIEW
The Midvale Slag site is an old smelter site encompassing approximately 330 acres of land located
immediately west of the city of Midvale, which is 12 miles south of Salt Lake City. The site was
added to the NPL on February Il, 1991. The site is bounded by public streets, and the Jordan River
(see Figure 1) (Reference 1, page 1-1). South of the site is the Sharon Steel/Midvale Tailings NPL
site, which is addressed in a separate Site Summary Report.
Wastes deposited onsite include slag, smelter waste, dross, and Baghouse dust, all containing high
concentrations of heavy metals. The contaminants of concern are arsenic, cadmium, chromium,
copper, lead, silver, and zinc (Reference 1, page 1-3). In 1985, the slag was analyzed and found to
contain elevated levels of arsenic, cadmium, and lead (Reference 2, page 1). Table 1 presents the
quantity of each waste type and the maximum concentrations of each contaminant of concern
(Reference 1).
According to the 1980 census, approximately 1,443 people live within .25 mile of the site, and 8,179
people live within 1 mile of the site. Immediately adjacent to the site are residential and commercial
areas, and across the River are agricultural lands (Reference 1, page 3-3). Two removal actions have
recently taken place.
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Midvale Slag (Valley MateriaLi Slag)
o so 100 200
—U
$CIIS set M
Mldvsli Slag Sit. Boundary
cam. saisisie esII s.c.
FIGURE 1. MIDVALE SLAG SiTE MAP
Figure 1.
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Mining Waste NPL Site Summary Report
TABLE 1. SOURCE AREA CONTAMINANT CONCENTRATIONS’
Source
Quantity
Contaminant
Maximum Concentration
(in ppm)
Slag
2 million tons
Arsenic
Cadmium
Copper
Lead
Silver
Zinc
340 (total recoverable)
45 (total recoverable)
2,380 (total recoverable)
9,410 (total recoverable)
36 (total recoverable)
58,500 (total recoverable)
Smelter Waste
69,000 cubic yards
Arsenic
Cadmium
Chromium
Copper
Lead
Zinc
15.80 (extractable)
2.55 (extractable)
2.3 (extractable)
132.5 (extractable)
3.5 (extractable)
379 (extractable)
Dross
44,100 cubic yards
Arsenic
Cadmium
Chromium
Copper
Lead
Silver
Zinc
10,490 (total recoverable)
40 (total recoverable)
130 (total recoverable)
410 (total recoverable)
7,750 (total recoverable)
47 (total recoverable)
1,610 (total recoverable)
Baghouse Dust
400 cubic yards
Arsenic
Cadmium
Lead
0.062 (extractable)
0.062 (extractable)
0.05 (extractable)
‘From Earth Fax, 1986
2 Extraction Procedure (EP) Toxicity
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Midvale Slag (Valley Materials Slag)
A uPreliminary Risk Evaluation and Conceptual Site Modeiw was developed based on data collected
and evaluated by EPA prior to the initiation of the Remedial Investigation/Feasibility Study work
Plan. The Remedial Investigation/Feasibility Study is currently undergoing an EPA review. This is a
fund-lead site with three of the four Potentially Responsible Parties having settled with EPA.
OPERATING HISTORY
The first smelter at the Midvale Slag site was constructed in 1871; however, most of the smelting
activity occurred between 1906 and 1958, when the United States Smelting, Refining and Mining
Company (USSRM) owned the property. Beginning in 1905, the smelter processed copper and lead
concentrates from the Sharon Steel/Midvale Mill facility (located directly south of the site) and from
custom shippers. In 1908, litigation concerning the damaging effects of smelter wastes on crops in
the vicinity curtailed production from the copper smelter. Further litigation and legal decree allowed
continuance of the lead-smelting operation from 1910 through 1958, with early forms of unspecified
pollution controls. In 1958, operations at the smelter ceased, and shortly thereafter, the smelter
facilities were dismantled (Reference 1, page 1-3). From 1918 to 1928, approximately 400,000 tons
of lead were produced from smelter operations (Reference 2, page 1).
Today, the smelter no longer remains, but remnants of the Smelter activity include a large Slag Pile,
approximately 100 acres in size (Reference 1, page 1-3). Blackhawk Slag, owned by Valley
Materials, Incorporated, processes the slag into a uniform-textured material used in railroad beds and
asphalt highway construction (Reference 2, page 1). Another product is a fine-grained slag used in
sand-blasting abrasives. This product is currently the basis of Midvale Slag’s commercial activity.
Extensive files exist on the smelter operation, including production records and even monthly
inventory of wastes which were assayed for various metals. However, due to limited historical
information regarding locations of disposal of wastes, it is difficult to identify the exact sources of
contamination. According to EPA Region Vifi, ground-water contamination is theorized to originate
from the dross pile onsite, with some contribution from Sharon Steel NPL site, located immediately
south (and upgradient) of Midvale Slag. In addition, slag from past smelter operations has been
exposed and entrained in the River for years, thus increasing the probability of river contamination.
(Reference 2, page 4)
Sharon Steel is reported to have received lead, copper, and zinc ores and extracted the sulfide
concentrate of these metals. These concentrates were then smelted at the Midvale Smelter site to
extract the metals in a purer form. The Sharon Steel facility also operated as a custom mill, receiving
ore from many sources and extracting a variety of metals. There are approximately 10 million tons
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Mining Waste NPL Site Summary Report
of tailings on the Sharon Steel site. The tailings contain concentrations of lead as high as 4,000 parts
per million (ppm) and also high concentrations of arsenic, cadmium, chromium, copper, and zinc. It
is highly probable that the high heavy-metal concentrations upgradient of the Midvale Slag site are
partially attributed to Sharon Steel (Reference 2, page 4).
SITE CHARACTERIZATION
The Midvale Slag site (Valley Materials Slag facility) is located adjacent to the Jordan River, and it
lies within its floodplain. Topographic relief is small but there is a marked surfacial gradient to the
east. Native soils have, in many places, become mixed with slag. The subsurface is composed of
interlayered silts and clays which are probably deep-water deposits from nearby Lake Bonneville. No
bedrock has been located in this part of the valley, and it is probable that basement rock is located at
great depth. There are no notable faults or other structural elements known in the immediate area
(Reference 3, page 373).
Though the site was fenced off from the public in the fall of 1990, onsite commercial slag operation
still results in extensive earth-moving and industrial vehicle activity. Fine-grained waste-source
material may be inhaled, ingested, deposited as household dust, or deposited on nearby soils. No
indication was given if any dust-control measures are being taken at the site. Contaminants from the
site also appear to be leaching into the ground-water system (Reference 1, page 2-1).
Ground Water
The Slag Pile is located within the Jordan River floodplain. In the vicinity of the slag, the average
depth to ground water is approximately 2 to 3 feet (Reference 3, page 373). A deep, confined aquifer
beneath the site and, possibly, the contaminated shallow unconfined aquifer (also beneath the site) are
used for the municipal water supply, private wells, and irrigated agriculture. Contaminants from the
site “appear to be leaching into the ground-water system,” which would account for the contaminated
shallow aquifer. Midvale wells, drawing from the deep aquifer, are used to meet peak summer
demands for the Salt Lake County Water Conservancy District (which serves 300,000 people). It is
also likely that the shallow aquifer discharges to the Jordan River (Reference 1, page 3-1).
There is an abandoned wastewater treatment plant to the north of the site, with several large ponds
and an abandoned artesian well. These may be complicating local ground-water flow, due to
mounding and/or hydraulic gradients created by the artesian well (Reference 3, page 374). Most of
the sludge deposits were removed during closure, and the lagoon area has been filled with “clean
fill. • Ground-water contaminants are presented in Table 2 (Reference 1, page 1-7). The highest
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Midvale Slag (Valley Materials Slag)
TABLE 2. ONSITE, NONSOURCE AREA CONTAMINANT CONCENTRATIONS
Maximum Concentrations 1
Contaminant
Soil
(in mg/kg)
Surface Water
(in mg/I)
Ground Water
(in mg/I)
Drinking-Water
Standard (MCL) 2
(in mg/I)
Arsenic
1,500
0.03
0.221
0.050
Cadmium
285
0.015
0.873
0.010
Chromium
200
ND
0.035
0.05 (hex)
Copper
2,290
463
0.123
1.3
Lead
9,150
0.045
0.538
0.05
Silver
25
ND
ND
- 0.05
Zinc
17,600
0.495
5.02
5.0
ND - Not detected
‘From Earth Fax, 1986
2 Maximum Contaminant Level
3 Proposed MCL Goal (MCLG)
4 Water Quality Criteria (Clean Water Act)
maximum metal concentrations detected in the ground water were cadmium [ 0.873 milligrams per
liter (mg/I)J and lead (0.538 mg/I). Table 2 presents the Maximum Containment Levels (MCLs) of
heavy metals detected compared to the drinking-water standards (MCLs as of 1987).
Surface Water
The Jordan River, at the edge of the site, is a receiving stream with ground water being discharged to
the River and its floodplain. In addition, several seeps and springs are located throughout the Slag
Pile area. Storm drains are located just north of the slag and along the property’s southern perimeter;
water in these drains is representative of upgradient surface water (Reference 3, page 374).
Sampling of surface water was conducted in 1985 along the east bank of the Jordan River. Results
showed levels of metals in the surface water; however, the Field Investigation Team could not
conclude that the Midvale site was responsible for contaminating the waters. The sample results were
compared to Primary Federal Drinking Water Standards (DWSs); it was concluded that the surface
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Mining Waste NPL Site Summary Report
water is not fit for human consumption (Reference 2, page 3). Concentrations of all contaminants
(from the 1985 sample analyses) are presented in Table 3 (Reference 2, Table 1).
Table 2 is excerpted from the 1987 Endangerment Assessment. Maximum concentrations of
constituents detected in the Jordan River and DWS s for those constituents are presented. Although
arsenic, cadmium, copper, lead, and zinc were detected, the maximum concentrations shown in Table
2 reflect sampling in onsite ponds and drains and one upstream sample (arsenic). Of the metals
listed, none were detected in the Jordan River downstream of the site (Reference 1, page 1-5).
According to the Endangerment Assessment, surface water is a potential pathway for contaminants
from the site, but, considering the 1986 sampling, surface water did not appear contaminated
(Reference 1, page 3-4).
Sediments
The major contaminants found in sediment samples taken from the Jordan River in 1985 were arsenic,
cadmium, chromium, cobalt, lead, manganese, mercury, and zinc. A comparison of upgradient and
downgradient samples does not conclusively indicate a release from the Midvale Slag site.
Upgradient samples had the highest concentrations of arsenic, cadmium, lead, manganese, mercury,
and zinc. The concentrations of contaminants in sediment samples are presented in Table 4
(Reference 2, page 3).
7
-------
Midvale Slag (Valley Materials Slag)
TABLE 3. SURFACE-WATER DATA (pg/I, ppb)
E]mo
Drinkiag Water
Criteria
VMS-SW-i
VMS-SW-I
VMS-SW-3
VMS-SW-4
VMS-EL-i
Aluminum
5,000
1,820
2,190
2,180
2,360
<30
Antimony
146
<5
<5
<5
<5
<5
Azernic
50
12
13
11
13
<5
Barium
1,000
85
90
89
92
<10
Beryllium
0.037
<10
<10
<10
<10
<10
Cadmium
10
<5
<5
<5
<5
<5
Calcium
— —
84,000
85,900
85,700
88,100
<1,000
Chromium
50
-------
NA - Not analyzed
Mining Waste NPL Site Summary Report
TABLE 4. SEDIMENT DATA (pg/g, ppb)
Element
VMS-SE-i
VMS-SE-2
VMS-SE-3
Aluminum
2,800
4,050
3,220
Antimony
<13
<17
<12
Arsenic
30
17
12
Barium
51
59
52
Beryllium
<1.3
<1.6
<1.2
Cadmium
8.7
3.6
3.0
Calcium
14,200
24,200
15,000
Chromium
8.6
17
13
Cobalt
3
3.5
3.8
Copper
180
44
28
Iron
12,400
7,810
7,580
Lead
1,490
309
99
Magnesium
2,600
4,320
3,280
Manganese
466
100
92
Mercury
0.08
<0.03
<0.03
Nickel
4.7
9.2
<4
Potassium
NA
NA
NA
Selenium
<13
<17
<12
Silver
3.1
1.4
<0.6
Sodium
I ,440
440
296
Thallium
<13
<16
<12
Tin
NA
NA
NA
Vanadium
15
16
15
Zinc
2,430
171
115
9
-------
Midvale Slag (Valley Materials Slag)
According to the 1987 Endangerment Assessment, sampling has indicated that contaminants from the
source area have migrated to soils. Maximum concentrations of soil contamination are presented in
Table 2 (Reference 1, page 1-7). Of the heavy metals sampled, arsenic, cadmium, zinc, chromium,
silver, and lead were found in elevated concentrations. Zinc and lead exhibited the highest soil
contaminant levels [ 17,600 milligrams per kilograms (mg/kg) and 9,150 mg/kg, respectivelyJ.
Arsenic, cadmium, and zinc are fairly mobile in soils and are generally persistent in the environment
(Reference 1, page 2-1). In addition, lead levels for residential soils in the Midvale area (as
determined by Sharon Steel studies), were 500 ppm for lead and 70 ppm for arsenic. As a result,
there is concern of exposure to metals from these contaminated soils, which can potentially occur
through inhalation of dust or from direct dermal contact by people at (or near) the site (Reference 1,
pages 3 and 4).
Mr
Air contamination was documented in the 1984 Preliminary Assessment (Reference 4, page 281).
The slag was found to be radioactive and to emit radon gas to the air. Concentrations were not
presented. Radium 226 was also present at up to three,times the accepted standard (concentrations
were not provided in the references). It is estimated that the population within 4 miles of the slag
(i.e., 135,000 people) would potentially be affected (Reference 4, page 281). It was noted that wind
patterns in the vicinity of the site suggest that inhalation of contaminated, suspended particulate matter
may be an important exposure route for the general population in the vicinity (Reference 1, page 3-1).
No further mention of radiation problems were discussed in the references.
ENVIRONMENTAL DAMAGFS AND RISKS
The site was initially called to the attention of the Utah Department of Health and EPA because of the
visual appearance of the slag and potential ground-water, surface-water, and air contamination from
the slag materials (Reference 1, page 1-1).
I0
C,
-------
Mining Waste NPL Site Summary Report
The routes of exposure of primary concern at the site are:
• Consumption of contaminated ground water
• Inhalation of contaminated dust particles
• Ingestion of contaminated soils or household dust
Midvale wells, supplied by aquifers beneath the site, serve 300,000 people in the Salt Lake County
Water Conservancy District. Consumption of ground water contaminated with arsenic may increase
cancer risks. Exposure to arsenic, cadmium, and lead may also result in noncarcinogenic effects such
as peripheral neuropathy, renal dysfunction, and neurological damage, respectively (Reference 1, page
5-1).
Inhalation and ingestion of contaminated, suspended particulate matter containing arsenic, cadmium,
lead, and silver is potentially a significant pathway of exposure for the general population due to local
wind patterns. Dust generation at the site may be from wind entrainment of contaminated soil or
waste particles and dust generated from human activities (e.g., onsite industrial vehicle use). In
addition, dermal contact and incidental ingestion may occur with workers onsite or possibly children
playing or riding bikes on (or near) the waste piles (Reference 1, pages 3-1, 3-3, 3-4, and 5-1).
As previously mentioned, surface-water contamination from the Midvale site has not been
documented. However, without remediation, such contamination may occur in the future, and the
potential receptors could include both aquatic communities and human populations (Reference 1, page
3-4).
Environmental concerns were also identified at the site during the Preliminary Assessment. It was
observed that vegetation does not grow on the slag, and that the smelter has had a history of damage
to vegetation. The Jordan River is a critical habitat for bald eagles, and hence, there is potential
damage to bald eagles through consumption of contaminated fish. Cattle have also been observed
feeding in the wetland/swamp within 100 feet north of the site; they may also be at risk (Reference 4,
page B-5).
REMEDIAL ACTIONS AND COSTS
Two removal actions have been conducted. In the early fall of 1990, the site was fenced off so
prevent access by the public. In December 1990, abandoned chemicals stored in the former assay
11
-------
Midvale Slag (Valley Materials Slag)
laboratory and silver refinery buildings were packed and removed. Also, about 20 pounds of Class A
explosives were detonated under supervision of local authorities in January 1991. Because the
Remedial Investigation is in its early stages, no remedial actions have been taken.
CURRENT STATUS
EPA added the site to the NPL on February 11, 1991. According to EPA, the Remedial
Investigation/Feasibility Study has been started; it has a 1993 target date for completion.
12
-------
Mining Waste NPL Site Summary Report
REFERENCES
1. Final Preliminary Level I Endangerment Assessment, Midvale Slag Site, Document Number:
347-ES l-RT-FBBL; Camp, Dresser & McKee; September 1, 1987.
2. Analytical Results for Valley Materials Slag (Midvale Slag), Midvale, Utah; Eric Johnson, EPA;
August21, 1985.
3. Site Inspection Report for Valley Materials Corp., Salt Lake City, Utah; Prepared for EPA
Region VIII by Utah State Division of Environmental Health, Bureau of Solid and Hazardous
Waste; September 14, 1984.
4. Preliminary Assessment; Utah State Department of Health, Bureau of Solid and Hazardous
Waste; February 23, 1984.
13
5)
-------
Midvale Slag (Valley Materials Slag)
BIBLIOGRAPHY
Camp, Dresser & McKee. Final Preliminary Level I Endangerment Assessment, Midvale Slag Site,
Document Number 347-ES 1-RT-FBBL. September 1, 1987.
EPA Region VIII. Site Inspection Report for Valley Materials Corp., Salt Lake City, Utah.
September 14, 1984.
EPA. Sampling Plan for Valley Materials Slag, Midvale, Utah. May 24, 1985.
Johnson, Eric (EPA). Analytical Results for Valley Materials Slag (Midvale Slag), Midvale, Utah.
August21, 1985.
Prepared for EPA Region VIII by Ecology and Environment. Potential Hazardous Waste Site
Inspection Report, Valley Materials Slag (Midvale Slag). August 19, 1985.
Utah State Department of Health, Bureau of Solid and Hazardous Waste. Preliminary Assessment.
February 23, 1984.
14
-------
Midvale Slag (Valley Materials Slag) Mining Waste NFL Site Summary Report
Reference 1
Excerpts From Final Preliminary Level I Endangerment Assessment,
Midvale Slag Site, Document Number: 347-ES1-RT-FBBL;
Camp, Dresser & McKee; September 1, 1987
, (J
-------
001238
FINAL
PRELIMINARY LEVEL I ENDANGERMENT ASSESSNE?
MIDVALE SLAG SITE
DOCUMENT NO.: 347-ESI-RT—FBBL
ENFORCEMENT CONFIDENTIAL
SEPTEMBER 1, 1987
CAMP DRESSER & McKEE INC.
2300 15TH STREET, SUITE 400
DENVER, COLORADO 80202
REM II
PERFORMANCE OF REMEDIAL RESPONSE
ACTIVITIES AT UNCONTROLLED
HAZARDOUS WASTE SITES
U.S. EPA CONTRACT NU 68-01-6939
DM Federal Programs Corporation
ADMINISTRATIVE RCOPD CAMPDRESSER&Md(EEINC.
ROYF.WESTONINC
W000WARDiCLYDE CONSULTAN1S
CEMENT ASSOQATES 4C
ICF INCORPORATED
CC JOHNSON & MAL&IOTRA. P.C
SF FILE NUMBER
-3.-?
.5 ’ -
-------
001245
1• 0 INTR0DUC ION
This document is a preliminary qualitative, Level I Endangerment
Aissument of the Ilidvals Slag site. Copper and lead smelter operations
resu ltsd in the deposition of slag, smelter vaste, dross, and baghous. dust
at the site over an 88—year period (1871-1958). miss vast., have
contaminated ground vater, soil, air, and possibly surface vater to an
extent that may endanger human health and the environment.
The site vu initially called to the attention of the Utah Department of
Health and EPA becaus. of the visual appearance of the slag, and potential
ground vater, surface vater. and air contamination fro. the slag materials
(USDEI 1984). EPA proposed the site for the National Priority List (NPL.)
in Update 05 in early 1986. Its current status is ‘in rulemaking.’
Sources of information for this assessment include a Utah State Division of
Environmental H.alth report (USDE! 1984), a scoping study report prepared
for Valley Materials Corporation (YNC) (Radian 1984), the Hazard Ranking
System (HRS) report prepared by EPA’s Field Investigation Team (FIT) (MITRE
1985), and a hydrogeocheaical characterization of the mite prepared for VMC
(Earth Pu 1986).
1.1 SITE DESCRIPTION AND DISTORT
The Nidvale Slag site is a parcel of land encompusing approximately 330
acres located immediately vest of the City of Nidvale, vhich ii 12 miles
south of Salt Lake City (Figure 1—1). The site is approximately bounded by
the follovings 7800 South Street on the south; the Jordan River on the
vest; an unidentified roadvay and a sevage disposal plant on the north
(approximately 7050 South); 700 Vest Strict on the northeast; and a set of
railroad tracks on the southeast.
1—1
-------
Midvais SIaa sit. Boundary
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1.2
.
-------
001 2 7
Although the first smelter v ia constructed at the Nidvale Slag aft. in
1871, •ost of the_smelting activity occurred between 1906 and 1958 when the
United States Smelting, Refining and Mining Company (USSRi4) owned the
property. Beginning in 1905, the smelter processed copper and lead
concentrates from the Sharon Steel/Nidvale Mill facility to the south of
the site (Figure 1-1), and from custom shippers. However, in 1908,
litigation concerning the damaging effects of smelter wastes on crops in
the vicinity curtailed production from the copper smelter. Further
litigation and a legal decree allowed continuance of the lead smelting
operation, with early forms of pollution controls, from 1910 through 1958.
In 1938, operations at th. smelter ceased, and shortly thereafter the
smelter facilities vera dismantled. Remnants of the see er activity
include a large slag pile, approximately 100 acres in s ..e, which is
currently utilized by YNC as a source of road and railroad bed construction
material.
Th. above information was derived from various historical references
(Nelson 1979, Billings 1948, Nidvale Plant Staff 1940). A detailed history
of the site is included in the Responsible Party Search Report for the
Midvale Slag site (EPA 1986a).
1.2 CONTAMINANTS FOUND ON-SITE
1.2.1 SOURCE AREAS
The various wastes deposited on—site include slag, smelter waste, dross,
and baghouse dust. All of these wastes contain high concentrations of
heavy metals. Table 1—1 lists the approximate quantity of each waste
source and th. maximum concentrations of selected heavy metals found at
each source. Listed heavy metals are those which may be hazardous to
public health and the environment and which have been found at elevated
concentrations in non—source areas.
1—3
-------
TABLE 1-1
SOURCE AREA CONTA) IKAJIT CONCENTRATIONSa
Oüi 248
Source
Quantity
Contuinant
Naxi.ua Concentration
(ppm)
Slag
2 •illlon tons
Arsenic (As)
Cadmium (Cd)
Copper (Cu)
Lead (Pb)
Silver (Ag)
Zinc (Zn)
340
45
2,380
9,410
36
58,500
(Total Recoverable)
(Total Recoverable)
(Total Recoverable)
(Total Recoverable)
(Total Recoverable)
(Total Recoverable)
S.elter
69,000 cubic yards
Arsenic (As)
15.80
(Extractable)
Vaste
Cadmium (Cd)
Chromium (Cr)
Copper (Cu)
Lead (Pb)
Zinc (Zn)
2.55
2.30
132.50
3.50
379.0
(Extractable)
(Extractable)
(Extractable)
(Extractable)
(Extractable)
Dross
44,100 cubic yards
Arsenic (As)
Cadmium (Cd)
Chromium (Cr)
Copper (Cu)
Lead (Pb)
Silver (Ag)
Zinc (Zn)
10,490
40
130
410
7,750
47
1,610
(Total Recoverable)
(Total Recoverable)
(Total Recoverable)
(Total Recoverable)
(Total Recoverable)
(Total Recoverable)
(Total Recoverable)
laghouse
Dust
400 cubic yards
Arsenic (As)
Cadmium (Cd)
Lead (Pb)
0.06
0.06
(0.05
(Extractable)
(Extractable)
(Extractable)
Sources
EP Toxic
Earth Pu (1986)
1-4
-------
‘1 % A
utJ I L-’
Figure 1—2 illustrates the location of contaminant source areas. Th. four
types of slag (iron, vatar—quenched, air—quenched, and copper) occupy the
largest area folloved by smelter vast., dross, and baghouse dust.
None of the vast. sources ire ad.quately secured and releases have occurred
through air and ground water pathv.ys. In addition, direct contact vith
these waste sources is very likely due to the extensive earth moving and
industrial vehicle activity at the site.
1.2.2 NON-SOURCE AREAS
On—site, non—source area sampling indicates that contaminants from the
source area have • lgrat.d to soils, ground water and, possibly, surface
water. Table 1-2 illustrates heavy •etal concentrations found in these
media. It should be noted that all of the surface vater maximum
concentrations shown on Table 1-2 represent various ponds and drains on-
site except for the arsenic concentrations vhich represent an upstream site
on the Jordan River. None of the other listed metals were detected in the
Jordan River except for zinc, which was detected at a concentration of 0.1
.g/L at the same upstream sits where arsenic was detected.
1—5
,;(pCrl
-------
TABLE ,l-2
ON-SITE, NON-SOURCE AREA CONTAflINANT CONCENTRATIONS
r’ i
UL, I
Maximum Concentrations’
Drinking Vaterb
Standard (MCL)
Soil
Surface Vater
Ground Water
Contaminant
(mg/kg)
(mg/L)
(mg/L)
(mg/ I.)
Arsenic
1,500
0.03
0.221
0.050
Cadmium
285
0.015
0.873
0.010
Chromium
Copper
200
2,290
ND
£63
0.035
0.123
0.05 (hex)
l. 3 c
Lead
9,150
0.045
0.538
0.05
Silver
Zinc
25
17,600
ND
0.495
ND
5.02
O.O
5.0
Source: Earth Tax (1986).
Maximum Conta ir .ant Level.
Proposed Maximum Contaminant Level Goal (MCLC).
Vater Quality Criteria, Clean Vater Act.
1—7
-------
001 2 2
2.0 ENVIRONMENTAL FATE AND T A11SP0RT
As discussed in Section 1.0 of this report, current studies indicate that
several metals are present in ground vater, air (by indirect inference),
and soil in the vicinity of the Nidvale Slag site at concentrations that
may endanger human health and the environment. Access to the sit. ii
currently not restricted and a commercial slag operation exists on-site
resulting in extensive earth moving and industrial vehicle activity
on-site. Fine grimed vast. source material •ay be inhaled, ingested,
deposited as household dust, or deposited on nearby soils. Contaminants
from the site also appear to be leaching into the ground vater system.
Th. fate and mobility of heavy metals in soil are influenced by soil
characteristics and vater movement. Soil parameters vhich are important
are clay, metal oxide content, fraction of organic matter, pH, and
oxidation—reduction potential (Eh). Arsenic, cadmium, and zinc are fairly
mobile in soils and are generally persistent in the environment.
The transport and fate of metals in aquatic systems are, in general,
controlled by sorption processes in the sediments. For several metals,
ambient pH and oxidation/reduction potential also strongly influences
transport and fate. In addition, metal-organic interactions, both in the
sediments and in the vater column, increase in importance as the organic
content incrsasss and strongly affect metal transport in polluted areas.
2.1 ARSENIC
The fate of arienic in the aquatic environment depends largely on ambient
pH and oxidation/reduction potential. A lover pH causes more arsenic to be
released from sediments to the vater column. Arsenic is relatively mobile
in the aquatic environment and cycles through the vater column, sediments,
and biota. In most cases, the sediments and the oceans are the primary
sinks for arsenic in the aquatic environment. lioconcentration factors for
2-1
.11
-------
00 ‘I : .
3.0 EXPOSURE EVALUATION
3.1 ROUTES OF EXPOSURE
Potential routes of exposure at the Nidvale Slag site are illustrated on
Table 3—1 and include:
1. Consuiption of contaainated ground water.
2. Inhalation of contaminated dust particles.
3. Ingestion of contaainated soils or household dust.
4. Ingestion of vegetables grown on contaainated soils.
5. Exposure of aquatic life to contaminated surface water.
The current routes of primary concern ar. the first three listed above.
Contaninant concentrations that could cause adverse human health effects
have been measured in ground vater at the sit, and in waste piles and soils
on-site. Transport of windblown vaste materials off-site is also very
likely to occur.
3.2 POPULATIONS EXPOSED
3.2.1 GROUND WATER
A deep aquifer beneath th. site and, possibly, a contasinated shallow
aquifer beneath th. site are used for municipal water supply, private
veils, and irrigated agriculture. Information regarding the potential for
interconnection between the shallow and deep aquifers is contained In a
USGS report (USGS 1984). In addition, it is likely that the shallow
aquifer discharges to surface vater at some locations. Nidvale veils are
essential for meeting peak summer demands for the Salt Lake County Water
3—1
-------
T Z 3-1
Rn lr1AL Pe%IWAYS 10 MWWflS
I TDC NIWALE A ShE
e IbPh P 1 I %i Pryi1ati jr qwne Mnt t.itIa1 ço,ize
xfaoe smff k ttc Ut. iuuL . R1 Direct it t; hr tiar
1 t Disd.zgeI y
.-itiui of VmS-
itralad Omtadiits
U t cf1rr1 tsI tteI di s1s Direct o itect; çt ;
1I tiG1
lia as.iIati i of taIs bdivl 1t m.bg J L. 1 Ri
fij i
QunI lbt& I ui1atIm t1I idi te Iidivii l iIi gmixl Alluvial wil Ii tla i
phl eat fOr éII*IITg wtar
Mr Vial ettraliit of Eat L i i . u-site, S1 te, 1t Ii* latiiu
k ieate pil c iduits ad 1iulivi ni te, ad
iwr site ti uae Eat
t at .thar h %&x* s cu-site, Slag te, ltar li alatic u i
Iii * tiviti (e.g., resic its ad bdivl’ 1Q te, dm , ad
rth Ir an tanvy iesr site icu Eat
dde an)
C)
Soil/SLag te Ouitadiatel a. ta,e soil Ikdt e ai—slte, SLag te, aniter Direct amt t; C)
r iEats ad I,d1vi&n1 iaste, diu , ad Ia iEata1 l tlcui
year site t uae Eat
-------
001 2ZR
Conservancy District vhich serves 300,000 people (UDNE 1981). Vater supply
villa driving f i. deep aquifers beneath the Midvale Slag sit. include the
folioving (MITRE 1985):
Location Number of Veils Population Served
Salt Lake City 5 (Part of blended 300,000
system)
Sandy City 7 83,700
Midvale 5 10,000
Murray 1 28,000
Private Veils Not Listed 325
Total: 422,035
3.2.2 AIR AND SOIL
According to 1980 census data, approximately 1,443 people live vithin 0.25
miles of the site and 8,179 people live vithin one mile of the site.
Occupied residential and commercial areas lie Immediately adjacent to the
site on the east and agricultural lands, in production. lie across the
river on the vest aide of the site. Vind patterns in the vicinity of the
sit. increase the likelihood that inhalation of contaminated suspended
particulate utter is an important exposure route for the general
population in the vicinity of the site.
Exposure to metals from vast. piles or contaminated soil can potentially
occur through inhalation of dust by people at or near the sites.
Mechanisms for dust generation at the Midvale sit. may include dust
resulting from vind entrainment of contaminated soil or vast. particles and
dust generated from human activities (in particular, earth moving activity
at the slag vaste piles and industrial vehicle use on-site). Currently,
slag is being removed from the site for use in constructing roads and
railroad beds. This activity, including operation of dump trucks and
front—end loaders, viii increase dust emissions from this area.
3-3
5 - 7 q
-------
51
001 2 9
In addition to inhalation, exposur, to metals in soil or tailings can also
occur by direct derail contact vith these materials and by incidental
ingestion. Vorkers on—site probably contact the vaste piles and probably
experience some degree of incidental ingestion, especially it they eat
food on-site. Older children living in the area, particularly those from
ages 6 to 16 vho generally have less parental supervision than younger
children, nay play or ride bikes at the vast, piles. The potential for
this type of exposure vould be greater in the summer months vhen school is
out and summer-typo clothing exposes more skin.
Consumption of crops or garden vegetables grovn in contaminated soils may
also increase human or livestock exposure to arsenic, cadmium, chromium,
lead, and silver. The Utah Department of Iealth (UDO8 1983) has
demonstrated that vegetables grovn on tailings contain 2.5 to 6 times the
normal range of cadmium, chromium, lead, and zinc.
3.2.3 SURFACE WATER
Although surface vater is a potential pathvay for contaminants from the
Midvale Slag site, surface vater contamination does not appear to have
occurred. Without remedlatlon, it may occur In the future and potential
receptors would include both aquatic communities and human populations.
3-4
-------
OO12 7
5.0 RISK AND IMPACT EVALUATION
Metal contamination from the Nidvale Slag site presents a potential
endangerment to human health and the environment due to actual and
potential exposure and toxicity. Consumption of contaminated ground vater
may increase the cancer risks in humans due to arsenic exposures. Various
non-carcinogenic effects such as peripheral neuropathy, renal dysfunction,
and neurological damage f roe exposure to arsenic, cadmium, and lead,
respectively, may also result. All residents adjacent to the Nidvale Slag
site are potentially subjected to arsenic, cadmium, chromium, lead, and
silver exposure via inhalation of contaminated dust. Older children near
the site and yorkers on-site are also potentially subjected to arsenic,
cadmium, chromium, lead, and silver exposure via direct ingestion of
contaminated soils. Consumption of crops or garden vegetables grovn in
contaminated soils may also increase human exposure to arsenic, cadmium,
chromium, lead, and silver.
Releases of various metals from the Nidvale Slag site also pose potential
risks to aquatic and terrestrial vildlife because of their tendency to
bloaccumulate in aquatic organisms and vegetation. Specific data on local
vjldlife and plant receptors is not currently available.
5-1
-------
Midvale Slag (Valley Materials Slag) Mining Waste NPL Site Summary Report
Reference 2
Excerpts From Analytical Results for Valley Materials Slag (Midvale Site),
Midvale, Utah; Eric Johnson, EPA; August 21, 1985
f11
-------
3,.’ 1)’
I I\/ \ i)( fl
I I I ( ON I R( )I
I )R I’ I( ).\
Rerned ial
Planning
Field
Investigation
Team
(REM FIT)
ZONE II
ON I \( I NO
I 1 i t )
‘ , !) ) 1_
(I \ •
I UI( ) \ \
Ii 1\ ! ( )f fl 1 1 it
-------
000337
ANALYTICAL RESULTS FOR
VALLEY MATERIALS SLAG
(MIDVALE SLAG)
MIDVAL( 1 UTAH
TOO Re-e,oB-o6
EPA REGIONAL SITE PRO. ECT OFFICER: ERIC JOHNSON
£&( PROJECT OFFICER: JEFF NOLCOMB
SUBMITTED TO: KEITH SCHWAB FIT—DPO
DATE SUBMITTED: AUGUST 21, 1965
( \
-------
ANALYTICAL RESULTS FOR 000340
VALLEY MATERiALS SLAG
(NIDVALE SLAG)
MIDVALE, UTAH
I. INTRODUCTION
Ihas report was pr,psred to satisfy the requirements of Technical
Directive Document (TOO) Re.850B.06, issued to the Ecology and
(nvironment, Inc. Field Investigation Tess (C&E Fit) by the Region
VIZ! Environmental Protection Agency (EPA).
The sample discussed in this report were collected by the FIT on
June 18, 1985 from Midvale Slag in Midvsle, Utah (Figure 1). Two pre-
vious reports, the Report of S.mpling Activities (R8—e5O5-25) end the
Ssmpling Plsn (R8—8505—12), present discussion regsrding project
objectives, site description, sampling procedure, Quality control,
s.mple docu.entstion and field observetion. The rasder is directed to
these earlier reports for further information.
Midvale Slag is an old smelter site. The Madvale Smelter was
constructed on this site in 1902 ss a copper plant. Over the years,
the plant uss changed to a lesd fscility, producing a gold—lead—silver
bullion. From 1918 to 1928, spproei.stely 400,000 tons of lesd were
produced. Today, the smelter no longer remains, but very large piles
of slag still esist on—site.
The current operators of the site, Blackhawk Slag, owned by Val-
ley Materials, Inc. of Illinois, process the slsg into a uniform tex-
tured material used in railroad beds and asphalt highway construction.
Slag sasples were collected by the State of Utah 8ureau of Solid and
Nszardous Waste (BSHW). The analyses of this slag indicated that the
slag contained elevated levels of arsenic, esdsius and lead. Thus,
the objective of this sampling effort wee to determine the presence
end extent of contamination at Midvale Slag due to past op,rstions.
I
- J 3
-------
11. QUALITY ASSURANCE REVIEW 00034 ‘1
All samples were shipped via red.r.l Express to the RegIon VIII
Lsboratory in Denver, Colorado on June 19, 1985. All sampiss were low
hazard and were analyzed for Task 1 and 2 metals and cysnides. the
surface water samples were also analyzed top sulfates. One blank
water sample, VNS-BL—I, was prepared in the field and also sent to the
Region VII ! Laboratory to be analyzed for Task 1 and 2 metals, cyan-
ides and sulfates. A triplicate surface water sample (triple volume)
was collected at simple station VMS—SW—i for isborstory quality assur-
ance. Also, a duplicate surface water sample (VHS—SW—a) was collected
from station VHS—SW—I to check laboratory procedure., accuracy and
precision.
A review or spike recovery, duplicate and blank data was per-
formed by Hilt Lammering of the EPA’s Region VIII Laboratory. Nothing
abnormal was reported; thus these data indicate that th. analytical
procedures used were acceptable. The raw data are in Appendix 8.
III. ANALYTICAL RESULTS
Analytical rsaults for the june, 1985 Hidv.le Slag saapling
effort have been compiled in Tables I and 2, and corresponding
sampling locations are shown in figure 2.
brief review of the data allow the following observations and
conc lua ions.
A. SURFACE WATER SAMPLES
Surface water ssmples VHS-SW-I, VMS—SW—2 and VMS-SW—I were
collected from the east bank of the jordan River. Surface water
sample VHS—SW—A was collected as a duplicste of VMS-SW-I.
A comparison of the upgradient simple, VMS-SW—I, to the downgra-
dient samples, VMS—SW—2 and VMS—SW—I reveals that the concentrations
2
-------
—
or • i eav metals detected are bssicslly the seas at all three
sample stations (Table 1). Thus, a conclusion of a release to the
Jordan River based on the Miter MRS model requirement that an order or
magnitude difference in concentrations it uDgradient and downgradient
locations must exist, can not be maae. However, comparison of the
water quality to the Matlonal interim Primary drinking water standards
indicates that iron, and manganese, were detected at elevated levels.
Iron is approximately ten times greater than the standard and
manganese exceeds the standards by about 1.5 times.
Any conclusion or reaulta from comparing the levels of iron and
manganese detected in the surface water to the drinking water standard
can only be used qualitatively. The drinking water standards apply to
public water systees which provide piped water to be used for human
consumption. The water sample, collected at Midvals Slag were not
from a public water eystem as the Jordan River is not used for
drinking water. Thus, the only conclusion that can be made is the
surface water is not fit for human consumption.
B. SEDIMENT SAMPLCS
Table 2 presente the inorganics that were detected in the
sediment samplea collected from the Jordan River. A majority of the
Task 1 and 2 metals were detected; of these elements arsenic, cadmium,
chromium, cobalt, lead, manganese, mercury and zinc mrs of ms)or
conceçn. The concentrations at which these elements were detected are
well above the detection limits. However, a comparison of the
upgradient (VHS —SE —I) sample to the downgradient samples (VMS—SE.2 and
VNS —SE—3) does not concluaivaly indicate a release of contaminants
from the Nidvals Slag Sit.. In fact, in the cases or arsenic,
cadmium, lead, manganese, mercury and zinc, the upgredisnt sample
(VMS-SE-I) has the highest concentration of theme metals.
3
-------
y. POSSIBLE SOURCES Or CDNTAHINATIOk 000343
Due to the limited historicsl information about operations at
Nadvale Slag, it ii difficult to identify the exact sources of contam-
ination using the •xisting data. Two possible sources are discussed.
The first possible source msy be from pest operations. As stated
In Section 1, the Hidvale Smelter produced 400,000 tons of lead. The
slag was deposited on-site and adjacent to the jordan River for many
years. Slag is generally cons dersd to be fairly inert, but the fact
thst it his been exposed and entrained in the river for years
increases the probability that the river has received contamination.
The second possible source of contamination could be Sharon
Steel, which is located immediately south of Midvale Slag across 7800
South Street (figure 3). Sharon Steel is reported to have received
lead, copper and zinc ores and extracted the sulfide concentrate of
these metals. These concentrites were then s.elted to extract the
metals in a purer form. The facility also operated as a custom mill,
raceiving ore fros many sources and extracting a variety of metals.
On the Sharon Steel Site there are ten million tons of tailings ap-
proximately forty to fifty deep in places. The jordan River also
flows adjacent to the tailings. Samples analyzed by the State of Utah
Department of Health showed that the tailings contained 4,000 ppm
lead. The State snalyses slam round high concentration. of arsenic,
cadmium, chromium, copper and zinc. Thus, given the close proximity
of Shsron Steel to Midvale Slag and the fsct that the upgrmdi.nt sedi-
ment ss.ples collected at Hidvale Slag mrs immedistely downgrudzent of
Sharon Steel and exhibit high concentrations of arsenic, cadmium,
lead, manganese, mercury and zinc, it is very probable that the high
heavy metals concentrstions can be partially attributed to Sharon
Steel.
It is vary likely that the explanation of contaminant occurrence
at Nidvala Slag is a combination of the past operations end from
Sharon Steel. This combination could eccount for the high metal
4
-------
TABLE I
SuRrA WATER DATA 00 0 34 6
(ugh, ppb)
DRINKING WATER
ELEMENT CRITERIA VMS -SW—I VM5—5W—2 VHS—SW—3 VHS SW—4
Aluminum 5 ,0 00(c) 1,820 2,190 2,180 2,360 (30
Antimony 146(b) (5 <5 (5 <5
Arsenic 50(a) 12 13 11 13 (5
Barium 1,000(s) 85 90 89 92 <10
Beryllium 0.037(b) <10 (10 <10 10
Cadmium 10(a) (5 (5 (5 (5 (5
Calcium • 84,000 85,900 85,700 88,100 i,ooo
Cr roruisn 50 (a) (3 (5 (5 (3 <5
Cobalt • <5 (5 (5 (5
Copper 1,000(b) 15 18 16 17
lr t 700(d) 2,400 3,030 3,000 3,300 11
Lead SO(s) (30 30 (30 <30 • (30
Kagnes iun • 43,900 44,000 43,000 44,500 (1,000
Manganese SO(s) 68 76 75 76 (5
Mercury 2.0 .) <0.1 <0.1 <0.1 (0.1 (0.1
Nickel 13.4(b) (.30 (30 (30 (30 <30
Potassium • NA NA NA NA NA
Selenium 10(s) <5 (5 (5 (5 <5
Silver SO(s) <5 (5 (5 <5 (5
Sodium NA 111,000 110,000 111,000 113,600 (1,000
Tha ll iiji 13(b) <100 (100 <100 (100 (100
Tin • NA NA NA NA NA
Vanadium • (10 (10 (10 (10 <10
Zinc 5,000(b) 24 22 28 25 (5
Cyanide 200Cr) (2 (2 (2 <2 (2
Sulfate 250,000(r) 199 204 194 214 <0.1
Chloride 250,000Cr) 179 206 225 201 0.52
Field pH 6. 5 —9. 5(f) 8.25 8.35 8.23 8.23 7.02
Field Conductivity — 1,000 1,100 1,100 1,100 6
(umho s/cm)
Field Temp ‘C — 26 27 27 27
Not available
NA = hot Analyzed
Note; For parenthesized letters see references
-------
TARLE2 000347
SEDD€NT DATA
(ug/çam, ppb)
ELEMENT VMS—SE-i VMS—St-2 VMS-SE-3
Aluminum 2,800 4,050 3,220
Antimony <13 <17 (12
Arsenic 30 17 12
51 59 52
Beryllium <1.3 (1.6 <1.2
C.dmii.sn 8.7 3.6 3.0
Calcium 14,200 24,200 15,000
Chromitr 8.6 17 13
Cobalt 3 3.5 3.8
Copper 180 44 28
Iron 12,400 7,810 7,580
Lead 1,490 309 99
Magnesium 2,600 4,320 3,280
Manganese 466 100 92
Mercury 0.08 (0.03 (0.03
N ekel 4.7 9.2 <4
Potassium NA NA NA
Selenitr <13 <17 <12
Silver 3.1 1.4 <0.6
Sodiimi 1,440 440 296
Thallium <13 (16 <12
Tin NA NA NA
Vanadium 15 16 15
Zinc 2,430 171 115
NA = Not Analyzed
-------
000348
—
POTENTIAL HAZARDOUS WASTE SITE
SITE INSPECTION REPORT
PART I SITE LOCATION AND INSPECTION INFORMATION
I I IDEN1IFIC*TI Pd
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000349
POTENTIAL HAZARDOUS WASTE SITE I i IDENTIFiCATION
EPA — SITE INSPECTION REPORT 101 s’
PART 2’ WASTE INFORMATION I (.A1 ’•
WASTE STATES QUANTITIES. AND CHARACTERISTICS
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000 3 5 0
POTENTIAL HAZARDOUS WASTE SITE ‘ IDENTIFICATION
S EPA SITE INSPECTION REPORT I _
P*RY 3• DESCRIPTION OF HAZARDOUS CONDITIONS AND INCIDENTS
II HAZARDOUS CONDITIONS AND INCIDENTS
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OOO3 1
&EPA POTENTIAL HAZARDOUS WASTE SITE IDENTIFICAtION
SITE INSPECTION REPORT
PART 3-DESCRIPTION OF HAZARDOUS CONDITIONS AND INCIDENTS 1111 WE ‘.A
(I MAZARDOUS CONDITIONS AND INCIDENTS
DAMAGE TO F (ORA 02 = OBSERVED DATE POTENTIAL = ALLEGED
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I
EPI OR&P2C7G 13 1$ii
00032
I ID(NTiFicay
POTENTIAL HAZARDOUS WASTE SITE
a, EPA SITE INSPECTION Lu
PART 4. PERMIT AND DESCRIPTIVE INFORMATION
II. PERMIT INFORMATION
a’
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000 3 3
POTENTIAL HAZARDOUS WASTE SITE ‘IDENTIFICATION
EPA SITE INSPECTION REPORT 0 j 1 C2 SITE I.ui B R
PART 5. WATER. DEMOGRAPHIC. AND ENVIRONMENTAL DATA
II. DRINKING WATER SUPPLY
01 rvPE 0’ IRIWGSijPei,, 02 STAtUS
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= YES COMMENTS
$ NO
II DISCI.ARGE AREA
YES COMMENTS
$140
V SURFACE WATER
3i SURfACE WATER USE c..u.,..
= A RESERvOtR RECREATION d B IRRIGATION. ECONOMICALLY = C COMMERCIAL INDUSTRIAL 0 NOT CURRENTL’P USED
DRIPØUNG WATER SOURCE IMPORTANT RESOURCES
( 3..u
2 AffECTED P t5P.TIA j , AffECTED 5001550’ WATER
NAME AFFECTED DISTANCE TO SITE
‘ot4 R jcr k bocde i JIlt
=
i
V DEMOGRAPHIC AND PROPERTY INFORMATION
A. P .A?ION WIT. .. 02 DISTANCE TO NEAREST P0’U.ATIOPI
ONE II • MI_E OF SITE TWO ( I MLE5 OF SITE T IREE 131 MILES OF SITE
A —i. 7 o B kw C .3 LL U.S IPIp
I .. ‘ PlS ._ NC 0’ Pf•N ..: 3’ ElS3s
IIJMSER Of Su’.O’ .GS WITH.. TWC 131 MU Of 5 1T 5 040151 APdCI ‘0 NCARISI O P SITS SLJ. OfI
05
5 00 J..,ATIQ% W.T VCWAT Of SITE IWU I 1.1.!.1 1.I: I.1S 1.. I V 110.4 4 1. 1. ,I M l I VI 111.1. II 1.
;, ii L*L44411 .Jh j Ij & r 4,f . d 4 j. I —‘ - ‘
( .y L 4 ( i4 4 s dij
J tA%.. T’& IE LI..4: ,. * I
9 /
-------
Mid ale Slag (Valley Materials Slag) Mining Waste NPL Site Summary Report
Reference 3
Excerpts From Site Inspection Report for Valley Materials Corp., Salt Lake City, Utah;
Prepared for EPA Region VIII by Utah State Division of Environmental Health,
Bureau of Solid and Hazardous Waste; September 14, 1984
-------
• it., .,
U J!ItJg
SITE II 6PECT ION RE RT
VALLEY MAT IALS RP.
SALT LAKE CITY, UTAH
SLB’IITTED TO:
Eric Johnson, EPA Region VIII
Si. mitted by:
Joel Hebdon, Team Leader
Utah State Division of Enviranm& ta1 Health
Bureau of Solid and I zardous Waste
Septenter 14, 1984
ADMINLSTRAT VE RECORD
SF FILE NUMBER
1)
•1
-------
000373
II. SITE D CRIPTION
A. Geology
The Valley P terials slag facility is locatea adjacent to
the Jordan River and sits squarely in its floodplain.
Topogra tiic relief is small but there is a marked surfaclal
gradient to the west. I’Etive soils have in many places become
mixed with the slag, sometimes slag is found 20 feet below the
apparent ground surface. The subsurface is composed of
interlayered silts and clays whith are probably Lake Bonneville
deep—water deposits. No bedrock has been located in this part
of the valley, and it is probable that as with other valleys in
the Basin and Range yslograØi1c province, basement rock is
located at great depth. There are no faults or other
structural elements of note known in the ininediate area.
B. ,drology
Being located in the bottom of the Jordan River floodplain,
the slag at Valley t terials is exposed to both surface and
groun aters. The Jordan River wa es along the slag piles on
their western side and springs bring grouidwaters to the
surface at n nerous places along the piles’ bases. In the
vicinity of the slag, average groundwater depth is
approximately 2 to 3 feet. The Jordan River throu this
c
-------
000 37
portion of its course is a receiving stream ana therefore there
are numerous seeps and springs located ranoomly throuqiout the
area. Storm drains, running full of water, are located Just
north of the slag and along the property’s southern perimeter.
This southern storm drain was sampled as being representative
of upgradient surface water.
FCrth of the site, a water treatment plant with several
large ponds may be complicating local grounCwater flow due to
ntunding and/or pressure gradients created by their artesian
well.
C. Sampling
Samples collected by the U.S. Bureau of Solid and Hazardous
Waste personnel during site inspection included upgracient
samples of soils, surface and ground waters, composites of
three different slags, and downgradient samples of surface and
ground waters. All samples were si mitted to the Utah State
Health Laboratory for analysis. The Bureau’s quality assurance
officer oversaw all sampling and documented the taking of eath
with the appropriate thain-cf-custody tags, forms, and entry in
the Bureau log bock. Copies of eath analysis sheet are
included In Appendix 3.
Samples collected by the Bureau of Solid and Hazardous
Waste include the following:
ø “I
-------
000375
Pb. 153 — surface stream at south gate — Valley Weterials
— entrance (upgraaient)
P C. 154 — ckground soil collected at 7509 South l 0 West
to. 155 — 7200 South storm drain — groundwater seep north of
slag piles (downgradient)
tO. 156 — 7200 South storm drain — surface water in ditch
north of slag piles (down adient)
tb. 157 — Composite, “iron” slag
P C. 158 — groisidwater pond (u elling) north—west of “iron”
slag
Pc. 159 — Composite, water—qLenched slag
tb. 160 — Groundwater west of water-quen ied slag
lb. 161 — Composite, air—q nthed slag
tb. 162 — air-quenthed slag
0. 176 — Groundwater collection, South Valley WRP — north of
slag
A comparison of up-gradient and down—gradient samples
indicates that the slag appears to be contributing arsenic,
bariui , lead, mercury, and silver to the ground arid surface
waters. l’b on-site soil was collected for analysis and in
future work it would probably be wise to obtain these samples.
For purposes of c nparison of soil contamination, since tl ie
ground at the facility is virtually blanketed by slag, the slag
soil mixture has been treated as down—gradient soil. to air
san les were collected.
0. Site Discussion and Recomendation
The environmental problems at Valley Weterials appear to be
both real and extensive. Slags iich appear to contribute
sig,ificant quanitites of contaminants to their surroundings,
(,O
-------
000 37
continue to be processed at this facility and sold for use
throu iout Utah and into Colorado. Contamination of ground and
surface waters has been documented at Valley P terials and a
sig ificant potential for air contamination by radioactive gas
exists.
()i the HRS scoring, Valley terials received a 77.08
composite score with a 100 score for direct contact
(potential). This score could very pr ably be raised if air
sampling was conducted at the facility. In any case, a
si ,ificant and imediate hazard appears to exist and prompt
attention by EPA is recomended. Future work that ou1d be
considered includes sampling of major surface water bodies,
sampling of nuiicipel wells, and the collection of air samples
for detection of radioactive gases. In sumatlon, it is the
recctmiendatcn of the Utah State Bureau of Solid and Hazardous
Waste I . nagement that Valley Waterials be included on the next
updete of the tior 1 Priorities List as a proposed site for
remedial actions under CERO..A.
-------
Midvale Slag (Valley Materials Slag) Mining Waste NFL Site Summary Report
Reference 4
Excerpts From Preliminary Assessment; Utah State Department of Health,
Bureau of Solid and Hazardous Waste; February 23, 1984
-------
•Si oii M %lathesofl
Goven ,o,
STATE OF LT. 1-{
DEPARTMENT OF HEALTH
DIVISION OF ENVIRONMENTAL HEALTH
tSO West 4 orch Temple. PD Box 2500 S lc L2ice C.:v. Luti 341 .0•5 O
imesO %1aso,,.’ 4D.DrPH February 23, 1 84
£ctcw,ve Osre ro, 533—4145
iOI.5Ji.6l!/
II
DIVISIONS
Co”.w ’ ,’y tkefrhSvvces
E , ..,o.,mn,os Hiasm
Pc#. , Iv H IM S,n.ces
Heas:a Ce,, fnesi ii
OFFICES
1dm ,I5Ire,, , t Sm. c,s
Cjmmu.uv H,aI,h
t’le ’ve ,mre, Pfenn.ng
l,thioI £xemn,v,
Stat, H,eirfl Law,atmv
i E u J oaor;un ,i E?ioyer
Mr. John Srink
U.S. Environmental Protection Agency
Region VIII
1860 LLncoln Street
Denver, Colorado 80295
Re: ?relininary Assessment R.e ort,
Midvale Slag Piles (Valley
Materials Site), no PA D
numoer, Salt La ce CLty, Utan
Dear Mr. Brink:
Submitted herewith is a final Preliminary Assesment repo -:
for the slag piles owned by Valley Materials, located in
Midvale, Utah.
3ased upon information available at the time this
assessment was made, it is recor ended that further action n
this site be cont .nued, and that it be given a hLgh prlor.ty.
A future site inspection is anticipated 1 either by tne State,
or Region VIII of EPA.
These slag piles contain air and water—quenched slags
produced by U.S. Smelting, Refining and MinLng Company
operations between 1902 and 1958. Ores came from Anaconda,
Kennecott and United States Mines and Xinerals mines, among
others. These sulfide ores were smelted to recover lead,
silver, copper, gold 1 zinc, arsenic, cadmium and associated
netals. As is usual with smelting residues of sulfide ores, a
signficamt quantity of arsenic is still present in the slag.
The major operations of this smelter were directed to the
recovery of lead and copper. Interestingly, until 1928 zinc
was wasted directly into the slag piles.
Today, about two million tons of slag remain on—site. An
unknown, but substantial, amount has been removed and used for
road bases and fill, and for saudb].asting concrete. One of
these sandblasting projects was reportedly a Bureau of
Reclamation dam.
ADMINiSTRATIVE RECORD
SF FILE NUMIER
K i,ieiI LI. akemi .re ,r
oom47a 3OI- 3. ’ .
-------
—
POTENTIAL HAZARDOUS WASTE SITE I EN ICA IOk
PRELIMINARY ASSESSMENT r’ .‘.‘i” ‘
PAMI 3 DESCRIPTION OF HAZARDOUS CDNDITIOWS AND INC IDENTS
•A.ZARDOUS C NDITIQw$ AND INCIDENTS
3 ’ A O T Tejms ,a7Oi _ 02 = 055 VEi T 5 __________i = .OYS 7 IAL C A3 —
3 O , UUU o oss ’ ’o
sna ow we i ocated just nor:n of the site, within three hundred feet, was samole
and found to contain 54 ppm As, 2575 porn SOS, 1125 porn Cl, 6138 ppm 105, and have a ,
of 6.8. Extent of distribution of this contamination is not known, but a De3rs tO e
significant. well (c-2-1)25ABB
Ci a SuNIaE A7E c NTAMN& lOw 86,0OO 02: 0eSE vL A E __________
3 OT TIA.I.I.Y AUEC?ED ____________ 0 P4 A IVE
The ite s ocated on the JQrdan R ver flooa piain. At lts edge, the pile slop s u—
to5u . ironi the top edge or the siag. the sioDe to the .iordan iver is aoorox i e yI
30%. As the slag is known to contain eachable materials, and no measures have eei
— e’ to stop the free runoff of surface wat rs, it is alleged that the Jordan River is ein
contaminated by s’aa oene ated materiaTs.
01 : : Tio 0’ 1 4 C2 = 0BS! VWILTE - : ‘o _
03 0u T IOw PO ! TI y 35 ,000 Naa v
The slag is 4 g l-y readioactive and emTts radon gas to the air. Radium 225 is
present at up to three times the accepted . ndard.
: cow rno s :; = 05ss vz: : z = I
03 ROPIJI.A? 1DN PCT!PJTIA. ... .Y £c;! D i NA RA7IVZ S MJ N
Not applicable
: ‘! ow 1 :i : oess v :3 UI - .
3 P &.I w *r ’5c 04 AAA? 5 3 5 Ø
The size is fenced, but easily accessed. Duck hunters were observed on site. There
have been no reported injuries from exposure to the slag. Cattle were seen grazing in
a field directly adjacent to the slag piles.
01 = Ta.wi& IQwQf inn I 3 .
:3 & & 5 i& £F 5 ! - 04 * * ivs s Iriow
The contamination of groi waters indicates that this material is very leachable arid
mobile. Although the soils on-site have not been tested for heavy metal contarninatin
they almost certainly contain Metals and inorganic chemi als leached from the slag.
Radio 1 active contamination has been documented.
C’ ±0 GrEaC0 T ATIow 4 ,,I r’nn _________ I =
; OE i&.&. .’ CiW 13 lJVV Q N&M &tIV DSs: IrnOw . -
me nearest municipal well is located on—site. Water districts afrected by OLIITTDIng
wells located within a 3 mile radius serve at least f million people, and induce tnore
than 25 wells. One of these is a water wholesaler who may be selling contaminated wate
to users throughout the ‘galley. At least 300 private wells are also located witrith 3
C l Zj 0 U £ZPCSL*5#W4J $Y unknown 02 0 0IDA E __________
03 wVQ,cE 3 7 1A.I.Y AFfECi ___________ D i NA P.4TM D€SCRIYflON
No recorded history.
= POP ION 5x Su 5.*4JU 470 000 32 = 0SS!IVt DATE _________ X POi•E rn &.:. :
03 PO J ..ATON POTE Th&... .Y AF EC ED __________ 04 I AiW5 D€S IP1lOW
This exposure is through contaminated drinking waters. Many more people may, n fact,
be affected. •Should radon gas be found ii substariial amounts, the hazards it nOula
create could 4’m’tich greater, popu.La. .o. .
!‘4P W CT0. ’lI’4 ’) 1. — h 3 - within 3 miles
2 - within 2 miles within 4 mi es
-------
55Z
&EPA .PRELIMIwAPyAS5 S5M NT
POTENTIAL ML2ARDOUS WASTE SITE I L
PART 3- DESCRIPT!ON 0; :owomows AWO INCIDENTS ____________________
: iONS £wD :IDENI’ c.—. ... . -
=., : = eu c e .it =
.a 3 flOw
No plants grow on the slag. The smelter has had a history of damage to pla ts Ca:--:
to its earliest operations in 1902.
: a. e o i ii l 2O 4
—
nis siag borders tne Jordan River, which is critical habitat—For bald ea.gles. hil
no eagles were observed, contamination of the river sysve could be very damaging
to this habitat, ar c the fish ot t fly etenbyraptc s.
c L P ! i - - __I. i1 i = £_Z
have been ooservea reeding in tne wetlaflo/swamp to t!ie r1cr:
of zne si witnin 100 ft). Duck hunters have also been observed hunting on-s :!. :c
leacnates are migrating into the surface waters the cattle, esoecially, could e
neavily contaminated. They both eat ano drink tentially contaminated sources.
smelter had a hi torv of ‘n,Urv t
V :2oes! v c o ’ 4 P jT
3Ec3w A.d Et. -rOrw&.s7!s
- a6 000 ’
P tJ’L 1
e s ag piles border a swamp/wetland to tne north, and the Jordan River to :. e es:.
No steos were observed to have been taken to prevent runoff of surface waters i- :: e :
f :n s . The wastes themselves do ot eooeer to slump or blow.
= o s v i 7 __________
ag nas oeen, and is being, removed for use as a road Sase, for use as fill , e::.
There is rio record of claimed or alleged damages, but the heavy metal content a c
radioactivity of the slag make damages quite possible.
c : o co o o; sew! s. s o ’ c ’ v _________ Z P I 1t4 =
a 3Th
i is iccated on—site. There has been no documentation of contamina: on : :
potenz al exists through surface water run-on and/or radioactive gases in : e :r.
=, rT ” Z JMPIW = .s:av o C A E i :
Cs ?R/ 5 sP,’fl
No
recorded history.
0 O1E
The nigh concentrations—of sulfides in this slag makes the production of sulfur-: c :
likely when water is percolating trirouch. This acid may be causing racid ecs : :
ar 1 d leaching of the slag.
37A P0° .A7ION POT! TIALl.T AF!C? _________________________
Iv. C E S
The migration of slag through wind and/or water erosion has not been docunentad, cut
is very lfkely.
v s uR:ZS O IwFQ ML TIO
U.S. Census Burew
Te]ethone interview
Teleprione interview
US.B.S.. .W. files,
tracts, 1980, well-water chemistry analyses, U.S.B Water
wjth Robin MçConr.el o 3laçkhawg slag, SLC -
with Robert tr nger ro Valley Materials 1 S. Beloit, : i
U.S.B. Radiation Control files includirig slac analses
: or
.
p*’,.bla ,c.12( .sI)’ihe Salt Lake Mining Review’ eoruary 15, 1910, and May 30, 12E
Perjri ter Survey, Joel Hebdort aM Don ‘/e bica, CJ.S.3.S.H.W., Jan. 1984
-- -- u S. De t. of Ir.terio:.
-------
557
Mining Waste NPL Site Summary Report
Militown Reservoir Sediments
Militown, Montana
U.S. Environmental Protection Agency
Office of Solid Waste
June 21, 1991
FINAL DRAFT
Prepared by:
Science Applications International Corporation
Environmental Health and Sciences Group
7600-A Leesburg Pike
Falls Church, Virginia 22043
0 q
-------
DISCLAIMER AND ACKNOWLEDGEMENTS
The mention of company or product names is not to be considered an
endorsement by the U.S. Government or by the U.S. Environmental
Protection Agency (EPA). This document was prepared by Science
Applications International Corporation (SAIC) in partial fulfillment of
EPA Contract No. 68-WO-0025, Work Assignment Number 20. A
previous draft of this report was reviewed by Julie DalSoglio of EPA
Region VIII [ (406) 449-5414], the Remedial Project Manager for the
site, whose comments have been incorporated into the report.
(,I
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Mining Waste NPL Site Summary Report
MILLTOWN RESERVOIR SEDIMENTS
MILLTOWN, MONTANA
INTRODUCTION
This Site Summary Report for the Milltown Reservoir Sediments site is one of a series of reports on
mining sites on the National Priorities List (NPL). The reports have been prepared to support EPA’s
mining program activities. In general, these reports summarize types of environmental damages and
associated mining waste management practices at sites on (or proposed for) the NPL as of February
11, 1991(56 Federal Register 5598). This summary report is based on information obtained from
EPA files and reports and on a review of the summary by the EPA Region VIII Remedial Project
Manager for the site, Julie DalSoglio.
SITE OVERVIEW
The Milltown Reservoir Superfund Site is located in Milltown Valley, 5 miles east of Missoula,
Montana (see Figure 1). The valley ranges from .75 to 1 mile in width and stretches 1.5 miles
upstream of Militown dam. The Milltown dam was built in 1906 and 1907 below the confluence of
the Clark Fork and Blackfoot Rivers. The Milliown Valley separates Mount Sentinel, with an
elevation of 5,806 feet, and Bonner Mountain, with an elevation of 6,813 feet above sea level. The
Towns of Milltown and Bonner are the main population centers in the study area (Reference 1, page
3).
The Milltown Reservoir Superfiznd Site is one of four Superfund Sites in the Clark Fork River Basin.
The Clark Fork River Basin Superfund Sites encompass the largest geographic area of all Superfund
assignments in the United States (U.S.) (Reference 2, page 1). All four sites have the potential to
contaminate the Clark Fork River. The three other sites, located upstream of Milliown Reservoir
along the Clark Fork River, are the Anaconda Smelter site, the Silver Bow Creek/Butte Area site, and
the Montana Pole site. Contamination at these sites, except for the Montana Pole site, is primarily
the result of mining activities. Contamination at the Montana Pole site is due to wood-treating
wastes.
The MiHtown Reservoir was designated as a Superfund Site in 1983 after arsenic was discovered in
four Militown community wells at levels between 0.54 and 0.90 milligrams per liter (mg/I) Lcompared
to the Maximum Contaminant Level (MCL) of 0.05 mg/I) (Reference 3, page 1). The Milltown
Reservoir Site consists of three Operable Units: Milltown Water Supply, Clark Fork River
1
-------
Militown Reservoir Sediments
M i i i
sow
CREEK $ITL
LOCATION OF
SUPERFUNO
$ITES
UONTANA
IAhO
CLARK FORK RIVER
DRAP4AQE iA3ii
FIGURE 1. LOCATION OF SUPERFIJND SITES IN THE CLARK FORK RIVER BASIN
UILITOWN SITE
I. ISSi
‘1
ANACONDA SMELTER SITE
‘U
IISII 5wØ
w*. SI Sea
£N*CO.•A (
—. — — —— / e*FVNIT I
• (I--J
oppoavusi’
PONDS \
NI r
jI CD III
CO s S IIY
2
-------
Mining Waste NPL Site Summary Report
Sediments, and Militown Reservoir/Sediments (Reference 4, page 20). A Record of Decision (ROD)
for the Milltown Water Supply Operable Unit was signed by the Regional EPA Administrator in
1984. Remedial activities at this Operable Unit included constructing a new drinking water well in a
hydraulically separate aquifer, cleaning the existing water distribution system, replacing household
water supply appurtenances, and ongoing sampling of the residential water system (Reference 5, page
1; Reference 6, page 1). These activities were completed in 1985 (Reference 4, page 39). The
Superfluid provided funds for the remedial activities at this site (Reference 4, page 39). The
estimated capital cost (in 1984 dollars) for this remedial action was $272,714, and annual Operation
and Maintenance (O&M) costs are $4,238 (Reference 2, page 1).
The Atlantic Richfield Company (ARCO) is currently performing a Remedial Investigation/Feasibility
Study for the Milltown Reservoir/Sediments Operable Unit to determine the need for, and possible
solutions to, the clean-up or containment of contaminated reservoir sediments and ground water
(Reference 8, pages 1 and 2). In addition, EPA was scheduled to conduct an Endangerment
Assessment concurrently with the ARCO Remedial Investigation/Feasibility Study (Reference 9, page
6). A final ROD is expected in 1994, pending completion of the Endangerment Assessment.
The Clark Fork River Operable Unit was redesignated from the Silver Bow Creek/Butte Area
Superfund Site to the Milliown Reservoir Superfund Site in 1990. The Clark Fork River Operable
Unit stretches 120 miles from Warm Springs Pond (at the Silver Bow CreeklButte Area Superfund
Site) to the Milltown Reservoir (Reference 4, pages 20 and 39). Contamination of the Clark Fork
River and the river banks has resulted from the transport and deposition of mine tailings from the
mining operations in Butte and Anaconda (Reference 4, page 39).
OPERATING HISTORY
The Milltown Dam was constructed in 1906 and 1907 below the confluence of the Clark Fork and
Blackfoot Rivers to provide hydroelectric power. A portion of the Dam was destroyed by dynamiting
to save the structure from total failure due to heavy flooding in 1908. The Dam was repaired and has
been in continual operation since 1908. The reservoir created behind the Dam is approximately 180
acres and appears as only a slightly widening of the Clark Fork and Blackfoot Rivers (Reference 7,
page 1-3).
Although mining, milling, and processing activities were never conducted at this site, the reservoir
has accumulated large volumes of river-borne sediments from upstream mining areas of Anaconda and
Butte. Sedimentation from mining-related activities has been determined to be the source of both
surface- and ground-water contamination in the area (Reference 7, page 1-1). Mining operations in
3
C,’
-------
Millto ii Reservoir Sediments
the Clark River Basin began with the 1864 gold discovery in Butte. Since 1864, there have been over
500 mines and shafts, and several smelters and milling operations developed. The result is an
estimated 3,000 miles of interconnected tunnels and mine shafts and approximately 150 major
unreclaimed waste piles (Reference 4, page 35). Mining wastes from these areas were discharged
directly into tributaries of the Clark Fork River. These wastes, containing arsenic, cadmium,
copper, iron, lead, and zinc, were added to the normal sediment load (Reference 7, page 1-3).
The Milliown Reservoir is subject to considerable sediment accumulation from both the Clark Fork
River and Blackfoot River watersheds. The Clark Fork and Blackfoot Rivers drain approximately
3,710 square miles and 2,290 square miles, respectively (Reference 7, page 1-3). In 1984,
Woessner, et al., estimated that the reservoir contains 120 million cubic feet of sediment. Assuming
a density of 1.8 grams per cubic centimeter (glcc), this translates into approximately 6.5 million tons
of sediment (Reference 1, page 106).
SITE CHARACTERIZATION
The 180-acre Militown Reservoir has been a sink for contaminated sediments since it was constructed
in 1906. These sediments have been determined to be the source of both surface- and ground-water
contamination (Reference 7, page 1-1). The Clark Fork River may continue to carry sediments into
and out of the Reservoir and deposit sediments further downstream (Reference 10, page 325). The
primary constituent of concern is arsenic.
Sediments
Sediments contaminated with heavy metals that originate from the Butte/Anaconda mining, milling,
and smelting areas have been transported by fluvial processes and deposited along the banks of the
Clark Fork River and in the Milltown Reservoir. The area and vertical extent of contaminated
sediments and variability of sediment composition in the Milltown Reservoir has been estimated by a
number of sources, including Arsenic Source and Water Suonly Remedial Action Study. Milltown
Montana: Final Report (Woessner, et al., 1984); Draft Milltown Reservoir Feasibility Study
(Harding Lawson Associates, 1986); and Application for Amendment of License - Militown Project
No. 2543 (Montana Power Company, 1985) (Reference 7, page 2-12).
In 1984, Woessner, et al., estimated the Milliown Reservoir to contain 120 million cubic feet of
sediment. Assuming a density of 1.8 g/cc, this equals approximately 6.5 million tons of sediment
(Reference 1, page 106). The sediments are estimated to be 29-feet thick at the base of the Dam
4
(DID
-------
Mining Waste NPL Site Summary Report
(Reference 11, page 2-3). The extent of upstream sedimentation has not been determined, but borings
in the upstream end of the Reservoir identified 3 to 4 feet of sedimentation (Reference 7, page 2-4).
The distribution of metals in Milltown Reservoir sediments varies between location and metals of
concern. Metal concentrations in sediments are greatest in swampy and slough areas away from the
main channel of the Clark Fork River. Metals concentrations in the Clark Fork Arm of the Reservoir
are 5 to 17 times greater than metal concentrations in the Blackfoot Arm. Iron concentrations are
similar in both Arms of the Reservoir. Table 1 shows the results from sediment grab samples taken
from the Militown Reservoir (Reference 7, page 2-12).
Sediment cores, driven to a maximum depth of 5 feet, were analyzed for metal concentrations. The
concentrations for total arsenic, manganese, copper, zinc, lead, and cadmium all increased with depth
in the sediment cores (Reference 7, page 2-12). For example, copper concentrations from core
sampling in a swampy area of the Clark Fork arm of the reservoir increased from 1,500 parts per
million (ppm) at the surface to 10,800 ppm at a depth of 30 inches. Similarly, the concentration of
arsenic increased from 75 ppm at the surface to 1,500 ppm at a depth of 5 feet (Reference 7, page 2-
15). Table 2 shows the results of core sediment samples taken from the Milltown Reservoir
(Reference 7, page 2-16).
Ground Water
The ground-water hydrology of the Milliown study area is dominated by the permeable alluvial
deposits of the Clark Fork and Blackfoot Rivers. The underlying bedrock has extremely low
porosity. The water table ranges from 32 to 75 feet below ground level in the Milltown area. The
aquifer is recharged by the Clark Fork and Blackfoot Rivers and the Milltown Reservoir except for
extended periods of low precipitation, when the flow of ground water may be reversed, and it
becomes a source of water for the Reservoir. Generally, ground water flows northwestward, away
from the Reservoir (Reference 7, page 2-3).
Ground-water sampling conducted in 1984 by Woessner, et al., showed the ground water to have a
sodium-bicarbonate chemistry type. Woessner, et al., found that ground water recharged primarily
from the Blackfoot River had lower concentrations of Total Dissolved Solids (TDS), iron, arsenic,
and manganese than ground water recharged primarily from the Clark Fork River. The aquifer to the
east and northeast of the Reservoir was found to be uncontaminated. This aquifer is recharged by the
Clark Fork River (upstream of the Reservoir) (Reference 7, page 2-15).
5
C.
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Militown R mvolr Sediments
TABLE 1. SEDIMENT QUALITY IN GRAB SAMPLES MILLTOWN RESERVOIR SEDIMENT’
I_________ _________ Woessner,_et al. 19842
BF - Blackfoot
CF - Clark Fork
n - Number of samples
NA - Not analyzed
‘All metals concentrations are mean totals [ in micrograms per gram (jtglg)J.
2 Woessner, et al.; Arsenic Source and Water Suoply Remedial Action Study. Militown. Montana: Final Report ;
1984.
3 Upstream of CF from reservoir sediments; Grab Sample Numbers 24, 26, 27, 28, and 31.
4 Harding Lawson Associates, Draft Militown Reservoir Feasibility Study ; 1986.
5 Application for Amendment of License - Milltown Project No. 2543 ; Montana Power Company; 1985.
‘Fotal levels in the soil at which adverse effects to plants may occur. Levels are dependent on plant species and soil
type, and may vary according to season.
Source: Reference 7, page 2-13
6
BF
Grab
CF
Grab
CF Grab
Upstream 3
lILA
(1986)’
MPC
(198S)
MPC
(1985)’
11
23
5
24
5
NA
As
7.7
58
43
207
NA
3-28
Mn
281
1,290
763
2,926
921
1,470
Fe
21,163
22,855
19,530
14,4.00
NA
NA
Cu
40
449
316
1,310
604
1,920
Zn
128
1,767
875
1,900
2,361
200-300
Pb
18
68
54
171
60
550-2,000
Cd
0.68
6.2
3.8
7
11
100
Ba
NA
NA
NA
36
NA
NA
Cr
NA
NA
NA
36
NA
NA
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Mining Waste NPL Site Summary Report
TABLE 2. MEAN SEDIMENT QUALITY OF CORE SAMPLES MILLTOWN RESERVOIR SEDIMENTS’
Woessner, et al. 19842
BF
CF
MPC
HLA
EP Tox
Mean
EP Tox
Max
EP Tox
Standard
Core
Core
(1985)
(l986)
(mg/I) 3
(mg/I) 3
(mg/I ) 3
6
64
17
81
17
As
6.4
320
18
199
0.024
0.07
5.0
Mn
255
1,648
702
922
54.6
844
NA
Fe
19,457
—
16,160
14,000
0.07
0.34
NA
Cu
37
2,182
1,140
1,296
0.14
0.80
NA
Zn
52
4,045
1,248
1,923
3.3
10.7
NA
Pb
19
262
109
166
0
0
5.0
Cd
0.98
15.2
16
—
0.018
0.07
1.0
Ba
—
—
162
203
0.35
0.80
100
Cr
—
—
27
—
0.07
0.31
5.0
— - Data not available (variations in results may be due to different analytical techniques used).
‘All metals concentrations are mean totals (milligrams per kilogram (mg/kg)].
2 Woessner, et al.; Arsenic Source and Water Sunnlv Remedial Action Study. Militown. Montana: Final Report ;
1984. Mean includes core depths up to 5 feet.
3 Montana Power Company; Ai,nlication for Amendment of License - Milltown Proiect No. 2543 ; 1985. Includes
samples from discrete depths at 3 to 4.5 feet (n=5); 8 to 9.5 feet (n=5); 13 to 14.5 feet (n=4); and 18 to 19.5 feet
(n=3).
‘Harding Lawson Associates, Draft Milltown Reservoir Feasibility Study ; 1986. Mean includes core depths up to 25
feet.
‘From 40 Code of Federal Regulations 261.24.
Source: Reference 7, page 2-16
7
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Militown Reservoir Sediments
EPA’s Technical Enforcement Support contractor for Zone 4, SAIC, estimated that the ground-water
flux from reservoir sediments into the alluvial aquifer carries the following amounts of metals:
arsenic, 18 pounds per day (lbs/day); manganese, 260 lbs/day; copper 23 lbs/day; zinc, 124 lbs/day;
and iron, 920 lbs/day. These figures were calculated using data reported by Woessner, et al., and
assuming a permeability of iO centimeters per second (cm/sec) [ 0.028-feet per day (ft/day)] for fine-
grained reservoir sediments, a gradient of 0.002, and 186 acres of Reservoir sediments (Reference 7,
page 2-15).
Ground-water sampling by Woessner, et al., indicated that the ground-water contaminant plume
extends downgradient of Militown Dam to the area northwest of the Blackfoot River and the
intersection of U.S. Highway 10 and Interstate 90. Harding Lawson Associates confirmed ground-
water contamination in this area, but did not determine the full extent of the contaminant plume. In
addition, Harding Lawson Associates indicated that the ground-water plume has the potential to
upwell and contaminate the Clark Fork River downstream of Milltown Dam (Reference 7, page 2-17).
Surface Water
Limited surface-water data has been collected to date, but data included in a 1989 Work Plan Scoping
Document, prepared by Camp Dresser & McGee, Inc., for the Montana Department of Health and
Environmental Sciences (MDHES), indicated that concentrations of arsenic, copper, and possibly
zinc, as well as Total Suspended Solids (TSS), increase from upstream to downstream of the Militown
Reservoir (Reference 7, pages 2-10 and 2-11). In addition, the mean metal concentration for copper
has exceeded Ambient Water Quality Criteria during sampling periods (Reference 7, page 2-1 1).
ENVIRONMEWI’AL DAMAGES AND RISKS
Initial interest in the site began in May 1981, when arsenic was found in four community supply wells
at concentrations ranging from 0.54 to 0.90 mg/I. In August 1981, residents were advised not use
water from these wells for potable purposes (Reference 3, page 1). In 1983, EPA and MDHES
initiated a Remedial Investigation to determine the environmental characteristics and the type and
extent of contamination in the Milltown area (Reference 4, page 39). Testing conducted during this
investigation indicated that contamination appeared to be hydraulically confined to the uppermost
aquifer in the present area (Reference 5, page 3).
In 1983, vegetables from two gardens in Milltown were analyzed for arsenic. Tests by MDHES
laboratory showed spinach to have an arsenic level of 2.66 ppm, lettuce had a level of 1.41 ppm, and
two rhubarb plants had arsenic levels of 1.1 and 0.2 ppm, respectively (Reference 12, page 1).
8
‘I
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Mining Waste NPL Site Summary Report
Levels of arsenic and copper in two plant species growing in the Militown Reservoir were studied and
were compared with levels of arsenic and copper in the same species located in the Blackfoot River
(representative of background concentrations). The study found that arsenic and copper levels for
both species were greater in the Reservoir samples, with the greatest levels occurring in the east
section of the Reservoir (in the roots of the plants) (Reference 13). Specific data is presented in
Table 3 below.
TABLE 3. CONCENTRATIONS OF COPPER AND ARSENIC IN PLANT SPECIES
I Mean Concentration (in ppm) dry weight
Blackfoot River Reservoir East Section
A 1988 study by the U.S. Fish and Wildlife Service also analyzed for levels of metals in plants and
fish in the Militown Reservoir. The report presented only total assays with no reference data or
sample location information (Reference 14. pages 11 and 18). Specific data is presented in Table 4
below.
ND - Not detected
TABLE 4. METAL CONCENTRATIONS IN PLANTS AND FISH
Concentration range (in ppm dry weight
9
Species
Arsenic
Copper
Arsenic
Copper
Cattail (root)
Sedge (root)
13.6
13.9
55.0
265.0
41.8
26.0
164.0
365.0
Species
Arsenic
Cadmium
Copper
Lead
Zinc
Plants
Smanweed
Sedge
ND
ND-3.0
ND
ND-O.73
7.8
3.3-14
1.9
ND-1.5
160
91-150
Fish
Rainbow Trout
Peamouth
Northern Squawfish
Longnose Dace
Redside Shiner
Largescale Sucker
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
11
2.0-7.1
1.3-2.4
5.3
2.1-3.4
ND
ND
ND
ND
ND
160
46-79
30-59
160
42-43
L
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Militown Reservoir Sediments
REMEDIAL ACTIONS AND costs
The Milliown Reservoir was placed on the NFL in 1983 (Reference 4, page 31). The Remedial
Investigation/Feasibility Study began in 1983 for the Water Supply Operable Unit (Reference 3, page
1). An interim ROD was signed on April 14, 1984, and described the two selected actions:
abandonment of the existing ground-water supply and replacement and relocation of water supply and
transmission facilities (Reference 5, page 1). The actions were funded and completed in 1985
(Reference 7, page 39). A supplemental ROD was signed on August 7, 1985, and described two
additional measures: replacement of household water-supply equipment (as needed to reduce
contamination) and on going sampling at residences (Reference 6, page 1).
Additional studies were completed to determine if releases of hazardous substances, pollutants, or
contaminants have occurred, or have the potential to occur, downstream from the Reservoir. ARCO
had started working on the Remedial Investigation/Feasibility Study for the Milltown
Reservoir/Sediments Operable Unit in 1990 (Reference 9, page 6). The main objectives of the
Feasibility Study include (Reference 8, page 2):
• Clean-up of contaminated ground water
• Clean-up/control of submerged contaminated Reservoir sediments
• Clean-up/control of contaminated soils and exposed sediments.
In addition, EPA will conduct an Endangerment Assessment to evaluate any present or future risks
that the sediments pose for human health and the environment (Reference 9, page 6). Work groups
are currently evaluating Risk Assessment work plans to assess the effects of contamination on public
health, fisheries, and wetlands, and continued releases from the Reservoir (Reference 8, page 2).
CURRENT STATUS
An interim ROD for the Milltown Water Supply Operable Unit was signed April 14, 1984. ARCO is
currently conducting an Remedial Investigation/Feasibility Study, under a Consent Order (signed on
April 25, 1990) for the Milltown Reservoir/Sediments Operable Unit (Reference 15). Phase I of the
site investigation was completed in October 1990. The completed work included seismic surveys,
continuous ground-water level recorders, water-level measurements, water-quality samples, and the
installation of monitoring wells. Validation of historical data has been completed. Ground-water
velocity data has been collected. Interim final work plans have been completed for the Risk
10
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Mining Waste NPL Site Summary Report
Assessment (Reference 16, page 21). Planning has begun on the Clark Fork Operable Unit efforts,
and it is anticipated that site characterization will begin in early 1991 (Reference 4, page 31). EPA
must complete an Endangerment Assessment prior to a final ROD. A final ROD is expected in 1994
(Reference 4, page 31).
11
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Militown Reservoir Sediments
REFERENCES
1. Arsenic Source and Water Supply Remedial Action Study, Militown, Montana: Final Report;
W.W. Woessner, et al., University of Montana, Department of Geology; 1984.
2. ROD Issues Abstract, Superfund Record of Decision: Militown Site, Montana, EPA ROD R08-
84-001; EPA; 1984.
3. Remedial Alternative Selection, Milltown Reservoir Sediments Site, Militown, Montana,
Superfund Record of Decision: Militown Site, Montana, EPA ROD R08-84001; EPA; 1984.
4. Clark Fork Superfund Sites: Master Plan; EPA and MDHES; 1984.
5. Record of Decision: Remedial Alternative Selection, Replacement Potable Water Supply,
Superfund Record of Decision: Milltown Site, Montana, EPA ROD R08-84-001; EPA; 1984.
6. Supplemental Superfund Record of Decision: Militown Site, Montana (Supplement to April 14,
1984, ROD); EPA; 1985.
7. Revised Final Remedial Investigation Completion and Feasibility Study Work Plan for the
Militown Reservoir Sediment Site; SAIC; 1990.
8. Milltown Superfiind Site Report Update; EPA; 1990.
9. Clark Fork Basin Superfund Sites Progress; EPA and MDHES; 1990.
10. “Copper, Zinc, and Arsenic in Bottom Sediments of Clark Fork River Reservoirs — Preliminary
Findings,” Clark Fork River Symposium: January 1986; C. Johns and J. Moore; 1986.
11. MilItown Reservoir Sediments Site Hydrogeologic Investigations Sampling and Analysis Plan,
Document Number 3496-001-200, ENSR Consulting and Engineering; 1989.
12. New Release; Montana Department of Health and Human Services; July 22, 1983.
13. “Accumulation and Partitioning of Arsenic in Emergent Macrophytes in a Reservoir
Contaminated With Mining Wastes” in the 6th International Conference for Heavy Metals in the
Environment, Volume 1; C.E. Jones; 1987.
14. Selected Trace Elements in Biological Samples Collected at the Milliown Superfund Site; U.S.
Fish and Wildlife Service; May 1988.
15. Fact Sheet; EPA Region VIII; 1990.
12
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Mining Waste NPL Site Summary Report
BIBLIOGRAPHY
ENSR Consulting and Engineering. Milltown Reservoir Sediments Site Hydrogeologic Investigations
Sampling and Analysis Plan, Document Number 3496-001-200. 1989.
EPA. Milltown Superfund Site Report Update. 1990.
EPA. Record of Decision: Remedial Alternative Selection, Replacement Potable Water Supply,
Superfimd Record of Decision: Militown Site, Montana, EPA ROD R08-84-0O 1. 1984.
EPA. Remedial Alternative Selection, Militown Reservoir Sediments Site, Militown, Montana,
Superfund Record of Decision: Milltown Site, Montana, EPA ROD R08-84-001. 1984.
EPA. ROD Issues Abstract, Superfiind Record of Decision: Milltown Site, Montana,
EPA ROD R08-84-001. 1984.
EPA. Superfund Record of Decision: Milltown Site, Montana, (Supplement to 4/14/84 ROD).
1985.
EPA and MDHES. Clark Fork Basin Superfund Sites Progress. 1990.
EPA and MDHES. Clark Fork Superfund Sites: Master Plan. 1990.
EPA Region VIII. Fact Sheet. 1990.
Johns, C., and I. Moore. “Copper, Zinc, and Arsenic in Bottom Sediments of Clark Fork River
Reservoirs — Preliminary Findings,” Clark Fork River Symposium. January 1986.
Jones, C.E. “Accumulation and Partitioning of Arsenic in Emergent Macrophytes in a Reservoir
Contaminated With Mining Wastes” in the 6th International Conference for Heavy Metals in the
Environment, Volume 1. 1987.
Montana Department of Health and Human Services. New Release. July 22, 1983.
SAIC. Revised Final Remedial Investigation Completion and Feasibility Study Work Plan for the
Milltown Reservoir Sediment Site. 1990.
U.S. Fish and Wildlife Service. Selected Trace Elements in Biological Samples Collected at the
Milltown Superfund Site. May 1988.
Woessner, W.W., et al. (University of Montana, Department of Geology). Arsenic Source and
Water Supply Remedial Action Study, Milltown, Montana: Final Report. 1984.
13
( Co
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Milltcmi Reservoir Sediments Mining Wastes NPL Site Summary Report
Reference 1
Excerpts From Arsenic Source and Water Supply Remedial Action Study,
Militown, Montana: Final Report; W.W. Woessner, et al.,
University of Montana, Department of Geology; 1984
-------
Final Report
ARSENIC SOURCE AND WATER SUPPLY RE1 IM. ACTION iuut
LL1 VN, MONTANA
Prepared for
Solid Waste Bureau
Montana flepart ent of Health and £twtronmentdl Setencec
Helena, Montana
Prepared by
William W. Woeganer and Johnnia N. Moore
Carolyn Johns
Mann A. Popoff
teglie C. Sarton
Mary Lou Sulltvan
Department of Geology
University of Montana
Mtssoula, Montana
July 31, 1984
V
-------
3
sedtments were suspected to be one of the sources of ground—water
contamination. With the ground—water system delineated and the source or
sources of contamination identified, the potential. for an uncontamtnate
ground—water supply to replace the affected one could be evaluated.
SITE DESCRIPTION
This section is intended to provide the reader with a brief overvjei
the study area. It describes the physiography, citmate, geology, and
hydrology.
PHYSIOGRAPHY
Militown Valley lies along a northwest—trending sectton of the Clark Fr
River five miles east of Missoula, Montana (Figure 1.1). The valley rangE
from three—quarters to one mile in width and stretches about one and one—1
mites upstream from Milttown Dam. The Mtlltown Reservoir, south of MLtltr
is formed behind Militown Dam at the confluence of the Clark Fork and
R1ackfoot rivers. The valley separates 5,806 feet high Mount Sentinel
southwest of the reservoir from. 6,813 feet high Bonner Mountain and the Ga
Range located to the northeast. The towns of Mtlltovn and ! onner are the
main population centers in the study area and Champion InternationaL operc
a plywood and stud mill immediately north of Militourt (Figure [ .2).
CLIMATE
The study area has a semi—arid climate with an average annual
precipitaton of 13 inches. May and June are the wettest months and March
driest. Temperatures average 22.70 F during January, the coldest month,
( D l
-------
106
of this sediment stored to the reservoir.
At the dam, the difference to elevation between the reservoLr surface
and the tailwater lit the base of the dam represents the maximum possible
sediment thickness. By finding the point where the river still follows its
gradient (acts Like a river rather than a reservoir) we can identify the
upstream posttton of reservoir sediment accumulation. Using these two
limits, the outline of the present reservoir then represents the maxiiuaum
area under which sediment can accumulate (Figure 4.3). Admittedly this is
an approximate estimate because it does riot take into account the
irregularity of the channel before reservoir sedimentation. ut by removing
the volume of water now remaining above the sediment surface (present
channels) we can get art “order—of—magnitude” approximation of the volume of
sediment residing in the reservoir. This volume is sigotfttcanc: 3.4
million cubic meters of sediment (120 million cubic feet)! Assuming a
density of 1.8 glee this translates into approximateLy 6.1 x iol2 grams (6.5
million tons) of sediment. Clearly the reservoir has acted
like a sediment trap since its construction.
