PB95-964411
EPA/ROD/R08-95/098
January 1995
EPA Superfund
Record of Decision:
Summitville Mine Superfund
Site (O.U. 4), Summitville, CO.
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ADMINISTRATIVE RECORD
. FILE P. AN
i..J ;0 (
INTERIl\1 RECORD OF DECISION
FOR
RECLAMATION
Summitville Mine Superfund Site
.. Summitville, Colorado
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INTERIM RECORD OF DECISION
for
RECLAMATION
.
Summitville Mine Superfund Site
Summitville, Colorado
DECLARATION FOR THE RECORD OF DECISION
Site Name and Location
Summitville Mine Superfund Site, Summitville, Rio Grande County, Colorado.
Statement of Basis and Purpose
This decision document presents the selected interim remedial action for reclamation of
non-point sources at the Summitville Mine Superfund Site (Site) in Rio Grande County,
Colorado chosen in accordance with the Comprehensive Environmental Response,
. Compensation and Liability. Act of 1980 (CERCLA), 42 U.S.C. ~ 9601 et seq., as amended by
the S1,1peIfund Amendments and Reauthorization Act of 1986 (SARA) and the National Oil and
Hazardous Substances Pollution Contingency Plan (NCP)( 40 CPR Part 300). .
This decision is based on the administrative record for this Site.
The State of Colorado Department of Public Health and Environment concurs with the selected
interim remedial action. . .
Assessment of the Site
Interim remedial actions are appropriate "to protect human health and. the environment from an
;mm;nent threat in the short term, while a final remedial solution is being developed." ("Guide to
Developing Superfund No Action, Interim Action ~ Contingency Remedy RODs", EP A.
OSWER Publication 93SS.3-02FS-3, April 1991 ). Therefore, actual or threatened releases of
hazardous substances from this Site, if n~t addressed by implementing the interim remedial
action selected in this Interim Record of Decision, may present imminent and substantial
endangerment. of public health, welfare, or the environment.
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Description of Selected Remedy
, ' .
This interim remedy addresses the reduction or elimination of acid generation by minimi7ing the
infiltration of surface water and oxygen into the sulfide mineral zones (including rock-filled
. areas) and the stabilization of surface areas on the Summitville Mine SUperfund Site through
. reclamation practices. The interim remedy will address the principal threat posed by surface
waters infiltrating areas that were not addressed in other operable units. This threat is the result
of historic (pre-l984) and recent mining and/or mining related activities. This interim remedy
will reduce the possibility of the generation and release of additional acid mine drainage (AMD)
at and from the Site.
This interim action is consistent with any future actions to complete the reclamation of the entire
Site, and is a logical step in the reclamation process. Future reclamation actions addressing final
. remedies for all disturbed areas of th,e Site will be detailed in a subsequent record of decision
(ROD).
The major componerits of the selected interim remedy are listed below:
.
Reclamation of approximately 200 acres of disturbed land;
Rough grading of all areas to be reclaimed to a 33 percent or less grade;
Using on-site topsoil that was previously stockpiled and stored;
Adding an optimum. amount of amendments needed to produce a topsoil capable
of promoting and sustaining plant growth;
Reconfigming the areas for slope stabilization, soil erosion and moisture
retention; . .
Seedirig with a seed mixture designed for the diversity ofbabitat found at the Site;
and .
Providing adequate weather protection for the sev~ Site conditions. '
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Annual monitoPng will be conducted on the Site for a period of up to ten years to reseed as
. needed, repair erosion features, and perform other revegetation manaeement requiIements.
No changes have been made to the selected remedy originaIly presented in the Reclamation
Focused Feasibility Study (FFS). However, the sequence of numbering ~e alternatives in the
IROD varies from that of the Reclamation FFS because some of the alternatives were not
retained after the FFS screening process. Therefore, Alternatives 2 and 3 of the IROD correspond
to Alternatives 4 and 5 of the Reclamation'FFS.
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Statutory Declarations
.
This interim remedial action is protective of human health and the environment, complies with
Federal and State applicable or relevant and appropriate requirements (ARARs) for this interim .
limited-scope action, and is cost effective. Although this interim action is not intended to
address fully the statutory mandate for permanence and treatment to ~e maximum extent
practicable, this interim action does utilize treatment and thus is in furtherance of that statutory
mandate. Because this action does not constitute the final remedy for the Site, the statutory
preference.for remedies that employ treatment that reduces toxicity, mobility, or volume as a
principal element, although partially addressed in this remedy, will be addressed in the final
response action. Subsequent actions are planned to fully address the threats posed by the
conditions at this Site. Because this remedy will result in ~ous substances remaining on-
site above health-based levels, a review will be conducted to ensure that the int~ remedy
continues to provide adequate protection of human health and the environment within five years
after commencement of the remedial action. Because this is an interim ROD, review of this Site
and of this remedy will be ongoing as the EP A continues to develop final'remedial alternatives
for the Site.
~ is-; /qq~
.
December 15, 1994
William P. Yellowtail
Regional Administrator
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TABLE OF CONTENTS
DECISION SUMMARY. . . . , , , . . , . . . , . , . . . , , , . . . . . . . . . . . , . . , . , . , . . . , . , , , . 1
1.1 Site Location and Description. , , , , . , , . . , . , . , , . , . , . , . . . . . . . ~ . . .. . , , . , , 1
1.1.1 Climate, . . , . . . . . . . . . , , , . , . . , . . . . . . , . , , , , , , . . , . . . . , . . . . . . , . . 1 '
1.1 ~2 Topography....,.........."."... " . , . . . , . , . . . , . . . . . . , . , . , , 1
1.1.3 Geology... . . . . . , ',' ~ , , , . . . . . . . . . , . , . , . , . , . . , , . . , . . . , , , , , . . . 2
1,1.4 Hydrogeology...,.,.....,...."...,.,...,."...,...,.,.... ,. 3
1.1.5 Present Surrounding Land Use and Populations. , , . . . . . . . , . , . , . , . , .4
1.2 Site History and Enforcement Activities. . . . . , . , . . . . . .. .. . . . . .. . . .. .. .. . 4
1.2.1 Site History. . . . . , . . ~ . . . , , . , . , . . . . . . . , . . . ~ . . , . . . . . . . . . , . , . . , 4
,1.2.2 EnforcementActivities ..,." ~.."..".,...,..,.,.......,...,. 6
Community Participation, . . . . . '. , . . . . . , . . . . . , . , " . . . . . . . . . , . , . , . , , , . , , 7
Scope and Role of Interim Remedial Action within Site Strategy, , , . : . , . , . . . 8
Site Characteristics, . , . . . , , . . . . , . , . , . , . . , . . , . . , , . . . . . . . . , . , . , , . . . . . 16
1.5.1 Nature and Extent of CODt~min~rion , , " . . . . . . . . . . . . . . . . . . . . . , ,. 16
1.5.2 Description of Impacted Water ....,.. ~ . . .. . .. . . . .. . .. . . . . . . . . . 17
1.5.3 Description of Non-point Sources. . , . . . . . . . . . . . . . . . . . . . . . . . . . . .23
1.5.4 Cont~minant Transport and Migration. . . . . . . . . . . . . . . . . . , ; , . . . . . . 25
1.5.5 ARARs.,.,...,.,.......,...,., " . , , . . . . . . . . . . . . . . . . . . , . , . . 26
1.6 Snmmary of Site Risks ............................................39
1.6.1 Screening Ecological Risk Assessment, .. ., . , . . . . . . , . . . ,. ,.. . . . .39
1.6.2 Environmental Rlsk. Assessment. . . ~ . . . , . , . .'. . . . . . . . , . , . , . . . . . . 40
1.6.3 Human Health Risk Assessment. . . , . . . , . . . , . . . . , . . . . . . .. . .. . . . 41
1.7 Description of Alternatives. . . . .. . . . , . . , . .. . . . . . . . . . . . . .. . . . . , . , . . . . 42
1.7.1 Alternative 1: No Action '. , . , .. . . . , . . . . . . . , . . . . . . . . . . . . . . . . . . . 43
.1.7.2 Alternative 2: On-site Topsoil with Amendments ......... .'.......43
1.7.3 ' Alternative 3: Imported Topsoil. . . . . . . . . . '. . . . . . . . . , . ,. .. . . , . .44
Summary of Comparative Analysis of Alternatives, . . . . . ~ . . . . . . . . . . . . , . . 44
'1.8.1 Criteria 1: Overall Protection of Human Health and the Environment
1.3
1.4
1.5
1.8
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1.9
1.10
'1.8.2 Criteria 2: Compliance with ARARS ... ~ . . . . . . . :. . . . . . . . . . . . 45
1.8.3 ' Criteria 3: Long Term Eff~veness and Permanence. . . . . . . . . . . 45
1.8.4 Criteria 4: Reduction of Toxicity, Mobility, and Volume. . . . . . . . .46
1.8.5 Criteria 5: Short-Term Effectiveness. . . . . . . . . . . . . . . .. ... . . . .46
1.8.6 Criteria 6: Implementability.. . . . . . .. . ..'. . . . . . . .. . .. . . . . . . .47
1.8.7 Criteria 7: Cost. . . . . . . . . . . . . . . . . . . . , , . . . . . . . . . . . . . . . . . . . 48
1.8,8 Criteria 8: State Acceptance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48
1.8.9 Criteria 9: Community Acceptance. '. . . . . . . . . . .' . . . . . . . , . . . . . , 48
Selected Remedy. . . , . . . . . , . . . . . , . . . . . . . . . . . . , . . . . . . . . ~ . . . . . . . . . . . 49
Statutory DeteJ:minations . . . . , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , . : . . . , 50
1.10,1 'Protection of Human Health and the Environment. . . . . . .. . . , .. . , . . 50
1.10.2 Compliance with Applicable or Relevant and Appropriate Requirements
. . . . , . . . . . . . . . . , . . . . . . . . , . . . , . . , . . . . . . . . . . , . " . . . , '.' . . . . . . 51
1.10.3 Cost-Effectiveness .................,...,....................51
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1.10.4 Utilization of Permanent Solutions and Alternative Treatment
Technologies or Resource Recovery TeC~ologies to the Maximum Extent
Practicable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S 1
1.10.5 Preference for Treatment as a Principal Element.. . .;. . . . . . . . . . . . . . . . S2
2.0
SITE RECLAMATION RESPONSIVENESS SUMMARy. . . . . . . . . ; . . . . . . . . . .". 53
2.1 Responsiveness Summary Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . S3
2.2 Response to Reclamation Specific Comments. e . . . . . e" . . . . . . . . . . . . . . . . . ". 54
2.2.1 Summary and Response to Local Community Concerns. . . . . . . . . . . . 54
2.2.2 Comprehensive Response to Specific Legal and Technical Questions.. 60
2.3 Response to General Comments. . . . . . . . . . . . . . . . . . . . ~ . . . . . . . . . . . . . . . . 68
2.4 " Summary and Response to ARAR Comments. . . 0 . . .0 . ". . 0 . . . 0 . . 0 . . . 0 . . . 82
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REFERENCES. . . . . 0 . . . . 0 . 0 . 0 0 . . 0 0 . . . . . . . . 0 0 . 0 . . 0 . . . . . . . . . . ~ 0 . . . 0 0 0 0 0 0 94
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LIST OF TABLES'
Table 1 -
Copper Content - Site Contaminated Water
. Table 2 -
Cyanide Content - Site Contaminated Water
Table 3a -
Site Surface Water and Treatment Plant Flow Rates
Table 3b -
Site Surface Water and Treatmeitt Plant Water Volume
Table 4-
Containment Content During High and Low Flow Periods
Table 5 -
Copper Concentration at W.F. 5.5
Table 6 -
Total Cyanide Concentration at W.F. 5.5
Table 7 - .
ARARs
. Table 8-
Numeric Surface Water Quality Goals and ARARs
Table 9-
Evaluation of Alternatives
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LIST OF FIGURES
"Figure 1 .
Figure 2 .
Area Map
Minesite Footprint
FJgUre 3 .
Geology. Cropsy Valley Section
FIgUre 4 .
Conrnmin~ted Surface Water Streams
Figure S ."
Alamosa River Stream Segment Classifications
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1.0
DECISION SUMMARY
1.1
. Site Location and Description
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The Summitville Mine Superfund Site is located about 25 miles south of Del Norte, Colorado, in
Rio Grande County (Figure 1). It is located within the San Juan Mountain Range of the Rocky
Mountains, approximately two miles east of the Continental Divide, at an average altitude of
11,500 feet. The 1,231 acre mine permitted area is positioned on the northeastern flank of South
Mountain. The disturbed area at the Site covers approximately 550 acres (Figure 2). On the
North, the this area is bounded by the deserted town of Summitville and by WightInap Fork
Creek. It is bounded by Cropsy Creek to the east and the peak of South Mountain to the
southwest. The Site is located in the Rio Grande Drainage Basin near the headwaters of the
Alamosa River. Two tributaries drain the Site - Wightman Fork Creek and Cropsy Creek. The
confluence of Cropsy Creek and Wightman Fork is located on the northeastern perimeter
downstream of the Site. Wightman Fork Creek drains into the Alamosa River approximately 4.5
. miles below the Cropsy Creek co~uence.
.LLl Climate
The Site's climate is characterized by long cold winters and short cool summers. W'mter
snowfall is heavy and thunderstorms are common in the summer (SRK, 1984). Temperatures
range from a high of 70°F and a low of 17°F in the summer to a high of 40°F and a low of -25 OF
in the winter. The Site receives an average of 55 inches of precipitation annually, mostly in the
form of snowfall, with annual. evaporation at approximately 24 inches (Remedial Measures Plan,
1992). .
There is a relatively 'snow-free period of 5-6 months from May through October. This time
period is regarded as the "construction season." Site access and operations during the'rest of the
year reqUires a significant amount of snow removal. Continued water treatment and flow, or
meticulous winterization, is required to prevent water from freezing in the pipes.
.LU Topo~pby
Approximately 550 acres of the Site is comprised of heavily altered temin due to mining .
operations. The Site's pre-1870 topography consisted of upland surfaces, wetlands, and South
Mountain peak. The predominant Site ground cover was alpine tundra at the higher elevations
with coniferous forest and subalpine meadow in the lower elevations. The mountains which
surround the Site, including Cropsy Mountain to the south, are between 12,300 feet and 12,700
feet in elevation.
The Wightman Fork drainage covers approximately 3.0 square miles upstream from the
. Wightman Fork diversion. The catchment elevations range from 11,225 feet to 12,754 feet. The
Cropsy Creek drainage area entails 0.85 square miles on the northeast slopes of the Cropsy
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Mountain and the southern slopes of South Mountain. Elevations within this drainage range
ftom 12,578 feet down to 11,200 feet at the Cropsy Creek confluence with Wightman Fork,
(Klohn Leonhoff, 1984). Wightman Fork drains into the Alamosa River approximately 4.5 miles
from the Cropsy Creek confluence. '
Disruption of the topography began, on a liniited scale, in 1870 with placer gold mining in
stream- formed alluvial deposits. Eleven stamp mills were in operation by 1884. Placer mining
was followed by open cut minine on gold-bearing quartz veins. Underground mining followed
using horizontal adits for access, hanlage, and mine'drainage. As mining production dep~
increased, several processing mills were constructed to handle the increased capacity and
produce a concentrate suitable for transit. This initial mining phase lasted through 1890.
Additional underground mining occurred ftom 1925 to 1940. In 1934, the district entered its
most productive period and a 100 ton-a-day flotatioDlcyanidation mill and gold retort was
installed close to the south bank of the original Wightmail Fork Creek at the site of the present
Beaver Mud Dump (BMD). This resulted in surface deposition of waste rock near the adit
entrances. Additionally, piles of mill tailings were placed downgradient ftom the stamp mills and
the 1934 flotation-cyanidation mill.
Further surface disruption of the topography resulted ftom work in the late 1960's when
Wightman Fork was diverted north to allow construction of a dam and tailings pond. With this,
,new impoundment, mill tailings were put on the BMD and water was impounded above the dam
in the Summitville Dam ImpoUndment (SDl) (p~viously called the Cleveland Cliffs Tailings
Po~~yEPA). .
~ most dramatic sUrface alterations started in 1984 with the construction of the mine pits and' ,
dumps by Summitville Consolidated Mining Company, Inc. (SCMCl) to support its open pit
heap leach gold mine operations. The main topographical feature is the highwall of South '
Mountain. This highwall is fraCtured and has a one to one (horizontal to vertical) slope.
LU GeolQKY'
Summitville is located near the margin of the Platoro-Summitville caldera ~omplex. Rocks in
the mine area consist of South Mountain Quartz Latite Porphyry. The porphyry is underlain by
the Summitville Andesite. The contact between the latite and andesite is Intrusive, faulted in
some areas and is nearly vertical. On the north side, the contact is fault-bounded by the
Missionary Fault. South Mountain is bounded on the southwest by a large northwest-southeast
trending regional fault called the South Mountain Fault. The South Mountain -Quartz Latite
Porphyry is bounded to the west, on both sides of the South Mountain Fault, by slightly older
Park Creek Rhyodacite. It is overlain at higher elevations by erosional remnants of slightly
younger Cropsy Mountain Rhyolite (Sto:ffi'egen, 1987). Figure 3 shows a geologic section of the
Cropsy Valley.
South Mountain, volcanic dome emplacement, alteration, and mineralization occuIred in rapid
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sequence approximately 22.5 million years ago (Rye, et. al., 1990). Magmatic, sulfate-laden
water expulsed from the quartz latite ma.gmas was hot and highly acidic (pH~2, temperature of
2500 C - StOffregen, 1987), and caused extensive alteration to the quartz latite. Altei-ation occms
in four sequential zones: the massive vuggy silica zone, the quartz-alunite zone, the quartz-
kaolinite zone, and the clay alteration zone. The massive vuggy silica zone is often a highly
porous zone in which all major elements but silica and iron were leached by acidic solutions and
, replaced in places by excess silica. This zone occms in irregular pipes and lenticular pods, and
generally shows greater vertical than lateral continuity (Stoffregen, 1990). The next outwardly
. occurring zone is the quartz-alunite zone, in which feldspars of the quartz latite porphryry were
replaced by alunite. This zone grades outward to a thin quartz-kaolinite zone, which is not
always present, and then into an illite-montmorillonite-chlorite zone in which feldspar and biotite
grains were replaced by illite and quartz, with lesser bolinite and montmorillonite. The quartz-
alunite and clay al~eration zones are the most volumetrically significant. Fine-grained pyrite is
disseminated thfough the groundmass in all zones (Stoffregen, 1987).
Summitville mineralization is an ~Xample of epithermal Au-Ag-Cu mineralization associated .
with advanced argilli~ alteration. Mixed I1)Rematic and surface water (derived from snowmelt
and rainfall), less acidic and more reducing than the IJ'IR.g1TtRtic water that produced the alteration
zones, deposited metals.and metallic sulfides at shallow «llan) depths (Rye, et al., 1990)., .
Mineralization is associated mostly with the porous wggy silica zone, and occurs as covellite +
luzonite + native gold changing with depth to covellite + tennanite. Gold also occms in a near-
surface barite + goethite + jarosite assemblage that crosscuts the vuggy'silica zone (Stoffregen,
1987).
, '
Post-volcaniC- geologic processes have been largely erosional. The tWO major streams that drain
. the Site, Cropsy Creek and Wightman Fork, tend to follow the quartz latitelandesite contact.
Numerous springs and seeps occur at this junction between the fractured quartz latite porphyry
aquifer and the underlying dense andesite aquitard. .
Site cover material consists of topsoil, silt, clays, and gravel.' The topsoil is described as
greylbrownlorange, non-plastic with a trace of roots and sand. Clays are of low to medium
plasticity with some gravel. . . . .
.l...l.! Hydroe:eoloey
Ground water at the Site is present as a series of intermittent, shallow, perched aquifers. Shallow
ground water occurs in surficial deposits consisting of colluvium, "slope wash" alluvium and/or'
glacial ground moraine; ~d weathered parts of the Summitville Andesite. These shallow
systems eventually discharge to surface water. The upper perched aquifer system also contributes
to the ground water recharge of the fractured bedrock system. Numerous springs and seeps cover
the entire Minesite, the ~ number at the locus of the distal edge of the dome. Most of the
springs and seePs flow in direct response to precipitation, with high and low flows corresponding
. to high and low flow of the surface water system in the area.
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A natural surface water drainage syStem exists along the southern portion of the Summitville
Site. The surface water drainage system includes Cropsy Creek and Wightman Fork. Extensive
re-working of both drainage systems has been conducted. .
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l..l...1 Present Surroundini Land Use and PQPulations
The Site is surrounded by National Forest Service land (Rio Grande National Forest). The
multiple-QSe designation of this land gives it a high level of desirability for snow mobiling, cross
country skiing, hiking, camping, horseback riding and picnicking. Additionally, logging activity .
is on-going adjacent to Park Creek Road and other roads adjacent to the Site. During the summer
months, domestic cattle and sheep graze in the surrounding area and during the winter monthS,
the surrounding area is heavily used for hunting. .
The distance to the nearest off-Site building is 2.1 miles to the east (EPA, 1992). The water from
the Site flows past the town of Jasper into Terrace Reservoir, both of which are recreational
areas. Private residences and a Phillips University Camp use water from wells adjacent to the
Alamosa River. Below the Terrace Reservoir, the river flows past the town of Capulin which
. contains two municipal wells and many domestic wells. Throughout this drainage area, homes,
farmsteads and ranches depend upon alluvial wells or river water for potable or agricultural water
production. However, recent EP A analysis indicates that the Site has not impacte4 alluvial
drinking water supply wells (Morrison Knudsen, 1994). Additionally, water from the Alamosa
River is used within the Monte Vista Wildlife Refuge and in the La Jara Creek system through
the Empire Canal (District Court, Rio Grande Co.,1992).
1.2 . Site History and Enforcement Activities
.l.2.J. Site Histo~
Placer gold was discovered in Wightman Gulch in the summer of 1870 (Guiteras, 1938). The
lode deposit was found near the headwaters in 1873 and by 1875 open cut workings had been
establiShed. The ore consisted of native gold in vein quartZ, reportedly associated with limomte
and other ion oxides, which comprised the surficial, oxidized zone of the deposit Because this
zone reportedly extended to 450 feet below the surface, adits and shafts had to be driven into the .
veins (Garrey, 1933). There was only minor production in the mine area from 1890 to 1925. -
In 1897, the Reynolds Adit was driven into the Tewksbury vein, located below the central
portion of the contemporary Summitville pit The Adit was completed in 1906 (Knight Piesold,
1993). RepOrts of acidic water exiting the adit soon followed (Ganey, 1933). .
A significant gold find occmred in 1926 when high grade ore was struck. From 1926 to 1931,
864 tons of ore was extracted. The Reynolds Adit was rehabilitateci to provide haulage and
. development access. Plans were made to connect the Reynolds to the Iowa Adit, 540 vertical
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feet above the Reynolds. This connection was completed in 1938. Iowa ores were then dropped
down to the Reynolds level for haulage. The Reynolds and the Iowa Adits also provided
drainage for the main workings (Knight Piesold, 1993). .
. - .. .
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In 1934, a 100 ton-per-day flotationlcyanidation mill and gold retort was installed at the site of
the present BMD. Records indicate that dewatering filtrate from the flotation circuit was
discharged directly into Wightman Fork throughout the mid-1930's.
In 1941, three tunnels were in operation: the Iowa, Narrow Gauge, and Reynolds. During W orId
War IT, the .govemment mandated the termination of mining of non-essential minerals to focus on
essential minerals needed for the war effort. Gold production ceased. . .
From 1943 to 1945, a high grade copper vein found in the Narrow Gauge and Reynolds was
developed. By 1944, only the Narrow Gauge Tunnel was operating. In 1947, the Reynolds was
again rehabilitated. ApproX:imately 4,000 feet of rail needed replacement due to deterioration
from acidic water. By 1949, the water flow discharge from the Reynolds ranged from 100-200
. gallons per min~ (gpm) (Stevens, T A, 1960).
From 1950 to 1984, the minesite was the target of several exploration arid underground
rehabilitation programs. ProdUction of copper, gold, and silver was sporadic. An extensive
drilling program was conducted by Tonto Drilling Services for ASARCO in the late 1970's and
early 1980's to delineate a potentially minable gold deposit (Knight Piesold, 1993).
. . . ~
The underground and surface operations during the original discovery of gold to the early 1980's
resulted in surface deposition of waste rock near adit entrances and deposition of mill. tailings
downgradient of the original mill. An attempt to process ore to extract copper content in the late
1960's and early 1970's resulted in a diversion of Wightman Fork from its original route to
. further north of the existing tailing.c:, construction of the SDI{1969) and deposition. of mill
tailings east of existing tailine.c: piles. .
During recent operations (1984-1991), Summitville Co~lida,ted Mining Company Incorporated
(SCMCI), a wholly-owned subsidiary of Galactic Resources, Inc., developed the rem~ining .
mineral reserves as a large tonnage open pit heap leach gold mine. Gold containing ore (9.7
million tons) was mined, crushed and heaped onto a constructed clay-and-synthetic-lined pad. A
solution CODmining 0.1-0.5% sodium cyanide was applied to crushed ore on the Heap Leach Pad
(HLP) and was allowed to percolate through the ore to leach out gold. The solution was then
pumped from the ore and gold was removed from the leach~tf" with activated carbon. The
leaching solution was rejuvenated by restoring the target cyanide level and recycled through the
heap. Gold was stripped from the carbon, precipitated from the stripping solution, smelted to
make dore metal, and sold. .
The Summitville HLP is a "valley fill" design. This design differs from more widely employed
designs' in that it is more of a lined depression, or rock filled pond, than a lined leaching "pad".
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Utilization of a valley fill design usually results from topographic limitations that make
construction of a flee draining pad difficult. The process solution was pumped directly from the
. HLP to the gold recovery plant. The more common leach pad design enables ~ter percolated
through ore to constantly drain to a "pregnant solution pond" outside of the HLP, rather than
being held in the' same containment area as the crushed ore. The design of the HLP as a.
continuous water containment structure prevents the natural drainage of water from the cyanide
bearing pad and complicates the closme of the ore pile.
The HLP containment feature was constructed in a portion of the valley occupied by Cropsy
Creek. Cropsy Creek was moved to allow construction of the HLP. After diversion of Cropsy
Creek, a portion of the valley was enclosed by dikes. The area between the dikes was contoured
and lined and became the HLP.
Open pit minine operations conducted by SCMel did not expose standing ground water in the
Iriine pit. Infiltration of surface water (derived from snowmelt and rainfall) through the pit may
have resulted in elevated dissolved metal concentration in the water draining from the Reynolds
Adit. This trend is observed when compared to the available pre-open pit drainage data.
. Dming the SCMCI operation, topsoil was stripped and placed intO stockpiles. Other overburden
and waste material was used for road and dike constructi~n, placed into the Cropsy Waste
Dump, placed in the North Pit Waste Dump, and placed over the historic mill tailings to form the
BMD. Difficulties in processing some of the ore resulted in foDriation.ofthe Clay Ore Stockpile,
near the present solution pumphouse location, and an in-pit stockpile. Figure 2 illustrates .these
areas.
The last ore tonnage was placed on the HLP in October 1991. Addition of sodium cyanide to the
ore continued mlti1 March 1992. After mining operations were concluded, SCMel proceeded
toward Site cleanup and closure by converting the gold recovery plant to a cyanide destruction
facility for HLP detoxification, converting the existing a1kaHne chlorination water treatment
plant to a sulfide precipitation process, and by installing a treatment plant to process Reynolds
Adit drainage.
l.U Enforcement Activities .
In February of 1991, after monitoring rising concentrations of cadmium, copper, zinc and
cyanide in Wightman Fork, the State of Colorado cited violations of water quality legislation and
. issued a Cease and Desist Order to SCMCI (Holm, 1991).
. .
On December 3, 1992, SCMCI declared bankruptcy and announced that financial support of Site
operations would not continue beyond December 15, 1992. On December 16, 1992 the EPA
Region vm Emergency Response Branch, as a part of an Emergency Response Removal Action
(ERRA), began treating cyanide-cootamin$lted leachate from the HLP and Acid Mine Drainage
. (AMD) from three significant sources: the French Drain Sump, the Cropsy Waste Pile, and the
6
-. ._'- ""
. . . .
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.
'--..~- -'"
...---.-.-....--- .__.-::-':- ...._._..~.- - ~--.- .
Reynolds Adit (Ecology and Environment, 1993).
'Site operation oversight was undertaken by the United 'States Bureau of Reclamation (USBR)
under an inter-agency agreement with the EP A. In December 1992, Environmental Chemical
Corporation (BCC), under the direction of the USBR., began conducting engineering evaluations
of the water treatment processeS and subsequently began improvements to water treatment
processes and facilities. '
The Site was added to the Superfund National Priorities List (NPL) on May 31, 1994.
1.3
Community Participation
The Proposed Plan for the Smnmitville Minesite was released to the public in August 1994. The
Proposed Plan, the Focused Feasibility Study, and other documents in the Administrative Record '
are available at infonnation repositories at the following locations: Del Norte Public Library
located mDel Norte, Colorado; the Conejos County Agricultural and Soil Conservation Service
located in La Jara, Colorado; and the EP A Superfund Records Center located in Denver, '
Colorado.
Public meetings were held in Alamosa, Colorado to present the Proposed Plans and to take
public comment. The comment period was extended 30 days to October 23, 1994. ,
~ghlights of community parti,cipatiC?n are summarize4 as follows:
.
When EP A took over the Site in December 1992, 'there was a great deal of public interest,
mostly from farmers downstream of the Site who were concerned that their inigation
water would be conmminS'lted. As EP A worked to reduce the chance for a Iafge toxic spill
and began more water treatment at the Site, ~e fanning community, became s8tis£ied that
there was no imminent danger of contaminS'lting their water supply. Since that time there
has ~ a decreased interest about the Site from the general public. The interest in the
Site nationally has been very high due to the media using Summitville as a "red flag" for
the need for mining reform. ' ,
.
In June 1993, a Superfund informational workshop Was provided to the public in La Jara, ,
Colorado.
.
On August 2, 1993, a public meeting was held in Alamosa, Colorado describing
alternatives for reducing acid mine drainage from the Cropsy Waste Pile (CWP), the
BMD, SDl, and the Mine Pits. An Engineering Evaluation/Cost Assessmen~ (EElCA) ..
fact sheet ~ published. Public comment was taken until September,3, 1993.
The Community Relations Plan for Summitville was written and distributed in September
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.8
1.4
1993. The Community Relations Plan provides a guide for EP A's community
involvement program based on interviews with local citizens.
8
'. .
. A Technical Assistance Grant (TAG) was awarded for the Site in February 1994. This .
. . group is now well organized and has hired several consultants. The TAG Group has been
active in the area m an attempt to generate interest in the Site. They have published .
regular Summitville columns in the Valley Courier newspaper and have held
informational meetings. . .
8
EPA held a briefing for Congressional aides in May 1994.
8
Press releases have been written dealing with the following:
Proposal to place on the NPL,
Listing on the NPL, .
Announcing meetings,
Availability t;>f materials, .
Comment periods,. .
Availability of work through bid process,
Bid awards, and .
Status of work at the Site.
8
Five Site Status Updates have been written and distributed to over 200 interested parties
as well as a year end report for 1993..
8
Articles about the mine were written by local newspaper writers and appeared at least
, weekly for the past year. Files of these newspaper articles are available in the .
Community Relations office and will be placed in the infoDnation repositories.
In December 1993, the EP A produced and distributee! copies of videos of the Summitville
Minesite. One hundred fifty copies have been circUlated to schools, officials, and
in~ co~unity members. The video gives an overview of the contaminAtion at the
Site, a briefhi$1Y of the Site, and a "video tour". . .
. .
Scope and Role of Interim Remedial Action within Site Strategy
. .
The original mine permitted area includes 1,231 acres; the area referred to as the Site is
comprised of approximately 550 acres ofland disturbed by historic as well as recent mining .
activities. The most common type of contaminat:ion associated with production of a metal mine
sUch as Summitville is the formation and discharge of large volumes of acidic water. The acid
generation can occur eith~ chemically or biologically; as part of the living processes of certain
microorganisntS. The acid is formed chemically when water, such as rainfall or snowmelt, and
air come into contact with metallic sulfide ores. The sulfide (S'2) then reacts to form sulfuric acid
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.. --- -- -'--'--- -- -... --_... .-. . -...-- .
'- --- ----.--.
and sulfates. The sulfuric acid and sulfates react with the surrounding rock or soils to generate
the metal concentrations within the acidic water and is then known as AMD. This process
continues as long as there is sulfide'or sulfates, water, and air. .
The primary metallic sulfides and secondary sulfates found at the Summitville Minesite are
pyrite (iron sulfide), alunite (potassium aluminum sulfate), and jarosite (potassium iron sulfate).
There are fourteen areas of concern at the Summitville Minesite including twelve which either
generate or may potentially generateAMD. The fourteen areas are briefly described below in
their general order of priority:
1. HEAP LEACH PAD: The HLP is approximately SS acres in size and 127 feet deep
at its lowest point. The Cropsy Creek was diverted around the HLP area and the HLP
" was then c'onstructed. in the former Cropsy Creek drainage bed. The HLP is underlain by
a French rmpn system and extends onto the toe of the CWP which is located upgradient
within the Cropsy Creek drainage bed. The leach pad liner is leaking, causing the water
within the French Drain t~ become contaminated with cyanide. The HLP consists of ore
containing hig];1levels of metaI1ic sulfides sitting in a vat of cyanide and heavy metals
contamin~ted ~er. In December of 1992, the Environmental Protection Agency (EP A)
took over operations of the Site water treatment plant to prevent overflow of the .
cont~minated water to the Wightman Fork and, ultimately, the Alamosa River during
Spring runoff. Currently the HLP is maintained at a pH of9 to prevent the evolution of
hydrogen cyanide gas. It is cmrently proposed that the Heap be' detoxified as one of four
interim actions. This action will also address the potential acidification of the heap once
the cyanide is removed and a high pH is no longer maintained. The former continuous
overflow of AMD to the HLP from the adjacent CWP is currently being addressed as
discussed in CWP section below. .
2. REYNOLDS ADIT SYSTEM: . The Reynolds System is composed of the
underground workings which still exist under the large open Mine Pit excavated by
SCMCI, and the remaining.adits which access those worldngs. The Adits include the
Reynolds, the Dexter Crosscut, the Chandler, and the Iowa. The Reynolds Adit is the
main adit which was driven to drain the workings and provide an.access and Ju-ulage
. route. The Dexter Crosscut, a drift branching westward from approximately 100 feet into
the. Reynolds Adit, also provided drainage, access, and haulage. The Chandler Adit .
accesses the upper areas of the underground workings at a higher elevation than the .
Reynolds Adit. The Iowa Adit accesses even higher levels of the workings and areas near
the rim of the Mine Pit. The Mine Pit was hydraulically connected to the Reynolds
System and contributed much of the AMD observed at the Reynolds Adit. The EP A
operated an interim treatment plant to treat the average 120 gallons per minute (gpm) of
AMD which exited the Reynolds Adit.. . .
. .
