PB95-963810
EPA/ROD/R02-95/256
February 1996
EPA Superfund
Record of Decision:
Niagara Mohawk Power Corporation
Superfund Site, Saratoga Springs, NY
9/29/1995
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RECORD OF DECISION
Niagara Mohawk Power Corporation Site
Town of Saratoga Springs, Saratoga County, New York
September 1995
United States Environmental Protection Agency
, Region II
New York, New York
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DECLARATION FOR THE RECORD OF DECISION
SITE NAME AND LOCATION
Niagara Mohawk Power Corporation Site
Town of Saratoga Springs
Saratoga County, New York
STATEMENT OF BASIS AND PURPOSE
This Record of Decision (ROD) documents the U.S. Environmental
Protection Agency's (EPA) selection of the remedial action for the
Niagara Mohawk Power Corporation (NMPC) Site (the Site) in
accordance with the requirements of the Comprehensive Environmental
Response, Compensation and Liability Act of 1980, as amended
(CERCLA) , 42 U.S.C. §§9601 - 9675 and the National Oil and
Hazardous Substances Pollution Contingency Plan (NCP), 40 CFR Part
300. This decision document summarizes the factual and legal basis
for selecting the remedy for this Site.
The New York State Department of Environmental Conservation
(NYSDEC) concurs with the selected remedy. A letter of concurrence
from the NYSDEC is attached to this document (see Appendix IV).
An administrative record for the Site contains the documents that
form the basis for EPA's selection of the remedial action, the
index for which is attached as Appendix III.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from the
Site, if not addressed by implementing the response action selected
in this ROD, may present an imminent and substantial endangerment
to public health, welfare, or the environment.
DESCRIPTION OF THE SELECTED REMEDY
The primary objectives of this remedy are to minimize the potential
for further migration of contaminants from source areas into soils
or ground water on the NMPC property; to collect and remove, to the
extent possible, any potential dense non-aqueous phase liquid
(DNAPL) beneath the NMPC property; and to minimize or eliminate the
potential for Site contaminants to be transported to off-site
locations, thereby minimizing any health and environmental impacts.
The major components of the selected remedy include the following:
Source and Surface Soil Removal
The purpose of this action is to remove source materials or areas
of concentrated coal tar having total PAH concentrations exceeding
1,000 parts per million (ppm) , that are accessible and are
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significant in terms of volume, concentration, and the potential
for continued, long-term subsurface impacts; and to remove
contaminated surface soils from 0 to 2 feet below ground surface.
The source areas include structures known as former Gas Holder
Nos. 1, 2, 3, and 5, and several other areas around the NMPC
property. During the remedial design phase, additional subsurface
sampling will be'conducted on the NMPC property, including Holder
No. 4 where concentrated tar contamination was visually observed,
to" determine if additional PAH source areas are present, thereby
requiring removal. This soil removal requires the demolition of
surface structures in and around the source areas, including the
Round House structure over Holder No. 2 and the gas regulator
station over Holder No. 1. Approximately 16,700 cubic yards of
source material and 3,500 cubic yards of contaminated surface soils
will be removed. These volume estimates do not include Holder
No. 4.
Excavation of contaminated soil, DNAPL, and associated source
material within and around the Holder No. 3, also known as the
tar/water separator will be implemented. The Holder structure will
remain in place and be filled with a suitable backfill material.
Excavated material that exhibits a hazardous characteristic will be
rendered non-hazardous by blending it with coal fines or other
suitable material on site prior to transport off site for
co-burning in a utility boiler, and/or treatment and disposal at an
off-site permitted hazardous waste facility. All non-hazardous
material encountered during excavation activities will be disposed
of at an off-site solid waste management facility, and contaminated
surface soil will be managed in an off-site cold batch asphalt
plant to produce asphalt paving for the NMPC property. Recovered
DNAPL and coal tar will be managed off site at a tar processing
facility. If these materials exhibit a hazardous characteristic,
they will be managed as hazardous waste as described above.
As set forth in the Institutional Controls and Monitoring Section
below, deed restrictions on the NMPC property will be required.
Installation of Subsurface Barriers and Ground Water Management
The purpose of the installation of subsurface barrier walls is
twofold: 1) to contain contaminated ground water on the NMPC
property, and 2) to contain and collect DNAPL residing in the
vicinity of the subsurface barrier walls. Subsurface barriers will
be installed at the southeast and southwest corners of the NMPC
property where contaminated ground water and DNAPL can potentially
migrate off site. The ground water in the shallow aquifer beneath
the NMPC property and the DNAPL residing in the vicinity of the
subsurface barrier walls will be collected by using drains
installed inside and along the lengths of the barrier walls. The
DNAPL and ground water collected will be transferred through a
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subsurface pipe into a collection sump, then pumped to the on-site
water treatment facility.
Construction of an on-site water treatment facility will be
required to pretreat contaminated ground water prior to discharge
to the local publicly owned wastewater treatment plant (POTW)
operated by the Saratoga Sewer District. The treatment process for
the contaminated water includes DNAPL/water separation, metals
removal by precipitation, and biological treatment.
Ground water upgradient of the NMPC property (which has not been
impacted by the NMPC property contaminants) will be collected using
a curtain drain and diverted to either the twin box culvert storm
sewer system west of the NMPC property or the culverted Village
Brook east of the NMPC property. The NMPC property will be capped
with asphalt to prevent infiltration of precipitation.
Soil Removal from the Skating Rink Area
The purpose of this action is to remove subsurface soils that
exceed cleanup levels in the vicinity of the municipal skating
rink. The long-term impact of this subsurface soil contamination
potentially could contaminate the skating rink ground water, and
this contaminated ground water could potentially migrate off-site.
Such contaminant migration could have adverse impacts on
downgradient ground water users. Therefore, in order to prevent
migration of contaminated ground water beyond the skating rink
area, and to restore the ground water by the skating rink area to
drinking water standards, all sources of contamination that are
contributing to 'ground water contamination in the vicinity of the
skating rink would need to be eliminated.
The contaminated skating rink area subsurface soils will be
dewatered and excavated. Approximately 4,200 cubic yards of
contaminated subsurface soil will be excavated. Confirmation
sampling will be conducted to assure attainment of cleanup levels.
The excavated material will be managed as described in the Source
and Surface Soil Removal Action Sections.
The remedial design phase will include further subsurface soil
investigation in the skating rink area to determine whether
additional soils are contaminated. This soil investigation will be
performed outside the boundaries of the skating rink structure.
Soil sampling beneath the skating rink structure is not feasible
while the building is intact. Such soil sampling will be conducted
when the soils become accessible. The soils will become accessible
if and when the skating rink is both taken out of service and
demolished. If sampling identifies contaminated soil at
concentrations above the soil cleanup levels, the affected soil
will be removed, and additional sampling will be conducted to
assure that the removal achieved cleanup levels.
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If contaminated soils are currently present beneath the skating
rink, they are inaccessible, and any contact with such soils is
unlikely. Moreover, the structure serves as a cover that prevents
infiltration of precipitation through such soils. Therefore if
present, such soils do not pose a risk to human health and the
environment.
After the contaminated soil is removed around the skating rink
area, and the barriers are erected on the NMPC property, the
sources of contamination impacting on the skating rink area will be
eliminated. Because the sources of contamination will be
eliminated, it is expected that the level of contaminants in the
ground water in the vicinity of the skating rink will decline over
time, and achieve compliance with the Federal and New York State
Drinking Water Standards and New York State Ground Water Quality
Standards through natural attenuation. The remedy requires
monitoring of the ground water to measure improvement in the ground
water quality. If improvement in ground water quality is not
observed upon review of the annual ground water monitoring results,
a program to evaluate contingency alternatives for ground water
remediation in the skating rink area will be initiated and
implemented in a timely manner.
As set forth in the Institutional Controls and Monitoring Section
below, EPA recommends the imposition of a notice in the property
records pertaining to the skating rink property to inform'
interested parties of the potential presence of contamination
underneath the skating rink. This notice should remain in the
property records until after the skating rink is taken out of
service, demolished, and any contaminated soils removed.
Sediment Removal
The sediment removal action involves the dredging and/or excavation
of approximately 1,200 cubic yards of impacted sediments and
wetlands soils at the confluence of Loughberry Creek and Village
Brook, near the outfall of the concrete box culvert, near the
outfall of the brick sewer, and at four locations on the NMPC
property. Confirmation sampling to assure attainment of cleanup
levels will be conducted. Contaminated sediments will be
transported off site for treatment and proper disposal.
Appropriate actions will be taken to restore the wetlands.
Remediation of the Sewer Migration Pathway
The purpose of this action is to eliminate the impacts to the
wetland surface water or Spring Run from the migration of NMPC
property contaminants through the underground brick sewer.
Stormwater flow through the brick sewer and Village Brook upstream
of the NMPC property will be 'diverted to the twin box culvert storm
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sewer, so no stormwater will flow through the NMPC property. At
the southeast corner of the NMPC property, the brick sewer will be
disconnected and a water/DNAPL collection sump will be constructed
to prevent any ground water which infiltrated the sewer from
leaving the property. The downstream section of the sewer from the
southeast corner of the NMPC property to the brick sewer outfall,
near Interstate 87, will be cleaned. Infiltration spots along the
downstream section of the brick sewer, from the point at which it
is disconnected to the concrete box culvert, will be sealed to
prevent infiltration of impacted ground water into the sewer. The
break in the brick sewer near the confluence of Loughberry Creek
and Village Brook will be repaired. The materials generated from
cleaning the brick sewer will be properly disposed of off site.
Control of releases from the brick sewer described above will stop
the potential for continuing impacts to sediments in Spring Run.
Institutional Controls and Monitoring
Because contaminants will remain on the NMPC property after
implementation of the remedy, deed restrictions to prevent future
residential use of the property and notifications to utility
companies will be required to limit exposure to the subsurface
contaminants that remain on the NMPC property. The implementation
of deed restrictions will be the responsibility of NMPC. NMPC has
indicated to EPA that it will maintain future ownership of the NMPC
property, thereby further restricting the potential for future
residential development of the property. EPA recommends the
imposition of a notice in the property records pertaining to the
skating rink property to inform interested parties of the potential
presence of contamination underneath the skating rink. This notice
should remain in the property records until after the skating rink
is taken out of service, demolished, and any contaminated soils
removed. No deed restrictions are necessary on the Spring Run
wetland area because the sediment and soil contamination above the
cleanup levels will be removed.
A monitoring program will be implemented to assess the
effectiveness of the remedial action. Samples for analysis will be
obtained from monitoring wells, the Old Red Spring, the diverted
ground water upgradient of the NMPC property (which has not been
impacted by the NMPC property contaminants) , and the discharge from
the on-site water treatment system, as required by the Saratoga
County Sewer discharge permit.
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DECLARATION OF STATUTORY DETERMINATIONS
The selected remedy meets the requirements for remedial actions set
forth in CERCLA §121, 42 U.S.C. §9621, is protective of human
health and the environment and is cost-effective. The remedy
utilizes permanent solutions and alternative treatment technologies
to the maximum extent practicable, given the scope of the action,
and will permanently reduce the toxicity, mobility, or volume of
contaminants at the Site. In addition, the cleanup actions to
remediate the NMPC property, the municipal skating rink, the
underground sewer, and the contaminated sediments in Spring Run
comply with Federal and State requirements that are legally
applicable or relevant and appropriate (ARARs) to the remedial
action.
Remediation of the NMPC property ground water in the shallow
aquifer is considered to be technically impracticable. Therefore,
this ROD waives the federal and state drinking water standards and
state ground water quality standards for the ground water in the
shallow aquifer beneath the NMPC property. The waiver is issued
pursuant to Section 121(d)(4)(C) of CERCLA, 42 U.S.C.
§9621(d)(4)(C), and §300.430(f)(1)(ii)(C)(3) of the NCP which
authorizes EPA to waive applicable or relevant and appropriate
requirements for ground water cleanup of the NMPC shallow aquifer
based on technical impracticability, from an engineering
perspective. There are technical limitations which make it
impracticable to recover all the DNAPL from the NMPC property. . In
order to remove air the DNAPL, approximately 7 acres of
contaminated aquifer materials, including soil, silt, peat, and
sand, residing above the subsurface clay layer (which begins
approximately 20 feet below the surface), would need to be
excavated for off-site disposal. In addition, all NMPC's operating
facilities would have to be demolished to gain access to the
contamination beneath them. Since it is technically impracticable
to excavate this large an area, some DNAPL and PAH impacted soil
will remain on the NMPC property. Because the DNAPL and residual
PAHs contribute to dissolved phase ground water contamination,
restoration of ground water on the NMPC property to ground water
cleanup levels has been determined to be technically impracticable.
EPA believes that the selected remedy for the ground water in the
shallow aquifer beneath the NMPC property remains protective of
human health and the environment. Recognizing that ground water
restoration in the shallow aquifer beneath the NMPC property is
technically impracticable, the goal of this remedial action is to
establish hydraulic control of the NMPC contaminated ground water,
to prevent ground water and DNAPL from flowing off site by using
physical and hydraulic barriers. This action complies with Federal
and State requirements that are applicable or relevant and
appropriate to this remedial action and is cost-effective. In
addition, the ground water remedy utilizes permanent solutions and
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alternative treatment technologies to the maximum extent
practicable for the Site.
A review of the remedial action, pursuant to CERCLA §121(c), 42
U.S.C. §9621(c), will be conducted no less than each five years
after the commencement of the remedial action to ensure that the
remedy continues to provide adequate protection to human health and
the environment, because this remedy will result in hazardous
substances remaining on the NMPC property above health-based
levels.
Jeanne M. f^L^(//^ ^T/ ' Date
Regional Administrator
VII
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RECORD OF DECISION
DECISION SUMMARY
Niagara Mohawk Power Corporation Site
Town of Saratoga Springs, Saratoga County, New York
United States Environmental Protection Agency
Region II
New York, New York
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TABLE OF CONTENTS page
SITE NAME, LOCATION AND DESCRIPTION 1
SITE HISTORY AND ENFORCEMENT ACTIVITIES 2
HIGHLIGHTS OF COMMUNITY PARTICIPATION 4
SCOPE AND ROLE OF RESPONSE ACTION 5
SUMMARY OF SITE CHARACTERISTICS 5
SUMMARY OF SITE RISKS : 10
REMEDIAL ACTION OBJECTIVES 15
DESCRIPTION OF REMEDIAL ALTERNATIVES 16
SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES 22
SELECTED REMEDY 29
STATUTORY DETERMINATIONS 34
DOCUMENTATION OF SIGNIFICANT CHANGES 37
ATTACHMENTS
APPENDIX I. FIGURES
APPENDIX II. TABLES
APPENDIX Ml. ADMINISTRATIVE RECORD INDEX
APPENDIX IV. STATE LETTER OF CONCURRENCE
APPENDIX V. RESPONSIVENESS SUMMARY
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SITE NAME, LOCATION AND DESCRIPTION
The Niagara Mohawk Power Corporation (NMPC) property is located in
the Town of Saratoga Springs, Saratoga County, New York. The NMPC
property is approximately 7 acres in size, and is bounded on the
north by Route 50, on the south by Excelsior Avenue, on the east by
East Avenue and on the west by Spa Steel Corporation. The NMPC
Superfund Site (the Site) includes the areal extent of
contamination and all suitable areas in very close proximity to the
contamination necessary for implementation of the remedial action.
Contamination at the Site has been found on property owned by the
NMPC, known as the NMPC property, and in nearby areas, including in
the vicinity of the municipal skating rink, and on the Spring Run
wetland. Figure 1 depicts all of the Site features described below.
