United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R10-88/017
September 1988
SEPA
Superfund
Record of Decision
Martin Marietta, OR
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REPORT DOCUMENTATION »• *EK>RT NO.
PAGE
EPA/ROD/R10-88/017
3. Recipient's Accession No.
4. Title and Subtitle
SUPERFUND RECORD OF DECISION
Martin Marietta, OR. j
Remedial Action - Fjinal
5. Report Oete
09/29/83
. Authors)
8. Performing Organization Rept. No.
9. Performing Organization Name and Address
10. Project/Task/Work Unit No.
11. Contract(C) or Grant(G) No.
(C)
(G)
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Report & Period Covered
800/000
14.
15. Supplementary Notes
16. Abstract (Limit: 200 words)
The 350-acre Martin Marietta Reduction Facility (MMRF) site is located in The Dalles,
Wasco County, Oregon. The site lies within an 800-acre area used primarily for heavy
industry .and manufacturing; land not used for industrial processes is leased for
agricultural purposes. Less than 20 homes and .businesses are located in the area of the
site. Ground water is an important source of water supply in The Dalles area for
domestic, industrial and agricultural uses and flows in an easterly direction, toward
|the Columbia River. From 1958 to 1970, Harvey Aluminum, Inc. operated a processing
facility designed to produce about 9U,000 tons of aluminum a year. Martin Marietta
Corporation (MMC) acquired the facility in 1970 and continued aluminum processing
operations until 1984, when the plant was shut down. In 1986, MMC leased the plant and
adjacent portions of the property to Northwest Aluminum Company, which resumed aluminum
operations in 1987. The MMRF site consists of 23 areas of significant contamination
resulting from treatment, storage, and disposal practices at the site. A 15-acre
landfill located near the aluminum reduction building contains approximately 200,000
yd3 of waste and plant construction debris. Leachate emanating from the landfill
operations prior to the installation of a leachate collection system has resulted in the
contamination of the area aquifer. Significant waste types in the landfill include
(See Attached Sheet)
17. JJocument Analysis a. Descriptors
Record of Decision
Martin Marietta, OR
First Remedial Action - Final
Contaminated Media: debris, gw, soil
Key Contaminants: metals (arsenic), inorganics
b. Identifiers/Open-Ended Terms
[asbestos), organics (PAH), VOCs (TCE)
c. COSATI Field/Group
Availability Statement
19. Security Class (This Report)
None
20. Security Class (This Page)
None
21. No. of Pages
73
22. Price
(See ANSI-Z39.18)
See Instructions on Reverse
OPTIONAL FORM 272 (4-771
(Formerly NTIS-35)
Department of Commerce
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EPA/ROD/R10-88/017
•artin Marietta, OR
^"irst Remedial Action - Final
16. ABSTRACT (continued)
asbestos, metallic wastes, and 5,000 tons of spent cathode waste materials containing
cyanide, PAHs, and arsenic. In addition to the landfill, approximately 64,670 yd3 of
cathode waste material was deposited in areas referred to as the unloading area and the
cathode waste management areas. And 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 affecting
the soil, ground water, and debris are VOCs including TCE, organics including PAHs,
inorganics including asbestos and cyanide, and metals including arsenic.
I
The selected remedial action for this site includes: excavation of the cathode waste
material and placement into the existing landfill, and covering the landfill with a RCRA
cap; placement of a soil cover over scrubbar sludge ponds 2 and 3; plugging and
abandonment of nearby production wells and: (connecting ground' water users to the City of
Dalles water supply system; collection and ;onsite treatment of leachate generated from
the landfill, the perched water east of River Road and the cathode waste management
areas, and the ground water in the unloading area using an aqueous treatment system with
onsite discharge to a recycling pond; ground water monitoring; establishment of a
contingency plan to perform additional recovery of ground water in the event further
contamination is detected; and implementation of institutional controls. The estimated
present worth cost for this remedial action is $6,707,400 with annual O&M of $144,000
fcor years 1-5 and $55,600 for years 6-30.
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RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION
REMEDIAL ACTION
MARTIN MARIETTA SITE
THE DALLES, OREGON
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RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION
Site
Martin Marietta site - The Dalles, Oregon.
Purpose
This decision document presents the selected remedial action for the
site, developed in accordance with the Comprehensive Environmental
Response, Compensation, and Liability Act of 1980 (CERCLA), as amended by
the Superfund Amendments and ReauthoMzatlon Act of 1986 (SARA), and
consistent with (where not precluded by SARA) the National Contingency
Plan (NCR, 40 CFR Part 300). The State of Oregon Department of
Environmental Quality concurs with the selected remedy.
*
Basis for Decision
decision is based upon the Administrative Record for the site.
This record Includes, but is not limited to, the following documents:
' iFlnal Remedial Investigation Report for the Martin Marietta site, The
Dalles, Oregon (March, 1988)
• "Final Feasibility Study Report for the Martin Marietta Site, (June
1988)
0 Decision Summary of Remedial Alternative Selection (attached)
* Responsiveness Summary (attached as Appendix 6)
0 A complete list of documents contained in the Administrative Record is
Included as Appendix C
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Description
This remedial action Is designed to:
• Consolidate the residual cathode waste material and underlying
fill material from the Former Cathode Waste Management Areas Into
the existing Landfill;
' Consolidate the cathode waste material from the Unloading Area
Into the existing Landfill;
• Cap the existing Landfill in place with a multi-media cap meeting
RCRA performance standards;
0 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 Dalles water supply system;
* .Collect and treat leachate generated from the Landfill and
perched water east of River Road and from the Former Cathode
Haste Management Areas;
• Recover contaminated groundwater from the Unloading Area;
* Implement groundwater quality monitoring and a contingency plan
to perform additional recovery of groundwater In the event that further
contamination 1s detected.
Institutional controls such as deed restrictions or fencing will be
Implemented during and after remediation. The purpose of these controls
will be to assure that the remedial action will protect public health and
the environment during its execution, and to ensure a similar level of
protection after the remedial actions have been Implemented.
Declaration
Consistent with CERCLA, as amended by SARA, and the NCR, EPA
determines that the selected remedy as described above Is protective of
human health and the environment, attains Federal and State requirements
which are applicable or relevant and appropriate, and Is cost-effective.
EPA Determines that this remedy utilizes permanent solutions and
alternative treatment technologies to the maximum extent practicable. The
statutory preference for treatment Is not satisfied because treatment was
not found to be practicable. Treatment of contaminated soils at the site
was not found to be practicable given the nature of the risks involved and
the protec.tlveness of the selected remedy. Treatment of contaminated
groundwater Is Included In the selected remedy.
Date Regional Administrator
Environmental Protection. Agedcy
EPA - Region 10
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DECISION SUMMARY
REMEDIAL ALTERNATIVE SELECTION
FINAL REMEDIAL ACTION
MARTIN MARIETTA SITE
THE DALLES. OREGON
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TABLE OF CONTENTS
I SITE DESCRIPTION AND BACKGROUND
Site Location and Description
Site Features
II ENFORCEMENT
III COMMUNITY RELATIONS SUMMARY ,
IV NATURE AND EXTENT OF PROBLEM ,
Contaminants Evaluated
Extent of Contamination
Potential Transport
Endangerment Assessment
V ALTERNATIVES EVALUATION
24
Summary of Alternatives and Evaluation Criteria
Screening of Alternatives
Alternative 3 Evaluation
Alternative 4 Evaluation
Alternative 5 Evaluation
Alternative 7 Evaluation
Alternative 9 Evaluation
VI SELECTED REMEDIAL ALTERNATIVE 4,
Description of the Selected Remedy
Groundwater Monitoring
Institutional Controls
Performance Standards
Statutory Determinations
APPENDICES
A. -APPLICABLE AND APPROPRIATE REQUIREMENTS
B. RESPONSIVENESS SUMMARY
C. INDEX TO ADMINISTRATIVE RECORD
D. STATE CONCURRENCE
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LIST OF TABLES
Table 1
Table 2
Table 3
Table 4
Table 5
Table 6
Figure 1
Figure 2
Figure 3
Figure 4
Figure 5
Figure 6
Figure 7
Figure 8
Figure 9
Chronological Hlstlry of MMRF Operations
Potential ARARs and Other Guidance To Be Considered
Remedial Measures Developed
Summary of Assembled Remedial Alternatives
Summary of Cost Effectiveness Screening
Groundwater Monitoring Plan
LIST OF FIGURES
Site Plan
Site Drainage Features
Site Specific Stratlgraphlc column
Flurolde Concentrations, S Aquifer
Approximate Location and Configuration of Landfill Cap
Cross Section of landfill Cap
Schematic Aqueous Treatment System
Soil Cover System Cross Section
Unloading Area Recovery Well
Page
— a
9
18
25
26
29.
50
Paqe
5
6
15
17
43
45
46
48
49
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I. SITE DESCRIPTION
The Martin Marietta Reduction Facility (MMRF) site Is located In the
Dalles, Hasco County, Oregon, west of the Columbia River and east of the
Union Pacific Railroad line. The site 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 In sections 21.28.33 and parts of sections 20 and 29 In T.2N.
R.13E., Willamette Meridian. The MMRF 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.
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.lplant was shut
down and MMC acquired legal title to the property. In 1936, MMC leased
the plant and portions of property adjacent to the plant;to Northwest
Aluminum Company, which resumed primary aluminum operations) In 1987.
;
During facility operation, waste constituents derived .from alumina
reduction were stored, treated, and disposed of at the MMRf. During past
plant operations, waste constituents, principally fluoride, sodium,
sulfates, cyanide, and polynuclear aromatic hydrocarbons !>(PAHs)j, were
released to the environment. J I
I
Site Features
The MMRF 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 540F. July Is generally the warmest month with a mean maximum
temperature of 86°F. The mean minimum temperature Is 34<3F 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 1s, evaporation exceeds precipitation.
Wind velocity measured at an on-site meteorological station during the
months of June and July 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 art associated with northwest winds. Typical wind speeds range
from 5 to 20 mph- and. the predominant wind direction is from the northwest.
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Land-surface elevations at the MMRF range from about TOO ft msl at the
Columbia River to more than 155 ft msl at the Landfill. The topography of
the site has changed over time Jue to fining of low areas; In general
the site Is level with the exception of distinct man-made and natural*
features. Th«se features include: man-made ponds, the landfill, drainage
ditches, stream channels, and road beds. These site features are shown In
Figure 1.
The topography at the MMRF 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. Surface-water flows
are shown In Figure 2.
Runoff from the landfill area is currently Intercepted by the leachate
collection system and the landfill ditch and then routed to the recycle
pond via the discharge channel. Prior to the construction of this
Interception network, landfill runoff followed ithree primary drainage
pathways, all of which discharged to the alluvia;! aquifer. Those flows
are now collected In the leachate collection system.
Surface' 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 area, and areas to the immediate south;and west of the plant,
and It discharges ]to the Columb:i River In accordance, with a National
.Pollutant Discharge Elimination System (NPOES) permit, j The recycle and
lined ponds are currently in use. The scrubber Siludge ponds are no longer
In use but Intersect the water table and are saturated) In proportion to
the relative groundwater 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 directly to Chenoweth
Creek.
