United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R02-88/060
June 1988
SEPA
Superfund
Record of Decision
Montgomery Township Housing, NJ
-------
30273-101
REPORT DOCUMENTATION
PAGE
lr REPORT NO.
EPA/ROD/R02-88/060
3. Recipient's Accession No.
4. Title and Subtitle
SUPERFUND RECORD OF DECISION
Montgomery Township Housing Development, NJ
econd Remedial Action - Final
5. Report Oeti
leport Oat*
06/30/88
Authord)
8. Performing Organization Rept. No.
9. Performing Organization Name and Address
10. Project/Task/Work Unit No.
11. ContracUC) or Grant(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 Covered
800/000
14.
15. Supplementary Notes
16. Abstract (Limit: 200 words)
The Montgomery Township Housing Development (MTHD) site is located in Somerset
County, New Jersey. The Rocky Hill Municipal Wellfield (RHMW) Superfund site is also
covered by this remedial action because of its proximity to the MTHD and the similarity
of the contaminants present. The 72-acre MTHD site is a development which includes 71
private homes, with an additional 6 homes affected by the contamination in the
surrounding residential areas. The RHMW consists of a two-acre tract of land in the
orough of Rocky Hill, which supplies public water to the residents of Rocky Hill. In
978, a study of the RHMW revealed TCE contamination, which led to closure of one well
and eventual installation of an air stripping treatment unit on the well in 1983.
Concern over the ground water contamination in Rocky Hill spurred the initial sampling
of residential wells in MTHD from December 1979 to January 1980. In March 1981,
Elizabethtown Water Company water lines were installed in MTHD, and residents were
advised not to use well water. Twenty homes initially elected to connect to the
municipal supply, and at the present time 38 residences have hooked up. In September
1987, an operable unit ROD was signed by EPA, which provided for the supply of alternate
water through the permanent hookup of all MTHD residences, and six residences outside of
MTHD, to the available public water supply system, incomplete field investigations have
(See Attached Sheet)
17. Document Analysis .a. Descriptor*
Record of Decision
Montgomery Township Housing Development,
Second Remedial Action - Final
Contaminated Media: gw
Key Contaminants: TCE
b. Identlfiers/Open-Ended Terms
NJ
c. COSATI Field/Group
Availability Statement
19. Security Class (This Report)
None
20. Security Class (This Page)
None
21. No. of Pages
59
22. Price
(See ANSI-Z39.18)
See Instructions on Reverie
OPTIONAL FORM 272 (4-77>
(Formerly NTIS-35)
Department of Commerce
-------
EPA/ROD/R02-88/060
Kontgomery Township Housing Development, NJ
econd Remedial Action - Final
16. ABSTRACT (continued)
identified 13 possible sjurces of contamination. The nearby Princeton Gamma Tech
property has been identified as a primary source of TCE contamination in the area. The
primary contaminant of concern affecting the ground water is TCE.
The selected remedial action for this site includes: ground water pump and treatment
using air stripping and reinjection of the treated water back into the aquifer;
connecting any remaining affected residences to the public water supply and sealing of
remaining private water supply and monitoring wells within the contaminant plume; and
implementation of ground water monitoring. Present worth cost for this remedial action
is $2,548,000 with annual O&M costs of $94,000.
-------
DECLARATION STATEMENT
RECORD OF DECISION
Montgomery Township Housing Development
SITE NAME AND LOCATION
Montgomery Township Housing Development, Montgomery Township,
Somerset County, New Jersey
STATEMENT OF PURPOSE
This decision document presents the selected remedial action
for the Montgomery Township Housing Development site, developed
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 applicable, the National Oil and Hazardous Substances
Pollution Contingency Plan, 40 CFR Part 300.
Montgomery Township Housing Development and RocJcy Hill Municipal
Wellfield are two Superfund sites in southern Somerset County.
Because of the close proximity of the sites, and the similarity
of the contaminants present, both sites were addressed in a
single remedial investigation and feasibility study. Similarly,
the attached Decision Summary and Responsiveness Summary cover
both sites.
STATEMENT OF BASIS
I am basing my decision primarily on the following documents,
which are contained in the administrative record, and that
characterize the nature and extent of contamination and evaluate
remedial alternatives for the Montgomery Township Housing
Development site:
- Operable Unit Remedial Investigation Report, Montgomery
Township Housing Development, prepared by Woodward-Clyde
Consultants, July 1987;
- Operable Unit Feasibility Study Report, Montgomery Township
Housing Development, prepared by Woodward-Clyde Consultants,
July 1987;
- Record of Decision (for first operable unit), Montgomery
Township Housing Development, September 1987;
- Remedial Investigation Report, Montgomery Township Housing
Development and Rocky Hill Municipal Wellfield, prepared by
Woodward-Clyde Consultants, April 1988;
-------
-2-
- Feasibility Study Report, Montgomery Township Housing
Development and Rocky Hill Municipal Wellfield, prepared by
Woodward-Clyde Consultants, April 1988;
- Proposed Remedial Action Plan, Montgomery Township Housing
Development and Rocky Hill Municipal Wellfield, May 1988;
- The attached Decision Summary for the Montgomery Township
Housing Development and Rocky Hill Municipal Wellfield sites;
- The .attached Responsiveness Summary for the sites, which
incorporates public comments received; and
- Staff summaries and recommendations.
