United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R05-92/202
December 1991
Superfund
Record of Decision:
South Andover (Operable Unit
2), MN
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NOTICE
The appendices lIsted In the index that are not found In this document have been removed at the request of
the issuing agency. They contaJn material which suppfement. but adds no further IppIIcIbte information to
the content of the document. All suppiementaI matenaJ is. howeYer. contain8d In the adr'*''''.tN. record
~rth.s_. .
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50272-101
REPORT DOCUMENTATION 11. REPORT NO.
PAGE EPA/ROD/R05-92/202
I 2.
3. Reclplen'" Acce..lon No.
4. TlUe and Subtille
SUPERFUND RECORD OF DECISION
South Andover (Operable Unit 2), MN
Second Remedial Action - Final
7. Author(a)
5. Report Date
12/24/91
6.
8. P8rformlng OrganlzeUon Rept. No.
9. Perlormlng Orgalnlzetlon Name and Addreaa
10. ProjectiT..klWork Unit No.
11. Contract(C) or Grant(G) No.
(C)
(G)
12. SpoMorlng Organization Name and Addreaa
13. Type 01 Report' Period Covered
U.S. Environmental Protection
401 M Street, S.W.
Washington, D.C. 20460
Agency
800/000
14.
15. Supplementary Notas
16. Abellact (LImit: 200 worde)
The 50-acre South Andover site is composed of several privately owned parcels of land
near Minneapolis in Anoka County, Minnesota. Land use in the area is predominately
commercial and residential, and several auto salvage and repair yards are located at,
or adjacent to, the site. The site contains part of a wetlands area with several small
recreational lakes in the vicinity. The site overlies three aquifers, one of which
supplies the surrounding community with drinking water. Between 1954 and 1981,
multiple waste storage and disposal activities occurred on several properties within
the site boundaries. Source areas include a drum storage area, waste storage area, and
waste burning area. During the 1960's and 1970's, solid and liquid chemical waste
dumping and open pit burning of solvents occurred. Investigations showed that drum
storage aod chemical waste disposal sites were partially obscured by both auto salvage
operations and an estimated 3 million waste tires. In 1976, citizen complaints of well
contamination prompted the state to investigate the site and issue violations for
improper chemical waste storage, and in 1980, for improper disposal of industrial
waste. Waste processing was discontinued in 1977, and waste acceptance ceased in 1978.
In 1981, the contents of approximately 700 drums were disposed of by mixing them with
(See Attached Page)
17. Document Anslysls L Deacrlptora
Record of Decision - South Andover
Second Remedial Action - Final
Contaminated Media: soil, debris
Key Contaminants: organics (PAHs,
(Operable Unit 2); MN
PCBs), metals (lead)
b. ldentiliers/Open-Ended Terma
c. COSA T1 Reid/Group
18. Avallablilly Ststement
19. Security CI..a (Thia Report)
None
20. Security Cia.. (Thla Page)
None
2 t. No. 01 Pagea
32
22. Price
(See ANSI Z3S.18)
Su Ins/rue/Ions on Reverse
-77)
(Formerly NTISo35)
Department 01 Commerce
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EPA/ROD/R05-92/202
South Andover (Operable Unit 2), MN
Second Remedial Action - Final
Abstract (Continued)
waste oil and using the mixture as fuel; then, in 1988 and 1989, two tire fires occurred
onsite. EPA investigations determined that soil and ground water contamination had
resulted from contact with leaking drums, electrical transformers, and/or salvaged
automobiles. A 1988 ROD addressed the contaminated ground water onsite as OU1. This ROD
addresses the contaminated onsite soil as OU2. The primary contaminants of concern
affecting the soil and debris are organics, including PAHs and PCBs; and metals,
including lead.
The selected remedial action for this site includes excavating and onsite treatment of
2,100 cubic yards of PAH-contaminated soil using ex situ biological treatment; excavating
and disposing of the remaining 9,300 cubic yards of PAH, PCB, and metal-contaminated soil
from areas 2, 3, 4, and 7 in an offsite solid waste landfill; sampling and removing
offsite approximately 20 onsite drums; and monitoring surface water and sediment. The
estimated present worth cost for this remedial action is $2,470,000, which includes an
O&M cost of $195,000.
PERFORMANCE STANDARDS OR GOALS:
Soil clean-up goals will meet AWQCs and Minnesota surface water quality
standards. Noncarcinogenic risk will be to a HI=l. Chemical-specific goals for soil
cleanup include PAHs 2 mg/kg; PCBs 2 mg/kg; antimony 25 mg/kg; and lead 500 mg/kg.
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SOUTH ANDOVER SALVAGE YARDS
DECLARATION FOR THE RECORD OF DECISION
SITE NAME AND LOCATION
South Andover Salvage Yards,
Andover, Anoka County, Minnesota.
STATEMENT OF BASIS AND PURPOSE
This decision document represents the selected soil operable unit
remedial action for the South Andover Salvage Yard Site (the site)
developed in accordance with the Comprehensive Environmental
Response, compensation, and Liability Act of 1980 (CERCLA), as
amended by the superfund Amendments and Reauthorization Act of 1986
(SARA), and to the extent practicable, consistent with the National
Oil and Hazardous Substances Pollution contingency Plan (40 CFR
Part 300). This decision is also in accordance with the Minnesota
Environmental Response and Liability Act of 1983.
The decision is based upon the contents .of the administrative
record for the South Andover Salvage Yard site.
The state of Minnesota and the united States Environmental
Protection Agency (U.s. EPA) agree on the selected remedy.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this
site, if not addressed by implementing the response action selected
in this Record of Decision (ROD), may present an imminent and
substantial endangerment to public health, welfare, or the
environment.
DESCRIPTION OF THE SELECTED REMEDY
This operable unit is the second of two operable units for the
site. The first operable unit addresses contaminated groundwater.
The remedy for the first operable unit was documented in a March
1988, ROD which specifies pumping the contaminated groundwater at
select locations across the site. The second operable unit which
is described in this decision document, addresses soil
contamination.
The remedy selected for contaminated soil incorporates excavation
and on-site biological treatment of 2,100 cubic yards of
contaminated soil. The remaining 9,300 cubic yards of
contaminated soil will be excavated and disposed of off-site in a
solid waste landfill permitted to receive industrial and/or
commercial wastes.
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The major components of the selected remedy include:
Excavate and treat approximately 2,100 cubic yards of
predominately PAH-contaminated soils using an above-ground
biological treatment unit. Use clean fill from other areas of
the site as backfill for the excavated areas.
Biologically treated soil will be returned to the Site after
performance testing confirms successful biodegradation of the
PAHs.
Excavate and transport approximately 9,300 cubic yards of
soils contaminated with PCBs, PAHs, lead and antimony to an
off-site solid waste landfill permitted to receive industrial
and/or commercial wastes. Included in this component is the
replacement of excavated soil with clean fill from other areas
of the site.
Sample and remove approximately twenty drums located on the
site.
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the
environment, complies with Federal and State requirements that are
legally applicable or relevant and appropriate to the remedial
action, and is cost-effective. This remedy utilizes permanent
solutions and alternative treatment (or resource recovery)
technology to the maximum extent practicable, and satisfies the
statutory preference for remedies that employ treatment that
reduces toxicity, mobility, or volume as a principal element.