Based upon the estimated release of 44.S percent oftota! copper loa.din~ directly from
the Reynolds Adit, it was determined that plugging of this system be conducted as a time-
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. .
critical Removal action. A contract to plug the Reynolds Adit System was awarded .on
October 4, 1993 and work began on November 22, 1993. After extensive technical
considerations, only the Reynolds and Chandler Adits were ultimately plugged. The
Dexter Adit was found to terminate approximately 450 feet from its intersection with the'
Reynolds so no plug was needed. Upon completion of the Reynolds plug, there was an
immediate decrease in flow and a 65 percent reduction in copper concentrations from the
Site overall. Copper loadings directly attributed to the Reynolds Adit were decreased by
97 percent .
On May 25, 1994, the Chandler Adit was discovered to be discharging high volumes of
water from porous/fractured ~ck surrounding the plug. The leak was initially estimated
. at 340 gallons per minute (gpm) and peaked at 72S gpm in June 1994 with high
concentrations of metals and low pH. However, this new contaminSlnt source produced
less flow and less copper concentrations than experienced nom the Reynolds Adit system
during the previous year. Work to fortify the Chandler plug was initiated in November
1994 and plug performance will be closely monitored through the 1995 spring runoff
season. Since November 20, 1994, AMD exiting the Chandler has been treated through
. the PITS water treatment plant and no longer discharges directly to Wightman Fork. .
. .
3. CROPSY WASTE PILE: The CWP was composed of approximately 6.5 million
. tons of low grade ore,' overburden, and waste rock excavated from the main Mine Pit
during SCMCrs mining operations. The CWP covered approximately 35 acres and was
. piled as high as 120 feet from the bottom of the old Ciopsy Creek drainage bed in which
it was placed. Although the CWP had been capped to prevent percolation of snoWI;1lelt
and rainfidl, upward infiltration of ground water has begun the process of acidifying the
CWP and AMD discharges are Occurring from the CWP. When the HLP was extended
onto the toe of the CWP~ the French Drain system beneath the CWP was severed from the
system below the HLP. As a result, water backed up behind the liner of the HLP into the
CWP - saturating that part of the CWP and creating as Ii1illion gallon reservoir of highly
contaminSlted water within the bottom of the CWP.' .
. .
. To prevent the overflow of AMD into the HLP, it was determined that the CWP woUld be
addressed as a non-time-critica1 Removal action. During development of the Engineering
Evaluation/Cost Analysis.report, it became apparent that the same response action would
also apply to the SDI and BMD, and that concurrent implementation would be cost
effeCtive. The response action selected in the Action Memorandum #4 issued by EP A on
September 24, 1993 required consolidation of the various waste piles in the Mine Pits.
Because this work would require more than one construction season to complete, the
design and actual construction were phased. Phase I work was initiated on October 1, .
1993 and concluded in February 1994. During this time, approximately 927,000 cubic
yards of the Cropsy Waste Pile was placed in the Mine Pits. The waste materials were
isolated from ground water by lining the surface of the Mine Pits with impermeable
material identified on-site. A protective layer of lime kiln dust was placed. on the liner
10
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..-- --. -'..- ._- --.'-" M.'
...--.-. . -- _.- - ._--- -_. --
prior to placement of the waste materials to neutralize any AMD generated during this ,
work. ' ' .
Phase n work was initiated in August 1994. The CWP was completed in November 1994'
and the SDI/BMD are expected to be completed in December 1994. Phase n will have
moved an additional 3.5 million cubic yards of waste material to the Mine Pits. '
Since Phase ill removal action work had not beguIl, EP A eValuated the removal action
alternative selected in the Action Memo as one of its remedial alternatives for the
CWP ,SDI, BMD, and Mine Pits. This alternative was ultimately selected as the interim
response action for these areas of the Site. This work will include construction of a final,
impermeable cap and vegetation of the "footprint" areas below the CW1», SDI, and BMD.
4. ,WIGHTMAN FORK, ALAMOSA RIVER, TERRACE RESERVOIR (OFF-
SITE): The release of large quantities of AMD from the Site have occurred since the
1870's when mining first began, though the concentrations have significantly increased
since the beginning ofminine activities by SCMCI. Much of the AMD generated at the '
Site finds its way into the Cropsy Creek or Wightman Fork creek, unless 'it is diverted for
'treatment. The Cropsy Creek flows into the Wightman Fork at the southeastern comer of
the Site. The Wightman Fork, located on the northern boundary of the Site, empties into
the Alamosa River approximately 4.5 miles from the Site. The Alamosa, in turn, flows
into the Terrace Reservoir about 18 miles from the Site. There are three small wetland
habitats ~ong the Alamo~ where several endangered species, including the bald eagle,
, whooping crane, and ~e falcon have been identified.' The closest we~d is 1.8
mil~ from the WightIIian Fork confluence. ' The other wetland areas are 4.2 and nine
miles downstream from the confluence: These wetlands are all upstream of the Terrac,e
Reservoir. Concerns regarding other water usage requirements, including drinking water
and farm irrigation needs, are being inv~gated.
5. BEAVERMUDDUMP: The BMD encompasses 15 acres and consists of
approximately 900,000 cubic yards .ofhistoric metallic sulfide tailings as well as
overburden from SCMCI's operations. It is located immediately adjacent to and south of
the Wightman Fork Creek and is a significant somce of AMD. The BMD is also
infiltrated by ground water and discharges AMD to the SDI. This area is being addressed
as part of the CWP Removal action and interim action. '
6. SUMMITVILLE DAM IMPOUNDMENT: Formerly referred to as the Cleveland
Cliffs Tailing Pond, the SDI is a historic sulfide rich tailings pond located within the ,
former Wightman Fork drainage bed. The Wightman Fork was routed around the '
impoundment. While the Impoundment only contains about 133,000 cubic yards of
material, it is thought to be hydraulically connected to the Wightman Fork and, therefore,
providing AMD directly into the creek. This area is being addressed as part of the CWP
Removal action and interim remedial action. '
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7. FRENCH DRAIN SUMP: The French Drain is a collection system which was
constructed underneath the CWP and HLP to intercept and route ground water flowing
from seeps below these units (CWP and HLP) back into the diverted Cropsy Creek.
Because much of this ground water flows through the CWP or becomes contamin~ted '
with cyanide when passing below the HLP, it is cmrently routed to the.water treatment
systems or pumped directly into the HLP. While the French Drain is not itself a source
generating contamin~nts, it serves as a point source discharge for cODtamin~tedwater in a
fashion similar to that of the Reynolds Adit system.
8. CLAY ORE STOCKPn.E (Stockpile): ,The Stockpile is located just north of the
CWP and HLP border and was originally meant to ,be ore for placement on the HLP.
" Because of its high clay content, SCMCI was unable to provide the special handling
'needed before the ore could be leached. The one million ton Stockpile was pmposely
, created,because of its high content of metallic sulfides and is considered'to be a source of
AMD.,' .'
9. MINE PITS: This is the location of the former orebody mined by SCMCI and the
location of the veins that were historically mined within the Summitville mining district. '
The 1 OO-acre' Mine Pit has consumed most of the underground mine workings with the
,exception ofth~ Reynolds Adit System described above. This area was and is highly
mineralized and contains high concentrations of metallic sulfides. Approximately 70
million gallons ofwater' (snow or rain) per year entered the Pit,'passed through the
remaining :undergroQD.d workings, and exited as AMD from the Reynolds Adit, prior to
plugging. The Pit is the origin of the rock in each ofthetaiHn~ areas on-site and the ore
in the HLP. This area is being addlessed as part of the CWP Removal Action and interim
action.. At ibis time, the Pit has been filled by the waste material and is free draining of
, surface water.
10. THE NORTH WASTE DUMP (DUMP): This refers to a large area located north, '
of the Pit composed of waste rock and overbmden from the Mine Pit. It contains '
relatively moderate amo~ts of metallic sulfides and is a potential source of AMD. The
northern portion of the dump, primarily the slope below the 11, 580 bench, was reclaimed
and upper portions of the dump were regraded with some subsoil and topsoil placement
during the 1991 operational season. Vegetation success has been limited due to high
wind exposure. ,
'II. GOMPERTS PONDS: These were a series of small ponds, located approximately
400 feet north of the HLP, that contained severely acidic and toxic metals CODtaJTiin~ted
water and sludges. The ponds were excavated and then covered with soils. It is unknown
if any sludges or contamin~ted soils remain where the ponds were. If so, this area is
another source of AMP. '
12
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---_... --- ..--.---.-
12. ACID ROCK DRAINAGE SEEPS: There are over 48 potential acid rock drainage
seeps identified on the Site. These are areas where ground water naturally comes to the
Surface though some may be a result of construction activities at the Site. The seeps have
not yet been evaluated to determine if they are an AMD source. .
13. Minesite ROADS: Many of the roads at the Site were constructed with waste rock
from the Mine Pit. The material in these roads has not yet been evaluated to determine if
they are an AMD source.
14. LAND APPLICATION AREAS: .There are areas where cyanide CODtamin::tted
A.MD was sprayed onto the soils as a treatment method. Aeration, as a result of spraying,
was meant to eliminate the cyanide contamin::tt1on while the soils were supposed to
attenuate the metals. These areas have not yet been evaluated to determine if they are a
current AMD source. .
Once these areas had been iden~ed, the EP A was able to establish Remedial Action Objectives
(RAOs) for the overall Site. Pursuant to 40 CFR section 300.43 (e)(2)(i), the RAOs were .
established to provide remedial goals for the Site and were developed in consideration of cum:nt
regulatory guidelines, compliance with ARARs, and other identified limiting factors. The
siteWide RAOs for the Summitville Minesite are: . . . .
1.
Reduce or elimin::tte deleterious quality water flow froIri the Summitville Minesite
into the Wightman Fork. . .
2.
. .
Reduce or eliminRte the need for continued expenditures in water 1:I;atment for the
Summitville Minesite.
3.
Reduce or elimin::tte the acid mine/rock drainage from the m::tnmRde sources on
the Summitville Minesite.
4.
Reduce or eliminate any human health or adverse environmental effects from
mining operations downStream from the Site, to include the Alamosa River. .
5.
Encourage early action and aCceleration of the Superfund process for the
Summitville Site.' .
An analysis of metal loadings attributable to each of the AMD source areas resulted in the
development of five primary areas of focus. ~y of these source areas are in drainages or are
located where large amounts of surface or ground water are available for continued generation of
AMD. The Cropsy- Wightman stream drainage system for the Site also serves as a way to
transport the generated AMD contamin::tnts off-site. The Table below illustrates the copper
. loadings and flows' from theSe drainage points as measured by SCMCI in July of 1991. .This
approach is also based on the water quality data regarding Copper loading into WigbtmRU Fork.
-------
The table lists the contaminat1t sources, the yearly copper contribution to the creek from each
source, and the relative percentage loading of each sourCe:
SOURCE POUNDS OF COPPER PER RELATIVE
YEAR . PERCENT
Reynolds Adit 143,000 44.5
Cropsy Waste Pile 33,400 10.4
Heap Leach Pad '
overflow potential 84,000. 26.2
French Drain . 14,600 4.5
Summitville Dam Impoundment! 17,000 5.3
Beaver Mud DUmp
. .
Other 29,000 9.0
TOTAL 321,000 100.0
. Due to the size of the Site and extent of the conrnmination, the Site-wide interim remediation
activities are being addressed in five separate, though related actiODS. These five actions are:
.
Plugging the Reynolds and Chandler Adits
. Movement of the CWP, SDI, and BMD .
HLP Detoxification/Closure
Site-wide ReclamatiQn .
Interim Water Treatment
.
.
.
.
The first action of the conrninmentlisolation and stabilization project was the plugging of the
Reynolds' and Chandler Adits. The second action is excaVation of the CWP, SDI, and BMD,
with subsequent placement of this material into the Mine Pits. Both of these removal actions
are in progress under Emergency Response authority as discussed above. .
The Phase m work for CWP, SDI, and BMD, as well as the remaining three actions will be
conducted as interim remedial actions~. The CWP, HLP, and Recl8marlon work are expected to
begin during the 1995 construction season. The Water Treatment action will continue without
interruption though modifications in actual treatment processes may be implemented during
1995. .
Reclamation of non-point somces of contamin~on is the subject of this interim record of
decisio~ The non-point somces referred to include the following areas:
14
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-. ..
North Waste Dump'
This 74 acre area consists of waste rock and overburden stripped from the mine pits
located at the extreme northwest edge of the Site.
~ .
Approximately 50 acres ofhaul roads on-site require reclamation.
Water Treatment Plant Sites
The disturbed areas smrounding the water treatment plant cover approximately 22 'acres.
Other Non-Point Sources .
Approximately 55 acres of the Site, although not directly involved in the mining and
processing of minerals, have been disturbed through efforts to regrade and prevent
~~~ ..
This Interim Record of Decision addresses the reduction of acid generation potential present in
the sulfide minerals found Within the ore and in various waste and tai1in~ piles. . The production
of AMD requires the presence of three ingredients, the sulfideminera1, water, and oxygen. The
selected remedy presented in this IROD will prevent, or reduce, the contact of surface waters
and oxygen with the sulfide minerals, eliminating two of the required ingredients. Sulfide
mineral oxidation by water and oxygen is a natural geologic process; however, mining and other
. land disturbances enhance this process by mechanically increasing the Surface areas of the
sulfide-bearing materials for chemical reactions. .
.lAJ. Remedial Action OQjectives and Goals
This interim remedial action is designed to achieve the reduction of acid generation potential of .
the non-point sources and contribute to the final Site remediation. The completed interim
reclamation action should produce a guide to determine what reclamation actions will be needed
. at each portion of the Site to achieve the final, site-wide remediation goal(s).
. '.
The implementation of the selected alternative as the interim remedial action protects human
health and the environment. The goals of this remedy are to
.
c;nsure compatibility with the sitewide remedy;
remove, reduce, stabiliZe and/or contain non-point sources of acid rock
drainage to prevent further releases to the Site;
e1iminate or minimi'7P. non-point source impacts to aquatic receptors in
Wightman Fork. the Alamosa River, and the Terrace Reservoir;
eHminatp. or minimi7.e potential water treatment for non-point source
contaminated waters; and .
- enhance and/or improve on-site biota habitat.
.
.
.
.
As an interim action, the reclamation alternatives are consistent with any future actions to
15.
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complete the reclamation of the entire Site, and are a logical step in the reclamation process.
.".,
. 1;.5
Site Characteristics
.l.U Nature and Extent of Contamjnation
The EPA (1992) identified the Contaminants of Potential Concern (COPC) based on elevated
concentration and potential toxicity of mobilized chemicals. The COPC will be fina li7P-tj upon
completion of the Baseline Risk Assessment. These concentrations were compared to Site-
specific background levels, which were determined by standard statistical analysis '(Morrison
Knudsen Corp., 1994). Potential adverse effects on human health and the welfare ofwildIife
were preliminarily assessed (EPA; 1992). The COPC identified for the Site are copper,
cadmium, chromium VI, lead, silver, zinc, arsenic, aluminum, iron, mercury, manganese, and
cyanide.
. .
All of these contmninant~, except cyanide, are found at the Site in naturally occurring minerals .
and compounds. They are made soluble during the AMD-generating chemical process. The
AMD process is accelerated by the mining activities which took place at the Site.
1.5.1.1 .
Acid Mine Drainage
At Summitville, mining activities resulted in additional sulfidic material surface area avall8ble
for contact with oxygen and water. Air and water cOntact with the additional surface area
provided by broken rock accelerates oxidation of minerals and creation of low pH drainage. This
drainage water is high in acidity, sulfate (80.).2 ions and dissolved metals.
AMD water contributes metal loads to Wightman Fork and Alamosa River. Thi$ creates adverse
conditions preventing the growth and maintPnance of a healthy aquatic ecosystem. These adverse
effects have been noted in various studies of water quality ofWigbtman Fork and the Alamosa
. River. '.. .
1.5.1.2
Water Containing Cyanide
Commercially manufactured sodium cyanide (NaCN) was used at the Site for extracting precious
metals ftom ore grade materials. . Cyanide has been used for this purpose in the mining industry
since the late 1800's. Cyanide is found either in simple form or in combination with other
elements. Simple cyanide forms desigJ1ated as "free" cyanide are the cyanide radical, CN", and
hydrogen cyanide, HCN. Cyanide also combines or complexes with alkali metal ions, heavy
metal ions, and transition elements. The complex cyanide bonding is very Strong, moderately
strong, or weak (defined by tendency to disassociate in an acidic environment). Presence of .
excess hydrogen ions (acid) will lead to the formation ofHCN, depending on the strength of the
. metal/cyanide bond. . ..
16
..
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....----- .. ----
..-...--..
.n'o, .. - _.. . -.
Cyanide content is found in residual process water contained in the HLP. The predominant form
of cyanide in solution is a Weak Acid Dissociable (WAD) complex (complex that has a
moderately strong bond and dissociates at a pH of 4.5 or greater) with copper. Complexes with
other elements - silver, sulfur, gold, iron and others - are also present. Thiocyanate (SCN) is .
present in significant quantities. The thiocyanates may migrate through the water treatment train
into Wightman Fork. The pH of contained residual process water within the HLP averages about
9.3.
. Leaks in the HLP containment liner result in the presence of cyanide in drainage that surfaces
downgradient of the HLP. These drainage streams (from the Valley Center Drain (VCD), and
several seeps in and below HLP Dike 1) are mixtures of residual process water, AMD, and
ground water. The AMD portion resultS in low pH (2.5 - 3.5), and cyanide exists as. either a
metal/cyanide complex (primarily with copper), or as free cyanide (HeN). These streams are
routed to the French Drain (FD) Sump to prevent release to Wightman Fork and Alamosa River
drainages. The water is pumped to the HLP and mixed with residual process water, or treated
separately. .
~ Description ofIII\Pacted Water
Tables 1-6 summarize data collected during water monitoring before treatment and during
discharge of surface water to Wightman Fork. The tables include recordings of copper and
cyanide loadings from May 1993 through June 1994. During this period, monitoring emphasis
was given to copper and cyanide. because these were the chemicals of highest concentration
. during the ERA. There was also a concern because of the potential toxicity of cyanide. .
. .. .
Table 1 shows data representing the copper load (lbs.) transported by the Site water. The ~
group exhibits copper load from water pumped from the FD.Sump. This sump contains water.
from the VCD and AMD seeps.
The second data group within Table 1 illustrates the copper concentration ofwater cont3med in
the HLP. The water from the HLP includ~.water pumped from the FD Slimp, water that
surfaced at the toe of the CWP, and process water contained in the HLP. All water in the HLP is
treated to remove cyanide and copper, as well as other metals, before release to Wightman Fork.
The Underground Workings section presents data on copper load that was transported by water
exiting from the Reynolds Adit and the Chandler Adit. Also shown is the amount of copper
removed through treatment at the Portable Interim Treatment System (pITS). The PITS treated
water exiting the Reynolds Adit, the Iowa Adit, and some conmmin~nt surface runoff. The plant
was deactivated after the Reynolds Adit plug was completed.
The rem~ining sections of the table present the copper content of surface water discharged into
Wightman Fork during this time period. These discharges include water from Cropsy Creek, seep
LPD-2 (which feeds into Cropsy Creek), and Pond P-4 (a sediment pond that receives surface
runoff from the mine pit area, haul roads, and other runofi). Other streams that contributed
-------
copper load to Wightman Fork inClude drainage from the SDI~ the North Pit Waste Dump
(NPWD), the Clay Ore Stockpile, and treatment plant eftluent.
. .
. Also shown are the pounds of copper that would have been added to Wightman Fork ifwater had
flowed into Wightman without treatment. Annual totals from July 1993 to June 1994 are given to
the right of monthly totals. The twelve month period, July 1993 through June 1994, represents
the time frame when existing-treatment facilities utilized maximum capacity.
Table 2 shows monitored cyanide loading (lbs.) or the potential for cyanide loading to Wightman
Fork dming the same period. .
Table 3a shows monitored flow rate for streams which are capable of cmying .contaminant load
to Wightman Fork. High and low flow rates illustrate seasonal fluctuations. Combined monthly
totals illustrate potentially required treatment volumes.
Table 3b shows the total gallons for streams capable of carrying contaminant load to Wightman
Fork. This table also shows the treatment plant capacity measmed in total gallons.
Table 4 shows other monitored constituents (manganese and iron) that should be taken into
consideration in the sel~on of treatment processes. -Manganese removal to <1 mg/liter is
necessary before cyanide destruction can take place. Significant iron content can produce sludge
volumes that affect plant efficiency. .
Tables 5 and 6 show copper and cyanide concentrations monitored at station WF 5.5 on
Wightman Fork from May 1993 through June 1994.
. -
General descriptions of monitored surface water affected by conditions at the Site are given
below. Figure 3 shows con~inated surface water streams. .
Stream A - The vaOq Center Drain
General: Comprised of dr3inage from the CWP, ground water frQm beneath the HLP,
and leakage from HLP containment. Contains cyanide as a resUlt of leakage from the
HLP. CWP drainage Contributes low pH and elevated m~. . -
. Volume: Significant flow throughout the year. Peak tIow is concmrent with spring
snowmelt. High tIow (78 gpm) recorded in April 1994; low tIow (57 gpm) ~ recorded
in.Iune 1993. .
Loading: Based on copper as the indlcator, the VCD ranked as the 4th highest peak flow
carrier of metals. 8,473 lbs. of copper dissOlved in solution were transported by drainage
from July 1993 through lune 1994.
18
-------
. . . . ... .
Stream B - CrQp$J' Waste Pile Drainafe '
General: Comprised of grotmd water flow from seeps and upgradient drainage through
colluvium and alluvium (Geraghty & Miller, 1992). Includes precipitation (snowmelt
and rain fall) infiltrating through mine waste materials. Significant aluminum content
effects must be considered when selecting a treatment process. Volume and makeup are
expected to materially change with planned relocation of CWP materials.
Volume: Seasonal release to the surface at the toe of the CWP . Year round contribution
to the VCD. High flow (364 gpm) recorded in May 1993. Surface flow was not
observed at the toe of the CWP between January - April 1994. '
.-. -
Loading: Based on copper as the indicator, water surfacing at the toe of the CWP is the
second highest peak carrier of metals. 23,305 lbs. of copper dissolved in solution were
transported by drainage from July 1993 through Jtme 1994 (includes water sent to the
Cropsy Water Treatment Plant (CWfP)).
Stream C - Drainafe from Underyround Workinp
General: Comprised of ground water and' precipitation (sno~elt and rainfall)
infiltrating the mine pit area. These infiltrating waters draining through mineralized rock
into the remaining undergrotmd workings have historically surfaced as flow from the
Reynolds Adit. Comparatively less water volume drains from the Iowa Adit. The
Reynolds and Chandler adits have been plugged. The long-term effects of plugging the , '
~eynolds Adit in February 1994 and CJw:1dler Adit in March 1994, and the 'consequent
rise in the South Mountain water table have not been determined. In May 1994; an AMD'
. stream developed as discharge from the Chandler Adit. It bas been observed that the
Water is flowing between the top of the, plug and the roof Qfthe adit (Abel, pers. com,
1994). Peak flow from the Chandler Adit leak in Jtme 1994 was 661 gpm with a copper
concentration of 409.40 mgll and a pH of2.16, determined by sampling the stream just
outside the adit entrance. This was almost, "instantaneous" (the discharge increased from
o gpm to 661 gpm in 11 days), mmca.ting a direct relationship between, the rise in the
South Mountain water table and the filling of the adit system with water. By the end of '
July 1994, the flow of the AMD stream decreased to 130 gpm with a copper content of
268 mgll and a pH of2.30. Eventual volume of AMD that may require treatment is
unknown. Corrective measures are planned. '
Volume: Significant flow throughout the year. High flow from the Reynolds Adit (763
gpm) was recorded in June 1993; low flow from the Reynolds Adit (6 gpm) was
recorded in April 1994. '
. Loading:' Based o~ copper as the indicator, Stream C is ranked as the highest peak flow
carrier of metals. 198,221 pOtmds of copper dissolved in solution were transported by
drainage from July 1993 through June 1994. Peak flow of AMD from the underground
workings in June 1994 was 14% less than flow in June 1993. Copper load from
-------
underground workings in June 1994 was approximately 23% less ~ the load in June.
1993. (Table 3). In July 1994 volume from the underground workings was 25% less than
in July 1993. Copper load from underground workings in July 1994 was 15% less than in
"" July 1993. - : ." "
Stream D - Summitville Dam /11fPoundment and Beaver Mud Dump draina,e "
. .
General: Comprised of the surface drainage into the SDI and surrounding area, and the
ground water migration through the mud dump. Possible ground Water migration through
tailings contained in the pond. Includes precipitation (snowmelt and rainfall) infiltrating
through BMD materials. Volume and makeup of this stream is expected to nuiterially
change with planned solid waste relocation in 1994-95 (Cropsy PhaSe IT operations).
Volume: High flow (202 gpm) was recorded in May 1993; low flow (33 gpm) was
recorded in November 1993. Monitoring was not possible from January 1994 through
Apri11994, due to snowpack.
Loading: Based on coPPer as the indicator, Stream D is ranked as the third highest peak
flow carrier of metals. 12,294 lbs. of copper dissolved in solution were transported by
drainage from July 1993 through June 1994. .
Stream E - North Pit Waste Du11fP drainare
General: Comprised primarily of surface runoff from waste dump materials. There is
some ground water seepage.
Volume: Significantly varies with precipitation (rainfall and snowmelt). Affected by
spring nmoft: High flow (284 gpm) was recorded in May 1993; low flow (1 gpm) was
recorded in October 1993. Monitoring was not possible from November 1993 through
April 1994, due to snowpack. "
LoadiJig: Based on copper as the indicator, Stream E is ranked as the 6th highest peak
flow carrier of ~etals. 4,3211bs. of copper dissolv~ in solution were transported by
drainage from July 1993 thro~ June 1994.
Stream F - C/..qy Ore Stockpile Drainare
General: ComPrised of surface drainage migration through lower portions of the waste
dump and precipitation (snowmelt and rainfall) .infiltrating through upper level materials.
Water migrating from beneath the CWP may also contribute.
Volume: High flow (66 .gpm) was recorded in June 1993; low flow ( 37 gpm) was
recorded in May 1994. .
Loading: Based on copper as the iIidicator, Stream F is ranked as the 8th highest peak
-------
. -. -.. ". .
. . -. ---- ..
flow carrier of metals. 1,113 Ibs. of copper dissolved in solution were transported by
drainage from July 1993 through June 1994.
. -. . .
Stream G - Sediment pond P-4 drain~fe
General: Comprised of surface drainage from upgradient disturbed areas~ Includes some
contribution from Iowa adit drainage. .
.... ... ..
Volume: Highly variable, dependent on precipitation events.; High flow ( 948 gpm) was
recorded in May 1994; low flow (4 gpm) was recorded in November 1993.
, -'.-' .-.-. ._.
..' . -. .-.
Loading: Based on copper as the indicator, Stream G is ranked as the 5th highest peak
flow carrier of metals. 4,508 Ibs. of copper dissolved in solution were transported by
drainage from July 1993 through June 1994. . '. . ..
Stream H - Drainafe from CrQpiy Creek
General: Comprised of surface drainage from upgradient undisturbed areas. Rerouted
around the CWP and HLP areas during SCMCI operations. Receives some metals
loading from surface runoff from the Cropsy Waste Pile and seep LPD-2, downgradient .
from the HLP and Dike 1. May receive loadings from effected ground water. Route does
not go through. sediment control features.
. Volume: Peak flow is' concummt with Spring runoff. Si~cantly affected by
precipitation (snowmelt and rainfall). High flow was recorded in May 1993; low flow
was recorded in February 1994.
Loading: . Based on copper as the indicator, Stream H is ranked as the 7th highest peak .
flow carrier of metals. 1,737 Ibs. of copper dissolved in solution were transported by
drainage from July 1993 through June 1994. .
The affected stream segments are summarized in the following table. The Streams are ranked in
decreasing order according to the metal load during peak flow:
-------
Ranking of Surface Water Streams at Peak Flow
without Operation of CWTP, CDP and MRP
Peak Flow Load Stream-
1 Stream C- Underground Workings Drainage
2 Stream B- CWP -. e
3 Stream D-SDIIBMD e
4 Stream A-VCD
5 Stream G-P-4 . e
6 Stream E-NPWD - e
7 - J.t'- ....,.,.,...."" Creek .... .
e
8 Stream F-Clav Ore StockDiIe Drain~e
.
RantiDgs are.lisred m cIccn:asiDg order.
Table docs DOt iDc1udc the HLP ~W1IICI' stream.
..
Freneh Drain Sump lDt10ws
The FD sump was originally constructed to prevent drainage from the VCD (Stream A) from
entering the Cropsy Creek and Wightman Fork. A collection and pumping facility was installed
after VCD drainage was found to contain cyanide. The sunip was also utilized to contain other
CODtmnin~ted water. These drainages (described below) were found to be contamin~ted in later
years. Tables 1 ;. 3b summarize data for copper, cyanide, and water volume for these streams.
General descriptions follow.
FD Sump -1 Seepage from Dike 1
General: Comprised of water exiting a point at the base of Dike 1.
Volume: .Peak volume (1,785,600 gal., June 1993) is concurrent with spring snowmelt
Loading: At peak flow, Stream FD Sump-I transports up to 83 lbs of copper per day.
Load declines to less than 3 lbs per day as flow decreases.
FDS~p~&~~~m~D~lr~
General: Comprised of water exiting a point on the access road that flanks Dike 1.
Volume: Peak volume (820,000 gal. in June 1993) is concwrent with spring snowmelt.
Flow ceases soon after the.peak snowmelt period. Water is acidic, and contains cyanide.
22
-------
- ,'. .-- --..~.
. . .
. -. .-
Loading: At peak flow, Stream FD Sump-2 transports up to 5.7 lbs of copper per day.
Load declines to less than one lb. per day as flow decreases.
FD Sump -3 Drainage from beneath the HLP
General: Comprised of water exiting rock drains built to divert water during HLP
construction at 11,510 and 11,530 elevations. Discharges are combined and routed to the
FD Sump. Wide range in copper content. Contains a slight amount (0.12 mglI) of
. cyanide at peak volume discharge.
Volume: Peak volume (1,116,000 gal. in June, 1993) is concurrent with spring
snowmelt. Significant flow continues throughout the year. .
Loading: At peak flow, Stream FD Sump-3 transports up to 27 lbs of copper per day.
Load declines to less than I lb. per day as flow decreases.
.LU DesCIiption of Non-point Sources
This interim action focuses on the reclamation of non-point sources while on-going remedial
actions are stabilizing the Site.
Site non-point sources of cODtamin~tion contribute AMD and metal loading to various surface
water streams. Listed below are the four non-point somce areas scheduled for reclamation, their
site characteristics, and the surface water streams to which they contribute: . .
. North Pit Waste Dunw . . .
This area consists of waste rock overburden stripped from the mine pits. The northern
. portion of the dump, primarily the slope below the II, 580 bench, was reclaimed and
upper portions of the dump were regraded with some subsoil and topsoil placement
during the !991 operational season. All slopes on the dump were graded to ..
approximately 33 percent grade or less. The storm: water nmoffftom the regraded slopes
conveys surface water to a series of sediment detention structures and from these ponds to
Wightman Fork. The sUrface wat,er and ground "Water from this area comprise Stream E.
Vegetation success has been limited due to the high wind exposure of the dump area.
Successful reclamation will establish a natural, self sustaining vegetative cover. The
vegetative cover will reduce surface erosion of the soil and decrease migration of
sediment and contaminents ftom these soils. The vegetative cover will also slow surface
water runoff and infiltration of water and oxygen through the soil layer into the waste
material. In:tiltration of precipitation will be reduced by solar evaporation and plant
transpiration during the summer and fall seasons. Reclamation activities including soil
testing, amendment evaluation, greenhouse studies, seeding, mulching, and additional
erosion controls will be implemented to reduce soil erosion and begin the establishment
of plant cover.. . .
-------
~ .
No roads (except the interior mine roads) were cut into the primary ore body. Roads
outside of the mine pit areas were cut into the natural materials ~unding the ore body.
and, where necessary, material from the mine pits was used as till. The natural materials
and the mine pit material contain elevated concentrations of sulfide-bearing substances
which contribute to contaminant loading; therefore, the Site roads are considered to
generate ~ causing any associated seeps or surface water to be contaminated. These
roads crisscross the Site contributing to surface water Streams B, C, D, F, G, and H.
Samples of road surface water have a pH range of2-S and copper content ofS-l0 j,pm.
. .
The steepest road has a 12 percent slope. Roads above timberline are exposed to strong
westerly winds and will require protection from wind erosion during reclamation.
Reclamation activities inclUding soil testing, amendment evaluation, greenhouse studies,
seeding, mulching, and additional erosion controls will be implemented to reduce soil
erosion and begin the establishment of plant cover.
Water Treatment Plant-Sites: .
The land smrounding the water treatment plants was disturbed during grading and
construction activities. Due to the need for level ground and the requirement to secure .
foundations to bedrock; the permanent treatment facilities were cut into the ground. Very
limited amounts of fill material were used. By design, these structures are at some
distance from the ore body, limiting a primary source of AMD. However, all natural
materials in the Site area contain concentrations of sulfide-bearing materials and are
considered potential acid generating areas. The runoff from the Metals Reduction Plant . .
(MRP) area enters Stream C.; runoff from the Cyanide D~tion Plant (CDP) and the .
Cropsy Water Treatment Plant (CWTP) areas enter Stream G. Although these areas
have. not been mined, they are considered disturbed areas designated for future
reclamation. .. .
ReClamation activities including soil testing, amendment evalUation, greeDhoUse studies,
seeding, mulching, and additional erosion controls will be implem~d t() reduce soil
erosion and begin the establishment of plant cover. .
Other Non-point Sources: .
Other non-point sources are non-mined areas that have been disturbed by grading and
construction. Such activities accelerate the normal geologic process of sulfide mineral
oxidation by mechanically increasing the exposure of the sulfide minerals to water and
oxygen. Analyzed seep and surface water samples from several non-point sources have
low pH values and metal contamination. . Surface water from these areas are a significant
contributor to Stream G. Reclamation of the above areas will contribute to the reduction
of flows from Streams B, C, D, E, F ,G, ~d H.
SCMCI started an active reclamation prograni on areas directly and indirectly affected by
-------
.._. ....------. .
- .-------."-
-. ...---..---..-.---.-..
mining or mineral processing. Some of these areas are sustaining plant growth; however, these
. vegetative cover areas may not meet applicable reclamation standards. These areas will be
included in the reclamation .plan to detennine if soll chemical parameters, soil cover, plant
composition and diversity, plant density, and soil erosion standards have been met and what
requirements are lacking. .
The reclamation of n~n-point sources is designed to achieve reduction 'of acid generation
. potential and to contribute to the final Site remediation. The completed interim reclamation
action will be a guide in determining what reclamation actions will be successful at each portion
of the Site in order to achieve the final, site-wide remediation goal(s). Planned reclamation
. activities including soil testing, amendment evaluation, greenhouse studies, seeding, mulching,
and additional erosion controls will be implemented to reduce soil erosion and begin the
establishment of plant cover.
~ Contaminant T~ort and Mi~tion
1.5.4.1
Surface Water
Surface \\later is considered the most significant media for .off-site transport of metals. Surface
water has been impacted by mining operations from the Site throughout the reach of Wightman
Fork, from the Site to the Alamosa River, and within the Alamosa River from Wightman Fork to
Terrace Reservoir and points further downstream. According to the Conceptual Site-wide
Remediation Plan prepared for the EP A, it has been determined that the Site is the predominant
source of metals 10a.diD.g to the, Alamosa River system. .
