Environmental Protection
Agency
Emergency and
R»m*di*l
July 1935
Superfund
Record of Decision:
McKin Site, ME
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TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
1. REPORT NO.
EPA/ROD/R01-85/009
2.
3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
SUPERFUND RECORD OF DECISION
McKin Site, ME
S. REPORT DATE
.Tilly 22.
6. PERFORMING ORGANIZATION CODE
7. AUTHOH(S)
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
12. SPONSOR*NG AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency
401 M Street, s.W.
Washington, D.C. 20460
13. TYPE OF REPORT AND PERIOD COVERED
Final ROD Report
14. SPONSORING AGENCY CODE
800/00
IS. SUPPLEMENTARY NOTES
16. ABSTRACT
The McKin Company site is located on the west side of Mayall Road
between Route 115 and Pownall Road in Gray, Maine. The site is approx-
imately seven acres with 4.5 acres cleared and partially excavated. Be-
tween 1965 and 1978, the McKin Company operated a waste collection,
transfer, and disposal facility at the site. The Remedial Action Master
Plan (RAMP) for the McKin site was prepared in April 1983. Initial
Remedial Measures (IRMS) implemented at the site included cleaning and
removal of all remaining above-ground tanks. This work was completed in
September 1985 and represents the most recent removal action to take
place on the site. Presently, the site consists of a fenced enclosure
containing an incinerator, a concrete block building, an asphalt-lined
lagoon, miscellaneous debris, and one buried fuel tank. An outer fence
along Mayall Road and portions of the northern and southern site bound-
aries restrict vehicle and pedestrian acess to the site.
The selected remedial action includes: on-site soil aeration; off-
site disposal of approximately 16 drums; soil tests; a groundwater ex-
traction, treatment, and surface water discharge system; off-site ground
water and surface water monitoring program to evaluate the effectiveness
of the on-site source control and off-site groundwater extraction and
17,
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lOENTIFIERS/OPEN ENDED TERMS C. COS ATI Field/Group
Record of Decision
McKin Site, ME
Contaminated Media: soil, gw, sw
Key contaminants; 1,1,1 Trichloroethane,
DCE, TCE, oils, methylene chloride,
volatile organics
21. NO. OF PAGES
57
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None
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None
22. PRICE
EPA F«rn 2220-1
v. 4-77)
i* OMOLCTC
RODRO185OO9
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16. ABSTRACT, Con't.
treatment system; and site removal and closure activities. Total
capital cost for the selected remedial alternative is estimated to
be $3,919/000 and O & M costs are approximately $38,900 per year.
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RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION
Site: McKin, Gray, Maine
DOCUMENTS REVIEWED
I am basing my decision primarily on the following documents
describing the analysis of cost-effectiveness of remedial
alternatives for the McKin site:
1. Remedial Investigation for McKin Company Hazardous Waste
Site, Gray, Maine, January 1985, prepared for the State
of Maine, Department of Environmental Protection, Augusta,
Maine, prepared by Camp Dresser and McKee, Inc., Boston,
Massachusetts.
2. Feasibility Study for McKin Company Hazardous Waste Site,
Gray, Maine, March 1985, prepared for State of Maine,
Department of Environmental Protection, Augusta, Maine,
prepared by Camp Dresser and McKee, Inc., Boston,
Massachusetts.
3. Summary of Remedial Alternative Selection (attached).
4. Community Relations Responsiveness Summary (attached).
5. The National Oil and Hazardous Substances Pollution
Contingency Plan, 40 C.F.R. Part 300.
6. 40 C.F.R. Part 264 - Standards for Owners and Operators
of Hazardous Waste Treatment Storage, and Disposal
Facilities.
7. Hydrogeologic Study, East Gray, Maine for the Maine
Department of Environmental Protection, November 29, 1982,
prepared by Robert G. Gerber, Inc.
8. Health Surveillance Program Protocol for persons Exposed
to Hazardous Wastes from the McKin Dump site, Gray, Maine,
prepared by State of Maine, Department of Human Services,
Bureau of Health, Division of Disease Control, August, 1983
9. Compilation of Information Generated since May 6, 1985,
Regarding Record of Decision for McKin Site, July 1, 1985.
10. Memoranda, letters, and recommendations of staff and
other Federal agencies.
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DESCRIPTION OF SELECTED REMEDY
- On-site aeration of soils in site areas of identified
hazardous substance contamination to achieve soil quality
levels protective of public health, welfare, and the
environment.
f Off-site disposal of approximately 16 drums found on the
site and their contents.
- Performing soil tests in petroleum contaminated areas to
characterize further the nature of contamination.
- Constructing a groundwater extraction, treatment, and
surface water discharge system and operating this system
as a remedial treatment unit for a period of five years
with a target groundwater performance standard of 92 ppb
1,1,1-trichloroethane and 28 ppb trichloroethylene for
groundwater quality.
- Re-evaluating the groundwater performance standard, if this
standard is not achieved at the end of the five-year period
or earlier if warranted by system performance or site
conditions.
- Initiating an off-site groundwater and surface water
monitoring program to evaluate the effectiveness of the
on-site source control and off-site groundwater extraction
and treatment system.
- Performing site removal and closure activities including
disposal of on-site debris, disposal of discrete areas
of significant non-volatile contamination not identified
in the RI, disposal of metallic structures, demolition
and disposal of the site's building, draining and filling
in the lagoon, removal and disposal of known buried drums
and their contents, removal and disposal of decontamination
rinsate and other waste materials that result from remedial
activities, removal and disposal of a buried fuel tank,
fencing the site with appropriate signs, learning the
site, and vegetating the site.
DECLARATIONS
Consistent with the Comprehensive Environmental Response
Compensation, and Liability Act of 1980 (CERCLA), and the National
Contingency Plan (40 C.F.R. Part 300), I have determined that at
the McKin Company site, on-site soil aeration, extraction and
treatment of groundwater from off-site contaminated areas and
the other measures as described above are the cost-effective
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renedies for the on-site soil and off-site groundwater
contamination and provide adequate protection of public
health, welfare, and the environment.
The State .of Maine has been consulted and concurs with the
selected remedy* In addition, the action will require
operation and maintenance activities to ensure the continued
effectiveness of the remedy. These activities will be
considered part of the approval action and eligible for Trust
Fund monies for a period of one year from the completion of
remedial actions.
I have also determined that the action being taken is the
cost-effective alternative when compared to other remedial
options reviewed and is appropriate when balanced against the
availability of Trust Fund monies for use at other sites. In
addition, the off-site transport and secure disposition of a
small quantity of contaminated drums and other material is
more cost-effective than other remedial action for this small
quantity of contaminated drums and other materials.
Date / Regional Administrator
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SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
McKin Company Site - Gray, Maine
SITE LOCATION AND DESCRIPTION
The McKin Company site is located on the west side of
Mayall Road between Route 115 and Pownall Road in Gray, Maine,
approximately fifteen miles north of Portland, Maine and the
Atlantic Ocean (see figure 1). The site is approximately
7 acres with approximately 4.5 acres being cleared and partially
excavated. Between 1965 and 1978, the McKin Company operated
a waste collection, transfer, and disposal facility at the
site.
Following removal actions, the site presently consists
of a fenced enclosure containing an incinerator, a concrete
block building, an asphalt-lined lagoon, miscellaneous
debris, and one buried fuel tank. An outer fence along
Mayall Road and portions of the northern and southern site
boundaries restricts vehicle access and deters pedestrian
access to the site.
The topography of the site area is relatively flat west of
Mayall Road. The topography of the site has been modified by
past excavations, with the on-site fenced enclosure surrounded
by steep upward slopes to the west, south, and north. At-grade
access is from Mayall Road, and beyond Mayall Road, the land
slopes steeply eastward to the Royal River. Elevations range
from approximately 300 feet mean sea level (MSL) at the site
to less than 200 feet MSL at the river, approximately 3/4 miles
due east. The site area is located on a relatively permeable
glacial outwash plain comprised of stratified sand, gravel, and
boulders overlying heavily weathered granitic bedrock (see
figure 2). Cores of the underlying bedrock were moderately
to heavily fractured and demonstrate a moderately high bulk
permeability as determined by computer simulations. No
surface run-off from the site has been observed, and it is
inferred that site surface drainage is contained on-site and
incident water either evapotranspirates or percolates into
the soil* The eventual surface discharge location of this
percolating water is the Royal River system. The Royal River
is a State Class C waterway, acceptable for recreational
boating and fishing, but not for water contact recreation or
as a drinking water source without treatment. The site is
not located in a wetland or floodplain based on a site evaluation
by the U.S. Army Corps of Engineers.
Neighboring lands include residential areas, wooded areas,
and rural farmland. The nearest residences are immediately north
and west of the site, located within 1500 feet of the site and
within a triangle formed by Pownal Road, Mayall Road, and
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Route 115. The closest home is within approximately 200 feet
of the site. The bedrock aquifer beneath homes to the north
of the site served as a private water supply until private
wells were contaminated with chlorinated organic compounds.
SITE HISTORY
In 1963 Richard A. Dingwell, the owner of the McKin Company,
purchased the McKin site and shortly thereafter began to use
the site to store and dispose of liquid wastes. Prior to use
by the McKin Company, the land was reportly used intermittently
as a sand and gravel pit. From 1965 to 1978 the McKin Company
operated a tank cleaning and waste removal business using the
Gray site for collection, storage, disposal and transfer of
petroleum wastes and industrial chemical wastes. Waste
handling facilities at the site used during McKin Company
operations included 22 above-ground storage tanks, an asphalt-
lined lagoon, and an incinerator (see figure 3). Liquid
wastes were trucked to the site by the McKin Company and
others. On-site waste handling procedures included discharge
to the ground, storage in tanks or the lagoon, transport
off-site by truck, incineration, and on-site burial. Approxi-
mately 100,000 to 200,000 gallons of waste were received
annually by the McKin facility between 1972 and 1977.
In 1972 the McKin Company business expanded and the on-site
asphalt lagoon and the incinerator began operating to accommodate
wastes generated by an ocean oil spill when a tanker owned by
Texaco ran aground off the Maine coast. The McKin Company held
a permit from the Maine Department of Environmental Protection
to operate the incinerator in the 1970*s. Use of the incinerator
ceased in or around 1973. Site operations ended in 1977 or 1978.
As early as 1973, nearby residents in East Gray reported
odors in well water and discoloration of laundry. Sampling
indicated the presence of organic contaminants in residential
wells, and the Town of Gray issued an Emergency Health Ordinance
placing a moratorium on any new construction within about two
miles of the site. In November 1977 Fred C. Hart Associates,
a contractor to EPA, conducted a hydrogeologic assessment of
the area, which indicated contaminants from the McKin site
had reached many local private wells. In December 1977, the
Town of Gray issued a Cleanup Order to the McKin Company.
Also in December 1977, sixteen private water supply wells were
capped, and emergency water supplies were brought in by truck
to service nearby residents. In August 1978 affected homes
were connected to a public water supply in an action funded by
a $300,000 "Imminent Threat Grant" from the U.S. Department
of Housing and Urban Development (HUD) and matching funds from
the Town of Gray. The Maine Attorney General's office filed a
suit against the McKin Company in 1978. This suit has not
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been resolved. A separate class action initiated by a Gray
citizens group was settled out of court. During the summer
of 1979, Maine DEP supervised the removal of pumpable liquid
wastes from the above-ground tanks and drums. This amounted
to approximately 33,500 gallons of oil and chemical waste.
