United States - Office of
Environmental Protection Emergency arid
Agency Remedial Response
EPA/ROD/R02-92/194
September 1992
PB93-963819
v°/EPA Superfund
Record of Decision:
Dover Municipal Well 4, NJ
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NOTICE
The appendices listed in the index that are not found in this document have been removed at the request of
the issuing agency. They contain material which supplement but adds no further applicable information to
the content of the document All supplemental material is, however, contained in the administrative record
for this site. .
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R02-92/194
3. Recipient's Accession No.
4. TMe and Subtitle
SUPERFUND RECORD OF DECISION
Dover Municipal Well 4, NJ
First Remedial Action - Subsequent to follow
S. Report Dirte
09/30/92
7. Author(»)
8. Performing Organization Rapt No.
9. Performing Organization Name and Address
10. ProfectfTaek/Worli Unh No.
11. ContracqC) or Gnnt(G) No.
(C)
(G)
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Report & Period Coveted
800/000
14.
15. Supplementary Notes
PB93-963819
16. Abstract (Limit: 200 words)
The Dover Municipal Well 4 (DMW-4) site is located within the 500-year floodplain of
the Rockaway River, in the Town of Dover, Morris County, New Jersey. Surrounding land
use is mixed residential and commercial/light industrial. Ground water in the area is
classified as Class II-A, a current source of drinking water. In the portion of the
valley close to DMW-4, two silt layers separate permeable sands into a "shallow
aquifer," an "intermediate aquifer," and a "deep aquifer," all of which are connected
hydraulically. Drilled in 1962, Dover Municipal Well 4 commenced pumping in 1965, as
one of the Town's primary water supply wells. In 1980, sampling and analysis of ground
water from DMW-4 identified the presence of VOCs—specifically, chlorinated
solvents—above federal and state drinking water standards. Subsequently, DMW-4 was
voluntarily removed from service by the Town, and standby Well 3 was activated as a
potable water production well. The sources of VOC contamination have been traced to
the Howmet Turbine Components Corporation (Dover Casting Division) and the New Jersey
Natural Gas Company, both of which are under state administrative consent orders to
remediate their
(See Attached Page)
17. Document Analyeis a. Descriptor*
Record of Decision - Dover Municipal Well 4, NJ
First Remedial Action - Subsequent to follow
Contaminated Medium: gw
Key Contaminants: VOCs (benzene, PCE, TCE), metals (lead)
b. Mentifiera/Open-Ended Terms
c. COSATI Reid/Group
18. Availabiity Statement
19. Security aasa (This Report)
None
20. Security Class (This Page)
None
21. No. of Pages
48
22. Price
(See ANSI-Z39.18)
See Inatructiona on Reverse
OPTIONAL FORM 272 (4-77)
(Formerly NT1S-3S)
Department of Commerce
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EPA/ROD/R02-92/194
Dover Municipal Well 4, NJ
First Remedial Action - Subsequent to follow
>
stract (Continued)
individual properties. This ROD addresses remediation of the contaminated ground water
in the shallow, intermediate, and deep aquifers at the DMW-4 site, as OU1. Future RODs
will address any additional ground water contamination onsite and the potential source(s)
of contamination. The primary contaminants of concern affecting the ground water are
VOCs, including benzene, PCE and TCE, and, metals including lead.
The selected remedial action for this site includes onsite pumping and treatment of
contaminated ground water from both the intermediate and deep aquifers using air
stripping to remove VOCs; discharging the treated water offsite to the public water
supply system to be used for potable water, with reinjection of surplus quantities;
performing a preliminary assessment of air stripper emissions and discharge requirements
to determine if vapor phase treatment using activated carbon will be necessary, and if
so, disposing of or recycling the spent carbon offsite; monitoring air emissions; and
monitoring ground water to ensure effectiveness of the treatment system and to determine
if pretreatment for inorganics is necessary. The estimated present worth cost for this
remedial action is $1,985,000, which includes an annual O&M cost of $106,000 for
21 years.
PERFORMANCE STANDARDS OR GOALS:
Chemical-specific ground water clean-up goals are based on federal and state MCLs,
including PCE 1 ug/1 (state); TCE 1 ug/1 (state); toluene 1,000 ug/1 (federal); 1,1,1-TCA
26 ug/1 (state); and lead 15 ug/1 (federal). Ground water will be treated to meet all
Applicable drinking water standards prior to offsite discharge to the public water
Supply. Any regulated equipment used in the selected remedy will be designed,
constructed, and operated to meet state Air Pollution Control and Noise Pollution Control
Act requirements.
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ROD FACT SHEET
SITE
Name:
Location/State:
EPA Region:
HRS Score (date)
ROD
Date Signed:
Selected Remedy
Groundwater:
Capital Cost:
O & M:
Present Worth:
LEAD
Dover Municipal Well No. 4
Dover, Morris Co., New Jersey
II
28.9 (December 1982)
September 30, 1992
Extraction of contaminated groundwater for
treatment via air stripping. Treated
groundwater will be conveyed to the municipal
water supply system to the extent
practicable, with reinjection of any surplus
quantity. Appropriate environmental
monitoring to ensure the effectiveness of the
remedy.
$
$
$
496,000
106,000
1,985,000
Agency
Primary Contact (phone):
Secondary Contact (phone):
Federal Remedial Lead
Courtney McEnery (212) 264-1251
Robert McKnight (212) 264-7509
WASTE
Type:
Medium:
Origin:
Groundwater - Elevated levels of VOCs,
primarily PCE.
Groundwater.
Unknown at this time. An additional operable
unit is planned to address contaminant
sources.
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DECLARATION STATEMENT
RECORD OF DECISION
DOVER MUNICIPAL WELL NO. 4
Site Name and Location
Dover Municipal Well No. 4
Dover, Morris County, New Jersey
Statement of Basis and Purpose
This decision document presents the selected remedial action for
groundwater contamination at the Dover Municipal Well No. 4 site.
The remedial action was chosen in accordance with the
Comprehensive Environmental Response, Compensation, and Liability
Act of 1980, as amended by the Superfund Amendments and
Reauthorization Act of 1986 and, to the extent practicable, the
National Oil and Hazardous Substances Pollution Contingency Plan.
This decision is based on the administrative record for the site.
The New Jersey Department of Environmental Protection and Energy
concurs with the selected remedy.
Assessment of the Site
Actual or threatened releases of hazardous substances from the
Dover Municipal Well No. 4 site, if not addressed by implementing
the response action selected in this Record of Decision, may
present an imminent and substantial endangennent to public
health, welfare, or the environment.
Description of the Selected Remedy
The remedy presented in this document addresses the current and
future threats to human health and the environment associated
with contaminated groundwater at the Dover Municipal Well No. 4
site. This Record of Decision provides for the restoration of
the contaminated groundwater to drinking water standards.
Additional studies will be necessary to investigate contaminant
sources and other areas of potential groundwater contamination.
A subsequent decision document is planned to evaluate the need
for further remediation of the groundwater and remediation of the
contaminant sources.
The major components of the selected remedy include:
Extraction of contaminated groundwater and restoration
of the groundwater to drinking water standards;
Treatment of extracted groundwater to levels attaining
drinking water standards;
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-2-
Discharge of treated groundwater to the public water
supply system to the extent practicable, with
reinjection of any surplus quantity; and
Appropriate environmental monitoring to ensure the
effectiveness of the remedy.
Statutory Determinations
The selected remedy is protective of human health and the
environment, complies with Federal and State requirements that
are legally applicable or relevant and appropriate to the
remedial action, and is cost effective. This remedy utilizes
permanent solutions and alternative treatment technologies to the
maximum extent practicable and satisfies the statutory preference
for remedies that employ treatment that reduces toxicity,
mobility, or volume as a principal element. Subsequent actions
may be necessary to address additional groundwater contamination
and the contaminant sources at the site.
Constantine Sidamon-Eristof1
Regional Administrator
' /
/
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State of New Jersey
Department of Environmental Protection and Energy
Office of the Commissioner
CN402
Trenton. NJ 08625-0402
Tel. # 609-292-2885
Scott A. Weiner Fax. # 609-984-3962
Commissioner
SEP 3 0 1992
Mr. Constantine Sidamon-Eristoff
Administrator
U.S. Environmental Protection Agency
Region II
Jacob K. Javits Federal Building
New York, New York 10278
Dear Mr. Eristoff:
The Department of Environmental Protection and Energy has evaluated and
concurs with the selected remedy for the Dover Municipal Well No. 4
Superfund site as stated below:
"The remedy presented in this document addresses the current and future
threats to human health and the environment associated with contaminated
ground water at the Dover Municipal Well No. 4 site. This Record of
Decision provides for the restoration of the contaminated ground water to
drinking water standards. Additional studies will be necessary to
investigate contaminant sources and other areas of potential ground water
contamination. A subsequent decision document is planned to evaluate the
need for further remediation of the ground water and remediation of the
contaminant sources".
The major components of the selected remedy include:
o Extraction of contaminated ground water and restoration of the ground
water to drinking water standards;
o Treatment of extracted ground water to levels attaining drinking water
standards;
o Discharge of treated ground water to the public water supply system to
the extent practicable, with reinjection of any surplus quantities;
and
o Appropriate environmental monitoring to ensure the effectiveness of the
remedy.
New Jersey Is an Equal Opportunity Employer
Recycled Paper
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The State of New Jersey appreciates the opportunity to participate in this
decision making process and looks forward to future cooperation with the
USEPA.
dfh
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DECISION SUMMARY
RECORD OF DECISION
DOVER MUNICIPAL WELL NO. 4
BITE NAME, LOCATION, AND DESCRIPTION
Dover Municipal Well No. 4 (DMW-4) is situated on Lot 15, Block
2314, approximately 450 feet north of the Rockaway River in the
Town of Dover, Morris County, in central northern New Jersey
(Figure 1).
Although most of Dover is residential, DMW-4 is located in a
commercial/industrial section of the town. DMW5-4 is located
approximately 1.5 miles east of three production wells (#1, #3,
and #5) which serve a community of approximately 22,000 people.
The Dover Water Commission owns and operates this municipal well
field. Groundwater in the area is classified as Class II-A, a
current source of drinking water.
The Town of Dover is located in the New England physiographic
province known locally as the New Jersey Highlands. The
Highlands consist of several broad, flat, or round-topped ridges
separated from each other by deep and generally narrow valleys.
Ridge lines are generally 1,000 feet above sea level and relief
is approximately 300 to 400 feet above sea level. The ridges
generally trend northeast to southwest. The Rockaway River
valley runs transverse to this trend in the vicinity of the
DMW-4 site.
Within the Rockaway River valley, stratified sands, silts,
gravels and clays (glacial outwash deposits) are typically over
100 feet thick and are emplaced on top of bedrock. An
interpretation of subsurface information shows the valley
sediments are composed primarily of stratified glacial outwash
materials which can be characterized into four layers. These
layers, in descending order, include: (1) an upper unit of
medium to course sand with gravel and cobbles; (2) a unit of
finer-grained deposits, typically consisting of two silt layers
bracketing a layer of fine sand; (3) a unit of fine to medium
sand; and (4) a deposit of medium to course sand, gravel, and
cobbles. This layer is the basal unit which lies directly above
the. bedrock.