The NMPC property was formerly used to manufacture gas. Since
1950, NMPC has owned and operated the NMPC property as a district
service center and headquarters for its electric line, natural gas,
and tree trimming crews servicing the Saratoga District. A service
and maintenance building is centrally located on the western
portion of the property with an office trailer located to the
north. A two-story brick storage building with an attached
electric substation, constructed in 1903, is located east of the
service and maintenance building. A brick round house (formerly
Gas Holder House No. 2) constructed in 1873 is located toward the
northeast corner of the property. A chain-link fence surrounds the
NMPC property with access through two gates on Excelsior Avenue.
Extensive subsurface structures are located throughout the NMPC
property. Active underground utilities (electric, natural gas,
water, surface drainage, and storm and sanitary sewer) along with
many inactive conduits associated with past manufactured gas plant
operations are present in the subsurface. In addition, a number of
subsurface structures and foundations related to past gas plant
operations are also present.
A waterway known as the Village Brook-Spring Run system is present
at the Site. Village Brook, which flows from west of the NMPC
property, was routed through a culvert under the property some time
after 1903. It ultimately discharges southeast of the NMPC
property to the 84-inch twin box culvert city storm sewer that
empties into Spring Run. Village Brook now carries some runoff
from the contaminated area northwest of NMPC property. A 36-inch
brick underground sewer line also traverses the southern portion of
the property. The brick sewer has been in place since 1874, the
early days of the manufactured gas plant operations at the NMPC
property. This sewer is no longer an active city sewer for
stormwater or sanitary flows. The brick sewer line leaves the NMPC
property in the southeast corner and runs into the downhill Spring
Run wetland. It extends approximately 5,000 feet beyond the NMPC
property.
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As indicated in the Spring Run detail inset depicted on Figure 1,
the Village Brook-Spring Run system begins approximately 700 feet
east of the NMPC property and extends eastward approximately 5,000
feet to Interstate 87, where the culverted stream flows underneath
the interstate highway. The most significant tributary to Spring
Run is Loughberry Creek, a major tributary draining Loughberry Lake
to the northeast of the NMPC property. The 36-inch brick sewer
mentioned above, which collects drainage from the NMPC property,
intersects Loughberry Creek and continues until its outfall,
approximately 4,000 feet down stream. A breach exists in the
36-inch sewer at the stream crossing and flow from the sewer enters
the creek.
The area surrounding the Spring Run ecosystem is a thickly settled
suburb. The ecosystem lies in a steep-sided valley which borders
the backyards of numerous residences and some commercial
operations. A bottled-water company occupies property down the
valley, near the Spring Run Stream. The wetland occupies the
nearly flat area on either side of the stream and is commonly 200
to 400 feet wide, and is approximately 5,000 feet long. Village
Brook-Spring Run is generally a shallow, low gradient stream with
a silty bottom. Village Brook and Spring Run are classified as
Class "C" streams. The NYSDEC "C" classification indicates that
those waters are suitable for primary and secondary contact
recreation as well as fishing and fish propagation. The U.S. Fish
and Wildlife Service and the NYSDEC did not identify any potential
impacts on endangered, threatened, or special concern wildlife
species, rare plant, animal, or natural community occurrences or
other significant habitats.
Residents of" the City of Saratoga Springs are served by a public
water supply which is drawn from Loughberry Lake, located
upgradient of the Site (approximately 1,400 feet northeast).
Outside of the City limits, private and public water supply wells
provide drinking water. Analytical results from local area private
and public supply water wells (Old Red Spring and High Rock
Springs) indicate that Site contamination has not impacted these
wells.
SITE HISTORY AND ENFORCEMENT ACTIVITIES
The NMPC property has been used for industrial purposes since 1868.
Prior to 1868, the parcel consisted of vacant land traversed by a
small stream. Numerous mergers, sales and consolidations of
property ownership have occurred throughout the years. Currently
the property is owned and operated by NMPC as a district service
center and headquarters for its electric line, natural gas, and
tree trimming crews servicing the Saratoga District.
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The development history of the NMPC property can be divided into
three eras:
- The manufactured gas plant era, 1868 to 1929
- The gas storage/distribution era, 1930 to 1950
- The current NMPC district service center era, 1950 to
present.
The manufactured gas plant era was the earliest and longest period.
In 1868, the Saratoga Gas Light Company began operations to produce
gas by using coal, coke and petroleum oils for illuminating
purposes only. Coal gas production continued until 1886 when the
process was modified to carburetted water gas production. Electric
power generation supplemented gas production briefly, between 1886
and 1903. Gas manufacturing ceased in 1929 and the plant was
converted to gas storage and distribution, until the introduction
of natural gas service into the region in the 1950s. The early gas
production operations left coal tars and other materials, which
were by-products of the gas production processes. These wastes,
which contain hazardous substances, were disposed of at various
locations on the NMPC property; consequently, the NMPC property
contains numerous coal tar waste beds. Few details exist
regarding the first gas manufacturing process at Saratoga Springs,
however from available literature it can be surmised that the gas
operations included the use of retorts, a cooling system, a
purification system, arid gas storage.
A total of six gas holders were formerly used on the NMPC property,
including one holder which was used as a tar/water separator. A
gas holder house is a structure in which gas was stored after the
gas was purified. Gas Holder Nos. 1 and 2 were circular brick
structures, built between 1868 and 1873. Both holders had below-
grade water seals contained in pits over 20 feet deep, with
diameters of approximately 70 feet. Gas Holder 1 and 2 had 50,000
and 60,000 cubic foot capacity, respectively. Holder Nos. 1, 4, 5,
and 6, and the original plant buildings used to manufacture gas
have been demolished. The circular brick building surrounding
Holder No. 2 remains on the NMPC property and is referred to as the
Round House. The tar/water separator (Holder No. 3) was apparently
decommissioned and filled with inert material. The former
substation building also remains on the property and is used as a
storage building. A Site Layout Map showing former and current
structures on the NMPC property is provided on Figure 1.
In 1982, NMPC notified the U.S. EPA that the Saratoga Springs
property was once the location of a gas manufacturing facility and
that previous owners may have disposed of coal tars on the
property. Between 1965 and 1985 a series of structure-related
evaluations were carried out during construction and modification
of buildings on the property. In addition, environmental
investigations were performed prior to the remedial investigation.
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The environmental investigations consisted of soil borings, a
geophysical survey, installation of five ground water monitoring
wells, soil and ground water sampling and analysis, and sediment
sampling and analysis. The results of the investigations indicated
the presence of polynuclear aromatic hydrocarbons (PAHs) and some
volatile organic compounds (VOCs) in groundwater, soil, and
sediment.
Based on the findings of environmental studies conducted between
1965 and 1985, EPA proposed the Site on the National Priorities
List (NPL) in June 1988, and subsequently placed it on the NPL in
February 1990. In September 1989, EPA entered into a Consent Order
requiring NMPC to conduct an RI/FS to determine the nature and
extent of contamination at the Site and to evaluate cleanup
alternatives.
HIGHLIGHTS OF COMMUNITY PARTICIPATION
The RI report, FS report, and the Proposed Plan for the Site were
released to the public for comment on June 19, 1995. These
documents were made available to the public in the administrative
record file at the EPA Docket Room in Region II, New York and the
information repository at the Saratoga Springs Public Library,
Saratoga Springs, New York. The notice of availability for the
above-referenced documents was published in the Daily Gazette and
the Saratogian newspapers on June 19, 1995. A press release
announcing the same was issued by EPA on June 8, 1995. The public
comment period on these documents was held from June 19, 1995 to
July 20, 1995.
On June 22, 1995, EPA conducted a public meeting at the Saratoga
Springs City Center, 522 Broadway, Saratoga Springs, New York to
inform local officials and interested citizens about the Superfund
process, to explain current and planned remedial activities at the
Site, and to respond to any questions from area residents and other
attendees.
Responses to the comments received at the public meeting and in
writing during the public comment period are included in the
Responsiveness Summary (see Appendix V).
EPA awarded a Technical Assistance Grant (TAG) to the Saratoga
Springs Hazardous Waste Coalition, a local environmental group
formed in 1990. Under the TAG program, EPA provides grants to
citizen groups to obtain assistance in interpreting information
related to cleanups at Superfund sites. These grants are used by
citizen groups to hire technical advisors to help them understand
site-related technical information during site response activities.
Members of the Saratoga Springs Hazardous Waste Coalition and their
consultants have reviewed the RI/FS and provided comments to EPA.
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SCOPE AND ROLE OF RESPONSE ACTION
This ROD addresses the entire NMPC Site and identifies the selected
remedy for source areas, contaminated soil, and ground water on the
NMPC property; contaminated soil and ground water in the vicinity
of the municipal skating rink; contaminated sediments on the NMPC
property and in the Spring Run wetland; and elimination of the
transport of contaminants to off-site locations via an underground
sewer line that traverses the NMPC property.
This is a final remedy which addresses the principal threats posed
by the Site and allows for continued industrial use of the NMPC
property in the future.
SUMMARY OF SITE INVESTIGATION AND CHARACTERISTICS
Under EPA oversight, NMPC conducted a series of environmental
investigations at the Site, collectively referred to as the RI,
from 1990 to 1992. The environmental media investigated included
surface soils (0 to 2 feet below ground surface), subsurface soils
(2 to approximately 20 feet below ground surface), surface water,
sewers, sediments, ground water, public and private wells, and air.
Stage IA and IB Cultural Resources Surveys and a Stage II
Archeological Data Recovery and Mitigation were performed at the
NMPC property as part of the investigation. A review of historic
site surveys identified two historic structures, the Round House
and a two-story brick storage building. Since the remedial action
requires the demolition of the Round House, which will have an
adverse effect on this historic artifact, additional documentation
regarding the Round House will be required during the remedial
design phase to comply with the National Historic Preservation Act
and the New York State Historic Preservation Act.
Site Geology and Hydrogeology
The NMPC Site is located within the Village Brook-Spring Run
Valley, which is a fairly broad valley trending east-west. The
Site is east of the City of Saratoga Springs. The majority of the
NMPC Site is relatively level with an average elevation of 270 feet
above mean sea level (MSL). The Site is bounded to the north and
west by escarpments related to the Saratoga Fault and by surficial
construction fill with elevations ranging from 280 to 310 feet
above MSL across this area. It is bounded to the east by the
steeply-sloped Village Brook-Loughberry Creek Valley wall with
elevations from 270 to 300 feet above MSL. The Site is bounded to
the south by the southern wall of the Village Brook-Spring Run
stream valley which rises to an elevation of 300 feet above MSL.
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The surficial geology beneath the NMPC property consists of, in
descending order, fill, upper fluvial deposits, peat, lower fluvial
deposits, glaciolacustrine clay, and till.
The fill material, which includes fine to medium-grained sand with
clay, rock fragment, and construction debris, ranges in thickness
from approximately 2 to 22 feet.
The upper fluvial unit is characterized by sediments associated
with Village Brook-Spring Run deposition. This unit consists of
fine to coarse-grained, poorly sorted sand with silt, clay, and
minor organic matter, with a thickness up to 9 feet.
The peat unit is a transitional unit between the upper and lower
fluvial units. It is characterized by the presence of highly
organic, woody material interbedded with sand lenses. This unit,
with thickness up to 6 feet, was found primarily in conjunction
with the lower fluvial unit.
The lower fluvial unit is characterized by sorted, medium to
coarse-grained sediments associated with postglacial stream
deposition. The thickness of this unit ranges up to 11 feet.
Because of the well-sorted and coarse nature of this unit, it acts
as the primary shallow unconfined aquifer.
The fluvial units described above are underlain by an areally
extensive clay associated with glaciolacustrine deposition. The
clay unit was identified in every soil boring located on and
adjacent to NMPC property, as well as in all off-site exploratory
borings. This clay unit was encountered at depths of around 20
feet, except where a significant rise in the clay elevation was
noted south of the NMPC property boundary. This rise appears to be
controlling both ground water flow direction and contaminant
migration. The clay thickness throughout the NMPC property ranges
from 27 to 53 feet. The clay unit is underlain by an extensive
till unit, with thickness ranging from 35 to 79 feet. The till
unit consists of a poorly sorted mix of boulders, cobbles, gravel,
sand, silt, and clay; and is generally dry. Bedrock was
encountered at a minimum depth of 86 feet and a maximum depth of
135 feet.
A shallow aquifer (ranging from 3 to 20 feet below ground surface)
and a deep confined aquifer (bedrock aquifer) were identified
during the investigation. The shallow aquifer is within the fill,
upper fluvial, peat, and lower fluvial units of the surficial
geological materials described above. The shallow and deep
aquifers are separated by the clay and till layers. The shallow
ground water generally flows from north-to-south, however its
gradient is affected by the presence of the storm sewer in
combination with the rise of the confining clay layer across
Excelsior Avenue from the NMPC property. Ground water is diverted
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around the clay mound prior to heading south near the 84-inch twin
box culvert. Flow measurements in the underground 36-inch brick
sewer that crosses the NMPC property indicate that this sewer may
have significant hydrologic influence on shallow ground water flow.
Therefore, the predominant flow direction of ground water exiting
the NMPC property boundary is to the southeast.
Nature and Extent of Contamination
The major conclusions of the RI for the Site are summarized below:
The results of the study indicate that subsurface tar
contamination is directly beneath most of the NMPC property,
typically at a depth of 15 to 20 feet below ground surface.
Dense nonaqueous phase liquid (DNAPL) was identified in several
locations (primarily in and around the gas holders) on the NMPC
property in the form of concentrated tar-saturated soil. DNAPLs
are heavier than water, and have a tendency to sink. A clay
confining layer present at approximately 20 feet below ground
surface acts as a barrier and prevents further vertical
migration of the tar contamination. Coal tar contaminants
typically include polynuclear aromatic hydrocarbons (PAHs) and
volatile organic compounds (VOCs). PAH compounds, which are the
principal components of coal tar, are extremely immobile and
tend to attach to the aquifer soil particles rather than move
with the ground water. The PAHs and VOCs detected in the soil
during the investigation are presented in Table 1. The PAHs
include anthracene, acenaphthene, acenaphthylene, chrysene,
benzo(a)pyrene, benzo(a)anthracene, benzo(b)fluoranthene,
fluorene, benzo(k)fluoranthene, dibenzo(a,h)anthracene,
dibenzofuran, fluoranthene, naphthalene, phenanthrene,
indeno(l,2,3-cd)pyrene, 2-methylnaphthalene, and pyrene. The
VOCs include benzene, toluene, ethylbenzene, and xylene, which
are collectively known as BTEX. Based on soil analytical data
and visual characterization of soil boring and test pit
materials, approximately 170,000 cubic yards of soil impacted
with tar and PAHs are present on the NMPC property.
The highest levels of soil contamination or areas of
concentrated coal tar have been found at the following locations
(see Figure 2): inside and around Holder #1 (up to 12,780 ppm
total PAHs); Holder #2 (up to 1,706 ppm total PAHs); Holder #5
(up to 1,076 ppm total PAHs) ; tar/water separator and area south
of it (up to 1,974 ppm total PAHs); the SB-7 (up to 33,060 ppm
total PAHs) and TP-2 (up to 1,910 ppm total PAHs) areas in the
northwest corner of the property; and the SB-13 (up to 4,420 ppm
total PAHs) and TP-18 (up to 6,379 ppm total PAHs) areas in the
southeast corner of the property. The total estimated volume of
the highly contaminated areas (containing PAH concentrations in
excess of 1,000 ppm) listed above is 20,455 cubic yards. The
highest concentration of tar was observed in soil boring SB06,
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located in the immediate vicinity of former Holder No. 1, where
over 20 feet of the subsurface exhibited evidence of tar. The
highest concentration was found at soil boring SB-7 (at 33,060
ppm total PAHs), at the former location of the gas plant. At
this location, the following PAHs were found: anthracene at
1,600 ppm, acenaphthene at 640 ppm, acenaphthylene at 3,300 ppm,
benzo(a)anthracene at 920 ppm, chrysene at 910 ppm,
benzo(a)pyrene at 570 ppm, dibenzofuran at 240 ppm,
benzo(b)fluoranthene at 320 ppm, benzo(k)fluoranthene at 160
ppm, fluorene at 1,900 ppm, fluoranthene at 1,600 ppm, pyrene at
3,500 ppm, naphthalene at 6,600 ppm, phenanthrene at 6,200 ppm,
and 2-methylnaphthalene at 4,600 ppm.