CHARACTERIZATION OF SEDIMENT
The complex interplay of channels, floodplain and chalveg environments
of depoetcion has created a mosate of sediment types and grain sizes in the
reservoir. Grab samples and cores of the sediment (Ftgure 4.4) show that
the main channels contain the coarsest sediment, and the swampy thaiwegs arid
floodplatns are rich in organics and mud. The channel of the Blackfoot
River contains very coar..—grained sediment, mostly gravel and cobbles, that
could not be sampled. Clay content of the reservoir sediment ranges from I
to 32% with all the Blackfoot samples containing Less than 20% clay with a
mean of 10.5 % (Figure 4.5, Table 4.2). CLark Fork arm sediments contain
63 .i
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Militown Reservoir Sediments Mining Wastes NPL Site Summary Report
Reference 2
Excerpts From ROD Issues Abstract, Superfund Record or Decision:
Milltown Site, Montana, EPA ROD R08-84-OO1; EPA; 1984
(J
-------
ROD ISSUES ABSTRACT
Site : Malltown Reservoir Sediments, Montana
Region : VIII
AA, OSWER
Briefing Date : March 21, 1984
SITE DESCRIPTION
The Militown Reservoir Sediments site is located in Missoula
County, Montana. The site is adjacent to the Mi].ltown Dam where the
aig Blackfoot River joins the Clark Fork River. Constructed in 1906,
this hydroelectric dam formed a reservoir that trapped sediments from
mining, milling, and smelting operations in the upper Clark Fork
Valley. During the years since construction, the reservoir storage has
been almost totally filled with arsenic contaminated se- s. In
May, 1981, Milltowns four community water supply wells -. - round to
be contaminated with arsenic and other heavy metals. The nignest
arsenic levels measured have been between 0.54 to 0.90 milligrams per
liter (mg/I).
SELECTED ALTERNATIVE
The selected remedial alternative consists of: construction of
new well from a hydraulically separate aquifer; construction of a nt..
distribution system; flushing the plumbing system r’ ‘ house to
remove suspended materials from the water syste and
testing the water quality in eac :ouse to ass .. senic
standard has been met. The cap.t cost for ::. - alternative
is estimated to be $262,714 and annual O M costs are $4,238.
ISSUES AND RESOLUTIONS
1. The affected community requested EPA to deve-
lop a new water supply system with increased
capacity to accommodate fire protection de-
mands in addition to normal domestic uses.
EPA considered th proposal but decidid that
the increased cost of fire protection was
beyond th. scope to remedy a contaminated
water supply. The reason for this decision
was that there was no previously existing
fire protection system. It was recommended
KEY WORDS
• Alternate Water
Supply
• Community Services
Enhancement
• Fire Protection
• Shared Cost
—1—
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MiIfto Reservoir Sediments Mining Wastes NPL Site Summary Report
Reference 3
Excerpts From Remedial Alternative Selection, Milliown Reservoir Sediments Site,
Militown, Montana, Superfund Record of Decision: Milltown Site, Montana,
EPA ROD R08-84-OO1; EPA; 1984
I ,
-------
RECORD OF DECISION
REMEDIAL,, ALTERNATIVE SELECTION
REPLACEMENT POTABLE WATER SUPPL!
Site : Militown Reservoir Sediments, Milltown, Montana
Analysis Reviewed :
I have reviewed the following documents describing the
analysis of cost—effectiveness of alternatives for a replacement
water supply at the Militown site.
— Militown Water Supply and Distribution System Study
Robert A. Peccia and Associates, December 198].
— Fire Protection System — Milltown Study
Robert A. Peccia and Associates, February 1984.
— Staff summaries and recommendations; and
— Recommendation by the Montana Department of Health and
Environmental Sciences (MDHES).
Description of Selected Option :
— Abandonment of existing Milltown ground water supply and
distribution system that has been affected by leaching of
heavy metals from reservoir sediments.
— Replacement and relocation of Milltown Water Users
Association water supply and transmission facilities
with a capacity of 0.29 MCD.
Declarations :
Cons is tent with the Comprehensive Envi ronmental. Response,
Compensation and Liability Act of 1980 (CERCLA), and the National
Contingency Plan, I have deter-mined that an alternative water
supply for the Milltoun Reservoir Sediments site is a cost-
effective remedy, and that it is a key action which is necessary
to effectively mitigate and minimize damage to public health,
welfare and the environment. I have deternined that this action
is approoriate when balanced against the need to use Trust Fund
money at other sites. Should individual houses not meet the
arsenic standard after flushing and testing, a Supplemental
Record of Decision may be considered.
3020602
100002
-------
- —2—
A Supplemental Record of Decision will be submitted for
consideration upon the completion of the State of Montana’s
technical analysis and evaluation of source control remedial
actions. --
- \ __ .
Lee M. Thomas
Assistant Administrator
Solid Waste and ergency Response
Office of
Date
( /O
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REMEDIAL ALTERNATIVE SELECTION
MILLTOWN RESERVOIR SEDIMENTS SITE
MILLTOWN, MONTANA
HISTORY
The Militown Reservoir Sediments site Is located in Missoula
County, Montana. The site is adjacent to the Milltown Dam where
the Big Blackfoot River joins the Clark Fork River, Constructed
in 1906, this hydroelectric darn formed a reservoir that trapped
sediments from mining, milling, and smelting operations in the
upper Clark Fork Valley. During the years since construction,
the reservoir storage has been aJ.most totally filled with these
sediments.
In May 1981, Milltown’s four community water supply wells
located betweer. Interstate 90 and the Burlington Northern railway
tracks were found by local lkealth officials to be contaminated
with arsenic and other heavy metals. The highest arsenic levels
measured have been between 0.54 to 0.90 milligrams per liter
(mg/i), up to 20 times the maximum Contaminant Level established
by EPA in the National Interim Primary Drinking Water Regulations.
Ingestion of arsenic in sufficient quantities can lead to
abdominal pain, vomiting, coma or death.
Residents were advised by State health officials on August 20,
1981, not to use waters from the affected wells for potable
purposes. Initially, the thirty—three residences supplied from
these wells were without a temporary water supply; the affected
populace obtained water from neighbors or businesses with uncon—
tainirtated well3. During the summer of 1983, volunteers using
National Guard equipment began supplying residents with potable
water from a tank truck, driven door—to—door bi—weekly. No source
of bottled water exists in the area.
In July 1983, the remedial investigation (RI) was formally
begun through a Cooperative Agreement with Montana Department
of fleaLth and Environmental Services (MDHES). An initial task
of the RI was to determine the source and extent of contamination
to the existing drinking water supply. In December 1983, the
consultant identified the sediments as the cause of ground water
contamination as well as identifying the present distribution
and likely future disposition of the contaminants in the water
supply. A focused feasibility study (FS) was begun in October
1983 which examined alternative water supplies to Milltowrt. The
feasibility study recommended a replacement ground water system
and extending an existing fire protection system Into the affected
area.
3020602
100003
-------
—3—
CURRENT STATUS
the contaminated reservoir sediments continue to pollute
Milltown’s weLls. Remedial investigation testing indicates this
contamination appears to be hydraulically confined to the
presently contaminated area. Lower aquifers do not appear to be
contaminated. Ongoing monitoring will deter uine the extent and
direction of the plume.
ALTERNATIVES SCREENING
The feasibility study initially considered five alternatives
(see table 1). Implementation of any one of t e five alternatives
would result in a potable water aystem that would provide residents
with uncontaminated water, The alternatives ere screened on the
basis of technical feasibility and costs of ImpLementation. No
alternative was considered that would have involved ingestion of
untreated water from the Milltown reservoir, due to health hazards.
The no action alternative would continue to provide bottled
water as a long term remedy. There is no local source of bottled
water available. Bottled water is currently being supplied by
the National Guard and is a very inconvenient and insufficient
supply for bathing. Because of the public health and welfare
considerations, this option is rejected. The remaining alternatives
were all, judged effective in protecting health, welfare, and the
environment. Alternative 1 was to connect the area to the
p unicipal supply of the City of Missoula. The cost of this
action is over twice the capital and twice the O&M costs of the
recommended alternative and was therefore rejected. Alternative
2 was to provide a new surface water treatment plant to the
area. The costs of this action are over twice the capital costs
and five times the O&M costs and was therefore rejected. Alternative
3 would treat the source of contamination at each existing well
head with a small treatment facility. The capital costs were
twice that of the recommended alternative and five times the
cost for 0&M and was therefore rejected. Alternative 5 was to
buy—out the community and relocate the residents. This alternative
was not only costly (3 times the capital costs of the recommended
alternative) but disruptive to the community and not necessary.
This alternative was therefore rejected.
Should houses not meet the arsenic standard after flushing,
further remedial, measures would be studied and ay be recommended.
At this time there is insufficient information to determine how
many houses would be affected and the extent of action required.
(The State and EPA do not expect any of the houses to fail, the
arsenic standard but this cannot be guaranteed in advance.)
Even if substantial remedial work is required to provide taps or
replace plumbing, Alternative 4 is clearly cost effective when
compared to buy—out of the community (Alternative 5). AlternatiVe
4 COStS $270,751 compared tO $829,000 for Alternative 5.
(,(; .21
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Militown Reservoir Sediments Mining Wastes NFL Site Summary Report
Reference 4
Excerpts From Clark Fork Superfund Sites: Master Plan; EPA and MDHES; 1984
(,LI ±1
-------
CLARK FORK SUPERFUND SITES
MASTER PLAN
U.S. Environmental Protection Agency November 1990
Montana Department of Health & Environmental Sciences
,
-------
OPERABLE
UNIT
ACTIVITY
TIME FRAME BY QUARTER
.
Militown
•
fl/IFS
1.99Q
4th
1*
1991 1992 1993
2nd 3,d 4 1.6 d 4th lit
Water
Supply
—
Clark Fork
RVFS
• —
RIver
—
— — — — — —
MiDtown
iip
— —
— —
— — — —
Reservoir/
— — — — — — — —
Sediments
Implementation A 1
— — . InvestigationlPlannjng • Public Involvement
OPpOttUnity
Public involvement is on-going. TheO indicates
specific periods of involvement. The public is
encouraged to stay involved throughout the process.
Clark Fork River Operable Unit
EPA and MDHES have reorganized
operable units to move responsibility for
the Clark Fork River operable unit from
the Silver Bow Creek/Butte Area site to
the Milltown Reservoir site. The Clark
Fork River operable unit stretches downstream from the
confluence of the discharge from the Warm Springs
Ponds and Warm Springs Creek to the Milltown Reser-
voir. The area is affected by a number of environmental
problems. Where Warm Springs Creek enters and
becomes the Clark Fork, it provides generally good
quality water and sustains a trout population
immediately below the confluence, However, the next
20- to 30-mile river segment shows general deterioration
of the fishery and water quality, and there are many ob-
vious areas of tailings deposits.
Although there is a general improvement in the fishery
farther downstream toward Missoula, mining-related
wastes still impact the river adversely. The agencies
want to. know how much contamination from mining,
milling, and smelting wastes is either presently or poten-
tially affecting the Clark Fork. The Clark Fork Screen-
Ing Study, anticipated to be completed in January1991,
—20—
will help answer this question; however, further study will
be needed to better understand the present and future
movement of contaminated sediment and dissolved
metals downstream into Milltown Reservoir. Recogniz-
ing this need, EPA plans to initiate a remedial investiga-
tion and feasibility study on the Clark Fork River
operable unit in 1991.
While EPA is studying many factors that contribute to
the environmental problems of the Clark Fork, an
ARCO-funded reclamation demonstration project is cur-
rently underway immediately downstream from the
ponds. It is evaluating several alternative actions,
including:
• Selective tailings removal;
• Streambank stabilization;
• Addition of lime to reduce metals mobility; and
• Revegetation of tailings and contaminated soils.
EPA and MDHES will incorporate into the Clark Fork
Riveroperable unit remedial investigation and teasebeliry
study all appropriate information gained through the
Streamside Tailings and Revegetation Studies ni iated
(.PLI 1
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APPENDIX B
INITIAL ACCOMPLISHMENTS:
MAKING PROGRESS IN THE CLARK FORK BASIN
Many human health and environmental problems at
the four Clark Fork sites are the result of mining, milling,
and smelting activities that have taken place in the Butte
and Anaconda areas since 1864. Problems at the
Montana Pole site and some contaminants at the Rocker
operable unit of the Silver Bow Creek/Butte Area site
relate to the use of organic compounds in wood
treating activities.
EPA began initial investigations of the upper Clark
Fork basin in 1982. Results of these investigations
prompted EPA to place the Silver Bow Creek, the
Anaconda Smelter, and the Milltown Reservoir sites on
the Superfund National Priorities List in 1983. Following
subsequent investigations, EPA added the Butte Area
and upper Clark Fork between Deer Lodge and Milltown
into the study area of the Silver Bow Creek site in 1987
Also in 1987, EPA added the Montana Pole site to the
National Priorities List as a separate site. Wastes from
the Montana Pole site had been addressed earlier in a
removal under the Silver Bow Creek Site.
EPA and MDHES have completed or have overseen
completion of significant amounts of work at the four
Superlund sites. What follows is a description of the
sites, their operable units and problems, and studies
and cleanups that have been conducted or are under.
way as of October 1990. These activities also are
described in greater detail in technical documents and
information sheets that EPA and MDHES have prepared
for individual sites, For copies of information sheets,
please contact either agency at the addresses shown on
page 9.
SILVER BOW CREEK/BUTTE AREA SITE
The Butte and Walker-
ville area is the location of a
very large ore body that has
____ been mined for copper,
_________ lead, zinc, molybdenum,
gold, and silver. The Butte
gold rush began in 1864, when prospectors discovered
gold in Baboon Gulch. By 1884, there were more than
300 operating copper and silver mines, 4,000 posted
,
claims, nine silver mines, and eight smelters. Over the
course of mining activities, more than 500 mines and
shafts were developed, and several smelters and mill.
ing operations were added. The result is an estimated
3,000 miles of interconnected underground workings
and approximately 150 major unreclaimed and re-
claimed waste rock dumps. These dumps, covering
approximately 350 acres, contain an estimated
9,850,000 cubic yards of waste. In addition, two major
tailings piles, the Colorado Tailings and the Clark Tail-
ings, encompass about 100 acres and contain an
estimated 1,250,000 cubic yards of material. At least
eleven silver and gold mills and three major smelting
operations also resulted in soil and water contamination
throughout the Butte Hill mining area.
Remnants of Butte and Walkerville’s mining history
constitute a potential hazard to human health and the
environment. Toxic metals from mill tailings and waste
rock dumps throughout the Butte area have con-
taminated and continue to contaminate significant
amounts of soil in the Butte area. Even though some
disturbed areas have been regraded, topsoiled, and
reseeded, potential environmental and health impacts
from both historical and modern mining operations
remain unresolved.
Human health concerns prompted removal actions at
Walkerville and Timber Butte. Residential yards at
selected properties were replaced, while waste rock
dumps were remedied and reclaimed. Initial removal
actions at Walkerville were completed in 1988 and
Timber Butte in 1989. In addition, EPA initiated a removal
in 1989 at the Travona mine shaft to divert and treat con-
taminated mine waters to prevent uncontrolled flow to
surface and ground water. After treatment, this water is
being discharged into Silver Bow Creek.
In June 1990, EPA began a time-critical removal
action on contaminated soils, which focuses on con-
tamination “source areas” in Butte. In addition, this
removal includes residential yards and areas affected by
an ore concentrate spill that occurred in 1978. EPA has
begun the remedial investigation and feasibility study
that will address mine flooding problems in the Butte
—35—
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an interim solution to health risks posed by arsenic and
other heavy metals at this location.
In September 1988, ARCO agreed to conduct addi-
tional investigations at Smelter Hill, Old Works, and Flue
Dust operable units. These activities will build upon the
earlierwork byARCO. In March 1990, ARCO agreed to
conduct accelerated removal projects on the Arbiter and
Beryllium Waste disposal sites. In addition, ARCO
agreed to conduct a mining, milling, and smelting waste
repository siting analysis on the Anaconda Smelter site.
Three potential sites were identified and discussed at a
public meeting in September 1990. A final site will be
selected by early 1991.
MILLTOWN RESERVOIR SITE
The Milltown Reservoir site is located at the con-
fluence of the Clark Fork and the Blackfoot River, adja-
cent to Milltown. The reservoir was created in 1907 when
a dam was constructed across the Clark Fork as part of
a hydroelectric power development facility. Since 1929,
the Montana Power Company has owned and operated
the project. Unusually high levels of arsenic, lead, zinc,
cadmium, and other metals were found in the approxi-
mately six million cubic yards of sediments that have
accumulated behind the dam. Contaminants in the sedi-
ments have seeped into the ground water that once
served as a water supply source for Militown. The reser-
voir was designated a Superfund site in September
1983.
In 1983, MDHES and EPA initiated a remedial investi-
gation and feasibility study on the ground water. As a
result, EPA provided funds for a new water supply sys-
tem for Milltown which was completed in 1985. MDHES
initiated additional site investigations to help determine
whether releases of hazardous substances have
occurred or have the potential for occurring downstream
from the reservoir. ARCO continues remedial investiga-
tion and feasibility study activities at Milltown under an
administrative order on consent. These studies will
address the extent of contaminated reservoir sediments
and ground water at Milltown and potential downstream
impacts from continued releases. ARCO is also directed
to assess various cleanup alternatives. In addition, EPA,
with the participation of ARCO and a local citizens
group, will be conducting a risk assessment to deter-
mine the current and potential impacts of the reservoir
and sediments on public health and water and land
wildlife.
Specific problem areas at the Milltown Reservoir site
are described briefly below.
Militown Reservoir/Sediments
Contaminated sediments transported by the Clark
Fork have accumulated in the reservoir.
• Source of ground water contamination, which was
used as a drinking water supply.
Remedy: record of decision for drinking water
supply issued; alternate water supply completed
in 1985.
• Potential source of contamination to Clark Fork
below the dam during flood events.
• Impacts to wildlife.
• Potential exposure of human populations to con-
taminated soils, sediments, and/or tailings.
Clark Fork River Operable Unit
Geographically, the Clark Fork River operable unit
begins below the Warm Springs Ponds and ends at the
start of the Milltown Reservoir, a total of 120 river miles.
Several major tributaries flow to the river. Tailings from
Butte and Anaconda mining activities were deposited
by river action along the river banks.
Releases from exposed and buried tailings, periodic
releases from the Mill-Willow Bypass, and run-off from
contaminated irrigated lands are the primary sources of
elevated metals contaminants in the river system.
Recent studies show that metals have entered the river
food chain, which may have long-term effects on the fish
population. In addition, occasional major storms have
deposited large amounts of contaminants in the river,
resulting in massive fish kills. The Clark Fork transported
contaminated sediments to the Milltown Reservoir and
may continue to add to downstream impacts. Specific
problem areas at the Clark Fork River operable unit are
described briefly below.
• Floodplain sediments contaminated by mining
wastes.
• Potential contamination of surface and ground water
irrigation and drinking water supplies.
• Wildlife impacts due to exposure to contaminated
sediments and surface water.
• Potential exposure of future human populations to
contaminated soils and/or tailings.
MDHES initiated a screening study in 1987to assess
the potential use of remote sensing techniques to iden-
tify locations of exposed and buried tailings. The study
also addressed current and/or potential ground water
contamination and impacts on agricultural lands from
irrigation with contaminated water. The screening study
will be completed by January 1991. Meanwhile. EPA will
hold meetings with potentially responsible parties,
affected land owners, local governments, public interest
groups, and citizens to assist in planning a remedial
investigation and feasibility study work plan for work that
may begin in 1991.
—39—
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MiIIto Reservoir Sediments Mining Wastes NPL Site Summary Report
Reference S
Excerpts From Record of Decision: Remedial Alternative Selection,
Replacement Potable Water Supply, Superfund Record of Decision:
MilItown SIte, Montana, EPA ROD R08-84-OO1; EPA; 1984
-------
RECORD OF DECIStON
REMEDIAL ALTERNATIVE SELECTION
REPLACEMENT POTABLE WATER SUPPLY
Site : Milltown Reservoir Sediments, Mjlltovn, Montana
Analysis Reviewed :
I have reviewed the following documents describing the
analysis of cost—effectiveness of alternatives for a replacement
water supply at the Militown site.
— Militown Water Supply and Distribution System Study
Robert A. Peccia and Associates, December 1983.
— Fire Protection System - M2lltown Study
Robert A. Peccia and Associates, February 1984.
— Staff summaries arid recommendations; and
- Recommendation by the Montana Department of Healt and
Environmental Sciences (MDHES).
Description of Selected Option :
— Abandonment of existing Militown ground water supply and
distribution system that has been affected by leachLng Cf
heavy metals from reservoir sediments.
- Replacement and relocation of Milltown W
Association water supply and transmissic:
with a capacity of 0.29 MCD.
Declarations :
Consistent with the Comprehensive Environmental Response,
Compensation and Liability Act of 1980 (CERCLA), and the National
Contingency Plan, I have determined that an alternative water
supply for the Militown Reservoir Sediments site is a cost—
effective remedy, and that it is a key action which is necessary
to effectively mitigate and minimize damage to public health,
welfare and the environment. I have determined that this action
is appropriat, when balanced against the need to use Trust Fund
money at other sites. Should individual houses not meet the
arsenic standard after flushing and testing, a Supplemental
Record of Decision may be considered.
-------
MiUtown Reservoir Sediments Mining Wastes NPL Site Summary Report
Reference 6
Excerpts From Supplemental Superfund Record of Decision: Milltown Site,
Montana (Supplement to April 14, 1984, ROD); EPA; 1985
-------
SUPPLD4ENTAL. RECORD OF DECISION
REJCDIAL ALTERNATIVE SELECTION
ADDITIONAL MEASURES TO REPLACEMENT POTABLE WATER SUPPLY
Site: Militown Reservoir Sediments 1 Milltown, Montana
Analysis Reviewed:
I have reviewed the following 4 ocuments describing the necessity for
additional measures to supplement the Record of Decision selection that was
decided on April 14, 1984, for this ilt.
- Data reports from the testing and flushing of household water systems
conducted under the remedial action approved in the 4/1V84 ROD.
— Recoemendations by the Montana Departeent of Health and Envi romnental
Sciences (MDNES).
- Monoranduin from John Wardell dated August 6, 1985 wIth attached staff
report titled Supplementary Analysis of Militown, Montana Drinking
Water Supply.
Description of Selected Options:
- Replacement of household water supply appurtenances that remain a
source for persistent arsenic and heavy metal contamination as
described in the support documentation referenced above.
- On—going sampling of individual residences to insure that the sources
of contamination have been removed.
Declarations:
Consistent with the Comprehensive Environmental Response, Compensation and
Liability kt of 1980 ( CERCLA ), and the National Contingency Plan (40 CFR
Part 300), I have determined that the replacement of water supply
appurtenances and on—going sampling of residential water systems Is necessary
to fulfill the intent of the original ROD and therefore are coat-affective
remedies, and that they are part of a key action necessary to provide adequate
erotecti on for public health, welfare and the environment. The State of
Montana has been consulted and agrees with the approved remedy. I have
determined that this action Is appropriate when balanced against the need to
use Trust Fund money at other sites.
The State Ii conducting additional rmuedial 1 nvestigation/feasibllity
study to evaluate the extent of Contamination. If additional remedial actions
are determined to be necessary, a record of decision will be prepared for
approval of the future remedial action.
II • Is
Regional Adeini strator
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Milhtown Reservoir Sediments Mining Wastes NPL Site Summary Report
Reference 7
Excerpts From Revised Final Remedial Investigation Completion and
Feasibility Study Work Plan for the Milltown Reservoir Sediment Site;
SAIC; 1990
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TZ4—C08005—WP03812
MILLTOWN RESERVOIR
SEDIMENT SITE
REVISED FINAL
REMEDIAL INVESTIGATION COMPLETION AND FEASIBIUTY STUDY
WORK PLAN
SEPTEMBER 1990
Prepared for:
U.S. Environmental Protection Agency
under
EPA Technical Enforcement Support Contract
by
Science Applications International Corporation
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1.0 INTRODUC11ON
The MiDtown Reservoir Sediments site, located east ci MISSOUIa. Montana is a National Pnor,ty
Supedund’ List site characterized by large volumes of mining, milling and smelting wastes in the
Reservoir and by uncontrolled metal and metalloid contamination ci local groundwater and attendant
potential risks to human health and the environment. In compliance with the Comprehensive
Environment Response Compensation and Uabibty Act (CERCLA) as amended by the Superfund
Amendments and Reauthorization Act (SARA) (hereinafter ‘CERCLA’), this Feasibility Study Work
Plan has been developed for the United States Enwonmental Protection Agency (EPA).
The Work Plan provides the steps and outline (or completion ci a Feasibility Study that will support
the selection of a final remedy for this site. The work tasks will be completed by the potentially
responsible party (PRP) with the oversight of EPA. in consultation with the Montana Department of
Health and Environmental Sciences (MDHES).
1.1 SITE HISTORY
The Milltown Reservoir site is located about 5 miles e of Missoula, Montana (Figure 1-1). MiDtown
Dam was constructed in 1906-1907 below the confluence ci the Clark Fork and Blackfoct rivers to
provide hydroelectric power. SInce the construction ci MiDtown Dam, the reservoir has accumulated
a large volume ci river-borne sediment. Contaminated sediments in the reservoir have been denved
from mining, milling, and smelting activities from upstream sources. These sediments have been
determined to be the source ci both surface and ground water contamination in the area (CDM,
1986 and Woessner si aL, 1984), and are subject to further release unless adequately disposed of.
The site may also be contaminated with dispersed soil contamination above the reservoir banks.
The object of this Supedund cleanup action is to remediate releases from the reservoir sediments,
and to arrange for the pennanent control of sediments to prevent further releases, to a level of
protectiveness requIred by CERCIA
Available hiswrkal irWormation indicates the town ci MiDtown was founded sometime around 1907.
1908 to house employees ci the new lumber mill at the site, which was constructed by WA Clark.
The area had been an important wood products center since 1885 when the Blackfoot Milling ad
Manufacturing plant was built in the adjacent town ci Bonner. Th. mill is cuuer*ly owned by
Champion International Corporation (Champion) and produces plywood and other wood products
1-1
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(Figure 1.2). Th. mill contains a log pond, which may be the source of organics contamination to
the aquifer.
The dam, constructed in 1906 and 1907 to provide hydroelectnc power to the mill and to Missoula,
was built using rock-filled timber cnbs housing five turbine generator units. During the flood of 1908,
which reportedly produced river flows of 50,000 cubic feet per second at Missoula, a portion of the
dam was destroyed by dynamiting in order to save the structure from total failure. The dam was
repaired and has been in continual operation since 1908. The reservoir created by the dam covers
about 180 acres and appears as only a slight widening in the Clark Fork and Blackfoot River
channels.
Since 1906, the reservoir has been subject to considerable sediment accumulation. The Clark Fork
River drains an area of approximately 3,710 square miles above Milltown and has a large capacity
for sediment transport. The Blackloot River drains 2,290 square miles. Woessner at al. (1984) have
estimated that 29 feet of sediment are present at the upstream face of the dam and that the
reservoir contains about 120 miflion cubic (2,750 acre-feet) of sediment This accumulation has
reduced the storage capacity of the reservoir over the years to its present estimated value of 820
acre-feat at the normal operating level (MPC, 1985).
The current situation in Militown is tied to historic events that occurred upstream of the Militown Dam
and Reservoir. The Clark Fork River Basin has been the setting for mining activity since at least
1864, when gold was discovered at Butte. By 1881, Butte was an important mining, milling, and
smelting center. At least 25 companies were mining copper ore at Butte in 1885 (Montana
Department of State Lands, 1981), and several mills and smelters were operated in Butte from 1885
until the 1930s. Anaconda, Montana was the site of ma or smelters and mills, which produced
several tons of mining, miwng, and smelting waste. Although Butte and Anaconda were the pnmary
mining centers, other smaller mining districts were active as well. Disposal of tailings, milling
byproducts, smelting w es, mine waste water, arid other mining, milling, and smelting wastes
directly Into rIvers and streams which are tributaries to the Clark Fork was common. These wastes,
containing concentrated arsenic, lead, cadmium, zinc, copper, and iron, were added to the normal
sediment load of the Clark Fork and transported doen rIver to the settling basin created by the
Milltown Dam.
The water supply for Mliftown has been supplied by water wall since the first recorded well was
drilled in 1908 (CH HU, 198 . Water samples of four comnuilty water supple. were taken on
1-3
I,
(9’
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(Banner) MUI (Woessner at aL 1984. page 9). The ailuMum consists 01 interbedded sand and gravel
with clay lenses (Woessner at al, 1984). The valley floor and the Surrounding mountains are
comprised of Precambnan age metasediments of the Belt Series. Recent reservoir Sediments reach
a thickness of 29 feet at the MiUtown Dam (Woessner at aL, 1984). Lithologies range from fine sand
and silt to medium sands with clay lenses.
Numerous faults Cut the complex geology 01 the area Although obscured by alluvium, the Clark
Fork Fault trends along the river valley (Nelson and Dobell, 1961), passes under the dam, and
outcrops on Jumbo Mountain east of the site. The Blackloot Thrust Faiit similarly roughly parallels
the Blackfoot River and intersects the Clark Fork Fault in the vicinity of the reservoir. The geology
is described in mare detail in the RI data reports.
2.1.3 HYDROLOGY
Ground Water
The ground water hydrology of the Milltown site is dominated by the permeable alluvial deposits of
the Clark Fork and Blaclcfoct Rivers. The bedrock units underlying the alluvium have extremely low
primary porosities and when fresh are considered water-bearing units only if fractured. The water
table in the alluvium ranges frOnt 32 to 75 feet below ground surface In the vicinity of Milltown.
based on a network 0126 wells Installed by Woessner at al. (1984). Sand points installed by
Woessner at al. (1984) in the unsubmerged reservoir sediments revealed a water table several feet
below the reservoir water elevation. Ground water In the alluvium is recharged by the rivers and
the reservoir, resulting in movement of ground water generally to the west, parallel to the two river
channels, with an added flow component generally northwestward and northward, away from the
reservoir. These flow paths merge In the vicinity of the original contaminated water supply wells and
continue generally westward parallel to the Clark Fork below Mllftown. During lower reservoir stages.
ground water In the alluvium could recharge the reservoir sediments. Steep downward gradients
010.5 to 1.0 urn are present In the reservoir sediments, while flow in the alluvium is essentially
horizontal (Woessnef at al, 1984). More racers work by Udaloy (1988) tends to support Woessner
at al yet indicates a very complex groundwater system due to the heterogeneous nature of the
alluvial/reservoir sediment aquifers.
2 . ’3
-------
Transrniss1vities di the alluvium measured by Woessner at ii. (1984) range from 170 to 13.000
ft 2 /day with velocities di between 0.17 to ao fl/day. Based on these values, estimates c i the flux
moving through the alluvium in the vicinity c i Milltown range from 1.25 million 1t 3 /day (CDM, 1986)
to 2.2 mWiori ft’fday (Woessner at al., 1984). These values are seasonal, and tend to vary in
response to nver stage.
Surface Water
The pnmaiy surface water bodies in the MiDtown vicinity are the Clark Fork and Blackfoot Rivers.
The U.S. Geological Survey (USGS, 1988) has conducted long-term flow measurements and water
quality sampling for both rivers, at established stations upstream and downstream of Militown.
These data are described in the Work Plan Scoping Document (CDM, 1989a). Both nvers are
large, with the Clark Fork maximum flow estimated at 48,000 cubic feet per second (CFS) and the
Blackfoct maximum at over 19,000 cfs. The drainage area for both rivers combined above Militown
Is about 6,000 square miles.
al.4 SEDIMENTS
Recent estimates (HLA, 1986) indicate that the reservoir contains 6.6 million yards of contaminated
fine-grained sediments (as compared to 4.4 million estimated by Woessner at al. (1984)). This
represents a significant part of the estimated initial storage capacity of the reservoir. It should be
noted that the upstream extent of these sediments has not been identified. Borings at the upstream
end of the reservoir found sediment thicknesses of 3 to 4 feet.
The RemedIal Investigation (RI), performed in 1983 and 1984 (Woessner at al. 1984), charactenzed
the reservoir sediments in the upper 5 feet only. A total di 34 grab samples and 6 sediment cores
were collected and analyzed by Woessner at al. (1984). The sediment cores were driven into the
reservoir bottom from 1.25 to 6 feet in depth and are representative only di the uppermost portion
the sediment mass. The upper 6 to 16 Inches di the cores were ligt* brown In color and oxidized:
sediment below w gray and reduced . The cores revealed a complex straligraphy that showed
evidence di scour, reworking, and redeposition with metals concentrations Increasing with depth.
The samples are descried in detail in the Work PLan Scoplng document (CDM, 1989a) and in
Woessner at aL (1984).
24
J
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he reservoir, inck ding the upland disposal slte. These probleme may result in impacts to
the local human population and the environment. Potential impacts are:
o ContaminatIon of wildlife habitat,
o Contamination of ground water near the reservoir, Including domestic water supply wells
in Militown,
o Contamination of ground water supply wells downgradient of the reservoir in adjacent
communities,
o Discharge of potentially contaminated ground water to surface waters downgradient of the
reservoir,
o Degradation of downgradient surface water quality resulting from release of contaminated
water or resuspended sediments from the reservoir and the threat of catastrophic releases
from the reservoir,
o Plant, animal, or human uptake of heavy metals through various pathways, and movement
c i these contaminants through the food thain and
o Reduction in aquatic habitat quality or habitat productivity in the Clark Fork River and in
Milltown Reservoir resulting from contact with the sediments and contaminated surface
water.
These impacts from contamination have been developed based on the RI data and results of the
Downstream Screening Study (CDM. 1989b). The extent ci contamination and potential pathways
are discussed bdefly in the following sections.
2.2.1 EXTENT OF CONTAMINATION
Metals contamination has been iderdled in surface waters (pilmanly connected with suspended
sediments), ground watsr reservoir sediments, soils, and vegetation at the Milltown Reservoir
Sediment site. Evidence for and the known extent of contamination is discussed below.
The water quality of the Clark Fodi River has been impacted by metals from mining, mifling, and
smelting activities upstream of Miltown. Mining, milling, and smelting wastes in the form c i fine-
gralned sediment have been transported via suspension or dissolution by the river. From limited
data presented in the Work Plan Scoping Document (CON 19891), It appears that total
2.10
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concentrations at copper, arsenic, and poe$ bIy ZIflC Increase from upstream to downstream of
Militown Reservoir (Aamodt. 1978), as do total suspended solids. Mean metals concentrations of
copper exceed M bient Water Ouality Criteria (AWOCs) during some sampling periods.
In MiUtown Reservoir, contaminated suspended sediments settle out, usually with organic matenal,
and are buried by subsequent deposits. Sediments deposited in the reservoir tend to be
resuspended during high flows by river scouring or during dratwdowns of the dam for mantenance.
Woesser at al. (1984) report the results of a drawdown performed by MPC on .July 7, 1980. Prior
to the drawdown suspended sediment was moving into the reservoir train the Clark Fork and
Blackfoot rivers at a rate of 4.065 grams per second. Sediment below the dam was 5.113 grams
per second, indicating re-suspension of sediment at the moderate flow rate c i 5,920 cubic feet per
second. Alter the dam Ilashboards were removed, decreasing the reservoir level by approximately
4 feet VIPC, 1985), the sediment load below the dam increased to 142,914 grams per second.
Although these results may beat limited value in accurately defining the physical mechanisms of
sediment resuspension processes , they do provide an indication that resuspension of contaminated
sediments can occur. Dam operation as described above was discontinued in 1981.
Activities in the Clark Fork River upstream ci Mifltown Reservoir have an in act on sediment loading
to the Clark Font River. Mine tailings and other mining, milling, and smelting wastes were carried
downstream from the Butte and Anaconda areas *o the Cleric Fork River without any restrictions
from the initiation of mining activities in Butte during the 1880s until 1911. In 1911, the Anaconda
Minerals Company (AMC) constructed a 20-fool.high tailings dam near Warm Spnngs, Montana. u t
an attempt to control sediment loading from Silver Bow Creek (Hydrometncs. 1983). This dam
resulted in the creation of a tailings pond, near the confluence ci Silver Bow Creek and the Clark
Fork River, which 1 known as Pond 1. An additional dam was constructed by AMC upstream of
Pond I in 1916, forming Pond 2 (Hydrometrics, 1983). Pond 3 was created by construction of a
284001-high dam which was completed between 1954 and 1959 (Hydrometrlcs, 1983). Together
these ponds are known as the Warm Springs Ponds In 1967 AMC initiated treatment of Pond 3
effluent by adding a Ilmelwater suspension to Sliver Bow Creek above Pond 3 to facilitate
precipitation ci dissolved heavy metals in the Warm Springs Ponds . An estimated 20 million cubic
yards ci tailings and sludges have accumulated In the Warm Springs Ponds since 1911 (CH2M Hill,
1988). SInce 1911 sediments have migrated down the Clark Fork during periods of high flow when
the pond system was bypassed or overtopped, after Pond I had filled with sediment and prior to
conatiuction of Pond 2, and when the pond system was not aderp y operated such as during
2-11
-------
labor strikes. In addition, waste from the Old Works area of Anaconda has migrated and continues
to migrate via Warm Springs Creek, and that Creek not intercepted by the Ponds. Hence a
significant volume of contaminated sediment may be present within the floodplain of the Clark Fork
River between the Warm Springs Pond and Militown Dam.
Below Milltown Dam in the Heligate Canyon reach Cf the Clark Fork, the valley narrows and contains
less alluvium. The Clark Fork at this point is likely a gaining reach, that is water discharges from
alluvium into the river. Surface waters In the area of Hellgate Canyon could potentially become
contaminated If the ground waters in this section were also contaminated, or if significant volumes
of contaminated sediments were released from the reservoir.
Sediments and Pore Water
Sediments contaminated with heavy metals that originate from the Butte/Anaconda mining, milling,
and smelting areas have been transported via Ituvial transport processes. Sediments have
accumulated in floodplain areas along the mainstem of the Clark Fork River (Moore, 1985b; Rice
and Ray. 1985) and behind Milltown Dam. The areal and vertical extent of contaminated sedimems
and variability of sediment composition at the Mitltown Reservoir Site have been estimated through
grab and core sediment sampling done as part c i the HI (Woesser at aL, 1984), the draft FS (HLA
1986), and by MPC (198$). AU data discussed in this section are taken from those reports. Metals
distribution in the Militown Reservoir sediments is highly variable between locations for all metals
of concern. The swampy or slough areas away front the main channel contain the highest
concentrations of metals. The Clark Fork arm ci the reservoir contains from 5 to 17 times the
concentration Cf metals present In the Blackfoot ann. Iron concentrations were similar in both areas.
Table 2-1 shows sediment grab sample metals content
Woessner at al. (1984) also analyzed pore water from the grab samples for which the data were
more variable. The distinctions between the Clark Fork and Blackfoot arms ci the reservoir were
not as condusive as with the sediment total metals results . Table 2-2 summarIzes the data for
sediment pore wae
In the RI, sediment cores , driven to a maximum ci 5 feet, were analyzed for metals and pore water.
as a function Cf depth. Total arsenic, manganese, copper , zinc, lsad, and cadmium all increased
in concentration wIth depU For example, In Core 3 taken from the northern swampy portion Cf
2-12
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TABLE 2-1
SEDIMENT OUALJTf IN GRAB SAMPLES
MILLTOWN RESERVOIR SEDIMENT’
Woess
ner at at. (1 984
HLA
(1986)4
MPC
(1985)’
Phytotoxic
L.eveP •‘
BF
Grab
CF
CF Grab
Grab Upstrearw
n 11
23 5 (1)
24
5
As 7.7
58 43 (12)
207
3-28
Mn 281
1,290 763 (600)
2,926
921
1.470
Fe 21,163
,855 19,530 (16,700)
14,400
Cu 40
449 316 (192)
1.310
604
1.920
Zn 128
1,767 875 (752)
1,900
2,361
200-300
Pb 18
68 54 (37)
171
60
550-2,000
Cd 0.68
6.2 3.8 (2.6)
7
11
100
Ba —
— — —
36
—
—
Cr -
— - -
36
-
-
Data
Source
Pages 126
126 444 (444)
19
E-75
E ..81
BF = Blackioct
cF-ClarkFok n=No. Samplea --NctAnalyzed
a All meta’ concervalons are mean totals ( g/g).
b Woessner at al., 1984, Arsenic Source and Water Supply Remedial Action Study.
c Upstream on CF from reservoir sedirnents Grab Sample Not 26,27.2824,31.
d lILA 1986, Dreft Mflltown Reservoir Feasibility Study.
e MPC, 1985, FERC Application for Alrsendmeil Ucenas.
Total levels ki the soil at which adverse effects to plans may occur . Levels are depende 1 on
— — end aol type, end may vary according to i t
2-13
0
-------
the Clark Fork ami of the reservoir ad ac.1 to Interstate 90. copper increased from I .500 ppm at
the surface to 10,800 ppm at a depth Cl 30 inches. Arsenic also increased In Core 3, from about
75 ppm at the surface to 1.500 ppm at Sleet. Table 2-3 summarizes the RI metals data for core
sediments.
Ground Water
Water samples from monitoring well networks installed by Woessner at al. (1984) and HLA (1986)
and from private wells were analyzed to determine the water quality of the alluvial aquifer. Locations
of samples and maps of observed contaminant concentrations are shown In Woessner at al. (1984)
and HLA (1986). In general, the water is a calcium-bicarbonate type. Samples from wells
completed in the upper weathered and fractured bedrock show a sodium-bicarbonate chemistry
type.
The highest values of TDS. iron, arsenic, and manganese are found in the reservoir sediments
directly north C l the reservoir, extending to about 1.300 feet north of Interstate 90. Low TDS and
metals values were observed north Cl MilItown, adjacent to the Champion plant This area is
recharged by the Blackfoot River. The aquifer east and northeast c i the site, which is recharged
by upstream ground water flow of the Clark Fork River, was uncontaminated. Based on Woessner,
at al.. 1984 and additional evaluation. EPA has concluded that the northward flow of contaminated
ground water originating from the reservoir sediments had caused contamination of a portion of the
alluvial aquifer.
Based on a permeability ci 10 cm/sec (0.028 ft/day) for the fine-grained reservoir sediments, a
gradient c i 0.002, and an area of the reservoir sediments Cl 186 acres, an estimated flux of about
250.000 1t 3 /day flows downward from the reservoir sediments into the afluvial aquifer. Based on
estimates of metals present In the pore waxer, the flux through the sediments carries the following
amounts of metals: arsenIc. 18 lbs/day; manganese, 260 lbs/day; copper, 23 lbs/day; zinc. 124
lbs/day; and Won, 920 ta/day. The above figures were estimated usIng data reported In Woesser
at al. (1984). Other flux values are presented in other studies such as Hydrometncs (1985).
The areal and vertical erdent Cl grcund water contamination upgradlerl of Mifitown Dam was
charactenzed by Woesaner at al. (1984). AddItional data collected during the supplemental field
investigations by HLA (1986) indicated that the contaminwi plume extends downgradlorl below the
2.16
-------
TABLE 2-3
MEAN SEDIMENT OUALrrY OF CORE SAMPLES
MILLTOWN RESERVOIR SEDIMENT
Woessner (1 984
BF CF MPC
Core Core (1 985)
HLA
(1 986)d
Mean
EP lOX
(mg i) ’
Max.
EP lox
(mgi)’
EP TOX
REGS
(mg/I)’
n
6
64
17
81
17
As
6.4
320
18
199
0.024
0.07
5.0
Mn
255
1.648
702
9
54.6
844
Fe
19,467
16,160
14,000
0.07
0.34
Cu
37
2,182
1,140
1.296
0.14
080
Zn
52
4,045
1,248
1.9
3.3
10.7
Pb
19
262
109
166
0
0
5.0
Cd
0.98
15.2
16
0.018
0.07
1.0
Ba
162
203
0.35
0.80
100
Cr
27
0.07
0.31
5.0
Data
Source
Pageal43-146
175,148
App. D
FIgs 3-9
App. D
AppL D
(.) Data not available. Variations W i results may be due to different analytical techniquies use.
a All values are total metals In mg/kg unless noted otherwise.
b Woessnsc et al, 1904, Arser c Source and Water Supply Remedial Aotlon Study. mean includes
samples from cars daç*hi to 5 feet.
c MPC, 1985, FERC Applicetlon for Amendment c i License - mean Inc ud samples from discrete
depths a 3 to 4.5 (n —S) 8 to 9.5 (n—S) 13 to 14.5 (n —4) and 18,0 19.5 (n —3) feet.
d HLA, 1986, Dralt Mlllcwn Reseivoir Feeslb y Study - mean Widudes samples from core depths
to 25 1et.
e Source: 40 cIT 26124 (-) No EP TOX regulation values easigned.
2-16
-------
dam to the area northw of the Blackfoot River and east of the intersection of Highway 10 and
1.90. However, the HLA (1986) InvestigatIon did not determine the full downgradient extent of
contamination. Umited sampling of walls was conducted due to low raseivoir stage, resulting in
many dry wells downgradient. Water level measurements by HLA (1986) also indicate a potential
for upwelling of contaminated ground water to the lower Clark Fork River.
Veaetation
Plant uptake of heavy metals le subject to variables that may Include inter-specific and sub-specific
genetic variation, climate, phenology, and physical ctiaracteilstlcs of the site (soils) as well as plant
availability of the metals. Based on work by Rennicic and coworkers (1984) and summanzed by
MPC (1985) various plant species growing on flooded or seasonally-saturated sedimems may
contain slightly elevated levels of arsenic, cadmium, and copper at the Militown site. Available
information on vegetation uptake of metals at the site is summarized m the Work Plan Scoping
Document (CDM, 1989a).
2.2.2 POTENTIAL CONTAMINANT PAThWAYS AND RECEPTORS
At the Milltown site, the environmental media of concern include surface water, ground water.
sediment and soils, and air. Potential contaminant pathways and receptors may be summanzed as
follows:
Media Pathwai ,
1. ground water ingestion/contact humans, wildlife
ingestior contact aquatic if e*
2. surface water incidental ingestion/contact humans. wildlife
ingestion/contact aquatic life
3. sediment incidental ingestion/contact humans. wildlife
inhalation humans, wildlife
ingestion/contact aquatic life
4. air Inhalation humans. wildlife
The effect of ground water on aquatic life depends upon the degree to which
ground wat& discharges to the surface water system.
2-17
— I ’
-------
Militown Reservoir Sediments Mining Wastes NPL Site Summary Report
Reference 8
Excerpts From Milltown Superfund Site Report Update; EPA; 1990
-------
Update May1990
MiDtown Superfund Site Report
By the US. Environmental Protection Agency
I TROOUCTXOI
The Atlantic Richfield Company (ARCO) viii begin field work
shortly for a Remedial Investigation/feasibility Study under the
oversight of the U.S. Environmental. Prstection Agency (EPA). [ The
Montana Department of Health and Environmental Sciences (PIDHES) vi ] ,],
continue to work in conjunction with EPA in th. remedial process at
Nilitovn.] EPA offers this update to inform residents and other
interested individuals of the Remedial Znvestl.gation/ Feasibility Study
objectives and of ARCO’s sampling plans.
In an experimental effort to involve the concerned public. EPA has
included a guest column from the Militovn EPA Superfund Site (NESS)
committee. The HESS committs• is an active participant in the remed2.al
process at the Mi1 .ltovn site and has useful comments on cit2.zen
involvement in the Sup.riund process.
I ortant Sote
Scue renders In Ui• Nilltovn/Iemn.r ares may have bees contacted by
ARCO seeking access agreements to do sampling work on local property.
Others will be contacted later. If those contacted have any questions
call Pea at the USDA at (405) 449—54 14 or I-$00— 54$—$4 5S (is state).
. — I
- ____
Inf ormatcnal Meetrig
What? Mother Superfuad Public Neetinqi
EPA is holding an intoruetional public meeting Wednesday Hay 23. 1990.
at 7:30 p.m. at the Sonnet School Music Roe.. EPA will detail field
york objectives, and ARCO representatives viii explain field techniques
and activities. EPA encourages residents of the Superlund site area
and ether concerned citizens to attend, ask questions, and learn about
activities planned for this field season.
-------
n, edial znv.stiqation/reasibtiity Study
The objective of the feasibility study is to identify and evaluate
alternatives for cleanup of site Coltta mination. Cleanup dSCi 5i vs,’
be based on data gathered during the remedial investigat o a a .
supplemental fi.id Investigations. including the r3.sk assess
Sased on the feasibility study, a final remedy viii be selected b r.&
in conjunction vitli NONES.
The central objectives of the feasibility study remedy select
I. Cl.anup of contaminated ground water.
2. Cleanup/control of submerged contaminated reservoiz
sediments.
3. Cleanup/control of contaminated soils and exposed
sediments.
Rationale for Sampling locations
The location and extent of additional ground water and sediment/so ,L
sampling was determined after analysis of existing data.
1. Q nd
Moni Thqves will be nstaiied in the area north and east of
the Milltevn Dam and vest of the Slackfoet River to gain ground water
information necessary to define and remediate the contamination plume.
The agencies and ARCO will determine the cites of the three nev wells
after surveys of the local geology and discussions vita landowners.
The nev monitoring veils and other existing veils will be sampled
to define the extent of contamination. The agencies and MCD have a
tentative list of 30 existing veils to be sampled. The list may change
based on permission to sample, access to an opening on the veil head,
condition of the veil, and continued evaluation of existing data bases.
MCO vili install additional monitoring veils if analytical
results indicate that elevated levels of arsenic are migrating into the
ground water from the Nilitovn Reservoir.
2. nt m
ARCO vi ta a three s iment samples to further characterize the
chemistry of the sediments. Each sampling location is representative
of other unsampied areas. Area I is located in the Nilltovn Reservoir
directly upstream of the da.i Area 2 is in a former channel of the
Clark Fork River (close to Nilltovfl)a and Area 3 is in the southeast
slough area directly upstream of the former railroad crossing (Banner
Junction). Exact sampling locations vill be refined based on
additional data collected through the ground water investigation.
Status of lick Aieesmaaat Usrtpiaas
The rish assessment viii characterize the threat to human health or the
environment fro. the Nilltevuu site. EPA set up york groups to increase
the efficiency of the assessment. These groups are producing
independent vorkpians. but viii continue intergroup cauniestion.
i. p a - Interim PAnel Norkplan
The ma vex p s coep etc. EPA Is vritinq a sampling and
analysis plan to direct the investigations. A survey of the public to
determine arme2c exposure vill bs conducted late summer/early fail.
2. • Interim PAnel W.rkplaa
The ma vorkpiaa is complete. It includes a fish toxicity study
(to find out if the fish are affected negatively) and sediment
analysis. EPA . 5 discussing funding and division of tasks internally.
3. Wt.Isndi - Pins Draft
The iiIi di york group is responding to comments an the final
draft vorkplam. The study proposes a tiered approach to assess
contamination vithin the vetlands community. EPA has initiated a
wildlife survey and vetiands definition. EPA is discussing division of
tasks internally.
4. Continued eleases from the Reservoir
The workgroup has met several, times to discuss the scope and
ob3ectivee of the, study. They agreed on general parameters of t! s
study objectives. EPA needs assistance from additional tecnnica
experts to vrite a vorkplan.
UPDATE
-------
MiIlto ii Reservoir Sediments Mining Wastes NPL Site Summary Report
Reference 9
Excerpts From Clark Fork Basin Superfund Sites Progress; EPA and MDHES; 1990
-------
PRO GRESS
of metals to soils and waters.
The U.S. Environmental Protection Agency
(EPA) and the Montana Department of Health and
Environmental Sciences (MDHES) Investigate arid
clean up Superfund sites in Montana. Periodi-
cally, the agencies produce public information on
site activities. This progress report summarizes
current Ckrk Fork Basin Superfund activities.
where the public can obtain more information
and how they can get more involved in the Super-
fund process
Clark Fork sites have colorful history
Four Superfund sites lie In the Clark Fork
Basin from Butte to Missoula. 138 river miles.
The Clark Fork sites include the Silver Bow
Creek/Butte Area. Montana Pole. Anaconda
Smelter and Milltown. Except for the Montana
Pole site. contamination at the sites Is primanly
mining wastes and heavy metals-laden soils and
water. The Montana Pole site which lies adjacent
to the Silver Bow Creek/Butte Area site in south-
western Butte is contaminated with wood treating
wastes
EPA and MDHES have designed a coordi-
nated plan emphasizing efficient Investigation and
cleanup of the sites In 1988. EPA published a
Clark Fork Master Plan This summer. EPA will
publish an updated and expanded Master Plan
Both the coordinated plan and the Master Plan
priorilve the activities of 25 operablc unils and
77 smaller problem areas of the Clark Fork
Superfund s Ies The Master Plan also includes
work underway by other agencies conducting
studies_In the basin
Printed os: recycled paper
May 1990
Clark Fork Basin Superfund Site ’
By the Montana Department of Health and Environmental Sciences
and the U.S. Environmental Protection Agency
Introduction
Superfund remediation activities are pro-
gressing at a rapid pace this spring in the Clark
Fork Basin Superfurid sites. Major events include
accelerated cleanup of the Mill-Willow Bypass.
emergency soils removal In Butte, and a study of
the Colorado Tailings, which is scheduled for
cleanup In 1991. More than 100 years of mining
have left a hazardous legacy along Silver Bow
Creek and the Clark Fork. Millions of tons of
tailings, rich in heavy metals, have contaminated
soils. groundwater and surface water. Planned
remediation activities will lessen the contribution
Inside
Silver Bow Creek/Butte Area 2
Montana Pole 4
Anaconda Smelter 5
Milltown Reservoir Sediments 6
Document repositories 7
Superfund hotline 7
Off iicial contacts 7
Clark Fork map 8
C I )
-------
Milltown Reservoir
Sediments
The Militown Dam is located on the Clark
Fork River about five miles southeast of MIUOUIS
below the Clark Fork’s confluence with the
Blac oot River. The darn was built In 1906 and
has been leconstructed three times during this
cernwy. The Militown Dam creates a slow flow.
ing area of Clark Fork water where sedniients
contaminated with mining wastes can settle to
the bottom of the reservoir. The darn holds back
between 4.5 and 6 r flfrir cubic yards of contami-
nated sediment. In 1983. the EPA , a2wipd Mill.
town Res ’oir a Superfund stte after arsenic
was diacoveled In groundwater In the MiDtown
c un*ty wells. The arsenic had migrated tram
the reservoir sediments Into the groundwater.
EPA and MD $ replaced the Militown coimnu-
mty wells with two new wells in 1985.
C & t £ ftViti
ARCO has agreed to perform a ramedlal
Investlgauon/f,a,4hthzy study at the site begin-
ning this spring. These investigations will lead to
the developm.nt of a varisty of alternatives for
cleaning up the site. The public will have the
opportunity to evaluate and ITnent an those
alternatives, before one is selected.
Concurrent with the remedial Investigation
EPA will conduct an Endangerment Assessment
to evaluate any present or future risks that the
sediments pose for human health and the envi-
ronment. This study is critical for property
evaluating cleanup alternauves. Including the no•
action alternative which is required by Superfu-d
guidance.
A cit n c iinnuttee continues to be active : i
ti ormg and contributing to the progress of the
Endangerment Assessment. The Mllltown EPA
Superfund Site (M.E.S.S.) eowmfttee is cornpnsed
of area residents who represent a “arlety at inter
ests Including the State. Missoula County. the
Lcague of Women Voters, residents of Militown
and Sooner Junction. and many private Interests
Since its formation one year ago the committee
has becuwe Involved In all aspects of site activi-
ties from planning to Investigation. Members
meet regularly with EPA and MDHES staff to
discuss arid resolve issues and concerns. The
group is Led by Phil Tourangeau. staff scientist (or
the Clark Pork C ’ n based In Missoula.
I — —l
ARE YOU ON OUR MAILING LIST?
Periodically. MDHES and EPA publish progress reports not only about the Clark Fork Basin
sites In general. but also about spsoi5c sites. If you did net receive this report by mall. please (ill
out this form and send it to: Pam Hlfl . U.S. EPA. Drawer 1009 . 301 South Park. Helena.
59626.
‘Name
Address
I Ctty.State
1 Z lp
All Clark Fork Basin sites — Militown — Silver Bow Creek —
I Butte Area — Montana Pole ____ Anaconda Smelter ___
L..
PROGRESS
6
-------
Militown Reservoir Sediments Mining Wastes NPL Site Summary Report
Reference 10
Excerpts From “Copper, Zinc, and Arsenic in Bottom Sediments of
Clark Fork River Reservoirs — Preliminary Findings,” Clark Fork River Symposium:
January 1986; C. Johns and J. Moore; 1986
-------
NOTE: This paper will be published in he Proceedings of the Clark Fork
River Symposium. January L 86.
COP! EK, ZINC, ARSENIC IN EOT OH SDIHF.NTS OF
c: z FORX IV!t kE3kavOLRS——?REu IL , Ry FLMjU .CS
Carolyn Johns and Johnnie 1oors
Ceo Loky Departmert
..n&versity of Nortaiia
hissoula, .t 5 8I2
Abstract——Acetic ac extracts of sediments from four . ark Fork P...ver e er—
voirs.—— ’ iltoun. Thompson Falls. Noxo Rapids. and Cabinet Corgo—— t d ca:s
that minnc and inciting operations in th. upper drainaRe havo ennichec ?.cai
concenc: :tons chrougnout the river. illtown Reservoir contains metal values
over O :.:ss th iack&round L evels for copper, ainc, and arsenic. ni:n:. c
over background decreases downstream where the lower reservoirs contain copper
and zinc concentrations 4 to IC times over bock reunJ values. In t) e 1 .cr
reservoirs arsenic L not elevated over background. These trends suggest c .ac
contamiliants have beun transported over 350 niles from he major sourac of
netala TT the upper drarnage and very Likely reside in he sediments c c e
Clzr& Fer.i River delta in Lake Pend Ureille.
L RODUC ON
The Clark Fork River originates in the Anaconda-butte region frcn he
confluenae of Silver Bow Creek, L1 Creek, .Llew Creek. and Warm Springs
Creek. siLver Sew Creek has received waacus iron r.ing activities in et:e
and a series of three settling ponds were built on its Liver reach to c:ncair.
smelting wastes from ore processing at the ..asrioe co;ip.r smelter n Anaconda.
nttl e settling ponds were constructed in L 54—5S, m&r.ing anc 5OS ti
operat cins discharged wastes directly into the cree’ . and these w. stes :oved
into the Clars Fork River unimpeded and untreated. Cver the interval from ::e
1080’s until the mid—1950’s. many thousands of tons of cC:luont found their
way int.i the upper Clark roth River drainage. Since tn. construction o: :..
settlim ponds and the subsequent liming treatment or the nduscr ai vasc..
contaminant input to the river from the ponds decreased dramatically except
for a f cv occasions when the dikes were breached.
— In addition to the miming and sneicieg vactes transported downstream ir
the r ver. river—borne tailings have been deposited across the flood plain in
the Deer Lodge Valley. causing significant impacc to riparian systems (:or
example. 7,8). RemobiLization of contaminated flood plain sediments may
provide a .irce of conti usd contaminant input to the C ark Fork River ( ).
the extent of the impacts to the river and adjacent rxparz.an areas dovnstro..:
have not been fully delineated.
In ovember 1981 the Montana Department of Health and Environmental
Scieness discovered elevated arseniC Levels in water from tour ceamunicy
-------
• $ .
cr tkin; e l la Li .:own, Mon agta. Arsenic concentrations rangcd fr : .::
:o 0.51 : /L in the wells. These levels caused immedi ce Concern on ch Mtt
o Sca:$ a e local i ealth officials since the Feceral Sai Cin ing ac.r
Scanu rd for or enic spscif es 0.05 rn JL as t.a upper s (ety . u. .
recon—. aance h:4rc eoLo;ical study i enctf ed ur possiols sources of :..e
dL en C acar r.acion: .) a wood products er:h of the v Ls, ) :.
a:a .c irdus : . Cunp southeast of th wgL s, (3 the adjacent
es,r’.j :: con ning n unknown quantity of s ei n; . nd ninin 5 sdincnt fro:
.c.r. and C-) a deep bedrock iround waccr system unaerl,. t . c cortcor.i-
-.i:ed aser:o :r (: .
:.ccing previous :ork on heavy metal concentrations in cne accu:u ated
-eservair se. e-c ). we thought that he rsscrvoir would be u :.sc
prabab o source of the well contamination and oota&nsd sour grab sacp.ss :
sei enc in February 1982 by cutting througn he it.. These seGment s:p
n:ain d 5.. to 135 ug/g arsenic, 5 to 95 ig,’g lead, 259 c L357 -b
— ancsc, and 66 ta Zn 0 gIg zinc. As a result of chm hv@rolcg.: work .
t i S On petaL evsis, the F.nvironmcntal i’rotsCtLOn Agoncy ?A) ran ei
: n k ,cr’ oir s i ce i9 of the initial ..C0 Super und cas. : .
.‘.:‘ L)c3 vs b.;ar. d s: dy of iLLtovn Heserve r seciment. as part of a
er.cdia funded by EPA and the ontana State Solid and ! azardous
:., t. l.i;cau to cva&ua :Q the sediments as the Likely source of arsenic conta..—
c.f :ne ou d hater in tllltown. e fcund arsenic, copper. zic. ar.a
other bCOvv :.cat co icenc;acions to be highly an4 significantly elevated :ii
tha Clar. Fork ar a.i he 1town Raservoir aa compared to both the 3lackf not
a of the rgservcir and leveis reported in the literature (5.,).
P: .l.:ovn Reservoir is thu first mayor inpeundmsac below the s .Lcing ond
mmmd cisermc s in :ne Anaconda—Butte area and may have trapped east ot c e
scdenc—:oirLud netals. However, uccasmonal releases from the Warm Sprmn
settLing ponda nave cocurrod and eyewitness reports cell of the Clirk Fork
River “ nnzr.g re ’ with sediment (ILC. Averotte, USCS atsr P.*oi.r: s
Dm ..iioni. If tho red” sediment contained Large am uncs of heavy metals anc
arser.mc, some portion may have continued to repositories downscr.am fram
llcown Reservoir. Addition of sediment from chur Large tr bucar es
r. ::errooc, FLichead. Joc&o. and Thompson R versi below illcown nay r aje
cm u:ed he meta.. passing through Mmllto n s that the reservoirs dc screa
:a c relatively uncontaminated. To expior. for the lever bour. ary f
ono smelting impacts to the Clark Fork River, e sampled bottom sed ..anca :r...
three oow strsam i: oundn.nts—Thompson Fails. ozon, ar.o caoinec o;;c
Raservu;rs——co I CC whether the sediments concamr.so elsvated hdavy :.ata a
arssnmc svals.
hs objectives of this paper are threefold: ( ) to summarize f ndmngs a:
mlcowm F esarvomr for comparative purposes; 2) to present sariv d n;s
from sediment extracts from the three downstream reservoirs; and (3) to
examin, some prslimir.ary dovnnver trends in arsenic, copper, and zmno canoen—
trarions in the reservoir bottom sediments.
PHYSICAL SET?I C
illtowm Reservoir. the first major impoundment on the Clark Fork iv.r,
Lisa approximately uS river miles downstream from the arm Springs Porics
(img. 1). The ressrveir i formed by a small dam built in 1907—38 at the c;n-
fluance of the Clark Fork and Diacktoot Rivers and is currently owned ; :n .
Montana Power Company. The dam presently contains five turbines wtu.ch prod CI
from 2.5 i at low flow to a maximum of 3. kW at ht;h flow (Phil Smith, m5.
oncar.a Power Company, Missoula). The Miiltowr. Reservoir itself is sra
onLy arout 1.23 miles in total length. The resirvoir as full of sed1m rt JAd
s therefore quits shallow chrOughoet sxcspt for the two main clmaiuiusls f
Clark Fork and Ilackfooc Rivers. Due to the lirge quantities of sedm:e
.324—
-------
..— ... • —
Ft$ re .. L.sset.s sap. I, tLlltovn Rsurve ; , Th. son Fai s ss
3, iss Lap s R servo$r; ‘. Cabtn.t Cues L.s.r’v.tr.
already u Lased. the rss.rvstr probably M L. pr stores t ch r e’ ss. :.nc
es4 east s! lb. rscsse uapsde4 sedlasat load o ib. CLsrr. F, tI : ::a:’
pus is iris$h lbs reservoir and on downstrsag.
second sajor t:aovnds enI Os the river is : . tloz; cn Fa . i
rwtad ar aporaled by ancana Pover C.upuy. C L ss Øpro:...ac.. •
43.vl.:rsas iros t’e ara Sprtn;a Panda. &: . resarv.ir ar:ao
s iii. rdLUivelv sail, 4 prozLD1ts1y 2 aLl.. : eLi.cttve 1.i : I
Ctar Lork chuasl bisects ih r.sarv &r into sb Uovai so’ IP.drr. a-: - - -
portions. ‘ace •t Pa sedtnante its sandy; stall arias o ssd&. n
CS ss1tLo 5 occur al u$ he bands.
—32S•
I
‘p
()
‘i
1
t
/
‘p
I
/
S
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Militown Reservoir Sediments Mining Wastes NPL Site Summary Report
Reference 11
Excerpts From Milltown Reservoir Sediments Site Hydrogeologic Investigations
Sampling and Analysis Plan Document Number 3496-001-200,
ENSR Consulting and Engineering; 1989
-------
ENSR Consulting and Engineering
(Formerly ERT)
Attorneys At Law
Billings, Montana
November 1989
Document Number 3496 OO1-2
Milhtowii Reservoir Sediiiients Site
Hydrogeologic hives tigatioiis
Sampling and Aiia lysis Plan
Holland and Hart
-------
Figure 2—2 is a site topographic map based on aerial photographs
taken August 17, 1989 when the reservoir was near a historic low stage.
2.3 Geoloqy,1!ydroqeoloqy
2.3.1 Geology
Information on the geology and hydrogeology of the study area is based
on Woessner et a].. 1984 and A 1987. Further details are provided in the
geologic map shown in Figure 2-3. Th study area is a wide alluvial
valley at the confluence of the Clark Fork and Blackfoot Rivers. The
valley is underlain by Quaternary alluviue deposits and Precambrian mate—
sedimants. Valley alluviue consists of both laterally and vertically
interbedded sand, gravel, and boulders with scma clay lenses. This complex
configuration of sedimant fades results from an apparent variation in
location of the Clark Fork channel over tima. This material is exposed on
both sides of the Clark Fork River and underlies recent reservoir sedimants
near the Milltown Dam. The reservoir sedimants consist of dark gray fine
sand to silt, often grading into brown to gray, generally poorly graded
sands with occasional lenses of light gray clay (IRA 1987). The thickness
of recent reservoir sedimants is estimated at 29 feet at the base of the
dam (Woessner et al. 1984). Well drillers’ geologic logs analyzed by
Woessner et a].. (1984) indicate that the alluvial deposits generally
thicken north of the reservoir and reach a depth of 155 feet within the
southern bo mdaries of the thampian Mill site.
Precambrian matasedimants of the Belt Series underlie the valley
alluviue. Argillite, quartzite , and limastone crop out on Mount Sentinel,
Bonner Mountain, and Sheep Mountain located near Milltown. Several
diabase sills and dikes intrude the matamorphosed sediments along the
argiUite—quartzite contact near the dam and on the slopes of Sheep
Mountain.
Structurally, the study area is complex. The metasediments north and
east of the Clark Fork River are folded, forming the Bolmer Mountain
anticline. The anticline is overturned west of Bonner and north of
Nilitown. Locally, a syncline of quartzite on Mount Sentinel plunges
towards the reservoir. The Clark Fork Shear Zone and the Sapphire Thrust
system further complicate the structure in this area. The Blackfoot
2—3
/
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Militown R ervoir Sediments Mining Wastes NFL Site Summary Report
Reference 12
Excerpts From News Release; Montana Department of Health and Human Services;
July 22, 1983
F)
-------
STATE OF MONTANA ‘
Department of Health and Environmentai Scienc
NEWS EL.EASE CONTACT: Vic Andersen
DATE 7/22/03
NELSNA——Relalivsly high ievsls of arsenic in v.gsubl.s taken fre, MIIlt n gardens
are no cause for alarui, but certainly reason for caution in conssi tion. Official;
of the hontani Dspartnant of Health and Environmental Sciences warned Friday.
A g the vegetablss frau tim gardens In the comeunity 5 miles east of Plisioula,
which were tested in the departitont’s laboratory, spinach shsw.d the highest arsenc
level at 2.66 parts per mIllion (pp..), a lettgc. sap.ls was 1.1.1 ppm., im rP ubarb
sapolus checked out at 1.1 end .2 ppm. and a radish lest registered .82 ppm.
Yb Anderesen, “Superfund” coordInator for the dspartosnt’s solid was;. ‘nunagemsivt
bureau, and Cal Capmb.ll of the food and consuner safety bursau announced the lateit
development in Mllltowm’s continuing arsenic pollution problem.
80th explaIned they were unable to determine a safety standard for the arsenic
levels in vegetables although they had checked with the U. S. Food and Drug Adainistra
and the Csncers for Disease Control in Atlanta.
For cop.arison, hmmver, they noted the background or nornal existence levels for
arsenic In vegetables shuied .001 ppm. for spinach and lettuce, .05 for such plant;
as rhubarb, and .012 for root vegetables such as radishes.
Another copeerison, med. by Cap.b.ll, was the U. S. parvesnt of Agriculture
“action” levels for arsenic in meat products fre, cattle at .7 ppm., swine at .5,
and dilckn and turkey also as .5, and liver ranging fro. 2.7 in cattle to 2 lv i swine,
— chicken and turkey. The action level is the point at whIch the product is restricted
frau eans. tlon and wlthdrmen fr i. rkats.
Saying, ‘Mien it coemi to public health, we’d rather err en the safe side, the
health officials iaslzed Milltown residents who had cansi d smell or sporadic
imts of their garden vegetables had no cause for alarm, “But our advce s net
3 t )!.14fl3
to cantlnue eating the..”
100
Nnavy natal aubscancea, such as arsenic, r in and collect in eh. body
So. although It might be safe to consie. snail ae,unts, continued usege coulo cad
to •ccijlations of dangerous levels, they noted.
Andersen sa,d the departoent will continue lasting vegetables. includ.’g iO5e
produced in nearby areas with good water, and will detarmin• what the ‘iaii raY
existing level of arsenic might be.
He believes the arsenic iiight be coning into the plants through l.a a ,c- on.
but will be checking further on flood—irrigated plants as well as chose . i’ are
(mere)
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Milltowu Reservoir Sediments Mining Wastes NPL Site Summary Report
Reterence 13
Excerpts From “Accumulation and Partitioning of Arsenic in Emergent Macrophytes
in a Reservoir Contaminated With Mining Wastes” in the 6th International
Conference for Heavy Metals in the Environment,
Volume 1; C.E. Jones; 1987
-------
iai&ei lidLiUlicti LUIIIt 1 eii&.e
Heavy Metals
in the
Environment
Volume 1
New Orleans — September 1987,
Editors: S E Lindberg
T C Hutchinson
1
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• lean Arsenic Concentrations in Rough Sedge
Militown Reservoir
Plant Organ B lackteot South Central East
Leaves
0 • 4 d
L 6 b
44 a
th .tzomes
2.2°
118 b
1S.
24.1
Roots
418 b
67 • 6 b
438 b
164 ’
M .1 msana are backtrarteform.d from log 10 except ].&v.s are (lOx)log, 0 .
All concsntrat .ons are ug/g, dry wt. basis. N • 3.
Means followed by diff rent letters, across rows, are different at
P(O.05 (T-Method, Sokal. and Rohif, 1981).
Mean Copper Concentrations in Rough Sedge
Militown Reservoir
South Central
Plant Organ
Slackfoot
East
Zaaveu
6.1°
208 a
135 b
178 a
Rhiz ss
7.9
798’
60.8©
461 b
Roots
26.OC
365’
176 b
235 gb
All concentrations are uq/g. dry wt. basis
All means are back-transformed from log 10 .
Means followed by different letters, across rows, are different
at P (0.05 CT—Method of Sokal and RohIf, 1981).
/
-------
\‘
Mean AXICttLC Concentrations in Catte 1s
Leaf tops
03 b
09 a
Leaf bases
a.lsc
03 b
07 a
Rhizomeg
2 . 5 C
91 b
255 a
oota
13 • 6 b
55 a
AL ]. concentrat Ions are uqfg, dry wt. basis
Means for roots and rhizoses are back-transformed from
log 10 . Means for Leaves are back—transformed from
(lOx) 1eg .
Means followed by different letters. across rows, are
djfferent at P(O.05 (T-Method, Soka]. and Rohif, 1981).
Mean Copper Concentrations in Cattails
Leaf tops
4 • 6 b
55 b
109 a
Leaf bases
39 b
53 a
59 a
5 • 7 c
241 b
45 55
toots
239 c
148 b
265 a
All concentrations are uqig, dry wt. basis.
All means are back—transformed from leg 10 .
Means followed by different letters, across rows. are
different at p (0.05 CT—Method of Sokal and Rohlf, 1981).
Plant Organ
M.tlltevn Reservoir
Blacktoot South East
Plant Organ
Mi .lltown Rsservo .r
S1ackfoot Sout i East
1•
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MiIlto iii R ervoir Sediments Mining Wastes NPL Site Summary Report
Reference 14
Excerpts From Selected Trace Elements in Biological Samples Collected at
the Milltown Superfund Site; U.S. Fish and Wildlife Service; May 1988
-------
SELECTED TRACE ELEMENTS IN BIOLOGICAL SAMPLES
COLLECTED AT THE MILLTOWN SUPERFUND SITE
Submitted to
U.S. Environmental Protection Agency
Federal Building, Drawer 10096
301 South Park
Helena, Montana 59601
by
Division of Fish and Wildlife Enhancement
U.S. Fish and Wildlife Service
P.O. Box 10023
Helena, Montana 59626
May 1988
-------
Table 1. Trace elament Concentrations in plants and aquatic Invertebrates from
the Militown Site. Dry weight concentrations are shown below wet weight ( m).
BDL means a concentration below the detection limit. NA means the san le was
not analyzed.
Plants
£AEeA SOP. £A sop. Polvonnimi spp. Aquatic
(shoots) (shoots) (flowers and Invertebrates
Metal (Sar le 1] [ Samele 2] seedheads)
en
Arsenic BOL 0.63 BDL 0.9
3.0 2.8
Cadmium BDL 0.15 BDL 0.5
0.73 1.7
Copper 0.70 1.7 1.5 NA
3.3 14.0 7.8
Lead BDL 0.28 0.24 NA
1.5 1.9
Mercury NA NA NA NA
Selenium BOL BDL BOL 0.5
1.5
Zinc 17 32 20 NA
91 150 160
con arabl. because of different species and different parts of plants used, the
data are thought to reflect a level of arsenic expected to be found In tissue
from plants growing in uncontaminated areas. Thus, the amount of arsenic found
In the plants from the Militown Site does not qppear unusu4h
Diet studies conducted at Patuxent Wildlife Research Center (Research Center)
indicated that there was reduced growth of mallard ducklings fed a diet
11
C
C
0
-------
Table 2. Range of trace element concentrations In whole—body fish collected
from Militown Reservoir. Dry weight concentrations are shown below wet weight
(ppm). San le sizes are shown in parentheses. BOL means a concentration below
the detection limit. U Indicates that the element or san le was not analyzed.
Analvte
Lead
Rainbow Trout
BOLU) 0.08(1)
.32
Pean uth
0.82(1) 39(1)
3.4 160
BDL(5) BDL(5) 0.5-2.20(5) BDL(5) 0.06—0.09(5)
2.0—7.1 0.21—0.27
0.61—0.74(5)
1.9—2.9
Northern Sauawf I sh
801(4) 801(4) 0.41—0.65(3) BDL(3) 0.07—0.09(3)
1.3—2.4 0.23—0.29
0.42—0.83(4)
1.7—2.7
BOLd) 801 (1)
NA
Lononoce flece
NA
NA
BOLd) 801(1) 1.0(1)
5.3
Redclde Shiner
BDL (1)
NA
Lar escale Sucker
BDL(2) BDL(2) 0.41—0.77(2)
2.1—3.4
BDL(2) 0.07-0.12(2)
0. 35—0.51
18
0.22—0.28(2) 8.4—9.6(2)
1.1—1.2 42—43
801(1) BDL(1) 2.6(1)
11.
14-22(5)
46-79
9. 4—16 (3)
30—59
1.0(1)
2.8
NA
0.33(1)
1.7
30(1)
160
i121
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Militown Reservoir Sediments Mining Wastes NFL Site Summary Report
Reference 15
Excerpts From Fact Sheet; EPA Region VIII; 1990
•713
-------
Environmental Protection Agency DATE: October 1990
Montana Office
Federal Building, Drawer 10096
301 South Park
Helena, Montana 59626—0096
EPA REGION VIII FACT SHEET
SUBJECT: Militown Reservoir Sediments Superfund Site
LOCATION: Militown, Missoula County, Montana
SUMMARY: Mine waste sediments have accumulated behind the
Militown Reservoir hydroelectric dam causing ground
water contamination of arsenic and heavy metals and
surface water quality problems. A replacement water
system for the residents of Milltown was installed as a
remedial action while the RI/FS process contin ies to
study the extent of contamination.
DESCRIPTION: Milltown Reservoir is located on the Clark Fork River,
downstream of Silver Bow Creek. In 1981, routine samples
taken from drinking water wells located in the community
of Milltown, Montana, showed elevated levels of arsenic
that exceeded the EPA Interim Primary Drinking Water
Standard. Four wells, serving a total of 33 residences,
were contaminated with up to ten times the Drinking
Water Standard of 0.05 mg/i As. Residents were advised
to not use the water for drinking and cooking and to
seek an alternate supply of potable water.
In the fall of 1983 the site was placed on the final
Superfund National Priorities List (NPL). Montana
Department of Health and Environmental Sciences (MDHES)
entered into a Cooperative Agreement with EPA to conduct
a Remedial Investigation/Feasibility Study (RI/FS).
Affected residents continued to obtain potable water
from noncontaminated sources. In the summer of 1983,
volunteers using National Guard equipment began
supplying residences with door-to-door potable water
service on a biweekly basis.
A Remedial Investigation study was undertaken to
determine the source and extent of contamination near
Milltown. Alternative water supply and distribution
systems were evaluated in a feasibility study in 1983
and an Interim Remedial Measure Record of Decision was
executed by EPA on April 14, 1984, implementing the
replacement of those wells contaminated with arsenic. A
replacement well was constructed in 1984. A
supplemental Record of Decision was executed on August
17, 1985 that implemented decisions regarding
19
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Milltovn (cont.)
Final determination of the litigation approach to be
used in the site cost recovery action was made in
December, 1987. A demand letter to recover
approximately $1.5 million in previous response costs
was issued to ARCO in June 1988. A referral was signed
by the Regional Administrator and sent to Department of
Justice on September 30, 1988. A Complaint was filed in
federal district court on June 23, 1989, which combines
cost recovery actions against Militown and Anaconda
PRP’s, and requests a determination of PR? l.iability.
Department of Justice is working with Militown and
Anaconda attorneys and project managers to prepare for
litigation.
STATUS AS OF
10/15/90: Phase I site investigation work was completed October
1990. Work completed includes seismic surveys,
continuous groundwater level recorders, water level
measurements and water quality samples, and monitoring
well have been installed. Groundwater velocity
measurements, using a heat pulsing flow meter, are also
complete and field data will be submitted to EPA. Data
validation of past data is completed and a cultural
resources survey is underway. For the risk assessment
process interim final workp].ans are completed for public
health evaluation, fisheries, wetlands, and continued
releases. Sampling and analysis plans are being
written. The ecological assessment team conducted site
reconnaissance work and will present field and
laboratory information to the public in November. A
public health exposure survey was drafted and reviewed.
EPA is contracting with Missoula County Health
Department to complete the survey in December.
CONTACTS: Branch Chief, Don Pizzini Phone No.: FTS 585-5414
Program contact,
Julie DalSogilo Phone No.: FTS 585-5414
Counsel contact,
Henry Elsen Phone No.: FTS 585-5414
21
-7,’ (0
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Mining Waste NPL Site Summary Report
Monsanto Chemical Company
Soda Springs, Idaho
U.S. Environmental Protection Agency
Office of Solid Waste
June 21, 1991
FINAL DRAFT
Prepared by:
Science Applications International Corporation
Environmental and Health Sciences Group
7600-A Leesburg Pike
Falls Church, Virginia 22043
- i7
-------
DISCLAIMER AND ACKNOWLEDGEMENTS
The mention of company or product namm is not to be considered an
endorsement by the U.S. Government or by the U.S. Environmental
Protection Agency (EPA). This document was prepared by Science
Applications International Corporation (SAIC) in partial fulfillment of
EPA Contract Number 68-WO-0025, Work Assignment Number 20.
A previous draft of this report was provided to Christina Psyk of EPA
Region X [ (206) 553.65 191, the Remedial Project Manager for the
site, whose comments were not received in sufficient time to be
incorporated into the report.
..flo
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Mining Waste NPL Site Summary Report
MONSANTO CHEMICAL COMPANY
SODA SPRINGS, IDAHO
INTRODUCTION
This Site Summary Report for the Monsanto Chemical Company is one of a series of reports on
mining sites on the National Priorities List (NPL). The reports have been prepared to support EPA’s
mining program activities. In general, these reports summarize types of environmental damages and
associated mining waste management practices at sites on (or proposed for) the NPL as of February
11, 1991 (56 Federal Register 5598). This summary report is based on information obtained from
EPA files and reports. In addition, the EPA Region X Remedial Project Manager for the site,
Christine Psyk, was provided with a copy of an earlier draft of the report in March 1991.
SITE OVERVIEW
The Monsanto Chemical Company site is an operating elemental phosphorus plant, located
approximately 2 miles north of Soda Springs, Idaho (population 3,000). This site was listed on the
NPL on August 30, 1990. The 530-acre site is accessed by State Highway 34 (see Figure 1) north of
the City of Soda Springs, and is in a broad, rural valley near the western base of the Aspen Range.
Located directly across Highway 34 is another NPL site, the Kerr McGee facility, which produces
vanadium pentoxide.
The Monsanto facility produces elemental phosphorus, which is used primarily for the manufacture of
phosphoric acid. Phosphoric acid can then be used as a feedstock for various commercial and
industrial products. The plant generates numerous wastestreams during its operation, which contain
inorganic compounds and metals. Most of these wastes are stored or treated in onsite piles or ponds
(Reference 1, page 1). Figure 1 shows the location of the various waste management units on the
site. They include the slag pile, effluent discharge stream, sewage evaporation ponds, effluent settling
pond, coke and quartzite slurry pond, Old underfiow ponds, seal water pond, phossy water surge
pond, and the onsice landfills (Reference 1, page 12).
In 1984, Idaho conducted a Preliminary Assessment at the site. Under contract to EPA, Environment
and Ecology conducted a Site Inspection and found elevated levels (concentrations either 10 times
greater than background or 3 times greater than analytical detection limits) of cadmium, arsenic,
manganese, nickel, selenium, potassium, vanadium, sodium, zinc, fluoride, sulfate, and phosphorus in
onsite monitoring wells (Reference 1, Abstract).
1 I
-------
Monsanto Chemical Company
S.waq. iva atJan
ponds (lb .d)
LEGDID
M ta Oi.iuI C m. b.mmd.y
N
•eo cgy & environment, inc.
MS: 0—l702—O$ * t. Vt 00024
0 ivn b 0. •. I0.t 2& IUSI
FIGURE 1. srr MAP
2
FIGURE 4
FE t.IAP
MONSANTO CHa4ICM. COMPANY
Soda Springs. ID
Nerth’wut pond
(lined)
Old undarllov ponds
(riot ui u..)
:
Phassy water
eurg. pond (lln.d)
Vonadlum
(buried in
p.ntax$ds
Effluent
MtIb q pond
Effluent
OII i. . Sb’s n
0 1000
2000
•cUi t.st 44
4000
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Mining Waste NPL Site Summary Report
Evidence collected during the EPA/Ecology and Environment Site Inspection indicates that the
Monsanto Chemical Company’s Effluent Discharge Pond and Old Underfiow Ponds located west of
the site are the two areas of concern (see Figure 1). In 1985, Golder and Associates identified two
aquifers beneath the site that had elevated concentrations of metals and anions. EPA concluded that
the contaminants of concern originated from the Unlined Underfiow Ponds and a Hydroclarifier
(Reference 1, page 1). Approximately 490,000 cubic yards of waste were contained in these
Underfiow Ponds (Reference 2, Attachment, page 6).
Onsite production wells provide drinking water for approximately 400 employees (Reference 1, page
2). The City of Soda Springs obtains its drinking water from two springs within 3 miles of the site.
Water from the Effluent Discharge Pond is pumped to Soda Creek. Water is withdrawn downstream
to irrigate 4,000 acres of land (Reference 2, page 11).
According to EPA, the Agency for Toxic Substances Disease Registry (ATSDR) has released a Health
Assessment for public comment (the comment period is from June 17, to July 17, 1991). An
Administrative Order concerning the Remedial Investigation and Feasibility Study was signed in
March 1991. The Potentially Responsible Parties (PRPs) are currently developing a Work Plan for
the Remedial Investigation/Feasibility Study.
OPERATING HISTORY
Monsanto Chemical Company purchased the site from Vernal Hopkins of Soda Springs, Idaho, in
1952. An elemental phosphorus plant was constructed on the property and has operated since that
time. Prior to its purchase by Monsanto Chemical Company, the land was used for farming. There
are a number of other industrial complexes located near the elemental phosphorus plant, including the
Kerr-McGee Chemical Corporation, situated directly across State Highway 34 (Reference 1, page 1).
The Monsanto Chemical Company produces elemental phosphorus using electric arc furnaces. The
phosphorus produced is shipped offsite and used in the manufacture of phosphoric acid (Reference 1,
page 1).
Phosphate ore, which is mined from a nearby mining site, is stockpiled onsite. The ore is crushed,
sized, and placed into a rotary kiln. Once in the kiln, organics are removed, and ore is agglomerated
into stable nodules. The nodules are then transferred (at a temperature relatively close to the melting
point of the ore) to the electric furnaces. The mixture in the furnace consists of nodules, silica rock,
and coke. The coke chemically reduces the phosphate ore to elemental phosphorus at the high
temperatures generated by the furnaces. The silica is added to create the proper composition and flow
3
-l
-------
Monsanto Chemical Company
properties in the resulting slag. Additionally, naturally occurring iron in the ore combines with the
phosphorus to produce a smaller quantity of a slag-like material called ferrophos (Reference 1, page
10).
The furnace gases pass through a scrubber, which removes the particulates, and then through a water
spray condenser, where the gaseous phosphorus is condensed. The phosphorus is then filtered to
remove residual particulates. To recover any remaining phosphorus, the sludge generated by
filtration is roasted. The elemental phosphorus produced is piped into rail tank cars for shipment. To
prevent exposure to oxygen, which results in a violent oxidation reaction, the phosphorus is stored
and transported under water (Reference 1, page 10).
Numerous process streams result from elemental phosphorus production. Phossy water, coke,
quartzite slurry, kiln-dust slurry, ferrophos slag, and calcium silicate slag are among these streams.
These wastes are continuously transferred to onsite ponds and piles for storage. Other wastes
generated at the site include waste oil and explosion seal water. The waste oil is stored in an above-
ground tank and then pumped from the tank periodically for removal offsite. The explosion seal
water is stored in a designated lined pond (Reference 1, pages 10 and 11).
Slag constitutes the greatest quantity of waste produced by the Monsanto Chemical Company. Molten
slag is tapped from the base of the furnaces and poured out to cool in piles. These piles are greater
than 150 feet in height; they cover a large portion of the site and are unlined (Reference 1, page 10).
The area is approximately 2,500 feet in length. The slag is mainly calcium silicate. The ferrophos
slag is cooled in separate piles. This is removed regularly and sold to Kerr-McGee Industries for its
vanadium (Reference I, page 13).
Phossv Water
Water used for the condensing, displacement, and storage of elemental phosphorus is called “phossy
water.” All phossy waters are placed in a designated surge pond (lined with bentonite) for cooling
and acidification before reuse. This pond is approximately 300 feet in length (Reference 1, page 13).
4
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Mining Waste NPL Site Summary Report
Kiln Dust Slurry
Considerable amounts of particulate matter are contained in the Rotary Kiln exhaust gas. A wet
scrubber is used to remove these particulates. The resultant slurry is sent to a Hydroclarifier for
dewatering. The excess water is recycled back to the wet scrubber. The remaining solids are sent to
the Underfiow Solids Ponds for storage. They are eventually recovered and fed back into the kiln.
When the Hydroclarifier is inoperative, the Underfiow Solids Ponds are used for dewatering. These
Ponds are now lined with bentonite. Previous ponds were unlined. In 1985, the Hydroclarifier was
discovered to be leaking. A new system, which included a leachate-collection system and a synthetic
liner, replaced the old system (Reference 1, pages 13 and 14).
Coke and Ouartzite Slurry
In the past, the coke and quartzite dust that resulted from the drier and scrubber settled out in a
Slurry Pond (Reference 1, page 14). The dust generated by the furnaces is now collected by
Electrostatic Precipitators and transported to a chamber where the residual phosphorus is oxidized.
The dust is then caught in a Baghouse where it is stored. The former Slurry Pond is dry, and
contains only sediment (Reference 1, page 13).
Other Wastes
Explosion seal water is a separate water system that prevents furnace gases from escaping at the point
where the electrodes enter the furnace. This water is cooled in the Seal Water Pond prior to
recycling. The pond is bentonite-lined and generates little sediment. Waste oil is kept in storage
tanks prior to collection. An outside recycler was contracted in 1974 to purchase the waste oil.
Since 1977, solvents that are generated by the facility have been purchased by an outside recycler.
Before 1977, these solvents were mixed with the waste oil and used as a dust suppressant on
Monsanto’s roads (Reference 1, page 14). Table 1 presents a summary of waste streams and
processes including the waste management status. Additionally, 32 tons of vanadium pentoxide,
asbestos-containing insulation, construction wastes, and office wastes are buried in plastic-lined drums
in an onsite Landfill (1,500 feet west of the buildings) (Reference 1, page 14).
5
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Monsanto Chemical Company
TABLE 1. MONSANTO PROCESS AND WASTFS REAM SUMMARY
Procnss/Wastestream
Storage Location
Uner
Current Status
Explosion seal water
from furnace
Seal Water Pond
Bentonite
Active
Displacement/process
water (phossy water)
from rail cars, storage
vessels, and spray tower
Phossy Water
Surge Pond
Bentonite
Active
Coke and quartzite
slurry from drier
Past - Coke and
Quartzite Slurry Pond
Present - collected in
baghouse
None
Inactive
Noncontact plant
cooling water
Effluent settling pond
(overflow water is
discharged to Soda
Creek)
None
Active
Kiln dust slurry
Hydroclarifler
Past - None
Present - Synthetic
Liner and leachate-
collection system
Active
Old Underfiow Solids
Ponds
None
Inactive
New Underfiow Solids
Ponds
Bentonite
Active
(backup for
Hydroclarifier)
Northwest Pond
Past - None
Active
(as Sanitary
Landfill)
Ferrophos slag
Pile on ground (removed
regularly)
None
Active
Calcium silicate slag
Pile on ground
None
Active
Waste oil
Above ground tank;
pumped monthly and
removed from site
Concrete
Active
Source: Reference 1, page 11
6
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Mining Waste NPL Site Summary Report
SITE CHARACIERIZATION
Ground Water
Ground water occurs in four hydrostratigraphic zones under the site. The uppermost zone
(overburden soils) and lowest zone (Salt Lake formation) exist only in the northern portion of the site
and produce limited amounts of ground water. The two other intervening zones are found in basalt
flows and transmit large quantities of ground water. The basalts supply all three plant production
wells (Reference 1, page 6).
I
The direction of ground-water movement in the Soda Creek Basin is generally to the west-southwest.
This flow is influenced by the northwest/southwest-trending normal faults that exist in the area.
Ground-water flow in the upper and lower basalt zones is reportedly to the south (Reference 1,
page 6).
The ground water under the site is reported to be contaminated by fluoride, cadmium, selenium,
chloride, sulfate, manganese, nickel, selenium, potassium, zinc, sodium, phosphorous, and vanadium
(Reference 1, Abstract). Both upper and lower basalt zones show evidence of contamination, with the
contamination being more widely distributed and concentrated in the upper zone.
Numerous elements were detected in downgradient monitoring wells at concentrations above those
detected in the background (upgradient) well. Elements detected at elevated concentrations (greater
than 10 times background concentrations or greater than 3 times the detection limit) include zinc,
selenium, and manganese (six wells); cadmium, nickel, potassium and vanadium (five wells); sodium
(four wells); aluminum, arsenic, and iron (two wells); and chromium (one well). Federal Maximum
Contaminant Levels (MCLs) for Primary Federal Drinking Water Standards (DWSs) were exceeded
for cadmium and selenium in 11 monitoring wells (Reference 1, pages 21 through 22).