Two or more aquifers are present in the unconsolidated sediments
which fill the Rockaway River valley. Fine sand and silt layers
act as confining units between the more permeable sands above and
below them. In the portion of the valley close to DMW-4, two
silt layers separate the sands into three aquifers: an upper
water-table aquifer (shallow aquifer) and two underlying semi-
confined aquifers, labelled as intermediate and deep. The
subsurface investigations conducted as part of the remedial
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investigation (RI) confirmed that, under non-pumping conditions,
groundwater in the lower aquifers in the vicinity of DMW-4 flo.;s
with the regional topographic gradient (i.e., to the east).
Groundwater in the shallow aquifer flows toward the Rockaway
River, with a slight down-valley (eastern) component.
The Town of Dover overlies two designated Sole Source Aquifer
areas. The United States Environmental Protection Agency (EPA)
designates areas as Sole Source Aquifers under the Safe Drinking
Water Act to protect principle drinking water sources.
SITE HISTORY AND ENFORCEMENT ACTIVITIES
Drilled in 1962, Dover Municipal Well #4 commenced pumping in
June 1965, and was one of the town's primary water supply wells
with an average pumping rate of 1,100 gallons per minute (gpm).
In March 1980, sampling and analysis of groundwater from DMW-4 by
the Town of Dover identified the presence of volatile organic
compounds (VOCs), specifically chlorinated solvents in excess of
250 parts per billion (ppb). Additional sampling conducted by
the New Jersey Department of Environmental Protection and Energy
(NJDEPE) in July and September 1980 revealed the presence of
trichloroethene (TCE). Based on these analyses, DMW-4 was
voluntarily removed from service by the Town of Dover in
September 1980. Since that time, standby well #3 has been used
in place of DMW-4 as a potable water production well.
Between January 1982 and March 1985, initial hydrogeologic
investigations were performed for the Dover Water Commission.
Separate subsurface studies were also conducted at two industrial
facilities located in the river valley east of DMW-4. A
hydrogeologic study of the Howmet Turbine Components Corporation
Dover Casting Division (Howmet) property in 1982 indicated the
presence of VOC contamination in the groundwater. Investigations
completed for the New Jersey Natural Gas (NJNG) Company property
in 1983 also indicated the presence of VOC contamination in the
groundwater. In June 1986, Howmet and NJNG were issued
directives from NJDEPE to pay for a remedial investigation and
feasibility study (RI/FS) at the DMW-4 site. To date, Howmet and
NJNG have not complied with the directives. However, both Howmet
and NJNG are under separate New Jersey Administrative Consent
Orders (ACOs) for remediation of their individual properties.
HIGHLIGHTS OF COMMUNITY PARTICIPATION
A Community Relations Plan (CRP) was developed to ensure the
public opportunities for involvement in site-related decisions,
including site analysis and characterization, alternatives
analysis, and remedy selection. In addition, the CRP was used by
NJDEPE and EPA to determine, based on community interviews,
activities to ensure public involvement and to provide
opportunities for the community to learn about the site.
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A meeting was held in April 1987 to provide residents and local
officials with an update on past activities and to inform the
public of current and future activities planned for the site.
The RI and FS reports, which addressed the groundwater
contamination, were released to the public in August 1992. A
Proposed Plan, that identified EPA's and NJDEPE's preferred
remedial alternative, was released on August 7, 1992. The
documents were made available to the public at information
repositories maintained at the Dover Free Public Library and the
Dover Municipal Building. The administrative record for the site
is located at the Dover Free Public Library. A public comment
period was held from August 7 through September 15, 1992. A
public meeting was held on August 19, 1992, to present the
findings of the RI/FS and the Proposed Plan, and to solicit
public input. The issues raised at the public meeting and during
the public comment period are addressed in the Responsiveness
Summary, which is part of this Record of Decision (ROD).
This ROD presents the selected remedial action for the Dover
Municipal Well #4 site, chosen in accordance with the
Comprehensive Environmental Response, Compensation, and Liability
Act of 1980 (CERCLA), as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA), and, to the extent
practicable, the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP). The selection of the remedy described in
this ROD is based upon the administrative record.
SCOPE AND ROLE OF ACTION
This document addresses remediation of the contaminated
groundwater at the DMW-4 site. It includes remedial alternatives
which address contaminated groundwater and focuses on the
protection of human health and the environment. The remediation
of the DMW-4 site will consist of at least two operable units:
one which will address the identified groundwater contamination
(the subject of this ROD) and one or more which will address
additional groundwater contamination at the site and the
potential source(s) of the contamination. This operable unit
will initiate remediation of the deep, intermediate, and shallow
aquifers. If further investigations define source areas of
contamination or additional areas of groundwater contamination,
remediation of these areas will accelerate cleanup of the shallow
and intermediate aquifers as separate operable units.
SUMMARY OF SITE CHARACTERISTICS
An RI was conducted at the DMW-4 site to define the site geology
and hydrology, define the nature and extent of groundwater
contamination, examine potential migration routes by which
contamination could reach DMW-4, and to identify potential
sources of contamination. The investigation also provided a
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basis for defining the zone of capture for DMW-4. The zone of
capture is the area over which groundwater flow is directed
toward the pumping well. The RI included geophysical surveys,
drilling of pilot borings and sampling of subsurface soils,
installation of clustered groundwater monitoring wells, a
nine-day pump test, and sampling of wells distributed around the
DMW-4 site.
Subsurface soil samples obtained during the drilling of the
monitoring wells were analyzed during the RI. The only detected
soil contaminants were metals, which were found at concentrations
consistent with New Jersey background levels. A soil gas survey
was then performed as an addendum to the RI to attempt to provide
an identification of potential sources of subsurface
contamination. The soil gas survey technique utilized on-site
gas chromatography to detect and quantify trace levels of VOCs
present within the interstitial pore spaces of soil. Under
suitable site conditions, VOCs will diffuse upwards from the
underlying soil and groundwater and can be evaluated by soil gas
methodology. Of the 22 suspected source areas sampled under the
soil gas investigation, five areas exhibited VOC contamination
equal to or greater than 1 ppb, with one area as high as 3,700
ppb. While this study identified elevated VOC concentrations in
these areas, further investigation will be required to
conclusively identify source areas.
Since the RI did not sufficiently identify contaminant source
area(s), remedial action objectives were developed only for known
groundwater contamination at this time. This initial phase of
remedial action is referred to as Operable Unit 1 (OU-1).
Further study will be required to identify contaminant source
areas.
The RI concluded that in the portion of the valley close to DMW-
4, two silt layers separate permeable sands into a "shallow
aquifer", an "intermediate aquifer", and a "deep aquifer". The
RI also demonstrated a hydraulic connection between the aquifers,
which indicates that the semi-confining layers do not act as
effective barriers to vertical contaminant movement. Under
non-pumping conditions, groundwater in the intermediate and deep
aquifers flows toward the east. Groundwater in the shallow
aquifer flows toward the Rockaway River.
A variety of chlorinated hydrocarbons were detected in
groundwater samples from various monitoring wells at
concentrations exceeding the promulgated federal and state
Maximum Contaminant Levels (MCLs) which have been developed to
protect drinking water. Contaminant concentrations and their
associated MCLs are shown in Tables 1 through 4. To the north
and west of DMW-4, tetrachloroethene (PCE) was detected in
shallow, intermediate, and deep wells at levels exceeding the MCL
of 1 ppb. During the RI, the highest levels of PCE contamination
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detected were identified in the intermediate aquifer. PCE was
detected at concentrations as high as 1,200 ppb in a portion of
the intermediate aquifer located northeast of DMW-4. PCE was
also detected in the shallow aquifer at concentrations up to 81
ppb and in the deep aquifer up to 48 ppb.
TCE was detected in the shallow aquifer as high as 17 ppb, in the
intermediate aquifer at up to 3 ppb, and in the deep aquifer up
to 7 ppb. All of these levels exceed the MCL of 1 ppb.
1,1,1-trichloroethane (1,1,1-TCA) was detected in a deep well
southeast of DMW-4 at 49 ppb which exceeds the MCL of 26 ppb.
1,2, dichloroethene (36 ppb) was found in a shallow well south of
DMW-4 exceeding the MCL of 10 ppb. Carbon tetrachloride was also
detected south of DMW-4 at an estimated concentration of 7 ppb.
Analytes other than chlorinated hydrocarbons detected in wells
(excluding the wells located on the NJNG property) include
bis(2-ethylhexyl)phthalate and lead.
While phthalates were detected in each of the aquifers, they were
also routinely detected in field, trip and/or method blanks, and
are typically a laboratory contaminant. Therefore, their actual
presence in the groundwater is questionable and requires
verification. Similarly, lead was present in a shallow well
(24.5 ppb) and deep well (12.3 ppb). However, lead was also
detected in the laboratory blank.
Contamination detected at the NJNG property included arsenic,
lead, benzene, xylene, benzidine and naphthalene. As previously
stated, NJNG is presently under a separate AGO from NJDEPE for
the cleanup of its property.
Although groundwater in the vicinity of DMW-4 was found to be
contaminated with VOCs, the overall extent of the contamination
was not fully determined. However, as previously discussed, a
relatively high contaminated portion of the intermediate aquifer
was detected in the area northeast of DMW-4. Further
investigation is necessary to determine the extent of groundwater
contamination in the three aquifers.
SUMMARY OF SITE RISKS
Based upon the results of the RI, a baseline risk assessment was
conducted to estimate the risks associated with current and
future site conditions. The baseline risk assessment estimates
the human health and ecological risk which could result from the
contamination at the site if no remedial action were taken.
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Human Health Risks
For the human health risk assessment, a reasonable maximum human
exposure was evaluated. A four-step process was utilized for
assessing site-related human health risks for a reasonable
maximum exposure scenario: Hazard Identification—identified the
contaminants of concern at the site based on several factors such
as toxicity, frequency of occurrence, and concentration;
Exposure Assessment—estimated the magnitude of actual and/or
potential human exposures, the frequency and duration of these
exposures, and the pathways (e.g., ingesting contaminated soil)
by which humans are potentially exposed; Toxicity Assessment—
determined the types .of adverse health effects associated with
chemical exposures, and the relationship between magnitude of
exposure (dose) and severity of adverse effects (response); and
Risk Characterization—summarized and combined outputs of the
exposure and toxicity assessments to provide a quantitative
(e.g., one-in-a-million excess cancer risk) assessment of site-
related risks.
Groundwater monitoring data obtained during the RI indicate that
chemicals have been released to and are being transported in the
groundwater. The baseline risk assessment began with selecting
contaminants which are likely to pose the most significant risks
to human health and the environment (chemicals of potential
concern). These contaminants include, but are not limited to,
PCE, TCE, TCA, arsenic, benzene and bis(2-ethylhexyl) phthalate.
These "chemicals of potential concern" and their concentrations
in groundwater are shown in Table 5. Of the above-indicated
contaminants, all but TCA are known to cause cancer in laboratory
animals and are suspected to be human carcinogens.