'. .
As pH of water. rises from the addition of water with higher pH, iron precipitates from solution as
a hydIated iron (llI) oxide product (femc hydroxide). This forms the red or yellow staining seen
on rocks in the streams or on banks. Copper, cadmium, andzinc Will co-precipitate with iron
precipitates. Metals concentrations are further reduced by dilution from downstream tributaries.
COPCs could be biologically transported through the aquatic food chain to birds, animal$, and
humans. .
1.5.4.2
Ground Water
Ground water depths vary at the Site. In general, water levels are relatively close to the surface
except in the vicinity of the old mine workings where depth to water can be as much as 300 feet.
The old workings act as effective underdrains. This interaction can be seen by the flow of water
from the adits. It is anticipated that the ground water level will rise as water backs up behind the
plugged Reynolds and Chandler Adits. .
. The ground water occurs in surficial deposits consisting of colluvium, alluvium, and/or glacial
moraine; and fractured andesite of the Summitville Formation. Ground water flow is within the
weathered arid fractured bedrock and, within alluvium near the Cropsy Creek and Wightman
Fork channels. Ground water flow and metals are capable of being transmitted to Wightman
-------
Fork through the alluvial and bedrock systems. Ground water is generally shallow (0.2 to 25 feet
within the alluvium) and flows northeast in both the Cropsy and Wigbtm~11 Fork drainages.
. Shallow ground water at the Site is present as a series of interinittent, perched systems. The.
perched aquifer system contributes to recharge of the shallow fractured bedrock ~ No
regional ground water table has been identified at the Site. Ground water is strongly influenced
by precipitation. Dming spring runoff: these shallow systems discharge. to surface water.
Numerous springs and seeps are evident throughout the Site and most flow in direct response to
precipitation.
1.5.4.3
Soil and Air
Site 'cover consists of topsoil, silt, clays, and gravel. The topsoil is descnoed as .
greylbrown/orange, non-plastic with a trace of roots and sand. The clays are low to medium
plasticity with some gravel. The gravel is indicative of colluvial deposits or tailings. The
disruption of the surface soils may be a secondary source of excess metals migration. .
.LU ARARs
ARARs are "applicable" or "relevant and appropriate" requirements of federal or ~ law which
. address a hazardous substance, pollutant, contamin~nt, remedial action, location or other
circumstance found at a Comprehensive Environmental Response, Co~pensation, and Liability
Act (CERCLA) site. Refer to T~le7 for a detailed summ~ry- and discussion of ARARs. The
NCP defines "applicable" requirements as cleanup standards, standards of control, and other
substantive environmental protection requirements, criteria, or limitations promulgated under
Federal or State law that specifically address a hazardous substance, pollutant, contamin~t,
remedial ~on location or other circumstance found at a CERCLA site. . "Relevant and
appropriate" req~ents' address problems or situations sufficiently similar to those
. encountered at the CERCLA site that their use is well suited to the environmental or technical
factors at a particular site. (See 40 CPR Section 300.5.) .
ARARs are grouped into three categories:
.
.
.
Chemical Specific
Action Specific
Location Specific
Cheniica1 specific ARARs include health or risk based Dmative standards, numerical values, or
methodologies that, when applied to site-specific conditions establish the acceptable amount or
concentration of a chemical that may remain or can be released to the environment Action
specific ARARs are usually technology or activity-based requirements or limitations on actions
taken with respect to hazardous substances, pollutants, or cODtamin~nts found at CERCLA sites.
Location specific ARARs are restrictions placed on the concentration of hazardous substances,
pollutants, or contaminants or the conduct ~f activities solely because they occur in special
-------
... ----.-.--. .
--U'-....-
locations. Examples of special locations include floodplains, wetlands, historic places and
sensitive ecosystems or habitats. (See "CERCLA Compliance with Other Laws Manual Draft
Guidance," :gPAl540/G-89/006, August 1988.)
In addition, the NCP has identified a fourth category of irifonnation "to be considered" when
evaluating remedial alternatives, known as TBCs. TBCs represent Federal and State advisories,
criteria or guidance that are not ARARs, but are useful in developing CERCLA remedies. (See
40 CFR 300.430(g)(3).) .
The analysis of ARARs has been limited to the scope of the interim action. The NCP allows
waiver of ARARs for interim remedial measures that do not exacerbate site problems or interfere
with final remedy (40 CPR 300.430(t)(1)(ii)(C)(1) and 55 FR 8747). Other ARARs may be
involved in enacting final remedy(ies).
The site-wide ARARs were identified in the addendum to the HLP FFSs. In response to
comments submitted during the public participation process on the Reclamation FFS and
Proposed Plan, EP A however is further defining the applicable or relevant and appropriate
requirements ftom Federal and State laws or regulations which must be met by any altemative
implemented as the Reclamation interim remedial action. Since the sitewide ARARs have
already been identified in the "ARARs Addendum to the HLP Focused Feasibility Study
Report", this further refinement of ARARs as they relate t~ the Reclamation mOD represents
only a minor change to the Reclamation FFS and Proposed Plan. Consistent with its "Interim
Final Guidance on Preparing Superftmd Decision Documents", OSWER Directive 9355.3-02
. (June 1989), EP A has determined that this minor change will have little or no impact on the
overall scope, performance, or cost of each alternative as originally presented in the Reclamation'
FFS or Proposed Plan. .
The following sitewide ARARs, or relevan~ portions of the sitewide ARARs, must be met in
accordance with Section 121(e) ofCERCLA and 40 C.F.R 300.430 of the NCP by each
potential Reclamation interim remedial action alternative:
1.5.5.1 Chemical SpecificARARs
Surface Water ARARs
The Colorado Water Quality Standards (CWQS) establish a system for classifying state surface
waters and procedures and criteria for assigning numeric water quality standards. (See 5 CCR
1002-8, Sections 3.1.0 through 3.1.17.) .
o
Colorado Water Quality Standards, Applicable
Criteria for Stream Classification
The C\Yqs require that surface waters be:
-------
. classified for the p~sent beneficial uses of the water, or the beneficial uses that
may be reasonably expected in the future for which the water is suitable in its
present condition or the beneficial uses for which it is to become suitable as a
goal.... Where the use classification is based upon a future use for which the
waters are to become suitable, the numeric standards assigned to such waters to
protect the use classification may require a temp.oIaIY modification to the
underlying numeric standard... (See ~3.L6.) .
The CWQS employ four broad types of beneficial use to frame the c~ification process:
.
-. .
.
.
recreational
. aquatic life
agriculture
domestic water supply
Recreational Use
The recreational uses ~ divided into two classifications. Recreational Use, Class 1 -
Primary Contact, addresses surface water quality concerns where ingestion of small
quantities of water during the pseis likely to OCCUI'. Recreational Use, Class 2-
- Secondary Contact, focuses on streamside activities where ingestion of water is unlikely
to occur. The effect of the recreation classification on numeric water quality criteria is
limited, the primary consideration being the concentration offeca1 coliform bacteria. The
Summitville Minesite is unlikely to contribute bacterial conmmination to the watershed. .
.F or that reason, the recreational use cIassifications have been met and will not be .
considered further.
. Aquatic Life
Two aquatic life classifications are cuIrent1y promulgated for stream segments of interest.
Class 1 cold water aquatic life is defined as:
... waters that (1) curren~y are capable of sustaining a wide variety of cold
water biota, including sensitive species, or (2) could sustain such biota but
for correctable water quality conditions. Waters shall be considered
capable of sustaining such biota where physical habitat, water flows or
levels, and water quality conditions result in no substantial impairment of
the abunwmce and divexsity of species. (See ~3.1.13(1)(c)(i).)
Class 2 cold and warm water aquatic life is defined as:
...waters that are not capable of sustaining a wide variety of cold or warm
Water biota:, including sensitive Species, due to physical habitat, water
flows or levels, or uncom:ctable water quality conditions that result in
28 .
. .
-------
..~-- ~ . -.-
substantial impairment of the abundance and diversity of species.
(See ~3.1.13(1)(c)(iii).)
. Domestic Water Supply
Domestic water supply is defined as:
...suitable or intended to become suitable for potable water supplies. A1W:
receiving standard treatment ... these waters will meet Colorado drinking
water regulations... (See ~3.1.13(1)(d), emphasis added.)
Agricultural Use.
Agricultural use is defined as:
...suitable or intended to become suitable for irrigation of crops usually
grown in Colorado and which are not hazardous as drinking water for
livestock... (See ~3.1.13(1)(b).) .
Three segments of the Alamosa River are classified for various uses according to this system:
Segment 6, the Wightman Fork at and below the mine; Segment 3b, the Alamosa River ftom
immediately above the confluence with Wightman Fork to Terrace Reservoir; and Segment 8,
Terrace Reservoir. Figure 5 shows segments of the Alamosa River Basin. .
. .
Segment 6 is classified for Recreation Class 2 and Agriculture~ It is not classified for aqu8nc
life. No numeric water quality standards have been assigned. The lack of an aquatic life
. clasSification was derived by the use attainability analysis performed by the Colorado Water .
Quality Control Commission (wQCC)~ The WQCC determined that an aquatic life classification
cannot be attained within 20 years. .'.
Segment 3b is classified as Class 1 told Water Aquatic Life. Numeric Standards are set for.
surface water downstream of the confluence of Wightman Fork and the Alamosa River.
Terrace Reservoir is classified as'Class 2 Cold Water Aquatic Life. This classification.
recognizes a limit on the ability of Terrace Reservoir to sustain a diverse aquatic community.
Numeric Water Quality S~dards .
The CWQS provides a three-tiered structure for establi~hing numeric water quality standards.
For unimpacted high quality waters, numeric levels known as the "Table Value Standards"
(TVS) are established and presumed to be protective. For impacted waters where pollutant
concentrations exceed TVS values but the beneficial uses are adequately protected, Ambient
. Quality-Based Standards can be adopted. For impacted waters where beneficial uses are not
currently adequately protected, TVS are adopted as a goal. Temporary modifications to numeric
-------
standards may be adopted in these areas. Where classified uses are not being protected and a use
attainability analysis has found nonattainability, Site-Specific-Criteria-Based Standards can be
developed. The TVS and Ambient Quality-Based Standards are applicable regulations for'
determining compliance with smface water discharges at the Site. Segment 3b of the Alamosa
River is downstream of the Site at the confluence of the Wightman Fork and the AIamosaRiver. .
These regulations were used to establish promulgated standards in this segment of the Alamosa
River. SpecificalIy, the Classifications and Numeric Standards for Rio Grande Basin are found
in Section 3.6.6. of the regulation. Table 8 illustrates these levels. These standards are
categorized into acute and chronic limits. Acute limits represent an upper level not to be
exceeded in any 24 hour period. Chronic standards are average levels which can not be exqeeded
in a 30 day period. .
Table Value Standards
The TVS are based upon the Federal.Water Quality Criteria. The TVS, however, have been
adjusted to protect the beneficial uses of Colorado waters. (See ~3.1.7(b)(i).) The TVS for
aluminum (acute), arsenic (acute), lead (acutelchronic), nickel (aCute/chronic), selenium
(acutelchronic), silver (acutelchronic), zinc (acute/chronic), chromium VI (acutelchronic),
chromium ill (acute), mercury (chronic), manganese (chronic), cadmium (acute/chronic), pH,
dissolved oxygen, Fecal Coli, ammonia, chlorine, sulfide, boron, nitrate and cyanide are set at
Segment 3b. It is important to note that many of the TVS for protection of aquatic life from
metal pollutants are hardness dependent. The WQCC has adopted an acute and a chronic copper
standard for Segment 3b. The acute copper standard for Segment 3b is established using the
TVS; however, the WQCC has adopted a less stringent temporary modification to this standard
based upon WQCC hearing testimony. The EP A has adopted and will meet the ambient quality
. based chronic copper standard as applicable for this interim action and is not using the less
stringent acute copPer standards from the TVS or the less stringent August 1994 temporary
modification. The IAL, as monitored at WF-S.S, were developed to meet the more stringent.
ambient quality-based chronic copper standard at Segment 3b.
Ambient Quality-based Standards
. Ambient quality-based numeric surface water quality st:andarQs are the mechaniqn where limited
water quality impacts are controlled through less stringent water quality ~dards. Ambient
quality-based standards are specificalIy intended to address circumstances where natural or
iIreversible man-induced ambient water quality levels are higher than the specific numeric levels
contained in the TVS Tables I, IT, and III, but are determined "adequate to protect classified
uses." (See ~3.1.7(1)(b)(ii).) The chronic standard for copper is estab~ed at Segment 3b using
this regulation. Copper is one of the primaIy contaminants of concern for water quality. The .
chronic copper standard was used as the most strict ARAR for copper at the Site. The IALs were
developed using this standard. The chronic standard for iron also falls into .ambient water quality
standards. There are no acute iron standards. .
To evaluate the ability of alternatives to meet the stream classification and numerical standard of
30
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. ...-.-... - .-.-. .--.- - -...--..-----
.-.-
the CWQS ARARs, EP A established interim action levels (IAL) for water quality. These IAL
can be found at page 23 of the Water Treatment FFS. The lAL are developed using a model
which utili,zed high flow and low flow average concentrations of the contamin~",ts to set
, threshold loadings allowable at Wightman Fork monitoring point 5.5. Numerical standards that ,
would enable the river water quality to meet the water quality ARAR at Segment 3b under
average conditions were then calculated. Based upon the WQCC numeric water quality
standards for Segment 3b, the TVS levels were used for all COPC at the Site with the exception
of copper and iron. EP A used the WQCC ambient quality standard for copper and iron. The
ambient level for copper is 30 ugIl based upon the 85th percentile ambient data in Segment 3a.
The methodology used to develop these levels is similar to the criteria applied in the' .. ,
development of the NCL, that is, back modeling the co"taniinant loading from the promulgated
ARARsat the Alamosa River. These lAL are formally adopted as remedial goals iD the IRODs.
The'discharge ~onitoring point, WF-5.5, is the interim monitoring point for the Site, and the
lAL are the interim water quality standards during this remedial action five year period. It is
important to note that the IALs are not "interim" due to their inability meet ARARs; rather, EP A
believes that these ARAR-derived limits at the point of comp~ce do attain the numerical
standards at Segment.3b. The ability of the IAL to achieve the applicable water quality
stmldards, however, will be reassessed by EP A upon the completion of the quantified Risk ,
Assessment and the State of Colorado use-attainability study. The results of these efforts will be
incorporated into a final remedy. '
o
Federal Water Quality Criteria, Applicable
, The preamble to the proposed NCP states:
(a) state numerical WQS is essentially a site-specific, adaptation ofa Federal
Water Qwility Criteria (FWQC), subject to EP A approval, and, when available, is
generally the appropriate standard for the specific body of water." (See 53 FR
51442, right column, top.)
As noted above, the FWQC would only be applicable in the absence of cUrrent, segment specific'
CWQS. In this circumstance, current, segment specific CWQS ale available and will be applied
as the surface water quality ARARs for the Site. The FWQC are considered applicable since this
ARAR establishes the basis for the State of Colorado's numerical standards.
Ground Water A.RARs
The Colorado Ground Warer Standards (CGWSs) provide for identification of specified ground
'water areas, classification of the specified areas, and numeric ground water quality standards.
5 CCR 1002-8 establishes a system for classifying ground water and adjusting water quality
standards to protect existing and potential beneficial uses. The ground water cl8ssmcations are
, applied to "specified areas," a concept identified in the definitions and explained in Section
. 3.11.4(C)(I). Those ground waters not classified as within "specifi~ areas" may be subject to'
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Statewide radioactive material standards listed in Section 3.1 1.5(C)(2) of the BaSic ,Standards of
Ground Water, 3.11.0 (5 CCR 1002-8) and organic standards identified 4t Table A ofSec;:tlon.
3.1 1.5(C).' .
, .
. Since the Colorado Water Quality Commission has yet to classify the Site as a "specified area," ,
there are no currently applicable or relevant and appropriate Colorado Ground Water numeric
standards for the Site. However, since the publication of the WTFFS,. the Colorado Water
Quality Control Commi~ion has adopted an interim narrative standard for all unclassified
ground waters of the State that supplements the Statewide stmidards for radioactive materials and
organic pollutants established in Section 3.1 1.5(C) of the Basic Standards for Ground Water.
This narrative standard requires that ground water quality be maintained for each parameter at
whichever of the following levels is less restrictive:
(i) existing ambient water quality as of January 3 I, 1994, or
(ii) that quality which meets the most stringent criteria set forth in Tables 1
through 4 of "The Basic Standards for Ground Water."
Ambient water quality is established by agencies "with authority to implement this standard"
using "their best professional judgment as to what consti~ adequate information to determine
. or estimate existing ambient quality, taking into account the location, sampling date, and quality
ofall data available" prior to January 31,1994. Based on Rule 1, Section 1.1(5) of the Mineral
Rules and Regulations, EP A believes the Mined Land Reclamation Board (MLRB) is the agency
that has the primary authority to implement the narrative standard for ground water at the
Summitville Site. MLRB and WQCD established Numeric Criteria Levels (NCL)for surface and
ground water quality at the Summitville Site in SCMCl's operating permit, as well as its 1991
Settlement Agreement between SCMCl and the State of Colorado. These NCLs are not
applicable or relevant and appropriate, since they are not legally binding, promulgated
regulations. However, these standards have been considered by EP A in estab1i~hi"g its interim
action levels for water quality because they provide useful information or recommended .
procedures in addressing the interconnected ground water and surface water at the Site.
This interim ground water narrative standard, since it became effective on August 30, 1994, Was
not 'identified as an ARAR in any ofthe'FFSs for the Site. However, since comp1ian~ with this
ground water ARAR will have little or no impact on the overall scope, performance or cost of the
alternatives evaluated, inclusion of this ARAR represents only a minor change to the FFS and
Proposed Plan. (See "Interim Final Guidance on Preparing Superfund Decision Documents,"
OSWER Directive 9355.3-02 (June 1989), at p. 5-3.
. ,
EP A further expects that once the CWQC completes its use attainability study and classifies Site
ground water, the interim narrative ground water standard will be replaced by a "specified area"
classification 'or "site-specific" standard for the Site. This ground water ARAR will be attained
by the final remedial action(s) for the Site.
32
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.-- .,..
Storm Water Management and Effluent Limitations ARARs
Storm water, {TIanagement is governed by the storm water permitting requirements and the
Categorical Standards for Ore Mining and Dressing. Both the stonn water pennitting prognmi ,
and the categorical standards are as applied pursuant to the Colorado Discharge Permit System.
Requirements (CDPSR) are collection and treatment of storm waters using the Best Available
Technology (BAT) for those storm waters which contact mine waste. In addition, both
regulatory programs require implementation of Site-specific Best Management Practices (BMP).
The Bill emphasize stonn water diversion and hind/soil reclamation to minimi7.e the contact of
storm water with mine wastes. .
o
Copper, Lead, Zinc, Gold, Silver and Molybdenum Ores Subcategory EftIuent
Limitations, Relevant and Appropriate
This ~ applies to "process waste waters" only. Process waters are defined in 40 CFR
401.11(q) as: , , '
"any waters which, dming manufacturing or processing, comes into direct contact
with or results from the production of any raw material, intermediate product,
finished product, by-product, or waste product. "
The effluent limitations fo~d in 40 CFR 440.103 would be appropriate and relevant to the
Water Treatment FFS activities but not applicable because the discharges are not "process waste
waters. n 'The tAL established by EP A to meet the surface water quality ARARs are more '
stringent than these categorical etlluent limitations. '
,0
Colorado Discharge Permit System RegnIationslFederal Storm Water J;»ennitting
Requirements .
Colorado's authoritY to require permits for the discmuge of pollutants from any point source into
waters of the state are derived from the Federal National Poll1itant Discharge EHmination System
(NPDES) regulations. See 40 CPR Part 122. Colorado's NPDES based progtam can be found in
the CDPSR The CWQCC Division Permit issued for the treatment plant at the Site (CDP #CO-
0041947), dated November 12, 1991, is the CDPSR document for the Site. Additional permit
modiiication activities are documented in the July 1991 Settlement Agreement and the July 1992
Amendment to the Settlement Agreement.
Storm water is defined in NPDES program as "storm water runoff: surface runoff: snow melt
runoff: and surface nmoffand drainage." (See 40 CFR 122.26(b)(13).) A permit application is
required for active and inactive mining' sites where an owner can be identified and when ,
, discharges of storm water runoff from mining operations come into contact with any overburden,
raw material, intermediate product, finished product, by product, 'waste product or areas where
, tailing. have been removed. (See 122.26(b)(14)(ili).) As such, the substantive NPDES Storm
Water permit requirements are applicable to discemable surface flows of storm water that
33
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contacts waste rock, the crushed ore currently contained in the heap leach pads, wet waste rock
(mud), clay ore, or tailings at the Summitville Minesite. Infiltration is not covered by this
program. (See 55 FR 47996, left column, center.)
The storm water permit regulations require compliance with Sections 301 and 402 of the Clean
Water Act. Sections 301 and 402 require use of BAT to control toxic pollutants, and where
necessary, further control to aChieve ambient water quality criteria. In addition, the storm water
regulations require implementation of stormwater BMP as part of the comprehensive program.
EP A ~ established effiuent limitation guidelines for storm water discharges from the Ore
Mining and Dressing category. These efiluent limits require application of BAT to the Ore
Mining and Dressing category. In those regulations, EP A has defined "mine" broadly and a in
manner which coincides with the definition provided in the Storm Water Permit requirements.
(See 40 CPR 440. 132(g). ) The effluent limitation guidelines for Ore Mining and Dressing also
provide an exemption for overflow of excess storm water caused by a greater than a 10 year 24
hour precipitation event when a facility has met certain design and operational prerequisites.
This ex;emption remains in effect as part of the new independent storm water permitting Program.
(See 55 FR48032, right column, bottom.) ,
Both the effiuent limits and the stonn water permitting program require application of BAT and,
if necessary, additional controls to meet ambient water quality standards. In addition, both
programs require implementation of stormwater BMP. The only jurisdictional distinction is that
the Ore Mining and Dressing Category effluent limits are not applicable, but instead relevant and
appropriate. 'The recognition by the storm water permit program of the overflow ~xemption '
demonstrates the existing equivalence of the programs. Thus, ~inment of the Efiluent
Guidelines and Standards for'Ore Mining and Dressing will enSure attainment of the storm water
discharge requirements. " ,
, ,
Eight outfalls were identified at the Summitville Mine site whicJ;1 meet the 'point source discharge
requirement for storm water permitting. The discharge from each of these outfalls have been
attributed to one of the three categories of precipitation related discharges defined by the storm
water regulations. (See 40 C.F.R. 122.26(b)(13); 55 Federal Register at 48065.)
, ,
Pursuant to the NPDES Storm Water Permitting requirements and in response to obligations
under the July 1, 1991 Settlement Agreement and Compliance Plan (the Compliance Plan) for
Summitville Mine, a two volume BMP plan dated October 31, 1991 was developed. The
Compliance Plan required that the BMP provide a reclamation plan and implementation schedule'
that included existing and planned pollution prevention practices. The BMP also evaluated the
need for long term treatment of stonn water drainage at the facility.
The BMP was designed to minimi7e or control contact between precipitation and potential
sources of pollutants. The BMP developed at the Summitville Minesite included housekeeping,
employee training, inspections. preventative maintenance. In addition, reclamation activities
such as grading, stabilization, revegetation, erosion control and sediment control were included
as part of the BMP. Each of the measures was designed'to protect the existing Water quality and
.
34
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. .
quantity during the operation phase and upon closure of the Summitville Mine.
. The existing BMP plan which is currently being implemented at the Site and will continue to ~e
unplemented regardless of which alternative is selected, attains compliance with the NPDES
stormwater and categorical point source standards.
1.5.5.2
Action Specific ARARs
RCRA Subtitle C
40 CPR 261.4(b)(7) specifically excludes "solid waste from the extraction, beneficiation, and
processing of ores and minerals..." from the rules governing management of hazardous waste in
Resource Conservation and Recovery Act (RCRA) Subtitle C. Mine wastes present at the .
Summitville Minesite, including waste rock, the crushed ore currently contained in the heap
leach pads, wet waste rock (mud), clay ore, and tailings, were generated as a result of the
extraction, processing, or beneficiation of ores and minerals. Accordingly, RCRA Subtitle C is
not applicable to the remediation of this mine waste. .
RCRA Subtitle C may be relevant and appropriate to actions at the Summitville Minesite if the
mine waste materials are sufficiently similar to RCRA hazardous waste, particularly if the
subject wastes fail the Toxicity Gharacteristics Leachibility Procedi1re'(TCLP) or exhibit other
characteristics ofRCRA hazardous wastes (e.g., low pH). See "Superfund Guide to RCRA
Management Requirements for Mineral Processing Wastes, 2nd Edition," OERR Directive
9347.3a-12 (August 199.1). . ,
Further, if the disposal activity involves the use of a waSte management unit sufficiently siDillar .
to a RCRA regulated unit, and the unit is to receive wastes sufficiently similar to RCRA
hazardous wastes, the RCRA Subtitle C requirements pertaining to that type of waste
management unit would be relevant and appropriate. (See SS FR 87630.)
. .
Th~ EP A has stated, when describing its overa1lliquids management strategy for RCRA Subtitle
C land disposal units:. .
as described in the preamble to the minimum technology regulations (47 FR
32274, July 26, 1982 and Sl FR 10706, March 28, 1986), the Agency's general
strategy for such units is to impose design and operation requirements to
minimi7e leachate generation (e.g. caps and prohibition on liquids in la1l1dfin~) and .
then to require removal of the leachate before liquids migrate into the
environment (See S2 FR 8712.)
Given the acid and contaminated leachate generating potential of the materials found at the .
. CWP, BMD, SDI and Mine Pits portions of the Site, EPA determined that the wastes are
sufficiently similar to hazardous wastes towmant imposition of selected portions ofRCRA
Subtitle C requirements. The Subpart L Waste Pile closure requirements, Subpart K Surface
Impoundment closure requirements, and Subpart N Landfill closure requirements are therefore
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relevant and appropriate to the closure of the CWP, BMD, SDI and Mine Pits. Accordingly,
following placement of the materials in the Mine Pits, the unit must be closed in a manner that
attains the following relevant and appropriate requirements:
.
provision of a low maintenance cover that mtntmt'T~ migration of liquids
through the closed unit; promotes effective drainage; min;m;'T.es cover
erosion; and is capable of accommodating settling and subsidence (40
CFR 264.31 O(a), 264.228(a), 264.258(b»; and
.
provision for long term maintenance of the cover, continued operation of the
leachate collection system and continued control of runon and runoff (40 CFR
264.310(b), 264.228(b), 264.258(b».
Colorado Mined Land Reclamation Act
The Colorado Mined Land Reclamation (MLR) regulations at 2 CCR 407-1 require the
reclamation of mined areas; The MLR regulations provide specific reclamation criteria which
are applicable to the Summitville Minesite. In particular, Rule 3 of the Mineral Rules and
Regulations of the Colorado Mined Land Reclamation Board is applicable to the remedial action
being implemented at the CWP. The remedial alternatives must attain the requirements for
reclamation measures and the reclamation performance standards found in ~~ 3.1.5 (Reclamation
Measures - Materials Handling), 3.1.9 (Topsoiling), and 3.1.10 (Revegetation). The general
water (~3.1.6), ground water (~3.1.7), wildlife (~3.1.8) and building arid structures (~3.1.11)
requirements, while also .applicable to the CWP interim remedial action, will be met with the
AttAinment of other federal or state ARARs which pfOvide more stringent standards for the same
subject matters. .
The conditions imposed by the Colorado MLR Permit #M-84-157 for the Summitville Mine
stipulated a phased approach to land reclamation which m;n;mt'Tes the total disturbed area at any
. point in time. When mining activities in e8ch area have been completed and the sections are no
longer needed, the permit requires that a1lland associated with waste dumps, leach heaps, roads,
mine pits and plant "facilities be reclaimed for forage and timber use. Reclamation activities at
the Summitville Minesite will emphasize surface soil stabilization (to include grading, top soil
management, and revegetation), preserVation ofwater quantity and quality, and concern for the
safety and protection of wildlif~.
The reclamation requirements of the MLR are ARARs, not the site specific MLR reClamation
plan. Regardless, the existing MLR reclamation plan does represent the site specific application
of the MLRs, and is, therefore, TBC frOm an ARAR perspective.
Clean Air Act
Federal and state ~ were identified for construction and generation of particulate matter
(PMI0) at the Site. An emission permit will be required if temporary construction activities
excee~ more than ~o years. (See 5 CC~ 1001, ~3(I)(B)(3)(e).) Control m~ to minimt'T~
36
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. . ...
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dust and air monitoring will be implemented if necessary during remedial construction activities.
Regulation 1 of the Colorado Air Pollution Control Regulations requires all sources of particulate
emissions to utilize technically feasible and economically reasonable control measures. This
. requirement is ;lpplicable to remedial activities that produce fugitive particulate emissions at the .
S~ .
An air pollution permit was applied for at Summitville Minesite for the emission of hydrogen
cyanide as a stationary source. The permit included a description of the cyanide heap leach pad
process at the Summitville Mine and all associated process chemistry. ,Permit # 92-RG.;.653 was
given an exempt status in September of 1992. The Summitville Site cIaiined uncontrolled
emissions ofless than one ton per year and no emissions of hazardous, odorous or toxic
pollutants and was therefore exempt. (See 5 CCR Section 3(ll)(C)Q)G).), Thus~ this'particular '
req~ent is not applicable or relevant and appropriate at the Site.
1.5.5.3 Localion Specific ARARs
National Kzstorical Preservation Act
The National Historic Preservation Act (NHP A) requires federal agencies to account for the
effects of any federally assisted undertaking on districts, sites, buildings, structures of objectS
that are included on the National Register of Historic Places. Executive Order 11593 also .
, requires consideration of the cultural environment. Siniilarly, the Colorado Register of Historic
Places establishes requirements for protection of properties of state historical interest. In
addition, the Historic and Archeological Data Preservation Act of 1974 establishes procedures to
" preserve historical and archeological data which might be destroyed through alteration of terrain
as a result otfederal construction projects. '
At the Summitville Minesite, an inventory of historic, cultur8l and archeological resourCes will
be performed. This inventory will serve to identify cultural and historic resources that must be
considered during the development,' analysis, selection and ~plementation of a remedy. In '
addition, the inventory will identify historic and cultural resources that are candidates for
inclusion on either the state or national historic registers.
Endangered Species
The Endangered Species Act requires that federal agencies ensure that federal actions will not
jeopardize the continued existence of any threatened or endangered species or impact critical
habitat. In response, a,Preliminary Natural Resource Survey will be performed to identify
natural resources, habitat types, endangered or threatened species, and any potential adverse
effects or injury to trust resources.
Protection 01 FloodplaiTis and Wetlands .
. Executive Order No. 11988 and Executive Order No. 11990 require federal agencies to evaluate .
. the poten~ ady;erse effects of proposed actions on Floodplains and Wetlands,:respectively.
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Floodplains and wetlands potentially. subject to adverse impacts from site remedial actions will
be inventoried and considered during the analysis, selection, and implementation of the remedy.
Clean Waler Act - Dredge and Fill Requirements.
Section 404 of the Clean Water Act prohibits the discharge of dredged or fill material into
navigable waters, including wetlands. The Section 404. requirements' are applicable if any
remedial action construction will involve dredge and fill activities. '
Fish and Wildlife Coordination Act
The Fish and WIldlife Coordination Act serves to protect fish and wildlife when federal actions
result in the control or structural modification to natural streams or water bodies. Federal
agencies must develop measures to prevent, mitigate, or compensate for project related losses of
fish and wildlife. Specifically included are projects involving stream relocation and water
diversion structures. If applicable, prior to modification of water bodies, the applicable
regulations will be followed.
Colorado Wildlife Act
The act establishes the Colorado WIldlife CQmmt~on, provides for wildlife management, and
prohibits actions detrimental to wildlife. The act is applicable if wildlife observed at the Site
would be adversely impacted by the implementation of the remedial action.
Wildlife Commission Regulations
Chapter 10 of the Colorado WIldlife Commission regulations 92 CCR 406-8, C1uq>ter 100
designates and protects certain endangered or threatened species. 'The regulations are applicable
if endangered or threatened species observed at the Site are adversely impacted by the "
implementation of the remedial action. "
Floodplain Management
The Executive Order on Floo~Iain Management (No. 11988) and 40 CPR ~6.302(b) and
Appendix A requires federal agencies to evaluate the potential effects of actions they may take in
a floodplain and to avoid, to the maximum extent possible,.any adverse impacts associated With
direct and indirect development in a floodplain., This requirement may be applicable if the
remedial activities take place in a floodplain.
Wetlands Protection
Executive Order on Protection of Wetlands (No. 11990) and 40 CPR ~6.302(b) and Appendix A
requires federal agencies to evaluate the potential effects of actions they may take in wetlands, in
. order to mtntmt7.e adverse impacts'to wetlands. This requirement is relevant and appropriate if .
the remedial activities take place in wetlands. ARARs are "applicable" or "relevant and
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-- .....
..- .-.---...
appropriate" requirements of federal or state law which address a hazardous substance, pollutant,
contaminant, remedial action, location or other circumstance found at a CERCLA Site. The NCP
.defines "applicable" requirements as cleanup standards, standards of control~ and other
substantive environmental protection requirements, criteria, or limitations promulgated ui:1der .
Federal or State law that specifically address a hazardous substance, pollUtant, contaminant,
remedial action location or other circumstance fotmd at a CERCLA site. ~Relevant and
appropriate" requirements address problems or situations sufficiently similar to those
encountered at the CERCLA site that their use is well suited to the. environmental or technical
factors at a particular site. (See 40 CPR Section 300.5.)
1.6
Su~ of Site Risks . -
The Human Health and Ecological Risk Assessment for the FFS was conducted using relevant
EP A guidance including the Risk Assessment Guidarice for Superfund (EP A, 1989)and the -
RCRA Facility Investigation (RFI) Guidance (EPA, 1989). This risk assessment was a screening
level risk assessment intended to briefly examine risks associated with the HLP.
.LQJ. Screenin~ Ecoloeical Risk Assessment
A Screening Ecological Risk Assessment for the Summitville Minesite was prepared by EP A in
April, 1993. The screening ecological risk assessment reviewed the nQ action alternative to
determine if there is an imminent hazard to the Wightman Fork from the site. Copper, zinc, and
. cyanide were chosen as the COPC for the assessment. '
, The assessment modelled, measured, and predicted concentrations and lo8ding of copper in
Wightman Fork for three scenarios:
.
April 1993 conditions (included treatment ofHLP contained water and discharge
from the Reynolds Adit);
CesSation of water treatment activities; and
Catastrophic release of water contain~ in the,HLP that could result from an event
such a faiI~ of Dike 1, ~e downgradient impoundment feature.
.
.
Effects of the contaminants on rainbow trout and brook trout were estimated by correlating acute
toxicity levels of the contaminant,s with measured and predicted concentrations. The degree of
metals toxicity for aquatic life as affected by the pH and hardness of water was described. Study
results of copper concentrations that are toxic to trout at differing water hardnesses were included
in the assessment to illustrate the variation of toxic copper concentrations with water hardness
(the sum of calcium and magnesium concentration expressed in terms of equivalent calcium
carbonate).
