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My staff and I are available to discuss this matter further with
you at your convenience.
Attachment
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EXPLANATION OF SIGNIFICANT DIFFERENCE
REICH FARM Superfund Site
Dover Township, Ocean County, New Jersey
INTRODUCTION
The purpose of this Explanation of Significant Difference (ESD)
is to explain the United-States Environmental .Protection Agency's
(EPA's) changes to the groundwater remedy selected in its
September 30, 1988 Record of Decision (ROD) an'd the subsequent
1995 ESD..'for the Reich Farm- Superfund Site (Site or Reich Farm.
Site) ... The. ROD called, for. extraction of. contamin-ated..ground-
water, treatment via air stripping and carbon ..adsorption, and
reinjection of the treated ground-water. The ROD also called for
remediation of., the contaminated soil on-site through low
temperature thermal desorption. The portion of the cleanup
addressing the soil was not modified, by the.1995 ESD.
In 1995, EPA modified the'ROD" by issuing an-ESD. A proposed ESD
was issued to the public ..n August 1995, and comments from the
public were addressed during an August 16, 1995 public meeting.
A responsiveness summary was prepared to address questions
related to the modification. The majority of commentors
supported the modification of the remedy as described in the 1995
ESD.
The selected remedy, as modified by the 1995 ESD, called for
ground water extraction from existing public supply wells, and
treatment of the contaminated ground water through an air
stripper located at the United Water Toms River's (UWTR's)
Parkway Well Field (Well Field) and distribution of the treated.
ground water to the municipal water supply. The modification to
the remedy, described in the 1995 ESD, did not require the ..
construction of a groundwater pump and treat system as called for
in the original ROD.
The 1995 ESD also indicated that the Well Field treatment system
would be monitored closely and upgraded, if necessary, to ensure
that the public water supply meets all state and federal safe
drinking water standards.
Currently, there are six wells (#22, #24, #26, #28, #29, and #44)
in the Parkway Well Field that draw water from the Cohansey
aquifer. In 1996, the New Jersey Department of Environmental
Protection (NJDEP) and the New Jersey Department of Health and
Senior Services (NJDHSS), as part of an intensive study of the
Dover Township water supply, found additional low level chemical
contamination, in. water, from Well #26.. The. contaminants, were . .
. sent i£ied;.as. by-products. of>Mix acT^lqTjitrile/atvrene;., reactions. > .
It was .also. deterrained".tha.t these, compounds-.were- disposed-of at- -
the Reich Farm. Site. ' :As there are no existing state- or federal'-'.
drinking water standards for these compounds and very little is
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known on their toxicity, UWTR agreed', as a precautionary measure,
to close the two wells (#26 and #28) that are capturing the Reich
Farm ground, water plume. When operating, Wells #26 and #28 have-
effectively protected the Well Field's remaining four Cohansey
wells from contamination. Since Wells #26 and #28 were closed,
the remainder of. the Parkway Well Field's wells were closed to
pr=--.-ent the plume from spreading to them. Potable water was
supplied from, other, well fields during, this. time, period.
Due to public concerns in Dover Township regarding an apparent
elevation in childhood cancer, cases, and .in.recognition.of the
unknown..toxicity of the recently identified compounds, EPA and"
the State agencies believe it prudent to be very conservative on
environmental matters in the area. Therefore EPA has chosen.to
modify the remedy described in the 1995 ESD, so that the water
from Wells #26. and #28 undergoes further treatment that includes
an activated carbon system. The activated carbon system removes
the recently identified compounds to below detectable levels. As
Maximum Contaminant: Levels. (MCLs) do nof exisf for the recently
identified compounds, the activated carbon units will remain in
operation until the concentrations of the recently identified
compounds are no longer detected in ground water from the wells
or are determined.to., be at an acceptable risk level in Wells #26,
#28, and in the monitoring wells within the Site's ground water
plume.
This ESD also allows the treated water to be distributed as
potable water supply, discharged to a designated recharge area,
or discharged to the Toms River at the discretion of the State
and local authorities.