The baseline risk assessment identified several potential
exposure pathways by which the public could be exposed to
contaminant releases from the DMW-4 site. The baseline risk
assessment evaluated the health effects which could result from
exposure to contamination through inhalation, dermal contact and
ingestion pathways, and considered both current and future land
use scenarios.
Under current EPA guidelines, the likelihood of carcinogenic
(cancer causing) and noncarcinogenic 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 noncarcinogenic risks
associated with exposures to individual indicator compounds were
summed to indicate the potential risks associated with mixtures
of potential carcinogens and noncarcinogens, respectively. The
health effects criteria for the chemicals of potential concern
are presented in Tables 6 and 7.
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Noncarcinogenic risks were assessed using a Hazard Index
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 per kilogram per 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 (e.g., the amount
of a chemical ingested from contaminated drinking water) are
compared with the RfD to derive the hazard quotient for the
contaminant in the particular media. The hazard index is
obtained by adding the hazard quotients for all compounds across
all media. A hazard index greater than 1.0 indicates that the
potential exists for noncarcinogenic 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.
Potential carcinogenic risks were evaluated using the cancer
potency factors developed by EPA for the indicator compounds.
Cancer potency factors (CPFs) have been developed by EPA's
Carcinogenic Risk Assessment Verification Endeavor for estimating
excess lifetime cancer risks associated with exposure to
potentially carcinogenic chemicals. CPFs, 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 CPFs. Use of this approach makes underestimation of the
risk highly unlikely.
For known or suspected carcinogens, EPA considers excess upper-
bound individual lifetime cancer risks of between 1 X 10" to
1 X 10"6 to be acceptable. This level indicates that an
individual has no greater than a one in ten thousand to one in a
million chance of developing cancer as a result of exposure to
site conditions over a 30-year period.
The Hazard Indices and cancer risks associated with the potential
exposure pathways at the DMW-4 site are presented in Table 8.
The "current use" cancer risk associated with residences located
within the zone of capture of DMW-4 is estimated to be 3 x 10"6
(three in a hundred thousand). The route of exposure for
carcinogenic effects of most concern for current use is
inhalation of VOCs present in groundwater. The chemical of
primary concern via the inhalation pathway is benzene (2 x 10"6) .
The cancer risks for adults and children associated with future
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residential use of groundwater within the capture zone of DMW-4
is 9 x ICT* for adults and 4 x 10"5 for children, respectively.
At the Dover site, the Hazard Index associated with current use
is .003. The Hazard Index associated with future residential use
of groundwater within the capture zone of DMW-4 is 0.7 for adults
and 2.0 for children. Current federal guidelines for acceptable
exposures are a maximum Hazard Index equal to 1.0 and an
individual lifetime excess carcinogenic risk in the range of IO"4
and 10* (one in ten thousand to one in a million).
The estimate of carcinogenic risk is within the range of
acceptable exposure and the Hazard Index exceeds one only for
children under a future residential land use scenario. However,
cleanup is warranted because, as discussed earlier, groundwater
contaminants are present at concentrations exceeding MCLs in each
of the three aquifers. Further, high concentrations of PCE are
present in the intermediate aquifer. These concentrations of PCE
and other contaminants in the shallow and intermediate aquifers
can migrate into the deeper aquifer because the confining layers
between the aquifers are not impermeable.
As in any risk assessment, the estimates of the risk for the
DMW-4 site may have many uncertainties. As a result of the
uncertainties, the risk assessment should not be construed as
presenting an absolute estimate of risks to human or
environmental populations. Rather, it is a conservative analysis
intended to indicate the potential for adverse impacts to occur.
Environmental Evaluation
The environmental evaluation provides a qualitative assessment of
the potential impacts involving the groundwater contamination
associated with DMW-4. The primary objectives of an
environmental evaluation are to identify the ecosystems, habitats
and populations likely to be found at the site and to
characterize the contaminants, exposure routes and potential
impacts to the identified environmental components. The only
media that will be discussed in this environmental assessment
will be the three contaminated aquifers within the zone of
capture of DMW-4 and the potential impact on the Rockaway River
ecosystem. Possible effects of surface soil contamination cannot
be evaluated because contaminant sources were not identified.
The environmental assessment considered potential impacts to the
Rockaway River associated with the site. There were no federally
endangered species within the area of investigation. There is
some indication that the potential exists for elevated inorganics
in groundwater to produce adverse environmental effects. Further
evaluation of this possibility would be required.
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Conclusion
Actual or threatened releases of hazardous substances from the
Dover 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.
REMEDIAL ACTION OBJECTIVES
Only the remediation of groundwater contamination is addressed in
this ROD for Operable Unit 1. Specific remedial objectives are
as follows:
Continue to prevent exposure, due to groundwater
ingestion and inhalation, to contaminants at levels
exceeding MCLs;
Minimize further contamination of DMW-4 and prevent
contamination of additional existing wells by
minimizing the migration of contaminants; and
Restore contaminated groundwater for future use.
The goal for the restoration of contaminated groundwater is to
achieve promulgated federal and state MCLs which have been
developed to protect drinking water. MCLs are enforceable
standards based on health risks associated with an individual's
consumption of two liters of water per day over a 70-year period.
SUMMARY OF REMEDIAL ALTERNATIVES
CERCLA, as amended, requires that each selected site remedy be
protective of human health and the environment, be cost
effective, comply with other statutory laws, and utilize
permanent solutions and alternative treatment technologies and
resource recovery alternatives to the maximum extent practical.
In addition, the statute includes a preference for the use of
treatment as a principal element for the reduction of toxicity,
mobility, or volume of the hazardous substances.
The RI identified the groundwater itself as the principal
environmental medium affected by contamination. The sources of
this groundwater contamination are not addressed by this ROD.
The FS evaluated, in detail, three main alternatives for
remediating groundwater. Under Alternative 3, there are two
extraction options, three treatment options and three discharge
options evaluated. In addition to the alternatives evaluated in
.the FS, the Proposed Plan discussed an additional alternative to
remediate the DMW-4 site, consisting of a modified Alternative 3,
Extraction Option El (Wellhead Extraction). Since the three
components of Alternative 3 (Extraction/Treatment/Discharge) are
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evaluated separately, to determine the total cost for Alternative
3, the selected options must be added. The estimated capital
cost, operation and maintenance (O&M) cost, and net present worth
cost for each alternative discussed below are provided for
comparison.
An estimated implementation timeframe is given for each remedial
alternative described below. It refers to the time required to
implement the alternative, including construction and operation
and maintenance.
Alternative 1 - NO ACTION
Estimated Capital Cost: -0-
Estimated Annual O&M Cost: -0-
Estiroated Present Worth Cost: $ 79,000
Estimated Implementation Timeframe: None
CERCLA requires that a "No Action" alternative be considered as a
baseline for comparison with other alternatives. The No Action
alternative would not involve any remedial action to reduce the
toxicity, mobility or volume of groundwater contamination at the
DMW-4 site. The site would remain in its present condition.
Additionally, the potential for off-site migration of
contaminants in groundwater would not be prevented under this
alternative. Because contamination would remain at the site, a
review of the No Action remedy would be conducted after five
years to determine the need for response measures at that time.
No other action is proposed under this alternative. The only
costs associated with the No Action alternative would be the cost
of the five-year review of the remedy.
Alternative 2 - Groundwater MONITORING WITH Groundwater USE
RESTRICTIONS
Estimated Capital Cost: -0-
Estimated Annual O&M Cost: $ 20,000
Estimated Present Worth Cost: $360,000
Estimated Implementation Timeframe: 30 Years
Alternative 2 consists of the institution of groundwater use
restrictions and continued groundwater monitoring. Groundwater
use restrictions would include restrictions on the installation
of process or potable wells. Groundwater monitoring involves
annual monitoring for 30 years. As with the No Action
alternative, a review of this alternative would need to be
performed after five years. The estimated implementation
timeframe noted above is associated with the long-term monitoring
program.
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Alternative 3 - Groundwater EXTRACTION/TREATMENT/DISCHARGE
Alternative 3 involves groundwater extraction, treatment, and
discharge, all of which are broken down further into separate
options. Extraction options include El (Wellhead Extraction) and
E2 (Multi-Well Extraction). Treatment options include T3 (Air
Stripping), T4 (Carbon Adsorption), and T5 (UV Oxidation).
Discharge options include Dl (Discharge to Groundwater), D2
(Discharge to Surface Water), and D4 (Discharge to Water Supply);
all of which are described below. Options Tl (Off-Site
Treatment), T2 (Biological Treatment) and D3 (Discharge to
Sanitary Sewer System) were discussed in the FS report, but are
not discussed in this ROD. Tl and D3 were not retained for
further consideration on the basis of limited effectiveness and
implementability constraints. Insufficient information
concerning T2 was available to thoroughly evaluate the option
against the nine evaluation criteria which are described later in
this document.
Implementation would include groundwater monitoring. Monitoring
would be conducted during the treatment period and for 5 years
subsequent to achievement of groundwater remediation goals. The
following summarizes the extraction, treatment and discharge
options of Alternative 3 which were evaluated in the FS and
Proposed Plan. Since the time period for remediation varies with
the extraction option (16 years for E-l and 6 years for E-2),
each treatment and discharge option contains two sets of present
worth costs.
EXTRACTION
Alternative 3 - Groundwater Extraction Option El- Wellhead
Extraction
Estimated Capital Cost: $ 2,000
Estimated Annual O&M Cost: $ 48,000
Estimated Present Worth Cost: $730,000
Estimated Implementation Timeframe: 16 Years
Groundwater Monitoring: 21 Years
Option El consists of groundwater extraction using DMW-4 only.
It is anticipated that DMW-4 would be pumped at approximately
1,000 gpm to ensure containment of contaminated groundwater
within the capture zone. This flow rate would be refined during
the remedial design. The extracted groundwater would be treated
and discharged using a combination of treatment/discharge
technology options. Based on modeling of the groundwater system
and the assumption that sources of contamination will be
eliminated, it is estimated that a 16-year extraction period
would be required to extract six aquifer volumes from the shallow
aquifer and twelve aquifer volumes from the deep and intermediate
aquifers. The actual time required to meet remedial goals could
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vary based on the effectiveness of the technology and success in
controlling the sources of contamination.
Alternative 3 - Groundwater Extraction Option E2 - Multi-Well
Extraction
Estimated Capital Cost: $590,000
Estimated Annual O&M Cost: $ 66,000
Estimated Present Worth Cost: $1,260,000
Estimated Implementation Timeframe: 6 Years
Groundwater Monitoring: 11 Years
Option E2 consists of extraction of contaminated groundwater via
the installation and pumping of an estimated eight extraction
wells. The specific number and extraction well'locations would
be defined during the design phase. Groundwater would be
extracted from the shallow, intermediate and deep aquifers at an
estimated average total rate of about 915 gpm. This system would
provide extraction of contaminated groundwater from the capture
zone of DMW-4, while also extracting contaminated groundwater
nearer to the potential source area(s) or from areas of
concentrated groundwater contamination. Based on groundwater
modeling and the assumption that sources of contamination will be
eliminated, it is estimated that extraction would occur over a
six-year period. Like option El, this extraction option would be
combined with a groundwater treatment option and discharge
option.