J~kJ4~~1
Date
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DECISION SUMMARY
South Andover Salvage Yards
Andover, Anoka County, Minnesota
I SITE NAME. LOCATION AND DESCRIPTION
The South Andover Salvage Yards Superfund site (the site) is
located in Anoka County, Minnesota, approximately 16 miles north-
northwest of Minneapolis and 3 miles northeast of the City of
Anoka. The Site is situated at 45 degrees, 16 minutes N Latitude,
and 93 degrees, 12 degrees West Longitude, in the south half of
section 34, Township 32 North, Range 24 West of Grow Township
(Figure 1).
The site is comprised of several privately owned parcels, which
jointly encompass more than 50 acres. Bunker Lake Boulevard
defines the northern extent of the site. The eastern site boundary
is roughly 500 feet west of Jay Street (Figure 2).
Small businesses and new residential developments are located near
the site. Several active businesses involved with used car and
auto parts sales, auto salvage operations, and auto body repair can
be found both at and adjacent to the Site. For many years the
area's population was minimal, however, residential development has
encroached the site since the early 1970s. Development continues
to occur around the Site.
There are several small recreational lakes in the area.
Lake is one mile west of the site and Bunker Lake is 1-1/4
the east. The site is in the Coon Creek watershed which
an oak savanna plant community.
Crooked
miles to
supports
Subsurface investigations confirmed the presence of three major
hydro-stratigraphic units within the unconsolidated sediment: an
upper sand aquifer which ranges from 23 to 40.5 feet thick, an
intermediate till and lacustrine aquitard that is 47 to 65 feet
thick, and a lower sand aquifer. These unconsolidated sediment
deposits are underlain by a sandstone bedrock. Major water users
in the Coon Creek watershed obtain potable water supplies from this
bedrock aquifer.
II SITE HISTORY AND ENFORCEMENT ACTIVITIES
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Waste storage and disposal activities began at the site during the
mid-1950s. More than 1,000 drums of waste were stored at the site.
Ink, ink and paint sludge, adhesives, chlorinated and
nonchlorinated solvents were stored, disposed of in trenches, and
burned at the Site. Solvent recovery, the storage of transformers
and salvaged electrical equipment, and smelting have also occurred
at the Site. Solid and liquid chemical waste dumping and open pit
burning of solvents occurred during the 1960s and 1970s. Drum
storage and chemical waste disposal sites were partially obscured
by auto salvage operations and more than three million waste tires
(Figure 3). .
Two tire fires occurred at the site. The first occurred during
July 1988 and was extinguished with water. A second much larger
tire fire occurred in February 1989. The fire was smothered with
sand.
Actions to limit waste handling operations at the site began in
1973 when Anoka County officials instructed Cecil Heidelberger, one
of the property owners, to remove and dispose of chemical wastes
stored on his property. Investigation of the site was initiated by
the Minnesota Pollution Control Agency (MPCA) in 1973 after a
citizen complaint of suspected residential well contamination. In
1976, the MPCA issued a Citation of Violation to Cecil Heidelberger
and his wife Marian Heidelberger for unregulated chemical waste
storage. These individuals continued processing waste until early
1977, and stopped accepting waste in 1978 when the property was
sold to Parmak, Incorporated.
The MPCA initiated actions to regulate other identified waste
handlers in 1980 and 1981. Notices of Violation for the improper
storage and disposal of chemical wastes were served to several
property owners. Cecil Heidelberger continued to dispose of
industrial waste by mixing the contents of 700 drums with waste oil
for use as fuel in an asphalt plant.
ACME Tag Company, Bemis Company, Color-Add packaging, and Standard
Solvents Company were notified by the MPCA in 1980 that they were
potentially responsible parties (PRPs). Sixteen parties, including
site owners, operators, and waste generators, were notified in 1982
by the u. S . EPA that the U. S . EPA was considering enforcement
actions at the site. All parties were also informed of their
potential joint and several liability related to these activities.
The MPCA took similar actions in 1983, outlining remedial actions
for the Site.
In July 1985, U.S. EPA notified twenty one PRPs that it intended to
conduct a Remedial Investigation/Feasibility Study (RI/FS) at the
Site, but that u.S. EPA would also consider an offer by the PRPs to
conduct the RI/FS. Failure on the part of the PRPs to negotiate
such action resulted in the U. s. EPA using Superfund monies to
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conduct the RIjFS.
III HIGHLIGHTS OF COMMUNITY PARTICIPATION
The Remedial Investigation (RI), Feasibility study (FS) and
Proposed Plan for the South Andover Superfund site were released to
the public for comment on October 9, 1991. These documents were
made available to the public in an information repository
maintained at the u. S. EPA Docket Room in Region V, Chicago,
Illinois. These documents were also maintained as part of the
administrative record at the following locations: Andover City
Hall located in Andover, Minnesota and the Minnesota Pollution
Control Agency located in saint Paul, Minnesota.
The notice of availability for the RI, FS and Proposed Plan was
published in the October 9, 1991 edition of the Anoka County
Shopper, the local newspaper. This notice also included a news
release which provided the dates of the public comment period as
well as the date of the public meeting. This news release along
with a fact sheet which described the preferred alternative, was
sent to all individuals on the South Andover Salvage Yards mailing
list. The mailing list includes but is not limited to, interested
residents, township and county officials, elected officials, and
site owners and operators.
The public comment period began on October 11th and ended on
November 9, 1991. A response to the comments received during this
period as well as during the public meeting, is included in the
Responsiveness Summary, which is part of this Record of Decision.
This decision document represents the selected remedial action for
the South Andover Salvage Yards Site, in Andover, Anoka County,
Minnesota, chosen in accordance with CERCLA, as amended by SARA
and, to the extent practicable, the National contingency Plan. The
decision for the site is based on the administrative record. A
pUblic meeting was held on October 30, 1991 at the Andover
Elementary School. At this meeting, representatives from u.S. EPA
and MPCA answered questions about problems at the Site and the
remedial alternatives under consideration.
IV SCOPE AND ROLE OF OPERABLE UNIT WITHIN SITE STRATEGY
The remedy for the South Andover Salvage Yards site has been
divided into two units or discrete actions, referred to as
"operable units" (OU). They are as follows:
OU One:
Remediation of contaminated
groundwater.
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OU Two:
Remediation of contaminated
soil.
The operable unit under consideration is Operable Unit Two:
Contaminated Soil. The remedial action objective for soil is to
clean-up the.contaminants of concern to a level which is protective
of human health. The selected remedy meets this obj ecti ve by
biologically treating contaminated soil or transporting it off-site
where it is contained in a secured, permitted landfill. Clean-up
levels were based on a cancer risk, a non-cancer hazard index, and
federal and state applicable or relevant and appropriate
requirements (ARARs).
Operable unit one addressed groundwater contamination at the Site.
U.S. EPA issued a Record of Decision (ROD) on March 30, 1988
documenting its decision to pump the contaminated groundwater at
selected locations on the Site. On March 4, 1991, the MPCA
concurred with this ROD. U.S. EPA and MPCA are currently
conducting a Design Investigation of this operable unit to obtain
more details on the character of groundwater contamination beneath
and near the Site. Initial sampling results do not indicate an
identifiable plume of contamination at this time. Based on these
new sampling results, U.S. EPA and MPCA will consider whether to
amend their original decision concerning groundwater. Any
amendment of the groundwater action would require public comment
and involvement.