DESCRIPTION OF SELECTED REMEDY
The remedial alternative presented in this document represents
a filial^remedial solution for the Montgomery Township Housing
Development site. It addresses ground water contamination in
the underlying aquifer. A previous Record of Decision, signed
in September 1987, provided for the connection of residences
with impacted or threatened wells to a public water supply and
the sealing of those private wells.
The specific components of the remedial action are as follows:
- Extraction of contaminated ground water from the primary
source area followed by on-site treatment and reinjection
of the treated water back into the underlying aquifer. The
ground water will be treated to achieve federal and state
cleanup standards;
- Connecting any remaining affected residences to the public
water supply;
- Sealing of remaining private water supply and monitoring wells
within the contaminant plume; and
- Implementation of a ground water sampling program to monitor
the effectiveness of the cleanup.
DECLARATIONS
Consistent with the Comprehensive Environmental Response, Comp-
ensation and Liability Act, as amended, and the National Oil
and Hazardous Substances Pollution Contingency Plan, 40 CFR Part
300, I have determined that the selected remedy is protective
of human health and the environment, attains federal and state
requirements that are applicable or relevant and appropriate
for this action, and is cost-effective.
-------
-3-
Furthermore, this remedy satisfies the preference for treatment
that reduces the toxicity, mobility or volume as a principal
element. Finally, I have determined that this remedy utilizes
permanent solutions and treatment technologies to the maximum
extent practicable.
The State of New Jersey has been consulted and agrees with the
selected remedy for the Montgomery Township Housing Development
site.
ift
4:
Date ' Christopher "Jj/ffaggett
Regional Administrator
-------
Decision Summary
Montgomery Township Housing Development Site
Rocky Hill Municipal Wellfield Site
SITE LOCATION AND DESCRIPTION
The Montgomery Township Housing Development (MTHD) and Rocky hill
Municipal Wellfield (RHMW) sites are located in Somerset County, New Jersey,
In the vicinity of the intersection of U.S. Route 206 and N.J. Route 518.
The MTHD includes approximately 72 acres located east of Route 206 and north
of Route 518. The development and surrounding area Include 77 private
homes. The RHMW is a 2 acre tract of land in the Borough of Rocky Hill,
which services the residents of Rocky Hill. The RHMW is located east of
Route 206, south of Route 518, and south of the MTHD. Figure 1 shows the
study area.
Properties along Montgomery Road, the northern border of the MTHD site,
are wooded, residential or agricultural lots. To the southwest are two,
shopping centers and an office center. To the south is a residential area
of Rocky Hill. The homes on the end of Cleveland Circle within MTHD are
bordered to the east by the Millstone River, which parallels the Delaware
and Raritan Canal.
The MTHD/RHMW sites lie within the Piedmont Physiographic Province and
are underlain by bedrock of the Brunswick Formation covered with a
relatively thin veneer of unconsolidated sediments (up to about 30 feet
thick). • Regionally, the Brunswick Formation primarily consists of varying
thicknesses of red shale and mud stone, and is the principle aquifer in the
area. Ground water exists in a number of water-bearing zones which are
generally under unconfined to semi-confined conditions. Intersecting
vertical and horizontal fractures have resulted from Jointing and provide
the principal means of storage and movement of ground water in the formation.
Drinking water for the MTHD is supplied by private residential wells
and by the privately-owned Elizabethtown Water Company. Thirty-eight of the
71 residences of MTHD are currently connected to Elizabethtown's system.
The remaining 33 residences of MTHD and 6 residences outside of MTHD
continue to use private wells but will be connected pursuant to the Record
of Decision signed for the MTHD site in September 1987. Individual septic
tanks are used to dispose of wastewater. The residential wells in the
affected area are at an average depth of 125 feet.
The RHMW which supplies public water to the Borough of Rocky Hill
extends to a depth of 278 ft. An air stripping treatment unit on the well
was Installed by the Borough in 1983 as a response to the presence of
contamination, and consists of two cylindrical towers operating in series
with a capacity of 250 gallons per minute.
The RHMW is located in the Rocky Hill Historic District and is listed
on both the State and National Register of Historic Places. The corridor
adjacent to the Millstone River has a potential for archaeological
-------
-2-
•ignlflcancc, according to the State Historic Preservation Officer.
SITE HISTORY AND ENFORCEMENT ACTIVITIES
Maps indicate that until 1961. the MTHD site was used for fanning.