Alternative 3 - Modified Groundwater Extraction Option El -
Wellhead Extraction with Additional Extraction Wells
Estimated Capital Cost: $150,000
Estimated Annual O&M Cost: $ 65,000
Estimated Present Worth Cost: $1,045,000
Estimated Implementation Timeframe: 16 Years
Groundwater Monitoring: 21 Years
This option is a modification of Extraction Option El, Wellhead
Extraction, which includes extraction of contaminated groundwater
from both the intermediate and deep aquifers. Contaminated
groundwater would be extracted from the deep aquifer through
pumping DMW-4 and from the more highly contaminated portion of
the intermediate aquifer through an estimated two new extraction
wells. The extraction system would be designed to minimize the
migration of the more highly contaminated groundwater from the
intermediate aquifer into the deep aquifer.
Like the t'.;o options above, the extracted groundwater would be
treated and discharged using a combination of treatment/discharge
technology options.
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TREATMENT
Alternative 3 - Groundwater Treatment Option T3 - Air Stripping
Estimated Capital Cost: $260,000
Estimated Annual O&M Cost: $ 41,000
Wellhead Multi-well
Estimated Present Worth Cost: $840,000 $560,000
Estimated Implementation Timeframe: 16 Years 6 Years
Option T3 consists of on-site treatment of contaminated
groundwater using an air stripping system. Air strippers would
transfer volatile groundwater contaminants from the extracted
groundwater to the gas phase. An air emission monitoring program
would be implemented during the operation of the treatment
system. Although a preliminary assessment of air stripper
emissions and discharge requirements indicate that vapor phase
treatment of effluent gases may not be required, a further
detailed assessment of vapor phase treatment would be necessary
prior to implementation of the air stripping system. If vapor
phase treatment were determined necessary, spent carbon would
require off-site regeneration or disposal. The cost associated
with this treatment is presented under the Supplemental Treatment
Costs section below.
Alternative 3 - Groundwater Treatment Option T4 - Carbon
Adsorption
Estimated Capital Cost: $520,000
Estimated Annual O&M Cost: $370,000
Wellhead Multi-well
Estimated Present Worth Cost: $5,400,000 $2,900,000
Estimated Implementation Time frame: 16 Years 6 Years
Option T4 consists of on-site treatment of contaminated
groundwater using a carbon adsorption treatment system. In
carbon adsorption, organic contaminants are adsorbed to the
carbon particles within a carbon filtration system. Carbon
adsorption treatment would require off-site regeneration or
disposal of the spent carbon. An air emission monitoring program
would be implemented during the operation of the treatment
system.
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Alternative 3 - Groundvater Treatment Option T5 - UV Oxidation
Estimated Capital Cost: $ 800,000
Estimated Annual O&M Cost: $1,400,000
Wellhead Multi-well
Estimated Present Worth Cost: $19,000,000 $9,500,000
Estimated Implementation Timeframe: 16 Years 6 years
Option T5 consists of on-site treatment of contaminated
groundwater using an ultraviolet (UV) oxidation system. UV
oxidation destroys chlorinated hydrocarbons by oxidation using a
combination of ultraviolet light, hydrogen peroxide, ozone,
and/or catalysts. The technology provides complete destruction
of most chlorinated contaminants without the creation of air
emissions or residual waste streams.
SUPPLEMENTAL TREATMENT COSTS
Continued monitoring of the extracted groundwater during design
and implementation of the extraction/treatment system would be
required to determine if supplemental treatment is necessary to
remediate the low levels of phthalate, NJNG contaminants, or lead
found during the RI (e.g., chemical precipitation, carbon
polishing, etc.). Monitoring of the extraction/treatment system
would also be required to determine if pretreatment of the
inorganics is necessary to prevent fouling of the organic
treatment process. The estimated present worth costs for
treatment of inorganics, assuming a treatment rate of 1,000 gpm,
would range from $2,000,000 for 6 years of treatment to
$5,000,000 for 16 years. The estimated present worth cost of
carbon polishing for phthalates or NJNG contaminants would be
$2,000,000 for 6 years of treatment to $3,000,000 for 16 years of
treatment.
Although a preliminary assessment of air stripper emissions and
discharge requirements indicates that vapor phase treatment may
not be required, a further detailed assessment of vapor phase
treatment would be necessary prior to implementation of the air
stripping operation. The estimated present worth costs
associated with vapor phase treatment, if it is required, would
be $800,000 for 6 years of treatment to $1,200,000 for 16 years
of treatment.
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DISCHARGE
Alternative 3 - Discharge Option Dl - Discharge to Groundwater
Estimated Capital Cost: $1,100,000
Estimated Annual O&M Cost: $ 59,000
Wellhead Multi-well
Estimated Present Worth Cost: $2,100,000 $1,700,000
Estimated Implementation Timeframe: 16 years 6 Years
Option Dl consists of discharge of the treated groundwater back
to the aquifer using infiltration galleries, reinjection wells or
a combination of the two. Due to the proposed high groundwater
extraction and treatment rate, combined reinjection of treated
groundwater to the shallow, intermediate, and deep aquifers is
assumed for the purposes of this evaluation. It is estimated
that reinjection would require the installation of a minimum of
19 reinjection wells. Under this option, groundwater would be
treated to MCLs prior to reinjection.
Alternative 3 - Discharge Option D2 - Discharge to Surface Water
Estimated Capital Cost: $56,000
Estimated Annual O&M Cost: negligible
Wellhead Multi-well
Estimated Present Worth Cost: . $67,000 $67,000
Estimated Implementation Timeframe: 16 years 6 Years
Option D2 consists of discharge of the treated groundwater to
surface water (the Rockaway River), using direct discharge via a
dedicated pipe or discharge to a storm sewer. Prior to
discharge, groundwater would be treated to levels which attain
New Jersey surface water discharge limitation requirements. The
major costs associated with this option are the capital costs
associated with the installation of the discharge piping.
Because costs for pumping are included in the treatment options,
O&M costs are estimated to be negligible for this discharge
option. A storm sewer located adjacent to DMW-4 which leads to
the Rockaway River was used for discharge of the treated pump
test water during the Phase I RI.
Alternative 3 - Discharge Option D4 - Discharge to Public Water
Supply System
Estimated Capital Cost: $86,000
Estimated Annual O&M Cost: negligible
Wellhead Multi-well
Estimated Present Worth Cost: $100,000 $100,000
Estimated Implementation Timeframe: 16 Years 6 Years
Option D4 consists of discharge to the public water supply
system, whereby the treated groundwater would be used for potable
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water supply. This alternative would require strict compliance
with potable water requirements (i.e., MCLs) to ensure protection
of public health. The major costs associated with this option
are the capital costs associated with permitting and the
installation of the discharge piping. Because costs for pumping
are included in the treatment options, O&M costs are estimated to
be negligible for this discharge option. This alternative could
also be combined with another discharge alternative and used on
an emergency basis.
SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
Evaluation Criteria
The alternatives noted above were evaluated using criteria
derived from the NCP and CERCLA, as amended by SARA. These
criteria relate directly to factors mandated by CERCLA, as
amended, in Section 121, including Section I21(b)(1)(A-G). The
criteria are as follows:
Threshold criteria
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 are eliminated, 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 or relevant and appropriate
requirements of Federal and State environmental statutes and
requirements arid/or provide grounds for invoking a waiver.
Primary Balancing criteria
3. Long-term effectiveness and permanence refers to the
magnitude of residual risk and the ability of a remedy to
maintain reliable protection of human health and the
environment over time, once remedial objectives have been
met.
4. Reduction of toxicity. mobility or volume through treatment
addresses the statutory preference for selecting remedial
actions that employ treatment technologies that permanently
and significantly reduce toxicity, mobility or volume of the
hazardous substances as a principal element.
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
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construction and implementation period, until the remedial
objectives are achieved.
6. Implementabilitv is the technical and administrative
feasibility of a remedy, including the availability of
materials and services needed to implement a particular
alternative.
7. Cost includes estimated capital and operation and
maintenance costs, and the present worth costs.
Modifying Criteria
8. State acceptance indicates whether, based on its review of
the RI/FS and the Proposed Plan, the State.,supports,
opposes, and/or has identified any reservations regarding
the preferred alternative.
9. Community acceptance refers to the community's comment on
the alternatives described in the Proposed Plan, and the RI
and FS reports. Responses to public comments are addressed
in the Responsiveness Summary of this ROD.
Comparisons
A comparative discussion of the major components of the
alternatives, using the evaluation criteria, follows. Where
differences exist among the various treatment and discharge
options for Alternative 3, those differences are noted and
discussed. In addition to the alternatives evaluated in the FS,
the Proposed Plan presented an additional alternative to
remediate the DMW-4 site for Operable Unit 1, consisting of a
modified Alternative 3, Extraction Option El (Wellhead
Extraction). After evaluating the two extraction options
presented in the FS report, it was determined that a combination
of the two extraction options might be more appropriate. Due to
the presence of relatively high levels of PCE contamination in a
portion of the intermediate aquifer, extraction wells in this
area in combination with wellhead extraction would be more
effective in remediating groundwater.
Overall Protection of Human Health and the Environment
Overall protection of human health and the environment is the
central mandate of CERCLA, as amended. Protection is achieved by
reducing health and environmental threats and by taking
appropriate action to ensure that, in the future, there would be
no unacceptable risks to human health and the environment through
any exposure pathway.
The "No Action" alternative is not considered protective because
the risks associated with the DMW-4 site would persist for the
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foreseeable future. Additionally, the potential for downgradient
migration of contaminants in groundwater would continue to exist.
Therefore, the "No Action" alternative will not be considered
further in the analysis of options for the site.
Alternative 2 provides some protection of human health through
the implementation of groundwater use restrictions, but does not
provide actual treatment to reduce groundwater contamination,
prevent further degradation of the aquifers, or restore the
aquifers.
Alternative 3 provides overall protection of human health and the
environment through active measures to restore the contaminated
groundwater. The modified Alternative 3(El) provides a
significant degree of protection of human health and the
environment by initiating the restoration of the deep aquifer and
by preventing the further migration of the highest contaminated
portion of the intermediate aquifer.
Compliance with ARARs
Section 121(d) of CERCLA, as amended, requires that remedies for
Superfund sites comply with federal and state laws that are
applicable and legally enforceable. Remedies must also comply
with the requirements of laws and regulations that are not
applicable, but are relevant and appropriate. Applicable
requirements are defined as cleanup standards, standards of
control, and other substantive environmental protection
requirements, criteria, or limitations promulgated under federal
or state law that specifically address a hazardous substance,
pollutant, remedial action, location, or other circumstance at a
Superfund site. Relevant and appropriate requirements are
defined as substantive environmental protection requirements,
criteria, or limitations promulgated under federal or state law
that, while not "applicable" to a hazardous substance, pollutant,
contaminant, remedial action, location or circumstance at a
Superfund site, address problems or situations sufficiently
similar to those encountered at the Superfund site that their use
is well suited to the particular site. EPA has also developed
another category of requirements, known as "to be considered"
(TBCs), that includes nonpromulgated criteria, advisories,
guidance, and proposed standards issued by federal or state
governments. TBCs are not potential ARARs because they are
neither promulgated nor enforceable. It may be necessary to
consult TBCs to interpret ARARs, or to determine preliminary
remediation goals when ARARs do not exist for particular
contaminants. However, identification and compliance with TBCs
is not mandatory in the same way that it is for ARARs.