.
Continuation of Site water ~ent prior to discharge and decrease of loading of
metals into the stream to State of Colorado NPDES permit levels;. .
Reduction of the flow of contaminated ground water through plugging the adits
.
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.
for long-term metal loading reductions to the Wightman Fork; .
Conducting an ecological survey of Wightman Fork to obtain Site specific
information to document actual discharge impacts and document recovery of
Wightman Fork after remediation; and . . .. . . ..
. Completion of a baseline risk assessment because the review of th~ no action
alternative produced an unacceptable risk, defined as exceeding the Low
Observed Adverse Effect Level (LOAEL).
.
The screening ecological risk assessment predicts an imminent hazard to the environment and
suggests that all appropriate response actions should be undertaken to prevent the adverse effects
from continuing to take place. The remedial actions are intended to stabilize specific portionS of
the site, prevent further environmental degradation, and achieve significant risk reduction.
~ . Environmental Risk Assessment
1.6.2.1 Aquatic Receptors.
In general, the potential risks to aquatic organi~~ posed by.an untreated release from the French
Drain are predicted to be immediate and pronounced. Chemicals of potential concern in the
French Drain exceed acute and chronic surface water goals by several orders of magnitude.
Modelling predicts that concentrations of cyanide discharging from Cropsy Creek remain acUtely
toxic until the confluence of the Wightman Fork with the Alamosa River. Fmthermore, the .
concentrations of cyanide would remain at levels in excess of the Colorildo TVS in the Alamosa
. River for some distance below Wightman Fork. The TVS are promulgated, risk based' standards
developed to protect aquatic life uses.
It is importai1t to note that the Site's impact on pH alone may contribute to toxicity to aquatic
organisms, as there is a limited range of pH levels tolerated by aquatic receptors.
Prior to treatment of the Chandler Adit, the Colorado TVSs, ARARs in Segment 3b of the
Alamosa River, were regularly exceeded for copper, zinc, aluminum, iron and manganese. TheSe .
exceedences are especially problematic as the hardness-depei1dent Colorado TVS may
underestimate the potential toxicity of metals in the acid drainage (low pH) environment below
the HLP. Normally, toxicity. is reduced as hardness is increased. . However, an underlying
assumption of the criteria is that al1ralinity increases as hardness increases. This assumption
holds for many natural waters, however, at the Summitville Minesite hardness is relatively high
and al1catinity is low. Ranges ofdata collected by the USGS in 1993 at Station 45.4 from
Segment 3b of~e Alamosa River are as follows:
Flow Season Ana!yte - . Maximum . Man TIS
May-July Dissolved Copper 2600.00~g/L I 084.22~g/L 30~g/L
October-March Dissolved Copper 780.00~gIL 780.~O~g/L 30~gIL
May-July Dissolved Zinc 450.00~gIL 301.44~gIL 230~gIL
October-March Dissolved Zinc 437.00~g/L 437.00~g/L 230~g/L
40
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The Colorado Division of Wildlife, in comments on the proposed ambient water quality standard
for the site, found that a self-maintaining population of brook trout was present in the Alamosa
. river segment that extends from the confluence of the South Fork of the Alamosa to SummitviUe
in '1987 (Colorado Division of WIldlife, 1993). The population appears to have been eliminated..
in the intervening years by contamination of the Alamosa River.
1.6.2.2 Terrestrial Wildlife
An untreated release from the French Drain would pose significant risks to bird and mammal
populations. Based on the modeled concentrations, risks to terrestrial wildlife from acute and
chronic exposures to cyanide would be high along Cropsy Creek and Wightman Fork. The
potential for chronic exposure is mitigated by the unsuitable habitats surrounding these sites.
The lack of suitable habitats makes regular use of these areas unlikely.
The other chemicals of concern that pose "potential acute risks to bird and mammal species in
Cropsy Creek include: ~um, copper, and manganese. Risks from acute exposure in
Wightman Fork are substantially lower, although the risks from chronic exposure in those areas
with suitable habitat (Le., natural, undisturbed habitats) may be present.
.l..2.J. Human' Health Risk Assessment
A baseline human health risk assessment (HHRA) will characterize the pgks posed by the
COPCs .at the Site. The assessment for human exposure to COPCs proceeds with the
identification and characterization of likely. exposure scenarios, identification and evaluation of
exposure pathways, estimation of exposure concentrations, and quantification of chemical
~. .. .
1. 6.3.1 Exposure Scenarios
The potential for exposure is based on the existing Site conditions and potential future Site .
conditions. Groups assessed for potential exposure pathways include on-site workers, on-site
. residents, off-site residents, and intruders/trespassers. Presently, access to the Site is being
controlled. Current on-site workers, trained under OSHA HAZWOPER, are required to use
personal protective equipment (PPE) and are routinely monitored; therefore, they are evaluated
under a separate process. Since the Site is a historic mining district, on-site residents are not
considered a viable exposed population currently or in the future. Off-site residents and potential
off-site recreational receptors will require evaluation during a baseline risk assessment.
1. 6.3.2 Expo~e Pathways
An exposure pathway describes the route a chemical may take from the source to the exposed ..
individual. . A complete pathway consists of four elements: a source and mechani~ of chemical
release to the environment, an environmental transport medium, a point of potential human
contact with contaminated medium,. and an exposure route. The transport medium can be air,
ground water, soil, surface water, etc. The route can be inhalation ingestion or dermal contact
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with the medium.
Evaluation of the potential pathways suggests that most exposure pathways at the Site are
incomplete: Currently, the only pathway with sufficient data for assessment is surface water. .
There is insufficient sampling data available to determine whether soil, ground water, and/or air
are exposure pathways. .
To evaluate current and future risks, EP A is planning to complete a quantitative human health
risk assessment in 1995.
1.7
Description of Alternatives
Interim remedial actions consistC?1t with..the remedial action objectives (RAOs) include standard
mining reclamation practices. These practices and their prpcess options are listed below:
.
No Acnon . .
Institutional Controls
On-Site Containment
Capping'
Erosion Control
Land Reconfiguration
Slope Stabilization
Erosion Control
Revegetation
Site Preparation
Plant Material Selection
Plant Introduction'
Revegetation Management
.
.
.
.
The appli~on of these process options will vary from area to area on the Site depending on the
area topography, surf3ce water flqw, and the chemical composition of the present cover material.
While the short-tenn goal of reclamation is erosion contro~ the long term goal for site
reclamation is the establishment of a permanent, self-sustaining vegetative cover of native or
introduced plant species that will maintain adequate soil protection of the remediated areas and
other disturbed areas. The eventual result of a successful reclamation program will be on-site
biota enhancement. .'
The alternatives discussed for this interim action will include on-site containment, land
reconfiguration, and revegetation which are standard reclam8tion practices for the mining
industry. Institutional controls are currently in place on-site and will be maintained throughout
the remediation activities. Land reconfiguration response actions employ various types of
engineering and agricultural technologies to produce land stability through slope modifications
and erosion control. Successful high-altitude revegetation is dependent on the following
42
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_._~_.-.__.~_. -...----- ..
combination of technologies: site preparation, selection of appropriate plant materials, plant'
introduction and establishment, and revegetation management. Site preparation technology
requires a selection of amendments to increase pH, if needed, and add nutrients and organic
material to Produce a soil with the possibility of sustaining growth. The amendments are needed'
since Summitville topsoil offers a poor substrate for plant growth due to a lack of nutrients and
organic materials, and its natural acidic pH condition. Therefore, the focused variable among the
process options is the choice of topsoil for site preparation. .
The following alternatives will be examined for the reclamation interim action:
1. No Action
2. On-Site Topsoil with Amendments
3. Imported Topsoil
Alternatives 2 and 3 of this IROD correspond With Alternatives 4 and 5 "f the Reclamation FFS,
respectively. . . .'. .." . .
With the exception of the no action alternative, the alternatives will achieve local reduction of
AMD production and stabilize the reclaimed portion of the Site. Through the reduction of AMD,.
these alternatives will reduce adverse effects on the environment.
Implementation of the alternatives will not interfere with current or futUre remediation activities
at the Site. .
'.LZJ. Alternative 1: No Action
The no action alternative would consist of no reclamation activities.. The Site would be
remediated only to the point of rough grading of the areas. No engineered structures would be
constructed to control erosion. Ground water and surface water would be monitored to evaluate
chemical migration. An Ecological Risk Assessment would be performed every five years.
The capital costs for the no action alternative are negligible. .The annual tn';atment and
assessment costs are $90 per acre. An ecological risk assessment every five years would cost
approximately $40,000. The present worth costs of this alternative is $530 per acre.
.L1.2 Alternative 2: On-site TQPsoil with Amendments
This alternative involves reclamation of non-point source areas of the Site after rough grading is
completed. This alternative uses on-site topsoil only with the optimum amount of amendments
needed to produce a topsoil capable of promoting and sustaining plant growth. On-site topsoil
would be tested to determine which amendments (limestone or lime kiln dust, wastewater sludge,
wood chips, mushroom or manure composts, and/or bactericides) would be most applicable.
Determination of soil amendment and seed mixtures will be made after the completion of the
Remedial DesignlRemedial Action activities that willbe tested and themn implemented in 1995-
1996. The amendments will be applied to the soil by blending, discing, or hy~seeding, .
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whichever method is appropriate for the particular amendment This alternative also includes the
following:
reconfiguring the areas for slope stabilization, erosion control, and moisture
~~ntion, .
seeding with a seed mixture designed to establish a natural, self-sustaining
vegetative cover, . . .
. providing adequate weather protection for the severe Si~ conditions.
Weather protection for seeds and seedlings may be furnished by rocks, mulch, and snow fencing.
The capital costs for the on-site topsoil with amendments alternative are $14,910 per acre. The
annual treatment and assessment costs are $6~50 per acre. The present worth costs of this
alternative is $21,260 per acre.
.
.
..LZ.l Alternative 3: ID:\Ported Topsoil
This alternative consists of using on-site and imported (one part on-si~ and 3 parts imported)
topsOil with the optimum amount of amendments needed to produce two feet of suitable topsoil
capable of promoting and sustaining plant growth. This alternative requires importation of soils
from the San Luis Valley. The mixture of on-site and imported topsoil would be tested to
determine the amendments to be added. This alternative should produce a satisfactory topsoil
with fewer amendments than the on-si~ topsoil since the imported topsoil will contain more
organic material before the addition of amendments. Included in this alternative is
. reconfiguring the areas for slope stabilization, erosion control, and moisture
~tion, .
. seeding with a seed mixture designed to establish .a natural, self-sustaining -
vegetative cover, .
. providing adequate weather protection for the severe Site conditions.
The capital costs for the imported soil alternative are $89,640 per acre. The annual treatment and
assessment costs are $6,350 per acre. The present worth cost of this altemativ~.is $95,990 per
. .
acre.
.
Summuy of ~omparative Analysis of Alternatives
Provisions of the. NCP require that a limited number of alternatives that represent viable
alternatives be evaluated against nine criteria in 40 CPR 300.430 (e) (9). The alternatives are
evaluated against each of these criteria and then against each other.to deteImine the preferred
alternative. Table 9 presents a summary of this ana1ysis~ .
1.8
l.U. Criteria I:
. Overall Protection of Human Health and the Environment
This criteria addresses whether or not a remedy provides adequate protection and describes how
risks posed through exposure pathways are eliminated. =Uced, or controlled.
. Alternative 1 - No action does nothing to allevia~ threats and potential threats to human health
and the environment until the final.remedy(ices) are enacted. The only protection afforded by no
44
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.
action is ground water and surface water monitoring and the five year ecological risk assessment.
Alternative 2 - The on-site topsoil with amendments alternative combines' on-site topsoil with a
variety of pH and soil amendments to produce a growth media approximately one foot deep. The
subsequent vegetative cover will effectively provide a cap reducing the surface water and air
contacting the waste or acid generating material. A vegetated cap will isolate sulfide-bearing
materials from transport by surface water. This isolation reduces the production of toXic
solutions, slows surface water velocities and mobility; and aidS soil moisture retention; thereby,
reducing the off-site migration of the contaminents of concern and protecting human health and
the environment.
Altemai:ive 3 -The jnworted to,psoil alternative combines on-site and imported (one.part on-site
and three parts imported) topsoil with an optimum amount of amendments needed to produce
two feet of suitable topsoil capable of promoting and sustaining plant growth. Approximately
1.3 million cubic yards of imported soils would be transported from the San Luis Valley. The
, subsequent vegetative cover will effectively provide a cap reducing the surface water and air
contacting 'the waste or acid generating material; thereby, protecting human health and the
environment. However, importing valley soils will cause an increase in haul truCk traffic which
will escalate the potential for accident encounters on the Forest Service access roads.
.LU Criteria 2:
Compliance with ARARS
Compliance with this criterion addresses whether or not a remedy will attain Federal and State
, environmental laws and or provide grounds for a waiver. Dependent upon the completion and
success of source control actions at the Site, the reclamation remedies will meet ARARs after
erosion control and effective revegetation measures are fully implemented and integnited into.the
overall Site Remedy. ' ,
With the exception of no action, all of the alternative employ' BMPs for controlling storm water
and thus attain the NPDES stormwater permitting requirements. Likewise, with the exception of
no action, all of the alternatives attain the narrative Mined Land Reclamation requirements.
Alternative 1, no action, does not attain the chemical specific ambient water quality ARAR
identified for Segment 3b of the Alamosa River. Alone, Alternatives 2, and 3 will not attain the
chemical specific ambient water quality ARAR identified for Segment 3 b of the Alamosa River.
Alternative 1 does not meet the reCprirements established within the ARARs section of this .
study. The waiver requirements established in 40 CPR 300.430(t)(I)(ii)(C) cannot be met
with alternative #1. The remaining alternatives, 2 and 3, will comply in with all ARARs when
impl~nted in concert with the other interim remedial actions proposed for the Site.
il.J., Criteria 3: - Lon~ Tenn Effectiveness and Pennanence
Long term effectiveness and Permanence refers to the ability of a remedy to provide reliable
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protection of human health and the environment over time.
Altepurtive 1 - The long-term monitoring portion of the no action alternative would determine
when the :COPC would impact the off-site environment. The no action alternative does not
result in long-term effectiveness or permanence since it delays any reclamation action until final
remedy(ies) are selected.
Alternative 2 - The use of on-site topsoil with amendments alternative, with proper management,
will establish a stable vegetative cover at the Site in approximately seven (7) to ten (10) years.
Once established, the vegetative cover becomes the upper barrier to infiltra.t:ii1g water and to the
effects of wind and water erosion. The established vegetative cover is self-perpetoaimg;
therefore, this alternative provides long-term effectiveness and permanence.. .
Alternative 3 - :The in\ported tOJ'soiJ alternative, with proper management, will establish a stable
vegetative cover at the Site in approximately seven (7) to ten (10) years. Once established, the
. vegetative . cover becomes the upper bamer to infiltrating water and to the effects of wind and
water erosion. The established vegetative cover is self-perpetl1~ting; therefore, this alternative
provides long-term effectiveness and permanence.
~ Criteria 4:
Reduction ofToxicitv. Mobility. and Volume
Reduction of toxicity, mobility, and volume refers to the preference for a remedy that reduces
health hazards, the migration of contaminants, or the quantity of contaminants at the Site.
Alternative I - The no action.alternative delays the reduction of toxicity; mobility, and volume of
the COPC since no'reclamation practices would be implemented.
Alternative 2 - The use of the on-site tQPsoil with amendments alternative utilizes standard .
reclamation practices to address the problem of AMD. Surface water is considered the most
significant pathway for off-site transport of metals. The vegetated topsoil, by reducing or
. eliminating infiltration of ~e waters to the sulfide ore body and/or sulfide bearing materials,
reduces acid generation and the'reSulting AMD. The vege~ layer also. assists in preventing
erosion and promoting evapotranspiration. Reduction of surface water infiltration to the sulfide
materials, by implementing a vegetated cover of non-point somce areas Will reduce the toxicity,
mobility, and volume of the AMD.
Alternative 3 - The ilI\Ported topsoiJ alternative utilizes standard reclamation practices to address
the Problein of AMD. An established vegetative cover of non-point source areas will reduce the
toxicity, mobility, and volume of the AMD by reducing the infiltration of water and oxygen.
~ Criteria 5:
Short- Tenn Effectiveness
This criteria addresses the period of time needed to complete the remedy, and any adverse effects
to human health and the environment that may be caused during the implementation of the
'46
'. . -
.~---:...
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-.....--' . .-...-- nO. .---.. .
remedy.
, ,
Alternative 1 - The no action alternative allows the risks to human health and the environment to
continue without any mitigation. .
Alternative 2 - The use of the on-site to,psoil with amendments alternative will involve some
short-term riskS to workers on the Site and the community at-large dming the implementation
phase of the remedy since truck transportation will be needed to haul the required amendments to
the Site. This additional truck traffic poses short-term risks tQ human health. . The use ofLKD as
a buffer for upward mobility of AMD yields some immediate protection. for human health and
the environment. No adverse environmental impacts are expected from implementation of"
Alternative 2. .
AltCrna.tive 3 - The i~orted topsoil alternative will also require truck transportation of the
imported topsoil and required amendments to the Site. This alternative will require more truck
loads than alternative 2 since topsoil is being brought to the Site. . The additional truck traffic
, poses short-term risks to human health only dming the implementation period of the ~ternative.
The two feet of growth media slows the infiltration of water to the acid generating layer
providing immediate protection for human health and the ~nvironment. No adverse
environmental impacts are expected from implementation of Alternative 3.
~ Criteria 6:
Im.plementabiIitv
Implementability refers to the technical and administrative feasibility of a remedy. This includes
the availability of materials and personnel needed to execute the remedy. It includes ,
coordination o(Federa1 and State government efforts to remediate the Site.
, Alternative 1 - The no action alternative offers'no implementability concerns since it is
technicaIly and administratively feasible and does not rely on the availability of personnel and
materials. ,
Alternative 2 - The use of the on-site to,psoil with amendments alternative will' Utilize standard ,
mining reclamation practices and existing equipment and personnel. The action is '
administratively feasible. Equipment not on-site is available locally. Amendments would be
transported to the Site on existing roads. The use of on-site topsoil in conjunction with soil
amendments substantially reduces the amount of truck traffic compared with the amount
necessitated by the mov~ent of imported soil.
Alternative 3 - The imported topsoil alternative will utilize standard mining reclamation practices
and existing equipment and personnel. The action is administratively feasible. Equipment not
, on-site is available locally. 'Imported topsoil and the necessary amendments would be
transported to the Site on existing roads. . ,
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l.B..1 Criteria 7:
~
The cost evaluations estimate the capital and the annual treatment and ~se~sment co$; of each
. alternative in comparison to other equally protective alternatives. . .
Alternative 1 - Negligible capital costs are anticipated for the no action alternative. Annual
treatment and assessment costs of approximately $41,080 are projected for sampling and
inspection. An ecological risk assessment every five years would cost approximately $40,000.
Assuming a treatment and assessment period of 10 years, this equates to a present worth cost for
the no action alternative of$ 1 06,000 for the 200 acres of non-point sources areas and $291,500
for the entire 550 site acres or $530 per acre. Present worth costs for this alternative were
calculated at a 10 percent annual discount rate for 10 years.
Alternative 2 - The present worth cost of capital costs for the on-site topsoil with amendments
alternative is $14,910 per acre (based on a one time investment). Annual treatment and .
assessment is $1,020 per acre per year for a period often years. The present worth cost of
treatment and assessment is $6,350 per acre. . Combining capital costs with present worth
treatment and assessment costs, the overall present worth of this alternative is $21,260 per acre
or $4,252,000 for 200 acres and $11,693~000 for 550 acres. .
. Alternative 3 - The present worth cost of capital costs for the iIJworted tQPsoil alternative for one
acre is $89,640 (based on one time investment). Annual treatment and assessment is $1~020 per
acre plus a per acre for a ten year period. The present worth cost of treatment and assessment is
$6,350 per acre. Combining capital costs with present worth treatment and assessment costs, the
overall present worth of this alteInative is $95,990 per acre or $19,198,000 for 200 acres and
$52,794,500 for 550 acres. . This cost is approximately four and one-~times more than
Alternative 2. . . .
l..U . Criteria 8:
State AccE;rtance
State acceptaD,ce describes whether the State agrees with, opposes, or has no comment on the .
preferred alternative or oth~ alternatives. The State acceptance also includes any comments the
State may have on the 8I;hievement or waiver of ARARs. . . .
The State has agreed that Alternative 2 (On-site Topsoil with Amendments) is the appropriate
remedial action and with EP A's analysis that Alternative 2 achieves the ARARs related to the
interim action. .
.1...S..2 . Criteria 9:
CommunitY Acc~ce
Community acceptance includes determining which components of the alternative interested
persons in the community support, have reservations about, or oppose.
The community response to the alternatives is presented in the responsiveness summ~& (Section.
48
"." .
. .. - . .
"
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2.0) which addresses comments received during the public comment period.
Comm1JI1ity acceptance of a plan to reclaim and revegetate the Summitville Minesite was
generally very favorable. Primary concerns were the availability and quantity of topsoil, the
degree of expertise needed for high altitude revegetation, the lack of detail presented in the FFS,
the time frame, and overall costs.
1.9
Selected Remedy
The goal of the Site in~ remedial action is to stabilize and reclaim areaS at the Site that were
disturbed by mining and mine related activities. "Based on the comparative analysis of the nine
NCP criteria, Alternative 2 (On-site Topsoil with Amendments) is selected as the interim action
for Site Reclamation. "
Alternative 1 does not meet the threshold criteria of protecting human health and the
en:vironment or comply with ARARs and is therefore rejected. While Alternatives 2 and 3 meet
these threshold NCP criteria, Alternative 2 provides greater overall protection of human health
and the environment, as well as presenting a better balance of all modifying NCP criteria,
including being cost effective. .
Alternative 2 addresses the reduction of acid generation caused by infiltration of surface waters
into the sulfide mineral zones (including rock-filled areas) and the stabilization of disturbed
surface areas. Alternative 2 recommends the .rti1i,-ation of LKD and biocides to neutralize the '
.. "
acid material and soil amendments to produce a growth medium that, promotes and sustains
vegetation. .Alkaline LKD provides an immediate neutralization ,capacity against the upward
movement of acidic solutions; biocides provide a long term (minimum of7 years) ne\It:r-l1i'7.ing
tIeatment. A Remedial Design treatability study will determine the soil treatment approach to be
used. The vegetative cover will slow surface water velocities and mobility, reduce ,erosion to
'acceptable limits, and reduce infiltration and migration ofwater and oXygen to contaminated
materials by aiding soil moisture retention in the growth media. This al~ve ~ reduce
contaminant lo~ from the reclaimed non-point sources and will inhibit contAminant
mi~on. "
Soil amendment and seed/plant selection has not been flnaJi7ed. Analysis of soil samples,
greenhouse studies, and on-site field trials will be required before the selections are made.
Amendment additions and seed/plant selections may also vary at different Site locations.
Locally available mushroom or potato compost, commercial fertilizers, wastewater sludge, lime
kiln dust, and biocides are some of the amendment additives which will be evaluated.
" The Implementation of this alternative as the interim remedial action protects human health and
the environment. The goals of this remedy are to: "
.
ensure compatibility with the Site-wide remedy; "
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.
remove, reduce, stabilize and/or contain non-point sources of acid rock
drainage to prevent further releaseS to the Site;
eliminate or minimi7e non-point source impacts to aquatic receptors in
Wightman Fork, the Alamosa River, and the Terrace Reservoir;
. eliminate or minimi?e potential water treatment for non-point source
contaminated waters; and . . .
- enhance and/or improve on-site biota habitat.
.
.
.
Approximately 200 acres of disturbed land is to be reclaimed and revegetated under this !ROD.
This requires the haulage and placement of 161, 300 cubic yards of on-site topsoil, 6000 tons of
lime kiln dust, 80 tons of biocide, 2000 tons of mushroom compost, 300 tons of mulch, 7 tons of
seed plus labor and- the required equipment. These volume estimates are for comparison .
purposes only. The Remedial Design treatability study will determine the actual amendments to
be used and their volumes. The capital costs for this alternative are approximately $14,910 per
acre plus annual treatment and assessment of $1 ,020 for present worth of $21 ,260 per acre. With
proper management, this alternative will establish a stable vegetative cover at the Site in seven
(7) to ten (10) years. Once established, the vegetative cover becomes the upper bmierto
infiltrating water and to the effects of wind and water erosion. This remedial action will be
monitored closely to determine the feasibility of further reclamation at the Site using this
alternative. Monitoring of each reclaimed area, will be conducted for a period of ten years to
reseed as needed, repair erosion features, and perform other revegetation management
requirements.
This interim action is consistent with any future actions to complete the reclamation of the entire
Site and is a logical step in the reclamation process. Future reclamation actions addressing final
remedies for all d.isttIlbed areas of the Site will be detailed in a subsequent ~ord of decision
(ROD). Specific points of compliance will not be defined for this interim action, but will be
appropriately designated for the final response action.
1.10
'. . .
Statutory Determinations
The selected remedy meets the statutory-requirementS of Section 121 ofCERCLA as amended
by SARA. These statutory requirements include protection of human health and the
environment, compliance with ARARs, cost effectiveness, uti1i~rion of permanent solutions and
alternative treatment technologies to the maximum extent practicable, and preference for
treatment as a principal element. The manner in which the selected remedy for this interim
action meets each of these requirements is presented in the following discussion.
lJD.J. PrQtection of Human Health and the Environment
This interim action is protective of human health and the enVironment by reducing infiltration- of
- water into the acid generating sulfide material through employment of a vegetated topsoil as a
cap. Studies have shown that in arid/ semi-arid climates, a well designed, vegetated topsoil cap
50
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. - '.,.. .. ~.:.-
can greatly reduce the need for an engineered subsurface hydraulic barrier. The vegetated
, topsoil, by reducing infiltration of surface waters to the sulfide ore body and/or sulfide bearing
waSte rock, prevents acid generation and the resulting AMD. The vegetated layer also assists in
preventing erosion and promotes evapotranspiration. '
1.10.2 Compliance with Awlicable or Relevant and Ap,propriate ReQuirements
Compliance with this criterion addresses whether or not a remedy will attain Federal and State
environmental laws and or provide grounds for a waiver. Dependent upon the completion and
success of source control actions at the Site, the selected alternative will meet ARARs after .
erosion control and effective revegetation measures are fully ~lemented and integrated into
theo~~S~remedy. .
With the exception of no action, all of the alternatives employ BMPs for controlling storm water
and thus attain the NPDES stormwater permitting requirements. Likewise, with the exception of
no action; the alternatives attain the narrative Mined Land Reclamation requirements.
.Lli2.l Cost-Effectiveness
The selected remedy is cost effective in terms of reduction in threat to human health and, the
environment per dollars expended when remediation of the entire site is considered. The interim
action utilizes available materials, equipment, and personnel to the extent possible. Revegetation
of previously mined areas is a proven technology in reducing erosion and acid mine drainage.
The estimated present worth cost is $21,263 per acre and provides an overall effectiveness
proportional to its cost. .
~ Utilization of Permanent Solutions and Alternative Treatment Technoloiies or Resource
Recovery Technolo~es to the Maximum Extent Practicable
The selected remedy represents the maximum extent to ,which permanent solutions and treatment
technologies can be utilized in a cost effective manner to address reclamation concerns at the'
Site. Of those alternatives that are protective of human health and the environment and comply
with ARARs, the selected remedy provides the best balance of trade-offs in terms of long term
effectiveness and permanence, reduction in toxicity, mobility, or volume achieved through
treatment, short-term effectiveness, implementability, and cost. Statutory preference for
treatment as a principal element and state and community acceptance were also considered.
The selected remedy treats the principal threats posed by the possibility of future acid generation
from hiStorically mined areas including waste piles, tailings, and other related land features. The
selected remedy provides the most effective and cost efficient treatment of the alternatives
considered.
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~ Preference for Treatment as a Principal Element
By using land reconfiguration practices, adding soil amendnients to assist in acid neutralization
and the improvement of soil properties, and revegetation to reduce erosion and the infiltration of
surface waters to the sulfide-bearing rock, this interim action address the principal threats posed
by AMD. Therefore, the statutory preference for remedies that employ treatment as a principal
element is satisfied. ... .
52
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2.0
SITE RECLAMATION RESPONSIVENESS SUMMARY
. This Responsiveness Summary was developed in accordance with the EP A gui~ce document,
"Community Relations in Superfund: A Handbook" (EP A/5401R-92/009).
2.1
Responsiveness Summary Overview
As part of the public comment period, the EPA and the Colorado Department of Public Health
and Environment (CDPHE) identified their preferred alternative for reclamation at the
Summitville Mine Superfund Site (Site) based on information provided in the Reclamation FFS.
This alternative as selected in the IROD addresses the reduction of acid generation caused by
infiltration. of surface waters into the sulfide mineral zones (including rock-filled areas) and the
stabilization of surface areas on the Summitville Mine Superfund Site through reclamation
practices. The interim remedy addresses the principal threat posed by surface waters infiltrating
areas that were not addressed in other operable units, but were previously disturbed by mining
and/or mining related activities. The interim action is consistent with any future actions to
complete the reclamation of the entire Site, and is a logical step in the reclamation pI'9cess.
The major components of the preferred alternative include:
.
Reclamation of approximately 200 acres of disturbed land;
.Rough grading of all areas to be reclaimed to a 33 percent or less grade;
U sing. on-site topsoil that was. previously stockpiled and stored;
Adding an optimum amount of amendments needed to produce a topsoil capable'
of promoting and sustaining plant growth; . .
.Reconfiguring the areas for slope stabilization, soil erosion, and moisture
retention; . .
Seeding with a seed mixture designed for the diversity of habitat found at the Site;
and' .
Providing adequate weather protection for the severe Site conditions.
.
.
.
. .
.
.
The comments received during the extended public comment period indicate that the public is
concerned about several issues regarding reclamation at the Site: availability and quality of
topsoil, the degree of expertise needed for high altitude revegetation, the lack of detail presented
in the FFS, time frame and costs for reclamation, and final water qualitY
All comments received by EP A prior to the end of the public comment period, including those
expressed verbally at the public meetings are summarized in the attached Responsiveness
Summary. . . .
53
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2.2
'Response to Reclamation Specific Comments
2.2J. Summarv and Re~onse to Local Communitv Concerns
, This section summarizes and responds to the major issues and concems(shown in bold) rmecI '
by the local community. In this document, "local community" refers to individuals who live in
and around the San Luis Valley, including members of the TAG group~
2.2.1.1 General
Comment 1:
The Site Reclamation FocDsed Feasibility Study (FFS) states 138 acres have been
"permanently reclaimed". Which agency has approved the reclamation?
R~onse: ,
There is no acceptance of the reclamation until the Site bas passed a bond release
inspection by the Division ofMinera1s and Geology (DMG). This statement was taken
ftom Summitvil1e Consolidated Mining Company (SCMCI) "Annual Report for Calendar
Year 1991 It, January 31, 1992, and represented the amount of reclamation SCMCI felt
had been completed. .
Comment 2: ,
The Reclamation FFS should be integrated with the other FFS plans.
Re~onse: ,
Due to the amount and diversity of work involved at the Site and the various technologies
required to ,solve the many associated problems, the evaluation of an oyerall solution had
to be developed in sections. The reclamation plan will be an integral part 'of the Site-wide
plan. ' .,
Comment 3: ,
What qualifications and knowledge does Environmental Chemical Corp. have in the field
of reclamation? .
Re~nse: , .
Environmental Chemical Company (BCC) is one of several nationally recognjzd
companies that has completed or cmrently is completing work at the Site. All of these
companies have submitted statements of their qualifications to the federal government.
The ECC project staffhas environmental remediation experience as well as extensive
mining and mineral processing and Site specific experience. All companies that prepare
feasibility studies are required to follow OSWER Directive 9355.3-01, Guidance for
Conductini Remedial Investi~ations and FeasibilitY Studies Under CERCLA (Interim
Final, October 1988).
ECC's preparation of the draft Reclamation FFS included revieWs of successful
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reclamation projects and incorporation of the expertise of professionals in the field of .
high altitude revegetation. ECC is a member ofthe'Summitville Technical Team (SIT)
which, is comprised of experts in the environmental field including 'personnel from the
EPA, the Bureau of Reclamation (BOR), CDPHE, Colorado Department of Natural
ResourCes (DNR), Morrison Knudsen Corporation (MK), as well as other orvni-mrions. ,.
The identification of the .
alternatives as well as the preferred alternative was determined by the SIT.
Comment 4: .
The Remedial Action Objectives for site reclamation state the need to control and/or
eliminate non-point sources of contamination. Will plugging the Reynolds Adit increase
non-point sources?
Res.ponse:
Plugging of the Reynolds Adit is of c.entral importance for reducing the metal loading to
Wightman Fork. Plugging of the adit is expected to result in Iesaturation of the South
Mountain slope. It is estimated that the resaturation will take about seven years. It also is
estimated. that it will take about 20 years for ground water to flow from the mine to
Wightman Fork. The mine workings that are drained by the Reynolds lie in sulfide ore.
Sealing this adit will substantially mitigate long-term acid-mine drainage by limiting the .
amount of oxygen that is available to oxidize the pyritic sulfides. While plugging the .
. Reynolds Adit may increase the non-point sources, water quality is expected to improve
due to the reduction of available oxygen.
Depth to water throughout the Site is variable. Generally, the ground water levels are
relatively close to the surface except in the vicinity of the old mine workings where depth
to water can be 300 feet. The old workings act as effective underdrains as evidenced by.
the flow of water from the adits in the base workings (Steffen, Robertson, & Kirsten,
1984). Numerous springs and seePs were evident over the entire Site during excavations
for SCMCI project facilities. The Iesaturation of the South Mountain slope will .
inevitably create seeps. However, the ground was probably saturated prior to mining and,
therefore, numerous seeps were probably in existence at the time, as evidenced by former
bogs. Any new non-point sources will be evaluated as part of the South Mountain
operable unit. .
2.2.1.2 PreferredAlternative
Comment 5:
Is the Preferred Alternative (No.4) applicable to all Site areas or will modificatioDS to this
. alternative be required for individual micro sites? .
Res.ponse: '
. Approximately 80 soil samples have been collected by the USBR from different areas
. throughout the Site for chemical and pH determinations. The evaluations of the samples
will determine amendments and seed species to be tested in green house and field studies
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for individual areas throughout the Site. These tests will determine the final reclamation
actions for individual areas. The preferred alternative of using on-site topsoil with
amendments is intentionally generic so it can be applied sitewide. A more detailed
reclamation plan will be developed for the 90% design document.
2.2.1.3 Design
Comment 6:
The Reclamation FFS is too general The complex topography, hydrology, and vegetation
of the site require the use of differing stabilization and revegetation technologies in
separate site areas or micro sites.
Re$ponse: .
The FFS is a conceptual design plan, uSed as a basis for development of the 90% design
document. Individual sites will be evaluated to determine what soil amendments to use
and what vegetation species may be successful. Data conceming this will be developed
by the CDPHE, EP A, and others with expertise in high altitude revegetation.
., .
. Comment 7:
. What engineering studies have been or will be conducted on the stability of materials?
Re~nse: . .
Regraded slopes will require stabilization prior to groWth medium placement. Loose.
material on slope surfaces will be packed by walking a bulldozer in an upslope direction. .