Additional DEP actions taken in 1979 and 1980 included moving
empty 55 gallon drums into the fenced area, performing a
magnetometer survey, installing and sampling monitoring wells
around the site and collecting and analyzing soil and groundwater
samples. In a November 1982 hydrogeologic study prepared by
Robert G. Gerber and funded by DEP, Gerber simulated groundwater
movement in the site area and concluded that local groundwater
contamination in the surficial and bedrock aquifer resulted
from waste disposal practices at the McKin site. Air quality
at the site was monitored by EPA in November 1982, and residual
materials in the above-ground tanks were sampled and analyzed
by DEP in March 1983. In April 1983, DEP contracted Jetline
Services to rinse and crush a number of on-site barrels and
containers and provide cost estimates to clean and dispose of
all remaining above-ground tanks.
A Remedial Action Master Plan (RAMP) for the McKin site was
prepared in April 1983 by Camp, Dresser and McKee (COM) under
contract to EPA. The RAMP recommended collecting the necessary
data, developing the required site area remedial action program
and implementing certain Initial Remedial Measures (IRM's)
to remedy potential hazards. DEP entered into a Cooperative
Agreement with EPA in June 1983 to implement the IRM's and the
Remedial Investigation and Feasibility Study (RI/FS) as recommended
in the RAMP. The IRM work conducted by Jetline Services included
the cleaning and removal of all remaining above-ground tanks from
the site. This work was completed in September 1983 and represents
the most recent removal action to take place on the site. In
January 1984, CDM was awarded a contract by DEP to undertake
the RI/FS for the McKin site. The Rl was completed in February
1985 and the FS in March 1985.
CURRENT SITE STATUS
As identified in the RI, there are two remaining major
contamination problems associated with the site. The first is
on-site soil contamination in specific areas, which serves as
a source for off-site groundwater contamination. The second
is groundwater contamination of the surficial and bedrock
aquifers downgradient of the site. These two problems are
considered in a series of source control alternatives and a
second series of off-site control alternatives in the FS.
On-site Soil Contamination
The nature and extent of the on-site contamination problem
was identified during the RI based on surface and sub-surface
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on-site soil sampling conducted by means of drilling (see
locations in figure 4), test pits (see locations in figure 5),
hand auger borings (see locations in figure 6), and monitoring
contamination in horizontal grids around contaminated locations.
Sample locations shown in figures 4, 5 and 6 were selected in
part based on detected magnetic anomalies, historical disposal
data and visual evidence of contamination. The laboratory
analytical results of on-site soil samples are summarized
in Table 1. The samples listed in Table 1 were analyzed
during the RI and found to contain all or some of the 17
hazardous substances listed in Table 1. In soil tests conducted
in 1980, other priority pollutants were detected in on-site
soils in concentrations ranging from zero to several parts
per million (ppm). These pollutants include polyaromatic compounds,
phenols, and phthalates. Based on Maine DEP records the
locations of these 1980 soils tests were near soil borings
SS08 and SS01 shown in Figure 6 taken during the RI.
Each of these 17 hazardous soil contaminants detected in the
RI can be classified as either a volatile organic compound or
a heavy metal. Generally, the volatile organic compounds
such as trichloroethylene and 1,1,1-trichloroethane are
soluble and susceptable to leaching and migration to the
groundwater. The detected concentrations of heavy metals
are relatively small {15 ppm soil or less) and within
ranges typically found in soils. Compared with the volatile
organics, the heavy metal contaminants are generally
less susceptable to leaching and migration to groundwater.
Of the contaminants detected in on-site soils only trichloro-
ethylene and 1,1,1-trichloroethane were detected in ground-
water during the RI.
Six areas of surface soil contamination were identified
and staked out in the field based on surface and subsurface
tests. These areas are identified on a site map in Figure 7,
as Areas 1 through 6. Area 1 is further divided in Areas 1A,
IB and 1C based on physical and chemical properties. Volume
estimates of the contaminated soil in each area are provided
in Table 2.
Areas 1A, 1C and 2 appear to be old oil disposal locations,
where oil soaked debris and other suspected contaminants were
disposed of and covered with various thicknesses of fill, in
areas 1A, 1C, and 2, the major contaminants appear to be
typical derivatives of petroleum refining, constituents
of petroleum, or incidental petroleum contaminants based on
laboratory analyses and physical observations. It is possible
that remedial actions in areas 1A, 1C, and 2 are not covered
by CERCLA given the discrete nature of this petroleum contami-
nation on this site and the lack of groundwater contamination
by typical constituents of petroleum. Further soil tests are
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required to make this determination and will be performed during
the remedial design. Prior to this determination areas lAr
1C, and 2 are not specifically included in the on-site CERCLA
remedy described herein.
Areas 3, 4, and 5 are the most contaminated areas found
remaining on the site. Aerial photographs reveal that areas
3, 4, and 5 exhibit obvious signs of discoloration and contami-
nation. Among the most contaminated soils found on-site are
those in test pit TP6A, in Area 3 (1400 rag/kg trichloroethylene,
49 mg/kg methylene chloride, 4.5 mg/kg 1,1 l-trichloroethanef
and other contaminants), and soils found in soil boring SS02
in Area 4 (1500 mg/kg trichlorethylene, 21 mg/kg xylenes,
9.2 mg/kg dichlorobenzene, and other contaminants).
The depth of contamination in Areas 1, 2, 4, 5 and 6 was
identified at six feet or less in the RI field studies. The
depth of contamination in Area 3 is at least 12 feet, and a
40 foot depth, the measured depth to groundwater in the area,
has been used to estimate conservatively the volume of contami-
nated soil in Area 3. In addition to soil contamination in
Areas IB, 3,4,5 and 6, sixteen drums were located on the
site as presented in Table 3. The FS addresses source control
remedial action for Area IB, 3, 4, 5 and 6, the 16 known
buried drums, and the remaining building and structures on
the site.
Off-site Groundwater Contamination
The off-site groundwater contamination problem caused by
the McKin site was investigated in the RI by groundwater
monitoring and modeling. Groundwater at various depths was
sampled in locations shown in Figure 8. Of the compounds
analyzed for in the RI (see Table 4) the only compounds
detected in the off-site groundwater were 1,1,1-trichloroethane
and trichloroethylene as presented in Table 5.
Previous tests identified 1,1,1-trichloroethane and
trichloroethylene as the major groundwater contaminants with
several other contaminants also identified in the off-site
groundwater. Some of the previously detected compounds such
as 1,2-dichloroethane, 1,1-dichloroethane, chloroform, and
tetrachloroetheylene were tested for specifically and not
detected during the RI. Others, such as dimethyl sulfide and
Preon, are not considered priority pollutants.
In the surficial aquifer, the location of the highest level
of contamination is B-l, which is approximately 600 feet
north, northwest of the site adjacent to Pownal Road (16,000
ppb trichloroethylene and 170 ppb 1,1,1-trichloroethane).
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The location with the next highest level of contamination in
the surficial aquifer is B-3, approximately 1200 feet north
northeast of the site (1,800 trichloroethylene and 65 ppb
1,1,1-trichloroethane). These levels and a computer simulation
of groundwater flow reveal a groundwater contamination plume.
In the surficial aquifer the contamination plume is located
from the site for roughly 1,000 feet, then swings to the east
towards the Royal River. The inferred surficial aquifer plume as
modeled with observed 1984 1,1,1-trichlorethane concentrations
is presented in Figure 9. A north-south bedrock ridge directly
east of the site appears to account for the swing in the
surficial aquifer direction in the site vicinity. Location
B-3 represents the furthest lateral extension of surficial
aquifer contamination detected in the RI field studies. The
well at B-4 which is screened at the soil-bedrock interface
approximately half-way between the site and the Royal River
did not show detectable contamination. This may indicate that
the contamination is contained entirely within the bedrock
at that point.
In the bedrock aquifer, which prior to 1977 served as the
drinking water supply of nearby residences, the groundwater
appears to be conducted in fractures and cracks. The location
of the highest level of contamination is B-l approximately
600 feet north, northwest of the site and adjacent to Pownal Road
(29,000 ppb trichloroethylene and 500 ppb 1,1,1-trichloroethane).
Downgradient concentrations of trichloroetheylene in the bedrock
groundwater at B-2, B-3, and B-5 are 56 ppb, 120 ppb and 190 ppb,
respectively. Figure 10 depicts the bedrock aquifer plume,
as modeled with the 1984 1,1,1-trichloroethane concentrations.
The information suggests that the centerline of the bedrock
contamination plume falls more or less under the surficial
aquifer contaminant plume, however the bedrock contamination
plume is more dispersed than the surficial aquifer contamination
plume. This is attributed to the fractured nature of the bedrock.
The eventual discharge location of both the surficial and
bedrock aquifers is the Royal River system. This system includes
a number of springs, including Boiling Springs, located on the
easterly sloping land between the site and the Royal River.
Previous sampling programs found trace amounts of volatile
organic contaminants in Collyer Brook, a tributary to the
Royal River. During the 1984 RI field study, surface water
quality monitoring was performed in both of these surface waters
as well as Boiling Springs and the on-site lagoon (see Figure 11).
The laboratory results presented in Table 6 indicate the levels
of trichloroethylene and 1,1,1-trichloroethane in Collyer Brook
and the Royal River are below a 1 ppb detection level. Concen-
trations of trichloroethylene (44 and 32 ppb) and 1,1,1-trichloro-
ethane (30 and 10 ppb) were detected in Boiling Springs. The
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absence of any volatile organic contaminants in the Royal
River or Collyer Brook indicate that these water courses are
not being adversely impacted by the McKin site. The most
probable explanation for these absences is the volatilization
of these contaminants from the surface water.
Risk Assessment
Current potential health and environmental risks involved
with no action alternatives are associated primarily with
contaminated groundwater. For exposures to other environmental
media, the risks are insignificant based on comparisons with
relevant guidelines and the risk assessment performed in the
FS. The risk assessment performed in the FS, as summarized below,
is based on hydrogeology, climate, toxicity data, and other factors
The concentrations of contamination in the Royal River
present neither a significant health risk through direct
ingestion of river water or dermal absorption during swimming
nor a significant environmental risk to aquatic species in
the river based on a comparison with applicable or relevant
EPA criteria. On-site air monitoring detected concentrations
of contaminants below available state guidelines for ambient
air levels. Ingestion of ten grams of the most contaminated
on-site soil would result in an exposure to trichloroethylene
below known acutely toxic effects and the risk from chronic
ingestion of contaminated soil is not significant based on
limited exposures to the site and the degree of soil contami-
nation. Acute or chronic public health affects from dermal
contact with on-site contaminated soil are not expected
based on soil concentrations, the volatile nature of the
contaminants, and toxicological literature.
The release of contamination to the off-site aquifer is an
impact to an environmental resource. It has caused the
closure of private wells. Since this aquifer also represents
a potential drinking water source, the existing contamination
may restrict future use of this resource. The public health
risk associated with the groundwater contamination is considered
potential because there are no known users of the groundwater
for a drinking water supply since extension of a municipal
water line in 1977. No EPA primary drinking water standards
exist for the two detected groundwater contaminants. For
1,1,1-trichloroethane, not classified as a suspected human
carcinogen, the most relevant guideline for risk assessment
is a proposed recommended maximum contaminant level (RMCL)
of 200 ppb. This level is exceeded in one of the groundwater
monitoring wells (B-l,bedrock). Trichloroethylene is a
suspected human carcinogen, and the concentrations associated
with a 10~5 lifetime risk of cancer for a 2 liter per day
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water intake by a 70 kg adult is 28 ppb based on Cancer
Assessment Group (CAG) data. This guideline level is
exceeded at most of the groundwater sampling locations.