Construction of the homes began in 1961 and the area was divided into 71
lots with private wells and septic tanks. \
"•»
RHMW wells numbered 1 and 2 were cuusn-u-ceo in 1936. Iheac two wells
provided a source of potable water to the Borough of Rocky Hill. Veil
number 1 was abandoned and sealed between 1976 and 1978. In 1978, a study
by Rutgers University on the RHMW revealed trichloroethene (TCE)
contamination levels of about 25 parts per billion (ppb). Continued testing
of this well by Rocky Hill from 1978 to 1983 indicated that the TCE
concentration ranged from about 50 ppb to 200 ppb. Due to the elevated
levels of TCE in the water, well number 2 was closed in November 1979.
Levels of TCE in the well water eventually declined, and the well was
subsequently reopened. Levels of TCE, however, increased, and the well was
closed for a second time in January 1982. During the shutdown of well
number 2, the Borough of Rocky Hill obtained potable water from
Ellzabethtown Water Company. After the installation of two air stripping*
units by the borough for well number 2, the well reopened as a potable
source of water in July 1983.
Concern over the ground water contamination in Rocky Hill spurred the
initial sampling of commercial and domestic wells in Montgomery Township
from December 1979 to January 1980. Figure 2 shows the results of potable
well samples prior to the initiation of the remedial investigation and
feasibility study (RI/FS) for the MTHD site. Data shown are averages of TCE
concentrations found in domestic wells between 1979 and 1985. Residences at
the ends of Robin Drive, Oxford Circle and Cleveland Circle were found to
have the highest TCE concentrations whereas lower TCE concentrations were
found in wells along Sycamore Lane. TCE was not detected in any domestic
wells proximate to the northern portion of Montgomery Road. The historical
results were insufficient to adequately delineate a plume of contaminated
ground water.
In March 1981, Elizabethtown Water Company water lines were installed
in MTHD, and residents were advised not to use well water. Twenty homes
initially elected to connect to the municipal supply. At the present time,
38 residences have hooked up. In January 1986, the New Jersey Department of
Environmental Protection (NJDEP), Division of Water Resources placed a
restriction on future well drilling for water supply wells in the area. In
September 1987, an operable unit Record of Decision (ROD) was signed by the
United States Environmental Protection Agency (USEPA), with the concurrence
of NJDEP. The September 1987 ROD provided for the supply of alternate water
through the permanent hookup of all MTHD residences and 6 residences outside
of MTHD to the available public water supply system.
Field investigative activities were initiated by NJDEP and USEPA to
identify the source(s) of contamination for both sites. Soil borings,
septic samples, site inspections, and continued ground water monitoring have
been used to Identify 13 possible sources of contamination. Figure 3 shows
these facilities. At the present time, Investigatory measures are
-------
-3-
incomplete. Requests for information are being sent to current owners, past
owners, and past tenants. No notice letters have been sent to potentially
responsible parties; and determination of enforcement actions, if any, will
be made upon review of all relevant Information.
COMMUNITY RELATIONS
Community Relations activities for the MTHD/RHMW sites\were initiated
by the NJDEP in 192. «rith Che development of a Community Relations Plan.
An initial public meeting was held in January 1986 to present NJDEP's
plans for the Rl/FS for the MTHD/RHMW sites.
In September 1987, a ROD was issued in which the USEPA and NJDEP agreed
to provide connections to an available public water supply. Public
participation was solicited as part of this ROD's development through a
public notice, public meeting, and public comment process similar to the one
discussed below.
On April 25, 1988 the completed draft Rl/FS and the Proposed Remedial
Action Plan (PRAP) addressing the overall ground water problem were made.
available for public review and comment at five public information
repositories. The PRAP defines NJDEP's and USEPA's preferred remedial
alternative for the sites. Notices regarding the PRAP, public meeting and
public comment period were sent to all contacts identified in the Community
Relations Plan and to the news media. The 30-day public comment period was
extended through May 31, 1988 at the request of a commentor.
A public meeting was held in May 1988 to discuss the results of the
Rl/FS and the PRAP for the MTHD/RHMW sites.
The primary concerns of the affected residents involve the location of
equipment and possible associated air and noise pollution. The owners of
one property, identified as a primary source of the contamination, expressed
concern regarding the necessity of remediating the aquifer, and proposed
that natural attenuation be relied upon for the entire remediation. A
Responsiveness Summary, which addresses the comments and questions raised,
is attached to this ROD.
The officials from Montgomery Township and the Borough of Rocky Hill
have requested continued involvement through the design and construction.
This interest is based on their concerns about equipment placement, noise,
and air emissions. NJDEP noted that continued updates would be provided.
SCOPE AND ROLE OF OPERABLE UNIT
This ROD addresses the second of two planned operable units for the
sites. The first operable unit addressed the provision of an alternate
water supply to MTHD residents. A water connection and well sealing program
Is currently being Implemented as identified in the ROD signed in September
1987.