According to the geotechnical studies performed bySCMCI, such compaction will
. achieve stability and permeabilities of less than IxIO.5 cmlsec (SCMCI,I992).
AdditiC?nal engineering studies will be conducted prior to the complet;ion of the 90% .
. design document.. .
Comment 8:
How will.the area bec:ontoured?
Re~nse: . . . .
Contoming will be evaluated for each individual area. In many areas, contouring will not
be required and grading to a suitable slope will be the only requirement prior to growth
medium placement. Contouring of the filled mine pits and the CCTPIBMD area will be
completed according to plans developed by the USBR. '
Comment 9:
How will the final cap be constructed to encourage plant growth and keep water from
percolating into acid generating materials?
R~nse:
. Conceptually, the design calls for a groWth medium of amended stockpiled soil to be
S6
....-
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.-.--....'----
placed over a compacted clay cap. Specific design details will be developed during the
remedial design phase of the reclamation plan and will be available for public view prior
to commencement of remedial design.
Comment 10: .
The Reclamation FFS did not address the need for a storm water management plan, a
grading plan, a drainage pian, an erosion control plan, and a sedimentation control plan
for the Site. .
Res,ponse:
These comments are specific design concerns which will be addressed during.the researCh
and development of the 90% design document. This Reclamation FFS is only a 30%
conceptual design document. While slope stability and erosion control are briefly
addressed in Section 3.4.3 of the Reclamation FFS under Land Reconfiguration, a Site-
wide stonn water manaeement plan, grading plan, drainage plan, erosion control plan,
and sedimentation control plan will be addressed by the 90% design document.
Stonn water manaeement is governed by the stormwater permitting requirements and the
Categorical Standards fqr Ore Mining and Dressing. The Colorado Discharge Permit
System Requirements require collection and treatment using the Best Available
Technology (BAT) of stonn water which contacts mine wastes: Site specific BeSt
Management Practices (BMP) emphasize stonn water diversion and reclamation to
minimi7,e the initial contact of stonn water with mine wastes.
The 90% design will identify ~ different types of areas for reclamation: capped areas,
. removal areas, and gene~ areas (including roads, water treatment plant sites, and other
disturbed areas usually associated with non-point sources of conmmination). Completion
of the 90% design will require additional data collection for Site characterization.
2.2.1.4 Topsoil
Comment 11: .
What is the average topsoil depth in the Summi~e area and where is the topsoil
stockpiled?
Response: . .
Depending on what the surrounding area encompasses, depth of naturally occmring
organic topsoil will vary ftom none to several feet. Topsoil stockpiles are located
throughout the permitted area. Some of the stockpiles have been moved to accomodate
the "Cropsy Removal Action - Phase Un.. .
. Comment i2: .
Will an average depth of one foot of soiVamendments be enough to slow infiItration of
water into the mine wastes?
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Re$pOnse:
It is not economically feasible to construct an "enhanced" cap over all reclaimed areas
that may have acid generating capability. In addition, it does not appear to be necessarY.
The primaxy barrier in preventing or slowing the infiltration of water through an
engineered cap is the vegetated topsoil. The vegetated topsoil. layer acts as the upper
barrier to infiltrating water and protects the deeper layers £lom the effects of wind and
water erosion. A one foot layer of local topsoil, augmented with proper amendments,
will be sufficient ~ promote the growth of selected plant species. Many areas on the Site
are sustJllning plant growth with less than 4 inches of organic rich topsoil.
Comment 13:
Are the 421, 000 cubic yards of topsoil tt clean" or will it be another source of
contamination? Will moving the topsoil create another area that will need to be reclaimed?
Re$,pOnse:
The estimated 421,000 cubic yards of topsoil are consid~ "clean" when compared to
the original background conditions which existed prior to recent minine activities. The
footprint beneath the topsoil stockpile will require reclamation when the stockpile is
moved to its designated reclamation site. .
Comment 14:
Will the on-site clay stockpile that is considered to be a source of acid mine drainage be
used in reclamation? . ..
Re$,pOnse: . .
The on-site clay stockPile was originally meant to be placed on the HLP and. leached for
its gold. Due to its high clay content, SCMCI was unable to. provide the special handling
needed to prepare the ore for leaching. This stockpile contains sulfides and is considered
a source of AMD. The clay ore stockpile is not being corisidered as growth medium. .
material. Any prospective use of tJ:1is material will be limited to its use as a subsurface
hydraulic barrier. . . .
2.2.1.5 Recordiguranon
Comment 15:
Given the enormous amount of precipitation that falls on Summitville, will slopes of 33
percent allow massive erosion to occur?
R~nse:
The.Site receives an average of 55 inches of precipitation an'1uaJ1y, approximately 24
inches of which is lost through evaporation. Most of the precipitation is in the form of
snowfall, which gradually enters the soil and does not rapidly flow across the. slope
~aces. . .
Several co~ted areas exist on the property that have slopes of 33 pCrcent. These
58
. -- ......
'-;,o.~
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. .--..-- - ._. ..-.
-_..~- -. .... .--.-
slopes have not been subjected to excessive erosion even though they lack vegetation.
There are many natural slopes greater than 33 percent that are not eroding, with the
assistance of natural plant growth. It appears that constructed slopes not in.excess of33
percent will be acceptable if used in conjunction with diversion structures and berms, and
if the surface water is routed to sediment control structures. Section 3.4.3 of the
Reclamation FFS under Land Reconfiguration addresses general questions oil slope
stability and erosion control. All areas will be evaluated individually dUring planning for
the 90% design phase.. .
Comment 16: .
The Reclamation FFS says that the Summitville Dam Imp'oundment may have a final slope
of over 33 percent (up to 40 percent).. Will a slope this steep hold?
Res.ponse: .
The USBR has written the specifications concerning excavation of the Summitville Dam
Impoundment (SDI) and reinforcement of the dam. The upstream side of the dam is
assumed to be 2 horizontal to 1 vertical (50 percent) and will remain as such.
Downstream the slope is 2.5 horizontal to 1 vertical (40 percent) and is to be reinforced at
this grade with relatively coarse aggregate. As shown in the "Cropsy Removal Action -
Phase IT" drawmg 1556-4-032-17, the downstream slope of the dam will be covered with
CWP material to a depth of approximately 15 feet. This material will consist of a
reasonably well graded material of clay, slit, sand, gravel and c
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2.2.1. 7 Cost Issues
Comment 18:
The cost estimates are of questionable value.
.-
..
Re~onse: .
Costs presented in the Reclamation FFS are based on vendors quotes, telephone
conversations with others involved in reclamation, literature sources, estimated
transportation costs, etc. Although the costs are estimates, based on best available.
knowledge, there will be possible errors. "Because daJa available at the site response
. assessment stage are very general any costs derived for this plan will be of an order-of-
magnitude or lesser level of accurt1CJl. This accuracy has been defined as afinal .
construction cost which will fall within the range of +50% to -30% of the cost estimated
at the site response stage" (EP A, 1987). The Reclamation FFS costs are derived for the
sole purpose of comparing the alternatives. Additional information will be obtained on
soil composition, greenhouse studies, field trials, seed species adaptability, and other
concerns that will help finalize the reclamation I'rocedures and corresponding costs.
Under requirements of the Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA), remedial aCtion costing is divided into three phases: an initial
Site response assessment plan phase; an alternative development and cost screening
phase; and a detailed cost estimation phase for feasibility studies. . This remedial action
cost estimation process begins with the initial Site response assessment Because data
available at the Site response assessment stage are very general, any costs derived for this
plan will be of an order-of-magnitude or lesser level of accuracy. . This accuracy has been
defined. as a final construction, cost which will fall within the range of +50% to -30% of
the cost estimated at the Site response assessment stage.
CODUDent19: .
Ten year period to complete reclamation is a minimum time period for revegetation. Cost
projections should reflect a more realistic 15 to 20 year time period. .
R~nse: .
The ten year time frame was used only for the cost comparisons of the various .
alternatives. It is not expected, during :the next ten years, that the reclaimed site will
assume the vegetative or growth status that existed prior to initial mining in 1870 or even
recent mining that started in the early 1980's. With an elevation of over 11,000 feet, a
high acid generating capability, and a shortage of growth medium, SummitviIle is a
chal1en~ mined land reclamation site. .
2.2.2 Conwrehen..'iive R~onse to Specific LeiaJ and Technical Ouestions
This section summarizes and responds to the specific legal and technical concerns raised during
. the public. comment period.
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'.--''''...-. -_.__._.-_.~. --_. ,.-
2.2.2.1 Applicable or Relevant and Appropriate Requireme'!ts (ARARS)
Comm'ent 10:
The EP A has failed to consider the authorities administered by the Colorado Mined Land
Reclamation Board (MLRB or the Board) and the rules and regulations of the Division of .
Minerals and Geology (DMG). The reclamation guidelines for hard rock mining have
been established and are implemented by DMG. The regulatory program provides that a
reclamation and restoration plan process is the most appropriate mechanism to govern a
mining site. .
Res.ponse: .
The DMG serves as an integral member of the SIT that developed these documents and
fully agrees with the proposed plans. All of the regulatory authorities vested in DMG are
. addressed in the ARARS process. The technology used for reclamation at the
Summitville Site will be standard mining reclamation practices. High altitude
reclamation experts will be an integral part of the remedial design team.
Comment 21: .
The reclamation plan developed by EP A has not addressed compliance with MLRB
criteria.
Res.ponse:
~e MLRB criteria and the Mineral Rules and Regulations are' considered in the ARARS
section of the Reclamation FFS (Section 3.2.2.3). The Summitville mine is now a
Superfund site and MLRB is no longer the sole regulatory authority.
Comment 22: . . .
. Evidentally EP A has decided to waive ~ for the site-wide reclamation plan and has
determined that EP A's implemented plan will not exacerbate Site problemS. .
Re51'0nse:. .
EP A has not decided to waive any ARARS at this 'point, the ARARS eValuation will not
be fin::iH7.ed until the'Site-wide ROD is issued. It is anticipated that ARARS will be
identified ip. the near future, as the remediation process proceeds. .
Comment 23:
Because of the lack of existing baseline data, the FFS recommendation to adopt "Class 1
Cold Water Aquatic Life classification" is prematUre. .
Res.ponse:
The "Class 1 Cold Water Aquatic Life" classification is an ARAR Superfund does not
develop standards; that is the responsibility of the particular State or Federal authority,
. which in this case is the CDPHE and the Water Quality Control Commission (wQCC).
. EPA, however, must meet all substantive regulations or requirements that govern media
affected by its Superfund clean-up.
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Comment 24: .
The Board (MLRB) already determined that the mine waste wouJd be stabilized and
, reclaimed in place to allow the mine pit to remain open for future mining activities.
Because EP A has backfilled the pit, future land use mining options have been precluded.
Re~nse;
SCMCl submitted the Remedial Measures PIan (RMP) on November 30, 1992 and
declared bankruptcy on December 2, 1992. Therefore, the DMG never completed an
evaluation of the RMP's implications derived ftom the previously approved and amended
mine plan. As stated in response to a previous comment, since Summitville is now a
Superfund site, MLRB is no longer the sole regulatory authoritY; therefore, all
environmental regulations along with consideration of human health and/or the
environment will be factored into the ARAR process.
The Superfund.process does not preclude future mining. The action ofbackfiIling the
pits was taken to stabilize the Site by minimi7ing the generation of AMD, reducing the
necessity for water treatment while protecting h~ health and the environment.
. Comment 25: .
The adoption of water treatment standards which are'more stringent than Best Available
Technology (BAT) is not appropriate.
Re~onse= .
Since the ARARS section of the Reclamation FFS is common to all four documents, the
commenter is 'directed to the Water Treatment FFS in response to the concern regarding
the BAT limits. In addition, this Water Treatment comment will be addressed in the
Respo~veness Summ3ry section of the Water Treatment (!ROD).
2.2.2.2 Remedial Actions
Comment 26: .
With regard to SummitVille , it was agreed that the mine pit would remain open, the Heap
Leach Pad (BLP) would be stabilized and reclaimed in place, the Beaver Mud Dump
(BMD)and Summitville Dam Impoundment (SDI) wouJd remain in place, and the North
Pit Waste Dump (NPWD) wouJd be stabilized and reclaimed in place and that the
discharge from th~ Reynolds Adit would be treated.
R~onse=
In the 1984 permit application and its 1989 amendment, the retention of the mine pit, the
in-place'stabilization and reclamation of the HLP, the retention of the BMD and SDl, and
the in-place stabilization and retention of the NPWD were approved. When it became
obvious in. 1991 that the approved reclamation pIan was inadequate to accomplish the
' required performance standards, SCMCl was required to enter two settlement agreements
. which stipulated the collection of ~ the preparation of a remedial measures plan, and
the submittal of a permit amendment. The question of treatment of the Reynolds Adit
62'
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.-...'.. . ....-.. ~.. ._- "---.. -..
.- -.-.- .~ -_. -. . -
effluent had not been resolved. Partial treatment was required by the second settlement
agreement. All of the original reclamation plan design components would have been
appropriate topics for amendment if deemed appropriate following evaluation of the
Remedial Measures Plan (RMP). As previously stated, SCMCI submitted the RMP on
November 30th, 1992 and declared bankruptcy on December 2nd, 1992. Therefore, the
DMG never completed an evaluation of the RMP's implications derived from the
previously approved and amended mine plan.
Comment 27:
The decision to bacldill the pit without considering the impacts high sulfide waste rock may
have oil acid mine drainage is technically unsound.
R~onse:
The decision to backfill the pit has a soundtechnica1 basis and has been performed
specifically to reduce the amount of AMD flowing off the Site. This action, as explained
in the Conceptual Site-Wide Remediation Plan (Morrison-Knudsen, 1994), includes the
remedial technologies of Removal, Disposal, Treatment, and Containment in the form of
excavation, on-$ite disposal, pH adjustment, and capping. The waste is excavated, hauled
to the mine pits, amended with ~1k~Jine material, and provided with a low permeability
cap to reduce infiltration. ,The adjustment of the pH and the provision of a low'
permeability cap addresses the impacts that high sulfide waste rock may have on AMD '
. generation. This action uses conventional construction effective in reducing
infiltration and, consequently, AMD. "
Comment 28:
EPA's decision to take the'observational approach (Reclamation FFS, page 1) regarding ,
costs and potential environmental impacts associated with bacldiIling the pit is not justified
or supported. "
ReS1)onse: .
The Statement in question is as follows: 'Therefore, the results of the remedial actions
will be routinely monitored, as part 01 an observational approach, to determine what
additional action will be needed at each portion of the Site to achieve the final, site-wide
remediation goal (s)." EP A is not taking an observational approach regarding costs and
potential environmental impacts.
Comment 29:
The CWP, HLP, BMD, and CCI'P waste rock could have been dewatered, stabilized, and
reclaimed in place without inducing significant discharges to the surface or ground water
flow regimes.
R~onse: .
EPA disagrees that the CWP, BMD, and SDI could be reclaimed in place. All were in
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'high w3.ter contact areas (naturally occurring seeps and springs) and, therefore, subject to
production of AMD. Removal of these wastes to. the mine pits places them in an area
where they can be treated (pH adjustment) and protected from the other ingredients
necessary for AMD production (water and oxygen) by capping and revegetation. The
HLP will be remediated in-situ.
Comment 30:
Reclamation ,activities related to the North Pit Waste Dump area have not been
recommended or addressed. ,The commenter is assuming that all waste rock material will
remain in place, stabilized ifneeessary, and revegetated as practicable.
Re~onse:
The reclamation of the North Pit Waste Dump (NPWD) area is addressed in Section 3.0
of the Reclamation FFS. While the remediation of the NPWD area is not specifically
mentioned in any of the' four FFS documents, it is incorporated into the Conceptual Site-
Wide Remediation Plan. As additional Site data becomes available, the NPWD area may
be reevaluated in the Site-wide RI/FS.
Comment 31: . ,
The outlined Removal Action Objectives for the Cropsy Waste Pile (cwP) are not sound. ,
The decisions to remove th~ cwP and the SDI/BMD waste materials to the pits may be '
totally devoid of technical justification without adequate undentanding of this action's
potential impacts. Also, there is no documentation that EPA's alternatives for the
remedial action to backfill the pits will meet the Remedial Action Objectives.
R~nse: , '
EP A has provided analysis of this action in the CWPFFS. , The commenter is directed to
this document in response to their geotechnical concerns. Specifically, the data is
presented in the Detailed Analysis C?f Alternatives. In addition, this CWP and SDI/BMD
remedial action comment will be addressed in the ReSponsiveness Summary section of
the Cropsy Waste Pile, SummitviDe Dam Impoundment, Beaver Mud Dump, and Mine
Pits !ROD. '
2.2.2.3 Water Quality
Comment 32: , ,
The FFS discusses other sources of water quality contamination identified on-site, but fails
to provide a detailed analysis of the chemical mass balances associated with water quality ,
in and adjacent to the property. ' ,
Re~onse:
The first chapter of the Reclamation FFS is common to all four documents. For
additional water quality discussion concerning chemical mass balances the eommenter is
64
_.~-'. ".
- ....~...-. . .
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. ---..--.
~ ----.
referred to the Water Treatment FFS. In addition, this Water Treatment comment will be
,addressed in the Responsiveness Summary section of the Water Treatment Interim
Record of Decision (IROD). ,
Comment 33: , '
Site specific surface water now data and an understanding of the hydrological balance
requires monitoring data to adequately benchmark site conditions. This information
should have been collected and analyzed by EP A before an Interim Remedial Plan that
purports to initiate a site-wide reclamation plan was adopted.
ReS1)Onse: " .
The reference section in the back of section 5.0 of the Reclamation FFS listS it number of
reports rev.iewed for Site inforination, including Galactic's 1984 reclamation permit
" application. An'investigation of the Site watershed to identify source areas that are major
contributors of cont:tminant loading to Wightman Fork was completed in 1993; EP A '
considers ~ the Site water data available is adequate for the development of a '
conceptual 30% design plan, such as an FFS. All available water flow and discharge data, ,
have been studied. More specific water data will be collected for the Reynold's Work
Plan and during the 90% design phase.
Comment 34: , .
Comments pertaining to ground water and ground water quality parallel the comments '
presented in the surface water section. Adequate baseline information does not exist to
determine if point and non-point sources are in compliance with water quality standards,
. nor does adequate data exist.to support the adoption of surface water quality s~dards for
ground water resources.
Response:
To reiterate the EP A position concerning S1.1l'faCe water data, EP A considers that the water .
data available is adequate for the development of a co~ceptua130% design plan, such ~ '
an FFS. All available water flow and discharge data has been studied." .
The EPA and its Summitville Technical Team, including the DMG and CDPHE, concur
with the content of Section 3.2.2.2 of the FFS. 'The shDllow, contaminated ground water
located beneath the Summitville Mine is of limited areal extent, is not currently being put
to beneficial use, and is unIila!ly to be beneficially used in the future. Because of the
potentiaI impact of the contaminated ground water on surface water quality, it is relevant
and appropriate to classify the contaminated Minesite ground water for surface water
protection. As a result, all ground water afftcting activities must achieve the surface
water quality ARARS." There are no Site specific ground water standards promulgated at
the Site for metals. Therefore, the Interim Action Levels (ILLS) as established for WF5.5
, apply to all surface water leaving the Site, including flow ftom gr9und water sources.
The fiLS will be approved when the !RODs are signed by CDPHE.
Again, EP A does not develop standards; that is the responsibility of the partiCular State or
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Federal authority in charge of that sector.
222.4 Reclamation Technologies
Comment 35:. .
Institutional controls such as fences and signs may be appropriate. However, limiting the
rights to remine or reprocess ore and existing waste ro~ should not unreasonably be
withheld. .
R~onse:
Future minine, if it occurs, must not interfere with the protection of human health and the
environment at and SUlTOunding the Site. As stated in Section 3.32 of the' FFS~
"institutional controls are non-engineering methods in the form of legal or physical
means thai are intended to protect human health and the emironment by limiting
potential exposures to a site or specific media of concern". EP A has determined,
however, that institutional controls are not sufficient to reduce or eliminate the risks to
human health and the environment found at the Site. The EP A Superfund process does
n'?t preclude future mining. .
Comment 36:
On-site containment is a preferred remedial action option where existing waste rock or
spent ore is stabilized in place. Whether or not the waste has been characterized as a
hazardous waste, RCRA performance standards should not be applied to the proposed
solutions. .
Re~nse: .
As explained in Section 3.4 and 3.4.2, on-site containment is a reclamati
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.---.--.,. -.
- ~ '-' -...u_--. ..-.-
-... .---.--.-.--. -.--..' '"
suggest an implementation schedule. The'Site Reclamation FFS lacks detail regarding the
plans for land reconfiguration, slope stabilization, erosion control, on-site topsoil
characteristics and its amendment needs, site preparation, plant material selection, plant
introduction, and revegetation management. '
Res.ponse: ,
The Reclamation FFS is a conceptual 30% design plan, used as a basis for development
and refinement toward a 90% design document Individual sites will be evaluated to
determine what soil amendments will be used and what vegetation species may be ,
successful. Comments regarding specific design concerns will be addressed during the
research and development of the 90% design document Data concerning this will be
developed by'the CDPHE, EP A, and others with expertise in high altitude revegetation.,
2.2.2.6 Cost Issues
Comment 38:
The reclamation costs ofS21, 300/acre (Alternative 4) proposed for the Site, are not
justified or documented, and are excessive.
Res,ponse: '
The evaluation of the costs ofeach alternative is located in Table 10 of the Reclamation
FFS. Costs presented in the Reclamation FFS are based on vendors quotes, telephone
conversations with others involved in reclamation, literature sources, estimated
transportation costs~ etc. According to the EP A Remedial Action Costing Procedmes
Manual, nBecause data available at the site response aSsessment stage are very general
any costs derived for this plan will be of an order-of-magnitude or lesser level of
accuracy~ This accuracy has been defined as a final construction cost which will fall'
within the range of +500'" to -30% of the cost estimated at the site'response stagen.
Under ~ents of the Comprehensive Environmental ResponSe, Compensation, and
Liability Act (CERCLA), remedial action costing,is divided into three phases: an initial
Site response ass~ssment plan phase; 'an alternative development and cost screening
phase; and,a detailed 'cost estimation phase for feasibility studies. This remedial aCtion
cost estimation process begins with the initial Site reSponse assessment. Because data
available at the Site response assessment stage are very genera4 any costs derived for this
plan will be of an order-of-magnitude or lesser level of accuracy. This accuracy has been
defined as a final construction cost which will fall within the range of -i:"50% to -30% of
the'cost estimated at the Site response assessment stage. . '
Although the costs are est1m!'lti'!s based on best available knowledge, there will be
possible errors. Costs are derived for the sole purpose of comparing the alternatives that
are presented in the Reclamation FFS and wi~ be further scrutini7ed during the 90%
design phase.' '.,
67
. . -. ." .~..
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2.3
Response to General Comments
Introduction On August 16, 1994, the United States Environmental Protection Agency, Region
vm (EP A), issued four Focused Feasibility Studies (FFS) relating to proposed remedial action
work at the Summitville Mining Site. These four FFSs relate to: (1) Cropsy Waste Pile,
Summitville Dam Impoundment, Beaver Mud Dump and Mine Pits; (2) Heap Leach Pad; (3)
Water Treatment; and, (4) Site Reclamation. EP A requested public comment on the foUr FFSs
and extended the dp~rl1ine for comment to October 24, 1994. .
Comment 1:
A number of commenten complained that some of the alternatives evaluated by EP A in
~ese FFSs are already being implemented without EP A having followed the remedy
selection and public participation procedures of the NCP.
In particular, various commenten objected to the continued placement of the Cropsy .
Waste Pile into the Mine Pits punuant to an emergency-like schedule, despite public
comment on EPA's previously issned Engineering Evaluation/Cost Analysis (EElCA). This
prior public comment.stated such action was inappropriate because EP A did not consider
the feasibility of capping the Cropsy Waste Pile in its original location and EP A failed to
consider potential short and long term impacts on acid mine drainage. Commenten .
believe remov8I of the Cropsy Waste Pile and its placement in the Mine Pits will exacerbate
site conditions. . .
In spite of these public comments, EP A awarded a contract in July 1994 to complete the
excavation and relocation of the Cropsy Waste Pile (CWP), Beaver Mud Dump (BMD) and .
S~e Dam Impoundment (SDI) int~ the Mine Pits according to the EEICA aDd
Action Memorandum. Commenten now object to EP A selecting the placement of the
Cropsy Waste Pile, BMD and SDI into the Mine Pits as a remedial action alternative.
. Commenten have suggested that by selecting the EEICA response action as the interim
remedial action;EPA has "pre-selected" the remedial action for the Cropsy Waste Pile and
has circumvented the public participation procedures mandated by the Comprehensive
Environmental Response; Compensation and Liability Act of 1980, as amended (CERCLA)
and the NatioDal Contingency Plan (NCP).
Commenten note that both CERCLA and the NCP establish specific steps and procedures
that EP A must fonow in selection a remedy for aU or a portion of a CERCLA Site. ~
. reneralty..42 U.S.C. 9604, 9621; 40 C.F.R. 300.430 and claim that EPA has not fonowed
the NCP procedures. ne commenter states that EP A-justifies the implementation of the
aIiegedly "pre-selected" remedy by arguing that the public participati~n undertaken
during the EEICA process last summer satisfies the public's right to participate in the
remedial selection process for the Target Areas. .
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ReS1'0nse:
Excavation and consolidation activities associated with .Cropsy Waste Pile, Beaver Mud
Dump, Summitville Dam Impoundment (formerly called the Cleveland Cliffs Tailings .
Pond), and Mine Pit were initiated under an EP A non-time critical removal action
pursuant to Section 300.415 of the National Contingency Plan. Such removal activities
are appropriate when, among other things, "excavation, consolidation, or removal of
highly cont~minated soils from drainage or other areas, .. will reduce the spread ot: or
direct contact with, the contamination." (See Section 300.415(d)(6) of the NCP at 55
Fed Reg. 8843 (March 8, 1990).) Once EP A determines such removal actions are
. appropriate, response actions shall begin as soon as possible to abate, prevent, minimi7e,
or eHmin~te the threat posed by the contamination to public health, welfare of the
environment. (See Section 300.415(b)(3) of the NCP at 55 Fed. Reg. 8843 ~h 8,
1990).) .
According to the NCP, if a six-month planning period exists before EP A initiates a
removal action, EP A must conduct an Engineering Evaluation/Cost Analysis (EElCA).
This analysis, although not as extensive as a Remedial Investigation/ Feasibility Study,
identifies the objectives of the removal action and analyzes the various alternatives that
may be used 10 meet these objectives, based on the alternative's cost, implementability
.and effectiveness. The EEICA is then released for public comment, according to the
public participation procedures established in Section 300.415(m)(4). Finally, after a
minimum 30-day public comment period, EP A issues an Action Memorandum which
docunients EP A's selection of an appropriate non-time critical removal response action.
See also. "Guidance on Conducting Non-Time Critical Removal Actions Under
CERCLA," EPA/540-R-93-057, Publication 9360.0-32 (August 1993). .
EP A meticulously followed the NCP-prescribed procedure in proposing .and selecting the
EEICA-based non-time critical removal for the Cropsy Waste Pile, Beaver Mud Dump,
Summitville Dam Impoundment (formerly called the Cleveland ciifrs Tailings Pond),
and Mine Pit (collectively, the Target Area). EPA published its EEICA in July of 1993,
solicited and accepted public comments on the EEICA until early September of 1993,
responded to those comments in its "Responsiveness Summary to the Engineering
Evaluation/Cost Analysis for the Cropsy Waste Pile, Beaver Mud Dump, the Cleveland
Cliffs Tailings Pond (now called the Summitville Dam Impoundment), and Mine Pits,
Summitville Minesite, Rio Grande County,. Colorado," and issued its Action.
Memorandum on September 24,. 1993. EP A let a contract to begin implementation of
this part of the EElCA-based..removal action inJuly 1994.
EP A is not arguing that providing the publi~ the opportunity to comment on the EEICA is
sufficient to substitute for soliciting public comment on the Target Area FFS and
Proposed Plan. EP A agrees that the NCP does not allow EP A to satisfy its public. .
. participation obligations for a proposed plan by reference to another document. EP A also . -
agrees that the analysis EP A conducts to evaluate removal alternatives differs greatly .
from the analysis conducted to evaluate remedial alternatives. For non-time critical
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removals, EP A evaluates the alternatives in terms of effectiveness, implementability and
cost alone. The evaluation of remedial alternative is conducted using the nine criteria of
Section 300.430 of the NCP. The two sets of evaluation criteria are n~t synonymous.
EP A, however, did fully comply with the NCP-prescribed procedures for screening,
proposing and selecting remedial alternatives for the Target Areas in its Focused
Feasibility Study, Proposed Plan and Interim Record of Decision (IROD). The removal
altemativepreviously selected in the Action Memorandum was. one of the alternatives
evaluated during EP A's remedy selection process. EP A took public comment on the
relative merits of all alternatives evaluated in the FFS vis-a-vis the nine NCP criteria and
proposed its preferred alternative in a Proposed Plan, issued in accordance with Section
117 of CERCLA. The alternative previously selected in the Action Memorandum, as
expanded in the FFS and Proposed Plan, met the threshold remedy selection criteria of
the NCP and provided the best balance of the NCP's "balancing" and "modifying"
criteria. It was selected as the appropriate remedial action in the Interim ROD for the
CWP. In accordance of the remedy selection criteria of Section 300.430(e) and (f) of the
NCP.
EPA therefore selected both the EElCA-based removal action and interim remedial action
according to the different, applicable standards and procedures of the NCP. The fact that
the two response actions are similar does not make tJte implementation of the previously.
selected removal action illegal or invalid. Moreover, with the letting of the July 1994
contract, EP A was merely initiating the implementation of its validly selected removal
action. EP A's publication of the Target Areas FFS and Proposed Plan has no.bearing on
and should not interfere with EP A going forward with this removal action. .
Comment 2: .
One commenter strongly recommends that EPA delay removal of the Cropsy Waste Pile
until all the potential ramifications have. been properly evaluated by the public and by
. competent technical consultants. Such an evaluation shoidd be conducted after EPA's
"Use Attainability Study," which will characterize and evaluate downstream effects from .
the Site, is completed. The commenter believes there is no reason to implement this remedy
on aD expedited schedule. .
R~nse: .
The Use Attainability Study is being completed by the State of Colorado, Division of
Minerals and Geology. The findingc:: of this study will be incorporated into EPA's final
response action for the Site. In the meantiine, EP A believes the environmental benefits
that will be gained from the implementation of interim remedial actions at the Site far
outweigh the continued releases of niine waste for the Cropsy Pile. .
Comment 3: .. . . .
Commenten requested an explanation of EP A's rationale for issuing interim rather than
final RODs. These commenten feel EP A has no legal or technical basis for issuing IRODs
and th~t there will be additional costs associated with lint implementing an interim
. .
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remedy prior to making a fmal remedy selection. They also expressed the belief that some.
of the interim remedial actions may actually exacerbate site conditions and contamination
or may prove ultimately incompatible with final remedial action(s) for the Site.
R~onse:.- .
According to EP A guidance, interim remedial actions are appropriate to "take quick.
action to protect human health and the environment from an imminent threat in the short
term, while a final remedial solution is being developed." See. "Guide to Developing
Superfund No Action, Interim Action and Contingency Remedy RODs," US EPA, .
OSWER Publication 93SS.3-02FS-3 (April 1991), atp. S. . .
Deterioration of site conditions will lead to continued and heightened exposure of .
sensitive human and ecological populations to heavy metals and chemicals (~ cyanide)
used by Galactic and others in their mining operations. The !RODs institute temporary
measures to stabilize the Site and prevent finther migration of contaminants of concern
from the Site into smrounding soil, air and water media. Further, the types of interiJ;n
actions selected in the IRODs, such as the relocation of contamination from one portion
of the Site (CWP) to another (Mine Pits) and the installation of caps to prevent further
migration of contaminants are exactly the types of response EP A guidance states are
appropriate to implement as interim remedial actions. ~ "Interim Final Guidance on .
Preparing Superfund Decision Documents," OSWER Directive 93SS.3..Q2 (June 1989), at
Chapter 9.
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Given the existing Sit~ conditions, EP A is certain that filling the Mine Pits will
significantly reduce the flow into the Pits and prevent discmqes of acid from the Mine
Pits into underground workings and ground water. Relocating other mine waste features
such as the Cropsy Waste Pile, Beaver Mud Dump and Summitville Dam Impoundment.
to the Mine Pit will also mitigate these areas as sourCes of acid mine drainage. Capping
the Mine 'Pits will serve to eliminate or significantly reduce the movement of .
contaminants of concern through water and air pathways. Treatment of smface water and
detoxifying the Heap Leach Pad will eHminate rel~ of metals ~d cyanide. Overall,
the implementation of interim response actions will quickly reduce the imininent threats
to human and environment receptors at and around the Summitville Minesite. EP A will
also continue to monitor the progress of these remedies in eliminatine or reducing the
release of hazardous substances from the Site and will determine what, if any, final
remedial actions are necessary to address the remaining risks at the Site.
Comment 4:
Many commenters sought clarification which applicable'or relevant and appropriate'
requirements (ARARS) of federal and state statutes and regulations must be complied with
for remedial actions at the Site. Commenters wanted an identification of which ARARS
will be met with by the interim actions and which ARARS will be waived. One commenter
cautions against the use of "Technical Practicability Waivers" as shortcuts in the
remediation.
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Res.ponse: .
The ARARS clarification is provided in the specific Responsiveness Summary on
ARARS. Each IROD also identifies the relevant portions of federal and state
.requirements are being complied with or waived in the implementation of the interim . .
remedial actions; Commenter should be assured that all ARARS waived with the .
selection of interim remedial act:ion will be re-evaluated for the final remedial action(s)
for the Site.
Comment 5:
One commenter noted that each of the FFSs states an "observational site approach" will be
taken as part ofEPA's interim remedial actions. This commenter believes that aD
. observational approach may be an effective approach to site remediation, provided that all
the possible outcomes of the proposed .action are identified, evaluated and momtored. The
commenter suggested that for potential outcomes that may have adverse consequences, the
impacts associated with those outcomes and the probability of their occurrence must .be
qualitatively defined. H adverse consequences are likely, or that site conditions could be
make more complicated and problematic, then implementation of the proposed remedy
must be reconsidered. Finally, the commenter declared implementation of a remedial
action without an overall plan for each dealing with range of the potential outcomes is
inconsistent with a responsible observational approach at a complex site like the
Summitville Minesite. .
Res.ponse:
As discussed in the "Analysis of Alternatives" section in each of the IRODs, EP A has
considered all the relative merits and detriments of the potential remedial actions
evaluated. "Potential adverse consequences" of.implementing the alternatives was .
evaluated, as was EP A's ability to deal with these potential adverse impacts. when EP A
reviewed the overall protection to human health and the environment, long-terin
effectiveness and permanence, short-term effectiveness, implementability criteria of the
NC~. The interim response actions selected in the IRODs represeIJt the alternatives that
provide the best balance of meeting these criteria. EPA will employ the. "observational
approach" to continue to evaluate these. interim remedial actions' effectiveness in meeting
these NCP criteria, EP A's remedial action objectives and performance standards and to
determine what, if any, additional final remedial actions are necessary to ensure that
human health and the environment are protected against unacceptable risks posed by
hazardous substances remaining at the Site. .