V SUMMARY OF SITE CHARACTERISTICS
The U. S . EPA and MPCA have determined that the South Andover
Superfund site contains hazardous substances which pose a risk to
human health. The hazardous substances which pose such a threat
are polycyclic aromatic hydrocarbons (PAHs) , polychlorinated
biphenyls (PCBs), lead and antimony. The source of these hazardous
substances is contaminated soil which has come into contact with
leaking drums which were disposed of at the Site, electrical
transformers and/or salvaged automobiles.
PAHs are probable carcinogens that exhibit a low subsurface
mobility. PAHs also have a low water solubility. They originate
as constituents of crude oil fractions. Such crude oil fractions
include fuel and motor oils, as well as coal tar fractions. The
highest PAH concentration found at the site is 30.3 ppm.
PCBs are probable carcinogens that also exhibit a relatively low
potential for subsurface mObility. PCBs are chemically inert and
insoluble in water. PCBs do adsorb strongly to soils, the amount
of PCBs adsorbed is proportional to the amount of organic material
in the soil. Based on their strong adsorption to soil organic
matter and their relative insolubility in water, PCBs can be
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persistent. PCBs can be found in oils, greases, dielectric
liquids, and thermostatic or insulting fluids, especially in
electrical equipment such as transformers. The highest PCB value
found at the site is 15.17 ppm.
Lead and antimony are non-carcinogens and have low subsurface
mobilities. Both are metals and can exist in a complexed form
which allows the metals to be mobile. Metal movement can occur in
sandy, acid, low organic metal soils which receive high rainfall.
Even under these conditions the extent of metal movement will be
limited. Lead can be found in paint wastes, inks and salvaged auto
parts. Antimony is used as a hardening alloy for lead. The
maximum concentration of lead found at the site is 1980 ppm.
Antimony's maximum concentration at the site was 75.9 ppm.
The horizontal extent of soil contamination at the site is
spatially discontinuous and heterogeneous which is characteristic
of a "hot spot" distribution. vertical soil contamination is
confined to surface soils. contamination is limited to a depth of
six feet. Soils at the site consist primarily of excessively-
drained to somewhat poorly-drained fine sand with limited areas of
poorly-drained, loamy fine sand. The total volume of PAR, PCB,
lead and antimony contaminated soil at the Site is estimated to be
11,400 cubic yards. The 11,400 cubic yards of contaminated soil
are distributed in seven hot spots (Figure 4).
Surface water and sediments samples were collected and analyzed as
part of the soil Remedial Investigation. The following
contaminants were detected in the surface water: methylene
chloride, acetone, toluene, bis (2-ethylhexyl) phthalate, lead,
cyanide, aluminum, cadmium, copper, mercury and zinc. Sediment
samples contained the following: methylene chloride, acetone,
toluene, bis(2-ethylhexyl)phthalate, 4,4'-DDT (a pesticide), 4,4'-
DDD (another pesticide), lead and cyanide. None of the above
mentioned contaminants were found at a level in either the surface
water or sediment which presented a risk to human health. A
Preliminary Ecological Assessment was performed to determine the
ecological risk presented by the surface water and sediments. The
results of this Assessment are discussed later in this Record of
Decision.
The site hydrogeology is represented by three major hydro-
stratigraphic units within the unconsolidated sediment: a shallow
upper sand aquifer which ranges from 23 to 40.5 feet thick; a till
and lacustrine aquitard that is 47 to 65 feet thick; and a lower
sand aquifer. These unconsolidated sediment deposits are underlain
by a bedrock aquifer composed of sandstone. The major water users
and residents in the area obtain drinking water from this bedrock
aquifer.
As mentioned earlier, a Design Investigation is currently being
performed to obtain more details on the character of groundwater
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contamination beneath and near the site. Initial sampling results
do not indicate an identifiable plume of contamination. Arsenic
was detected in one shallow upper sand aquifer monitoring well
above the Maximum Concentration Limit (MCL). However, no on-site
source of arsenic could be found in the soil to account for this
exceedence.
Several drums are present on-site. Approximately twenty drums were
counted during a December 2, 1991 site visit. The majority of
drums were numbered. These numbers correlate with the inventory
numbers of drums which were counted by the MPCA in the Summer of
1989. Most of the drums had partially rusted surfaces but none
appeared to be punctured. A third of the drums sounded as though
they contained frozen material when tapped with a broom handle.
u.s. EPA expects to address these drums through a removal action to
determine the nature of the material contained within the drums as
well as have the drums removed from the Site.
VI SUMMARY OF SITE RISKS
Human Health Risk
The baseline risk assessment for the South Andover Superfund site
was conducted to determine the potential exposure an individual
could have to the chemicals detected at the Site. This was
accomplished by estimating how much of each chemical could be
absorbed by various body parts (i.e. skin, lungs, or intestines)
and then estimating how often, for how long, and under what
conditions such exposure could occur.
Based on the frequency of occurrence, concentration, and health
effects, the baseline risk assessment identified the following soil
contaminants as contaminants of concern for the Site: polycyclic
aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs),
lead and antimony. .
As mentioned earlier, the July 1991 Remedial Investigation
determined that the nature and extent of soil and buried
contamination at the site is distributed in localized "hot spots".
Seven hot spots exist at the site which present a risk to human
health. These hot spots were generally found in surface soils at
a depth of six feet or less.
All residential wells sampled were free of site related
contaminants and safe for drinking. Only one on-site shallow
aquifer monitoring well had an arsenic level which exceeded federal
and state drinking water standards but, no on-site source of
arsenic could be found which could have caused such a level to
occur in groundwater.
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The baseline risk assessment also determined that the contaminants
detected in surface water and sediments do not pose a risk to human
health.
When conducting the risk assessment, the highest concentrations of
contamination found at the site are used when determining the risks
posed. Consequently, the risk calculations do not represent the
average value of that contaminant found at the Site as much as a
maximum estimated risk. For example, when the cancer risk for
groundwater was determined the concentration of arsenic found in
the shallow aquifer monitoring well was used. This well exceeded
the Maximum contaminant Level (MCL) for arsenic but it was not
representative of arsenic values found in groundwater across the
site which were an order of magnitude lower than the MCL. The MCL
is the maximum level of a contaminant permitted in drinking water
which is delivered to the consumer's tap and used by the general
public for drinking.
The baseline risk assessment also must take into consideration the
possible present and future uses of the Site in order to determine
the exposure pathways and populations affected. In determining
exposure pathways and populations affected a plausible maximum
exposure scenario is assumed. As a result, the potential exposure
or risk is intentionally conservative. The actual risk is likely
to be less than the estimated risk.
Given these assumptions, people likely to be exposed
contaminants at the site under current conditions are:
to
Workers in the active on-site auto parts
businesses exposed to contaminated surface soil.
Adult residents of on-site dwellings exposed to
contaminated surface soil and groundwater.
Adults and children scavenging or trespassing
in nonbusiness areas of the site exposed to
contaminated surface soil.
Children scavenging or trespassing in nonbusiness
areas of the site exposed to contaminants detected
in the surface water or sediments.
For the future exposure scenario, the risk assessment developed a
scenario that the entire site would be developed for residential
use. Under this scenario, the people who could be exposed would
be:
Construction workers exposed to contaminated
subsurface soil.
Adult and child residents exposed to contaminated
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surface soil and groundwater.
Given these exposure assumptions the baseline risk assessment
determined clean-up levels for the contaminants of concern found in
the soil. These clean-up levels are based on cancer risks and a
hazardous index value. Cancer risks are determined by mUltiplying
the intake level with the cancer potency factor.