The second operable unit Rl/FS addresses identification of the
source(s) of contamination, determination of the nature and extent of
-------
-4-
contamination. and evaluation of alternatives for the remediation of ground
water. Upon completion -of this operable unit the concentrations of the site
contaminants are expected to be significantly reduced, such that they comply
vith all applicable or relevant and appropriate requirements (ARARs) as
required by Section 121 of the Superfund Amendments and Reauthorlzation Act
(SARA), and no longer pose a threat to the public or the environment.
Therefore, no further operable units are anticipated. •
SITE CHARACTERISTICS
In 1984, the NJDEP entered into two Cooperative Agreements with the
USEPA under which it would perform the RI/FSs for the MTHD and the RHMW
sites. Because of the proximity of the two sites and the similarity of
contaminants found, a single RI/FS for the two sites was performed under one
professional contract.
Investigative activities under this project were developed to identify
possible sources of contamination in an attempt to eliminate continued
discharges, and to determine the nature and extent of the ground water.
contamination. These activities included a file search; ground water flow
studies; along with ground water, septic tank, surface water, sediment, and..
soil boring sampling. In addition to information collected directly under
this program, results from other sources (such as RHMW water analysis and
site investigations conducted outside this program) provided information.
Once the ground water data were compiled under this program, the
feasibility of supplying several alternative drinking water sources was
evaluated in an Interim RI/FS Report in July 1987. The associated risk
assessment indicated that many of those residents using their private wells
as a water supply were being exposed to increased health risks, and in
September 1987, the USEPA issued the previously mentioned ROD with the
concurrence of NJDEP.
The Brunswick Formation in this area was observed to strike N40° to
N50°E and dip gently to the NW about 10 to 15°. Most of the fractures in
the bedrock were not bedding plane joints, but rather sets of near vertical
fractures at an acute angle to the bedding. The predominant trend of
fractures was found to average N60°E. Nevertheless, the geophysical survey
also identified some near-horizontal fracture zones, which may be associated
with the bedding planes.
Nearly all of the porosity in the Brunswick Formation occurs in the
fractures. Although the distribution of fractures decreases with depth in
the Brunswick Formation, site data suggests that water-bearing zones persist
to a depth of at least 500 ft. The slug test data suggests that locally,
most of the fractures intercepted by an individual well are limited in
extent with respect to their ability to transmit water. However, more
extensive water-bearing fractures which persist laterally in excess of 1,500
ft. are evidenced by the results of the pumping test.
Depth to ground water in the shallow wells (screened in the weathered
top of bedrock) was found to range from approximately 5 to 54 ft. below
ground surface. Deeper wells (to depths of 100 to 250 ft.) uniformly
exhibited lower plezometric heads than the paired shallow well, Indicating a
-------
-5-
potential for downward vertical flow of ground water.
Contours of ground water elevations and piezometric head appear
concordant with the topographic contours in the MTHD. That is, the ground
water table is a subdued expression of the land surface. Static
ground-water flow in both shallow and deep aquifers appears to be toward the
Millstone River (eastern region) and Beden Brook (western and northern
regions). The shallow aquifer intersects and discharges to\ the Millstone
River and Beden Brook and to several small streams which .re tributaries *f
the Millstone River and Beden Brook. Figures 4, 5 and 6 present the ground
water contours for the shallow ground water, deep ground water under static
conditions, and deep ground water during the pumping test, respectively.
Although the potential for downward vertical flow exists, hydrologic
and geochemlcal evidence suggests that zones of high vertical permeability
may be discontinuous and limited in extent. This is exemplified by the fact
that the RHMW pump test caused drawdowns in the deep wells, but none of the
shallow wells appeared to be affected during the period of pumping.
On 19 occasions between November 1979 and July 1987, ground water
samples were collected and analyzed for either volatile organics or for TCE_
only. The ground water samples collected during the RI in 1986 were also
analyzed for other organics and inorganics. Table 1 lists the contaminants
detected in the ground water during the Rl sampling events. This table
presents the maximum and mean concentrations of compounds which were
detected.
The RI ground water results are further summarized in Table 2 by
comparing the results for the indicator chemicals identified in the risk
assessment with the remedial response objectives (see the "Description of
Alternatives" section of this ROD and Table 3 for the discussion of the
response objectives). This comparison presents two significant issues. The
first item to note is that TCE is the most predominant site contaminant,
both with respect to concentration and areal extent.
The second item noted from Table 2 is that several compounds are only
sporadically present. Chlordane, for example, was present only in 2 samples
out of 86. Examination of the locations of these findings found no
relationship to the TCE contamination, nor was any other evidence of a
separate plume of chlordane found. Similar findings were noted for arsenic,
barium, beryllium, chromium, lead, nickel, and silver. These compounds were
not considered to be related to the TCE contamination, and were not
considered when the effectiveness of remedial alternatives were evaluated.
1,1-dlchloroethene was found in only one sample, but the coincidental
presence of significant levels of other compounds related to the plume (eg:
TCE) prevented the elimination of this compound from consideration.