Comment 6: .
A number of commenters are concerned about EP A's estimate of costs to be expended at
the Summitville Site are too low. Commenters have calculated those costs (both removal
and remedial) as exceeding EP A's $120 million estimate. They are concerned thafthe
staggering amounts for intenm respons~ do not include the cost of the final remedy or .
. remedial investigation/feasibility studies presently being conducted at the Site.
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ReSi'0nse:
The commenters are correct in their observation that EP A's initial ~o~ estimate has been
exceeded with the collective costs of the interim remedial actions selected in the IRODs.
The alternatives selected in the IRODs were screened for cost, and EP A believes that they'
are cost-effective. As studies at the Site provide additional information and as remedial
actions are implemented, costs for remediation of the Site will continue to be reassessed.
Comment 7:
Commenters object to the backfilling of the Mine Pits and the plugging of the Reynolds
Adit, since in their view, these actions preclude a future beneficial use, that ofre-mining.
. The commenters believe that EP A's remediation activities should be immediately
terminated or suspended until the impact to future mining uses can be thoroughly
evaluated. .
Re~nse:
None of the proposed or completed EP A activities preclude further mining activities at
the Site. However, any future mining activities must be consistent with and not interfere
with the response actions EP A has implemented at the Site. EP A's remedial actions are
intended to prevent the exposure of humans and ecological populations to hazardous
substances. Any future mining activities that do not exposure these populations to .
hazardous substances may be acceptable to EP A. It is anticipated, however, that EP A
will have to review any future mining plans to ensure the protection of human hea1~ and
the environment.
Comment ~: . '.
Commenters object to EP A's lack of a comprehensive Record of DeciSion for the Site and
the implementation of' parallel or isolated and disjointed actions at the Site Without any
overall plan or remedial strategy for the Site.. To remedy this lack of coordination, the
commenters suggest that an bidependent board of technical experts review and select Site
response actions.
ReSi'0nse: .
EP A believes that the interim remedial actions selected in the IRODs provide a .
comprehensive, coordinated approach to addressing the risks at the Site. Specifically,
EP A believes that all the remedial measures to be implemented according to the IRODs
will go a long way in improving site-wide water quality by controlling surface run-on and
run-oft erosion, leaching and metals and other contaminant loadings to the Alamosa .
River.
Empowering an independent board of technical experts to review and select remedial
actions at the Site is improper under the Superfund law. Congress explicitly ~harged..
. EP A with the authority to select response actions to cleanup releases of hazardous
substances 1;U1der theCERCLA Section 121 ofCERCLA. In fact, this section of
CERCLA unequivocally states that "the President shall select appropriate remedial
actions determined to be necessary to be carried out under section 104 or secured under
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section 106 which are in accordance with this section, and to the extent practicable, the
national contingency plan... n [emphasis added]. The President has delegated that
authority to select response actions at Superfund sites to the A~r ofEP A. The
PrQcedures the Administrator must follow in selecting these cleanup actionS are contained
the National Contingency Plan. 1 The NCP provides that affected and interested parties,
such as States, PRPs and citizens are given the opportunity to participate in the selection
process, but it is clear that the Administrator retains the responsibility to select the .
appropriate remedy. .
Thus, while EP A welcomes input from the community and ne~ third parties
concerning the actual health risks from lead CODtam;n~ted mining wastes, EP A cannot
abrogate statutory responsibility to be the decision IDaker in selecting remedial actions for
Superfund sites. EP A can also not allow a third party to determine the appropriate scope
.ofEPA's .remediation plan, since it is our experience in identifying health and
.' enviro~ental risks and designing the remedies to address them that Congress. relied
upon when it empowered us with the authority to select and implement remedial actions
under Superfund.
Comment 9:
One commenter noted that downstream impacts are currently being ignored and avoided
despite the above stated Remedial Action Objectives. Avoidance of downstream impacts
adversely affects Terrace Reservoir, household and l,IIunicipai wells and allows agricultural
land to further degrade. .
Re$ponse: .
Due ~o the Chandler Adit drainage, all downstream targets are being addressed as quickly
as possible. All three areas mentioned above are part of major research efforts included
in the justification of remedial actions at the ,Site. Ter7:ace Reservoir is cuuent1y,
undergoing a study cOnducted by the U.S. Geological Survey. Agricultural lands have. ,
, undergone several studies, including those conducted by Colorado State University. With
regard to household water use, local water supplies have been sampled twice and are
undergoing long-teml Water sampling.
Comment 10:
The same commenter stated a site drainage plan~ which provides control for
surface/subsurface drainage, storm water and sedimentation management and nonpoint
source coll~tionl treatment, is needed. ' .
Response:
A site drainage plan has been implemented. A copy of the plan is available in the
1 See, e.g. Section 120(e)(4) ofCERCLA (where if the head of the relevant federal agency and
the Administrator ofEP A cannot reach an agreement of the remedial action to be selected, the
. . Administrator selects the remedy). '
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Comment 11:
One commenter identified a need for a waste management plan.
Res;ponse:
A number of the IRODs have elements is designed to meet waste manaeement ARARS.
The Sampling and Analysis Plans describe how investigative derived wastes are
I]'1anaeeci. Also, used oil is being recycled and, as stated in the Focused Feasibility Study,
sludge produced on-site is being recycled for metals recovery. .
Comment 12:
One commenter is concerned that EP A does not have sufficient date to establish the
Summitville Dam Impoundment (SDI) as a source of sulfide-rich tailings and metals-laden
acidic water discharged to Wightman Fork. The lack of this data calls into question the
need to remediate the SDI at all, or at least the nature and extent of such remediation. The
commenter suggestS EP A collect additional data regarding the nature and extent of
.contamination at the Beaver Mud Dump (BMD) and SDI before proceeding with
remediatjon of these areas.
Res;ponse:
Historically, the Summitville Dam Impoundment and the Beaver Mud Dump area have
been of significant concern to regulators from the State. W;iter discharges emanating
from these ~terials has been recorded as being of poor quality. Based on existing data,.
historical precedent, mid current sampling and analysis information, EP A detemrined that
the SD~ and BMD are significant contributors of man-made AMD at the Site. Data
collected by Anaconda prior to SCMCI operations states that the mill tailings disposed of
in this area are strong AMD generators. Movement of these sources and the Cropsy
Waste Pile to the Mine Pits allows capping of four AMD sources in one action.
Comment 13: .
One commente~ argues that the FFSs and Proposed Plans fails to comply with the NCP
because: (1) these documents evaluate the "No Action" alternative for the Site as a whole, .
rather than by the subject matter of each interim remedial action, (2) they fail to consider
naturally-occurrlng background concentrations of metals and acids in EPA's analysis of
alternatives, and (3) compliance with ARARS and/or ARAR waivers have not been
identified with any amount of specificity.
Re51)onse: ...
Alternative No; 1 for each of the Focused Feasibility Studies is a No-Action Altemative
related to that particular portion or media of the Site.
Naturally-occurrlng background levels of metals. and acids were taken into account when
evaluating ARARS for the interim remedial actions. For example, EP A determined it
was appropriate to waive the Segment 3b stfeam classification as an applicable
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requirement that must be met by the IRODs because of the historic contributions of
metals and acids fromnaturally-occurring sources. EPA will determine if this ARAR
should be waived in any final ROD(s) for the Site when additional b~kground and load
reduction information is collected. .
Comment 14:
Cleveland-Cliffs Iron Co. and Union Pacific Resources Company submitted information
regarding their (or their predec::essor-in-interest's) operations at the Site, their analysis of
the current state of CERCLA case law related to liability and legal arguments evaluating
their lability at the Site. These commenters also requested that EP A refer to the area
adjacent to the Beaver Mud Dump, which EPA has referred to' as the Cleveland-cJiffs
Tailings Pond, as the Su.mmitviIIe Dam Impoundment or some similar appellation.
R~onse: .
While EP A appreciates information regarding parties' prior activities at the Site,
particularly if this information supplements EPA's CERCLA 104(e) information requests
or helps EP A to characterize the wastes at the Site, EP A believes a submission that
pmports to provide comments on an FFS and Proposed is an inappropriate forum to state
one's view of its liability at the Site. Such comments are more appropriately submitted as
part of a party's response to EP A's CERCLA Section lO4( e) request, EP A's Notice Letter
or in confidential settlement correspondence between EP A 'and the submitting party. A
specific response to Cleveland-C!ifi7UPRC's legal arguments wjll be forwarded .under
separate cover.
Without any qualitative judgment on the m~ts of Cleveland-C!ifi7UPRC's legal .
arguments, EP A nonetheless agrees to hereafter refer to the area below the Beaver Mud
Dump as the Summitville Dam Impoundment. . Corresponding 'changes to this .
nomenclature will be made in all future EP A documents. .
RESPONS~SS SUMMARY: GENERAL WRI1TF.N COMMF:NT~ RECEIVED FR.OM
CITIZENS AT LARGE OF THE SAN LUIS VALLEY
These written commf!nts repreSent the universe of comments received through the end of the public
' comment period. .
Comment 15:
To whom it may concern: My name is Roger Gallegos I have lived in the San Luis VaDey juSt
about all my life. Before the Summitville Mine came to exist, life was good. After they
exploited the government and us, life became much more difficult. Take for instance, when
we would water our fields, we could catch fish in our ditches. Another thing I have noticed is
the crop yield. Before the mine came in my meadow would yield 3000 to 3200 bales of hay.
When the mine had there spills I yielded 1642 bales. My best.yearwhile the water quaJity
improved was about 2853 bales. Now tlW! may not sound important, but it is. I used to sell
. hay for a living, and now I feed it to my cows. The mine has hurt my family in the pocketbook.
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We have all been hurt by the mine in this community. The gove~ent should never have let
them start to begin with. Galactic Mining should be made responsible for the clean up. then
the Government for allowing them to do this. Since the'mining company has gotten away with
this, we should not be made to suffer for other peoples mistakes. I say Summitvilleshould be'
cleaned up and restored, and our water be put back to normal My Great Grandfather made
a living with my ranch, as did my Grandfather and Dad. I want my kids and their kids to
continue making a living on what is theirs. They have that right, and not be forced to suffer
for what someone else was allowed to do. I myself believe the plan to filter the water down
below where the creeks meet, is the best idea. That system for 8 million, could save money and
. work. Thank you for listening. The Gallegos Family. [Letter; undated; no other data given]
. Comment 16: .
Dear Ms. Williams: As a farmland owner with land irrigated from the Alamosa River I am
. deeply concerned and worried what the continued use of the contaminated water will
eventually do, not only to the land, drinking water from the weDs, but also to the livestock and
products which are ultimately consumed by the general public. . There are those who say it has
no ill effects on Crops or livestock ~ but for how long. I do know it has played havoc. with the
steel structures in the irrigation system. I'm under the Capulin Ditch and we have had to
spend over $40,000.00 replacing all steel structures. I may say that I was Water Commissioner.
for this district and know the Alamosa River quite welL In this time I never saw when so many
irrigation structures all deteriorated in such short time. As for those who say there never were
any fish in the Alamosa River - it is not true. Why else would the Game and Fish Department
consider it a fishing st;ream. People would ice fish all winter in the Terrace Resen'oir up to the
time. the mine started to dump the mess into the stream. I have lived here. all my life and can .
remember when we were little Dad would take us fishing there. ~ for the different options
to solve the problem it seems to me one that would treat all the water before it got into the
Alamosa River would be the one - probably in just one pond.. Thank you Sincerely, Leo .B. .
Gonzales (Letter; dated Oct. 19, 1994; address and phone number given]
. .
Comment 17: .
. Dear Ms. Williams & EP A Summitville Team: Although I may be writing too bite for the case
record, perhaps your comment period's been extended; in any case, the info~ation leading
me to voice my concerns reached me after the original deadline. Your recommended plans
generally seem to stress reliance on systems that won't need too much up-keep once set in
place. The biotreatment aspect soUnds favorable. However, it has come to my.attention that
"caps" or "plugs" contributed to poorer water quality late in this year's irrigation season,
since the caps rechanneled contaminated water into other dr3inage channels that weren't
semced by your water treatment facilities. This indicates two planning factors to D;le: 1. you'll
want to assess where water will eventually seep out before you start filling the mine pits with
waste materials that are likely to displace. ground water, and 2. it would make most sense to
locate your water treatment unit(s) as far downgradient as possible, even if this entails
relocation of the existing facilities. I was also surprised that the reclamation plan *mentions
no reseeding or tree transplanting details. Although it mayor may not mean anything
scientifically, I notice that the Alamosa creekbed's rocks have a much less "rusty" surface
coloration near my house than they ever did during SMC's last four years. . Thanks for your
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efforts. Sincerely, Paul Sinder .[Letter; dated 9/27/94; address given]
Comment 18: . '. .
. T,o Laura WilJiams: I am writing to voice my concern on the clean-up efforts being taken. at
the Summitville. Minesite. Mainly, I would like to state that I fully support the alternatives
researched and proposed to you by the T .A.G. committee. I hope the E.P .A. system is flexible
and the T .A.G. proposals not only be reviewed, but also implemented. I thought the public
meeting on October 12th, was very informative and positive. . It led me to believe that, although
you have plans made and on paper, you are open to suggestions, criticism and change. The
T .A.G. proposal on water treatment is to my opinion a priority. It will make an immediate
difference in the water quality coming downstream and into our valley. I do hope ~ will be
realized as soon as ,possible, it seems common sense. Looking at the T .A.G. proposals, I think
they have found several solutions which promise more ~ting and better resultS (and in'some
cases a smaller price tag). A.question I have too, is whether the E.C.C has the experience to
tackle the job up there. aow many other experts and companies have been approached for
their expertise and advice? I am optimistic that you will find a way of working together with
the T .A.G. team in finding the right solutions. I appreciate the work you are doing and am
keeping my fingers crossed that all goes welL I realize it's a tough and very complicated job.
Sincerely Lisa ter K~e A rural resident surrounded by Terrace irrigated land. (Letter;
undated; no other data given] , . .
Comment 19: . .
Dear Ms. Williams: We want to support the recommendations made by the TAG for the
Summitville Minesite. We are concerned here in Conejos County about water qualitY and the
long term ,effects of the Summitville Minesite. We want the agricultural community in our
county to remain stable so our role as County Co~ioners must look toward the future and
address the long term consequences connected with this site. Please take the ,TAG'
recommendations seriously, the quality of our land and water will determine the future of our
community. Sincerely, Le Roy Velasquez, Chairman Conejos CountY. Commissioners
[Letter; da~ed October 18, 1994; typed on Conejos County Governme~t letterhead)
Comment 20:
Dear Ms. Wi1liaUlS: We, as Board of:Directors of the Valle del Sol Community Center in
Capulin, are extremely concerned about the SummitviDe Minesite and its continuation clean-
up efforts. We are very interested in the quality of our water for our homes as well as for our
farms. We support the enclosure made by the Technical Assistance Grant Committee. We
have showed our interest by making our community center available for meetings so that the
community will continue to be informed and to participate in .the process. If there is anything
else we em be doing, please let us know. We are fully aware that the results of the 5ummitviDe
Minesite on the quality of our water will determine our livelihood in Capulin. Sincerely, Valle
del 501 Community Center Board of Directors.. (Letter; dated October 18, 1994; five
signatures, spelling approximate: Rev. Randy Breunig; Delma Ramirez, James A. Quintana,
,Cindy Medina, Julia Gomez-Nuanes; typed on Valle del 501 Community,Center letterhead]
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Comment 21: .
.. Dear Ms. Williams, After reading the TAG newsletter and listening to Maya ter Kuile, 1 have
some misgivings about the E.P.A. plans for Summitville. The TAG suggestions surely seem
much more reasonable and straight forward than the EP A's approach. Their cost effectiveness.
seems much more desirable also. As a new resident to the area I urge you to look again at
what has occurred to the Alamosa River; consider all of us who drink and irrigate in this area
and rethink your approach to what you (Le. EP A) are doing at Summitville. Thank you
[Letter; dated 21 Oct 94; unreadable signature; address given]
Comment 22:
. .
Dear Ms. Williams, 1 am writing you to voice my support for the Technical Assistance Grant
Committee's response to the EP A's action plan for clean-up .of the Summitville Minesite. 1
encourage your department to work with the TAG Committee for a thorough clean-up
operation with SL V citizen input. Thank you for your consideration - Sincerely, Susan Sawyer
[Letter; undated; address given] .
Comment 23: .
Dear Ms. Laura Wi1liam!il, 1 am writing concerning the Summitville mine clean-up. .1 attended
and appreciated the meeting on Oct. 12, where the EP A presented their progress and future
for clean-up, and the TAG presented their answer and their suggestions on how to improve
the current trend. I have heard and read both sides of the issue. I, as do the residents of this
community, appreciate the work and the concern that the EPA has shown to clean up this
mess. Receiving Superfund status at such a fast rate was excellent. We are really grateful to
the organization. My concern, as most of the community's, is the form.in which .the clean-up
is being performed. Some things were done in obvious haste due to the situation and the
consequenCes are now being observed Le.: the Reynolds adit plug and the Chandler adit leak.
The best thing to do, I believe, is to sit back and really assess the situation before any more
mistakes are made. '.The TAG has gone up there, researched the situation, consulted with
experts and presented a different point of view . I listened to both sides (EP A venus TAG) and
came to the conclusion that the TAG had much better and faster results than the current
method. I was much more comfortable with the research done by the TAG group, seeing. that
it was done more in depth and with well experienced experts. The cost, being of great concern
to many, would also be les.s ifyo.u reviewed the TAG group's point of view. There are many
that say that this river has always been polluted. Most of these people do not reside close to
this river or even in the vicinity. Many live in other counties. I, as many other people.in"this
community did, fished, not only in this river but also on Terrace Reservoir, not too long ago
(1984-85). This river has not always been polluted. Maybe it's .had it's ups and downs, but
,it has never been dead. Not only do fish not exist any more but algae can't even grow any
longer. I am stating this because I have heard of people wanting the EP A to pull out, saying
that thiS river has always been polluted. These people do not know the facts and magnitude
of the damage that can occur and won't see into the future at what will happen to this valley
. if'nothing is done. 1 really hope that you really take careful consideration on all our letten,
and take the TAG group's suggestions seriously and implement their id~. Thank you for
your time and hope you will have another update meeting soon. Sincerely, Nitschka ter Kuile
. and Steven Miller Home and Land Owners, 1/4 mile from Alamosa River.~ [Letter; dated Oct
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20,1994; other data not given)
Comment 24: .
Dear Ms. Williams: I have reviewed the TAG committee's recent .newsletter and have
disc:ussed the feasibility studies that were done and submitted to the E.P.A. with a TAG
committee member. I would like to comment. First, I would like to tell you that our ~ has
been in our family .for five generations. It is irrigated with water from the Alamosa river
which flows through our farm. My husband and I worked for over forty years to purchase.
various parcels of land to make up what is now the present 435 acres. . It would be a severe
financial loss to my family and to the other farm families here to be forced to abandon our.
farms should the water quality of the Alamosa become incompatible with safe crop and
livestock production. I feel the TAG committee has done an excellent job in their feasibility
study and in the suggestions they have made. I urge the E.P.A. to consider water treatment
to become a top priority and .to ~e the TAG committee's suggestion to build a water
treatment plant at the bottom of the Minesite, rather than to continue with the current
treatment plan, which is not only more costly, but would delay the treatment of the water in
time to prevent damage to thousands of acres of farmland. Sincerely youn, Leola T. Miller
(Letter; dated October 20, 1994; address given]
£FA RESPONSE TO WRITIEN coMMENTs RECEIVED FROM
CmZENS AT LARGE OF TIIE SAN LUIS VALLEY
EP ~ will address citiZen written comments in one response. All but one of the ~itizen comments. .
expressed direct concem with water quality issues as related to water quality .conditions in the
AIamosa River resulting ftom niininf activities at the Summitville Mine. Many citizen .
comments received expressed support for the TAG coIiunittees' ~mmendations, particularly
regarding the location of the existing on-Site Water TreatJnent Plant and asso~ costs.
. EP A appreciates the fact that citizens have taken the time to attend the public meetings and
review the proposed plans and recommendations. EP A feels that citizen input is a component of
the decision malcing process and the concems raised regarding water qualitY are v81id and
deserve consideration. EP A further recognizes the time and effort expended by the TAG to
evaluate the proposed plans and develop constructive recommendations. As with citizen
involvemen~ EP A realizes that impartial technical assistance provides value in the decision
malcing process. . .
EP A is also cogJ"i7JInt of water quality issues which are central to human health, agricultural
impacts, and activities related to fi~hing, recreational or othel!vise. EP A agrees with citizen
concems especially as they relate to water quality. .
. .
It is the intent ofEPA to integrate recommendations made by the TAG into the final
consideriltion of 3ltematives. These may be esPecially pertinent to specific elements of the Site .
Reclamation options. In a letter ftom the Forest Supervisor of the San JuanlRio Grande National
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Forest dated October 17, 1994, the Forest. Service expressed agreement-in-principle with the
preferred alternative #4 for site reclamation, stating that "it certainly seems to be the most
. reasonable and cost effective in terms of restoring the area to a productive capacity".
The letter also stipulates that, pursuant to the current Master MOU (Memorandum of
Understanding) between EPA and the USDA Forest Service, the Forest Service agreed to
"provide expertise related to natural resource management and protection... ". In response to the
proposed plan for site reclamation, the Forest Service has offered exPertise, "particularly in the
area of soil/surface reclamation", based upon its "considerable experience in conducting high
elevation reclamation". EP A feels that recommendations made by the Forest Service are
valuable and will be carefully considered in fii1al selection of specific elements of the
. reclamation plan, particularly those relevant to revegetation. .
Regarding the alternatives for water treatment, EP A recognizes TAG concerns in discriminating
between Alternative 5 and Alternative 6 and TAG suggested modifiCations to Alternative 6.
EP A further recognizes similarities between the two alternatives. EP A acknowledges TAG
efforts in acquiring cost estimates from potential vendors. Relevant to costs for constructing a
new water treatment facility, EP A is cognizant 9f potential difficulties associated with acquiring
.broad-based cost estimates from potential vendors who. mayor may not be as familiar with site-
specific conditions. Site specific conditions can dramatically affect proposed costs regardless of
the experience and intentions of potential constructors.. However, EPA will take TAG
recommendations under advisement and continue to seek comment from TAG members.
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2.4
Summary and Response to ARAR Comments
Comment 1: ,
'One commenter questioned whether the surface water-chemical specific'ARARs will meet,
the Colorado Mined Land Reclamation regulations requirement to minimize ~pacts to the
existing hydrological baJance. The commenter noted that EPA's ability to design and
implement a sound environmental management strategy requires an understanding of the
amount and quality of water that may be affected by a mining operation during and
following site activities. Such an understanding of the hydrological balance requires
monitoring data to adequately benchmark site conditions. The commenter charges that
EP A has failed to collect adequate Site prior to adopting a sitewide reclamation plan. The
commenter also states water quality standards will not be achieved by EP A's reclamation
activities. The commenter offered its own Conceptual Restoration Program for addressing
the Site.
Re$,pOnse:
The Colorado Mined Land Reclamation Act and its implementing regulations have been
identified as an ARAR for the Site Reclamation IROD. These regulations speak to
"disturbance of the prevailing hydrologic balance" and require that "the quantity and
quality ... shall be minimi'T.ed". EP A does not interpret this narrative requirement as a
mandate to tmderstand every detail of Site hydrology. "EP A haS at this juncture, however,
cond~ted sitewide water quality modeling to ensure that the ~r quality standards
adopted for Segment 3b of Alamosa River and the water qwility requirements of the
Mined Land regulations and the applicable ARARs, will be met by the interim remedial
actions for the Site. Any data necessary for final design will be collected and compiled
for that pmpose.
EP A has reviewed and seriously considered the commenter's Conceptual Restoration
Program. EP A does not believe that the implementation of such a plan will comply with
, its CERCLA and statutory mandate or with the requirements of the NCP. '
Comment 2:
A number of commente~ noted that the'ground water A.RARs are also poorly defin~
causing EPA difficulty in determining whether ground water ARARs can be met by EP A
remedial activities. These commenters challenged EP A's adoption of surface water quality
standards for ground water resources, citing a lack of data. CommeDters Doted the fact
that surface water consists of snow melt and stormwater runoff, plus baseflow
contributions from ground water sources. The commeDter argued the Site has historically
exhibited high total dissolved solids (TDS) in the ground water and that EP A has not
adequately characterized other background water quality conditions. Water quality data
from surface water sources typically shows less IDS than from ground water tributary
sources. The commenter believes EP A has failed to account for this data in selecting
ground water quality standards.
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'-'-.
Response:
EP A has determined that the classification system prescribed by the Colorado Ground
Water Standards is applicable or relevant and appropriate to assignment of standards to
ground water at Superfund sites within Colorado. Since the Colorado Water Quality
Commission has yet to classify the Sitewide ground water, numeric ground water
standards are not currently applicable or relevant and appropriate to ground water quality
at the Site. The interim ground water narrative standard adopted by the Colorado Water
Quality Control Commission on July 29,1994, however, is applicable to the Site. This
standard, which became effective on August 30, 1994, requires that the ambient water
quality as of January 31, 1994, continues to be met. This ARAR will be metby
compliance with EP A's interim action levels and with all surface water quality ARARs, -
as discussed in each of the IRODs.
EP A, like the commenter, moreover, recognizes the hydrological interconection between'
the surface and ground water flows at the Site, particularly during baseflow periods. EP A
expects, therefore, that once the CWQC completes its use ~trnin~bility study and
classifies Site ground water, this classification will be applicable to the Site. This ARAR
will be attained by the final remedial action( s) for the Site.
Comment 3: '
Two commenters objected to the use ofRCRA Subtitle C performance standards and
design criteria for containment of existing waste rock, spent ore, and tailings at the Site.
Response:
While EP A agrees thai RCRA Subtitle C requirements are 'not applicable to "Bevill
exempt" wastes, i.!w those from the "extraction, beneficiation, and processUlg of ores and,
minerals," EP A has determined that RCRA Subtitle C requirements may be relevant and
. appropriate to actions at CERCLA min1ne sites if the mine waste materials are
sufficiently similar to RCRA hazardous waste, particularly if the subject wastes fail the
Toxicity Characteristics Leacbibility Procedme (TCLP) or exhibit'other characteristics of
RCRA hazardous wastes (u, low pH). See, "S~d Guide to RCRA Management
Requirements for Mineral Processing Wastes, 2nd Edition," OERR Directive 9347.3a-12
(August 1991). Further, if the disposal activity involves the use of a waste tnanagement
unit sufficiently similar to a RCRA regulated unit, and the unit is to receive wastes
sufficiently similar to RCRA hazardous wastes, the RCRA Subtitle C requirements
pertaining to that type of waste management unit would be relevant and appropriate.
(See 55 Fed. Reg. 87630).
The portions of the RCRA Subtitle C performance standards and design criteria that are
relevant and appropriate to EP A's interim remedial actions at the Summitville site are
identified in the CWP, HLP and Reclamation IRODs.
Comment 4:
Commenters question EPA's use of the most stringent stream classification - that of
Segment 3b of the AlamosaRiver - as the controlling surface water and ground water
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quality ARAR. They state EP A has adequately explained why it has selected this stream
classification as the" controlling" standard. Further, commenters argue that the numeric
criteria based on the most stringent stream classification does not account for the lower
.classifications of other stream segments or for high background levels o{ copper, zinc aDd .
other hazardous substances in the Wightman Fork and Alamosa River which are the result
of naturally occurring oxidation and transport processes acting upon highly mineralized,
onmined and unprocessed rock in the area. EP A, they opiBe, cannot remediate water
quality below naturally-occuning background levels. Lastly, commenters argue that the
State erred in designating Segment 3b of the AJamosa River as Class 1 Cold Water Aquatic
Life, and that this standard can never be attained because of background levelS of metals..
They suggest that EP A waive this flawed classification based on the technical
impracticability of achieving these water quality standards and the. State's failure to
. consistently apply them, as evidenced by the creation ofNCLs in the permit and 1991
Settlement Agreement. .
R~onse:
First, the commenters should understand that despite a Class 2 designation in Terrace
Reservoir (Segment 8), Segment 8 carries hardness-based TVS as the ambient stan~.
Because the hardness in the Alamosa River decreases with increasing distance from the
water treatment plant at the Summitville Site, the ambient water quality standards in
~errace Reservoir (Class 2) are more stringent thaI1 those assigned to Segment 3b (Class
1).
The commenters should also note that the Colorado Water Quality Control Commi~ion .
(WQCC) originally proposed to upgrade Terrace Reservoir to Cold Water Aquatic Life
Class 1 but declined because of limited data. In fact, review of Exhibit 12 to November'
. 1, 1993 hearing held by the WQCC in Alamosa, reveals the intention to coll~ needed
data. and review suitability for upgrade to a Class 1 designation. As stated in the
. HLPFFS, at this tUDe EP A believes that employing the Segment 3bstandards will
contribute to atrnining Class. 1 uses in Terrace Reservoir aDd should contribute to
atrnining the existing, more stringent, hardness-based TVS assigned to Terrace Reservoir.
As the commentor is aware, the re-evaluation of water quality' standards in Colorado
.. streams, rivers and ~oirs is an ongoing pro~ controlled by the WQCC. In its
discussion, EP A specifically recognized the inconsistencies and concluded that the
Colorado Water Quality Standards (CWQS) for Segment 3b of the Alamosa River, as the
applicable ARARs, will serve as the numeric interim remedial action goals for the Site.
At this time EP A does not have a basis for usurping the WQCC authority to determine
appropriate classification and water quality standards for the Alamosa River and its
tributaries. As additional data is gathered and the effects of the interim actions are
. quantified, it is within the WQCC's authority to address all of the issues identified in
these comments. Until that time, EP A will use the existing standards as numerical goals
. for the remediation.
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In the HLPFFS, EP A made its intention to attain surface and ground water quality .
ARARs at Segment 3b of the Alamosa River clear. The attainment of the ARAR for
Segment 3b will be monitored using a "bubble". approach at the downgradient boundary
of the Site, monitoring point 5.5 in the Wightman Fork (WF 5.5). In this way, no single.
interim remedial action alone is expected to bear the burden of ARARs attainment.
Where the action-specific ARARs associated with interim remedial actions at the
Summitville Site require identification ofan ambient-water-quality-based-end point (iJh
NPDES point source permitting), the applicable CWQSs for Segment 3b are established
using a model to back calculate compliance at WF 5.5. This modeling. resulted in EP A's.
establishment of interim action levels (IALs). .
As noted in the HLPFFS, given the active interchange typical of alluvial ground water
and surface water in high mountain valleys, EP A has determined that attaining
compliance with surface water quality ARARs and the ground water interim narrative
. standard will protect both surface and ground waters. This interchange will only compel
ground water cleanup to the extent required, in combination with other actions, to attain
ARARs at the point of compliance (WF 5.5) and thereby meet the standards established
for Segment 3b. .
The commenter should also be aware that the background concentrations of metals and
acids have been considered. At the triennial review of the Rio Grande Basin the
Colorado Water Quality Control Commission (wQCC) did recognize that background
metals concentrations in Segment 3a can be attributed to natural acid mine drainage from
Iron, Alum and Bitter Creeks. Consistent with those findings, the WQCC promulgated
. standards in Segment 3b which reflect $e elevated background concentrations and the
wider pH range documented in Segment 3a. EP A believes it has made its reliance on the
WQCC's work very apparent in the table on page 3-6 ofHLPFFS (see the values for
chronic copper and chronic iron). .
EP A did not participate in the development of the NCLs. These negotiated numbers are
not duly promulgated and they are not the result of applying site specific data to duly
promulgated NPDES requirements ~ mass balance, low flow, etc.) to establish a
discharge limit. The NCLs may indicate the appropriateness of a waiver at some time in
the future, but at the present EP A will reserve judgement on the use of and scope of
. .
WaJ.vers.
The EP A believes that, as an objective, the protection of the Alamosa River as habitat for
a diverse range of cold water aquatic life is appropriate until the combined effects of the
interim actions come into effect. Although it is impossible to precisely quantify, EPA
believes that when the combined, beneficial effects of the IRODs are realized, ARARs
will be attained in Segment 3b of the Alamosa River.
At that time, EP A will be able to better quantify the results and determine if additional
action or waiver is required. Likewise, the WQCC wiJl have another opportunity in three
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years to evaluate the results of the interim RODs and use its own use attainability
authorities and ground water site-specific classifications to a9.just standards accordingly-.
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2.5
Summary and Response to Reynolds and Chandler Adit Comments
Although ~e Reynolds and Chandler Adit system is not a part of the current focused feasibility
'studies, EP A l'e(;ognizes -the actual and potential contribution that this system may provide to
overall ~ contamination at the Site. Of the four FFSs, the Adit system is of most importance'
to the Cropsy action since it is known that precipitation - approximately 72 million gallons per
year - and ground water were funneled by the Mine Pits into the historic underground workings.
The Adits previously drained this water (now ground water) from the mine workings which are .
interspersed throughout the sulfide ore body. Contact with the sulfide ore resulted in the
transformation of the natural precipitation/ground water into AMD. This AMI> then ~ted the
Reynolds Adit and flowed into the Wightman Fork stream. ' -
As part .of ongoing emergency activities, it was determined that the continual generation of AMD
from the Reynolds.Aditcould be substantially reduced by plugging the Adit system. (See
Attachment F to Summitville Action Memorandum #2 dated January 28, 1993.) .This.would
result in the re-establishment of the historic ground water table, thereby eliminatiug oxygen from
the mine workingslAdits. Concmrent evaluation ofaltematives to address the Cropsy Waste Pile
included moving the CWP to the Mine Pits from which it was originally excavated. Overall
evaluation of the two actions (Reynolds and CWP) strongly favored the filling and capping of the
Mine Pits to prevent water infiltration through the sulfide ore body.
If the evaluation of the two actions bad been unfavorable, it is likely that the Mine Pits would
have needed to be regraded and a drainage notch constrUCted to reclaim the area. The movement
of the waste piles to the Mine Pits, therefore, has actually resulted in a cost savings overall since
the CWP ~edy meets the needs of both portions of the Site. In addition, the reduction in
volume of AMD generated by CWP and the Adits system will result in the decrease of Water
Treatment required at the Site and, therefore, costs for this third action. Evaluation of the Adit
plugs and the re-eStablishment of the groun4 water 'table is ongoing and the information'
developed will be incoIporated into RIlFS documents to support a separate Reynolds AditlSouth, .
, Mountain ground water ROD. '
The evaluation of the two actions was discussed in Attachment F of Action Memorandum #2 and
section 5.0 of the EEICA for.the Cropsy Waste Pile, et al. An interim'p~ject report on the
Reynolds and Chandler Adit plugs was released on October 12, 1994. Each of these documents
is included as part of the Summitville Adm;ni~tive Record and is available to the public.
. '.
Comment 1:, .
The discussion in all the FFSs regarding AMD concentrations! volumes attributed to
various sources should have provided a detailed analysis of the chemical mass balances
associated with water quality in and adjacent to the property [Summitville Site].
Re$ponse: . ' ..