The sources of contamination in the upper zone were identified as the Underfiow Solids Pond, the
Northwest Pond and the Hydroclarifier (Reference 1, pages 1 and 27). The plumes generally follow
the predominant ground-water flow direction to the south-southeast, with a fluoride plume being the
most widely dispersed. Above-background levels of fluoride were detected in a 1,000-foot-wide
zone south of the site’s boundary. Selenium and sulfate plumes also extend beyond the site’s
boundary. Cadmium, chloride, and vanadium plumes appear to be restricted to the site area. The
contaminants detected in the lower basalt zones were fluoride, cadmium, selenium, chloride, and
sulfate (Reference I, page 15).
7
-
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Monsanto Chemical Company
Surface Water
Soda Creek is the closest surface water source to the Monsanto site, located 2,000 feet to the west. It
is used for irrigation and stock water. Some of the water from onsite production wells is used for
noncontact cooling purposes and discharged into Soda Creek under a National Pollutant Discharge
Elimination System (NPDES) permit which only regulates temperature (Reference 2, page 8). The
creek flows into the Alexander Reservoir, which is used for recreation and power generation. In
addition, the effluent discharge stream that enters Soda Creek is used downstream to irrigate
approximately 4,200 acres of land (Reference 1, page 7; Reference 2, pages 2 and 8).
Morman Springs and Monsanto’s wastewater effluent were sampled during EPA’s Site Investigation.
Any sampling that may have been conducted on Soda Creek was not reported in the references. The
Morman Springs sample showed elevated levels of selenium 191 micrograms per liter (jig/I)],
vanadium (23 ig/l), and zinc (122 igll); however values for selenium and vanadium were estimated
because quality-control criteria were not met or concentrations were below certain levels (Reference
1, page 22). The effluent discharge showed contaminant levels of 111 g/l aluminum, 32 ig/l
cadmium, 100 ig/l iron, 17 gFl selenium, 33 ig/l vanadium, and 1.8 mg/I total phosphorous.
However, values for aluminum, selenium, and zinc were estimated because quality-control criteria
were not met or concentrations were below certain levels (Reference 1, pages 22 and 23).
Air and Soils
Air and soils have not been evaluated at this site to date (Reference 2, page 2).
ENVIRONMENTAL DAMAGES AND RISKS
A Hydrogeological Investigation performed by Golder Associates (in 1985) identified several
contaminant plumes in two aquifers beneath the site. Several samples were taken, and elevated levels
of contaminants of cadmium, arsenic, manganese, nickel, selenium, potassium, vanadium, sodium,
zinc, fluoride, sulfate, and phosphorus were detected (Reference 1, page 14). Cadmium (781 ig/l)
significantly exceeds the Primary Federal Drinking Water Standard (of 10 gig/I) (Reference 2, page
2). Golder Associates concluded that the contaminants originated in the locations of formerly used
Unlined Ponds and a Hydroclarifier (Reference 1, page 27).
8
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- Coke ana quart:ite
slurry pond
(net in us.)
Mining Waste NPL Site Summary Report
------7
l.EGE.NO
Monsanto Chemical Co. boundary
Buldlnq
e Composit. seøanent sample
Pond or surface waist s npts
Sprinq
N
ecology & environment. Inc. I
Jot: F1O-4702—06 Waste S1t, 100024
Drawn b Q. P. Datr MQCfl 2 . 19 8j
FiGURE 6
SEDIMENT, POND AND
SURFACE WATER 5A}4PLE
LOCAtON S
MONSANTO CHEUICAL COMPANY
SodG Springs, O
FIGURE 2. SEDIMENT, POND, AND SURFACE -WATER SAMPLE LOCATIONS
9
4orthw.,t oono
(lined)
Landfill
Seal water pond (lined)
I ,
Ptiossy watif
surge pant (lined)
Under ow solids
setUing panes (lined)
Old uncertlow ponds
(not in use)
Landf Ill
U
— Hyaro—clarifler
‘I.
Plant
Ssveq. avaporalion
pants (lined)
U
S
1 $
I
a
tfl
0 1000 2000 3000 4000
scala in feat
1
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Monsanto Chemical Company
The ground water derived from wells in the Basalt Aquifer and Springs in the Soda Springs area is
used for domestic and public drinking supplies, irrigation, and industrial purposes. There are 22
domestic wells within 3 miles of the Monsanto facility, serving an estimated population of 80. In
addition, Monsanto uses two onsite production wells for employees. Use of an additional onsite
production well for drinking water was discontinued when it was found to be contaminated with
cadmium and fluoride. Seven wells located within 3 miles of the site are used solely for irrigation
(Reference 1, page 9). ATSDR has released a Draft Preliminary Health Assessment for public
comment, which end July 17, 1991.
REMEDIAL ACTIONS AND COSTS
The PRP is in the first stages of conducting an Remedial Investigation/Feasibility Study. The PRP is
preparing a Remedial Investigation/Feasibility Study Work Plan, which will be submitted for EPA
approval. The investigation will proceed pending approval.
CURRENT STATUS
According to EPA, ATSDR has released a Draft Preliminary Health Assessment for public comment.
The comment period is from June 17, 1991 to July 17, 1991. In March 1991, an Administrative
Order concerning the Remedial Investigation and Feasibility Study was signed and the PRPs are
currently developing the Remedial Investigatlon/Feasibility Study Work Plan.
10
f -
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Mining Waste NPL Site Summary Report
REFERENCES
1. Site Inspection Report for Monsanto Chemical Company, Soda Springs, Idaho; Ecology and
Environment; April 1988.
2. Hazard Ranking System Score Sheet and Documentation for the Monsanto Chemical Company;
Lynn Guilford, EPA; May 16, 1988.
11
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Monsanto Chemical Company
BIBLIOGRAPHY
Ecology and Environment. Final Inspection Report for Monsanto Chemical Company, Soda Springs,
Idaho. April 1988.
Guilford, Lynn, (EPA). Hazard Ranking System Score Sheet and Documentation for the Monsanto
Chemical Company. May 16, 1988.
12
73. ,,
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Monsanto Chemical Company Mining Waste NPL Site Summary Report
Reference 1
Excerpts From Site Inspection Report for Monsanto Chemical Company, Soda Springs, Idaho;
Ecology and Environment; April 1988
-------
SITE INSPECTION REPORT FOR
HONSAI TO CflEMICAL COMPANY
SODA SPRINGS, IDABO
TDD P10—8702—06
Report Prepared by: Ecology and Environment, Inc.
Date: April 1988
Submitted to: J.E. Osborn, Regional Project Officer
Field Operations and Technical Support Branch
U.S. Environmental Protection Agency
Region X
Seattle, Washington
1
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ABSTRACT
Under U.S. Environmental Protection Agency (EPA) Contract Number
68—01-7347 and Technical Directive Document (TDD) F10—8702—06, a file
review and site inspection of the Monsanto Chemical Company, Soda
Springs, Idaho, was conducted to evaluate the facility’s status within
the Agency’s Uncontrolled Hazardous Vaste Site Program. As a part of
this inspection, 12 ground water, two surface water, tvo process water,
and two sediment samples were collected to verify the presence and pos-
sible sources of contaminants in ground water under the site. The
samples vere analyzed for EPA Target Compound List (TCL) inor anics, as
veil as fluoride, sulfate, and phosphorous. Elevated levels (i.e.
concentrations either ten times greater than background or three times
greater than analytical detection limits) of cadmium, arsenic,
manganese, nickel, selenium, potassium, vanadium,.sodium, zinc,
fluoride, sulfate, and phosphorous vere detected in on—site monitoring
veils. Elevated levels of selenium, vanadium, and zinc vere detected in
an off—site spring and an effluent discharge stream.
-------
1.0 INTRODUCTION
The Monsanto Chemical Company (MCC) plant near Soda Springs, Idaho,
is an active facility that has been identified by the Region X U.S.
Environmental Protection Agency (EPA) and the Idaho Hazardous Materials
Bureau from Preliminary Assessment (PA) screening as requiring addi-
tional information concerning ground vater contamination under the Site.
Ecology and Environment, Inc. (E&E), under EPA Contract No. 68—01—7347
and Technical Directive Document (TDD) No. P10—8702—06, conducted a site
inspection and sampling program at the MCC plant to evaluate the nature
and degree of ground vater contamination and ascertain the need for and
scope of additional york.
A Site Inspection represents the final step of a three—step inves-
tigative process utilized by the EPA to identify and rank potential or
actual hazards at a particular site relative to other sites across the
nation. Specifically, the SI is intended to gather sufficient addition-
al data, supplemental to that gathered during the Site Discovery and PA
activities, to rank sites for possible remedial york and aid in the pro-
cess of determining the scope of such york. The SI is not intended to
provide complete environmental characterization of a site.
The Monsanto plant produces elemental. phosphorous vhich is used
primarily for the manufacture of phosphoric acid. The plant generates a
number of process vaste streams vhich contain numerous inorganic com-
pounds and metals. Most liquid and solid vastes are stored or treated
in on—site ponds or piles.
A hydrogeological investigation performed by Colder Associates in
1985 (1) identified several contaminant plumes in tvo aquifers beneath
the site with elevated concentrations of metals and anions. The in-
vestigation concluded that the contaminants originated in the locations
of former unlined ponds and a hydroclarifier.
This document presents results of E&E’s site inspection efforts.
Included is information pertaining to ownership, history, environmental
setting, and operations of the site, as veil as field data developed
during sampling and site characterization activities. Photographic
documentation is presented in Appendix A and information collected
during the inspection is starized on EPA Form 2070-13 in Appendix B.
2.0 0VN /0PERAT0R
14CC purchased the site from Vernal Hopkins of Soda Springs, Idaho
in 1952, and built an elemental phosphorous plant on the property. The
property was used for farming prior to its purchase by 11CC (2). MCC’s
corporate offices are located at 800 N. Lindbergh Boulevard, St. Louis,
Missouri, 63167.
1
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3.0 LOCATION
The facility is located approximately one mile north of the City of
Soda Springs, Idaho, in portions of Sections 29, 30, 31, and 32,
Township 8 South, Range 42 East of the Boise ileridian. The site is
accessed via State Highway 34, north of Soda Springs (Figure 1).
4.0 SITE DESCRIPTION AND SURROUNDING AREA
The P1CC facility occupies 530 acres in a broad rural valley near
the western base of the Aspen Range. Significant agricultural crops in
the area include wheat and hay. A number of other large industrial com-
plexes are located in the valley, including the Kerr—McGee Chemical Cor-
poration, directly across State Bighvay 34 from P1CC, and the Nu—West
Industries facility, located approximately four miles to the north.
The largest population center in the area is the City of Soda
Springs, vith an approximate population of 3,000. Population demo-
graphics within a three—mile radius of the facility are sttmm rized in
Table 1.
TABLE 1
POPUUXION DEMOGRAP CS (2, 3)
Radial Distance Demographic Description
On Site Number of Employees: 400
One Mile Residents: approx. 27
Buildings: 45
Tvo Miles Residents: approx. 1,400
Buildings: 400
Three Miles Residents: approx. 3,100
Buildings: 800
5.0 TOPOGRAPET AND DRAIN&GE
The P1CC Site is located in the Bear River Valley of southeastern
Idaho. The basin is a broad, flat valley bordered on the east by the
Aspen Range and on the vest by the Soda Springs and Chesterfield Ranges.
These mountain ranges rise 1,000 to 1,500 feet above the valley floor.
The northern boundary of the drainage basin is formed by the Black-
foot Reservoir which lies 12 miles north of the site (Figure 2). Sur-
face drainage within the valley flovs dominantly to the south, with Soda
p
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6.3 Regional Hydrogeology
Ground water occurs in both the bedrock and overburden deposits.
The overburden sediments yield variable amounts of water, but production
is limited because of the predominantly silty and unsaturated nature of
the deposits. Wells completed in these units are used primarily for
!o ” tic and stock needs (5).
The basalts of the Blackfoot Lava Field contain the most productive
aquifers in the region. Ground water occurs primarily between individ-
ual lava flows in porous zones of rubble and cinder. Ground water from
the basalts is used for industrial, domestic, and irrigation purposes
(5).
The rocks of the Salt L.ak.e Formation and the pre—Tertiary rocks
yield variable amounts of water to veils. The water is used locally for
domestic and stock purposes (5).
Recharge to the aquifers in the overburden sediments and basalts
occurs by infiltration of meteoric water and leakage from the Blackfoot
Reservoir. Recharge to the older formations is thought to occur by in-
filtration of meteoric water along the flanks of the bordering moun-
tains. - -
Construction of the B].ackfoot Reservoir had a dramatic affect on
the water table in the Soda Creek Basin. After construction of the
reservoir in 1910, the Five Mile Meadova area located seven miles to the
south was transformed from productive crop land to marsh land. In
addition, the flow volumes of Soda Creek, which drains the central
portion of the basin, reportedly doubled as a result of the elevated
ground—water levels (5).
The direction of ground—water movement in the Soda Creek Basin is
generally to the vest—southwest (5). This pattern is locally affected
by the northwest—southeast trending normal faults that exist in the area
(4). The faults serve as conduits for the movement of ground vater and
cause local t h nges in the vertical and/or horizontal patterns of flow.
Springs are common in the Bear River Valley. Some of these springs
have precipitated large deposits of calcium carbonate in the form of
travertine or tufa. Often, the mineral content of the springs renders
the water unsuitable for domestic use.
6.4 Local Bydrogeology
Ground water is reported to occur in four hydrostratigraphic zones
under the site (1). The overburden soils and the Salt Lake Formation
comprise the uppermost and lowest zones, respectively. These zones
exist only in the northern portion of the site and produce limited
quantities of ground water. The remaining two zones are found in the
basalt flows. The basalts transmit large quantities of ground water and
supply all three plant production wells. The basalts are divided into
6
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two hydrostratigraphic zones, an upper zone and a lover zone. The divi-
sion is based on the presence of basaltic aquitards which hydraulically
separate the two zones.
Ground water flov in the upper and lover basalt zones is reportedly
to the south (1). A ground water flow map prepared by Colder Associates
(1) for the upper zone is reproduced in Figure 3. The nap shows flov
directions being strongly influenced by pumpage of the supply wells
which have created a cone of depression. Ground water flow is also
strongly influenced by the fault that traverses the site. The fault is
thought to act as a barrier to ground water flow.
Recharge to the upper basalt zone and overburden sediments is
thought to be via precipitation, regional underf low, and in places, up-
ward leakage from the lover basalt zone. Recharge to the lover basalt
zone is by upward leakage from the underlying Salt Lake formation and
induced leakage from the upper basalt zone in response to production
well pumpage (1).
7.0 CLIMATE
- Southeastern Idaho has a semi—arid climate that is characterized by
hot summers and cold winters. A National Weather Service weather sta-
tion, is located four miles northeast of the NCC Site in Conda, reports
approximately 19 inches of precipitation annually, with June having the
highest monthly precipitation (2.15 inches) and July having the lowest
monthly precipitation (0.78 inches). Average annual lake evaporation In
the area is 35 inches per year, yielding a net precipitation value of
minus 16 inches annually (6). The one—year, 24—hour maximum rainfall
for Soda Springs is 1.06 inches (7). $nov typically remains on the
ground from early November through April.
8.0 GROUND WATER AND SURFACE WATER USES
8.1 Surface Water
The closest surface water to the 14CC Site is Soda Creek, located
2,000 feet to the vest (Figure 1). Soda Creek is used for irrigation
and stock water.
Soda Creek flovs into the Alexander Reservoir, located near Soda
Springs. The Alexander Reservoir is used primarily for recreation and
power generation.
Approximately 4,200 acres of land are irrigated with a contribution
from water derived from the Monsanto facility. The water is obtained
from the on—site production wells, used for non—contact cooling pur-
poses and discharged to Soda Creek which is diverted for irrigation one
and one—half miles downstream.
7
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8.2 Ground Water
Ground vater (derived from veils and springs) in the Soda Springs
area is used fordomestic and public drinking supplies, irrigation, and
industrial purposes. Within three miles of the site, ground water
serves a population of approximately 3,500.
The City of Soda Springs Water Department distributes water to all
residences within the city limits. This water is obtained from tvo
springs (Formation and Ledge Creek Springs) located north of the city.
The Water Department serves a population of over 3,000 (8).
There are 22 registered domestic veils vithin three miles of the
site (9, 10), serving an estimated population of 80. Total depths of
the domestic wells range between 19 feet and 400 feet belov ground
surface (10). MCC uses three on—site production veils. Two of the
wells PV2 and PV—3) also serve approximately 400 employees with drinking
water.
Seven registered veils located within three miles of the site are
used for irrigation of approximately 4,300 acres (9). Table 2
summarizes ground water use within three miles of the MCC Site.
TABLE 2
GROUND VAT USE
Approximate
Populat ion/
Depth Acreage Served
Number of (feet below vithin a
Vells/ ground three—mile
Type of Well/Intake Intakes surface) radius
Domestic Wells 22 19 to 400 84 persons
Industrial Supply 4 200 to 250 480 persons
Veils
Municipal Supply — 2 Surface 3,000 persons
Natural Springs
Irrigation Veils 7 Unknown 4,309 acres
9
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9.0 OVERVIEV OF SITE OPERATIONS
The 11CC Plant produces elemental phosphorous using electric arc
furnaces. The phosphorous produced is shipped off site and used in the
manufacture of phosphoric acid. Phosphoric acid is a feedstock for
numerous commercial and industrial products. A brief overview of the
plant’s operations from information obtained during the site inspection
is presented below.
Phosphate ore, mined from the nearby Henry Mine, is stockpiled on
site. The ore is crushed and sized prior to insertion into a rotary
kiln. In the kiln, organics are removed and the ore is agglomerated
into stable nodules for use in the electric furnaces. The nodules are
then transferred, at close to the melting point of the ore, into the
electric furnaces. The furnace feed consists of a mixture of nodules,
quartzite (silica rock) and coke. The coke and quartzite is passed
through a drier prior to entering the furnaces. Coke is used to
chemically reduce the phosphate ore to elemental phosphorus at the high
temperatures generated by the furnaces. Silica is added to yield the
proper composition and flow properties to the resulting slag. In addi-
tion, naturally—occurring iron in the ore combines with phosphorous to
produce a smaller quantity of a slag—like material called ferrophos.
The furnace gases containing the phosphorous, carbon monoxide, and
silicon tetrafluoride pass through a scrubber, which removes the parti—
culates, then into a water spray condenser where the gaseous phosphorous
is condensed. The residual gas is predominantly carbon dioxide vhich is
rerouted into the kilns as supplemental fuel.
The molten phosphorous is then filtered to remove residual particu-
lates. The sludge generated by filtration is roasted to recover any
remaining phosphorous. The elemental phosphorous is piped into rail
tank cars for shipment and is always stored and transported under vater
to prevent exposure to oxygen which results in a violent oxidation
reaction.
10.0 CBARACT IZATION OF VASTE STREAMS
10.1. Production Related
Elemental phosphorous production involves numerous process streams,
some of which produce wastes. A brief discussion of the major process
and waste generating streams is presented below. Table 3 is a compila-
tion of the vaste and process streams discussed.
Slag constitutes the greatest quantity of waste produced by 11CC.
Molten slag is tapped from the base of the furnaces and poured out to
cool in piles (Figure 4). The piles cover a large portion of the site
and are greater than 150 feet in height.
10 —11
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TABLE 3
MONSANTO PROCESS AND WASTE STREAJI SUMMARY
Current
Process/Waste Stream Storage Location Liner Status
Explosion Seal Seal Water Pond Bentonite Active
Water from Furnaces
Displacement/process Phossy Water Bentonite Active
Water (phossy water) Surge Pond
from rail cars, storage
vessels, and spray tower
Coke and Quartzite Past — Coke and None Inactive
Slurry from drier Ouartzite Slurry Pond
Present — collected
in baghouse
Non—contact plant Effluent settling None Active
cooling water pond (overflov water
- is discharged -to
Soda Creek)
Kiln Dust Slurry Rydroclarifier Past - Active
none
Present —
synthetic liner
and leachate
collection system
Old Underf low Solids None Inactive
Ponds
New Underflov Solids Bentonite Active
Ponds (backup
for
hydroclar—
if icr)
Northvest Pond Past — Active
none (as san—
i tary
landfill)
Ferrophos Slag Pile on ground None Active
(removed regularly)
Calcium Silicate Slag Pile on ground None Active
Waste Oil Above ground tank; Concrete Active
pumped monthly and
removed from site.
I ) 11
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Northwest pond
(lined)
Old uriderfiow ponds
(not in use)
Substation
Vanadium pentoxide
(buried In drums)
0 1000 2000 3000 4000
LEC ’1D
Monsanto Chsm c Co. boundary
BuddIng
sca i n tilt
N
ecology & envfronment. Inc.
Job: F10-’6702—08 Wait. SIts 1D0024
Drawn a o.
P.
Dotr
Uovcfl
2 . 9 6I
FIGURE 4
SITE MAP
MONSANTO CHEMICAL COMPANY
Soda Springs, ID
\ .,4 Seal water pond (lined)
Phossy water
surge pond (lined)
Landfill
i4Jnderflow solids
settling ponds
(lined)
0
0
.@-uus Hydra-clarifier
‘II
Plant
I
Coke and quart!te
slurry pond
KERR—McGEE
C1- EMI CAL
CORPORATION
Effluent settling pond
Sewage evaporation
ponds (lined)
1
m l.
7’ ’
12
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TABLE 4
EP TOELLII RESULTS - MONSANTO SLAG, AUGUST, 1980
Hazardous Vaste Limit
Component (mg/i in extract) (mg/i)
Arsenic as As < 0.005 5.0
Barium as Ba < 0.5 100.0
Cadmium as Cd < 0.005 1.0
Chromium as Cr < 0.09 5.0
Lead as Pb < 0.02 5.0
Mercury as Hg < 0.001 0.2
Selenium as Se < 0.005 1.0
Silver as Ag < 0.01 5.0
Source: 2
The composition of the slag is dominantly calcium silicate. A
sample of the slag was submitted by Monsanto for Extraction Procedure
(EP) Toxicity testing in August, 1980. As indicated in Table 4, no test
parameters were exceeded.
The ferrophos slag is cooled in separate piles. It is later sold
to Kerr-McGee Industries for recovery of its vanadium content. -
Dust generated by the furnaces is collected by electrostatic pre—
cipitators and transported to a chamber vhere any residual phosphorous
is oxidized. The dust is then sent to a baghouse where it is stored.
The elemental phosphorous is condensed in a spray tover. The
liquid phosphorous is then sent to storage location and rail cars under
a vater seal. The spray tover, storage, and rail car displacement
waters are termed “phossy vater because they directly contact
phosphorous and have a high phosphorous content. All phossy waters are
sent to the phossy vater surge pond (Figure 4) for cooling and
acidification prior to being reused.
The furnaces have a separate vater system, called the explosion
seal, to prevent furnace gases from escaping at the point where the
electrodes enter the furnace. The vater is cooled in the sea]. vater
pond (Figure 4) prior to being recycled. Both the phossy water surge
pond and seal water pond are bentonite—lined and generate little sedi-
ment.
The rotary kiln exhaust gas contains considerable particulate
matter. A vet scrubber is used to remove these particulates. The
resultant slurry is sent to a hydroclarifier (Figure 4) for devatering.
The excess water is recycled back to the vet scrubber. The solids are
sent to the underfl v solids ponds for storage (Figure 4) and are
eventually recovered by feeding into the kiln. Occasionally, the under-
13
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flow solids ponds are used for devatering vhen the hydroclarifier is
inoperative.
The underflov solid ponds are now bentonite-lined. Previous ponds
were unlined. - In 1985, the hydroclarifier was discovered to be leaking
(2). It was replaced vith a new system which includes a leachate
collection system and synthetic liner.
Coke and quartzite dust resulting front the drier and scrubber vere
formerly settled out in a slurry pond (Figure 4). Presently, the dust
is collected in a baghouse. The former slurry pond is currently dry,
containing only sediment.
The plant uses a non—contact water cooling system for certain
equipment. The water is taken from the three production veils and is
discharged to Soda Creek via an effluent discharge stream (Figure 4).
The temperature of this discharge vater is permitted under the NPDES
system. Prior to being discharged, the effluent vater passes through a
settling pond for particulate removal (Figure 4).
10.2 Other Wastes
The 11CC plant once received 32 tons of vanadium pentoxide front a
Florida facility for possible recovery of the vanadium. After the
vanadium pentoxide vas determined to be unrecoverable, it vas put into
plastic-lined drums and buried as vaste in an on—site landfill. Also
buried in on—site landfills are asbestos—containing insulation, con-
struction debris, and office wastes.
Since 1977, the vaste solvents generated by the facility have been
containerized and picked up regularly by an outside recycler. Prior to
1977, the spent solvents were commonly mixed with vaste oil and used as
a dust suppresent on facility roads (2).
Beginning in 1974, an outside recycler vu contracted to purchase
vaste oil for recycling. The vaste oil is kept in a tank prior to col-
lection.
Over the last several years, a]]. PCB—containing transformers were
replaced at the MCC facility (2). Also, four underground storage tanks
for fuel oil and gasoline vere replaced vith above—ground tanks. The
underground tanks were observed to be in good condition during removal
(2).
11.0 PREVIOUS ENVIRONMENTAL STUDIES
In 1984, M C issued a contract to Colder Associates to conduct a
hydrogeological investigation of the Soda Springs facility (1). The
investigation via performed to assess the impact of past and current
operations on ground and surface water quality. As part of the investi-
gation, 31 monitoring veils were installed around the facility to sup-
plement seven existing veils. In addition, pump tests vere performed on
numerous monitoring wells and the three production veils. Water level
14
-------
measurements and vater quality sampling were performed on all veils
including monitoring veils, nearby domestic wells, and production veils.
The hydrogeologic results of the Golder investigation have been
briefly summarized in Section 6.2. The impact of the facility on local
ground—water quality is summarized below.
Ground water under the site appears contaminated by various ions
and metals including fluoride, cadmium, selenium, chloride, sulfate, and
vanadium. The upper and lower basalt zones show evidence of contamina-
tion, vith the contaminant plumes being more widely distributed and con-
centrated in the upper zone .
The sources of the contaminants in the upper basalt zone were iden-
tified as the site of the underflov solids pond, the northvest pond and
the hydroclarifier. The plumes generally follov the predominant ground-
water flow direction to the south—southeast, with a fluoride plume being
the most widely dispersed. Above—background levels of fluoride were de-
tected in a 1,000—foot wide zone south of the site’s boundary to at
least Mormon Springs. Selenium and sulfate plumes also extend beyond
the site’s boundary. Cadmium, chloride, and vanadium plumes appear to
be restricted to the site area.
- - None of the contaminants in the upper basalt zone were detected -
• immediately southeast of the production veils. It is thought that the
cone of depression created by these veils intercepts the southeasterly
transport of the plumes.
-. The contaminants detected in the lover basalt zone vere fluoride,
dmium, selenium, chloride, and sulfate. The plumes appear to extend
southeast from the old underflov solids area. No elevated concen-
trations of vanadium were detected. The plumes in the lover basalt zone
are smaller and less concentrated than those in the upper basalt zone.
It is thought that the ground—vater quality in the lover basalt zone was
impacted by either a dovnvard component of the hydraulic gradient in the
contaminated upper basalt zone, or leakage of contaminated vater re-
sulting from faulty veil construction of TV 5.
A separate plume of chloride, sulfate, and vanadium may exist in
the southeastern portion of the site. The plume appears to originate to
the east of the MCC Site.
12.0 SAMPLING- PROGRAM
12.1 Objectives and Scope
The objectives of the E&Z site inspection were to:
o verify the presence and concentration(s) of TCL compounds and
major ions in ground water under the site;
15
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13.2 Inorganic Analyses
13.2.1 Ground—Water Samples
Table 6 is i compilation of results for elemental analyses
performed on the veil water samples. Included are separate columns for
the unfiltered and filtered analyses.
Comparison between the filtered and unfiltered sample results re-
veals, for the most part, little differences in elemental concentra-
tions. The values for the unfiltered samples are usually slightly
higher than the filtered. The exception is TV 38, where the unfiltered
values are significantly greater than the corresponding filtered values.
This is probably a result of the turbid nature of the unfiltered vater
from this veil. All other veils produced clear water.
In several cases, the elemental value for the filtered.sample is
greater than the unfiltered sample. In most of these occurrences, the
reported concentrations are below the contract required detection limit
and, therefore, are listed as an estimated values only. Such
discrepancies are assumed to result primarily from the inaccuracy of the
analytical method in detecting very low concentrations of elements. - In
ve Il 11740, however, thallium was reported at 43 ugh in the filtered -
sample and was not detected in the unfiltered sample. This discrepancy
is large enough that laboratory or field contamination is likely
involved. Thallium was not found in any other sample.
Examination of the unfiltered results indicates that numerous
elements were detected in dovngradient veils at concentrations above
those detected in the background (upgradient) veil (TV 35). Elements
detected at elevated concentrations (greater than 10 times background
concentrations or greater than three times detection limit) include
zinc, selenium, and manganese (six wells); cadmium, nickel, potassium
and vanadium (five veils); sodium (four veils); aluminum, arsenic, and
iron (two veils); and chromium (one veil).
The most contaminated veils appear to be TV 37 and TV 40 vith 12
and eight elements at elevated levels, respectively. The least
contaminated veil was the dovngradient domestic veil (SWG) where no
elements were detected at elevated levels. Table 7 is a summary of
those elements detected at elevated levels in all unfiltered samples.
Elements detected in unfiltered samples at concentrations above
Federal Maximum Contaminant Levels (MCL) for drinking water are cadmium
(veils PV—1, TV 22, TV 36, TV 37, and TV 40) and selenium (veils PV—1,
TV 22, TV 36, TV 37, TV 39, and TV 40).
21
-------
TAOLZ 6
SUIOOABT or ZP090AIIC P.IJLTSIS — WILL. W fIl SAIIPLIS
•SA TO g1UC&1. CONPAIT. SODS SPIIUGS . !bPHo
lug/I)
9 1 11 9 1 12 9113 TW IS TW17
c1...ne UntiIt.r.d Fl ltsr.d Uaf lLt.r.d ?ilt.r.d Unfl lter.d rilesrad Unfiltsr.d Ft lt.r.d UnftLt.rad PiIt.r.d
k lua lnuu 20U 263 233 20U 203 20U 303 lOU 293 223
AntI.ony 31 U 11 U 31 U 31 U 31 U 3* U 31 U 31 U 31 U 31 U
Ara.nLc 63 63 43 (U 411 (U (U ( I I 53 U
Barlu. 7 13 163 5)3 543 633 643 6(3 643 493 50
•.ry l l lu. LU LU I I I Lu iu RU LU LU Lu iu
Cad .Iua IS 90’ 7 6 Su *0 513 su 7 su
CaIclu. 114000 113000 109000 109000 110000 109000 104000 105000 43700 (5500
Chro. Iu. SI) Su SU SI? SU SU 51 1 511 511 SU
Cobalt 611 611 (U II I 6U 611 lU 611 73 63
Coppar 163 31 103 103 I I I 911 911 9U 911 913
Iron 31 U 31 U 31 U 31 U 31 U 31 U 31 U 31 U 56 3 140
1..ad LU LU 111 1 1? LU LU LU 43 LU LU
flagn.s*u. 61500 60600 52400 52600 49500 49600 42200 42700 166000 171000
Mangan... 50 5 *1 3 *1 30 511 SU . SU SU 1320 1330
Marcury 0.211 0.2U 0.2U 0.2U 0.211 0 .2 *1 0.213 0.2U 0.21? 0.2*1
lStck.1 7U 711 13 71) 711 711 711 7U IIJ 213
Potaa ju . 10(00 9760 4630 3 4740 3 4600 4630 3 2700 3 3060 3 17600 17100
S.I.nlu• 193’ L4J• 23 1011 5 10.7 73 L i i i IOUR 23 23
S hy., SU 511 SU 5*1 5 * 1 511 SU 511 5* 1 Su
lodju. 51300 50600 16200 15300 22900 22900 6360 6530 90600 91600
ThaIllu. 211 211 211 211 lOU 211. 2U 211 20*1 20U
Vanadlu. *03 LI 113 113 303 373 13 2*1 33 33
ZInc 112 1 *6 14 3 21 13 3 20 13 U 11 .7 27 25
U — ms •st.r IaL was ana ly..d for, but v.a not d.t.ct.d. Th. .aaoclat.d nu..rlca l Yalu. is tb. ..ti.atad d.t.ction 11.It.
3 — Via •aaoclat.d nu..rica l valu. La an •.ti.at.d quantity b.c.ua. quality control crlt.rIa us c. not sat or conc.ntratlona r.port.d w.r.
l.a. than lb. ClOT..
I — Quality Control Lndicat.a that data at. unuaabl. c..pound •ay or say not b. pr.s.ntp. R.aa.pLing and rsanaLya la at. n.c.aaacy
for variflcation.
— C.caada Naslaus C.nta.Inant Lav.1 (MCL I for Prisary Drinking Watar Standards.
-------
hULl 6 lCoat.I
3W A1T OF IUOIG3U!C & <SI5 — WILl. WATU CAISPLES
I IC*UTO I1UC&l . CONP aT, SOD1 SPZIUG S. ID&flO
lug/I)
TWZ 2 rW36 rw li TW3I TW39
I1.aent lhitilt.r.d riLt.t.d Unfilt.r.d rilt.r.d lInfilt.r.d r11t.r.d UnfIlt. r.d Filtered Unfiltered Filt.t.d
AlumInum 513 55J 343 113 1260 1210. 9990 753 453 493
Ant i.ony 31 U 32 U 31 U 31 U 32 U 31 Il 31 U 31 U 31 U 31 U
Arsenic 13 103 43 53 25 31 12 4U 53 63
CerIum 33.3 333 323 313 153 453 1633 57 . 2 253 253
I.ry l liu. IU IU IV LU LU LU II I LU 111 IU
Cadmium 41 ’ 16’ 57’ 51’ 791’ 752’ 5 U S 10 S
CaLCIUm 160000 157000 95300 93700 133000 132000 131000 121000 100000 99500
Cbro.iu. SU SU SU SU 34 26 su Su Su su
Cobalt CU Cu Cu Cu 93 73 103 6U 6u 611
Copp.r 9U 9U 9U 9U 93 103 223 911 911 9U
Iron 31 U 31 U 31 U 31 U 1130 919 23100 125 31 U 31 U
L.ad 1 13 IOU LU 13 123 13 103 111 111 PU
MagnesIum 10500 10200 14509 73900 73000 72500 50900 46500 99200 102000
Mangan.s. 1300 1300 27 26 2150 2170 324 13 .2 9 .2 S 3
H.rcury 0.213 0.ZU 0.213 0.2 1 1 0.2U 0.IU 0.2U 0.211 0.211 0.2u
Nickel 16 13 363 343 346 345 133 7U 253 213
Potassium 75300 73600 11900 19900 14100 12300 5510 4950 3 21300 20600
S.1.n iu. 1994’ 1613’ 5503’ 6563’ 2913’ 1513’ 23 1 J 115 .1’ 590 .1’
Cii ,. , SU 513 SU SU SU 313 313 SU SU 511
Sodium 135000 133000 52200 54500 55500 54600 66600 66000 66500 64900
Thallium 30V IOU 2013 ZU 20 11 23 2U 2013 2011 2011
Vanadium S 3 5 3 21 3 21 3 151 145 105 53 I I 3 14 3
ZInc 132 134 60S 594 6160 6130 45 40 199 175
I I — The •aterial was analyu.d for, but was not detected. rh. a.sociat.d nu..rical value Is the •sti.ated detection Limit.
3 — The associated numerical value is an estimated quantity because quality control criteria wer. not met or concentrations reported wer.
less than the CRQL.
— laceeda Masimum Contaminant Lev.1 (NCL) for Pri.ary Drinking Water Standards.
-------
TAMZ 6 ICont.I
SUIVIA1T Or ThOIG VIC *IALTSIS — lOlL!. TU S?JIPLIS
UIISkVTO vuciu. coisPiVI 1 sons Siaz.os, IDASO
lug/ i)
I V 40 Sun Tranaf.r Slant r.d.r.l Maxt.um
______________________ ______________________ _____________________ Contaminant
Limit for
Unfiit.r.d rilt.r.d Unfiit.r.d 1it.r.d Unftltsr.d rllt.r.d Drinking Wat.r
Aluminum 703 503 223 200 303 203
Aflt imOnV 31 U 31 U 35 U 31 U 31 U 31 U
ArasnIc 73 53 SU 4U 4U 40 50
Sarlu. 46 3 46 3 100 3 105 3 1 U I U 1000
Ssry l liu. IU IU IU LU 10 LU
Cadmium 5 520 5 520 S U 11 10 7 10
Calcium 205000 197000 116000 114000 16S 3 270 3
Chro.Iu. S U S U S U S U S U S U 50
Cobalt SU SO IU 60 60 C i
Cepp.r 103 *03 9U 9U 90 9U
Iron 310 310 310 31U 310 31U
L.ad LU 111 1%) *3 13 13 50
Sagns.iu. 100000 96400 61100 59900 115 3 90 U
lOangan... 1260 1220 5 U S 3 5 U S U
fl.rcury 0.5 0.4 0.2U 0.2U 0.2U 0.2U 2
NIck.i 125 121 70 7U 70
Pota..ium 00700 03200 9960 9610 111 U 11* U
S.1.n iu . 359 J 315 3’ 20 U 20 U 4 3 3 U 10
SiLv.r SU SU SU 50 SU Su so
Sodium 266000 256000 11200 14300 1500 U 1500 U
Thallium 2U 433 2U 2U 20 20
Vanadju. 5 5 56 - 53 53 2U
Sinc 10200 9430 17 .7 IS 16 3 21
U — Tb. .at.ria L was •nalys.d for, but was not d.tsct.d. Tb. •..ociat.d nua.rlc.* valu. 1. th. . .ti..t.d d.t.ction limit.
J — lb. aaaociat.d nu..rical valu. Is an •.tI.at.d quantity b.caua• quality control crit.rla v.r. not •at or conc.ntratlona
c.portid war. 1... than th. CRQ1..
• — !zca.da flaii.um Contaminant L.v.l INCI.) for Primary Drinking Vat.r Standard..
-------
T*ILZ 7
SUIWJT OP CONPOU DI OZTICI’ZD IT ZIOVATID’ LOTUS II
UITILT1110 0*0010 SOD SUOPACI VA I* SAIIPLIS
ODISAITO I1UCAL NP1iuT. SODk 5901105 1*5*0
ug/1)
Dackqround
Valus
Coapound TW IS •PW I PWI PW3 1W17 1W22 TW36 TW3J TW3$ TW39 TW4O MS i CD
&lu.Inu. 34 3 1260 9990 111 3
Arsenic 4 U 25 12
Cad. iu. S Ii OS 41 57 751 5520 32
Chromium S U 34
Iron 31 U 1130 23700 100
Mangan... S U 1320 1300 27 2130 324 1260
Nickel 7U 76 363 246 25.3 125
Potassium 2700 3 4430 .7 75300 17900 74100 33700
S.len iu m I U I 19 3 139 3 550 3 291 .7 775 .7 359 3 91 3 *7 .7
Sodium $310 90300 135000 05300 266000
Vanadium 2 3 35 3 27 3 153 103 5 1 23 3 3) 3
Zinc $3 Il 112 132 600 6160 199 10200 122
SulIat. 2 2 34 940 400 640
Pluorid. 2 11 22
Total Phospkorou. •.oi 2.2 4.5 3.9 1.5
U — Tb. •atscisl was analyu.d tore but was not d.t.ct•d. Th. •ssoci.t.d nua.rical valu. is th. .sti.at.d d.t.ction limit.
3 — The asaociat.d nuasrical vain. is an .stlmat.d quantity becaua. quality control crit.ria w.r. not ..t or conc.ntrations r.port.d var.
1... than the CIQI..
ft — Quality Control indicat.. that data are unusable (compound •ay or may not be pr.aent). R.a..plinq and r.analy.ls are n.c.saary br
..ritication.
• — Oic..ds Maai.u. Contaminant L.v.1 (MCL I t sr Pri..ry Drinkinq Water Standards.
I — D.tln.d as grsat.r than or .qual to 10 tines background value or 3 ti..s d.t.ction limit It und.t.ct.d In background s..pL..
2 — Concentrations reported in ag/I.
-------
Analyses for hydrolyzable phosphorous and orthophosphate were also
performed. These analyses indicated the presence of other forms of
phosphorous (possibly present as aqueous species) In concentrations
typically veil below the corresponding total phosphorous concentration,
except in the two pond liquid samples.
The sediment sample from the old underflov solids pond was
determined to contain 4.5 weight percent of fluoride, vith much lesser
concentrations of sulfate (2,000 mg/kg) and phosphorous (0.02 mg/kg).
In comparison, the coke and quartzite slurry pond sediment contained
less fluoride (0.25 vtZ) and sulfate, but significantly more phosphorous
(115 mg/kg).
13.4 Discussion
Elevated levels of TCL compounds were detected in the majority of
the monitoring veil samples, the effluent discharge sample, Mormon
Springs, and two production veils. TCL compounds detected include
cadmium, manganese, nickel, potassium, selenium, sodium, vanadium, and
zinc. In addition, fluoride, sulfate, and phosphorous were detected at
elevated concentrations in several monitoring veils. It is possible
that the elevated levels of vanadium may result from a contaminant plume
(identified in the Colder Associates Report) entering the site from the
east.
Primary Drinking Water Standards are exceeded for either cadmium,
selenium, and fluoride in several monitoring well samples Fyi. PW1 was
a partial source of drinking vater for employees until 1984. Elevated
levels of vanadium and potassium were detected in PV3 and PVZ, respec-
tively. Both are currently used to supply drinking water to site
employees. Bovever, no MCL currently exists for vanadium or potassium.
For ground water samples, the highest concentrations of analytes
vere generally detected in TV 37 and TV 40. These monitoring veils are
installed immediately dovngradient of the old underf low solids pond and
hydroclarifier, which are two of the three sources of ground—vater con-
tamination identified in the Colder Associates Report (1). Analysis of
the sediment from the old underfiow solids pond, and of vater in the
phossy water surge pond and seal water pond indicated the presence of
TCL compounds and ions that were also identified in the gtound—vater
samples.
14.0 SUMMARY AND CONCLUSIONS
The MCC operates on elemental phosphorous plant in southeastern
Idaho. The plant is within three miles of the City of Soda Springs,
vhich has a spring—fed municipal water supply serving approximately
3,000 people. Ground water contamination under the Monsanto site was
identified in a preliminary assessment conducted in 1984. £ later.
report by Colder Associates in 1985 identified the sources of contami-
nants as a leaky hydroclarifier and several unlined ponds. Monsanto has
f
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Monsanto Chemical Company Mining Waste NPL Site Summary Report
Reference 2
Excerpts From Hazard Ranking System Score Sheet and Documentation for the
Monsanto Chemical Company; Lynn Guilford, EPA; May 16, 1988
‘1
-------
nsanto Oeiucal “ (S 0t L 1 .Spr’&ij5 PI 1 +)
Soda Sgrincs, idam
I
-
EPARS 10
8ob C ddis. Erwirt nt nta1 ngir r (2 47- 4l1
L n, Gsilford May 16. 1988
O.ie rU di....i1.U... . tis f l y
(F . ...,L ls U. af øM. çr sv e s 04 Pis L a’ I 04
f& ty 1amWi& on mut• al mai ‘ n : D l h f m a0ori ra Q aQI Xy OI1. i .)
I’t,nsants) O nical Comanv prod,ces eleTental D SD nJS. VLaSte water fr e
plant is disthar ed on-site ponds. fl old unc rflcw xmds re u,lired and
are cirrently r t used. Samle analysis of qr .g,djater Frau on-site n nimrina
l1s indicates orwnct iater contanination. includinp ars iic. cadiiitm. chr iuui,
The effl uent dj crFuar t jc roeo pç rrn-mnr - #-‘ • 1 i!! _
rt i, V1 CFh2r l P C 4 f.’c . Wfl1f ‘ •ic j•?.t’I I
N ..f C 4 rI 1 I?1 11ç !r!l fl,, r :....r. - - ¶ I. — . -
raait . -
lB • 0
5 FE r tsCored
C t SCOred
FiGURE 1
HRS COVER SHEET
, 4.
I_i I.
4Z1 “
I —
L
- 1
1’7 0003
1-’
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GROUND WATER ROUTE
1. OBSERVED RELEASE
la. Contaminants Detected j niaximutn in Ground Water
Arsenic, cadmium, and chromium, were found in monitoring well TW37.
Cadmium, and manganese were found in TW4O (Ref. 2, pp. 17—18, 22—23;
Ref. 6).
OBSERVED REEEASES TO GROUND WATER
(Sampling Analysis November 3, 1987, Ref. 2)
Compound Detection Concentration
Detected Sample Number Limit Detected
Arsenic TW15*
Arsenic TW37
4 ug/l Undetected
4 ug/]. 25 ugh
Cadmium - TW15*
Cadmium - .Transfer Blank
Cadmium - TW4O
Cadmium TW37
Cadmium PW1
5 ug/]. Undetected
5 ugh 10 ug/1
5 ug/l 5,520 ug/1
5 ugh 78]. ug/1
5 ugh 88 ugh
.
Chromium TW15*
Chromium TW37
5 ugh Undetected
5 ugh 34 ugh
.
* Denotes background
TW = Monitoring Well
COMPOUNDS IN SEDIMENT SAMPLE P1
(Sampling Analysis
FROM THE OLD UNDERFLOW PONDS
November 4, 1987)
Compound Detection
Detected Limit
Concentration
Detected
Arsenic 1 mg/kg 248 mg/kg
Cadmium 8 mg/kg 2,140 mg/kg
Chromium < 44 mg/kg 1,220 mg/kg
- Rationale for attributing the contaminants to the fac J.ity:
Monsanto monitoring wells TW37, TW4O, production well PWI, and ac :arou
well TW15 are u gradient of any potential contamination from Kerr c ae
Chemical Corooration, whicn 1.5 adjacent to Mon5anto (Ref. 1, p. ‘5: :
pp. 8, 12, and 17; Ref. 5, f:cures 5.7, 5.3, 5.15). The same
found in tne ground water of TW37 were found n P1 (a 5edi ent
the old underfiow pond which received wastewater). The backgrcu .: p
2
-------
compound(s) with highest score:
Arsenic, cadmium, and chromium.
S Section Score : 18 (Ref. 4)
b. Hazardous Waste Quantity
— Total amount of hazardous substance at the facility, excluding
those with a containment score of zero. (Give a reasonable estimate,
even if the quantity is above maximum.):
The one time waste quantity volume of the two old underf low ponds.
which contain elevated levels of arsenic, cadmium, and chromium
is 488,889 yds. (Ref. 2, P. 25). The ponds that are no longer in use an
were not lined are the waste quantities used (Ref. 2, pp. 11, 12, 14).
- Basis of estimating and/or computing waste quantity (must be docu-
mented quantity and not assumed):
400 x 600 X 20 = 4,800,000 ft3 ]
÷ 27 ft/yd3 = 488,898 yd3
700 x 600 x 20 8,400,000 ft3] -
The surface areas were measured from a USGS map (Ref. 6). The
depth of 20 feet was used for computing purposes and reflects a
conservative figure. This depth is less than one half the depth of
feet (calculated from engineering maps) to the lowest point (Ref.
16). Other waste quantities exist but were not used to calculate
the total waste quantity (Ref. 2, pp. 11, 12).
HRS Section Score : 8 (Ref. 4)
****** ****
TARGETS
a. Ground Water !
- Use(s) of aquifer(s) of concern within a three—mile radius of the
facility:
The aquifer of concern is the shallow ground water system. All of the on-
site wells are screened in the Shallow Ground Water System. The shallow
aquifer meets the Mead Thrust Aquifer on the east side of the valley
where the mountains meet the zalley. The strings are round near faults
therG the a ifers meet (Ref. 15, c . 2-8 and 2 9). ound atar :s usa
or drinking water, irrigation, and industr al purposes wiz u.n z ree
miles of the site. The Cit’, of Soda Springs uses t dge Creek spr q3
drinking water (Ref. 2, . 9; Ref. 5). There is no unthreatened
alternate source availaDle (Ref. 18).
fRS Sect.oli Sc re : 2 (Ref. 4
6
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SURFACE WATER ROUTE
1. OBSERVED RELEASE
la. Contaminants Detected fl Surface Water at the Facility Q Down-
gradient j j maximum )
Cadmium was detected in the effluent discharge stream at 32 ugh with
a detection limit of 5 ugh. The transfer blank contained cadmium at
10 ugh. I4onsanto’s NPDES permit only reg .i1ates temperature (Ref. 2,
pp. 11, 12, 14, 18, 19, 22c, 23, and 25; Ref. 6; Ref. 10).
- Rationale for attributing contaminants to the facility:
Cadmium was detected in the effluent discharge. Cadmium in the blank was thcu&hc tc’
be the resnit of residnal carryover from a previously analyzed sample (Ref. 13).
Cadmium has been detected in the effluent twice before, in November, an. 4
February, 1985. at levels of 22 ugh, and 30 ugf 1, respectively (Ref. 15. pp. 3—23,
3—24 and Appendix A).
• Cooling water from the plant enters an effluent discharge pond (sample
ED was collected just past the effluent discharge). Water from the pond
is pumped Soda Creek 2,000 feet away via a discharge stream. The
discharge water perennially flows to Soda Creek. One and one-quarter
miles downstream, water from Soda Creek is withdrawn to Soda Canal where
it is used for irrigation (Ref. 2, pp. 11 12, and 14; Ref. 9).
S Section Score : 45 (Ref. 4)
2. ROUTE CHARACTERISTICS
2a. Facility SloDe flg Intervening Terrain
- Average slope of facility/site in percent:
N/A
- ;lame description of nearest down-slope surface water:
N/A
- Average slope of terrain between facility and above-c ted surfac
iater body in percent:
N/A
,
-------
Is there tidal influence? Yes I (circle one)
The site is not near an ocean and a reservoir is downstream (Ref. 6;
Ref. -11)
HRS Section Score : 2 (Ref. 4)
b. Distance Sensitive Environment
- Distance to 5 acre (minimum) coastal wetland, if 2 miles or less:
coastal wetland greater then two miles (Ref. 6; Ref. 14).
- Distance to 5—acre (minimum) fresh-water wetland, if 1 mile or
less:
The 1/2 mile stretch of Soda Creek is listed as a wetland. However, thE
total area is less than 5 acres. The distance from the site is 1/2 milE
(Ref. 6; Ref. 14).
- Distance to critical habitat of federal endangered species or na—
tiona]. wildlife refuge, if 1 mile or less:
There are no endangered species living -within one mile. Some bald
eagles winter in the area (Ref.l2).
S Section 0 (Ref. 4)
5c. PoDulation Served g Water
- Location(s) of water-supply intake(s) within 3 miles (free-flowing
bodies) or 1 mile (static bodies) downstream of the hazardous sub-
stance and population served by each intake:
The only surface water intakes are for irrigation (Ref. 2, p. 7) (Ref.
6; Ref. 25). Surface water is used to irrigate 4,040 acres (Ref. 8) as
well as 200 acres of hay (Ref. 25). Although the point of diversion o
water from Soda Creek for the 4,040 acres is within the three mile liini
the point of actual use is several miles beyond the three mile limit.
This acreage will not be included in the population count, however EPA
Region 10 views the use of cadmium contaminated irrigation water as
presenting a serious threat to human health and the environment.
- Compute land area irrigated by above-cited intake(s) and convert to
population (1.5 ‘people per acre):
200 acres of land are irrigated for food and fcrage crops (Ref.
200 x 1.5 = 00 people
- Total population served: 00
4’ ‘‘L
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Mining Waste NPL Site Summary Report
Monticello Mill Site
San Juan County, Utah
U.S. Environmental Protection Agency
Office of Solid Waste
June 21, 1991
FINAL DRAFT
Prepared by:
Science Applications International Corporation
Environmental Health and Sciences Group
7600-A Leesburg Pike
Falls Church, Virginia 22043
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DISCLAIMER AND ACKNOWLEDGEMENTS
The mention of company or product names is not to be considered an
endorsement by the U.S. Government or by the U.S. Environmental
Protection Agency (EPA). This document was prepared by Science
Applications International Corporation (SAIC) in partial fulfillment of
EPA Contract Number 68-WO.0025, Work Assignment Number 20.
A previous draft of this report was provided to Paul Mushovic of EPA
Region VIII [ (303) 294-7079], the Remedial Project Manager for the
site, whose comments have been incorporated into the report.
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Mining Waste NPL Site Summary Report
MONTICELLO MILL SITE
SAN JUAN COUNTY, UTAH
INTRODUCTION
This Site Summary Report for the Monticello Mill Site is one of a series of reports on mining sites on
the National Priorities List (NPL). The reports have been prepared to support EPA’s mining program
activities. In general, these reports summarize types of environmental damages and associated mining
waste management practices at sites on (or proposed for) the NPL as of February 11, 1991(56
Federal Register 5598). This summary report is based on information obtained from EPA files and
reports and on a review of the summary by the EPA Region VIII Remedial Project Manager for the
site, Paul Mushovic.
SITE OVERVIEW
The Monticello Mill Tailings site is an abandoned uranium/vanadium mill occupying 78 acres in, and
adjacent to, the City of Monticello, San Juan County, Utah (see Figure 1). The tailings and residual
ore remaining at the site have contaminated soils, ground water, and surface water in Montezuma
Creek, which flows through the Mill site. An additional 300 acres of peripheral properties (properties
adjacent to the Mill site and a 3.3-mile reach of Montezuma Creek between the Town of Monticello
and Vega Creek) have been contaminated by airborne particles from tailings and water-transported
tailings and ore from leftover piles.
According to EPA, approximately 1.8 million cubic yards of tailings and contaminated soil are
located in the tailings-impoundment area on the east side of the mill. An additional 100,000 cubic
yards of contaminated materials have been identified in the Mill area (Reference 2, page 1). The
tailings and contaminated soils contain elevated levels of both radioactive and nonradioactive
contaminants of concern. These constituents are products of the uranium 238-decay cycle (including
radium 226) arsenic, cadmium, chromium, copper, lead, mercury, molybdenum, nickel, selenium,
vanadium, and zinc.
As of 1990, the population within 1.5 miles of the site was estimated at 1,900 (Reference 2, page 1),
The population is concentrated north and west of the Monticello Mill site (Reference 1, page 2-1).
The Mill site is located in a controlled land zoning district that permits a mix of agricultural,
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residential, commercial, and industrial use (Reference 1, page 2-11). The average annual
precipitation in the Monticello area is 18.3 inches. Prevailing annual winds are generally from the
south, west-southwest, and northwest (Reference 2, page 4).
The site has been separated into three Operable Units for remediation. Operable Unit 1 consists of
the mill tailings, Operable Unit 2 encompasses the peripheral properties, and Operable Unit 3 has
been defined as the contaminated ground water and surface water. The selected remedy for
remediating Operable Unit 1 is the stabilization of the tailings piles. This effort is estimated at a
present value of $42.3 million (Reference 2, page 33). The peripheral properties (Operable Unit 2)
will be remediated using a variety of excavation/construction techniques. A present value of $12.6 to
$18.5 million is estimated for the remediation of Operable Unit 2 (Reference 2, page 36). A separate
Record of Decision (ROD) will be prepared for Operable Unit 3 following the completion of an
Remedial InvestigationlFeasibility Study (Reference 2, pages 6 and 7).
OPERATING HISTORY
The Monticello Mill site began operation as a vanadium ore-buying station in the 1940’s. As ore
production increased, a vanadium mill was constructed with government funding. The Mill began
vanadium production in 1942 and uranium-vanadium sludge production in 1943 for the Manhattan
Engineer District. The mill was closed in February 1944; ii was reopened in 1945 and produced
uranium-vanadium sludge until 1946 (Reference 1, page 1-9). A salt-roast process was used to
convert vanadium minerals to soluble form. After pyrite was added to react with some of the calcium
(in the excess lime in the ore) to form calcium sulfate, the hot ore was quenched in sodium carbonate
to dissolve most vanadium and precipitate out calcium carbonate. Remaining sands, after successive
washings, were transferred to tailings ponds. The addition of sulfuric acid to the “pregnant liquor”
(i.e, the vanadium-bearing solution) induced the precipitation of vanadium pentoxide. The precipitate
was washed to remove sodium chloride and sodium sulfate, and the wash water was discharged to the
creek (Reference 1, page 1-10).
In 1948, the Atomic Energy Commission (AEC) bought the Monticello Mill site from the War Assets
Administration and operated a uranium mill at the site until January 1960. Numerous uranium
milling processes were used during this period to accommodate the wide variety of ore types received
at the mill. Up to 1955, processes included raw ore carbonate leach, low-temperature roast/hot
carbonate leach, and salt roast/hot carbonate leach; acid leach-Resin-in-Pulp (RIP) and raw ore
carbonate leach from 1955 to 1958; and a carbonate pressure leach RIP process from August 1958
until closure of the mill in 1960. The ore-buying station remained open until March 31, 1962
(Reference 1, pages 1-9 and 1-10). Other than parts of the land transferred to the U.S. Bureau of
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Monticello Mill Site
Land Management, since 1949, the site has remained under the control of the AEC and its successor
agencies [ first the U.S. Energy Research and Development Administration and, more recently, the
U.S. Department of Energy (DOE)) (Reference 1, page xv).
Four tailings impoundments were constructed at the Monticello Mill site. Two tailings
impoundments, the Vanadium Pile and the Carbonate Pile, received waste material prior to the 1955
installation of the acid leach RIP plant. The Carbonate Pile received tailings from the AEC salt
roast/hot carbonate leach milling process. It is not known which of the several milling processes in
use prior to acid leach-RIP produced the tailings in the Vanadium Pile. The Vanadium Pile and the
Carbonate Pile may have been used simultaneously. The Acid Tailings Pile received waste in 1955
and 1956 from the operation of both the acid leach-RIP and carbonate-leach plants. Tailings from the
acid leach process were combined with carbonate plant tailings and calcium hydroxide for
neutralization and then pumped to the Acid Pile (where a portion of pond overflow was recycled
through the leach circuit). The remaining overflow was discharged to Montezuma Creek. To reduce
discharges to Montezuma Creek, the Acid Pile was constructed with a 6-inch liner of compacted
bentonite to prevent seepage; tailings-pond effluent was partially recycled. A fourth tailings
impoundment, referred to as the East Pile, was constructed to increase capacity. ft received tailings
from 1956 to 1960 (Reference 1, pages 1-10 through 1-14).
During the Mill’s period of operation, the tailings impoundments were moist. However, within a
year of shutdown, the surfaces dried out and tailings sand began to migrate as sand dunes. In
addition, water erosion “became a problem” (Reference 1, page 1-17).
AEC began stabilizing the piles in the summer of 1961 by grading, adding 8 to 12 inches of fill,
adding topsoil, and planting native grasses. Concurrent with the tailings-pile stabilization, the Mill
facilities were dismantled. Equipment was sold, burned, or buried onsite in trenches excavated near
the Carbonate Pile (and covered with tailings) (Reference 1, page 1-17).
During the summer of 1965, contaminated surface soil was removed from peripheral properties
previously used for ore storage. This soil may have been used as fill material to partially bury the
mill foundations.
Following a radiation survey of the South Stockpile Area and Ore-buying Station in 1972,
contaminated soil was removed from these areas in May 1974 and August 1975. Nearly 15,000 cubic
yards of contaminated soil, which was placed on top of the East Pile, was graded, contoured, and
reseeded. Mill foundations were demolished and bulldozed into adjacent pits (Reference 1, page 1-
17).
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Mining Waste NPL Site Summary Report
The Monticello Mill site was accepted into the Surplus Facilities Management Program in 1980 and
the Monticello Remedial Action Project was established to restore the government-owned Mill site to
safe levels of radioactivity; to dispose of (or contain) the tailings in an environmentally safe manner;
and to perftnn remedial actions at offsite (vicinity) properties that had been contaminated by
radioactive material from mill operations. Site characterization activities commenced in 1981. In
1983, remedial activities for vicinity properties were separated from the Monticello Remedial Action
Project. The Monticello Remedial Action Project Site Analysis Report (covering the Mill site only)
became final in 1984 (Reference 1, pages 1-1 and 1-2). The Monticello Vicinity Properties are the
subject of a separate NPL Site Summary Report.
DOE, EPA, and the State of Utah entered into a Federal Facility Agreement pursuant to
Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Section 120 in
December 1988. The Agreement stipulates the procedural framework for developing and
implementing response actions under CERCLA, as amended. On November 16, 1989, the Monticello
Mill site was listed on the NPL (Reference 1, page 1-2).
SITE CHARACTERIZATION
The major source of contamination at the site is the estimated 903,000 tons of radioactive mill
tailings. Residual uranium ore found in ore-stockpile areas is also a minor, additional contamination
source (Reference 1, pages 3-3 and 3-4). There are an estimated 1.5 million cubic yards of
contaminated soils and tailings at the site. Radionucleides of concern include products of the
uranium-238 decay series, including radium 226. Nonradiological constituents of concern include
arsenic, cadmium, chromium, copper, lead, mercury, molybdenum, nickel, selenium, vanadium, and
zinc (Reference 2, pages 12 through 14).
Ground Water
Two primary aquifers underlie the site: an Alluvial Aquifer (composed of unconsolidated sands, silts,
and gravels) and the confined-to-semiconfined Burro Canyon Formation (composed primarily of
sandstones). The Alluvial Aquifer is approximately 15 feet thick near Montezuma Creek, but thins
toward the valley sides. Montezuma Creek is hydraulically connected to the Alluvial Aquifer on the
site. Downstream, a realigntnent of the Creek has resulted in the direct contact of the stream with the
Dakota Sandstone rather than the Alluvial Aquifer. Precipitation and surface-water infiltration
recharge the Alluvial Aquifer (Reference 1, page 4-26).
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Onsite sampling performed from 1984 to 1986 found elevated concentrations of contaminants in the
Alluvial Aquifer downgradient of tailings piles. Most of the highest concentrations were associated
with the tailings area. Radium 226 was detected at a maximum of 44 pico Curies per liter (Pci/I);
uranium at 12.8 milligrams per liter (mg/I); arsenic at 0.19 mg/I; vanadium at 4.7 mg/i; molybdenum
at 1.44 mg/I; and selenium at 0.16 mg/I. Cadmium, lead, chromium, and mercury were Not
Detected (ND) or detected at “very low concentrations” (Reference 1, page 4-44). Levels of “most”
contaminants in the Burro Canyon Aquifer “were similar to those observed in an upgradient well”
(Reference 1, page 4-46).
Surface soil has been contaminated by tailings, ore residue, tailings-pond overflow, emissions from
the roaster stack, and the erosion of tailings piles by wind and water. Uranium, radium 226, arsenic,
cadmium, chromium, copper, lead, molybdenum, vanadium, and zinc are present in the ore and
tailings at elevated concentrations (Reference 1, page 4-5).
It should be noted that radium was used as a proxy for the other metals and only results of radium
sampling were provided. Thus, “where the radium concentration is high, the concentrations of the
other elements will likely be high.” The Remedial Investigation indicated that the Mill site soil-layer
concentrations of radium 226 averaged 20 pico Curies per gram (Pci/g), with a maximum of over 500
Pci/g in an ore-stockpile area. [ The EPA standard for the top 15 centimeters (cm) of soil is 5 Pci/g
above background; below 15 cm, the standard is 15 Pci/g.J The average background concentration is
0.6 to 1.4 Pci/g. In offpile areas, subsurface radium 226 can be detected up to 6.5 feet. Soils and
alluvium were determined to exceed the EPA radium-226 standard for the entire thickness beneath the
tailings piles (Reference 1, pages 4-5, 4-9, and 4-10).
Two hundred acres of peripheral properties (properties adjacent to the Mill site but excluding the
Monticello Vicinity Properties NPL site), north, south, and east of the Mill site, also contained
elevated levels of radium 226. Properties include two former ore-storage areas, the weigh and buying
stations, three residences, and farm properties. In the ore-storage areas, radium 226 ranged from 6 to
5,763 Pci/g, with an average of 90 Pci/g. The depth of contamination, with some exceptions, was
generally less than I to 1.5 feet. At the weigh and buying stations, concentrations ranged from 6 to
7,185 Pci/g (no mean was provided) at maximum depths ranging from 0.5 to 6 feet. In the
residential and fanning areas to the north, surface-soil concentrations from 6 to 494 Pci/g were found
up to 0.5 mile from the Mill site boundary (the result of air transport). To the east (up to 0.25 mile
offsite) air, and waterborne radium-226 contamination (concentrations were not provided) was found
in surface soils. Along an old pathway of Montezuma Creek within 1,000 feet of the east boundary,
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Mining Waste NPL Site Summary Report
radium-226 concentrations up to 500 Pcilg extended to depths of 4 feet. Finally, Montezuma Creek
has deposited eroded tailings for several miles downstream. Sediments in locations as far downstream
as the confluence with Vega Creek (more than 4 miles downstream from the site) showed
concentrations (in 1982) up to 54 Pcilg. Average concentrations at the various downstream sampling
points ranged from 4.6 to 25.1 Pci/g; there was no correlation between distance and concentrations
(i.e., locations nearer the site were not necessarily more contaminated) (Reference 1, pages 4-10 and
4-11).
Surface Water
Montezuma Creek flows south of the remaining Mill buildings and between the tailings piles. As a
result of activities related to milling and (later) reclamation, the original channel was relocated south.
In addition, flow also exists in a drainage between the Carbonate and Vanadium piles. Numerous
seeps in the tailings-pile area contribute to seasonal flow in Montezuma Creek (Reference 1, pages 5-
I and 5-13).
Tailings-pond seeps and overflows discharged to Montezuma Creek throughout the operation of the
tailings impoundments, and liquid effluents from the salt roast/hot carbonate leach plant were
discharged to the Creek. In 1954, samples of Montezuma Creek detected chloride, sulfate, carbonate,
bicarbonate, sodium, and other contaminants at levels exceeding Utah water-quality standards. In
addition, soluble-radium activity in Montezuma Creek was found to be 160 Pci/g in 1958 (compared
to the standard of 1 Pci/g over background) (Reference 1, pages 1-14 and 1-16).
Samples obtained from onsite seeps and ponds and the unnamed drainage from 1984 to 1986 showed
concentrations of arsenic, molybdenum, radium 226, selenium, uranium, and vanadium. Levels of
radium measured in the seeps and ponds increased significantly moving eastward (and downstream),
from 4 Pci/I (at a seep between the Carbonate Tailings Pile and the Vanadium Tailings Pile) to 17
Pci/I (measured in the pond east of the Acid Pile) (see Figure 2) (Reference 1, pages 5-13 through 5-
15). Nonradiological contaminants (arsenic, zinc, manganese, molybdenum, selenium, and vanadium)
were elevated in Montezuma Creek downstream of the Mill site (Reference 1, page 5-18).
Uranium concentrations in Montezuma Creek begin to increase below the mill, and further increase
by an additional 40 to 50 percent toward the downstream boundary of the property below the tailings.
Concentrations of uranium, molybdenum, selenium, vanadium, and radium 226 all continue to
increase downstream of the Vanadium Pile. Uranium and molybdenum concentrations are even
higher offsite, the result of contributions from ground water in the Alluvial Aquifer (Reference 1,
pages 5-13 and 5-14).
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The salt-roast process used prior to 1955 produced large quantities of dust, chlorine, and hydrogen
chloride gas that were exhausted through the roaster stack. According to the Remedial Investigation,
local residents complained about corrosion of wire fences, clothes lines, galvanized roofs, etc.
(Reference 1, page 1-14).
Atmospheric-radon concentrations in 1983 and 1984 exceeded the EPA edge-of-pile standard of 0.5
pico Curies (pCi) above background [ 40 Code of Federal Regulations (CFR) Part 1921 at every
monitoring location on the Piles and on the DOE property boundary. With one exception (a location
610 meters northeast, where radium may have been transported and deposited on a narrow alluvial
floodplain), offsite concentrations met the standard (Reference 1, page 6-1 through 6-9).
Monitoring (in 1984) found that the EPA standard for radon emissions (40 CFR Part 192) at inactive
uranium-processing sites of 20 pico Curies per square meter per second (pCi/m 2 /sec) was exceeded at
each of the four tailings piles. The highest radon flux weighted average was 765 pCi/m 2 /sec (at the
Carbonate Pile); the lowest was 133 (at the East Pile) (Reference I, page 6-14).
Results of radiological air-particulate monitoring conducted at the Monticello Mill site from 1984 to
1986 are presented in Table I below. Onsite concentrations are inclusive of natural background,
while standards are given for levels above natural background.
TABLE 1. ANNUAL AVERAGE LEVELS OF ONSITE RADIOLOGICAL AIR PARTICLES
Constituent
Maximum
Concentration
DOE Standard
Radium 226
0.0006 pCi/rn 3
3.0 pCi/rn 3
Thorium 230
0.0004 pCi/rn 3
0.8 pCi/rn 3
Uranium 238
<0.0012 g g/m 3
9 ig/m’
pCi/m’ - pico Curies per cubic meter
- micrograms per cubic meter
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Monticello Mill Site
Levels of radium, thorium, and uranium were considerably below the standards applicable to
Monticello, as required by DOE Order 5480.1(b) - Environmental Safety and Health Program for
the Department of Energy Operations (Reference 1, page 6-25).
DOE’s Remedial Investigation Report stated that, of the nonradiological particulates measured, only
lead is regulated by a specific standard. The maximum concentration of lead measured at the site was
0.0490 micrograms per cubic meter (gig/rn’), which is below the National Ambient Air Quality
Standard (NAAQS) (under the Clean Air Act) for lead of 1.5 gig/rn’ for a 3-month average
concentration. Other nonradiological contaminants were compared to other published data since no
specific standards exist. Air concentrations of copper were compared to data obtained from a total
suspended particulates analysis performed in 1981 at Canyonlands National Park. The levels
measured in this 1984 to 1986 air-particulate study were similar to those obtained in the Canyonlands
Study. Vanadium measurements at one sampling station were only slightly above the background
station measurement. Iron, potassium, and manganese concentrations were higher on the east side of
the site, but were still considered below concentrations reported for urban desert settings (Reference
1, pages 6-25 and 6-27).
ENVIRONMENTAL DAMAGES AND RISKS
Radiological Contamination
The Public Health Assessment identified radon gas and gamma radiation as the major radiologic
contaminants of concern (Reference 2, page 12). Adverse health effects arise from the inhalation of
radon gas (a decay product of the radium 226 found in the tailings), as the lungs are exposed to the
full radiation dose of the radon daughters (Reference 2, page 12). In contrast, gamma radiation
creates adverse health effects as a result of full-body exposure (Reference 2, page 12).
Five potential exposure pathways were identified and considered fur quantitative analysis:
(I) inhalation and ingestion of airborne radioactive particulates; (2) ingestion of contaminated foods
(plant and 2nimal ) produced in areas contaminated by wind-blown tailings; (3) ingestion of surface
water contaminated by tailings; (4) inhalation of radon and radon daughters; and (5) direct exposure
to gamma radiation emitted from the tailings (Reference 2, pages 12 and 13).
The first two pathways were concluded to present insignificant exposure to humans since radiologic
analysis of air particulate samples typically yielded levels below detection (Reference 2, page 13).
The third pathway (ingestion of contaminated surface water) was not considered a probable pathway
because: (I) elevated radium concentrations have not yet been detected in Montezuma Creek; and
(2) although elevated concentrations of uranium have been detected in the Creek, the uranium dose
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Mining Waste NPL Site Summary Report
rate is low at low concentrations and it has a very long half-life (because of this, uranium exposure
was examined under nonradiological risks) (Reference 2, page 13).
Two pathways remained: (1) inhalation of radon and radon daughters; and (2) direct exposure to
gamma radiation emitted from the tailings. The cancer risk associated with inhalation of radon and
radon daughters from the Mill site and peripheral properties was estimated to be 0.0038 excess annual
cancer incidences to the Monticello population. Cancer risks from whole-body gama radiation
exposure were an estimated 0.02 excess annual cancer incidences for the Monticello population. (The
Radiological Risk Assessment was performed on a population basis prior to recent EPA guidance on
performing radiological risk assessments on an individual basis) (Reference 2, pages 12 and 13).
N dioI i l
The following nonradioactive elements were selected as “highest risk” or indicator contaminants at the
Mill site or peripheral properties: arsenic, copper, lead, molybdenum, selenium, uranium, vanadium,
and zinc (Reference 2, pages 13 and 14). Noncarcinogenic health effects can arise from acute and
chronic exposures to all eight elements; only arsenic is considered to be a human carcinogen
(Reference 2, page 15).
Four potential exposure pathways were identified based on the population and activity patterns in the
vicinity of the Mill site: (1) resuspended dust inhalation; (2) soil ingestion; (3) vegetable ingestion;
and (4) beef ingestion (Reference 2, page 14). The first pathway was excluded from further
quantitative analysis because particulate concentrations were at background levels or below, and the
Remedial Investigation determined that lead concentrations were well below NAAQS (Reference 2,
page 14). The second pathway was also excluded because current and expected future access to the
site (it is currently fenced) is, and will be, very limited (Reference 2, page 14). The vegetable and
animal ingestion pathways were retained for quantitative analysis, since the pathways are considered
to be indirect exposure routes resulting from contaminated surface water used to irrigate fields and
water livestock.
A human “dose” (intake) was calculated for each indicator metal and pathway (vegetable and beef
ingestion) for both adults and children based on the average and maximum concentrations of indicator
metals found in soils (Reference 2, page 15). (The relationship between the soil concentration and
vegetable or beef tissue concentration was not explained.) Each “dose” was compared to an EPA-
developed reference dose for chronic (long-term) exposure to each metal. This comparison revealed
that no reference doses were exceeded based on average metal concentrations; and therefore, the
calculated doses are not likely to be associated with health risks (Reference 2, page 15). However,
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when maximum metal concentrations were used, uranium, copper (including the vegetable pathway),
and zinc (the beef pathway, including or excluding the vegetable pathway) “doses” for children were
exceeded. It was concluded, however, that it was unlikely that individuals would receive chronic
exposure to these maximum concentrations (because the site is uninhabited and because of past land-
use patterns). Thus, there was “no apparent health risk” (Reference 2, page 15).
Arsenic is the only Mill site contaminant of concern that is considered a carcinogen by EPA
(Reference 2, page 15). Cancer risk due to ingested arsenic (via the vegetable pathway) was
calculated using soil concentrations. (Again, the relationship between soil concentrations and
vegetable concentrations was not provided.) At maximum soil concentrations, the excess lifetime
cancer risk is 2.7 x 10’; and it is 7.0 x l0 for average soil concentrations (Reference 2, page 16).
Calculated cancer risk due to ingested arsenic (via the beef pathway) was calculated using soil
concentrations. At maximum soil concentrations, the cancer risk is 2.0 x 10-’; and it is 2.0 x 10 for
average soil concentrations. It was concluded that “arsenic may pose a public health impact under the
existing conditions at the site” (Reference 2, page 16).
REMEDIAL ACTIONS AND COSTS
The ROD for the site was signed in September 1990 (Reference 2, page 4). The remediation includes
two of the three Operable Units at the Mill site.
Operable Unit 1, the Mill Tailings Piles, will be remediated by relocating and stabilizing 1.9 million
cubic yards of mill tailings and contaminated materials at a repository site approximately .5 mile
south of (and adjacent to) the Mill site. The Montezuma Creek channel will be reconstructed to
accommodate average stream flow and a minimum of a 100-year inflow design flood event. The
excavated areas will be backtilled with clean soil; graded; and revegetated. Remediation of Operable
Unit I is estimated to cost $52.1 million in capital outlays, $8.69 million in contingency costs, and
$40,846 a year for operation and maintenance costs from 1996 to 2020. The total present value cost
is estimated to be $42.3 million (Reference 2, pages 1 and 29 through 32).
Operable Unit 2 comprises peripheral properties. The proposed remediation consists of a combination
of removing contaminated soil through conventional construction techniques; removing soil using
environmentally sensitive techniques (i.e., hand-shoveling); and allowing contaminated soil to remain
in place where removal could cause undue environmental damage. Remedial soil will be placed in the
repository named above for Operable Unit 1. An estimated 311,600 cubic yards of contaminated
material are present, including 8,000 cubic yards that may be left in place. The estimated present
value cost of this remediation is $12.65 to $18.46 million (Reference 2, page 34).
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CURRENT STATUS
According to the Remedial Project Manager for the site, a phased remedial design is currently
underway for Operable Units 1 and 2. Construction of the new repository and relocation of the
tailings is expected to begin in 1994.
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Monticello Mill Site
REFERENCES
1. Surplus Facilities Management Program, Monticello, Utah, Revised Draft Remedial Uranium
Mill Tailings Site Investigation; Prepared for DOE by UNC Geotech; April 1989.
2. Declaration for the Record of Decision and Record of Decision Summary, Monticello Remedial
Action Project; DOE, Idaho Operations Office, Grand Junction Projects Office; August 1990.
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BIBLIOGRAPHY
DOE, Grand Junction Projects Office. Monticello Remedial Action Project Site Analysis. October
1984.
DOE, Grand Junction Projects Office. Proposed Plan for the Monticello Mill Tailings Site. October
1984.
DOE, Idaho Operations Office, Grand Junction Projects Office. Declaration for the Record of
Decision and Record of Decision Summary, Monticello Remedial Action Project. August 1990.
Lamb, Laurie (SAIC), Meeting Concerning Monticello Mill site with Paul Mushovic, Remedial
Project Manager, EPA Region VIII. October 22, 1990.
Lamb, Laurie (SAIC), Meeting Concerning Monticello Mill site with Paul Mushovic, Remedial
Project Manager, EPA Region VIII. May 17, 1991.
Marurzky, S.J. et al., (DOE, Grand Junction Projects Office. Radiological Characterization of the
Peripheral Properties Adjacent to the Monticello, Utah, Mill Site (GJ-26). Undated.
Prepared for DOE by UNC Geotech. Surplus Facilities Management Program, Monticello, Utah,
Revised Draft Remedial Uranium Mill Tailings Site Investigation. April 1989.
Prepared for DOE by UNC Geotech. Surplus Facilities Management Program, Monticello, Utah,
Uranium Mill Tailings Site Remedial Investigation/Feasibility Study, Volume II, Revised Draft
Feasibility Study. April 1989.
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Reference 1
Excerpts From the Surplus Facilities Management Program, Monticello, Utah,
Revised Draft Remedial Uranium Mill Tailings Site Investigation;
Prepared for DOE by UNC Geotech; April 1989
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0010053
l I
.3. Dce
Monticello, Utah, Uranium Mlii Tailings Site
Remedial inveetlgatlon/Feasiblilty Study
Volume I
Revised
Draft Remedial Investigation
April 1989
Woik perfuimid under DOE Coidr& 1 No. DE-ACO7-861D1 2584
for the U.S. Duperlinent Energy
G,arid Juni hon Pvvje s Omcs
oc a
W M
UNC Geotech
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I O;oc
DOE/ID/12584-21
UNC/GJ-MRAP- 2
REVISED DRAFT REMEDIAL INVESTIGATION
FOR THE MONTICELLO URANIUM MILL TAILINGS SITE.
MONTICELLO. Ui ’AH
Apr11 1989
UNC Geotech
Grand Junction, Colorado 81502
Prepared for the
U.S. Department of Energy
Surplus Facilities Manageaent Progra.
Under Contract No. DE—ACO7—861D12584
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EXECUTIVE SUT.NARY
The Monticello MilIsite is a 78—acre tract located along Montezuma Creek south
of the City of Monticello. San Juan County. Utah. The miii was constructed by
the Vanadium Corporation of America (VCA) In 1942 with funds from the Defense
Plant Corporation. Initially, vanadium was produced, but from 1943 to 1944 a
uranium-vanadium sludge was produced by VCA for the Manhattan Engineer
District (MED). After milling operations ceased In 1944, VCA leased the mill
from 1945 to 1946 to produce the uranium-vanadium sludge for MED. The Atomic
Energy Commission (AEC) bought the site In 1948. Uranium milling commenced 15
September 1949 and continued to 1 January 1960, when the mill was permanently
closed. Part of the land was transferred to the Bureau of Land Management.
but otherwise the site has remained under the control of the AEC and Its
successor agencies, the U.S. Energy Research and Development Administration
and the U.S. Department of Energy.
Approximately I million tons of uranium ore were processed at the mill; the
resultant tailings are stored in four piles. The total volume of tailings and
tailings-contaminated soil is estimated to be 1.570,000 cubic yards. In
addition, some properties adjacent to the site (referred to as peripheral
properties) are contaminated by residues from ore stockpiles and dispersed
tailings. A number of business and residence properties in the City of
Monticello are contaminated from the use of radioactive mill tailings as
construction and till material. The tailings piles were stabilized and
covered with soil in 1961 to eliminate the possibility of further dispersal or
use.
The chemical composition of the tailings is described in terms of the average
concentrations of 17 elements. With one exception, these elements are listed
as CERCLA hazardous substances at 40 CFR 302.4. The average concentrations of
these elements indicate that most are enriched in the tailings and ore
relative to typical or “average” sandstones.
Dispersal of ore and tailings during and after milling operations resulted in
the contamination of surface soil on the millsite. Vanadium and uranium were
the only substances extracted in the milling process; other radioactive and
nonradloactive constituents of the ore remained In the tailings and were not
separated prior to disposel. Consequently, dispersal of the tailings results
in the dispersal of all of these substances. Measurement of a single
constituent will adequately portray the areal distribution of the others.
Radium-226. a product of the decay of uranium, was selected to portray the
distribution of these ele.ents because of the ease of measurement and because
a standard for soil has been established at 40 CFR 192.12.
The background concentration of radium—226 in soil In the Monticello area Is
about I picocurie per gram (pCi/g). or about 0.037 disintegrations per second
per gram. The regulations at 40 CPR 192 require remediation of open land if
the radium—226 concentration in the upper 15 centimeters of soil exceeds 5
pCl.’g above background. Thus, the remedial action standard for radium at the
mlllsite is 6 pCi/g. Areas of elevated radium concentration are expected to
have elevated concentrations of CERCLA hazardous substances that were enriched
in the ore. Areas where radium is at or near background concentration will
have correspondingly low concentrations of CERCLA hazardous substances.
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1.0 lI fl ’R0DUCT ION
1.1 PROGRAM OVERVIEW
The U. S. Department of Energy (DOE), under the authority of the Atomic Energy
Act, initiated the Surplus Facilities Management Program (SFMP) in 1978 to
assure safe caretaking and decommissioning of government facilities that had
been retired from service but which still had radioactive contamination. In
1980, the millaite operated by the Atomic Energy Commission from 1948 to 1960
at Monticello Utah, was accepted into the SFMP, and the Monticello Remedial
Action Project (MRAP) was established to restore the government-owned mlllsite
to safe levels of radioactivity, to dispose of or contain the tailings in an
environmentally safe manner, and to perform remedial actions on off—site
(vicinity) properties that had been contaminated by radioactive material from
the mill operations. In 1983, remedial activities for vicinity properties
were separated from MRAP with the establishment of the Monticello Vicinity
Properties (MVP) Project. Both I AP and MI/P are currently administered by the
Grand Junction Projects Office (GJPO) of the DOE.
From Its inception, the SPI1P has mandated that decommissioning activities
follow the procedural provisions of the National Environmental Policy Act
(NEPA). Guidance and requirements for compliance included, but were not
limited to, the following:
1. Regulations for Implementing the Procedural Provisions of the National
Environmental Policy Act, Issued by the Council on Environmental
Quality at 40 CFR 1500 — 1508.
2. Final Guidelines for Compliance with the National Environmental Policy
Act, issued by the U. S. Department of Energy at 45 PR 20694 - 20701
on March 28, 1980, and amended at 52 FR 47862 - 47670 on 15 December
1987.
3. The Environmental Compliance Guide, volumes 1 and 2. issued by the
U.S. Department of Energy, Assistant Secretary for Environmental
Protection, Safety, and Emergency Preparedness, Office of
Environmental Compliance and Overview, National Environmental Policy
Act Affairs Division, on 21 February 1981.
4. Implementation of the National Environmental Policy Act, U.S.
Department of Energy Order 5440.1C. issued 9 April 1985.
In accordance with SFMP policy, NRAP initiated surveillance activities at the
millaite in 1980. These activities at first consisted of water quality
analysis but were later expanded to include atmospheric radon monitoring and
air particulate sampling. Results are described in annual environmental
monitoring reports issued at the GJPO (Korte and Thul, 1981, 1982. 1983, 1984
Korte and Wagner, 1985, 1986; Sewell and Spencer. 1987; U.S. Department of
Energy, 1988, 1989). These activities continue.
Site characterization activities at the Monticello Milisite commenced in 1981
The resulting Nonticeilo Remedial Action Projec t Site Analysis Report was
issued in draft form in 1983 and was finalized In 1984 (Abramiuk and others.
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1984). The Site Analysis Report describes the sites history, geology and
hydrology, the extent of surface and subsurface contamination of soil and
water, and engineering alternatives for remediation of the site. On the oasis
of the findings In the draft Site Analysis Report. the GJPO Issued an Action
Description Memorandum in November 1983 recommending stabilization In place as
the preferred remedial action alternative and preparation of an Environmental
Assessment. The Draft Environmental Assessment of Remedial Action at the
Monticello Uranium Mill Tailings Site. Monticello. Utah was completed in July
1985 (BendIx Field Engineering Corporation. 1985); It includes descriptions of
remedial action alternatives and supporting information from the Site Analysis
Report and on-going studies.
The Superfund Amendments and Reauthorization Act of 1988 (SARA) placed the
SFMP activities at Monticello under the regulatory fraaework of the
Comprehensive Environmental Response, Compe atIon. and Liability Act (CERCLA)
and has resulted in a number of new developa its. The DOE submitted Its
Hazard Ranking System Score for the MIllsite to the Environmental Protection
Agency (EPA) on 31 October 1987. During 1987. existing environmental site
characterization and engineering documents were revised Into the format of the
CERCLA Remedial Investigation/Peas lb llity Study (RI/PS) and were issued for
DOE Internal review in January 1988. The DOE, EPA, and the State of Utah
entered into a Federal Facility Agreement (FFA) pursuant to CERCLA Section 120
In December 1988. This agreement stipulates the procedural framework for
developing and implementing response actions under CERCLA/SARA.
1.2 SITE BACXGROUND INFORMATION
1.2.1 Site Location and Description
The Monticello mill tailings site is a 78—acre tract located in San Juan
County, Utah (Figure 1—1). The site lies in Section 36, T. 33 S.. R. 23 E
and Section 31, 1’. 33 S., R. 24 E. (Salt Lake Meridian). It Is bordered on
the south and southeast by land held by the Bureau of Land Management (BLM)
Elsewhere, the site is bordered by the City of Monticello and private
property. Land survey 4Figure 1—2) indicates encroachments on all boundaries
of the site, the largest being on the east and southeast sides. The
encroachment onto the property directly east of the millaite has been
remedied. The •illsite and areas under investigation are shown in relation to
the city of Monticello in Figure 1—3.
The Monticello site lies in the valley of Montezuma Creek which has Incised a
broad erosional surface that slopes eastward from the Abajo Mountains.
Elevations of the property range fro. 8990 feet (ft) at the northwest corner
to 6820 ft at the southeast corner. The topography of the milisite and
adjacent areas is detailed in Figure 1—4.
A plan of the site is shown in Figure 1—5. The mill area covers approximately
10 acres and the tailings impoundment area covers the remaining 68 acres.
During the period of mill operation, the site also Included private land to
the north and south that was leased for the stockpiling of ore. The tailings
are contained in four piles: the Carbonate Pile, covering 6.3 acres; the
Vanadium Pile, covering 4.5 acres; the East Pile, covering 24 acres; and the
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Acid Pile, covering 11 acres. The tailings impoundment area contains almost 2
million tons of tailings and contaminated soil. All ofthe piles presently
have a vegetative cover consisting of alfalfa and mixed native grasses.
1.2.2 History of the Monticello Mill Operations
The uranium mill at Monticello was one of the earliest to operate on the
Colorado Plateau and was at the forefront of developments in uranium-milling
technology throughout its period of operation. The Monticello mill was one of
the first two plants in the United States to use the acid leach resin-In-pulp
(RIP) process and was the first to use the carbonate leach RIP process. Mill
operations at Monticello were also a focal point of early environmental
concerns. After the mill closed in 1960, it was the first Inactive site to
undergo extensive tailings stabilization.
This synopsis of the history of the Monticello mill is intended to provide
general background information for understanding the environmental problems
posed by the mill both during its operation and after its closure.
1.2.2.1 Miii Ownership
Vanadium Corporation of American (VCA) Operations, 1941 to 1946
In late 1940, the Vanadium Corporation of America (VCA) opened a vanadium ore-
buying station at Monticello in order to stimulate vanadiu, mining in the
region. Within a short time, ore production increased sufficiently to Justify
construction of a vanadiu, mill, and, in September 1941. the War Production
Board approved the proposal submitted by VCA for mill construction. Funding
for the construction was provided by the U.S. Government through the Defense
Plant Corporation. The Metals Reserve Company assumed operation of the ore-
buying station in April 1942. while the VCA operated the mill. The first
vanadium was produced at the new mill on 24 August 1942. Zn 1943. VCA began
producing a uranium—vanadium sludge for the Manhattan Engineer District (MED).
which had recently initiated a program to obtain domestic uranium (Albrethsen
and McGiniey, 1982). The mill closed in February 1944.
The VCA reopened the mill from 1945 to 1946 under lease from the Defense Plant
Corporation and purchased stockpiled ore from the Metals Reserve Company
(Albrethsen and McGinley, 1982). During this period, the VCA produced a
uranium-vanadium sludge which it sold to the Manhattan Engineer District.
Atomic Energy Commission (AEC) Operations, 1948 to 1962
The Atomic Energy Commission (AEC) bought the Monticello •illsite from the War
Assets Administration in 1948. The American Smelting and Refining Company
(AS&R) acted as the ore—buying agent for the AEC, and The Galigher Company was
engaged to design and operate a uranium .111 at the site (Butler, 1951:
Albrethsen and McGInley, 1982). In February 1956. Lucius Pitkin, Inc.,
replaced AS&R as ore-buying agent, and, in April 1956, the National Lead
Company (NLC) assumed operation of the mill. Shortly thereafter, the NLC also
took over ore weighing, sampling, and stockpiling activities, while Lucius
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PItkin, Inc.. continued to conduct administrative activities associated with
ore purchase contracts. assaying. and settlements. The mill closed In January
1960. but the ore-buying station remained open untIl 31 March 1962 (Albrethsen
and McGIney. 1982).
1.2.2.2 Milling Processes
VCA Salt Roast Process
During VCA operations at the Monticello mill, a salt roast process was used to
convert vanadlu. minerals to soluble form. However. tt e nigh lime content of
the carnotite ore processed at the mill presented metal -gic problems. The
calcium carbonate caused excessive slagging, and the ca .ua liberated by
roasting formed insoluble vanadiu, compounds (Merritt. 71). To counteract
these problems. pyrite was added to cause some of the calcium to form calcium
sulfate. The hot ore was quenched in a solution of sodium carbonate, at which
point most of the vanadium dissolved and calcium remaining as calcium chlorate
precipitated as calcium carbonate. After successive washings, the sands were
transferred to tailings. Precipitation of vanadium pentoxide (V 2 0 5 ) from the
pregnant liquor was Induced by the addition of sulfuric acid. The prec Ipitate
was washed to remove sodium chloride and sodium sulfate, and the wash water
was discharged to the nearby creek (Anonymous, 1944).
AEC Processes
Ores received at the AEC ore-buying station and processed at the mill came
from a wide geographic area and had a broad spectrum of metallurgic properties
that affected the milling. As many as 27 different ore types were recognized
among Colorado Plateau ores (Philippone. 1955). which required a variety of
milling processes. Tests on the ores for process amenability were performed
by the Monticello Plant, by the U.S. Bureau of Mines In Salt Lake City, and by
the AIC Pilot Plant in Grand Junction (Hollis and others, 1954; Moulton.
1954a and 1954b; Jones and others, 1956).
A number of milling processes were used at Monticello during the 11 years of
AEC operation. These included raw ore carbonate leach, low—temperature roast!
hot carbonate leach, and salt roast/hot carbonate leach up to 1955; acId leach
resin-in—pulp (RIP) and raw ore carbonate leach from 1955 to 1958; and a
carbonate pressure leach RIP process from August 1958 to mill closure in 1960
Descriptions of some of these processes are provided in Butler (1951). Allen
and Kleusenic (1954), Philippone (1955). Philippone and Johnson (1956). Joyce
and Johnson (1956). and Whitman and Beverly (1958). Three of the AEC
processes used at the Monticello mill are summarized below.