Lltholoqy/Geoloqy. 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 River
Basalt Group (CRBG). The rock strata at the site are generally flat lying
except In the north where the Chenoweth Fault transects the site. The
CRBG Is overlain by Pleistocene Age alluvial deposits in the northern
parts of th« site.
Existing and Future Land and Groundwater Use. The MMRF, as noted
previously, is located within 800 acres zoned for heavy industry and
manufacturing. Northwest Aluminum is currently the largest industry in
this zoning area, employing 250 to 300 persons.
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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. The
northern part of the area contains the Mountain Fir facility and two small
areas zoned as community facilities. Located within these community
facilities art the Wasco County Animal Shelter, Rockllne (which consists
primarily of a machine shop employing about four people), and an electric
power substation. A gravel pit owned by Munson Paving Is also located In
the northern part of this zoning area.
Currently, there is little development along the Columbia River
waterfront In the vicinity of the MMRF, 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 company is
located on the waterfront approximately 0.5 mile southeast of the MMRF.
The remainder of the zoning area is lightly vegetated or wooded; MMRF
land that Is not used for industrial processes is leased for agricultural
uses such as cattle grazing. Cattle grazing takes place primarily In the
vegetated areas northeast of the facility and In the area near the rodeo
grounds.
Interstate 84 separates the light and heavy Industrial manufacturing
area from residential areas. Directly west of the Interstate and
approximately one-third of a mile from the MMRF site are several areas
zoned for residential development. General commercial sites, such as a
drive-in theater, are located in and around these residential areas,
approximately two-thirds of a mile west of the MMRF. Additional
residential areas zoned for single-family, multi-family, and mobile home
dwellings are located southwest of the site.
A gravel pit is operated within the quaternary gravels of the alluvial
aquifer northeast of the MMRF. This operation is relatively small, and
probabl.y could not be expanded significantly owing to the limited extent
of the. al luvium.
Nearby Residences. A strip of land zoned for light industrial and
manufacturing development Is located between the railroad tracks and
Interstate 84 directly west of the MMRF main building. In addition to
several small businesses, this' area currently Includes a few residential
homes. These homes were in place prior to zoning, and upon new ownership
or destruction of the homes, the area will be used strictly for light
industrial and manufacturing development. Based on recent aerial
photographs, less than 20 homes and buslnes-ses are in the area west of the
site.
-3-
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Natural Resources. Groundwater 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 Dalles Groundwater Resevolr (DGWR); the
alluvial aquifer located in the Chenoweth Creek area is used by the Animal
Shelter.
The Columbia River and its tributaries represent the major
surface-water resources in the area, with an impoundment on Mill Creek
used as the principal source of water supply for the City of The Dalles.
The Columbia River and its tributaries provide habitat for important
commercial and sport fisheries; with salmon, trout, steel head, walleye.
and bass being among the many game fish common to the river. Many of the
tributaries serve as hatcheries for the sal monoids.
-4-
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I it: iff/
QMCE
Ctu COHIU.fMa (MQMIM. HC
SITE PLAN
ai; MMm HMITU mu
MAftTW MAfUETTA COflPOflADCN
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"
INTERCEPTOR
^ TRENCH
Martin Marietta Corporation
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II. ENFORCEMENT
In the spring of 1983, the presence of cyanide compounds were detected In
the groundwater and the EPA ranked the facility for Inclusion on the NPL. The
site was proposed for the NPL in October 1984. In 1987 the site was formally
placed on tht NPL.
MMC has been Identified as a Potentially Responsible Party for the site.
MMC entered Into a Consent Order with EPA In September 1985 that directed MMC
to'perform an RI/FS for specific areas at the site that might have been
Impacted during plant operations. The Final FS report was submitted in July,
1988. MMC is In compliance with the terms of the order.
Special Notice has not been issued in this case to date.
III. COMITY RELATIONS
Community concern about the Martin Marietta site has never appeared to be
widespread, although several issues and questions were raised. These three
Issues were raised by several community members:
* the concern over cyanide contamination;
* the Importance of the aluminum reduction facility to the local economy; and
* concerns about various airborne emlsslojhs from the smelter.
The remedial investigation addressed the concerns about cyanide,
concluding that there is no significant cyanide contamination In groundwater
beneath the site. The reduction facility was leased and reopened by NW
Aluminum, which has improved their practices for handling the wastes which
earlier caused the contamination now beneath the site. Finally, as a result
of a lawsuit, Martin Marietta installed new flouride emission control
equipment.
Judging from the fact that EPA received no written comments on the
Feasibility Study despite 2 public meetings, 2 fact sheets, and several public
notices about the Feasibility Study and comment period, EPA concludes that the
community's concerns have been addressed and that they are relying on EPA and
DEQ to select an appropriate remedy. The selected remedy takes into account
the concerns mentioned above.
-7-
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IV. NATURE AND EXTENT OF PR081EH
Site Characterization
The site consists of a number of areas of contamination that have resulted
from past practices at the site. These areas are shown on Figure 1 and
Include:
Landfill
Landfill Runoff Areas
Area A
Area 8
Area C
Area 0
Former Cathode Waste management Areas
Metal Pad Storage Area
Bath Recovery Pad Area
Old Cathode kaste Pile Area
Salvage Area
Potllner Handling Area
, Cathode Wash Area
Duck Pond
Lined Pond |
Recycle Pond
Scrubber Sludge Ponds
SSP1
SSP2
SSP3
SSP4
Drainage Ditches
Surface Drainage Ditch
Leachate Collection Ditch
Landfill Ditch
North Ditch
River Road Ditch
River Road Curb
Discharge Channel
Drainage Ditch
Old NPOES Discharge Channel
Abandoned Scrubber Sludge Channel
More detailed descriptions of those areas where significant contamination
was detected are included in the next section entitled "Waste Characterization
of Areas Investigated".
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Table 1 shows a chronology of significant events at this site that have
contributed the present state of these areas. The chronology shows that many
of the past practices, particularly those Involving disposal of cyanide
containing waste, have been corrected prior the Initiation of the RI/FS. In
this resp«ct the selected remedy Is considered as a supplement to corrective
actions that have already been performed.
Table 1 Chronological History of MMRF Operations
Dates
Event
1957
through
1960
1958
T960
1961-
1971
1970
1974-
1984
1980
1981
1983
1984
Plant construction debris placed In the Landfill.
Process operations initiated by Harvey Aluminum, Inc. Plant air
emissions collected in a wet primary fluoride scrubber system (known
as the "Old Tower" system) and discharged to Scrubber Sludge Ponds 2
and 3.
Old Cathode Waste Pile started at northeast corner of the
plant. Old Cathode Wash Area constructed east of plant and
next to River Road.
Brides separated from cathodes taken out of service
placed In the Landfill. Other cathode waste shipped off-site, for
processing.
Secondary wet fluoride scrubber system added to primary air pollution
control system.
Waste from the Casthouse, Paste Plant, and plant operations
deposited In the Landfill.
Lined pond constructed to reduce volume placed in the Scrubber Sludge
Ponds.
Use of Scrubber Sludge Ponds 1 and 4 discontinued; ponds capped.'
State of Oregon Department of Environmental QualIty. 1Ists potliner
waste as hazardous. Permitted waste pad built to store waste
potliner; potliner waste previously stored at the Old Cathode Waste
Pile relocated to the permitted storage area.
Martin Marietta Corporation acquires legal
Martin Marietta Aluminum, Inc. Martin
constructs leachate collection system for
Cathode Waste Pad. Remaining Old Cathode
title to property from
Marietta Corporation
the Landfill and new
Waste Pile waste and six
inches of soil relocated to the new Cathode Waste Pad.
-9-
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Waste Characterizatiop of Areas Investigated
Landfill
Shown In Figure 1, the landfill occupies approximately 15 acres just north
of the alumina reduction building. Former drainage pathways from the landfill
area correspond to the landfill runoff areas.
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); "target wastes" such as spent cathode waste
materials, refractory bricks, 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 of asbestos
disposal and handling practices, asbestos and materials containing asbestos
were disposed of 1n a random fashion within the landfill. Since regulation of
these materials, MMRF disposed of asbestos In discrete areas of the landfill.
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 99,200 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, 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.
-10-
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To confirm the composition of the landfill, five test pits were
excavated. The materials observed ranged from fine dust to very large basalt
boulders. Samples from the five test pits Indicate the presence of the
following contaminants:
EP Toxldty - Barium
Total cyanide
Free cyanide
Sodium
Fluoride
PAHs
0.234 mg/l (one sample)
0.32 - 70 mg/kg
0.27 - 54 mg/kg
3,400 - 82.200 mg/kg
204 - 2.880 mg/kg
276 - 2,406 mg/kg
Former Cathode Haste 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 potllner handling area and the old cathode waste pile. In addition to the
perched water Identified In this area, the potllner handling area was
identified as the main area of concern in terms of direct human exposure to
soils, and Is described In more detail below. In addition, these areas were
Identified as potential sources of fluoride contamination to groundwater.
Potllner Handling Area. The potllner handling area (PHA) occupies
approximately 0.9 acre, just east of the reduction bulldtng (See Figure 1).
The PHA was used during the period when waste cathode was crushed and loaded
onto railroad cars for off-site recycling. As a result of the crushing
process, cathodlc dust, pitch, and coke residuals have accumulated. Sampling
of the PHA indicated the presence of the following contaminants:
0 Cyanide
- Total
- Free
8 Fluoride
8 Sodium
• PAHS
14 mg/kg
4 mg/kg
673 mg/kg
29,600 mg/kg
9,041 mg/kg
-11-
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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. Tht large surface area and retention capacity of the SSPs allowed
for partlculatt settlement of slurry waters from the air pollution control
system prior to discharge of accumulated water to the Columbia River.
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. 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
SSP1
SSP2
SSP3
SSP4
Cover
7,970
4,640
63,730
6,820
43,600
17,660
Subsoil
2,760
14.500
6,200
TOTAL
Subtotal
71,700
9,580
58,100
28.500
167,880
In addition, prevalent winds have scattered approximately 538 cubic yards
of sludge south of SSP2 and SSP3.
Samples from the scrubber sludge ponds Indicate.the presence of the
following contaminants:
Cyanide
- Free
Fluoride
Arsenic
Sodium
VOCs
PAHs
Surface Drainage Ditches
Below detection Hm1t(8DL)
204 - 613 mg/kg
BOL - 77 mg/kg
6,250 - 45.000 mg/kg
8DL
1,940 - 8,570 mg/kg
Leachate generated by the landfill Is contained.by a leachate collection
system that consists of the following ditches (Shown in Figure 2):
0 Surface Drainage Ditch;
9 teachate Collection Ditch; and
a Landfill Ditch.