MCLs are applicable drinking water standards and are, therefore,
ARARs for aquifer restoration, discharge to the potable water
supply, and reinjection to the groundwater. Other ARARs for the
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site include the promulgated New Jersey Surface Water Quality
Standards, Clean Water Act Ambient Water Quality Criteria,
Occupational Safety and Health Administration Standards, the
Resource Conservation and Recovery Act, and the Clean Air Act.
New Jersey's Air Pollution Control Regulations for VOC and toxic
emissions and OSWER Directive 9355.0-28, Control of Air Emissions
from Superfund Air Strippers at Superfund Groundwater Sites are
also ARARs for the DMW-4 site.
EPA has divided ARARs into three categories to facilitate their
identification:
Action-Specific ARARs are usually technology- or activity-
based requirements or limitations on actions or conditions
involving specific substances.
Chemical-specific ARARs are usually health- or risk-based
numerical values or methodologies used to determine
acceptable concentrations of chemicals that may be found in
or discharged to the environment.
Location-specific ARARs restrict actions or contaminant
concentrations in certain environmentally sensitive areas.
Examples of areas regulated under various federal laws
include floodplains, wetlands, and locations where
endangered species or historically significant cultural
resources are present.
The goal for the cleanup of groundwater contamination at the DMW-
4 site is to restore the groundwater to the more stringent of the
federal or state promulgated MCLs which have been devised to
protect drinking water.
Alternative 2, Groundwater Monitoring with Groundwater Use
Restrictions, would not achieve ARARs because contaminants would
remain on site above MCLs. Alternative 3 and the modified
alternative are intended to meet MCLs in the aquifer under
certain assumptions. The modified alternative will improve the
effectiveness of Alternative 3 by reducing the contamination in
the intermediate aquifer. Pumping the relatively high
contamination in the intermediate aquifer by the use of
additional extraction wells is intended to significantly reduce
contamination and enhance the remedial action.
The groundwater treatment options of Alternative 3, Options T3
and T4, Air Stripping and Carbon Adsorption, are both expected to
achieve ARARs. Option T5, UV Oxidation, is expected to meet
chemical-specific ARARs for most contaminants, although
achievement of the ARARs for TCA may require supplemental
treatment prior to discharge.
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Options Dl and D2, Discharge to Groundwater and Surface Water,
respectively, would have to be designed with floodplain and
historic preservation requirements under consideration. All
discharge options would be required to meet associated
action-specific requirements. Promulgated surface water quality
standards would apply to surface discharge of treated
grpundwater, and promulgated Federal and State MCLs would apply
to discharge to the aquifer or the potable water supply.
Lonq-Term Effectiveness
This evaluation criterion refers to the ability of the remedy to
maintain reliable protection of human health and the environment
over time.
Alternative 3 is considered to provide more long-term
effectiveness and permanence than Alternative 2 since, under .
Alternative 2, no groundwater treatment is provided and
contaminated groundwater migration is not prevented. Under
extraction Option El, Wellhead Extraction, the higher level of
contaminated groundwater in the intermediate aquifer would be
drawn into the less contaminated deep aquifer before being
extracted, thereby negatively impacting long-term effectiveness.
The modified alternative would increase the long-term
effectiveness of Option El by preventing the further migration of
the relatively highly contaminated portion of the intermediate
aquifer and would provide long-term effectiveness for the deep
aquifer by initiating restoration.
The effectiveness of Option E2, Multi-Well Extraction, would
depend on the ability to identify the extent of contamination of
the three aquifers. Alternative 2 would provide long-term
effectiveness to the extent that the institutional controls
remain effective. This would require continued monitoring and
enforcement efforts over the long term.
Groundwater treatment option, T4 - Carbon Adsorption, is expected
to have the greatest long-term effectiveness because it treats
both chlorinated and aromatic organic compounds and results in
destruction of these compounds through spent carbon regeneration.
Option T3, Air Stripping, is also expected to be effective in the
long term for the contaminants of concern.
The discharge option of Alternative 3, D2 - Discharge to Surface
Water, has the greatest long-term effectiveness due to relative
ease of maintenance. This is followed by Discharge Options D4,
Discharge to Public Water Supply, and Dl, Discharge to
Groundwater, which are also easily operated and maintained,
although closer monitoring of the performance of these systems
would be required. Under Dl, however, additional potential
operational problems associated with the reinjection system, such
as clogging of reinjection wells, might need to be addressed.
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Reduction of Toxicity. Mobility, and Volume
This evaluation criterion relates to the performance of a
technology or remedial alternative in terms of eliminating or
controlling risks posed by the toxicity, mobility, or volume of
hazardous substances.
In comparison to Alternative 2, Alternative 3 provides a greater
reduction of toxicity, mobility, and volume through treatment
because it provides active treatment of contaminated groundwater.
Alternative 2 does not provide any reduction in toxicity,
mobility, or volume of contamination. The modified alternative
reduces the toxicity, mobility, and volume of contaminants in the
aquifers, provides reduction for the intermediate aquifer through
the removal of the relatively highly contaminated portion of that
aquifer, and prevents the migration of the intermediate aquifer
into the deep aquifer.
Groundwater extraction option E2, Multi-Well Extraction, would
provide the most timely reduction of mobility and volume by
extracting the contaminated groundwater closer to the potential
contaminated source areas, if the source areas were known. At
this time, source areas and other potential highly contaminated
areas have not been fully identified. Extraction Option El,
Wellhead Extraction, requires that the contaminated groundwater
be drawn through the aquifers to the extraction well in the deep
aquifer. This would result in higher concentrations of
contaminants being drawn into the deeper aquifer. The modified
alternative provides for the removal of the higher level of
contaminated groundwater from the intermediate aquifer in
addition to the restoration of the aquifers.
Treatment option T4, Carbon Adsorption, provides the greatest
reduction of contaminant toxicity through off-site thermal carbon
regeneration. Option T3, Air Stripping, is second for reduction
of contaminant toxicity. Option T5, UV Oxidation, is next since
it is not effective in the treatment of certain chemicals of
concern.
Except for Option Dl, Discharge to Groundwater, which could have
a beneficial effect, the discharge options have no effect on the
toxicity, mobility, or volume of contaminated groundwater. If
properly located, reinjection can enhance contaminant mobility to
augment extraction.
Short-Term Effectiveness
This criterion considers 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 period until cleanup goals are achieved.
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Alternative 2 would be the quickest to implement, since the only
action needed would be to institute groundwater restrictions, and
would have no short-term impacts. Groundwater extraction option,
El - Wellhead Extraction, provides the least short-term impact of
the active remediation alternatives since it requires no well
installation activities. The modified alternative would require
the installation of several extraction wells in the intermediate
aquifer and would take slightly longer to implement than Option
El alone. However, the modified alternative would provide a
greater degree of short-term effectiveness than would only the
wellhead extraction under El, since the highest level of
contaminants present in the intermediate aquifer would begin to
be extracted sooner. Option E2, Multi-well Extraction, requires
the installation of a more extensive extraction well system than
either Option El or the modification to Alternative 3(El), and
would, therefore, require a longer implementation period.
None of the options under Alternative 3 would create any
significant short-term, health-related concerns for the public
beyond those associated with normal construction activities.
Increased traffic during construction and transportation of
treatment residuals would be expected.
Implementability
This criterion examines the technical and administrative
feasibility of a remedy, including availability of materials and
services needed to implement the chosen solution.
Alternative 2 is relatively easy to implement as it only involves
a groundwater monitoring program and groundwater use
restrictions. Alternative 3 and the modified alternative are
also relatively easy to implement and rely on technically
feasible and reliable technologies to actively restore
groundwater quality. Alternative 3 has few associated
administrative difficulties which could delay implementation.
The treatment technologies have been used successfully to address
similar contaminants at other Superfund sites. Skilled workers
needed to implement the remedies are readily available in the
area, and the treatment units can be easily operated and
maintained.
The groundwater extraction option of Alternative 3,
El - Wellhead Extraction, is the easiest to implement since it
involves utilizing only the existing well. Option E2, Multi-Well
Extraction, entails the installation of extraction wells which
would increase the operation and maintenance requirements and
administrative requirements for the acquisition of easements and
rights of way necessary for the extensive piping network to
transport the extracted groundwater to the treatment system.
Because the sources and extent of groundwater contamination have
not been fully identified, selecting locations for the extraction
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wells for Option E2 would be difficult. The modified alternative
would be easily implemented since it would rely on the use of
DMW-4 and the installation of extraction wells in the portion of
the intermediate aquifer that exhibited the highest level of
contamination.
The groundwater treatment options of Alternative 3, T3 - Air
Stripping and T4 - Carbon Adsorption, are expected to be easily
implemented because they are readily available and easily set up.
However, Option T4, Carbon Adsorption, may have additional
operation and maintenance requirements due to the need for
disposal or regeneration of spent carbon. Option T5, UV
Oxidation, is next based on its limited availability and more
intensive operation and maintenance requirements.
Implementation of Alternative 3 may also require the provision of
an inorganic pretreatment system. While inorganic contaminant
levels in the groundwater were not found in concentrations above
MCLs, pretreatment for inorganics may be required to prevent
fouling of the organic treatment system. The need for inorganic
pretreatment will be determined during the design phase.
Installation of the extraction and injection wells and their
associated piping may have to take place on private properties
and may be expected to require some administrative and legal
efforts.
Option D4, Discharge to Public Water Supply, is the easiest to
implement due to existing connections to the public water supply
system. Options D2, Discharge to Surface Water, and Dl,
Discharge to Groundwater, are also implementable. Under Dl,
however, potential operational problems associated with the
reinjection system, such as clogging of reinjection wells, might
need to be addressed.
Costs are evaluated in terms of remedial action capital costs,
operation and maintenance costs, and present worth.
Long-Term Groundwater Monitoring with Water Use Restrictions has
an estimated present worth of $360,000, which is associated
primarily with the long-term groundwater monitoring program.
Alternative 3 consists of a combination of extraction, treatment,
and discharge technologies. The groundwater extraction options,
which include groundwater monitoring for five years beyond
achieving remedial levels, are Wellhead Extraction (Option El)
with a present worth of $730,000, Multi-Well Extraction (Option
E2) at $1,260,000, and the modification to Alternative 3(El) with
a present worth of $1,045,000.
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The groundvater treatment options, based on 16 years (Wellhead
Extraction) and 6 years (Multi-Well Extraction) of treatment,
respectively, are $840,000 and $560,000 for Option T3, Air
Stripping; $5,400,000 and $2,900,000 for Option T4, Carbon
Adsorption; and $19,000,000 and $9,500,000 for Option T5, UV
Oxidation.