Cancer potency factors (CPFs) have been developed by U.S. EPA's
Carcinogenic Assessment Group for estimating lifetime cancer risks
associated with exposure to potentially carcinogenic chemicals.
CPFs, which are expressed in units of mgjkg-day, are multiplied by
the estimated intake of a potential carcinogen, in mgjkg-day, to
provide an upper-bound estimate of the excess lifetime cancer risk
associated with exposure at that intake level. The term "upper
bound" reflects the conservative estimate of the risks calculated
from the CPF. Use of this approach makes underestimation of the
actual cancer risk highly unlikely. Cancer potency factors are
derived from the results of human epidemiological studies or animal
bioassays to which animal-to-human extrapolation and uncertainty
factors have been applied.
Excess lifetime cancer risks are determined by multiplying the
intake level with the cancer potency factor. These risks are
probabilities that are generally expressed in scientific notation
(e.g. 1E-06). An excess lifetime cancer risk of 1E-06 indicates
that an individual has a one in one million chance of developing
cancer as a result of site-related exposure to a carcinogen over a
70 year lifetime under the specific exposure conditions at a site.
The acceptable cancer risk range for clean-up of carcinogens is 1E-
04 to lE-06.
The hazard index value represents the risk of noncancer effects
from site related contaminants of concern. The hazard index is
determined by adding the hazard quotient for all contaminants
within a medium or across all media to which a given population may
reasonably be exposed. The hazard quotient. is a ratio that is
estimated by determining the intake derived from the contaminant
concentration in a given medium to the contaminant's reference
dose. The reference dose is aU. S. EPA standard which measures the
potential for adverse human health effects from exposure to
noncarcinogenic chemicals.
Once the hazard quotients have been determined for the various
contaminants, they are added. The resultant sum is the hazard
index. The hazard index (HI) provides a threshold level for
gauging the potential significance of multiple contaminant
exposures within a single medium or across media. When the hazard
index is less than or equal to 1, no noncancer health effects are
considered to be likely. Conversely, an HI greater than one
indicates a potential noncarcinogenic health threat exists.
8
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A cancer risk of between 2E-05 and 3E-05 was determined as
appropriate for the clean-up of PAHs and PCBs. These clean-up
levels are within the u.s. EPA acceptable risk ranges for clean-up
of carcinogens. Additionally, clean-up to a risk range of between
2E-05 and 3E-05 would be cleaning up the hot spots to a level where
they could just be detected using current u. S. EPA analytical
methods. Lower clean-up levels would be difficult to consistently
confirm. Resultant clean-up levels would be 4 ppm for PAHs and 2
ppm for the PCBs.
site noncancer risks result from exposure to lead and antimony. A
clean-up level based on a hazard index value of 1 is needed to
remediate antimony. This results in a clean-up level of 25 ppm.
The target levels for noncancer risk from lead exposure are
selected as a 5 percent chance of exceeding a 10 ug/dL blood lead
level in children. The target soil lead concentration to achieve
a predicted percentage below 5 percent is 500 ppm, this value will
be the clean-up level for lead.
Environmental Risks
A Preliminary Ecological Assessment was performed on the Site. The
objective of this assessment was to determine whether contaminants
detected during the Remedial Investigation in the surface waters
and sediments of the four wetland areas located within or adjacent
to the site pose, or could in the future pose, an unacceptable risk
to non-human biological receptors (Figure 5).
The assessment determined that several surface water and sediment
standards were exceeded mainly in two of the four wetland areas.
These are Wetland Areas 1 and 4. U.S. EPA's Ambient Water Quality
criteria (AWQC) standards were exceeded for cadmium, copper and
cyanide in the surface waters of Wetland Area 1. Minnesota surface
water quality standards were also exceeded for cadmium and copper
in Wetland Area 1. The AWQC standards for lead and zinc were
exceeded in the surface waters of Wetland Area 4. Minnesota
surface water quality standards were exceeded for aluminum and zinc
in Wetland Area 4. See Table 1.
Sediment values were evaluated using u.S. EPA guidance and other
published research material. Sediments in Wetland Area 1 exceeded
guidelines for copper, iron, lead, manganese and zinc. Sediments
in Wetland Area 4 exceeded guideline levels for copper, lead, DDD
and DDT. See Tables 2 and 3.
'If Wetland Area 1 which is located within the site, is to be
remediated according to human health concerns, the Preliminary
Ecological Assessment recommends that the clean-up of contaminated
soils surrounding the wetland be designed to avoid contamination of
the wetland area via surface water runoff. The assessment also
recommends that once clean-up of the soil has occurred follow-up
sampling of surface water and sediments within this wetland should
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be done to determine if any impacts were caused to the wetland due
to remedial activities.
Wetland Area 4 is located south and adjacent to the site. This
wetland appears to contain elevated levels of inorganic
contaminants and pesticides. In order to more completely assess
the ecological risk posed by contaminants present in this wetland,
the Preliminary Ecological Assessment recommends that further
investigations, including surface water and sediment sampling,
should be conducted.
VII DESCRIPTION OF ALTERNATIVES
The alternatives under consideration for soil contamination were
developed by examining a number of possible remedial technologies
and compliance of these alternatives with applicable or relevant
and appropriate requirements (ARARs) of federal and state
environmental statutes.
The remedial alternatives developed include various combinations of
containment, treatment and disposal. A total of four alternatives
were evaluated in detail for remediating contaminated soil. The
alternatives analyzed are as follows:
Alternative 1:
Alternative 2:
Alternative 3:
Alternative 4:
Alternative 1:
NO ACTION.
No Action.
On-Site Aerobic Biological
Treatment with Capping of
contaminated soil.
Monitoring of Surface Water
and Sediments in Wetland Areas
1 and 4.
On-site Aerobic Biological
Treatment in Tandem with Above
Ground Stabilization and Disposal
in an On-site Landfill. Monitoring
of Surface Water and Sediments in
Wetland Areas 1 and 4.
On-Site Aerobic Biological
Treatment with Disposal in an
Off-Site Landfill. Monitoring
of Surface Water and Sediments
in Wetland Areas 1 and 4.
Estimated Capital Costs: $0.
Estimated Operation and Maintenance Costs:
$0.
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Estimated Present Worth Costs: $0.
Estimated Implementation Timeframe:
Not applicable.
The superfund program requires that the "no action" alternative be
evaluated at every site to establish a baseline for comparison.
Under this al ternati ve, no further action would be taken to
remediate soil.
Alternative 2:
ON-SITE
CAPPING.
AEROBIC BIOLOGICAL TREATMENT WITH
MONITORING OF WETLAND AREAS 1 AND 4.
Estimated
Estimated
Estimated
Estimated
Capital Costs: $1,000,000.
Operation and Maintenance Costs: $270,000.
Present Worth Costs: $2,500,000.
Implementation Timeframe: 2 years.
Under this alternative a total of 2,100 cubic yards of PAH-
contaminated soil from three hot spot areas (Areas 1, 5 and 6)
would be excavated and treated in an above-ground biological
treatment unit. Treated soil would be returned to the site as
clean fill. The remaining 9,300 cubic yards would be covered by
two non-RCRA caps. One cap would cover a contiguous area defined
by three hot spots (Areas 2, 3 and 4). The second cap would cover
Area 7. A total area of approximately 1.7 acres would be covered.