Results of these sampling programs have revealed that a plume of TCE
contamination roughly extends from Route 206 east to the Millstone River
north to Sycamore Lane and south to Route 518. Concentrations of TCE within
the plume range from below the detection limit, 5 ppb, to 650 ppb in
monitoring wells. A TCE concentration as high as 950 ppb was detected in a
domestic well on Robin Drive on one occasion in 1982, prior to the RI/FS.
Figure 7 shows the areal extent of the contaminant plume by graphically
-------
-6-
depictlng the distribution of ICE.
Neither the surface water nor the sediment samples from the Millstone
River or Beden Brook identified the presence of contamination. The septic
tank sampling found some compounds in low concentration but TCE was not
detected.
«
The following compounds were present in _the soils in ^excess of the
NJDEF action levels; xylenes, PC£s, -irsenic, copper} and mercury. Xylenes,
PCBs, arsenic, and copper wert- identified ~St the location of 1377 Route
JQ&. This contamination is currently being addressed as part of other NJDEP
actions (Administrative Order with property owners)» and will not be
addressed as part of this remedial action. Mercury was identified in a
septic field boring in concentrations only slightly above the action level
(3.7 parts per million (ppm) vs. 1 ppm), and at a depth of 16 feet. Mercury
was not identified in the ground water. Due to the low concentration and
depth of this compound, it will not be addressed in the remedial action
alternatives. None of the compounds found to be of concern in the ground
water were identified in excess of action levels in the soils. Identlfled-
soil contamination is therefore not a concern for the MTHD/RHMW sites
because links to ground water contamination have not been made, and the-
presence of those compounds is being addressed further by appropriate NJDEP
programs. If any additional sampling identifies other contaminated areas,
those areas would have to be addressed accordingly.
An investigation at the Princeton Gamma Tech property located on Route
518 was conducted under NJDEP's Environmental Cleanup Responsibility Act
program (ECRA). ECRA is designed to resolve environmental problems prior to
the sale or closure of certain industrial properties. The investigation
found TCE in the shallow ground water beneath the Princeton Gamma Tech
property at concentrations of 5,000 ppb. This information combined with
findings of shallow TCE contamination in an onsite RI/FS well, and the
property location with respect to the upgradient edge of the ground water
plume led to the conclusion that this property was a primary source of TCE
contamination in the area.
While an earlier septic tank sample at this property identified the
presence of TCE, a recent sample found only residual TCE in the septic
tank. The RI reported results for 28 soil samples at the property, none of
which showed TCE contamination. The property owner is currently involved in
independent soil sampling activities under the guidance of NJDEP. The above
information indicates the likelihood that some past discharge was the source
of contamination presently found in the shallow ground water.
As indicated above, TCE Is currently detected in the ground water. No
TCE has been found in any surface water samples. Thus, the major transport
of TCE is via ground water. The direction of ground water flow is generally
to the northeast in the eastern part of the MTHD/RHMW sites and to the
northwest in the northwestern part of the sites (See Figures 4, 5).
\_
The primary impact of the TCE contamination is on the quality and
potential use of the ground water. In addition, ground water discharge to
the Millstone River is likely; however, as previously noted TCE has not yet
been detected in surface water samples.
-------
-7-
SUMMARY OF SITE RISKS
A public health assessment was conducted for the sites in accordance
with the Superfund Public Health Evaluation Manual (1986). Since the site
characterization noted that soils and surface waters are not currently being
Impacted by the site related contamination present in the ground water,
exposure to soils and surface waters was not included £n the health
aasessi»*nt of the MTHD/RHMW sites. Thus, the risk assessment only
-V2d exposure to contaminated ground waters.
A comparison of calculated total dose levels for indicator chemicals
with "reference dose levels (RfD) and acceptable daily intake levels (ADI)
shows that the estimated maximum dose exceeds the cited threshold level in
seven of the eleven cases of total adult dose levels investigated, and
eleven of the eleven child dose levels calculated. This indicates that
exposure to contaminants at the maximum concentration detected, over a
lifetime, may lead to noncarcino genie adverse health effects. The hazard
index from an adult exposure to plume contamination is 13.21 and 175.07, for
mean and maximum exposures respectively. The background hazard index is.
0.60 for mean dose and A. 03 for maximum doses of indicator chemicals. A
hazard index in excess of 1.0 is indicative of the presence of a_
noncarcinogenic health concerns.
Dose calculations for the MTHD/RHMW sites indicate that the largest
estimated dose for organic compounds occurs from inhalation (caused by
volatilization of compounds from ground water used for cooking or
showering) , followed by ingestion and dermal adsorption. All of the
increased lifetime cancer risks associated with exposure to organlcs and
metals in the ground water are larger than one in one hundred thousand (1 x
10 ). The total upper, bound risk level is between four in one hundred and
six in ten (4.14 x 10~ to 5.47 x 10~ ). Increased lifetime cancer risks
from exposure to background levels of indicator chemicals at the sites are a
maximum of two in one thousand (2.52 x 10~ ).