Therefore, there is a public health risk associated with the
long term consumption of groundwater at its present contami-
nation levels. Furthermore, groundwater is considered an
integral portion of the environment, and therefore, the
presence of groundwater contamination at levels found in the
RI represents a risk to the environment.
ENFORCEMENT ANALYSIS
Potentially responsible parties (PRP's) for the McKin site include
the former owner and operators, generators, and transporters.
To date, approximately ten notice letters have been sent to
generators or transporters based primarily on McKin Company
records, which suggest these parties contributed hazardous
substances to the site. EPA is continuing to identify additional
responsible parties and may send out further notice letters
as new evidence is developed. There are also over two hundred
additional parties which apparently sent petroleum wastes to
the site.
Richard Dingwell is the former owner and operator of the
McKin Company at the Gray site. Dingwell was sued by the Maine
Attorney General's Office in 1978 and this case has not been
resolved, in addition, a separate class action suit was filed by
a Gray citizens group and was settled out of court.
Several of the potentially responsible parties have expressed
written interest in participating in the remedial design and
construction process. EPA is continuing negotiations with these
parties. Representatives of these companies have also participated
in the public hearing and public comment period. Given the
interest in responsible party cleanup by potentially responsible
parties there is a chance of concluding successful negotiations
for construction.
EPA1s overriding concern is ensuring that the selected remedy
complies with the National Contingency Plan. In this regard,
there is no flexibility for negotiations. Technical differences
in design and construction approaches used to achieve this
remedy may be the subject of negotiations. Technical differences
between the selected remedy and the remedies proposed by the
potentially responsible parties are contained elsewhere in this
document and in the attached Responsiveness Summary.
COMMUNITY RELATIONS
Community interest in the McKin site has been strong since
the detection of contamination in the 1970's. A public meeting
to describe the RI/FS and to respond to citizen's questions was
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held at Stinson Hall in Gray, Maine on April 17, 1985. Approxi-
mately 40 persons attended including citizens, elected officials,
and technical and legal representatives of potentially responsible
parties. On April 24, 1985, a public hearing was held at the same
location to record comments by the public including potentially
responsible parties. Comments were given by Maine DEP, the
Town Council, the Gray Conservation Commission, private
citizens, the Maine's People's Alliance, two state congressmen,
and three representatives of potentially responsbile
parties. Written comments from some of the same parties and
additional parties were received during the remainder of the
public comment period. These comments and EPA's responses
are included in the attached responsiveness summary. In
addition, the comments are summarized below. Following two
tine extensions, the public comment period on the RI/FS was
extended twice to ensure that all interested parties had an
opportunity to comment and was open from March 27 to May 6, 1985.
On July 2, 1985, EPA representatives participated in a
Gray Town Council Meeting to inform the Council and the public
of EPA's proposed remedial action and to answer questions
from the Council and the public.
Regarding source control alternatives, oral and written
statements against capping have been made by Cathy Hinds of
the Maine's People Alliance (speaking for a number of citizens
at the public hearing), other citizens, State Representative
Donnell P. Carroll and State Representative James Mitchell.
The Maine's People Alliance favored on-site incineration.
The Town Council considered the proposed alternatives and was
split with three councilors endorsing a cap and two councilors
preferring incineration. The Town Council stated a preference
for a clay cap rather than a synthetic cap. A letter represent-
ing four residents near the Gray site indicated a changed
preference from incineration to capping. Capping was endorsed
as the least objectionable source control method in a separate
letter from a member of the Gray Planning Board and the McKin
Site Evaluation Committee. The State DEP and potentially
responsible party representatives presented comments in favor
of on-site aeration as a source reduction method. Public
health concerns regarding airborne emissions are the
most often cited objection to both aeration and incineration
while public objection to capping centers on the argument
that a cap covers but does not eliminate the waste and
eventually contaminants will emerge.
A number of comments also were received regarding off-site
control alternatives. Many comments centered on the inequity
of possibly having the state tax-payers saddled with the burden
for payment of operation and maintenance costs. Comments
received from citizens and from the Town Council endorsed
extraction and treatment of groundwater from the contaminated
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aquifer. The Maine's People Alliance and citizens were in
favor of Alternative 1C, specifically. Considerable opposition
to an off-site groundwater extraction system and questions
regarding the system were raised by potentially responsible
parties and by Maine DEP. Concerns primarily centered on the
cost effectiveness of an off-site groundwater recovery system,
the system's feasibility, and the need to accelerate actively
the restoration of the aquifer which is not presently being
used as a drinking water supply.
CONSISTENCY WITH OTHER FEDERAL ENVIRONMENTAL LAWS
One measure used by EPA in determining whether a remedial
alternative at Superfund sites adequately protects public
health, welfare, and the environment is whether the alter-
native attains the substantive provisions of other federal
public health and environmental standards. The primary
Federal Standards which are relevant to the McKin site are
the provisions and regulations of the Resource Conservation
and Recovery Act (RCRA) describing site closure and groundwater
monitoring requirements for RCRA treatment, storage, and
disposal facilities. In addition, the requirements of the
National Pollutant Discharge Elimination System (NPDES)
program are applicable to the discharge of waste streams to
surface waters.
The following source control alternatives have been proposed
to meet RCRA requirements for hazardous waste facilities and
hazardous waste handling when applied to the site, either
individually or combination:
Qn-site Aeration; The RCRA closure regulations require
either closure by removal of waste and waste residues which
is equivalent to closure as a surface impoundment or closure
as a landfill by capping and appropriate post closure care.
The proposed aeration process, will meet the intent and
technical requirements of the general RCRA closure standards
(40 C.F.R. Part 264 Subpart G) and the specific closure
standards of 40 C.F.R. Part 264 Subpart K (Surface
Impoundments). The surface impoundment standards, and
specifically 40 C.F.R. §264.228 the applicable closure standard,
require the removal or decontamination of all waste
residues and contaminated subsoils. As discussed
herein, the residual soil contamination level after the
aeration process that will be protective of human health
and the environment is 0.1 ppm trichloroethylene. This
level was determined by site specific solute fate and
transport modeling that considered the potential impact
of this level on groundwater. This level was reviewed
by the Centers of Disease Control and found to pose no
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hazard for direct soil ingestion, particulate ingestion or
dermal contact. A groundwater monitoring program will be
implemented to monitor water quality and verify the assumptions
made in the fate and transport modeling.
Excavation of Contaminated Soil, Debris, and Buried Drums
with Off-site Deposition:This alternative meets the
relevant requirements of RCRA. Disposal of wastes will be
in accordance with the appropriate RCRA regulations for
the transportation and disposal of hazardous waste.
Off-site facilities used for disposal or incineration will
be RCRA approved facilities which have a permit or interim
status and are in compliance with the RCRA regulations.
Proper manifesting of wastes will be conducted. Off-site
disposal will not require on-site treatment, storage
beyond staging time or disposal of hazardous wastes, and
therefore, there are no issues involving the consistency
of on-site actions with RCRA other than the need to charac-
terize each load of material.
Regarding off-site controls, the relevant federal laws are
RCRA hazardous waste facility regulations regarding groundwater
protection (40 C.F.R. Subpart F) and the 1984 RCRA Amendments.
The RCRA groundwater regulations require the setting of
groundwater protection standards, which are levels that are
protective of human health and the environment. Corrective
action is required if these levels are exceeded. The ground-
water protection standard of RCRA requires the contamination
levels (MCL's) or alternate concentration limits (ACL's).
ACL's are site specific levels that are demonstrated to be
protective of human health and the environment. The 1984
RCRA Amendments require off-site groundwater corrective action
to attain the groundwater protection standards. Generally,
RCRA regulations and RCRA Amendments provide for ensuring that
groundwater contamination levels do not cause a hazard to human
health or the environment. The selected off-site control alter-
native, provides for groundwater extraction to the extent
practical followed by treatment and surface water discharge.
This alternative is consistent with the intent of RCRA by
restoring the aquifer. A groundwater monitoring program to
demonstrate the effectiveness of the extraction program will be
performed as required in the RCRA regulations. In extracting
groundwater from the surficial aquifer and in the uppermost
portion of bedrock, the system reduces flow of contaminated
groundwater to the bedrock aquifer, actively treats the surficial
aquifer, and treats a substantial portion of the bedrock aquifer.
In this decision, performance standards to be achieved in the
five-year remedial treatment unit of groundwater extraction and
treatment are established as target groundwater concentrations
in the off-site aquifer. These performance standards are 28 parts
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per billion (ppb) trichloroethylene and 92 ppb 1,1,1-trichloroethane,
The analysis in the FS and this document used in setting these
performance standards is based on environmental and health criteria
This analysis is technically equivalent to a RCRA ACL determination
The selected groundwater extraction and treatment option
includes a surface discharge of treated groundwater. Design
specifications for the treatment plant, effluent concentrations
and discharge structures will be consistent with the provisions of
the relevant federal program.
ALTERNATIVE EVALUATION
Remedial Action Objectives
As identified in the National Contingency Plan, the objective
of the evaluation of alternatives is to select the "lowest cost
alternative that is technologically feasible and reliable and
which effectively mitigates and minimizes damage to and provides
adequate protection of public health, welfare or the environment."
40 C.F.R. S300.68(j>.
With certain exceptions that are consistent with EPA policy,
the adequacy of protection of public health, welfare, and the
environment posed by each alternative will be determined based
on the alternative's attainment of the substantive provisions of
other Federal public health and environmental standards.
The following list identifies EPA's specific public health and
environmental objectives for remedial action selection at McKin,
as well as applicable or relevant standards which are used, in part
to judge attainment of these objectives:
0 To maintain adequate safe drinking water for the population
that could be affected by groundwater contamination.
Applicable federal drinking water standards are used, when
possible, to determine the attainment of this public health
objective.
0 To prevent exposure of the public to inhalation of harmful
amounts of airborne contamination. Relevant ambient air
levels recommended by the Centers for Disease Control
are used, when possible, to determine the attainment of
this public health objective.
0 To prevent the subsurface discharge of contaminated
groundwater from the site to off-site aquifers. Relevant
federal standards for hazardous waste facilities
(40 C.F.R. 264 and recent RCRA Amendments) will be
used to determine the attainment of this environmental
objective.
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0 To restore, within a reasonable time and practical limits,
the off-site aquifer that has been contaminated by groundwater
migrating from the site to levels protective of public health
as a drinking water supply and the environment. Relevant
federal standards will be used to determine the attainment of
this public health and environmental objective.
* To protect state-designated Royal River surface water uses
and aquatic life in the Royal River. Applicable state water
quality criteria will be used to determine the attainment
of these environmental objectives*
0 To prevent hazardous dermal contact with or hazardous
ingestion of contaminated soil by the public.
ALTERNATIVES CONSIDERED
The following remedial action alternatives were considered:
Source Control
0 No action
0 No action with monitoring
9 Capping the site.
0 Installing a containment wall and capping.
* Excavation and off-site disposal.