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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 were Identified In the leachate collection ditch
Identified the presence of the following constituents:
Volatile Organic Compounds
Trlchloroethylene
Cyanide
- Total
- Free
Fluoride
Sodium
Sulfate
8 mg/L (one sample)
0.11 - 29 mg/L
0.01 - 4.7 mg/L
1 .490 - 2,440 mg/L
4,270 - 5,900 mg/L
840 - 2,660 mg/L
Analyses of leachate samples from the
presence of the following constituents: .
landfill ditch Identified the
PAHs (Including BlsCZ-ethyl-
hexyUPhthalate)
Cyanide
- Total
- Free
Fluoride
Sod1um
Sulfate
Chloride
0.01 - 206 ug/L
373 - 1,280 mg/L
34.2 - 77.2 mg/L
5,400 - 8,000 mg/L
36.600 - 99.800 mg/L
10.500 - 49,300 mg/L
1.210 - 3,430 mg/L
Sediments from the
contaminants:
* Cyanide
- Free
• Fluoride
' Sodium
surface drainage ditch showed the following
< 0.62 - 3.6 mg/kg
189 - 519 mg/kg
2.720 - 5,600 mg/kg
-13-
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Groundwater Characterization
General Hydroqeoloqy
The groundwater flow system at the MMRF Includes a water-table aquifer (S
aquifer) overlying a series of confined aquifers (A and B aquifers and
DGWR). figure 3, a site specific stratlgraphlc column, shows the vertical
relationship between the principle aquifers at the site. Zones of perched
water near the surface of the old cathode waste pile and an alluvial aquifer
are also present locally.
Distribution of Main Aquifers. The unconfined S aquifer 1s present within
the relatively low permeability 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 horizon
of the subaqueous portion of the Rosalia flow. The A aquifer ranges from 100
to 150 ft below the surface and is 5 to 45 feet in thickness. The 8 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 150 to 200 ft below the surface
and is 30 to 50 ft In thickness. In areas where the lava lobe Is absent, the
A and 8 aquifers combine to form a single hydrogeologlc unit. A thick, low
permeability slltstone and sandstone unit forms the confining unit between the
8 aquifer and the underlying OGWR. The top of the OGWR occurs at depths
greater than 220 feet below 'the surface.
Localized Groundwater. An alluvial aquifer, approximately 400 ft wide and
at least 60 ft deep, is 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 Chenoweth Fault. Flow in the alluvial aquifer Is expected to be east,
toward the Columbia River.
Perched water has been identified at the old cathode waste pile, salvage
area, and potliner handling areas within the permeable fill material that
exists above competent basalt. The saturated thickness of the perched zone
varies, ranging from 0 to 3 ft during the RI. One source of the perched water
is precipitation; other potential sources Include infiltration from the
landfill ditch and north ditch1, and leaks in below-grade water distribution
lines.
Groundwater Flow. Groundwater flow in the S aquifer is generally to the
east and northeast; discharge from the S aquifer is beli-eved to be into the
alluvial aquifer where it Intersects the S-aquifer at the northern portion of
the facility, and to the Columbia River. Groundwater 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. Groundwater flow in the 8 aquifer
is generally to the west and south; hydraulic gradients vary, however,
depending on the hydrologic and pumping conditions.
-U-
-------
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CHOUR SUOCaOUP
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-------
Chemical Characterization of Groundwater
The constituents of concern identified In the groundwater system Include
total and free cyanide, fluoride, sodium, and sulfate. 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 well below health
based standards. Table 2 lists potential ARARs and other health based
standards for groundwater to be considered In selecting a remedy.
Localized Groundwater. "Perched water samples from the old cathode waste
pile show elevated concentrations of free cyanide (3.01 mg/L), fluoride (3,000
mg/L), 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. Other
wells in the alluvial aquifer were above detection limits but below health
based standards.
S Aquifer. Elevated constituent concentrations were identified 1n the S
aquifer at several locations:
.(1) Near the landfill and former cathode waste management area. Fluoride
concentrations range from <1.0 mg/l"to 4.7 mg/L. Free cyanide ranged
from <0.09 to 0.136 mg/L, and sodium ranged from 57.2 to 82.2 mg/L.
(2) Scrubber sludge ponds. This area contains fluoride (4.8 to 7.1
mg/L), sodium (246 to 658 mg/L), and sulfate (117 to 3,020 mg/L)'.
Free cyanide is below detection limits.
(3) The new cathode waste area near 'the alumina unloading building. Free
cyanide was found at a concentration of 0.215 mg/L in well MW-5S.
Sulfate is found at concentrations of up to 1,270 mg/L. Groundwater
samples show detectable fluoride as high as 57 mg/1.
(4) Recycle pond. Samples from well MW-31 downgradient of the pond
Indicate fluoride concentrations of 5.5 mg/L, sodium concentrations
of 90.5 mg/L, and sulfate concentrations of 871 mg/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 the
landfill and the former cathode waste management area. The highest readings
are reported for well MW-9A, but they are suspected to be an artifact of well
construction. The monitoring and contingency plan described in the selected
remedy will allow for a determination and appropriate action should these
concentrations be found to be representative of groundwater conditions.
-16-
-------
Seen * '«"
500 '000
Figure 4 Fluoride
Concentration. S Aquifer
August L987.
CLIENT NAME:
Martin Marietta Corporation
-------
TABLE 2
POTENTIAL ARARS AND OTHER GUIDANCE TO BE CONSIDERED
i
Chemical
Federal MCL
(SMCL) [a]
Fe leral MCLG [b]
Oregon MCL (c]
Other
Bicarbonate
Calcium
Carbonate
Cyanide (free)
Fluorides
Lead
Magnesium
Sodium
Sulfate
Zinc
4 mg/L (2 mg/L)
50 ug/L
(250 mg/L)
(5 mg/L)
(20 ug/L)
1.4-2.4 mg/L [g]
250 mg/L
5 mg/L
220 ug/L (child)
770 ug/L (adult)
400 mg/L [h]
(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 ( ) and are goals for drinking water quality based
on aesthetic considerations such as taste, odor or straining 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 Water
Drinking Act. MCLGs are entirely health-based and ara always less than or equal to the
proposed or final MCLs subsequently developed.
(cj Oregon Administration Rule 333-61
Id) Health advisory by USEPA Office of Drinking Water for longer-term exposure, March 1987;
based on exposure to free cyanide.
[e] Health advisory by USEPA Office of Drinking Water for life time exposure for adults, March,
1987; based on exposure to free cyanide.
[f] National Primary and Secondary Drinking Water Regulations. Federal Register 51: 11396-11412,
April 1986.
(g] Temperature dependent
,, ^--^^oc-oH HW iif'FPA office of Drinking Water 50 FR 46936, 13 Nov. 1985.
-------
Contaminants are also present In the A aquifer near the scrubber sludge
ponds. Sodium ranges from 44.7 to 84.8 mg/L, sulfate from 23 to 153 mg/L and
fluoride from <0.1 to 1.0 mg/L. '
B Aquifer. In the 8 aquifer, elevated constituent concentrations ar»
chiefly confined to a single location: the landfill and old cathode waste
management area. The highest readings are reported for wells MW-98 and MW-88,
but they art suspected to be an artifact of well construction. The monitoring
and contingency plan described in. the selected remedy will allow for a
determination and appropriate action should these concentrations be found to
be representative of groundwater conditions. In other wells, levels of total
cyanide range up to 1.0 mg/L. Free cyanide concentrations are 0.10 mg/L or
less and fluoride concentrations are less than 1.4 mg/L.
Establishment of ACLs in the S Aquifer
An ACL 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 more stringent standard at this site. Proposed ACL's are as
follows:
Fluoride - 9.7 mg/1
Sulfate - 3.020 mg/1
Criteria for Establishment of an ACL. Section 121 which is not currently used
for water supply purposes in the area. Is not really extensive, and is of low
productivity and thus not likely to be utilized in the future for water supply
purposes. Groundwater In the S-aqu1fer flows toward, and discharges to the
Columbia River which borders the MMRF site. The Columbia River is extremely
deep adjacent to the site, and there Is essentially no potential for underflow
from the S-aqulfer.
-19-
-------
The only surface-water potentially affected by groundwater which contains
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 discharged
under the NPDES permit from the site Is 123 pounds/day during the dry season
and 246 pounds/day during the wet season.
Estimated Increase In Concentration at the Point of Entry. Fluoride and
sulfate are both naturally occurring In the groundwater and surface-water
environment. Background concentration of fluoride In the Columbia are
reported to range from 0.24 mg/l to 0.7 mg/L. Background concentrations of
sulfate In surface water are likely to range from 15.9 mg/L to 34 mg/L.
The hydraulic conductivity of the S-aqulfer is approximately 2.1 ft/day;
the hydraulic gradient in the S-aquifer is estimated to be 0.05 ft/ft.
Assuming a cross sectional area of the S-aqulfer which discharges Into the
Columbia River from the MMRF of approximately 6000 ft long (based on the
length of the facility) by 50 ft deep (thickness of S-aqu1fer) 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 portion of the aquifer
affected by site conditions. Groundwater discharge from the S-aqulfer to the
Columbia River is estimated to be 10 L/sec using this assumption.
The Columbia River in (he area of the MMRF, Is very deep and flow is
controlled by several dams in the area. The average flow In the Columbia
River Is approximately 192,820 cfs or 5,500,000 L/sec. The 7-day, 10-year low
flow of the Columbia River in the area of the site Is estimated to be 81,800
cfs.
Fluoride has been detected as high as 57 mg/L In groundwater at the MMRF;i
however, as part of the final remedy for the site, any groundwater with a
concentration of greater than 9.7 mg/L will be remediated. Based upon a
groundwater flux of 10 L/sec containing a worst case concentration of 9.7 mg/L
of fluoride, the mass flux of fluoride to the Columbia River would be 97
mg/sec or 18.5 pounds per day. Under average flow conditions in the Columbia
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/L is estimated assuming low'flow
conditions and a zone of mixing. For a maximum detected sulfate concentration
of 3,020 mg/L In S-aqu1fer groundwater, the concentration in the Columbia
River would be 5.5 X 10-3 mg/L under similar flow conditions.
These estimated concentrations of fluoride and sulfate as a result of
groundwater discharges from the site are several orders of magnitude below
acceptable concentrations, below detection limits and below background
concentrations. Therefore, although a definable mass, the discharge of
fluoride and sulfate to the Columbia River from on-site groundwater is
statistically insignificant (hot measurable).
Measures to Preclude Huran Exposure. Institutional controls such as deed
restrictions will be imple'ented in the selected remedy to prevent the
installation of wells on-site that draw water from the S-Aquifer.
-20-
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ContamjnantTransgort
Ah:
In ordtr to assess fugitive dust from the site, soil sieve analyses and
fugitive participate modeling was carried out. The results of this modeling
Indicated that the potential for significant risks from windblown dust were
minimal.
Groundwater
Based on the hydrostratlgraphy of the site, the principal route of concern
for contaminant migration to Chenoweth Irrigation wells Involves horizontal
migration from the landfill to the alluvial aquifer with subsequent downward
migration to the 8 aquifer, and from there to the OGWR. A mathematical model
was 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 wells were estimated as shown
below. These can be compared to the health advisories shown In Table 2.
CONSTITUENT CONCENTRATION (mg/V)
Initial B-Aqulfer Production Well
Free CN 0.051 0.012 0.003
-21-
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Risk Assessment
Exposure Evaluation
Chemicals of potential concern were evaluated in the 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 MMRF and surrounding areas. Many pathways Involving
human exposure to contaminated soils and dust were possible; therefore, for
each category of exposure to soils (I.e., Industrial or general population
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. For each exposure scenario evaluated, an average case
(populations 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. Because
groundwater was the only exposure medium for which ARARs or health advisories
were available for all chemicals of potential concern, risks associated with
groundwater were assessed by comparing concentrations of chemicals In
groundwater at points of potential exposure (both on and off site) to ARARs or
health advisories, as has been previously discussed. Such comparison values
were not available for all chemicals In other site exposure media (I.e.,
surface-water, and soil); 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
toxlclty values. '
Risks from Non-Carcinogenic 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 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 dally Intakes of
non-carcinogenic substances by potentially exposed Individuals to the-lr
corresponding relevant reference dose or allowable intake).