A monitoring program would need to be established in order to
evaluate the long-term physical integrity and effectiveness of the
cap. Supplemental controls such as deed restrictions would be
considered as. necessary to maintain the effectiveness of the
remedy.
A total of twelve surface water samples would be collected from
Wetland Areas 1 and 4. These samples would be analyzed for pH,
alkalinity, Total Organic Carbon, major anions, the Hazardous
Substance List metals, and chronic aquatic toxicity testing would
be performed. Surface water samples would be collected on a semi-
annual basis with one of the sampling events occurring during the
spring snowmelt. Twelve sediment samples would be analyzed for
grain size, Total organic Carbon, Total Volatile Solids, the
Hazardous Substance List metals, and toxicity testing would be
performed. Sediment samples would be collected annually.
This particular alternative will require a cap to be installed as
close as possible to the wetlands. Cap construction, increased
runoff and, potentially, sedimentation may be major impacts to the
wetlands. As a result, temporary controls will be necessary during
the construction of the cap. Temporary controls during
construction might include the installation of silt fences or straw
bales. supplemental measures to control post-construction runoff
and/or sedimentation which may be considered if determined to be
necessary, might include grassed swales and grading on and around
the cap and surrounding areas to direct runoff away from the
wetlands.
11
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Alternative 3:
ON-SITE AEROBIC BIOLOGICAL TREATMENT IN TANDEM
WITH ABOVE GROUND STABILIZATION AND DISPOSAL IN
AN ON-SITE LANDFILL. MONITORING OF WETLAND
AREAS 1 AND 4.
Estimated
Estimated
Estimated
Estimated
Capital Costs: $2,600,000.
Operation and Maintenance: $280,000.
Present Worth Costs: $4,000,000.
Implementation Timeframe: 2 years.
Alternative 3 involves excavating and biologically treating 2,100
cubic yards of PAH-contaminated soil from Areas 1, 5 and 6 in the
same manner as described in Alternative 2. Alternative 3, however,
provides for the excavation and stabilization of the remaining
9,300 cubic yards of PCB-, PAH-, and metal-contaminated soil from
Areas 2, 3, 4 and 7. These treated soils would then be placed in
an on-site landfill. As with Alternative 2 a monitoring program
would need to be established in order to evaluate the integrity and
effectiveness of the landfill over time. Also, supplemental
controls such as deed restrictions would be considered as necessary
to maintain the effectiveness of the remedy.
Surface water and sediment samples would be analyzed for the same
parameters and at the same frequencies and locations as described
in Alternative 2.
Alternative 3 will require excavation adjacent to wetlands.
Temporary controls similar to those in Alternative 2 will be needed
to prevent runoff from entering the wetlands.
Alternative 4:
ON-SITE AEROBIC BIOLOGICAL TREATMENT WITH
DISPOSAL IN AN OFF-SITE LANDFILL. MONITORING
OF WETLAND AREAS 1 AND 4.
Estimated
Estimated
Estimated
Estimated
Capital Costs: $2,200,000.
Operation and Maintenance Costs: $195,000.
Present Worth Costs: $2,470,000.
Implementation Timeframe: 2 years.
Alternative 4 also involves excavating and biologically treating
2,100 cubic yards of PAH-contaminated soil from Areas 1, 5 and 6.
Treatment would occur in an above-ground unit and treated soil
would be returned to the Site as clean fill (see Alternative 2).
The remaining 9,300 cubic yards of PCB-, PAH-, and metal-
contaminated soil from Areas 2, 3, 4 and 7 would be taken to a
permitted landfill for final disposal.
The July 1991 Remedial Investigation determined that soils from the
Site are not hazardous waste as defined under the Resource
Conservation and Recovery Act (RCRA). This determination was made
based on the results of Toxicity Characteristic Leaching Procedure
(TCLP) testing and knowledge of the materials disposed of at the
12
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Site. Consequently, soils excavated from Areas 2, 3, 4 and 7 may
be disposed of at a landfill which is permitted to receive
commercial and/or industrial solid waste.
Surface water and sediment samples would be analyzed for the same
parameters, and at the same frequencies and locations as described
in Alternative 2.
Alternative 4 will require excavation adjacent to wetlands.
Temporary controls similar to those in Alternative 2 will be needed
to prevent runoff from entering the wetlands.
VXXX SUMMARY OF COMPARATXVE ANALYSXS OF ALTERNATXVES
The National Contingency Plan and Section 121 of the Superfund
Amendments and Reauthorization Act of 1986 (SARA) form the
regulatory basis for the nine evaluation criteria to be utilized in
determining the appropriate remedial action at a CERCIA site.
Specifically, Section 121 of SARA requires that the selected remedy
is to be protective of human health and the environment, cost-
effective, and use permanent solutions and alternative treatment
technologies or resource recovery technologies to the maximum
extent practicable. .
The following is a summary of the nine evaluation criteria used to
evaluate remedial alternatives:
Overall Protection" of Human Health and the Environment
addresses whether or not a remedy provides adequate
protection and describes how risks are eliminated, reduced
or controlled through treatment, engineering controls,
or institutional controls.
ComDliance with ARARs addresses whether or not a remedy
will meet all of the applicable or relevant and appro-
priate requirements of other Federal and State environ-
mental statutes and/or provide grounds for invoking a
waiver.
Lonq-term Effectiveness and Permanence refers to the
ability of a remedy to maintain reliable protection of
human health and the environment over time once cleanup
goals have been met.
Reduction of Toxicitv. Mobilitv. or Volume throuqh Treatment
is the anticipated performance of the treatment technologies
that may be employed in a remedy.
Short-term Effectiveness refers to the speed with which the
remedy achieves protection, as well as the remedy's potent-
13
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ial to create adverse impacts on human health and the envi-
ronment that may result during the construction and imple-
mentation period.
Imclementabilitv is the technical and administrative feasi-
bility of a remedy, including the availability of materials
and services needed to implement the chosen solution.
Cost includes capital, operation and maintenance costs.
state Accectance indicates whether, based on its review of
the Remedial Investigation, Feasibility study and Proposed
Plan, the state concurs with, opposes, or has no comment on
the preferred alternative.
Community Accectance indicates the public support of a given
alternative. This criteria is discussed in the Responsive-
ness Summary.
Overall Protection of Human Health and the Environment
Al ternati ve 1, no action, does not satisfy the requirement for
overall protection of human health and the environment. The risk
associated with the no action alternative pertains to the release
of contaminants to the air and surface water pathways and for
exposure of contaminated soils through direct contact and
ingestion.
Alternatives 2, 3 and 4 are more protective of human health and the
environment than Al ternati ve 1. These al ternati ves can all achieve
a cancer based risk clean-up of between 2E-05 to 3E-05. Each
alternative includes treatment and containment of the contaminated
soils, and thus eliminates the potential pathways of concern for
both human and non-human exposure. Alternative 4 would either
treat or remove all contaminated soil at the site so that no
residuals would remain on-site. Alternatives 2 and 3 would require
continued long-term monitoring of residuals left on-site.
compliance with ARARs
currently, several Federal Ambient Water Quality criteria for the
Protection of Aquatic Life (AWQCs) and Minnesota surface water
quality standards are being exceeded for several inorganic
compounds in surface waters at the site (Table 1). Alternative 1
would allow this continued exceedence.
Alternatives 2, 3 and 4 provide for the monitoring of surface
waters and sediments in wetland areas 1 and 4 once contaminated
soils have been remediated. This will ensure compliance with
Federal standards (AWQCs) and Minnesota regulations concerning the
protection of state surface waters.