The three groundwater discharge options evaluated are Option Dl,
Discharge to Groundwater, at $1,800,000 for 16 years and
$1,600,000 for 6 years; Option D2, Discharge to Surface Water, at
$67,000; and Option D4, Discharge to the Public Water Supply
System, at $100,000.
State Acceptance
The State Acceptance factor addressed whether the State of New
Jersey supports, opposes, and/or has identified any reservations
with the preferred alternative.
The State of New Jersey agrees with and supports the selected
alternative presented in this Record of Decision.
Community Acceptance
This evaluation factor addresses public reaction to the remedial
alternatives which were considered, and the preferred
alternative.
Issues raised during the public comment period and at the public
meeting held on August 19, 1992, are addressed in the
Responsiveness Summary section of this ROD. Comments received
during the public comment period indicated that the local
residents were generally satisfied with the preferred alternative
for the cleanup of contaminated groundwater. Upon review of
these comments, EPA and NJDEPE have determined that no
significant changes to the remedy, as it was originally
identified in the Proposed Plan, were necessary.
THE SELECTED REMEDY
Section 121(b) of CERCLA, as amended, requires EPA to select
remedial actions which utilize permanent solutions and
alternative treatment technologies or resource recovery options
to the maximum extent practicable. In addition, EPA prefers
remedial actions that permanently and significantly reduce the
toxicity, mobility, and volume of hazardous substances found at
the site.
After careful consideration of the remedial alternatives, EPA has
selected an alternative believed to provide the best balance
among alternatives with respect to the evaluation criteria for
groundwater remediation for Operable Unit 1. The RI/FS reports
24
-------
should be consulted for more information on the remedial
alternatives.
The selected alternative to remediate the DMW-4 site is a
modified Alternative 3 with Extraction Option El (Wellhead
Extraction), Treatment Option T3 (Air Stripping), and Discharge
Option D4 (Discharge to Public Water Supply System). Because the
presence of relatively high levels of contamination in the
intermediate aquifer could adversely impact the effectiveness of
the wellhead extraction system by drawing contamination into the
deeper aquifer, it has been determined that these high
contaminant levels in the intermediate aquifer must be removed.
Therefore, the selected remedy includes extraction of
contaminated groundwater from both the intermediate and deep
aquifers. Contaminated groundwater would be extracted from the
deep aquifer through pumping DMW-4 and from the more highly
contaminated portion of the intermediate aquifer through an
estimated two new extraction wells. The extraction system would
be designed to minimize the migration of contaminants from the
intermediate aquifer into the deep aquifer.
The input received during the public comment period, consisting
primarily of questions and statements submitted at the public
meeting held on August 19, 1992, and written comments, is
presented in the attached Responsiveness Summary. Public
comments encompassed a range of issues, but did not necessitate
any major changes in the preferred alternative for the site.
Accordingly, the preferred alternative has been selected by EPA
and NJDEPE as the remedial solution for the site.
This operable unit will initiate remediation of contamination
present in the deep, intermediate, and shallow aquifers.
However, if further investigations define source areas of
contamination or additional areas of groundwater contamination,
remediation of these areas may accelerate cleanup of the shallow
and intermediate aquifers as additional operable units.
The estimated present worth cost of this modified alternative is
$1,985,000. This cost is based on extraction of groundwater from
the deep aquifer using DMW-4, extraction of the high level of
contaminants found in the intermediate aquifer using an estimated
two new extraction wells, treatment through air stripping, and
discharge to the potable water supply system over a period of
approximately 16 years.
Groundwater contamination at New Jersey Natural Gas is being
addressed through NJDEPE administrative actions. Other potential
contaminant sources will be further investigated and a subsequent
remedial decision made. Any additional cleanup work determined
to be necessary will be performed as a second operable unit
action.
25
-------
If it is determined during design or implementation that the
entire volume of remediated groundwater cannot be discharged to a
public water supply system, the surplus quantity would be
reinjected into the groundwater. The goal of the remedial action
is to restore the groundwater to MCLs. Based on information
obtained during the remedial investigation and on a careful
analysis of the remedial alternatives, it is anticipated that the
selected remedy will achieve this goal. However, studies suggest
that groundwater extraction and treatment remedies are not always
completely successful in reducing contaminants to health-based
levels in an aquifer. Actual operation of the remedial system
may indicate the technical impracticability of reaching
health-based water quality standards using this approach.
Promulgated federal and state MCLs and New Jersey Ground Water
Quality Standards promulgated under state law are the groundwater
cleanup goals for the remedy selected in this ROD. EPA
recognizes NJDEPE's request that groundwater at the site be
remediated to the levels specified in the proposed "Cleanup
Standards for Contaminated Sites" which NJDEPE distributed to the
public for comments earlier this year. EPA has not identified
these proposed state regulations as ARARs since they have not
been promulgated by the state at this time. Therefore, any
additional actions which might be required (beyond the remedy
selected in this ROD) to remediate groundwater at the site to the
levels specified in the proposed state regulations are not
required by CERCLA, nor are they eligible for federal funding
under CERCLA. Any such additional actions may be undertaken if
they are not inconsistent with the remedy selected in this ROD,
and if they are performed with NJDEPE funding.
In summary, the selected alternative is believed to provide the
best balance of trade-offs among the alternatives with respect to
the criteria used to evaluate alternatives. Therefore, based on
information available at this time, EPA and the State of New
Jersey believe that the selected alternative would provide
overall protection of human health and the environment, would
comply with ARARs, and would be cost effective. This action
would utilize permanent solutions and alternative treatment
technologies to the maximum extent practicable, given the scope
of the action.
The selected remedy will include groundwater extraction for an
estimated period of 16 years, during which time the remedial
system's performance will be carefully monitored on a regular
basis and adjusted as warranted by the performance data collected
during operation.
Some additional activities will be performed during the remedial
design and remedial action phases for the site. These activities
are described below.
26
-------
The aquifers will be periodically monitored during the
remedial design and remedial action phases, as well as
following the completion of the remedial action. During the
remedial design, studies will be undertaken to further
delineate the extent of contamination and groundwater flow
patterns, and to determine if the remediation of the
groundwater contamination can be accelerated by optimizing
the extraction system.
An analysis will be made during the remedial design to
ensure that any adverse impacts to any wetland areas will be
mitigated. If appropriate, some of the treated groundwater
could be discharged to wetland areas to help offset any
dewatering effects created by the groundwater extraction.
Since the remedial action will occur within the 500-year
floodplain of the Rockaway River, a floodplain assessment
will be conducted during the remedial design.
A Cultural Resources survey will be prepared to ensure
compliance with the National Historic Preservation Act.
STATUTORY DETERMINATIONS
Superfund remedy selection is based on CERCLA, as amended, and
the regulations contained in the NCP. EPA's primary
responsibility at Superfund sites is to undertake remedial
actions that achieve adequate protection of human health and the
environment. Additionally, several other statutory requirements
and preferences have been established. These specify that, when
complete, the selected remedy must comply with ARARs, unless a
statutory waiver is justified. The remedy must also be cost
effective and utilize permanent solutions and alternative
treatment or resource recovery technologies to the maximum extent
practicable. Finally, there is a preference for remedies which
employ treatment that permanently and significantly reduce the
toxicity, mobility, or volume of hazardous wastes as their
principal element. The following sections discuss how the remedy
selected for the DMW-4 site meets these requirements and
preferences.
Protection of Human Health and the Environment
The selected remedy protects human health and the environment
through the extraction and treatment of contaminated groundwater.
The extraction and treatment of the contaminated groundwater will
significantly reduce the threat of potential exposure to
contaminated groundwater.
There are no short-term adverse impacts associated with the
selected remedy which cannot be readily controlled. While no
27
-------
cross-media impacts are expected from the remedy, any
environmental impacts associated with site-related contaminants
or remedial activities will be addressed in the remedial design.
Compliance with Applicable or Relevant and Appropriate
Requirements
The selected remedy will comply with all applicable or relevant
and appropriate action-, contaminant-, and location-specific
requirements. The ARARs are presented below.
Action-Specific
The selected remedy will be in compliance with all federal and
state ARARs. The cleanup goals for the remediation of the
groundwater are the more stringent of the promulgated state and
federal MCLs which are standards for drinking water.
Emissions from the treatment unit would conform with the
provisions of the Clean Air Act. This will be accomplished
through the installation of appropriate air pollution control
equipment if necessary. Occupational Safety and Health
Administration requirements would be complied with during the
implementation of the remedy.
With respect to state action-specific ARARs, the air stripper and
any other regulated equipment will be designed, constructed, and
operated to meet the Air Pollution Control and the Noise
Pollution Control Act requirements and regulations.
Chemical-Specific
The more stringent of the state and federal MCLs will be used as
cleanup goals for the groundwater remediation.
Location-Specific
The site is not within the coastal zone as defined by the State
of New Jersey. Additionally, there are no federally designated
wild and scenic rivers and there are no significant agricultural
lands in the vicinity of the site. The project area may be
sensitive for the discovery of cultural resources. Therefore, as
discussed earlier, a cultural resources survey will be prepared
during remedial design. Additionally, a wetlands delineation
will be performed at that time to determine the presence of and
potential impacts on wetland areas. Since the remedial action
will take place in a floodplain, a floodplain assessment will be
conducted during the design phase.
28
-------
Utilization of Permanent Solutions and Alternative Treatment or
Resource Recovery Technologies to the Maximum Extent Practicable
EPA and the State of New Jersey have determined that the selected
remedy represents the maximum extent to which permanent solutions
and treatment technologies can be utilized in a cost-effective
manner for the DMW-4 site. Of the alternatives that are
protective of human health and the environment, and comply with
ARARs, EPA and the State of New Jersey have determined that the
selected remedy provides the best balance of tradeoffs in terms
of long-term effectiveness and permanence, reduction in toxicity,
mobility, or volume achieved through treatment, short-term
effectiveness, implementability, cost, and State and community
acceptance.
The selected alternative reduces toxicity, mobility, and volume
of contaminants in the groundwater; complies with ARARs; provides
both short-term and long-term effectiveness; and protects human
health and the environment. Contaminants in the groundwater will
be removed and treated. This will significantly reduce the
toxicity, mobility and volume of the contaminants, and offer a
permanent solution to the risks posed by the contaminated
groundwater.
Cost Effectiveness
The selected alternative is determined to be cost effective
because it provides the highest degree of protectiveness among
the alternatives evaluated, at reasonable cost.
Preference for Treatment as a Principal Element
By extracting and treating the contaminated groundwater, the
selected remedy addresses the threats posed by the site through
the use of treatment technologies. Therefore, the statutory
preference for remedies that employ treatment as a principal
element is satisfied by the selected remedy.