PAHs also were found in surface soils covering much of the NMPC
property ranging from 5.45 to 433 ppm total PAHs. See Table 1
for the PAH constituents and concentrations detected in surface
soils.
Analysis of samples taken from several NMPC property monitoring
wells revealed levels of VOCs and PAHs which exceeded the
Maximum Contaminant Levels (MCLs) promulgated pursuant to the
Safe Drinking Water Act (SDWA) and the levels promulgated by the
New York State Drinking Water Standards. Table 2 summarizes the
results. Significant contamination was detected in samples
taken from monitoring wells SB62, MW02, and MW03. Total VOCs of
5,600 parts per billion (ppb) and total PAHs at 9,200 ppb were
detected at well MW02, located at the southwest corner of the
NMPC property. Ground water sampling from monitoring well MW-03
detected VOCs at 7,600 ppb and PAHs at 6,100 ppb. Samples taken
from SB62, located also at the southwest corner of the property,
contained- 26,900 ppb VOCs and 7,786 ppb total PAHs. These
levels exceed MCLs and the New York State drinking water
standards. For example, benzene was detected at concentrations
as high as 14,000 ppb in the shallow aquifer under the NMPC
facility. By comparison, the drinking water standard for
benzene is 5 ppb. Similarly, 3,500 ppb of ethylbenzene was
detected, as compared to the drinking water standard of 5 ppb;
5,700 ppb of toluene was detected, as compared to the drinking
water standard of 5 ppb; 3,700 ppb of xylene was detected, as
compared to the drinking water standard of 5 ppb; and 6,400 ppb
of naphthalene was detected, as compared to the drinking water
standard of 50 ppb. No contamination has been detected in the
bedrock aquifer. An extensive clay layer underlies the NMPC
property, which prevents the travel of contaminants downward to
the bedrock aquifer.
Ground water sampling from off-site wells located south of
the NMPC property directly across Excelsior Avenue (SB-3, and
SB-4) detected no contamination. However, monitoring well
SB-2, which is also located south of the NMPC property,
detected benzene at 91 ppb. Ground water samples collected
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from two off-site wells (SB-10 and SB-11) located across East
Avenue to the east of the NMPC facility did not contain PAHs.
However, benzene and toluene were detected in SB-11 at 38 ppb
and 1 ppb, respectively. VOCs were not detected in
monitoring well SB-10. Metals analysis were also conducted
and the results are summarized in Table 2.
Analysis of subsurface soil and ground water samples collected
in the vicinity of the municipal skating rink, located southeast
of the NMPC property, has revealed the presence of subsurface
tar contamination. Table 3 summarizes the test results. This
subsurface contamination appears to be - the result of tar
migration along the subsurface conduits, the 36-inch brick sewer
and the historic Village Brook. However, the Village Brook
culvert is not believed to be a significant potential transport
route of contaminants. Ground water contamination was
identified adjacent to verified zones of tar-contaminated soils.
Most notably, analytical results from soil boring SB01, located
immediately west of the public skating rink, detected 7,348 ppm
of total PAHs in soil. Ground water analytical results from the
monitoring well located at SB01 detected 246 ppb total PAHs.
Two types of PAHs were detected at this monitoring well which
exceeded drinking water standards; 79 ppb of acenaphthene was
detected, as compared to the drinking water standard of 20 ppb,
and 71 ppb phenanthrene was detected, as compared to the
drinking water standard of 50 ppb. VOCs were detected below
drinking water standards at this monitoring well.
Samples were collected from Village Brook, Spring Run, and the
brick sewer. Analysis of these samples suggest that NMPC
contaminants have infiltrated the brick sewer, which transported
the contaminated ground water from the NMPC property to
downstream areas. NMPC contaminants have been found in the
Spring Run sediments as far as the outfall of the brick sewer
(near Interstate 87) and in soils in the associated wetlands
(see Table 4) . The highest levels were found at three locations
in Spring Run, as follows: near a break in the brick sewer, in
the vicinity of the confluence of Loughberry Creek and Village
Brook, at levels ranging from 516 to 707 ppm total PAHs; near
the outfall of the twin box culvert, at levels ranging from 35
to 71 ppm total PAHs; and near the outfall of the 36-inch brick
sewer, at levels ranging from 4.7 to 70 ppm total PAHs.
Sediment samples on the NMPC property were collected and
analyzed at four locations. Contaminated sediments were
found in a catch basin where Village Brook originates along
the western fence line; in two small areas in the southeast
corner; at the northern fence line directly behind the office
building; and in the swale along the northern fence line in
the northeast corner of the NMPC facility. The samples from
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these four locations revealed total PAHs ranging from 31 to
364 ppm.
In addition, background sediment samples collected in Loughberry
Creek and in the 84-inch twin box culvert indicate the presence
of other PAH sources to Spring Run sediments. Results of
background sediment samples range from 8.5 to 22 ppm total PAHs.
Analytical results from local area private and public water
supply wells (Old Red Spring and High Rock Springs) indicate
that Site contamination has not impacted these water wells. No
Site-related contaminants were detected above permissible limits
in air samples collected during the RI.
SUMMARY OF SITE RISKS
EPA conducted a baseline risk assessment to evaluate the potential
risks to human health and the environment associated with the Site
in its current condition. The Risk Assessment focused on
contaminants in the soil, sediments, air and ground water at the
Site, and surface water and sediment contamination in nearby
wetlands, which are likely to pose significant risks to human
health and the environment. A summary of the contaminants of
concern in sampled matrices is provided in Table 5-1 for human
health and the environmental receptors.
EPA's baseline risk assessment addressed the potential risks to
human health by identifying several potential exposure pathways by
which the public may be exposed to contaminant releases at the Site
under current and future land-use conditions. EPA was concerned
that industrial workers and excavators at the NMPC property could
be exposed to contaminants in the soils and evaluated these
potential exposures in the risk assessment. In addition,
adolescents using the wetlands area for recreation could be exposed
to contaminants, now and in the future. EPA was also concerned
about potential future health risks to adults and children if the
Site was ever developed for residential use. Therefore, the
baseline risk assessment considered the potential health effects
for workers (industrial workers and excavators) that could result
from dermal contact or incidental ingestion of contaminated soils
and sediments, and inhalation of volatile chemicals from soil
vapors. For the residential use scenario, the baseline risk
assessment considered potential health effects that could result if
future on-site residents (adults and children) came into contact
with contaminated soil; accidentally ingested contaminated soil; or
drank or showered with ground water from the shallow on-site
aquifer.
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A total of ten (10) exposure pathways were evaluated under possible
on-site current and future land-use conditions. The exposure
pathways considered under current and future uses are listed in
Table 5-2. The reasonable maximum exposure was evaluated.
Under current EPA guidelines, the likelihood of carcinogenic
(cancer-causing) and non-carcinogenic health effects due to
exposure to Site chemicals are considered separately. It was
assumed that the toxic effects of the Site-related chemicals would
be additive. Thus, carcinogenic and non-carcinogenic risks
associated with exposures to individual compounds of concern were
summed to indicate the potential risks associated with mixtures of
potential carcinogens and non-carcinogens, respectively.
Non-carcinogenic risks were assessed using a hazard index (HI)
approach, based on a comparison of expected contaminant intakes and
safe levels of intake (Reference Doses). Reference doses (RfDs)
have been developed by EPA for indicating the potential for adverse
health effects. RfDs, which are expressed in units of
milligrams/kilogram-day (mg/kg-day), are estimates of daily
exposure levels for humans which are thought to be safe over a
lifetime (including sensitive individuals). Estimated intakes of
chemicals from environmental media (the amount of a chemical
ingested from contaminated drinking water) are compared to the RfD
to derive the hazard quotient for the contaminant in the particular
medium. The HI is obtained by adding the hazard quotients for all
compounds across all media that impact a particular receptor
population.
An HI greater than 1.0 indicates that the potential exists for non-
carcinogenic health effects to occur as a result of site-related
exposures. The HI provides a useful reference point for gauging
the potential significance of multiple contaminant exposures within
a single medium or across media. The reference doses for the
compounds of concern at the Site are presented in Table 5-3 (see
columns identified as chronic). A summary of the non-carcinogenic
risks associated with these chemicals across various exposure
pathways, for different populations (i.e., workers, residents) is
found in Table 5-4.
The hazard index exceeding the threshold of 1, which reflects
non-carcinogenic effects, was estimated to be 60 for ingestion of
contaminated ground water from the shallow aquifer and .2 for
ingestion of on-site contaminated soils by children, both of which
exceed the hazard index of 1 (see from Table 5-4) . The non-
carcinogenic risk for ground water ingestion was attributable
primarily to naphthalene and antimony, while the non-carcinogenic
risk for ingestion of soil by children was attributable primarily
to antimony, iron and arsenic.
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Potential carcinogenic risks were evaluated using the cancer slope
factors developed by EPA for the contaminants of concern. Cancer
slope factors (SFs) have been developed by EPA's Carcinogenic Risk
Assessment Verification Endeavor (an Inter-agency workgroup of
scientists with expertise in carcinogens) for estimating excess
lifetime cancer risks associated with exposure to potentially
carcinogenic chemicals. SFs, which are expressed in units of
(mg/kg-day)"1, are multiplied by the estimated intake of a potential
carcinogen, in mg/kg-day, to generate an upper-bound estimate of
the excess lifetime cancer risk associated with exposure to the
compound at that intake level. The term "upper bound" reflects the
conservative estimate of the risks calculated from the SF. Use of
this approach makes the underestimation of the risk highly
unlikely. The SF for the compounds of concern are presented in
Table 5-3 (see columns identified as carcinogenic).
For known or suspected carcinogens, EPA considers excess upper-
bound individual lifetime cancer risks in the range of 10"4 to 10"6
to be acceptable. This level indicates that an individual has not
greater than a one in ten thousand to one in a million chance of
developing cancer as a result of Site-related exposure to a
carcinogen over a 70-year period under specific exposure conditions
at the Site (i.e., ingestion of 2 liters of water per day for 350
days per year over 30 years in residence at the Site). Under the
current Site conditions, the risks to human health are within EPA's
acceptable risk range. Evaluation of risks to on-site employees
and excavation workers, as well as children playing in the wetland
areas, are within EPA's acceptable range. However, surface soils
and ingestion of shallow ground water would pose unacceptable risks
to human health 'if the Site was developed for residential use in
the future without remediation (see Table 5-5). In addition, if
the Site is not remediated the contaminated ground water on the
NMPC property and the skating rink area would continue to migrate
and impact off-site ground water. Potential consumption of on-site
ground water (from shallow wells) without remediation by a future
resident would result in an incremental cancer risk exceeding 1 x
10'3; that is, EPA would expect that among 1,000 people drinking 2
liters (about 8 glasses) of water per day over a 30-year residence
period, averaged over the lifetime of 70 years, one person in the
population may develop cancer caused by contaminants in the ground
water.
The carcinogenic risk for incidental ingestion of soil by future
residents (including children) exceeds 1 x 10"4 (see Table 5-5) ;
that is, one additional resident in a population of 10,000 exposed
to soil daily over a residence time of 30 years, averaged over a
lifetime, would be at risk of developing cancer over the lifetime
if the Site is not remediated, and later developed for residential
use.
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The cumulative upper-bound cancer risk for current employees at the
Site is 7 x 10'5, including indoor air risk; 9 x 10'5 for current
workers, including outdoor inhalation risk; and 2 x 10"3 for the
future resident at the Site. Hence, the risks for carcinogens at
the Site for the workers are at the high end of the acceptable risk
range of 10"4 to 10^ , arid risks to future residents are above the
risk range at 2 x 10'3 (see Table 5-6) . The estimated total risks
for the future residents are primarily due to benzene and arsenic,
which contributed approximately 97 percent and 3 percent,
respectively to the carcinogenic risk calculations. The
calculations were based on the contaminants detected in on-site
monitoring wells, and not the residential wells. It was assumed
that in the future, the ground water would be used for residential
purposes (i.e., ingestion of ground water and showering). These
estimates were developed by taking into account various
conservative assumptions about the likelihood of a person being
exposed to these media. However, current and future users of
public/private wells could be at risk if Site ground water
contaminants were to migrate.off site.
Ecological Risk Assessment
An ecological assessment was conducted to study the effect of Site
Contamination on the Spring Run system and surrounding wetlands.
A four-step process is utilized for assessing site-related
ecological risks for a reasonable maximum exposure scenario:
Problem Formulation a qualitative evaluation of contaminant
release, migration, and fate; identification of contaminants of
concern, receptors, exposure pathways, and known ecological effects
of the contaminants; and selection of endpoints for further study.
Exposure Assessment a quantitative evaluation of contaminant
release, migration, and fate; characterization of exposure pathways
and receptors; and measurement or estimation of exposure point
concentrations. Ecological Effects Assessment literature
reviews, field studies, and toxicity tests, linking contaminant
concentrations to effects on ecological receptors. Risk Character-
ization measurement or estimation of both current and future
adverse effects.
Available criteria and guidelines were reviewed for use as
benchmark values for evaluating chemical toxicity to Site-specific
organisms and habitats. NYSDEC Water Quality Regulations for
surface waters, EPA Ambient Water Quality Criteria (AWQC), Ontario
Ministry of the Environment (MOE), NYSDEC, and National Oceanic and
Atmospheric Administration (NOAA) sediment guidelines were used for
comparison to Site surface water and sediment contaminant
concentrations.
Potential ecological risks were evaluated for toxic effects to
biota by using a hazard index. The hazard index is the ratio of
the chemical concentration in a particular medium, to the benchmark
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concentration for that chemical in that medium. Benchmark
concentrations, based on the ecological screening guidance
previously discussed, were determined to evaluate both acute and
chronic effects. A benchmark concentration is assumed to pose
minimal risk; therefore, a hazard index less than 1 indicates that
there is a low probability of adverse ecological effects from site
contamination. A hazard index greater than one signifies that an
effect threshold has been exceeded (i.e., receptor exposure to
contamination exceeds known benchmarks) and there is potential risk
to the ecological receptor.
The results of the ecological risk assessment indicate that
contaminated surface water and sediment may pose a risk to aquatic
plants, invertebrates, and vertebrates inhabiting portions of the
Spring Run system. Potentially hazardous contaminants to aquatic
organisms were assessed by comparing mean and maximum
concentrations with AWQC or other appropriate toxicity effect
levels. The calculated mean and maximum total acute hazard indices
for surface water are 6 and 11, respectively. The estimated high
acute hazard indices are primarily due to pyrene, which contributed
67% to the mean and 36% to the maximum risk calculations. Pyrene
was detected in two of six surface water samples. The risk to
aquatic organisms inhabiting sediment was assessed by comparing
mean and maximum sediment concentrations with MOE levels. Total
mean and maximum hazard indices based on severe effect level
sediment guidelines are 6 and 60, respectively. PAHs comprise 72
percent of the total risk.
The U.S. Fish and Wildlife Service and the NYSDEC did not identify
any impacts to Federal and State listed or proposed endangered,
threatened,~ or special concern wildlife species, rare plant,
animal, or natural community occurrences or other significant
habitats.