-22-
-------
Carcinogenic Compounds. 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. These areas are listed
below with details of the exposures, media, and chemicals which have been
associated with this risk. The carcinogenic risks presented show a range that
reflects both average exposure and high exposure values for dlfferenct
scenarios that were considered. Including a residence scenario and a worker
scenario.
Area
Landfill and associated areas:
direct contact with PAHs in
landfill soils;
direct contact with PAHs
in surface drainage ditch sediments.
Potllner Handling Area:
direct contact with PAHs in soils.
Discharge Channel:
direct contact with PAHs in sediments,
Estimated Carcinogenic Risk
10-4 - ID'2
lO-4 - TO'2
10~4 - 10'1
10-4 - lO-2
Scrubber Sludge Ponds:
direct contact with PAHs in pond sediments; 10~4 - 10~2
Ecological Effects
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. Estimated ecological impacts Included:
* Ingestlon by wildlife of fluoride in leachate collection ditch water; and
* Ingestlon by wildlife of cyanide and fluoride in landfill ditch water;
Remediation Criteria
"Based on the human health risks identified above and the potential for
contaminant leaching to groundwater, remediation criteria for contaminated
soils were established as follows:
Arsenic - 65 mg/kg
PAHs - 175 mg/kg
Fluoride - 2,200 mg/kg
-23-
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V. ALTERNATIVES EVALUATION
Summary of Alternatives and Evaluation Criteria
This section summarizes the detailed evaluation of the final candidate
remedial action alternatives. First, alternatives are subject to a screening
for compliance with the protectiveness and ARAR criteria. An additional
screening of cost effectiveness is then done to ensure the selected remedy is
a cost effective one. Those that pass the screening are then evaluated
against all nine criteria and an alternative is selected that best addresses
the combination of criteria. This alternative is considered to represent
treatment to the maximum extent practicable.
Alternatives were developed by first targeting areas for remediation based
on identified public health and environmental concerns. These areas Included:
* Landfill,
* Unloading Area,
* Former Cathode Waste Management Areas,
* Scrubber Sludge Ponds, and
* Groundwater
Table 3 shows the various remedial measures that were considered for each
of these target areas. Table 4 shows how these measures were combined Into
the Final Candidate Alternatives.
The Final Candidate Alternatives, Identified briefly, are:
Alternative 1 - No Action Alternative (presented to provide a baseline for
evaluating the other alternatives).
Alternative 2 - Consolidation and Asphalt/Soil Capping of Target Areas;
Limited Groundwater Treatment.
Alternative 3 - Consolidation and RCRA/Soil Capping of Target Areas;
Limited Groundwater Treatment.
Alternative 4 - Consolidation and RCRA/Soil Capping of Target Areas;
Hydraulic Barriers at Scrubber Sludge Ponds; Limited Groundwater Treatment.
Alternative 5 - Full Consolidation and RCRA Capping of Target Areas;
Limited Groundwater Treatment.
Alternative 6 - Full Consolidation into RCRA Landfill; Limited Groundwater
Treatment.
Alternative 7 - Full Consolidation and RCRA Capping of Target Areas;
Complete Groundwater Treatment.
Alternative 8 - Full Consolidation into RCRA Landfill; Complete
Groundwater Treatment.
Alternative 9 - Consolidation and RCRA/Soil Capping of Target Areas;
Stabilization of Scrubber Sludge Ponds; Complete Groundwater Treatment.
Alternative 10 - Incineration with Complete Groundwater Treatment.
-24-
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/" FAAGfit
REMEDIATION AREA
REMEDIAL MEASURE
CAPPWG W PLACE
PARTIAL WASTE REMOVAL
AND CAP W PLACE
CONSOLIDATION INTO
EXISTING LANOFLL
CONSOLIDATION INTO
ON-SJTE RCRA LANOFU.
CONSTRUCT ON-SITE
HEAP-LEACHING FACILITY
I^STTU HEAP-LEACHNG
INCINERATION
STABILIZATION IN PLACE
SC*. COVER
SOft. COVER WITH
SUBSURFACE BARRIER
GROUND-WATER RECO-
VERY AND TREATMENT
P & A EXISTNG WELLS
AND PROVIDE CENTRAL
WATER SUPPLY
RECASE EXISTING
WELLS W THE DGWR
CAPPING N PLACE WITH
A HYDRAULIC BARRER
luMTEO ACTION
LANOFLL
•
9
9
9
*
•• 'i
i
\
UNLOADING
AREA
•
%
9
o
•
*
'
O
DORMER
CATHODE
WASTE
""ttSf"
O
•
•
9
0
9
a
SCRUBBER
SLUDGE
PONDS
•
O
®
O
0
9
a
^v
GROUND
WATER
t
%
®
©
©
•'
(TABLE 3 J
GMCE
GAM CONSULTING ENGMEERS
REMEDIAL MEASURES
CONSIDERED FOR
IMPLEMENTATION
FEAS8W.ITY STUDY: MAHTH MAAC1 TA REDUCTION FAC1
MARTIN MARIETTA CORPORATIO
. THE DALLES, OREGON
-------
TABLE 4
JM ••*'"• »*
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*IUm*M.« IU«*4NI »•«•* e.l»W. •*•!•
I,,. «H*r>*llM I.MIIM *>lM«t»« ATM i*M>*f*Mt V... l«r«»»*r ll^|. »Wi i
H. Atlt*. »ll*r.*H.* I Wll ll«ll*« AtllM »ll ll«ll»4 A.II.* »t«ll 1UII*« *l* mti e«» I* ri.t. IHi Utl C»..r »..
*lf»r»>IU» I Ifti C»» I* PtM* Wtl £*•••! !<>>• rt»«l C*ni«M<«l* !•!• 1'Jl 1*11 C*»r »<»
ll'J •»< liri
l/li ttt I* flM* «tl C**>«U«»I* !•»• rt««l e«.t»IUl»« l.»» IMi C.»
If It ftp I. '!•«• Wtl (•.«•! Kit* !••• fC»«l CMl<*H«>l* l«f» Vll CMI«ll<>t* l«l» 0»»i er»M4-.>l.r C«U UU rCVil CM«*IK>I* )•(• tP*l C*M*M««I* !•!• *CMI| »..*«•«•«•' to-lr.l. .Ilk
lot* !«.. O.- M>« B«-,ll« KHA HM ••-•II* MCKI IV> ••-(II* «CM II.IIW t,..l.^l
III* KM t.«l- U'fllll I*«««MI U«4IMI
III!
U i*i» OM
l>llltkf
•ll*n
I«* I If tl CMMll«*l« «••! CmMllltl* I.I. rc«>t (^.l.lll.t. Ut»
1.1. !•>.•>- fV> ••••It* ICM HM •••III* KM HM «.-«M* NCM tr**tM«t
til* (CM U«>4- IM4IIII UMllll
till
•
l.» t Ifli C*» I* riM« •»!• CMMH«*I* l.l« ft»«i CwMlUt
l*.lll-w4UI f.lill** IM4IMI t>litl«t
- '
I* lf
-------
Evaluation Criteria
Mine factors were be considered In evaluating the Final Candidate
Alternatives:
Long-term effectiveness and permanence;
Reduction In toxlclty, mobility, or volume;
Short-term effectiveness;
Implementablllty;
Cost;
Overall protection of human health and the environment;
Compliance with applicable or relevant and appropriate
requirements (ARARs) that are shown In Appendix A;
State acceptance; and
Community acceptance.
The process begins by applying the protectlyeness and ARAR factors to
each of the candidate alternatives. Alternatives that do not satisfy
these requirements will be screened out. Then a cost effectiveness
screening Is done to ensure that each of the alternatives would be a cost
effective solution to the problems at the site. Finally, for the
remaining alternatives which have passe.d these screening steps, all of the
factors are weighed In determining the best overall solution to be applied
at this site.
Screening of Alternatives
Potential ARARs and TBCs
Table 2 and Appendix A lists the potential ARARs and federal and state
standards to be considered in selecting a remedy for this site.
Listing of Cathodlc Haste. On September 13, 1988 EPA listed spent
aluminum potllners from primary aluminum production as hazardous waste
(EPA HW # K088). The effect of this listing on the evaluation of
alternatives will be to change the status of certain of the RCRA potential
ARARs from Relevant and Appropriate to those which are legally applicable
In Instances where materials at the site Involve spent potllners.
The agency Is also undertaking a Land Disposal Restriction Rulemaklng
that will specifically apply to soil and debris. Until that rulemaklng Is
completed, the CERCLA program will not consider LOR to be relevant and
appropriate to soil and debris that does not contain RCRA wastes.
Alternatlvt 1
This alternative falls the protectlveness screen for the following
reasons:
0 The alternatives rely heavily on institutional controls and
monitoring for the protection of public health and the.
environment.
' Uncontrolled wastes would be left in place on site.
* Continued migration of site contaminants into the groundwater
aquifers wi11 occur.
The alternatives fail to meet ARARs identified in Table 2.
-27-
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Alternative 2
Thls'alternatlve Is not considered to be adequately protective because
It Involves only an asphalt cap over the landfill. Since the landfill has
been Identified as a potential source of leachate, the use of a cap that
relied only on tht Integrity of an asphalt coating was not considered to
offer long ttra protection of public health and the environment.
Screening for Cost Effectiveness
The alternatives which pass Initial screening are 3 through 10. These
are then evaluated to determine if any one falls to provide for a solution
that Is cost effective. A summary of the cost effectiveness evaluation
for these alternatives In shown in Table 5.
Based on the analysis shown in Table 5, Alternatives 6, 8 and 10 are
determined to be not cost effective. The RCRA landfill Included in
Alternatives 6 and 8 Is considered to provide a similar level of
protection as a cap at this site, considering the basalt material on which
the wastes sit. It Is therefore not considered cost effective compared to
alternatives 3, 4 or 5. Alternative 10, although providing the greatest
level of treatment, Is also not considered cost effective In light of the
protectlveness provided by Alternatives 3, 4 or 5.
Alternatives 3, 4, 5, 7 and 9 are determined to be cost effective
ones. Each of these alternatives appear to provide a level of
effectiveness and reduction in toxlclty, mobility, or volume (both
criteria evaluated together) that is commensurate with the cost. These
alternatives are evaluated in detail against, the nine evaluation criteria
In the following section.
-23-
-------
Alternatives Evaluated
Cost
Alternatlvc
3 $6.700,000
4
5
6
7
8
9
10
$10,900,000
$10,800,000
$20.000.000
$11,900,000
$21.300.000
$16.200,000
$10.300.000
Effectiveness
Minimizes risks via containment
Containment Is similar to Alt 3
Full consolidation minimizes area,
similar level of containment
Containment of RCRA landfill
similar to cap In this Instance
Full consolidation minimizes area
provides similar containment
Containment In RCRA landfill
similar to cap In this Instance
Reduction In
Toxlclty.