Groundwater from all other Well Field wells that are shown to
have no detectable levels of the recently identified compounds,
or are at acceptable risk levels and that meet all other state
and federal drinking water standards, will be available for use
as potable water supply. Furthermore, if ground water from any
other Well Field well is found to contain site-related
contaminants at levels deemed to be unsafe, additional treatment
as necessary will be provided to ensure compliance with all state
and federal safe drinking water levels.
EPA issues this ESD in accordance with Section 117(c) of the
Comprehensive Environmental Response, Compensation and Liability
Act of 1980, as amended (CERCLA), 42 U.S.C. §9617(c), and Section
300.435 (c) (2) (i) of the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP), 40 C.F.R. §300.435(c) (2) (i) .
Site Location, History, Contamination Problems, Selected Remedy
~:ie: Reich'"Farm property/ which''.comprises" parcvdr"1 the' bveradl*
Sitei-.--.is-.located.-oh Lakewood-1 Road'in the Pleasant Plains section
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of Dover Township, New Jersey. The property encompasses three
acres and is surrounded by commercial .and residential areas.
In December 1971, approximately 4,500 drums containing wastes and
450 empty drums from Union Carbide Chemicals' (UCC's) Bound Brook
chemical manufacturing facility were discovered at the Site. In
1972 and 1974, UCC removed the drums and some contaminated soil
from the. Site.
In 1974, the Dover Township Health Department .(now the Ocean
County Health Department) issued a zoning ordinance- restricting
private, well .use around, the. Site. due. to. contamination.-, found: in
the. ground water. Currently, all residences and businesses
within the area affected by groundwater contamination associated
with .the. Site are connected, to the public water supply. The
public water supply has continuously met the federal and sr.ate
safe drinking water standards . .
In September 1983 , EPA" included the Reich- Farm Site on its
National Priorities List of Superfund Sites. In 1986, EPA
commenced a Remedial Investigation and Feasibility Study (RI/FS)
at the Site pursuant to CERCLA, in order to identify the nature
and extent of contamination, and to develop cleanup alternatives.
The RI confirmed the presence of groundwater and soil
contamination. Contaminants identified in the groundwater and
soil included 1, 1, 1, -trichloroethane, trichloroethene, and
tetrachloroethylene. These chemicals are hazardous substances
within the meaning of Section 101(14) of CERCLA, 42 U.S.C.
§9601(14} .
On September 30, 1988, EPA issued a ROD that described the
selected remedy for contaminated ground water and soil at the
Reich Farm Site. The remedy called for the following:..
(1) additional groundwater and soil sampling to further
delineate contamination related to the Site;
(2) the excavation and treatment of contaminated soil by
enhanced volatilization (thermal desorption) to remove
volatile organic compounds (VOCs) and semivolatile organic
compounds ; and
(3) the installation and operation of a groundwater pumping,
treatment and reinjection system to remove VOCs from ground
water at the Site.
POST -ROD ACTIVITIES
a, issuance. -or. che.-.RCPv.. EPA'/entered-^'int'ov av.-:j:.udi:cial<. •' . '
•Jonsent. .Decree .with.. UCC. in., September: 198.9 for -performance: of • -.-
remedial design and construction; of: the-'selected- "remedy .. The.'
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decree was entered by the federal district court of New Jersey on
March 28, 1990.
Since the issuance of the ROD, UCC conducted two phases of pre-
design activities. Phase I, which was conducted during 1990-1992
and summarized in the May 1992 Remedial Design/Remedial Action
Report, included additional soil and groundwater sampling to
further delineate the. extent of. contamination. Based on the
sampling results, EPA concluded that: (1) groundwater.
contamination from the Site extends approximately one-mile south
to the UWTR Parkway Well Field; .and. (2) the: volume of/ .
contaminated, soils at. the Site, was .approximately.. 15, 000" cubic
yards (which significantly exceeded the initial estimated ..volume
of 2,000 cubic yards).
Phase II activities included a thermal desorption treatability
study for soil treatment. The thermal treatment of the 15,000
cubic yards of.contaminated soil.and restoration of the Reich
Farm property was completed in May 1995'. Phase II activities
also included an evaluation of groundwater remedial design
scenarios based upon the results of the Phase I sampling and
modeling. This evaluation is. presented in a February 1995 report
entitled "Evaluation of Groundwater Remedial Design Scenarios."