0 Excavation with on-site incineration and disposal.
0 Excavation with on-site treatment and disposal.
0 Excavation with off-site treatment and disposal.
Off-site Control
* No action.
0 No action with monitoring.
0 Pumping, treating, and reinjection of groundwater
to aquifer or discharge to Royal River.
0 Restriction on future development.
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Site Closure Activities Common to all Alternatives
0 Disposal of all above-ground on-site debris (i.e. hoses,
rags, etc.).
0 Removal and disposal of on-site metallic structures
(i.e. incinerator, conveyor system, tubing, etc.).
0 Demolition and disposal of the masonry block building.
* Draining and filling in the existing asphalt lagoon.
9 Removal and disposal of all known buried steel and fiber drums
and their contents.
0 Removal and disposal of decontamination rinsate and other
waste materials that result from remedial actions.
* Removal and disposal of the buried 3,000 gallon tank located
south of masonry building.
0 Fencing entire cleared site with placement of appropriate
warning signs.
0 Loaming and vegetating the site.
As described in FS, a review and initial screening process
eliminated the following alternatives or portions of alternatives
as not mitigating identified public health or environmental
threats, being technically infeasible or providing no substantially
greater public health or environmental benefits over alternatives
incurring less cost:
1, No action (does not mitigate public health or environmental
threats).
2. Capping entire cleared area of the site (no substantially
greater benefits).
3. Installing a containment wall around the contaminated areas
(no substantially greater benefits).
4. On-site soil encapsulation (no substantially greater benefits).
5. Systematically recovering contaminated groundwater from
fractured bedrock to clean the bedrock aquifer in a
comprehensive manner (technically infeasible).
The screening of remedial alternatives indicates that a
source control remedial action will be necessary to mitigate
the threat to public health and the environment. A source control
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action to lessen the generation of groundwater contamination and
further prevent direct contact with the site is required. For
this reason the "No Action" alternative does not warrant further
consideration as a source control remedial action alternative.
The remaining alternatives were then evaluated based on
environmental and technical concerns, reliability, implementability,
operations and maintenance (O&M) requirements, health and safety
considerations and detailed cost estimations, including distribution
of costs over time in accordance with 40 C.F.R. $300.68(i). The
alternatives evaluated during this detailed review and screening
included both on-site source controls or off-site controls:
On-Site Source Control
0 Alt. 1 - No Action with monitoring.
0 Alt. 2 - Capping of contaminated soil areas.
* Alt. 3A - Excavation of contaminated soil with off-site
landfill disposal.
0 Alt. 3B - Excavation of contaminated soil with off-site
incineration.
0 Alt. 4 - on-site incineration of contaminated soil with
on-site landfilling.
0 Alt. 5A - On-site aeration and landfilling of contaminated
soil.
0 Alt. 5B - Off-site aeration and landfilling of
contaminated soil.
0 Alt. 5C - On-site aeration and capping of certain
contaminated soil.
Off-Site Control
0 Alt. 6 - No Action with monitoring.
• Alt. 7 - Groundwater extraction and treatment
and on-site recharge.
7A - Groundwater extraction wells at one location.
7B - Groundwater extraction wells at two locations.
7C - Groundwater extraction wells at three locations.
0 Alt. 8 - Restrictions on Future Development.
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A brief description of these alternatives is given below, and
Table 7 summarizes the costs, (capital, O/M, present worth),
technical considerations, environmental considerations, public
health considerations, and public comments for each alternative.
1. No Action with Monitoring. Monitoring wells would
be installed around the site and periodically sampled;
these samples would be analyzed for hazardous substances
in order to monitor contamination of the groundwater.
2* Capping. An impermeable cap would be placed over
contaminated areas of a site. Contaminated areas IB, 3,
4, and 5 (see Figure 2) would be capped under a single
cap and consistent with RCRA requirements, the contaminated
soil in area 6 either would be removed for disposal
off-site or would be placed under the on-site cap.
3. Excavation and Off-Site Disposal. Contaminated soil
from the site would be removed and transported off-
site for disposal. Two disposal alternatives were
considered: (1) landfilling, which would involve
disposal of hazardous material in a licensed hazardous
waste landfill, or (2) incineration, which would
destroy the contaminants by burning the contaminated
soil at very high temperatures.
4. On-Site Incineration. Contaminated soil would be
excavated and incinerated in a mobile incinerator
set up with appropriate auxiliary facilities on-site,
and the ash residue remaining after incineration
would be disposed of on-site.
5. Aeration. Contaminated soil would be rototilled or
otherwise broken up and exposed to the air, allowing
the contaminants to volatilize. Three versions of
this alternative were considered:
A. Aerate soil on-site
B. Transport contaminated soil off-site for aeration; and
C. Transport contaminated soil off-site for aeration,
except Area 3, which would be capped.
6. No Action with Off-Site Monitoring. Off-site monitoring
wells would be sampled periodically; these samples would
be analyzed for hazardous substances to monitor contamination
of the groundwater.
7. Groundwater Extraction and Treatment. Contaminated ground-
water would be pumped from the ground by extraction wells
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then treated to remove the contaminants. Three versions of
this alternative were considered in the FS:
A. One series of extraction wells,
B. Two series of extraction wells, or
C. Three series of extraction wells.
This alternative would remove contamination already in the
groundwater. To do this, contaminated groundwater would be
intercepted as it leaves the site and further extracted
from the off-site contaminated areas then pumped out by a
series of extraction wells. Extraction well locations
proposed in the FS are shown in Figure 12. The extracted
water would be treated to remove the contaminants. It
is estimated that groundwater extraction and treatment would
reduce contamination of the groundwater to a level of 50 ppb
of volatile organic contaminants in about five-years.
Based on the groundwater characterization in the RI, air
stripping and carbon filtration would be used to remove
contaminants from the extracted groundwater. The air
stripping process causes the contaminants to evaporate
from the water into the air, and the air would then be
sent through containers of activated carbon to remove
contaminants from the air. In the three extraction and
treatment options considered in the FS, treated water
would be the discharged back to the groundwater on site.
An additional groundwater extraction and treatment
alternative was proposed after the completion of the
draft FS. This alternative does not specify the
exact number or locations of groundwater extraction
wells but proposes to extract groundwater and restore
the offsite aquifer to the extent practical in a
timely manner. To meet this objective, new wells
developed for extraction most likely would be screened
in the surficial aquifer and in the uppermost portion
of the bedrock. The necessary treatment operations
anticipated to remove contaminants from the extracted
groundwater are the same as presented in the FS,
however these operations and the treatment design
will be assessed during a remedial design treatability
study. This treatability study will evaluate groundwater
quality for all priority pollutants in the contaminated
aquifer and treatment efficiencies. Unlike the
alternatives described in the FS, this alternative
proposes to discharge treated groundwater to local
surface water rather than to the groundwater. The
costs, advantages and disadvantages of this groundwater
extraction and treatment alternative are presented
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in Table 7. The cost estimate for this alternative
is based on cost data in the FS modified by the
development of 25 extraction wells with an estimated
withdrawal rate of 5 gallons per minute and a surface
discharge to the Royal River.
8. Restrictions on Future Development. Future development
in areas affected by the groundwater plume would be
restricted, which would preclude the need to provide
public water to new developments and would prevent the
development of any contaminated water supply wells in
presently undeveloped areas.
RECOMMENDED ALTERNATIVE
Section 300.68(j) of the National Contingency Plan (NCP)
states that the appropriate extent of remedy shall be determined
by the lead Agency's selection of the remedial alternative, which
the Agency determines is cost-effective (i.e. the lowest cost
alternative that is technologically feasible and reliable and
which effectively mitigates and minimizes damage to and provides
adequate protection of public health, welfare or the environment).
Based upon our evaluation of the Rl, the FS, the comments
received on these reports, and the options specified in these
reports and comments, EPA has determined and the state has
agreed that the following remedy meets the NCP criteria:
- On-slte aeration of soils in site areas of identified
hazardous substance contamination to achieve soil quality
levels protective of public health and the environment.
- Off-site disposal of approximately 16 drums found on the
site and their contents.
- Performing soil tests in petroleum contaminated areas to
further characterize the nature of contamination.
- Constructing a groundwater extraction, treatment, and
surface water discharge system and operating this system
as a remedial treatment unit for a period of five-years
with a target groundwater performance standard of 92 ppb
1,1,1-trichloroethane and 28 ppb trichloroethylene
for groundwater quality.
- Re-evaluating the groundwater performance standard, if this
standard is not achieved at the end of the five-year period
or earlier if warranted by system performance or site
conditions.
- Initiating an off-site groundwater and surface water
monitoring program to evaluate the effectiveness of the
on-site source control and off-site groundwater extraction
and treatment system.
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- Performing site removal and closure activities including
disposal of on-site debris, disposal of discrete areas of
significant non-volatile contamination not identified in
the RI, disposal of metallic structures, demolition and
disposal of the site's building, draining and filling in
the lagoon, removal and disposal of known buried drums
and their contents, removal and disposal of decontami-
nation rinsate and other waste materials that result from
remedial activities, removal and disposal of a buried
fuel tank, fencing the site with appropriate signs, learning
the site, and vegetating the site.
The following discussion describes the recommended alternative
and the reason for its selection.
Source Control Remedy
Regarding the source control alternative, Alternative 1,
No Action with Monitoring, was not selected because it is not
responsive to the groundwater contamination issue and does not
fulfill the site objectives. The implementation of Alternative
1 would result neither in the timely restoration of the off-site
contaminated aquifer to the extent practical nor in the institu-
tional controls to ensure no possible exposure to the contaminanted
aquifer*
Each of the remaining source control alternatives is proposed
to control further migration of pollutants from the contaminated
unsaturated zone to the groundwater. Contamination below the
high water table is addressed with off-site controls rather
than source controls.
Alternative 5B, off-site aeration was not considered because
it was found to be infeasible. During the PS no local off-site
areas could be identified which would receive the contaminated
soils for aeration and final deposition.
The remaining source control alternatives, Alternatives
2,3,4, and 5A, were all judged to be technologically feasible
and reliable and to mitigate and minimize damage effectively
and to provide adequate protection of public health, welfare,
or the environment. Given the effectiveness of each of these
alternatives, consideration of cost is appropriate in selecting
a source control option. The estimated total present worth of
capping the contaminated areas using a clay cap is $430,000
($192,000 capital, $38,900 annual operation and maintenance)
and is essentially the same as the estimated total present
worth of on-site aeration, which is $440,000 ($424,000 capital
and $1,600 annual operation and maintenance). The estimated
present worth of the remaining alternatives are significantly
higher: $1,863,000 for excavation and off-site landfilling,
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($1,847,000 capital, $1,600 annual operation and maintenance);
$5,103,000 for off-site incineration ($5,087,000 capital and
$1,600 annual operation and maintenance); and $6,855,000 for
on-site incineration ($6,840,000 capital, $1,600 annual
operation and maintenance). Therefore, the cost-effectiveness
of two alternatives, capping and on-site aeration, are judged
to be essentially equivalent and the remaining source control
alternatives are judged to be not cost-effective. Given the
essentially equivalent cost-effectiveness of capping and
on-site aeration, EPA has selected on-site aeration as the
source control based on the Agency's policy to pursue response
actions that use treatment over land disposal to the greatest
extent practicable, consistent with CERCLA requirements for
cost-effective remedial actions. In selecting this remedy
EPA also selects target performance standards to be used in
assessing the remedy's effectivenss. One performance standard
is an average soil concentration of 0.1 ppm trichlorethylene
averaged over a treatment volume. For heavy metal soil
contaminants, the levels established in the Extraction
Procedure (EP) toxicity tests (40 C.F.R. Part 261.24) or the
results of solute fate and transport modeling using these test
results represent performance standards. These performance
standards are based on a health-based assessment specific for
the McKin site and are applicable to soils removed from or
remaining in the contamination Areas IB, 3, 4, 5, and 6 identified
in the RI. An on-site pilot study will be initiated to determine
the extent to which soil aeration can be utilized to remove
contaminants from the site, and the specific engineering
methodologies to be used to aerate soils in a manner protective
of public health.