Uncertainties
The procedures and inputs used to assess risks in this evaluation,
as in all such assessments, are subject to a wide variety of
uncertainties. In general, the main sources of uncertainty
include:
environmental chemistry sampling and analysis
environmental parameter measurement
fate and transport modeling
exposure parameter estimation
toxicologicai data.
Uncertainty in environmental sampling arises in part from the
potentially uneven distribution of chemicals in the media sampled.
Consequently, there is significant uncertainty as to the actual
levels present. Environmental chemistry-analysis error can stem
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from several sources including the errors inherent in the
analytical methods and characteristics of the matrix being sampled.
Uncertainties in the exposure assessment are related to estimates
of how often an individual would actually come in contact with the
chemicals of concern, the period of time over which such exposure
would occur, and in the models used to estimate the concentrations
of the chemicals of concern at the point of exposure.
Uncertainties in toxicological data occur in extrapolating both
from animals to humans and from high to low doses of exposure, as
well as from the difficulties in assessing the toxicity of a
mixture of chemicals and the availability of toxicity data for all
chemicals of concern. These uncertainties are addressed by making
conservative assumptions concerning risk and exposure parameters
throughout the assessment. As a result, the Risk Assessment
provides upper-bound estimates of the risks to populations near the
Site, and is highly unlikely to underestimate actual risks related
to the Site.
More specific information concerning public health risks, including
a quantitative evaluation of the degree of risk associated with
various exposure pathways, is presented in the Risk Assessment
Report.
Actual or threatened releases of hazardous substances from this
Site, if not addressed by implementing the response action selected
in the ROD, may present an imminent and substantial endangerment to
the public health, welfare, or the environment.
REMEDIAL ACTION OBJECTIVES
Remedial action objectives are specific goals to protect human
health and the environment. These objectives are based on
available information and standards such as ARARs and risk-based
levels established in the risk assessment.
The following remedial action objectives were established:
1) minimize the potential for migration of contaminants from source
areas into soils or ground water;
2) minimize or eliminate the potential future migration of
contaminated ground water, prevent the potential ingestion of
contaminated ground water by future residents or workers, and
improve ground water quality;
3) minimize or eliminate the potential for Site contaminants to be
transported through the brick sewer; and
4) minimize the potential risk to ecological receptors posed by
NMPC-impacted sediments.
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DESCRIPTION OF REMEDIAL ALTERNATIVES
CERCLA §121(b)(l), 42 U.S.C. §9621(b)(l), mandates that a remedial
action must be protective of human health and the environment, cost
effective, and utilize permanent solutions and alternative
treatment technologies or resource recovery technologies to the
maximum extent practicable. Section 121(b)(1) also establishes a
preference for remedial actions which employ, as a principal
element, treatment to permanently and significantly reduce the
volume, toxicity, or mobility of the hazardous substances,
pollutants and contaminants at a site. CERCLA §121(d), 42 U.S.C.
§9621(d), further specifies that a remedial action must attain a
level or standard of control of the hazardous substances,
pollutants, and contaminants, which at least attains ARARs under
federal and state laws, unless a waiver can be justified.
This ROD evaluates in detail four remedial alternatives
(Alternatives 1, 7, 8, and 9) for addressing the contamination
associated with the Site. The other alternatives developed in the
FS were eliminated in the alternatives screening process because of
limited effectiveness or difficult implementability. The time to
implement a remedial alternative reflects only the time required to
construct or implement the remedy and does not include the time
required to design the remedy, negotiate with the responsible
parties, or procure contracts for design and construction, or
conduct operation and maintenance at the Site.
The remedial alternatives are:
Alternative l - No Action
Capital Cost: $0
O & M Present Worth Cost:$0
Present Worth Cost: $0
Construction Time: None
The Superfund program requires that a "no action" alternative be
considered as a baseline for comparison of other alternatives. No
action would be taken to address Site contamination. In accordance
with Section 121 of CERCLA, the Site would be reviewed at least
once every five years to assure that the remedial action is
protective of human health and the environment.
Alternatives 7 through 9
Alternatives 7 through 9 consist of a combination of actions to
address the various contaminated media at the Site (i.e., source
areas, surface soil, subsurface soil, surface water, sediments, and
ground water). A number of the actions which are common to all
three alternatives, including variations for specific alternatives,
are described below. Construction of an on-site water treatment
system would be required for pretreatment of contaminated ground
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water and surface water prior to discharge to the local wastewater
treatment plant operated by the Saratoga Sewer District.
Conceptually, the treatment process for the contaminated water
includes DNAPL/water separation, metals removal by precipitation,
and biological .treatment.
Source and Surface Soil Removal
The purpose of this action is to remove source materials having
total PAH concentrations in excess of 1,000 ppm, that are
accessible and are significant in terms of volume, concentration,
and the potential for continued, long-term subsurface impacts; and
to remove surface soils (approximately 3,500 cubic yards ) from 0
to 2 feet below ground surface. The source areas include Holder
Nos. 1, 2, 3, and '5, and several other areas around the NMPC
Property. During the remedial design phase, additional subsurface
sampling would be conducted on the NMPC property, including Holder
No. 4 where concentrated tar contamination was visually observed,
to determine if additional PAH source areas are present, thereby
requiring removal. This soil removal requires the demolition of
surface structures in and around the source areas, including the
Round House structure over Holder No. 2 and the gas regulator
station over Holder No. 1. Approximately 16,700 cubic yards of
source material- would be removed under Alternatives 7 and 8.
Alternative 9 would involve less extensive source removal via
excavation because subsurface flushing would be used to remediate
source areas that are not associated with former gas holder
structures. Therefore, approximately 12,000 cubic yards of source
material would be excavated under Alternative 9.
Excavation of contaminated soil, DNAPL, and associated source
material within and around the Holder No. 3, also known as the
tar/water separator would be implemented. The Holder structure
will remain in place and be filled with a suitable backfill
material.
Excavated material that exhibits a hazardous characteristic would
be rendered non-hazardous by blending it with coal fines or other
suitable material on NMPC property prior to transport off-site for
co-burning in a utility boiler, and/or treatment and disposal at an
off-site permitted hazardous waste facility. Most of the non-
hazardous material encountered during excavation activities would
be disposed of at an off-site solid waste management facility, and
some would be managed in an off-site cold batch asphalt plant to
produce asphalt paving for the NMPC property. Recovered DNAPL and
coal tar would be managed off site at a tar processing facility.
If these materials exhibit a hazardous characteristic, they would
be managed as hazardous waste as described 'above.
As set forth in the Institutional Controls and Monitoring Section
below, EPA would require deed restrictions on the NMPC property to
prevent future residential use of the property, and notifications
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to other utility companies to limit exposure to the subsurface
contaminants that remain on the NMPC property.
Soil Removal from the Skating Rink Area
The purpose of this action is to remove subsurface soils that
exceed cleanup levels in the vicinity of the municipal skating
rink. The long-term impact of this subsurface soil contamination
potentially could contaminate the skating rink ground water, and
this contaminated ground water could potentially migrate off-site.
Such contaminant migration could have adverse impacts on
downgradient ground water users. Therefore, in order to prevent
migration of contaminated ground water beyond the skating rink
area, and to restore the ground water by the skating rink area to
drinking water standards, all sources of contamination that are
contributing to ground water contamination in the vicinity of the
skating rink would need to be eliminated.
The skating rink area subsurface contaminated soils would be
excavated, and confirmation sampling would be conducted to assure
attainment of cleanup levels. Approximately 4,200 cubic yards of
contaminated subsurface soil would be excavated. The excavated
material would be managed as described in Source and Surface Soil
Remova1 action.
The remedial design phase will include further subsurface soil
investigation in the skating rink area to determine whether
additional soils are contaminated. This soil investigation will be
performed outside the boundaries of the skating rink structure.
Soil sampling beneath the skating rink structure is not feasible
while the building is intact. Such soil sampling will be conducted
when the soils become accessible. The soils will become accessible
if and when the skating rink is both taken out of service and
demolished. If sampling identifies contaminated soil at
concentrations above the soil cleanup levels, the affected soil
will be removed, and additional sampling would be conducted to
assure that the removal achieved cleanup levels.
If contaminated soils are currently present beneath the skating
rink, they are inaccessible, and any contact with such soils is
unlikely. Moreover, the structure serves as a cover that prevents
infiltration of precipitation through such soils. Therefore if
present, such soils do not pose a risk to human health and the
environment.
After the contaminated soil is removed around the skating rink
area, and the barriers are erected on the NMPC property, the
sources of contamination impacting on the skating rink area would
be eliminated. Because the sources of contamination would be
eliminated, it is expected that the level of contaminants in the
ground water in the vicinity of the skating rink would decline over
time, and achieve compliance with the Federal and New York State
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Drinking Water Standards and New York State Ground Water Quality
Standards through natural attenuation.
The remedy requires monitoring of the ground water to measure
improvement in the ground water quality. If improvement in ground
water quality is not observed upon review of the annual ground
water monitoring results, a program to evaluate contingency
alternatives for ground water remediation in the skating rink area
would be initiated and implemented in a timely manner.
As set forth in the Institutional Controls and Monitoring Section
below, EPA would recommend the imposition of a notice on the
property records pertaining to this property concerning potential
contamination underneath the skating rink. Such notice could be
removed after the contamination is removed.
Remediation of the Sewer Migration Pathway
The purpose of this action is to eliminate the impacts to the
wetlands surface water from the migration of NMPC property
contaminants through the brick sewer. Stormwater flow through the
brick sewer and Village Brook upstream of the NMPC property would
be diverted to the twin box culvert storm sewer. At the southeast
corner of the NMPC property a brick sewer cutoff and a water/DNAPL
collection sump would be constructed. The brick sewer, from the
collection sump to the outfall of the brick sewer near Interstate
87, would be cleaned. The walls of the brick sewer, from the
collection sump to the concrete box culvert outfall, would be
sealed to prevent infiltration of impacted ground water into the
sewer. The recovered DNAPL and coal tar would be managed off site
as described above.
Sediment Removal
The sediment removal action involves the dredging and/or excavation
of approximately 1,200 cubic yards of impacted sediments and
wetlands soils at the confluence of Loughberry Creek and Village
Brook, near the outfall of the concrete box culvert, near the
outfall of the brick sewer, and at four locations on the NMPC
property. Confirmation sampling to assure attainment of cleanup
levels would be conducted. Contaminated sediments and soils would
be transported off site for treatment and proper disposal. The
break in the brick sewer in this area would be repaired, and
appropriate actions would be taken to restore the wetlands.
Control of releases from the brick sewer described above would stop
the potential for continuing impacts to sediments.
Institutional Controls and Monitoring
Deed restrictions to prevent future residential use of the property
and notifications to other utility companies would be required to
limit exposure to the subsurface contaminants that remain on the
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NMPC property. The implementation of deed restrictions would be
the responsibility of NMPC. NMPC has indicated to EPA that it will
maintain future ownership of the NMPC property, thereby further
restricting the potential for future residential development of the
property. EPA would recommend the imposition of a notice in the
property records pertaining to the skating rink property to inform
interested parties of the potential presence of contamination
underneath the skating rink. This notice should remain in the
property records until after the skating rink is taken out. of
service, demolished, and any contaminated soils removed. No deed
restrictions would be necessary on the Spring Run wetland because
the contaminated sediment and soil would be removed.
A monitoring program would be implemented to assess the
effectiveness of the remedial action. Samples for analysis would
be obtained from monitoring wells, the Old Red Spring, the diverted
flows from the upgradient interceptor trench installed under
Alternative 7, and the discharge from the on-site water treatment
system as required by the Saratoga County Sewer discharge permit.
Because contaminants would remain on NMPC property under each
alternative, EPA would review the Site at least once every five
years to assure that the remedy selected continues to be protective
of human health and the environment. If justified by the review,
additional remedial actions may be implemented to remove or treat
the wastes.
Alternative 7 - Source Removal and Subsurface Barrier
Capital Cost: $14,000,000
O & M Present Worth Cost:$ 1,300,000
Present Worth Cost: $15,300,000
Construction Time: 2 years
Alternative 7 consists of several remedial actions including: the
excavation of source areas and contaminated surface soils on the
NMPC property; remediation of the sewer migration pathway;
excavation of contaminated soils from the skating rink area;
removal of contaminated sediments, and institutional controls and
monitoring. In addition this alternative includes installation of
subsurface barriers to contain contaminated subsurface soils and
ground water on the NMPC property.
The purpose of the installation of subsurface barriers in
Alternative 7 is twofold: 1) to contain contaminated ground water
on the NMPC property, and 2) to contain and collect DNAPL residing
in the vicinity of the subsurface barrier walls. Subsurface
barriers would be installed at the southeast and southwest corners
of the NMPC property where contaminated ground water and DNAPL can
potentially migrate off site. The ground water in the shallow
aquifer beneath the NMPC property and the DNAPL residing near the
subsurface barriers would tie extracted by toe drain and sump
systems installed inside the subsurface barriers. The extracted
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contaminated ground water would be treated on site by a new
wastewater treatment facility prior to discharge to the local
wastewater treatment plant operated by the Saratoga Sewer District.
Ground water upgradient of the NMPC property (which has not been
impacted by the NMPC property contaminants) would be collected
using a curtain drain and diverted to either the twin box culvert
storm sewer system west of the NMPC property or the culverted
Village Brook east of the NMPC property, and the majority of the
NMPC property would be capped with asphalt to prevent infiltration
of precipitation.
Ground water contamination underneath the skating rink-is expected
to be reduced over time through natural attenuation because all
contaminated soils in the skating rink area would be removed, the
shallow aquifer underlying the NMPC property would be nearly
eliminated, and the subsurface barriers would prevent migration of
the residual ground water contamination from the NMPC property.
Alternative 8 - Source and Extended Soil Removal
Capital Cost: $47,900,000
O & M Present Worth Cost:$ 600,000
Present Worth Cost: $48,500,000
Construction Time: 6 years
Alternative 8 consists of several remedial actions including: the
excavation of source areas and contaminated surface soils on the
NMPC property; remediation of the sewer migration pathway;
excavation of contaminated soils from the skating rink area;
removal of contaminated sediments; and institutional controls and
monitoring. In addition, Alternative 8 includes more extensive
soil removal than is planned in Alternative 7 to address subsurface
soil contamination on the NMPC property. The soil cleanup levels
established for this alternative are based on a 10* (1 in one
million) excess cancer risk to residential receptors and NYSDEC
TAGM HWR-4046, which is a "to be considered" requirement, for the
protection of ground water. A large portion of the NMPC property
would be excavated to a depth of approximately 20 feet to remove
all impacted subsurface soils, excluding the soils which are
located directly below the service center and maintenance garage,
the storage building, and the fenced area immediately adjacent to
the storage building since these structures would not be
demolished. Approximately 16,700 cubic yards of source material
and 140,000 cubic yards of impacted soil would be excavated as part
of this action, followed by confirmation sampling to assure
adequate removal. As a result of extended subsurface soil removal,
ground water contamination underneath the NMPC property and the
skating rink would be reduced over time through natural attenuation
because all contaminated soils would be removed.
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Alternative 9 - Subsurface Flushing and In Situ Biological
Treatment
Capital Cost: $14,600,000
0 & M Present Worth Cost $ 3,800,000
Present Worth Cost: $18,400,000
Construction Time: 2 years
Alternative 9 consists of several remedial actions including: the
excavation of source areas associated with former gas holder
structures and contaminated surface soils on the NMPC property;
remediation of the sewer migration pathway; excavation of
contaminated soils from the skating rink; removal of contaminated
sediments; and institutional controls and monitoring. In addition,
Alternative 9 uses physical subsurface flushing to address source
areas that are not associated with former gas holder structures,
followed by in situ biological treatment of subsurface soils and
impacted ground water on the NMPC property.