Moblllty or Volume
Limited gw treatment reduces volume
of fluoride contamination
Limited gw treatment reduces volume
of fluoride contamination
Limited gw treatment reduces volume
of fluoride contamination
Limited gw treatment reduces volume
of fluoride contamination
Full gw treatment further reduces volume
of fluoride contamination
Full gw treatment further reduces volume
of fluoride contamination
Containment and Solidification of SSPs Solidification reduces mobility of fluorides
Potential exposure minimized by
destruction of contaminants
Incineration minimizes long term management
of wastes
-------
Alternative 3 Evaluation
Remedial Alternative 3 Includes the following actions:
• Consolidation of the residual cathode waste material and underlying fill
material froa the Former Cathode Waste Management Areas Into the existing
Landfill;
' Consolidation of the cathode waste material from the Unloading Area Into
the existing Landfill;
* Capping the existing Landfill In place with a multi-media cap meeting RCRA
performance standards;
• Placing a soil cover over Scrubber Sludge Ponds 2 and 3;
0 Plug.and abandon nearby production wells and connect users to the City of
The Dalles water supply system;
* Collection and treatment of leachate generated from the Landfill and
perched water east of River 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 and treat
additional groundwater If further contamination In the A or B-aqulfers Is
detected.
Short-Term Effectiveness
Implementation of Remedial Alternative 3 should reduce risks to the
community and would pose minimal threats to on-slte construction workers. The
only potential risks to on-s1te workers would result from handling the waste
materials from the Unloading Area. Former Cathode Waste Management Areas and
Landfill during remediation. However, the use 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.
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Reduction of Toxldtv. Mobility or Volume
Remedial Alternative 3 treats the leachate generated from the Landfill, -
perched water collected east of River Road and from the Former Cathode Waste
Management Ar«as which reduces the toxlclty of these waste streams. However,
the contaminated soils, sediments and waste materials remaining at the
Landfill and Scrubber Sludge Ponds are not treated.
Implementablllty .
The technologies associated with Remedial Alternative 3 are Implementable
at the MMRF. Potential fugitive dust emissions may result from waste handling
activities at the Landfill, Former Cathode Waste Management Areas and
Unloading Area. However, dust suppressants would be utilized to minimize dust
generation.
Implementation of this remedial 'alternative requires the establishment of
an ACL for fluoride and sulfate ARARs In the groundwater as presented In
Section V. This alternative also requires the approval of Institutional
controls to prevent the use of potentially affected groundwater on site. Deed
restrictions must also be approved to prevent future development on the waste
disposal areas.
The equipment, materials, specialists and work force necessary to -
Implement this remedial alternative are available. Also, the technologies
associated with this alternative have been proven at other waste sites and
could be Implemented at the MMRF. A bench scale study would be required ta
evaluate the aqueous treatment system prior to the final design of the full
scale system.
Compliance with ARARs
Remedial Alternative 3 meets all action and location specific and most
chemical-specific ARARs for the areas of contamination. However, groundwater
beneath the Landfill, Former Cathode Waste Management Areas, Scrubber Sludge
Ponds and Recycle Pond will remain in excess of the ARARs for fluoride and
sulfate. With the establishment of an ACL for the fluoride and sulfate ARARs,
discussed In Section IV, Remedial Alternative 3 would meet all
chemical-specific ARARs.
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Overall Protection
Alternative 3 provides protection to the community of The Dalles, on-s1te
workers and the environment. The risks at the MMRF would be reduced by
containing tht waste, recovering groundwater and treating affected leachate
and perched water. Containment of the waste reduces the potential for direct
contact with tht waste as well as the generation of leachate and fugitive dust
emissions. Recovery of groundwater and treatment of the leachate and perched
water greatly minimizes the potential for off-site migration of contaminants.
Thus. Remedial Alternative 3 effectively mitigates the exposure pathways
Identified for the target remediation areas.
Cost
The capital cost of Remedial Alternative 3 Is $5.728,400. The annual O&M
costs for years 1 through 5 will be $144,00. The annual O&M costs for years 6
through 30 will be $55,600. The total present worth value of this alternative
using a discount rate of 81 is $6,707,400.
The capital cost of implementing a groundwater contingency plan in the
A-aqulfer would be $277,000. The annual"O&M cost for this plan would be
$48,000. The total present worth of this p.lan using a discount rate of 81 1 s
$767,000.
The capital cost of Implementing a ground water contingency plan 1n the B-
aqulfer would be $495,000. The annual O&M cost for this plan would be
$55,000. The total present worth of this plan using a discount rate of 81 Is-
$1,114,000.
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Alternative 4 Evaluation
In addition to those actions that would be Implemented under Alternative
3. Remedial Alternative 4 adds the following actions:
* Capping the Scrubber Sludge Ponds In place with a multi-media cap meeting
RCRA performance standards and creating a hydraulic barrier to minimize
contact between the waste and the groundwater;
Short-Term Effectiveness
Like Alternative 3, implementation of Remedial Alternative 4 should reduce
risks to the community and would pose minimal threats to on-site construction
workers. Remedial Alternative 4 would also take less than two years to
Implement upon Initiation of remedial actions.
Lonq-Term Effectiveness
In addition to the long term effectiveness provided by Alternative 3,
Implementation of hydraulic controls around the Scrubber Sludge Ponds would
lower the S-aqulfer beneath the bottom of the ponds, thus reducing the
potential for leaching of fluorides from the sludges.
Like Alternative 3, long-term maintenance would be required for the cap
systems. The long term effectiveness of the hydraulic barriers Is
questionable 1n that they will require essentially permanent maintenance.
Reduction of Toxicity. Mobility or Volume
Like Alternative 3, Remedial Alternative 4 treats the leachate generated
from the Landfill, perched water collected east of River Road and from the i
Former Cathode Waste Management Areas which reduces the toxlclty, mobility and
volume of these waste streams. However, the contaminated soils, sediments and
waste materials remaining at the Landfill and Scrubber Sludge Ponds are not
treated.
Implementabil 1ty
As with Alternative 3, the technologies associated with Remedial
Alternative 4 are implementable at the MMRF. Potential fugitive dust
emissions may result, however, dust suppressants would be utilized to minimize
dust generation.
Implementation of this remedial alternative requires the establishment of
an ACL for fluoride and sulfate ARARs in the groundwater as presented in
Section IV. This alternative also requires the approval of institutional
controls to prevent the use of potentially affected groundwater on site. Deed
restrictions must also be approved to prevent future development on the waste
disposal areas.
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The equipment, materials, specialists and work force necessary to
Implement this remedial alternative are available. Also, the technologies
associated with this alternative have been proven at other waste sites and
could be Implemented at the MMRF. A bench scale study would be required to
evaluate tht aqueous treatment system prior to the final design of the full
scale systw. The hydraulic barriers would require permanent maintenance,
however.
Compliance with ARARs
Remedial Alternative 4 meets all action and location specific and most
chemical-specific ARARs for the areas of contamination. However, groundwater
beneath the Landfill, Former Cathode Waste Management Areas, Scrubber Sludge
Ponds, and Recycle Pond wil remain In excess of the ARARs for fluoride and
sulfate. With the development of an ACL for the fluoride and sulfate ARARs,
discussed In Section IV, Remedial Alternative 4 would meet all
chemical-specific ARARs.
Overall Protection
. Alternative 4 provides protection to the community of The Dalles, on-slte
workers and the environment similar to that provided In Alternative 3. In
addition, this alternative would also reduce future leaching of fluoride from
waste In the Scrubber Sludge Ponds.
Cost
The capital cost of Remedial Alternative 4 Is $9,229.100. The annual O&R
costs for years 1 through 5 will be $207,600. The annual O&M costs for years
6 through 30 will be $119,000. The total present worth value of this
alternative using a discount rate of 81 Is $10,922,600.
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Alternative 5 Evaluation
In addition to the remedlal'actlons contained In Alternative 3, Remedial
Alternative 5 adds the following actions:
• Consolidation of the scrubber sludge material and underlying soils from
Scrubber Sludge Ponds 1 through 4 Into the existing Landfill;
Short-Term Effectiveness
Implementation of Remedial Alternative 5 would pose more potential short
term on-slte risk than Alternative 3 due to the movement of material from the
scrubber sludge ponds to the landfill. It Is expected that Implementation of
this remedial alternative would take approximately two years, somewhat longer
than either Alternative 3 or 4.
Long-Term Effectiveness
Like Alternatives 3 and 4, Alternative 5 would effectively mitigate the
existing risks associated with direct contact with contaminated perched water,
leachate and/or waste. In addition to those areas covered In Alternative 3,
waste material from the Scrubber Sludge Ponds will be removed, reducing any
existing or future risks from these areas.
As with Alternatives 3 and 4, the overall potential for failure of the
Landfill cap Is minimal, given the environment that the cap and cover will be
used In.
Reduction of Toxicity, Mobility or Volume ,
Like Alternatives 3 and 4, Remedial Alternative 5 treats the leachate
generated from the Landfill and Former Cathode Waste Management Areas which
reduces the toxldty, mobility and volume of these waste streams. However,
the contaminated soils, sediments and waste materials remaining in the
Landfill after capping are not treated.
Implementablllty
Like Alternatives 3 and 4 the equipment, materials, specialists and work
force necessary to implement this remedial alternative are available.
Compliance with ARARs
t
Like Alternatives 3 and 4, Remedial Alternative 5 meets all action and
location specific and most chemical-specific ARARs for the areas of
contamination. However, groundwater beneath the Landfill, Former Cathode
Waste Managwwnt Areas, Scrubber Sludge Ponds and .Recycle Pond wil remain in
excess of the ARARs for fluoride and sulfate. With the establishment of an
ACL for the fluoride and sulfate ARARs, discussed in Section IV, Remedial
Alternative 5 would meet all chemical-specific ARARs.
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Overall Protection •
Remedial Alternative 5 provides protection to the community of The Dalles,
on-slte workers and the environment similar to that provided In Alternatives 3
and 4. In addition, the potential for leachate generation at the scrubber
sludge ponds 1s reduced under this alternative.
Cost
The capital cost of Remedial Alternative 5 Is $9,807,100. The annual OiM
costs for years 1 through 5 will be $146,000. The annual O&M costs for years
6 through 30 will be $57,400. The total present worth value of this
alternative using a discount rate of 8% Is $10,807,100.
Alternative 7 Evaluation
In addition to the remedial actions contained In Alternative 3, Remedial
Alternative 7 consists of the following actions:
'•Consolidation of the Scrubber Sludge material and underlying fill from
Scrubber Sludge Ponds 1 through 4 Into the existing Landfill rather than
placing a soil cover over Scrubber Sludge Ponds 2 and 3;
' Groundwater recovery and treatment for all areas which exceed ARARs, In
addition to the Unloading Area;
Short-Term Effectiveness
Like Alternative 5, implementation of Remedial Alternative 7 would pose
more potential short term on-site risk than Alternative 3 due to the movement
of material from the so-ubber sludge ponds to the landfill. It Is expected
that Implementation of this remedial alternative would take approximately two
years, somewhat longer than either Alternative 3 or 4.
Lonq-Term Effectiveness
Like Alternatives 3 to 5, Alternative 7 would effectively mitigate the
existing risks associated with direct contact with contaminated perched water,
leachate and/or waste. In addition to those areas covered In Alternative 3,
waste material from the Scrubber Sludge Ponds will be removed, reducing any
existing or future risks from these areas.
As with Alternatives 3 to 5, the overall potential for failure of the
Landfl-11 cap and soil cover over the Scrubber Sludge Ponds is minimal, given
the envlronnwnt that the cap will be used in.