SaJt Roast/Carbonate Leach Process -— Until 1955. vanadium was recovered with
uranium. After being crushed, the ore was mixed with sodium chloride (common
salt). 6 to 9 percent by weight, and roasted at temperatures near 850 C T’
hot ore was quenched in a sodium carbonate solution, ground to natural grain
size, and passed through a series of agitators and thickeners to dissolve the
uranium and vanadium.
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Sodium uranyl vanadate (yellowcake) was precipitated f roe solution by adding
sulfuric acid to a pH of 6 and heating. Precipitation was considered complete
when the filtrate contained less than 10 ppm U 3 0 8 . The filtrate was further
acidified by the addition of sulfuric acid to pH 2.5 to precipitate vanadium
oxide (red cake). The dried yellowcake was further refined by adding sodium
chloride, sodium carbonate, and sawdust, and then fusing the substance in a
furnace to produce uranium oxide (black cake). The vanadium and other
impurities were removed by washing, and the wash solution was further treated
to recover vanadium (Butler, 1951).
Acid Leach RIP Process -- In 1955, the salt roast process and vanadium
recovery were discontinued in order to improve uranium extraction. In
November 1955, an acid leach RIP plant began operation. The existing
carbonate leach plant was retained so that the mill could run two circuits
simultaneously. Testing of ores for amenability had been conducted previously
(Hollis and others, 1954; Jones and others, 1956; Moulton, 1954a and 1954b).
The acid plant flow sheet used at the mill is described in Whitman and Beverly
(1958) and Joyce and Johnson (1956).
After being crushed and ground, the ore was mixed with sulfuric acid and
manganese dioxide (oxidant) and passed through a series of eight agitators.
Water for the leach circuit was recycled from the tailings pond overflow. The
leached ore was passed through a series of classifiers to separate the sand
and slime fractions. Sands were passed to the tailings pond, and slices
containing dissolved uranium were passed through a series of banks with screen
baskets containing the ion exchange resin. The loaded resin was washed and
eluted with a sodium nitrate solution acidified with sulfuric acid. Calcium
hydroxide was added to the pregnant eluate to raise the pH to 3.4, whereupon
white cake, consisting mostly of calcium sulfate (gypsum), was precipitated.
The white cake was recycled through the leaching circuit and the filtrate
advanced to the second stage of precipitation where yellowcake was produced by
the addition of magnesium oxide to neutralize the filtrate.
The acid tailings were combined with the tailings from the carbonate plant to
obtain partial neutralization. The combined tailings were then treated with
calcium hydroxide to achieve complete neutralization and to flocculate the
pulp, after which they were pumped to the tailings pond. About 130 gallons
per minute of pond overflow was recycled through the leach circuit while 180
gallons per minute was discharged to Montezuma Creek (Whitman and Beverly,
1958). CombIned capacity at this time for the acid leach RIP and alkaline
leach plants was about 600 tons of ore per day (Merritt, 1971).
Carbonate Leach RIP Process -— Conversion of the acid leach RIP plant to a
carbonate leach RIP plant began in June 1958. The new plant began processing
ore on 8 August 1958 at a capacity of 150 tons per day. Jones and others
(1955) and McArthur and others (1955) describe pilot plant studies that used
ore from the Monticello stockpiles. In the study described by Jones and
others (1955), the resin was eluted with a sodium chloride solution.
Precipitation of yellowcake was induced by the addition of sulfuric acid;
neutralization with magnesiu. oxide followed.
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Neither a flow sheet nor a reference describing the carbonate pressure leach
RIP process has been located. However, the process used at Monticello is
known to have been similar to the process later used at the uranium mill in
Moab, Utah. There, the ore was ground to -65 mesh in a solution of sodium
carbonate-bicarbonate. The pulp was then thickened to about 50 percent solids
and subjected to pressure leaching with mechanical agitation in steam-heated
autoclaves. After cooling, the leached pulp was passed through a sand-slime
separation circuit. The uranium—bearing solution and slimes were then passed
through the RIP circuit (F. E. McGinley, personal communication).
Relation of Tailings Piles and Milling Process
Prior to the installation of the acid leach RIP plant in 195$, tailings were
discharged to two areas designated herein as the Carbonate Pile and the
Vanadium Pile. The Carbonate Pile is believed to be the oldest of the
tailings piles; it received tailings from the AEC salt roast/carbonate leach
process. The Vanadium Pile apparently obtains Its name from the fact that
vanadium concentrations are higher in this pile than in the other tailings
piles. However, the origin of these higher concentrations is unknown because
of the uncertainty regarding the date of the pile’s construction and its exact
relation to the milling processes in use prior to start-up of the acid leach
RIP plant.
There is evidence that the Carbonate and Vanadium Piles were operated
simultaneously. The Operating Reports issued for 1951 and 1952 state:
“A few hours with the dozer maintained an adequate sand tailings dam; the
solution was syphoned to the settling pond, with no overflows from either
sand or solution ponds going to the creek.” (Galigher Company, 1951, p. 3)
“... the liquor from the clarifier pond was pumped back to old tailings
pond area.” (Galigher Company. 1952, p.4).
These statements suggest that two separate ponds were used in the tailings
disposal during-this time per -lcd.- It seems reasonable to equate the “sand
pond” and “old tailings pond” with the Carbonate Pile and the “settling pond”
and “clarifier pond” with the Vanadium Pile.
According to the June 1955 Financial and Operating report, the salt roast
performed for vanadium recovery was discontinued on 10 June 1955. Vanadium
precipitation in the circuit was continued, but the precipitated vanadium was
passed to the “high vanadium tailing pond storage” (Galigher Company, 195$,
pp. 4-5). This practice suggests that the Vanadium Pile may have been used to
stockpile h1gh—va ad1um tailings for a short period of time following the
cessation of vanadium recovery, although H. A. Johnson. resident manager of
the mill at the time, has no recollection of a separate stockpiling (F.E.
McGinley, personal communication, 1983). It is certain, however, that the
Vanadium Pile was not constructed for this purpose. A photograph of the
milisite (Figure 1-6) shows the Vanadium Pile near its final size in August
1955, just two months after cessation of vanadium recovery at the mill. The
volume of tailings is too great to have been produced by a plant that
processed no more than about 100 to 120 tons of ore per day.
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Figure 1-6.
Aerial View of the Milisite and Tailings Piles at Monticello. Utah. At the time
this photo was taken (31 August 1955). the Carbonate and Vanadium Tailings Ponds
were in use and the South or Acid Pond wee under construction.
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Because the acid leach RIP process required sore water, a third pond was
constructed south of Montezuma Creek to accommodate the added volume of dis-
charge. How the Acid Pond (or South Pond) as It looked shortly after the
opening of the acid leach RIP plant can be seen in Figure 1-7. This pond,
referred to herein as the Acid Pile, contains the combined tailings, produced
in 1955 and 1958. from the acid leach RIP and carbonate leach circuits.
After construction of the Acid Pond. it soon became apparent that a larger
tailings pond mould be required. Additional land, some of which had already
been damaged by mill release., was purchased east of the AEC property, and a
new pond was constructed to retain a projected 578 acre—feet of tailings
(Tonry, 1958). This pond, referred to herein as the East Pile, received
tailings from 1956 to 1980 when the mill closed.
1.2.2.3 Environmental Problems Associated with Mill Operations
Air Pollution
Prior to 1955, the environmental problems receiving attention at the
Monticello mill arose from the salt roast procedure used to enhance vanadium
recovery. Large quantities of dust, chlorine, and hydrogen chloride gas pro-
duced in this step of the sill flow sheet were exhausted through the roaster
stack. One study indicated that an average of nearly 2600 lb of dust con-
taining 0.363 percent U 3 0 8 and 1.52 percent V 2 0 5 escaped daily through the
stack. This amounted to annual losses of 14,000 lb V 2 0 5 and sore than 3000
lb U 3 0 8 . Local residents complained about corrosion of wire fences, clothes-
lines, galvanized roofs, etc.; these complaints were verified by The Galigher
Company (Allen and klesenic, 1954).
Water Pollution
Liquid effluent from the salt roast/carbonate leach plant, which contained sub-
stantial concentrations of chloride, sulfate, carbonate, bicarbonate, sodium,
and other dissolved species, was released into Montezuma Creek. The resulting
water pollution attracted the attention of the Utah Water Pollution Control
Board who contacted the Atomic Energy Commission and requested that the situa-
tion be corrected (Allen and ElemenIc, 1954). The solution to this problem
was not immediately forthcoming. Although problems relating to stack releases
largely disappeared when vanadium recovery was discontinued in 1955. seepage
from the Carbonate Pile continued to release chloride to surface water and, it
was suspected, to ground water as well (Lennemann, 1956).
Elimination of effluent releases to Montezuma Creek became a goal in the sub-
sequent design of tailings ponds and in research on milling processes. The
Acid Pond was lined with S inches of compacted bentonite in an atte.pt
to prevent seepage. Water from this pond was partly recycled to th. acid
plant, and research was conducted to obtain 100 percent recycling. About 3500
gallons of barren eluate were bled from the elution cycle daily to prevent
resin poisoning. However, this solution contained high concentrations of
nitrate and could neither be released into Montezuma Creek nor be recycled.
Instead, it was disposed of in separate ponds and allowed to evaporate. It
was hoped that pond overflow could be eliminated entirely with changes in
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milling process. but use of solar evaporation in the East Pond was considered
should such changes prove impractical (Tonry, 1956).
A water-sampling program was begun in March 1956 and continued through March
1959. The data acquired In the survey indicated that even with the East Pond.
discharge of salts exceeded Utah water quality standards (George. 1958). In
particular, when the carbonate leach RIP plant began operation, the pH values
and concentrations of total dissolved solids, carbonate, bicarbonate, sodium.
and chloride increased to levels above those observed during operation of the
acid plant (George, 1959).
Emphasis shifted toward radiologic aspects of uranium eilling in 1957 when the
AEC released the “Standards for Protection Against Radiation” as Title 10,
Part 20, of the Code of Federal Regulations (Federal Register, v. 22, no. 14.
22 January 1957). Included were standards for exposure of Individuals to
radiation and maximum permissible concentrations of radlonuclides In water and
air. Part 20 applied specifically to AEC licensees, so the Monticello mill
was not legally subject to these standards. However, a directive was issued
to achieve compliance at Monticello in order to provide a model for private
mills (Johnson. 1958). The program developed to reach compliance also
included approval of sampling and analysis methods and development of controls
for disposing of hazardous substances. A summary of this program is given in
Beverly (1958).
Release of radium—226 was of special concern. As early as 1950. it was recog-
nized that radium levels in water and stream sediments were increasing as a
result of uranium mill operations. In 1955. the flow In Montezuma Creek below
the Monticello mill was noted to consist mostly of overflow and seepage from
the tailings ponds. Soluble radium in the mill effluent was measured at 81
pCi/L (Tsivoglou and others, 1956; Tslvoglou, 1964). The radium—226 balance
in the Monticello acid leach RIP plant was examined to determine what fraction
was dissolved In the milling process and the ultimate disposition of radium
through the various chemical separations. It was found that only about 3
percent of the radium in the ore was dissolved in the leach circuit. Of this
amount, 10 percent precipitated with yellowcake. Most of the remainder of the
dissolved radium was removed upon neutralization of the tailings In the tail-
ings treatment step. Ultimately only 0.03 percent of the radium fed to pro-
cess entered Montezuma Creek as solute. Soluble radium activity in Montezuma
Creek was found to be 160 pCIIL; the maximum permissible concentration was 4
pCi/L above natural background. It was also recognized that the suspended
solids contained considerable radium activity and that dry tailings were being
washed into the creek (Whitman and Beverly, 1958).
A number of studies were subsequently conducted to determine methods for
removing the small amount of dissolved radium (Beverly, 1958; DeSesa, 1958;
DeSesa. 1959). Barium sulfate was found to be the most effective compound for
removing radium from tailings solutions. A test circuit was set up at
Monticello to determine the feasibility of the treatment on a plant scale.
Significant reductions of radium—226 were achieved (DeSesa, 1958), although
the average concentration was still above 4 pCi/L. A second test circuit
included iron sulfate heptahydrate (FeSO 4 7 H 2 0) as treatment to flocculate
suspended solids; this brought dissolved radium concentrations to within
acceptable levels (DeSesa, 1959). -
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Early Cleanup Activities
During milling operations, the tailings were normally moist so that erosion by
wind was minimal. Within a year after shutdown, however, the tailings dams
and surfaces of the piles dried out, and tailings sand started migrating as
dunes. Erosion by water also became a problem. The condition of the tailings
piles at that time is illustrated in Figures 1—8 through 1—15.
In Summer 1961, the Atomic Energy Commission began to regrade, stabilize, and
vegetate the piles. This work was initiated on the East Pile because, being
the largest pile, it presented the greatest potential for wind erosion and
migration of tailings off site. At the onset, a small pond still existed in
the lowest part of the East Pile and it was drained to the extent possible.
Slimes retained considerable moisture, even in dry” parts of the pile, and
many areas would not support heavy equipment. To overcoie this obstacle.
tailings sand was hauled from the other three piles and spread over the sur-
face. These tailings mixed with the fluid slimes to provide a stable surface
over which cover material could be spread. The depth of sand fill reached as
much as 6 ft in places but averaged 3 or 4 ft. After the grading was complet-
ed. 8 to 12 in. of fill dirt and rock, excavated nearby, were spread over the
tops and s&des of the piles. Topsoil was added to the tops of the piles,
fertilized, and a variety of native grasses were planted (U.S. Atomic Energy
Commission, 1963).
The mill facilities were dismantled concurrently. Equipment was sold to
private firms, and unsold scrap material was buried or burned. Trenches were
excavated near the Carbonate Pile and scrap was buried under several feet of
tailings (Figures 1—16 and 1-17). These tailings were covered with rock and
soil and seeded in the sane way as the piles (Paas, 1966).
Within a few years, it was evident that erosion problems were under control
(Atomic Energy Commission. 1966). Data suggested that dissolved and particu-
late radium concentrations in Montezuma Creek were diminishing (Federal Water
Pollution Control Administration, 1968). A radiologic survey of the site
conducted in May 1965 concluded that exposure rates on the piles were slightly
above background but did not result in a dose that exceeded the Federal
Radiation Council Guide hut of 0.5 rem/yr for the general public. This was
not true of the ore—storage areas. These areas had been cleared of visible
ore fragments when the mill closed, but ore apparently remained buried in the
soil. During the Summer of 1965. 6 to 12 inches of topsoil was removed from the
ore-storage areas. Photographs archived at the Grand Junction Projects Office
suggest that the contaminated soil was used as fill material to partially bury
the mill foundations .(Flgures 1-18 and 1—19). A subsequent radiologic survey
of the ore—storage areas was conducted by the AEC Grand Junction Office,
results of which indicated that a radiation hazard no longer existed according
to standards in effect at that time (Pass, 1966).
In 1972, the AEC requested additional radiation surveys of the south stockpile
area and the ore—buying station. These surveys indicated that considerable
contamination remained (Ward, 1972: Preytag. 1972), and recommendations were
made to remove nearly 15,000 cubic yards of contaminated soil from these
areas. Removal of contaminated soil and the mill foundations was undertaken
between May 1974 and August 1975. Ore—contaminated soil scraped from the ore—
storage areas was dumped on the previously stabilized surface of the East
1-17
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2.0 SITE FEATURES INVESTIGATION
2.1 DEMOGRAPHY
2.1.1 Population
The Monticello project area is located in sparsely populated San Juan County
in southeast Utah. No residences are located within the milisite boundary,
but residences do lie adjacent to the north and east edges of the site. The
closest population center is the City of Monticello. which is contiguous with
the site’s north-northeast boundary.
The 1980 Census of Population listed the county’s 1980 population as 12.253
and the city’s as 1,929. As of 1980, an estimated 2,469 persons were living
within a 1.5—mile ( ci) radius of the milisite (Abrasiuk and others. 1984), the
majority to the north and west within 0.5 and 2.0 ml of the site (see Tables
2-1 and 2-2). The racial composition of the 1980 population in Monticello and
San Juan County Is shown in Table 2—3. As the data demonstrate, Native
American Indians, who live on the Navajo Reservation in the southern portion
of the county, constitute nearly one-half of the county’s population.
However, Native American Indians represent only a small percentage of the
city’s population.
San Juan County and the City of Monticello have experienced dramatic
fluctuations In population during the past four decades. The population
growth rate of San Juan County varied from 70.1 percent during the 1950s, to
6.3 percent during the 1960s, to 27.5 percent during the 1970$. The
county’s share of the total population of the state increased fro. 0.9 percent
In 1970 to 3.7 percent in 1980. largely due to population growth increases of
38.6 percent in Blandlng (22 mi south of the project area) and 34.8 percent
in Monticello.
Between 1940 and 1960 the population of Monticello tripled. This was followed
by a 22 percent decline during the 1960$ and the previously mentioned increase
of 34.8 percent during the 1970s. In 1985, the population of the city was
estimated to be between 1,600 and 1,700 (Terry, 1985), which represented a
significant reversal in the city’s population growth trend due to the recent
economic downturn.
On the basis of historic trends in population growth and the most recent
estimates of population for the City of Monticello, It is difficult to project
estimates of future population for the city or the county. The extremely
variable economic conditions that have characterized the area over the last
few years. such as those associated with the construction, closure, and
reopening of the White Mesa Uranium Project, require that economic and
demographic forecasts be frequently revised and updated. This ii reflected In
Table 2-4, in which are population estimates for the city and county as made
by the Utah Agricultural Experiment Station (Abrasluk and others, 1984), by
the Utah State Planning Coordinator’s Office using the Utah Process Economic
and Demographic (UPED) Impact Model, and by the City of Monticello (Terry.
1985).
2—1
-------
Monticello. Lake Powell lies approximately 100 ml to the southwest; some
1,000 ml of Its coastline are in San Juan County. Other nearby
recreational areas include:
Natural Bridges National Monument Dead Horse Point State Park
Rainbow Bridge National Monument Muley Point Overlook
Hovenweep National Monument Grand Gulch
Goosenecks State Park Valley of the Gods
Edge of the Cedars State Park Recapture Pocket
Indian Creek State Park Sand Island
2.2.2 ZonIng and Land Use
Five zoning districts have been established within San Juan County:
multiple-use, agricultural, rural residential, controlled, and Indian
Reservation. Within the city limits of Monticello. areas have been zoned for
heavy and light commercial use and for residential use (Abramiuk and others.
1984). CommercIal zoning along the major thoroughfares of Monticello, U.S.
Highways 191 and 686, has established a central business district; commercial
growth has occurred to the north and east, out from the center of town along
these routes. Heavy commercial (formerly industrial) zoning exists in the
southeastern corner of the city. The milisite and tailings piles lie south
of this area, within a controlled district. A controlled district permits a
mix of agricultural, residential, industrial, and commercial use (San Juan
County, 1985). Figure 2-3 conveys some idea of the use and development of
land adjacent to the site. Several residences have been built to the east
and immediately north of the site, but otherwise •ost of the land is
nonresidential. Alfalfa is raised immediately east of the site. Land to the
south Is marginal for grazing.
Monticello is less suited for development to the south than in any other
direction. The large east-west drainage of Montezuma Creek through the
millsite is a natural barrier to intensive development in that direction.
whereas relatively flat vacant land exists in all other directions. The
zoning north of the site (i.e., controlled district) discourages residential
growth there.
2.2.3 Land Values and Ownership
Land values in and around the City of Monticello have varied in recent years
(Abramluk and others, 1984). In 1981, dry farmland 2 to 6 ml outside the
city was valued at approximately $550 per acre: better farmland was
available for up.to $3,000 per acre. Unimproved lots inside the city were
scarce but were available for $6,500 to S7,000. Since that time. real estate
activity has fallen off considerably. in 1984. prices for farmland ranged
from $185 to less than $1,000 per acre. Values of homes and residential lots
are difficult to determine since there has been very little sales activity
during the past few years, though one would expect that values have decreased
in response to this inactivity (Abramluk and others, 1984). Property
ownership near the site is shown in Plate 2-1.
The land associated with the silisite was valued at $21 per acre at the tl.e
ownership was transferred to the Atomic Energy Commission in 1948. Because
2-11
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124
The emphasis of the statistical estimation is on the average concentrations of
the combined data of all piles. The maximum—likelihood method of Cohen (1959.
1961) is used where possible to incorporate data below the detection limit in
the combined data sets. Because the distribution of many of the elements Is
more nearly lognormal than normal, various lognorual estimators were checked
against the arithmetic average of the raw data (see Atchinson and Brown, 1957.
pp. 8, 45). With the exceptions of copper and vanadium. lognormal and
arithmetic estimators agreed to within the laboratory precision of reporting.
The various estimates of copper and vanadium agreed to within about 10
percent. Therefore, the arithmetic averages are used.
The average concentrations of the individual piles are also the arithmetic
means of the data. However, Cohen’s method is not applied to incorporate data
below the detection limit for individual piles. Rather, If more than half of
the determinations of an element in a particular tailings pile are below the
detection limit, the pile mean Is simply reported as less than the detection
limit. If more than half of the determinations are above the detection limit,
the pile mean is reported as less than the average of data above the detection
limit.
Principal components analysis was applied to 118 observations of radium-226,
uranium, molybdenum, arsenic, copper, nickel, and vanadium using the
correlation matrix. Principal components analysis is a technique used to
discover the relationships among aultivarlate data. When applied to geologic
or geochemical data, it frequently yields an insight into processes
responsible for the observed relationships (Davis, 1973; MorrIson. 1976).
Results of the principal components analysis are described in section
3. 2. 3. 18.
3.2 WASTE TYPES
3.2.1 Waste Quantity and Containment
According to Aibretheen and McGlnley (1982), 903,296 tons of uranium ore were
processed at the Monticello mill between 1948 and 1960 to yield approximately
4.6 million pounds (2290 tons) of uranium oxide, U 3 0 8 , and 2.3 million pounds
(1170 tons) of vanadium pentoxide. V 2 0 5 . Most of the original constituents of
the ore, as well as the-chemicals added during the milling process, reside in
the tailings. Therefore, the tailings quantity is estimated to be about
903,000 tons.
The tailings generated by the operations are contained in four piles referred
to, in order of their construction, as the Carbonate Pile. Vanadium Pile, Acid
Pile, and the East Pile. The Carbonate and Vanadium Piles were constructed
during the period from 1949 to 1955 when the mill was recovering vanadium as a
by-product. The process used for the recovery was a salt roast/carbonate
leach flow sheet. The Vanadium Pile is so called because of the high vanadium
content of these tailings; it is in no way related to tailings produced by the
Vanadium Corporation of America (VCA) mill that preceded the Atomic Energy
Commission (AEC) mill. Use of the Acid Pile commenced about 1955. This pile
3-3
(I
-------
received tailings from the acid leach RIP process and a carbonate leach
circuit. The East Pile was operated from 1956 until .111 shutdown In 1980 and
received tailings from the acid leach circuit and the high temperature,
carbonate leach RIP circuit. Details regarding the mill circuits and their
relation to the tailings piles can be found in Section 1.
Photographs taken during the operation of the milisite indicate that earthen
beris were Initially used to impound the tailings. As the impoundment tilled,
sandy tailings were apparently used as berm material to maintain the ponds.
After closure of the mill, the piles were regraded and stabilized by covering
with pit-run gravel and top soil. The total quantity of tailings, earthen
berms, cover material, and contaminated substrate is estimated to be about 1.9
million tons.
3.2.2 Ore
The Monticello mill received ore from a wide area in western Colorado, south-
eastern Utah, and northwestern Arizona. A map by Chew (1956). which details
the locations of uranium deposits yielding more than 1000 tons of ore,
suggests the geographic area which may have been tributary to the ore-buying
station at Monticello at one time or another. Specific areas or districts
known to have delivered ore to the Monticello station include Uravan In
Colorado, Monument Valley in Arizona, and White Canyon, the Henry Mountains,
Big Indian Wash, and Temple Mountain in Utah (Albrethsen and McGinley, 1982).
Milling processes at Monticello were changed through time to accommodate
various types of ore (see Section 1 for historical discussion), and the
character of the tailings reflects this history.
Unfortunately, very few analyses describing the composition of uranium ore
milled at Monticello are available. Therefore, limited data published In
geologic literature are used to describe the general characteristics of ore
fed to process. The discussion of ore composition which follows is organized
according to the classification described by Weeks and Thompson (1954) and
Weeks and others (1959). Because of the control exerted by vanadium on
uranium mineralogy, uranium ores are classified Into one of two major
categories, vanadiferous and non—vanadiferous. Further subdivision of
these categories may be mmde on the basis of whether the ore is unoxidized
(primary) or oxidized.
3.2.2.1 Vanadiferous Ores
Vanadiferous ores are those with vanadium—uranium ratios greater than 1;1. In
unoxidized ore, uraninite ((UT z,LJ 6 )O 2 , J and coffinite (U(SiO 4 )i_ (OH) 4 x]
are the typical uranium minerals. Upon oxidation, these yield carnotite
[ k 2 (U0 2 ) 2 (V0 4 ) 2 3H 2 0J and tyuyamunite [ Ca(U0 2 ) 2 (V0 4 ) 2 ‘ 5—8H 2 0]. Ores of
this type occur extensively in the Salt Wash Member of the Morrison Formation.
3-4
-------
Ov Ui7O
4.1.2.4 Carbonate Tailings Pile
Boreholes 85—01 and 85—02 are located in the Carbonate Tailings Pile (see
Cross Section C—c on Plate 4—4). The clay cover is 2.0 ft thick and Is evenly
distributed over the pile. Borehole 85-03. located on the west slope of the
tailings pile near the bottom of an erosional gully, has a sand covering 3.0
ft thick and is underlain by 1.5 ft of sandy tailings. Boreholes 85-01 and
85-02 were drilled in sandy tailings, some clay (slime) layers, and thin
interbedded layers of sand/slime mixed. The clay (slime) and sand tailings
layers vary in color (red, brown, and purple). In Borehole 85-02. a distinct
organic clay ‘ayer interfaces with the tailings and clay substrate below,
while in Borehole 85-01 a trace of organics (roots) was found at the
interface. Moisture content of the sand tailings ranges from 7.0 to 11.1
percent. while for the clayey slimes it ranges from 16.0 to 30.4 percent.
Natural dry density averages 96.4 lb/ft 3 for the Carbonate tailings.
4.1.3 Extent of Contamination
4.1.3.1 Introduction
Surface soil has been contaminated by tailings and ore residue through the
storage of ore in open stockpiles, the emissions from the roaster stack, the
overflow of tailings ponds, and the erosion of tailings piles by wind and
water. As described In Section 3, the ore and tailings are not only enriched
In uranium and radium—226, but also contain elevated concentrations of
arsenic, cadmium, chromium, copper, lead, molybdenum, vanadium, and zinc. The
dispersal of tailings and ore residues has also contaminated soil with
nonradloactive elements.
The contamination of surface soil by these radioactive and nonradioactive
elements is readily portrayed by mapping the distribution of radium-226. The
use of radium as a proxy for other metals contained in the ore and tailings is
justified by the fact that, apart from uranium and vanadium, these other
elements passed through the .ill circuit with radium to the tailings piles
where they reside in concentrations approximating those found in the ore. No
mechanism has been identified which would account for the segregation and
dispersal of one of the npn—ore elements independently of the others.
Therefore, where the radium concentration is high, the concentrations of the
other elements will likely be high. Where the radium concentration Is low or
near background, other elements’ concentrations will likely be near
background. -
Studies of surface contamination on the milisite were reported in the
Monticello Remedial Action Project Site Analysis Report (Abramiuk and others.
1984). A contour map of these data is shown in Figure 4-2. Characterization
data from the BLM Compound and adjacent properties are described in the
document Radiologic Characterization of the Peripheral Properties Adjacent to
the Monticello, Utah, MiUsite (Marutzky and others, 1985). Additional soil
and sediment data were collected along the course of Montezuma Creek in 1987.
Radium concentration data from the 1985 and 1987 studies are posted on Plates
4—5a and 4—5b; methods and results of these investigations are summarized
below.
4-5
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1 (J±(fl.73
Above approximately 11 pCl/g. the In—situ results tended to be lower than the
laboratory results, probably because of the effects of lnhomogenelty, soil
moisture, and disequilibrium (Abraaiuk and others. 1984. pp.3-13 ft.).
The radlologic characterization of the properties peripheral to the milisite
was based on data collected primarily from analysis of soil samples. In-situ
measurements were made to guide collection of soil samples. At depths greater
than 1.5 ft. in-situ measurements were used to determine depth of contamination.
4.1.3.3 Results
Results of previous studies performed at the site are presented here: more
detail is available in the reports previously mentioned. Discussions have
been separated by general area. Areas are considered contaminated if the
radium-226 concentration in soils exceeds the EPA standard (40 CFR 192.12) of
5 pCi/g above background in the top 15 cm of soil or 15 pCi/g above background
in any 15 cm layer below the top 15 cm.
Rack round-CharacterIzation Results
Background radloelement concentrations and gamma—ray exposure rates were
established by Marutzky and others (1985. pp.30—31). Analytical results on
soil samples, together with results of in—situ spectrometer measurements.
indicated an average background radium—226 concentration of 1.0 , 0.4 pCi/g.
In-situ spectrometer measurements indicated average concentrations of thorium-
232 and potassiu.—40 at 1.1 0.1 pCi/g and 17.8 1.3 pCi/g, respectively.
Average background gamma—ray exposure rate as determined by a pressurized
Ionization chamber Is 14.7 pR/h.
Millslte Results
Results of the surface radiometric survey of the •lllsite presented in the
Site Analysis Report (Abramiuk and others. 1984) indicate that most of the
surface soil layer contains concentrations of radium—228 exceeding EPA
guidelines (see Figure 4—2). Contamination of the cover material on the piles
is believed to be due largely to the re—distribution of tailings by burrowing
animals. Some surface soil contamination on the East Pile was caused by the
disposal of contaminated soil from the 1974-1975 vicinity properties cleanup
activities.
The average concentration of radiua—226 in the surface soil layer is 20 pCi/g
over the site. The maximum concentration of radiun-226 (greater than 500
pCi/g) was found in an ore-stockpile area south of Montezuma Creek and west of
the Acid Pile. The total radium—226 activity of the surface layer (0-15 cm)
is estimated to be 4 to 5 curies.
Radiometric logs of borings drilled in the study by Ridolfi and others (2986)
indicate apparent radlum—226 concentrations of subsurface materials. In of f-
pile areas, contaminated soil exceeding the PPA subsurface criterion of 15
pCi/g above background extends no deeper than about 4 to 6.5 ft in borings
4—9
-------
( U U .L.
85-13. —21. and —25 (Plate 4-1). No subsurface radium contamination exceeding
EPA standards was indicated In borings 85-14. —23. and —24. Radlometric logs
of borings drilled on the piles indicate that locally, EPA standards may be
exceeded through the entire thickness of soil and alluvium beneath the
tailings. This appears to be the case in boring 85—01 on the Carbonate Pile.
where the thickness of soil and alluvium between the tailings and Dakota
Sandstone Is 18 ft. and in boring 85—04 on the Vanadium Pile, where there Is
at least 18 ft of soil and alluvium beneath the tailings. On the Carbonate
Pile, contamination extends to depths of 15 ft beneath the tailings in boring
85-08 but does not appear to extend below the tailings-soil Interface in
boring 85-06. The thickness of contaminated soil beneath the tailings of the
Acid Pile as indicated in boring 85—10 is 15 ft.
Peripheral Properties Results
Properties adjacent to the millsite. excluding the designated vicinity
properties, include two former ore—storage areas., the weigh station, the
buying station, mill buildings, three residences, and farming properties. A
total of approximately 200 acres is affected by rad.tua—226 levels that exceed
EPA standard 40 CFR 192.12 (Plates 4-Sa, 4-Sb). Highway 191 bounds the area
to the west. To the south, elevated radium—226 concentrations extend to the
southern boundary of the former ore storage area. Windblown and waterborne
rad ium-226 contamination extends to the north and east Into residential and
farming properties.
The weighted average depth of radiua-226 contamination is 0.9 ft; the range is
0.5 ft to greater than 6 ft. Radium concentrations above the EPA standards
range from 6 pCi/g to 7185 pCi/g; average concentration is 70 pCi/g. About 75
percent of the 832 soil sample analyses of Marutzky and others (1985). exceeded
5 pCi/g (Figure 4—3).
Former Ore Storage Areas—-Two areas were used for ore storage during the
period the plant was operating. Previous cleanup activity had brought these
former ore-storage areas Into compliance with earlier standards. However the
largest volume of material requiring removal to meet current standards lies
within these areas to the north, west, and south of the alilsite. Radium
concentrations above EPA guidelines range from 6 pCI/g to 5763 pCi/g and
average 90 pCi/g.
In the north ore—storage area. radium-226 contamination extends to a depth of
4.5 ft In isolated locations, but It is generally limited to less than 1.5 ft.
In the south ore—storage area, depth of radiua—226 contamination is limited to
1 ft with one exception: a ravine thought to have been used as a dump site
has radlum—228 contamination extending to 7 ft (Ridolfi and others. 1986.
p. 16).
BLM Compound-—The BLM compound housed the former alllsite administration and
maintenance facility. In—situ radium measurements Indicate the entire site is
contaminated above EPA guidelines to depths ranging fro. 0.5 to 5.0 ft. Soil
samples analyses yielded radium concentrations above EPA guidelines that range
from 6 pCl/g to 7185 pCi/g. Results from in-situ measurements range from 6
pCI/g to 3312 pCi/g and average 45 pCi/g. -
z
4-10
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C,
-9
200-
190 -
180-
170
160-
150-
140-
: 130-
120-
.c 110- __
‘ 100 -
0, UJJ 4 /I//I
90-
° o
E 8
70- __
60- __
50-
40-
30-
20-
10-
0 1 5 10 15 25 50 100 200 500 1000 5000
C
Ro—226 Concentration (pCi/g)
I—
Fl gore 4 3 Iii t o i .tm or An . 1 y( I c t I Rt su Its ror Rd 226 Iii Sii II s iii hi i Iberd I Piope (1 t s —
(1 ro Mdrutzky and otliet’s, I98 i)
-------
Radlum-226 contamination Is also present beneath several buildings which were
constructed alter the .111 had been operating for some time. Depth of
contamination ranges from 0.5 ft beneath buildings constructed on grade to 6
ft beneath buildings constructed above grade.
Residential and Failing Areas—-Areas which are contaminated with radium-226
above EPA standard 40 CFR 192.12 to the north and east are predominantly
farming lands but include some residences. To the north, airborne contamin-
ation Is found on the surface as far as 0.5 ii from the mlllsite boundary.
Radium concentrations above EPA standards range from B pCi/g to 494 pCi/g and
average 27.
Waterborne radiua-228 contamination extends to a depth of 1.5 ft as far as
1 m l from the site along the banks of an irrigation ditch which runs through
part of the site. Radiua—228 contamination on the banks of the ditch results
from periodic clianing of the ditch.
To the east of the tailings piles, radium—226 contamination has been
distributed via wind and water. Windblown radium—226 contamination extends
eastward less than 0.25 .1 from the fence on land used for I ar.ing and
grazing, and it is limited to the surface (0—8 in.) soil layer.
Within 1000 ft of the east boundary of the site. Montezuma Creek has been
rerouted south of its old pathway. Along the old creek pathway, which
probably ran beneath a stock pond on the east edge of the site, radiui-226
contamination extends to depths of 4 ft. Radium concentrations as great as
500 pCi/g are present.
Montezuma Creek Results
Tailings have been carried via Montezuma Creek and deposited along its banks
several miles from the site. Beyond approximately 0.25 ml from the site,
radium contamination is sporadically deposited (Plate 4-Sb). Details are
described in Section 5.4.
4.2 GEOLOGY
4.2.1 Refional Setting
The Monticello milisite Is situated In the southern part of the Canyonlands
section of the Colorado Plateau physiographic province. Two major landscape
features dominate the region: the broad, nearly flat upland surface known as
the Great Sage Plain and the deeply incised canyon network of Montezuma Creek
and its tributaries (FIgure 4—4). Five miles west of Monticello, the Abajo
Mountains rise approximately 5,700 ft above the Sage Plain and are the most
conspicuous feature on the western horizon.
4—12
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Gu. ’)138
4.3 GROUND-WATER INVESTIGATION
4.3.1 Introduction
This section describes the hydrostratigraPhY and the hydraulic properties of
the project area. There are two primary aquifers in the project area: one is
an alluvial aquifer composed of unconsolidated materials deposited by
Montezuma Creek, the other is a confined to semiconfined sandstone aquifer,
the Burro Canyon Formation. The latter is separated from the alluvial aquifer
by the Mancos Shale and shale units of the Dakota Sandstone. which act as
major aquitards in the project area.
Locations of wells referred to in this section are shown in Figure 4—11.
4.3.2 Alluvial Aquifer
4.3.2.1 Description
The areal extent of the alluvial aquifer in the project area was determined by
examination of well-log data and aerial photographs. Logs of wells drilled in
the project area were used to determine the nature, thickness, and location of
saturated alluvial materials (sands, silts, gravels). The approximate
boundary between saturated Montezuma Creek alluvium and the adjacent h.illslope
is shown in Figure 4-12. Only the approximate extent of the saturated
alluvium is shown: this alluvium should not be confused with the Quaternary
alluvium shown in Figure 4—7.
The alluvial aquifer underlying the west half of the millaite is approximately
15 ft thick near Montezuma Creek and thins gradually toward the valley sides.
The lateral extent of the aquifer is quite broad in the west part of the
valley where the tailings are located. Montezuma Creek Is in hydraulic
communication with the aquifer on the upstream side of the East Tailings Pile.
Because of a realignment of the stream channel, however, the aquifer and
Montezuma Creek become geographically separated In the vicinity of the East
Tailings Pile (Figure 4—12). At this location, the aquifer underlies the
tailings pile itself, whereas Montezuma Creek flows over the Dakota Sandstone.
The creek and the alluvial aquifer are reunited downstream from the tailings
pile. Sources of recharge to the alluvial aquifer are infiltration of
precipitation and surface water.
4.3.2.2 Hydraulic Characteristics
Water levels in the alluvial aquifer fluctuate seasonally due to the effects
of snowuelt runoff. The saturated thickness of the aquifer ranges to a
maximum of about 21.8 ft. The average saturated thickness for the unit as a
whole is approximately 10.0 ft.
Hydraulic conductivity of the alluvial aquifer was determined using the
Hvorslev method (1951) for bail tests in unconfined aquifers. Water was
removed from the well bore by air lifting. Recovery—versus-time was then
recorded using an air line and a pressure gauge.
4-26
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Downgradieflt ground water (Figure 4—20) Is characterized by a sulfate anion
dominance and a calcium cation dominance. The well-defined groupings observed
in the on—site wells are not observed in the downgradient wells because of the
mixing and diluting effect of the downgradient ground water as it moves away
from the source area.
Data reported in Table 4-2 are based on analyses of samples collected In 1984
through 1986 (Appendix B). The concentrations shown are averages based on all
measured values above the detection limit. Values preceded by a less-than (<)
symbol In the table represent the minimum detection limit. Table 4-2 Is
divided to distinguish wells upgradient of the Monticello millslte from those
on the milisite property and downgradlent of the millslte.
Background water-quality data reported here for the alluvial aquifer are from
upgradient Wells 20 and 43 (Figure 4—11). Elements found in very low
concentrations or not detected include Ag. Al, As, Ba. Cd. Cr. F. Fe. Hg.
Mo. P. Pb, Se, V. and Ra—226. The pH ranged from 6.5 to 7.35: specific
conductance was measured at 550 to 1,056 micromhos/cm, and alkalinity at 192
to 500 mg/L.
Analytical data (Table 4-2) for selected ground—water constituents from seven
on—site wells show considerably elevated concentrations relative to the up-
gradient wells. In general, most of the highest concentrations are associated
directly with the tailings area. Mans of these are found In the vicinity of
the Carbonate and Vanadium Piles and in Well 36-A, near the east edge of the
milIsite property. In all cases, the maximum concentrations detected for
these constituents are from wells on the elilsite property (Table 4-3).
Table 4-3. Maximum Concentratlonsa Measured for Constituents
Reported in Table 4-2.
As
Cl
Fe
Mn
Mo
Ra-226
Se
SO 4
u
v
Maximum
Concentration
0.19
190
3.0
21.0
1.44
44
0.16
3900
12.8
4.7
Detected
Well No.
30B
08
51
36A
36A
36A
308
36A
36A
308
aResults are in rng/L except Ra—226. which is in pCl/L..
Samples from the on-site wells have also been analyzed for other constituents
not Included in Table 4-3. Those which proved to be undetectable or present
In very low concentrations include Ag, Ba. Cd, Cr. Pb. and Hg.
Downgradient wells typically have concentrations that are elevated relative to
upgradient wells. The distribution of maximum concentrations of selected
elements in the alluvial aquifer are shown in Figures 4-21 through 4-24.
Arsenic was chosen to represent toxic elements, uranium to represent mobile
heavy metals, and radiu. to represent radiologic contaminants. Chloride, a
mobile, conservative (i.e., non—reactive) species, portrays the maximum extent
4-44
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( J £ L’ a...’)
of the contamination plume. The southward extent of contaminati.on in the
alluvial aquifer is limited by Montezuma Creek. into which the aquifer
discharges. The northern extent Is uncertain but is probably Just south of a
line drawn from the northeast corner of the East Pile to the position of Well
82-13. The elevated concentrations observed In well 82-13 probably reflect
discharge of the alluvial aquifer to Montezuma Creek as It approaches the
canyon. The contamination plume cannot extend much beyond Well 82-13 because
of valley configuration.
4.4.3 Burro Canyon Aquifer
Ground-water samples collected from wells completed In the Burro Canyon
Formation show a bicarbonate dominance in almost all samples and variable
cation dominance between calcium, sodium. and no cation dominance (Figure 4-
25). As demonstrated in Section 4.3, the Burro Canyon aquifer under the
milisite is isolated from the alluvial aquifer by the Dakota Sandstone
aquitard. That tritium occurs in the alluvial aquifer but not in the Burro
Canyon aquifer also indicates that ground water in the Burro Canyon Formation
has not mixed with water from the alluvial aquifer (see Section 4.3.6).
Analytical data for selected chemical constituents further support the
argument that the alluvial aquifer and the Burro Canyon aquifer are
hydraulically Isolated. In Table 4-4 are presented average concentrations for
several constituents of environmental concern. Although the data represent
seven samplings of the monitoring wells, only concentrations above detection
limit were used to calculate averages.
Table 4 L Average Concentrateonsa of Selected Ccnst’ uents ‘
the Surro Canyon Aquifer
Wel’
No.
As
Fe
Mn
No
Ra—226
Se
U
V
Loca:iori
77
0 005
0 1
0.32
(0.05
0 5
<0.005
0.001
<0.05
Uogradient
70
7L
75
‘3 005
<0 005
<0 005
0.28
0 14
(0.1
0.25
0.16
0.35
(0.05
<0.05
(0.05
(1.0
0.8
0.3
<0.005
(0.005
<0 305
CC 001
0.002
0 002
3 05
<0 05
0.’O
Dowri rad en
Downgrad’erit
Downg id en:
i ll
results
are in
mg/L
exceot
those
for
Ra—225,
wn c
are n
pC i/I.
Concentrations of most constituents measured in the downgradlent wells are
similar to those observed in the upgradient well, which suggests that the
Burro Canyon aquifer is not affected by the contaminated alluvial aquifer. Of
most importance is the fact that the elevated levels of certain constituents
found in the alluvial aquifer are not found in the Burro Canyon aquifer. For
example, the average uranium concentration for three downgradient wells (08,
09, 13) in the alluvial aquifer is 0.41 mg/C .. whereas the average uranium
content of downgradient Wells 70, 74, and 75 in the Burro Canyon aquifer is
approximately 0.002 mg/L..
4-46
-------
5.0 SURFACE WATER INVESTIGATION
5. 1 SURFACE WATER
5.1.1 Montezuma Creek Watershed
The east flank of the Abajo Mountains is drained by two principal watersheds,
North Creek and South Creek. These two creeks join just west of Highway 191
to form Montezuma Creek, which flows through the tailings area (Figure 5-1).
Other smaller creeks also drain the east slope of the Abajo Mountains, but
they circumvent the tailings area and join Montezuma Creek downstream.
The highest point in the drainage basin is Abajo Peak, the elevation of which
is 11,358 tt; the elevation of the drainage outlet Is 6,955 ft. The length of
the flow path along South Creek is about 7 mi and along North Creek about
9.5 •i.
Two major soil types dominate the Montezuma Creek watershed, the Abajo Series
and the Monticello Series (Olsen and others, 1962). Both types are classified
in hydrologic soil group B (Soil Conservation Service (SCS] classification).
Soils in this group exhibit moderate-fine to moderate-coarse textures, and a
moderate infiltration rate when thoroughly wetted. On the basis of these soil
types and the type of vegetative cover (scrub oak) found in the watershed, an
SCS Curve Number (CN) of about 66 was calculated. The SC$ Curve Number is a
runott coefficient In the sense that it permits a conversion of rainfall depth
to the quantity of direct runoff.
Stream-gauging records for Montezuma Creek are maintained by the U.S.
Geological Survey. Until Spring 1986. flow data were collected at a stream-
gauging station approximately 0.25 mile downstream from the confluence of
North and South Creeks (Figure 5-1). The gauging station was moved to
immediately above Monticello Reservoir (Lloyd’s Lake) during spring 1986.
Documentation of monthly mean flow rates was not initiated until the 1979/1980
water year, but available records indicate that maximum discharges occur In
the spring and early summer months and that low- to no-flow conditions prevail
in the late su•mer, fall, and winter months. In the project area, base flow
in Montezuma Creek is maintained year-round by ground-water discharge from the
alluvial aquifer and by releases from Monticello Reservoir.
The original Montezuma Creek channel was significantly altered as a result of
activities related to the milling process and subsequent reclamation work.
The stream channel was relocated to the south, the stream course straightened,
the energy grade line reduced, and the channel lined with cobble and boulder
armoring. At the east end of the tailings site, a drop structure was built to
return the altered streambed to its original base level and to prevent
headward erosion of the creek into the tailings area. Excessive erosion
occurred downstream from the drop structure prior to Its erection In 1974
because of the artificial base level produced by the relocation of the stream.
5-1
-------
r
5.5 SURFACE-WATER CHEMISTRY
5.5.1 CharacterIzation of Background
Background surface-water quality has been monitored for so.e years at the
location labeled W-3 in Figure 5-5. This sampling point is east of the
culvert under Highway 191. Upstream samples have also been collected at site
I—I (west of the highway culvert) to verify that the W—3 location accurately
represents the background water quality of Montezuma Creek (Korte and Thul,
1982).
Prom 1980 to the present, the water at site W—3 has been characterized by low
or nondetectable levels of trace elements or mill-tailings-related material.
Trace elements not detected or found in very low concentrations include silver
(Ag), aluminum (Al), arsenic (As), barium (Ba), cadmium (Cd). cobalt (Ca),
chromium (Cr), fluorine (F), iron (Fe). mercury (Hg). manganese (Mn),
molybdenum (Mo). phosphorus (P). lead (Pb) 1 selenium (Se). uranium (U).
vanadium (V), and zinc (Zn). Radlum-226 also was not detected. The pH was
found to range between 7.4 and 8.6: specific conductance was measured at 400
to 500 micromhos/cm. and alkalinity at 150 to 200 mg/L (as CaCO 3 ).
5.5.2 On—Site Surface Water
Surface water on the government property consists of perennial flow In
Montezuma Creek and drainage between the Carbonate and Vanadium Piles
(drainage designated W—2 on the map in Figure 5—5). There is intermittent
water in seeps south of the Carbonate and Vanadium Piles and east of the Acid
Pile. The seep below the Carbonate Pile forms a small pond covering
approximately 160 square feet (ft 2 ). This pond contains water throughout the
summer and supports a few cattails. Seeps in the vicinity of the Vanadiu, and
Acid Plies usually contain water in the spring months. The pond adjacent to
the Vanadium Pile generally covers an area up to 50 ft 2 to a depth of 6-12 In.
The seep near the Acid Pile is contained by a small detention basin which
when full creates a pond whose area is about 210 ft 2 .
Analytical data on water taken from the seeps and the W-2 drainage are
presented in Table 5—5. Very high concentrations of several toxic elements
are evident.
Montezuma Creek flows through the middle of the property. Flow is perennial.
although it can be quite low during the late summer. Data obtained from a
September 1981 intensive sampling of the creek are presented in Table 5-6;
sample locations are shown in Figure 5-5. These data indicate that uranium
concentrations in the creek begin to increase above the point at which the
creek traverues the actual tailings piles. The sample location 1-2 is west of
the Carbonate Pile but downstream from the old mill and north ore-stockpile
areas.
Uranium levels in the creek increase an additional 40 to 50 percent toward the
downstream boundary of the property. Concentrations of arsenic, molybdenum.
vanadium, and uranium all increase below the entrance of the W—2 seep Into the
creek. On the downstream side of the Vanadium Pile, concentrations of
5-13
-------
Table 5-5. Sample-Analysis Results from On—site Seeps and Ponds
Results represent averages from two to six
1984 to 1986.
bThe Pare Pond is located on private property just east of the
tailings area.
uranium. •olybdenum. salenium, vanadium, and radium all continue to increase.
However, that concentrations of both molybdenum and uranium are considerably
higher off site indicates that the main contribution of the alluvial aquifer
to Montezuma Creek occurs below the drop structure.
5.5.3 Oft-Site Surface Water
5.5.3.1 Far. Pond
A stock pond is located on private property directly adjacent to the east
tailings area. The pond is filled with Montezuma Creak water diverted from
the top of the drop structure. Analytical results for this pond, which has
been sampled on several occasions, are presented as the last entry In Table
5—5. Elevated concentrations of arsenic, molybdenum, vanadium, and
particularly uranium are evident. However, the concentrations are lower than
those found in the nearby creek or In the underlying shallow ground water.
This location Is still upstream from that portion of the creek where flow and
solute concentrations Increase through alluvial-aquifer discharge.
Sample
Location s
Constituent
Coneentratlonsa
Cl Fe Mn
Mo N0 3 -N
Ra-226 Se
SO 4
U
V
Seep Between
Carbonate and
Vanadium Piles
(Site W—2) 0.56
946 —— 0.08
4.1 47
4 0.63
2521
0.7
52
Seep Below
Carbonate Pile 0.22
182 (0.1 3.8
4.5 8
(4 0.92
6405
1.7
54
Seep on
Vanadium Pile 26
890 0.34 295
26 <2
5 2.2
17.000
160
830
Pond East of
Acid Pile <0.05
42 <0.05 <0.1
2 51
17 0.037
1736
3.1
O.05
Pare Pondb <0.05
10 1 (0.1
<005 <1
(2 <0.01
63
0.06
0.29
5 All results are
in mg/L except
those
for Ra—226 which are in pCi/I.
samplings made over the period
5-14
-------
Uu 1 0229
S.
S.—.—
c J
t- .- .-. .. .— .... .—.
?I ure 5-5. Surt.c.-Wa(.r Sa.pH Locstlons et th. Monticeflo NIIJ.It.
5-15
-------
(iu u2 ,. j
5.5.3.2 Montezuma Creek
Seeps from the shallow aquifer are visible along the creek below the stock-
watering pond. Discharge in the creek increases for a mile or so, and is
perennial along this reach. Solute concentrations also increase along this
reach. The W—4 site is located approxImately 325 ft downstream fro. the east
boundary of the property. Average concentrations of selected elements are
presented In Table 5—7.
Table 5-7. Average Concentrations of Selected Constituents
in Montezuma Creek
Concentrationa
Sample
Gross
Location
As
Fe Mn
Mo
N0 3 -N
Se
U
V
Alpha
Background
(Site W—3)
<0.01
<0.07 0.17
0.178
3.0
(0.01
0.002
<0.05
<2
Site W—4
0.016
0.100 0.074
0.120
3.9
0.017
0.183
0.279
379
Sorenson
Site
<0.01
0.163 0.12
0.071
1.8
0.012
0.124
0.077
200
nAil results are in mg/L except those for gross-alpha activity which
are in pci/i. Results represent average concentrations of samples taken
during the period 1984 through 1986. The mean is calculated using only those
values above the detection limit. See Appendix B for raw data.
Samples have routinely been collected at what is known as the Sorenson (not
property owner’s name) site, located approximately 1.3 ml downstream from the
government property. Analytical results from samples collected at that
location are also presented in Table 5-7. It is apparent from data comparison
that most solute concentrations differ very little between the W—4 site and
the Sorenson site. The shallow aquifer contains elevated concentrations of
uranium, molybdenum, selenium, and vanadium as far downstream as it has been
sampled, and thus maintains high concentrations of these elements in Montezuma
Creek for a considerable distance off site.
Samples have also been collected between the Sorenson site and the Junction of
Montezuma Creek and Montezuma Canyon. During August 1982, streamflow was
intermittent from P0.5 ml below the Sorenson site to Montezuma Canyon. Flow
was continuous when the area was resampled during July 1983. In the August
sampling, base flow showed no significant changes In chemistry. However, when
flow was continuous, dilution was observed--a result of the side canyons
contributing clean water to the creek. The downstream water quality of
Montezuma Creek is addressed in detail in the following subsection.
5-18
-------
(J’J.LU 36
8.0 MR INVESTIGATION
Two types of substances having the potential to adversely affect the air
quality have been identified at the Monticello site: (1) radon-222, a
radioactive gas produced by the natural decay of radiua-228. which is
contained in the buried uranium mill tailings, and (2) airborne radioactive
and nonradloactive particles associated with the tailings. Environmental
monitoring programs were established In 1983 to evaluate the radon levels and
to measure select elements in the total suspended particulate burden.
The purposes of establishing the environmental •onitoring programs were to:
• Determine the air concentrations of radioactive and select nonradloactive
elements;
• Define the extent of atmospheric transport of radioactive elements;
• Provide a data base for use in estimating health effects on the general
public:
• Provide baseline measurements with which future measurements can be
compared; and
• Collect data to compare with Federal and State standards.
The results of the radon monitoring and the air particulate sampling are
presented in the following subsections.
8.1 ATMOSPRERIC RADON
8.1.1 Sampling Method
Atmospheric radon concentrations were measured 1 meter above ground level at
19 samplIng locations during the period 2 November 1983 to 19 November 1984.
Terradex Track Etch• Type F alpha—sensitive detectors, purchased from Terradex
Corporation, Walnut Creek, California, were used. These detectors are modeled
after a design described by Alter and Price (1981), whereby a strip of alpha-
sensitive film, protected by a special membrane filter that allows only radon
to penetrate, is placed inside a plastic cup, the cup is placed in an
environmental canister, and the canister Is deployed in the field (Karp,
1986a). After the detector is exposed, the cup is returned to the Terradex
Corporation, which analyzes the film by measuring the density of the alpha
tracks produced by radon decay. The density of the tracks is related to the
radon concentration in the atmosphere sampled. Detectors for the current
project were analyzed at their greatest level of sensitivity (0.2 picocuries-
month per liter [ pCia/L]) by Terradex.
The 19 sampling stations were located in three regions defined on the basis of
expected radon concentrations, prevailing wind direction, population
distribution, and radon measurements obtained previously in the Monticello
area (Shearer and Sill. 1989). The three regions are (see Figure 6-1):
• On site, near the center of the Acid (A), Carbonate (C). Vanadium (V), and
East (E) Tailings Piles (four locations: A, C, V, and K).
8-1
-------
\
L
S .’
+
Figure 0—1. Sa.pling Locations for Radon Monitoring in
the Monticello Study Ares
4-
(iU.LtitJ
f - i
I -
- - -,
1
4 uI
I - ’ ..
ST.,,.
— —I i.. 1.1
ST.)
••s”, S ’?
I .
— I
• R . Ma bnq LocoI n
® a Perticulots S rØs Locct OI
0—2
C
-------
(J J.L U )’)
• Edge of pile -- Along the DOE property boundary, which essentially
coincides with the perimeter of the inactive milisite pile (seven
locations: ST-i, 2, 3, 5, 6, 7, and 8).
• Off site to the west, north, and east (eight locations: ST—4, 9. 10. ii,
12. 13, 14, and 15).
A pair of detectors was placed at each sampling location to obtain duplicate
measurements.
6.1.2 Analytical Control
Quality control of the radon analyses performed for this study was accom-
plished in several ways. One involved the duplication of measurements, as
mentioned above. Another entailed the analyses of eight unexposed detectors--
5 percent of the total survey--to determine the inherent average background
track density of the detectors and the average amount of additional exposure
that each detector would be expected to receive during shipping. Still
another Involved the exposure of 23 detectors-—15 percent of the total survey-
-to known radon concentrations in the Grand Junction Projects Office
Radon/Radon-Daughter Environmental Chamber (Langnei and Nelson, 1985). The
radon concentration in the environmental chamber is determined by means of a
continuous Padon monitor and daily grab sampling using flow-through sclntil-
lation cells; the cells are calibrated with radium solutions obtained from the
National Bureau of Standards (NBS). A cross-calibration with the DOE/Monsanto
Chamber located at the Mound Laboratory In Ohio was also conducted. The
results of each calibration exercise for this study are listed in Table 6-1.
The calibration equation (see Figure 6—2) indicates that the Terradex
calibration factor overestimates the radon concentration by 9 percent.
Table 6-1. Terradex Track Etch• Calibration Results
DOE
Calibration
Chamber
Known Radon
Concentration
(pCi/L)
No. of
Track Etch 6
Detectors
Mean Terradex Radon
Concentration (pCi/L)a
Ratio of
Known to
Terradex
GJPO
0.95
4
0.94 0.34
1.01
Mound
0.91 .
4
1.30 0.72
0.75
GJPO
0.49
2
1.05+0.74
0.47
GJPO
3.27
2
2.83+0.10
1.16
GJPO
•6.19
2
7.05 • 0.76
0.88
GJPO
0.56
3
0.60 + 0.06
0.93
GJPO
1.05
3
1.33 0.28
0.79
GJPO
2.31
3
2.27 0.87
1.02
standard deviation
MEAN - 0.88
based on Poisson counting
‘Uncertainties are 1
statistics.
8-3
-------
70•
.E R i 0.98
Ys000+09 1X
.2 60
o
50
40
U
C
.
.2 30
0 •,.
U
2°
i0•
I I I I
0 10 20 3.0 40 5.0 6.0 7.0 8.0
Mean Radon Concentration Reported by
Terradsx (pCi/ I.)
Figure 6-2. Calibration Curve for Track Etch• Detectors
6.1.3 Measurement Results and Comparison With Federal Standards
The duplicate Track EtchS detectors were exposed quarterly at each of the 19
sampling locations over a period of 1 year. Quarterly analytical results
reported by Terradex Corporation for each detector are presented In Tables 6-2
through 6-5, respectively. The annual average radon concentrations, less the
background of the detector, are summarized in Table 6-8.
The natural background radon concentration for the Monticello area can be
inferred by examining the results tro. the off-site sampling locations. Only
one location, ST—4, is statistically different from the rest at the 95 percent
confidence level. This monitoring station is situated on a narrow alluvial
floodplain deposit of Montezuma Creek that extends one—third of a mile down
drainage from the East Tailings Pile. The deposit contains hundreds of
picoCuries per gra, of radium—226 in places (Marutzky and others, 1985: and
Plate 4-5A, this document) and is probably the reason for the anomalous
atmospheric radon concentration measured at ST-4. The elimination of ST-4 as
a representative background location yields a mean radon concentration of
0.41 • 0.08 pCi/I, (1 standard deviation uncertainty) which ii considered to
be the average annual background concentration at Monticello. This value is
consistent with the average annual background of 0.34 pCi/L determined by
Shearer and Sill (1969).
The EPA standard (40 CPR Part 192) for atmospheric radon concentration at the
edge of an inactive uranium mill tailings pile is 0.50 pCi/L above background.
If 0.41 pCi/I. is used as the average annual background for Monticello, the
site-specific EPA standard ii calculated to be 0.91 pCi/I.. Examination of the
data In Table 6—6 reveals that the EPA standard is exceeded at every on-pile
location end at every edge—of-pile location. The only off-site location
exceeding the standard Ii ST-4.
6-4
-------
Table 6-2. Radon Concentrations Reported by Terradex for the
Period 2 Noveaber .1983 to 9 February 1984
Sa.p ling
Location
Radon Concentration (pCi,L)a
veteccor 1 Detector
On Pile
ST—A
ST-E
ST-V
ST-C
1.36 + 0.48 2.63 + 0.50
1.85 0.42 4.30 0.84
4.60 0.67 1.95 0.43
5.13 0.68 5.38 0.73
Edge of Pile
SI-i
ST—2
ST—3
ST-4
ST-S
ST—8
ST—I
ST—8
1.46 + 0.24 3.32 + 0.84
1.85 0.33 2.93 0.66
0.69 0.11 0.89 0.16
0.890.14 0.82:0.13
0.40 0.05 1.24 0.28
1.46 0.37 1.06 0.15
3.71 0.59 1.36 0.35
1.46 0.37 4.20 0.63
Of f Site
ST-9
ST—lU
ST-li
ST-12
ST-13
ST-14
ST-iS
0.82 + 0.13 0.42 0.09
0.47 T 0.10 0.30 T 0.07
0.33 0.08 0.35 0.08
0.42 0.10 0.07 0.01
0.52 0.10 0.07 0.01
0.25 0.07 0.40 0.09
0.45 0.09 0.52 0.10
5 Uncertainties
counting statistics.
are I standard deviation based on Poisson
Table 6-3. Radon
Period
Concentrations Reported by Terradex f or the
9 February 1984 to 9 May 1984
Sa.pling
Location
Radon Concentration (pCi/L)a
uetector i Detector
On Pile
ST—A
ST-E
ST—V
ST—C
2.76 + 0.53 2.33 • 0.49
1.48 0.39 3.82 0.61
1.59 0.40 1.80 0.43
2.55 0.51 2.76 0.53
Edge of Pile
ST-i
ST-2
ST—3
ST—4
ST-S
ST-6
ST—7
ST-8
0.60 + 0.12 0.73 + 0.13
1.80 0.43 0.94 0.15
0.54 0.11 0.41 0.09
0.78 0.13 0.78 0.13
0.82 0.12 1.48 0.39
0.760. 13 O.570.11
1.89 0.41 1.80 0.43
1.89 0.41 0.78 0.13
Off Site
ST-9
ST-b
ST-Il
ST-12
ST—13
ST-14
ST-IS
0.24 + 0.04 0.49 + 0.10
0.06 0.01 0.08 0.02
0.42 0.09 0.46 0.10
0.13 0.02 0.38 0.09
0.41 0.09 0.41 0.09
O.180.03 O.380.09
0.14 0.02 0.52 0.11
auncertainties are 1 standard deviation based on Poisson
counting statistics.
6—5
-------
Table 6-4. Radon Concentrations Reported by Terradex for the
Period 9 May 1984 to 16 August 1984
sa.p iing
Location
Radon Concentration (pCl/L) 5
Detector 1 Detector z
On Pile
ST-A
ST-E
ST-V
ST-C
3.84 • 0.30 3.84 • 0.30
8.93 0.92 3.14 0.27
4.34 0.32 6.50 0.79
8.51 0.91 9.61 0.96
Edfe of Pile
ST-i
ST-2
ST-3
ST-4
ST-5
ST-6
ST—7
ST-a
3.05 + 0.27 1.10 + 0.09
1.47 T 0.18 2.25 0.23
1.93 0.21 1.64 0.19
0.86 0.08 0.98 0.08
0.65 0.07 2.08 0.22
3.05 0.27 3.46 0.28
4.19 0.31 3.68 0.29
3.24 T 0.27 2.05 0.22
Of f Site
ST-9
ST-l0
ST-il
0.66 • 0.07 0.42 + 0.05
0.40 0.05 0.35 0.04
0.34 0.04 1.10 0.15
ST-12
ST-13
0.37 0.05 0.37 0.05
0.42 0.05 0.33 0.04
ST-14
0.87 0.07 0.25 0.04
ST-15
0.58 0.08 0.54 0.06
auncertainties
are 1 standard deviation based on Poisson
counting statistics.
Table 6-5. Radon
Period
Concentrations Reported by Terradex for the
16 August 1984 to 19 Noveiber 1984
Sa.pling
Location
Radon Concentration (pCi/L)a
Detector 1 Detector z
On Pile
ST-A
5.35 + 0.74 5.14 + 0.72
ST-E
ST—V
5.59 0.74 9.80 0.98
. 8.18 0.90 7.27 0.85
ST-C
8.89 0.93 8.08 0.90
Edge of Pile
ST—i
ST—2
1.98 + 0.22 1.82 + 0.19
2.59 0.25 4.94 0.70
ST-3
1.22 0.17 1.65 ; 0.20
ST-4
2.51 0.24 1.83 0.21
ST-S .
ST-S
2.21 0.23 1.30 0.17
3.22 0.28 2.28 0.23
ST-7
3.08 0.27 3.08 0.27
ST—S
4.36 T 0.33 2.81 0.26
Of f Site
ST-a
0.54 + 0.06 0.39 • 0.05
ST-iO
0.23 0.03
ST—li
0.65 0.07 0.23 + 0.03
ST-12
0.47 0.05 0.22 0.03
ST-13
0.58 0.07 0.58 0.07
ST- 14
0.43 T 0.05 1.18 0.16
ST—iS
0.55 0.06 0.45 0.05
5 Uncertainties are I standard deviation based on Poisson
count ng statistics.
“Destroyed in the field. -
6-8
-------
Ut, . . U -1 ‘
Table 6-6.
Annual Average Radon Concentrations Reported by Terradex for
the Monticello Area
Sampling
Location
Radon
Concentration (pCt/L)a
Annual Average
Minimum
Maximum
On Pile
ST-A
ST-E
3.40 •
4.83 •
0.37
0.47
1.36 + 0.48
1.48 0.39
5.35 + 0.74
9.80 • 0.98
ST-V
4.53 +
0.45
1.59 + 0.40
8.18 • 0.90
ST-C
6.44 +
0.55
2.55 + 0.51
9.61 • 0.96
Edge of Pile
ST—i
1.73 +
0.24
0.60 + 0.12
3.32 + 0.84
ST-2
ST-3
ST-S
2.34 •
1.11
1.24 .
0.29
0.11
0.15
0.94 • 0.15
0.41 + 0.09
0.40 • 0 05
4.94 • 0.70
1.93 + 0.21
2.21 • 0.23
ST-6
1.98
0.17
0.57 • 0.11
3.46 • 0.28
ST-I
2.82 •
0.27
1.36 + 0.35
4.19 • 0.31
ST-8
2.57 +
0.23
0.78 + 0.13
4.36 • 0.33
Off Site
ST-4
1.18 •
0.11
0.78 . 0.13
2.51 • 0.24
ST-9
0.49 •
0.05
0.24 • 0.04
0.82 + 0.13
ST-b
0.26 •
0.03
0.06 0.01
0.47 • 0.10
ST-li
0.48 •
0.06 .
0.23 ‘ 0.03
1.10 • 0.15
ST-12
0.34 +
0.04
0.13 • 0.02
0.47 • 0.05
ST-13
0.41 +
0.05
0.07 • 0.01
0.38 + 0.07
ST-14
0.46 +
0.06
0.16 + 0.03
1.18 + 0.16
ST-iS
0.46 •
0.05
0.14 • 0.02
0.58 • 0.06
are I standard deviation
based on Poisson counting
aUncertaint lea
statistics.
The reduction in annual average radon concentration to background levels as a
function of distance away from the tailings site is illustrated in Figure 6-3.
The average annual radon concentration measured at ST-7 (edge of Vanadium
Pile) is 2.82 • 0.27 pCi/L. The radon concentration is reduced to background
levels at ST—9. which is located 1100 ft northwest of the DOE property
boundary.
6.1.4 Ongoing Atiospheric Radon Monitoring
To maintain continuity In the radon data during and after remedial action.
atmospheric radon continues to be monitored, although the number of sample
locations has been reduced from 19 to 8 since the conclusion of the 1983-1984
sampling period. The radon detectors were exposed quarterly over the two-year
period from November 20. 1984 through November 14. 1986. The ongoing radon
sampling locations and their respective annual average radon value, are listed
in Table 6-7.
8-7
(
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(;ti j. ti 24 1 i
3.5
2.5
2.0 -
1.5 -
P.O
0.5
0.4
0.3
0.2
0.1
0 1000
LEGEND
Predicted by thi Atmospheric
Transport Model (ATM)
• Measured with Track ElehCI Detectors
— — Average Annual Natural Background,
Bounded by One-Sigma
Confidence. Bands
— a — — —
ST- 12
a — — —
2000 3000
Olstancs from Vanadium Pile (feet)
— a a — — —
I I
4000 5000
FIgure 6-3. Cross-Sectional View of Reduction In Radon Concentration
as a Function of Distance fro. the Tailings Site
3.0
ST- i
Edge of Vanadium Pile
(DOE Property Boundary)
U
Standard
— a — — — a — — -
- k. ST-9
— — _ — a — — — a — a —
: ‘Average Background
6-8
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Table 6-7. Ongoing Radon Measurement Results
(J1J402 -14
Sampling
Radon
(pCi/L).
1985 a
Radon
(pCl/L),
1986 b
Annual
Annual
Location
Average
Minimum
Maximum
Average
Minimu•
Maximum
ST-4
1.45
0.56
3.86
1.44
0.77
2.97
ST-6
1.16
0.39
3.06
1.29
0.58
1.80
ST—7
1.57
0.81
2.58
1.84
1.09
2.91
ST-b
0.35
0.18
0.48
0.50
0.16
0.71
ST—Il
0.36
0.25
0.46
0.68
0.39
1.02
ST—13
1.00
0.17
3 g 8 C
0.51
0.18
0.76
ST—14
0.32
0.20
0.53
0.40
0.25
0.58
ST-15
0.85
0.14
1.60
0.42
0.20
0.63
2O November 1984 through 22 November 1985
b 22 November 1985 through 14 November 1986
C j 5 value is inexplicably high
For control purposes, three radon detectors were also exposed each quarter in
the GJPO radon/radon-daughter environmental chamber as previously described.
The results reported by Terradex for each quarterly calibration are presented
in Table 6-8. They show excellent agreement with the radon concentrations
determined in the environmental chamber.
Table 6—8.
Terradex Track EtchS Calibration Results
For Ongoing Radon Monitoring
Known Radona
Concentration
(pCi/ I ,)
Number of
Track Etchi
Detectors
Mean Terrade
Radon Concentra
(pCi/L)
x
tion
Ratio of
Known to
Terradex
1.30
3
1.48
0.88
2.09
3
1.90
1.10
1.62
3
1.73
0.94
1.87
3
1.97
0.95
1.41
3
1.57
0.90
1.70
3
1.92
0.89
0.94
3
1.08
0.87
1.31
.
•
3
exposure was per
1.21
formed concurrentl
y with
MEAN
the q
1.08
- 0.95
uarterly
aEach calibration
field •easurements.
•1
During the two core recent measurement periods, the annual
standard specified by 40 CFR 192 was consistently exceeded
ST-7. These values are consistent with the results of the
annual averages (see Table 8-6).
6—9
average radon
at ST-4, ST-8. and
previous year’s
-------
(JIJ.L 0245
8.2 RADON FLUX
6.2.1 Measureaent Method
All radon-flux aeasurements were performed using a large-scale (0.107.2)
activated-charcoal canister (Karp, 1986b). This passive charcoal device was
selected largely because it is easily deployed and collected in the field, but
also because it de.onsttates excellent agreement when compared with the GJPO
Technical Measurements Center (TMC) thin—layer-model radon—flux reference
source (Rogers and others. 1984). To ainilize the effects of weather-Induced
temporal variations on the radon flux, all field measurements were made during
stable weather conditions. To minimize diurnal effects on the radon flux, all
measurements were performed over an exposure period of 24 hours.
A control location was established near the center of the Acid Tailings Pile
(see Figure 6—4) to exaaine seasonal variations in the radon flux. Radon-flux
measurements made at this control location from April 1984 through November
1984 are listed in Table 8-9 and plotted in Figure 6—5. Exaalnation of these
data reveals a strong seasonal pattern in radon flux at the site: the lows
occur during the wetter winter months, the highs occur during the drier su.aer
months. This is not surprising in view of the extreme variations in annual
climatic conditions that characterize the Monticello area.
Table 8—9. Radon-Flux Measure.ents Made at the Control Location
During 1984
Date of Measurement Radon Flux (DCI..2secl)a
April 5 141 • 3
April 18 85 + 1
April 19 188 • 2
May10 148±2
June 15 418 • 5
June 19 395 + 4
July 19 508 + 7
July 28 411 + 4
August 13 442 ± 4
August 14 485
August 15 489 . 4
August 16 458 . 3
Septeaber 24 46 1
September 25 72 ± 1
September 26 169 • 2
October 31 115 • 2
November 1 89 ± 2
November 19 302 ± 3
auncertainties are 1 standard deviation based on Poisson
counting statistics.
6-10
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6.2.2 Results of On-Site Maasure.ents
A detailed radon—flux survey was performed at the Monticello tailings site
over the period 13-16 August 1984. Eighty-two measurements were obtained on
the Acid. Carbonate. Vanadium, and East Tailings Piles, including daily
measurements at the control location (Figure 6-4). Results of the survey are
listed in Table 6-10 (following pages); these data were also plotted on a base
map and hand contoured (Figure 6-6).
The radon source strength for each tailings pile was determined by first mea-
suring with a planimeter the area between each isopleth shown on Figure 6-6,
multiplying each area •easure.ent by the appropriate average radon flux, and
summing the resultant values. A weighted-average radon flux was determined by
dividing the radon source strength by the total area Qf the source. The radon
source strength, area, and weighted—average radon flux for each tailings pile
are presented in Table 8-li.
The EPA standard (40 CPR Part 192) for radon emissions at inactive uranium-
processing sites ii 20 pCi.m 2 ’sec’. The data presented in Tables 6—10 and
6-11 reveal that the EPA standard is exceeded at each of the four tailings
piles.
Table 8—11. Radon Source Strength. Area. and Weighted-Average
Radon Flux for the Monticello Tailings Piles
Tailings
Pile
Radon Source
Strength
(oCi/sec)
Area
Weighted-Average
Radon Flux
(pC1 ’m ’sec 1 )
Acid Pile
16.226.246
52,070
312
Carbonate
Pile
18.108,948
23,657
765
Vanadium
Pile
2.800.657
16,216
173
East Pile
12,747.706
95,746
133
6.2.3 Results of Off-Site Measurements
As noted earlier, atmospheric radon concentrations measured at ST-4 for each
quarterly exposure are anomalous when compared with the concentrations
recorded at off-site locations. Because ST—4 is located nearly 610 meters
from the DOE property boundary, it was considered unlikely that the elevated
radon concentration measured here was due solely to atmospheric transport from
the tailings piles. Recent findings (Marutzky and others, 1985; also Plate 4-
5A) suggest that radium was transported from the tailings site and deposited
on a narrow alluvial floodplain. This deposit extends southeast from the DOE
property boundary to within 60 meters of ST-4.
To characterize the radon flux in this apparently anomalous area, measurements
were made at four locations exhibiting high concentrations of radiua-226 In
soil (Plate 4-5A), at ST—I, and at the control location o the Acid Pile.
Results of these measurements are presented in Table 8-12.
6—14
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1.
vU .
6.4 AIR PARTICULATE MONITORING
6.4.1 Saaplin Method
Continual air particulate monitoring was initiated at the Monticello site In
August 1983. High-volUme Sierra-Anderson 300 air particulate samplers were
installed 9 ft above the ground level at three locations in the Monticello
area (see Figure 6-1). SamplIng stations at the site were located along the
paths of two principle wind directions, to the north and to the east (see
Section 2.4 for windrose data). In addition, a background station was
established west of the site. The samplers were programmed to operate at 40
SCFM, for 24 hours, every sixth day. Sampling was not conducted during the
winter months because of inclement weather and snow cover on the tailings
pile. Flow-rate calibration was performed using a Kurz Model 341 electronic
mass flow meter. Samples were collected on Whatnan No. 40 cellulose filters
or Pallfiex-type 2500 quartz filters in accordance with procedures described
in the UNC Technical Services, Inc. Environmental Sciences Procedures Manual
(1986). In March 1987. 10-mIcron size screens were added to the samplers to
allow only the inhalable particles to be collected.
6.4.2 Analytical Results and Comparison with State and Federal Standards
The air particulate filters were analyzed by the UNC chemistry laboratory In
accord with methods described in the Handbook of Analytical and Sample-
Preparation Methods (UNC Geotech, 1987). The radioactive elements radlum-226
and thoriua—230 were detected through alpha spectroscopy. uranium—238 through
fluorometry. Copper, manganese, iron and vanadium were investigated by
inductively coupled plasma. Potassium and lead were detected by atomic
adsorption. A blank filter was analyzed with each air particulate filter, and
the results were subtracted to correct for the inherent contamination of the
filter. The results of the air particulate study conducted 1984-1986 are
si... aarized in Table 6-14.
6.4.2.1 Radiologic Air Particulatee
Radlologic air particulate levels are regulated at the Monticello site by DOE
Order 5480.1; the stand rds applicable to Monticello are given as
concentrations above natural background. The reported limits, averaged over
one year. are 3.0 pCi/m 3 radiua—226, 0.8 pCi/m 3 thorlum-230, and 9 pg/rn 3
uranium-238. Examination of the data in Table 6-14 shows the highest annual
average concentrations of the subject elements (inclusive of background
levels) to be 0.0006 pC i ]. 3 radjum-fl6, 0.0004 pCi/rn 3 thoriua-230. and
<0.0012 pg/m 3 uranium, values that are clearly below the standard.
The results of the sampling were compared to background measurements obtained
from other rural areas of the Western United States. For example. Van De
Steeg and others (1982) reported background airborne concentrations in the
range of 0.1 to 0,5 pCi/a 3 for radiua-226 and 5 to 10 pg/m 3 for uranlum-238 in
the Ambrosia Lake uranium district In New Mexico. These background values are
UNC Technical Services, Inc., was changed to UNC Geotech in May 1987.
6-25
z O
-------
Ou ’J23J
several orders of magnitude higher than the maximum concentrations measured at
the Monticello site.
6.4.2.2 Nonradiologlc Air Particulates
Lead is the only nonradloactive airborne particulate measured at the
Monticello Facility that ii regulated by a specific standard. Acceptable
levels of this element are defined by the U.S. Environmental Protection Agency
(EPA) under the National Ambient Air Quality Standards (NAAQS). The standard
specifies that a 3—month average concentration of lead is not to exceed 1.5
pg/ i 3 . The maximum concentration measured at the site is 0.0490 pg/rn 3 (see
Table 8—14), a level clearly below the compliance standard.
Because no specific standards exist with which to compare the remaining
nonradiologic air particulate data (see Table 6—14). these data were evaluated
relatively against other published data. Copper and vanadium were
studied because both are found in the Monticello tailings in concentrations
that exceed the crustal average by more than two orders of magnitude (Abramluk
and others, 1984, Section 3). The air—particulate data for copper indicate
that concentrations are well within the results of a TSP analysis conducted by
Flocchini and others (1981) at a site in Canyonlands National Park. The
vanadium results indicate a slightly elevated concentration at the east
station (0.0050 pg/a 3 ) as compared with the background station (0.0015 pg/rn 3 ).
Even this Is extremely low, however, when compared with vanadium
concentrations encountered in certain industrial environments. For example.
Small and others (1981) reported average results of 0.059 pg/a 3 vanadium in
samples collected near a copper smelter in Arizona.
Iron, potassium, and manganese were included as typical soil-related elements.
The data do indicate a higher loading at the east station, which is not
surprising when one considers the proximity of dirt roads, agriculture, and
the City of Monticello. Other contributors include traffic on the tailings
plies and the related dumping of contaminated material removed from the
Monticello vicinity properties. Still, results for these elements are
significantly less than those reported by Moyers and others (1977) for an
urban desert setting; data collected on the University of Arizona campus
indicate Iron, potassium, and manganese concentrations that are almost twice
those found at the Monticello east station. These studies agree that most of
the particulate mass issoil material.
In Table 6-15 are summarized the radiologic and nonradlologic air particulate
data collected at Monticello. Background data from other western sites are
presented for purpose. of comparison.
6-27
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Monticello Mill Site Mining Waste NPL Site Summary Report
Reference 2
Excerpts From the Declaration for the Record of Decision and Record of Decision Summary,
Monticello Remedial Action Project; DOE, Idaho Operations Office,
Grand Junction Projects Office; August 1990
-------
DOFIID/123$4-5O
Monticello Mill Tailings Site
Declaration for the Record of Decision
and Record of Decision Summary
August 1990
U.S. Departnient of Energy
Idaho Operations Office
Grand Junction Projects Office
Grand Junction, Colorado
L
-------
MO ICZ. M: . rAILINGS sIr
DEcLARKr:3N FOR r ’i Rzco o ec:s:oN
-------
MONTICELLO MILL TAILINGS SITE
DECLARATION FOR THE RECORD OF DECISION
Site Name and Location
Monticello Mill Tailings Sit.
San Juan County. Utah
Statement of Basis and Puroose
This decision document presents the selected remedial action for the
Monticello Mill Tailings Site (Operable Units I and II) in San Juan County.
Utah. The selected remedial action was chosen in accordance with the
requirements of the Comprehensive Environmental Response. Cop.nsation. and
Liability Act of 1980. as amended by the Superfund Amendments and
Reauthorization Act of 1986 and the National Oil and Hazardous Substances
Pollution Contingency Plan. This decision document explains the factual and
legal basis for selecting the remedy for this site.
The State of Utah and the Environmental Protection Agency concur with the
selected remedy. This remedial action decision is based on the aoministrative
record for this site.
Assessment of the Site
Actual or threatened releases of hazardous substances from this site, if not
addressed by implementing the response action selected in this Record of
Decision. may present an imminent and subs’antial endangerment to public
health. welfare, or the environment.
Description of the Selected Remedy
The selected remedies for Operable Units I and II are described in this Record
of Decision. Final remediation of Operable Unit I. Mill Tailings and Milisite
Property. requires completion of the selected remedy for Operable Unit II.
Per pheral Properties. Remediat on of Operable Unit III. Ground Water and
Surface dater. will be addressed in a separate Record of Decision as it
requires implementation of the selected remedy for Operable Units I and II. A
summary of the extent of contamination in Operable Unit III has been included
in this Record of Decision to assist in defining the extent of contamination
from the millsite.
Operable Unit I - Mill Tailings and Millszte Property
Remediation of this operable unit is the first of three final actions that are
planned for th. site. Operable Unit I addresses the source of contamination
by excavation of uranium mill tailings and other by ’product materials (as
defined in Section 11(e)(2) of the Atomic En.rgy Act of 1954 as amended. and
in 40 CFR Part 192 as utailings or waste produced by th. extraction or
concentration of uranium from any ore processed primarily for its source
material content). contaminated buildings and equipment material. ore. and
contaminated soils on the milisite that present a so irce of ground-water
contamination or threat of direct exposure. After excavation, the
contaminated material will be contained in a repository that will be built
approximately one mile south of the present nilisite. The remedy addresses
the principal threats at the site. which are associated with radon emmisicrs
and d .rect exposure to gamma radiation from the existing mill tailings p. ..es
1
-------
The major components of the selected remedy for Operable Unit I include:
Removal of approximately 1.5 million cubic yards of tailings, ore, and
process-related material (brproduct material, contaminated building
materials, and mill equipment) from their present location where they
are within the floodplain of Montezuma Creek or are in contact with the
ground water to a repository one mile south of the present mill tailings
site. h repository would be designed to meet requirements of the
Uranium Mill Tailings Radiation Control Act of 1978 and the Uranium Mill
Tailings Remedial Action Program technical standards. Thes. standards
require the repository be effective for up to 1.000 years to the extent
reasonably achievable, and that the escape of radon gas be controlled to
within acceptable limits. This remedy has been determined to be an on-
site remedy pursuant to the National Contingency Plan.
• Capping the repository to protect the ground water. isolate the waste
from the environment, and to control the escape of radon gas;
• Construction of surface-water controls necessary during remedial action
construction activities and for the repository;
• Treatment of contaminated runoff water and construction/dewatering water
collected during construction activities in accordance with applicable
standards prior to release to the environment, with disposal of
residuals in the repository or another licensed repository. Treatment
may be performed by evaporation, reverse osmosis, or another appropriate
technology and will be determined during the design stage:
• Revegetation of the millsite and repository site:
• Long-term surveillance and environmental monitoring to ensure the
effectiveness of the remedial action and compliance with ground-water
and surface-water standards:
• Land acquisition and access control as necessary.
Operable Unit II - Peripheral Properties
Remediation of this operable unit is the second of the three final actions
planned for the site. Remedial action at Operable Unit II addresses the
removal of radioactively contaminated soils and processing by-product
materials located on peripheral properties. The remedy would reduce radiation
exposure to the public by either removing contaminated materials by
conventional construction techniques or environmentally sensitive construction
techniques. or by proposing the use of supplemental standards. As allowed
under the principal relevant and appropriate requirement. supplemental
standards allows leaving some or all of th. contamination in place where
removal would cause undue environmental damage. Materials removed from the
properties would be placed on the existing tailings pile for final disposal
with tailings from Operable Unit I. In areas where supplemental clean up
standards under Title 40 Code of Federal Regulations, Part 192.22 could apply
(the cemetery and densely vegetated hillsides south of Montezuma Creek).
institutional controls may be used to restrict access and control the use of
the land to prevent future exposure.
2
j
-------
The major components of the selected remedy include:
• Removal of an estimated 300.000 cubic yards of tailings from peripheral
properties and eventual disposal. in the same repository as described for
Operable Unit I:
• Vegetation after removal of tailings;
• The use of institutional controls. if necessary.
Operable Units I and II are scheduled to be completed over a 5-year period.
Reviews of the selected remedy are scheduled under the Comprehensive
Environmental Response. Compensation. and Liability Act at five-year
intervals, commencing with the initiation of remedial action.
Operable Unit III - Ground Water and Surface Water
Remedial action of Operable Unit III addresses clean up of ground-water and
surface-water contamination. The Upper and Lower Montezuma Creek peripheral
properties will also be remediated in this operable unit. During the remedial
action of Operable Units I and II. the characteristics of the ground water in
the alluvial aquifer and the surface water in Montezuma Creek (Operable Unit
III) will be altered. Remedial action construction activities will cause the
following changes:
1. Surface water, a principal source of ground water, will be diverted
around the site. This will cause unknown effects in the attenuation
and chemical properties of soils below the site.
2. The soils in the alluvial aquifer contaminated by mill tailings or
leachate will be excavated to the standards in 40 CFR 192 during the
remedial activities proposed for Operable Unit I. The contaminated
pore water retained in the excavated soils will be removed with the
soils.
3. During construction, portions of the site must be dewatered to
facilitate removal activities thus removing a large amount of water
from the alluvial aquifer. All water from dewatering of tailings and
soil and from construction activities will be treated and released to
the environment in compliance with the applicable requirements.
The results of these changes will have an unknown effect on the
characteristics of the aquifer.
Throughout remediation of Operable Units I and II. a ground-water and surface’
water monitoring program of the alluvial and Burro Canyon aquifers will be
conducted upgradient from. downgradaent from. and on the milisite. This
monitoring program will continue for three years after removal of the
contaminated material. As monitoring continues during the three year period.
the U.S. Department of Energy. the U.S. Environmental Protection Agency. and
the State of Utah will periodically review the results of the monitoring
program and determine what additional steps. if any. will be required to
complete aquifer restoration. When sufficient data have been gathered through
a focused remedial investigation/feasibility study to warrant a final decision
for ground-water and surface-water restoration. a Record of Decision will be
produced for Operable Unit 111.
Institutional controls. including buying or leasing of land and water rights.
will be implemented for Montezuma Creek and the alluvial aquifer prior to
remedial action construction on Operable Units I and II. These controls will
be maintained until such tame as a decision is made regarding surface’water
and ground-water remediation.
3
-------
Declaration of Statutory Determinations
The selected rem.dy is protective of human health and the environment.
complies with Federal and State of Utah requirements that are legally
applicable or relevant and appropriate to the remedial act on. and is cost-
effective. This remedy utilizes permanent solutions and alternative treatment
(or resource recovery) technologies to the maximum extent practicable for this
site. This remedy does not satisfy the statutory preference for treatment as
a principal element for several reasons. Due to the large volume of
contaminated materials, treatment is not practicable. Further. none of the
proven treatment technologies available for radiological contaminants reduces
the total volume or toxicity of these contaminants, nor do they irreversibly
reduce contaminant mobility. Technologies that could reduce the total volume
of contaminated soil produce residuals that would present a threat to human
health and the environment.
Because this remedy will result in hazardous substances remaining en site
above health-based levels, a review will be conducted within five years after
commencement of remedial action to ensure that the remedy continues to provide
adequate protection of human health and the environment.
- - - ‘4
Regionai i.nistr or (Region VIII) Date
U.S. Environmental Protection Agency
U.S.
Department of Energy
Idaho
Operations Office Manager
,
,
Concurring in this determination:
State of Utah.
eparwent of Health
f/ (.
Date
4
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MONTICELLO MILL TAILINGS SITE
DECISION SU)U(ART FOR TEE RECORD OF DECISION
1.0 •SETE NAME. LOCATION. AND DESCRIPTION
The Monticello Mill Tailings Site (the Site) is located in San Juan County.
Utah. near the City of Monticello (Figure 11). in the southeastern corner of
Utah. Mill tailings and associated contaminated material remain on the
nillsite as a result of milling for uranium and vanadium. The tailings piles
are within the floodplain of Montezuma Creek and are partially in contact with
an alluvial aquifer. Tailings particulate material has been windblown and
transported by surface water to properties peripheral to the millsite. The
site 3.5 bordered by land owned by the U.S. Department of the Interior s Bureau
of Land Management, the City of Monticello. and private owners. No residences
are located within the mi.llsite boundary. but residences ace adjacent to the
north and east edges of the site. The City ha. a population of approximately
1.900.
The site includes the millsite. where radioactive tailings and associated
contaminated material are located, and peripheral properties. The millsite. a
78-acre tract within the City of Monticello. is owned by the U.S. Department
of Energy. During the period of mill operation. private land to the north and
south of the existing site was leased for the stockpiling of ore. The former
ore-stockpile areas and areas contaminated by airborne-tailings particulate
matter or surface-water transport cover approximately 300 acres around the
site and contain most of the estimated 300.000 cubic yards of peripheral
property material to be remediated. Peripheral properties also include the
bed and banks of a 3.3-mile reach of Montezuma Creek between the City of
Monticello and Vega Creek.
The millsite consists of the form.r mill area and the tailings-impoundment
area. An estimated 100.000 cubic yards of contaminated material have been
identified in the mill area: and approximately 1.4 million cubic yards (2
million tons) of tailings, contaminated soil. by-product material, and
contaminated building material are located in the tailings-impoundment area.
Figure 1-2 depicts the millsite property. associated buildings. and tailings
piles.
The tailings are contained in four piles. These piles are located within the
floodplain of Montezuma Creek. They are also partially in contact with a
shallow alluvial aquifer underlying the site. This alluvial aquifer is not
presently used as a private or public drinking water source. However, it does
have a potential for agricultural use. A deeper aquifer. Burro Canyon. is
used as a drinking water supply and monitoring has shown no evidence of
contamination. Two aquitards. the Mancos Shale and part of the Dakota
Sandstone. separate the Burro Canyon aquifer from the overlying alluvial
aquifer under most of the millsite.
Montezuma Creek. which flows through the millaite. is a small perennial stream
with headwaters in the Abajo Mountains immediately west of Monticello.
Low-flow condition prevail in the Late summer. fall, and winter months.
Within th. project area, base flow in Montezuma Creek is maintained year-round
by ground-water discharge from the alluvial aquifer and by releases from
Monticello Reservoir (located on South Creek. one mile west of Highway 191).
1-
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Domestic surface-water resources for th. Monticello aria are located
topographically upgradi.nt from the site. The source of domestic water for
those people living outside the City of Monticello is predominantly ground
water, drawn chiefly from wells drilled into the Burro Canyon aquifer.
The total annual average precipitation for the Monticello area during the
period of 1982 through 1986 was 18.3 inches. The annual average potential
evapotranspiration is 24 to 26.9 inches.
Th. prevailing winds are generally from the south. west-southwest, and
northwest. The strongest winds, ranging from 7 to 13 miles per hour. are
those from the south and northwest.