Alternative 9 includes the construction of a subsurface barrier
wall, continuous on the west, south, and east borders of the NMPC
property to prevent the flow of contaminated ground water and DNAPL
from the NMPC property.
Subsurface flushing would be used to recover DNAPL from the
designated source areas by injecting steam or hot water into the
subsurface soil to mobilize the DNAPL, which is then removed using
ground water extraction wells. An estimated 41,000 gallons of
DNAPL would be collected during subsurface flushing over a two-
month operating period. Following subsurface flushing, an in situ
biological treatment process would be implemented to further reduce
subsurface contamination by enhancing the subsurface environment to
promote breakdown of contaminants into less toxic compounds by
naturally-occurring bacteria. The extracted ground water would be
treated on the NMPC property and enriched with nutrients and oxygen
before reinjection. In situ biological treatment would continue
for a period of approximately ten years. The PAHs that remain in
the subsurface following implementation of Alternative 9 would be
the heavier PAHs that tend to adsorb onto soil particles and would
not readily leach into the ground water. Ground water
contamination underneath the skating rink would be reduced over
time through natural attenuation because all contaminated soils in
the skating rink area would be removed, the shallow aquifer
underlying the NMPC property would be nearly eliminated, and the
subsurface barriers would prevent migration of the residual ground
water contamination from the NMPC property.
SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
In selecting a remedy, EPA considered the factors set out in CERCLA
§121, 42 U.S.C. §9621, by conducting a detailed analysis of the
viable remedial alternatives pursuant to the NCP, 40 CFR
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§300.430(e)(9) and OSWER Directive 9355.3-01. The detailed
analysis consisted of an assessment of the individual alternatives
against each of nine evaluation criteria and a comparative analysis
focusing upon the relative performance of each alternative against
those criteria.
The following "threshold" criteria must be satisfied by any
alternative in order to be eligible for selection:
1. Overall protection of human health and the
environment addresses whether or not a remedy
provides adequate protection and describes how risks
posed through each exposure pathway (based on a
reasonable maximum exposure scenario) are eliminat-
ed, 'reduced, or controlled through treatment,
engineering controls, or institutional controls'.
2. Compliance with ARARs addresses whether or not a
remedy would meet all of the applicable (legally
enforceable), or relevant and appropriate
(requirements that pertain to situations
sufficiently similar to those encountered at a
Superfund site such that their use is well suited to
the site) requirements of federal and state environ-
mental statutes and requirements or provide grounds
for invoking a waiver.
The following "primary balancing" criteria are used to make
comparisons and to identify the major trade-offs between
alternatives:
3. Long-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. It also addresses the
magnitude and effectiveness of the measures that may
be required to manage the risk posed by treatment
residuals and/or untreated wastes.
4. Reduction of toxicity, mobility, or volume via
treatment refers to a remedial technology's expected
ability to reduce the toxicity, mobility, or volume
of hazardous substances, pollutants or contaminants
at the site.
5. Short-term effectiveness addresses the period of
time needed to achieve protection and any adverse
impacts on human health and the environment that may
be posed during the construction and implementation
periods until cleanup goals are achieved.
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6. Implementabilitv refers to the technical and
administrative feasibility of a remedy, including
the availability of materials and services needed.
7. Cost includes estimated capital and operation and
maintenance costs, and the present-worth costs.
The following "modifying" criteria are considered fully after the
formal public comment period on the Proposed Plan is complete:
8. State acceptance indicates whether, based on its
review of the RI/FS report and the Proposed Plan,
the State supports, opposes, and/or has identified
any reservations with the preferred alternative.
9. Community acceptance refers to the public's general
response to the alternatives described in the
Proposed Plan and the RI/FS reports. Factors of
community acceptance to be discussed include
support, reservation, and opposition by the
community.
A comparative analysis of the remedial alternatives based upon the
evaluation criteria noted above follows.
Overall Protection of Human Health and the Environment
The No Action alternative (Alternative 1) is not protective of
human health or the environment because the risks to off-site
ecological receptors and potential future residents remain
unchanged, which is unacceptable. Therefore, the No Action
alternative was eliminated from further consideration and will not
be discussed further.
All of the other alternatives provide adequate protection of human
health and the environment. Alternatives 7, 8 and 9 require the
use of institutional controls to prevent future residential use on
the NMPC property.
The overall protectiveness of the remedy at the skating rink area
to human health and the environment is considered to be equivalent
for all three alternatives. The soil removal action included in
each of the Alternatives 7, 8 and 9 would protect human health from
potential exposure to contaminated soils. Risks to human health
from potential exposure to the ground water under the skating rink
area would be diminished under Alternatives 7, 8 and 9 by
preventing the migration of contaminants into ground water, and
eventually the contamination would be eliminated through natural
attenuation.
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Compliance with Applicable or Relevant and Appropriate Requirements
(ARARs)
Actions taken at any Superfund site must meet all ARARs of federal
and state law or provide grounds for waiving these requirements.
All of the alternatives have been designed to comply with the
ARARs.
Since the ground water at the skating rink area is a future
potential source of drinking water, Federal and New York State
Drinking Water Standards and New York State Ground Water Quality
Standards are ARARs. These drinking water standards would be
achieved over time through natural attenuation. The remedy would
require removal of all contaminated soils in the skating rink area;
dewatering the soil in areas to be excavated, treatment of this
contaminated ground water and discharge to a Publicly Owned
Treatment Works (POTW); and containment of residual contaminated
soils and ground water on the NMPC property by the subsurface
barriers. Upon completion of these actions, all potential sources
of ground water contamination in the skating rink area would be
eliminated, thus, allowing for natural attenuation of the ground
water contamination. For all alternatives, a technical waiver of
the above ground water ARARs is invoked by EPA for the NMPC
property shallow ground water based on technical impracticability,
from an engineering perspective, because of the presence of DNAPL.
There are technical limitations to recovering residual DNAPL from
the environment.
Sediment removal actions would be conducted in compliance with the
Federal Clean Water Act, Federal Executive Order 11990 for the
Protection of Wetlands, Federal Fish and Wildlife Coordination Act,
New York State Freshwater Wetlands Act, and New York State Water
Quality Classification.
Alternatives 7, 8 and 9 would comply with the National Historic
Preservation Act and the New York State Historic Preservation Act.
Historic and archaeological investigations have already been
conducted at the Site and documented in a report. Since source
removal actions require the demolition of the Round House, which
would have an adverse effect on this historic artifact, additional
documentation regarding the Round House would be required during
the remedial design phase to comply with ARARs.
The removal and disposition of residuals during implementation of
each alternative (except for Alternative 1, No Action) would be
done in accordance with federal and New York State solid and
hazardous waste regulations. The use of contaminated soil in the
cold mix asphalt process would be accomplished in compliance with
the Beneficial Use Determination Program of the New York State
Solid Waste Management Regulations.
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The discharge of water and recovered ground water generated during
remediation would be regulated by the Federal Clean Water Act
regulations for discharges to a POTW, and the City of Saratoga
Sewer Use Ordinance. A sewer discharge permit from the Saratoga
County Sewer District may be required for discharge of water to the
local wastewater treatment plant under all alternatives (except for
Alternative 1, No Action). Permit requirements would be met by
treating the water in an on-site water treatment system prior to
discharge to the'POTW.
During soil and sediment excavation and on-site water treatment,
New York State Air Pollution Control Regulations may apply. Air
pollution control devices would be included in the design of the
on-site water treatment system as appropriate to comply with air
regulations. Temporary structures would be used to cover the
excavation areas for control of volatile and odor emissions. In
addition, ambient air conditions would be monitored during
excavation activities to assure acceptable air quality. The
ability to meet regulatory requirements for controlling dust,
nuisance odors and volatile emissions during the soil excavation
would be more difficult to achieve given the volume of soil
excavated and handled under Alternative 8 versus Alternatives 7 and
9.
Long-term Effectiveness and Permanence
Alternatives 7, 8 and 9 would provide for the permanent reduction
in the migration of the contaminated ground water from the NMPC
property into the ground water under the skating rink.
Alternatives 7 and 9 use subsurface barriers to contain subsurface
contaminated soil and ground water on the NMPC property. In
addition, Alternative 7 uses an asphalt cap in combination with
upgradient flow diversion and ground water pumping of the shallow
aquifer underlying the NMPC property to nearly eliminate the ground
water contamination. Alternative 9 uses subsurface flushing and in
situ biological treatment to reduce the concentrations of mobile
contaminants in the NMPC property subsurface soils and ground
water. Alternative 8 removes the majority of the subsurface soil
contamination on the NMPC property and would permanently reduce the
volume of hazardous constituents remaining at the NMPC property.
All three alternatives also remove contaminated subsurface soil
from the skating rink area that could contaminate the ground water.
The subsurface barriers under Alternatives 7 and 9 are considered
to be reliable over the long-term and easily maintained. The
reliability of subsurface flushing and in situ biological treatment
under Alternative 9 is considered to be low with respect to this
criterion because of the variability of subsurface geologic
materials in the shallow ground water aquifer. The efficiency of
subsurface flushing and in situ biological treatment would be
highly variable with much lower levels of treatment occurring in
geological units having lower permeability. In addition,
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subsurface flushing has not been successfully demonstrated to date
at the field scale.
Reduction of Toxicity, Mobility, or Volume Through Treatment
Alternative 7 provides significant reduction of contamination on
the NMPC property by removing contaminated surface soils, source
areas, and any migrating DNAPL. Alternative 9 also provides
significant reduction of NMPC property contamination and reduces
the mobility of contaminants remaining on the NMPC property using
in situ biological treatment. In situ biological treatment
biodegrades the lighter PAHs to less toxic compounds, leaving
behind primarily the heavier PAHs which tend to adsorb onto soil
particles and thus do not readily leach into the ground water.
Alternative 8 provides nearly complete removal of PAH constituents
from NMPC property soils. Because heavier PAHs would remain
adsorbed onto soil particles in source areas after implementation
of Alternative 9, Alternative 7 provides greater removal of PAH
contaminants in source areas than Alternative 9. All of the
alternatives include recycling of impacted soils into asphalt or
management through permanent off-site treatment.
Alternatives 7, 8 and 9 provide comparable reduction of ground
water contamination in the skating rink area, albeit by different
means. By removing the vast majority of the subsurface soil
contamination under Alternative 8, the volume of subsurface
contaminants available for leaching into the ground water for
potential transport beyond the NMPC property boundaries is
minimized. Alternatives 7 and 9 use subsurface barrier systems to
contain subsurface contamination on the NMPC property, thereby
reducing the mobility of contaminants from the NMPC property.
Short-term Effectiveness
Alternatives 7 and 9 are considered to have equivalent short-term
effectiveness because they each have relatively few negative
impacts to human health and the environment, and the actions that
provide the most significant reduction in risk can be implemented
within a two year time frame.
Alternative 8 is expected to have significantly greater negative
impacts to human health and the environment during implementation
and require a significant time period to implement. Approximately
six years would be required to excavate and transport the large
volume of soils off site. The increased truck traffic associated
with the removal of subsurface soils would create some degree of
risk to the community.
The sediment removal would impact the quality of the wetland
ecosystem. Dredging operations would utilize silt fences and other
control techniques to minimize the impact to water quality during
dredging operations.
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Implementability
Alternative 7 is considered to be readily implementable.
The extended removal of subsurface soils conducted as part of
Alternative 8 would require excavation around foundations and below
the ground water table. Sheet piling would be required to
stabilize foundations during excavation. The excavations would be
performed within a temporary structure to minimize releases of
volatile emissions, nuisance odors and dust. The extensive
excavation of soils under these conditions would lead to more
technical delays than normally encountered if extraordinary
measures were not necessary.
Although the technologies required to install the subsurface
barrier and the injection and recovery wells under Alternative 9
are conventional and readily implementable, the implementation of
subsurface flushing and in situ biological treatment is likely to
encounter difficulties associated with the variability in
permeability of subsurface geologic materials. In addition,
subsurface flushing technology has not been successfully proven at
the field scale.
Cost
The cost estimates associated with the alternatives are presented
above. Alternative 7 is the lowest cost alternative with the
present worth of $15.3 million. Alternative 9 (present worth of
$18.4 million) has only a slightly higher cost than Alternative 7;
however, the costs for Alternative 9 are the most uncertain because
the subsurface flushing technology has not been successfully proven
at the field scale. Alternative 8 has by far the highest costs
with a present worth of $48.5 million. Alternative 8 is
approximately three times more costly than the other two
alternatives.
State Acceptance
The State of New York concurs with the selected alternative. The
letter outlining this concurrence is attached to this ROD as
Appendix IV.
Community Acceptance
Community acceptance of the preferred remedy has .been assessed in
the Responsiveness Summary portion of this ROD following review of
all public comments received on the RI/FS report and the Proposed
Plan. All comments submitted during the public comment period were
evaluated and are addressed in the attached Responsiveness Summary
(Appendix V). Many of the public's concerns were related to the
demolition of the Round House and the removal of all contaminated
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soils in the vicinity of the skating rink. In general, the public
is supportive of EPA's preferred remedy.
SELECTED REMEDY
EPA has determined, after reviewing the alternatives and public
comments, that Alternative 7 is the appropriate remedy for the
Site, because it best satisfies the requirements of CERCLA and the
NCP's nine evaluation criteria for remedial alternatives.
The major components of the selected remedy are as follows:
Source and Surface Soil Removal
The purpose of this action is to remove source materials or areas
of concentrated coal tar having total PAH concentrations exceeding
1,000 (ppm), that are accessible and are significant in terms of
volume, concentration, and the potential for continued, long-term
subsurface impacts; and to remove contaminated surface soils from
0 to 2 feet below ground surface. The source areas include Gas
Holder Nos. 1, 2, 3, and 5, and several other areas around the NMPC
property. During the remedial design phase, additional subsurface
sampling will be conducted on the NMPC property, including Holder
No. 4 where concentrated tar contamination was visually observed,
to determine if additional PAH source areas are present, thereby
requiring removal. This action requires the demolition of surface
structures in and around the source areas, including the Round
House structure over Holder No. 2 and the gas regulator station
over Holder No. 1. Approximately 16,700 cubic yards of source
material and 3,500 cubic yards of contaminated surface soils will
be removed. These volume estimates do not include Holder No. 4.
Excavation of contaminated soil, DNAPL, and associated source
material within and around the Holder No. 3, also known as the
tar/water separator will be implemented. The Holder structure will
remain in place and be filled with a suitable backfill material.
Excavated material that exhibits a hazardous characteristic will be
rendered non-hazardous by blending it with coal fines or other
suitable material on site prior to transport off site for
co-burning in a utility boiler, and/or treatment and disposal at an
off-site permitted hazardous waste facility. All non-hazardous
material encountered during excavation activities will be disposed
of at an off-site solid waste management facility, and contaminated
surface soil will be managed in an off-site cold batch asphalt
plant to produce asphalt paving for the NMPC property. Recovered
DNAPL and coal tar will be managed off site at a tar processing
facility. If these materials exhibit a hazardous characteristic,
they will be managed as hazardous waste as described above.
As set forth in the Institutional Controls and Monitoring Section
below, deed restrictions on the NMPC property will be required.
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Installation of Subsurface Barriers and Ground Water Management
The purpose of the installation of subsurface barrier walls is
twofold: 1) to contain contaminated ground water on the NMPC
property, and 2) to contain and collect DNAPL residing in the
vicinity of the subsurface barrier walls. Subsurface barriers will
be installed at the southeast and southwest corners of the NMPC
property where contaminated ground water and DNAPL can potentially
migrate off site. The ground water in the shallow aquifer beneath
the NMPC property and the DNAPL residing in the vicinity of the
subsurface barrier walls will be collected by using drains
installed inside and along the lengths of the barrier walls. The
DNAPL and ground water collected will be transferred through a
subsurface pipe into a collection sump, then pumped to the on-site
water treatment facility.