14
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The Land Disposal Restrictions (LDRs) of the Resource Conservation
and Recovery Act (RCRA) do not apply to this Site. Contaminated
soils were analyzed using Toxicity Characteristic Leaching
Procedures (TCLP) testing to determine if they were characteristic
hazardous wastes. Testing results indicated that the soils are not
RCRA characteristic hazardous wastes (Table 4). Earlier
investigations concluded that no RCRA listed hazardous wastes were
disposed of at the site.
Long-Term Effectiveness and Permanence
The evaluation of alternatives under this criterion address the
risk remaining at the South Andover site at the conclusion of
remedial activities. The primary focus of this evaluation is to
determine the extent and effectiveness of controls that may be
required to manage the risk posed by treatment residuals and/or
untreated waste. Alternative 1 provides no long-term effectiveness
and would result in the continuation of elevated site risks.
Alternatives 2, 3 and 4 each include excavation and above-ground
biological treatment of the PAH-contaminated soils. No untreated
residuals from this process would remain on-site since the PAHs are
destroyed. The primary difference between Alternatives 2, 3 and 4
relative to long-term effectiveness and permanence is the approach
taken in managing the risk associated with contaminated soils in
Areas 2, 3, 4 and 7.
Alternative 2 assumes the perpetual containment of these soils
under an engineered cap on-site. Alternative 3 provides for the
stabilization of contaminated soils and assumes that the stabilized
material will be permanently contained in an on-site landfill.
Alternative 4 exports the contaminated material to an off-site,
permitted landfill and assumes that continued compliance with
landfill regulations will address any potential containment
problems which may arise from managing these wastes. with regards
to the site, no untreated residuals remain on-site when Alternative
4 is implemented.
Reduction of Toxicity, Mobility and volume
This evaluation criterion addresses the statutory preference for
selecting remedial actions that employ treatment technologies that
permanently and significantly reduce toxicity, mobility or volume
of the untreated waste.
Alternative 1 provides no reduction in toxicity, mobility or volume
of the contaminant mass. The remaining alternatives each include
the degradation of PAHs in contaminated soils. This treatment
element provides for the destruction of the PAH molecule in the
soil and thus meets the preference for implementing irreversible
treatment processes that reduce the volume of contamination.
15
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Alternatives 2 and 4 do not include the use of treatment for
addressing the PCB and metal-contaminated soils form Areas 2, 3, 4
and 7. Both of these alternatives incorporate capping and
landfilling of the contaminated soils to cause a reduction in the
mobility of the contaminants. Alternative 3, however, provides the
most reduction of toxicity, mobility and volume because of the use
of stabilization for immobilizing all contaminants of concern.
Short-Term Effectiveness
This evaluation criterion addresses the effects of the alternatives
on human health and the environment during construction and
implementation phases. The short-term effectiveness period extends
until the remedial response objectives are attained. All of the
alternatives, with the exception of no action, include mitigative
measures for minimizing short-term impacts during construction.
The no action alternative provides unacceptable risks through all
exposure pathways to the community.
Alternative 2 includes the installation of surface caps over Areas
2, 3, 4 and 7, while Alternatives 3 and 4 entail excavation and
containment of soils. All three of these alternatives involve the
excavation and treatment of PAH-contaminated soils. There may be
dust, noise and traffic issues associated with the cap
installation, treatment and excavation activities for these
alternatives; These potential threats to the community will be
minimized through control of emissions, noise and traffic during
installation of the cap and excavation of the soils.
Issues related to worker construction are similar for all three
alternatives. There are risks associated with normal construction
activities, particularly for remediation efforts that are primarily
excavation or site work related. Health and safety plans will
require that workers are adequately protected during any site work
related activities.
In evaluating the time required until remedial action objectives
are met, there are no distinguishing features to Alternatives 2, 3
and 4. Each will require approximately one construction season and
possibly a second year to accommodate the biological treatment
component of the alternatives.
Implementability
This criterion addresses the technical and administrative
feasibility of implementing an alternative, and the availability of
various services and materials required for its implementation.
Technically, Alternative 2 through 4 are implementable and can be
readily constructed of available materials. The technologies
considered, which include biological treatment, capping,
stabilization, and landfill disposal, are available from multiple
vendors and can be designed with minimum implementation concerns.
16
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There are several site-specific implementation issues, however,
which need to be addressed in order to meet the site remedial
objectives. Specifically, the proximity of wetlands to Areas 4 and
7 will require some sort of engineered device to prevent impact to
these wetlands if a cap or a landfill is to be constructed. Also
the siting of an on-site landfill is further complicated by the
high water table at the Site.
Long-term monitoring will be required for Alternatives 2 and 3
since residuals are either contained on-site under a cap or
stabilized material is contained in an on-site landfill. No site
monitoring as part of the Second Operable Unit would be required
for Alternative 4 since no residuals would remain on-site.
Cost
Alternatives are evaluated for cost in terms of capital costs,
operation and maintenance cost (O&M), and present worth cost. The
present worth analysis is used to evaluate expenditures that occur
over different time periods by discounting all future costs to a
common base year. This allows the cost of remedial action
al ternatives to be compared on the basis of a single figure
representing the amount of money that, if invested in the base year
and disbursed as needed, would be sufficient to cover all costs
associated with the remedial alternatives over its planned life.
The estimated present worth costs of the various alternatives are
as follows:
Alternative 1:
Alternative 2:
Al ternati ve 3: .
Alternative 4:
$ 0
$2,500,000
$4,000,000
$2,470,000
state Acceptance
U.S. EPA and MPCA agree on the preferred alternative (Alternative
4). Both Agencies have been involved in the technical review of
the Remedial Investigation Report, Feasibility Study and the
development of the Proposed Plan and the ROD.
community Acceptance
Community acceptance is assessed in the attached Responsiveness
Summary. The Responsiveness Summary provides a thorough review of
the public comments, received on the Remedial Investigation,
Feasibility Study and Proposed Plan, and U.S. EPA's and MPCA's
responses to the comments received.
IX SELECTED REMEDY
17
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The U.S EPA selects Alternative 4 as the most appropriate
alternative for soil remediation at the South Andover Superfund
site. Alternative 4 involves the on-site aerobic biological
treatment of 2,100 cubic yards of PAH-contaminated soil; the
excavation of 9,300 cubic yards of PCB-, PAH-, and metal-
contaminated soil with disposal into a permitted
industrial/commercial landfill; and monitoring of surface water and
sediments in Wetland Areas 1 and 4. MPCA concurs with the selected
alternative.
Implementation of this alternative provides a permanent remedy for
the Site in which long-term cancer risks are reduced to a level
which is protective of human health. Specifically, cancer risks
are reduced to a level of between 2E-05 to 3E-05 when Alternative
4 is implemented. Resul tant carcinogenic clean-up levels are 4 ppm
for the PAHs and 2 ppm for the PCBs. Clean-up to these levels
would be cleaning up the seven hot spot areas to a point where they
could just be detected using current u.S. EPA analytical methods.
Implementation of Alternative 4 will also reduce the risks of
exposure from the noncarcinogens, lead and antimony, present at the
Site. A clean-up level based on a hazard index of 1 was used to
establish the remediation goal for antimony. This results in a
clean-up level of 25 ppm. The remediation goal for lead is
expressed as a 5 percent chance of exceeding a 10 ug/dL blood lead
level in children. The soil lead concentration to achieve a
predicted percentage below 5 percent is 500 ppm, this value is the
clean-up level for lead.