As Tables 1-4 of the FFSs plainly demonstrate, there is not a steady release of chemicals
over time with which.to develop chemical mass balances. The bulk of the contaminants
are released during periods of high surface water flow such as spring snowmelt or large'
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storm events. As discussed in section 1.3.2.3 of the FFSs, such an attempt is further.
complicated by the varying nature of the geologic features encountered at the Site. To
attempt to develop a chemical mass balance for each chemical and geologic feature for
the various time frames does not add any greater understai1ding of the risks presented by.
the Site. . .
Comment 2: .
There is concern associated with backfilling of the Mine Pits (with CWP, SDI, and BMD
waste materials) since the data suggest that the Mine Pits and the Reynolds Adit are
hydraulically interconnected. Because of this hydrogeological connection, a greater
understanding regarding the geochemical interrelationship should have been undertaken
prior to commencing backfilling'activities. .
The combined impacts of implementing these two actions is still unaddressed, despite the
fac;t that the combined efforts could weD be the reason that another or other alternatives
would be preferred.
Re~onse:
EP A agrees that the hydraulic interconnection between the Mine Pits and the Reynolds
Adit is an area which bears special attention. If the ground water table - as a result of the
Adit plugging - were to rise above the level of the Mine Pits, then the relocated waste
piles Could be subjected to a varying saturated condition. Because of this concern, EP A
. placed a continuous three-foot (finished thickness), highly-impermeable clay liner on the
bottom and all sides of the Mine Pits. Placement and subsequent compaction by nonnaI
construction traffic of the waste piles appear to have resulted in impermeable Waste piles.
As a result, it is EPA's assessment that saturation of the relocated waste piles is unlikely
. to occur as a result of ~tration by the ground water tabl~.
. "
A :final cap over the Mine Pits is intended to divert surfRce infiltration so that saturation
. of the piles does not occur as a'result of precipitation events. The cap also serves to .
elimin~te oxygen, which is required for AMD generatjon, ftom entering the waste piles.
As a precautionary measure, a continuous five-foot layer ofIime kiln dust was placed
over the clay liner for both the North and South Mine Pits (approximately 1,800 tons of
lime kili1 dust). The lime kiln dust is intended to neutralize any AMD generated as a
result of moisture present within the waste piles as they are excavated and placed, and
AMD generated by precipitation events occmring during construction. In addition, any
surface water infiltration which may occur through the interim caps over the winters of
1993 and 1994 will also be neutralized.
Should the waste piles become saturated despite the design and construction safeguards
described above, any AMD generation within the Mine Pits would take place under
saturated conditions in a high pH environment (high pH as a result of dissolving the lime
kiln dust). As .with the ore body, this saturation would result in the elimination of oxygen
from the waste piles. This lack of oxygen would prevent the generation of AMD. While
88
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.-- -- -'.- -.-.
-.- ...-.--- .. "-"--.'.
a more detailed geochemical discussion may be useful for actual design considerations, it
can generally be ~derstood that the sulfide ore body below the Mine Pits presents the
highest AMD generating potential for the entire Site. If saturated conditions can
rninimi'7.e the AMD reaction for the sulfide ore body, then the same conditions will also
I]1inimi7e AMD reaction within the lesser sulfide-containing wa$e materi31s.
Comment 3:
This section [1.4.1.3 of the CWP FFS] indicated that the Reynolds and Chandler Adits have
been plugged, but that the long term effects of plugging the Reynolds Adit and Chandler
Adit, and the consequent rise in the South Mountain water table have not been determined.
EP A indicated in its response to Comments on the EEICA that a state-of-the-art ground
water flow model that accounts for flow in fractures is being developed in order to perform
such 'evaluations. However, the Reynolds Adit was plugged prior to completion of such a .
ground water flow model evaluation and any publication of results of such evaluations.
Re$pOnse:
The intent of the "long tenD effects" statement was to convey that EP A does not
definitively know the actual long-tenD effects which the plugging will achieve since
plugging was only recently completed in March 1994. However, the referenced model
has been able to provide an approximation of the resul~t ground water table. At this
time, a report on the findings of this model is in the final stage~. of review prior to its
release to the public.
The development of the model.was never expected to be completed prior to commencing
plugging activities. Instead, it was anticipated that the model would be used to study the
effects of changes in site conditions (i.e., removal/remedial actions) on the ground water
and Adit system. The model bas oJ;Lly recently achieved a relative level of accuracy and is
now being evaluated based upon actual field conditions. Because the Adit pluggings
were conducted as a time-critical,' removal action, no fonnal public review process was
~ though the alternatives analysis for the Reynolds Adit bas been a part of the
public record since January 28, 1993.'
Comment 4:
PluggiJig of the Reynolds Adit should have been evaluated as a long-term solution at the
Site rather than an Interim Remedial Action (IRA). Plugging of the Reynolds Adit couId
cause the following: (1) increase of the water table into the Mine Pits, (2) ground water to
exit the mountain via another shaft or adit (as was .the case with the Chandler Adit), and/or
(3) the creation of additional point sources of Acid Rock Drainage (ARD) through seeps.
Re$p<>nse:
As discussed previously, the Reynolds and Chandler Adits were plugged as a time-
. critical, emergency removal action. However, this does not imply that the plugging of the
. Adits is considered to be interim in nature. After initial consideration by EP A of the
three potential effects as listed by the commenter, EP A felt it best to evaluate the impacts .
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to the ground water table and the actual performance of the plugs as a whole system. As
more about the South MoUntain ground water regime is known, then a final decision
regarding the regime can be developed for long-term considerations.
Comment 5:
EP A apparently has not performed adequate ground water investigations to evaluate the
short- and long-term effects of the Reynolds Adit plugging. Because of the cpmplexity of
the ground water fIow system at the Site, as related to fracture fIow and the hydrogeologic
significance of the mine workings and adits, a ground water fIow model is necessary to
evaluate rises in the ground water table and the potential for significant ground water
discharges through existing adits and shafts. Such modeling efforts. must take into account
the effects of fractures on ground water fIow characteristics, ground water recharge
primarily through the Mine Pits before and after filling and capping, ground water
discharge seeps, and other significant hydrogeologic boundary conditions such as the
underground workings.
R~onse: .
EP A agrees that the South Mountain ground water regime is complex in nature and can
have significant impacts upon the various actions discussed for the Site. .As a'result, EP A
has directed the development of a state-of-the-art, three-dimensional model with
. assistance from the Office of Surface Mining. Each of the parameters identified by the
commenter and other considerations have been incorporated into development of the
modeL The model has only recently achieved a relative level of accuracy and is no~
. being eyaluated based upon actual field conditions. It is anticipated that the model can be
developed into a predictive tool for evaluating futme actions to be taken at the site.
Comment 6: . .
As ~ticipated. bY individuals commenting on the EEICA, plugging of the Reynolds Adit. in
February 1994 apparently caused discharge. of ground water through the existing Chandler
Adit thus providing another source of ARD. As a result, EP A plugged the Chandler Adit
in March 1994. Shortly thereafter, the plug began leaking low pH metals-laden w8:ters. An .
explanation for the failure of the Chandler Adit plug is not discussed in the FFS. Failure of
the plug could be primarily a result of one or both of the fonowing flaws in establishing the
plug design parameters: 1) failure to use conservative' hydraulic parameters, such as using'
the ma'l'imum possible hydrostatic head expected at the plug that would result from
plugging of the Reynolds Adit; and 2) failure to select suitable competent rock for keying
the plug. This section also mentions that corrective measures are planned for the Chandler
Adit, however, no specific discussion of the nature of the contemplated corrective measures
is provided.
Response:
Concerns regarding potential discharge from the ~dler Adit once the Reynolds Adit
was plugged did festiIt in EP A including plugging of the Chandler Adit as part of the
. removal action. . However, the work for both Adits, was conducted in a co~current fashion
and was not based upon actual discharge observed from the Chandler. The Chandler did
-------
----'-.
- .--- -. . .- .._--
. -..----
not fail until May 23, 1994, which is a sufficient amount of time after construction for the
plug to have been fully effective.
EP A agrees that the subsequent failure of the Chandler plug is likely to be associated with
the plug design or the surrounding rock conditions. The corrective measures for the
Chandler are not discussed primarily because the plug failure was still being evaluated.
This assessment effort was initiated in November 1994 and it is anticipated that work to
repair or replace the Chandler Adit will be completed by Spring 1995.
Comment 7:
EP A should not repeat the same mistake of replugging the Chandler Adit without" .
performing the appropriate hydrogeologic investigations and evaluations. Replugging the
Chandler Adit may cause, as was the case in the Reynolds Adit plug, water,exiting out of
another adit or shaft or significant hydrostatic pressures in the mountain that would cause
the .development of multiple point sources via seeps at the base of the mountain. AS
indicated aboye, the Chandler Adit is presently discharging low pH metals-rich waten
directly into Wightman Fork. It is not known why EP A did not open the valve in the
Reynolds Adit to reduce or preclude flow from exiting the Chandler Adit and treat this in
the PITS facility prior to discharge to Wightman Fork. This demonstrates a failure on
EPA's part to develop an overall environmental strategy at the Site, as opposed to a
number of disconnected and uncoordinated individual actions. .
From an emergency response standpoint, it may have been appropriate to keep the
Reynolds Adit open since w~ter from the Reyn~lds Adit could be readily treated. .
Re~onse:, .'
Based upon the short success during the time that the .chandler Adit was functional, it is '
unlikely that replugging of the Adit will result in discharges from other'amtslshafts. The
ground water model being developed tends to support this conclusion. However, it ~
known that historic SeePs did eXist on South Mountain and it is reasonable to expect that
these seeps would redevelop. Even so, the ratioDale for plugging the Adit system was to
flood the mine workings and thereby e1imin~te oxygen from the reaction ~ch generates
AMD. This will result in the gradual improvement of the South Mountain ground water
and, therefore, the water quality of the seeps. .
The design for the Reynolds Adit included two separate plugs with piping between the
plugs. A valve which would allow EP A to drain the water behind the two plugs was to be
iIistalled once the second plug was completed. After observing the better-than-expected
performance from the first plug, EP A determined that a second plug would be a
redundant expenditure and it was e1imin~tfl'd from construction. As a result, 'the
capability to open the valve - as originally considered - did not exist at the time that the
Chandler began to discharge to the Wightman Fork. This valving capability has since
been installed and EP A has been treating the Chandler discharge at the PITS fucility.
Rather than a lack of an overall environmental strategy for the Site, this incident is more
representative of the extreme physical and timing realities presented by the Site. Overall,
-------
discharge from the Chandler Adit produced less flow and less copper concentrations than
experienced from the Reynolds Adit during the ~e time frame of the previous year.
Comment ~:
Plugging the Reynolds Adit may not, in the long term, .reduce acid mine drainage flows and
may turn out to be a very expensive experiment. Also, this interim action may actually
exacerbate site problems and, thus conflict with the National Contingency Plan.
Re$,pOnse: .
Base upon current data gathering efforts and the recent predictive capability of the ground
water model, EP A has de~ed that plugging of the Reynolds Adit will result in a
reduction of contaminant transport from the Site. Therefore, these actions will not
exaCerbate Site problems or interfere with the final overall site remedy. However, should
monitoring of the South Mountain ground water indicate that the plugging is actually
exacerbating Site conditions, the (now installed) valve within the Reynolds Adit can be
opened and treatment of the water initiated in the PITS.
. Comment 9:
It is stated that. "In 1993 and 1994, Emergency Response Removal Actions (ERRA) were
taken to reduce contaminant load in untreated Site water. This was achieved in part
by_prevention of AMD flo~ from underground workings._" Plugging the Reynolds Adit .
probably did not reduce the contaminant load in untreated Site water.
. .
H no immediate reduction of contaminated water flows was expected, what was the
rationale for the precipitous action in. 1993 and 1994 regarding plugging of the Reynolds
Adit? Alternative actions and consequences of combined actions could have been evaluated
on sound scientific bases thus providing for recommended alternatives with higher
expectations of achievements for interim rem~es and final overall sit~ remedies.
Re~onse: .
In the spring of 1993, discharge from the Reynolds Adit reached a peak flow of 763
gallons per minute with supersaturated concentrations of copper. Due to treatment
capacity limitations at the PITS facility, approximately 600 gallons per minute of the
dischargeovert1owed the holding pond and escaped untreated into the ground or
overflowed into the nearby creeks. While this occurred over a limited 3-4 week period,
plugging of the Adits eliminated this highly contaminlited discharge to the Alamosa
drainage during the 1994 spring season. .
In general, each of the remedies discussed in the FFSs are anticipated to have a gradual.
impact upon water quality and cannot be guaranteed to dramatically improve conditions
over a short time frame. Also, because of on-going water treatment, implementation of
the remedies is expected to allow EP A to discontinue water treatment while maintaining
compliance with current water quality standards. . .
-------
..... _. .._... _.~--
.__..
Comment to:
This section [1.4.4.2 of the CWPFFSI does not provide an adequate description. of the
ground water flow conditions at the Site. A discussion of the prevailing ground water flow
systems should'be provided, including the ground water flow direction, permeabilities, and'
storage coefficients. Also, there is no discussion provided on the regional and local
hydrogeologic boundary conditions at the Site. It is unclear where the recharge and
discharge (seep) areas occur, and the hydrogeologic effect of the underground workings
and their significance as a hydrogeologic boundary conditions are unknown. The text does
not discuss how plugging of the Reynolds Adit will effect the ground water table conditions
at the Site. If these conditions are unknown, at least a qualitative description is necessary.
The FFS' does not include a description of the promise~ state-of-the-art ground water flow
model that was supposedly developed to. make these necessary evaluations. The model, as
weD as information on model assumptions, model hydrogeologic boundary conditions,
should be included in an adequate FFS. The results of such modeling evaluations may
significantly alter the conclusions of the FFS with regard to replugging the Chandler Adit.
Such simulation would have provided insight into the water table levels which could affect
conclusions regarding the effectiveness of the selected alternative.
. In addition, EP A does not provide in the FFS a description of the proposed monitoring to
determine the effectiveness of the plugging in the short- and "long-term. Evaluating the
effectiveness of the Reynolds Adit Plug will require monitoring of: - (1) fluctuations in the
. water table; (2) existing seeps; (3) changes in flow quantity; and (4) changes in water
. quality through th~e seeps. Also, monitoring the development of additional seeps is
criticaL Information regarding what EP A is currently considering as baseline for
monitoring and what methods will be used to evaluate the effectiveness of plugging is
necessary to determine the impact of plugging these two adits, particularly with regard to
final site remediation. Further, information on the monitoring efforts currently being
performed by EP A to monitor the potential development of addi~onal seeps as a result of
. the Reynolds Adit plug, and. the results of such monitoring; are critical to evaluate the
effectiveness of the remedy.
R~nse: . .
EP A agrees that inclusion of the ground water model in an FS is essential to evaluating
the effectiveness of a selected alternative for the South Mountain ground water regime.
EP A also agrees that the results of monitoring for the various considerations outlined by
the commenter are essential in assessing the impact of the Adit system plugging,
particularly with regard to final Site remediation. However, the plugging of the Reynolds
and Chandler Adits and their impact on the ground water are not the focus of any of the
four FFSs provided for public review and inclusion of the suggested information in these
FFSs is therefore inappropriate. Nonetheless, the modeling and monitoring efforts are
actively being pursued arid EP A anticipates that this information will be incorporated into
future RIlFS documents to support a separate Reynolds Adit/South Mountain ground
water ROD. These documents will be provided for public review and comment prior to
remedy selection.
-------
3.0
REFERENCES
ALL REFERENCE MATERIAL AVAILABLE IN TIm EPA ADMINIS1RATIVERECORD.
-------
i
I
.1
I
199311994 ENVIRONMENTAL ANAlYSIS.SUMMITVlllE SUPERFUND SITE
COPPER ILBSI '1883. 11894
JULY TO JUNE PERCENT OF PERCENT OF
'AMPLE MAY JUN JULY AUQ IEPT OCT NOV OEe JAN FEI MAR APR 'MAY JUN COPPER LOAD CURRENT POTENTLAL
LOCATION ILISI LOAOINO LOADINO
fRENCH DRAiN lUMP
STREAM A 663 1.121 831 622 1.888 683 414 411 483 409 381 364 608 2.160 8.818
VALLEY CENTER DRAIN
FDS.' 1.138 1.418 282 181 188 120 147 122 104 83 60 37 632 1,801 3.434
DIKE I SEEP IIIIf
FDS.l 12 384 Ii::::!::;!.:::';':'; 18 36 38 22 16 ::::i::';.({ ::{/;:':i'. 64 302 483
lPD.I . ROAD SEEPS ,::::,,::,,<::':,:,: I:':::':':'::,'::::
FDS.3 827 314 'I 34 46 31 28 28 23 11 18 139 268 78 767
LPD'4 II II COMBINED
FRENCH DRAIN SUMP 3.191 3.840 1.823 1.613 888 629 481 482 438 374 381 492 2.238 2.410 12.269 2.12%
TOTAL FLOW
IIEAP UAC/I PAD 26 . 41';,::::r,:,,':..
STREAM 8 8.348 4.037 781 333 349 146 76 1.181 1.484 4.378 0.81%
CWP OVERFLOW 1660.001
CRDPSY WATER .. I:::;.:':::,: :.'::\i ':,?;:::=:O:: I:':::::::';::::: .':;'.}::.' .:::::'.:':':::: ~<:, 1.:::;:;;::Ii: 2.843 1.840 7.411 8.833 18.927 4.20%
ITIIEA TMENT PLANTI .. ',:'::/:.::'..,.
/lLP LEACHA TE 39.384 31.886 33.162 24.688 22.708 21.602 19.036 16.082 13.873 9.334 9.047 7.836 8.103 8.018 192.488 42.16%
(INFLUENT TO CDPI
UNDEROROUND WORKINOS
STREAM C 63.242 110.139 34.432 20.212 18.272 12.362 8.983 6.319 2.883 142 112 86 1.126 102.879 12.76% 22.80%
REYNOLDS ADIT IAD.OI
PITS 12.110 111.661 19.760 18.472 18.272 12.362 6.863 6.319 2.882 84 140 164 0 0 86.178
REYNOLDS ADIT TREATMENTI
CHANDLER PORTAL ,'.,..",,-',. ::;:'~r:):.::::f: ,~~::::,,::::::::::':~:::. '(::'~:;.::-;:';:;':.' :':;:=.i::~:;~:::;:':: /':{i:;:~;t~i': ;";:'.;:.d:::..::::.; ';::;::>';:';:;';;::::' .::g::::.::~' ':::':::::';:;:~'::'::':: :~:::::-:::~;:::::::::.;' II 164 83.788 86.642 88.83% 21.22%
'''',-,'';.'.:.'-.:. .'::.:::--.:.;:;-:';V .._,-:...-.:.:-.;... ::.:~::::':';:::::-;'::.,.. .."-:-:.":.":.;'..;_.'. ....,:,:,:.'.;..,,"'.
CROPSY CREEK
IPD.2 28\ 188 31 118 34 28 1 .....",..x.>-,.. 184 288
0:,:.:,;::"::,,,., 821
lEAST Of F. D. SUMPI ~~tM~Mt~
STREAM H 3.824 880 121 III 67 62 28 21 21 16 26 168 642 671 1.731 1.27% 0.39%
CROPBY CREEK
POND 4 :_:.~:.{i:;:f::'. ~
STREAM F 0 161 406 728 323 .78 8 . ..:.'..:..:::,. 1.002 1.886 4.608 3.29% 1.00%
POND 4 DISCIIARGE :.:;::\:;-:A.j:
.. .....;.-.:.::.:.;:...-. :-:-.';';...:.;..':.:'.':' ::';::::.::::;:;:;;:-::::; f?:;t~:::t?:. .;....-:.-.:,;.'.-;... -
IOWA AOIT :"'::::...: ..::;..:::;'::.:.:::;'.:. ';':'.:.'.-;.;:." .....::'::;:.;~:-:::':~, ."::<:'.:::;'-.':-:.: ::.:. .. .~:.::.~.' "::,':;',':V'.": 37 22~ NIM
OTHER CONTRiBUTORS TO WIGHTMAN FORK 00~.
STREAM D 4.436 3.804 1.281 1.788 1.&26 873 809 844 468 5.110 12.294 8.98'" 2.73%
CLEVELAND CLIFFS I,;;'. ..
STREAM E 3.389 3.466 868 91 31 4 .;:;:1.1.~;:~:;i ~;:;:::~Hf.. 1.613 1.810 4.321 3.16% 0.88%
);::::::}:}:~;:::
NORT" DUMP DRAINAGE . ~:;:::::::'::{;;',~':'
STREAM G 2.306 1.028 i:fiii;:i.i,\'( ':';;jt:~~}~n: :;rj:;:~N;!:!r J.i:I:'::;;!f:;'; .:-~!{J~):r;::. 878 237 1.113 0.81% 0.26'"
CLAY ORE STOCKPILE ISEEP LI ':f~:;~.(t?- 'r~f k~~ (::
TREATMENT DISCHARGE 23 46 31 22 28 32 21 13 II 0 ° 0 8 24 189 0.14% 0.04%
TO WIGHTMAN FORK
MONTIILY TOTAL 0' 64.249 1011.231 17.389 4.486 1.974 1.039 882 878 33 83 .3 82 18.161 84.830 137.204 100.00%
CURRENT CONTRl8UTORI
-
MONTlfLY tOTAL Of ALL 117.997 188.880 72.894 48.470 45.173 36.836 27.188 22.674 16.799 9.886 12.411 10.412 33.088 114.332 460.266 100%
POTlN!LAL CONTRIBUTORS
WF".5 WIQIITMANFDRIt 41.436 71.181 20.1148 8.424 3.682 838 180 870 419 314 389 809 20.424 87.4110 143.011Z
Table 1 Copper Content - Site Contaminated Water, 1993-1994 Record
;
"
. ~
,
-------
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l.~':. .~! .
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Table 2 Cyanide Content - Site Contaminated Water, 1993-1994 Record
.' .
1813/1884 ENVIRONMENTAL ANAL YSIS.SUMM'TVlllE SUPERfUND SITE
CYANIDE
11181 JJ894
JUly AUO lEfT OCT NOV DEC .IAN FEI MAli APII MAY JUH CYAN- tOAD ~~~:.a!!.T 0' '::~=
I-I MAY .IUII CURRINT
tOCA TION 'lll' lOADING lOADING
'IIINCH DIIAIN lUMP .
"IIEA"" 41S0 142 I" 483 248 382 884 888 848 822 420 808 1181 388 '.4'8
VAlLEY CENTER DRAIN
fD$of 48 31 II 7 7 7 14 I 3 2 I 0 8 14 81
DUll ' IU'
fDS.1 . 112 iff::;!iW.~t 20 I 21 12 17 ;ii~~~~~j~!Ii~~~~~ ~r~~f~l~~~~ ;~~?~lt~t~~f ~~1~~~~f.**1.fi~: 8 12 '02
IPO." IIOAD IUN
fDS.' 0 0 0 2 0 0 0 0 0 0 0 0 0 0 2
tPO.4 . , COMIINID
fRENCH DIWN SlIMP '.145 ..,,, '.011 ..". II' 411 495 ..4 495 4" 464 1:10 .99 488 7.141 4.4'"
If'fLUfHTI
HlA' UACH'AD =~ ~
srRE"". 0 0 ° 0 0 0 0 0 0 0 0 0
CWP OVERfLOW 188~. . -
Cllpi'SY W" rER '/::.:L' ::.". ..S~}i~~~~r~~~~t. :'::"'::::',,:,:,'1(.::.::. ';~~~~w~j~~~~1!~: :~;I;~*!~~F :j:;~;~;1;~i~if~t~~~:: 0 0 0
ITIIIAtMENf PtA'fTI )ftf!~~Wg
H/I'/fJ4CHJt ff '4.115 It. OJ, U..'1 11."4 ...1St1 '1.11' '4.'/s1S 13.312 ""I '..J1 1.1'4 '.11t 1.126 161.711 1.,84"
IIHflUENf TO CDI'!
UNOfllGROUND WOIIIINGI
srRE.4" C 0 0 0 0 .0 0 0 0 0 0 0 0 0 0 0 0.00" 0.00"
REYNOLDS "III' IAD.OJ
,,,. 0 0 0 0 0 ° 0 ° 0 0 0 0 ° 0 0 0.00"
IIIEYNOLDS AIIIT TREATMINT!
CHANDlER PORr", ..-:'.0:.':':.::':" :.:::::t::.:::}::;:::::.:: .:.;;.~t:t:~:~ ~i::.: %;~~:::::~~;{.~:::i:: ::::{~:~:'*(.~~;:~:~ ~.:?::~;~:;~::=:::~~:' : ~:~~W~:~~:::~::::: .:;i:;~::::::g::~:::f :.::;::;::.;:::;:;:...:::.::: :;::.%~;~::.~:::~::: :::~~r:~:::m::::~i~: .:~'::;::;~~;;::~*::~~:: 0 0 0 0.00" 0.00"
.'."..:..:.'....,:-..'.
CI!OPIY Clllf.
/1'0-1 ° 0 ° 0 0 0 0 0 ~~:~~~~~~f:~~(1~i ;;(!~~if~tj~I .:~i~r~~l.~rJ.l !I;1~llr ~~f~tff*~fJ~~~. 0 0
lEAST 01' '.D. SUMP!
SI'IIE.4M H II .04 , .1 , 0 lIS ° 0 . 0 , I 7 84 ...." O.OJ"
CIIOPSY CRIE.
POND 4 ::::::i:::'::~ I .:::.t:i\:~ I: '::::'~~'N~~ :~:::::;.r,tq'::::1 \.::m,v},.~~::..~::.:t%W'::[:::::'fM~:::,:;:~!!;!!!:r~:,:}::{:?::::",:;":~:!j!1!..!!!.1'~!~!!~i!!:,, :i::?':\@:1
srfIIAM F 0 1 1.02" 0,00"
I'OHII 4 DlSCHAllGI
IOWA "01' 0 NIM
OTHIII CONTiulUfOll1 TO WlGHfMAN '0111 : :.j.==
SrR£Uf D , 0 -0 0 0 ° 0 0.00" 0,00"
CUVILAND CLiffS ~
$fRE.4" E 0 0 ° 0 0 ° 0.00" 0.00"
NO"'" DUMP DRAINAGE ~
S rll£Uf G 0 0 :i::i~:i:mf:;:;!::i:; :::ii:::MiiWi{.[?i:;:iI:ei*:;ii. :.:.' ::i::ii1[{)::W.;!::: ;:;;.iiI!!;!;!ii::: .;:1::~:~);i!i!t 0 0 0.03" 0.00"
ClAY ORE BTOCIPIll ISEEP U
rRE.4 rloflNr OISCH.4IIGE 163 114 74 IJ 89 84 43 18 0 0 0 38 117 722 '2.09" 0.43"
fO WlGltTMAH 'ORI
MONllIi Y TOr At Of 110 281 201 II .5 107 70 4J II , , 1 41 124 784 100.00"
CURRIN' CONfIUIUIO"1
IoIONfHiY fOfAL 0' AU 38.417 30.4" 28.888 11.128 17.230 17.248 11.219 11.189 13.178 '.241 1.101 7.784 8.138 '.111 1I1.12i 100"
POTfHflAL CONTlUlUfOll1
-------
r
1993/1994 ENVIRONMENTAL ANAL YSIS.SUMMITVILLE SUPERFUND SITE
FLOW RATE IGPMI h8n 11884
HIGH fLOW LOW flOW
IAMPLE MAY JUN JULY AUO IEPT OCT NOV DEC JAN fE8 MAli APII MAY JUN IGPMI IGPMI
LOCATION 11/83 TO 8/841 17183 TO 8/84.
fRENCH DRAIN lUMP
STIlEAM A IS 111 }2 118 82 71 70 14 73 70 10 18 .32 118 132 58
VALLEY CENTER DRAIN
FOS.' 40 28 8 II II 3 4 3 . 1 1 . 14 38 38 .
DIKE . SEEP III
FOS.2 . .8 ::t~!~i[r(~11.~!til~1i~l; 3 3 3 3 2 : .';';':':-:';':"~"-':'. :'i:!:i:r::l::~j;:;,: .':';';';';'.~.:-;.z...:.:.:.:. 4 20 20 2
LPD.' & ROAD SEEPS ~:~~j\~*~1~~~~~~1:~~ (~t\1ill~~~H~r:
FOS.:J 25 211 .4 12 12 .3 11 .0 1 8 II II 10 13 14 6
LPD.4 & II COMBINED
FRENCH DRAIN SUMP 151 180 124 103 86 10 10 10 70 10 10 87 185 181 185 10
IEffLUENTI
HEAP LEACH PAD II![RI
STREAM B 384 181 41 18 15 8 4 2 0 " 28 44 47 0
CWP OVERflOW 111110.001 .,..:::,:":,.:\t.._.. - ~ - [II[
CROPS" WATER ..'..:':::':".::.':'. ::<0", 108 14 n8 182 178 74
ITREATMENT PLANTI ..
HlPlEACHATE 684 723 8n 1188 841 n4 814 838 860 821 848 88. 1134 160 774 534
IINfLUENT TO COPI
UNDEROROUND WORKINOS
STREAM C 488 183 388 212 228 180 "8 81 48 8 7 8 68 3B8 8
REYI/OLOS ADIT IAD.OI
PITS 14 113 182 218 231 180 118 8} 88 81 }2 88 0 0 231 0
(REYNOLDS ADIT TREATMENTI
."..".'v.;';-."."."..". ;')i:':.t:':ii'.:':,:;:., ".....,".'..".'.',"."...' .,-:.";.-.:.:.',.,':.:".'.: ."::.".:;,;,::;..::..;::,,:.:- ~ "i:~:;:::;~f:::H:::;
CHANDLER POR1AL .. .. ':':;:;:~':(':':;::,:.":' . '~':'. ... '.;'.. .;. .,':. :,.,,,:,,:.....:.;.;.:...;.:;' ;:.::..:::'~':;';:;:;:;:-:;: ';';':';';';':':';':';':';':.' ;;:.:::;<;::'~~~::::.:.: 389 611 .811 388
. . . ".. ".'.".'.'.. ''':''':-:'::--';':-:''':.
CROPSY CREE. III
LPO-2 28 28 2 6 2 2 ;;:r;f!f,@ri;f{ ':$J1m;~m~m~~m :::;i~~:~~~;i::: ~~ 13 28 28 2
lEAST Of f. D. SUMP! ;~~:;::*1[~;:~r~:;
SfIlEAMH. 2.805 2.608 843 321 238 104 88 82 62 38 41 89 1.348 2.450 2.450 38
CROPSY CREEK
POND 4 4~ ..",:.
S111EAAI F ::::..,:::.::::: 188 116 318 138 33 ;;?:,~:,.,i 848 188 848 4
POND 4 DISCHARGE :
IOIVA AOl1 : .. ,. .. :.. .:::!,'.. ./"/;.:..' I..:to ..':~;i/:::'"':t:/': .";':"';-:;-.-:''''.::... . :;'''',>\':';.;':.1. ,,".1:")<':':.., ;:':.:f,}::::!:. 201 134 HIM
.. .. .. ... .. "~".: ::.~';:"::)- ::~. HIM
OTHER CONTRIBUTORS TO WIGHTMAH fORK =-
S1REAM 0 202 188 62 83 69 43 33 31 ;;~~[f~:lf~;~jj~ i! 109 188 18S 33
CLEVELAND CLIffS 2.
STIlE AM E 284 282 87 13 4 '~~11~~:ir~;~:~;jfj~1:;': ;:~~~f\~;~i;i:~ 264 314 314 2
HORTII OUMP DRAINAGE
STREAM 0 48 88 ;:;:~:t~1i~~i~)~~~~~ ~~~tf:~It~it:. ~~frt~~~1jff~~~r; - ;:):iiJ;tmj{: ~~:~~~*-r~~~j:: ;1t.~}1,t:f;.' )~~~fl@~~~;r ~t~~~i~i~~~;t 31 41 41 37
CLAY ORE STOCKPILE ISEEP II
/<:'of::..'.,',.. . :~;:~J~ .:::(:;:::::\;:;: - :~~i~ff;:~~1:~~~~;;~; ~~~t=t~i;~~lj1~;~~;~" ; ~{;j~~:~:~:~~r:~~~', :'::~:~~:::ft:~{: ;ifi~~~Jj~~: r~1~]~:i;;11~;: ~~~~;Jj~t~~~t~r ;::.:::::::::.:::.::',....; ::'?:{1:;i;\i:J;i~!::j:1i\;
' ..."".,...",.".::.':,:,....: .....,.. .. .. :::irWN~~lE ":~~if:~;:~N~:F' .,
..'.":. .'
MONJHL Y TOTAL 0' 3.162 4.440 1.083 186 440 182 100 88 62 38 41 88 3.083 4.388 4.388 38
CURRENT CONTRIBUTORS
MONTHLY TOTAL Of All 4.836 6.861 2.123 1.100 1.428 1.214 873 801 818 738 814 811 3.888 11.484 11.484 738
POTENTLAl CONTRI8UTORS
WF.5.5 WIGII1A1AN FORK 16.668 13.823 3.3113 2.328 '.13' 896 108 483 344 233 298 I.n8 10.483 12.028 12.1128 233
Table 30 Site Surface Water and Treatment Plant Flow Rates, 1993-1994 Record
-------
.'
:'.: 'j
~i ,
; .; : .; ~
''''.. .
",i:' ..,
:..:.~ :
".' 'j
,:',
r.
,~.
,F 'j'
:';':L
.\':1: ;t
':)1 :'
:k,:.
:L."~'
'".
"j:: '!.
"," ;:
..,(:
M~"k
Mn
. ~11,: .'1
';f!~l: 'I
: ~'.;1 '
';~';i
.H"
f\~!'
'i..~r
, i!~
~'" j
\' '
, ..)
"~t11
. .~~.
"'I
:h
.:fiil'"
"~,.
,;~I
.:jll.i
11
'1'
;
1.
\
J
i 1
P
'. I
':l~
fl
,:~~~
'i ~:i
'i :\
i
~
t~ '
'4't
Table 3b Site Surface Water end Treatment Plant Water Volume
188311814 ENVIRONMENTAL ANALYlIB.BUMMITVILU! IUPERfUNO SITE
fLOW IGALlONSI
_AII"I IIA' '12 .AlN 'IJ .alLY 'IJ AUQ '12 il" 'IJ OCT '12 NOV 'IJ OfC 'IJ .IAN 'I' fll ... MAlI 'I' AI"'" IIAY ... .AlN 'I' :~~:~:: ~:::~~:
LOCA 'ION niu TO .,141 mil TO .,14
''''NeH 01lA1N IUM'
"MAMA 2.811.120 2,'11.'00 2,21'.080 un.710 1."1.400 1.111.440 I.024,ODD 1.101.380 3.111.720 1.112.400 1.12'.100 1.111,'00 '.'12.480 1."1.'40 1.882.480 2.811.180
VAlIlY CI"TI" 01lA1It
10$., 1,7~"'00 '.212.100 '87.120 22'.200. 211.ODD In.120 17uoo 131.120 A'.140 40.120 44.140 42.200 124."0 1.837.210 '.In.280 40.120
10111. . III'
10..' 44.140 120.'00 UU20 UI.'oo In.120 UUOO 'U80 171.880 14'.720 1'1'.720 11.280
LPIH . IIOAD inps
10..J ',"'.ODD '.OIO.ODD .2U80 IU,UO 111.400 880.120 471.200 44'.400 2U,480 24 U20 223.100 21t.ODD 448.400 ICO.ODD .24...0 211.ODD
UIH ... CDMalNID,
lMNCH DllAIN $1JWo 8.740.'40 1.201.DDD 1.111.110 4.187,120 U04.DDD I. U4.8oo 1.024.ODD I. U4,loo 1."4.100 2.822.400 1."4.100 U8I.4oo U8I.4oo '."1~200 1.281.400 2.812.400
IlffLUINTI
IlIA, UACH 'AD
STREA"" o~ 1.249.120 1."1.080 2.098.080 0
CW, DVIIIILOW .110001
Cllo,n WATER ?i*ttv'\'r r ,":" :'x ", ";: ;k.~ n<: 4.821.UO 2.IIUOO 7.11'.''10 '.1'1.400 7."'."'0 1.'''.800
TRIATMENT "ANTI ,t/.:'2;:~~:~.;I~ IUIUOO ,0,22U80 2U'1.240~n~110.4~ 1"'''.180 '21:.'I8:IOC: 2...2UIO :1.011.;;'; 21.011.72~ 2U2'.720 2UII.200
HL'LEACHATE 2U27,710 n400.ooo 14.181.110 2U27.780
U",LUI"T TO I;QPI
UHDf"a"OUHD WOIIXIIO.