The data collected for the RI indicates that many of the compounds used
in estimating the risk were sporadically detected, and are not site related
(inorganics and chlordane) . Negating these compounds Inclusion when
estimating the risks of the sites, the increased^, lifetime cancer risk ranges
from a mean of eight in. ten thousand (8.6 x 10 ) to a maximum of seven in
one thousand (7.0 x 10 1, as compared to a maximum background risk of four
in one million (3.8 x 10 ).
DOCUMENTATION OF SIGNIFICANT CHANGES
The PRAP presented the preferred remedy illustrated in the following
excerpt:
"NJDEP and USEPA recommend that an aquifer treatment system
consisting of pumping at the source area, air stripping units and
upgradient reinjection be selected as the most appropriate site
remedy (Alternative 7 with consideration to combine some air
strippers as discussed in Alternative 5B) . This system would
protect public health and the environment in the most cost
effective and implementable fashion, and best meet all applicable
-------
TABLE 3, SHEET 1 OF 3
CRITERIA REVIEWED FOR GROUND WATER REMEDIAL OBJECTIVES
NJ HCL
(A-280)
HCL(c)
Substances
NJ CW
Quality
Standards
(ug/lKt)
HCtG(d)
(ug/1)
NJ Interim
Grounduatar (Uferance
Haalth Claan-up Levels for
•dvtaorlaa Guidance Carcinogens
Trans- 1 ,2-01chloroathana( -ethy lane)
Dlatny Ipbthalata
2 5(y)
2 7(y)
10
0
7
70(p)
0.95(q)
0.2D(q)
350
(»)
5(v)
5(»)
(»)
-
0.38
0.06
2
2
10
(v)
0
0.06
10
(v)
2
2
10
Dt-n-butytphthlata
EthyIbansana
Hathylana Chlorlda
N-NItroaodIphanylaalna
Phenol
68a(p)
680
5(q)
1,500
680
2
3.500
680
2
3.500
Tetrachloroethene
1.2.4-trlchlorobensene
1,1,1 Trlchloroethane
Tr lchloro*thene( -ethy lene)
TrlchlorofluoroMethana
Toluene
1
8
26
1
200(y)
5(y)
(1)
200
0
2.000(p)
0.7(q)
22.000(q)
10.100
5(v) 0.69
-
5<»» 3.2
-
(v)
1
a
26
1
0.69
26
0
(v)
1
8
26
1
| (V)
SOURCE!
RI/FS
-------
TABLE 3, SHEET 2 OF 3
CRITERIA REVIEWED FOR 6ROUND WATER REMEDIAL OBJECTIVES
Substances
AluBlnuB
Arsenic
BarluB
Beryl HUB
Cadmium
Calcium
ChroaluB
Cobalt
Copper
Cyanide
Iron
Lead
MagnesluB
Manganese
Mercury
Nickel
PotasstuB
Silver
SodluB
Thai HUB
NJ GH
NJ NCL Quality
(A-280) NCL(c) Standards HCLG(d)
(ug/IMb) (ud/l) (ug/lMl) 1,000 I.SOO(p)
IO
-------
TABLE 3, SHEET 3 OF 3
CRITERIA REVIEWED FOR GROUND WATER REMEDIAL OBJECTIVES
NOTESl
• . Federal and State criteria reviewed to prepare this table.
b. Nail MB Contaminant Level, Stale Sate Drinking Water Act.
e. Minimum Contaminant Level, Federal Safe Drinking Water Act.
d. Hailmum Contaminant Level Coal, Fed ere I Safe Drinking Mater act.
e. EPA drinking water health advisories, based on life tie* eipoaure.
r. The reference concentration for carcinogen* la calculated baaed on a 1 • 10 risk and the cancer potency factor (CPFI provided In the Superfund Public
Health Evaluation Manual (USEPA. 19666) as follow*!
reference concentration (ug/l) • (I • IO~°)/CPf
Where available oral rout* Off a are uaed, sama reference concentrations are baaed on Inhalation rout* CPFs.
g. Host stringent site specific applicable or relevant and appropriate requirement.
h. Host stringent health-based goal to be considered for action being considered.
I. An MCLG MBS proposed but subsequently withdrawn, a new HCLO currently under dlaouaalon (USEPA, MM, I98T).
J. DCHP Included as per Input fro* NJDEP.
k. Based on Health Advisory of 20 ug/day and IngeatIon of I liters per day.