Construction of an on-site water treatment facility will be
required for pretreatment of contaminated ground water prior to
discharge to the local wastewater treatment plant operated by the
Saratoga Sewer District. The treatment process for the
contaminated water includes DNAPL/water separation, metals removal
by precipitation, and biological treatment.
Ground water upgradient of the NMPC property (which has not been
impacted by the NMPC property contaminants) will be collected using
a curtain drain and diverted to either the twin box culvert storm
sewer system west of the NMPC property or the culverted Village
Brook east of the NMPC property. The NMPC property will be capped
with asphalt to prevent infiltration of precipitation.
Soil Removal from the Skating Rink Area
The purpose of this action is to remove subsurface soils that
exceed cleanup levels in the vicinity of the municipal skating
rink. The long-term impact of this subsurface soil contamination
potentially could contaminate the skating rink ground water, and
this contaminated ground water could potentially migrate off-site.
Such contaminant migration could have adverse impacts on
downgradient ground water users. Therefore, in order to prevent
migration of contaminated ground water beyond the skating rink
area, and to restore the ground water by the skating rink area to
drinking water standards, all sources of contamination that are
contributing to ground water contamination in the vicinity of the
skating rink would need to be eliminated.
The skating rink area subsurface contaminated soils will be
excavated, and confirmation sampling will be conducted to assure
attainment of cleanup levels. Approximately 4,200 cubic yards of
contaminated subsurface soil will be excavated. The excavated
material will be managed as described in Source and Surface Soil
Removal Action.
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The remedial design phase will include further subsurface soil
investigation in the skating rink area to determine whether
additional soils are contaminated. This soil investigation will be
performed outside the boundaries of the skating rink structure.
Soil sampling beneath the skating rink structure is not feasible
while the building is intact. Such soil sampling will be conducted
when the soils become accessible. The soils will become accessible
if and when the skating rink is both taken out of service and
demolished. If sampling identifies contaminated soil at
concentrations above the soil cleanup levels, the affected soil
will be removed, and additional sampling will be conducted to
assure that the removal achieved cleanup levels.
If contaminated soils are currently present beneath the skating
rink, they are inaccessible, and any contact with such soils is
unlikely. Moreover, the structure serves as a cover that prevents
infiltration' of precipitation through -such soils. Therefore if
present, such soils do not pose a risk to human health and the
environment.
After the contaminated soil is removed around the skating rink
area, and the barriers are erected on the NMPC property, the
sources of contamination impacting on the skating rink area will be
eliminated. Because the sources of contamination will be
eliminated, it is expected that the level of contaminants in the
ground water in the vicinity of the skating rink will decline over
time, and achieve compliance with the Federal and New York State
Drinking Water Standards and New York State Ground Water Quality
Standards through natural attenuation.
The remedy requires monitoring of the ground water to measure
improvement in the ground water quality. If improvement in ground
water quality is not observed upon review of the annual ground
water monitoring results, a program to evaluate contingency
alternatives for ground water remediation in the skating rink area
will be initiated and implemented in a timely manner.
As set forth in the Institutional Controls and Monitoring Section
below, EPA recommends the imposition of a notice in the property
records pertaining to the skating rink property to inform
interested parties of the potential presence of contamination
underneath the skating rink. This notice should remain in the
property records until after the skating rink is taken out of
service, demolished, and any contaminated soils removed.
Sediment Removal
The sediment remedial action involves the dredging and/or
excavation of approximately 1,200 cubic yards of impacted sediments
and wetlands soils at the confluence of Loughberry Creek and
Village Brook, near the outfall .of the concrete box culvert, near
the outfall of the brick sewer, and at four locations on the NMPC
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property. Confirmation sampling to assure attainment of cleanup
levels will be conducted. Contaminated sediments will be
transported off site for treatment and proper disposal.
Appropriate actions will be taken to restore the wetlands.
Remediation of the Sewer Migration Pathway
The purpose of this action is to eliminate the impacts to the
wetland surface water or Spring Run from the migration of NMPC
property contaminants through the underground brick sewer.
Stormwater flow through the brick sewer and Village Brook upstream
of the NMPC property will be diverted to the twin box culvert storm
sewer, so no stormwater will flow through the NMPC property. At
the southeast corner of the NMPC property, the brick sewer will -be
disconnected and a water/DNAPL collection sump will be constructed
to prevent any ground water which infiltrated the sewer from
leaving the property. The downstream section of the sewer from the
southeast corner of the NMPC property to the brick sewer outfall,
near Interstate 87, will be cleaned. Infiltration spots along the
downstream section of the brick sewer, from the point at which it
is disconnected to the concrete box culvert, will be sealed to
prevent infiltration of impacted ground water into the sewer. The
break in the brick sewer near the confluence of Loughberry Creek
and Village Brook will be .repaired. The materials generated from
cleaning the brick sewer will be disposed of off site properly.
Control of releases from the brick sewer described above will stop
the potential for continuing impacts to sediments in Spring Run.
Institutional Controls and Monitoring
Because contaminants will remain on the NMPC property after
implementation of the remedy, deed restrictions to prevent future
residential use of the property and notifications to utility
companies will be required to limit exposure to the subsurface
contaminants that remain on the NMPC property. The implementation
of deed restrictions will be the responsibility of NMPC. NMPC has
indicated to EPA that it will maintain future ownership of the NMPC
property, thereby further restricting the potential for future
residential development of the property. EPA recommends the
imposition of a notice in the property records pertaining to the
skating rink property to inform interested parties of the potential
presence of contamination underneath the skating rink. This notice
should remain in the property records until after the skating rink
is taken out of service, demolished, and any contaminated soils
removed. No deed restrictions are necessary on the Spring Run
wetland because the sediment and soil contamination above the
cleanup levels will be removed.
A monitoring program will be implemented to assess the
effectiveness of the remedial action. Samples for analysis will be
obtained from monitoring wells, the Old Red Spring, the diverted
32
-------
flows from the upgradient interceptor trench, and the discharge
from the on-site water treatment system as required by the Saratoga
County Sewer discharge permit.
Cleanup Goals
EPA has established soil cleanup levels for the skating rink area
based on a 10"6 (1 in one million) excess cancer risk to residential
receptors and NYSDEC TAGM HWR-4046, a "to be considered"
requirement, for the protection of ground water. The soil cleanup
levels for the skating rink area, which apply to both surface and
subsurface soils, are presented in Table 3.
Sediment cleanup levels are based on background concentrations.
The cleanup level for the sediments and wetland soils in Spring Run
is 22 parts per million (ppm) total PAHs.
Remediation of the NMPC property ground water is considered to be
technically impracticable. Therefore, issuance of this ROD waives
the federal and state drinking water standards and state ground
water quality standards pursuant to Section 121(d)(4)(C) of CERCLA,
42 U.S.C. §9621(d)(4)(C), and §300.430(f) (1) (ii) (C) (3) of the NCP
which authorizes EPA to waive applicable or relevant and
appropriate requirements for ground water cleanup of the NMPC
shallow aquifer based on technical impracticability, from an
engineering perspective. EPA's memorandum Guidance for Evaluating
the Technical Impracticability of Ground water Remediation (OSWER
Directive 9234.2-25, September 1993) recognizes that there are
circumstances under which ground water restoration may be
technically impracticable. There are technical limitations which
make it impracticable to recover all the DNAPL from the property.
In order to remove all the DNAPL, approximately 7 acres of
contaminated aquifer materials, including soil, silt, peat, and
sand, residing above the subsurface clay layer (which begins
approximately 20 feet below the surface), would need to be
excavated for off-site disposal. In addition, all NMPC's operating
facilities would have to be demolished, to gain access to the
contamination beneath them. Since it is technically impracticable
to excavate this large an area, some DNAPL and PAH impacted soil
will remain on the NMPC property. Because the DNAPL and residual
PAHs contribute to dissolved phase ground water contamination,
restoration of ground water on the NMPC property to ground water
cleanup levels has been determined to be technically impracticable.
Recognizing that ground water restoration in the shallow aquifer
beneath the NMPC property is technically impracticable, the goal of
this remedial action is to establish hydraulic control of the NMPC
contaminated ground water, specifically to prevent ground water and
DNAPL from flowing off site by using physical and hydraulic
barriers.
Compliance with Federal and New York State Drinking Water Standards
and New York State Ground Water Quality Standards for the ground
33
-------
water underneath the skating rink area will be required following
implementation of the selected remedial alternative. These
drinking water standards will be achieved over time through natural
attenuation. The remedy will require dewatering the soil in areas
to be excavated; removal of all contaminated soils; treatment of
this contaminated ground water; and prevention of the migration of
contaminated ground water from the NMPC property to the skating
rink area by the erection of subsurface barriers on the NMPC
property. Upon completion of these actions, all potential sources
of ground water contamination in the skating rink area will be
eliminated, thus, allowing for natural attenuation of the ground
water contamination. The remedy will require monitoring of the
ground water to measure improvement in the ground water quality.
If improvement in ground water quality is not observed upon review
of the annual ground water monitoring results, a program to
evaluate contingency alternatives for ground water remediation in
the skating rink area will be initiated and implemented in a timely
manner.
STATUTORY DETERMINATIONS
As previously noted, CERCLA §121(b)(l), 42 U.S.C. §9621(b)(l),
mandates that a remedial action must be protective of human health
and the environment, cost effective, and utilize permanent
solutions and alternative treatment .technologies or resource
recovery technologies to the maximum extent practicable. Section
121(b)(1) also establishes a preference for remedial actions which
employ treatment to permanently and significantly .reduce the
volume, toxicity, or mobility of the hazardous substances,
pollutants, or contaminants at a site. CERCLA §121(d), 42 U.S.C.
§9621(d), further specifies that a remedial action must attain a
degree of cleanup that satisfies ARARs under federal and state
laws, unless a waiver can be justified pursuant to CERCLA
§121(d)(4), 42 U.S.C. §9621(d)(4).
For the reasons discussed below, EPA has determined that the
selected remedy meets the requirements of CERCLA and provides the
best balance of trade-offs among alternatives with respect to the
evaluation criteria.
Protection of Human Health and the Environment
The selected remedy is protective of human health and the
environment. The limited source area removal action will address
the most contaminated subsurface zones. Contamination in the NMPC
property ground water will be eliminated through effective
containment, dewatering, and treatment of this ground water. All
potential sources of ground water contamination in the vicinity of
the skating rink will be eliminated, thus, allowing for natural
attenuation of this ground water contamination. The potential for
off site migration of contaminants through the sewer line will be
eliminated. The impacted sediments in Spring Run will be removed
34
-------
for off site disposal and treatment using methods to minimize
short-term impacts to ecological receptors.
Compliance with ARARs
Action specific ARARs for the selected remedy include the New York
State Solid Waste Management Regulations (6 NYCRR Part 360 and
364), the Federal Resource Conservation and Recovery Act and the
New York State Hazardous Waste Management Regulations
(Identification and Listing of Hazardous Waste - 40 CFR Part 261,
Standards for Hazardous Waste Generators - 40 CFR Part 262,
Standards for Hazardous Waste Transporters 40 CFR Part 263,
Standards for Hazardous Waste Facilities - 40 CFR Parts 264, and
Land Disposal Restrictions - 40 CFR Part 268) . The use of
contaminated soil in the cold mix asphalt process will be
accomplished in compliance with the Beneficial Use Determinat'ion
Program of the New York State Solid Waste Management Regulations.
Implementation of institutional controls which will seek to
restrict future usage and ground water usage of the NMPC property
will be conducted in accordance with the Saratoga Springs Master
Plan and the Federal Resource Conservation and Recovery Act (Land
Disposal Facility Notice in Deed - 40 CFR §264.116-264.119(b)(1)).
Department of Transportation (DOT) Rules for Hazardous Materials
Transport (49 CFR Parts 107, 171-177) and Occupational Health and
Safety Act (29 U.S.C. §651-678 and 40 CFR §300.38) apply.
The discharge of water and recovered ground water generated during
remediation will be regulated by the Federal Clean Water Act
regulations for discharges to POTW (40 CFR Part 403) , and the City
of Saratoga Sewer Use Ordinance. The substantive requirements of
a sewer discharge permit from the Saratoga County Sewer District
may be required for discharge of water to the local wastewater
treatment plant. During soil and sediment excavation and operation
of the on-site water treatment facility, the Federal Air
Regulations (40 CFR Part 50) and the New York State Air Pollution
Control Regulations (6 NYCRR Parts 200, 211, 212, 219, 257 and Air
Guide-1) apply.
Location-specific ARARs for the selected remedy include the
National Historic Preservation Act and the New York State Historic
Preservation Act. Sediment removal actions will be conducted in
compliance with the Federal Clean Water Act, the Federal Executive
Order 11990 for the Protection of Wetlands, Management Practices
(Federal Register/Volume 51, No. 219/Part 330.6), Federal Fish and
Wildlife Coordination Act (16 USC 661), New York State Water
Quality Classification, and the New York State Freshwater Wetlands
Act (6 NYCRR Parts 662-665) .
Chemical-specific ARARs for the ground water at the skating rink
area include the Federal Safe Drinking Water Act Maximum
Contaminant Levels (MCLs) (40 CFR Part 141.11-141.16 and Part
141.60-141.63), the New York Public Water Supply Regulations (NYCRR
35
-------
Title 10, Part 5-1), and New York State Water Classifications and
Quality Standards for Class GA Ground Water (NYCRR, Title 6, Parts
701-703). For surface water, Chemical-specific ARARs include the
New York State Surface Water Quality Standards (NYCRR, Title 10,
Part 5-1 and NYCRR, Title 6, Parts 701-703). The remediation of
the NMPC property ground water in the shallow aquifer is considered
to be technically impracticable. Therefore, issuance of this ROD
waives the federal and state drinking water standards and state
ground water quality standards pursuant to Section 121(d)(4)(C) of
CERCLA, 42 U.S.C. §9621(d)(4)(C), and §300.430(f)(1)(ii)(C)(3) of
the NCP which authorizes EPA to waive applicable or relevant and
appropriate requirements for ground water cleanup of the NMPC
shallow aquifer based on technical impracticability, from an
engineering perspective. There are technical limitations which
make it impracticable to recover all the DNAPL from the NMPC
property. In order to remove all the DNAPL, approximately 7 acres
of contaminated aquifer materials, including soil, silt, peat, and
sand, residing above the subsurface clay layer (which begins
approximately 20 feet below the surface), would need to be
excavated for off-site disposal. In addition, all NMPC's operating
facilities would have to be demolished, to gain access to the
contamination beneath them. Since it is technically impracticable
to excavate this large an area, some DNAPL and PAH impacted soil
will remain on the NMPC property. Because the DNAPL and residual
PAHs contribute to dissolved phase ground water contamination,
restoration of ground water on the NMPC property to ground water
cleanup levels has been determined to be technically impracticable.
Recognizing that ground water restoration in the shallow aquifer
beneath the NMPC property is technically impracticable, the goal of
this action is to establish hydraulic control of the NMPC
contaminated ground water, specifically to prevent ground water and
DNAPL from flowing off the NMPC property by using physical and
hydraulic barriers. This action complies with Federal and State
requirements that are applicable or relevant and appropriate to
this remedial action, where possible.
Cost-Effectiveness
The selected remedy is cost-effective because it has been
demonstrated to provide overall effectiveness proportional to its
costs. The selected remedy is technically and administratively
implementable and represents the lowest cost of the alternatives
considered. The present worth of the selected alternative is
$15,300,000.