"IIIAIoIC 2','".D'l0 11..11.100/ 17.711.720 11,142.010 1.812.'00 1.011.200 '.140.100 4.110.0'0 2.011.184 11...10 30il.021 244.0'0 2.'1".180 17.78'.720 244.080
RfYIfOIDS ADlt 1AL!,jIj -
PIT. 2.301.180 4.18'.800 '.110.180 1.711.120 10.118.400 1.011.200 8.140.800 4.110.0'0 1.010.1'0 2.701.'140 1.214.080 1.718.200 0 0 10.228.400 0
RIYIfOIDI AOIT T"IATMEHTI
CIIA-EII_TAL ,1{$1::~~~~~: '~':f»' ", ,< " i " .' .:< . ~.~; ". ~f. ~~; .::: 'Yo:: ::; '. . '. . :':.J:- dr: ~;::. "', '-01. ~~~:r-m~: 11.472.180 24.'1'1.2'10 24.'1'1.2'10 11.472 180
" ,. .. - . .
ICIIO'" CIIIU
LI'O., '.110.'40 1.201.800 11.280 211.300 1'.400 ..-- 180.120 '.282.'00 1.282.'00 ".400
IIA" O' ,. D. lUMP! 4.'42.110 3.180.100 U.7.lIO" U31,21~ I.41U20 ~ 1.Ii3~.~4~ 1.144.100
nREAMIl 121.21'.200 101,"1.'00 21.10U20 14.187.280 '0.124.'00 10.011.4'10 101.1".110 105,811.110 '."".820
CIIOPSY CMU
-0 4
STMAM' ~i*1~.'1 1I.01Uoo 1.111.800 '4.IIU20 '.'''.'00 1.~7I.120 172.800 42."8.720 11.081.100 42.1'I.HO 172.800
PO/fD 4 DlSCHARGI
IOWA ADIT ::~.,~~ ~::::.:: '::':.::-,::: :;{ .:.: . ..-. . . ;t: .:~:. :. ", ~ ?-=..., ,,,,;,.'1$ ,. x ,': .~. ~: ....;: 112.1001 8.771 8201 HIA' HIA
' ..
OTHf" CONT"IIUTOR. TO WlOHTMAN '0"1
. SIMA" 0 1.017.210 7.287.800 2.121.280 1,701.120 2.848.800 1.111.820 1.421.800 "'''.880 ...88.7.0 7.241.104 7,24U04 1.42UOO
CLEVELAHD CUff. ..
STREA" f 12.817,780 U.II'.'IOO 2.190.880 110.120 172.800 IU80 11.118.1&0 13.18'1.100 ".18'1.800 "."0
"DIIT" PUMP OIlAINAOI
"REAM a 2..117.110 1.111.200 " 1.881.880 1.711.120 1.711.820 1.811.180
CLA' 0111 8T I'ILI SUP L
. .~ .
IIO"'IILY TOTAL 0' 117.4'1.280 ""'01.000 41.14I.UO 1'.4".100 ' 1.008.ODD '.102.180 4.1".200 4.411.180 2.221.280 1.4".820 "'10.240 1.144.'00 "'.722.120 111.'''.114 "1."'.284 1.'1"'110
CUMINT CO"TIII.IiTO'"
IIO"T"" TOTAL 0' AU 210.2".'100 244.112.400 14.170.720 n.I".ODD 11.103.100 84.170.140 '12.011.100 40.4".480 28.417.884 21.'71.120 11.00'.412 11.811.210 177.'11.040 UI."I,O'4 118."1.014 21.811.120
IPOTI"'~LCONTIIIIUTORI
-------
Table 4
Contaminant Content at High and Low Flows -
Identified AMD Streams
Scn:am:. '.:.. .~:-.
ReconliJleDate- . ~{:::
. StftaID A.. Stram B Stre:aat C
."
.-
I~ 5114193 6/10/93
9108193 Im6l93 5113/93
: " "~': : ""';:'4_'" .,~.
-~ - .'
:~. '"'. '. ~ ~..,:'; ",. .'
.. :
7~.& 5!r7.5 910
62.1 1 7~
..
-
HigtI Flow
Low Flow
GPM<;,~;'.,~~2~~~ ~1~~:.2
~4:~:~~:
Higb
56.6
35.1
r.
Low
&3.S4
15..&
JS.61
. .. """:."""-" . " .,.; ~,... :
Inc..r.R:;."""':"-,,o;:.~".. '-'~~.' -;':" '.' .
.~..,. ~~~~~~'~~f?~: _:..: ..'.~:.
,.,~ f\~i4:\':.
~~~~2~~:.:'
,. '-'.
HiP
37.6
1738
1:%40
Low
'&"''"8.1
793
361U
:'Iio-~C""'Oda,;.;;~:,f.....;.~.-. . ~..:.:: . .'.:,: '--'''~- - .
IAAo. :l~~''''.'-~....- "~''''r:':i ' . ~...:.. .~... . ",,"
.'~ ..',:':" ~t.~~..=:-~~~: :,.;:"' .." '.. . .:' ::',..;.'j.". ", ~
,
,. .~.
~:~~;T-:.~'
Higb Flow
:s.:lS
NR
NR
Low Flow
NR
:vR
1G.95
Stram D
: Stream £
., --
.'.
610"'.-193 6ID8I93
Il105J93 91%1193
" ::'~~~'f~:.:
:'~:~;.
34
m
19
I
:;i\f;~Z;~; ~:is
~
".&0
66.119
1"
'.
;::f:~lrfi~~ ~~:;~
636
447.5
310.8
76.88
.::-;?:::~~~,::: ~~~it.~
0.017
NR
<.01
~"R
Aluminum and Zinc Coatent at Ifjgh aad Low .Flo~ -
Identifed AJ.~ Streams
._0____0._.
StR:Iaz F
610"'-193
611 0193
".
,,'w"'..- -
-.," ~ .-. ,.,
105
~
----..-....
S~-S
'-.zg
..:.~
6115193
1111;193
. i :<~;\1
1176
0.5
.: @~~~ >.:~i#;g
SS.5
54.75
10
65.53
'. f.~!f:~~~;: :~;,:,&.~
2157.1
800
. "--~- ~.:~}~~.~'.
I <.01
I <.01
109.:5
26.11
...
.-' '~::'.~~~
<.01
<.01
StraIII:. .~~~i;~4;~:~>~S:.~~ .StreaDk .. SIft:IIIIC Stram Do- Straar.'£ ,Streaar:.P" ,: SlftaaG.::' Sb:eaB Ii .~~
ReaIrdi~Date':" ,'-<.:--'-;;"':: .~ ~ .' .. : -:~ .. ~~:~': , .. ..:..~ '. ,:'::":::'.. .. "..:;~~
.' .~..=~ , .' '. " ....
Bigla Flow 61%:194 6/20194 No Informacion .~nil.able 6/21/94
Low Flow 21"-5194 5101J94 SI03J94
Ziac. diges~ - .' ..- , ~:~
....-
H"agJI 101 9.73 105
Low 15.98 64.1 ~.!)9
AluIlliDaar.dC-
Hi~ l&.u 154.5 9'n.l
Low ~ 96-~ 60.;8
,oJ
All concener-nious . me'!
-------
3S
8i 30
~ 2S
01 20
E
.: IS
CD
8: 10
o
OS.
. 0
24- 8-
May- Jun-
93 93
29- . 13-
Jun- Jul-
93 93
Table 6
. COPPER CONCENTRATIONS AT WF-6.6
29- 11- 23- 7- . 29-
Jul- Aug- Aug- Sep- Sep-
93 93 93 93 93
Date
16- 6- 24- IS- 2-. 21- 4- 2- 23- 20-
Dec- Jan- Jan- Feb- Mar- Mar- Apr- May- May- lun-
-------
Table 6
tOTAL CV ANI DE CONCENTRATIONS AT WF-6.6
.. 3
at
~ 2.5
m
E 2 .
oj
~ 1.5
~. I..
o
! 0.5..
o
.t-
o H-
. 24- 8- 29- 13-
May- Jun. Jun- Jul.
93 93 93 93
-I I-t-H-
5- 16- 16-
Nov- Nov- Dec-
93 93 93
-H- -
6- 24-
Jan- Jan.
94 94
15- 2- 21- 4- 2-
Feb. Mar. Mar. Apr- May.
94 94 94 94 94
-------
Standards. Requlremenls.
CrUerla. LlmUalions
OROUNDW A TER;
Nallonal Primary Drinking Water
Siandards
National Secondary Drinking
Waler Standards
Maximum Contaminant Level
Goals
Colorado Ground Waler
Siandards
-'
Table 7
Potential CI,emicnl Specific ARARs
CltalioQ
40 C.r-.R. Part 141, Subpal1 0
pursuant to'42 U.S.C. If 300g-1
and 300j-9.
State: , CCR 10.03-1 pursuant to
C.R.S. f 25-1-107(1)(x) .
40 C.F.R. Part 143~ pursuant to
42 U.S.C. If 300g-l(c) and 300J-
9
40 C.F.R. Part 141, Subpart F,
pursuant to 42 U.S.C. f 300g-1
State: 5 CCR 1002-8 II 3.11.0-
3.11.8
Description.
ESlablishes numeric standards
for public waler syslems.
Maximum contaminant leyels
(MCLs) arc cSlablished to .
protect human life-time drinking
water exposure.
Establishes aesthetics-related
standards for public water
systems (secondary maximum
contaminant level).
Establishes drinking water
quality goals set at levels of no
known or anilclpaled adverse
heallh effects, willi an adequate
margin ofsafety.
Establishes a scheme for
IdentifYing groundwater
specltied areas, for classlticatlon
of Colorado ground water and
provides numeric standards.
Also, establishes an interim
narrative standard for all
unclassltied ground water,
supplemenling stalewlde
standards.
Potentially Applicable or
Relevant and Approprlatc
No
No
No
Applicable
Comment
No public water supplie~
are present, the Slate of
Colorado has
comprehensive ground-
water classlticallon system,
including numeric slandards
equivalent 10 (MCLs).See
seclion 3.2.1.
Protects aesthetic character,
".ot rel~vant to protect/on of
human heallh or .
environment.
No non-zero MCtOs set at
levels less than MCts were
idenlitied for conlamlnanls
. of concern.
-------
Siandards, Requlremenls,
CrUer'a. I.Imllallonl
RCRA Groundwater Prolection
Standard (RCRA GPS)
SURFACE WATE~;
Colorado Water Quality
. Standards
Federal Water Quality Criteria
Allt
. National Primary and Secondary
Ambient Air Quality Siandards
Nalionat Emission Standards for
Hazardous Air Pollutants
Table 7 (continued)
Chemical Specific Criteria To-De-Considered (TDC).
CItRllon
40 CFR ii 264.92 - 264.101
Slate: 6 CCR 1001-3
State: S CCR 1002-8, U 3.1.0 -
3.1.17 .
40 C.F.R. Part 131
Quality Crllerla for Water, 1986,
pursuant t033 U.S.C. g 1314
40 C.F.R. Part SO, pursuant to 42
U.S.C. g 7409.
State: C.R.S. f 25-7-108, S CCR
1001-14. .
40 C.F.R. Part 61, Subparts N, 0,
P pursuant 10 42 (.!.S.C. f 7412.
State: C.R.S. f 25-7~108, S CCR
1001-10
Potentlnlly Applicable or
DescrlpllcJII Relevant and AppronrJn1c
.Eslablishes standards for ground. No
waler qualily related to RCRA
hazardous wasle facililles.
Establishes standards and.
classifications for Colorado
surface waters.
Sets criteria for surface water
quality ba.sed on toxicity to
aquatic organisms aud human
health.
ESloblishes siandurds for
ambient air quality to protect
public health and welfare
(Including slandards for
particulate matter and lead).
Sets emission stnndards for
designated hazardous pollutants.
Applicable
Relevant and Appropriate
Applicable
No
Comment
The State of Colorado has
comprehensive ground-
water classification system,
Including numeric standards
equivalent to MCLs and
RCRA OPS.
See section 3.1.1.
See section 3.1.2.
See seclion 3.4.
Air emissions are not
anticipated after
construction activities are
-------
Advisories to be .
Considered and Gllielanee
~
Toxic Substances Control Act, PCB
Spill Cleanup Policy .
Interim Guidance on Establishing
Soil Lead Cleanup Levels at
Superfund Sites
..
Table 7 (continued)
. Chemical SpeclOc Criteria To-Dc-Considered (TOC)
CltRtloq
52 FR 10688 April 2, 1987
EPA Directive 1#9355.4-02,
September 1989.
DescrlptloQ
Establishes guldunce cleanup
levels for PCD contaminant
soils.
. Established guidance cleanup
levels for lead contaminated
50115. .
To De Considered
Commeq&
Not considered
There Is no evldence'that
PCB spills have occurred.
Considered
-------
Potentially Applicable or
Uclevlllltatnd Appropriate
. Tobie 7 (continued)
Potential Action Specific ARARa
SOLID W ASTH DISPOSAL ACT l"SWDA"\
Cllatlon
Guidelines for the Thermal
Processing of Solid Wastes
Guidelines for the Land Disposal of
Solid Wastes
Colorado Regulations Perraining to
Solid Waste Disposal Sites and
Facilities
Guidelines for the Storage and
Collection of Residential,
Commercial, and Institutional Solid
Waste
Source Separation for Materials
Recovery Guidelines
40 C.F.R. Part 240, pursuant to
42 U.S.G. f 6901, m.ttQ.
40 C.R.S. Part 241, pursuant to
42 U.S.C. g 6901, ~ . I
State: 6 CCR 1007-2, pursuant
to C.R.S. f 30-20-101 and
C.R.S. A30-20-102,~
. 40 C.F.R. Part 243, pursuant to
42 U.S.C. A6901,~ .
40 C.F.R. Part 246, pursuant to
42 U.S.C. g 6901, ~
Descrlptloq
Prescribes guidelines for .
thermal processing of municipal
solid wastes.
Establishes requirements and
procedures for land disposal of
solid wastes.
Establishes requirements and
procedures for land disposal of
solid wastes and the siting of
disposal facilities.
. Establishes guidelines for
collection of residential,
commercial, and Institutional
solid wastes.
Establishes requirements and
recommended procedures for
. source separation by federal
agencies of residential,
commercial, and institutional
solid wosles.
Polentlally Applicable or
Relevant and Appropriate
Comment
No
i
I
i
i
Thermal processing will not
occur.
No
Disposal or mine wastes
and closure of mines are'
specifically addressed by
the Colorado Mined Land
Regulations. See section
4.2.
No
Disposal of mine wastes
. . and closure of mines are
specifically addressed by
the Colorado Mined Land
Regulations. See section
4.2
i
I
No
Not relevant.
No
Not relevant. Creates no
substantive cleanup
-------
Potentially Applicable or
. nelevant and Appropriate
Guidelines for .Development and
Implementation of State Solid
Waste Management Plans
Criteria for Classification of Solid
Waste Disposal Facilities and
Practices
Hazardous Waste Management
System: General
Identification and listing of
Hazardous Waste
Standards Applicable to Generators
of Uazardous Waste
Table 7 (continued)
Potential Action Specific ARARs
Citation
40 C.F.R. Part 256. pursuant to
42 U.S.C. i 6901. nwt.
40 C.F.R. Part 257. pursuant to
42 U.S.C. i 690.1. ~
40 C.F.R. Part 260
State: 6 CCR 1007-3 Part 260
40 C.F.R. Part 261. pursuant to
42 U.S.C. i 6921
State: 6 CCR 1007-3 Part 261. .
pursuant to C.R.S. i 25-15-302
40 C.F.R. Part 262. pursuant to
42 U.S.C. f 6922
State: 6 CCR IOQ7-3 Part 262.
pursuant to C.R.S. f 25-15-302
. .
Description
Establishes requirements for
federal approval of state
programs to regulate open
dumps.
. Establishes criteria for solid
waste disposal facilities and
practices.
Establishes procedures aitd
criteria for modification or
revocation of any provision In
ports 260-265.
Defines those solid wastes
which are subject to regulation
. as hazardous wastes under 40
C.P.R'. Parts 262-265 and Parts
124.270.271.
E'stobllshes standards for
generators of hazardous waste.
Potentially Applicable or
nelcvanl and Appropriate
No.
No
No
Applicable
Applicable
Comment
Creates no substantive
cleanup requirements.
Disposal of mine wastes
and closure of mines are
specifically addressed by
the Colorado Mined Land
Regulations. See section
4.2.
Creates no substantive
cleanup requirements.
Provides for the.
Identification of hazardous
wastes; used to determine.
disposal criteria for sludges
& spent process chemicals
generated from water
treatlnent.
. If hazardous waste are
generated onslte and
. managed offslte the
requirements are applicable.
Used 10 handle process
chemicals and sludge
management for water
-------
Table 7 (continued)
Potential Action Specific ARARs
Potentially Applicable or PotenUally Applicable or
"clevo"t and Appropriate . CUallon llllirIlltiml Uelevant and Approprlatc Comment
Standards Applicable 10 40 C.F.R. Part 263, pursuanl to Establishes standards which Applicable If hazardous wasles are
Transporters ofllazardous Wa~le 42 U.S.C. ~ 6923 apply 10 persons transporting Iransported offsite Ihe
hazardous waste within the U.S. requirements are applicable.
Slale: 6 CCR 1007-3 Part 263, iflhe Iransportallon requires a
pursuanllo C.R.S. f 25-15-302, manifest under 40 C.P.R. Part
4 CCR 723-18 262.
Siandards for Owners and 40 C.F.R. Part 264, pursuant 10' ESlilblishes standards which Yes See section 4.1.
Operators of hazardous Wasle 42 U.S.C.g6924,.6925 define Ihe acceptable
Treatment, Siorage, and Disposal managemenl of hazardous waste
Facilities Stale: 6 CCR 1007-3 Part 264, for owners and operators of
subparts B, C, D, E, P, 0, K, L, facllilles which treol, store, or
and N, pursuanl to C.R.S. f dispose of hazardous waste.
25-15-302
Inlerim Standards for Owners an 40 C.F.R. Pari 265 Establishes standards for Relevant and Approprlale ESlablishes no subslantive
Operators of Hazardous Wasle managemenl of hazardous waste slandards applicable or
Treatment, Storage, and Disposal Slale: 6 CCR 1007-3, Part 265 during Interim slatus. relevanl and appropriate 10
Facilities the IILP.
Standards for the monogemenl of 40 C.F.R. Port 266 ESloblishes requircmenls which No Nol relevant 10 activities at
Specific haZardous Wastes and apply 10 recyclable malerlals the site.
Specific Types of Hazardous Wasle Siale: 6 CCR 1007-3, Part 267 Ihal are reclaimed to recover
Managemenl Facllilles economlcaily slgnlficanl
amounts of precious metals,
Including gold and sliver.
Interim Slandards for Owners and 40 C.F.R. Part 267 ESlablishes minimum national No Part 267 regulallons are no
Operators of New Hazardous Wasle . slandards thaI define acceptable longer effective after'
Land Disposal Facililies 8lalo: 6 CCR 1007-3, Part 267 managemenl of hazardous wasle February 13, 1983.
-------
Potentially Applicable or
Relevant and Approprlat~
lIazardous Waste Pennlt Program
Underground Storage Tanks
Cllalloq
40 C.P.R. Part 270
To~le 7 (continued)
Potential Action Specific ARARs
40 C.P.R. Part 280
State: 6 CCR 1007-3, Part 100 .
Deserlptlol)
Establishes provisions covering
basic EPA permiuing
requirements.
Estoblishes regulations related to No
. underground stomgc tanks.
Potenllally Applicable or
Relevant and Appropriate
No
Com men,
A penn it Is not required for
onslte CERCLA response
actions.
The use of or remediation
of underground storage
-------
PotenUally Applicable or
Relevant and Appropriate
. SAFE ()JtINKINO WATER ACT
Underground Injection Control
Regulations
CI.EAN WATER'ACT
Notional Pollutant Discharge
Elimination System
Amendment to the Selliement of
July I, 1991
Ernuent Limitations
Table 7 (continued)
Poten~lnl Action Spccllic ARARs
Citation
40 C.F.R. 11144.12,144.24,
and 144.25, pursuant to 42
U.S.C. I 121 (c)(I)
40 C.F.R. Parts 122, 125,
pursuant to 33 U.S.C. I 1342
S CCR 1002-2, It 6.1.0 to
6.18.0, pursuant to C.R.S. f 25-
8-501 '
July 21, 1992 agreement
between Co. Mined Reclamation
Board, Cpo Mined Reclamation
Division, CO. Water Quality
Control Division, the Executive
Director of the CDPHE and the
SCMCI
40 C.F.R. Part '440, pursuant to
'33 U.S.C. t 1311
S CCR 1002-3, It 10.1 to
10.1.7, pursuant to C.R.S. f 25-
8-503
Descriptio..
Establishes requirements for
injection of waste water into
wells and aquifers.
Requires permits for the
discharge of pollutants from any
point source into waters of the
United States including
stormwater.
I!stabllshcs Numerical Criteria
Limits for water quality for
outfall 004 (WFS.5) an a
compliance plan
Sets technology-based ernuent
, limilations for point source
discharges In the Ore Mining
, and Dressing Point Source
category. Also provides
exemption for release of storm
water where defined 8MP
, 'criteria are Implemented.
Potentially Applicable or
"elevant and Appropriate
No
Applicable
Considered
Relevant and Appropriate
Commeqt
Underground Injection is
not anticipated,
See sections 4.3 and 4.4.
-------
Table 7 (continued)
Potential Action Specific ARARs
Potenllally Applicable or Potentially Applicable or
Relevant and Appropriate Cltatioq Description Relevant and Appropriate Comment
Nallonal Pretreatment Standards 40 C.F.R. Part 403. pursuant to Sets standards to control No No discharge to a publicly
33 U.S.C. i 1317 pollutants which pass through or owned treatment works is
Interfere with treatment anticipated.
processes In publicly owned
treatment works or which may
. contaminate sewage sludge.
Toxic Pollutant Effluent Standards 40 C.F.R. Part 129. pursuant to Establishes effluent standards or No The discharge of specified
33 U.S.C. i 1317 prohibitions for certain toxic pollutants Is not anticipated.
pollutants: aldrin! dieldrin.
PDT. endrin. toxaphene,
benzidine. PCDs.
Dredge or Fill Requirements 40 C.F.R. Parts 230, 23 I Requires permits for discharge No No construction activities
(Section 404) of dredged or fill material Into are applicable involving
33 C.F~R. Part 323, pursuant to navigable waters. dredging In water treatment.
33 U.S.C. i 1344
Marine Protection, Research &. 13 U.~.C. If 1401-1415 Regulates ocean dumping. No Ocean dumping will not
Sanctuary Act occur.
Toxic Substances Control Act PCD IS U.S.C. I 2605(e) Establishes disposal No At this time it Is not
Requirements 40 C.F.R. Part 761 requirements for peDs anticipated that remedial
activities will Involve the
disposar of PCBs.
Uranium Mill Tailings Radiation 42 U.S.C. U 7901-7942 . Establishes requirements related No Uranium mill talilngs aro
Control Act to uranium mill tailings. not present at the site.
42 U.S.C. 12022
Surface Mining Contro~ and 30 U.S.C. U 1201-1328 Establishes provisions designed No Not relevant. Creates no
Reclamation Act to protect the environment lTom substantive cleanup
the effects ofsurface coal requirements.
-------
.
Potenthdly AplJllcable or
nclcvant and Appropriate
Occupalional Safely and Heahh Act
Federal Mine Safely and J leahh Act
Hazardous Materials Transportation
ACI, D.O.T. Hazardous Malerials
Transportation Regu lalions
. Colorado Noise Abatement Statute
Colorado Mined Land Reclamalion
Acl
Tobie 7 (continued)
Potential Action Specific ARARs
Cllatlon
29 U.S.C. fl6S 1-678
30 U.S.C. II 801-962
49 U.S.C. II ISOI-iSIJ,
49 C.F.R. Parts 107, 171-177
Slate: C.R.S. II 2S-12-1O I,
~
State: C.R.S.134-32-101
~ and regulations, 2 CCR
407-1
Description
RegulAtes worker heallh D"nd
safely.
Regulates working conditions In' No
underground mines to assure
safety and health of workers.
Regulates transportation of
hazardous materials
Establishes standards for
controlling noise.
Regulates QII aspects of mining,
including local Ion of operalions,
reclamation, IInd other
environmental and
socioeconomic impacts.,
Potentially Applicable or
Relevant and Appropriate
No
Applicable
No
Yes
Comment
While not an ARAR, these
requirements will apply
during Implementation of
remedies at the site.
While not an ARAR, the
requirements will be met If
It becomes necessary t~ .
access underground mine
workings.
(fhazardous materials are
transported offsite these
regulations will be attained.
Will apply to sludges or
spent or process chemicals
if determined hazardous.
While not an ARAR,
applicable standards will be
met during construction
actlvilies atlhe Summllville
site. '
-------
rotelltl~lIy Applicable or
Relevant and Appropriate:
NationallJistoric Preservation Act
Archeological and.Historic
Preservation Act of 1914
Historic Sites Act of 1935,
Execulive Order 11593
Colorado Wildlife Enforcement and
Penalties
Table 7 (continued)
Potential Action Specific ARARs
CUatlon
16 U.S.C. f 410
40 C.F.R. f 6.301(b)
36 C.r-.R. Part 800
State: C.R.S. U 24-80-101-108
16 U.S.C. f 469
40 C.r-.R. f 6.301(c)
16 U.S.C. U 461 ~
40 C.F.R..f 6.301(a)
State: C.R.S. fA 33-1-101,
n.wa.
DeserlptlQO
EPA must account for the
. affects of any aClion on any
property with historic,
archilectural, archeologlcal.or
cultural value thai is lis led or
. eligible for listing on Ihe
National Regisler of llistorlc
Places, or the Colorado Register
ofHlsloric Places.
Establishes procedures to
preserve historical and
archeological data which might
be destroyed through alteration
of terrain as a result ora federal
constl1lctlon project or a
federally licensed activity or
progranl. .
Requires federal agencies to
consider the existence and
location of landmarks on the
National Registry of Natural
Landmarks to avoid undesirable
impacts on such landmarks.
Prohibits aCllons detrimental to
wildlife.
Polentlally Applicable or
Relevant and Appropriate
Applicable
Applicable
Applicable
Applicable
Comment
A survey will be performed
50 that the Colorado Slate
Historic Preservation
Officer may delemline if
ports of the site are eligible
for Inclusion on the Siale or
National registers. (See
section 5.2).
A survey will be performed.
10 Identify data Ihat requires
prolection during remedial.
activities.
. A survey will be performed
to identify potenlial natural
landmarks.
During the design phase of
the remedy, consideration
will be given to the
-------
Potenllally Applicable or
Uclevant and Appropriate
Wildlife Commission Regulations
Fish and Wildlife Coordination Act
Endangered Sl1ecles Act
Coastal Zone Managemenl Act
Tobie 7 (continued)
Potential Action SI)edlic AltARs
Cltallon
Siale: 2 CCR 405-0
16 U.S.C. U 661-666
,40 C.F.R~ f 6.302(g) ,
16 U.S.C. If 1531-1543
50 C.F.R. Paris 17,402
40 C.r-.R. f 6.302(h)'
State: C.R.S. U 33-2-101,
~
16 U.S.C. II 1451-1464
Descrlpllon
Establishes specific
requirements for protection of
wildlife.
Requlres'consultation when
federal department or ogency
proposes or authorizes any
modification of any stream or
other woter body to provide for
adequate provision for
protection of fish and wildlife
. resources.
Requires that fedemlagencles
Insure thai any acllon
authorized, funded, or carried
out by the agency Is not likely to
jeopardize the continued
existence of any Ihreatened or
endangered species or destroy or
adversely modifY critical'
habitat.
Prohibits federal agenc:les from
undertaking any activity that Is
not consistent with a slate's
approved coastal zone
management program.
I'otentlally Applicable or
Uclevant and Appropriate
Applicable
Comment
During the design phase of
the remedy, requlremenls
for the protection of
wildlife will be met in the
Summltville Mine area.
. .
. Applicable
Prior to modification of
water bodies appropriate
agencies will be consulted.
See section 5.1.
Applicable
A survey of threatened and
endangered species Is
underway. Prior to any
action thai would jeopardize
the continued existence of
any threatened or
endangered species or
destroy or adversely modifY
critical habitat, appropriate
State and Federal agencies
will be consulted. See'
section 5.3.
No
The site Is nolln the
-------
, Potentially Applicable or
Relevant and Apprpprlate
Wild and Scenic Rivers Act
Executive Order on Protection of '
Wetlands
Executive Order on floodplain
Management
Rivers and Harbors Act of 1899,
Section 10 Penn it
Table 7 (continued)
Potentlnl Action Speclfic,ARARs
CUatlo!)
16 U.S.C. U 1271-1287
40 C.F.R. g 6.302(e)
36 C.F.lt. Part 297
Exec. Order No. 11,990
40 C.F.R. g 6.302(b) and
, Appendix A
Exec. Order No. II, 988
40 C.F.R. g 6.302(b) and
Appendix A
33 U.S.G. g 403
33 C.F.R. Parts 320-330
Description
Establishes requirements
applicable to water resource
development projects affecting
wild, scenic, or recreational
rivers wilhln or studied for
. Inclusion in the National Wild
and Scenic Rivers System.
Requires federal agencies to
evaluate the potential effects of
actions they may take in
wetlallds to minimize adverse
impacts to the wetlands.
Requires federal agencies to
evaluate the potential effects of
actions they may take in a
floodplain to avoid, to the
maximum extent possible, the
adverse impacts associated with
. direct and indirect development
of a floodplain.
Requires permit for stmctures or
work in or affecting navigable
waters.
Potentially Applicable or
Relevant and I\pproprlnte
Applicable,
Applicable
Applicable
No
Comment
The site is not a wild,
scenic, or recreational river,
in the National Wild and
Scenic River System's. It
will be detennined if any
part of the site is included
In the Inventory of rivers
under consideration.
Wetlands will be
,inventoried and considered.
Floodplains potentially
impacted will be
inventoried and considered.
Surface water oflhe
Summltville Mine Site are
not navigable within the
meaning of Section 10 of
the Rivers and Harbors Act
-------
Table 8
Nmneric Surface Water Quality Goals and ARARs
. Alamosa River - Monitoring Station AR-45.4.
METAL StJRFACE WATER QUALITY GOALS
Class 1 (TVS)
pH .u 6~9.0
AbmIimIm. c:IInIIK I'7vpI cIisIDmd. May IIiInIqII ScpD:mbc:r 30 lIIIIy. For baIaa&:e or
year Chmaic - AcuII: TVS - 7SOa111 dissolVed
AneDic. - SOu!!llIDlal ~c. I~
Cadmium. c:Iaaaic 2.Ju9I dissolved @ 25Om~ b8rdDI:ss
CIIrame VI. c:IInIaic II ugf1 dis.som:d
. Copper, c:IInIIK 3Oa&fI dissoIwd. buai upgalSth pa=IIiIe 8mbiaa cilia u- segIIICIII
3.
Cymide Sugf1. l~
Iroa. cbroIIic I2,OOOagfllDlllreamrable. buaJ upoa ISth ~ IIIIbiatt cilia
L=d. c:!IIaaic 14qIl dissoIved@25Om!ll1b8rdD1:ss
Mqm:sc. dIroaic lOOOugf1. dissolved
Mercury. cbnmic O.OIugf1.1D1a1 ~e
N"acb:I. cbnmic I ~l dissolved @2S0Iqf\ IIII'cIIIess
. SiM:r. cbraaic. InIUt O.36ugf1 dissolved @2SOmgll b8niDess
ZiIic. c:broaic ~ dissolved@25Om!Vl b8niDess
.
.
Nore: Based upon WQCD fiDdiDg of 2S0mgIl hardness.Reservoir.
.
-------
Table 9
EVALUATION OF ALTERNATIVES
Criteria AJtenlative No. I AJternative No. 2 AJteruative No.3
NoAcrioa Oa-site tapsoiJ wiCla amaulmaru Imported tapsoil
. Overa11 ProteCtion of No. docs not provide any Yes Yes
Human Health and the measure of protection.
Environment
Compliaace with ARAR's No Yes Yes
Loag-tem1 effectiveness No Yes, biocides are designed Yes. importing sufficient
and pezmaaence to provide acid DeUtraIization soil provides two feet of .
for seven years. Infiltration growth medium, ~isIs
to the acidic rock: wiII be in reducing the
reduced.. iDfiItraaon by surfiIce
waters.
Reduction oftoxic:ity, No Yes, bioc:ides reduce acidic Yes, two feet of growth
mobility, or volume mobility 8Dd vegetirion medium reduces
reduces iafikrmcm to the infiltration to the acidic
acid ~c:radag layer. genemring layer.
Shon-term effeaiveaess No Yes, reduces acid Y cs. reduces iDfi1trar:ion.
generation. to acid material
Implememability Yes, periodic moairoring Yes Yes
required.
CostS Capital / Acre 'SI4,910 S89,64O
COStS Capital! 200 Acres S2,982,000 SI 7,928,000
Costs Capital I SSO Acres S8,200.5OO S49,302,000
M~ I Acre S90 S1,020 S1,020
. .
Moniroring! 200 Acres S18.000 S204,OOO S204,OOO
Monirodng / 550 Acres S49.5oo $561,000 SS61,000
Present Worth / Acre $500 .. $21,260 S9S,990
Present Worth 1200 Acre SI06,OOO S4,252,000 SI9~198,OOO
Present Worth/ 550 Acres $291.500 S11,693,ooo S52.794.500
.
-------
?
a..
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=- :!'8fta
.
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8E:CCII
"f8V
ENLARGED AREA MAP -
o. ... ..
'- ....- ~ ,-...- _.1_.. .1_- 1:3"...-.. C::"",,..,ffvilla
t::olnrado
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:- -.
FIGURE 1 -:
,- ,AREA MAP
!!'I'R0NMENTAL CHEMICAL
-------
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LEGEND
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FIgure 2
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Foolprlnl
8
INVIROHl/lHtAl I;HIIflCA\
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FIGURE 5
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!is!! ~~'TRO\I[~A "0:4
------- |