In determining both the carcinogenic and non-carcinogenic clean-up
levels, the risk assessment developed a scenario that the entire
site would be developed for residential use. Under this scenario,
the people who could be exposed would be: construction workers
exposed to contaminated subsurface soil; and adult and child
residents exposed to contaminated surface soil and groundwater.
In summary, Alternative 4 provides a permanent remedy in which all
contaminated soil is either treated through biological treatment or
is transported off-site where it is contained in a secure,
permitted landfill. As a result, there are no residuals left on-
site which would require long-term monitoring. Also, there is no
need for imposing deed restrictions or other institutional controls
as part of this remedy.
Alternative 4 also requires that the approximately twenty drums
located on the site will be sampled and removed. U.S. EPA expects
to address these drums through a removal action.
The selected alternative is believed to provide the best balance of
trade-offs among the alternatives with respect to the nine
evaluation criteria. Based on the information available at this
time, the selected alternative would be protective of human health
18
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and the environment, would comply with ARARs, would be cost
effective, and would utilize,permanent solutions and alternative
treatment technologies or resource recovery technologies to the
maximum extent practicable. The selected alternative should also
satisfy the preference for treatment as a principal element.
X STATUTORY DETERMINATIONS
Protection of Human Health and the Environment
The selected remedy is protective of human health because all
contaminated soil is either treated or removed from the site. As
a result, no unacceptable health risks will remain once the
selected remedy is implemented. Remediation of PAH and PCB
carcinogens to within a cancer risk range of 2E-05 to 3E-05 will
result in clean-up levels of 4 ppm for the PAHs and 2 ppm for the
PCBs. Remediation of the non-carcinogen antimony to a hazard index
value of 1 will result in a clean-up level of 25 ppm. The non-
carcinogen lead will be cleaned up to a level of 500 ppm. This
clean-up level is based on, permissible blood lead levels in
children. These clean-up levels and their associated risk ranges
are in compliance with u.s. EPA and MPCA standards and policies and
are protective of human health.
It is anticipated that the selected remedy is protective of the
environment as well. Once contaminated soils are removed from the
Site, the primary source of contaminated surface water run-off will
have been removed and surface water quality in the wetlands should
improve. Monitoring of surface water and sediments after
remediation will ensure compliance with Federal and State
regulations concerning the protection of aquatic life in surface
waters. Additionally, precautions will be taken when soils are
being excavated so as to avoid contamination of the wetland area
via surface water runoff. Such temporary controls might include
the installation of silt fences or straw bales.
The selected alternative involves the excavation and treatment of
contaminated soils. There may be dust, noise and traffic issues
associated with these activities. However, a site specific health
and safety plan will be developed as part of the Remedial
Design\Remedial Action Work Plan. The purpose of the health and
safety plan would be to address these potential threats to the
community, environment and on-site workers.
compliance with ARARs
The selected alternative meets all applicable and relevant and
appropriate requirements (ARARs) of federal and state environmental
laws. The Federal Ambient Water Quality criteria for the
Protection of Aquatic Life (AWQCs) and the surface water quality
19
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standards under Minnesota Rules, Chapter 7050 are considered
relevant and appropriate considering the purposes of this remedial
action.
Currently, several Federal AWQCs and Minnesota surface water
quality standards are being exceeded for several inorganic
compounds. After contaminated soil is excavated and either treated
or removed from the Site, it is anticipated that the surface water
quality standards will improve. Monitoring of surface waters after
soil remediation will ensure compliance with federal and state
surface water quality standards.
Also, precautions will be taken so that surface water quality in
the wetlands will not be degraded further by remedial activities at
the site. Specifically, temporary controls such as silt fences and
straw bales could be used to prevent run-off into the wetlands.
As mentioned earlier, contaminated soils were analyzed using TCLP
testing to determine if they were characteristic hazardous wastes
as defined under the Resource Conservation and Recovery Act (RCRA).
Testing resul ts indicated that the soils are not RCRA
characteristic hazardous waste (Table 4). Earlier investigations
concluded that no RCRA listed hazardous wastes were disposed of at
the site. Therefore, the Land Disposal Restrictions (LDR) of RCRA
do not apply to this remedy. u.S. EPA generally will not consider
the Land Disposal Restrictions (LDRs) to be relevant and
appropriate for soil and debris contaminated with hazardous
substances that are not RCRA restricted wastes. The basis for this
determination is that soil which is primarily of a geologic origin,
is not sufficiently similar to a listed RCRA waste code or family
of waste codes such that the LDR standard for that waste code is
relevant and appropriate. Consequently, neither the RCRA
regulations nor the land disposal restrictions would be ARARs at
the Site.
Additionally, RCRA closure regulations are not ARARs for the cap or
landfill proposed in Alternatives 2 and 3 because the contaminated
soil is being excavated and treated to health based levels.
cost Effectiveness
The selected remedy is cost-effective because it has been
determined to provide overall effectiveness proportional to its
costs, the net present worth value being $2,470,000. The selected
remedy is the least most expensive alternative; however, it is the
most consistent with the overall Site strategy for remediating the
soil.
utilization of Permanent Solutions and Alternative Treatment
Technologies or Resource Recovery Technologies to the Maximum
Extent Practicable
20
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The selected remedy represents the maximum extent to which
permanent solutions can be utilized in a cost-effective manner for
the soil remedy at the South Andover Superfund Site. Of the
alternatives that are protective of human health and the
env ironment and comply with ARARs, U. S. EPA and the State have
determined that the selected remedy provides the best balance of
tradeoffs in terms of long-term effectiveness and permanence,
reduction of toxicity, mobility or volume, short-term
effectiveness, implementability, cost, also considering the
statutory preference for treatment as a principal element and
considering State and community acceptance.
Implementation of the selected remedy provides a permanent solution
for the Site in which long-term cancer risks are reduced to a level
which is protective of human health. The remedy will also reduce
the amount of contaminated surface water run-off to the wetlands
and thereby reduce environmental risks. All contaminated soil is
either treated through biological treatment or is transported off-
site where it is contained in a secure, permitted landfill. As a
result, there are no residuals left on-site which would require
long-term monitoring. Also, there is no need for imposing deed
restrictions or other institutional controls as part of this
remedy.
The selected alternative is therefore considered to be the most
appropriate solution to soil contamination at the site because it
provides the best trade-offs with respect to the nine criteria.
The selected alternative also ulitizes treatment technologies to
the maximum extent practicable.
Preference for Treatment as a principal Element
The selected alternative meets the statutory requirement to utilize
permanent solutions and treatment technologies, to the maximum
extent practicable. The selected alternative provides for the
biological destruction of the PAR molecule in contaminated soil.
The aerobic biological treatment process se.lected for the PAR
contaminated soil is irreversible. This treatment process
permanently reduces the toxicity, mobility and volume of the PAR
contaminated soil.
XI DOCUMENTATION OF SIGNIFICANT CHANGES
No significant changes have been made since the publication of the
Feasibility Study or Proposed Plan.
21
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Figure 5
On-site. Surface Water Features
-------
0.