Wildlife inhabitants of the millsite are few due to the sparse vegetation on
the tailings piles and in the mill area. The only “residents” appear to be
rodents. three species of rabbits. and several species of birds. None of the
wildlife inhabitants or vegetative species are considered to be threatened or
endangered. Occasionally, transient big game animals. such as mule deer, or
predators, such as coyotes. have been found on the site. Th. entire length of
Montezuma Creek through the site (17.8 acres) has been designated as wetlands
by the U.S. Army Corps of Engineers. Archaeological finds are scattered over
several peripheral properties. Several significant finds exist in Montezuma
Creek canyon.
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
2.1 SITE HISTORY
In late 1940. the Vanadium Corporation of America opened a vanadium ore-buying
station at Monticello to stimulate vanadium mining in the region. Within a
year. ore production in the area had increased sufficiently to Justify
construction of a vanadium mill. The mill was constructed by the Vanadium
Corporation of America in 1942 with funds from the Defense Plant Corporation.
Initially, only vanadium was produced. but from 1943 to 1944 a uranium-
vanadium sludge was produced by the Vanadium Corporation of America for the
Manhattan Engineer District. The Atomic Energy Commission bought th. site in
1948. Uranium milling commenced 15 September 1949 and continued until January
1960. when the mill was permanently closed. Part of the land was transferred
to the Bureau of Land Management: the remaining parts of the site have
remained under the control of the Atomic Energy Commission and its successor
agencies, the U.S. Energy Research and Development Administration and the U.S.
Department of Energy.
Numerous milling processes were used at the Monticello milisite during its
tenure of operation. These processes included raw ore carbonate leach.
low-temperature roast/hot carbonate leach, and salt roast/hot carbonate leach
up to 1955: acid leach resinin-pulp and raw ore carbonate leach from 1955 to
1958: and a carbonate pressure leach resin-in-pulp process from August 1958 to
mill closure in 1960.
In the summer of l?61. the Atomic Energy Commission began to regrade.
stabilize, and vegetate the piles. This work was initiated on the East
Tailings Pile. Tailings sand was hauled from the other three piles and spread
over the surface. After the grading was completed. fill dirt and rock were
spread over the tops and sides of the piles. The plant was dismantled and
excessed by the end of 1964. During the summer of 1965. 6 to 12 inches of
topsoil were removed from the ore-storage areas. Photographs suggest that the
contaminated soil was used as fill material to partially bury the mill
foundations.
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This decision document presents the selected remedial action for two of the
three operable units at the Monticello Pull Tailings Site in Monticello. Utah,
chosen in accordanc. with the Comprehensive Environmental Response.
Compensation. and Liability Act. as amended by the Superfund Amendments and
Reauthorization Act. and the National Contingency Plan. The decision for
remediation of this site is based on the administrative record. This document
addresses the millsite (Operable Unit I) and the peripheral properties
(Operable Unit II)
4.0 SCOPE AND ROLE OF OPERABLE UNITS WITHIN SI”E STRATECY
The Department of Energy. with concurrence from the Environmental Protection
Agency and the State of Utah. organized the remedial work into three operable
units. These are:
• Operable Unit I: Mill Tailings and Millsite Property
• Operable Unit II: Peripheral Properties
• Operable Unit III: Ground Water and Surface Water
The remedial actions planned for these operable units are interdependent.
This Record of Decision addresses the remedial actions for Operable Units
I and II. Following the initiation of remedial action fqr Operable Units
I and II and collection of additional surface- and ground water monitoring
data. a Record of Decision will be prepared for Operable Unit III.
Operable Unit I addresses the tailings. ore. and milling by-product materials.
This Operable Unit also includes contaminated buildings and equipment. and
contaminated soils at the millsit.. Th. principal threats to public health
from the tailings and associated materials are exposure to radon gas and gamma
radiation. Nonradiological risks have been shown to be minor in comparison to
the radiologic risk. Additional environmental threats include surface-water
contamination of Montezuma Creek and radiological contamination found in the
alluvial aquifer due to tailings in contact with that aquifer. The
remediation of Operable Unit I will reduce health threats from tailings and
associated material to acceptable levels, and will reduce the potential for
further contamination by removing and containing the contamination source.
Operable Unit II addresses the properties peripheral to the mi].lsite
contaminated by wind-blown tailings particulate matter. tailings migration via
surface water. and residual radioactive material at ore-buying stations. Nine
separate land types have been identified, including the Monticello Cemetery.
pasture land, hillsides, creek-bottom areas. and Montezuma Creek. Remedial
action activities may show that the areal extent of peripheral properties
differs from the current estimated acreage. The principal threats to the
public from peripheral properties are exposure to gamma radiation and radon
gas. The contaminated soil of peripheral properties generally exhibits lower
levels of contamination when compared to the mill tailings. The remedial
response to Operable Unit II would remove and/or control the source of these
health threats.
During the remedial action of Operable Units I and II. the characteristics of
Operable Unit III (ground water and surface water) will necessarily be
altered. Source removal will cause three changes to the alluvial aquifer:
(1) The diversion of surface water will cause unknown effects in the
geochemical attenuation of soils below the site: (2) Devatering of tailings
during excavation activities arid relocation to the repository may result in
removing a large amount of water from the alluvial aquifer. This water will
be treated in accordance,with the Clean Water Act. Utah Pollution Discharge
Elimination System. and other applicable regulations: and (3) Contaminated
pore-water retained in the contaminated soils will also be removed, treated t
acceptable standards. and released. Removal of contaminated sediments in
Montezuma Creek will affect the contamination levels in the creek. Since the
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results of thee. changes will have an unknown effect. a monitoring program for
the alluvial and Burro Canyon aquifers and Montezuma Creek will be conducted
during remediation of Operable Units I and II. This monitoring program will
continue for three years following removal of th. contaminated material. Upon
collection of adequate data •to support selection of a remedial action and the
completion of a Remedial Investigation/Feasibility Study. a Record of Decision
will then be prepared for Operable Unit II!.
5.0 SUMMARY OF SITE CHARACTERISTICS
5.1 MILL TAILINGS
The uranium mill tailings characterization included sampling for radium-226
and uranium to describe the uranium-238 decay series. A number of
elements are generally present in uranium mill tailings in concentrations
above background. This characteristic is due to their elevated levels in
uranium ores as well as being concentrated as a consequence of milling
operations. Nonradioactive elements sampled for in the tailings
characterization were antimony. arsenic, beryllium, cadmium. chromium. copper.
lead, mercury. molybdenum. nickel, selenium. silver. thallium, vanadium, and
zinc.
The tailings generated by the millsite operations are contained in four piles
referred to. in order of their construction, as the Carbonate Pile. Vanadium Pile.
Acid Pile, and the East P le. The Carbonate and Vanadium Piles were constructed
when the mill was recovering vanadium as a by-product using a salt roast/carbonate
leach flow sheet. The Acid Pile received tailings from the acid leach Resin-in-
Pulp process and a carbonate leach circuit. The East Pile received tailings from
the acid leach circuit and the high-temperature. carbonate leach Resin-in-Pulp
circuit.
Results of the mill tailings characterization indicate that arsenic, cadmium.
chromium. copper. lead. molybdenum. radium-226. uranium. vanadium, and zinc
are enriched in the tailings due to the milling process. The Carbonate and
Vanadium Piles are distinctly high in vanadium and contrast sharply in this
respect with the East and Acid Piles. Beryllium, copper. molybdenum. nickel.
and seleáium are found in higher concentrations in the East and Acid Piles.
5.2 SOIL
Surface soil on the millsite and the peripheral properties has been
contaminated by tailings and ore residue from mill operations through the
storage of ore in open stockpiles. the emissions from the roaster stack. the
overflow of tailings ponds. and the erosion of tailings piles by wind and
water. The dispersal of tailings and ore residues has contaminated soil with
both radioactive and nonradioactive elements. Areas are considered
contaminated if the radium- 226 concentration in soils exceeds the
Environmental Protection Agency standard (40 CYR 192.12) of 5 pCi/g above
background n the top 15 cm of soil or 15 pCi/g above background in any 15 cm
layer below the top 15 cm. A summary of millait. contamination as compared to
the standards is presented in Table 5-1.
The contamination of surface soil by these radioactive and nonradioactive
elements was portrayed by mapping the distribution of radium-226. The use of
radium as a proxy for other metals contained in the ore and tailings is
ustified because the other elements. excluding uranium and vanadium, passed
through the mill circuit with radium to the tailings piles where they reside
in concentrations approximating those found in ore. Further, no transport
mechanism has been identified that would account for the segregation and
dispersal of one of the non-ore elements independently of others.
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Ground -water samples collected from villa located downgradi.nt from the
ailisite and completed in the Burro Canyon Formation are similar to those
observed in the upgradient well in the alluvial aquifer. suggesting that the
Burro Canyon aquifer is not affected by the contaminated alluvial aquifer.
Elevated levels of nonradioactive and radioactive elem.nts found downgradient
in the alluvial aquifer are not found in the Burro Canyon aquifer. Current
data show the average uranium concentration for three downgradi.nt wells in
the alluvial aquifer is 0.41 mg/L. whereas the average uranium content of
downgradient wells in the Burro Canyon aquifer is approximately 0.002 mg/L.
6.0 SUMMARY OF SITE RISKS
A baseline risk assessment was conducted to evaluate the public health and
environmental risks resulting from th. existing contamination at the milisite.
The risk resulting from ground-water and surface-water contamination will be
addressed in detail after remediation of the millsite and peripheral
properties begins. Actual or threatened releases of hazardous substances from
this site, if not addressed by the preferred alternative or one of th. other
active measures considered. may present an imminent and substantial
endangerment to public health. welfare, or the environment. The following
risk summary explains why this endangerment exists. Information included in
this summary has been excerpted from Chapter 8 of the remedial investigation
report where details of the assessment can be found.
The radiologic health threat is attributed predominantly to uranium and
rada.um-226. Uranium is a health concern as well due to its toxicity. Of the
nonradiologic elements. arsenic is a proven carcinogen. The other elements
are potential health concerns depending upon the concentration and type of
exposure.
Dispersion of uranium mill tailings from the milisite occurs through natural
and man-caused actions. Wind- and surface-water dispersion have caused the
spread of tailings to peripheral properties. while use of the tailings as
construction material has distributed the tailings to local residential and
commercial properties. Dispersion to numerous residences and businesses in
the City of Monticello has resulted in the identification and remediation of
the Monticello Vicinity Properties. This site was included on the National
Priorities List in 1986.
6.1 HUMAN HEALTH RISKS
6.1.1 Radioactive Contaminants
The two major contaminants of concern for the radiological public health
assessment are radon gas and gamma radiation, both of which are attributable
to the tailings piles and the contaminated soils and materials on the milisite
and peripheral properties. Radon gas migrates through the tailings into the
atmosphere. Gamma radiation is emitted from the tailings. Th. adverse health
effects of radon emanation arise from inhalation of the short-lived radon
daughter products ‘which can expose the lungs to their full radiation dose.
Gamma radiation delivers its dose to the entire body.
Five potential exposure pathways were identified:
• ingestion of contaminated food produced in areas contaminated by the
tailings:
• inhalation and ingestion of airborne radioactive particulates:
• ingestion of surface water contaminated by the tailings:
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• inhalation of radon and radon daughters: and
• direct exposure to gamma radiation emitted from the tailings.
The first two pathways, which include ingestion of plant material “dusted
with windblown tailings, ingestion of animal food products from animals
ingestinj such plant material, inhalation and ingestion of airborne
particulates. and ingestion of household dust. are considered insignificant
because concentrations of uranium and radium associated with airborne
partieulatea are below background levels. Th. third pathway is nor considered
to be a probable pathway becaus. elevated radium concentrations have not been
detected in Montezuma Creek. Elevated uranium levels have been detected in
off-site wells and Montezuma Creek. however, uranium is being considered under
nonradiological risks for the following reasons. First. the radiological
exposure dose rat. from uranium is low because of its low concentration in the
water. Secondly. uranium is a strong nephrotoxin and because it has a very
long half-life will persist in the environment. Therefore. two pathways
remained for consideration: inhalation of radon and radon daughter., and
direct exposure to gamma radiation.
For each of these two pathways. the excess cancer incidence to the Monticello
population was determined by multiplying the population dose commitment by a
factor representing the estimated cancer risk per rem of exposure. Rem
(Roentgen Equivalent Man) is a unit used to measure exposure to radiation
which applies qualitative and otner modifying factors to account for the
particular character of the radiation exposure. Population dos. commitment
was determined by multiplying the average annual individual rate of exposure
by the total population: it is expressed in units of person-rems per year
(person- emIyr). For radon. an individual lung cancer risk factor of
20 x 10 v per rem. or 20 excess cancer deaths per year per 1 mi’lion person-
rem. was used. For gamma radiation, a risk factor of 120 x 10 p.r rem was
used. This factor is equivalent to 120 excess cancer deaths in an exposed
population for each 1 million person-rem of collective dose equivalent.
For the scenario representing inhalation of radon from the milisite and
peripheral properties. th. excess annual ancer incidence. to the Monticello
population are estimated to be 0.38 x 10 (or. 0.0038 excess cancer
incidences for the Monticello population). Whole body exposure to gas 9
radiation resulted in an estimated excess cancer incidence of 2.0 x 10 per
year. or 0.02 excess cancer incidences for the entire Monticello population
annually. The radiological risk assessment was performed on a population
basis prior to recent EPA guidance on performing radiological risk assessments
on an individual basis.
As an indicator of potential individual risk due to baseline radiological
conditions. a gross estimate of the lifetime excess cancer incidence to the
individual was estimated to be 1 x 10 . Although this rough estimate is
within th. Environm.nral Protection Agency’s acceptable risk range (1 x 10
to 1 x 10 ) the milisite will still be remediated to comply with the
pertinent health-based applicable or relevant and appropriate requirements in
40 CFR 192 which requires remediation of uranium mill tailings to specific
levels regardless •f risk.
6.1.2 Nonradioaceive Contaminants
A preliminary screening was conducted to identify the higheat risk. or
indicator, elements found on the site. Excluded from consideration as
indicator elements were those elements found in upgradierit surface-water at
equal or higher concentrations than those appearing on the site. Those
elements found in soil and air particulates at concentrations not exceeding
background levels were also excluded. The following elements were selected as
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nonradiologic ‘indicator’ elements: arsenic. copper. lead, molybdenum.
selenium, uranium. vanadium, and zinc. With th. •xception of molybdenum, all
of the elements characterized in the tailings puss ar. listed as
Comprehensive Environmental Response. Comp.nsatuon. and I.iabulity Act
hazardous substances at 40 CFR 302.4.
Under existing conditions. the major aourc. of nonradiologic elements are the
tailings piles and mill process-related by-product material at the muilsite.
Nonradiological constituents in the tailings piles can be leached from the
tailings and released into other environmental, media. Contaminants may be
transported or released from the tailings pile into the ground water, surface
water, and air. Toxic elements are leached from the tailings into the shallow
alluvial aquifer.
Potential exposure pathways were developed based on the populations and
activity patterns in the vicinity of the uranium mill tailings site. These
pathways are:
• inhalation of resuspended dust:
• ingestion of contaminated soil:
• ingestion of contaminated vegetables: and
• ingestion of contaminated beef.
The first pathway, inhalation of resuspended dust, was excluded from further
consideration because monitored particulate concentrations indicated that the
levels were not elevated above background. Further. several nonradiologic
elements were analyzed for in the particulate samples obtained. Lead is the
only nonradioactive airborne particulate measured at the milisite that is
regulated by a specific standard. Acceptable airborne levels of this element
are defined by the Environmental Protection Agency under the National Ambient
Air Quality Standards. Th. standard specifies hat a 3-month average
concentration of lead is not to exc!ed 1.5 Jg/m . The maximum concentration
measured at the site is 0.0490 ag/w . well below the compliance s’ tandard.
The second pathway, ingestion of contaminated soil, was also excluded from the
assessment because although limited entry may occur at the milisite. the
frequency is very low due to existing fences. The chance that a tr.spassec
would ingest contaminated soil is low because ingestion is associated
predominantly with very small children. Further, the existing soil cover
serves as an additional barrier to ingestion of the tailings material, which
contains the greatest concentration of nonradiological constituents.
The potential future risk for the soil ingestion pathway has been
qualitatively estimated, although the potential for the access controls
currently used by the Department of Energy to be removed in the future is
extremely low. The Department of Energy has strict requirements for
controlling radioactively contaminated sites, which do not allow sites to be
released for unrestricted use unless radiation levels are within acceptable
limits. It is highly unlikely that the Department of Energy, or other
successor Federal agency. would loos.n this policy for a contaminated site.
However, under a future risk scenario, it us anticipated that riaka to the
exposed population will be minimal because of a low exposure frequency due to
the area’s sparse population. Also. the exposure dose will, be low (under 60
mg/day) because only older. unsupervus.d children are likely to enter this
area. Therefore. assuming it is possible to enter the site under a future
scenario, risks associated with nonradioactuve contaminants through the soil
ingestion pathway should be negligible.
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Pathways (3) and (4) were retained for consideration. They are considered to
be indirect exposure routes resulting from contaminated surface water in the
area, used to irrigate fields arid water livestock. Contaminants in the water
can enter the food chain through the ingestion of contaminated vegetables and
beef.
Noncarcinogenic health effects can arise from acute and chronic exposures to
all eight elements. Reference doses have been developed by the Env3.ronmerltal
Protection Agency to indicate the potential for adverse health effects from
exposure to chemicals exhibiting noncarcinogenic effects (e.g.. persistent
neurological effects. neurotoxicity. respiratory problems. skin rashes). A
reference dose is an estimate of a lifetime daily exposure level (specific to
a particular exposure route) for humans: including sensitive individuals.
which is unlikely to result in an appreciable risk of deleterious (adverse)
effects during a lifetime.a Estimated intakes of chemicals from environmental
media (e.g. the amount of a chemical ingested from contaminated drinking
water) can be compared to the reference dose (or acceptable intake for chronic
exposure). Both parameters are expressed in units of milligram per kilogram-
day (mg/kg.day).
Intake estimates of each indicator element were computed for the potential
exposure pathways for both children and adults. Maximum and average soil
concentrations were used in exposure dose calculations. Total oral intake for
the contaminated vegetable and contaminated beef pathways were then compared
with the acceptable intakes for chronic exposure.
Exposures were then calculated for the two exposure scenarios retained for
consideration. Comparison of existing contaminant concentrations with the
acceptable intakes for chronic exposure resulted in no apparent health risk.
When average concentrations of contaminants in soil were used. none of the
dose levels were exceeded. Copper. uranium (including the vegetable pathway)
and zinc (including or excluding the vegetable pathway) exceeded recoended
levels for children when maximum soil concentrations were used. However.
because the mii .lsite is uninhabited, and considering historical land use
patterns in the area. it is unlikely that individuals would receive chronic
exposure to these maximum concentrations. Because average exposure doses do
not exceed the acceptable intakes for chronic exposure. use of surface water
to irrigate pasture or alfalfa, on which cattle graze. appears to be
acceptable.
Arsenic is the only indicator chemical that is considered to be a human
carcinogen. According to the Environmental Protection Agency veightof
evidence classification system for carcinogenicity. arsenic is included in
Group A. meaning it is a confirmed human carcinogen. The slope factors
(analogous to cancer risk factors for radiologic contaminants) foc 1 arsenic for
the inhalaci 1 n and ingestion exposure pathways are 50 (mg/kg.day) and 1.5
(mg/kg.day) . respectively.
aThe original risk assessment used Nacceptable intakes for chronic exposureN
instead of reference doses. Acceptable intakes for chronic exposure and
reference doses are similar in concept. but reference doses are derived using
a more strictly defined methodology. Acceptable intakes for chronic exposure
were recommended by the Environmental Protection Agency when the original risk
assessment was prepared. but the Environmental Protection Agency now
recommends the use of reference doses. Therefore. this terminology has been
used in this discussion.
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Excess lifetim, cancer risks due to exposure from arsenic levels at the
millsite. for pathways 3 and 4. were determined by ultiplying the intake
level by the slope factor. Calculated canç r risks frog arsenic contamination
are within the health goal range of 1 x 10 1 x 10 lifetime cancer risk.
This rang. has • point of departure at 1 x 10 . An excess lifetime cancer
risk of 1 a lO indicates that. as a plausible upper bound. an individual has
a one in one million chance of developing cancer as a result of site-related
exposure to a carcinogen over a 70-year lifetime under the attributable to the
mill 9 te for an individual due to ingestion of contaminated vegetables is 2.7
a 10 . or 2.7 cancers in lOO OOO peopl. exposed. using maximum soil
concentrations; and 7.0 a 10 (or 7 cancers in 1.000.000 people expo,aed) for
average soil concentrations above background. Cancer risks for arsenic
attributable to the milisite f r an individual due to ingestion of
contaminated beef is 2.0 a 10 (or 2 cancers p r 100.000 people exposed)
using maximum soil concentrations and 2.0 a 10 (or 2 cancers per 1.000.000
people exposed) using average soil concentrations above background. On the
basis of this information, arsenic may pose a public health impact under the
existing conditions at the millsite.
6.2 ENVIR0N1 NTAL RISKS
Risks to the natural environment that were considered in the remedial
investigation/feasibility study are also addressed in this Record of Decision.
Specific environmental concerns at the millsite and on peripheral properties
include impacts to archaeology, vegetation. wildlife, fisheries, and
floodplain/wetlands.
An inventory of the lower Montezuma Creek drainage identified one historic
site on the floodplain and numerous prehistoric sites along the walls of the
canyon. The historic site was field-evaluated as nonsignificant. Several of
the prehistoric sites were field-evaluated as significant because they are
likely to possess undisturbed stratified cultural deposits; determinations of
these sites’ eligibility for the National Register of Historic Places must be
made prior to their disturbance, and will be dealt with under Operable Unit III.
Threatened or endangered plant species were not encountered during the
remedial investigation, although the area is within the potential range of two
species of cacti. one of which is listed as threatened and one of which is
listed as endangered by the U.S. Fish and Wildlife Service. No plants of
State concern were found in the area.
According to the U.S. Fish and Wildlife Service, no threatened or endangered
avian species occur at or near the Monticello millsite. although the
endangered American peregrine falcon and the threatened bald eagle could occur
in the area. Use of the millsite by either species is considered remote
because of the lack of arboreal vegetation.
Fishery species of concern which occur in the San Juan River approximately 30
miles south of the millsite include the Colorado squawfish. the razorback
sucker. and the roundtail chub. In the upper reaches of Montezuma Creek where
sampling occurred. no fish were found. The principal reason for this is
thought to be the seasonal dewatering of the creek. especially prior to 1986.
Present stream conditions in the lower creek indicate deep pools with cover
that could support a fishery.
The U.S. Army Corps of Engineers performed a wetlands assessment in August
1989. It was determined that Montezuma Creek and adjacent wetlands areas
constitute 18.63 acres of wetlands, beginning at Highway 191 and ending at the
creek’s confluence with Vega Creek.
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9.0 SELECTED REMEDY
The selected remedy for the Monticello Mill Tailings Site involves removal of
tailings, by-product material (as defined in Section 11(e)(2) of the Atomic
Energy Act of 1954 as amended, and i.n 40 CER Part 192 to mean “tailings or
waste produced by the extraction or concentrat3.on of uranium from any ore
processed primari.ly for its source material content”), and contaminated
buildings and equipment material, with disposal of these .materials on site for
Operable Unit I; and remediacion to 40 CFR 192 standards for Operable Unit II.
peripheraa properties, by either conventional or environmentally sensitive
construction, or in limited cases. the use of supplemental standards. Ground-
water and surface-water restoration will be addressed in a separate Record of
Decision following initiation of remediation for Operable Units I and II.
Detailed descriptions of the selected alternatives follow. The remediation
goals. corresponding risk levels to be attained, and points of compliance for
each medium addressed by the remedy. are discussed. Finally, a detailed
discussion of the costs of each component of the remedy is presented.
9.1 SELECTED ALTERNATIVES
9.1.1 Ooerable Unit I -- Removal of Tailings and Disvosal in a Repository
On Site. South of tne Present Location
The selected alternative for Operable Unit I would relocate the mill tailings.
by-product material, and contaminated building and equipment materials, to
property south of and adjacent to the pressnt millsite (see Figure 9-1). The
contaminated materials will be moved out of the Montezuma Creek floodplain and
the tailings piles will be removed from their current contact with the
alluvial aquifer. This action has been determined to be an on-site response
action by the Environmental Protection Agency. On the basis of current
information, this alternative provides the best balance of trade-offs among
the alternatives with respect to the five balancing criteria used to evaluate
alternatives (see Table 8-1).
This remedy will require removal to a property contiguous to and adjacent with
a contaminated peripheral property south of the milisite. The proposed
repository site is not owned by the Department of Energy and would need to be
purchased. Remedial activities would be conducted on site and would be exempt
from the necessity of obtaining all Federal. State. and local permits:
however, the substantive requirements of these permits would be met.
The primary goal of the remedial action for Operable Unit I is to eliminate
the potential for exposure of the population of Monticello to enhanced levels
(above backgrouna) of radon gas and gamma radiation that pose excess cancer
risks. Following remediation. the radiologic risk to the population will be
reduced by 407. from the current conditions.
The occurrence of chemically hazardous substances not associated with tailings
or process-waste exposure has been pursued. but has yielded no substantive
evidence of contamination by these substances. Therefore. no public health
evaluation was performed for these substances. If during remedial action.
hazardous wastes ar. encountered on site. they shall be rewediated and
disposed of in accordance with the Resource Conservation and Recover Act and
any other applicable regulations. By-product material associated with mill
processing will be disposed of in the repository.
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Figure 9—1.
On—Site Stabilization South of Present Site Operable Unit I —
Alternative 1
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Radiologically contaminated building materials and mill equipment will be. to
the extent prac-tica]. and in accordance with prevailing standards.
decontaminated and either released for unrestricted use as defined by
Department of Energy Orders, released for restricted use as defined by
Department of Energy Orders. or disposed of in a sanitary landfill. The
repository will be used for disposal of some of this radiologically
contaminated material, but the quantity will be kept to a minimum and
materials will be disposed of in strict accordance with the repository design
specifications.
An additional remediation goal is to eliminate the potential for leaching of
contaminants in the mill tailings to ground water and surface water. These
goals will be achieved by diverting Montezuma Creek away from its current
channel where it is in contact with mill tailings piles, removing the tailings
and relocating them to the secure repository. replacing the tailings piles
with clean fill, grading and revegetating the site to provide proper surface
drainage, and reconstructing the channel of Montezuma Creek to its pre-
milisite historic location. In addition, any dewatering of tailings or water
removed from contaminated soils will be treated and released to the
environment. If discharged to Montezuma Creek. the waste water would be
treated to meet Utah’s requirements for discharge to surface waters (U.C.A.
Title 26. Chapter 11: R-448-8 U.A.C.).
The remediation of the mill tailings and associated materials will comply with
the principal relevant and appropriate requirement. 40 CFR Part 192.12. which
specifies the maximum permissible concentration of radium-226 above background
levels. Soils with radium-226 concentration above 6 pCi/g in the 0-to 6-inch
(15 cm) layer. and 16 pCi/g in any subsequent 6-inch (15 cm) layer below 6
.nches (15 cm) are considered to be contaminated and will be removed (using an
average background level of 1.0 0.4 pCi/g).
The tailings repository would be designed to contain approximately 2.5 million
cubic yards of tailings and contaminated materials and would cover
approximately 40 acres of disposal area. It is estimated that about 1.9
million cubic yards of contaminated material will be removed and transported
to the repository. Materials removed from peripheral properties will be
temporarily stored at the mill tailings site, and then transported to the
repository. Included in the contaminated material to be received at the
repository is approximately 100.000 cubic yards of contaminated soil and
building materials from the Monticello Vicinity Propert es National Priorities
List site (this material was the subject of the Nontice.L].o Vicinity Properties
Record of Decision).
Design components of the tailings repository will be based on the Department
of Energy’s Uranium Mill Tailings Remedial Action Program research and
practice standards (including the latest revision of the Technical Approach
Document. Revision 2. December 1989. DOEIAL-050425.0002). During design.
engineering considerations will take into account such factors as radon gas
minimization, erosion control, dust control, water infiltration control. and
site security. The State of Utah and the Environmental Protection Agency will
have review authority on remedial design activities to ensure that the most
appropriate technology is used in the final design. The repository will be
designed to comply with the requirements of 40 CYR Part 192. which requires
that the cepository’be designed to:
• Be effective for at least 200 years an to the extent reasonably
achievable, to be effective for up to 1.000 years:
• Provide reasonable assurance that releases of radon-222 from residual
radioactive material will not exceed an avera e release rate of 20
picocuries per square meter per second (pCi/rn Is); and
31
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Provid, reasonable assurance that r.l.as.s of radon-222 from residual
radioactive material will not increase the average concentration of radon-
222 in air at or above any location outsid. the disposal site by more than
0. 5 pCi/ I ..
The compliance point for the standards applying to radon-222 emissions is the
entire surface of the repository. In addition. proposed additional standards
to 40 CFR Part 192.32 (Subpart D). require that uranium mill tailings be
managed to conform to the ground-water protection standards and with
monitoring requirements of 40 CYR Part 264.92 (Subpart F). The point of
compliance for monitoring is defined in 40 CFR Part 264.95 as being the
vertical surface l cat.d at the hydraulically downgradient limit of the waste
management area that extends down into the uppermost aquifer underlying the
regulated units.
The costs of remediation of Operable Unit I are presented in Table 9-1. The
total capital cost of the project. in 1989 dollars. is estimated to be $52.1
million, including contingency costs of $8.69 million. Annual operation and
maintenance costs in 1989 dollars ar. estimated to be S40.800 per year for the
period 1996 to 2020. including contingency costs of S6.800 per year. The
total pro3ect cost in 1989 dollars calculated using a discount rate of 5
percent is estimated to be 542.346 million.
Some changes may be made to the selected remedy as a result of the remedial
design and construction process. In general. such changes will reflect
relatively minor modifications resulting from the engineering design process.
9.1.2 Onerable Unit II - Perioheral Properties Clean Uo to 40 CTR 192.12
Stancards
The proposed action consists of removal of contaminated materials and
relocation to the milisite tailings pile. with ultimate disposal in the
repository described for Operable Unit I. Removal will be achieved by
environmentally sensitive construction practices. and/or conventional
construction techniques to meet the standards of 40 CFR 192.12. Techniques
will vary depending on the degree of contamination and the environmental
consequences of remadiating specific land types.
The occurrence of chemically hazardous substances not associated with tailings
or process-waste exposure has been pursued. but has yielded no substantive
evidence of contamination by these substances. Therefore, no public health
evaluation was performed for these substances. If during remedial action.
hazardous substances or materials not excluded from the Resources Conservation
and Recovery Act (e.g.. 40 CFR 261.4(a) (ii) (4) source. spent nuclear, or by-
product material as defined by the Atomic Energy Act of 1954. as amended.
U.S.C. 2011. et seq.] are found on site. they shall be remedjated and/or
disposed of in accordance with applicable regulations. including Resource
Conservation and Recovery Act requirements, if determined to be applicable or
relevant and appropriate. Any by-product material associated with mill
processing and found on peripheral properti.s. will be disposed of in the
repository.
32
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Table 9-1. Estimated Costs of the Selected Remedy for Operable Unit I
(Removal of Tailings and Disposal On Site. South of
Present Location)
CaDital Costs
Millsite Site Preparation
Repository Site Preparation
Millsite Remediation (removal)
Construction of Repository
Millsite restoration
Repository restoration
Mobilization/demobilization
Indirect Costs
Subtotal
Contingency (at 20%)
Total Project Costs
(1989 dollars)
Total
$ 740.000
7.160.000
7.350.000
7.480.000
2.125.000
2.360.000
815.000
15.420.000
S 43.450.000
8.690.000
$52. 140.000
OBeration and Maintenance Annual Costs
Groundwater monitoring and surveillance (1996-2020)
Contingency (at 20%)
Total annual 0&M costs (1989 dollars)
1989 TOTAL PRESENT WORTH
(present worth calculated using a 5% discount rate)
33
Annual Cost
534.038
6.808
$40 . 846
$42. 346 . 400
£9
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Soils with radium concentrations above 6 pCi/g in the 0 to 6 inch lay.r of
soil and concentrations above 16 pCi/g in each subsequent 6 inch increment
below vh. top layer are considered to be contaminated (using a background
concentration of 1.0 + 0.4 pCi/g) and will be removed. The peripheral
properties include irrigated mesa pasture lands. areas of dense hillside
vegetation. low hillside vegetation, hilltop dryland pasture, creek-bottom
pasture. the U.S. Bureau of Land Management compound. creek banks along upper
Montezuma Creek and the Monticello Cemetery. The properties constituting
upper and lower Montezuma Creek will be remediated with Operable Unit III.
following initiation of remediation for Operable Units I and II.
In areas with mature dense vegetation, hand excavation could be used
successfully to remove the contaminated soils and to minimize environmental
damage to those areas that have important wildlife habitat. An option to hand
excavation would be the use of high-suction vacuum equipment specifically
designed for cleaning up hazardous waste spills. This equipment has costs
similar to hand excavation yet would tend to clean up more precisely the
actual areas of contamination.
Where acceptable. conventional construction techniques will be used to remove
contaminated soils from specific areas, including those previously disturbed.
such as farm land. This involves the use of large earthmoving equipment to
remove the contaminated soil. The removed soil would be replaced with clean
material and the site would be revegetated. On several properties. a
combination of conventional and environmentally sensitive construction
techniques will be used. As a result of meeting the contaminant-specific
applicable or relevant and appropriate requirements. it is expected that
exposure of inhabitants in the Monticello area to health risks from radiation
in excess of background levels will be reduced to acceptable levels.
Radiation risks are primarily associated with inhalation of radon-222 and
exposure to gaa radiation. Where conventional or environmentally sensitive
construction techniques are used to remove contaminated materials. radiologic
risks will be reduced to background levels. Nonradiologic long-term risk to
individuals after peripheral property remediation was included in the
comparative analysis of Operable Unit I. and is considered insignificant.
The Environmental Protection Agency and the State of Utah will evaluate
proposals for the use of supplemental standards on densely vegetated hillsides
south of Montezuma Creek and at the Monticello Cemetery during remedial
design. Supplemental standards. which allow leaving contamination in place.
are standards included within the principal relevant and appropriate
requirement. 40 CFR 192. These standards an, typically applied to areas where
physical removal of materials would cause undue environmental damage in
comparison with the derived environmental and health benefits. In areas where
supplemental standards may be applied, radiation dose is currently estimated
to be within 1 percent of health-based standards.
Operable Unit II consists of an estimated 311.600 cubic yards of contaminated
material (including 8.000 cubic yards of material to which supplemental
standards may apply). The capital costs of remediation of this operable unit
are presented in Table 9-2. Unit costs have been presented for each land type
and each construction alternative where more than one construction alternative
is available. Therefore, a range of total costs is presented. The costs
range from S12.648 million (assuming conventional construction techniques are
used on all properties except that supplemental standards are applied to the
cemetery and south hillside) to S18.460 million (assuming that supplemental
standards are not used. environmentally sensitive construction techniques are
used to the maximum extent possible. and conventional techniques are used
elsewhere). The total costs are provided in 1989 dollars. and calculated
using a discount rate of 5 percent. The costs include transporting the
contaminated material to the millsite. Costs of subsequent transport and
disposal of the material at the repository south of the millsite are included
in the cost of remediation of Operable Unit I.
34
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U I
Table 9-2. Estimated Costs of the Selected Remedy for Operable Unit II
(Peripheral Properties Clean Up to 40 CFR 192 Standards)
Direct and
Indirect Capital Costs of
Site
Preparation. Removal.
Restoration
Land Type
Constructio?
Alternative
Cubic Yards
Cost Per
Cubic Yard
Subtotal
Contingencies
20%
Total
1989 Dollars
A (Mesa irrigated
Pasture)
Conventional
16.360
$24.33
$ 398.000
$ 79.600 $ 480.000
B (Hillside dense
vegetation)
Conventional
33.120
38.53
1.276.000
255.200
1.530.000
B (Hillside dense
vegetation)
Environmentally
Sensitive
33.120
117.81
3.902.000
780.400
4.680.000
BSS (Hillside dense
vegetation
including BSS)
Conventional
24.800
47.34
1.174.000
234.800
1.410.000
Environmentally
Sensitive
24.800
120.32
2.984.000
596.800
3.580.000
BSS (Properties
South of
Montezuma
Creek)
Supplemental
Standards
6.000
0
(120.32)
0
( 722.000)
0
(144.000) C
0
866.000)
C (Hillside low
vegetation)
Conventional
55.550
37.59
2.088.000
417.600
2.510.000
D (Hilltop dryland
pasture)
Conventional
70.800
32.34
2.290.000
458.000
2.750.000
E (Creek bottom)
Conventional
95.230
31.52
3.002.000
600.400
3.600.000
Should Supplemental Standards not be approved, incremental coats would be as shown.
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Table 9-2 (continued). Estimated Costs of the Selected Remedy for Operable Unit 11
(Peripheral Properties Clean Up to 40 CU 192 Standards)
Land Type
Constructio 1
Alternative
Cubic Yards
Coat Per
Cubic Yard
Direct and indirect Capital
Site Preparation. Removal.
Contingencies
Subtotal @ 20%
Costs of
6 Restoration
Total
1989 Dollars
FSS (Monticello
Cemetery)
Conventional
2.000
59.50
119.000
23.800
140.000
Supplemental
Standards
2.000
0
0
0
0
G (BUt Compound)
Conventional
7.070
59.12
418.000
83.600
500.000
H (Upper Montezuma
Creek Bank)
Conventional
6.670
21.29
182.000
36.400
220.000
Kinimum Total
Project Costs 2
Conventional and
supplemental
standards
303.600
10.534.500
2.106.900
12.647.500
Maximum Total
Project Costs 3
Conventional and
Environmentally
Sensitive
311.600
15.383.000
3.076.600
18.460.000
1 Supple.antal standards may be applied
to land types
BSS and FSS.
2 Hinimuii total project cost assumes that conventional construction techniques
except BSS and FSS where supplemental standards will apply. Cost per cubic
construction only.
will be used in all areas.
yard applies to conventional
3 iiaximuni total project cost assumes that environmentally sensitive construction techniqueà
land types B. BSS. and BSS’. and conventional techniques elsewhere.
will be used for
‘4
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Mining Waste NPL Site Summary Report
Monticello Vicinity Properties
San Juan County, Utah
U.S. Environmental Protection Agency
Office of Solid Waste
June 21, 1991
FINAL DRAFT
Prepared by:
Science Applications International Corporation
Environmental and Health Sciences Group
7600-A Leesburg Pike
Falls Church, Virginia 22043
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DISCLAIMER AND ACKNOWLEDGMENTS
The mention of company or product names is not to be considered an
endorsement by the U.S. Government or by the U.S. Environmental
Protection Agency (EPA). This document was prepared by Science
Applications International Corporation (SAIC) in partial fulfillment of
EPA Contract Number 68-WO-0025, Work Assignment Number 20.
A previous draft of this report was reviewed by Paul Mushovic of
EPA Region VIfl [ (303) 294-70791, the Remedial Project Manager for
the site, whose comments have been incorporated into the report.
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Mining Waste NPL Site Summary Report
MONTICELLO VICINITY PROPERTIES
SAN JUAN COUNTY, UTAH
INTRODUCTION
This Site Summary Report for the Monticello Vicinity Properties is one of a series of reports on
mining sites on the National Priorities List (NPL). The reports have been prepared to support EPA’s
mining program activities. In general, these reports summarize types of environmental damages and
associated mining waste management practices at sites on (or proposed) for the NPL as of February
11, 1991 (56 Federal Register 5598). This summary report is based on information obtained from
EPA files and reports and on a review of the summary by the EPA Region VIII Remedial Project
Manager for the site, Paul Mushovic.
SITE OVERVIEW
The Monticello Vicinity Properties site is located in Monticello, San Juan County, Utah (see
Figure 1). This site is associated with, and located adjacent to, the Monticello Mill site NPL Site.
Between 1944 and 1960, the Federally owned Monticello Mill site was operated as a vanadium and
uranium mill (Reference 1, page 1). Tailings from the milling process, which contained high
concentrations of residual radionuclides and metals, were stored at the Mill site in tailings ponds.
The tailings were removed and used primarily in local residential construction projects (Reference 1,
pages 1 and 2). Approximately 135,000 tons of tailings are believed to have been removed from the
Mill site for these projects. In addition, tailings have been wind eroded from the ponds, and
transported to, and deposited on, properties in Monticello (Reference 1, page 2). The properties
contaminated with radionuclides are aggregated as the U Monticello Vicinity Properties site.
The primary contaminants of concern are thorium 230, radium 226, and radon 222. The exposure
pathways of significance for human health effects are inhalation of radon 222 and daughter products;
external whole-body gamma exposure; and inhalation and ingestion of wind-blown tailings and dust
(Reference 1, pages 6 and 7).
In 1984, the U.S. Department of Energy (DOE) began clean-up of properties with contamination that
exceeded established levels in accordance with EPA’s standards for Remedial Action at Inactive
Uranium Processing Sites. On June 10, 1986, the Monticello Vicinity Properties site was formally
included on the NPL (Reference 2, page 3).
1
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Monticello Vicinity PropertI
FIGURE 1. MONTICELLO VICINITY PROPERTIES PROJECT AREA
2
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Mining Waste NPL Site Summary Report
Remediation of the properties began in 1984. The December 1988 Federal Facilities Agreement
entered into by EPA, the State of Utah, and DOE [ pursuant to the Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA) Section 120] required that a Record of
Decision (ROD) be issued for the site. The September 1989 ROD identified the selected
clean-up remedy (Reference 1, Declaration for the Record of Decision, page 1).
The selected remedy consists of the excavation, removal, and relocation of uranium mill tailings to
the east tailings pile at the Monticello Mill site, and restoration with clean materials or modifications
of existing structures to isolate radiation sources from inhabitants (Reference 1, page 11). According
to EPA, the estimated present value of the remedial action is $60,000 per property for the 114
identified properties.
One hundred and fourteen properties were included in the Monticello Vicinity Properties Project as of
the signing of the ROD on November 29, 1989 (Reference 5). Since that time, Oak Ridge National
Laboratory (ORNL) has conducted additional surveys for DOE. According to EPA, an additional 106
properties were recommended for inclusion by DOE in April 1991 (Reference 5).
OPERATING HISTORY
The Federally owned Monticello Mill site operated as a vanadium and uranium mill from 1942 until
January 1, 1960. An estimated 900,000 tons of ore were processed at the Mill during its active
years. The ores were transported to the Mill from a variety of regional mines. During the mill’s
active years, tailings piles were created from the disposal of mill tailings in bermed ponds. In 1961
and 1962, the mill tailings piles were stabilized. Throughout the mill’s operating period, tailings
from the Mill site were used in construction projects in the City of Monticello (Reference 1, page 1).
Because radium and thorium (principal contributors to radioactive emissions) are not normally
removed from uranium ores during milling, approximately 85 percent of the original radioactivity
remained in the tailings (Reference 2, page 11). Therefore, the use of tailings as a material of
construction resulted in the contamination of many properties. Tailings were used as fill for open
lands; backfill around water, sewer, and electrical lines; and sub-base for driveways, sidewalks,
concrete slabs, and against basement foundations. Tailings were also used as sand mix in concrete,
plaster, and mortar. In August 1975, a fence was erected around the site to prevent unauthorized
access and removal of tailings (Reference 1, page 2).
3
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Monticello Vicinity Properties
Contamination of vicinity properties has also resulted from airborne particulates originating from
tailings piles (Reference 1, pages 1 and 2).
SITE CHARACTERIZATION
The report “Results of the Survey Activities and Mobile Gamma Scanning in Monticello, Utah” was
determined to be the functional equivalent of a Remedial Investigation for the Monticello Vicinity
Properties by EPA and the State of Utah (Reference 4, page 3). It provided details of the 1983
radiologic survey conducted in Monticello, Utah, and it also summarized three other earlier surveys.
Four separate radiologic surveys in the Town of Monticello were used to identify the extent, nature,
and magnitude of radiation exposure from tailings originating at the Monticello Mill site. In 1971 and
1980, mobile scanning surveys were performed by DOE contractors. Ninety eight properties
exhibiting “anomalous” gamma radiation levels were identified as a result of these surveys. In 1982,
another DOE contractor investigated and identified 114 anomalous properties, including the
previously identified 98 properties and an additional 16 properties surveyed at the request of
landowners (Reference 3, page 1; Reference 1, pages 2 and 3).
In 1983, another survey was conducted to: (1) determine the gamma exposure background and
nominal radium 226 content of the soil; (2) confirm the presence or absence of uranium mill tailings
on properties previously identified as contaminated; and (3) determine whether or not additional
properties in Monticello were contaminated. The investigation began with a gamma scanning of the
Town conducted by the ORNL mobile van. The scanning identified an additional 36 properties
exhibiting “anomalous” gamma radiation levels, bringing the total number of “anomalous” properties
to 150 (Reference 3, pages 9 through 13).
The 1983 investigation continued with onsite surveys and soil sampling of 145 of the 150
“anomalous” properties. The maximum concentration of radium 226 detected in the soil was 23,000
pico Curies per gram (pCi/g); the maximum uranium 238 concentration was 24,000 pCi/g (Reference
2, page 10). A multi-elemental analysis was conducted for the collected soil samples, but only two
nonradiologic elements, copper and vanadium, were considered to be of interest. Maximum
concentrations of vanadium and copper in soil were 16,500 and 39,000 parts per million (ppm),
respectively (Reference 3, pages 5 and 10). The vanadium and copper results were analyzed to
demonstrate that some of the tailings used in construction originated at the Dry Valley Mill site, not
the Monticello Mill site (Reference 3, page 13).
4
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Mining Waste NPL Site Summary Report
Soil sampling results were used to place properties into one of four categories: uncontaminated,
contaminated building materials, contaminated by residual ore, or contaminated by tailings. Of the
145 properties investigated, 122 appeared to have some type of radiologic contamination present.
Survey results indicated that 48 properties could be eligible for remedial action under EPA Uranium
Mill Tailings Remedial Action Project criteria, and 21 warranted further investigation (Reference 3,
pages 10 and 13).
In 1984, the 21 properties identified during the 1983 survey as warranting further investigation were
scanned for indoor gamma and/or measured for radon-daughter concentrations. Ten of the properties
had radon-daughter concentrations in excess of 3 pico Curies per liter (pCi/I) of radon 222 and were
recommended for further investigation (Reference 3, pages 13 and 14).
When the ROD was signed in September 1989, 114 properties were included for remediation in the
Monticello Vicinity Properties Project (Reference 5). In April 1991, DOE recommended that another
106 properties be included for remedial action.
ENVIRONMENTAL DAMAGES AND RISKS
Human health risks for the site are presented in the 1985 “Environmental Evaluation on Proposed
Cleanup Activities at Vicinity Properties Near the Inactive Uranium Millsite, Monticello, Utah.” This
document describes human health risks associated with radiologic contaminants found at the site.
Although tailings contained elevated radionuclide and toxic metal (copper and vanadium)
concentrations, human health risks related to the metal concentrations were not presented in the
environmental evaluation (Reference 2, pages B-I and B-3).
The principal environmental radiologic impact and associated effects on human health are attributed to
the thorium 230, radium 226, radon 222, and daughters of radon 222 contained in the uranium mill
tailings and residual ore. The exposure pathways of significance are: (I) inhalation of radon 222 and
daughter products; (2) external whole-body gamma exposure; (3) inhalation and ingestion of wind-
blown tailings dust; (4) ingestion of ground water and surface water contaminated with radioactive
elements; and (5) ingestion of food potentially contaminated through uptake (Reference 2, page 13).
The environmental evaluation report estimated the maximum number of human health effects (defined
as a death due to radiation-induced cancer) resulting from exposure to three of the pathways identified
for the Monticello Vicinity Properties (Reference 2, page 4). Human-health effects resulting from the
ingestion of ground water and surface water pathway and the ingestion of food pathway were
considered insignificant. The exposed population may experience 0.02 health effects (2 radiation-
5
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Monticello Vicinity Properties
induced cancer deaths per 1,000) from a whole-body radiation dose (a whole-body radiation dose
includes the external whole-body gamma exposure pathway and the inhalation and ingestion of wind-
blown tailings dust pathway) and 0.06 health effects (6 deaths per 1,000) from the lung-radiation dose
(a lung-radiation dose includes the inhalation of radon 222 and daughter products pathway and the
inhalation and ingestion of wind-blown tailings dust) (Reference 2, pages B-i and B-3).
REMEDIAL ACTIONS AND COSTS
The Monticello Vicinity Properties ROD (September 1989) describes the remedial actions and satisfies
the requirements of the Federal Facilities Agreement and CERCLA, as amended (Reference 1,
Declaration, page 3).
DOE began clean-up of contaminated properties in the summer of 1984, in accordance with EPA’s
standards for Remedial Action at Inactive Uranium Processing Sites (Reference 1, Declaration, page
3). According to EPA to date, 92 of the original 114 properties have been remediated. An additional
106 properties have been recommended for inclusion (Reference 5). DOE, through ORNL, is
currently continuing surveys to identify additional contaminated properties. EPA estimates that as
many as 400 properties may require remediation.
The remedy selected for the Monticello Vicinity Properties consists of the excavation, removal, and
temporary relocation of uranium mill tailings to the east tailings pile at the Monticello Mill site (these
materials will be permanently disposed of under the Monticello Mill site remedy; see the Monticello
Mill site NPL Site Summary Report). It also includes property restoration using clean materials or
modification of existing structures to isolate radiation sources from inhabitants (Reference 1, page
11). Remedial activities may require the demolition of sidewalks, sheds, patios, and other
improvements. Excavations are back filled with clean soil and regraded. The contaminated materials
are temporarily relocated to the east tailings pile at the Mill site (Reference 1, page 11). According
to EPA, the estimated present value of the remedial action is about $60,000 per property.
CURRENT STATUS
Remedial action continues at the vicinity properties. Surveys are on-going in areas originally thought
to be uncontaminated. Evidence from these surveys suggests that a total of 400 properties may
require remediation. According to EPA, clean-up activities at all affected properties are scheduled to
be completed by 1996, to coincide with remediation at the Monticello Mill site.
6
0
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Mining Waste NPL Site Summary Report
REFERENCES
1. Superftind Record of Decision: Monticello Vicinity Properties, Utah; EPA Region V I II;
September 1989.
2. Environmental Evaluation on Proposed Clean-up Activities at Vicinity Properties Near the
Inactive Uranium Millsite, Monticello, Utah; DOE; August 1985.
3. Results of the Survey Activities and Mobile Gamma Scanning in Monticello, Utah; ORNL;
November 6, 1985.
4. Monticello Vicinity Properties Equivalency of Documentation; DOE; April 1989.
5. Letter Concerning Proposal for Including Additional Vicinity Properties in the Monticello
Vicinity Property Program; Joseph Virgona, DOE, to Paul Mushovic and Brent Everett, EPA;
April 10, 1991.
7
%‘1I
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Monticello Vicinity Properties
BIBLIOGRAPHY
DOE. Monticello Vicinity Properties Superfund Site, Monticello, Utah, Community Relations Plan
Update. April 1990.
DOE. Environmental Evaluation on Proposed Cleanup Activities at Vicinity Properties Near the
Inactive Uranium Milisite, Monticello, Utah. August 1985.
DOE. Monticello Vicinity Properties Equivalency of Documentation. April 1989.
DOE. Proposed Plan for the Remedial Action at the Monticello Milisite, Monticello, Utah.
October 1989.
EPA Region VIII. Superfund Record of Decision: Monticello Vicinity Properties, Utah.
September 1989.
Lamb, Laurie (SAIC). Meeting Concerning Monticello Vicinity Properties with Paul Mushovic, EPA
Region VIII. October 22, 1990.
Lamb, Laurie (SAIC). Meeting Concerning Monticello Vicinity Properties with Paul Mushovic, EPA
Region VIII. Remedial Project Manager. May 17, 1991.
ORNL. Results of the Survey Activities and Mobile Gamma Scanning in Monticello, Utah.
November 6, 1985.
Virgona, Joseph (DOE) Letter Concerning Proposal for Including Additional Vicinity Properties into
the Monticello Vicinity Property Program, to Paul Mushovic and Brent Everett, EPA.
April 10, 1991.
8
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Monticello Vicinity Properties Mining Waste NFL Site Summary Report
Reference 1
Excerpts From Superfund Record of Decision:
Monticello Vicinity Properties, Utah,
EPA Region VIII; September 1989
-------
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Record of Decision:
Monticello Vicinity Properties,
g3iON VIII
PERFUND
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UT
-------
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REPORT DOCUMENTATION 1. RWORT N 2.
!AOE EPA/ROD/R0889/025
3 UPI..(S A51..n No
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SUPERFUND RECORD OF DECISION
Monticello Vicinity Properties, UT
First Remedial Action — Final
09/29/89
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401 N Street, S.W.
Washington, D.C. 20460
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15 Su . .uNu ,y NoN.
IS Ab.*ict(Lhlt mo uoid.)
The Monticello Vicinity Properties site, also known as the Monticello Radiation
Contaminated Properties, is a federally-owned abandoned vanadium and uranium mill area
in the city of Monticello, San Juan County, Utah. Land use in the area is residential,
however, there is limited conunercial use as well. Milling of vanadium and uranium
occurred from 1944 to 1960. Throughout the operating period, mill tailings were used
in the city of Monticello for construction purposes including fill for open lands;
backfill around water, sewer, and electrical lines; sub-base for driveways, sidewalks,
and concrete slabs; backfill against basement foundations; and as sand mix in concrete,
plaster, and mortar. Currently, the site consists of a dismantled vanadium and uranium
mill, and stabilized mill tailings piles. The Monticello Radiation Contaminated
Properties were accepted into the Department of Energy’s Surplus Facilities Management
Program in 1980 for remedial action. The Vicinity Properties were formally included on
the NPL in 1986 and, therefore, must comply with requirements of CERCLA. In October
1989 the Millsite itself was also listed on the NPL. DOE established an official list
of Vicinity Properties designated for remedial action based on radiological surveys
conducted from 1971 to 1984. As of March 1989, 91 properties had been identified to be
included in the Monticello Vicinity Properties. Of these 91. properties, 53 remedial
actions have been completed and 12 additional properties (See Attached Sheet)
$7. D. aN.fl * 157 . 1 1 &
Record of Decision - Monticello Vicinity Properties, UT
First Remedial Action — Final
Contaminated Media: construction material and debris contaminated with uraniun
(mill tailings)
Key Contaminants : radium—226 and radon-226 in uranium mill tailings
S I IL..J t BlSd Tuu
c. cosaim mui ’a,us.
II. Avj $y ,u.l IS. Nosoifty (lii . Nopsol) 21 No of Pug..
None 30
. S11I5O.N(lNSPS9.)
None
O 11ONAL FQ M 272 14.77 1
(FomNily NTIS- 35)
DuNJ .1fl sq ComnNt
(S.. ANSImLIl)
-------
EPAIR0D/Roa—89/025
Monticello Vicinity Properties, UT
F .rst Remedial Action — Final
16. Abstract (continued)
are slated for remedial action in 1989. Approximately 100,000 cubic yards (135,000 tons)
of contaminated construction debris and wind blown deposited contamination is estimated to
be within the Vicinity Properties. The primary contaminants of concern in construct .on
material and debris are thoriuni-230, radiuin—226, and radon-222 contained in the vanad um
and uranium mill tailings.
The selected remedial action for this site.includes excavation and removal of resi.dual
radioactive material from affected properties and restoration/reconstruction using clean
materials, or modification of existing structures to isolate radiation sources from
inhabitants; filling and regrading excavated areas; and disposal and temporary storage of
all contaminated material at the Monticello Millsite. The millsite is addressed
separately under a 1988 Federal Facilities Inter—agency Agreement. The estimated present
worth cost of this remedial action is $65,000 per Vicinity Property for 91 “included’
properties, or $5,915,000.
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DECLARATION
FOR THE
RECORD OR DECISION
SITE NAME AND LOCATION
Monticello Vicinity Properties Project
D.par ment of Energy Facility — Surplus Facilities Management
Program
Monticello, San Juan County, Utah
STATEMENT OF BASIS MD PURPOSE
This decision document presents the selected remedial action for
the Monticello Vicinity Properties NPL site.
The Environmental Protection Agency (EPA), the State of Utah (the
Stat.) and the U.S. Department of Energy (DOE) have agreed to
ccinduct the remedial action(s) at the site pursuant to the
Federal Facilities Agreement of December 1988 under Section 120
of the Comprehensive Environmental Response, Compensation and
Liability Act of 1980, as amended by the Superfund Amendments and
Reauthorization Act of 1986 (CERCLA), and the National
Contingency Plan. As part of this Agreement, EPA the State have
reviewed DOE’s project documentation. On May 24, 1989, the State
and EPA concluded that DOE had complied with the CERCLA
requirements by performing th. functional equivalent of a
Remedial Investigation/Feasibility Study at the Monticello
Vicinity Properties.
This decision document is based upon the administrative record
for the Monticello Vicinity Properties. The attached Record of
Decision Summary identifies the items comprising the
administrative record upon which the selection of the remedial
action was based. The State concurs on the selected remedy.
ASSESSMENT OF TUE SITE
Actual or threatened releases of hazardous substances from this
site, if not addressed by implementing the response action
selected in this Record of Decision, may present an imminent and
substantial endangerment to public health, welfare, or the
environment.
DESCRIPTION OF TUE SELECTED REMEDY
In consultation with EPA and the State, DOE developed a remed a
action plan to stabilize and control uranium mill tailings and
related contaminated material at the Monticello Vicinity
-------
Properties 1* a long-term manner that complies with EPA’s
Standards for Remedial Action at rnactive Uranium Processing
Sit.i (40 Cfl Part i92).
Conc•rn reqardi ig the potential health hazards that result from
exposure to radiation emanating from uranium mill tailings and
from contaminated structures in the vicinity of such sites
(‘vicinity properties’ or ‘off-site properties’) prompted the
U.S. Congress to enact legislation that authoriz•d DOE to
undertake remedial action to prevent or minimize
this type of environmental hazard. The Uranium Mill Tailings
Radiation Control Act of 1978 authorized remedial action at
certain inactive uranium milling sites that were not owned by the
Federal government. Since the Monticello mill site is owned by
the Federal government, it was included instead in the Department
of Energy’s Surplus Facilities Management Program in 1980 for
remedial action. Subsequently, the Monticello Vicinity
Properties Project was initiated.
The purpose of the Monticello Vicinity Properties Project is to
reduce the public’s exposure to radiation either by removing
contaminated material from properties or by modifying existing
structures to isolate radiation sources. The ‘Standards for
Remedial Action at Inactive Uranium Processing Sit• ’ identified
in 40 CTR 192 and the Hot Spot Criteria established by
radiological protection guidelines in the U.S. Department of
Energy Guidelines for Residual Radioactive Material at Formerly
Utilized Sites Remedial Action Program and Remote Surplus
Facilities Management Program Sites (Revision 2, March 1937),
will be the basis for remedial action under the proposed plan.
Because mill tailings from the Monticello millsite were us.d in
the city of Monticello for construction of residential buildings,
the cleanup activities for the Monticello Vicinity Properties
will require excavation of contaminated materials and, in some
cases, demolition of sidewalks, patios, sheds, and other
improvements. All excavations will be refilled with clean
fill and reqrad.d; all affected structures and other
improvements viii. be reconstructed. All, contaminated material
wi]l be removed to the Monticello milisite and temporarily stored
art the East Tailings Pile. The milisite is addressed separately
under the 191$ Federal Facilities Agreement. If Resource
Conservation and Recovery Act (RCRA) hazardous wastes are found,
disposal plans will be prepared fez ’ that specific hazardous waste
and approved by EPA in consultation with the State. All remedial
actions shall meet applicable or relevant and appropriate
requirements of Federal law and these State lava more stringent
than Federal laws in accordance with Section 121 of CEACLA.
After remediation is completed, DOE will prepare a completion
report for each property certifying that the property has been
cleaned up in compliance with the standards discussed above.
2
U
-------
Verification •i th. site remediatien viii be performed by an
independent contractor as an additional assuranc, that standards
have been met.
The proposed cleanup activities must be accomplished before
remedial action at the Monticello millsite is complete, since the
contaminated material from the vicinity properties viii be
addressed along with the tai1i gs and other contaminated material
remaining at the milisite. This Ricord of Decision covers all
prop.rties that were contaminated, including these that have been
remediated, those that are currently included but have not been
remsdiated, and all future properties that might be included for
remediat ion.
The purpose of the Monticello Vicinity Properties Record of
Decision document is to show that selection of the preferred
alternative, vhich is currently being used to complet, remedial
actions in Monticello, was an appropriate selection and to
satisfy the requirements of the Federal Facilities Agreement and,
the Comprehensive Environmental Response, Compensation, and
Liability Act as amended.
STATUTORY DETERMINATIONS
Based on the standards established pursuant to CERCLA; the
National Contingency Plan; and the Standards for Remedial Action
at Inactiv• Uranium Processing Sites, vs have determined that tNe
selected remedy for the Monticello Vicinity Properties Project is
protective of human health and the environment, attains
applicable or relevant and appropriate requirements to this
remedial action, and is cost-effective considering current
technology.
This remedy utilizes permanent solutions (removal of all
radioactive tailings and other contaminated material) to the
maximum extent practicable for this sits. This remedy does not
satisfy the statutory preference for treatment as a principal
element of the remedy, because treatment of the principal
potential risks from the site was not found to be practicable.
Pursuant to CE*CLA, EPA will review the response action no less
often than each five (5) years for portions of the remedial
action involving waste being left on-site, as required by the
Federal Facilities Agreement, after the initiation of the final
respons, to assur, that human health and the environment are
being protected by the remedial action being implemented.
3
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.2
9-Fe
Date
.
..
Date
R.g1q VAdminptrator (Region VIIIF
US. !r vironm.nta1 Protection Agency
U.S. Department of Energy
Concurring in thu determination:
,? ‘f)7
Date
Departrne t of Realth
4
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MONTICELLO VICINITY PROPERTIES
RECCRD OF DECISION S MM? RY
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1.0 SITE NAME, L.OCAflON. AND DESCRIPTION
The city of Monticello is located in San Juan County, which
occupies the southeastern corner of Utah (Figure 1). Ths city
lies i t t the Paradox 3asin just east of the Abajo Mountains and
north of Montezuma Creek. The major highway in the Monticello
area is U.S. Highway 191, which runs generally in a
north-south direction, connecting Monticello with Moab 56 miles
•to th.a north and with Blartding 22 miles to the south.
The t:vn of Monticello is located at an average elevation of
7,000 ft. above sea level. Land use within the majority of
Monticello Vicinity Properties is for residential housing.
Adjacent land usage includes heavy and light commercial use and a
“controlled” zoning district allowing a mix of agricultural,
residential, industrial, and commercial use. Natural resource
use in the immediate area includes domestic water supply systems,
with the city being supplied by springs near the Abajo Mountains. 1
Local groundwater usage includes rural drinking water and
farmland irrigation. Surface water usage ii primarily for
irri atiort. No mineral exploration exists within the immediate
vicinity of the properties.
2.0 SITE HISTCRY AND ENFORCEMENT ACTIVITIES
The original MontIcello mill was f nanc.d by the United States
Government through its agent, the Defense Plant Corporation, to
provide an additional source of vanadium needed during World War
II. The Vanadium Corporation of America operated the mill for
the Government until 1944, and privately under a lease from the
Government from 1944 to 1946. The U.S. Atomic Energy
Commission reactivated the mill in 1948 and engaged the Galig”er
Company to rebuild it. The mill, was operated for the U.S. At:m c
Energy Commission from 1949 to 1956 by The Galigher Company, and
from 1956 through 19S9 by the National Lead Company, under
cost-type contracts to produce both uranium and vanadium. Cu:.-.g
the years following U.S. Atomic Energy Commission takeover of t e
mill, uranium was the primary product.
Mill operations were terminated on , anuary 1, 1960, and the plar.t
was dismantled by the end of 1964. The mill tailings piles e:e
stabilized over the period 1961 to 1962. Removal of contam .na:ed
soil, from associated ore—buying stations was undertaken bet.eert
May 1974 and August 1976. The mill foundations were also
demolished and bulldozed into adjacent pits during this same
period of time. It is estimated that during its years of
operation, the mill processed approximately 900,000 tort, of c:e.
Throughout the operating period, mill tailings from the
Monticello mi llsite were used itt the city of Monticello for
oonstruction. These tailings were used as fill for open lands.
I
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backfill around water, se eY , and electrical lines; sub-base for
driveways, sidewalks, and concrete slabs; backfill against
basement foundations; and as sand mix in concrete, plaster, and
mortar. The total tonnage of uranium mill tailings removed from
the millsits for, construction purposes, although never
document.d, is believed to be approximately 135,000 tons. This
retrievAl of contaminated tailings from the Monticello millsits
was controlled by August 1975 as a fence was erected around the
sits to prevent unauthorized access and the ore—buying stations
were cleaned up. Figure 2 outlines the Monticello Vicinity
Properties project area and shows the adjacent millsit. location.
Concern regarding the potential health hazards that result from
exposure to wind and water borne contamination and radiation
emanating from uranium mill tailings and from contaminated
structures in the vicinity of such sites (“vicinity propertLes ”
or “off-site properties”) prompted the U.S. Congress to enact
legislation, which authorized the Department of Energy to
undertake remedial action to prevent or minimize this type of
environmental hazard. The Uranium Mill Tailings Radiation
Control Act of 1978 authorized DOE to undertake remedial action
at certain inactive uranium milling sites never owned by the
Federal government. Since the Monticello milisite is a Federally
owned facility, it was not elegible for remediation under the
Uranium Mill Tailings Radiation Control Act and was instead
accepted into the Department’s Surplus Facilities Management
Program in 1980 for remedIal action. Subsequently, the
Monticello Vicinity PropertIes Project was initiated.
DOE established an official list of Vicinity Properties
designated for rs!!ledial action under its Surplus Facilities
Management Program on the basis of radiologic surveys. Radiologic
surveys conducted throughout the city of Monticello to identify
the existence, nature, and magnitude of radiation exposure from
mill tailings originating from the Monticello millsite included:
1. In 1971 and 1980, EPA—subsidized mobile scanning surveys
(U.S. Environmental Protection Agency, 1972; Bendix Field
Engineering Corp., 1982) were performed by DOE contractors.
These surveys identified 98 anomalous properties.
2. In 1982, Bendix Field Engineering Corporation, under
contract to DOE, investigated a total of 114 properties,
including the 98 properties identifIed above plus an additional
16 properties, which were surveyed at the request of landowners.
3. Oak Ridge National Laboratory performed a survey in 1983,
which added 36 more properties to the investigation.
4. In June 1984, a radiation survey of buildings in Monticello
was conducted by EPA Region VIII personnel together with
personnel from the State of Utah and DOE. As a result of the
2
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A
I
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. — . — . S .uLi . _ . —. —
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‘-
1/
/
/
/
/
/
I
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1•. Jvs Ca ..uy
4’
Fltur, 1. MontLcsllo. ttah, .gLona1 t,oc$tLOl$ Map
-------
L
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-p.
/
/
1-—
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I.
.- .
•6 _
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— — — — -- CITY SIOUNOARY
•————i MONTICELLO VICINITY
I S PR oPERTIES PROJECT
s..___i *ist*
: f’ 1i FAST TAN. $ 1405 AREA
I
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fl-c
-‘----.. I,
‘ , - -. - Jci
4
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/
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Figure 2. IkMltiCel)o Vicinity Properties Project Area
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surveys, 10 additional buildings vere identified for further
investigations.
In October 1984, the Monticello Vicinity Properties wer, proposed
for inclusion (as “Monticello Radioactively Contaminated
Properties”) on the National Priorities List pursuant to CERCr...
and wire formally included on the National Priorities List on
June 10, 1986. As a result, cleanup activities at the Vicinity
PropertLes must satisfy requirements of CERCLA.
Through its Grand Junction Projects Office, the Department of
Energy began cleanup of properties that exceeded levels for
inclusion in the program in the summer of 1984 in accordance with
EPA’s Standards for Remedial Action at Inactive Uranium
Processing Sites. DOE has accepted responsibility for properties
contaminated with tailings from the Monticello milleite. DOE has
also conducted cleanup action, which was funded by EPA iii 1984 at
two properties not included in DOE’s Surplus Facilities
Management Program, under an interagency agreement.
As of March 1989, 204 properties have been identified as
anomalous properties with 91 identified by DOE to be included in
the Monticello Vicinity PropertLes Project. Of these 91
“included” properties, the Department of Energy has completed 53
remedial actIons and has scheduled 12 additional properties for
remed a1 action irt 1989. There are probably other contaminated
propert es in addition to the 204 screened properties mentioned
above. As other contaminated properties are identified, they
w li be considered for addition to the Monticello Vicinity
PropertIes Project according to the process set forth in Section
XIII of the Federal Facilities Agreement. rh. 204 screened
properties include some where owners have refused surveys and/or
remedial action and some where the cleanup responsibility is
still being disputed. EPA and the State of Utah viii develop a
plan for resolving owner refusals en specific properties. If CE
disputes responsibility for response activities at any given
property, the procedure found in Part XIII of the Federal
Facility Agreement viii be used to determine who shall be
responsible for cleanup.
EPA, the Stat., and DOE have agreed to conduct the response
action(s) at the site pursuant to the Federal Facilities
Agreement of December 1908 under Section 120 of the CERCLA, as
amended. As part of this Agreement. EPA and the State have
reviewed the DOE documentation and have agreed that DOE has
complied with CERCLA requirements by performing the functional
equivalent of a Remedial Investigation/Feasibiiity Study for
Monticello Vicinity Properties currently address.d by DOE.
Property investigations had begun and some remediations had
concluded before the site was listed on the National Prjorit .es
List and prior to the passage of the Superfund Amendments and
Reauthorization Act of 1986. Therefore, EPA and the Stat. ag:’.e
3
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to evaluate all completed, ongoing, and future work for
equivalency to CERCL.A. The Record of Decision is a primary
document, which is specifically referred to in the Federal
Facilities Agreement at Section XII.C.1.i.
DOE submitted to EPA a document titled Monticello Vicinity
Properties Equivalency of Docw entation, dated April 1989, which
EPA subsequently approved on May 24, 1989, concluding that the
documentation was functionally equivalent to the Remedial
Inveetigation/Feasibility Study for the Monticello Vicinity
Properties.
3.0 COMMUNITY P.ELATIC?4S HISTORY
A proposed plan was developed for the Monticello VIcinity
PropertIes Project in June 1989. The Proposed Plan is a public
partic ;ation decision document and, as such, there was
opportunity for the public to comment to DOE, EPA, and the State.
Public comment on the Proposed Plan (for 30 days) began June 30,
1989 and extended through July 30, 1939. A summary of responses
to the questions raLsed during the public comment period is
attached as Appendix A. All written c: -tsnts were sent to:
Mr. Pete Mygatt, Public Affairs SpecialIst
U.S. Department of Energy
P.O. Sox 2567
Grand ‘unction, Colorado 31502
(303) 248—6015 (collect calls accepted)
An index to the AdministratLve Record is attached as Appendix 3.
Verbal comments vera made at a public hearing bet reen 7 p.m. a..d
O p.m. on July 6, 1989, at the San Juan County Courthouse .n
Monticello, Utah. Documentation developed by DOE for the
Monticello Vicinity PropertLes can be reviewed at the
Administrative Record Repository:
San Juan Public Library
80 North Main Street
Monticello, Utah 84535
(801) 587—2281
Overall public acceptanc. of the work plan for the re edia1
action of the Monticello Vicinity Properties has been very gocd.
Questions and comments received from the audience during the
public meeting held on July 6, 1939, related primarily to the
steps of the remedial action process for individual propert .es.
overall costs of the program. and warranty questions for
properties that had already been remediat.d.
The only new area of concern voiced by the public related t
enforcement of cleanup under the program. EPA responded to
4 , 9o
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concern by indicating that the program was not one of voluntary
participation and that, by law, EPA was required to ensure the
properties identified on the National Priorities List were
cleaned up. Th. exact methods of enforcement, in cases where
owners refuse to allow access to the property or to participate
in th. cleanup, remain to be determined.
4.0 SUMMARY OF SITE CHARACTERISTICS AND SITE RISKS
Mill .cperations were terminated on January 1, 1960, at the
Monticello milisite, and the plant was dismantled by the end of
1964. The mill tailings piles were initially stabilized with 6
to 18 inches of c:ver and revegetated during th. period of 1961
to 1962.
Throughout the operating period, tailings from the Monticello
mills3.te were wind-blown into the city of Monticello or used in
the city of Monticello for construction. These tailings were
used as fill for open lands; as backfill around water, sever, and
electrical lines; as sub-base for driveways, sidewalks, and
concrete slabs; as backfill against basement foundations; and
as sand nix in concrete, plaster and mortar. Th. total tonnage
of uranium mill tailings removed from the milisite for
construction was not documented. Movever, contaminated material
from vicinity properties (in the Monticello area currently b. ng
remediated) is estimated at 100,000 cubic yards (135,000 tons).
This includes wind blown deposited contamination.
Specific properties were investigated and an environmental
evaluation completed by 1985 (before passage of the Superfund
Amendments and Reauthorization Act). These inve.tigatLons and
.nviron .ntal evaluations are found in two documents, Results of
the Survey Activities and Mobile anuna Scanning in Monticello,
Utah, July 1984, Oak Ridge National Laboratory (ORNLITM 9733) ar.d
Environmental Evaluation on Proposed Cleanup Activities at
Vicinity Properties near the Inactive Uranium Millsite,
Monticello, Utah, August 1985, 3endix FL.ld Enqir.eerinq
Corporation. These documents are contained in the Monticello
Vicinity Properties Equivalency of Documentation, April 1989,
U.S. Dapartm.nt of Energy.
Summary of Sit. Risks
The following summarize, the predicted health effects that may
occur to the general public due to contaminated material existi g
at vicinity properties. Calculations are based on exposure rates
affecting persons at the fifteen properties initially sutheri:ed
for cleanup. Detail, of the health risks are found in the
Monticello Vicinity Properties Equivalency of Documentation
(compiled April 1989, for the Monticello Remedial Action Pro;ec
Administrative Record), specifically within the Enviromental
Evaluation en Proposed Cleanup Activities at Vicinity Propertes
S
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lear the Inactive Uranium MilIsite, Monticello, Utah, App.ndix B,
DOE—GJ-35, Bendix Field Engineering Corporation. August 1985.
The principal environmental radiological impacts and associated
effects on human health are attributed to thorium—230,
radium-226, radon—222, and daughters of radon—222 contained in
the uranium—mill tailings. Although these radionuclides occur in
nature, their concentrations in tailings material are several
orders of magnitude greater than their average concentrations in
the earths crust.
The major potential environmental routes of exposure to man are
listed below:
o Inhalation of radon—222 and daughter products that result
f:om the continuous radioactive decay of radium—226. The
greatest hazard to human health results from the inhalation of
radon—222 daughters, which emit alpha radiation that affects the
lungs.
o External whole—body gamma exposure directly from
radionuclides in th. tailings.
o Inhalation and ingestion of windblown tailings dust. The
primary h.alth hazard results from the alpha emitters thorium-230
and radium—225, both of which affect the bones and lungs.
o Ingestion of groundwater and surface water contaminated with
radIoactive elements, primarily radium—226.
o I’;.stion of food potentially contaminated through uptake
and concentration of radioactive elements by plants and anirnals.
A summary of radiation doses from all potential exposure pathways
is presented in Table 1. The potential Ingestion pathways of
food, groundwater, and surface water were determined to be
insignificant exposure routes. The number of potential health
effects (defined as radiation-Induced cancer deaths) expected
from the whole—body radiation dose listed in Table 1 is
approximately 0.02. The number of potential health effects
expected from the lung-radiation dose is approximately 0.06.
(Table 1 is presented on the next page)
6
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Table 1. Predictions of Radiation Doses from Exposure Pathway.
•
Pathway
cse m:e
m)
Whole 3ody
Lung
Exposure to Radon and Radon Daughters
——
400
Exposure to External Gamma Radiation
438
——
Inhalat cn of ALrborne Radioparticulates
0.033
2.5
Ingestion of Water
. 0
0
Ingestion of Food
Totals (rounded)
0
0
438
403
Actual or threatened releases of hazardous substances from this
s te, if not addressed by L ;lement ng the respons. action
selected in this Record of Decision may p:es.nt an Imminent and
substantial endangerment to publ±c health, welfare, or the
envi::nm.flt.
5 0 M? 4ThT?Ct OF STG’J’P’C 4T C A 4G’S
Section 117(b) of CERCLA :e u1:es doc=e taticn ef any
s gnif cant changes from the preferred alternative as originaly
;:.sen .d in the Proposed Plan. Since the preferred alternative
has not changed- for this Record of DecisIon, no further
doc’ m.ntatIan is required. For comparIson of the preferred
alte:natI s in the Plan for the cleanup actIvities at vicInity
propertIes, Monticello, Utah, wIth the selected remedy, see
Sect.on 7.0.
6.0 CESCRIPTTO OF ALT!RN TIVES
1 r - o basic alternatIves for remedial action for VicInity
Preperties exist.
a Removal of Ldentif Led residual radioactive material and
restoration with clean materials, or modifIcation of exIsting
structures to isolate radiation sources from inhabitants, is the
preferred alternative. Cleanup activ t es will require
excavation of c:ntaminated materials, and in some cases,
demolition of sidewalks, sheds, patios, and other improvements.
All excavations vIll be refilled v .th clean till and :.graded;
all affected structures and other Lmproem.nts viii be
7
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reconstructed. The contaminated materials relocated temporarily
to the East Tailing. Pile at the milisite would be disposed of
with vuilsite tailings in a permanent repository, covered by a
separate action under CZRCI 1 A.
No Action.
No other alter atiVes, such as stabilization in—place or
treat,ent are considered practical or if fictive at r.duc ng the
r sk o human health.
Applicable or Relevsit and A;propr±ate ecui:ements (ARARs):
The ARARs for the onticello Vicinity PropertIes are the
standards on vh .: :ieanup activitIes are based. In March 1983,
EPA published its tandards for Remedial Action at Inactive
Uranium Process : Sites (40 CTR 192). These Environmental
Protection k;enc atandards established requirements for the
control of ta li :s piles, cleanup of buildth;s, cleanup of open
lands, and suppl.ental standards. DOE has adopted the
concentratIon limits and assocIated requirements of these EPA
standards into th, DOE gu de1Ines for resIdual radioactive
material. As a result, the Standa:ds for RemedIal ActIon at
Z act ve Uranium Processing Sites while not appllcabl., ha..
been found to be relevant and approprIate to the MontIcello
Vicinity P::;e:tles remedIal actIons. DOE has also adopted the
“hot—spot” criteria establIshed in its awn guidelines, U.S.
epa:tnent of Energy GuidelInes for Residual Radioactive Mater a1
at For e:ly Util :ed Sites RemedIal ActLon Program and Remote
Surplus Facilities anagemsnt Program Sites (RevisIon 2, Ma:ch
937). The EPA standards at 40 CTR 192 and the Department of
E e:;y “sot Spot” crIteria are attached as Appendix C.
Cther ApplIcable or Relevant and ApproprIate Requirements that
also apply are presented in DOE letter dated May 3 1, 1939,
Transmittal of Detailed Analysis of Federal and State PotentIally
ApplIcable or Relevant and Appropriate Requirements for the
MontIcello Vicinity Properties, (MV?), and the State of Utah
letter to EPA dated une 21, 1939 (3S W-57O5—1) include:
o U.S. Occupational Safety and Health Act of 1976. as amended
o Utah Occupational Safety and (ealth Standards
o Utah Bureau of Water PollutIon Control Standards
o Utah Air Conservation Rules
o Utah 3ur.au of RadIation Control Standards
o Utah Bureau of Hazardous Waste Standards (except State RCRA
criteria)
7.0 SUMMARY OF CDMPARATI’JE ANALYSS OF ALTERMATIVES
Nine evaluatIon criteria tave been developed by EPA to address
CERCIA requirements and cons d.:ations, and to address the
additional technical and polIcy c:ns .derations that have proven
B
l)
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Pave s iular averag. e stI. T’e %o—action a ertat..ve would
obv ousl,y not incur these costs.
Cr .rior, Jo’ S — State Acceotance
The State of Jtah is currently an actIve ?artic ant In the
rionticello Vicinity Properties Prc .ct and supports the prefer:sd
alternative. Likewise, The Stat. opposes the no-actIon
aeriat .ve.
CrIterlen Io. 9 - C munity Acc.;tanc .
C mmunity acceptance of th. p:efer:ed alternative is assessed n
the ecord of Decisicn espcnsivsnesa Summary foll:ving a :sv ev
of the public comrnents received on ths Proposed Plan. The
‘esponsiveness Summary. whIch includes community relatIons
activ t.es, is attached as Ap;end x A.
Saud on past c: munity :.latlcns and the fact that 53 ;ro;.:t es
av. already been reedlatad. it can be assumed that the:e is
basic general support for the ;:ef•r:ed plan. The nc-action
alternative may be expected to hive little support In the
community because potential health rIsks would not be
.l m nated. cvever. it is re :qnl:ed that scm . local :es an :
do not bel eve remedIal actIon is necessary.
5 3 ;? ?3y $ J v
At ttls t.ms. the preferred alter—atlve, removal and reloca:::n
of u:ani n m ll tailIngs, p:ovides the best balance of
trads-oUs. :esp.ct tø the EPA standards at 40 CT 92 and
ct S;ot’ ci’.ra used to evaluate :ei edies e pe’e ed
act .cn consIsts of removal of IdentIfied :esduai radicact .ve
mater al and restoration with clean materIals, or modIfLcat :n :
•xIst .ng s:rjctu:es to isolate radiatIon sources from
.nhabitants. Cleanup activitIes will :eçui:e excavatIon of
contaminated materLals, and in some cases, demolition of
s dewalks, sheds, ;atioe, and other Improvements. All
exca:at :ns viii be refilled wIth clean fill and reçradsd; a
affected str ctu:es and other improvements will be
rec:nst:’ oted. The contaminated mate:Lals relocated tempora /
to the East Tailings Pile at the millsite vould be dIsposed of
with mills te tailLnqs in a permanent repository, covered by a
separate actIon under CEACLA and the 198$ Tederal Fac iitIes
Agreement.
Therefore, based on the jnf:rmatLon available at this time. t e
Cepartment of Energy, the Environmental Protection Agency, and
the State of Utah believe the preferred slternatLve would be
1$
-------
Monticello Vicinity Properties Mining Waste NPL Site Summary Report
Reference 2
Excerpts From Environmental Evaluation on Proposed Clean-up Activities
at Vidnlty Properties Near the Inactive Uranium Millsite,
Monticello, Utah; DOE; August 1985
-------
GJ-35
ENVIRONMENTAL EVALUATION ON
PROPOSED CLEANUP ACTIVITIES AT
VICINITY PROPERTIES NEAR THE INACTIVE
URANIUM MILLSITE, MONTICELLO, UTAH
August 1985
U.ndlx FIs d EngIn.. Ing Corporation
rind Junction, Colorado
-Ai IIEfl Bendix
( W Aer pac.
C l
-------
part of the Grand Junction Vicinity Properties Project. Estimate. of the
radiation levels and descriptions of tailings use for th. 15 initially
authorized properties are presented in Appendix A.
Accomplishing the cleanup activities will require approximately 20 man—years
of labor over a period of 3 years. Total cost of the effort is estimated to
be 2.25 million, approximately half of which will be expended for construc-
tion costs. The cleanup activities began during the sommer of 1984.
To estimate the scope and impact of th. proposed action, it is assemed that
the average voleme of material to be removed from each property, based on
previous work done in Monticello. is 300 cubic yards. Bence, a total of some
15.000 cubic yards il1 be removed fro. the approximately SO properties that
are proposed for inclusion in the MVP Project.
The cleanup activities will require excavation of contaminated materials and.
in some oases, demolition of sidewalks, patios, sheds, and other improvements.
All excavations will be refilled with clean fill and regraded; all structures
and other improvements will be restored to their original condition or better.
All contaminated material will b. removed to the Monticello millsite and
stored on the East Tailings Pu..
The proposed action will require haulage of contaminated material and clean
fill on public roads. The properties to be cleaned up generally lie within 1
mile of the millsite, and clean fill is assuned to be available within 10
miles of Monticello. To prevent the spread of radioactive contamination,
access control points will be established at th. remedial action properties.
Access will be limited to those personnel specifically trained as to the risks
of radiation exposure, industrial safety, and safety procedures. Prior to
exiting the property, personnel and equipment will be monitored for radio-
active contamination and decontaminated, if necessary. Trucks hauling the
tailings will be lined and covered during haulag. to the disposal site.
Haulag. routes will be designated prior to the connencenent of work and will
be chosen with a view to minimizing the potential f or accidents and exposure
to the general public. If the matsrials an, hauled using a 10—cubic—yard—
capacity truck, approximately 1500 trips will be r.qutred f or the contaminated
material and another 1500 for the clean fill. On this basis, some 33.000
miles of additional truck traffic will occur during ths 3—year period.
The proposed cleanup activities must be sccompliah.d before remedial action at
the Monticello millsite is complete, since the contaminated material from the
vicinity properties will b. stabilized along with the tailings and other.
contaminated material remaining it the .illsite. It is assuned that the
tailings at the millaite will be stabilized in place.
1.3 ALTE (ATivxS TO P P0 RD ACTION
1.3.1 No Action
If no action were taksn approximately 0.02 health effect from whole—body dose
and 0.06 health effect from lung dose per year of exposure could be expected
to result from the public’s .iposur. to radiation at vicinity properties in
Monticello, Utah. (Pow th. purposes of this report, ‘health effect’ is
3
-------
defined as a death due to a radiation—induced cancer.) No action would save
some *2.25 million in cleanup expense.
No action. however, is an unacceptable alternative. Statutory responsibili-
ties of the Department of Energy, as well as a variety of regulatory standards
established as guidelines for the Monticello Vicinity Properties Project,
would not be satisfied under this alternative.
2.0 AFPEC VIRCNJ(E ff
2.1 E AFFECIED AREA
All cleanup activities at the Monticello vicinity properties would take place
in and near Monticello. Utah, in San Juan County. The sites are scattered all
over the city, but most are within 1 mile of the •illsite. The millsite
itself lies in the valley of Montezuma Creek, an erosional surface that slopes
eastward fro. the Abajo Mountains. Figure 2—1 shows the location of the
millsite and the locations of gaa—screening surveys performed on properties
in the Monticello area; each survey location is identified by a property
number. Appendix A contain, a listing by property number of the 15 initially
authorized sites, together with a characterization of each.
2.2.
2.2.1 Wind
Wind is the most significant weather factor affecting the proposed action.
The prevailing annual winds are generally from the south, west—southwest, and
northwest. The strongest winds ranging from 3 to 6 meters per second
(n/sic), are those from the south and northwest. Night winds are character-
ized by a general northeasterly trend, changing to an east—southeast direction
in the early morning hours. Day winds are predominantly from the south. The
highest winds sill be capable of raising dust from disturbed sites during
excavation and hauling. Mean—velocity winds (4.2 n/sic) will blow dust raised
by eartbnoving equi ent. but will not raise dust by themselves.
2.2.2 ecijita 4on
Th. total average annual precipitation for the Monticello area over the period
1982 to 1984 was 477.6 millimeters (Bendix Field Engineering Corporation.
1985). The Monticello area is characterized aeteorologically by dry condi-
tions such that the annual potential evapotranspiration of 609 to 683 milli-
meters exceeds total average annual precipitation. Average annual rainfall is
approximately 180 millimeters and occurs for the most part from July to
September as short—lived thundershowers. Average annual snowfall is 1000 to
1750 millimeters, with an average annual water—to—snow ratio of 1:3.5.
2.2.3 18BR! tEll
Temperatures range from 32’C in the sumer to —14’C in the winter.
4
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1’
‘ h
l i ‘ri
_ Ii r \ . ‘
— —-—-I
J
L__ - - — _ _ _ -— —
•4
0—
0
Figure 2—2. Monticello, Utah. Vicinity Land Use
(fro. Abra iuk and others, 1984)
10
•
• - - •:••. .
I •
I ’ __
4
I.
I.
I: :.
I •‘.
‘2
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exploration and production activity levels fluctuate; oil and gas d .velo .nt
work is presently in progrsss in the Anath and Lisbon fields ‘located in San
Juan County.
Tourism has recently assomed increased Importance for the local economy.
Providing an ongoing base for the tourism industry are five national parks,
three national monunents, a national recreation area several state parks, and
five national forests, all of which ii. within a 100—mu, radius of the
county.
The 1980 census record.d a population of 12.253 for San Juan County. Although
Monticello is hi county seat. Blanding. 22 miles to th. southwest is the
largest city Lu the county, having a recorded population of 3118. Over the
past 40 years, the population of MontLc.llo has fluctuated dramatically. Pr .—
1980 census figures for the county ref luct growth rates that have varied from
6 to 70 percent per decade over the last four decades (Abramiuk and others.
1984).
The major highway in the Monticello area is State Highway 163, which runs
generally in a north—south direction, connecting Monticello with Moab 56 miles
to the north and ‘with Blinding 22 miles to the south. Th. second major artery
is State Highway 666. which trends southeast from Monticello, connecting it
with Dove Creek, Colorado, 22 miles away Cs.. Figure 2—3).
3.0 WIlCN1 fl’AL IIIPACT OP mE PROPOSED ACTION
The proposed action requires construction activities such as excavation,
demolition, rebuilding, backfilling, and haulage. In those cases where
occupancy of the property is not permitted during cleanup activities,
relocation assistance will be provided.
The impact of cleanup activities at 50 vicinity properties was estimated
largely on the basis of the charact.rizations of the 15 initially authorized
properties (see App.ndiz A) and past experienc, with two EPA—funded and seven
SFMP—funded remedial actions performed in the Monticello area. It is antici-
pated that cleanup activities at all 50 vicinity properties will be accom-
plished prior to acspl.tion of remedial action at the Monticello millsite,
since th. contaminated material from th. properties will be removed to th.
millsite. The ultimate disposition of all contaminated material at the mill-
site including that which is removed from th. vicinity properties, will be
determined in accord with regulations of the National Envirormental Policy
Act. -
3 • 1 IIIpAC OP 1 -EASE OP RADL&TIOt4
3.1.1 Pathways and Mechanism, for the Transuort of Radioactive Material to
Approximately 85 percent of th. radioactivity originally contained in uranism
ore remains in the tailings after removal of the urani, because radiom and
thoriom, principal contributors to radioactive emissions, are act normally
removed from uraaima ores during milling (Bendix Field Engineering Corpora—
ii
-------
tion, 1983). The principal environmental radiologic impact and associated
effects on human health are attributed to the thorium—230, radium—226, radon—
222. and daughters of radon —222 contained in the uranium—mill tailings.
Although these radionuclides occur in nature, their concentrations in tailings
material are several orders of magnitude greater than their average concentra-
tions in the earths crust.
The major potential environmental routes of exposure to man are listed below:
• Inhalation of radon—222 and daughter products that result from the
continuous radioactive decay of radium—226. Radon is a gas that
diffuses from the tailings. The greatest hazard to human health
results from the inhalation of radon—222 daughters, which emit alpha
radiation that affects the lungs.
• External whole—body gana exposure directly from radionnol ides in the
tailings.
• Inhalation and ingestion of windblown tailings dust. The primary
health hazard results fro. the alpha emitters thorium—230 and radium—
226, both of which affect the bones and lungs.
• Ingestion of groundwater and surface water contaminated with
radioactive elements, primarily radium—226.
• Ingestion of food potentially contaminated through uptake and concen-
tration of radioactive elements by plants and animals.
3.1.2 Radiation Doses Donna Normal Cleanun Activities
The estimates of radiation doses presented in this section are typical of
those that would be encountered by construction workers engaged in the
proposed cleanup activities (of. Section 1.2). The potential effects of these
doses on the general public are also discussed.
Exposure-rate and radmum—226 measurement a have been made at some of the
authorized properties; these results may be used to interpret general trends.
They are believed to be adequate as order—of—magnitude estimates that yield an
upper limit of the impact resulting from cleanup activities at all 50 sites.
The basis for the following discussion is detailed in Appendix B.