Utilization of Permanent Solutions and Alternative Treatment
Technologies to the Maximum Extent Practicable
The selected remedy addresses all of the media of concern and
utilizes permanent solutions and treatment technologies to the
maximum extent practicable. In addition, the selected remedy
36
-------
provides the best balance of trade-offs among the alternatives with
respect to the evaluation criteria.
The selected remedy will reduce the toxicity and volume of source
areas and highly contaminated soils at the NMPC property by their
excavation and off-site treatment and disposal, and the off-site
treatment and disposal of sediments with total PAHs greater than 22
ppm. This will significantly reduce the toxicity, mobility and
volume of the contaminants at the Site, and offers a permanent
solution to the risks posed by these wastes. In addition, the
selected remedy will eliminate ground water contamination.
Contamination in the NMPC property ground water will be eliminated
through effective containment, dewatering, and treatment of this
ground water. All potential sources'of ground water contamination
in the vicinity of the skating rink will be excavated and disposed
of off site, allowing for natural attenuation of this ground water
contamination. This approach is - the most reliable and
implementable solution to management and treatment of ground water,
given the heterogeneity of the shallow ground water aquifer and the
technical impracticability of remediating an aquifer impacted by
DNAPL.
Preference for Treatment as a Principal Element
In keeping with the statutory preference for treatment as a
principal element of the remedy, the remedy provides for the
treatment of all hazardous soils, contaminated ground water and
sediments at the Site. By treating the hazardous portion of the
contaminated soils, rendering them nonhazardous for co-burning in
a utility boiler; and, by excavating contaminated sediments for
off-site treatment and disposal, which pose the primary threat at
the Site, all exposure pathways will be eliminated. Contaminated
ground water will be treated and will also satisfy the preference
for treatment as a principal element.
DOCUMENTATION OF SIGNIFICANT CHANGES
There are no significant changes from the preferred alternative
presented in the Proposed Plan. However, the Proposed Plan did not
specify the time frame for removing contaminated soils under the
skating rink. The ROD specifies that contaminated soils under the
skating rink will be removed when the skating rink is taken out of
service and demolished. In addition, EPA's recommendation to
impose a notice on the property records pertaining to the property
of the skating rink to inform interested parties of the potential
presence of contamination, and that such notice should remain in
the property records until after the skating rink is taken out of
service, demolished, and any contaminated soils removed was not
presented in the Proposed Plan.
37
-------
APPENDIX I
FIGURES
Figure 1 - Site Layout Map
Figure 2 - Total PAHs and Visual Hydrocarbons in Borings and Test
Pits
Figure 3 - Selected Remedy (Alternative 7)
-------
u
199? SmPllMC:
*»-< nsi m uKAnoM
u-i «M uXAto,
Mi-1 MOWtOM; «CU LflCADOM
1993 SAUPUNC:
NMC 10CAWI
0M-U Kytotf UKATO*
M-3f MOWKMMC MU lOCAHON
NOTE: CHEMICAL DATA IS mq/kg OR ppm.
MO J5 Ji J5 0 »0 1<0
APPROXIMATE SCALE IN FEET
NIAGARA MOHAWK POWER CORPORATION
3-03:2-999
FIGURE I
TOTAL PAH AND VISUAL HYDROCARBONS
IN BORINGS AND TEST PITS
tJTEFF
£2-
SARATOGA SPRINGS. WCW Vofik
S3S
. M, i/i./w r
-------
PROPERTY UNE
EXISTING STRUCTURE
FORMER STRUCTURE
CHAIN LINK FENCE
DIRECTION OF FLOW
APPROXIMATE WETLAND AREA
/FORMER, / FORMERS
I HOLDER ! I HOLDER ]
\ '5 J \ *6 /'
b"'
ROUNDHOUSE
(FORMER HOLDER |2)
STORAGE BUILDING
ER SUB!
BUILDING
NMPC
T MAINTENANCE
_J I GARAGE
.^
/ (FORMER SUBSTATION
/ . BUILDING)
-X-5
FORMER HOLDER 13 - (
TOR I
TA/I/WATER SEPARA
8'»20'BOX CULVERT
(LOCATION & DIMENSIONS APPROX.)
SPRING RUN DETAIL
NUPC PROPERTY
(SOUTHEAST CORNER)
BRICK^SEWER
SEE 'SPRING RUN DETAIL'
FOR CONTINUATION
TO THE SOUTHEAST
FIGURE 1
SITE LAYOUT MAP
NIAGARA MOHAWK POWER CORPORATION
SARATOGA SPRINGS, NEW YORK
-------
V
. PROPOSED
GROUNDWATER DIVERSION '
PUMPING STATION
WAI!ELEATM£Ar7lLDG.
PROPOSED
SEWER CUT-OFF,
AND DIVERSION
MANHOLE
EXCELSIOR AVE.
SKATING RINK MUNICIPAL
SPRING RUN DETAIL
NMPC PROPERTY
300
EXTENT OF SEWER
TO BE SUP LINED
300 600
GRAPHIC SCALE IN FEET
-------
DSPLB05
LEGEND.
SOURCE REMOVAL AREA
SURFACE SOIL REMOVAL AREA
SUBSURFACE BARRIER AND TOE DRAIN
GROUNDWATER INTERCEPTOR DRAIN
CLEAN SEWER AND SUP LINING
CLEAN SEWER ""
ASPHALT CAP
APPROXIMATE WETLAND AREA
MUNICIPAL SKATING RINK
SEE 'SPRING RUN DETAIL'
FOR CONTINUATION
TO THE SOUTHEAST
-------
APPENDIX II
TABLES
Table 1 - Primary Constituents of Concern Detected in Soils on
Niagara Mohawk Property
Table 2 - Primary Constituents of Concern Detected in
Groundwater
Table 3 - Primary Constituents of Concern Detected in Soils by
the Skating Rink Area and Soil Cleanup Levels
Table 4 - Primary Constituents of Concern Detected in Sediments
in Spring Run Wetlands
Table 5-1 - Risk Assessment: Contaminants of Concern
Table 5-2 - Risk Assessment: Summary of Exposure Pathways
Table 5-3 - Risk Assessment: Non-carcinogenic and Carcinogenic
Toxicity Values
Table 5-4 - Risk Assessment: Non-carcinogenic Risk Estimates
Table 5-5 - Risk Assessment: Carcinogenic Risk Estimates
Table 5-6 - Risk Assessment: Cumulative Carcinogenic Risk
Estimates
-------
PRIMARY CONSTITUENTS OF CONCERN DETECTED IN SOILS ON NIAGARA MOHAWK PROPERTY
NIAGARA MOHAWK SITE, SARATOGA SPRINGS, NEW YORK
Constituent
Benzene
Ethylbenzene
Toluene
Xylenes
Acenaphthene
Acenaphthylene
Anthracene
Benzo(a)anthracene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Chrysene
Dibenzo(a,h)anthracene
Dibenzofuran
Fluoranthene
Fluorene
lndeno(1 ,2,3-cd)pyrene
2-Melhylnaphthalene
Naphthalene
Phenanthrene
Pyrene
Antimony
Lead
Mercury
Soil Standard
(ppm)
0.06
5.5
1.5
1.2
50
41
50
0.224 or
MDL
1.1
1.1
0.061 or
MDL
0.4
0.014 or
MDL
6.2
50
50
3.2
36.4
13
50
50
28
400
0.1
Surface Soils
Minimum
Concentration
Detected (ppm)
< 0.005
< 0.005
< 0.005
< 0.005
<0.35
<0.35
<0.35
<0.34
<0.35
<0.35
<0.35
<0.40
<0.34
<0.34
<0.35
<0.34
<0.35
<0.35
<0.35
<0.35
<0.35
<3.3
7.6
<0.08
Maximum
Concentration
Detected (ppm)
<0.007 J
< 0.007 J
< 0.007 J
< 0.007 J
1.7
1:1 J
30
31
41
41
60
35
6.9
0.37 J
40
1.0 J
38
0.87 J
1.5
11
57
18.0 J
999
5.0
No. of
Samples
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
16
No. of
Exceedances
0
0
0
0
0
0
0
12
8
8
12
11
8
0
0
0
8
0
0
0
1
0
2
11
Subsurface Soils & Test Pits
Minimum
Concentration
Detected (ppm)
< 0.006
< 0.006
< 0.006
< 0.006
<0.40
<0.40
<0.40
<0.40
<0.39 J
<0.39 J
<0.40
<0.41
<0.39J
<0.40
<0.40
<0.40
<0.40
<0.40
<0.40 J
<0.40
<0.40
<3.1
1.7
<0.08
Maximum
Concentration
Detected (ppm)
1,000
330
1,700
1,200
740
3,300
1,600
920
320
160
570.0 J
910
24
240.0 J
1,600
1,900
94
4,600
6,600
6,200
3,500
4.3
502.0 J
3.6
No. of
Samples
48
48
48
47
49
48
48
47
49
45
48
49
49
48
48
48
49
49
49
47
49
44
42
48
No. of
Exceedances
9
14
3
11
14
4
11
38
24
20
33
35
21
8
9
11
24
16
19
14
13
0
2
12
KEY:
MDL method detection limit
ppm parts per million (mg/kg)
J laboratory estimated value
Note: Remedial Action for the NMPC Property soils is to remove source materials or areas of concentrated coal tar. as described in Source and Surface Soil Removal section of this ROD.
-------
TABLE 2
PRIMARY CONSTITUENTS OF CONCERN DETECTED IN GROUNDWATER
NIAGARA MOHAWK SITE, SARATOGA SPRINGS, NEW YORK
Constituent
Benzene
Toluene
Ethylbenzene
Xylenes
1,1-Dichloroethene
1,1-Dichloroethane
Chloroform
Methylene Chloride
*
Naphthalene
2-Melhylnaphthalene
Acenaphthylene
Dibenzofuran
Acenaphthene
Fluorene
Phenanthrene
Anthracene
Fluoranthene
Pyrene
Standard
(ppb)
0.7a
5a,c
5a,c
5a.c
5a.c
5a.c
7a
. 5a'c
10b
50C
50C
20b
20b
50b'c
50b'c
50b'c
50b'c
50b'c
NMPC Property
Groundwater
Minimum
Concentration
Detected (ppb)
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<2.0
<10
<10
<10
<10
<10
<10
<10
<10
<10
<10
Maximum
Concentration
Detected (ppb)
14,000
5,700
3,500
3,700
< 1,000
<1,000
3.0 J
52.0 J
8,200
1, 100.0 J
360
13
30.0 J
90.0 J
110
500.0 J
8.0 J
8.0 J
No. of
Samples
I 19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
19
No. of
Exceedances
7
6
5
7
0
0
0
1
8
8
2
1
8
8
8
1
0
0
Skating Rink Area
Groundwater
Minimum
Concentration
Detected (ppb)
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<1.0
<2.0
<10.0
<10.0
<10.0
<10.0
<10.0
<10.0
<10.0
<10.0
<10.0
<10.0
Maximum
Concentration
Detected (ppb)
91 .OJ
1.0 J
1.0
1.0 J
<10
0.9 J
10
<10
19.0
17.0
<10.0
9.0 J
87.0
33.0
71.0
9.0 J
16.0
10.0
No. of
Samples
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
20
No. of
Exceedances
4
0
0
0
0
0
2
0
1
0
0
0
2
0
1
0
0
0
KEY:
8 NYSDEC Groundwater Quality Standards
b NYSDEC Groundwater Quality Guidance Value
c NYSDOH MCLs for Public Drinking Water Sources
d USEPA MCLs for Drinking Water
9 USEPA Lifetime Advisories for Drinking Water
(ppb) parts per billion (iig/\)
J laboratory estimated value
Page 1 of 3
-------
TABLE 2 (Continued)
PRIMARY CONSTITUENTS OF CONCERN DETECTED IN GROUNDWATER
NIAGARA MOHAWK SITE, SARATOGA SPRINGS, NEW YORK
Constituent
Phenol
Benzyl Alcohol
2-Methylphenol
4-Methylphenol
2,4-Dimethylphenol
Benzole Acid
2,4-Oinitrophenol
Dimethylphthalate
Di-n-butylpthalate
Bis(2-ethylhexyl)pthalate
Di-n-octylpthalate
Pentachlorophenol
Carbazole
Methoxychlor
Heptachlor
Standard
(PPb)
la
50C
1a
1a
1a
50°
1a
50b'c
50a'c
50a'c
50b'c
.ja.d
50C
35a
0.4"
NMPC Property
Groundwater
Minimum
Concentration
Detected (ppb)
<10
<10
<10
<10
<10
<50
<25
<10
<10
<10
<10
<10
30
<0.5
<0.05
Maximum
Concentration
Detected (ppb)
31
<200
8.0 J
15
<500
< 1,000
< 1,200
<500
1.0 J
26
<500
1,OJ
30
<0.6
<0.06
No. of
Samples
19
16
19
19
19
16
19
19
19
19
19
19
1
17
17
No. of
Exceedances
2
0
2
2
3
0
0
0
0
0
0
0
0
0
0
Skating Rink Area
Groundwater
Minimum
Concentration
Detected (ppb)
<10.0
<10.0
<10.0
<10.0
<10.0
<50.0
<50.0
<10.0
<10.0
<10.0
<10.0
<50.0
<0.52
< 0.052
Maximum
Concentration
Detected (ppb)
25.0
3.0 J
<10.0
<10.0
<10.0
4.0 J
<50.0
2.0 J
<10.0
<10.0
19.0
<50.0
<0.60
<0.06
No. of
Samples
20
20
20
20
20
20
20
20
20
20
20
20
15
15
No. of
Exceedances
3
0
0
0
0
0
0
0
0
0
0
0
0
0
KEY:
a NYSDEC Groundwater Quality Standards
b NYSDEC Groundwater Quality Guidance Value
c NYSDOH MCLs for Public Drinking Water Sources
d USEPA MCLs for Drinking Water
e USEPA Lifetime Advisories for Drinking Water
(ppb) parts per billion (iig/\)
J laboratory estimated value
Page 2 of 3
-------
TABLE 2 (Uontinued)
PRIMARY CONSTITUENTS OF CONCERN DETECTED IN GROUNDWATER
NIAGARA MOHAWK SITE, SARATOGA SPRINGS, NEW YORK
Constituent
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Selenium
Silver
Sodium
Thallium
Zinc
Cyanide
Standard
(Ppb)
3d,e
25a
1,000a
3b
5c.d,e
50a
200a
300a
15d
35,000b
300a
2a,c,d,e
100d'e
10a,c
50a'c
20,000a
0.4e
300a
100a
NMPC Property
. Groundwater
Minimum
Concentration
Detected (ppb)
<20
<2.0
<50
<1.0
<3.0
<5.0
<3.0
<35
<2.0
15,100
19.0
<0.2
. <5.0
<1.0
<3.0
15,400
<2.0
21.2
<5.0J
Maximum
Concentration
Detected (ppb)
' 40.0 J
9.6 J
3,200.0 J
<3.0
7.5
113
<6.0
11,300
4.3 J
99,800
858
<0.2
28.0 J
2.4 J
<7.0
672,000
<15.0J .