While EPA regards Alternatives 2, 3, 4, and 5A as effective,
there is variation in the approach each alternative uses to
achieve this effectiveness. EPA recognizes uncertainties
associated with each approach and has considered the advantages
and disadvantages of each approach in its decision. For each
approach, these considerations are summarized in the following
discussion, beginning with the selected source control alter-
native.
The selected source control alternative, on-site aeration, is
a means of actively and significantly reducing the amount of
contamination that remains on the site in a relatively simple
and expedient manner, in selecting this alternative EPA has
weighed the advantages and disadvantages of this approach as
well as the technical concerns associated with applying this
remedy to the McKin site. These concerns include (1) attaining
non-hazardous levels of contaminants in the soil; (2) confirming
a determination of the depth of contamination in contamination
Area 3; and (3) maintaining ambient air quality protective of
public health once volatile organic compounds in the soil are
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exposed to air. While EPA recognizes these concerns and
uncertainties, the Agency feels there is sufficient reason to
proceed with soil aeration as the source control method with the
precautions and provisions described herein and that the benefits
of this waste reduction method offset the potential disadvantages
associated with technical concerns.
A cap constructed and maintained in a manner consistent with
RCRA is an effective means of isolating the soil contamination
from the primary transport mechanism of infiltration to the
groundwater. Engineering the construction of the cap is a
relatively routine process, and measures are established to ensure
reliable construction. The major negative factor associated with
capping is that wastes remains in-place and are not reduced or
eliminated. Essentially, this closure method renders the site a
permanent land disposal area. in addition, the effectiveness of
capping is dependent in part on monitoring the cap's long-term
integrity and, if necessary, taking future maintenance or corrective
measures. Cap inspections and groundwater monitoring during the
30-year post closure period would provide substantial assurances
that significant leakage is not occurring. Regarding flushing
resulting from water table fluctuations, the cap cannot assure
containment of those contaminants present below the high water
table. Uncertainty regarding the significance of this effect
would be minimized by monitoring the effects of this flushing
in downgradient monitoring wells, particularly during the period
of the remedial treatment unit to extract groundwater immediately
downgradient of the cap for treatment. Finally, there are a number
of advantages associated with avoiding the soil disturbances
associated with soil removal and treatment. These include
avoidance of the following: (1) possible uncontrolled volatili-
zation of organic contaminants when soils are exposed to air, (2)
confirming a determination of the depth of contamination in contami-
nation Area 3, (3) confirming a determination of the hazardous
nature of a treatment end product and the appropriateness and
risks of redeposition of this material on-site and off-site.
The primary advantage of incineration is that the contaminant
reduction associated with thermal degradation is the most effective
destruction technology considered. Incineration of many waste
streams is a proven technology, however site specific test burns
would be necessary to demonstrate the effectiveness of incineration
for several types of on-site contaminated soils. Of the alternatives
considered, incineration is the most difficult engineering technique
for source control. For on-site incineration, uncertainties,
concerning effectiveness would be addressed by testing emissions
and combustion efficiency to meet air quality licensing requirements
or their technical equivalents. The use of a portable incinerator
is a relatively new technology which, as of this writing, has been
fully utilized on only a small number of hazardous waste sites and
only one Superfund site in an experimental capacity. Significant
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time delays can be expected associated with demonstrating incinerate
effectiveness and safety, on-site scheduling of mobile incineration,^
or permitting. Based on recent test burns of dioxin contaminated
soils in Missouri substantially more site preparation and mobilization
effort would be required than estimated in the FS. This would
probably include the mobilization of approximately five tractor
trailors on temporily foundations, contruction of two temporary
buildings and development of water supply and waste water disposal
capabilities for quench water. The comments expressed by Maine DEP
which call for further "thorough examinations" of the technology to
ensure it is effective and implementable reflect a high concern for
public health and the environment but suggest what may be a lengthy
period before the on-site source is actually controlled. Finally,
there are a number of uncertainties that must be addressed in
on-site incineration as a technique proposed to treat soils on-site
in a batch process. These uncertainties center on:
(1) the possible uncontrolled volatilization of organic
'contaminants when soils are excavated and exposed to air;
(2) confirming a determination of the depth of
contamination in contamination Area 3; and
(3) confirming a determination of the hazardous nature
of the ash and the appropriateness and risks of
redeposition of ash on-site or off-site.
Off-site disposal alternatives, Alternatives 3A and 3B,
share the advantage of off-site incineration in that they
remove contamination from the site rather than controlling
migration of the waste, in addition, off-site disposal
alternatives share with on-site incineration similar
disadvantages associated with soil removal. These include
(1) possible uncontrolled volatilization of organic contaminants
when soil is exposed to air during excavation; and (2) confirming
a determination of the depth of contamination in contamination
Area 3. An additional disadvantage of off-site disposal is
the transfer of the contamination and safe disposal problem
to another community. Whether that disposal is via incineration
or a secure landfill, there are a number of technical issues
to be addressed in that receiving community to ensure adequate
protection of human health, welfare, and the environment. In
some Superfund cases obtaining the assurance that human
health, welfare, and the environment is adequately protected
in the off-site facility receiving the waste has lead to time
delays in implementing source controls by off-site disposal.
The selected on-site alternative consists of aerating the
soil of Areas IB, 3, 4, 5, and 6 at a rate dictated by
maintaining off-site air quality protective of public health.
This action includes continously monitoring ambient air,
establishing site specific, health based performance standards
for soil that will be left on site and establishing a verification
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monitoring program to evaluate the appropriateness and attainment
of performance standards. If, the soil aeration pilot study
demonstrates that soil aeration in specific locations is
ineffective in meeting these soil performance standards or
infeasible to accomplish while maintaining acceptable ambient
air quality, a determination regarding selection of another
remedy will be made by the Region Administrator. Regardless
of any future determinations, certain removal and site closure
activities will be performed including disposal of on-site
debris, disposal of discrete areas of significant non-volatile
contamination not identified in the RI, disposal of metallic
structures, demolition and disposal of the site's building,
draining and filling in the lagoon, removal and disposal of
known buried drums and their contents, removal and disposal
of a buried fuel tank, fencing the site with appropriate signs,
learning the site, and vegetating the site. Regarding the
disposal of buried drums, the 16 fiber and steel drums identified
in the RI will be disposed of off-site.
In pursuing on-site aeration as a remedial action it is
necessary to establish health based, site specific performance
standards which represent soil contamination levels which can
safely remain on-site following aeration and provide a degree
of certainty that these levels can be attained. Health based
performance standards must consider each route of exposure
including potential groundwater contamination, dermal exposure,
soil ingestion and inhalation.
Regarding potential off-site groundwater impacts, a maximum
average soil concentration of 0.1 ppm of trichloroethylene,
averaged over a treated volume of soil, is judged conservatively
to be protective of possible off-site ingestion of groundwater
contaminated by the migration of pollutants from residual
on-site soil contamination. This value is derived using
solute fate and transport modeling to estimate the on-site
soil concentration associated with the off-site groundwater
concentration protective of human health as drinking water.
{This groundwater concentration is judged to be 28 ppb for
trichloroethylene based on a 10-5 lifetime cancer risk as
described in this document's discussion of the selected
off-site remedial measure). Calculations, assumptions, and
methodologies used in this solute fate and transport modeling
are attached to this Summary of Remedial Alternative Selection
as Attachment A. As described in this attachment, trichloroe-
thylene is selected as an appropriate organic indicator for
this evaluation based on its elevated environmental concentrations,
its toxicity relative to other organic chemicals detected in
the soil, and other factors. During the pilot soil aeration
study, it is possible that the Agency's understanding of the
nature and concentrations of organic soil contaminants will
improve. Should the soil performance standard of 0.1 ppm for
-------
-24-
trichloroethylene or the solute fate and transport modeling
provided in Attachment A prove to be inappropriate based on
further information regarding mathematical modeling, hydro-
geology, or on-site conditions, improved solute fate and
transport modeling may be utilized to adjust the trichloroe-
thylene soil performance standard or establish soil performance
standards for additional organic compounds.
For those metal contaminants detected in soils at the McKin
site, the extraction procedure (EP) toxicity standards contained
in 40 C.F.R. $261.24 or the results of similar solute fate
and transport modeling using these test results are judged to
be protective of public health via groundwater contamination
exposures for the McKin site. EPA recognizes that aeration
will not effectively remove heavy metal contaminants from
soil, however, based on RI soil analysis results it is likely
that the above performance standards for metals are attainable
without further metal removal.
Regarding the risks associated with dermal exposure with
soils, soil ingestion, and inhalation of soil particulate, the
Centers for Disease Control has reviewed the soil performance
standards previously described and has found that attainment
of these performance standards will provide more than adequate
public health protection from these exposure routes. This
evaluation is based in part on acute and chronic dermal
toxicity data.
The extent of volatilization of susceptable compounds from
soil during the aeration process is dependent in part on
the amount of soil surface area exposed to air and the duration
of this exposure. The selected remedy is to aerate soils
until the above performance standards are met or exceeded
based on random soil sampling of treatment volumes. EPA
EPA bases the feasibility of this remedy on theoretical and
experimental evidence which demonstrates if aeration is
allowed to proceed for sufficient time essentially all volatile
organics will volatilize from the soil. Soil aeration has
been used to remove volatile contaminants from soil at other
locations.
As described in the PS, the rate of aeration will be dictated
by ambient air conditions. Ambient air quality will be monitored
continuously during soil aeration. If air concentrations approach
site specific health based standards developed by the Centers for
Disease Control then actions will be taken to abate the volatilization
of organics on the site. The practicality and effectiveness of
abatement methods will be evaluated during the pilot aeration study.
Possible abatement methods to be evaluated during the pilot
aeration study include ceasing excavation and soil mixing,
covering exposed soil, aerating within an on-site enclosure,
and subsurface aeration using a forced soil aeration technique.
-------
-25-
An air quality monitoring plan for volatile organics and
particulates will be developed during remedial design in
order to assure ambient air levels are protective of public
health. This plan will rely on multiple continuous air
monitors and will stipulate contingency actions to be taken
if threshold levels are exceeded. EPA has requested the
Centers of Disease Control to establish the necessary thres-
hold levels in consultation with the Maine Bureau of Health.
These levels will serve as the basis for the air quality
monitoring plan for volatile organics. If these level are
violated work will be discontinued and the feasibility of
the ongoing process evaluated. The potential for dust
generation during on-site aeration also will be evaluated
in the pilot treatment study, and dust control measures will
be addressed in the remedial design.
Regarding on-site Areas 1A, 1C, and 2, EPA feels there is
insufficient evidence to determine the applicability of
CERCLA to remedial actions in these areas. Therefore, further
soil testing in these areas will be performed during remedial
design and a determination of the appropriate remedial response
will be made.