External g.mm radiation (801) levels at a typical vicinity property in
Monticello are expected to range from 16 MR/hr to approximately 960 i&BIh,
averaging perhaps 75 pR/br. To make rough dose estimates, a gamma exposure
rate of 1 aR/hr in air may be assumed to be equal to a doss equivalent of
about 1 microrem in tissne. It may be assumed that construction workers at a
sits are subject to 801 doses in the range of 16 to 960 micror per hour
while cleaning up contaminated areas. That this assumption is conservatively
high may be seen from reports on the cleanup at Middlesex. New Jersey, per-
formed under the authority of the Formerly Utilized Sites Remedial Action
Program (FUSRAP). Radiation exposure from the excavation and loading of
23,000 cubic yards of contaminated material at that site was estimated to be
10 millirem to each worker (Ford, Bacon and Davis Utah. Inc., 1980).
13
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Appendix B
ESTIKAT OP HEALTH nz’r nCTS OP RADIATION
Contaminated material at a vicinity property exposes people who live and work
there to low levels of radiation. The doses received by these people may
produce health effects, principally cases of cancer. Ax estimat, of the
maximna number of health effects that might be expected in people who live and
work at the 50 Monticello vicinity properties and in the workers who carry out
the cleanup activities at those properties can be made using the limited data
available.
B .1 METH000LOGT
The estimates presented in this appendix are based largely on data contained
in a report entitled The Effects on Ponulations of Exuosure to Low Levels of
lonixini Radiation (referred to as the BEll III report), which was issued
by the National Research Council of the National Academy of Sciences (National
Academy of Sciences, 1980) • The BEll III report La based on a SO—year
ccitted dose.
8.1.1 Ezuosure to Radon Dauihters
When radon gas escapes f rue tailings into a building, the radioactive daughter
nuclides produced from its decay become concentrated in the air. Persons who
live or work in the building breathe this air and are therefore exposed to the
radiation emitted by the radon daughters. The BEll III report presents esti-
mates of the health effects of such exposures derived f ran data obtained in
studies of cancer incidence in miners who have been exposed to airborne radon
daughters in their work. The unit of concentration used in the B ItE III
report for these estimates is the working level (VL), which is the concentra-
tion of radon daughters that will release a certain amount of energy in each
liter of the contaminated air. A person exposed to a concentration of 1 WL
for 170 hours is said to have received an •xpo sure of 1 working—level—month
(liii), becaus. a person who works a normal 8—hour day works about 170 hours
each month.
Based upon data compiled for the Monticello Remedial Action Project Site
Analysis R.port, the radiation doss to human lungs exposed to radon and radon
daughters is approximately 400 mram/year du. to contributions primarily f ron
the tailings piles. This lung—dose calculation is made assuming a resident
breathes air blown f rue th. Monticello tailings piles 24 hours a day for 1
year.
B.1.2 Ex osire to External Gina Radiation
Exposur, to gina radiation from the tailings is considered an external whole—
body radiation dose. Based upon external exposure—rats measurements made at
the vicinity properties, ax average gina exposure rats of 75 ui/hr has been
determined. If an individual wire to be exposed to this rats 16 hours a day
for 1 year, a whole-body radiation doss of 43$ mrem would result.
3—1
-------
3.1.3 Inhalation of Airborne Tailinis Dust
A possible radiation—exposure pathway is the inhalation of airborne tailings
dust. Air-pazticulate ssnpling was áondacted at the Monticello .illsite over
the period March to 5.pts.ber 1984 (Eorte and lagner, 1983). Analysis for
uraniun, thorinn—230, and radiu.—226 indicated average concentrations of
(0.0007 ‘s/ ’. (0.0003 pCi/&, and (0.0002 pCi/s 1 . respectively the sane as
those reported for sisples collected at a background site in the Monticello
area. Applying the appropriate dose conversion factors (U.S. Nuclear
Regulatory Coission, 1982) to these values yields estisates of inhalation
dose for the general population of Monticello. The dose conversion factors
and resultant conservativ, inhalation doses are presented in Tables 3—1 and
3—2. respectively.
Table B—i. Inhalation Dose Conversion Factors
Type
of Exposure
Dose Conversion
U
Factor (uris/yr ner uCi/u 1 )
Th—230 Ra—226
Vhole
Body
2.48
101
40.0
Bone
41.0
3600
400
Mass
Average
Lung
2660
1380
2840
Table 3—2. Dose Conitsent to an Individual Breathing Dust at the
Tailings—Site Perineter 24 Hours a Day
Type
of Exposure
Dose Cissitsent
(urea/vr)
Thole
Body
0.033
Bone
Mass
Average
Lung
086
2:5
3.1.4 Innestion of Groundwater and Surface later
Another possible radiation-exposure pathway is th. ingestion of groundwater
and surface water oontisinated with radioactive aterials. A review of the
data available ( [ orti and Tagner. 1985) indicates that potable water supplies
for Monticello do not exceed EPA standards for water quality. Therefore, the
ingestion of groundwater and surface water is not eousidered a significant
radiation—exposure pat ay.
8—2
cj()
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3.1.5 Ineestion of Food
Exanination of the available data (lotte and Vaguer, 1985; Bendix Field
Engineering Corporation, 1985) reveals that insignificant mounts of contani—
nation occur in lands used for pasture and crop growing in the Monticello
area. Therefore, the ingestion of food potentially contaninated through
uptake and concentration of radionuclides by plants and minus constitutes a
negligible risk relative to increased health effects.
8.2 BEALTh EPFECrS
A s .ary of radiation doses fros all potential exposure pathways is presented
in Table 3—3, Th. n ber of health effects (defined as radiation—induced
cancer deaths) expected frc. the whoirbody radiation doe, listed in Table 8—3
is approxiaatsly 0.02. Th. nber of health effects expected iron the lung—
radiation dos. is approxinately 0.06.
Table 3—3. Predictions of Radiation Doses frau Exposure Pathways
Pathway
Dose (uren)
Whole Body
Luni
Exposure to Radon and Radon Daughters
—
400
Exposure to External Gaa Radiation
438
—
Inhalation of Airborne Radioparticulates
0.033
2.5
Ingestion of Tater
0
0
Ingestion of Food
0
0
TOTALS (rounded)
438
403
3—3
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Monticello Vicinity Properties Mining Waste NPL Site Summary Report
Reference 3
Excerpts From Results of the Survey Activities
and Mobile Gamma Scanning in Monticello, Utah,
ORNL; November 6, 1985
-------
OAK RIDGE
NATIONAL
LABORATORY
L U auiiQV - 6
‘a,
ORNL
MASTER Copy
ORNL/T*9738
M.Q 77N’ .cARIE77A
OPERATED BY
MARTIN MARIETTA ENERSY SYSTEMS. INC.
FOR THE UNITED STATED
O AR1MENT OP ENERGY
Rasults of th. Surv•y AC vffl.
and Mobils Gamma Scanning
In MontIc.IIo, Utah
C. A. Liftis
B. A. Birven
Cl ”
-------
Mary W5muin
..:r t r : 2
ORNL/TI — 973 8
REALfl AND SAFETY RESEAR DiVISION
Nuclear and Chemical east. Programs
(Activity No. AR 10 05 00 0; ONLWCO1)
RESULTS OF 1 E SURVEY ACTIVITIES AND. NOB n.E
GAJOUI SCANNING IN NONTI LOI UTAR
C. A. Little
B. A. Berven
Manuscript Completed — July 1984
Date of issue — November 1985
Prepared by the
OAL RIDGE NATIONAL LABORATORY
Oak Ridge. Tennessee 37831
operated by
MARTIN MARIETYA U4 GY SYSTE L INC.
for the
U. S. DEPAR1 4T OF 4 GT
under Contract No. DE—ACOS—840R21400
-------
RESULTS OF THE SURVEY ACflVITIES AND M9BILE
GAIGIA SCANNThG IN IONTI(Z ..LO, UTIE
C. A. Little
B. A. Berven
ABS1RAC
The town of Monticello, Utah, was once the site of an active
mill which processed vanadiom ore (1942—1948). and urani ore
(1948—1960). Properties in the vicinity of that mill hav, become
contaminated with radioactive material from ore processing. The
Radiological Survey Activities (RASA) group at Oak Ridge National
Laboratory (ORM.) was requested by the division of Remedial Action
Projects (DRIP) in the Department of Ener (DOE) to: (1) identify
potentially contaminated properties; (2) assess natural background
radiation levels and (3)rapidly assess the magnitude. extent, and
type (i.e. ore, tailings. etc.) of contamination present on these
properties (if amy). This survey was conducted by RASA during
April l9 . In addition to the 114 properties previously identi-
fied from historical information, the ORM. mobile gemma scanning
van located 36 new properties exhibiting anomalous gamma radiation
levels. Onsite surveys were conducted on 145 of the 150 total pro-
perties identified either historically or with the gamma scanning
van. Of these 145 properties. 122 of them appeared to have some
type of contaminated material present on them, however, only 48
appeared to be contaminated to the extent where they were in excess
of Enviro.mtal Protection Agency (EPA) criteria (40 CER 192).
Twenty—one other properties were recommended for additional inves—
tigatiom (indoor gamma scanning and radon daughter measnzements)
of these, only ten required further analysis.
Ibis report provides the detailed data and analyses related to the
radiological survey efforts performed by ORM. in Monticello. Utah.
• The survey was performed by members of the Radiological Survey
Activities Group of the Health and Safety Research Division at Oak
Ridge National Laboratory under DOE contract DE—ACOS—840R21400.
c
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2
IN1 1O 7 CT ION
The town of Monticello, Utah. was once the site of an active mill
which processed vanadi ore frem 1942 through 1948 and urani ore
thereafter until closing in 1960. Vicinity properties in the town have
been the subject of radiological surveys conducted in 1971, 1980, and
1982. During thos. surveys, 114 properties were listed as having or
being suspected of having “anemalous” levels of radioactive materials
within their confines. Due to limited soil sampling during those sur-
veys, the presence or absence of urnni mill tailings on these proper-
ties was neither confirmed nor denied.
During the period April 11—22. 19 , members of the Radiological
Survey Activities (lJ,SA) Group of Oak Ridge National Laboratory (OIM.)
visited Monticello. The objectives of the radiological survey were
threefold: first, to take soil and gaema exposure measurements at
nnaerous locations within the confines of the cemmumity to ascertain the
gamma exposur. background and the neminal 226 Ra content of the soil
second, to confirm or deny the presence or absence of urani mill tail-
ings on the previously listed properties; and third, to determine
whether or not additional properties in Monticello were contaminated by
scanning all accessible streets with the mobile gamma scanning van.
SURVEY EmODs
BAC C ND ASUTh f1E
Background samples of soil and measurements of gsa exposure were
taken at 30 locations throughout Monticello. The locations were chosen
systematically by utilizing a city map. Sample locations were evenly
spaced at about two blocks apart. The soil samples were taken at a
depth of 0—15 cm f rem undisturbed soils or turf whenever possible. Pro-
perties suspected of bezng contaminated were avoided. Samples and meas-
urements were taken at curbside locations or public property rather than
on private property. The 30 locations of background samples are listed
in Table 1.
91(4•
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3
Gamma exposure measuraments were made using a Pressurized loniza—
tion chamber (P lC) certified accurate by the National Bureau of Stan—
duds (PBS). Measurements were made at a height of 1 m above the ground
surface. An average of about 10 instantaneous measurements was taken to
be the gamma exposure in pR/h at that location. Measurements of the
gamma exposure rate in counts per minute (cpm) were mad. at the same
location using a hand—held scintillator.
VALE-ON SURVEY
The walk—on surveys conducted in Monticello were for the express
purpos, of confirming or denying the presence of uranimm mill tailings
on the property. The survey al so had the previous information as sup-
plied by Bendix Field Engineering Corporation (see Appendix I). For
each property, this information included a picture of the property, a
rough drawing of the boundaries and structures, and a gamma map from a
previous survey.
Each property was completely gamma—scanned using hand—held gamma
scintillators at the ground surface. The resulting regions of elevated
radioactivity, if any, were drawn on the existing map of the property.
If no map was available, a rough sketch of the property was drawn. The
regions of contamination were compared with the extant gamma maps in an
attempt to verify that no region had been missed.
Following complete gamma scanning of the property, samples were
taken from the contaminated regions of the soil. Samples were taken at
the location of highest gamma exposure rates. If necessary, a posthole
digger was used for access to the contaminated region. Sampling pieces
of uraniom ore was avoided whenever possible sines the pressmc. of these
ore pieces would not accurately reflect concentrations of radionuclides
in soil. If more than one region of contamination was found on a pro-
perty, several samples may have been taken. At least one sample was
taken from each property. On uncontaminated properties, a soil sample
was taken from the location of naximiz gaa exposure sines this sample
would reflect the maximmm concentration of radionuclides in soil present
on that property.
•1
-------
4
Properties that exhibited unexpectedly high gamma exposures in
building materials were so noted. If possible. • uaple of the suspect
building material was taken for analysis. Such samples were frequently
unavail able.
3I 3ILE GAIfM& SCANND1G
Tb. following ii a brief description of the scanning methods util-
ized for the mobile scanning of the Monticello ares. Details of the
syste. description and operation are described elsewhere. 1
lus trunenta t ion
Tb. gamma radiation detection system employed in the OW . scanning
van consists of three 4 z 4 z 16—in. NaI(Tl) log crystals housed in a
lead—shielded steel frame to provide a 12 a 16—in, detector surfac. area
for acceptance of gamma radiation through one side of the survey van.
The detector and shield height can be varied with a hydraulic lift
mechanism to to optimize the detector field—of—view. lb. detector out-
put is transferred to a computer—controlled, eight—channel discriminator
end interface, which provides for continuous analysis of data inputs for
correlation of system location with count rate information. Six
separate ener regions—of—interest are analyzed and a 226 Ra—specific
algorithm is employed to identify locations containing residual radiem—
bearing materials. Multickanmel analysis capabilities are Included in
the system for additional qualitative radionuclide identification.
Mobile Scannin. Methods
The data analysis method employed on the O ll. van is based on com-
putations involving background count rates in specific ener regions.
These background levels are normally obtained within emaIl (10 square
block) survey areas, based on coverage of at least 7 of the accessible
streets in that area. Subsequent street—by—street scans of these areas
are conducted at a slow speed ((5 mph). minimizing the distance between
the detectors and the subject properties. All accessible streets,
alleyways. and other public thoroughfares are scanned in both directions
to maximize the nember of views obtained for each property. Anomaly
-------
5
locations are highlighted by the computer system when the preset hit
criteria are ezceed.d during the scsi.
LABORAI *Y ANALYSIS MWIEODS
R #iolo1ical Analysis
Samples collected for both background determination aid from sur-
veyed properties were analyzed for both 226k and 238 ’J Samples were
dried at 1100 C for 24 h, ground, placed in capped sample vials and
weighed. Samples counted for 226k on a high purity germanium semi-
conductor detection system coupled with $ Nuclear Data Corporation ND
2400 gaoma spectrometer. Details about the counting system, its opera-
tion, and specifications are given in section 15.1 of Reference 2. Sam-
ples were analyzed for by the Analytical Chemistry Division of
ORNL. A 5 cm 3 aliquot of soil is subjected to a thermal neutron flux in
the Oak Ridge Research Reactor counted for 235 U and converted to con-
centration of 238 D. Details of this procedure are given in section 15.2
of Reference 2.
Elemental Analysis
Multi—elemental analysis was conducted for each property and back-
ground soil sample taken in Monticello. The samples were analyzed using
an inductively coupled plaa optical emission sp.ctrometry (I P—O )
system. 3 Samples wire analyzed for concentrations of the following ele—
mints: aluminum, barium. beryllium, boron. calcium. cesium. chromium.
cobalt, copper, iron. lanthanum, lead, lithium. magnesium. manganese.
molybdenum, nickel, niobium, phosphorus, potassium, scandin. sodium,
strontium, thorium, titanium. vandadium, zinc, and airconium. Relative
to results of the surveys conducted in Monticello. only two elements
were of interest — vanadium and copper; therefore, in this document.
concentrations for only these two elements hay, been reported. These
two elements (vanadium and copper) were the only elements which were
found to be helpful in discriminating between material originating from
the Dry Valley and Monticello mill sites.
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6
cRITERIA R R WNTAJIDIATION a.ASSIFICATION
Three criteria were ased to jndgs the extent of contamination or
need for remedial action: (1) 226k concentration in soIl. (2) 238
concentration in soils and (3) areil extent of contamination in the
soil. In addition. because the tailings in the Monticello region con—
ceivably come from several sonzces (Monticello and Dry Valley mills) and
several different processes (acid leach, carbonate leach. etc.) they are
difficult to Identify visually. Therefore. we instituted a criteria to
separate tailings from ore when found in soil. This criteria and the
three above will each be discussed briefly in the foiloviug sections.
If remedial action is found to be required based on data within this
report, the remedial action would be based on EPA ’s Standards for 2eme—
dial Action at Inactive Ursni Processing Sites “ 40 CPL 192, and not
on site—specific health effect assesements.
RADI M ONcThThA1 10t4 U I SOIL
Soil samples were analyzed for 226k concentration in soil by the
methods described above. A property vie considered to be in violation
of 1k. radiun criteria if it exceeded 5 pCi above background per dry
grem of soil. This was the interim guideline for remedial action pub—
lish.d by the U. S. Envirounental Protection Agency (EPA) for surface
soil at the time of the surveys (40 PE 192.12). Because no angering
was done during the soil sampling, and no ssmpi.s were taken below 15 cm
of depth, the more comservstivs 5 pCi/g guideline was applied rather
than th. less stringent 15 pCi/g standard for subsurf ace soils. Based
on he background sampling done in Monticello. this means that any sea—
pie having 226 k in concentration equal to greater than 7.5 pCi/g would
exceed the criterion. Mo attempt was made to apply statistical or pro-
babilistic teats to th. mean or any simple when comparing with the cr —
tenon.
0
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7
URANIUM aN DI1RATI0N D l SOD..
Soil samples were also analyzed for in soil by the methods
described above. A property was considered to exceed the criterion
jf it exceeded 75 pCIIg above background. This criterion is equivalent
the “soil remedial action guideline” suggested by the Department of
Energy (DOE) for the Formerly Utilized Sites Remedial Action Program
( SRAP). 4 Again, the background sampling at Monticello imply that the
238 U criterion would be exceeded by a soil concentration of 77 pCi/g of
dry soil. As before, no attempt was made to apply statistical tests to
the mean or any sample when comparing with the criterion.
A&EAL EXT 4T OF cDNTAMThA IION
The areal extent of contamination criterion applied to the surveyed
properties is 100 m 2 . Any property which appeared to have a contaminated
region exceeding this area, either in on. contiguous region or several
substantial subregions, was considered to be in excess of the criterion.
This criterion is in concert with the distribution of contamination used
to estimate health effects when developing the FUSRAP radiological
guidelines. 4 As with the 226k and 238 U criteria, the areal extent cri-
terion was considered to be deterministic rather than probabilistic.
TALINGS IDENTIFICATION
As previously mentioned, the tailings found at Monticello represent
several different sources and processes. The two potential sources of
tailings include the Monticello mill which processed during its history
f or both nrani and vanadi , and the Dry Valley site which processed
for vanadL alone. Anecdotal evidence indicates that residents of the
egiom have bsd at som. time, access to both sites and the tailings
ocated at each. This varying of both source and process made visual
‘entificatlon of the tailings materiel difficult and unreliable.
Because suspected tailings could not be reliably identified vies—
y. an arbitrary criterion was established to classify a property ac
og tailings—contaminated. Polloving completion of soil sample
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8
analysis for both 226k and the concentrations of these two radio—
nuclides were ratioed. The j criterion was established that if the
ratio exceeded 1.5 for any soil sample on a property, the property would
be classified as being contaaiuated with tailings. This criterion is
independent of the 226k criteria discussed above.
The rationale for this criterion comes frc. the collection of 327
and 355 background soil samples across the U.S. and analyses for concen-
trations of and 238 U. respectively. 5 In those samples 1 the mean
concentration of wis found to be 1.1 pCi!g. The mean concentra-
tion for was 1.0 pciig. Thes, data suggest, as might be expected,
that the radiom was in equilibrita with the natural urani in back-
ground sites. Without formally accounting for the variation expected in
both the nunerator and denominator of the ratio, the vain. of 1.5 seems
to be a prudent indicator of the breakpoint between a background ratio
and one indicative of tailings. Since there is no standard or guideline
to describe “tailings”. encept for the 226 Ra and criteria described
above, the classification of properites as tailings—contaminated should
be considered qualitative only.
ORE ID 4TIFIC&TION
Ore is more easily identified than tailings in many instances.
This is because ore may take the form of rocks which are both visible
and characteristically it more localized gaa radiation. In some
cases in Monticello, however, there seemed to be properties on which ore
was found, but for which no “rock” existed. Local residents stated that
during mill operations, ore dust from ore stockpiles, haul trucks, and
the ore crusher were common in portions of Monticello nearest the mill.
Ro,e,er, this material appeared to be more “tailings—like” in quality.
In such cases, the decision to list a property as contaminated with ore
was again made using the 226 La to 238 D ratio. Inverse to the situation
with tailings, a property was classified as having ore involvement when
the La/U ratio was below 1.5. As with th. tailings classification, the
ore designation should be considered only qualitative because of the
probabilistic nature of the La/U ratio, and because he classification
may include visual sightings alone.
•2 :‘:-
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(‘1
C\ r
9
RESULTS
BACIGRaIND RADIATION LEV S
The results of the thirty soil samples taken throughout the city of
Monticello are shown in Table 1. The concentration of 226k in the 30
samples ranged from 0.88 to 9.7 pCi/g. with a mean concentration of
2.4 pCi/g. The 238 U concentrations of the sans samples ranged from 0.80
to 7.3 pCi/g and averaged 2.0 pCi/g. The ratio of 226k 238. ranged
in these samples from 0.39 to 1.7 and averaged 1.2. A 226k to
ratio of abont unity ii generally accepted as indicative of background.
The gamma exposure rite measured at the same 30 locations was much
less variable than the 226k and 238 ’J concentrations in soil samples.
Measurements with a PlC tend to average over a much greater area than
the discrete soil samples, and therefore, tend to display much less
variability. The range of measurements was from 11 to 15 nE/h with as
average value of 13 uI/h.
!ALI- 4 SURVEYS
The previous listing of properties by Bendix (Table 2) was utilized
as a source of potentially contaminated sites which required walk—on
gamma surveys. In addition, properties were surveyed which fell into one
or more of three categories:
1. possible contamination as indicated by a hit from the mobile gamma
scanning van;
2. r.qust for a walk—on survey from the property owner or occupant;
3. evid.nce of contamination during a walk—on survey of the adjacent
property.
A list of 38 such “nsv properties which were surveyed during the April
1983. trip is included as Table 3. Property #150 was an owner request,
and #151 fell into category 3 above; the remaining 36 properties were
all detected by the ORNL mobile gamma scanning van which scanned the
entire community.
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10
SOIL SAI LE R VL1
Results of soil samples taken on the surveyed properties are listed
in Table 4. Nearly 200 samples were collected fr the 145 properties
that were surveyed. The concentration of in the sampled medii
(soil or building matinal.) ranged fr background levels to as high as
23,000 pCi/g; conc.ntrations for exceeded that range to a maxim
of 24.000 pCilg. Vauadi and copper concentrations ranged frem back-
ground to 16,500 and 59,000 ppm. respectively.
Th. soil simple data in Table 4. coupled with the gana maps
developed during walk—on scanning of th. properties, were used to place
each property into a contamination category based on the criteria dis-
cussed above. These categories, along with the criteria exceeded for
each property, are listed in Table 3. Contamination categories are
defined as follows:
1. gontsmin ;d - no evidence of contamination; gina exposure rate,
Ba and VU concentrations in soil are within the normal range
of background.
2. Building materials — indication of artificially high gaa expo-
sures emanating f rem building materisls; likely contamination with
mill tailings.
3. Ore — visible 22 ge. hig 3 ;ana levels associated with rocks, or soil
samples with Ba to “U ratio less than 1.5.
4. Tailings — soil sample. with 226 Ra to ratio greater than 1.5.
As indicated by Table S. there are several cases in which a pro-
perty may fall within one or more contamination categories, but not
exceed any of the criteria for inclusion for remedial action. Con-
versely, properties listed as uncontaminated give no evidence whatsoever
of contaminated materials onsite and, therefore, exceed no criteria.
For each property that exceeds the 226k criterion. exclusive of the
100 m 2 criterion, a figure displaying the contaminated region is
included in Appendix II.
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11
u ART OF NT?JITh AXED PROPERTIES
Th, radioactively contaminated status of the properties surveyed in
the Monticello community is s .arized by Table 6. This table is merely
a tally of the various contamination categories and criteria exceeded as
listed in Table 3. The s matiou Indicates that 86 properties hid Es
in excess of 5 pCi!g above background (e.g. greater than 7.4 pCi/g).
Forty-four properties appeared to have soil contamination that exceeded
100 .2 in area. Nineteen properties appeared to hive tailings involve—
meat as indicated by the but did not necessarily exceed the
S pCilg criteria. Radioactivity in building materials exceeding normal
expectatfois was detected at 21 propertIes; this was prea ably the
result of tailings use in mortar or concrete. Ore (either visible, or
indicated by the P.aIV) was found on 104 properties. A total of 23 pro-
perties were thought to be uncontaminated (radiation levels not above
background).
RADIOLOGICAL AND EIThTAL MPARIS0NS OF MILLSITES
An ancillary activity to the property surveys In Monticello was to
investigate th. possibility that one or more signatnres” or set of
chemical or radiological characteristics could be ascertained for each
of the millsites. To this end samples of materials from each pile were
analyzed for both radiological and elemental concentrations as previ-
ously discussed. This section briefly describes comparisons between
those s.ts of samples.
As shown in Table 7, a total of 17 samples were taken from five
piles at the two .111 sites. The five piles were chosen because they
were distinct and because there was at least anecdotal evidence that the
four Monticello piles were created during different types of ore pro-
c. a sing.
Mean concentrations for the five types of piles are also shown in
Table 7. Data are shown only for 226 Es V. and Cu. Although 28
elemental concentrations were determined for each soil sample, only
copper and vsnadina are reported herein. These appear to be the only
two elements which may be used to assign a ‘signature.’ A statisti c i i
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12
analysis of th. data in Table 7 indicates that sean 226k and con-
centrations for the Dry Valley piles are different fron the other piles.
The Monticello Vanadi piles (upper and loner) appear to have both
higher and V concentrations than the other three piles. however.
the variability in the data prevent any statistical significance. The
vanadi concentrations are so widely spread that no significant differ-
ence (p).OS) is observed between any of the piles or processes. The
copper concentrations are significantly loner in the Dry Valley piles.
However, when the Dry Valley tail3ngs are sized with undistazbed soil,
the concentration of copper would be indistingaisheble frc natural
background concentrations.
Several sets of calculations hive been sad. that atte.pt to segre-
gate tailings involvesent on vicinity properties in Monticello into two
groups: those contaninated by Dry Valley tailings and those contaninated
by Monticello tailings. The purpose of this section is to describe the
results of those calculations and to interpret the results. -
The ratio.d concentrations of Ra to V and Cu to V for sauple. taken
at the Dry Valley pile and the four distinct Monticello piles have been
averaged. The results of these calculations are provided in Table 8.
Confidence levels were not calculated for these values because the con-
fidence intervals between concentration ratios between Dry Valley and
Monticello soil data overlap. Because this overlap occurs even at the
6 confidence level, there is no way to decide which properties were
contaninated by naterials f row which sills. However, there do appear to
be sowe distinct differences between the sean values for Dry Valley and
the sean for A. four Monticello.. It should be noted that the variance
is larg. enough and the siuple sizes a11 enough that 9 confidence
intervals on the sean Cu/V ratio would overlap zero for several Monti-
cello pil... Therefore, any projections sade using these data should be
considered very unreliable.
Because the Cu/V ratio had greater separation between the Monti-
cello and Dry Valley sasples. the Cu/V ratio was used for purposes of
segregation. The breakpoint chosen for this separation was a Cu/V ratio
of 0.01. Therefore, any sauple with a Cu/V ratio of 0.01 or aller ‘as
considered to hay, cone frow Dry Valley. A listing of such sauples s
given in Table 9. By cutension. any sasples not list.d in Table 9 would
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13
be judged to have case from the Monticello milisite. These differentia-
tions are subject to dispute and are given for information only. This
j especially true with the present analysis. because it makes no
attempt to consider statistical attributes of the data sets involved in
the analysis.
$IGNIF!ChNCI OF FINDINGS
The results of these surveys have been used to develop a list of
properties which may be in excess of EPA criteria for inclusion in the
Uranias Mill Tailings Remedial Action Project (UMTRAP). the major DOE
project which is active in performing remedial action at properties
similarly contaminated to those at Monticello.
Forty—eight properties are believed to be contaminated to the
degree that they could be eligible for remedial action under the EPA
UM1KA criteria. These properties are listed in Table 10. Additionally.
the milisite where the contaminated material nost probably originated
(based on the preceding section’s analysis) is listed in this table.
The fact that a property exceeds both the 226 P and the 100 .2 criteria
does not by extension indicate that a 100 .2 area is uniformly contam-
inated to greater than S pCi/g. The present .ill tailings remedial
action criteria (40 C l 192) were not in effect during the Monticello
survey (April 19 ). Further. DOE guidance given to the survey team did
not dictate compliance to the then—existent draft criteria. Rather, the
surveys performed in Monticello by O L were for the purpose of deter-
mining whether or not tailings contamination existed on the property.
Therefore, it is possible that some properties listed as exceeding both
the 226 Ra and 100 2 criteria are not actually in excess of the present
EPA standards.
Twenty—one properties were not sufficiently contaminated to warrant
an inclusion recommendation, and requite further information before a
decision could be made. It was recommended that the properties listed
in Table 11 receive indoor gamma scanning and/or radon daughter measure-
ments. In June 1984. these 21 properties were the subject of further
investigation by the EPA. 6 Ten buildings were found to have radon
daughter concentrations in excess of 0.01 it or 3 pCl/L of 222 If
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14
was reco svds4 that these ten properties be the subject of additional
investigstion. and the r aieing properties be dropped fr further con-
sideration. These properties are given in Table 12. The EPA report
describing these suveys is provided in Appendiz III.
q )
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Monticello Vicinity Properties Mining Waste NPL Site Summary Report
Reference 4
Excerpts From Monticello Vicinity Properties
Equivalency of Documentation;
DOE; April 1989
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DRAFT
Monticello Remedial Action Project
MONTICELLO VICINITY PROPERTIES
EQUILAVENCY OF DOCUMENTATION
UNC Geotech
Grand .Junction Colorado
Prepared for
U.S. Department of Energy
Grand Junction Projects Office
Under Contract No. DE-ACO7—861D12584
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____ DRAFT
MONTICELLO VICINITY PROPERTIES
EQUIVALENCY OF DOCUMENTS
FUNCTIONAL EQUIVAL.ENCY STRATEGY
Equivalency of Documents for Vicinity Properties is based on the definition in
Part III, Paragraph J. of the Federal Facilities Agreement (FFA), which
defines “Functional Equivalency” as ‘. . .an activity or element of work
undertaken or performed pursuant to this Agreement including a document.
submittal, contract, or action (that] meets appropriate procedural and
substantive objectives, standards, and requirements set forth [ by
environmental legislation] in effect at the time of performance of the
activity or element of vork. (Bold added for emphasis.)
This concept for functional equivalency of Vicinity Property documents is to
demonstrate that, while not necessarily meeting now current guidelines to the
letter, previous activities were performed in accordance with then current
environmental “.. .U.S. EPA guidelines, regulations, rules, criteria.. .“
DOE’s position on Vicinity Properties Is that a functionally equivalent Record
of Decision (ROD) was made to clean up all contaminated properties, both known
and those included at a later date. Through Its documents. submittals,
contracts, and actions the DOE made this tacit decision to clean up all
properties. EPA and the State concurred in this decision through their
actions.
It is Important that the reader clearly understand that the process for
reaching the Vicinity Properties ROD cannot be compared directly with current
RI/FS guidelines. The process that was followed does not conform to current
procedures; however, the process that was followed conformed to then-current
practices. Furthermore, the decision that was reached to clean up all
Vicinity Properties, both known and those Included in the future, was proper
and is functionally equivalent to the current RI/FS process for decision
making.
Based on this concept of functional equivalency of documents, an overview of
existing CERCL.A requirements as related to past actions is presented and the
documents supporting the ROD equivalency are listed and attached. An
explanation of why these documents are functionally equivalent Is provided
with this overview. This listing of documents is not intended to replace the
equivalency submittal, but rather to Indicate the nature of the actions that
have occurred that are functionally equivalent to the CERCLA requirements.
Supporting documentation Is divided Into the following categories which
clearly show that a functional -eqnivalent ROD was made by the DOE:
• Contracts
• Annual Budgets
• Investigations/Environmental Evaluations
• Decision Making
1
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DR.&FT
ABTRACTS
Contracts are the fundamental assertion that DOE decided/contracted to
remediate all vicinity properties in Monticello to meet EPA standards. There
are two DOE contracts which fulfilled this decision:
Document A - U.S. Department of Energy, Grand Junction Projects Office,
Contract No. DE—ACO7—766J01664 with Bendix Field Engineering Corporation,
effective date 1 January 1982.
Document B — U.S. Department of Energy, Grand Junction Projects Office,
Contract No. DE-ACO7-861D12584 with UNC Technical Services, Inc.,
effective date 15 August 1986.
ANNUAL BUDGETS
While authorization to perform remedial action is found in contracts, in
reality it is the authorization of funds through the budgetary process which
demonstrates that DOE fully intends to remediate all known vicinity
properties. This authorization of funds is composed of two parts - The Field
Task Proposals and the allocation of funds for the Monticello Vicinity
Properties. These documents include:
Document C - U.S. Department of Energy FY—87 Field Task Proposal for
Monticello Vicinity Properties Project, Bendix Field Engineering
Corporation
Document D - U.S. Department of Energy FV—88 Field Task Proposal for
Monticello Vicinity Properties Project, Bendix Field Engineering
Corporation
Document E — U.S. Department of Energy FY—89 Field Task Proposal for
Monticello Vicinity Properties Project, UNC Technical Services, Inc.
Document F - U.S. Department of Energy FY—90 Field Task Proposal for
Monticello Vicinity Properties Project, UNC Geotech
Document G — FY—84 Surplus Facilities Program Office Mid-year Review and
Funding Authorization, 4 May 1984.
Document H — FY—85 Surplus Facilities Program Office Mid-year Review and
Funding Authorization, 17 May 1985,
Document I — FY-87 Surplus Facilities Program Guidance for Planning FY-89
work, 1 October 1986
Document .3 - FY—87 Surplus Facilities Program Guidance for FY-87 Funding
Document K - FY—88 Field Notification of the FV-88 Surplus Facilities
Management Program Budget Submission and Authorization, 5 June 1986
Document L - FY-89 Authorization Letter, 7 October 1988
Document M - FY-90 Budget GuIdance, 19 September 1988
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DRAFT
INVESTIGATIONS/ENVIRONMENTAL EVALUATION
For the Monticello Vicinity Properties the functional equivalency of the RI/FS
is a combination of two separate documents. Document N - Results of the
Survey Activities and Mobile Gamma Scanning in Monticello, Utah. July 1984.
Oak Ridge National Laboratory ORNL./TM-9738 - serves as the RI functional
equivalent. This document investigated 145 properties and found contamination
on 122 properties with 48 properties exceeding 40 CFR 192 criteria.
Document 0 - Environmental Evaluation on Proposed Cleanup Activities at
Vicinity Properties near the Inactive Uranium f4illsite, Monticello, Utah.
August 1985. Bendix Field Engineering Corporation - serves as the FS
functional equivalent. This document investigated the environmental Impact of
the proposed remedial action. The proposed cleanup activity consists of
excavation or surface removal of residual radioactive material from each
property, followed by replacement to the inactive Monticello Millsite. Final
disposal will be that selected for the Milisite tailings. The alternative to
removal of the tailings from the vicinity properties is “no action.” No
action, however, was considered an unacceptable alternative. The document
also clearly states that the “...cleanup activity proposed to accomplish
remedial action at these sites and any additional properties that might be
authorized...” is the removal of the tailings from the vicinity properties.
Thus, it is apparent that DOE determined that all contaminated property both
currently known and those Identif led in the future were to be cleaned up.
DECISION MAKING
Decision—making on the vicinity properties is the functional equivalent to the
ROD. It is clear through DOE actions that DOE made a tacit decision to clean
up all properties. Documents that support this contention are
Document P - Action description memorandum for the cleanup activities in
Monticello, Utah. June 1984. DOE.
Document Q - DOE memorandum, 27 January 1984. designation of 15 vicinity
properties at Monticello, Utah for remedial action. (Copied to EPA and
State of Utah.)
Document R — DOE memorandum, 6 February 1984. authorization to initiate
remedial action activities in Monticello, Utah. on 15 properties.
Document S - DOE memorandum, 8 June 1984. authorization for remedial action
of 28 vicinIty properties at Monticello, Utah. (Copied to EPA and State
of Utah.)
Document T - DOE memorandum, 16 August 1984. review relative to NEPA
requirements for proposed decontamination of vicinity properties in
Monticello, Utah. This memorandum states that the NEPA process was
followed and that neither an environmental assessment nor an
environmental impact statement will be required for the proposed remedial
action.
3
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DRAFT
Document U - DOE memorandum. 1 November 1984, authorization for remedial
action of five vicinity properties at Monticello, Utah. One property,
the Montgomery Ward property, was deleted because EPA conducted remedial
action on this property. (Copied to EPA and State of Utah.)
Document V - DOE memorandum, 25 February 1985, desIgnation of one additional
Monticello Vicinity Property for remedial action.
Document W - DOE memorandum, 29 April 1985, deletion of two properties ( 1O
and *116) from the MVP program because contamination was not attributable
to the Monticello millsite. (Copied to EPA.)
Document X - DOE memorandum. 5 September 1985. designation of one vicinity
property at Monticello. Utah for remedial action.
Document Y - DOE memorandum. 9 October 1985. designation of one vicinity
property at Monticello. Utah for remedial action. (Copied to EPA.)
Document Z — DOE memorandum, 26 June 1987, authorization for remedial action
for 14 additional vicinity properties at Monticello. Utah.
Document AA - UNC correspondence with DOE. 2 May 1988. Identification of 34
“hot spot” properties, 24 “suspect” properties and 9 problem properties.
Document AB - DOE memorandum, 7 October 1988, authorization for remedial
action for 8 additional vicinity properties at Monticello, Utah.
Document AC - DOE memorandum, 14 October 1988, authorization for remedial
action for 5 additional vicinity properties at Monticello, Utah.
Document AD - DOE memorandum, 1 March 1988, authorization for remedial action
for 15 additional vicinity properties at Monticello, Utah.
EQUIV. DOC: 1989FS:DZ
4
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I
Monticello Vicinity Properties Mining Waste NPL Site Summary Report
Reference 5
Letter Concerning Proposal for Including Additional Vicinity Properties
Into the Monticello Vicinity Property Program;
Joseph Virgona, DOE, to Paul Mushovic
and Brent Everett, EPA; April 10, 1991
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4 .
Department of Energy SH’.’.’ ’ —FFR
\ . A/ Grand Junction Projects Office “ ri ‘ r
Post Office Box 2567 I ) I ri
Grand Junction, Colorado 81502—2567 - :- -
April 10, 1991 .:: -
Mr. Paul Mushovic, Regional Project Manager
Environmental Protection Agency, Region VIII
Suite 500, Mail Stop 8HWM-FF
999 18th Street Denver Place
Denver, CO 80202-2405
Mr. Brent Everett
State of Utah Department of Health -
Bureau of Environmental Response and Remediation
P. 0. Box 16690
Salt Lake City, UT 84166—0690
SUBJECT: Proposal Por Including Additional Vicinity Properties
Into The Monticello Vicinity Property Program
Dear Mr. Mushovic and Mr. Everett:
Enclosed is a Geotech memorandum which includes a list of 114
vicinity properties (Phase 1) included in the Monticello Vicinity
Properties (MVP) Project at the signing of the MVP Record of
Decision on November 29,. 1989. Also included is a list of an
additional 106 vicinity properties (Phase 2) which DOE
Headquarters has recommended to be included for remedial action.
Oakridge National Laboratory (ORNL) and Chem-Nuclear Geotech,
Inc. conducted radiological surveys on the 106 Phase 2 vicinity
properties and determined that they contain radiological
contamination in excess of the standards in 40 CFR 192, Remedial
Action at Inactive Uranium Processing Sites. These results were
reviewed by DOE Headquarters prior to issuing inclusion
reconunendations.
The DOE, in response to the requirements of the Monticello
Federal Facilities Agreement, is submitting these 106 vicinity
properties for your consideration and concurrence for inclusion
in the remedial action.
‘ I C . ’
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Mr. Paul Mushovic —2- April 10, 1991
Mr. Brent Everett
If you have any questions or require any additional information
regarding these properties, please call me at 303—248—6006 (FTS
326—6006).
Sincerely,
i oseph E. Virgona
Supervisory General Engineer
Enclosure
cc: W. Murphie,DOEIHQ, EN-423, w/att.
J. Lilly, Weston OTS, w/att.
H. Moore, DOE/HQ, EM-423, w/att.
H. Perry, Geotech, w/o att.
J. Solecki, DOE/ID, MS-1115, w/o att.
quO
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Geotech. Inc.
DATE: April 5, 1991
TO: Harry Perry
FROM: Melvin Madril, Engineering
SUBJECT: MONTICELLO VICINITY PROPERTIES, PHASE 1 L 2 PROPERTIES
Per your request, attached is a list of the Phase 2, Monticello
Vicinity Properties. This consists of properties that have been
included in the program after the signing of the MVP Record of
Decision, on November 29, 1989. As of April 1, 1991, 106 properties
have been included into the program by DOE.
Also attached is a list of the Phase 1 properties which consists of
those that were included in to the program at the sigung of the MVP
Record of Decision. At the time of the ROD signing, 114 properties
had been included by the DOE into the program. An earlier list
submitted to you on January 14, 1991 listed 112 properties.
Properties MS0001O and M500l88 were inadvertently left off of that
list, but have now been included.
cc: 3.E. Elmer
1.1. Stewart
HPSTAT.MM:DZSFMP. B:DZ
i. . .. -•. .. . I
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MONTiCELLO VICINITY PROPERTIES
PHASE 1 PROPERTIES
PROPERTIES INCLUDED PRiOR TO NOVEMBER 29, 1989
(updated 4/1/91)
I, I I _____ _ ___ _ I I II II
II I II II
H D.O.E. : DOE INCL. REC. INCL. REA CONSTRUCTION H D.O.E. H
H I.D. NO. APPROVAL APPENDIX M TO DOE : START END H I.D. NO. ::
II I I I I II II
II II I I
i : Ms000lO 06/08/84 : 02/08/85 2/21/85 EPA DISPUTED : MS0001O
2 H MS000 I2—RS 06/08/84 02/01/89 03/01/89 07/10/89 07/26/89 MS00012—Rs
3 : MS00014—RS 01/27/84 07/03/84 07/19/84 06/21/85 09/17/85 MS00014—Rs:
4 :: Ms000l6—MR: 03/10/89 06/16/89 07/31/89 09/19/89 10/02/89 1 MS000]6—MR I
5 : MS00022—RS 10/14/88 12/05/88 03/13/89 05/09/89 1 06/12/89 MS00022—Rs:
6 H MS00025—RS 03/10/89 06/23/89 09/27/89 I 05/08/90 05/23/90 Ms00025—Rs:
7 MS00028—RS 10/14/88 : 12/09/88 03/06/89 06/19/89 07/27/89 1 Ms00028—Rs:
8 1 MS0003O—RS 03/10/89 08/17/90 09/14/90 I 1MS0 0030—Rs I:
9 MS00031 06/08/84 OWNER REFUSAL MS00031
10 MS0004O—vLl 03/10/89 1 12/01/89 03/07/90 06/11/90 1 07/06/90 MSOOO4O—VL
11 MS00041—CS 11/01/84 10/10/84 : 06/07/85 09/25/85 1 10/29/85 :Ms0004 l—cs::
12 Ms00042—cs: 02/25/85 10/10/84 06/07/85 09/25/85 10/29/85 1MS00042—CS
13 MS00043—CSI 06/08/84 10/10/84 06/07/85 1 09/25/85 10/30/85 1 :MS00043—CS
14 H MS00048—RS 03/10/89 05/12/89 (2)02/14/9 04/30/90 : 05/18/90 HMs00048-RS::
15 H MS00049-VLI 06/08/84 03/25/85 04/19/85 08/12/85 10/29/85 MS00049—VL::
16 11 M 500050—MR 01/27/84 06/01/84 06/20/84 09/10/84 10/25/84 MS0005 O—HR
17 : MS00051 1 06/08/84 05/29/85 05/29/86 10/01/87 11/24/87 1 1MS00051
18 H Ms00053—RsI 03/10/89 06/16/89 09/29/89 04/09/90 1 04/19/90 HMS00053—RSH
19 11 MS00054—RS 03/10/89 06/16/89 09/27/89 04/10/90 04/19/90 HMS00054-RSH
20 H MS00055—RS 10/14/88 12/09/88 03/06/89 1 06/19/89 08/22/89 HMs00055—RsH
21 H MS00062—RS 10/14/88 12/05/88 1 03/23/89 06/23/89 1 09/15/89 HMS00062-RSH
22 H MS00068—RS 03/10/89 06/16/89 07/31/89 I 09/13/89 09/27/89 :IMs00068-RsH
23 :: Ms00069—MR: 06/08/84 : 01/07/85 :012/25/85 1 08/29/88 : 09/23/88 Ms00069-MR
24 : : MS00071—RS 06/08/84 : 03/14/86 07/10/86 10/08/87 11/25/87 :MS0 00n—RS:
25 H Ms00072—Rs: 03/10/89 05/26/89 (2)o2/14/9: 04/30/90 1 05/31/90 HMS00072—RSH
26 1: MS00073—RS 01/27/84 05/09/84 06/20/84 09/10/84 10/23/84 MS00073-RS
27 H MS00074—MRI 01/27/84 06/28/84 07/06/84 11/20/84 I 12/11/84 HMS00074-MRH
28 H Ms00075—Rs: 01/27/84 06/01/84 06/19/84 09/10/84 10/25/84 MS0O075—RS
29 H MS00076—RS 01/27/84 06/01/84 06/29/84 11/20/84 01/09/85 MSOOO76—RS
30 H Ms00078—RsI 10/14/88 12/05/88 03/23/89 OWNER REFUSAL HMs00078-RSH
31 H Ms00079—Rs: 03/10/89 06/30/89 (2)02/14/9 04/30/90 05/23/90 HMS00079—RSH
32 Ms00083—Rs: 01/27/84 06/01/84 1 06/20/84 1 06/21/85 1 06/21/85 1 1MS00083—Rs:
33 H MS00084—OT 01/27/84 06/28/84 07/06/84 : 09/10/84 1 01/09/85 HMS00084—OTH
34 H Ms00085—Rs: 01/27/84 1 09/21/84 1 10/01/84 I 08/12/85 09/25/84 HMS000B5—Rs:I
35 H MS00086—RS 01/27/84 07/11/84 07/31/84 06/21/85 09/26/85 HMS00086—RSH
36 H MS00087 01/27/84 : 05/09/84 1 06/20/84 1 09/06/84 1 01/09/85 HMS00087 :1
37 H MS00088—RS 01/27/84 1 07/30/84 1 /13/84 1 04/27/89 1 06/13/89 1 :MS00088-R5H
38 H MS00091—RSI 11/01/84 1 12/31/8 1 02/2’/85 1 08/11/86 1 09/19/86 HMS00091—RSH
39 :: MS00092-RS 06/08/84 : 01/09/85 1 01/25/85 1 08/12/85 1 10/29/85 ::MS00092—Rs::
40 H MS00093-RS 06/08/84 : 01/09/85 01/25/85 1 08/12/85 1 10/29/85 :1Ms00093-Rs::
41 :: Ms000g4—Rs: 06/08/84 01/09/85 : 01/25/85 : 08/12/85 1 10/29/85 ::Ms00094—RsH
42 :: Ms00097—cH: 06/08/84 1 12/07/84 : 01/07/85 1 08/19/86 1 10/17/86 HMS00097—CHII
43 :: ‘1S00099—R5 06/08/84 1 12/12/84 1 03/01/85 1 08/19/86 1 10/09/86 HMs00099—Rs:
C.-’
-------
MONTICELLO VICINITY PROPERTIES
PHASE 1 PROPERTIES
PROPERTIES INCLUDED PRIOR TO NOVEMBER 29, 1989
(updated 4/1/91)
II S I I I II II
II S II II
:: D.O.E. : DOE INCL. REC. INCL. REA CONSTRUCTION :: D.O.E. ::
I.D. NO. APPROVAL APPENDIX A: TO DOE START END I.D. NO.
I I I_ I I I I I I II
II I — S II
44 :: MSOO100 : 06/08/84 : 11/07/84 : 01/20/87 : 08/01/88 : 09/29/88 MS001OO ::
45 :: MsOOlOl 01/27/84 07/11/84 07/20/84 : 05/04/87 08/06/87 : MS00101
46 :: Msoolo2—MR: 06/08/84 : 04/02/85 05/06/85 09/08/87 09/30/87 :Msoo lo2—MR::
47 U Msoolo3—vL : 06/08/84 : 04/03/85 : 05/06/85 05/04/87 : 08/06/87 :MS00103-VLH
48 U MSOO1O4— 1 06/08/84 1 12/03/85 07/30/86 05/04/87 : 08/06/87 1 MS00104— U
49 I MSOOIO5—VL 01/27/84 08/29/84 1 03/24/89 06/15/89 09/25/89 1 MS00105—vL
50 U Ms00108—oTI 06/08/84 06/09/89 09/28/89 07/05/90 :Msoolo8—oT::
51 MSOO114—RS 10/09/85 11/22/85 03/11/86 08/19/86 10/17/86 1MS00114—Rs:
52 MS00124-MR 10/23/89 09/07/90 09/21/90 1 EPA DISPUTED UMsoo124—MR::
53 U MsOO126—MR: 03/10/89 12/22/89 04/06/90 1 06/11/90 07/07/90 1 IMsOO126—MR::
54 : Ms00130—cs: 03/10/89 PROPERTY DISPUTE I :MsOO13O—csII
55 U Ms00133—Rsl 01/27/84 08/21/84 I 08/31/84 1 06/20/85 1 08/27/85 IMs0o133—RsI
56 II MS00134—MR 06/08/84 11/19/84 11/30/84 06/21/85 09/17/85 1Ms 00134—MR U
57 Ms00135—Rs: 11/01/84 01/22/86 1 04/11/86 08/11/86 10/07/86 MS00135—RS U
58 U Msool36—vL: 06/08/84 11/25/85 05/08/86 09/24/86 1 10/28/86 I MS00136—VL
59 U MS00137—CS 03/10/89 06/23/89 08/29/89 04/11/90 1 04/18/90 UMSOO137—CSU
60 U MS00138—RS 06/08/84 03/01/85 04/01/85 06/19/85 09/25/85 UMSOO13B—RSU
61 U MS00139 06/08/84 11/07/84 09/29/87 09/07/88 09/30/88 UMSOO139
62 U MSOOI4O—RS 11/01/84 1 12/26/85 02/27/86 09/09/86 10/21/86 1 MSOO14O—RS
63 U MSOO14I-MR 11/01/84 03/05/86 1 04/30/86 1 10/07/86 10/28/86 UMSOO141—MRU
64 MS00143—RS 06/08/84 I 03/25/86 1 05/08/86 07/09/87 1 08/13/87 Mso0143—Rs
65 U MS00145—RS 06/08/84 11/07/84 05/09/86 06/08/87 I 08/05/87 MS00145—RS
66 U MS00147 1 06/08/84 10/15/84 I 10/14/85 09/29/87 1 11/12/87 MS00147
67 U Ms00148—RS 09/05/85 1 11/22/85 1 09/29/87 I 07/21/88 1 09/30/88 1 MsOO148—Rs
68 U MSOO15O—MR 06/08/84 I 11/30/84 12/06/84 1 06/21/85 10/07/85 1 :Ms00150—MR:
69 U !1S00151—RS 03/10/89 1 05/26/89 1 07/31/89 1 09/12/89 1 09/27/89 UMSOOI51—RSU
70 U MS00152 1 10/23/89 1 EXCLUDED ON 1 05/30/90 1 UMS00149-MRU
71 U MS00153—VL 06/26/87 1 08/28/87 I 09/25/87 1 06/06/88 1 07/01/88 1 MsOO153—VL
72 U M 500154—MRI 06/26/87 I 12/24/87 1 12/24/87 06/23/88 : 07/01/88 UMsOO154—MRI:
73 U MS00155—VL 06/26/87 08/28/87 1 09/24/87 1 06/16/88 1 07/01/88 1 1MS00155—VL
74 U MS00156—RS 06/26/87 1 09/24/87 10/30/87 1 08/17/88 I 09/20/88 UMs00156—RSU
75 U NS00157—RS 06/26/87 11/04/87 I 04/01/88 1 10/12/88 1 10/21/88 1 1Ms00157—RSI
76 U MS00159—RS 06/26/87 I 11/20/87 U2)02/28/8 05/13/89 I 07/10/89 UMSOO159—RSU
77 U MSOO161—RS 06/26/87 1 10/02/87 1 10/30/87 1 08/18/88 1 09/30/88 1 MS00161—RSI I
78 U MSOO162—MR 06/26/87 1 11/03/87 I 11/23/87 1 08/18/88 I 09/30/88 1 1MS00162—MR
79 U MS00163—CS 06/26/87 : 12/01/89 : 04/11/90 : 08/09/90 1 08/29/90 11Ms00163—CSU
80 U MS00164—CS 06/26/87 1 08/21/87 1 09/27/87 : 08/18/88 I 09/30/88 HMS00164—CSU
81 U Ms00165 06/26/87 1 09/23/87 I 09/25/87 I I 1 MS00165 11
82 I I MS00166-RS 06/26/87 1 09/23/87 I 09/25/87 1 1 :Ms00166—Rs
83 U MS00167—RS 06/26/87 : 12/24/87 12/24/87 09/17/68 1 09/30/88 1 MS00167—RS 1
84 :: MS00168-VL I 06/26/87 1 08/28/87 : 09/24/87 1 06/16/88 1 07/01/88 1 :Ns00168— VL I 1
85 U Msool7o-Rs: 07/06/87 1 09/21/87 :2)02/28/8: 05/11/89 I 06/03/89 ::Ms00170—Rs::
86 U MSOO171-Rs 03/10/89 05/26/89 07/31/89 1 09/13/89 1 09/27/89 Msoo l7l—Rs:
-------
MONTICELLO VICINITY PROPERTIES
PHASE I PROPERTIES
PROPERTIES INCLUDED PRIOR TO NOVEMBER 29, 1989
(updated 4/1/91)
II I
II I
I
I
I II II
I SI ii
D.O.E.
DOE INCL.
REc. INCL. REA
CONSTRUCTION :: D.O.E. :
I.D. NO.
APPROVAL
ApPENDIX A
TO DOE
START END :: 1.D. NO. ::
II I
II
I
I
I I II
II II
87 : : MSOO174
11/07/88
1 I 1MS00174
88 11 MS00175—MR
11/07/88
12/05/88
06/23/89
09/04/89 1 12/06/89 MSOO175—MRI
89 MS00176 1
11/07/88
1 OWNER
: REFUSAL
I I:Ms00176 ::
90 MS00177—RS
11/07/88
12/05/88
06/23/89
09/04/89 1 12/06/89 HMSO0177-RS
91 MS00178-OT 11/07/88 CONVERTED TO PERIPHERALPROPERTY HMSOO178-oT::
92 MS00179 11/07/88 ICONVERTED 1 TO PERIPHERALPROPERTY MSO0179
93 MSOO18O-CS 11/07/88 CONVERTED TO PERIPHERALPROPERTY MSO0180—CS
94 MSOO18I-OT 11/07/88 1 05/12/89 08/28/89 PERIPHERALPROPERTY IMSO0181—OT
95 MS00183—VL 10/23/89 11/09/89 1 03/28/90 HMs00183—vL::
96 MS00184-VL 10/23/89 1 12/01/89 08/21/PD 1 HMSOO184—VL I
97 NS00185—RS 10/23/89 11/09/89 1 03/08/90 05/21/90 06/14/90 HMSOO185—RS
98 MS00186—MR 10/23/89 12/22/89 1 03/16/90 1 05/21/90 1 06/14/90 :MS00186—MR:I
99 Msool87-Rs: 10/23/89 : 12/08/89 03/15/90 07/12/90 1 08/16/90 HMSOO187—RSH
100 Ms00188—VL: 10/23/89 1 12/08/89 03/20/90 1 07/24/90 09/05/90 HMSO0188—VL
101
MS00189-RS 10/23/89 12/15/89 03/23/90 I 07/12/90 08/23/90 IMsoolS9—Rs:
102
MSOO19I—RS 10/23/89 11/09/89 05/31/90 09/11/90 10/05/90 HMSO0191—RS
103
MS00192—RS 10/23/89 12/15/89 05/30/90 09/11/90 09/13/90 MS00192—RS
104 1
105 1
MS00193—RS 10/23/89 12/08/89 05/25/90 09/11/90 : 09/13/90 1 :MsoO’ 93—Rs:
MS00194—RS 10/23/89 MS00194—RSI
106
MS00195—CS 10/23/89 09/07/90 09/21/90 1 :Ms0 0195—cs
107
MS00196-MR 10/23/89 OWNER REFUSAL HMS00196—MR I
108 MS00197—RSI 10/23/89 OWNER REFUSAL 1 1MS00197—RS
109 1 1 MSOO200—VL 10/23/89 1 11/Og/89 1 04/23/90 : 08/09/90 1 08/29/90 1 :Msoo200—vL: I
110 11 Msoo2ol—Rs: 10/23/89 1 05/08/90 1 06/14/90 08/22/90 1 09/08/90 1 MSO O2 O1—RS 1
111 MS00202—RS 10/23/89 1 05/08/90 1 06/14/90 1 08/21/90 1 09/08/90 1 1MS00202—RS I
112 1 MS00203—VL 10/23/89 1 05/08/90 1 06/14/90 1 08/21/90 1 09/08/90 NS00203—VLI I
113 MS00204—RS 10/23/89 1 05/08/90 1 06/14/90 1 08/21/90 : 09/08/90 ::Msoo2o4—RsI:
114 11 MSOO2O9—RS 10/23/89 1 1 MS00209—RS 1
-------
MONTICELLO VICINITY PROPERTIES
PHASE 2 PROPERTIES
PROPERTIES INCLUDED AFTER NOVEMBER 29, 1989
(updated 4/1/91)
I, I ___________ I ____ _____ I ___ — — _ —_ _ I II _ _________
I II II
D.O.E. DOE INCL. REC. INCL. REA CONSTRUCTION D.O.E.
I.D. NO. APPROVAL APPENDIX A TO DOE START END I D NO ::
1 I I I I I I I I I
II I I UI
1 MS00018 11/05/90 : MS00018
2 MS00024-RS 04/03/90 MS00024—Rs::
3 :: MS00029—VL 01/23/91 : Ms00029—vL:
4 Ms00031 : 02/21/91 1 1 :Ms00031 ::
5 MS00034—RS 06/19/90 1 1 1 1 : :Ms00034—Rs:
6 Ms00038—Rs: 06/19/90 1 1 1 MsOO038—Rs1
7 I MS00044 01/31/91 1 I MS00044 I l
8 1 Ms00045—Rs: 01/23/91 1 MS00045—RS
9 MS0007O—RS 01/25/90 1 07/13/90 08/16/90 1 :Msoo238-vL:
10 11 Ms00081—Rs: 05/30/90 1 03/01/91 :Ms00081—Rs:
11 1 MS000B2—RS I 07/25/90 09/28/90 :Ms 00082—Rs:
12 1 MS00089—RSI 02/26/90 MS00089—RS
13 MS00098—RsI 06/19/90 1 09/28/90 12/12/90 : MS00070—RS
14 I MSOO1O6 1 06/19/90 • I MS 00106
15 MSOO111—CS 05/30/90 1 1 :Msooiu—cs:
16 MSOO112 06/19/90 1 MS00112
17 MS00128—CS 05/30/90 MS00128—CS
18 MSOO131 01/31/91 1 I IMSOO131 11
19 Ms00132—Rs: 01/25/90 08/17/90 09/14/90 1 MS00235—Rs
20 MS00144—RS 01/25/90 : 08/10/90 09/28/90 1 STATE OF UTAH BOUNCE :MS00144—RSH
21 MS00146 : 12/05/89 1MS00146
22 Ms00149—MRI 06/19/90 1 MS00149—MR
23 11 Msool58—vL: 07/25/90 09/28/90 1 1 I MSOO158—VL
24 MSOO1B2—VL 02/26/90 I 1 IMs00182—VL
25 MSOO198—VLI 01/25/90 1 1 : 1Ms 0 0198—VL
26 11 MS00199—RS 07/25/90 09/28/90 1 12/12/90 1 I MS00212—VL I
27 Msoo2O5—Rs: 01/25/90 1 1MS00205—RS
28 Il MS00206 11/26/90 1 HMSOO2O6 I:
29 MS00207 1 01/25/90 1 HMSOO2O7
30 MSOO2II—VL 01/25/90 MS0O21I—VL
31 MS00212—VL 01/25/90 07/20/90 : 08/29/90 ::MSO0132—RS
32 1 MS00213—OT 01/25/90 1 1 1 1 1 :Msoo2 l3—oT
33 :: MS00217—RS 01/25/90 CONTAINS MILL/NON MILL CONT. MATERIAL I :Msoo2I7-Rs:I
34 Il Msoo2l8—VL: 04/03/90 1 MS0O218 ’L
35 MS00224—CS 01/25/90 1 ::NsOO224-CS
36 MsOO225—VL: 07/25/90 : MS00225—VL
37 MS00230—CS 01/25/90 1 09/28/90 : MSU0230—CS
38 1 1 MS00233—MR 01/25/90 : I I 1 :Ms00233—MR I
39 MsO0235—Rs: 01/25/90 1 07/13/90 1 08/27/90 ::MsoO274—Rs::
40 MS0O238—VL 01/25/90 : 05/08/90 : 06/14/90 1 :Ms0 1 061-Rs:
41 1 MS00239—Ofl 02/26/90 1 1 1 MS00239—OT
42 MSOO241—CS1 01/25/90 1 1 : ::Msoo241—cs
43 11 MS00242—VL 01/25/90 1 : 1 1 MSO0242— L
1
-------
MONTICELLO VICINITY PROPERTIES
PHASE 2 PROPERTIES
PROPERTIES INCLUDED AFTER NOVEMBER 29, 1989
(updated 4/1/91)
II I __ _________ I I __________ I ____._____..___.___....___ _II II
II I I _II________—_ II
D.O.E. 1 DOE INCL. REC. INcL.: REA I CONSTRUCTION I D.O.E. H
H I.D. NO. I APPROVAL APPENDIx Al TO DOE 1 START END H I.D. NO. H
II I I I I I II II
I I I I II II
44 H MS00267 1 11/26/90 1 1 1 MS00267
45 H MS00270 1 04/03/90 1 1 HM5002TO ::
46 H Msoo274—Rs: 05/30/90 1 09/07/90 1 09/21/90 1 MS00098—RSH
47 H MS00275 04/03/90 1 MS00275 1
48 MSoo28l—Rs: 07/25/90 09/07/90 I 09/24/90 ISTATE OF UTAH BOUNCE MS00281—RS
49 1 MS00282—RS 04/03/90 1 09/07/90 1 09/24/90 1 11/09/90 1 11/16/90 I 1MS00282—RSI
50 11 MS00283 1 11/26/90 1 I MS00283 I
51 H MS00284 02/21/91 1 1 1 1 1MS00284 1
52 MS00289 1 11/05/90 1 1 1MS00289 1
53 1 MS00293 11/26/90 1 1 I MS00293 I
54 H MSOO3O1 1 11/26/90 1 HMSOO3O1 H
55 H MS00308 1 01/23/91 1 HMSOO3O8
56 1l MS00315 12/11/90 : : I 1MS00315 I
57 H MS00318 I 01/23/91 1 I HM500318 ::
58 H MS00328 : 02/21/91 1 : I MS00328
59 1 MS00329 1 12/11/90 I I IMS00329
60 MS00336 02/26/91 : I 1MS00336 1
61 H MS00345—VLI 06/19/90 : I IMS00345—VL
62 1 MS00347 02/21/91 1 1 1MS00347 1
63 H MS00363 1 03/27/91 1 I MS00363 I
64 H Msoo364—Rs: 06/19/90 09/28/90 1 1 1 1 1MS00364—RS
65 1 MS00365 1 03/27/91 I : 1 I I MS00365
66 II MS00367 1 03/27/91 1 :Msoo367 1
67 H MS00368 1 03/27/91 1 1 I 1 MS00368
68 H MS00369 I 03/27/91 1 1 I I 1MS00369 I
69 11 MS00370 1 03/27/91 1 1 MS00370 I
70 H MS00384 01/31/91 I 1 1 1MS00384
71 H MS00391—VLI 06/19/90 1 1 IMs00391—vLI
72 MS00396—RSI 04/03/90 1 I : MS00396—RS
73 1l MS00397 1 02/21/91 : I 1 MS00397 1
74 H MS00405 1 01/31/91 1 1 HMSOO4O5
75 11 MSOO41I 1 11/26/90 1 : I MSOO411 1
76 H NS00424 1 02/26/91 1 1 1MS00424
77 1l MS00425 02/21/91 1 1 1 MS00425 1
78 11 MS00451—RS 07/25/90 1 1 1 : MS00451—RS
79 H MS00462 I 02/21/91 1 I 1 IMS00462
80 1 MS00476—RS 04/03/90 1 1 : 1 MS0 476-RS
81 H MS00512 1 01/31/91 1 1 1 HMS00512 1
82 11 MS00513 1 01/31/91 1 1 :Ms00513
83 1 MS00520 I 02/26/91 1 I MS00520 1
84 1 MS00523 1 01/31/91 1 1 ‘1S00523
85 H Ms0 0529 01/31/91 : I MS00529 1
86 1: MS00534 1 06/19/90 1 1 1 MS00534 1
-------
MONTICELLO VICINITY PROPERTIES
PHASE 2 PROPERTIES
PROPERTIES INCLUDED AFTER NOVEMBER 29, 1989
(updated 4/1/91)
I, __________ II
IS I I
DOE
II • • • II
I.D. NO.
II
I,
I, SI
II II
MS00535 ::
MS00551
II
Ms00620 ::
MS00685
IS
MS00688
II
MS0074’
MS00748 ::
MS0078 9
— SI
MSO082
‘., SI
MS00831
SI
MS00848
SI
MS00876
SI
MS0087”
MSO0962
I I
MS00981
SI
MS00990
‘I
MS01026
II
MSO IO2’
I IS
Ms01033 SI
I I
II
M5 00199—RS 1
,
I I I
I
S
D.0.E. DOE INCL. REC. INCL.: REA
CONSTRUCTION
I.D. NO. APPROVAL APPENDIX A TO DOE
START END
I I I
,— I I
S I
87
MS00535 01/31/91 1
1
88
: Ms00551 1 01/23/91 I
89
1 MS00620 : 01/31/91
90 MS00685 02/21/91 1
91 I Ms00688 1 02/21/91
92 MS00747 02/21/91 1
93 MS00748 1 02/21/91 1
9 : : MS00782 : 02/21/91
95 MS00826 01/31/91
96 MS00831 1 02/26/91
97 11 MS00848 01/23/91 1
98 MS00876 02/21/91 1 1 -
99 MS00877 02/26/91
100 MS00962 01/31/91
101 I I MS00981 1 02/21/91 1
102 MS00990 1 11/05/90 1
103 I l MSGIO26 I 11/05/90 1 1
104 1 MS01027 11/05/90 1 1
105 Il MS01033 1 11/05/90 1 1 1
106 MSOIO61—RS 07/25/90 : 09/28/90 12/12/90
-------
Mining Waste NPL Site Summary Report
Mouat Industries
Columbus, Montana
U.S. Environmental Protection Agency
Office of Solid Waste
June 21, 1991
FINAL DRAFT
Prepared by:
Science Applications International Corporation
Environmental and Health Sciences Group
7600-A Leesburg Pike
Falls Church, Virginia 22043
I - ’
-------
DISCLAIMER AND ACKNOWLEDGEMENTS
The mention of company or product names is not to be considered an
endorsement by the U.S. Government or by the U.S. Environmental
Protection Agency (EPA). This document was prepared by Science
Applications International Corporation (SAIC) in partial fulfillment of
EPA Contract Number 68-WO-0025, Work Assignment Number 20.
A previous draft of this report was reviewed by Sarah Weinstock of
EPA Region VIII [ (406) 449-5414J, the Remedial Project Manager for
the site, whose comments have been incorporated into the report.
-------
Mining Waste NPL Site Summary Report
MOUAT INDUSTRIES
COLUMBUS, MONTANA
INTRODUCTION
This Site Summary Report for the Mouat Industries is one of a series of reports on mining sites on
the National Priorities List (NPL). The reports have been prepared to support EPA’s mining program
activities. In general, these reports summarize types of environmental damages and associated mining
waste management practices at sites on (or proposed for) the NPL as of February 11, 1991 (56
Federal Re2ister 5598). This summary report is based on information obtained from EPA files and
reports and a review by the EPA Region VIII Remedial Project Manager for the site, Sarah
Weinstock.
SITE OVERVIEW
Mouat Industries formerly operated a sodium dichromate processing facility and stored waste sodium
sulfate containing sodium chromate and dichromate in an uncornained area on the site. Timberweld
Manufacturing Plant, a laminated wood products firm, currently leases the site. The site is located in
the southeast corner of Columbus, Montana (see Figure 1). The land is owned by the City of
Columbus. The Mouat Industries site was proposed for the NPL in October 1984 and added to the
NPL in June 1986.
The site is located in the Yellowstone River floodplain; it is less than 0.6 miles north of the river
channel. The surficial aquifer is an alluvial deposit consisting of dense, poorly sorted gravel bounded
by claystone bedrock at a depth of 20 to 30 feet. Depending on the season, the water table ranges
from 3 to 11 feet below the land surface. The land surface slopes gently to the southeast and ground
water flows southeast in the direction of the Yellowstone River. Both total and hexavalent chromium
have been found in the soil, surface water, and ground water on and/or adjacent to the Mouat
Industries site. The principal constituent of concern is hexavalent chromium (Cr 6 ) (Reference 1,
page 1). Virtually the entire City of Columbus falls within a 1-mile radius of the site. The 1980
census for Columbus recorded a population of 1,431 people (Reference 1, page 10). The ground
water downgradient of the site is not used as a drinking water source. The nearest well believed to be
used for drinking water supply purposes is located approximately 1 mile west of the site. When this
well was tested in 1984, no chromium was found (Reference I, pages 9 and 10). EPA estimates that
within 3 miles of the site, 277 people rely on private wells for drinking water (Reference 3, Section
5).
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Mouat Industries
FIGURE 1. MAP OF MOUAT INDUSTRIES NPL SITE
9 .
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‘0W
LOCM1 MA
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Mining Waste NPL Site Summary Report
The areas east of the site are leased for industrial use. The area south of the site is used by the city
as an airport, and further south is the city’s golf course. A former channel of the Yellowstone River,
now a marshy slough, runs parallel to the present river channel between the airport and the golf
course. To the north of the site are rightof-ways for the railroad and for U.S. Highway 10
(Reference 1, pages 1 through 6; Reference 2, page 16).
To date, a Preliminary Endangerment Assessment has been conducted for the Mouat Industrial Site
(for EPA by Ecology and Environment, Inc.). A Remedial Investigation/Feasibility Study may be
begun in fiscal year 1992.
OPERATING HISTORY
Mouat Industries leased the site from the City of Columbus from the late 1950’s to 1963. The site
was used to process chromium ore (chromite) mined in South Central Montana into a high grade
sodium dichromate for use as a corrosion inhibitor at the Department of Energy’s (DOE’s) Hanford
facility in Washington (Reference 1, page 1).
The chromite ore was calcined with soda ash to form sodium chromate, which was placed in a slurry
and separated from the process residues by filtration. The addition of sulfuric acid to the sodium
chromate produced a liquid sodium dichromate solution, which was concentrated and separated, by
filtration, from sodium sulfate process wastes. This waste contained residual sodium dichromate as
well as sodium chromate (Reference 2, page 14).
According to the EPA’s July 1990 Report to Congress on Soecial Wastes from Mineral Processing ,
only two facilities are currently engaged in sodium dichromate production. These are the Corpus
Christi, Texas, plant operated by American Chrome and Chemicals (ACC) and owned by Harrisons
and Crossfield’s; and the Castle Hayne, North Carolina, plant owned and operated by Occidental
Chemical Corporation. The production process used at these sites is the same as that formerly used at
the Mouat Industries NPL site (Reference 4, page 4-1).
The liquid sodium dichromate was stored in a sealed tank while sodium sulfate was stockpiled for
future processing for the removal of the remaining sodium dichromate. This processing did not take
place while Mouat Industries operated the chromium processing facility (Reference 2, page 14).
Monte Vista Corporation (MVC) assumed control of the facility in 1963. Between 1963 and 1973,
Monte Vista removed from the site the chromium processing plant and an onsite chromium ore
stockpile (Reference 1, page 1). In 1973, Anaconda Minerals Company removed the remaining
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Mouat Industries
process wastes to Butte, Montana, and attempted to treat the contaminated soil (Reference 2, page 15;
Reference 1, page 1). Anaconda’s treatment process consisted of reacting the hexavalent chromium in
the soil with an acid ferrous sulfate solution to reduce precipitate the chromium as trivalent chromium
salts and then stabilize the precipitated chromium in the soil using lime. Anaconda’s lease expired in
1974 (Reference 1, page 1).
In 1975, the City leased the site to the Timberweld Manufacturing Company, a laminated wood
products firm. The new lessee covered the former waste site (i.e., where the sodium chroinate piles
were located) with from 6 inches to 3 feet of gravel. Timberweld uses the site as a storage yard. By
the fall of 1976, the gravel surface showed evidence of yellow mineral deposits characteristic of
sodium chromate (Reference 1, pages 1 and 2). In 1982, EPA estimated the contaminated site
covered 10 acres, and 3.9 tons of chromium was contained in the soil (Reference 3, page 4).
During Timberweld’s early years, waste glues were stored in a 30 by 55-foot waste pit before being
landfarmed on a 1.6-acre area immediately east and south of the site (Reference 2, page 19). Some
phenol surface-water contamination was found during a 1977 study; however, the contaminant of
primary concern is chromium.
SITE CHARACTLKIZATION
The Preliminary Endangerment Assessment (1989) indicates that possible exposure pathways include
ground water, surface water, soil, and air (Reference 1, page 9). Only chromium (total hexavalent)
and antimony were found in soils at concentrations significantly above background, and these are the
contaminants of concern. (The antimony findings were said to be suspect, possibly the result of
interference from high chromium concentrations, so the Endangerment Assessment focused on
chromium).
Chromium was originally released to the soil as a result of spills and sodium dichromate leaching
from the waste piles that were stored onsite. Chromium reached the ground water via infiltration by
precipitation. Chromium (primarily the bexavalent form) has been transported offsite by ground
water and discharged to surface water in the slough and the golf course pond to the south and
southeast of the site, respectively (Reference 1, page 7).
Ground Water
The aquifer of primary concern is located in a permeable quaternary alluvial deposit consisting of
dense, poorly sorted gravel bounded by a claystone bedrock unit at a depth of 20 to 30 feet. The
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Mining Waste NPL Site Summary Report
source of ground water may be a combination of the Yellowstone River and shallow ground water
moving from the uplands areas northwest of the City of Columbus. Sources of the ground water
from the northwest, in turn, may be infiltration of precipitation, seepage from irrigation, and recharge
from Keyser Creek (Reference 1, page 8). Depending on the season, the water table ranges from 3 to
11 feet below the land surface. The land surface slopes gently to the southeast and ground water
flows southeast toward Yellowstone River (Reference 1, page 1).
A site analysis (1983) has shown the bulk of the chromium in contaminant plume to be in the
hexavalent form. The most recent ground-water analyses (1983 and 1985) indicated that the
contaminant plume is continuing to migrate southeast toward the Yellowstone River (Reference 1,
page 7).
The nearest drinking water well is 1 mile west of the site, which is cross-gradient; as of 1984, no
chromium had been detected in samples from this well (Reference 1, page 10). Within a 3-mile
radius of the Mouat Industrial Site are 73 wells serving 277 people (Reference 3, page 5).
Hexavalent chromium concentrations (1977) found in ground-water monitoring wells ranged from less
than 0.05 to 63.5 parts per million (ppm), with higher concentrations (> 1.0 ppm) in downgradient
wells (Reference 1, page 3). During the most recent sampling (1985), hexavalent chromium
concentrations were detected at 2.8 ppm downgradient of the site (Reference 1, page 9). Levels
detected in downgradient wells are considerably higher than the Federal primary drinking water
standard of 50 parts per billion (ppb) for hexavalent chromium, as Table I shows. Nexavalent
chromium concentrations in background wells north of the City were found to be less 0.02 ppm
(Reference 1, page 2).
Surface Water
The Mouat Industrial site is located on the Yellowstone River floodplain approximately 0.6 miles
from the main channel of the river (Reference 1, page 1). A former channel of the Yellowstone
River, now a marshy slough, runs south of the site and parallel to the present river channel between
the airport and the golf course (Reference 1, page 21 and Figure 3).
Hexavalent chromium has been found in surface water downgradient from the Mouat Industries site.
The contaminated ground-water plume is moving southeast and is likely to eventually discharge to the
Yellowstone River (Reference 1, page 21). Grab samples taken from the Yellowstone River above
and below the site (1977) showed total and hexavalent chromium of less than 0.02 and 0.01 ppm
respectively (Reference 2, page 24). Hexavalent chromium was found in surface-water samples taken
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Moual Industries
TABLE 1. HEXAVALENT CHROMIUM (in mg/I) FOR MOUAT
(COLUMBUS, MONTANA)
Ground-Water Analyses
Sample I.D.
1977’
1980’
1983’
1984”
1985”
GWO1
<0.05
<0.01
<0.05
<0.01
<0.02
GW-02
<0.05
<0.01
<0.05
<0.01
<0.02
GW-03
<0.05
<0.01
0.06
<0.01
—
GW-04
6.20
4.60
3.90
3.80
3.80
GW-05
13.20
6.10
4.50
—
—
GW-06
<0.05
—
—
—
—
GW-07
0.35
0.38
0.53
<0.01
—
GW-08
—
—
—
<0.01
—
GW-09
<0.05
<0.01
<0.05
—
—
GW-10
<0.05
<0.01
<0.05
—
—
GW-11
<0.05
—
<0.05
—
—
GW-12
<0.05
—
<0.05
—
—
GW-13
—
<0.01
<0.05
—
—
GW-14
1.30
—
—
—
—
GW-15
8.10
6.20
3.80
<0.01
—
GW-16
0.48
0.30
0.42
0.60
1.20
GW-17
<0.05
<0.01
—
—
—
GW-18
<0.05
<0.01
—
—
—
GW-19
63.50
—
—
—
—
sSample locations shown in Figure 2
s*samplmg locations shown in Figure 3
—No sample
— Exact location unknown
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Mining Waste NPL Site Summary Report
TABLE 1. IIEXAVALENT CHROMIUM (In mg/I) FOR MOUAT
(COLUMBUS, MONTANA) (Continued)
Sample I.D.
Slough
Location
Surface Analyses
1977’
1980’
1983”
1984”
1985”
SW-OI
Dump
—
—
—
<0.01
<0.02
SW-02
Golf course
—
—
—
0.23
—
SW-03
Junkyard
—
—
—
<0.01
—
SW-04
Wegner
Ranch
—
—
—
<0.01
<0.02
SW-05
Northwest
of Mouat
-
—
-
-
0.54
SW-06
West of
landfill
—
—
—
—
0.14
SW-07
Golf course
pond
—
0.59
0.50
—
—
— Yellowstone R.
Upstream
<0.01
—
—
—
—
—Yellowstone R.
Downstream
<0.01
—
—
-
-
‘Sampling locations shown in Figure 2
“Sampling locations shown in Figure 3
—No sample
— Exact location unknown
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Mouat Industries
from the golf course pond in 1980 and 1983 (500 to 590 ppb) and in slough samples (1985) south of
the site (140 to 540 ppb) (Reference 1, page 21). Table 1 shows results of surface-water analyses for
hexavalent chromium. In 1984, cattle died on the Wegner property, 1.5 miles east of the Mouat
Industries site. Water samples taken from the slough 1 mile west of the site of the cattle deaths had a
hexavalent chromium concentration of 100 ppb (Reference 1, page 21). According to EPA, tissue
samples taken from the dead animals were accidentally destroyed before testing, and the cause of
death was never determined.
Qil
In April 1988, EPA’s Emergency Response Branch collected surface soil samples and analyzed the
samples for hazardous substances, including total chromium but not hexavalent chromium (Reference
1, page 2). Total chromium concentrations at the location of the former waste pile were found to
range from 9,000 to 15,900 ppm (Reference I, page 5). In November 1988, EPA’s Technical
Assistance Team’s contractor collected 25 surface and subsurface soil samples and tested them for
both total and hexavalent chromium (Reference I, page 2). Concentrations of total chromium in
surface and subsurface samples ranged from 66 to 3,100 ppm and 35 to 3,100 ppm, respectively.
Concentrations of hexavalent chromium in surface and subsurface samples from onsite ranged from
1.2 to 630 ppm and 1.3 to 880 ppm, respectively (Reference 1, page 6).
Analyses of the November 1988 soil samples indicated that in most of the surface samples, hexavalent
chromium accounted for very little of the total chromium, the largest fraction being about 20 percent
in one sample. Substantial concentrations of chromium still remain in the soil, particularly in
Timberwelds stockyard (Reference 1, page 13). This contamination can serve as a source for
releases both to ground water and air.
Although air monitoring was not conducted during the Preliminary Endangerment Assessment, site-
derived particulate concentrations were estimated using methodologies described in the EPA manual
Rapid Assessment of Exposure to Particulate Emissions from Surface Contamination Sites (Reference
1, Appendix B).
The site-derived airborne particulate concentration was obtained for the Mouat Industrial site by
separately estimating the particulate concentrations that would result from simple wind erosion and
from resuspension by vehicular traffic, then combining the two estimates (Reference 1, page 28).
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Mining Waste NPL Site Summary Report
Total site-derived airborne particulates (PM 10 ) were estimated to be 0.06355 milligrams per cubic
meter (mg/rn 3 ) (Reference 1, page 32).
ENVIRONMENTAL DAMAGES AND RISKS
Even though antimony and trivalent chromium are also present at the site, hexavalent chromium is the
only carcinogen, and it is only carcinogenic through inhalation. The Preliminary Endangerment
Assessment concluded that potential exposure pathways include: (1) direct contact with surface
contaminants, both on and off ite, by workers and members of the general public (this includes direct
dermal contact, ingestion, and inhalation); (2) consumption of contaminated ground or surface water
as drinking water; (3) inhalation of contaminated aerosol mists generated by using contaminated
ground or surface water in spray irrigation applications; and (4) direct dermal contact and ingestion of
contaminants while swimming, bathing, or wading in contaminated surface waters (Reference 1, page
9). Only direct contact with onsite surface contaminants, including inhalation, was considered likely
to result in exposures that could pose a health risk (Reference 1, page 9).
Tunberweld employees, who would be the maximally exposed individuals, were evaluated (in the
Preliminary Endangerment Assessment) and were not expected to experience any adverse
noncarcinogenic health effects from exposure to site contaminants (Reference 1, page 17).
The potential for carcinogenic effects to onsite workers from hexavalent chromium (via inhalation
exposure, the only route found to be carcinogenic) was evaluated by calculating the worker’s excess
lifetime cancer risk. The results indicate the carcinogenic risk for the average exposure scenario is
5.13 x 106 (1 in 200,000), and for the worst case scenario, it is 4.67 x 10 (1 in 21,000) (Reference
I, page 19). (It should be noted that a fence has been constructed around the area of greatest
contamination, which would reduce or eliminate inhalation and other direct exposure by onsite
workers).
The impact of the Mouat Industries site on nonhuman species has apparently not been assessed.
However, ambient water quality criteria for the protection of fresh water aquatic life is 16 ppb for
acute exposure and 11 ppb for chronic exposure to hexavalent chromium. The chronic value for
Rainbow and Brook Trout is 265 ppb. In addition, five daphnid species have chronic toxicity values
ranging from <2.5 to 40 ppb. In comparison, the drinking water Maximum Contaminant Level
(MCL) for humans is 50 ppb for hexavalent chromium (Reference 1, page 21). See Table I for
concentrations of hexavalent chromium in surface water affected by the site.
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Mouat Industries
REMEDIAL ACTIONS AND COSTS
Remedial activities conducted as of December 1990 consist of erecting a chain link fence around the
site of the former waste pile. The enclosed area is approximately 100 by 100 feet and was fenced in
1990. In addition, monitoring wells that were drilled in the 1970’s were capped during the summer
of 1990. Information was not available concerning the estimated cost of these emergency remedial
activities.
CURRENT STATUS
According to EPA Region VIII, a Remedial Investigation/Feasibility Study has not been initiated for
the Mouat Industries site. EPA anticipates beginning the Remedial Investigation in fiscal year 1992.
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Mining Waste NPL Site Summary Report
REFERENCES
1. Preliminary Endangerment Assessment for Mouat Industries Sites; Prepared for EPA by Ecology
and Environment, Inc.; Undated.
2. Water Quality Study for Middle Yellowstone Areawide Wastewater Management Program;
Prepared for Mid-Yellowstone Areawide Planning Organization by HKM Associates; March
1977.
3. Documentation Records for Hazard Ranking System, Mouat Industries Site; Unpublished, EPA
Region VIII; Undated.
4. Report to Congress on Special Wastes From Mineral Processing; EPA; July 1990.
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Mouat Industries
BIBLIOGRAPHY
EPA Region VIII. Documentation Records for Hazard Ranking System, Mouat Industries Site.
June 28, 1982.
EPA. Hazardous Ranking System Summary Description. April 16, 1984.
Prepared for EPA by Ecology and Environment, Inc. Preliminary Endangerment Assessment for
Mouat Industries Site. Undated.
EPA. Draft Press Release. Undated.
EPA. Fact Sheet. June 1987.
EPA. Hazardous Waste Site Identification and Preliminary Assessment. September 20, 1979.
EPA. Potential Hazardous Waste Site Inspection Report. Undated.
HKM. Water Quality Study for Middle Yellowstone Areawide Management Program. March 1977.
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Mouat Industries Mining Waste NPL Site Summary Report
Reference 1
Excerpts From the Preliminary Endangerment Assessment
for Mouat Industries Sites; Prepared for EPA by
Ecology and Environment, Inc.; Undated
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DRAFT
zwrRODUCrIoN
1.1 Sit. Description
The Mouat facility site is located north of the Columbus airport and
just south of Columbus, Montana (Stilivatet County), in the southv.st
1/4 of the northvest 1/4, Section 27, Tovnship 25, Range 20E of the
Columbus East Quadrangle. The site location is shovn in Pi ure 1. The
tovn of Columbus has ovnd the site since 1933. The site is currently
occupied by the Timberveld Manufacturing facility (manufactures
luinated vood products) and a chromium ore (chromite) stockpile ovned
by the American Metallurgy Corporation. South of the airport are a
number of private residences and a golf course.
The site is located on the floodplain of the Yellovetone River and is
less than 0.6 miles north of the present river channel. The surf icial
aquifer is located in permeable Quaternary alluvial deposits consisting
of dense, poorly sorted gravel and bounded by a cisystone bedrock unit
at a depth of 20 to 30 test. Depending on location and season, the,
vater table ranges betvesn 3 to 11 feet belov the Land surface. The
land surface slopes gently to the southeast. Groundvater f love in a
southeutvard direction tovard the Tellovstone River.
1.2 Site History
Prom the late 1950s to the early 1960s, Mouat Industries operated a
processing plant that converted chramite (mined fro. the Stillvater
couples in south central Montana) to a high-grade sodium dichro.ate.
The sodium d lchromate vu purchased by General Electric for use at the
Hanford Project, Richland, Vuhington, as a corrosion inhibitor.
The Nouat plant produced, along vith the high—pads sodium diebromate, a
sodium sulfate vaste vhich contained sodium chrosate and sodium
dichro.ate. Hexavalent chromium, (VI), leached from the sodium
sulfate vaste piles into the surrounding soils and groundvater. Another
source for the (VI) contamination came from occasional dichrosate
spills (PRP Report, October 11, 1985) that occurred during operation of
the facility.
Control of the plant vms transferred from Nouat Industries to the Monte
Vista Corporation (NyC) in 1963. The chromium processing plant and an
on-site chromium ore stockpile vere removed by N yC from the site betveen
1963 and 1973. In 1973, Anaconda Minerals Company removed the remaining
sodium chronte and sodium dichro.ate process vutes to Eutte, Montana,
and attempted to treat the contaminated soil in exchange for certain
.ineral rights in the Stilivater Complex. Their tr.ataent process
consisted of reacting the (VI) in the soil vith an acid ferrous
sulfate solution to reduce the chromium to the nontoxic trivalent stat.,
precipitate it, and then stabilize it in the soil using lime. Anaconda
Minerals Company’s lease expired in 1974.
In early 1975, the nev leases, Timberveld Manufacturing Company, covered
the site vhere the sodium chrosate vute piles resided vith a layer of
gravel and is currently using the area for a storage yard. In the fall
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.,f 1976, the gravel surface shoved evidence of yellov ulneral deposits
characteristic of sodium chro.ate. The Nouat site is currently listed
on the NP ! ..
.3 History of Investigative Activities
The pre-remedlal program of EPA conducted a Preli.inary Assessment (PA)
of the Houat Industries site on June 27, 1979. The PA noted several
potential hazards including contamination or Lhreatened contamination of
soil, surface vater, and groundvater at the site. EPA folloved this
information up vith a Site Inspection (SI) in August 1980. The SI
report references data collected in 1977 indicating (VI) contamination
of the groundvater and CR(VI) contamination of the soil.
In September 1980 EPA collected S soil samples, 13 groundvater samples,
and 3 surface vater samples. Analysis indicated elevated levels of both
Cr(VI) and total chromium. Subsequently, a letter vu sent by EPA to
the Mayor of Columbus stating that 6 of the 18 .onitoring veils sampled
exceeded the recommended drinking vater standards for chromium.. It vas
recommended that the contaminated groundvater not be used for human or
animal consumption.
EPA conducted further soil and groundvater sampling at the site in
August 1983, July 1984, and April 1983. The results 0 f these
investigations are summarized in tables discussed in Section 1.4.
In 1986 EPA investigated the site u a candidate for a removal action.
Rovever, it vas determined that the site did not meet the criteria for a
removal action at that time (Weston 1986). The finding via due in part
to the absence of data or hexavalent chromium concentrations in the soil
and sediment.
In April 1988, EPA’s Emergency Response Branch collected additional
surface soil samples of opportunity vhich vere analyzed for hazardous
substance list metals, including total chromium but not hexavaient
chromium. On November 23, 1988, EPA’s TAT contractor collected 23
surface and subsurface soil samples vhich vere analyzed for both total
and hexavalent chromium. On this occasion the samples collected from
the former location of the sodium sulfate vaate pile on the site vere
collected in a systematic fuhion in order to obtain representative
results. The result for these sampling activities are also summarized
in tables discussed in Section 1.4.
1.4 Contaminants Pound At The Site
Both total and hexavalent chromium have been found in the soil, surface
vater, and groundvater on and/or adjacent to the Monat Industrial site.