29
-------
X\ff U
ft
* ( C
Ni* \ S
"0
—
^
D
-»LJ1
J^^IJ[^^^==^^^^^g;
"~1 I __ ««'• *UArw>il Jf \\\V • »l T '•^^I'.'V j^r ;£\\
/rm^s*
v^'r//**^^
,r<:
-------
TABLE 1
COMPARISON OF DETECTED SHALLOW GROUND WATER
CONTAMINANTS TO APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS (ARARs)
'
PARAMETER
•* VOAs (ppb) ••
Hans- 1,2-Ofchlor
-------
TABLE 2
COMPARISON OF DETECTED INTERMEDIATE GROUND WATER
CONTAMINANTS TO APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS (ARARs)
PARAMETER
••VOAs (ppb)M
TekacMoroetwM
1,1.1 -TrtchtoroettarM
••BNAs (ppb)«*
Outylbeniylptttulale
Olelhylphttalale
Dl-n-ociytonfialele
BIsp-ettyMejtyQpfclMtali
••INORGANICS (ppt>)"
Arsenic
Copper
Me.cuiy
Ztnc
"General Par ameters**
PH
Total Dissolved Solids (mg/l)
MAXIMUM CONCENTRATION
DETECTED IN INTERMEDIATE
GROUND WATER AQUIFER
Round 1 Round 2 Rounds
9/87 10/87 5/89
1200 1000
18 16
S
2
35
170
RH RB|
3
8.5
0.33
IC7
6.9-92 6.6-96 63-78
309 3b& 4930
— FEDERAL ARARs/-
1 2
MCL MOO
(ppb) (ppo)
S 0
200 200
50
1300* •
2 2
— NJARAR*-- -
NJMCL
(Ppb)
1
26
60
2
1. MCL - Maximum Contaminant level National Pilmary Dilnhlng WoKii
Final Mule AnianJniunls to SDWA. U.S. EPA. ENuclvu July VJ-J2
2. MCLG- Matdmum Contamlnanl Lewi Goal, baaad on healBi condUwiaflons only
Final Hula Amendments to SOWA. U.S. EPA, Effecfee JuV
3. Maximum Cunlamlnanl Level tor DrtnMng Water; NJ Sate Drinking Water
Act. NJAC 7 10- 16 7.
•-AOkJM level* lepiesenialve of drinking water qualty at tw lap, U.S. EPA, May 7.1991.
Re|-0ala rejected during data valdatan.
Note. NJNG wells MW-C1D and MW-C3D are not Included In tils summary because remediation of NJNG die-related contarnlnaton to not • prime objectfve of Ms study.
See Table 3-6.
-------
TABLE 3
COMPARISON OF DETECTED DEEP GROUND WATER
CONTAMINANTS TO APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS (ARARs)
'
PARAMETER
•* VOAs (ppb) ••
Caibon Teliachlorlde
trans- 1.2-DlchloroetlMn*
Telrttchtoroethene
Toluene
l.l.l-Trtcntoroethan*
Trtchloroeihen*
••BNAr. (ppb)**
Bulylbenzylphthalate
Dl-n-octylphlhalale
Bte(2-ethyrhexyl)phtialat«
••INOhOANICS (ppb)**
Copper
Lead
Mercury
Selenium
Zinc
••General Parameters**
PH
Total Dissolved Solids (mg/l)
MAXIMUM CONCENTRATION
DETECTED IN DEEP GROUND
WATER AQUIFER
Round 1 Round 2
9/87 10/87
7
17 37
4
11 49
3(0) 2
Re| Re|
6.1-8.5 6.4-112
280 384
Roundd
5/89
2(T)
48
B
7
4
2
76
31
12.3
O.84
5.25
298
6.2-9.3
3890
— FEDERAL ARARs/ —
TBCs
1 2
MCL MCLG
(ppb) (ppb)
100 100
5 0
1000 1000
200 200
S 0
1300*
15*
2 2
— NJARAR*
4
NJMCL
(PPb)
10
1
26
1
2
I. MCL - Maximum Cc .amlnanl Level Notional Primary Uilnking Waioi Regulations.
Final Rule Amendments to SDWA. U.S. EPA. Effective July 1992
2 MCLG- Maximum Contaminant Level Goal, based on heallh consldeiailons only,
Final Rule Amendments to SDWA. U.S. EPA. Effective July 1992
•-Action levels representative of dilnhlng water quality at the lap, U.S. EPA. May 7, 15*91.
Re| - Dala^fjTfecled during data validation.
3. Maximum Contaminant Level for Oflnhlng Water; NJ Safe Dilnhlng
Water Act. NJAC 7:10-167.
(R) - Data collected during resampling round (12/87).
(T) - 1.2 - Dlchtoroelhene (Total).
••» nuMf «4 centum son* and are not tnchided to fit*
-------
TABLE 4
SUMMARY OF GROUND WATER CONTAMINANTS
DETECTED AT DMV #4 TO APPLICABLE OR RELEVANT
AND APPROPRIATE REQUIREMENTS (ARARs)
CONCENTRATIONS
DETECTED IN GROUND WATER AT DMW04
PUMP TEST
PARAMETER
"ORGANICS (ppb)«*
1.2-Dlchtofoetwne
wans- 1 ,2- DIchkMoetMna
as- 1 .?- DfchkNoetttn*
TettachkMoettene
1.1.1 -Trtchtoroeltam
Trichtoraetwne
9/80 1/62
START
9.4 NO
122 7.6
118 0.73
2 ND
1/62
MAX
1.9
56.4
116
0.45
PUMP TEST
4/BS
START
ND
15
1
"*
5/85
MAX
1
54
23
• ^™
PUMP TEST
10/87
START
-
15
-
**
10/87
MAX
ND
36
ND
ND
-FEDERAL ARARs/
TBCs
1
MCL
(Pf>t>)
100
100
70
5
200
s
2
MCLG
(PPb)
100
100
70
0
200
0
— NJ ARARs —
NJMCL
(PPb)
10
10
10
1
26
1
1. MCL - Maximum Canlan*iant Uwel. Natonal Primary OrtnWng Watoi Regulators,
Final Ruto Amendments to SOWA, U.S. EPA, ElteeUve July 1992.
Z MCUQ - Manmum Contaminant Level Goal, based on health considerations onty.
Final Ruto Amendments to SOWA. U.S. EPA, Effective July 1992.
3. Maximum Contaminant level tar Drinking Watt; NJ Sate Drinking Water
Acl,NJAC7:10-16.7.
ND-Not Detected
Note: The January 1982 pump test was performed by Altrod Crews Consulting Engineers.
The Aprtl-May 1985 pump test was performed by Allied Crows Consulting Engineers.
Ihe October 1987 pump test was performed by TRC Environmental Consultants. Inc.
-------
TABLE 5
SUMMARY OF MONITORING WELL DATA
(CONTAMINANTS OF CONCERN)
COMPOUND NAME
INORGANICS
ARSENIC
COPPER
CYANIDE
LEAD
MERCURY
SELENIUM
ZINC
VOLATILE ORGANICS
1,1,1 -TRICHLOROETHANE
1.2-DICHLOROETHENE (trans)
BENZENE
TETRACHLOROETHENE
TOLUENE
TRICHLOROETHENE
BASE NEUTRAL /ACIDS
bis(2-ETHYLHEXYL)PHTHALATE
BUTYLBENZYLPHTHALATE
DETHYLPHTHALATE
DI-N-OCTYL PHTHALATE
FREQUENCY
OF
DETECTION
4/20
10/20
10/44
6/18
6/19
3/20
19/20
9/53
3/53
4/52
9/53
5/53
5/53
5/17
4/20
3/20
5/20
RAN lib
OF
SQL
(ug/L)
3
7
2.5-5
3
0.2
2
4
5
5
5
5
5
5
10
10
10
10
HANUb
OF
DETECTION
(ug/L)
3-7.06
7.1-31
2.5-33
7.91-24.5
0.24-0.84
2.06-5.25
10.1-471
2-49
1-36
4-460
2-1200
3-101
2-17
43-170
1-5
1-2
2-35
ARITHME
TIC
95% UCL FOR
SCENARIO
(ug/L)
NA
NA
NA
NA
NA
NA
NA
*
NA
NA
NA
NA
1(a)
4.62
8.05
111.97
15.67
11.44
4.94
ARITHMETIC
95% UCL FOR
SCENARIO 2(b)
(ug/L)
2.53
10.70
4.88
9.68
0.26
1.83
140.57
6.10
4.14
36.46
95.67
8.96
3.32
61.66
5.00 @
2.00 @
10.20
(a): The 95% UCL is calculated based on data from the shallow aquifer and three sampling rounds
(b): The 95% UCL is calculated based on data from three aquifers and three sampling rounds
(@): Highest detected value used in place of 95% UCL
NA : Not Applicable
-------
TABLE 6
SUMMARY OF TOXICITY VALUES ASSOCIATED
WITH CARCINOGENIC EFFECTS
INHALATION
COMPOUND NAME
NORGANICS
Arsenic
Copper
Cyanide
Lead
Mercury
Selenium
Zinc
VOLAT1LES
1,1.1-Tricr*Toetwne
1 2-Dichloroelhene
Benzene
Tetrachtoroethene
Toluene
Trichloroettiene
SEMIVOLAT1LES
Bis(? — ethyffvxyOphlhalate
Butytoenzylphlhalate
Diethylphtnalate
Di-n-octylphthalale
SLOPE FACtOR
INHALATION
(MG/KG/DAY)-1
5E+01
NA
NA
NA
NA
NA
NA
NA
NA
2J9E-O2
lflE-03
NA
1.7E-02
NA
NA
NA
NA
WLIUHT-OF-
EVIDENCE
CLASSIFICATION
A
D
D
B2
O
D
D
D
A
B2
D
B2
B2
C
D
TYPE OF
CANCER
Respiratory Tract
Leukemia
Leukemia, liver
Lunq
SF BASIS/
SOURCE
Oocupational/HEAST
NA/IRIS^EAST
NA/IR1S>HEAST
NA/IRIS^EAST
NA/IRtS^EAST
NA/IWS.HEAST
NA/1RISJHEAST
NA/IRiS^EAST
NA/IRISXEAST
Occupatranal/IFUS
HEAST
NA/IRIS.HEAST
HEAST
NA/inSXEAST
NA/IWS.HEAST
NA/IWS.HEAST
NA/IRJSJHEAST
NA: Not Applicable
-------
TABLE 6 (continued)
SUMMARY OF TOXICITY VALUES ASSOCIATED
WITH CARCINOGENIC EFFECTS