Off-site Remedy
Regarding the off-site groundwater contamination, EPA has
decided to implement groundwater extraction and treatment as
a positive, cost-effective means of restoring the off-site
contaminated aquifer and thereby minimizing damage to public
health, welfare and the environment. The selected remedy is
to extract contaminated groundwater to the extent of technical
practicality in order to to restore the off-site contaminated
aquifer in a timely manner. Extracted groundwater will be
treated and discharged to local surface water. In making
this decision, EPA has carefully considered several other
off-site alternatives (1) No Action, (2) No Action with
Monitoring Alternative 6, (3) Restricting off-site development
Alternative 8, (4) Treating recovered water at Boiling Springs
and/or the Royal River as proposed by several potentially
responsible parties, (5) Less extensive off-site groundwater
extraction systems, Alternatives 7A and 7B and (6) the ground-
water extraction treatment and recharge system configuration
described in Alternative 7C. The basis for EPA's selection
is that the Agency sees the groundwater extraction and treat-
ment system selected as the only alternative which is feasible,
and effective in meeting the remedial action objectives set
forth in this Summary of Remedial Alternative Selection.
-------
-26-
As previously stated, EPA's remedial action objective re-
garding off-site groundwater is to restore the off-site
aquifer to contamination levels protective of human health
and the environment within a reasonable period of time and
practical limits. A No Action Alternative for off-site
control coupled with the selected source control remedy is
likely to restore the contaminated aquifer eventually through
natural flushing and dispersion mechanisms. The FS predicts
this will occur within about ten years based on a 50 ppb
total volatile organic chemical target concentration. Given
the feasibility of restoring the aquifer in a shorter period
of time with an extraction and treatment system, the uncer-
tainty in this ten year estimate, and the possibility of
other, less mobile constituents in the groundwater, EPA has
determined that a No Action Alternative, the No Action with
Monitoring Alternative and No Action with both monitoring
and restrictions on future development alternatives are not
responsive to correcting the present levels of contamination
that have migrated from the site and that these alternatives
are not effective in meeting the remedial action objectives.
Furthermore, EPA recognizes the contaminated aquifer as an
environmental resource and finds a No Action Alternative to
be inadequate protection of the environment.
Alternative 8, restricting future development in affected
areas, is aimed at ensuring that no one will be exposed to
water from the contaminated aquifers. This alternative was
not selected because of the difficulty and uncertainty of
guaranteeing the implementation and enforcement of such
restrictions for the time period until safe water quality
levels are achieved. Moreover, this alternative does not
seek to mitigate or minimize the threat to the environment.
Notwithstanding this decision, EPA requests the State and
Town to take measures to ensure that the contaminated aquifers
are not used as a water supply during the period of aquifer
restoration.
E. C. Jordan, a technical consultant to a potentially respon-
sible party, has suggested an off-site alternative which
possibly includes the treating of water as it discharges from
the contaminated aquifers at Boiling Springs, the Royal River
or both. Based on available information, EPA has determined
that this off-site alternative is neither directed nor respon-
sive to the objective of restoring the off-site aquifer that
is presently contaminated. The objective of this proposed
alternative appears to be protection of surface water quality
and uses. EPA shares this objective with the commentors but
-------
-27-
has determined from the present evidence that this objective
is being met currently without treatment at the groundwater
discharge location in the area of the Royal River.
Alternatives 7A and 7B as described in the FS represent
groundwater extraction and treatment systems less extensive
than Alternative 7C. EPA has determined that the intent of the
selected Alternative is to restore the contaminated aquifer
in a timely manner to the extent of practical feasibility, and
Alternatives 7A and 7B were not selected because Alternative 1C
was viewed as a more extensive treatment alternative.
Comments received from local citizens and elected officials
either endorsed a groundwater extraction system as an off-site
control or were silent with respect to an endorsement. Comments
from potentially responsible parties were opposed to the
groundwater and the extraction system proposed in the FS.
Major reasons for this opposition include the views that the
system is unnecessary to protect adequately public health
since an alternative drinking water supply is in use and
appears to meet additional future needs and that the system
is not cost-effective compared to implementing source controls
and allowing natural mechanisms to cleanse the aquifer. EPA
recognizes that the existing public water supply greatly
reduces the public health risk associated with the contaminated
aquifer, but is not confident that long-term institutional
restrictions could be implemented and enforced on the affected
land to ensure that contaminated groundwater is not utilized.
Furthermore, EPA's selection of the effective off-site remedial
action is based on the NCP standard of effectiveness which
provides for adequate protection not only of public health and
welfare but also of the environment. The contaminated aquifer
is a former and potential environmental resource. Restoration
of this environmental resource which was degraded by the
migration of contaminants from the McKin site is consistent
with provisions of other Federal laws (i.e. the 1984 RCRA
Amendments) as well as the EPA Groundwater Protection Strategy.
The National Contingency Plan requires EPA to select the the
remedial alternative which the Agency determines is cost
effective. In the case of this contaminated aquifer, EPA has
determined that expedient restoration to the extent practical
as provided by a groundwater extraction and treatment system
is the only off-site alternative which meets this standard of
effectiveness, and therefore, this alternative is the cost
effective alternative.
EPA has studied comments received from Maine DEP and
potentially responsible parties which raise technical concerns
associated with Alternative 7C as described in the FS. These
technical concerns include:
- the abililty of attaining the projected well yields
at the described locations due in part to questionable
saturated thickenesses in the aquifer in these locations.
-------
-28-
- the feasibility of discharging treated groundwater on the
site as described in the FS which may cause unacceptable
adverse environmental effects.
- the appropriateness of groundwater modeling assumptions.
- the possible creation of a stagnant zone of contaminated
groundwater between Mayall Road and Boiling Springs.
On the basis of EPA1s review of these concerns the Agency has
sufficient reason to question the feasibility of Alternative 7C
as proposed in the FS with its specified extraction well and
discharge locations. Therefore, the Agency does not consider
Alternative 7C to be an effective off-site alternative at this
time. EPA feels, however, that the above concerns can be
adequately addressed in the selected groundwater extraction
and treatment alternative and finds the selected off-site
control alternative to be reliable and effective.
Regarding the discharge of treated groundwater, this discharge
will be to local surface water rather than to on-site groundwater
as proposed in Alternative 7C. Regarding the other concerns
listed above, although EPA feels that the selected extraction
and treatment system is the cost effective remedy, more precise
determinations regarding well yields, modeling assumptions,
and groundwater flow will be made during the remedial design.
Available well logs presented in the RI, permeability generally
associated with the surficial materials presented in these
logs, and recent pump test and hydraulic conductivity data
collected at the site further demonstrate that an effective
groundwater extraction system can be constructed in the
contaminated aquifer. This recent pump test indicates a
significantly greater permeability than assumed by potentially
responsible parties in their comments regarding the infeasibility
of a groundwater extraction system. The remedial design will
include field tests to characterize more accurately the
off-site contamination plume between the site and its surface
water discharge and to determine well yields, drawdowns,
saturation thickness, and the most effective placement and
pumping rates of the extraction wells. A degree of flexibility
in the extraction and treatment systems is allowable based on
design studies in order to achieve the objectives of the
remedial action and the concepts of design outlined in the
FS. Areas of flexibility include the number of wells, the
location of wells, and the need for the three series of
extraction wells as proposed in Alternative 7C if significant
increased effectiveness as a result of additional wells
cannot be demonstrated.
Another area of study during the remedial design is a treat-
ability study using the contaminated groundwater. This
treatability study will address all priority pollutants in
-------
-29-
determining an effective treatment design. A five-year
period of groundwater extraction and treatment is being
stipulated in this decision as a remedial treatment unit.
Relative to the off-site remedy, performance standards are
established in this decision to be achieved by the five-year
remedial treatment unit for the two detected groundwater
contaminants. The performance standards set for the extraction
and treatment system at the McKin site are 92 ppb of 1,1,1-
trichloroethane and 28 ppb trichloroethylene applicable
throughout the aquifer contaminated affected by the migration
of these chemicals from the McKin site. These performance
standards are based on levels that protect human health, welfare
and the environment at this site with consideration to potential
exposures and possible synergistic or additive effects.
Regarding protection of the aquatic environment, the risk
to surface water use of the Royal River presently does not
appear to be significant and will not increase with the
attainment of these performance standards.
EPA has determined that exposures at or below these
performance standard levels at this site will be at levels
which do not pose a substantial threat to human health and
the environment. The trichloroethylene performance standard
is based on a cancer risk of 10"^ (i.e., that a person
exposed to this level of contamination in drinking water
throughout his or her lifetime (70 years) will bear an
increased risk of less than or equal to 1 in 100,000 of
contracting cancer as a result of ingesting trichloroetheylene).
EPA recognizes trichloroethylene as a suspected carcinogen
and has made a determination of its performance standard for
this site through the risk management process. In general,
the Agency has made decisions to reflect specific situations
to allow concentrations of suspected or known carcinogens
where the individual risk values have been within a range of
10~8 to 10~*. in selecting 10"^ as the appropriate lifetime
statistical cancer risk value within this range, EPA has
considered the following site specific factors:
0 There will be a relatively low level of uncertainty
regarding the levels of contamination in the affected
aquifers following five-years of monitoring local
groundwater, surface water, and the effectiveness
of the extraction and treatment system.
0 There is presently no known regular human use of the
contaminated aquifer, a situation which is expected to
continue based on the availability of an alternative
drinking water supply. The areas of the most concentrated
contamination are developed areas least likely to
utilize the aquifer for a drinking water supply by
developing new private wells.
-------
0 Based on the physical and chemical characteristics of
the waste {mobile organic solvents), the hydrogeological
characteristics of the site (fractured bedrock and
relatively permeable surficial material in areas of
greatest contamination), and the groundwater flow rate
and direction, natural attentuation mechanisms are
expected to diminish groundwater contamination further
in areas where the extraction and treatment system is
successful following the five-year remedial treatment
unit. Based on these factors, this further decrease
in contamination levels is expected to reduce further
the lifetime cancer risk relatively rapidly.
* The groundwater extraction and treatment system
is expected to be effective and reliable in
attaining the performance standards.
* The models used in calculating public health risks
were structured to be conservative in nature.
The 1,1,1-trichloroethane performance standard is based on
the recommended maximum concentration limit (RMCL) of
200 ppb, as a toxic, non-carcinogenic contaminant having a
threshold. The 200 ppb level is adjusted to a performance
standard of 92 ppb based on a consideration of possible
synergistic or additive effects with trichloroethylene,
This adjustment is based on the fractional approach for
estimating guidance levels for multiple toxicant exposure.
This approach assumes additive and similar systemic effects.
The determination of the 92 ppb performance standard for
1,1,1-trichloroethane is calculated from: (1) a 52 ppb adjusted
acceptable daily intake (ADI) level for trichloroethylene
in drinking water; (2) the 28 ppb performance standard for
trichloroethylene previously described; and (3) the 200 ppb
recommended maximum concentration limit for 1,1,1-trichloroethane.
The extraction and treatment system selected in this decision
is a five-year remedial treatment unit. If at the end of this
five-year treatment period the performance standards are not
achieved, an evaluation of the system, concentration limits,
and public exposures will be made. In this case, following
this evaluation, the Regional Administrator with concurrence
from the State of Maine will make a decision regarding appro-
priate actions. This decision may mandate continued operation
of the system beyond the remedial treatment period. The
remedial treatment unit will be allowed to operate less than
the five-year period only after the performance standards are
achieved or after a determination and decision regarding the
treatment system, potential exposures, or concentrations
limits is made by the Regional Administrator with concurrence
from the State of Maine.