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Reduction-of Toxlcltv. Mobility or Volume
In addition to those areas covered In Alternatives 3 through 5, Remedial
Alternative 7 recovers groundwater from the Scrubber Sludge Ponds and Recycle
Pond. The toxlclty of these waste streams Is therefore, greatly minimized.
However, tht contaminated soils, sediments and waste materials contained In
the Landfill after capping are not treated.
Implementabllltv
Like Alternatives 3 through 5. the technologies associated with Remedial
Alternative 7 are Implementable at the MMRF. Unlike these earlier
alternatives. Implementation of this remedial alternative would not require
the establishment of an ACL for fluoride and sulfate ARARs.
Compliance with ARARs
Remedial Alternative 7 includes collection and treatment of the
contaminated leachate, perched water and groundwater to meet remediation
criteria prior to discharge. Remedial Alternative 7 would meet all applicable
chemical specific, location specific and a-ctlon specific ARARs.
Overall Protection
Remedial Alternative 7 provides protection to the community of The Dalles,
on-slte workers and the environment similar to that provided In Alternatives 3
through 5. In addition, the potential for groundwater contaminants migrating.
Is minimized under this alternative.
Cost
The capital cost of Remedial Alternative 7 Is $10,255,500. The annual O&M
costs for years 1 through 5 will be $315,600. The annual O&M costs for years
6 through 30 will be $57,400. The total present worth value of this
alternative using a discount rate of 81 Is $11,932,600.
Alternative 9 Evaluation
In addition to the remedial actions contained In Alternative 3, Remedial
Alternative 9 would add following actions:
' Stabilization of Scrubber Sludge Ponds 1 through 4 and covering the
stabilized material;
0 Groundwater recovery and treatment for all areas which exceed ARARs, In
addition to the Unloading Area;
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Short-Term Effectiveness
Like Alternatives 5 and 7, Implementation of Remedial Alternative 9 would
pose more potential short term risk on-slte than Alternative 3 due to the
movement of material during the solidification process. It Is expected that
Implementation of this remedial alternative would take approximately two
years, somewhat longer than either Alternative 3 or 4.
Long-Term Effectiveness
Like Alternatives 3 to 5. Alternative 9 would effectively mitigate the
existing risks associated with direct contact with contaminated perched water,
leachate and/or waste. In addition to those areas covered In Alternative 3,
waste material from the Scrubber Sludge Ponds will be stabilized, reducing any
existing or future generation of leachate.
The cap Installed on the Landfill would effectively reduce leachate
generation and Isolate the waste, including that from the Scrubber Sludge
Ponds, from direct contact with humans or wildlife. Groundwater treatment
will be applied In all areas that exceed ARARs, eliminating the need for
establishing an ACL.
Reduction of Toxlclty. Mobility or Volume
In addition to those areas covered in alternatives 3 through 5, Remedial
Alternative 9 recovers groundwater from the Scrubber Sludge Ponds and Recycle
Pond. The toxlclty of these waste streams is therefore, greatly minimized.
In addition, .the contaminated soils in the scrubber sludge ponds are
stabilized, reducing their mobility.
ImplementablHty
Like Alternatives 3 through 5, the technologies associated with Remedial
Alternative 9 are implementable at the MMRF. Potential fugitive dust
emissions may result from waste handling activities, including those at the
Scrubber Sludge Ponds for this alternative.
Unlike these earlier alternatives, implementation of this remedial
alternative would not require the establishment of an ACL for fluoride and
sulfate ARARs.
The .equipment, materials, specialists and work force necessary to
Implement this remedial alternative are available. Also, the technologies
associated with this alternative have been proven at other waste sites and
could be Implemented at the MMRF. 'A bench scale study would be required to
evaluate the aqueous treatment system prior to the final design of the full
scale system. An additional study would be required to identify the proper
mix for stabilization of the scrubber sludge ponds.
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Compliance with ARARs
Like Alternative 7, Remedial Alternative 9 would also meet applicable
chemical specific, location-specific and action-specific ARARs without
requiring tht establishment of an ACL.
Overall Protection
Like Alternative 7, Remedial Alternative 9 provides protection to the
community of The Dalles, on-site workers and the environment similar to that
provided in Alternatives 3 through 5. In addition, the potential for
groundwater contaminants migrating is minimized under this alternative.
Costs
The capital cost of Remedial Alternative 9 Is $14,530,700. The
annual OiM costs for years 1 through 5 will be $312,000. The annual O&M costs
for years 6 through 30 will be $53,800. The total present worth value of this
alternative using a discount rate of 3X Is $16,167,400.
Evaluation of Alternatives Against State Acceptance Criteria
The State of Oregon has expressed support for Alternative 3 as opposed to
the other Alternatives evaluated.
Evaluation of Alternatives Against Community Acceptance Criterion
Based on the lack of community response during the public comment period,
EPA has determined that the community supports Alternative 3 as being the
preferred alternative for remedying the risks at the site.
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VI SELECTED ALTERNATIVE
Description of Selected Remedy
The selected remedy Is based on Alternative 3 and comprises the following:
* Consolidate the residual cathode waste material and underlying fill
material from the Former Cathode Waste Management Areas Into the
existing Landfill;
• Consolidate the cathode waste material from the Unloading Area Into
the existing Landfill;
* Cap the existing Landfill in place with a multi-media cap meeting
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 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 groundwater from the Unloading Area;
* Groundwater quality monitoring and a contingency plan to perform
additional recovery of groundwater In the event that further contamination Is
detected above ARARs or health based standards.
Institutional controls such as deed restrictions and fencing will be
Implemented during and after remediation. The purpose of these controls will
be to assure that the remedial action will protect public health and the
environment during Its execution, and to ensure a similar level of protection
after the remedial actions have been Implemented.
Consolidation Into Landfill. The Landfill and associated areas will be
consolidated to limit the actual lateral extent of the cap. The Unloading
Area and Former Cathode Waste Management Areas will be excavated down to
competent basalt and consolidated Into the existing Landfill. Leachate will
be collected after capping the Landfill. Perched water, beneath the Former
Cathode Waste Management Areas will be collected during excavation activities
and treated. This should be effective in collecting perched water on both
sides of River Road. However, temporary sump(s) may be necessary to collect
perched watar east of River Road if the collection pumps in the Cathods Waste
management Areas are not effective. A .soil cover will be placed over Scrubber
Sludge Ponds 2 and 3. Groundwater controls will consist of institutional
controls and limited groundwater recovery. Dust controls will be utilized
during remediation to minimize fugitive dust emissions. Fencing and deed
restrictions will be utilized to limit access and prevent future use of areas
where materials are managed on-site. Only authorized personnel would be
allowed entry to the Landfill and Scrubber Sludge Pcnds after remediation is
complete.
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The Unloading Area will be excavated resulting In the removal of
approximately 200 cubic yards of cathode waste residuals and placement Intd
the existing Landfill prior to Its capping. Backfilling win be performed to
promote drainage.
The cathode waste residuals and underlying soils from the Former Cathode
Haste Management Areas will be excavated and placed Into the existing Landfill
prior to capping the Landfill. The Former Cathode Waste Management Areas will
be excavated down to competent basalt resulting In a total volume of material
removed of 64,470 cubic yards. The excavation for the Bath Recovery Pad Area
will also remove the cathode waste materials along the Landfill Ditch. After
removal activities have been completed, the Former Cathode Waste Management
Areas will be backfilled as required to promote drainage. Capping will not be
required because cathode waste residuals and subsoils from the Former Cathode
Waste Management Areas will be removed and placed Into the Landfill for
management. The perched water will be collected during remedial activities
and treated for cyanide and fluoride by the aqueous treatment system.
Long-term collection and treatment of perched water will not be required
because materials from the Former Cathode Waste Management Areas will be
removed and placed In the Landfill.
Landfill Cap. The Landfill will be covered with a multi-media cap meeting
the performance standards as defined In 40 CFR 264.310 after consolidating
materials from the Unloading Area and the Former Cathode Waste Management
Areas. The volumes of material estimated to be removed and consolidated from
each area are presented below:
' Unloading Area 200 cubic yards
' Potllner Handling Area 9,910 cubic yards
Old Cathode Waste Pile Area 24,200 cubic yards
' Salvage Area 28,700 cubic yards
9 Bath Recovery Pad Area 1,660 cubic yards
The total volume of additional material from these areas (64,670 cubic
yards) will not alter the overall lateral extent of the cap as Illustrated In
Figure 4. However, the overall finished elevation will be Increased to
accommodate the additional fill.
Regradlng of the Landfill Into a central location will be performed to
minimize the areal extent of the cap to approximately 10 acres as Illustrated
in Figure 5. This activity wl 1-1 Include the remediation of the Leachate
Collection, Landfill and Surface Drainage Ditches by consolidating material
contained In the areas under the cap for the Landfill. The known asbestos
disposal areas shall not be disturbed during the regrading activities but will
have the RCRA performance cap over them.
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o
LIMIT OF
EXISTING
LANDFILL
0 IQO 200FT.
SCALE
POWER TRANSMISSION TOWER
POWER TRANSMISSION
TOWER
.
PROPOSED CAP
FOR CONSOL1DAT
WASTE
LEGEND:
-- •— LEACHATE COLLECTION TRENCH
TOP SLOPE
SLOPE. H=HORIZONTAu V=VERTICAL
OftAWOM MOl
TH00184MS-A3S
G4M CQNSUI.IING 6NGIN66RS.
APPROXIMATE LOCAT1C
AND CONFIGURATION C
LANDFILL CAP
FEASfiUTY STUDY; MAftTN MAACTTA flSXCTO4 ffCJ
MARTIN MARIETTA CORPORAT1C
THE DALLES, OREGON
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The cover system will be a multi-media cap designed to meet RCRA
performance standards. The multi-media cap shown In Figure 6 would consist of
a rock cover, a geotextlle layer, 6-inches of clean sand, a wire mesh for
rodent control, another 6-1nches of clean sand, a HOP£ geomembrane, a lower
layer of low permeability soil or clay material, and 6-1nches of clean sand
overlying the waste which will serve as part of a passive gas venting system.
The piping for the gas venting will be constructed of HOPE for compatibility
with the geomembrane In the cap. The top and side slopes of the cap will be
constructed as to minimize erosion and the drainage controls around the
Landfill would be Improved to redirect surface water runoff.
Leachate collection trenches will be constructed to Intercept the flow of
leachate utilizing the historical surface drainage pathways prior to capping
the Landfill. These trenches will be placed such that once the cap is
constructed, they are located under the cap and will only collect leachate
generated from the wastes after capping. Depending on the grade of the
subsurface topography, collection sumps may be necessary to transmit the
collected leachate to a central location. The collected leachate will be
pumped to an on-site aqueous treatment system for cyanide and fluoride
removal. The MMRF Is located in an arid region and because of this climate, a
moisture deficit of approximately 15 Inches per year exists. Therefore, It Is
anticipated that the leachate generated from the Landfill after being capped
will gradually decrease from its existing average annual flowrate of
approximately 10 gpm to a negligible flow within five years.