ORAL
COMPOUND NAME
INORGANICS
Arsenic
Copper
Cyanide
Lead
Mercury
Selenium
Zinc
VOLATILES
1,1,1-Trichloroethane
12-Dtchloroethene
Benzene
TetracNoroethene
Toluene
TrJchkxoethene
SEMI VOLATILES
Bis(? -ethylhexy1)phthalate
Butylbenzylphtnaiate
Oielhylphthalate
Di-n-octylphthalate
SLOPE FACTOR
(SF) ORAL
(moykpydav)-l
NA
NA
NA
NA
NA
NA
NA
NA
NA
2.9E-02
5.1 E -02
NA
1.1E-O2
1.4E-2
NA
NA
NA
WEIGHT -OF
EVIDENCE
CLASS
A
D
D
B2
D
D
D
D
A
B2
D
B2
B2
C
D
TYPE OF
CANCER
Skin
Renal tumors
Leukemia
Liver
Liver
Liver
Leukemia
SF BASIS/
SOURCE
NA/1RJS.HEAST
NA/IRIS.HEAST
NA/IRJS,HEAST
OraVIHS
NA/IRIS.HEAST
NA/IRIS.HEAST
NA/IFttSJHEAST
NA/IRIS^EAST
NA/IRIS^IEAST
Occupational/IRIS
Gavaga/HEAST
NA/IRIS^EAST
GavapjB/HEAST
IRIS
Diet/IRIS
NA/IRIS.HEAST
NA/IFUSJHEAST
NA: Not Applicable
-------
TABLE 7
SUMMARY OF TOXICITY VALUES ASSOCIATED WITH
NONCARCINOGENIC-CHRONIC EFFECTS
INHALATION
COMPOUND NAME
INORGANICS
Arsenic
Copper
Cyanide
Lead
Mercury
Selenium
Zinc
VOLAT1LES
1.1.1 -Trfchtoroethane
l,?-Dfchloroethene
Benzene
Tetracnkwoethene
Toluene
TricNar oelhene
SEMIVOLATILES
Bis(2-ethytnexyl)pnthalate
Bulylbenzylphlhalate
Diethylphthalate
Di - n - oct ylphihalate
CHRONIC RFD
INHALATION
(mpAg/day)
3E-048
NA
2E-028
NA
9E-06
NA
2E-018
3E-01
NA
NA
NA
6E-01
NA
2E-02«
2E-018
8E-01a
2E-02B
CONFDENCE
LEVEL
CRITICAL
EFFECT
MyeNn degeneration
CNS effects
Neuroioxicily
HepatotoxicHy
CNS effects, eyes and nose Irritation
INHALATION
RFD BASIS/
SOURCE
NA0RIS.HEAST
NA/WIS.HEAST
Occupational A1 EAST
NA/WIS.HEAST
HEAST
NA/IRIS.HEAST
NA/WIS.HEAST
NA^niS.HEAST
HEAST
' NA/WIS.HEAST
UNCERTAINTY AND
MODIFYING
FACTORS
-
UF=30
UF-1000
UF=fOO
a: The oral Rid was used when an Inhalation value was not available
-------
TABLE 7 (continued)
SUMMARY OF TOXICITY VALUES ASSOCIATED WITH
NONCARCINOGENIC-CHRONIC EFFECTS
ORAL
COMPOUND NAME
INORGANICS
Arsenic
Copper*
Cyanide
Lead
Mercury
Selenium
Zinc
VOLATILES
t.M-Trfchtoroethane
1 ,2-Dichtaroeihene
Benzene
TetrachJoroethene
Toluene
Tricolor oethene
SEMIVOLATILES
Bis(2-ethylhexyl)pnlhalate
Butylben/ylphthalate
Diethyfphthalate
Di - n - octylphthalate
CHRONIC RFD
(ORAL)
(moAg/day)
3E-04
4E-02
2E-02
NA
3E-04
5E-03
2E-01
9E-02
1E-02
NA
IE -02
2E-OI
NA
2E-02
2E-OI
BE -01
2E-02
CONFIDENCE
LEVEL
Medium
Medium
High
Medium
Medium
Medium
Low
Low
CRITICAL
EFFECT
Keratosis and hyperpigmenlation
Local Gl irritation
Weight toss.lhyrokJ ellecls.myein degeneration
Neurobehavioral effects
Kidney effects
Clinical sdenosis
Anemia
Hepatotoxidly
Decreased hematoait and hemoglobin
Hepatotoxicity .weight gain '
Changes in liver and kidney weights
Increased relative Kver weight
Effects on body weight gain, lestes.liver .kidney
Decreased growth rate.food consumption
rale and altered organ weights
Elevated kklncv and weitihts.incrcascd SGOT.SGPT
ORAL
RFD BASIS/
SOURCE
OraMRIS
HEAST
Diet/niS
NA/KIS.HEAST
Oral/HEAST
Diet/His
Therap./HEAST
lnhal./HEAST
GavageA^EAST
NA/NIS.HEAST
Gavage/IRIS
Gavage/IRIS
NA/HIS.HEAST
Dket/WIS.HEAST
Diet/niS.HEAST
Diet/niS
Dlet/HEAST
UNCERTAINTY
AND MODIFYING
FACTORS
UF*1
Uf=100;Mf=5
UFelOOO
UF=3.MF=1
UF = 10
UF-tOOO;MF«1
UF=3000
UF=100;MF=t
UF=1000.MF«=t
UF=1000;MF=1
UF=1000;MF=1
UF-1000.MF-- 1
UF^'OOO
HEAST uses current drinking water standard for RD - conversion made to mo/kg/day
-------
TABLE 8
SUMMARY OF CANCER RISK ESTIMATES
SCENARIO 1
AVERAGE DAILY
DOSE (L*«)
(mq^qfdtlA
ADJUSTED FOR
ABSORPTION
POTENCY FACTOR
(mgfrgtoyM
WLIljiMI CJr
EVIDENCE
lYPt OF
CANCER
SF BA5IS/
SOURCE
CHEMCAL
SPEOFIC
HSK
EXPOSURE PATHWAY: INDOOR VOC INHALATION
BENZENE
TETRAOHLOROETHENE
TRCHLOHOETHENE
6.5E-04
S.SE-04
6.1E-05
No
No
No
2.9E-02
1.8E-03
17E-02
A
B2
B2
L«i*«mia
L««J<«mia. Ltor
Lv«f
OoeufM«ona|/IRIS
HEAST
Goi/aq*A€AST
2E-05
1E-06
1E-06
TOTAL
CANCER
RISK
2E-05
SUMMARY OF CHRONIC HAZARD INDEX ESTIMATES
SCENARIO 1
TOTAL
< HAZARD
INDEX RATIO
EXPOSURE PATHWAY: INDOOR VOC INHALATION
-------
TABLE 8 (continued)
SUMMARY OF CANCER RISK ESTIMATES
SCENARIO 2 (ADULTS)
CHEMICAL
ID It ON 1C DAILY
INTAKE
COI • I •
ADIIKUDFOR SF Iwi IGirTOF 1 TYPEOf 1 SFBASIST
ABSORPTION ln**i/d«l-| 1 IVIDWH 1 CAN( IR | SOURCE
LXTOSURF PATHWAY INGTSTKN GFCItrMICALSIN DRINKING WATIK
VOI.ATILE ORGAN ICS
BFN7FNK
iirw ATI rtoRoni IFNE
B AST NF.UTRAL/ ACIDS
MZ-niiYi.in-XYi.irimiAi.AT
4.3E-04
1.1E-03
7.2E-04
No 2.9E-02 /
No 5.1E-02 B
No 1.4E-02 B
\ Leukemia Oocupadonal/IR
2 Liver Ga/age/HEAST
2 Liver IRS
ICMIWICAL I TOTAL 1 TOTAL
VIvCIHC 1 PATHWAY 1 CANCHR
RISK 1 RISK 1 RISK
8E-05 9E-05
S 1E-05
6E-05
IE-OS
EXPOSURE PATHWAY INHALATION OF AIRBORNE (VAPOR PHASO CHEMCALS 4E-Ofil
VOLATILE ORGAN KS
HENZENt-
1.1E-M
No 1 2.9E-Oel A 1 Leukemia lOocuoatond/IHS 1 3.0E-06
EXPOSURE PATHWAY- DERMAL CONTACT WITH CHEMCALSIN WATER
VOLATILE ORGAN ICS
IIFNTIrNE
1.6E-05
9.8E-05
No 29E-02 /
No 51E-02 B
k Leukemia lOccupattonaVIH
2 Liver I GavaqeAHEASl
SE-OE!
S 5E-07
5E-OB
SUMMARY OF CHRONIC HAZARD INDEX ESTIMATES
SCENARIO 2 (ADULTS) •
PATHWAY
HAZARD
INDEX
EXPOSURE PATHWAY: INGESTION OF CHEMICALS IN DRINKING WATER 7E-01
EXPOSURE PATHWAY: INHALATION OF AIRBORNE (VAPOR PHASE) CHEMICALS 3E-04
EXPOSURE PATHWAY: DERMAL CONTACT WITH CHEMICALS IN WATER 2E-02
TOTAL
HAZARD
INDEX
7E-01
-------
TABLE 8 (continued)
SUMMARY OF CANCER RISK ESTIMATES
SCENARIO 2 (CHILDREN)
IUKUMK DAILY I CDI III III TOTAL 1 TOfAL
INTAKE IADJUSIT-DFIK 1 SF |WI:IOICTOF| TVTF.OF 1 SFBASIS ICIIFMSPEC. IrATiiwAY IEXTOMJRE
(mfAiL'd") 1 ADSatl'llON |(n*%e'NE
BASENEUIRAL/ACIDS
hiK 2- Pll lYIIII-JCYIIfimiALATi
H (fCinMICAISfN nRINKINnWATTR
2.1E-W
5.4E-04
3.5E-04
No
No
No
2.9E-02
5.1E-02
1.4E-02
A
B2
B2
•IE-OS 4E-05
Leukemia
Liver
Uver
Oocupatlonat/ins
Gavage/HEAST
IRS
6E-06
3E-05
5E-06
EXPOSURE PATHWAY: INHALATION OF AIRBORNE (VAPOR PHASE) CHEMCALS
VOLATILE ORGAN ICS
HfN/ENE
1.0E-M
No
2.9E-Q2
A
Leukemia
OocupBttonaMHSl 3E-06
EXPOSURE PATHWAY: DERMAL CONTAa WITH CHEMCALS IN WATER
VOLATILE ORGAN ICS
HI-NZFWF.
linRAOIljOROETirFNE
69E-06
4.1E-05
. No 1 29E-02
No 1 5.1E-02
A 1 Leukemia
62 1 Liver
Oocupaflonal/IRS
GavaqeA^EAST
2E-07
2E-06
4E-06I
2E-06|
SUMMARY OF CHRONIC HAZARD INDEX RATIOS
SCENARIO 2 (CHILDREN)
[IIHUPV. IMIL1 • 1 111 • • |
IKTAKE |AOIIBTU>Fnit| RFO ITONFIOENrel CKrTCAL
^Jjl^JUjJ^ 1 AlfORrTIOH 1 ImtiMnl 1 LFVPL 1 EFMCT
:XmSI>RP PATHWAY: INTiPSTIINOFrllPMrAlX INOIIINKIND WATFR
INOWMNrS
ARSF.Nr
opri-'R
•YANIUE
II AD
MIM'IIRY
slieNIUM
/IW
VOIAnLEORGANCS
i.i-oniinRORTHKNp (u>i)
IKIR/CIIUIKUFTIIENE
BASPNPIfTRAI (ATIDS
kiMl-KTIIYI.IIFXVI.|PIIT1IALATI
Of H~^^*TY1 PIITIfALATP
EXPOSURE PATHWAY* INH^jl
1JE-W
7.1E-(M
32-04
e«-04
1B6-05
1X-04
OS -03
27E-04
63E-M
4 IE-OS
B7E-Q4
No
No
No
No
No
No
No
No
No
No
No
30E-04
•ICE -02
?BC-02
NA
30E-04
SOE-03
20E-01
1.CE-07
1.0E-0?
3
------- |