-------
-31-
In association with the selected source control and off-site
remedial actions, groundwater and surface water monitoring
programs will be developed in order to evaluate the effective-
ness of the actions, verify predictive modeling assumptions,
and monitor concentrations in the groundwater plume and
receiving surface water. New groundwater monitoring locations
may be developed for this program if warranted.
OPERATIONS AND MAINTENANCE (O&M)
Regarding the source control remedy, operation and maintenance
(O&M) actions associated with on-site aeration of the contaminated
areas involve site maintenance activities such as mowing. Projected
O&M costs as estimated in the FS as $1,600 per year. Operation and
maintenance costs for groundwater quality verification monitoring
is included in the cost estimate for the off-site remedy.
Regarding the off-site remedy, the groundwater extraction
and treatment system is selected as a remedial treatment unit
to treat contaminated groundwater for a five-year period. As
such, no operation and maintenance costs are associated with this
remedy during this five-year period. Performance standards have
been established to be achieved in this five-year treatment. If
they are not achieved, the performance standards and method of
achievement at the McKin site will be evaluated at the completion
of the treatment unit. That evaluation may include a commitment to
take further corrective action to remedy groundwater contamination,
and O&M costs may be associated with these future actions. However,
with the present expectations of a successful remedial treatment
unit, there are no O&M costs associated with the remedial action
decision for the off-site groundwater contamination, outside of
continuing groundwater monitoring costs. The purpose of this
program is to monitor the effectiveness of the source control
alternative and the extraction and treatment system. Costs for
initiating and utilizing a groundwater and surface water
monitoring program during the five-year treatment unit are
associated with the construction of the remedial action
treatment unit and are not considered operation and maintenance
costs. Continuation of the monitoring program beyond the
remedial treatment unit will result in operation and maintenance
costs estimated to be $37,300 per year.
The state has made a commitment to provide the operation and
maintenance costs to fund surface water and groundwater
monitoring and on-site maintenance after completion of the
five-year remedial treatment unit. Assuming a successful
five-year groundwater remedial treatment unit, these costs
are estimated at $38,900 per year. The state funding mechanism
is the Uncontrolled Hazardous Substance Site Bond Account, and
the Maine Department of Environmental Protection is the state
agency responsible for O&M.
-------
SCHEDULE
The following are the key milestones and dates for
implementation of the selected remedy:
Approval Remedial Action (sign ROD) July 18, 1985
Award Contract for Design July 19, 1985
Start Design July 19, 1985
Complete Aeration Pilot Study and September 6, 1985
Design to a Reasonable Cost Estimate
Obligate Funds for Construction September 20, 1985
Complete Design March, 1986
Start Construction May, 1986
Begin Remedial Treatment Unit for 1986
Treatment of Groundwater
End Remedial Treatment Unit 1991
-------
FUTURE ACTIONS
A sufficient characterization of the soils and petroleum
wastes in on-site contamination Areas 1A, 1C, and 2 is not
available at this time. Soil testing in these areas will be
performed during remedial design to determine the applicability
of CERCLA to these areas and the appropriateness of including
these areas in the remedial response described herein.
Regarding the selected source control remedy, a pilot
soil aeration study will be performed during remedial design.
If during this pilot study or during the remedial action, it
is determined that soil aeration of the contaminated areas
identified in PS cannot be performed in a manner protective
of public health and the environment, a determination regarding
the selection of another source control remedy will be made
by the Regional Administrator. This determination is a
possible future action.
As additional possible future actions, a re-evaluation of
performance standards for off-site groundwater contamination
levels or the on-site soil contamination levels may be
necessary. Regarding off-site groundwater contamination
levels, any decision to alter these performance standards based
on such an evaluation would be made by the Regional Administrator.
It is anticipated that this evaluation will be made if necessary,
at the conclusion of the five-year remedial treatment unit
based in part on information gathered from the off-site ground-
water and surface water monitoring program. If site conditions
warrant, a reevaluation and decision can be made by the Regional
Administrator at an earlier date. Such site conditions include
the performance of the extraction and treatment system, off-site
groundwater contamination levels, and exposures to and impacts
of the contaminated water. This decision may include additional
remedial actions to ensure adequate protection of public health,
welfare or the environment.
-------
LOCUS
10 MUM
SCALE
McKIN SITE , GRAY MAINE
REGIONAL MAP
N
CAMP DRESSER t UcKEE MO.
Or* C«nUr Pita
Borton, MMMCtiuwtti 0210*
FIGURE
-------
SITE AREA - GEOLOGIC MAP
McKIN SITE. GRAY MAINE
McKIN SITE AREA GEOLOGIC MAP
(1982 OERBER HYOROOEOLOOIC 8TUDY)
N
CAMP DRCMCT 4 MdCCEIHC.
On* Ctnttr Ptau
Bo»ten,Ma»MchuMtta 02108
FIGURE
5-2
-------
MONITORING
WELL. ITYP)
•LOCK BLOC
INCINERATOR
HORIZONTAL
TANK ITYP)
L TANK FILL
UNIDENTIFIED
DClRlStHOSlNO)
55 SA;.. DRUMS
APPROXIMATE IDSt
CLEARED AREA
VERTICAL TANK (TYP)
CHAIN UNK
FENCE
*»OTTOM OF SLOPE
TOP OF SLOPE
APPROXIMATE SCALE* f« 100*
Me KIN SITE GRAY. MAINE
SITE PLAN
TRUE
CAMP DACMCX A MeJCII MC
-------
r^JW) / ,<
\. "' , v' /
*'.'.£. /"-1
i i i i i i i i i i i i i i /i i
mm
SCALE
KEY
BORING LOCATIONS
McKIN SITE. GRAY MAINE
McKIN ON-SITE SOIL BORING LOCATIONS
(MARCH 1984)
N
TRUE
CAMP DRESSER * McKEE INC.
On* Center Plata
FIGURE 4
-------
I I I
I I ^ " "rl^-,
i j i i i i i i i "i
MH.CMI*
SCALE
RAY MAINE
.OCATIONS FOR EXf LORATURY
CAMPMESSCRAMcK]
O«w Cvntar Plata
Bo«lon.
-------
i i i i i i : i i i \L i i i i i
inns
SCALE
j MeKIN SITE. QRAY MAINE
I LOCATIONS OF HAND AUGER BORINGS (APRIL 1984)
TRUE I CAMP DRESSER * McKECINC.
On* C«nl«r Plata
Botlon. MatMchuMlti >
FIGURR 6
-------
TABLE I
LABORATORT ANALYTICAL RESULTS OF ON-SITE QUALITY NONITORW5 <«gA9)
* ApprexlMttljr
•• SMplt Uktn July 10. 1M*. «Mly«d Stptt^tr 4. 198*
tfut to dtliy sptctflc cenctfitr*tlent «rt unknowi
• • ^yltn« not tMlyzcd for In this sup It.
MO • ttlOM Otttctlon L1«1tl.
6 • FUld Blink
-------
i
*-•
in
AREA n
I I I I I I I I I I \L I I I I I
MKIt
p *«•% Mrf
SCALE
I I I I I I I I I i I I 'I I
&*
SITE, QRAY MAINE
PRIMARY AREAS OF SHALLOW SOIL CONTAMINATION
N
TRUE
CAMP DME86BI ft McKOE INC;
On* Cantor Pl«u
BMlon. M«tMCtiuMtti 021M
-------
TABLE 2
SUMMARY OT SIGNIFICANT CONTAMINATED SOIL AREAS
Estimated Dimensions
Description of Surface
Area Contamination** Area fs,f.) Depthfft.) Volume (c.y.)
Area IB Grey and black sludge 400 5 74
(see TP13A * TP13B Lab Tests)
TPI 1A , Soil Around Burled Drum
(Area 6) (See Figure 6-1)
Area 3 See TPfiA Lab Tests
Area 4 See SS01 A SS02 Lab Tests
TP* 15 See TP15 Lab Tests
(Area 5}
TOTAL
ESTIMATE 5,200 s.f.
ESTIMATE 2.700 c.y
HOTES:
1. Areas 1A, 1C, and 2 were not determined to be significantly contaminated
based on laboratory analysis and physical observations. The major con-
taminants In these areas appear to be typical derivatives of petroleum
refining and not covered under CERCLA.
2. The estimated depth for Area IB Is estimated as debris would not allow
auger penetration. The remaining depths are estimated based on physical/
visual field observations.
* Due to limitations of sampling device exact depth of contamination cannot
be determined, therefore the depth to groundwater was used as a conserva-
tive figure.
+* See Table 1-2 for lab test results.
-------
TABLE
LOCATION AND TYPE OF BURIED DRUMS TO BE REMOVED
Location1
TP-1
TP-4
TP-6
TP-8
TP-9
TOTAL
Number of ,
Known Drums'
1
8{4)
3(2)
1
3(2)
16(8)
Type of Drum
Deteriorated Fiber w/LID
Metal
Fiber
Metal
2 Metal-1 Deteriorated
Fiber
1
see Figure 6-1
Numbers 1n parentheses denote contingency quantity for possible unknown
drums.
ANALYSIS OF CONTAMINATED SOIL
ASSOCIATED WITH DRUMS (ppm)
LOCATION
TP-1
TP-4
TP-6
TP-8 TP-9
Dlchloroethylene
1,1,1-Trlcholorethane
TMchloroethylene
Ethyl benzene
Xylene
Toluene
JO. 3
J560
J220
0150
JO. 9
49
J4.5
J1400
Jl.O
J0.6
*
*
*
*
*No sample taken
J - Approximately
6-9
-------
TABLE 4
COMPOUNDS ANALYZED IN GROUNDWA7ER SAMPLES'
ACROLEIN
ACRYLONITRILE
BENZENE
CARBON TETRACHLORIDE
CHLOROBENZENE
1.2-DICHLOROETHANE
1,1,1-TRICHLOROETHANE
1,1-DICHLOROETHANE
1,1.2-TRICHLOROETHANE
1,1,2,2-TETRACHLOROETHANE
CHLOROETHANE
2-CHLOROETHYL VINYL ETHER
CHLOROFORM
1.1-OICHLC30ETHYLENE
TRANS-1.2-DICHLOROETHYLENE
1,2-DICHLOROPROPANE
TRANS-1,3-0ICHLOROPROPYLENE
CIS-1.3-DICHL030PROPYLENE
ETHYLBENZENE
METHYLENE CHLORIDE
CHLOROMETHANE
BROMOMETHANE
BROMOFORM
OICHLOROBROMOMCTHANE
TRICHLOROFLOUROMETHANE
DICHLORODIFIOUROME THANE
CHLORODIBROMOMETHANE
TETRACHLOROETHYLENE
TOLUENE
TRICHLOROETHYLENE
VINYL CHLORIDE
* Of all the compounds analysed for only 1,1,1-trichl oroe-hsne and
trichloroethylene were detected.
7-31
-------
TABLE 5
LABORATORY ANALYTICAL RESULTS
OF GROUNOWATER QUALITY MONITORING
Location
6-1 (shallow soil)
B-l (bedrock)
B-2 (shallow soil)
*
B-2 (deep soil)
B-2 (bedrock)
6-3 (shallow soil)
B-3 (bedrock)
B-4 (deep soil)
B-5 (deep soil)
B-5 (bedrock)
Date
(1984)
3/21
3/21 .