The on-site aqueous treatment system would Include a chemical oxldatton
unit for destruction of cyanide followed by a chemical precipitation unit to
remove fluoride to an approximate concentration of 9.7 mg/L. A schematic of
the aqueous treatment system is shown In Figure 7. The treatment plant will
be located between the Cathode Wash Area and River Road. Effluent from the
aqueous treatment system will be discharged to an existing sewer which flows
to the Discharge Channel and ultimately to the Recycle Pond.
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-- •.••• -.••••..••••.:•:•:.••.=.•.••.•.•:
ROCK COVER
GEOTEXTILE FABRIC
SAND UVfER
HOPE
LOW PERMEABLE' LAYER
SUB-BASE
GEOTEXTILE FABRIC
GAS VENTING LAYER
COMPACTED WASTE
OATti
GAM CONSULTING ENGJN6EflS. INC
FIGURE 6
J
PROPOSED CAP
CROSS SECTION
STUDY: MARTIN MARIETTA REDUCTION FACILITY
MARTIN MARIETTA CORPORATION
THE DALLES, OREGON
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REAGENTS
0-
1
OXIDATION UNIT
REA3WTS
CHEMICAL PRECIPITATION UNIT
FILTER
TO LAND DISPOSAL
NOTEt
BENCH STUDIES WILL BE REQUIRED
• TO DETERMINE EXACT CONFIGURATION
• OF TREATMENT SYSTEM.
WO«
ItOOIiPOS A«S
0**WH »T
\/j£,\*t»
cm c/ to-
o*rc>
OtM CONSUUINO CNOINtCnS. INC
8 >
-------
Recovery of perched water east of River Road w<111 be limited to a one time
extraction during remedial activities. The use of the roof scrubber return
line beneath the former Cathode Waste Management Ajj-eas would require temporary
disruption of flows to relocate the line or repilace It during remedial
activities. Any damaged lines will be repaired as) part of this process.
Scrubber Sludge Ponds Cover. The Selected. (Remedy involves covering
Scrubber Sludge Ponds 2 and 3 with a soil cover/. A cross-section of the
proposed cover system is illustrated In Figure 8. The soil cover consists of
two feet of soil and a vegetative cover placed on the Scrubber Sludge Pond
sludge. The top and side slopes of the cover system will be constructed to
minimize erosion. Drainage controls will be installed or Improved as
necessary to redirect surface-water runoff. Scrubber Sludge Ponds 1 and 4 are
already covered with established vegetation and do not require additional
efforts under this alternative.
Ground.water Recovery. With the establishment of an ACL for the fluoride
and sulfate ARARs, groundwater recovery and treatment are currently proposed
at the Unloading Area. To recover groundwater from the Unloading Area, a
4-Inch diameter recovery well will be installed in the area of monitor well 5S
as shown In Figure 9. This recovery well, RW-1, will be equipped with a
submersible pump which will be operated at a continuous flowrate of 2 gpm. It
Is expected that recovery from RW-1 would continue for approximately five
years. Recovered groundwater from RW-1 will be discharged Into the Recycle
Pond where It will be recycled to the roof scrubbers or treated by the In
plant process, which is designed to reduce fluoride levels.
Well Abandonment. The selected remedy also Includes replacement of the
existing Animal Shelter, Rockllne, Klindt and Residence wells with water from
the City of The Dalles water supply system and properly abandoning the
existing wells at these locations.
Groundwater Monitoring
Groundwater monitoring would be conducted to* monitor variations in'
groundwater quality and would serve as the basis for monitoring remediation
effectiveness and initiating future actions if required. Table 6 presents the
monitoring wells and the associated target areas that, at a minimum,- w1l1 be
part of the monitoring plan.
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24'
TEOOU-POi-ASJ
onAWN m
cxecxnx
0»TCl
J-L
c
VEGSTATIVH COVEfl
SOt.
SLUOGE
FIGURE 8
J
G4M CONSULTING ENGIN66RS INC
SOIL COVER SYSTEM
CROSS-SECTION
FEASBUTY STVXJY: MAATN MAfiCTTA flaXCTCN WOJTY
MARTIN MARIETTA CORPORATION
THE DALLES, OREGON
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\ --?•«•-•. \\.
PROPOSED GROUND-WA
RECOVERY WELL
LEGEND:
RW-1
OATC<
G
G4M CONSUUIING 6NGIN66BS. INC-
UNLOADING AREA
RECOVERY Wl
F€AS««JTY STUDY: MAflTW MAW6TTA I
MARTIN MARIETTA CORPORATK
^_ THE DALLES, OREGON
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TABLE 6
GROUNDWATER MONITORING WELLS
MARTIN MARIETTA REDUCTION FACILITY
THE DALLES, OREGON
Aquifer System Wells to. be Monitored
S 2S, 5S, 8S, 9S, 15S, 173, 18S, 19S, 21S, 24S,
26S, 27S, 29S,
A . 1A, 4A, 6AA, 7A, 8A, 9A, 10A, 12A, 13A, 14A,
ISA, 27A, 30S, 33A
B IB, 3A, SB, 9B, 12B, 14B, ISA, 26B, 27B, 33B,
34A
DGWR PW-1
Other Chenoweth Irrigation 1, 2, and 3
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Contingency Plan. The following plan would be Implemented If the
groundwater monitoring program Indicates that appropriate ARARs or remediation
criteria are exceeded. Different scenarios exists which would require
groundwater response actions. These Include: 1) contamination above an ARAR
or other remtdlatlon criteria In the A-aqulfer beneath the Landfill; and 2)
contamination above an ARAR or other remediation criteria in the B-aquifer
beneath tnt Landfill. Should an ARAR or other remediation criteria be
exceeded In both the A- and 8-aquifers, the response actions for both
scenarios would be conducted simultaneously.
A-Aqulfer Response Plan. It is anticipated that recovery of groundwater
could be conducted by installing two four-inch diameter recovery wells
downgradlent of the Landfill. It has been estimated that each well would be
pumped at a continuous flowrate of 20 gpm for a total recovery rate of 40
gpm. The recovered groundwater would be transmitted to a treatment unit and
then routed to the roof scrubber system or sent to the in-plant process.
B-Aqulfer Response Plan. The recovery system here would be constructed by
Installing three four-inch diameter recovery wells in the B-aquifer
.downgradlent of the Landfill. The recovery wells would be operated at a
continuous flowrate of approximately 100 gpm for a combined flowrate of 300
gpm. The recovered groundwater would be transmitted to a treatment unit and
would then be routed to the roof scrubber system or sent to the In-plant
process.
Institutional Controls
Institutional controls such as' deed restrictions or fencing will be
established on-site to prevent the installation of wells that draw water from
the S Aquifer. Institutional controls will also be used as appropriate during
Implementation of the selected remedy to ensure that remedial actions are
protective of public health and the environment.
Performance Standards
Capping - The Landfill cap shall be designed and maintained to provide
protection against surface exposure of humans or animal or plant life to the
stabilized soil contaminants, and protect this material .from weathering. A
four Inch soil cover will be placed over the Scrubber Sludge Ponds 2 and 3 and
revegetated.
The Landfill cap must also meet the following design requirements of 40
CFR 264.310.a: 1) function with minimum maintenance; 2) promote drainage; and
3) accommodate settling and subsidence so that the cap's integrity is
maintained.
The performance standard for groundwater treated for fluoride
contamination shall be 9.7 mg/1.
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The remediation criteria that shall be used to determine the volumes of
soils to be remediated are as follows:
Criteria Basis
Arsenic - 65 mg/kg Carclnlgenlc Risk
PAHs - 175 mg/kg Urban Background
Fluoride - 2,200 mg/kg Protection of Groundwater
Statutory Determinations
A. The Selected Remedy is Protective of Human Health and the Environment
The remedy at this site will permanently reduce the risks presently posed
to human health and the environment by:
* Preventing exposure to contaminated soils by consolidation and capping of
areas where direct exposure risks were Identified, and
* Minimizing the generation of leachate from the landfill by the use of a
RCRA cap
* Institutional controls such as deed restrictions and fencing to prevent
exposure to contaminated soils and groundwater.
8. The Selected Remedy Attains ARARs
With the establishment of ACLs for fluoride and sulfate In the S Aquifer
at the site, the Implementation of this remedy will attain all applicable or
relevant and appropriate federal and state requirements that apply to the
site. These are summarized in Appendix A. A summary of key ARARs follows:
The proposed remediation at the site will attain the general RCRA closure
performance standards as specified In 40 CFR §264.111
A groundwater monitoring system will be Implemented consistent with 40 CFR
264.100(d) to determine the effectiveness of the.remedy at the site.
C. The Selected Remedial Action Is Cost Effective.
Given the nature of the risks at the site, Alternative 3 provides an equal
measure of effectlvenesss compared to the other more costly alternatives,
which are also determined to be protective. The selected remedy is therefore
determined to provide a level of protection In a manner that is cost effective.
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0. The Selected Remedy Utilizes Permanent Solutions and Alternative Treatment
Technologies or Resource Recovery Technologies the the Maximum Extent
Practicable.
The selected remedy provides groundwater treatment for those areas where
It Is considered practicable, taking Into account the nine evaluation criteria.
E. Satisfying the Preference for Treatment as a Principle Element.
The principal element of the selected remedy Involves capping and
consolidation of areas of contamination. Although this does not satisfy the
preference for treatment as a principal element, the remedy does adress the
principal health threats at the site. Treatment of contaminated soils at the
site was not found to be practicable given the nature of the risks Involved
and the protect!veness of the selected remedy. Treatment of contaminated
groundwater Is Included in the selected remedy.
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APPENDIX A
POTENTIALLY APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
LAHS AND REGULATIONS TO BE CONSIDERED
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A. FEDERAL LAMS AND REGULATIONS THAT ARE POTENTIAL ARARs FOR THE MARTIN\
MARIETTA SITE \
* Resourct Conservation and Recovery Act (RCRA) (42 USC 6901) I
Subtltlt C:
Landfills: must comply with 40 CFR 264 standards for a hazardous
waste landfill. I
'•/
Capping: must comply with 40 CFR 264 Subpart G standards for a
cover over hazardous waste at closure.
Closure with waste In place; must comply with 40 CFR 264 Subpart
G standards for closure performance and post-closure care and
monitoring.
' Clean Air Act (CAA) (42 USC 7401):
National Ambient Air Quality Standards for particulate matter and
PM]Q - Requirements are specified under Oregon ARARs.
' OSHA 29 CFR 1910:
Regulations governing worker safety at hazardous waste sites.
• Safe Drinking Water Act (SHOW) (42 USC 300):
Drinking Water Standards .(40 CFR 141), Including maximum
contaminant levels (MCLs) for fluoride.
• Clean Water Act (CWA) (33 USC 1251):
National Pollutant Discharge Elimination System (40 CFR 122)
B. OREGON STATE LAWS AND REGULATIONS THAT ARE POTENTIAL ARARs FOR THE
MARTIN MARIETTA SITE
Chemical Specific ARARs
Regulation Standard
OAR 333-61-030 1.0 mg/1 Drinking Water Standard for barium
1.4 - 2.4 mg/1 Drinking Water Standard for
fluoride
250 mg/1 Drinking Water Standard for sulfates
0.05 mg/1 Drinking Water Standard for arsenic
OAR 437.100.010 No employee exposure to inorganic arsenic at
concentrations, greater than 10 ug/m3 of air
averaged over any 8 hour period.
OAR 340-31.055 Ambient Air Quality Standard of1.5 ug/m3 lead.