•. Interim NCL.
p. Proposed value.
q. Reference concentrations for potential carelnogena, corraaponda to a potential cancer.
r. DKethylhevyDphthlate or Bls(?-ethylheiyl)phthlate.
a. talue of Chromlum(«6).
t.. NJAC 719-6. New Jersey Croundwater Quality Standards. Primary Standard. Clasa CW?.
u. N*ew Jersey Interim Croundwater Clean-up Guidance, developed 1906. On an Interim basis the corrective action level of 5 ppb (ug/l) Is applied to
Individual cheatcaIs categorised as carcinogens by NJDEP.
v. On an Interim basis, the corrective action criteria for groundwatar of SO ppb total volatile organla toilo pollutants In groundwater shall apply to the
SUM of all compounds Indicated.
w. NJAC 7i9-6. New Jersey Croundwater Quality Standards, Secondary Standard!, Glass ON?.
y. U.S.EPA 1987 National Primary Drinking Water Regulations - Synthetic Organ I o Chemicals. Federal Reglater 5* (IJO)i »689-?STIT.
i. EPA Aablent Water Quality Criteria (WQC) for Protection of Human Health.
aa. value calculated froa CPF for Inhalation route of 7.0 (ag/kg/day)~', waa below the Method detection Halt and below background quality. Since this '
an objective to be considered for cleanup, the goal will be set at the lowest technically achievable level (I.e. the aethod detection llalt).
bb. "MA" Indicates that the Information la not available
cc. "09/1" la equivalent to parta per billion (ppb)
SOURCEI MTHD/RHMM RI/FS
-------
TABLE 4, SHEET 1 OF 5
SUMMARY OF REMEDIAL ATLERNATIVES
ALTERNATIVE
1. NO ACTION:
Ground water monitoring,
5-year site reviews.
2. AQUIFER ISOLATION:
Public water hookups,
seal private wells,
ground water monitoring,
5-year site reviews.
3A. PUMP/AIR STRIP IN
ENTIRE PLUME, DISCHARGE
TO SURFACE WATER AND
GROUND WATER:
Extraction wells (13),
air stripping,
some discharge to SW,
some discharge to GW,
public water hookups,
seal private wells,
ground' water monitoring.
3B. PUMP/AIR STRIP IN
ENTIRE PLUME, DISCHARGE
TO GROUND WATER:
Extraction wells (13),
air stripping,
discharge to GW,
public water hookups,
seal private wells,
ground water monitoring.
3C. PUMP/AIR STRIP IN
ENTIRE PLUME, USE TREATED
WATER AS A POTABLE SUPPLY:
Extraction wells (13),
air stripping,
use treated water as a
potable supply,
public water hookups,
seal private wells,
ground water monitoring.
CAPITAL
COST
($1000)
13
94
ANNUAL
O&M
COSTS
($1000)
PRESENT
WORTH
($1000)
222
303
TIME TO
ACHIEVE
ARARs
(years)
10
124
4,296
4,713
151
5,641
3,204
131
4,132
-------
TABLE 4, SHEET 2 OF 5
SUMMARY OF REMEDIAL ATLERNATIVES
ALTERNATIVE CAPITAL ANNUAL PRESENT TIME TO
COST O&M WORTH ACHIEVE
($1000) COST ($1000) ARARs
U1000) (years)
MA. PUMP/CARBON *»,153 1,059 10,653 U
ADSORPTION IN ENTIRE
PLUME, DISCHARGE TO
SURFACE WATER AND
GROUND WATER:
Extraction wells (13),
carbon adsorption,
some discharge to SW,
some discharge to GW,
public water hookups,
seal private wells,
ground water monitoring.
MB. PUMP/CARBON 5,332 1,081 11,998 4
ADSORPTION IN ENTIRE
PLUME, DISCHARGE TO
GROUND WAT.ER:
Extraction wells (13),
carbon adsorption,
discharge to GW,
public water hookups,
seal private wells,
ground water monitoring.
HC. PUMP/CARBON 3,823 1,081 10,H89 UO
ADSORPTION IN ENTIRE
PLUME, USE TREATED WATER
A* A POTABLE SUPPLY:
Extraction wells (13),
carbon adsorption,
use treated water as a
potable supply,
public water hookups,
seal private wells,
ground water monitoring.
-------
TABLE H. SHEET 3 OF 5
SUMMARY OF REMEDIAL ATLERNATIVES
ALTERNATIVE
5A. PUMP/AIR
SOURCE AREA,
GROUND WATER
GRADIENT:
Extraction wells
air stripping,
discharge to GW down
gradient,
public water
seal private
ground water
STRIP IN
DISCHARGE TO
DOWN
(3)
hookups,
wells,
monitoring.
CAPITAL
COST
($1000)
1.971
ANNUAL
O&M
COST
($1000)
PRESENT
WORTH
($1000 )
2,5U8
TIME TO
ACHIEVE
ARARs
(years)
5B. PUMP/AIR STRIP IN
SOURCE AREA, DISCHARGE TO
GROUND WATER UP GRADIENT:
Extraction wells (3),
air stripping,
discharge to GW up
gradient,
public water
seal private
ground water
2,516
hookups,
wells,
monitoring.
5C. PUMP/AIR STRIP IN"
SOURCE AREA, USE TREATED
WATER AS A POTABLE
SUPPLY:
Extraction wells (3),
air stripping,
use treated water as a
potable supply,
public water hookups,
seal private wells,
ground water monitoring.