Table 1
SUMMARY OF DETECTED INORGANIC COMPOUNDS
SURFACE WATER
South Andover RI/FS
1990
U.S. EPA Ambient
Water Quality
Criteria (For MPCA
Protection of Surface Water
Aquatic Life)ppb Quality St80dards ppb
Compound Acute Chronic Acute Chronic Detected, ppb Field 8lank 8lanks
Aluminum NE. NE 2,145 125 43.8 - 695 (SW04) ND
Arsenic 360 190 720 10 2.18 - 6.638 (SW04) ND
8arium NE NE NE NE 26.48 - 3743 (SW04) ND
Beryl! iUII 130 5.3 NE NE 2.38 - 3.18 (SW04) ND
. Cadmium 1.8a 0.668 146.1 a 1. 95a 3.08 - 8.0 (SW01) ND
Calcium NE NE HE NE 15,100 - 56,200 (SW02) 3858
Chromium 16 l! J2b lIb 2.03B - 7.038 (SW01) ND
Cobalt HE NE HE NE 5.68 - 9.58 (SW04) HD
Copper 9.28 6.5a 68.2a l5.la 7.738 - 39.3 (SWOl) ND
Iron NE HE HE NE 1223 - 6,890 (SW04) 23.438
Lead 34 1.3 396a 1.7a 1. 28 - 6.6 (SW04" swo I) ND .
Magnesium NE NE NE NE 3,9903B - 13,400 (SW01) 71. 4J8 ...--
Manganese HE NE NE NE 9.88 - 619 (SW04) ND
Mercury . 2.4 0.012 4.9 0.0069 0.28 (SW02) ND
Hickel 1,1008 56a 5,098a 2138 10.1J8 (SW03) ND
Potassium HE NE HE NE 1,150J8 - 9,260J (SW01) ND
Selenium 260a 35 40 5 2.08 - 3.08 (SW048) ND
Sodium NE NE HE NE 6,640J - 39,400J (SW02) 99.98
Thall ium 140 40 HE NE 1. 8JB (SW04) ND
Vanadium HE NE HE NE 2.18 - 6.88 (SW04) NO
Zinc 130a 47a 421a 191a 16.8J8 - 219J8 (SW04) 22.5J
Cyanide 22 0.52 HE NE 2.38 - 7.58 (SWO') ND
NE: No level established.
J: Value 8estimated8 due to minor OC deviations.
B: Value above instrument detection limit, but below contract required detection limit.
a8ased on water hardness equal to 50 mg/l CaCD).
bChromium +6.
Values in parentheses are sample locations of hIghest detected concentrations.
MPCA Site-Specific Surface Water Quality Standards are from the Water Quality Division, MPCA.
A/RP/SANDOVER/AQ7
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.---.
Table 2
SUMMARY OF
DETECTED INORGANIC
. SEDIMENT
South Andover RIfFS
1990
COMPOUNOS
Range of Concentrations
Oetected, ppm
Aluminum
Arsenic
Barium
Calc ium
Chromium
Coba 1 t
Coppe r
Iron
Lead
Magnesium
Manganese
Nickel
Potassium
Selen i um
Silver
Sod i um .
Tha 11 i um
Vanadium
Zinc
Cyanide
1,850 - 12,500J (S004)
1.38 - 5.1J8 (S004)
11.1JB - 192 (SOOI)
1,040B - 16,200 (S002)
3.4 - 17.7 (S004)
1.68 - 14.88 (SOOI)
3.2J8 - 54 (S004)
1,700J - 40,500J (SOOI)
1.2J - 442J (SOOI)
5588 - 6,570 (S002)
21.5 - 825 (SOOI)
6.78 - 18.48 (SOOI)
174J8 - 910J8 (S004)
0.33J8 - 2.8J8 (S004)
1.88 (S002)
799JB - 5,140JB (S004)
4.88 (SOO1)
3.68 - 27.38 (S004)
9.8 - 290 (SOO1)
0.65 - 2.5J (SOOI)
J:
8:
Value "estimated" due to minor QC deviations.
Value above instrument detection limit but below contract
required detection limit.
Values in parentheses are sample locations of highest detected concentrations.
A/RP/SANDOVER/AQ7
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"
-
Tab 1 e 3
SUMMARY
OF DETECTED PESTICIDE/PCB COMPOUNDS
SEDIMENT AND SURFACE WATER
South Andover RI/FS
1990
Range of Concentrations Detected, ppb
Pesticides/PCB
Sediment
4,4'-000
4,4'-DDT
130 (SD04)
120-140 (SD04)
J:
B:
Value -estimated- due to minor QC deviations.
Compound detected in associated laboratory blank.
Values in parentheses are sample locations of highest detected
concentrations.
A/RP/SANOOVER/AQ7
~'
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£ontilmlnllnt
Acetone
Aluminum
Barium
Cadmium
CaalclulII
Cobalt
Copper
Ol-n-butylphthalat~
tleptachlor (and Its
hydro-tde)
Iron
leiad
MiagnttslUiR
Milnuan,uill
Methylene Cnlorlda
Nickel
Potassium
Sudlum
Toluene
1.I,I-Trlcnloroethane
Xylanes(total)
Z Ir,c
Table 4
COMPARISON Of SOILS CllfMI5TRV AND TClP
Soutn AmJo\ler SuperfulIlJ S I ttt
Socond Operable Ulllt
Andu\lttr, Mlnntt50td
Hf5UlTS
TCLP(I)
(moll )
TS 13(2) TS 11 (3)
Soli Soli
S.mple TClP Sample TClP
1m9L!al ( 100 II ) imsili 1 ( mal I )
0.0045 0.056 0.0115 0.075
26.285 0.204 5,895 0.196
81.3 0.106 59.25 1.350
7 0.0035 0.4 0.003
23.1 136.0
2.125 0.0063 8.9 0.04
0.363 0.0119
0.1975 0.28 0.004
0.0001 0.00028
4,165 0.0161 14,510 8.5U
356.55 0 . 0917 27 0.0094
53.4 38.5
0.142
0.0035 0.027 0.0045 0.024
51.35 0.0216 14.75 0.0661
8.72
605.0 602.0
(I.n03 0.003 0.0045
0.003 0.004
0.003 0.004 0.002
2.21 0.30
= J
T5 20(4)
5011 ---
5ampl~ ICLI'
!malUl !muLlL
0.013 0.091
5,300 0.6115
37.2 1.510
0.7 0.0175
38.6
2.975 0.0"4
I .IIUO
0.02
O. till/I 1:1
5.680 0.191
291.35 0.341
U.!.IU
5.4]
0.003 IJ.027
9.9.,5 O. fl44U
bO 1 . II
0.0075
0.003 0.OU4
0.003 0.004
b. 10
100.0
1.0
0.006
5.0
(I) Md-Imum IIlIo..aLJI~ concentrations of contaminants III To.lclty Clliaracterl:>tlc L"dLlliny Proc~(lul'I.j (TCLP) IUdclldttt.
Oalitu,s Indicate tnls Is not a paranotttttr un&Jtlr TCLP.
(2) Tronch sample T5 13 datia.
Oa.hel> Inc.Jlo;;iUtt not uuteetad III I>aonpltt.
(3) Trom;h sdonpltt T5 17 ditta.
Oalillo:> 11I<.Ileitte not UtlteLttHJ in
sitllllJl...
Ma.llllum utlt..tt&n sample and duptlcattl I" prttl>ttnted.
(4) Tn,ocli sample 15 20 and duplicate &Jata.
Dashes Indicate not dutttcted In sample.
A/RP/SANOOVfR/AW8
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