Arithmetic average concentration of all samples
collected during any one calendar quarter period.
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OAR 340.20.225 Afr/ Significant Emission Rate of 3 tons/year fluoride
OAR 437.111.010 No employee exposure at lead concentrations greater
than 50 ug./m3 of 4lr avtraged over an 8-hour period.
;i
ug./nH or *ir ^eraged over an 8,-hour period.
ilatl
Suspended Particulate Matter
OAR 340-45 Regulations Pertaining to NPOES and WPCF Permits
OAR 340-31.015 '(
Annual Geometric Mean 60 ug/m3
24 hour concentration 100 ug/m3
for more than 151 of
samples In one calendar
month.
24 hour concentration 150 ug/m3
not more than once
per year.
Fine Participates/ PM1Q
Annual Arithmetic Average 50 ug/m3
24 hour average concentration, 150 ug/m3
not exceeded more than average
of one day per year.
Action Specific ARARs
Hazardous Haste
OAR 340.100-002
(Federal Regulations Incorporated by Reference)
Capping
surface Impoundments - 40 CFR 264.228
waste piles - 40 CFR 264.253(b)
landfills - 40 CFR 264.310
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Closure with waste In place
Stabilization - 40 CFR 264.228 (a)(2) and 40 CFR 264.258(t»
Install final cover - 40 CFR 264.310
30 ytar post closure care - 40 CFR 264.310
Operation and Maintenance - 40 CFR 264.310
Surface Hater Control - 40 CFR 264.251
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Air Quality
Depending on the type of action designed, the regulations described below mav
contain specific requirements In addition to the chemical specific air
pollution regulations cited earlier.
Regulation Standard
OAR 340-20 Air . Pollution Control - details contained In
regulations cited below.
OAR 340-20-001 Highest and Best Practicable Treatment and Control
Required
OAR 340-20-040 Methods
OAR 340-20-240 Requirements for Sources In Non-attainment Areas
OAR 340-20-225 Significant Emission Rate
OAR-340-20-245 Prevention of Significant Deterioration
OAR 340-20-245<5) PM10 Monitoring Requirements
OAR 340-21 General Emission Standards for Partlculate Matter
OAR 340-31 , , Ambient Air Quality Standards
Oregon Occupational Safety and Health Code
Regulation Standard
OAR 437-40 General Provisions
OAR 437-50 Personal Protective Equipment
OAR 437-83 Construction
OAR 437-100 Inorganic Arsenic
OAR 437.114 Air Contaminants
OAR 437.129 Protective Equipment. Apparel, and Respirators
OAR 437.136 General Occupational Health Regulations
Transportation of Hazardous Materials
OAR 860.66.055 to 860.66.072
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\
C. FEDERAL LAWS AND REGULATIONS TO & CONSIDERED
Safe Drinking Water Act (SWDW) <|l2 USC 300):
Drinking Water Standards .'(40 CFR 141), Including secondary
standard for sulfate. /
• Clean Hater Act (CWA) (33 USC 1251):
Water. Quality Criteria (EPA440/5-86-001).
D. STATE OF OREGON LAWS AND REGULATIONS TO BE CONSIDERED
Oregon Land Use Goals:
OAR 660.15.000(6)
Goal 6. Air, Water and Land Resources Quality - Establishes that
discharges shall not exceed the carrying capacity of air water or
land and shall not violate applicable Federal or State
environmental quality statutes and regulations.
Water Quality Regulations
OAR 340-41-445 2.2 mg/1 Arsenic Standard for Protection of
Human Health from Water and Fish Ingestlon
17.5 mg/1 Arsenic Standard for Protection of
Human Health from Fish Ingestlon Only
1.00 mg/1 Barium Standard for Protection of Human
Health from Water and Fish Ingestlon
2.8 ng/1 Polyaromatlc Hydrocarbon Standard for
Protection of Human Health from Water and Fish
Ingestlon
31.1 ng/1 Polyaromatlc Hydrocarbon Standard for
Protection of Human Health from Fish Ingestlon
only
42 ug/1 Fluoranthene Standard for Protection of
• Human Health from Water and Fish Ingestlon
54 ug/1 Fluoranthene Standard for Protection of
Human Health from Fish Ingestlon only
OAR 340-41-525 22 mg/1 Cyanide Standard for Protection of
Aquatic Life - Fresh Acute
5.2 mg/1 Cyanide Standard for Protection of
Aquatic Life - Fresh Chronic
1.700 ug/1 Acenapthene Standard for Protection of
Aquatic Life - Fresh Acute
520 ug/1 Acenapthene Standard for Protection of
Aquatic Life - Fresh Chronic
3,980 ug/1 Fluoranthene Standard for Protection
of Aquatic Life - Fresh Acute
OAR 340-41-001 to State Wide Water Quality Management Plan -
340-41-029 "emulates groundwater quality.
OAR 340-41-442 to 470 ••>'• '< ' amette Basin - establishes beneficial uses to
:•? :^3tected and water quality criteria not to be
r • . . i:ea.
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
. REGION 10
1200 SIXTH AVENUE
SEATTLE, WASHINGTON
RECORD OF DECISION,
DECISION SUMMARY AND
RESPONSIVENESS SUMMARY
FOR
FINAL REMEDIAL ACTION
MARTIN MARIETTA SITE
THE DALLES, OREGON
SEPTEMBER, 1988
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\
APPENDIX B
RESPONSIVENESS SUMMARY
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Overview:
EPA conducted community Interviews, sent out fact sheets, published
notices, and held two public meetings to Identify community concerns and
ensure two-way communication about progress and the results of the RI/FS.
Community concern about the' Martin Marietta site has never appeared to be
widespread, although several Issues and questions were raised. These three
Issues were raised by several community members:
1) the concern over cyanide contamination;
2) the Importance of the aluminum reduction facility to the local
economy; and
3) concerns about various airborne emissions from the smelter.
The remedial Investigation addressed the concerns about cyanide,
concluding that there Is no significant cyanide contamination in groundwater
beneath the site. The reduction facility was leased and reopened by NW
Aluminum, which has Improved their practices for handling the wastes which
earlier caused') the contamination now beneath the site. As a result of a
lawsuit. Martin Marietta had previously Installed new flourlde emission
control equipment.
Judging fr<^m the fact that EPA received no written comments on the
Feasibility Study despite two public meetings, two fact sheets, and several
public notices iabout the Feasibility Study and comment period, EPA concludes
that the communjlty's concerns have been addressed and that they are relying on
EPA and OEQ tO\select an appropriate remedy. The selected remedy takes Into.
account the concerns Mentioned above and all other questions discussed below.
/ !
Background on Community Concerns:
1) At the time this site was listed, there was community concern about
cyanide contamination or other groundwater contamination that might
potentially affect Chenoweth Irrigation Cooperative wells which rely on the
deep water aquifer.
EPA Response: The Remedial Investigation revealed low levels of cyanide 1n
the.groundwater that were below health standards. Based on the RI, EPA
beleves that such groundwater contamination which does exist is within the
site boundaries and does not seem to be moving to off-site receptors. To
ensure that no future problems occur without warning, on and off-site
monitoring will continue for at least five years after the remedial action
is completed.
2) Many Individuals stressed the Importance of the aluminum reduction
'facility to the local economy and their concern that Superfund requirements or
actvltles might preclude sale or reopening of the then-closed facility.
EPA Response: The facility, which was closed when this concern was
expressed, has subsequently been leased to Northwest 'Aluminum, which
continues to operate the facility. Since Martin Marietta, not NW
Aluminum, has been involved in remedial work at this site, the selected
remedy is not expected to affect Northwest Aluminum operations or the
local economy.
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3) Some community members have been critical of the aluminum plant because of
the odor and air pollution It created.
EPA Response; This Superfund investigation focussed on hazardous soil and
groundwrter contamination from past practices. EPA did not Identify any
significant risk from air emissions from the Superfund site.
4) Port representatives expressed concerns about possible impacts of
contamination or the "stigma" of Superfund affecting future development of
Industrial property along the Columbia River.
EPA Response: It Is not expected that the contamination found, or
remedial actions to be taken, will affect development.
5) Some Individuals who own cherry orchards fought with and successfully sued
Martin Marietta over damages to cherry crops that the orchardists attributed
to flourlde emissions from the plant. The cherry growers won several lawsuits
and >
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3. Which way Is groundwater under the landfill flowing - Is It flowing toward
the Columbia River?
EPA Response;
GroundWtttr flow 1n the S Aquifer Is generally to the east and northeast;
groundwattr flow In the A Aquifer Is predominantly east to west; groundwater
flow In tht B aquifer Is generally to the west and south; In the OGWR
groundwater flow Is largely determined by local pumping conditions.
4. What considerations are being given to long-range monitoring of off-site
wells In the area?
EPA Response: EPA's selected remedy will Include an appropriate level of
groundwater protection, including monitoring. EPA will be working with
the City of The Dalles and the Clearwater Irrigation District to develop
adequate monitoring. Superfund remedies are also reevaluated after 5
years to ensure that they are working properly.
5. Was there any study on sturgeon in the river and whether the pollution has
affected them?
EPA Response: No specific studies, although relevant information,
received by NOAA for national resource Implications, do not indicate any
such problems. Several people requested more Information, which was
provided.
Issues for further consideration: ; '
Community members should be informed of monitoring plans. All other
Issues appear to have been addressed.
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APPENDIX C
ADMINISTRATIVE
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APPENDIX D
STATE LETTER OF CONCURRENCE
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SEP.27 '88 16:23 EPfl OREGCNxOPERATIONS OFFICE P.02
Department o/ Environmental Quality
811 SW SIXTH AVENGE, PORTLAND, OREGON 972>H-1334 PHO N6 (503) 229-5096
Septaober 26, 1)8&
Robie feuaall
Regional Adainiiter
ERvirosnental Protection Agency
1200 Sixth Avenue
Seattle, «A 98101
Re: Martin Marietta SeJ.«ct«d
Raaadlal tetion Certification
Dear Mr. Russell:
The Oregon Department of Environmental Quality (DBOJ h*.n carefuU r reviewed the EPA
•elected remedial action in the draft record of declaim* (*CD). flu Deparunent ccncuza
with EPA'i selected remedy baaed on alternative 3 of the fee* iHlity study. Thia sela«tad
remedial action satiafiaa the statutory requir-oenta for i. r«a«V *» required by the State
of Oregon. It has) been determined that the selected reMdinl action coopliea with the
applicable or relevant and appropriate requira.ient* (AR.V.\j) lloving cicupttionu:
irnmti
Fluoride 9,7 mg/i
Sulfate 3,020 mg/1
t /
Theae alternate concentration liaita (Ada) have bee .1 r«vi«.^l by the Department. It has
been determined that theae ACLs will be p,rotactisA of hutan he*I*, welfare and the
•nvironaent in the context of this selected remedy.
Departaent ataff are available to provide you addielaM.^ inforv^cion, if na^eatary. The
appropriate DBQ contact ia Ullliaa Renfroe, (503) 229-690C.
Sincerely,
WR:f
ZT3470
ce: Mike Dovns, ECD
Kurt Burkholder, AC
Dick Hichola, UQ
Ten Sisphaa, RO
Jia Boydaean, HD
Chuck ?indley, EPA
Bill Sobolewskl, EPA 000
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