The groundvater and surface vater results are given in Table 1. The
locations from vhich these samples vere obtained are shovn in Figures 2
and 3. In addition, the IRS suary report (EPA 1984) notes that tvo
veils (R. B. Fradet Wells 01 sad 02) located northvest (upgradient) of
the site vers fare (less than 0.01 and 0.02 uig/L) of hezavalent
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TABLE 1
AVAL ,r oiaiis ( /L)
NOUAT, COLUMBUS NOI1 ANA
GROUNDVATER ANALYSES
Saapl. I.D. j977* 1980* 1983* 1984** 1985**
Gv-01 <0.05 <0.01 <0.05 (0.01 (0.02
CV—02 <0.05 (0.01 <0.05 (0.01 (0.02
GV-03 (0.05 <0.01 0.06 (0.01 --
GV—04 6.20 4.60 3.90 3.80 3.80
GV-05 13.20 6.10 4.50 —- --
CV-06 <0.05 -- -- -— --
cv-07 0.35 0.38 0.53 <0.01 --
GV-08 —- -- —— <0.01 --
GV-09 <0.05 (0.01 <0.05 —- --
GV-10 <0.05 (0.01 <0.05 -— --
Gv-11 <0.05 -- <0.05 —- -—
GV .-12 <0.05 —— <0.05 ——
CV—13 —— (0.01 <0.05 —— —
GV—14 1.30 —— —— — — --
GV—15 8.10 6.20 3.80 (0.01 ——
GV—16 0.48 0.30 0.42 0.60 1.20
Gv-17 <0.05 (0.01 -— —— -—
G i l -lB <0.05 <0.01 — — --
GV—19 63.50 —— —— —— -—
Sampi. Slough SURFACE ANALYSIS
I.D. Location 1917* 1980* 1983* 1984** 1985**
sV-O1 Du.p - - —— -— <0.01 (0.02
SV-02 Golf cours. —— —— -— 0.23 -—
SV-03 Junkyard -— —— -- (0.01 - —
SV-04 V.gn.r Ranch —— —— — (0.01 (0.02
SV-05 Northvest of Nouat —- —— —— —— 0.54
SV—06 Whit of landfill —— —— —— —— 0.14
SV—07 (golf course pond) —— 0.59 0.50 —— -—
Tellovstone R. (upstrsa.) <0.01 —— —— —— -—
yellovstone B. (dovuatrean) <0.01 —— —— —— -—
* Sanpling locations shovn in Figure 2
** Supling locations ahovn in Figure 3
—- No sanple
- Exact location unknovn
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TAILI 2
ANALT!ICAL USULTS (a) P01 SOIL S&IIP1
NOUAT INDUSTRIES
COUIECL’ED IT EPA 3
April 1988
Chromium (total) Antimony
Sample ( mg/kg) ( mg/kg )
Zone 1 — Ti.bsrvsld stockyard (b):
N8L876 15,900 42.1 N
N8L877 12,600 34.3 N
M8L878 15,700 46.8 N
N8L879 9,000 27.1 N
Zone 2 — Existing chrome ore stockpile: -
N0L880 11,300 33.8 N
M8L881 10,900 27.1 N
Zone 3 — 0ff—site north of railroad:
N 8L882 57 <6.4 UN
N8L883 49 <6.3 UN
(a) - Results significantly abov, natural background levels (Shacklette
end Boerngen 1984).
(b) - Former location of dichroaate manufacturing process vests pile.
N — Spik. recovery not vithin control limits.
U — Analyte not detected at indicated detection limit.
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YULE 3
C 0IIIUN AMLYTICAL RESULTS (g/kg dry vsigbt)
HOUAT INDUSTRIES
TDD 1T08-8810-067
Sample Number Sa.ple Location Chromium Chromium (VI) Z Solids
NSV—01 rinsate* 5 U MR N E
MSV—02 38-07 surface 510 6.0 J 90.3
HSV—03 88—07 4 ft. 51 1.8 J 76.9
MSV-04 38-07 9 ft. 55 1.9 J 76.4
WSV..05 38-06 surface 850 1.8 .1 87.1
MSV—06 38-06 4—6 ft. 45 1.3 UJ 77.1
NSV—07 38—06 10 ft. 43 1.3 UJ 76.9
NSV-08 38-08 surface 66 1.2 UJ 84.1
PISV-09 38-08 5 ft. 42 1.3 UJ 78.3
MSV-10 38—09 5 ft. 35 1.3 U 78.9
NSV-11 31-09 surface 1100 2.2 86.5
NSV-12 38-03 surface 3100 630 89.0
NSV—13 38—03 3.5—4.5 ft. 3100 880 82.1
NSV-14 38—03 8—9 ft. 140 3.34 N 78.2
NSV-15 NSO—15 32 1.0 1W 93.5
MSV-16 MSO—16 41 1.2 UN 84.1
NSV-17 NSO —17 34 1.1 UN 92.8
NSV-18 NS O—18 39 1.1 UN 90.5
NSV—19 MSO—19 31 1.2 UN 85.3
NS’V-20 NS O-20 580 4.2 N 90.1
MSV-21 NS O—21 69 1.0 1W 99.6
NSV—22 NSO—22 62 1.0 UN 97.3
MSV-23 MS0—23 40 1.1 UN 89.9
NSV—24 MSO—24 56 1.0 UN 97.3
NSV—25 NS O—25 19 1.2 UN 86.2
a — Results in ugiL
U - Analyzed for but not detected
MR - Not requested
J - Value is estimated
N - Sa.ple spike recovery is not vithln control limits
6
‘p
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1.5 Contaiinants of Concern
The only eonta.inaflts found at the Houat Industries site at
concentrations significantly above typical natural concentrations were
chromium and antimony. Thus, chromiu. and antimony were selected u the
contaminants of concern at this site. As discussed in Section 1.4, the
antimony results may be suspect in that they may represent false
positive results due to interference from the high chromium
concentrations present. Encause of the uncertainty surrounding the
antimony results, the potential effects of antimony at the Nouat
Industries site on human health and the environment viii not be
discussed in detail in the balance of this report. lovever, a
toxicological profile has been included for antimony and it was included
in the Endangerment Assessment calculations. Since the apparent
occurrence of antimony on the site was highly correlated vith the
chromiu . contaminations found, any remedial measures adopted to address
the chromium contamination would also address any antimony that might
actually be present.
Eoth trivalent (Cr 3 ) and hexavalent (Cr”) chromium have been found on
sit.. The h.xavalent form is much more toxic mad mobil, than the
trivalent form; however, both forms viii be considered in the
Endangerment Assessment.
1.6 Contaminant Releases To The Environment
Chromium was originally released to the environment as a result of
sodium dichromate leaching fro. the by product sodium sulfate vaste pile
stored on site, and as a result of various spills that occurred during
plant operations (EPA 1984). The chromium v ia initially released to the
soil on site. It vu then carried to the groundwater by precipitation
infiltrating the soil. It has sine, been transported off—site by the
groundwater and been discharged to surface water in the slough and the
golf course pond south and southeast of the site. Site analyses have
shown (EPA 1983) that the bulk of the chromiu, in the groundwater plum.
is in the h.xavalent form, which would be expected since the hexavalent
form is •uch more water soluble mad mobile than the trivalent form.
Analyses of the soil samples collected in November 1988 indicate that
substantial concentrations of hexavalent chromium still remain in the
site soils. This contamination can serve u a source of on going
releases to the groundwater and the air. The most recent groundwater
analyses (1983 to 1985) indicated that the hexaval.nt chromium
concentration was Increasing in NV16 located down gradient from the site
(see Table 1). This indicates that the groundwater plume s continuing
to migrate southeast vaxd toward the Tellovstone River.
7
71/
-------
c 15
2.0 ENVIRONMENTAL PATE AND TRANSPORT
2.1 Site Specific Factors Affecting Transport
2.1.1 Geology
The geological formation of primary interest in the study aria is the
alluvial gravels of Quaternary Age. No data is available on the
character and thickness of the alluvial deposits other than that
obtained from the excavations for observation veils constructed for the
study of the Nouat Industries site.
The alluvial and terrace gravels consist of moderately dense, to dense,
poorly sorted gravel ranging In size ho. cobbles to boulders.
Thickness of the alluvial deposits in the study area are not definitely
known, as there are no drillers logs available for water veils in the
Columbus area. Thickness of the gravel is believed to be greater than
10 feet as bedrock was not encountered in any of the excavations for
observation veils. Depth to bedrock or thickness of gravel in the study
area is estimated to be betveen 20 and 30 feet. Bedrock vas encobntered
at 21 to 22 feet in the vicinity of the city dump southeast of the Nouat
Industries site during excavations for observation veils in 1984 CE 5 E
1984). Descriptions of materials encountered in constructing the
observation veils for the Mouat Industries site studies are given in
reports by 0KM Associates (1977) and E 5 E (1984).
2.1.2 Hydrogeology and Hydrology
The groundwater of main interest in the study area is that occurring
under water tale conditions in the alluvial deposits. Sources of
groundwater in these gravels are believed to be a combination of the
Yellovstone River and shallow groundwater moving tovards th. river from
upland areas northwest of the study area. Possible sources of
groundvater moving fro. the northwest could be the infiltration of
precipitation, seepage from irrigation operations and recharge from
Keyser Creek which enters the Teliovstone River approximately 0.5 miles
vest of Columbus (0KM 1977).
Depth to groundwater in the alluvial gravels vi thin the study area
ranges between 3 and 11 feet below the land surface depending on
location. Depth to groundwater at the location of the old sodium
dichromate pile in the Timberweld storage yard was 7.83 feet below the
land surface (V.19) in 1977 ( 0KM 1977). Vater level data collected in
January and February 1977 indicated that the Yellowstone River was a
gaining stream in the reach that passes through the study area t that
tine. It appears, however, that seasonal variations in groundwater
levels could be considerable due to the influence of the Yellowstone
River during high runoff periods (0KM 1977).
2.1.3 Climatology
Historical meteorological data is not available for Columbus, Montana,
but it is available for Billings, Montana, vhich is located about 40
miles east of Columbus and vould be expected to have similar weather
8
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conditions. The annual average temperature in Billings is 46.7’ P with
normal daily lows and highs ranging from 11.8 to 29.9’ P in January and
72.3 and 86.6’ F in July. Billings receives an average of 15 inches of
precipitation annual and receives at least 0.01 inches of precipitation
on 96 days of the year. The mean vind speed is 11.3 mph and the
prevailing vind direction was from the southwest through 1963, however,
in 1987, it was from the northeast (NOAA 1987).
2.2 Contaminant Specific Fate and Transport
Information on the environmental fate and transport of chromium and
antimony is included in the toxicological profiles In Appendix A.
3.0 EXPOSURE EVALUATION
3.1 Potential Pathways of Exposure
Potential pathways of exposure include the following:
Direct contact with surface contaminants on—site by workers
employed on the site and by members of the general population who
might enter the site for miscellaneous purposes. This pathvay
includes direct der.al contact with contaminants, ingestion of
contaminants as a result of hand—to-mouth transport and
inhalation of contaminants carried by airborne particulate.
on—site.
Direct contact by members of the general population vith surface
contaminants off—site that vere transported off—site on airborne
part iculates as a result of wind erosion or vehicular
resuspension of surface soils.
Consumption of contaminated ground or surface water as drinking
water.
• Inhalation of contaminated aerosol mists generated by using
contaminated ground or surface water in spray irrigation
applications by irrigation workers or members of the general
public.
Direct derual contact and incidental ingestion of contaminants
vhile sviing, bathing, or vading in contaminated surface waters
in the slough or the golf course pond.
Of these potential pathways, only direct contact with contaminants
on—site appears likely to result in exposures that could pose a health
risk. Surface contamination has been found in the Timberveld stockyard,
which occupies the former location of the sodium sulfate waste pile, and
Timberveld employees regularly work in the area. Direct contact which
contaminants have been transported off—site is possible, hovever,
chromium has not been found in surface soils off-site and concentrations
significantly above naturally occurring concentrations.
Nexavalent chromium has been found in groundwater down gradient from the
site at 3.8 mg/L. (see Table 1), which is 76 times the federal primary
drinking water standard for hexachro.e, during the most recent round of
9
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sasp]ing on 1985. Fortunately the groundwater down gradient I roe the
site is not used as a drinking vater source. The nearest veil that is
believed to be used for drinking water supply purposes (SC! 1 ) 1989) is
located about 1 nile vest of this site at the Grit tel tarn (referred to
as the Al Vegner far. in earlier saupling reports). This veil is
located across gradient fro. the apparent southeasterly path of the
chrone plus.. When this veil was tested in 1984, no chro.iua was found.
Inhalation of aerosol •ists generated by spray irrigation of lawns or
crops is a potential concern particularly since hexavalent chroeiu. is
considered to be carcinogenic via the inhalation route. However, this
pathway does not appear to pose a .ajor concern because the contaninated
groundwater is not believed to be used extensively for irrigation (sc
1989) and hu.an exposure to such .ists would probably not be substantial
in any case.
None of the conta.inated surface waters are known to be co..only used
for svianing or bathing (SCDH 1989) and any incidental contact, such as
retrieving golf balls, is not likely to result in a significant
exposure.
3.2 Potentially Exposed Population
Populations potentially exposed by specific exposure pathways having
been Identified in Section 3.1 along vith the potential pathways of
exposure. The ERS sury description for the site (EPA 1984) esti.ated
that about 1100 people live within one •ile of the site. The site is
located at the southeast corner of the town of Coiu.bus end virtually
the entire town falls within a one •iie radius of the site. The final
1980 census for Colunbus vu 1431 (Rand McNally 1988).
3.3 Levels of Exposure
Direct contact with contaminants on—site Is the exposure scenario that
alnost certainly vould result in the greatest potential exposure to, and
hence, the greatest risks f roe site contaminants. The other potential
exposure pathvays either do not appear to be cosplete at this ti.e or
would almost certainly result in substantially low levels of exposure
and will not be evaluated in detail at this ti..
Tvo es t mates of the level of exposure have been prepared, the probable
average exposure and the plausible worst cue. The usu.pt lons used in
esti.ating the potential exposure to yorkers employed on-site are
su..arised in Table 4. The average on-site worker exposure scenario
assumes 6 hours of exposure per day (8 hours April to October, 4 hours
Nove.ber to March), 5 days per week, 50 weeks per year for 7 years • The
plausible worst case scenario assunes 8 hours exposure per day (year
around), 5 days per week, 50 veek.s per year for 30 years. Thu
concentrations of site derived fugitive dust in the air vu estimated
using .ethods f roe the EPA Manual Rapid Assessment of Exposure to
Particular Enissions from surface contamination sites which are
described in Appendix B (Cowherd 1985).
10
-------
Antimony concentrations in surface soils vere measures only in the grab
sampies collected by the EPA IRE team f roe obviously stained areas of
the site in April 1988. Since theae are the only values available for
anti.ony, the average concentration found in the samples taken in
Ti.berveld’s stockyard viii be scenarios. Total chromium concentrations
in surface soils vere measured in both the April 1988 samples and the
representative samples collected by the EPA TAT team in November 198$.
Four of the April samples (Table MEL 876—79) and one of the November
samples (Table 3 - NS0-12) vere taken inside the stockyard. The
analytical results fro. the November samples indicated that in most of
the surface samples, hexavalenc chromium accounted for very little of
the total chromium, the largest fraction being about 202 in one sample.
The trivalent chro.ium concentrations vere therefore assumed to be
essentially equivalent to the total chrome values and the average of the
one November and Four April samples taken inside the stockyard vere used
for both the average and vorat case exposure estimates. lexavalent
chromium vu measured only in the samples collected in November 1988 and
only one of these samples, MSO—12, vms collected inside the Timbervelda
stockyard. The h.xavalent chromium concentration from this one sample
vms used for both the average and vors t case exposure estimates:
Lifetime average daily doses (LADO.) vere calculated for each route of
exposure using the folloving equations.
Dermal exposure:
(C )(SAE)(CSS)(?A)(EP)
ADD. __________________
(EV) (LI)
Inhalation exposure:
(C )(SDAPC)(IR)(DED)(EP)
LADD. _________________
( IV) (LI)
Oral exposure:
(C )(SAI)( SS)(FA)(IP)
ADD. _________________
(IV)(1 )
The symbols used in these equations are defined as follows:
route specific average daily doses
,0,
SDAPC site derived airborne particulatea concentration (PK 0 )
IV body weight
C 5 contaminant concentrations in the soil
13
97 ¶
-------
chro.iua is classified U a floncareinogen by th. oral and deraal routes
of exposur, but as a hulan carcinogen by the inhalation route of
exposure.
The toxicological properties of anti,ony and chrosiuc are sussarised in
toxicological profiles in Appendix A.
5.0 RiSk AND IHPAcr EVALUATION
5.1 Rusan Resith Effects
The potential for noncareinogenic husan health ef fects arising trot
on—site yorker exposure to site conta.inants vu evaluated by co.partng
the lifetise average daily dose estisated in section 3.3 to the
acceptable d.ily intakes or reference doses ( MD .) for the contasinants
as described in Section 4.0. The results of this coeparison are
susaarized in Table 6. The huard indices for both the average and
plausible vorst case scenarios are buoy 1 for all of the contaniftants.
This indicates that the on—site yorkers, who are expected to be the
saxisal exposed individuals at this site, vould not be expected to
experience any adverse noncarcinegenie health effects f roe exposure to
site contasinants.
17
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c carcinogenic effects arising from on—site yorker
valent chroeius (the only potential carcinogen found on
ated by calculating the yorker’s excess lifetim, cancer
j done by multiplying the average and vent case lifetime
doses via the inhalation route (the only route by vhich
:o.iua has been found to be carcinogenic by the
potency factor for hexa chrome via the inhalation route.
vhfch are summarized in Table 7, indicate chat the
risk corrgsponding to the average on—site yorker exposure
5.13 I 10 or about 1 in 200,000 and h. risk corresponding
gsible vonst case scenario is 4.67 2 10 or about 1 In
esti.at.d carcinogenic risks are greater then the 12 io .6 risk
pos.d by EPA (1988) as a ‘point of departure’ for selecting an
1. risk level at hazardous vaste sites, it appear, that re.ed al
a that vould reduce the estimated risk to no more than 1 1 10
be considered. In order to reduce he estimated avenge and
case on—site yorker risks to 1 I 10 the soil concentrations of
Lien c chro.iu• vould need to be reduced to no more than 123 and
mg/kg, respectively.
oted above the on—site yorkers are expected to be the maximally 100
s.d individuals at this site. Therefore, any remedial measures that
id adequately protect the health of these yorkers vould also 67
.quac.iy protect the health of the general public. Members of the
neral population that sight enter the site for miscellaneous purposes
ould experience much lover exposures because the aao at of time they
. ould reasonably be expected to spend on—site vould be •uch lass
19
rho
Si
(‘iotth re
6, “it
“St
e
-------
Finally, if or vhen the containated groundvater begins to discharge to
the Tellovstone River it could have adverse impacts on the sport fishery
supported by the river as discussed in Section 5.2. The fishery lien
important econo.ic and recreational resource for the area (S DI 1989).
Thus, adverse impacts on the fishery vould also constitute and adverse
impact on public velfare.
6.0 CONCLUSIONS
Potential adverse effects of the contamination on and off he Mouat
Industries site on human health, the environment and the public velfare
have been described and docusented in this Preliminary Endangerment
Assessment. The potential effect of greatest and most iediate concern
is the potential excess cancer risk posed by the surface contamination
found in the Timberveld stockyard to the vor ers employed at that site.
Since the esti.ated riska exceed the 1 I l0 level, vhich EPA has
proposed as a ‘point of departure’ for selecting acceptable risk levels
for hazardous vute sizes, remedial egsures that vould reduce the
estimated risk to no more than 1 I 10 should be considered. The soil
contamination at that site appears to be an on going source of
groundvater contamination u yell as a source of direct contact exposure
to the yorkers, therefore, remedial measures that address both the
exposure to yorkers and the release to the groundvarer vould be
preferred.
23
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ESTIMATION 0? SIT3- IV £flI PARTI IL&TI {0P(IIftUTIONS
The site—derived airborne particulate concentrations vere estimated
using •.thodologi.s described in the EPA manual entitled rapid
assessment of exposure to particulate emissions from surface
contamination sites (Covherd it ml 1983). These methodologies have been
used recently by the EPA (1988) for estimating exposures to dioxins via
inhalation of contaminated airborn, soil particles.
For the Moust Industries site, the site—derived airborne particulate
concentration vu obtained by separately estimating the particulate
concentrations that would result from simple vied erosion and from
resuspension by vehicular traffic then summing the tvo estimates. In
both cues the estimated airborne particulate concentration is the
result of a two step process. The first step is estimating the
particulate emission rate that results from wind erosion or vehicular
resuspension. For wind erosion this is expressed u the mus of
particulates emitted from a unit area of soil and for vehicular
resuspension it is given as the .us emitted per vehicle—kilometer
driven. The second step is calculating the air concentration that would
result assuming the estimated mass of particulates emitted is
distributed throughout an appropriate air volume selected to take into
account the site size, the mean vind speed at th. site end the breathing
zone of potential human receptors.
Since the site—derived airborne particulate concentration estimate would
be used in an on—site worker exposure scenario the source area via
assumed to be the Timberveld stockyard vhich vu assumed to be
approximately 30 meters square. The vehicle responsible for
resuspending soil particulates vas assumed to be a fork lift type
vehicle which 100 transits of the stockyard per 8 hour days.
28
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TAILI 1-1
PROr TUS *110 PA11AIIZTRS U 111 ISTDIAtwa VU
SITR—DUIV £ 111010 1 5 PARTI JLAT1 . dI I ATI0N
Property or Paraneter
Site Dimensions (approximate)
WIND UOSION NOOSLs
Surface Character
Nonerodible Element
Vegetative Cover
Mean Wind Speed (U 1 )
Threshold Frictional Velocity (U* )
Terrain Roughness Height (2 )
Ut /Uat
Threshold Wind Speed (Us)
Ration x’
F(s)
(vied)
PM 10 (vind)
VUI IU1 USUSPUSIOP NO :
Silt Content of Surface Material(s)
Mean Vehicle Speed CS)
Mean Vehicle Weight CV)
Nuaber of vh.sla (v)
Days vith at lesit 0.01 in. precipitation
Vehicle Kiloesters Traveled (VKT)
o (veh)
PM 10 (v.h.)
To’r&L Si 1— .IVND AUIOUS PARTI ILATISi
PIl (TOT)
unerusted, unliiit.d reservoir
Absent
ox
5.1 a/s (11.3 mph)
0.50 u/s
4.5 ca
13
6.5 u/a
1.10
1.47
0.00711 .15/. 2 —sec
0.02318 ag/u 3
U
10 Ru/Hr
3Mg
4
96
3ka
3.558 ag/day
0.04037
0.06355 ag/u 3
Value
30 a 5 30 a
32
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YNUIS WILD
PhD Vt$T A1 fd OF % T UD
IY.Z US ?t mi s
,ua au • • ,us s.•.*.
‘““SAMPLING LOCATIONS
NOUAT INDU$TRIIS,
COLUMSUS, MT
T.$a. NS-1401- 5I
, , d . ..L t. s .
,.,. s•Iss ..
i— 1 I 1. ,. TN __ ____
MI-S
M%JNPCWAL DUMP
GLUt
MIKiD CARS
POND
cM 1-QW -7
1’MI-GW-a
AL WIGNIR PAIN
MI —SW—4
MI-8ED-4”-
SLOUGN
AS! LAGOONS
TILLOWIyOiit NIVIR
q
-------
4
Mouat Industries Mining Waste NPL Site Summary Report
Reference 2
Excerpts From the Water Quality Study for
Middle Yellowstone Area ide Wastewater Management Program;
Prepared for Mid-Yellowstone Areawide Planning Organization by
11KM Msociatea; March 1977
-------
,fttI.0w510t4C EEAW
p Mfl4U4G ORGA17 hIOH
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ec .
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. 5 ...4 S.. , ‘p ISI ’ •
:
f’_
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,. .‘. . ... .:.
L;T ’: ‘Q:
i 1) ‘CL :: p’
v FWE P CI’I 4 1 SUITE rJO. 2
• II.L r’, A’’
• . — —“ ‘ S.. “. I J . ‘
P l,.—•;,
:.:.
:.;
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s C T gu : C
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T E rr T !: : i-: ’ ¼T . .‘ Fi:• .t . L• {i Y’. A
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II ,.. .. .. f I •‘. • • • • • • i 5_• .,...•
i U. ., . i i ’ LC I I i :.t!.
-------
COLUMBUS CflOUNDW? TER STVPX
The location of this investigation is the present Situ of Timber-
weld Manufacturing in and near Columbus, Montana, in the SW NW¼,
SEC. 27, T.2S. RIOE (Exhibit 2). One objective otthis investiga-
tion was to define the extent and degree of degradation Of ground-
water from the old sodium chromate waite pile from M uat Industric .
-- chrome ore processing facilities at the above location. The secor.d
objective was to determine the affect on groundwater quality of i.
berweld’s glue machine waste disposal practices. The item of
primary interest under the second objective was the effect of the
disposal pit used for wash waste disposal at the site on the ç .
of groundwater.
Sodium Dichrcrr.ate Investiaation — Background Infori a ion
The chrernate affected area at Columbus is located south and east
of the existing Timberweld site and on an area of land prcscr:.y
used for storage of laminated products.
The site was owned by the City of Columbus and leased to ouat
Industries for the operation of a chromiwn ore proccssinc3 site.
The processing plant operated in the late 1950’s until the early
1960’s to produc. a high grade sodium dichromate which was nec ed
by the Atom .c Energy Wdrk at the Hanford Project, Richiand. Wash-
ington, as a corrosion inhibiter. The sodium dichromate w s pur-
chased for the AEC by General Electric. /
The chrome ore was mined from rights owned by Mouat IndustrieS
in the Stillwate.r Complex and stockpiled at a site near Ny c. Thc
ore was than transported to the Columbus plant as needed.
.The process of conversion at the Columbus plant was as fellows:
—12-
-------
Chremite Ore (FeCr 2 O4) + Na 2 CO 3 Na 2 CrO 4
2000F
Na 2 CrO 4 + N 2 S0 4 Na 2 Cr 2 O 7 .2R 2 0 CL)
The chromite ore was calcined with soda ash (Na 2 CO 3 ) to Cor n
sodium chromate (Na 2 CrO 4 ). The sodium chromate was placed n
a slurry and separated from process residue by filtration. S l-
furic acid was then added to the sodium chromate to produce a
- liquid sodium dichromate solution. The sodium dichrematc w s
concentrated and separated from process waste by filtration.
This process waste was described as sodium sulfate which was
removed from the process as a solid.
The liquid sodium dichromate was stored in a scaled tank while
sodium sulfate containing sodium dichromate was stockpiled at
the site for further processing to remove the remaining sodiun
dichromate. This processing did not take place before the plant
control was transferred to Monte Vista Corporation’ in 1DG3. The
waste sodium sulfate remained on site until removed by Anaconda
Company. 11/
The waste sodium sulfate pile with its significant residual sodium
dichromate concentration exposed to the wcathcr and plant sp llage
are the source for the hexavalcnt chromium found in the area to-
day.
The chromium ore as it was mined from the St.illwatcr CornplC w S
in a trivalent (Cr’ 3 ) oxidation state. It remained in this state
until processed at the Columbus plant. The chromium n the low
oxidation state forms is not considered to be physio ogic il3.y
—14-
-------
harmful. Hexavalont chromium (Cr 4 6 ), a high oxidation
form is limited by drinking water standards to 0.05 mg/i. There
is little evidence, however, to sustain such a low limit. pj
Zn 1973, thc Anaconda Company became involved with the Columbus
chromate situation after a number of contractual agreemcnts in-
voiving Meuat Industries, Monte Vista Corporation, and the Ana-
bonds Company. Involved in these agreements were the transfer
of certain mineral rights in the Stillwater Complex from Mouat
to Anaconda, the agreement by Anaconda to perform certain cor-
rective measures to restore the Columbus Site to a morc nat . :a
condition, and an indemnity clause involving Anaconda, Monte V.sta
and Mouat Industries, the extent of which has not been clearly
defined. 11/
At the time between the pilot plant cxchange with Monte ViSLa i.n
1963, and th. work done by Anaconda in 1973, the Monte Vista
Corporation removed the plant equipment, its buildings, and the
raw chrome ore piles leaving only the building foundations and the
process waste piles. The date at which these changes were nade
can not be clearly defined, however, it is known that they d .d
occur during that 10-year period. 11/
The Anaconda Company maintains that their involvement in 1973,
at the Co1w thus Sit. was to provide only temporary relief for
observabl, chromium deposits. The work performed by the Ma-
conda Company after studying the extent of the contaminatc d area
was to remove the piles of sodium chremate and sodium dichror.ate
bearing process wastes. These wastes are bei3cved to have been
transferred to a sit, in Butte, the location being known by the
Anaconda Company. The surf ace water was drained from tli” p1 r t
site by moans of a ditch and the area was trc. tcd with sulfuric
£cid to reduce the soil pH to 45. Ferrous Sulfate :(Fc50 4 ) w s the:
—15—
-------
Inspection of Plates 3 and 4 will show the higha coflcentr t ons o
chromium to be located at the site of the old Sodium diChr rr . e
pile and iuvsadiately downgradicnt and southeast of the O1c Mouat
site.
Examination of Table 2 will show that concentrations of total
chromium in aLl seventeen wells sampled for this study in t. ie
Timberweld vicinity had concentrations greater than the two rradc,.
wells sampled for background information in Columbus. Of
particular interest are the concc’ntrations of 0.04 mg/i in
W-l and W—2 located outside the main groundwater flow zone fro•- ç
old chromate pile as defined in Plate 3. One possible bu:
explanation for these concentrations could be due to seascr. i
variations in groundwater levels and the consequent c?fange i
pattern of groundwater in the study area. It’s bclieved t t
total chromium concentrations of 0.04 mg/i in Weilz W-1. a d n-2 re
due to the existing chrome ore haujtng operations to the exist .r 1 g
chrome ore loading area east of the Timberweld sitc.
Two grab samples were taken from the yellowstone River above a d
below the study area and analyzed for total and hc .avalent
chromium. Concentrations of total and hexavalent chromium ab v
and below the study area ware the same (less than 0.02 mg/i and
less than 0.01 mg/i respectively) indicating no significant
pickup of chromium from the study area.
Timberweld Glue Wait. Pit Investigation . Concentrations of
phenol in the effluent from the Timberweid plant s.impled December
16, 1976 was 3050 mg/i. The concentration of phcno in the sample
of water from the waste disposal pit taken on the n e date w s
1400 mg/i. Analyses of samples taken on the Janu. ry . l. 1977
through February 16, 1977 sampling of the sevcntoci wells shcwcd
no measurable concentrations of phcnol. The second et of sampics
gathered on February 16, 1977 on Wells W-2, W—3. W 4 and W-6 also
had no measurable concentrations of phenol.
—24—
-------
One possible cxplanation Cot the lack of detectable phenol n the
groundwater at the sito is that the pit is discharging very littic
waste to groundwater due to the sealing of tho pit bottom by gluc’
residue. The fact that Timberweld has to frequently pump the pit.
and dispose of the waste on the land sUrface east and south of the
study area supports this explanation. It’s believed that in
addition to the above that any waste that is discharged to thc
water table either undergoes biological decomposition or is
diluted by groundwater.
The analyses indicate the waste discharged to the land surf. :
previously described are not presently degrading groundwa .o . I
believed that the waste is subject to both evaporation and
biological decomposition. The fact that the water table is n
excess of five feet below the land surface in the land app1 .cati. .-
areas could mean that enough soil profilc is being provided f r
the aerobic destruction of the phenol before it reaches the w cr
table.
Conclusions
The conclusions of this invcstig3tion are as follows:
1. Groundwater in the study area is and will continue to be
seriously degrad.d by sodium dichromate present in the so l
profile at the sit, of the old Nouat operations.
2. The pollutant plum. is gradually moving southeast of the site
and will eventually reach the Yellowstone River. There w s
insufficient data to accur3tcly estimate when the plume wou
reach the river.
—25—
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.. .&.J . I— I— I I’ I ___ I I . . — —
BILLINGS REGIONAL OFFICE
,&D 5CM I IO(.N. COVtMPIO
STATE OF MONTANA
ale Quald? 5U C lu 140e 1 ads 3a.4
WAiCC QLJM.ITV SLle(.Ml ‘4051552 565
P0 5 cOalh ’. I4UTV SuRidu aoS’ ass s os,
John Stevenson
co1ogy and Environment
4105 East Florida Ave. Suite 350
Denver, CO 80222
RC: Water Simpics - Al W.gner Property, Columbus, MT
Dear John:
Enc1o cd please find the results from the water samples taken on tIu Al egr r
property at the po nt where the affected cattle were drinking.
The IC ? scan results chat I provided to you on M.arch 23, 1984, had not becti
requ sced by me but were done by the lab as a courtesy. For this reason, the
levels of aluminum, antimony, boron, iron, manganese and vanadium were not
recorded with the usual Q.C. The levels, however, do reflect the ru cd for
further analysis.
The parameters enclosed have been checked with the Q.C. as outlin d in tP
memo from Kathy Smit of Northern Engineering and Testing.
Resulci from the water samples taken at the dump site have not as yet been
received.
If you have any questions please contact me at (406) 252-5697.
Sincerely,
%
Kathy let—Hoard
tnvirolRsntal Eng.
Water Quality Bureau
Billings Regional Office
.: r c
i.;. C :.F::.1.:v .L .‘
,u,a IT C 1
cc Andy Alting, Cloverleaf Veterinary Clinic, Columbus, NT
Kevin Ksenan, Water Quality Iure3u, helena, NT -
Puke Rubich, Siia’V.initock SolSA Wastq
Rod Fink, Stiliwater County Sanitarian
Steve Pglch.r, Water Quality Bureau. helena, MT
File
3304 SECOPIdOAvENU NORYM/PO SOX 20296 BILLINGS. MONTANA 591040296
4PII A. l&HIIl.II
April 3, 1984
I0fH/cc
end.
a
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Mouat Industries Mining Waste NPL Site Summary Report
Reference 3
Excerpts From the Documentation Records for
Hazard Ranking System, Mouat Industries Site;
Unpublished, EPA Region VIII; Undated
qq6
-------
S
DOC ME:;T : N D5
Z R ’
INSTRUCTIONS : The purpose of .i .-; : pr i.d ii
way to prepare an audicable rec t4 f ‘c .i in ocurnt’i:a:Lon us. j :
apply tht }Iazard Ranking System r. i g : e’ :. iL:v. As rief v a i s-
sible sua arize the infor atton i u’ed tue score fo •.
factor (e.g. “Waste quantity — dr . plus 800 CJbLC yards . f
sludges”). The source of tnfotmatL ’n sh l “e provided f r e .h el::y
and should be a bibliographic—type fer •ic iat will - a :h d .
used for a given data point ea i “ ide th’
document and consider appending pv ii i.’ievant pige(s) Li i..
in review.
•FACIL.ITY NLME: CJ ’1Ibk1 {LE fi , Ct1L 1E(Z, 4T
LOCATION: Cf1UM 1 CJ’ ThISJF
R 4E Y CJ U.Et MCC T
• rr
1
-------
3 CONTAINMENT
Containment
Method(s) of waste or leachate containment evaluated:
Method with highest score:
4 WASTE CHARACTERISTICS
Toxicity and Persistence
Compound(s) evaluated:
1o r( i. e.c t b
lv & .•. ‘ tO tW L’ t ‘4 .gç
$.t.,
9 v.& (O. &e,.j
Compound with highest score:
Hazardous Waste Quantity
Total quantity of hazardous substances at the facility, excluding
those with a containment score of 0 (Give a reasonable estimate even
if quantIty is above maximum):
, (v ,
,•c % C, C ( 1 .e%%. * ‘
Basis of estimating and/or computing waste quantity:
o C c - cc
• lb u ‘b . ’ ,.
0 o % c, i’)
1) “
c C
-------
S TARGETS
Ground Water Use
Use(s) of aquifer(s) of concern within a 3-mile ridiu of the
facility: -
I A
% h *4 ‘4 * 3
% W i jP tPl4.) Wb I YJ(, ( ‘ t’P. & jr
Wb tV .
Distance to Nearest Well
Location of nearest well drawing from aquifer of concern or occupied
building not served by a public water supply:
oc
Pb 3M ‘1
9 ce•. t1\ ii
‘h % •t ’. %
Distance to above well or building:
Eb’ c * a o t F %
c .T
Population Served by Ground Water Wells Within a 3-Mile Radius
Identified water-supply well(s) drawing from aquifer(s) of concern
within a 3-mfle radius and populations served by each:
*u,. % & * i* .c cS(, ?R% e. t )
‘ ‘ ‘- .% O, ‘
a S
9.. 7 • t • &,
Sm pP. %t %,.. 4.
Coiv utation of land area lrrIgated by supply well(s) drawing from
aquifer(s) of concern within a 3-mile radius, and conversion to
population ( .S people per acre):
Total population served by ground water within a 3-mile radius:
11
f) 00
-------
Js the fsclflty completely Surrounded by areas of higher elevation?
1-Year 24-Hour Rainfall In Inches
Distance to Nearest Downslope Surface Water
Physica’ State of Waste
3 CONTAINMENT
Containment
Method(s) of waste or leachate containment evaluated:
Method with highest score:
7
-------
is there tidal influence?
Distance to a Sensitive Environment
Distance to 5-acre (minimum) coastal wetland, If 2 miles or less:
Distance to 5-acre (minimta i) fresh-water wetland, if 1 mile or less:
‘ c*iR’ ’( is. ‘bc
Qi 1 SCt %. -‘
jcl )(
Distance to critical habitat of an endangered species or national
wildlife refuge, If I mile or less:
Population Served by Surface Water
Location(s) of water-supply intake(s) within 3 miles (free-flowing
bodies) or I mile (static water bodies) downstream of the hazardous
substance •nd population served by each Intake:
bco w c ;, c ,v . , % t
t k WI. & iw
D*c qD
4l • 33 C * %
9
,0
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Mouat Industries Mining Waste NPL Site Summary Report
Reference 4
Excerpts From the Report to Congress on
Special Wastes From Mineral Processing;
EPA; July 1990
-------
Un ed States Solid Waste and
Environmental Protection Emergency Response EPA,530-SW-90070C
Agency (OS-305) July 1990
IEPA Report to Congress on
Special Wastes from
Mineral Processing
Summary and Findings
Methods and Analyses
Appendices
-------
Chapter 4 ?77
Sodium Dichromate Production
The sodium chromate and dichromate (also biown as bichromate) production sector consists of two
facilities that, as of September 1989, were active and reported generating a special mineral processing waste:
treated residue from roasting/leaching of chrome ore. Prior to treitment. the roastAeach residue is not a
special waste and thus, is subject to applicable RCRA SubtiUe C requirements (see 55 2322. January 23.
1990.)l Facilities that are no longer operational. such as the Allied-Signal facility in Baltimore. . are not
addressed in this report. The data included in this chapter are discussed in additional detail in a technical
background document in the supporting public docket for this report.
4.1 Industry Overview
Sodium dichromate, convened from sodium chromate. is the primary feedsrock for the production
of chromium-contanung chemicals and pigments. Chromium-ointaimng chemicals (e.g., chromic acid, basic
chromium sulfate, tanning compounds) are used In chromium plating, etching, leather tanning, water
treatment, and as catalysts. Other uses of chmmium.con?nlntng hetmcals are in drilling operations to provide
drilling mud fluidity and in wood preservative procasses to bind copper and aniemc to wood. Chromium
pigments represent the largest use of chromium in the chemical industry, with sodium dichrornace used to
manufacture a multitude of pigments (e.g., chrome green and yellow, nnc chroinale) that are used in paints
and inks, often for materials that require corrosion inhibition. 2
The two sodium dicbromate production ibduldes studied in this report arc the Corpus Chrisu. as
plant operated by American Chrome and Chemicals (ACC) and owned by Hamsons and Crossflcld Inc.
(Harcross), and the Castle Hayne, North Carolina plant owned and operated by Oecidental Chemical
Corporation (0CC). The ACC facility initiated operations in 1962 and was modernized in 1985; the 0CC
facility began operations in 1971 and was modernized in 19 . The annual production capacity, total 1988
production, and rate of capacity ucillmdon for the two indlities as reported in the SWMPF Surveys have all
been designated confidential by the facilities and, th jz , are not reported in this document 3 A published
data sourm Lists the annual sodium dlchromate production capa ty ’ of the ACC plant at 41.000 metric tons
and the 0CC plant as 109,000 metrIc tons. 5 A rd1ng to Bureau of Mines souron, long term capacity
utilitzauon (1990 to 1995) is forecast to be 100 percant of capacity.’
Because these two facilities have iflnd their production statisuci as confldontial, no specific
information can be given on production trends in the sodium chroutate and dlcbzomate Industries. The U.S.
Bureau of Mines, however, reports that apparent U.S. consumption of chromium has risen from 343,000 metric
tons in 1985 to 540,000 metric tons in 1989
I The tuaduc hvu r—uiiiJ—tii of inn. un ‘1 bund’ (to ‘ ‘— by EPA for pwp of dtoamlme the of
the M on 5 Waite “— — ii appian to naniil , ..-- 4 bai at . z iaun the pavdunun aid, thin.
a spanai wale at the poum of gaianms. H wr . dt u— i (pH j—— ’ aie auln pioysd by the two
fi iaiato. the miduc . 1ow hund’ aid th d.4n 1 IpS ai Lc bsouue at. ale bib iwisinc.
of Main, 1987. Mla .II Y k . Ed. p. 373.
- - Ø i .il p P to the U J 1ii l Sww of Solid Waiiai fron
MaiauJ Prv ..ng U.S. EPA. 1989.
Canotan ale c i a 100 peront aediuto dialeuale bun aid “ “ thromate.
5 SRI ie nau sI , 1987. Dijnscjv of emr-’ Peoduoni-Unnid Slain . Ed. p 964.
‘Bureau of Muito. 1990. Pinuosal tw uoi with r. Aqy Sp-r . ’ Jobs Papp.
John F. Papp. 1987 U.S. Bureau of Mann. ‘ umiuto.’ Minerals Ynehoot . E4. pp. 1, .
on
-------
01
Mining Waste NPL Site Summary Report
Ormet Corporation
Hannibal, Ohio
U.S. Environmental Protection Agency
Office of Solid Waste
June21, 1991
FINAL DRAFT
Prepared by:
Science Applications International Corporation
Environmental and Health Sciences Group
7600-A Leesburg Pike
Falls Church, Virginia 22043
-------
DISCLAIMER AND ACKNOWLEDGEMENTS
The mention of company or product names is not to be considered an
endorsement by the U.S. Government or by the U.S. Environmental
Protection Agency (EPA). This document was prepared by Science
Applications International Corporation (SAIC) in partial fulfillment of
EPA Contract Number 68-WO-0025, Work Assignment Number 20.
A previous draft of this report was provided to Rhonda McBride of
EPA Region V [ (312) 886-72421, the Remedial Project Manager for
the site, whose comments have been incorporated into the report.
p0’’
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Mining Waste NPL Site Summary Report
ORMET CORPORATION
HANNIBAL, OHIO
INTRODUCTION
This Site Summary Report for the Ormet Corporation site is one of a series of reports on mining sites
on the National Priorities List (NPL). The reports have been prepared to support EPA’s mining
program activities. In general, these reports summarize types of environmental damages and
associated mining waste management practices at sites on (or proposed for) the NPL as of February
11, 1991(56 Federal Re!ister 5598). This report is based on information obtained from EPA files
and reports and on a review of the summary by the EPA Region V Remedial Project Manager for the
site, Rhonda McBride.
The Remedial Investigation for this site has been completed, and preparation of the Remedial
Investigation Report is currently in progress. EPA will have more accurate and updated information
on this site once this report has been completed.
SITE OVERVIEW
The Ormet Corporation site is located on 175 acres adjacent to the Ohio River in southeastern Ohio,
approximately 2.5 miles northeast of Hannibal (see Figure 1) (Reference 1, page 2). The facility is
an active primary aluminum-reduction facility, in operation since 1958 (see Figure 2) (Reference 1,
page 37). The facility uses the HullIHeroult process. In this process, alumina is dissolved in a
molten bath of cryolite and an electric current is applied. Oxygen migrates to the anodic surface and
aluminum is deposited on a cathodic surface. The reaction is carried out in a cellar “pot” lined with
carbon. Typically, when these “potliners” become spent, they’re considered waste and are disposed
of. In addition, large amounts of waste are generated from air pollution control devices (wet
scrubbers).
Five unlined wastewater ponds, totalling 10 acres, are present: four are of 1 acre or less, while Pond
5 covers 8 acres. The Ponds are used for the disposal of wet scrubber sludges. (Reference 1, page
17) Scrubber sludges consist mainly of calcium-based salts, including calcium sulfite, calcium
fluoride, calcium hydroxide, and sodium aluminum fluoride. Two Spent Potliner (SPL) storage areas,
totalling 10 acres, are also located at the facility (see Figure 2) (Reference I, page 14). Potliner was
to consist of carbon-based material with impurities, which, upon weathering, produce an alkaline
leachate containing fluoride, cyanide, sodium and ammonia. No other construction information
IO\ 15
-------
Ormet Corporation
Ger ghty Miller. Inc.
/ 2}ç,/ \
+
• “S ‘ ‘WI • ‘ - ‘ i ‘_
‘N$S tIIflI P — / —::L—: I -
Z l ,jj;
; . 4 c r jy
p.:. 4J/ r
4 ’1 ?
[ J ’c
p $4. vSU 4V __________________________
FIGURE 1. LOCATION OF THE ORMET CORPORATION PLANT SITE,
HANNIBAl ., 01110
2
I
-------
0
z
0
P1
I
2.
:1
-------
Ormet Corporation
exists for these storage areas. Sludge-disposal and potliner-storage practices at the facility have
resulted in ground-water contamination (Reference 1, pages 3 and 5).
Geraghty and Miller Inc., contracted by Ormet, concluded that principal ground-water contaminants
include fluoride, cyanide, and sodium. The consultant determined that as a result of pumpage from
production and interceptor wells, leachate plumes are largely contained onsite (Reference 1, page 5).
According to EPA, Phase I and II Remedial Investigations have been completed and a Remedial
Investigation Report is being prepared. A Feasibility Study, which began in December of 1990, is
underway.
OPERATING HISTORY
The Ormet Corporation developed the site in 1958, and continues to operate the facility. The facility
obtains alumina from its Louisiana refinery for reduction to produce aluminum metal. Approximately
6 million gallons per day of ground water, supplied by two Ranney Collector Wells, are used for
process water (Reference 1, pages 1 and 12).
Beginning in 1958, SPL was accumulated in two storage areas in the northeast section of the plant;
wet scrubber sludges were disposed of in five unlined ponds, also in the northeast section of the plant
(see Figure 2) (Reference 1, page 37). In 1968, Pond 5 began to receive sodium alkaline sludges
from the recovery of cryolite. Monitoring data indicate that this practice resulted in ground-water
contamination observed in the Ranney Well in 1971 (Reference 1, pages 37 and 38). In 1976, Ormet
began to neutralize the alkaline sludges before disposal in Pond 5. In 1981, the cryolite- recovery
plant was shut down and onsite sludge disposal was terminated. SPL located in the storage area was
hauled away around 1981. However, it is suspected that some potliner spent material still remains in
the disposal areas (Reference 1, pages 37 through 41). No wastes are presently disposed of onsite.
According to EPA, the facility currently stores wastes onsite (for up to 90 days) and ships the waste
offsite to a Resource Conservation and Recovery Act permitted landfill. Use of a wastewater-
treatment lagoon was discontinued in 1983, due to ground-water contamination (Reference 1, Exhibit
B.9.N, page 4). Other details concerning this treatment lagoon were not available.
SITE CHARACTERIZATION
The facility is located adjacent to the Ohio River, but receives its process and sanitary water from
ground water because of the generally better quality (Reference 1, page 11). One production well,
the Ranney Well, is located onsite, providing process water for the facility. A second production
well, the Consolidated Aluminum Ranney Well, is located .2 mile downgradient and offsite, providing
4
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Mining Waste NPL Site Summary Report
drinking water for the Ormet site and drinking and process water for the adjacent facility.
Contaminated ground water is collected by three interceptor wells, two installed in 1972 and a third
installed in 1982. Water pumped from the two wells installed in 1972 is discharged (untreated)
through Outfall 004 into the Ohio River (Reference 1, pages 38 and 39 and Exhibit B.9.N, page 4).
The ocher waters discharged through Outfall 004 are storm water, Electrostatic Precipitator (ESP)
cooling tower overflow, boiler blowdown, and compressor noncontact cooling water (Reference 1,
Exhibit B.9.N, page 4). Discharge from the third interceptor well is pumped to disposal overflow
Pond 5. Fluid pumped from this well is alkaline, tea/coffee colored, and contains fluoride and
cyanide (Reference I, page 41). The third well was being pumped at several hundred gallons per
minute in 1984; it’s current status is unknown. The contribution to volume and toxicity of the first
two wells relative to contaminated ground water was not indicated in the available information.
Ground water is characterized primarily by elevated pH and concentrations above background of
fluoride, cyanide, and sodium. To a lesser extent (i.e., with lesser consistency), there is reduced
light transmittance and elevated levels of chloride, bicarbonate, carbonate, sulfate, iron, aluminum,
silica, Total Organic Carbon (TOC), and (probably) ammonia (Reference I, page 5). Based on data
collected monthly from March 1982 to August 1983, levels of fluoride in the new Interceptor Well
ranged from 58 to 89 par Is per million, while pH ranged from 8.7 to 9.0 (Reference 1, page 133).
Data collected from the new monitoring wells demonstrated fluoride levels as high as 460 milligrams
per litter (mgi!); total cyanide as high as 110 mg/I, and sodium levels as high as 3,150 mg/I
Background levels of fluoride, cyanide, and sodium were recorded as 0.6 mg/I, 0.069 mg/I, and 24
mg/I, respectively, at two monitoring wells upgradient of potential source areas (Wells 19 and
MW2O). Background concentrations of fluoride ranged from 0.3 to 0.6 mgI!; total cyanide was from
0.050 to 0.068 mg/i; and sodium was from 22.9 to 24.0 mg/I (Reference 1, pages 128 through 131).
Leachate plumes are largely contained within facility boundaries due to pumping from the Ranney
Well and the Interceptor Wells (Reference 1, page 5).
Pond 5, holding cryolite recovery sludge waste, covers 8 acres. Monitoring data have indicated an
improvement in ground-water quality downgradient from this unit (Reference 1, page 58). Two
storage areas were used for SPL disposal (Reference 1, page 37). Monitoring has indicated
degradation of quality of ground-water downgradient from these units. Four disposal ponds, each I
acre or less, may also contribute contamination to ground water at the site (Reference 1, pages 50 and
55).
Thirty-nine monitoring wells were installed on the site. Twenty monitoring wells were installed by
Fred Klaer and Associates in 1972. Geraghty and Miller installed 19 additional monitoring wells in
1983 (Reference 1, pages 13, 17, and 38). In addition, three Interceptor Wells were designed to
capture contaminated ground water to prevent contamination of the two Ranney Wells and the
5
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Ormet Corporation
remaining aquifer. Based on fluoride, cyanide, pH, and Total Dissolved Solids (TDS) data, the
Ranney Well is significantly less contaminated than the Interceptor Wells (Reference 1, page 135;
Reference 1, Attachment 3).
The two Ranney Wells draw from a sand and gravel alluvial aquifer (Reference 1, pages 11 and 12).
A second aquifer, underlying the affected aquifer, consists of Paleozoic bedrock, is of generally
poorer quality, and is not extensively developed as a ground-water supply (Reference 1, page 12).
All 1983 monitoring wells were installed in the upper aquifer (Reference 1, pages 73 through 119).
No construction information concerning the remaining monitoring wells was available. Ground water
has been encountered at depths ranging from 12 to 84 feet at the site (Reference 1, page 123 and
124). Ground-water velocity is approximately 9 to 10 feet per day (about 3,300 to 3,700 feet per
year), such that ground-water travelling beneath the storage areas should reach the Ranney Well
within 1 year (Reference 1, page 30). The hydraulic conductivity of aquifer sediments typical of the
central portion of the facility was determined to be 10’ centimeters per second (cmls) from aquifer
tests conducted in 1972 (Reference 1, page 30). No information concerning contamination of air,
surface water, or soils (other than soils directly associated with the units of concern) was presented.
ENVIRONMENTAL DAMAGES AND RISKS
Ground-water contamination was first observed in the Ranney Well in 1971 (Reference 1, pages 37
and 38). This well is used for process water. The nearest drinking-water well, located approximately
.2 mile downgradient from the site, provides drinking water for 3,133 Consolidated Aluminum and
Ormet plant personnel. No other Ohio drinking-water wells are present within 3 miles of the site
(Reference 1, Exhibit D, Addendum). Population within 3 miles of the site, which includes the
Towns of Hannibal, Missouri, and Steelton, West Virginia, was not given.
The alluvial aquifer represents the sole source of drinking-quality ground water in the area. No
information exists regarding degradation of the deeper bedrock aquifer as a result of site activities.
However, the deeper aquifer is not extensively developed (Reference 1, page 12). Information
concerning drinking-water wells for West Virginia was not available.
Analyses of lagoon sediment (unspecified) and Outfall 004 effluent have revealed the presence of
Polynuclear Aromatic Hydrocarbons (Reference 1, Attachment 5; Reference 1, Attachment 6).
Screening toxicity studies have been performed on Outfall 004. Species tested were the Fathead
minnow and Daphnia pulex . All organisms were dead after 24 hours, demonstrating the acute
toxicity of the Outfall (Reference 2, page 1). Outfall 004, therefore, poses a potential environmental
risk.
6
I (i
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Mining Waste NPL Site Summary Report
REMEDIAL ACTION AND COSTS
Fieldwork tbr the Remedial Investigation, for this facility, initiated in 1988, has been completed and
the report is being prepared. The Feasibility Study is also under preparation. A Record of Decision
(ROD) is expected in late 1991, after the Feasibility Study has been completed.
A report prepared for Ormet Corporation in 1984 proposed four components that could be used for
site remediation:
• Ground-water monitoring
• Continued ground-water pumping at current rates
• Injection of fresh water into the ground to control migration of contaminated ground water
• Removal of all SPL from the site (Reference 1, pages 60 through 67).
No cost estimates for these components were presented.
CURRENT STATUS
The potentially responsible party started work on the Remedial Investigation during 1988 and a
Feasibility Study was initiated in December 1990 and is currently ongoing. A ROD is expected in the
fourth quarter of 1991.
7
iO
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Io
Ormet Corporation
REFERENCES
1. Hydrogeological Conditions at the Ormet Corporation Plant Site; Prepared for Ormet Corporation
by Geraghty and Miller, Inc.; May 1984.
2. A Report on the Acute Toxicity of Effluents from Ormet Corporation Outfall 002 and Outfall 004
to Pimenhales nromelas and Danhnia nulex ; Ohio Environmental Protection Agency; Undated.
3. Site Inspection Report: Ormet Corporation; EPA; January 17, 1985.
8
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Mining Waste NPL Site Summary Report
BIBLIOGRAPHY
EPA. Site Inspection Report: Ormet Corporation. January 17, 1985.
Ohio Environmental Protection Agency. A Report on the Acute Toxicity of Effluents from Ormet
Corporation Outfall 002 and Outfall 004 to Pimephales promelas and Danhnia nulex . Undated.
Prepared for Ormet Corporation by Geraghty and Miller, Inc. Hydrogeological Conditions at the
Ormet Corporation Plant Site. May 1984.
Stevens, Mary (SAIC). Telephone Communication Concerning Ormet Corporation to Rhonda
McBride, EPA. August 9, 1990.
9
I
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Ormet Corporation Mining Waste NPL Site Summary Report
Reference 1
Excerpts From Hydrogeological Conditions at the Ormet Corporation Plant Site;
Prepared for Ormet Corporation by Geraghty and Miller, Inc.;
May 1984
-------
/
1
HYDROGEOLOGIC CONDITIONS
AT THE
ORMET CORPORATION PLANT SITE
HANNIBAL, OHIO
PREPARED FOR
ORMET CORPORATION
HANNIBAL, OHIO
MAY 1984
. .Q ”rgghiy & Mile, Inc .
GROUNDWATER CONSULTANTS
ANNAPOLIS. MARYLAND
-------
s f - I ”
“3
Ger2gh y & Miller, Inc.
I 1TRODUCTXOp1
Plant Setting arid Ooerational History
The Ormet Corporation (Ormet) plant site in Monroe
County, Ohio, is situated along the west bank of the Ohio
River, approximately 35 miles south of Wheeling, west
Virginia. The plant occupies the northeastern half of art
area known as Buck Hill Bottom, a lens—shaped stretch of
land approximately 2.5 miles long and about 0.5 miles wide,
at its widest point (see Pigur. 1). The southwestern half
of Buck Hill Bottom is occupied by another industrial
facility.
Ormet has used this plant site for more than 25 years,
over which time, their main process has ben the reduction
of alumina to produce aluminum metal. Throughout the life
of the plant, groundwater has constituted an important
source for processing— and sanitsEy water supplies, and is
produced via twe Ranney collector wells located to the south
of the Ormet plant and the neighboring facility. At the
present tin., these wells are producing a total of about six
million gallon. of water per day (gpd).
As a result of past storag. and disposal practices,
inorganic constituents have seeped into Onset’s groundwater
-------
—‘ . - •‘ ‘ee ’,
— / $ ‘ ) \.øe i
+
: j) : ç;
_ )! /
I
_____ I •)j j
( __
— • -
tJ:
••
p
7 IL1
_
S ‘ W S W VlS ? SUU
Figure 1. Location of the Ormet Corporation Plant Sit.,
Hannibal, Ohio.
2CCO
rIc ILL C
*NNUY -
lff4I ;
2
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G: .i;? i & Inc.
supplies; and, in some areas, ccncentrations of extraneous
substances have reached levels that are undesirable for
process—water uses. AS a result, several interceptor wells
have been installed to recover degraded groundwater before
it reaches the Ormet Ranney well.
As a preliminary effort to identify and define the
nature and extent of impacts to groundwater supplies, Ormet
has sponsored several site hydrogeologic investigatictg,
including studies by Fred Klaer and Associates (1972) and
Dames & Moore (1977 and 1978). Results from these studies
indicated that water quality problems were probably mainly
related to sludge disposal and potliner storage practices
that were conducted in the northeastern portion of the Ormet
plant site (see Figure 1).
Study Objectives and Approach
In October 1983, Geraghty & Miller, Inc., was retained
by Ormet to conduct an additional hydrogeologic site inves-
tigation to better define the source(s), nature, and extent
of groundwater effects, as well as possible remedial alter-
natives for abating existing and potential ccr.ditions. The
specific objectives of this study were to:
• Assess (and contour) groundwater flow patterns
beneath th. site, and identify main factors wh3 ch
control groundwater flow.
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Ge: hcy & MiI!cr, Inc.
• Document the cher?ical makeup of leachate plumes and
(to the limits of available data) identify specific
parameters ar.o/or parameter relationships that may
account for the appearance and chemical behavior of
these fluids.
• Evaluate the extent to which leachate plumes have
spread beneath the site and identify main factors
controlling plume !nigration7 and estimate future
plume movement under present pumping conditions.
• Assess and qualitatively define contaminant/source
area relationships, particularly with regard to the
potential for further seepage of effluents into the
groundwater system.
• Discuss long and short range groundwater quality
trends and evaluate possible remedial measures
(conceptual) that could be implemented to abate
existing and potential impacts to groundwater
resources.
In addressing the above objectives, Geraghty & Miller,
Inc., first conducted a review of existing data (Phase I).
In this review, previous groundwater flow patterns and
water—quality trends were inspected, and significant data
gaps were identified. A groundwater monitoring program
was then designed and implemented to fill data gaps and
provide the information needed to fulfill the established
study objectives.
4
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Ger hrv & Miller, Inc.
PRINCIPAL FINDINGS
The principal findings of the recent investigation
conducted at the Ormet site are as follows:
1. Groundwater flow beneath the northeastern portion
of Buck Hill Bottom is primarily in the direction
of the Ormet Ranney and old interceptor wells.
2. Under present pumping conditions, it is estimated
that a unit volume of groundwater moving beneath
potliner storage and sludg. disposal areas should
reach the Ranney and old interceptor wells within
about a year’s time (based on calculated flow
veloctties of 3,300 to 3,700 feet per year);
travel times for dissolved groundwater constituents
are probably longer, depending on th. net retarda-
tion factor for a particular constituent.
3. Groundwater effected by storage and/or disposal
practices is characterized primarily by elevated
pH and above background concentrations of fluoride,
cyanide, and sodium, and to a lesser extent (i.e.,
with lesser consistency), reduced light trans-
mittance and elevated levils of chloride, bi-
carbonate, carbonate, sulfate, iron, aluminum,
silica, total organic carbon (TOC), and probably
ammonia.
4. Pumping (and resultant drawdowns) within the water
table aquifer hay, lowered groundwater heads below
the water level in the Ohio River and water is
moving from the river into the aquifer (i.e.,
induced r.charge); there is no. apparent natural
discharg. of groundwater to the surface water body
along most of Ormet’s river/plant boundary.
S. Under present conditions, leachat. plumes within
th. groundwater system are being largely contained
within Ormet’s site boundaries as a result of
pumpage from Ranriey and interceptor wells. These
withdrawals (at or near current rates) must con-
tinue in order to prevent offsite migration of
leachate plumes.
5
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& Mi1I r, Inc.
averaging about 630, end 665 feet above mean sea level,
respectively. The upper terrace, which is occupied by the
main plant facilities, is bounded on the northwest by a
steep valley wall that rises to an elevation of 1300 feet
within less than a mile. The lower terrace comprises a
relatively narrow strip of land that is bounded by the Ohio
River; the Ohio River pool elevation in this area ranges
from 620 to 624 feet above mean sea level and, as a result
of the Hannibal lock and darn, tends to remain fairly con-
stant throughout high— and low—flow periods.
Water Resources
The Ohio River represents th. main body of surface
water in the ar.a and, with respect to volume, constitutes
an almost unlimited supply. The quality of water from the
Ohio River is suitable for many industrial uses; however,
owing to suspended sad i .nts and thf possible presence of
undesirable chemical constituents resulting from upstream
operations, sow. treatrn.nt is usually required prior to us..
In the Buck Bill Bottom area, groundwater constitutes
a main so rce for process— and drinking—water supplies.
The most important water—bearing unit is the water—table
aquifer, which is comprised of the sand and gravel alluvial
I o3 “
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Geughcy & Miller, Inc.
materials of the Ohio River Valley. Relatively high yields
can be obtained from wells penetrating these sediments, and
natural groundwater quality is generally good with total
dissolved solids concentrations of 500 mg/i or less;
locally, water nay be hard and sulfurous (Price, and others,
1956).
At the present time, a total of about 6 million gallons
of water is pumped daily (Dames & Moore, 1977) from the
alluvial aquifer via the t Ranney wells. B.caus• these
withdrawals greatly exceed precipitation r.charg., pumping
has induced river recharge of th. aquifer. Consequently,
the quality of water derived from pumping wells Li closely
related to river water quality, and is thus susceptible to
numerous upstream sources of contamination. Owing to this
condition, treatment of groundwater used for sanitary water
supplies may be necessary.
The Paleozoic bedrock units, which undsrlis the sand
and gravel aquif.r, are also capabl. of producing ground-
water. However, bacaus. well yields ar. generally low and
water quality is often poor Ci..., mineralized), these units
have not been extensively developed as a groundwater supply
in the immediate study area.
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Geraghty & Miller. [
SITE INVESTIGATION
Drilling arid Soil—SaznDling Program
During December, 1983, Geraghty & Miller, Inc., con-
ducted a drilling program at the Ormet Corporation plant
site. The main objectives of the program were to collect
geologic data and establish a system of monitor wells to
facilitate the collection of water—level and water—quality
data. A total of 20 boreholea were drilled, 19 of which
were equipped with 2—inch—diameter monitor well assemblies.
Efforts were made to locate most of these wells in areas
suspected to be hydraulically downgradient from possible
sources of contamination, i.e., sludge disposal ponds and
potliner storage areas. Several wells CMW-19 and MW—20)
were also installed at locations hydraulically upgradient
from the potential source areas, in order to define back-
ground water—quality conditions. New monitor—well locations
(Mw—i through MW—20), old monitor—well locations (TH—O
through TR—19), and other important site features are shown
on Figure 2. Drilling, soil sampling, and monitor—well
installation and development was done by Bardin—Ruber, Inc.,
of Pasadena, Maryland, under the supervision of a Geraghty &
Miller, Inc., representative.
13
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EXPLANAII Otj
/
TH-I2
S TN-I)
PLAI ,Y
, TN
•TH-I WELLS INSTALLED DURING 1q72
FRED $(LA(R 6 ASSOCIATES STUDY
1MW-I WELLS INSTALLED DURING ISS)
SERAGHTY I MlLLLR $NC STUDY
Geraghty & Milkr, Inc.
I-icjure 2. I ocation of MW—Series Monitor Wells,. TU—Series Monitor Wells, and Other
Important Features at the Ormet Corporation Plant Site, Hannibal, Ohio.
01110
RIVER
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Figure 3. General Monitor Well Construction at the Ormet
Corporation Plant Site, Hannibal, Ohio.
17
1
4 r%cfI.djom.t, sfI —.-—
p’Otictive covv with locking I
lid
C mini
( prox 1 . 5 feit thick)
8r.thdsørn.t,, borW —
2-r ch.thcm.t.ç threadid — —
f sh.psnt, PVC cosing
• _____
_ .: B
B itanite pluç( vo .a.5 —
t n t thick)
2 nch-diornstsç 0.010— .
inch slot, throdsd flush— .. .
jornt,PVCw.llscrnn
C
F wmotioncoIlapss d/br —
sandpcck
? •.•:
PVCpluq . .
A
No.
pproxirnate
Di en jor s
1 1 1—1
A
69
B
69
tlW-’2
86
84
49to 69
54to
1 1 1—3
77
76
84
46to
111-4
94
74
76
54to
1 11—5
90
90
74
6Oto
111-6
52
No ll
90
installed
1*7
79
78
58to
11-4
98
98
78
68to
P11-’9
101
101
98
71 to
11—10
100
100
70 to
lI—li
95
95
65th
11—12
67
67
27 to 67
111-13
88
87.
57 to 87
11—14
86
86
46 to 86
11 1-15
56
56
36 to
111—16
84
81
46 to 81
11—17
77
76
36to 76
11—18
59
59
39to 59
11-19
64
44 to 64
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G: .i;hc r & Mii:e , Inc.
Data obtained from an aquifer—testing progra n Conducted
by Fred Klaer and Associates (1972), indicate that aquifer
sediments typical of the central plant area are charac-
terized by a coefficient of transmissivity CT) of about
60,000 gp /ft and a coefficient of permeability (k) of about
1900 gpd/ft 2 (or a hydraulic conductivity, K, of about
10_i cm/see). The coefficient of storage is calculated to
be about 0.19 (dimensionless).
Using the K value of 10_i cm/Sec. a hydraulic gradient
(I) of 0.008 to 0.009 ft/ft. and an assumed effective
porosity (n) of 0.25 (dimensio;lesa), it is estimated
that groundwater beneath northeast parts of the plant area
is moving toward the Ormet Ranney well at a rate (V) of
about 9 to 10 feet per day (about 3300 to 3700 feet per
year); by equation V • . Based on these flow velocities,
n
groundwater traveling beneath the storage and disposal
facilities should reach the Ormet Ranney well, within about a
year’s time. Travel times for dissolved groundwater con-
stituents may be (probably are) somewhat slower, depending
upon the net retardation factor for a particular constituent.
- -----
Flow velocities calculated by Geraghty & Miller,
Inc., are roughly four times faster than flow velocities
30
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1 ft ANA Qf
• $ tLL LOCA II AIdO *AT [ Ø L(VLL
‘I’ IUI M$L
— — ATL* LIVIL COPITOU Wd FLU
ER
— øSLCI I OF G O *T( FLOW
A RLJIT MAMCC Osv.OC
- GUS5$IIyMsfle, P . C.
Figure 12. Inferred Water-Table Contour Map Depicting Present Conditions at the Orinet
Corporation Plant Site, hannibal, Olilo.
(Bused on 01/31/84 waLer-level data)
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Gerighcy & Milkr, Inc.
Figures 11 and 12 also reflect conditions before and
after closing of the Bannibal, Lock and Darn in 1973, ich
caused roughly a 20—foot rise in river—pool elevation.
Aside from an overall rise in groundwater levels (more
than 10 feet in the area of the disposal ponds and more
than 5 feet in the vicinity of Ormet’s Ranney well) the rise
in river—pool elevation does not appear to have greatly
changed the configuration of the water—table aquifer under
pumping conditions. Damming the river probably has caused
an increase in silt accumulation along the bottom, which
some authors suggest may be reducing th. capacity for river
recharg. of the water—table aquifer. Although silting
may cause some reduction in th. permeability of subjacent
deposits, th. overall increas. in saturated aquifer thick-
ness suggest! that increased hydraulic heads Cf rorn the
rising river) have more than compensated for any such
reductions; and the water—tabl• aquifer appears to be
potentially mor• productive as a result of increasing the
river pool elsvation, barring overall decr.as•s in aquifer
permeability.
?o th. northwest of disposal pond No. 5 (near TR—10
and, particularly, near TE—Il), relatively little change in
water—table elevation appears to have resulted from raising
the river pool. This is probably because these wells are
34
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Geraghcy & Miller, liic
situated-more toward the valley wall, where rising bedrock
deposits (Figure 4) support a water table that, although
hydraulically connected to the main aquifer body, is con-
siderably less susceptible to pumping (drawdown) stresses;
i.e., this portion of th. water—table aquifer is sustained
primarily by precipitation recharg. which, given the aqui-
fer’s limited capacity to transmit water vertically and
laterally, is sufficiently plentiful to maintain a rela-
tively elevated body of groundwater. Owing to this con-
dition, veils TU—lO, Tif—it, and MW—la, draw froni a portion
of the water—tabli aquifer that receives recharge emanating
primarily from the north: ana, these monitor veils appear
to be situated hydraulically upgradi.nt from all of the
disposal ponds.
It is, therefore, reasonable to assum that groundwater—
quality alterations that may be observed at the.. locations
are probably mainly attributabl. to past potliner storage
practices, barring the presence of heretofore unidentified
sourc. areas. Although somewhat less certain, current
groundwat.r flow patterns further suggest that monitor wells
MW—2, MW—16, and possibly other wells, may also be situated
in areas that receive recharge emanating primarily from the
north.
35
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G r g cy & Miller, Inc.
It is important to note that 1972 water—level data
(Figure 11) imply a considerable degree of fluid mounding
beneath the No. 5 disposal pond; whereas, 1984 data (Figure
12) do not indicate the presence of a discernible mound.
This change probably mainly reflects retirement of the No. 5
pond in 1981, when th’ cryolite recovery plant was closed
and sludge disposal practices were discontinued.
Under present pumping conditions, the water—table
aquifer is receiving recharge both from the Ohio River and
from infiltrating precipitation; relatively minor amounts of
recharge may also issue from inactive disposal ponds.
Based on estimates by Fred Klaer and Associates (1972),
90 percent or more of the 6 mgd being pumped from the
alluvial aquifer is probably derived through induced re-
charge from the Ohio River. As a result, there does not
appear to be any natural discharge of groundwater into the
Ohio River along most of the river/plant boundary.
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Gcr2ghry & MLHCr, Inc.
GROUNDWATER QUALITY
Past Cause—and—Effect Relationships
Starting in 1958, when the Ormet plant began operation,
spent cathode material (i.e., potliner) was accumulated in
several areas to the northeast of the plant site, and
surface impoundment facilities (ponds No. 1 through 5)
were used for the disposal of wet scrubber sludges (see
Figure 2 for locations). In general, potliner wastes con-
sist of carbon—based material with impurities which, upon
weathering, produce an alkaline leachat. containing para-
meters such as fluoride, cyanide, sodium, and a I onia; and
scrubber sludge consisted mainly of calcium—based salts
including CaS0 4 , CaF 2 , and Ca(OH) 2 , as well as Na 3 ALF 6 .
In August 1968, Orm.t started operating a cryolite
recovery plant, and the (then activ.) No. 5 disposal pond
began to receive very alkalin, sludge consisting of sodium—
based salts including Na?, Na 2 SO 4 , Na 2 CO 3 , Na 3 A1F 6 , and
NaA1O 2 , as well as Ca(OB) 2 and CaCO 3 ; this material was
placed on top of th. older calcium—based compounds. Based
on available data, it appears likely that this chang. in
thern disposal process was largely responsible for changes
37
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G u hcy & Miller, Inc.
in Ranr.ey well water quality that became apparent in July
1971; i.e., the well began to produce alkaline, discolored
water.
The deteriorated quality of water produced from the
Ranney well prompted a site hydrogeologic study by Fred
Klaer and Associates (during 1972), which involved the
installation of some 20 monitor wells (TH—serjea) to assess
water—quality conditions and groundwater flow patterns (see
Figure 2 for well locations). Resultant data indicated that
-
fluid was mounded beneath the No. 5 disposal pond and
groundwater was being pulled from storage and disposal... areas
toward the Ormet Ranney well (Figure 11). Data also indi-
cated that virtually all of the wells located in the vicin-
ity of, and hydraulically dowrtgradient from the No. 5
disposal pond (i.e., TN—3, TH—5 through TS—9, Ta—14A, and
8-Inch) showed substantial decrees of water—quality degra-
dation by parameters that appeared to be closely related to
pond effluents; the quality of water sampled at the TH—10
and TB—li locations did not show an appreciable degree of
alteration at this tia. (see Appendix D—3 for water—quality
data from TB—series wells). As an interim solution, two
interceptor wells were eventually installed (12/72) several
39
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Giz tri & MiIk , Inc.
hundred feet north of the Ranney well to intercept the plume
of discolored groundwater before it reached this pumping
center.
In 1976, Ormet began to neutralize sludge from the
cryolite recovery plant prior to discharge into the No. 5
disposal pond. This process change appears to have signi-
ficantly reduced water—quality impacts resulting from pond
seepage; as evidenced by a supplemental study conducted by
Dames and Moors (1977 to 1978), which demonstrated a con-
siderable improvement in the quality of groundwater sampled
from wells that still existed in the vicinity of the No. 5
disposal pond. However, groundwater sampled at the TE—lO
and TH—11 locations may have becom. slightly more affected
than it was in 1972. Comparisons of 1972 and 19 8 water—
quality data are presented in Table 1.
In October 1981, the cryolite recovery plant was shut
down and sludg. disposal practices were discontinued.
Shortly befors this time, a plant clean up effort was also
initiated, whereby, spent cathode and other debris accumu-
lated in the potliner storage areas wars hauled away; how-
ever, it is likely that equipment used in the clean up
effort broke and crushed some quantity of potliner material,
39
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TABLE 1..
COMPARISONS OP WATER-QUALITY DATA COLLECTED FROM TB-SERIES
MONITOR WELLS AT TIlE ORMET CORPORATION PLANT SITE, HANNIBAL, OHIO
u LC
IIJAUCII
0 Th
CNAO8
8I’tD
C*SUG
WUI€
IUS3RICS
(en/Il
Dl i9IJ(MW
9 LII
(en_/li
UA 3I*
(en/ i)
IIIN6IdI?IIND
( 8)
Ou.onloc
( ii’I)
cvi uiu . 1 AJ*U.IIt
(.i /l) ( /l)
W l dl
1912 8afl9 5
210- 1100
096
10.1-10.9
2766—1100
—
--
08-35—78
166.1
6.8
66.1
3.500
65
24
LI
80
(0.01
0.00
11-09—71
—
2
62.3
2.200
—
II
8.7
—
0.02
U II 111-3
1972 Ilanje
—
—
110—46 1
—
—
0—09
9.2—10.1
3!J0-e43
—
—-
01-2 5- lI
378.0
8.8
9.9
500
100
91
9.1
39
0.uI
( 1.00
11-09—78
—
12
11.5
600
125
113
8.9
.‘i
0.01
0. 17
0 1- 84
—
3
1.9
—
—
96
7.5
—-
C II
--
02-el
—
3
3.4
—
—
—
7.4
3 .
0.IG
i .Il11I-7
1972 R.rnjO
08-2 9—78
—
66.0
4.2
250364
34.1
700
10
0
9
9.0-10.0
7.9
4)
(0.01
2. 10
I i.ll iu-1o
1972 R y s
11-09—71
—
—
—
2.4
0.9—10.0
43.4
—
1500
—
—
2—98
0
7.2—8.1
7.9
128
——
——
0.00
—-
0.00
t ll ill—Il
1972 Ran s
08-28—78
—
18
—
1
1.4—10.1
8.6
—
500
—
120
0—9 5
15
.9—7.9
6.6
117—112
51
—
—
—
0.49
.li Ill—IS
1972 Kwq
12-0 1— 11
—
198.5
—
S.)
1.0-2.7
2.2
—
—
—
07-99
7.2—8.2
7.3
21—32
—
—
—
—
- —
0 1- 14
—
3
(1.0
—
25
7.4
—
0.03
——
02-84
—
3
1.0
—
—
—
7.5
13
(0.01
0.00
%clL 111—16
1972 kanljs
11-09—71
—
—
4.6
1.0-IS
0.2
300
165
90—99
100
7.9—5.6
7.7
27
30
0.00
—
1.02
t .1l Ill—Il
1972 8an
0 5-28—70
1 1-09- 18
—
$590
—
—
5.3
2.05
0-0.24
(0.2
(0.2
—
500
400
—
255
260
30-99
lO S
100
7.3-7.9
7.3
7.3
34-39
43
42
——
0.01
0.00
—-
0.00
0.00
• 1984 ConcentratIons rellect total cyanldes 1978 concentratIons nay represent tree cyanide.
•& cei 1972 d. ita l lected c5irin Fred Claer aed Asanciate5 etisly 1975 data collected airing *5 6 I re stixly; 19114 d ta collected
air Inij Gcr.jsly I I d llor In c. 4 LwIy. 611 dunical n. ly.e ro pcctonnd by the 0 t corporation lat catoy.
IJ
01
n
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Gera hcy & Milkr, Inc.
which pr0bably remains within the upper few feet of soil
beneath this area. One could reasonably speculate that such
a change in the consistency of potliner wastes should make
this material more susceptible to leaching; i.e., crushing
increases specific surface area, which, for a given volume
of material, exposes relatively greater quantities of
soluble components.
In March 1982, a third interceptor well was also in-
stalled adjacent to the southwest corner of the No. 5 dis-
posal pond in an effort to collect degraded groundwater
before it migrates toward the Ormet Ranney v•ll. This
well is currently pumped at several hundred gallons per
minute, which is discharged to the No. 5 disposal pond
overflow. Fluid pumped from the well is alkaline, tea to
coffee colored, and contains fluoride and cyanide. Averaged
water—quality data (1982 to 1983) for the new intercepter
well, the old intercepter wells (collectively regarded as
one well), and the Ormet Ranney well are presented in
Appendix 0—4.
In the time since the Ormet Rannsy well was installed,
a gradual decrease in well yield has become apparent.
Initially, this may have been largely due to carbonate in-
crustation or siltation; however, recent decreases (since
41
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Inc.
5 colored water began entering the well are largely
attributed to varying degress of incrustation by dark,
medium to hard material, which has been ObServed in well
laterals 5 through 8 (Ranney Company, 1982). Decreases in
old interceptor well yields have also OCCU red, and are
attributed to similar causes. One possible explanation for
the apparent increase in well screen incrust3tion is that,
upon reaching the pumping center, mixing of high pH plume
fluids with relatively unaffected groundwater probably
results in a net lowering of pH. This pH reduction may
cause certain plume constituents (e.g., si].jca, aluminum,
organic carbon) to become less soluble which, in turn,
results in precipitation (incrustation) at the well screen
and within adjacent sediments; a more detatled discussion
of this phenomenon is presented in future sections. In
addition, certain dissolved constituents within unaffected
groundwater (e.g., calcium), which become less soluble
under higher pH conditions, may also precipitate as a result
of fluid mixing.
Current Water—Quality Trends
Chemical analyses of recently collected (1983—1984)
groundwater samples suggest that former pQtliner storage
areas and sludge disposal ponds (particula ly Pond No. 5)
42
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Ger2ghcy & Mi11cr Inc.
located beneath the western portion of the plant site, also
contains fairly low levels of leachate indicator parameters,
and is believed to be a result of interrupted pumping at the
Ormet Ranney well, which may have allowed intermittent
shifting of leachate plumes (A and/or B) to the west.
A more detailed (and more speculative) assessment of
Plume A conditions is presented in Figures 16 through 19.
Based on these interpretations, it appears that levels of
primary leachate indicators (i.e., pH, F, Q1, and Na) are
highest in the vicinity of former potliner storage areas,
and become reduced as the distance from the source in-
creases. It is likely that some quantity of leachate is
continually being generated from this area, and that concen-
tration versus distance trends characterizing these plumes
are probably largely controlled by groundwater dilution
or other attenuation mechanisms (e.g., sorption and natural
buffering). However, it is also likely that rates of
leachate generation have been periodically increased as a
result of excavation and other disturbances within this area
(such as the cleanup effort in 1981), and concentrated
slugs’ of effluent may have been introduced to the aquifer
system. Consequently, plums concentration trends could also
reflect fairly r :ent increases in the rate of leachate
50
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Gerighty & Miller, Inc.
generation. If this is the case, a relatively concentrated
slug of leachate iay be moving outward from the former
storage area.
It is interesting to note that Plume ‘A” effluents
exhibit a strong positive correlation between total cyanide
and total iron concentrations; i.e., high cyanide corre-
sponds to high iron (see Figure 20). Because iron is rela-
tively insoluble under high pH conditions characteristic
of ccncentrated leachate plumes, this trend is believed to
reflect the presence of iron—cyanide complexes within plume
fluids.
Water—quality trends within Plume Section B are
probably largely a result of effluent seepage from abandoned
disposal ponds (especially pond No. 5), but may also be
influenced by contaminant residues, remnant from past con-
ditions, that have not yet been flushed from the aquifer
system; flushing mediums include induced river recharge and
infiltrating precipitation. In general, (although not con-
sistently) wells situated within this plume show slightly
elevated pH. (up to pH 8), low to moderate fluoride levels
(<1 to 5 mg/i), and low concentrations of total cyanide
(<0.5 mg/i). Higher—than—background levels of sodium also
seem to characterize Plume “B”, but this trend is less
consistent.
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G :ighcy & Millet, Inc.
SOURCERELAT!D EFFECTS ON GROUNDWATER
Sludge Disposal Area
water—quality impacts resulting from sludge disposal.
practices appear to have been partially abated by neutra-
lizing sludge prior to discharge (1976), and probably became
further reduced as a result of discontinued sludge disposal
in 1981. Under present conditions (based on 1983—1984
data), the quality of groundwater moving beneath the No. 5
disposal pond appears suitable for many processing uses. In
particular, the pH has dropped to a near—neutral range, and
potential problems related to incrustation by silicate and
organic carbon precipitates are probably much less apt to
occur as a result of No. 5 disposal pond effluents.
It is possible (perhaps probable) that the quality
of groundwater affected by disposal ponds will continue
to improve with time, barring major changes or disturbances
in sludge bid conditions. However, affected groundwater
probably will not be suitable as a source for drinking water
supplies in th. near future.
Former Potliner Storage Area
Under present conditions, the quality of groundwater
apparently emanating from beneath former potliner storage
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G:: ghcy & M 1cr, Inc.
As can b. seen on Figure 13, Si0 2 Versus pH data
for several wells (e.g., Mw 18 and MW-2) plot within an area
of the silica solubility range where fairly minor reductions
in pH would result in super saturatjon of djSiOlv.d silica;
i.e., points would be shifted to the left of the Calculated
solubility curve for amorphous silica (Curve A), which
probably represents th. upper limit of saturation for
dissolved silica. Solubility data for organic carbon
species are less precise, but it is believed that similar
trends may also apply.
Future Considerations
At the present time, pumping of Orm.t’s Ranney and old
interceptor wells appears to be preventing migration of
degraded groundwater beyond the plant boundaries. However,
if yields from these wells continue to decreas, over time,
or _________________
Therefore, in order to maintain control over leachate plume
migration using the existing system of wells, it is neces
sary that pumping be continued at or near current rates.
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Geraghty & MiUer, Inc.
- ALTERNATIVE REMEDIAL MEASURES
General
The previous section listed some existing and potential
effects that have, or may, occur as a result of effluent
discharges from disposal ponds and potliner storage areas.
For the most part, these effects relate to limitations to
which groundwater resources beneath the Orntet Site can be
utilized, with respect to both process—water and sanitary—
water supplies. In addition, a potential also exists for
migration of leachate plumes beyond Orinet’s site boundaries.
Consequently, considerations of possible remedial measures
to abate potential and existing groundwater impacts should
focus on two basic objectives: 1) controlling migration of
leachate plumes within the aquifer system and 2) improving
aquifer conditions beneath the Orziet plant site. Possible
means by which these objectives could be accomplished are
discussed in the following sections.
controlling L.schate Plume Migration
Under present conditions, pumping of Ranney and inter-
ceptor wells within Buck Hill Bottom has created two large
cones of influence which converge to form a gently roun ed
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Gcr2ghcy & Miller, Inc.
crest, or drainage dLvide, that appears to be Situated
roughly parallel to Ormet’s west property boundary (see
Figure 12). This divide acts as a hydraulic barrier to
lateral groundwater flow and is essential in preventing
westward migration of leachate plumes. Consequently,
in order to control plume migration to the west, it is
necessary that the drainage divide be maintained at or
near its current position. This may becom. increasingly
more difficult if incrustation at Orset’s Rartney and old
interceptor walls continues to decrease pumpage i.e., as
punpage at the Ormet wells decreases, the resultant cone of
influence, and the ability to control plume migration, will
also decrease.
Owing to this potential, it is recommended that Ormet
monitor water—level and water—quality conditions beneath
western plant areas so as to provide early warning of any
changes in the position of the drainag, divide. If monitor-
ing results begin to indicate that the divide is shifting
s ward, it may be in Orinet’s best int.rest to establish
additional facilities that could be used to maintain (or
perhaps even increase) the integrity of the drainage divide.
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Geraghcy & Miller, Enc.
The most feasible alternatives for accomplishing this
objective include removal and/or injection of water.
Removal would basically involve installing additional
pumping wells that could be operated to maintain necessary
drawdowns beneath the Ormet site. These wells should be
located in the vicinity of (perhaps north of) the Ranney and
old interceptor wells so as to compound the drawdown effects
(i.e., overlap cones of influence) from existing and
new pumping facilities. The volum, of groundwater that
would have to be produced (and the number of wells needed)
probably depends largely on the extent of decreas, in Rann.y
and old interceptor well production. A potential disad-
vantage of the pumping well alternative is that the satur-
ated thickness of the aquifer beneath this area of the plant
ranges from only 20 to 30 feet, which limits th. yield that
can be obtained from a single well. This could necessitate
the installation of a greater number of wells (at a greater
expense) in order to create the drawdowns needed to control
plume migrations. Also, it ii likely that, over time, new
pumping wells may also experience incrustation problems and
may have to be serviced on a fairly regular basis.
The second alternative of injecting water into the
aquifer would involve installing several wells (probably
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G:: ghcy & Miller, Inc.
at least three) in a line roughly parallel to the existing
drainage divide. These wells could then be used to inject
the volumes of water needed to maintain a hydraulically
high zone beneath Ormet’s west plant boundary. Unlike
pumping facilities, the injection wells would not be sus-
ceptible to problems relating to incrustation and/or limited
aquifer thickness. However, for the injection systems to
operate efficiently over the long term, it is necessary that
injected water be virtually free of suspended sediments,
which would eventually clog the well. screen and adjacent
aquifer deposits. If clean groundwater were used, suspended
sediments probably would not pose a problem. However, if
river water represents the oniy feasible source, treatment
would have to be performed, and the resultant increase in
costs could become a discouraging factor. In addition, it
may oe necessary to obtain injection well permits in order
to legally operate this type of system.
It should be noted that other physical—type barriers,
such as slurry walls and sheet pilings, can also be used to
block plums migrations. However, depthi to bedrock (+100
feet) and the presence of buried cables and pipes beneath
this area of the Ormet plant diminish the technical and
economic feasibility of implementing these types of control
systems.
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Gerighcy Miller, Inc.
Improving Ormet’s Groundwater Conditions
Alternatives for accelerating the improvement of aquifer
conditions basically fall into on. of two categories,
namely: aquifer management and source—area management. In
general, aquifer management strategies focus on alleviating
or controlling adverse conditions that already exist within
the groundwater system, whereas, Source—area management
practices are aimed more at reducing or preventing further
degradation of the system. Some of th. more common methods
that can be used in these management programs ar. listed in
Table 2.
A reasonable initial goal for improving aquifer
conditions beneath the Ormet plant site would be to re-
store groundwater quality to a level acceptable for pro-
cessing uses. Under present conditions, it appears that
groundwater moving beneath the No. 5 disposal pond (and
probably other disposal ponds) may already be approaching
this level of quality; and it is possible (perhaps probable)
that, over tim., th. quality of groundwater beneath this
area will becom. more improved as solubl. and/or reactive
sludge components become depleted. It is, therefore, prob-
ably in Ormet’s best interest to continue groundwater
monitoring at selected locations around the disposal ponds,
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Gcr z cy & Miller, Inc.
TABLE 2.
COMMON ALTE1 NATIVES FOR ACCELEP.ATING IMPROVEMENT
OP AQUIFER CONDITIC S
‘1
Aquifer Management
Alternatives
• Removal of contaminants
via pumping wells,
collection drains, or
ditches
• Containment of con—
aininants via physical
and/or hydraulic
barriers
• In—situ stabilization
(neutralization) of
contaminants via
chemical and/or
biological treatment
66
Source—Area Management
Alternatives
• Removal of contaminant
source materials via
excavation or pumping
• Reduction of leachate
generation via
grading or capping
• Encapsulation of
source materials and
effluents via
physical barriers
• Stablization of
source material.
via chemical and/or
biological treatment
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Ger ghty & Miller, Inc.
because long—term water quality trends (collectea over at
least a one—year period) could indicate stable or improving
conditions that may not warrant implementation of high—cost
remedial actions,
Groundwater that appears to be moving beneath former
potliner storage areas exhibits water—quality conditions
that can promote incrustation of pumps and well screens, and
increased scaling within pipes and heat exchange equipment.
Consequently, accelerating improvement of potliner—related
groundwater conditions may be desirabi., in that, it could
help to reduce Orm.t’s dependency on outside water sources;
and may also help to increase the reliability of pumping—
type remedial measures that may be used to maintain hy-
draulic barriers beneath western plant areas.
A first step toward accomplishing this objective
would be to complete the removal of any remaining piles or
accumulations of potliner material, and establish a grade
that prevents pooling of surface water in former potliner
storage ar.as. The next logical step would be to continue
groundwater monitoring(for at least a year or more) at
selected locations to assess the effectiveness of source—
area management efforts. If water—quality trends indicate
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G ughcy & MiIIcr, Inc.
that conditions are beginning to show a progressive improve-
ment, it may only be necessary to restore vegetation to
this area in order to prevent erosion. If water—quality
trends show no change or indicate worsening conditions, it
may be necessary to consider additional remedial measures
for reducing leachate generation.
Oritet is currently implementing an aquifer management
alternative, in that, pumping of their Ranney and inter-
ceptor wells serves to remove leachate plumes already
present within the aquifer system, and controls migration of
these plumes beyond Ormet’s property boundaries. In the
event that a more intensive aquifer management is needed,
such as additional wells to control plume movements beneath
western plant areas, a further investigation of aquifer
hyudraulic properties is suggested in order to determine
th. most effective methodologies for accomplishing the
established aquifer management objectives.
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Ge:a;hcy & Miller, In
APPENDIX A
LITHOLOGIC DESCRIPTIONS AND MONITOR WELL
CONSTRUCTION DETAILS FROM THE DECEMBER 1983
DRILLING/WELL INSTALLATION PROGRAM AT TEE
OR T CORPORATION PLANT SITE
HANNIBAL. OHIO
Note: Material referred to as rock fragments
probably mainly represents broken or
weathered pebbles
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Ge: ,ghcv & Mi!Ier, Inc.
WELL. MW—l
(installed 11128/83)
Sample Depth Blow
Interval (ft) Count Description
0.0 — 1.5 grab Pebbles, sand, and silt,
black to dark brown color;
probably represents fill
5.0 — 6.5 7—6—5 Pebbles, sand, silt, and
clay, dark brown color;
probably represents fill
10.0 — 11.5 5—6—6 Pebbles, rock fragments,
sand, and silt, brown color
15.0 — 16.5 10—12—15 Pebbles and medium sand,
minor black (peat type)
material, grey to green
color; probably natural
20.0 — 21.5 5—6—15 Sand, medium, with minor
rock fragments, grey to
green color
25.0 — 26.5 10—23—32 Sand, mediws, with pebbles,
rock fragments, and several
thin layers of black (peat
type) material, grey to
green color
30.0 — 31.5 7—11—12 Sand, medium, with black
(peat type) layers, and
pebbles, grey to green
color
35.0 — 36.5 6—12—17 Sand, medium, with some
pebbles, grey to green color
40.0 — 41.5 8—10—12 Sand, medium, with some
pebbles, grey to green color
45.0 — 46.5 7—8—13 Sand, fine tO medium, with
pebbles and minor amounts of
silt, grey to green color
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Gcrighcy & MiUcr, Inc.