3/22
3/22
3/22
3/20
3/20
3/21
3/20
3/16
1,1,1 TMchloroethane
(ppb)
170** (230)
470** (500)
9
16
5
65
3
ND
KD (HD)*
7 (8)*
Trichloroethylene (TCE)
(ppb)
16,000
29,000
' 91
160
56
1,800
120
NO
ND (NO)*
190 (177)*
* duplicate
ND • not detected
** These samples were diluted for the analysis of trichloroeth/lene. The
companion results 1n parentheses for 1,1,1-tMchloroethane are for the
undiluted sanple.
7-33
-------
McKIN SITE. GRAY MAINE
EAOY STATE SURFICIAL AQUIFER (1
rU-TRICHLOROETWANE CONTAMINANT
N
CAMP MmSEM * McKCE INC.
On* C«nt«r
Boclon. Ma«Mc
-------
MoKIN SITE, QUAY MAINE
STEADY STATE BEDROCK AQUIFER (1084)
1.1,1-TRICHLOROETHANE CONTAMINANT PLUME
N
CAMP OUKStOI ft MeKEC MC.
On* Cottar Plata
Button. MMMclWMlU 021 (M
FIGURE
-------
APPROXIMATE SCALE 1" EQUALS
O SAMPLING LOCATION
FIGURE
Ctmo Dr»»i»r t
Ir
-------
TABLE 6
LABORATORY ANALYTICAL RESULTS OF
SURFACE WATER QUALITY MONITORING
Location
SW-1
SW-2
SW-3
*
On-slte lagoon
Boil 1ng Springs
Date Trichloroethylene (TCE)
(1984) and 1,1,1 TMchloroethane (ppb)
3/16
3/16
3/16
4/11
4/11
4/11
ND (NO)*
ND
ND
*D
44 (TCE) and 30
32 (TCE) and 10 **
* duplicate
** second Boiling Springs sample
ND • not detected (detection limit « 1 ppb)
7-4
-------
TABLE 7*
KKI* COHPAHT SITE. WINE
SOURCE CONTROL REKOIM. ALTEWttTIVTS
1.
2,
Alternative
No Action with/
Monitoring
Capping Con- {
laminated Areas
PROJECT COST {$1,000}
Present
Capital OKH Worth
20 37.3
19? 38.9
430
3A. Limited Excavation
w/Off-Slte Land-
filling
1,847 1.6 1.S63
38. Limited Excavation
w/Otf-Slte Incin-
erators
5.0B7 1.6 5.103
Public Health
Considerations
Continued contamination
of groundwater by con-
taminated soils remain-
ing on-site.
Groundwater remains
contaminated although
additional contamination
is eliminated. No ex-
cavation required there-
fore no emissions.
Eliminates future gen-
eration of contaminated
groundwater. Oround-
water still contaminated.
Potential risk due to
emissions during ex-
cavation. Transfers
hazard to off-site
location.
Environmental
Considerations
No Source Control. Con-
tinued contamination of
groundwater. Relatively
rapid leaching with source
continuing for at least K
years.
Effective source control.
Inhibits migration. No
waste reduction. Ground-
water 20-40 ft. below
surface. Low water
table eliminates impact
of fluctuating water
table elevation.
Effective source control
via source removal. Site
regrading required. Po-
tential for contamination
during transport or as
result of off-site land-
filling.
Same as Alt. 3A, except
that EPA and State
permitted incinerator
must be used.
Same as Alt. 3A, except
no off-site potential
contamination at land*
fill.
Technical Considerations
Adjustments in Ranedle)
Action may be required
based on response to
monitoring. Inconsistent
w/RCRA. C8h required for
groundwater monitoring.
High reliability w/proper
Installation and .long-term
maintenance. Low level of
technology required. Meets
RCRA requirements. Long-
term OW required to en-
sure long-term effective-
ness. Estimated construc-
tion perlod-90 days.
Reliability dependent on
contamination boundary de-
finition and availability
of off-site landfill. Low
level technology required
on-site. RCRA Compliance
assuming Licensed Trans-
porter and Landfill. Each
load of soil must be
characterized. Air tanl-
toring required. Mln-
mum long-term OJM. Esti-
mated excavation perlod-
90 days.
Reliability dependent on
contamination boundary
definition and permit
status of Incinerator.
RCRA Compliance assuming
Licensed Transporter and
Incinerator and non-
hazardous ash. High level
of mechanical technology
required. Air monitoring
required. Minimal long-
Public and Elected
Officials Comments
Unacceptable. Hat re-
sponsive to problem.
Acceptable to some. Some
very opposed due to lack
of source reduction.
Clay cap preferred to
synthetic.
No Comment.
Acceptable.
Assumed
No Conment.
Acceptable.
Assumed
-------
t«LE 7A
*KIN COVHft Silt.
SOURCE CONTROL REKDIAL ALTERNATIVES
(CtKT'D)
Alternative
PROJECT COST (11.000)
Present
Capital PUN Worth •
Public Health
Considerations
4. Limited Excavation
w/Oi-Slte Incln-
eratIon and Disposal'
6.840 1.6 6,856
Eliminates future gen-
eration of contaminated
groundwater. Ground-
water still contamina-
ed. Potential risk due
to missions during ex-
cavation and Incinera-
tion.
5A. Limited Excavation0
w/On-S1te Aeration
and 01sposal*
424 1.6
440
Envlmnnental
Considerations
Effective source con-
trol via source removal.
Environmental assurances
of stack emissions. In-
cineration efficiency and
production of a non-
hazardous ash required.
Obtaining permits may be
time consuming. Treat-
ability (Test Burn) In-
formation required. Site
regrading required.
Eliminates future gen-
eration of contaminated
groundwater. Groundwater
still contaminated. Air
emissions during aera-
tion are potential ha-
zard.
Effective source control
via source removal. En-
vironmental assurances
of treatment efficiency
and non-hazardous residual
soil required. Signifi-
cant odors produced
temporarily during
aeration.
Public and Elected
Officials Comment*
Acceptable and favored
by sane. Opposed by sane
based on potential
air emissions.
Technical Considerations
tenn OH* required. Each
load of soil requires
characterization. Esti-
mated excavation perlod-
90 days.
Reliability dependent on
contnlnation boundary de-
finiton and permitting
Issues. RCRA Conpllance
assuming either permit
obtained or technical
equivalency shown and non-
hazardous ash. Etch load of
soil requires characteri-
zation. Air Monitoring
required. Minimal long-
term CUM required. High
level of mechanical
technology required.
Estimated Incineration
period-180 days.
Reliability dependent on Little or no public
contamination boundary de- acceptance.
flniton. Design pilot study
required to determine treat-
ment effectiveness. RCRA
Compliance assuming ef-
fective treatment obtained.
Soil requires testing after
treatment. Action limits
and testing procedures need
to be established. Low
level of mechanical tech-
nology required during
aeration. Extensive air
monitoring required. Mini-
mal (KM. Estimated aeration
period-40 weeks spread
over a 2 year period.
-------
TABLE IK
HcKIN CWAKT SITE. NKIIC
SOURCE CTHTROL REPCDIAL ALTERNATIVES
(CONT'D)
Alternative
58. Limited Excavation
w/Off-S1te Aeration
and Disposal
SC. fh-SUe Aeration
«nd Cap
1.3
PROJECT COST (f1.000)
Present
Capital «H Uorth
Public Health
Considerations
246 1.6 262 Same as Alt. 5A, except
hazard Is transferred
to off-site location.
177 38.9 415 Combination of Alt. ?
and 5A.
Environmental
Considerations
Sane as Alt. SA. except
off-site location 1s
Impacted.
Combination of Alt. 2 and
SA.
Technical Considerations
SMC as Alt. SA. Estimated
aeration peHod-10 weeks.
Catenation of Alt. 2 and
5A.
Public and Elected
Officials
to public cement ob-
tained.
Combination of Alt. 2 and
5A cements.
^Selected Remedial Action
1. Use of clay cap Instead of synthetic liner reflected
In revised F.S. cost.
2. Revised F.S. cost estimate based on the following
assumptions:
. Use of EPA Portable Incinerator
. 1 cubic yard capacity/hour
. 501 down time
. 523,000/day operational cost
3. Revised F.S. cost estimate due to more conservative
estimate as to duration of aeration than was
presented In the F.S.
-------
TABU n
KCK.W comuff SITE,
OFF-SITE CONTROL RDCDIA1 ALTERMTIVES1
6.
Alternative
No Action
w/Honltorlng
PROJECT COST (11,000)
Present
Capital ON Horth.
3.5 37.3
226
PuMIc Health
Considerations
Groundwater still
contaminated with de-
creases due to source
control and natural
mechanisms only. Alter-
nate water supply re-
duces potential for
exposure. M> guarantee
of use restriction.
Environmental
Considerations
No action to restore
aquifer. Time to re-
duce Total Volatile
Organlcs to SO ppb
estimated at 10 years,
assuring source control.
Withdrawal fells,
Treatment and
Discharge of
Treated Ground-
wter*3
3,495 37.3 3,128 Groundwater contamination Active restoration to
8.
Restrictions on
Future Development
115 37.3
reduction accelerated,
particularly 1n sur-
flclal aquifer, because
of extraction and treat-
ment. Alternate water
supply further reduces
potential for exposure.
266 Same as Alt. 6 except
use restrictions
eliminate exposures.
restore aquifer. Time
to restore Total Vol-
atile Organlcs to SO
ppb estimated at 5
years, assuming source
control. Treatment
standards for groundMater
discharge and air
emissions from treatment
system needed.
No action to restore
aquifer. Tine to re-
duce Total Volatile Or.
ganlcs to 50 ppb esti-
mated at 10 years,
assuring source control.
Technical Considerations
Public and Elector
Officials Comments
Reliability based on COM- Unacceptable to most.
outer Modelling of aquifer.
Adjustments 1n response to
monitoring nay be necessary.
Low level technology required.
Inconsistent'with RCRA. OH*
required for groundwater
monitoring.
Reliability based on
accurate location, depth
and pumping rate of ex-
tracton wells and ground-
water discharge and. In
part, on uncertain sub-
surface conditions. Access
to Installation and moni-
toring of wells on private
property Is needed. No
operation and Maintenance.
other than Monitoring costs,
If performance standards
are met.
Most are 1n favor of
this action with
reservations regarding
state costs.
Reliability based on un-
certain ability to Im-
plement and enforce re-
strictions. Aerial extent
of restrictions needs to be
defined In legal restrictions.
tto public comment ob-
tained.
* Selected Remedial Action
1. Each off-site control assumes the Implementation of a source control location other than Alternate 1.
2. Assunes 5-year remedial treatment unit achieving performance standards, see text of Remedial Alternative Selection.
3. Revised F.S. costs reflect revised, selected groundwater extraction and treatment optton based on:
. 25 wens 9 5 gpm/well
. discharge of treated groundwater to surface water.
-------
IM
AREA OF INFLUENCE OF
WITHDRAWAL WELL
-700- Itocoft. »»»
McKt&JMTE. QUAY MAINE
WITHDRAWAL WELL LOCATIONS SUPE
1,1.1-TniCHLORQETHANE SURFtCIAL A
PLUME
N
OM Canto* Wea«
L1IRE 12
------- |