35.9
195.0 J
No. of
Samples
17
17
17
17
17
17
17
17
15
17
17
17
17
17
17
17
17
11
17
No. of
Exceedances
0
0
4
0
1
1
0
13
0
2
9
0
0
0
0
15
0
0
1
Skating Rink Area
Groundwater
Minimum
Concentration
Detected (ppb)
,<20.0
<2.0
<50.0
<1.0
<3.0
<5.0
<3.0
<35.0
<2.0
12,100
<9.0
<0.20
<5.0
<1.0
<3.0
40,400
<2.0
80.4 J
<5.0
Maximum
Concentration
Detected (ppb)
<30.0J
<3.0
4,260
<3.0
17.5
62.9 J
29.6 J
16,400
<10.0
79,900
639
<0.20
137
<3.0
<7.0
614,000
<15.0
117
<10.0
No. of
Samples
16
16
16
16
16
16
16
16
14
16
16
16
16
16
16
16
16
6
16
No. of
Exceedances
0
0
4
0
1
2
0
14
0
3
7
0
1
0
0
16
0
0
0
KEY:
a NYSDEC Groundwater Quality Standards
b NYSDEC Groundwater Quality Guidance Value
0 NYSDOH MCLs for Public Drinking Water Sources
d USEPA MCLs for Drinking Water
8 USEPA Lifetime Advisories for Drinking Water
(ppb) parts per billion (/tg/l)
J laboratory estimated value
Page 3 of 3
-------
TABLE 3
PRIMARY CONSTITUENTS OF CONCERN DETECTED IN SOILS BY THE SKATING RINK AREA
NIAGARA MOHAWK SITE, SARATOGA SPRINGS, NEW YORK
Constituent
Benzene
Ethylbenzene
Toluene
Xylenes
Acenaphthene
Acenaphthylene
Anthracene
Benzo(a)anthracene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Chrysene
Dibenzo(a,h)anthracene
Dibenzofuran
Ruoranthene
Fluorene
lndeno(1 ,2,3-cd)pyrene
2-Methylnaphthalene
Naphthalene
Phenanthrene
Pyrene
Antimony
Lead
Mercury
Cleanup
Level
(ppm)
0.06
5.5
1.5
, 1.2
50
41
50
0.224 or
MDL
1.1
1.1
0.061 or
MDL
0.4
0.014 or
MDL
6.2
50
50
3.2
36.4
13
50
50
28
400
0.1
Minimum
Concentration
Detected
(ppm)
< 0.005 J
< 0.005 J
< 0.005 J
< 0.005 J
<0.36
<0.37
<0.37
<0.37
<0.37
<0.37
<0.37
<0.37
<0.36
<0.36
<0.37
<0.36
<0.37
<0.37
<0.36
<0.37
<0.37
<4.8J
1.3
<0.10
Maximum
Concentration
Detected
(ppm)
0.25
0.63
0.01
0.76
580.0 J
35.0 J
510.0 J
340.0 J
290.0 J
180.0 J
340.0 J
320.0 J
32.0 J
300.0 J
870.0 J
400.0 J
180.0J
370.0 J
960.0 J
1, 400.0 J
890.0 J
<6.6J
329
2.2
No. of
Samples .
15
15
15
15
15
15
15
15
15
15
15
15
15
15
.15
15
15
15
15
15
15
9
13
15
No. of
Exceedances
1
0
0
0
2
0
2
3
2
2
3
3
1
2
2
2
2
2
2
2
2
0
0
3
KEY;
MDL
ppm
J
method detection limit
parts per million (mg/kg)
laboratory estimated value
-------
TABLE 4
PRIMARY CONSTITUENTS OF CONCERN DETECTED IN SEDIMENTS IN SPRING RUN WETLANDS
NIAGARA MOHAWK SITE, SARATOGA SPRINGS, NEW YORK
Constituent
Benzene
Ethylbenzene
Toluene
Xylenes
Acenaphthene
Acenaphthylene
Anthracene
Benzo(a)anthracene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Chrysene
Dibenzo(a,h)anthracene
Dibenzofuran
Ruoranthene
Fluorene
lndeno(1,2,3-cd)pyrene
2-Methylnaphthalene
Naphthalene
Phenanthrene
Pyrene
Antimony
Lead
Mercury
Minimum
Concentration
Detected (ppm)
< 0.006
< 0.006
< 0.006
< 0.006
0.20
0.06
<0.40
<0.80
. 0.42
0.68
0.62
0.093 J
0.30
0.10
0.13 J
<0.30
<0.44
<0.05
<0.05
0.45
0.40
<0.71
17.4
<0.06
Maximum
Concentration
Detected (ppm)
< 0.081
0.006 J
0.22 J
<0.081
14.0 J
37
39
69
55
38
67.
84
5.2 J
0.54 J
130
6.9 J
23
4.0 J
0.40
88
190
<20.8 J
352.0 J
4.3
No. of
Samples
22
22
22
22
33
33
33
33
33
33
33
33
33
22
33
33
33
22
33
33
33
26
21
27
KEY:
ppm
J
parts per million (mg/kg)
laboratory estimated value
Note: The cleanup level for the sediments and wetland soils in Spring Run is 22 parts per million (ppm) total PAHs.
-------
TABLE 5-1 NIAGARA MOHAWK SITE: CONTAMINANTS OF CONCERN
Vnlallta
Acclnnc
Bcnr.cnc
2-Bulnn(mc
Cnrlmn DisulHdc
Cmlmn Tclrncliloridc
CllldHlfollll
I.l-Diclilnroelhnnc
1,2-Oidilnroellinnc
Irans-U-
Uiclilimipropcnc
Ktliyllicnrciic
Mclhytcnc Chloride
Slyrcnc
Tclrnclilorocthylcne
Toluene
I.l.l-Triclildnicllinnc
Tricliliiroclhylcnc
Total X'ylcncs
(I'riiiind
Wnlcr
X
X
X
X
X
X
X
.Surfncc
Soil
X
X
.SuliMirfncc
Snll/Onslle
Scdlmcnls
X
X
X
X
X
X
X
Drnlnnfjc
System
Scillmcnls
X
.X
X
X
X
l)own)>nullctit
Sediment*
X
X
X
X
X
Onsllc
Surfncc
Wnlcr
X
X
X
X
X
DrnliinRc
System
Siitfncc
Wntcr
X
X
, X
X
X
Drnvngrmllcnt
.Surfncc
Water
X
X
X
X
X
Indoor
Mr
X
X
X
X
X
X
X
X
X
X
Outdoor
Air
X
X
X
X
X
X
X
X
X
X
X
X
X
X
1 of 5
-------
TABLE 5-1 (CONTINUED)
m.p-xylcnc
o-xylene
UNA*
Accnaptilhcue
Acenophthylene
Anllitnccnc
Itcii7.o(n)nnllunccnc
Ilcn7.n(n)pyrcnc
Rcti7.o(b)nuoranlhcnc
Bcnzo(g.li.i)pcrylene
Ilcn7.(i(k)niiinnnllicnc
Rciwyhiilylphthnlalc
Bciuoic Acid
His(2-
cthylhexyljphthalnte
Cmlwolc
Chryxcnc
Dibcnr.ofurnn
I)il'cii7(n.li)nnlliinrcnc
Ground
\Vnlcr
X
X
X
X
Surface
.Soil
X
X
X
X
X
X
X
X
X
X
X
Subsurface
Stilt/Onslle
Sediments
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Drninnjjc
System
Sediments
. i
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Dunn^rndlciit
Sediments
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Onsllc
Surface
Wnlcr
X
X
X
X
X
X
X
X
X
X
X
X
X
Drnlttngc
System
Surface
Wnlcr
X
X
X
X
X
X
X
X
X
X
X
X
X
Downgrndlcnl
Surface
\Vntcr
X
X
X
X
X
Indoor
Air
X
X
Outdoor
Air
X
X
X
X
2 of 5
-------
TABLE 5-1 (CONTINUED)
Di-n-hnlylphlhalatc
Di-n-nclylphlhnlntc
Hwitnntlicnc
Himtcnc
In Jcm>( 1,2,3-
cdjpytcnc
2 Mctliylna|i|illinlcue
4-Mclhylphcnol
Nnplitlinlcnc
Pcnlnchlnroplicuol
I'licnnnllitcnc
Phenol
I'yrcuc
Pesticides
Aldfiii
gnininn-Cltlnrdaitc
Aroclor-1254
4.4-DDD
(Jrouud
Wnlcr
X
X
X
X
X
X
X
Surface
.Soil
X
X
X
X
X
X
X
X
X
X
Subsurface
Soll/Onsltc
Scdlincnd
X
X
X
X
X
X
X
X
X
Drnlnngc
System
Sediments
X
X
X
X
X
X
X
X
X
X
X
X
X
l)fmn|>rndlcnt
Scdlmcnl*
X
X
X
X
X
X
X
X
X
X
X
Onslle
Surface
Wnlcr
X
X
X
X
X
X
X
X
X
X
Prnllingo
Sy.ilcm
Stirfncc
Wnlcr
X
X
X
X
X
X
X
X
X
X
Downgrndlcnt
Surface
Wnlcr
X
X
X
Indmir
Air
Outdoor
Air
X
X
X
X
3 of 5
-------
TABLE 5-1 (CONTINUED)
4,4'-DI.)H
4.4'-DI)T
delta-Ill 1C
DiclJrin
liiHlosulfnn II
Rndosulfan Sulfotc
r.iulriiv.
lindthi Kctotic
gannna-HHC (limlnnc)
Hcptnchlor
llrptnclilor c|xixitlc
InntRnnlcs
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
(Jnmnd
Wnlcr
X
X
X
X
X
Surfnco
Soil
X
X
X
X
X
X
X
X
Snlism fncc
Soll/Oii.sllo
.Sediments
X
X
X
X
X
X
X
X
X
X
X
Drnlnn^c
System
Sediments
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Dtiwttfifmlicnt
.Sediments
X
X
X
X
X
X
X
X
X
X
X
X
X
Onsilc
Snrfncc
VVMcr
X
X
X
X
X
X
X
X
X
l)rnhmi>c
.System
Siirtncc
Wnlcr
X
X
X
X
X
X
X
X
X
X
Downnrmllcnl
Surface
Wnlcr
X
X
X
X
X
X
X
Indoor
Air
Outdoor
Air
4 of 5
-------
TABLE 5-1 (CONTINUED)
Chromium
Cobalt
Ci*|<|icr
Cymmic
lion
Lead
Maiif-ancsc
Mcicmy
Nickel
Selenium
Silver
Thallium
Vanadium
Zinc
(Jronml
Water
X
X
X
X
X
X
X
X
X
X
X
Surface
Soil
X
X
X
X
X
X
X
X
X
X
X
SnliMirfncc
Soll/Onsllc
Sediment*
X
X
X
X
X
X
X
X
X
X
X
X
Drnlnngo
System
Sediment*
X
X
X
X
X
X
X
X
X
X
X
X
X
Dowrmrmllcnl
Sediments
X
X
X
X
X
X
X
X
X
X
X
X
X
Onsltc
Surfncc
Wnlcr
X
X
X
X
X
X
X
X
X
X
X
Drnlnngc
System
Surfncc
Water
X
X
X
X
X
X
X
X
X
X
X
Uowngrmllcnt
Surfncc
Water
X
X
X
X
X
X
X
X
X
X
Indoor
Air
Outdoor
Air
5 of 5
-------
Pathway
hfrairtii Wife? ] '& S',^'\V
Inprsliiin «f (irmiml Water
Inhalation of (iround Water
Contaminants During
Showers
Inhalation of Contaminants
that Vnlnlilirr from (iround
Water and Seep into
HascmcnH
Dermal Contact with (.Iround
Water
Surface' SniU, °{J* ," ^v\£T £ N
Incidental Ingcslion of Onsite
Surface Soils
Dermal ('mil. id with Onsile
Surface Soils'*
Time-Frame Evaluated
Receptor Present Future
*...:. ?!&?.>J.!y - v .< ;>. >. . >r?»5^ £'£. *. >v^.?5. !.'. .^. .^ ^ > > *...-. c. .£ '.^ ''.
Hrsidrnl No Yes
Resident No Yes
Resident
Employee
Resident No No
,.., \£. ^ - .. \0 .s ,\<>-\;, ^\ - ; * ^" ""-"";-. > " " " " v""" " ", ^>
Employcc Yes Yes
Resident No Yes
Employee Yes Yes
Resident No Yes
Dcj^pf Assessment
Quant. Qu.il. Rationale for Selection or Exclusion
& 5 K ^f ^ ' ^ '' ^"f l\ V 0 ^ '""*& "rf " - ^ 4 $?£%
X X Adjacent areas nir wuied rrsidcnlial.
Althougli resiilcnls currently rely on
municipal water, ground water is
potable. Public/inivnte/cimuncrcial
wells exist within 1 mite of site.
X X Concentration.* of volatile* in
overburden ground water are high.
See air pathways.
Considered Insignificant compared to
oilier ground wnlcr exposures.
t-- -A %!", £ " -V^V s %WA^*/«, , '.^'"XV''"'"''^^"^
.> .-.>..:.,.<. .^....1.< ?'. ;..!>?.,. ..'. . ...?f.'....*.'.s. v v, ;^^;i jt ,;\ : ££> u^fe *;> ,U * ? ^.iv \ £ r \ A:?:;- ,?&$ s ?i:L',r i& i:^f
-------
Pathway
Sedmiettts
Incidental Ingcstion of
Drainage System Sediments
Dermal Contact with
Drainage System
Sediments'**
.Surface'.V/nier
Incidental Inpcstion of
Surface Water .
Dermal Contact with Surface
Water
Alt
Inhalation of Emissions and
I'ailictilales from Soils
Receptor
Recreational User
llxcavation
Worker
Recreational User
P.xcavation
Worker
V
Recreational User
Uxcavation
Worker
Recreational User
I'jrnvation
Worker
<" ""*,
Employee
Resident
Excavation
Worker
llme-Pramc Evaluated ^^^P^ "' Assessment
IVescnl Pulurc Quant. Qual.
Yes Yes X
No Yes X
(see
subsurface
soils alxwc)
Yes Yes X
No Yes X
(sec
subsurface
soils alxivc)
'
No No
No No
Yes Yes X
Yes Yes X
" /^X , % ''''' '°,* \,
Yes Yes X
No No
No Yes X
Rationale for Selection or (inclusion Data (irottping
"" ','>.'
Youths have been observed in Downgradient sedimcnti for
downgradicnt wetland areas. present exposure. All sediment
samples for future exposure.
Combined with snlismfacc soils.
Youths have been observed in Downgradicnt sediments for
downgradicnl wetland areas. present exposure. All sediment
sample) for future exposure.
Combined with subsurface soils.
- -> ^f ;:%:y4§
Anticipated activities Involve
negligible exposure via the oral route.
Anticipated activities involve minimal
exposure due to low contaminant
concentrations.
i
- ;/;< ^ ; <;' - Ytlfe^-i ^-V'7' ;:
Significant contaminant concentrations Available outdoor air data.
in soils. Daily activity at site involves
physical disturbance of surface soils.
Airborne contaminants detected.
Anticipated exposure Is minimal due to
mosl surfaces Ving covered (e.g..
paved roads, lawns).
Significant contaminant concentrations
In soils. Airlrarne contaminant)
detected.
2 of 3
-------
Pathway
Inhalation of Indoor Air
**cadmli|in mid Aroclor-1254
***caumium only.
Receptor
Employee
Krsidcnl
only.
Time-Frame Evaluated
Present limirc
Yes Yes
No Yes
D^p of Assessment
Quant. Qnal. Rationale for Selection or (inclusion Dati (Jrmtping
X Employee mty be exposed to Available indoor air data.
measurable contaminant levels.
X Contaminants from ground water may
volatilize and seep into basements.
Airborne contaminant* detected.
3 of 3
-------
TABLE 5-3 TOXICITY VALUES FOR CONTAMINANTS OF CONCERN ATTIJB NIAGARA MOHAWK SITE.
Clicmicnl
Volatile!
Acetone
Uenrene
2-Dutanone(MEK)
Catbon Disulfide
Carbon Tetrachlorldo
Chloroform
1,1 DicMinncllmnc
l,2-l)iclil
------- |