The groundwater data collected and the modeling done during the
two phases of pre-design work increased EPA's understanding of
the movement and configuration of the groundwater contaminant
plume. Based on this information, EPA issued the 1995 ESD.
In 1996 and 1997, additional information was collected regarding
the contaminants comprising the plume. Additional site-related
compounds were identified in two wells within the Well Field
(Wells #26 and #28) . The toxicity of these compounds, which were
found in low part per billion concentrations, is unknown. As a
conservative precautionary measure, NJDEP has recommended that at
this time, the water from these wells should not be used as
public water supply unless necessary to meet the public's demand
for potable water. However, Wells #26 and #28 must continue to
operate to ensure the protection of the remaining wells
comprising the Well Field (Wells #22, #24, #29 and #44). In
addition, Wells #26 and #28 must operate to facilitate the
ultimate cleanup of the groundwater plume.
In May 1997, UCC added activated carbon treatment following the
air stripper treatment system at the Parkway Well Field.
Effluent sampling has shown that activated carbon effectively
treats the recently identified compounds to non-detectable
levels, at an analytical..detection.-limit..of 100:parts per..
-ril'liarr... .;••• •.., -. •
In addition, due to. special'.'public, health' concerns in. Dover-
Township, EPA chose to evaluate several discharge options for the
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water from Wells #26 and #28. One option was determined to be
immediately implementable. Currently,. after treatment, the water
from Wells #26 and #28 is discharged to the ground on an area
close to the intersection of Route 9 and the Garden State Parkway
(discharge area). To date, inspection, of the discharge area
indicates that the treated water is being adequately recharged to
the aquifer. EPA and NJDEP will evaluate the discharge via
confirmation of.modeling-and..effects on the discharge area (i.e.,
recharge effectiveness) and on other public wells in. the area to
determine if a discharge line should be extended to the Toms
River... At NJDEP's discretion, the treatedwaterrmayalso.be used.
as a source of, potable-water.
Wells #22., #24,. #29, and. #44 were sampled and analyzed in May
1997. Samples collected frcT. Wells #29 and #44 were found to
contain levels of radiological contamination above the Federal
safe drinking water levels. (MCLs). . NJDEP and EPA suspect this
may be due to high levels of naturally occurring radium 224. The
radiation is not due to any contamination at the Reich Farm Site.
Compliance for radiological compounds is not based on samples
collected from each individual well; rather, the MCLs must be met
after the water from the respective wells is blended within the
water distribution system. After blending, the water from the
Parkway Well Field meets the MCLs for radiological compounds.
The data collected from Wells #22, #24, #29, and #44 demonstrate
that the recently identified compounds have not been detected in
these wells. The water from these wells meets all safe drinking
water criteria prior to distribution; therefore, these wells are
being used as public potable water supply. A contingency plan
.will be put in place to ensure that action is taken in the
unlikely event that these wells become contaminated with site-
related compounds at levels that would cause an unacceptable risk
to human health.
DISCUSSION OF SIGNIFICANT DIFFERENCES
EPA, in recognition of the special health concerns in Dover
Township, and after consultation with the NJDEP, modifies the
groundwater remedy as described in the September 30, 1988 ROD and
previously modified in the 1995 ESD as follows:
* The Well Field's groundwater treatment system has been
upgraded by including an activated carbon system after air
stripping to treat' the entire groundwater plume emanating
from the Reich Farm property.
Rather than.vdi-strifautingvthe t^ra*c^d/.wa,ter.;to';,ciies;aruaicipal .•:,
water supply (as., presented iiuthe:.1395., ESDF, this ESD1"
provides three options.? recharge-of the treated water to the
aquifer via the discharge area; discharge of the treated
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The modified remedy complies with the federal and state drinking
water standards as specified- in the ROD. In addition, the
modified remedy is technically feasible, and provides treatment
that permanently and significantly reduces the toxicity, mobility
and volume of-hazardous substances in.the groundwater.
Jeanne. K. F
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