WELL MW—i (Cont)
(installed 11/28/83)
Sample Depth Blow
Interval (ft) Count Description
50.0 — 51.5 10—13—15 Sand, medium, with pebbles,
brown to tan color
55.0 — 56.5 10—13—11 Sand, medium to coarse, with
pebbles and silt, rust brown
color; hit water at about
54.5 feet
60.0 — 61.5 8—6—8 Sand, medium to coarse, with
pebbles and silt, rust brown
color
65.0 — 66.0 dropped Sand, fine to medium, with
rods—26 some pebbles, rust brown
color
66.0 — 69.0 — Bedrock at about 67 feet;
auger refusal at about 69
feet; bedrock appears to
consist mostly of grey shale
and/or mud stone
Borehole depth: 69 feet
Well depth: 69 feet
Screened interval: 69 to 49 feet
Well construction: 49 feet of 2—inch—diameter PVC casing
over 20 feet of 2—inch—diameter, 0.010—
inch slot PVC screen; about 2 feet of
PVC stick up
Comments: Cave—in to about 45 feet; sand pack to about 35
feet; 0.5 feet of bentonite on top of sand;
formation cuttings to about 5 feet; cement up to
ground level; protective cover installed
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Geraghcv & MWer, Inc.
WELL MW—2
(instaLled 11/29/83)
Sample Depth Blow
Interval (ft) Count Description
0.0 — 1.5 grab Cinder—type material, sand,
and a few rock fragments,
black color; probably repre-
sents fill
5.0 — 6.5 No sample attempted to avoid
potential damage to buried
pipes
10.0 — 11.5 5—3—3 No recovery
15.0 — 16.5 8—10—16 Rock fragments, sand, and
silt, brown to green color;
maybe natural
20.0 — 21.5 5—5—8 Sand, fine to medium, with
pebbles and several thin
layers of dark (peat type)
material, brown color; hit
perched water at about 20
feet
25.0 — 26.5 6—7—8 Pebbles, rock fragments,
sand, and silt, brown to
green color
30.0 — 31.5 9_So/lu Rock fragments, pebbles,
sand, and minor silt and
dark (peat type) material,
brown to tan color
35.0 — 36.5 6—5—13 Rock fragments, pebbles,
sand, and minor silt and
dark (peat type) material,
brown color
40.0 — 41.5 7—9—10 Sand, medium, and pebbles,
with minor rock fragments,
brown color
45.0 — 46.5 11—21—29 Sand, medium, and pebbles
and rock fragments, with
minor dark (coal type)
material, brown to green
color
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Geraghty & Miller, Inc.
WELL MW—2 (Cent)
(installed 11/29/83)
Sample Depth Blow
Interval (ft) Count Description
50.0 — 51.5 28—29—27 Sand, medium, and rock frag-
ments and pebbles, brown to
tan color
55.0 — 56.5 22—24—27 Sand, medium, and pebbles,
brown to tan color
60.0 — 61.5 15—27—21 Pebbles, medium to coarse
sand, and some rock f rag—
ments, brown color; hit water
at about 57.5 feet
65.0 — 66.5 Sand, medium to. coarse, and
small pebbles, brown color;
sample taken from auger
run—up
70.0 — 71.5 21—27—26 Sand, medium to coarse, with
small pebbles, brown color
75.0 — 76.5 26—17—20 Sand, medium to coarse, and
small pebbles, with minor
silt, brown color
80.0 — 81.5 26—28—17 Sand, medium to coarse,
changing to predominantly
rock fragments at base of
sample, brown color
85.0 — 86.0 16—51/3’ No recovery; split spoon
broke off and was left in
bottom of hole
86.0 Bedrock and auger refusal
at about 86 feet
Borehole depth: 86 f eat
Well depth: 84 feet
Sceened interval: 84 to 54 feet
Wellconstruction: 54 feet of 2—inch—diameter PVC casing
over 30 feet of 2—inch—diameter, 0.010—
inch—slot PVC screen; about 2 feft of
PVC stick—up
Comments: Cave—in to about 48 feet; sand pack to about 39
feet; 0.5 feet of bentonite on top of sand; for-
mation cuttings to about 5 feet; cement up to
ground level; protective cover installed
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G raghcy & Miller, Inc
WELL MW—3
(installed 11/29/83 to 11/30/83)
Sample Depth Blow
!nterval Cf t) Count Description
0.0 — 1.5 grab Pebbles, sand, and silt,
brown color; probably repre-
sents fill
5.0 — 6.5 3—5—6 Clay with silt, minor sand,
and a few pebbles, brown to
dark brown color; probably
natural
10.0 — 11.5 1—2—5 Clay with silt, minor sand,
and a few small pieces of
cinder—type material, brown
color; probably natural
15.0 — 16.5 2—3—6 Clay with silt, mottled
brown to rust brown color
20.0 — 21.5 2—3—2 Clay with silt, soft and
plastic, brown color
25.0 — 26.5 3—3—6 Clay with silt, very soft
and plastic, brown color
30.0 — 31.5 WOR—1 Silt with clay, minor amounts
of very fine sand, very soft
and plastic, brown color;
probably hit water at about
31 feet
35.0 — 36.5 WOR—WOH—l Silt and very fine sand,
with minor clay, very soft,
brown color
40.0 — 41.5 WOR—3—4 Silt and very fine sand,
with minor clay, very soft,
brown color
45.0 — 46.5 WOR—2—4 Silt and very fine sand,
oozy soft, brown color
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Gerighcy & Miller, In
WELL MW—3 (Cont)
(installed 11/29/83 to 11/30/83)
Sample Depth Blow
Interval (ft) Count Description
50.0 — 51.5 14—21—14 Pebbles and medium to coarse
sand, brown color
55.0 — 56.5 18—17—18 Pebbles, fine to coarse sand,
silt, and some rock fragments
and clay, brown to grey color
60.0 — 61.5 7—7—7 Sand, coarse, and small
pebbles, brown color
65.0 — 66.5 4—8—6 Sand, medium to coarse, and
several layers (up to 2-inch—
thick) of black (peat type)
material, brown color
70.0 — 71.5 Sand, medium to coarse,
brown color; sample taken
from auger run—up
75.0 — 76.0 Sand, medit to coarse, and
small to large pebbles;
sample taken from auger
run—up
76.0 — 77.0 Bedrock at about 76 feet;
auger refusal at about 77
feet
Borehole depth: 77 feet
Well depth: 76.5 feet
Screened interval: 76.5 to 46.5
Well construction: 46.5 feet of 2—inch—diameter PVC casing
over 30 feet of 2—inch—diameter, 0.010—
inch—slot PVC screen; about 2 feet of
PVC stick—up
Comments: Cave—in to about 31 feet; sand pack to about 29
feet; formation cuttings to about 5 feet; cement
up to ground level; protective cover installed
79
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Ger3ghcy & Miller, Inc.
WELLI MW—4
(installed 11/30/83)
Sample Depth Blow
Interval -(fe) Count Description
0.0 — 1.5 grab Silt, roots, and a few small
rock fragments, soil texture,
brown color; probably repre-
sents fill
5.0 — 6.5 2—1—2 silt, fine sand, pebbles, and
a few rock fragments, soil
texture, brown color; may
represent fill
10.0 — 11.5 3—3—5 Clay with some silt, mot-
tled brown color; may repre-
sent fill
15.0 — 16.5 4—7—7 Sand, medium to fine, with
rock fragments and some silt,
brown color
20.0 — 21.5 5—3—6 Sand, fine to medium, with
some silt and minor clay, and
a few pebbles, brown color
25.0 — 26.5 5—6—5 Clay with silt, pebbles,
and a few rock fragments,
brown to dark brown color
30.0 — 31.5 10—13—16 Pebbles and silt with some
clay and a few rock frag-
ments, brown to dark brown
color
35.0 — 36.5 6—8—11 Clay, with minor silt,
fairly dens., dark brown to
olive green color
40.0 — 41.5 4—7—8 Clay, with some silt, fairly
dense, mottled tan to brown
color
45.0 — 46.5 7—10—13 Clay, with minor silt, and
hairline fractures filled
with black (peat type) mate-
rial, fairly dense, brown
color
50.0 — 51.5 6—7—9 Silt, very fine sand, and
clay, brown color
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Geraghty & Miller, Enc.
WELL MW—4 (Cont)
(installed 11/30/83)
Sample Depth Blow
Interval (ft) Count Description
55.0 — 56.5 8—13—14 Silt, fine to medium sand,
- pebbles, and some clay and
black (peat type) material,
brown color
60.0 — 61.5 5—7—7 Pebbles, rock fragments,
and silt, with minor clay,
brown color; sample is damp
65.0 — 66.5 WOR Sand, medium to coarse,
pebbles and silt, brown
color; hit water at about 62
feet
70.0 — 71.5 11—10—9 Sand, medium to coarse, and
a few small pebbles, brown
color
75.0 — 76.5 12—22—25 Sand, medium to coarse, and
a few small pebbles, brown
color
80.0 — 81.5 11—13—15 Sand, medium to coarse, brown
color
85.0 — 86.5 37—24—19 Sand, medium to coarse, and
a few small pebbles, brown
color
90.0 — 91.5 14—11—12 No recovery, probably same
as above
93.0 — 94.0 Bedrock at about 93 feet;
auger refusal. at about 94
feet
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G righcy & Miller, Inc.
WELL MW—4 (Cont)
(installed 11/30/83)
Borehole depth: 94 feet
Well depth: 74 feet
Screened interval: 74 to 54 feet
Well construction: 54 feet of 2—inch—diameter PVC casing
over 20 feet of 2—inch—diameter, 0.010—
inch—slot PVC screen; about 2 feet of
PVC stick—up
Comments: Bottom 20 f eat of augers broke off and were left
in borehole beneath the monitor well; cave—in
to about 61 feet; sand pack to about 44 feet;
0.5 feet of bentonite on top of sand; formation
cuttings up to about 5 feet; cement up to ground
level; protective cover installed
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Geri hcy & Miller, Inc
WELl. MW—5
(installed 12/01/83)
Sample Depth Blow
Interval (ft) Count Description
0.0 — 1.5 grab Black top (about 4 inches
thick) changing to fill con-
sisting of rock fragments,
clay, silt, and some pebbles,
dark brown to black color
5.0 — 6.5 grab Pebbles, silt, and clay,
brown color; probably repre-
sents fill
10.0 — 11.5 2—3—4 Rock fragments, pebbles,
silt, sand, minor clay, and
some cinder type material,
brown color; probably repre-
sents fill; sample La wet
15.0 — 16.5 11—12—13 Pebbles, silt, rock frag-
ments, and fine to medium
sand, brown to tan color;
probably mostly represents
fill; hit perched water at
about 11 feet
20.0 — 21.5 5—7—8 Sand, medium grained, with
pebbles and silt, and a layer
(about 1 inch thick) of black
(peat type) material, brown
color; sample is probably
natural
25.0 — 26.5 3—6—8 Sand, medium, pebbles and
silt, with some black (peat
type) material, brown color
30.0 — 31.5 5—8—11 Sand, medium, with some
pebbles and silt, and a few
rock fragments, brown color
35.0 — 36.5 9—9—9 Sand, medium, with pebbles,
some silt, and minor black
(peat type) material, brown
color; sample is damp
40.0 — 41.5 4—5—8 Sand, medium to coarse, with
some pebbles and rock frag-
ments, and minor silt, brown
color; sample is damp
83
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G r2ghty & Miller, Inc.
WELL MW—S (Cont)
(installed 12/01/83)
Sample Depth Blow
Interval (ft) Count Description
45.0 — 46.5 7—9—19 Sand, fine to coarse, peb-
bles, and some silt, brown
color; sample is damp
50.0 — 51.5 6—7—9 Sand, medium to coarse, with
pebbles and some rock f rag—
ments, brown color; sample is
d amp
55.0 — 56.5 20—25—23 Sand, coarse, with rock frag-
ments, pebbles, and minor
silt, brown color; hit per-
ched water at about 54 feet
60.0 — 61.5 10—16—19 Sand, coarse, with some small
pebbles and minor silt, brown
color; sample is damp
65.0 — 66.5 20—24—25 Sand, medium to coarse, with
some pebbles, brown color;
sample is damp
70.0 — 71.5 15—21—25 Sand, medium to coarse, and
pebbles, brown color; hit
water at about 67 feet
75.0 — 76.5 10—12—14 Sand, medium , with some
small pebbles,. brown color
80.0 — 81.5 drop—16—42 Sand, medium to coarse, and
some pebbles, brown color
85.0 — 86.5 8—10—11 Sand, medium to coarse, and
some pebbles, brown color
91.0 — 93.0. 35—20—16—16 Sand, medium to coarse,
changing to rock fragments
and silty to sandy clay at
bottom of sample, brown
color
93.0 — 95.0 No sample, drove rods until
refusal; bedrock at about 95
feet
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Gerighcy & Miller, Inc.
WELL MW—5 (Cont)
(installed 12/01/83)
90 to 60 feet
60 feet of 2—inch—diameter PVC casing
over 30 feet of 2—inch—diameter, 0.010—
inch—slot PVC screen; about 2 feet of
PVC stick—up
Cave—in to about 21 feet; sand pack to about 19
feet; 0.5 feet of bentonite on top of sand;
formation cuttings to about 5 feet; cement up to
ground level; protective cover installed
Borehole depth: 90 feet
Well depth: 90 feet
Screened interval:
Well construction:
Comments:
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D
Gcr ghcy & MU1e . Inc.
WEL L MW—6
- (installed 12/01/83)
Sample Depth Blow
Interval (ft) Count Description
0.0 — 1.5 grab Sand, medium, and silt with
some small pebbles, brown
color; probably represents
fill
5.0 — 6.5 5—3—3 Sand, clay, silt, and some
pebbles, brown color, prob-
ably represents fill
10.0 — 11.5 3—2—3 Sand, medium to fine, with
some silt and rock fragments,
brown color; material is
probably natural
15.0 — 16.5 4—7—8 Sand, fin, to medium, and a
few small pebbles, brown
color; only about a 3—inch
recovery
20.0 — 21.5 3—5—4 Sand, medium to fine, with
some black (peat type) mate-
rial, brown color; lower part
of sample is damp
25.0 — 26.0 3—4—5 Sand, fine to medium, with a
few pebbles, brown color;
hit perched water at about 22
feet
30.0 — 31.5 3—2—2 Sand, medium to fine, with a
few pebbles, changing to
silty clay, brown color;
change at about 31 feet
35.0 — 36.5 WOB Clay, silty to sandy, brown
to orang. color, changing to
sand, fine grained, with a
few pebble , grey to green
color; change at about 36
feet
40.0 — 41.5 2—10—9 Sand, fine to medium, with
silt and clay, some black
(peat type) material, and
some small rock fragments,
dark grey to green color
86
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Gcrighry & Miller, Inc
WELL MW—6 (Cont)
(installed 12/01/83)
Sample Depth Blew
tntetval (ft) Count Description
45.0 — 46.5 19—26—47 Clay, very hard and stiff,
green to dark grey color;
sample is very dry
50.0 — 51.5 50/4” Coal, black color, changing
to very stiff, hard clay,
grey color
51.0 — 52.5 Bedrock at about 51 feet;
auger refusal at about 52.5
feet
Borehole depth: 52.5 feet
Comments: No well was installed because of suspected
limited extent of the water table aquifer in
this area, i.e., it is believed that mostly
perched water was encountered; hole was back—
filled with cuttings and marked by flat rock.
87
10
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‘ii
Gc:ighty & Miller, Inc.
WELL MW—7
(installed 12/02/83)
Sample Depth Blow
Interval Cf t) Count Description
0.0 — 1.5 grab Blacktop (about 4—inches
thick) changing to fill con-
sisting of sand, silt, and
pebbles, brown color
5.0 — 6.5 2—3—5 Sand, medium to fine, silt,
rock fragments, and pebbles,
brown color; probably repre-
sents fill
10.0 — 11.5 7—7—7 Sand, medium to coarse, silt,
rock fragments, and pebbles,
brown color
15.0 — 16.5 6—9—9 Sand, fine to medium, and a
few pebbles, brown color;
sample is probably natural
20.0 — 21.5 14—21—20 Sand, medium to fine, with
som. pebbles and rock frag-
ments, brown color; augers
were bringing up water,
possibly storm drain leakage
25.0 — 26.5 11—15—26 Sand, medium to fine, with
some pebbles and a few rock
fragments, brown color
30.0 — 31.5 12—20—23 Sand, medium to fine, with
some pebbles, brown color
35.0 — 36.5 9—11—13 Sand, medium to fine, with
som. pebbles, a few rock
fragments, and a layer (about
2 inches thick) of black
(peat type) material, brown
color
40.0 — 41.5 18—16—20 Sand, fine to medium, with
some pebbles and a few rock
fragments, brown color
45.0 — 46.5 21—19—22 Sand, medium, with some
pebbles and rock fragments,
and minor silt, brown color
88
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Geraghcy & Miller. Inc
WELL MW—7 (Cont)
(installe l2/02/B3)
Sample Depth Blow
Interval (ft) Count Description
50.0 — 51.5 18—11—11 Sand, medium, with pebbles
and a few rock fragments,
brown color
55.0 — 56.5 9—10—11 Sand, fine to medium, with
some pebbles, brown color
60.0 — 61.5 13—7—10 Sand, medi to coarse, with
pebbles and some silt, brown
color, changing to clay and
silt, with pebbles and some
sand, rust brown color;
change at about 61. feet;
sample is damp
65.0 — 66.5 11—7—8 Clay and silt, with sand
and some pebbles and rock
fragments, brown to rust
brown color; hit water at
about 64 feet
70.0 — 71.5 14—13—14 Pebbles, sand, and silt,
brown to green color
75.0 — 76.5 67/6 Sand, silt, and rock frag-
ments, changing to decom-
posed rock, brown color
77.0 — 79.0 Bedrock at about 77 feet;
auger refusal at about 79
feet
Borehole depth: 79 feet
Well depth: 78 feet
Screened interval: 78 to 58 feet
Well construction: 58 feet of 2—inch—diam.ter PVC casing
over 20 feet of 2—inch—diameter, 0.010—
inch—slot PVC screen; about 2 feet of
PVC stick—up
Comments: Cave—in to about 21 feet; 1 foot of bentonLte
on top of cave-in; formation cuttings up to
about 5 feet; cement up to ground level; pro-
tective cover installed
89
Io’ 7 ’i
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(‘C’
I ’)
G::aghcv & MLIICr. Inc
wEr L. MW—8
(installed 12/02/83 and 12/04/83)
Sample Depth Blow
Interval (ft) Count Description
0.0 — 1.5 grab Sand, silt, and some small
pebbles, brown color; prob-
ably represents fill
5.0 — 6.5 3—2—2 Silt and sand, with some
clay and a few pebbles, brown
color; probably represents
fill; sample is damp
10.0 — 11.5 2—2—2 Clay with silt, some sand,
and a few pebbles, brown to
rust brown color, sample is
probably mostly natural;
sample is damp
15.0 — 16.5 3—4—5 Clay with minor silt, fairly
dense, brown to rust brown
color
20.0 — 21.5 5—8—9 Clay with some silt, minor
sand, and a few pebbles,
brown color
25.0 — 26.5 7—8—11 Clay with minor silt, brown
to rust brown color
30.0 — 31.5 6—11—23 Clay with some silt and minor
fine sand, fairly dense and
plastic, mottled brown to
green color, changing to silt
with som. clay and a few
pebbles, fairly hard and
stiff, grey color; change at
about 31.5 feet
35.0 — 36.5 6—7—7 Sand, fine to very fine, with
minor silt, brown to tan
color
40.0 — 41.5 788 Sand, fine to very fine,
brown to tan color
45.0 — 46.5 6—7—9 Sand, fine to very fine,
brown to tan color
90
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Geright)’ & Miller, Inc.
WELL MW—8 (Cont)
(installed 12/02/83 and 12/04/83)
Sample Depth Blow
Interval Cf ti Count Description
50.0 — 56.5 9—10—7 Sand, medium to coarse, with
pebbles, a few rock frag—
ments, and pebbles, brown to
tan color
55.0 — 56.5 4—8—10 Sand, medium to coarse, with
pebbles, a few rock fragments,
and minor black (peat type)
material, brown color
60.0 — 61.5 6—6—10 Sand, fine to medium, with
some pebbles, brown color
65.0 — 66.5 13—13—16 Sand, medium to coarse, with
pebbles, brown color
70.0 — 71.5 12—14—15 Sand, medium, with some
pebbles and a minor silty
zone, brown color
75.0 — 76.5 7—9—11 Sand, medium to coarse,
and some pebbles, brown
color; hit water at about 75
feet
80.0 - 81.5 dropped Sand, medium to coarse,
with some pebbles, brown
color
85.0 — 86.5 9—16—25 Sand, medium to coarse,
and some pebbles, brown
color
90.0 — 91.5 13—18—18 Sand, medium to coarse,
and pebbles, brown color
95.0 — 96.5 11—14—20 Sand, medium to coarse,
and a few pebbles, brown
color
97.0 — 98.0 Bedrock and auger refusal
at about 98 feet
91
I a
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Gerighcy & Miller, Inc.
WELIL MW—8 (Cortt)
(installed 12/02/83 and 12/04/83)
98 to 68 feet
68 feet of 2—inch—diameter PVC casing
over 30 feet of 2—inch—diameter, 0.010—
inch—slot PVC screen; about 2 feet of
PVC stick—up
Cave—in to about 50 feet; sand pack to about 48
feet; 0.5 feet of bentonite on top of sand pack;
formation cuttings to about 5 feet; cement up
to ground level; protective cover installed
Borehole depth: 98 feet
Well depth: 98 feet
Screened interval:
Well construction:
Comments:
92
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Gcr ghty & MiUer, Inc.
WELL MW—9
(installed 12/05/83)
Sample Depth Blow
Interval (ft) Count Description
0.0 — 1.5 grab Clay, silt, and pebbles,
brown color; probably repre-
sents fill
5.0 — 6.5 2—2—2 Clay, silt, pebbles, and some
black (cinder type) material;
probably represents fill
10.0 — 11.5 5—8—10 Clay, with silt and some fine
sand, and a few rock frag-
ments, fairly dense, brown
color; probably natural
15.0 — 16.5 5—7—22 Clay with silt, becoming more
pebbly and sandy towards
base, fairly dense, brown
color; probably natural
20.0 — 21.5 5—7—10 Clay with s e silt, fairly
dens., brown color
25.0 — 26.5 5—17—24 Pebbles and silt, with some
clay and miner sand, dark
brown color
30.0 — 31.5 7—7—10 silt with clay, dark brown
color
35.0 — 36.5 5—8—9 silt and very fine sand, with
minor clay, brown color
40.0 — 41.5 5—7—8 Sand, very, fin., and silt,
brown color
45.0 — 46.5 5—8—9 Sand, very fine, and some
pebbles, brown color
50.0 — 51.5 5—8—9 Pebbles, with some sand and
silt, brown color
93
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G :îg!icy & MiUer. Inc
WELL, NW—9 (Cortt)
(installed 12/05/83)
Sample Depth Blow
Interval (ft) Count Description
55.0 — 56.5 5—6—8 Pebbles, with medium to
coarse sand, and minor silt,
brown color
60.0 — 61.5 10—11—15 Sand, fine to medium, with
pebbles and a layer (about
1—inch thick) of black
(peat type) material, brown
Co 1 or
65.0 — 66.5 18—19—18 Sand, medium to coarse, and
pebbles, brown color
70.0 — 71.5 8—8—9 Sand, medium to coarse, and
pebbles, brown color; hit
water at about 70 feet
75.0 — 76.5 15—18—20 Sand, medium to coarse, and
pebbles, brown color
80.0 — 81.5 14—15—19 Sand, medium to coarse, and
some small pebbles, brown
color
85.0 — 86.5 18—16—16 Sand, medium to coarse, and
some pebbles, brown color
90.0 — 91.5 9—10—11 Sand, medium to coarse, and
pebble., brown color
95.0 — 96.5 10—11—16 Sand, medium to coarse, and a
few pebbles, brown color
100.0 — 100.5 5 1/6 Sand, medium to coarse, with
some small pebbles, brown
color, changing to clay with
sand, pebbles, and rock
fragments, grey to brown
color
100.5 — 101.0 Bedrock and auger refusal at
about 10]. feet
94
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Gcri hry ê. Miiler. Inc.
WELL MW—9 (Cont)
(installed 12/05/83)
Borehole depth: 101 feet
Well depth: 101 feet
Screened interval:
Well construction:
101 to 71 feet
71 feet of 2—inch—diameter PVC casing
over 30 feet of 2—inch—diameter, 0.010—
inch—slot PVC screen; about 2 feet of
PVC stick—up
Comments: Cave—in to about 55 feet; sand pack to about 53
feet; formation cuttings to about 15 feet; 1 foot
of cement and 0.5 feet of bentonite on top of
cuttings; formation cuttings to about 5 feet;
cement up to ground level; protective cover
installed
95
I
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G ri hcy & M Ikr. Inc.
WELIZ& MW—l0
(installed 12/05/83)
Sample Depth Blow
Interval (ft) Count Description
0.0 — 1.5 grab Silt, sand, some clay and
pebbles, and some alumina
powder, brown to grey color;
probably represents fill
5.0 — 6.5 6—6—6 Sand, fine, and silt, with
a few pebbles and minor clay.
brown color; probably repre-
sents fill
10.0 — 11.5 WOR No recovery; based on blow
count must be fairly Qezy;
probably represents fill;
hit perched water at about 10
feet
15.0 — 16.5 19—17—21 Pebbles, rock fragments,
silt, and some sand, dark
brown color; probably repre-
sents compacted fill; driller
through the lithology change
occurred at about 13 feet
20.0 — 21.5 27—39—32 Poor recovery of only gravel7
may be the sam. as above
25.0 — 26.5 10—B—S Sand, medium, and silt with
some pebbles, brown color;
probably natural
30.0 — 31.5 7—14—19 Sand, fin., with som. silt,
brown color
35.0 — 36.5 7—9—12 silt with fine sand, brown
color
40.0 — 41.5 9—9—10 Sand, fine, with silt, brown
color
45.0 — 46.5 910—12 Sand, fine, with minor silt
and pebbles. brown color
96
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Gerighcy & Miller, Inc.
WELL MW—1O (Cant)
(Lnstalled 12/05/83)
Sample Depth Blow
Interval (ft) Count Description
50.0 — 51.5 7—9—10 Sand, fine, with some silt
and pebbles, brown color
55.0 — 56.5 12—18—17 Sand, medium to coarse, with
pebbles and minor silt, brown
color
60.0 — 61.5 9—10—10 Sand, medium to coarse, with
pebbles, minor silt, and some
black (peat type) material,
brown color
65.0 — 66.5 9—11—17 Sand; medium to coarse, with
som. pebbles, brown color
70.0 — 71.5 14—21—24 Sand, medium to coarse, and
p.bbl.s, with sos. rock f rag—
sent., brown color
75.0 — 76.5 13—11—10 Sand, medium, brown color;
hit water at about 74 feet
80.0 — 81.5 15—16—21 Sand, medium to coarse, and
some pebbles, with minor
silt, brown color
85.0 — 86.5 9—19—24 Sand, medium to coarse, with
some pebbles, brown color
90.0 — 91.5 14—18—23 Sand, coarse, with pebbles,
• brown color
95.0 — 96.5 17—30—28 Sand, medium to coarse, and
pebbles, brown color
100.0—100.5 51/3 Bedrock at about 100 feet;
• aug•r r•fuaal at about 100.5
feet; decomposed rock on lead
auger is grey color and looks
like wsathered shale or mud-
stone
97
1 C)
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‘1
& Miller. Inc.
WELL. MW-b (Cont)
(installed 12/05/83)
Borehole depth: 100 feet
Well depth: 100 feet
Screened interval: 100 to 70 feet
Well construction: 70 feet of 2—inch—diameter PVC casing
over 30 feet of 2—inch—diameter, 0.010—
inch—slot PVC screen; about 2 feet of
PVC stick—up
Comments: Cave—in to about 31 fe.t; sand pack and more
cave—in to about 10 feet; 1 pack of cement plus
more cave—in to about 5 feet; cement up to
ground level; protective cover installed
98
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G r3Shcy & Miller, Inc.
WELL MW—il
(installed 12/06/83)
Sample Depth Blow
Interval (ft) Count Description
0.0 — 1.5 grab Blacktop (about 4—inches
thick) changing to pebbles,
silt, and sand, brown color;
probably represents fill.
5.0 — 6.5 No sample attempted because
of buried pipes
10.0 — 11.5 3—3—4 Pebbles, silt, sand, and
some clay, brown color;
probably represents fill
15.0 — 16.5 9—12—18 Sand, medium, and silt,
with some pebbles and rock
fragments, brown color;
probably natural; sample is
damp
20.0 — 21.5 4—5—6 Silt with very fine sand,
brown color
25.0 — 26.5 3—5—4 silt with some very fine
sand, changing to pebbles
with medium to coarse sand,
and minor silt, brown color
30.0 — 31.5 6—9—8 Sand, medii to coarse, with
pebbles, rock fragments, and
some silt, brown color
35.0 — 36.5 6—8—9 Sand, medium, with some
pebbles and a few rock frag-
ments, brown color
40.0 — 41.5 3—5—6 Sand, coarse, and pebbles,
with some silt, brown color
45.0 — 46.5 4—6—5 Sand, coarse, with pebbles
and some silt, brown color
99
10
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‘U
G:r3g 1cy & MzI!er. Ir c.
WEL 1 I MW—il (Cont)
(installed 12/06/83)
Sample Depth Blow
Interval (ft) Count Description
50.0 — 51.5 9—11—10 Sand, medium to coarse, with
some pebbles, a few rock
fragments, and minor silt,
brown color
55.0 — 56.5 22—22—25 Sand, medium to coarse, and
pebbles, brown color
60.0 — 61.5 15—12—14 Sand, medium to coarse, with
some pebbles and a layer
(about 1/2—inch thick) of
black (peat type) material,
brown color
65.0 — 66.5 15—15—19 Sand, medium to coarse, with
pebbles and a few rock frag-
ments, brown color
70.0 — 71.5 17—26—27 Sand, medium, with a few
pebbles, brown color
75.0 — 76.5 8—9—11 Sand, medium to coarse, and
small pebbles, brown color;
hit water at about 72 feet
80.0 — 81.5 8—11—16 Sand, medium to coarse,
with som. pebbles, brown
color
85.0 — 86.5 52/4 Rock fragm.nts, dark grey
color; driller thought he may
have augere.d through cobbles
from about 85 to 87 feet
90.0 — 91.5 7—8—9 Sand, medium to coarse, with
a few small p.bbl.s, brown
color
95.0 — 95.5 65/3 Bedrock and auger refusal at
about 95.5 feet; no recovery
on sample attempt
100
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Ger ghcy & Miller. Inc.
WEIJ.I MW—li (Cont)
(installed 12/06/83)
Borehole depth: 95.5 feet
Well depth: 95.5 feet
Screened interval: 95.5 to 65.5 feet
Well construction: 65.5 feet of 2—inch—diameter PVC casing
over 30 feet of 2—inch—diameter, 0.010—
inch—slot PVC screen; about 1.5 feet of
PVC stick—up
Comments: Cave—in to about 25 feet; sand pack to about 23
feet; 1 sack of cement and 0.5 feet of bentonite
on top of sand pack; formation cuttings to about
5 feet; cement up to ground level; protective
cover installed
101
(.1 /
I’. ‘
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G r hcv J Miner. Lr c.
WELJL —l2
(installed .L2/07/83)
Sample Depth Blow
Interval (ft) Count Description
0.0 — 1.5 grab Silt and sand, with some
clay and a few pebbles, brown
color; probably represents
fill
5.0 — 6.5 2—2—2 Silt, sand, clay, and a few
rock fragm.nes, brown color;
may be natural,
10.0 — 11.5 2—2—2 Clay with some silt, very
soft and plastic, grey to
green color; probably natural;
sampl. is damp
15.0 — 16.5 4—3—5 silt, fine sand, and some
clay, brown color, becoming
more sandy and grey colored
toward baa.
20.0 — 21.5 5—4—5 silt and sand, with some
clay and a few pebbles, brown
color
25.0 — 26.5 5—8—7 Sand, medium, and pebbles,
with some silt, brown color;
hit water at about 26.5 feet
30.0 — 31.5 4—3—6 Sand, medium, and pebbles,
brown color
35.0 — 36.5 4—4—6 Sand, medium to coarse, and
pebbl•s, brown color
40.0 — 41.5 9—5—10 Sand, medium to coarse, and
small pebbles, brown color
45.0 — 46.5 7—8—10 Sand, medium to coarse,
brown color
102
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Geraghcy & Miller, Inc.
WELL. MW—12 (Cont)
(installed 12/07/83)
Sample Depth Blow
Interval (ft) Count Description
50.0 — 51.5 7—11—17 Sand, medium, with small
pebbles, brown color
55.0 — 56.5 23—37—34 Sand, medium to coarse, and
pebbles, brown color
60.0 — 61.5 16—22—19 Sand, medium to coarse, and
a few pebbles, brown color
65.0 — 66.5 21—18—51/5’ Sand, medium to coarse, and
some pebbles, brown color
66.5 — 67.0 Bedrock at about 66.5 feet;
auger refusal at about 67
feet
Borehole depth: 67 feet
Well depth: 67 feet
Screened interval: 67 to 27 feet
Well construction: 27 feet of 2—inch—diameter PVC casing
over 40 feet of 2—inch—diameter, 0.010—
inch—slot PVC screen; about 2 feet of
PVC stick—up
Comments: Cave—in to about 15 feet; 1 sack cement and 0.5
feet of bentonite on top of cave—in; formation
cuttings to about 4 feet; cement up to ground
level; protective cover installed
103
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G ughty & Mikr, Inc.
WELL MW—13
(installed 12/07/83)
Sample Depth Blow
Interval (ft) Count Description
0.0 — 25.0 No sampling attempted because
this zone is comprised of
fill and rubble, i.e., brick,
cinders, carbon, etc.
25.0 — 26.5 3—13—19 Silt, sand, and clay, with a
few small pebbles, brown
color; probably natural;
fill/natural contact believed
to be between 20 and 25 feet
30.0 — 31.5 5—6—7 Silt and fine sand, with some
clay, brown color
35.0 — 36.5 5—4—4 Silt and fine sand, with some
clay, brown color
40.0 — 41.5 3—3—4 Silt and fine sand, with some
clay, brown color
45.0 — 46.5 WOil—2—2 Silt, fine sand, and clay,
brown color
50.0 — 51.5 WOB—4—5 Sand, fine, and silt, with
some clay, brown color;
hit water at about 48 feet
55.0 — 56.5 2—4—7 Sand, fine, with silt, brown
color
60.0 — 61.5 3—4—9 Sand, fine, and silt with
some clay, brown color
65.0 — 66.5 24—27—28 Pebbles and medium to coarse
sand, brown color
70.0 — 71.5 7—9—14 Pebbles and medium to coarse
sand, with minor silt, brown
color
104
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Ger3ghcy & Miiler, Inc.
WELL MW—13 (Cone)
(installed 12/07/83)
Sample Depth Blow
Interval (ft) Count Description
75.0 — 76.5 7—7—9 Sand, medium to coarse, with
some pebbles and some black
(peat type) material at base
of sample, brown color
80.0 — 81.5 10—12—14 Sand, medium to coarse,
brown color
85.0 — 86.5 29—34—40 Sand, medium to coarse, with
pebbles and sos. rock frag-
ments, brown color; decom-
posed rock towards base
88.0 Bedrock probably at about 88
feet; driller did not want to
stress augers until refusal
Borehole depth: 88 feet
Well depth: 87 feet
Screened interval: 87 to 57 feet
Well construction: 57 feet of 2—inch—diameter PVC casing
over 30 feet of 2—inch—diameter, 0.010—
inch—slot PVC screen; about 2 feet of
PVC stick—up
Comments: Cave—in to about 49 feet; sand pack to about
44 feet; cave—in to about 25 feet; 1 sack of
cement and 0.5 feet of bentonite on top of cave—
in; formation cuttings to about 5 feet; cement
up to ground level; protective cover installed
105
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G r ghty & Milkr. Inc
WELL MW—l4
(installed 12/08/83)
Sample Depth Blow
Interval (ft) Count Description
0.0 — 3.5 grab Sand, silt, rock fragments,
and some brick, dark brown
color; probably represents
fill
5.0 — 6.5 6—2—3 Sand, silt, pebbles, and some
slag, dark brown color; prob-
ably represents fill
10.0 — 11.5 1—2—8 silt with some very fine
sand, a few pebbles, and some
clay, brown color; probably
natural
15.0 — 16.5 3—2—3 Silt and fine sand, with a
few pebbles, and minor clay,
brown color
20.0 — 21.5 3—2—3 Clay with silt, and some
sand and pebble., grey color;
could also be called silt
with clay
25.0 — 26.5 2—1—2 Silt and clay, with some
sand and pebbles, dark brown
to grey color; very poor
recovery
30.0 — 31.5 3—2—4 Clay with some silt, soft and
plastic, grey color
35.0 — 36.5 4—6—9 Clay with.aome silt, soft and
plastic, mottled green to
grey color; pushed Shelby
tube from 35 to 37 feet with
full recovery
40.0 — 41.5 4—5—6 Clay with some silt, mottled
green to grey color
45.0 — 46.5 5—12—16 Sand, medium, with pebbles,
brown to grey color; tip of
sample is wet
1 06
0
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Geraghty & Miller, Inc.
WELL MW—14 (Cont)
(installed 12/08/83)
Sample Depth Blow
Interval (ft) Count Description
50.0 - 51.5 8—10—13 Sand, medium to coarse, with
some pebbles, brown color;
hit water at about 44 feet
55.0 — 56.5 2—4—10 Sand, medium to coarse, and
pebbles, brown color
60.0 — 61.5 6—11—17 Sand, medium to coarse, and
small pebbles, brown color
65.0 — 66.5 15—14—12 Sand, medium to coarse, and
some pebbles, brown color
70.0 — 71.5 17—23—24 No recovery; probably same
as above
75.0 — 76.5 12—19—25 Sand, medit to coarse, and
pebbles, brown color
80.0 — 81.5 12—12—12 Sand, medium to coarse,
brown color
85.0 — 86.0 51/1 Bedrock at about 85.5 feet;
auger refusal at about 86
feet; no recovery from
sampling attempt
Borehole depth: 86 feet
Well depth: 86 feet
Screened interval: 86 to 46 feet
Well construction: 46 feet of 2—inch—diameter PVC casing
over 40 feet of 2—inch—diameter, 0.010—
inch-slot PVC screen; about 2 feet of
• PVC stick—up
Comments: Cave—in to about 13 feet; 0.5 feet of bentonite
on top of cave—in; formation cuttings to about 5
feet; cement up to ground level; protective cover
installed
107
/ C ( ,
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I
G :3ghcy & Miilcr, Inc.
WELL MW—15
(installed 12/12/83)
Sample Depth Blow
Interval (ft) Count Description
0.0 — 1.5 grab Cinder type material with
silt and pebbles, black
color; probably represents
fill.
5.0 — 6.5 5—6—7 Sand, medium, and some peb-
bles, black (peat type) mate-
rial towards base, brown to
tan color, probably natural
10.0 — 11.5 5—7—10 Sand, medium, with some peb-
bles, brown to tan color
15.0 — 16.5 6—9—8 Sand, medium, with some
pebbles, brown to tan color
20.0 — 21.5 7—13—19 Sand, medium, with some
pebbles and minor silt,
brown to tan color
25.0 — 26.5 13—19—19 Sand, medium, with pebbles
and a few rock fragments,
brown to tan color
30.0 — 31.5 15—17—20 Sand, medium, with pebbles,
tan color
35.0 — 36.5 6—9—19 Sand, medium to fine, with
some pebbles and a layer
(about 1 inch thick) of black
(peat type) material, brown
to tan color
40.0 — 41.5 . 16—23—26 Sand, medium to coarse,
with pebbles and minor silt,
brown color
45.0 — 46.5 7—8—8 Sand, medium to coarse,
with some pebbles and minor
silt, brown color; hit water
at about 42 feet
1 oa
-------
Geraghcy & Miller, Inc.
WELL 1 MW—l5 (Cont)
(installed 12/12/83)
Blow
Count
Sample Depth
Interval (ft)
Description
50.0
—
51.5
6—9—14
Sand, medium to coarse, and
pebbles, brown color
55.0
—
56.0
40—51/2”
Bedrock at about 55 feet;
auger refusal at about 56
feet; sample consisted of
decomposed rock, brown color
Borehole depth: 56 feet
Well depth: 56 feet
Screened interval: 56 to 36 feet
Well construction: 36 feet of 2—inch—diameter PVC casing
over 20 feet of 2—inch—diameter, 0.010—
inch—slot PVC screen; about 2 feet of
PVC stick—up
Comments: Cave—in to about 18 feet; 0.5 feet of bentonite
on top of cave—in; formation cuttings to about 5
feet; cement up to ground level; protective cover
installed
109
-------
Gerighty & MiIIcr. Inc.
WELIL MW—16
(installed 12/12/83 to 12/13/83)
Sample Depth Blow
Interval (ft) Count Description
0.0 — 1.5 grab Silt, with some clay and
minor sand, brown color;
probably mostly represents
fill
5.0 — 6.5 2—5—9 Clay, with silt, a few peb-
bles, and some cinder—type
material, brown color; prob-
ably represents fill
10.0 — 11.5 7—7—7 Pebbles, with sand and silt,
brown color; probably natural
15.0 — 16.5 6—9—7 Sand, medium, with some peb-
bles and silt, brown color
20.0 — 21.5 9—14—15 Sand, medium, with pebbles
and minor silt, brown color
25.0 — 26.5 8—10—10 Sand, medium, with pebbles,
brown color
30.0 — 31.5 7—8—8 Sand, medium to coarse, and
a few pebbles, brown color
35.0 — 36.5 12—18—24 Sand, medium, with some peb-
bles and a few rock frag-
ments, brown color
40.0 — 41.5 27—24—28 Sand, medium, with some peb-
bles and a few rock frag-
ments, brown color
45.0 — 46.5 16—17—24 Sand, medium, with some
pebbles and rock fragments,
brown color
50.0 — 51.5 11—20—27 Sand, medium, and pebbles,
with minor silt, brown color;
hit water at about 50 feet
110
-------
G::i;hty & Miller, Inc.
WELL MW—17
(installed 12/13/83)
Sample Depth Blow
Interval (fe) Count Description
0.0 — 1.5 grab Cinder type material with
pebbles and silt, brown
color; probably mostly repre-
sents fill
5.0 — 6.5 4—3—2 Sand, medium to coarse, peb-
bles and silt, brown color
10.0 — 11.5 4—6—7 Sand, medium, with pebbles,
brown color
15.0 — 16.5 5—6—6 Sand, medium, with pebbles,
brown color
20.0 — 21.5 7—8—5 Sand, medium, with pebbles
and some black (peat type)
material, brown color
25.0 — 26.5 10—10—13 Sand, medium, with some peb-
bles and some black (peat
type) material, brown color
30.0 — 31.5 12—23—33 Sand, medium to coarse, and
pebbles, brown color
35.0 — 36.5 24—44—49 Sand, medium, with pebbles
and rock fragments, brown
color
40.0 — 41.5 11—16—22 Sand, fine, with a few peb-
bles and some black (peat
type) material, brown color;
hit water at about 40 feet
45.0 — 46.5 14—20—20 Sand, medium, and pebbles,
brown color
50.0 — 51.5 11—11—15 Sand, medium to coarse, and
small pebbles, brown color
112
1100
-------
Gerighcy & Miller, Inc.
WELL MW—17 (Cont)
(installed 12/13/83)
Blow
Count
55.0 — 56.5
9—13—16
Sand, medium to coarse, and
small pebbles, brown color
60.0 — 61.5
14—31—24
Sand, medium, and some peb-
bles, brown color
65.0 — 66.5
70.0 — 71.5
11—23—22
l1—31—5 1/2
Sand, medium, with some peb-
bles, changing to hard silty
clay at base, brown color;
change at about 66 feet
Sand, medium to coarse, and
pebbles, changing to hard
sandy clay (probably decom-
posed rock) , brown color;
change at about 71 feet
75.0 — 76.5
15_3 1_51/lu
Clay, dense, hard, and
stiff, grey to brown color;
probably represents decom-
posed rock
Bedrock and auger refusal
at about 77 feet
76 to 36 feet
36 feet of 2—inch—diameter PVC casing
over 40 feet of 2—inch—diameter, 0.010—
inch—slot PVC screen; about 2 feet of
PVC stick—up
Cave—in to about 5 feet; cement up to ground
level; protective cover installed; owing to
weather conditions, there was standing surface
water (a few inches up to a foot) all around this
location, so a gravel (10 tons) pad was installed
at the drilling location
Sample Depth
Interval (ft)
Description
77.0
Borehole depth: 77 feet
Well depth: 76 feet
Screened interval:
Well construction:
Comments:
-
113
-------
G:: hty & Milkr, Inc.
WELL MW-18
(installed 12/13/83)
Sample Depth Blow
rnterval (ft) Count Description
0.0 — 1.5 grab Sand, medium, and pebbles,
brown color; probably natural
5.0 — 6.5 7—9—6 Sand, medium, with some
pebbles, brown color
10.0 — 11.5 4—6—8 Sand, medium, with minor
amounts of black (peat type)
material, brown color
15.0 — 16.5 8—17—14 Sand, medium with one large
rock fragment, brown color
20.0 — 21.5 8—13—17 Sand, medium, with some peb-
bles, brown color
25.0 — 26.5 9—7—7 Sand, medium, with a few peb-
bles and rock fragments, and
minor amounts of black (peat
type) material, brown color
30.0 — 31.5 7—9—11 Sand, medium to coarse, with
some rock fragments and
pebbles and a few rock frag-
ments, brown color
35.0 — 365 11—10—14 Sand, medium, with some peb-
bles and a few rock frag-
ments, brown color
40.0 — 41.5 9—10—12 Sand, medium to coarse, with
pebbles and minor silt,
brown color; hit water at
about 39 feet
45.0 — 46. 5 47—21—19 Sand, medium to coarse, with
pebbles and some silt, brown
color; driller thought he had
augered through cobbles from
about 40 to 45 feet
114
-------
Ger2ghcv & Miller, Inc.
WELL MW—18 (Cone)
- (installed 12/13/83)
Sample Depth Blow
Interval Cf t) Count Description
50.0 — 51.5 15—26—38 Sand, medium, with silt,
pebbles, and a few rock
fragments, brown color
55.0 — 56.0 35—51/5” Decomposed reck (saprolite),
hard and friable, grey color;
may represent weathered shale
59.0 Bedrock and auger refusal at
about 59 feet
Borehole depth: 59 feet
Well depth: 59 feet
Screened interva’.: 59 to 39 feet
Well construction: 39 feet of 2—inch—diameter PVC casing
over 20 feet of 2—inch-diameter, 0.010—
inch—slot PVC screen ; about 2 feet of
PVC stick—up
Comments: Cave—in to about 18 feet; 0.5 feet of bentonite
on top of cave—in; formation cuttings to about 5
feet; cement up to ground level; protective cover
installed
115
-------
Ge c & Miller, Inc.
WELL. IW—l9
(installed 12/14/83)
Sample Depth Blow
Interval (ft) Count Description
0.0 — 1.5 grab Clay, with some silt, brown
color; probably natural
5.0 — 6.5 5—16—16 Clay, with some silt and a
few pebbles, brown color;
probably natural
10.0 — 11.5 6—4—6 Silt and pebbles, brown color
15.0 — 16.5 5—8—8 Sand, medium, and a few peb-
bles, brown color
20.0 — 21.5 4—6—6 Sand, medium to coarse, with
a few pebbles and a thin
layer of black (peat type)
material, brown color
25.0 — 26.5 4—9—18 Sand, medium to coarse,
with a few pebbles and a thin
layer of black (peat type)
material, brown color
30.0 — 31.5 10—13—14 Sand, medium to coarse, and
rock fragments (broken peb-
bles), brown color
35.0 — 36.5 30—38—50 Sand, medium, and pebbles,
brown to tan color
40.0 — 41.5 16—24—24 Sand, medium to coarse, and
pebbles, brown color
45.0 — 46.5 19—13—12 Sand, medium to coarse, with
pebbles and a few rock f rag—
ments, brown color; hit water
at about 45 feet
50.0 — 51.5 21—21—23 No recovery, probably mainly
sand
55.0 — 56.5 8—3—3 sand, medium to coarse, with
a few pebbles, brown color
I 16
‘1
0
-------
Gerighty & Miller, Inc.
WEESI MW—19 (Cont)
(installed 12/14/83)
64 to 44 feet
44 feet of 2—inch—diameter PVC casing
over 20 feet of 2—inch—diameter, 0.010-
inch—slot PVC screen; about 2 feet of
PVC stick—up
Cave—in to about 31 feet; sand pack to about
29 feet; 1 foot of bentonite on top of sand pack;
formation cuttings to about 5 feet; cement up to
ground level; protective cover installed
Sample Depth
Interval (ft)
Blow
Count
•
Description
60.0
—
61.5
6—9—12
Sand, medium to coarse, with
some silt, and clay toward
base, brown color
63.0
—
64.0
—
Bedrock and auger refusal at
about 64 feet; probably en-
countered decomposed rock at
about 62 feet; material on
lead auger looked like decom-
posed grey shale
Borehole depth: 64 feet
well depth: 64 feet
Screened interval:
Well construction:
Comments:
117
-------
G ity & Miller, Inc
WCLL MW—20
(installed 12/14/83)
Sample Depth Blow
Interval Cf t) Count Description
0.0 — 1,5 grab Clay, with some silt, brown
color; probably natural
5.0 — 6.5 4—5—7 Clay, with minor silt, fairly
dense and stiff, brown color
10.0 — 11.5 4—5—7 Clay, with minor silt, fairly
dense and stiff, brown color;
clay is similar in appearence
to that observed at MW—8, but
appears to be less silty than
clays found at the ZIW—12 and
MW—l3 locations
12.0 — 14.0 Pushed Shelby tube with no
recovery
15.0 — 1.7.0 Pushed Shelby tube with full
recovery; material consists
of clay with some silt, brown
color
20.0 — 21.5 Silt and clay, with very fine
sand, very soft and plastic,
brown color; sample taken
from auger run—up
25.0 — 26.5 4—3—3 Silt and clay, with very fine
sand, very soft and plastic,
brown color
30.0 — 31.5 9—16—20 Silt, with clay and very fine
sand, changing to sand and
pebbles, with some silt,
brown color; change at about
31 feet
35.0 — 36.5 9—12—18 Pebbles with coarse sand,
brown color
118
-------
\\ 0
Ger ghcy & Miller, Inc.
WELL MW—20
(installed 12/14/83)
Sample Depth Blow
Interval (ft) Count Description
40.0 — 41.5 9—17—18 Pebbles with medium to
coarse sand, brown color
45.0 — 46.5 14—13—17 Sand, medium to coarse,
with pebbles, brown color
50.0 — 51.5 9—25—30 Sand, medium to coarse,
brown color; base of sample
resembles decomposed sand-
stone
55.0 — 56.5 27—23—31 Sand, medium, with rock
fragments toward base, brown
color
60.0 — 61.5 23—32—23 Sand, medium, with some
pebble. and rock fragments
toward base, brown color
65.0 Bedrock and auger refusal
at about 65 feet
Borehole depth: 65 feet
Wall depth: 64 feet
Screened interval: 64 to 34 feet
Well, construction: 34 feet of 2—inch—diameter PVC casing
over 30 feet of 2—inch diameter, 0.010—
inch—slot PVC screen; about 2 feet of
PVC stick—up
Comm•nta: Cave—in to about 20 feet; 1 foot bentonite on
top of cave in; formation cuttings and more
cave—in to about 9 feet; 1 foot of bentonite on
top of formation cuttings; cement up to ground
level (i.e., about 7 to 8 feet of cement; pro-
tective cover installed; due to weather con-
ditions, surface water is several inches deep
all around this location
119
-------
TN— 3
Til—lO
Til-I 1
Ill—IS
TH—16
Ill—Il
S—inch
667 • 12.
658.17
6 58.fl
663.65
664.6 5
663.96
664.62
61.60
72 •s 3
73.33
72.63
31.00
20.3
606.22
590.02
$91.35
591.33
613.62
622.9
61.36
40.51
17.07
71.32
71.20
70.78
51.16
‘9.5
606.46
6 17.b6
621.611
592.33
5 l3.48
593. lB
613.46
623.7
Appendix C-i
Water-Level Data From 1983-1984 Measurements at MW-Series
and TM-Series Monitor Wells
•
Well
Elevation of
measurIng
December
2B
1983
January
II .
19114
Depth
Below
to W.ner
Measuring
t ievation,
of
Depth to Water
Below Measuring
Elevation
of
Number
Point
Point
Water
Point
Wister
(ft above
NIL)
(It)
(ft
above
lISt.)
((11
(ft aI ovc
P1St.)
0
I ’
-I
1.)
0 0
Re
-i
—
n
.
1%)
t. 1
NW—I
66 5.33
54.96
613.37
54.9)
613.40
NW—2
66 S.11
60.29
607. 52
60.20
607.91
NW—)
645.20
39.67
605.53
31.50
60 1.(.l
NW—4
661.0,
63.75
597.34
62.10
598.39
NW—S
660.17
69.05
599.12
60.23
599.94
MW— 6
104—7
‘
661.94
61.73
C
606.21
C
60.88
C
607.06
MW—S
6 7.76
76.85
590.91
75.31
592.45
1114—9
666.63
75.10
590.93
14.01
592.62
I IW—lO
667.20
77.11
590.02
75.47
591.73
MW—fl
667.30
69.04
595.26
68.12
599.18
1114— 12
636.77
25.62
611.15
25.71
611.06
1114—13
11 14—14
MW—iS
1114— 16
11W—il
NW—IS
1114—19
1114—20
661.4)
653.66
657.26
662.68
654.99
660.53
661.94
632.33
44.15
40.63
40.57
5 1ã32
4 1 18
4052
43.59
12.90
617.28
613.03
616.69
611.36
613.11
620.33
61 1.35
619.43
44.15
40.73
40.90
51.49
41.93
40.42
44.00
12.97
611.28
612.93
616.36
611.19
613.06
620.43
617.94
619.36
River (RP—1) 643.17
• No well installed
— 110 measurement collected
Notes water level measurements (except measurements of 1114-9. TIl—IS. TlI—16 1 and ill—I l. l/31/04
collected with an 11-scope) collected uxing steel tape/chalk methodi measurln9 point (or
2-Inch diameter wells La top of PVC Casingi measuring point of 6—inch and larger diameter
well is top of steel camingi measuring point for river is top of steel beam along a
walkway.
-------
Geraghcy & Miller, Inc.
APPENDIX C—2
MEDIAN WATER—LEVEL DATA FROM TN—SERIES MONITOR WELLS
.
Total
Median
Well
Number of
Depth to
Median Water
Number
Time
Span
Measurements
Water
(ft)
ElevatLort
(ft)
TH—0
2/18/72 — 9/13/72
10
84.31
581.69
TH—1
1/19/72 — 9/13/72
17
80.78
583.22
TH—3
1/6/72 — 9/13/72
18
70.79
596.70
T}1—4
1/13/72 — 9/13/72
13
40.33
611.43
T —5
1/18/72 — 9/13/72
15
50.22
603.52
TH—6
1/6/72 — 9/13/72
14
41.88
604.48
Ta—7
TH—8
1/13/72 — 9/13/72
1/13/72 — 9/13/72
9
18
52.80
46.31
605.39
603.26
TH—9
1/13/72 — 9/13/72
15
44.89
603.51
TH—10
TN—il
TH—12
TH—13
TH—14
1/19/72 — 9/13/72
1/19/72 — 9/13/72
2/18/72 — 9/13/72
2/23/72 — 9/13/72
-
14
15
7
5
—
43.36
37.11
36.12
28.42
Dry Hole
614.81
621.64
602.43
602.88
-
TH—14A
TN—iS
TH—16
TN—li
TH—18
TH—19
8—inch
River
7/25/72 — 9/13/72
7/11/72 — 9/13/72
6/30/72 — 9/13/72
6/30/72— 9/13/72
—
7/11/72 — 9/13/72
1/26/72 — 9/13/72
7/72
5
8
9
9
—
8
12
1
49.79
78.52
78.49
77.88
Dry Hole
79.40
51.58
—
603.58
585.08
585.83
585.67
-
583.23
602.67
602.6
124
-------
G . hcy & MiIIcr, Inc.
A?PENDrX D—2: Sample Set 1
Results of Laboratory Analyses of December, 1983
Groundwater Samples from MW—Series Monitor Wells
(samples collected 12/29/83 to 12/31/83; all values
expressed in mg/i unless otherwise specified)
-i 44-2 —3 PiI-4 P34-S P 3 4 - . 9 , -iO -lT
It) I)
?i.ld Ts,p.rature 1C )
6 lard. w LrS)
Ccr icewIty (t Ilca/caI I II
ocaL OranLc Ca
1’ 3taL DiaLvud Solids
brol Ukalinity tC 0 3 )
8tcsr iaro (I 3 )
C ! LS l 3)
R dica&dS (Oil)
Ctlorids
fliacidi
Ilitrats Nttsvui
5i4fat.
C sletia
r lssu.
Zr
Silica 1S60 2 )
taL e (1)
Fr.sCysnid. (9)
(9)
2. MUm
99 99 65
13 28 13
7.7 7.7 9.6
704 1205 980
36 5.1 2.3
437 854 603
250 246 368
303 300 283
o 0 80
• 0 0
20 73 33
4.. 6.9 33
1.6 1.3 2..
23$ 77
I I I 199 23!
2.3 8.0 1.6
60 93 2.3
6.0 8.7 0.3
0.92 0.60 0.lb
(0.01 0.26 0.06
(0.1 0.1 0.3
(1) hrSsr .ialy i & ssy, all ceI r pres aIlLyad b ’ Mrtèl ( utcay Ssrvtcss. !i . lof Bait i crs. Mar/
-
• r 9$ _ .,,.rt .4 9$ a sa 6*fi It Li8Uro 1 9$ 4i 9$diqr ad
— 6341 a lyad
0 Mls dstsc11
341s All a lyt1cal tJ v LtMr trca Itadarl l ti th IIIII1 c( I34tsr ad Wts tsr. or u.s. Divi... - nta2
Protira&ai £qu. . I34UI .3 aiscal Misiyuis Of I4$9$ d I34stss .
128
100 0 99 900 2 100 92
II I S IS IS 12 22 93
6.4 10.3 6.3 7.1 9.7 0.8 9.3
270 6000 753 613 305$ 113 320
1.4 400 2.! 3.! 260 2.3 9.4
226 7560 413 611 3040 464 623
59 3980 357 249 1340 84 303
72 9440 436 304 952 100 226
0 1630 0 0 331 0 72
• 0 0 0 0 0 0
37 300’ 31 32 500’ 126 27
0.1 400 0.1 1.3 133 0.1 II
0.1 1.6 0.1 2.2 07 (0.6 2.2
19 333 164 60 437 57 9 5
14.1 1950 3.2 41.3 4 .0 202
1.3 4.3 1.2 3.2 4.! 2.7 1.4
33.3 20.6 144 II 90.4 61 3.5
4$ 3.0 13.2 14.9 LI 13.1 0.6
0.04 35.2 0.92 0.04 17.3 1.09 0.30
0.43 1.98 3.03 4.71 1.61 7.83 0.01
(0.1 6.6 0.1 (0.9 4.1 (0.6 0.5
23 390 22 12 55 40 93 17 23 13
0.01$ 34.0 0.23 0.031 98.3 0.019 0.32 0.41 9.36 0.52
0.0)4 0.27 0.014 0.011 0.064 0.030 0.017 0.013 0.013 0.0
0.09$ (0.001 (0.009 0.008 20.0 0.338 2.25 0.211 0.027 3.0!
0.3$ 3.90 1.26 1.30 1.70 0.3 7.43 3.70 2.60 7.21
4.4 16.4 4.9 2.0 98.9 0.6 4.0 1.6 2.7 4.6
it)
-------
G:r.t hrv & MIller, 1x c.
APPENDIX D—2: Sample Set 1 (Cont.)
Results of Laboratory Analyses of December, 1983
Groundwater Samples from MW—Series Monitor Wells
(samples collected 12/29/83 to 12/31/83; all values
expressed in mg/i unless otherwise specified)
s —oI. C. catiCi W—l2 —l3 3# t4 PWIS Wl6 N1 17 P I$ NI— 19 20 Th—3 ,—I5
•rraI &ttaAc. (U ( I) 100 100 100 100 I I 13 37 100 100 96 95
F rId Ts’p.r.tur. (C1 13 IS 13 II 12 I I ii 10 13 — —
i ,t . itito) - 7.5 7.2 1.0 1.9 1.6 7.1 9.1 7.2 6.7 7.5 (l) 7
Cctiviiy (r* oaJ i I I) 476 540 635 560 3992 6)3 10526 511 500 — —
mt L Ocqanlc C toi 2.5 2.0 2.1 4.5 220 2.1 320 2.3 2.6 — —
1 tal DIMolv06 SO1I 311 311 311 393 2130 403 5640 397 353
lol A3MllnLty (C 3 ) 67 255 161 I II 1039 277 6310 23$ 16 162(I) I$Ic
8iear iate (ll 3) 204 311 205 233 512 376 2410 31) 215 19 1 (1) i 7
0 0 0 0 360 0 2130 0 0 0 0
II r oz.tds(00 ) 0 0 0 0 0 0 0 0 0 0 0
OI1er di 37 39 . 39 34 60 33 700 31 31 1.5( 1) C l.
ri ortds 2.) 1.2 30 0.) ItO 9.6 400 0.3 0.6 — —
Iiitzat. wltt un I.) 4.4 0.4 2.6 6.5 2.4 0.6 0.1 0.1 — —
Sullais 11 56 61 I I 130 71 603 57 68 - -
24.3 26.t 40.7 39.0 130 70 3190 22.9 24.0 — —
2.6 3.2 2.6 1.2 3.0 .6 ILl 6.4 1.5 — —
Calc& a 74 76 59 Ill 4.1 I I 3.6 101 04 — —
‘aqrss&Ju 11.1 13.5 9.9 5.3 4.4 1.3 4.) 10.5 12.0 — —
(0.01 (0.01 0.30 0.14 2.4 0.44 10.7 (0.01 (0.01 — —
qassto 0.51 5.10 0.23 0.03 0.11 13$ 0.26 0.14 2.02 — —
(0.) CO.) (0.) 40.) 2.4 0.1 6.6 0.) 0.1 — —
Silica 1S10 2 ) I I 13 14 16 53 4 230 17 I I • —
ctal C ’an ds (I) 0.074 0.22 0.16 0.44 7.33 0.19 110.0 0.061 0.050 0.41 0.C
?r Cyanids ( I I 0.031 0.02) 0.0)6 0.011 0.034 0.02) 0.45 0.0)3 0.023 0.054 0.1
lir I. (II 0.073 0.100 0.036 0.020 (0.00) 0.002 (0.00) (0.001 (0.001 - —
1 I 1 Patio 0.90 0.67 1.4$ 0.13 0.00 2.69 4S0 0.74 0.77 — —
%OItqs Iooalamc, 3.1 16.0 1.2 S.) 30.1 0.6 4.3 1.9 3.3 — —
(I) Par t.r wly by ( ra00iy all otl lsr p .rs .laly 6 by rtol L00orat y $.lvt . Ilir. (of Mtt 00. Paryl )
thoU cU uvl00 .C66t.
Analytical nogto r.51(606 10 aL ii1icmi* S I urs i. to Ii4i 10 r l40 Intsgtorul00u.
— 101 • aIy d
0 1al dctscta ,
ot.t All .rn.IytIcal .,U i us .Lthsr C r Sto aid br tj (a initI i of Wat.v ud Wsui 1st, or U.S. l wisirseIal
PTCteeti AqII y WU i of C1 Ic.t AnaLylil 06 hater - wa.t...
1 29
“
-------
G righcy M Ik; . Inc.
APPENDI C D—2: Sample Set 2
Results of tiaboratory Analyses of February, 1984
.Grourtdwater Samples from MW—Series Monitor Wells
(samples collected 02/01/84 to 02/04/84; all values
expressed in mg/i unless otherwise specified)
‘ 1—l 2 P5 —) IS 4 PW4 Pw.7 isi. I pW.$
ta1 A3JuMJ iLty (C 3 1
•Lcu ati ( 3)
Ca cs (c0 3 )
N re jds (DI)
F1 rids
Ni1z
sgfu.
S Li 2 0
?DtNSk
Ca1cii
Pi.qi ssa a
ALiim
3&llca
tal Cyaisde (1)
,T.. Cyarn (I)
? waiLa ( I )
N øCl P.ItiQ
IS II
31 13
5.1 1.5
ISI 420
1.4 43
35 425
41 314
71. 234
I 74
• I
13 3 7
0.1 1$
41.1 (LI
55 .01
41.2 13
2.2 l.a
44.2 2.1
114 1.1
1.0 0.23
4.72 0.04
0.1 0.5
42 12
(0.01 0.14
• 0
0.3$ 3.34
5.7 5.5
9$ 99 SI
IS 23 12
7.7 7.6 1.1
645 520 142
I.? 3.4 17
443 S93 775
259 224 351
314 273 323
S 0 73
I 0 I
25 47 49
11 5.5 2?
1.3 3.3 ( LI
00 43 101
II I lOS 232
2.0 3.2 4.1
SI 7 5 3.3
37 7.6 2.1
1.10 0.30 7.9
0.02 0.25 0.37
0.2 0.2 20
I I 20 44
042 0.79 0.25
0 3.4 0
4.24 2.21 3.16
.5 3.7 5.4
(I) Pu tit alalyad I all cuis, p.1L1a a’islyad b rtsl I . S i..j Ssivl , Ii . (•f Salt ‘.n. PaIy&lrd
mIlls Lss s.t1I.
— t C lAslyad
0 m.1. dii 1ai
:Gts, 141 .1yttc.1 ma .ltP 5 ma $5 SI4 — 5 .( ad ii.mm . LI. bwIf v.n a1
P 0IictIm aqu. $.l2. .J _ Oilesl lysti .1 Ws00e ad w.st.s. tmsly.41 r.e sUL . t . ad alimtam pSttsflsd i N .
FflSfl sap1 M bu ttt oS aia5ytL 1 lu ,rlsy.
130
I i
TTaitta. ( 11 ( 1) I I 0 94 90 I
tL.ld ?a, ra ig. (‘C) 14 I I I I 13 2
t 1 . a tta) 4.1 10.3 6.2 0.1 9.6
C ictLvIty (id / 1 C I) 270 7732 725 420 3131
Total O ic CubA 0.7 1600 2.0 4.7 230
ta1 Ojilsivud SOLIdS 226 6490 314 421 2030
33 4)40 II I 263 1410
44 1220 230 32) 1010
O 1150 0 0 340
0 0 0 0 0
35 1200 22 34 750
0.1 420 0.3 .5 120
0.1 2.5 0.1 2.4 0.0
31 331 I I I 45 361
14.9 3$0 41.3 31.2 103$
1.2 3.4 1.7 3.1 4.7
32.4 20.7 103 75 9.1
3.4 2.3 15.4 14.4 3.6
0.01 35 0.53 (0.01 15.0
0.34 2.46 3.53 4.01 1.31
0.1 1.0 0.1 0.1 0.5
24 100 11 11 63
0.04 41.0 0.1$ 41.01 45
0 0 0 0 0
041 1.11 1.3$ 1.13 1.37
3.0 11.1 0.2 7.1 1.2
-------
G r ;hcy & Milkr. Inc.
S4 1. 6 ICI
APPENDIX D—2: Sample Set 2 (Cont.)
Results of Laboratory Analyses of February, 1984
Groundwater Samples from MW—Series Monitor Wells
(samples collected 02/01/84 to 02/04/84; all values
expressed in mg/i unless otherwise Specified)
II P.rmter all.lyrtd by ts I Li . .., , oil oIlier psr e.n is1 by IIuWl t L.j tse,15, Il . (of Salt L Is. NaIyL1M)
aIl,,s othelwu ctH40.
- ?cC alislytud
0 Osiov dct.cttai
cts: Z1 analyt*cal . ..JI..L r.LtSor I r $tadaud lietlieds for ISa Ci Ilsiol l sr sd Wtais36r. or U.S. tt s,eu.ital
P otoc lai Aqsiicy 7Nth of O cal Molysti of Water aid Wastes. Malysts for silica. . ad aliaIaIa p.uI.... . .4 ai t4 It
,oaeWud .. l.s have bsil esittud tecaisi of aaalytlcal Ui iresy.
—I2
PW— 13
‘50.14
50—t5
50 —74
N.—77
P5 1.11
PJ1. 19
50—20
‘I—)
i —’
(3 )71)
0 efaIl g (C)
pi (5.4. g )
C3’e.ic vLty ( i / )
(I)
99
14
7.5
476
99
16
7.5
324
99
4
1.1
500
99
13
6.9
330
2
12
9.7
2049
93
13
7.6
367
32
32
9.6
9613
99
I I
7.1
575
9
13
6.6
50)
—
—
7.4(l)
536
—
•
7.
476
a1 C!7aA C Car i
1.4
1.6
1.7
.4
190
1.1
170
1.2
2.1
—
—
aL isao&vid SolIds
305
352
337
362
1110
371
7440
369
335
—
? oL A. aUnLty (C 3 I
9iea flaIs (II ))
C1 t• ( 3)
W/dr z ds(CN)
1erid.
tLori4u
141
(72
0
0
29
2.0
737
747
0
0
36
1.9
732
11$
0
0
31
3.1
66
23
0
0
34
0.1
1010
732
244
0
367
90
226
270
0
I
29
4.4
3370
2570
2625
0
330
243
294
0
0
26
0.3
156
363
0
33
0.3
171( 1 )
—
—
.
36(l)
3.4(l)
176(1
—
—
43(1
7.0
S as &es en
0.4
0.1
1.1
2.7
3.3
0.5
0.3
0.1
40.7
—
—
S i .’a:s
63
1(3
94
60
III
49.553
67
73
i i
23.0
31.2
52
29.4
970
53
2730
20.2
22.9
—
—
2.5
2.4
2.3
1.3
3.6
1.7
13.0
6.9
7.7
.
66
64
54
94
33.1
46
6.2
97
76
-
—
11.4
11.1
6.6
5.7
6.S
11.7
4.7
10.5
12.1
—
—
! i
0.02
0.74
0.01
0.13
13.9
0.39
11
0.03
0.04
—
—
?a.çL-ess
0.71
2.26
0.74
(0.01
1.41
7.77
0.50
0.26
7.99
—
—
A . nr&u
0.2
0.2
0.2
0.3
4.7
0.2
II
0.2
0.2
—
—
S . ;a SLO3)
:al Cyss iI . I I)
4
0.02
13
0.34
13
0.75
14
0.53
5$
3.1
12
1.03
110
33.0
73
0.04
(4
0.04
0.74
(0.0
Cysnido (I)
—
.. &a (7)
3.7
2.9
2.4
0
0
30
0
0.2
1.5
0
0
%a13 11110
0.12
0.62
14$
0.U
1.53
1.79
4.10
0.70
0.49
C.a: i 7 2sesi
1.6
3.7
2.3
0.2
79.1
2.1
72.4
2.5
0.2
131
-------
G ragiicy & MiI1 r, Inc.
APPENDIX D-3
RESULTS OF LA )RATORY ANP ILYSES OF 1972 GPCUN tR SAMPLES
FF 4 Th—S IES ZCNIIOR W US
February 1972 July 1972
Test Fluor. % T np. Fluor. % Cl. Ten .
Hole pH ppn. Trans. °F pH pan. Trans. p
TH—0 7.9 1.6 92 55 8.0 1.0 96 62 58
T M—i 7.9 1.0 98 57 7.9 1.3 77 29 56
TH—3 10.1 468 0 57 10.2 325 0 443 59
TH—4 7.0 9 74 54 7.1 15 29 132 59
TH—5 10.5 980 0 59 10.4 340 0 2792 59
pw 8 10.2 550 0 57 10.7 585 74 4100 59
‘11 1—6 11.1 950 58 51 9.8 100 17 1817 68
TIf—7 9.8 250 0 — — — — —
1 11—8 10.4 770 0 54 10.3 520 0 647 57
TH—9 9.9 430 0 54 9.3 133 2 355 58
TH—10 7.9 10 98 7.9 7 2 — 59
TM—li 7.1 6 0 58 7.7 8 60 142 57
111—12 6.9 0.82 97 58 6.9 0.25 80 19 60
111—13 7.1 0.74 98 55 6.7 0.15 73 79 56
TH—14A 10.5 1260 0 122 69
TH—15 — •— — — 8.1 1.0 87 21 63
TH—16 — — — — 8.2 1.0 98 27 59
111—17 7.4 0.16 93 39 58
111—19 8.0 1.3 96 29 56
- Not s npled Adapted fran Fred Klaer ard Associates,
SepteTiber 27, 1972
132
(I
I,’
-------
/
Ge ighty & Miller, Inc.
- APPENDIX D—4
AVERAGED 1982—1983 WATER—QUALITY DATA FOR THE
NEW INTERCEPTOR WELL
New Interceptor Well.
Average Average Averag
Average Average Trans— Total Free
DATE pH Fluoride nhittance Cyanide Cyaru
(std. units) (ppm) (percent) (ppm) (pDm)
March 82 8.7 84 65 5.1 <0.15
April 82 9.0 77 69 5.5 0.14
May 82 9.0 68 76 6.7 0.1.1
June 82 9.0 76 76 6.0 0.01
July 82 9.0 72 74 5.9 0.12
August 82 9.0 81 70
September 82 8.8 82 69
October 82 9.0 82 71
November 82 8.9 86 71
December 82 8.9 58 74
January 83 8.8 89 66
February 83 8.8 68 66
March 83 8.8 73 71
April 83 8.7 65 78
May 83 8.8 69 70
June 83 8.8 72 65
July 83 8.8 71 66
August 83 8.7 81 65
— Not analyzed
Note: All analyses perfor’i ed by Ormet Corporation laboratory
133
-------
Gerighcy & M !!er, Inc.
- APPENDIX D—4 (CONT’D)
AVERAGED 1982-1983 WATER-QUALITy DATA FOR THE
ORMET RANNEY WE LL 1
Rarmey Well
Average Average Averaç
Average Average Trans— Total Free
DATE pH Fluoride mittance Cyanide Cyan
(std. units) (ppm) (percent) (ppm) (o m)
March 82 8.6 25 71 4.8 <0.10
April 82 8.7 16 80 2.3 0.05
May 82 8.5 13 82 2.4 0.02
June 82 8.5 15 81 2.5 0.01
July 82 8.3 15 77 2.8 0.04
August 82 8.6 14 79
September 82 7.6 6.0 91
October 82 7.6 2.6 98
November 82 7.5 2.6 97
December 82 7.5 1.9 98
January 83 7.5 2.5 90
February 83 7.5 2.1 97
March 83 7.5 2.9 99
April 83 7.5 2.3 99
May 83 7.7 2.2 99
June 83 7.4 1.6 99
July 83 7.4 1.9 99
August 83 7.3 3.4 97
— Not analyzed
Note: All analyses perforr ed by Or et Corporation laborat y
135
‘II ’ ,
-------
REGION V
liastern fli.itrict Office
ItTTACIIMEIIT 3
(conti nucd)
indicated.
Ranney hell
84ER02S17
<
C
C
,
(1.9
3
3
“Old” Interceptor Well
84tfl02S18
(5
3!
114
‘15
“Mew” I iterceptor Well
MEItO2S19
12
13
3I
1
2.0
‘ .ui’Ir’ t tc
U I , VII I ,
June 26, Iq,vl
All parameters arc In mg/I unLc s otherwise
Sc
2’i C
1 VC
lm:’k Type
‘ :‘Ic Tune
c
1115
G
1130
G
1205
Field Measu cincnts
k,.v, MCD
‘npcratu e, °c
I, s.u.
‘u cI’ictivIty, pmlios
r e Available Chlorine, mg/i
‘c olvcd Oxygen, mg/I
—
15
7.0
375
.
—
21.5
0.98
1400
.
17.0
8.28
1400
Laboratory Analysis
.
L Lab (s.u.)
7.4
9.3
8.5
irductivity — Lab (umhos)
447
13fl2
1469
•t i1 Oicsolved SolIds
294
1050
1126
t.,1 SusoendedSol ids
H)
I C.
“l Phenol (4AAP)
< noo
0.003
0.003
r njd
0:008 5.3 LIS
‘c olved Fluoride
-——
———
“
)t.1l__Fluoride___________________
LIu.oruy (ucj/lJ
il and Grease
(2.0 ‘C 20
-------
‘
hh1’!’t ’ l).iI :
June Pt;— 7, 1 J 1
MI par3unctcrs 3rc
Rt 1 R)N V
L! stcrn t) :;tckt 0111cc
! TTACIIflEH1 3
Outfall 001
84 CR02S04
U.UIb
0.7
I J
II
Outfall 002
04ER02S08
U.4ID
1.2
lb
4
Outfall 003
04Efl02S 12
0.060
b.’I
1
3
is i liii I $ I%l I 1111111
in ingfl unkss othcr vkc incflc tcd.
n 1
r. V(•
C; -
‘.‘,ntk Type
‘3 ’nuIC Time
24 EVC
0836-0806
24 EYC
0900-0830
24 EVC
0930-0900
FkId . icasuremcnts
M CI )
(utper . Iure,
!:, .u.
Cenchi tLvity, pmhos
Iree Available Chlorine, mq l
)i soIvcd Oxygen, mg/I
1,06
21; 21; 24
6.5; 6.9; 6.9
350; 405; 440
0.03; cO.03
6.55; 6.65; 6.8
2.23
• 30
,
6.65; 7 3 7 2
. . .
360; 360; 400
<0.03
7.0; 7.1; 6.85
0.027
10; 21.!; 18
7.1; 7.8; 7.5
575; 500; 575
<0.03
7.4; 8.5; 8.85
L borntory An Iysis
•
91 — L b (c.u.)
7.4
1.8
. 8.1
i. .,iiiIucLivity — Lab (umhos}
400
355
i T i Oissolve4 Solids
! iusr’eniied Solids
214 .
34
224
30
356
< 5
‘It.)
I’ita
Cyanide
uIlJ
“C
Phenol (4MP)
0.012
0.005
0.007
1j lycd Fluoride
0.?
ii
5.4
Intdl Fluoride
!il .in’t Greace
c i
c 1
2
! 1 _ ” J 1y (uqfl)
( .U.
< 2.0
< 4.11
-------
‘,
0 :: T co’.po: ATio
H dfflIBAL, OHIO
84Ek02
JU S 26-2?, 1984
Volatfles
Concentration
Sriple Site ( ppb) Volatile Cornpound
c -_rall 002 . . . . . . . . 6.3 inethylene chloride
0 tfall 003 . . . . . . . . 0.8 chloroform
Citfall 004 . . . . . . . . 1.2 1,1,1—trich loroetharie
1.6 toluene
‘ Cld Interceptor tell 0.7 1,1—d lch loroethene
1.0 1,1—dichioroethane
0.7 trans—i ,2—dlchloroethene
6.4 1,1,1—tr lchioroethane
1.2 carbon tetrachioride
2.5 tr lchloroethene
11. toluene
Interceptor Uell . . 1.0 methylene chloride
17 trans—i,2—dfchloroethene
1.2 1,1,1—tr lch loroethane
0.6 tr lchioroethene
?.iv r Intake • . . . . . . 0.9 ch1orofor
Lagoon Sediment . . . . . . 0.03 ppm methylene chloride
3 ank . . . . . . . . . . . 4.3 methy lene chloride
1.2 styrene
-------
ATT E T S
0 1ET CORPORArIo;i
J1Afl U9AL, OHIO
84ER02
JUlIE 26-27, 1994
Acid and Base fleutral Compounds
Concentrat ton
Sample Sfte Actd & Base fleutral Compound ( ppb )
OutfaU 001 bis(2—ethyIhexyl) phthalate 3.5
Outfall 002 bls(2—ethylhexyl) phthalate 4.6
Outfall 003 bts(2-.ethylhexyl) phthalate 31
Outfall 004 phenol 1.1
2-rnethyl phenol 4.2
4- eth l p! enol 2.9
benzoic acid 6.1
acenaphthyl ens 0.5
phenanthrene 5,5
fluoranthrene 52
pyrene 50
butyl benzyl phthalate 7.3
chrysene 43
benzo(c.) anthracene 21
bls(2-ethylhexyl) phthalate 20
benzo(b) fluoranthene 43
benzo(k) fluoranthene
benzo(a) pyrene 9.5
lndeno(1 ,2,3-cd) pyrene 6.3
benzo(ghl) perylene 4.6
‘01dm Inter:eptor ieU bls(2—ethylhexyl) phthalate 1.1
“I aw” interceptor Well dl-n—butyl phthalate 1.1
bis(2—ethylhexyl) phthalate 4.1
S
9lank nap! thalene 0.9
bis(2-ethylhexyl) phthalate 2.7
Blank phenol 0.6
bis(2—ethylhexyl) phthalate 4.7
gIc2O
-------
ATTI CKME;IT 6
ORMET CO P0RATI0fL
H rU1IaAL, OHIO
84ER02
JUfIE 26—27, 1984
Lagoon Sediment Sample Analyses
Tota’ Soflds 79.6%
Metals (ug/g) Phenollcs : 1.0 mg/kg
Ag 1.4 Cyanide : 120 mg/kg
B 200
Ba 183 Acid/Base fleutral Compounds (mg/kg)
Be 17
Co 2.7 phenanthrene 13
Cr 14 anthracene 10
Cu 19 fluoranthene 12
Fe 5000 pyrene 12
LI 670 crysene 8.4
Mn 110 benzo(a) anthracene 9.0
HI 23 benzo(a) pyrene 160
Sr 230
V 17 Volattles (ppu)
V 4.6
Zn 38 methylene chloride 0.03
( mg/g) PCBs (mgI kg)
Ca 54 Aroclor 1242 (0.17
K (1.0 Aroclor 1248 <0.17
Mg 0.99 Aroclor 1254 (0.17
Na 26 Aroclor 1260 (0.17
Al 91
“I-
-------
-2-
Al
C. U.S. iro erZal rot tion Agency - EDO
phflip Gehring, Leed r, Field Sjppart Team
Larry Lins, EngifleeMn Technician
Michael Patton En;in erlng Technician
David S rna, Enviror. ental Engineer (report author)
V. CL JECTIYE
The purpose of this survey :as to determine compliance with UPDES permit
limits and ccndttio s. Additionafly, priority pollutant analyses were
obtained to provide the state a data base upon which the flPDES permit may
be reissued.
7. SUM•IARY OF FIHDI GS A; •) CC;;CL’JSL0;iS
A. Survey results sho ;ed Or .:et to be In coLipliance with its mass loading
limitatioas for TSS and dissolved fluoride as expressed in its expired
NPDES permit.
B. Ori.iet’s PD!S per it ex?Ired In May 1980. The permit needs to be
reissued to address The follo lng concerns:
1. Current plant o eratlng status.
2. BAT requlre!ier.ts.
3. Direct discharge of contaminated ground water through Outfall 004.
C. Contaminated grour.J water collected by interceptorwells is discharges
through Outfall O . Survey data indicate that the 004 dIscharge is
characterized by eie:ated cancentratlons of total fluorIde (43 m;fl),
cyanide (1.45 mg//i), and alu i1num (6.71 mg/i). Several polyar3matic
compounds were Identified tn Outfall 004 In the range of 50 ppb or less.
0. Lagoon sediment analyses showed the following: aluminum (91 mglg);
phen lics (1 mg/p;); cyanide (120 mg/kg); and benzo(a) pyrene (160
mg/kg).
::. DESCRrPTtO l OF PEP:IITTE!
A. Facility Description
The Ormet facility, located in Hannibal, Ohio, is a producer of primary
alu.i1n .i. Ormet C,rporation is jointly owned by Consolidated Alumtnu.i
Corporstion and R ere Copper and Brass, Inc. flomal production is
about !7’ ,OOO short tons per year. Ormet employs 1800—2000 wDr:ers
and operates 7 days per week, 24 hour per day under normal oper t ng
conditions.
Refer t3 Attach. ient 1 for an area location map.
-------
L .i 4 A’ - -
0. tIastew ’ er Sourc
A major aste ,eter sOurce is Contaminated ground water pun ed fro.i
interceptor w l1s naintained by Orn t to protect its production ;e1l
(Ranney ie1l). 0 her plant flows Include contact and floncontact cool 1n3
water (LICCU), storn run3ff, and bofler b1owdo m.
Sources of wastewater tributary to the four Ormet outfalls are outflned
belo i:
1. Outfafl 001
a. Rectifier coolin; water (once through r CCtl).
b. Cast house cooling water — Contact cooling water from the direct
chill casting process which cools th molds and castings.
c. Furnace d3or HCC .
d. Storm water, runoff.
2. Outfall 002
a. Rectifier cooling water.
b. Storm water, runoff.
C. Overflow fro:n interceptor well sump (infrequent).
3. O itfall 003
Storm water, runoff.
4. Outfall 004
a. Contaminated ground atar from interceptor wells 1 and 2 (gold”
Interceptor :ell) and 3 (“new Interceptor well).
b. Storm water, runoff.
c. Overflow fro o £57 cool thy towers.
d. Boiler blow owr..
e. Compressor UcCtI.
The Ormet plant seni tary wastes are treated at the adjacent Consolidated
Aluminum facility.
A diagram showing plant layout and sewers tributary to the NPDES outfal1s
is presented in Attach ient 2.
. Wastewiter Treatment
Ormet presently provIdes no on-site Industrial wastewater treatrnent.
Ornet iad maintained a lagoon through which wastewater was routed
prior to discharge from Outfafl 004 to the Ohio River. However, the
lagoon was subject to significant infiltration to the ground iater. In
October 1933 Or iiet discontinued use of the lagoon.
-------
ORMET CORPORATION
EXHIBIT D
-------
Ormet Corporation HRS Package
Addendum to-Exhibit C
The impoundment observed in the March 19, 1985 inspection
contained no drainage diversion structures. The dikes
were apparently constructed of unsound materials, capable
of eroding and leaking waste constituents. The level of
waste was at or near the top of these unsound dikes.
L ‘ L’
Brian Blair
April 11, 1985
Addendum to Exhibit D
The town of Bannibal,and adjacent villages, obtain water
from 2 wells. These wells are located at latitude 39
37’14” and longitude 80°54’32. Thus, these wells are
over 3 miles from the Ormet site.
Brian Blair
April II, 1985
-------
0
Ormet Corporation Mining Waste NPL Site Summary Report
Reference 2
Excerpts From A Report on the Acute Toxicity of Effluents
from Ormet Corporation Outfall 002 and Outfall 004 to
Pimenhal Dromelas and Danhnia oulex ;
Ohio Environmental Protection Agency; Undated
-------
A e2crt on the Acute Toxicity
of Eff1uer ts From Ornet Corporation
Outfall 002 and Outfall 004 to
Pimepha s pro el s and o)rnia puiex
Bioassay eport Number 81—222—SE
3icnit ,r r’., action
Chic ru’: r. r tal ?ro ct n ;ency
-------
‘ • Uf? t L’Jr? r ,
C—’ , .. rL. of fljent from each c._cfafl 032 a
::: re cc te se in a t taI of eight scr enlng bioe says.
:;en .S cijtfall 002 here cO lected at ]430 hours on 16 3une 1 31 and
:: h rs on 17 iu e 1 81. Outfall O 4 effluents were collected at 1403
. —s on 16 J ..ie 1131 and C940 hours on 17 June 1981. The fathead mInnow
‘aies Vc’.aias , arid a hr a puleA were used as test organis ns In thee
!! T reening bioassays f eath grab sample of effluent. Details of the
tests ay be fc r.d on the attached bicessay report form. Neltherof the two
effluent saicler from outfall 002 were acutely toxic to the fathead minnow or
0. pulex . Both of the effluent samples from outfall 004 were acutely toxic to
h fathead mirm3w and 0. puiex . All of the test organisms exposed to the
effluent from outfall 0 4 exhibited adverse effects within 24 hours of the
3-h3ur expesure period. One 24—hour composite sample of the effluent from
each outfall 00? and outfall 004k collected during the com3liance sanpIfrig
irspection, was submitted for chemical analysis of selected paramPters.
Screening bloa says are utlized to determine if an effluent Is acutely
t ic to the test :-ganisms arid indicate If definitive bloassays to determine
ta median lethal coicentration should be conducted. Based upon the results
c.f these eiqht screening bioassays, definitive bloassays should be conducted
cn outfall 004 but no def1nitIv bicassays need to be conducted at this time
cn outfall 002 of the Orinet CorporatIon.
e4Ldo. a i
[ R.producsd Iron ,
bill .vaII I. copy.
-------
: ts: 61-222-SE______
OutfalC4 ——
Percent of tes or; s’i exhibiting adverse
effect
-.
Sample
Collected
arab
1 hours
Start of
bioassay
1715 hours
effluent
P. promelas
Time (hours)
D.
Ti e
pulex
(hours)
24 48
24
48
100 100
100
100
control
0 0
0
0
15 J ne 1961
17 June 931
Srab
C 4O hours
1715 hOJ’-S
effluent
100 100
100
100
control
7 J me 1981
17 Jure 198].
effluent
control
‘a a’ t infor ation:
Fish in the 0940 hours sa’ ie were swi mting errat caUy and some had
t -rued belly—up after one-h 1f ho.jr exposure. AU fish deaths had occurred
ng a 17-hour exposure. E ’-ty percent of the D. pulex In the 1400 hours
e’ ent , and all D. p’jiex t’ e 0940 hours sample, were dead after a 17—hour
e;: sure. One D. uiex r. the 1LOO hours samp’e was barely alive after
- ours expos.re an as at S—h urs.
F /5502 S
II3’.
-------
I
Ormet Corporation Mining Waste NPL Site Summary Report
Reference 3
Excerpts From Site Inspection Report: Ormet Corporation;
EPA; January 17, 1985
-------
POTENTIAL HAZARDOUS WASTE SITE Ii. IOE ; T o
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SITE INSPECTION REPORT Li I O ’ i 3? 37.D
PART 1 - SIT! LOCATION AND INSPECTION INFORMATION
a Sl E NAME ANO LOCATION
: . .ORSPECI CLOC ;IONIOE,,TI IEA
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•g• iS’!CTION INFORMATION
-
O25 iTESTA7’. S c3v so o . rIo,,
I “ i 85 ACTNE /95(, UNK?IOWN
,;. , C INACTIVE BEGINNW4GY ENOIIIC YEAR
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= A EPA C B EPA CONTRACTOR C C MUNICIPAL. CO. MUNICIPAL CONTRACTOR
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POTENTIAL HAZARDOUS WASTE SITE I. IOE .TIFiC 7: ,
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-------
POrENTIAL HAZARDOUS WASTE SiTE
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POTENTIAL HAZAROOUS WASTE SITE I i . 13ENT 1
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PART S• WAT!R, OEMOGRAPIIIC. AND ENVIRONMENTAL DATA Lo ID o 1 3i
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— — - — . . a...a.a ,mWt.
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-------
— POTENTIAL HAZARDOUS WASTE SITE
SITE INSPECTION REPORT
‘ 1 PART 10.PASTRE$PONSEACTIVITIES
I. I0ENTI;ICATIØ ,
JOl Si 1II —
t n
As— P€5 ON$ ACTIVITIU
C I = A AT2fi Su, .y 0S 0 02 CAT!____________
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0.1 DESCRIPTION
O3AGWICY
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01 ! WAS1’! R!PAO(AGED 02 OAT!
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03 AGENCY
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C I = L ENCAPSULATION 020*11
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03 AGENCY
03 AGENCY
03 AGENCY
-------
= I ACCE5STO5 T!R!STRICT!D
04 !SC iP11O
31 = 2 PQP Jt.ATION R!I.OCATEO
04 E5CR 11OP4
- j
,
I
POTENTIAL HAZARDOUS WASTE SITE
SITE INSPECTION REPORT
PART 10. PAST RESPONSE ACTIVITIES
I I3 TIPI
—
‘
ii ?AST RES?Op SEACTIViT1U.c.....,. ,
•
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03
AGEJ4CY____________________
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AGEDCY_____________________
01 = U OROUTCURTAJP4 CONSTRUCTED
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AGEI4CY__________________
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.
UI. SOURCES OF INFORMATION
.3
-------
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