9U
2,081
UO
-------
TABLE H, SHEET 4 OF 5
SUMMARY OF REMEDIAL ATLERNATIVES
ALTERNATIVE CAPITAL ANNUAL PBESENT TIME TO
COST 04M WORTH ACHIEVE
($1000) COST ($1000) ARARs
($1000) (ye? ••:•
6A. PUMP/CARBON 2,123 579 5,677 5
ADSORPTION IN SOURCE
AREA, DISCHARGE TO
GROUND WATER DOWN
GRADIENT:
Extraction wells (3),
carbon adsorption,
discharge to GW down
gradient,
public water hookups,
seal private wells,
ground water monitoring.
6B. PUMP/CARBON 2,091 579 5,6U5 5
ADSORPTION IN SOURCE
AREA, DISCHARGE TO
GROUND WATER UP GRADIENT:
Extraction wells (3),
carbon adsorption,
discharge to GW up
gradient,
public water hookups,
seal private wells,
ground water monitoring.
6C. PUMP/CARBON 1,592 579 5,U6 HO
ADSORPTION IN SOURCE
AREA, USE TREATED WATER
AS A POTABLE SUPPLY:
Extraction wells (3),
carbon adsorption,
use treated water as a
potable supply,
public water hookups,
seal private wells,
ground water monitoring.
-------
TABLE 4, SHEET 5 OF 5
SUMMARY OF REMEDIAL ATLERNATIVES
ALTERNATIVE
7. PUMP/AIR STRIP IN
SOURCE AREA WITH
VICINITY INJECTION
(3 AIR STRIPPERS):
Extraction wells (3)
air stripping (3 units)
discharge to GW near
treatment,
public water hookups,
seal private wells,
ground water monitoring.
CAPITAL
COST
($1000)
/'
1,618
ANNUAL
04M
COST
($1000)
84
PRESENT
WORTH
($1000)
2,136
TIME TO
ACHIEVE
ARARs
(years)
NOTE:
1) Present worth is calculated using an interest rate of 10},
and a project duration of 10 years. System operation for the
full period was assumed in calculating the present worth.
2) Estimated times presented are relative times for remediation
of the contaminated ground water, and are based on
assumptions of the degree of aquifer flushing caused by
implementing each alternative and the necessary amount of
flushing required for remediation.
-------
TABLE 5
The Nina It •••dial Evaluation Criteria
Short-Tat*
Effectiveness
Long-ten
Effectiveness
and
Permanence
Reduction of
Toxlclty, Hoblllty
' and Volusie
(TMV)
Implementabllity
Coat
Potential impacts on
community during RA
Implementation
Potantlal impacts on
workers during RA and
the effectiveness and
reliability of protective
messures
Potential environmental
Impacts of RA and the
effectiveness and
reliability of mltlgatlve
measures
Time until protection la
achieved
HapiItode of total residual
rlak In terms of untreated
waate & treatment
residuals
Adequacy and suitability
of controls (engineering 6
Institutional) used to manage
untreated waste and treatment
residuala
Reliability of controls over
time, Including potential
for failure and potential
resulting rlak
Treatment proceas and
amount of material to be
treated
Amount of hazardous
materlala that will be
deatroyed or reduced
including how principal
threat la addressed through
treatment
Degree of expected TMV
reduction (e.g. percent
of total, order of magni-
tude)
Degree to which treatment
la irreversible
Type and quantity of
residuals reaultlng from
treatment process
Technical feasibility
- Difficulties & unknowns aasociated
with technology
- Reliability of technology
- Eaae of undertaking additional
action, if required
- Reliability • effectiveness of
monitoring
. Administrative feasibility
- Ability 6 time necessary to obtain
required approvals/permits
- Stepa required to coordinate with
other Agenciea and aaaoclated
time requirements
Availability of services and materlala
- Treatment, atorage or disposal
capacity
- Existence of multiple vendors
- Availability of needed equipment
& apeclallsta
- Timing of technology availability
Capital
Operation
and
mainten-
ance
Present
worth
Compliance
with ARARa
Overall
Protection
State
Acceptance
Community
Acceptance
Attainment of chemical-
location-, and action-
specific requirements
Compliance with other
criteria, adviaorles,
and guidance
Grounds for invoking
a waiver
How alternative eliminates
reduces, or controls existing
and potential risks to human
health and the environment
through treatment, engineer*
Ing controla. and/or Institu-
tional controls
Features of the alterna-
tive the State supports
Featurea of the alterna-
tive about which the State
strongly opposes
Featurea of the alternative
the community anpporta.
Featurea of the alternative
about which the community
has reservations.
Elements of the alternative
(he community etrongly opposes
-------
MOCHV MIL
MUNICIPAL
WIllFlflO
FIGURE 1
STUDY AREA FOR MOMTCONBRV TOWNSHIP
HOUSING DEVELOPHEHT AHD ROCKV HILL
MUNICIPAL WELLFIELO SITES j
SOURCE: MTHD/RHMW RI/FS
-------
AVERAGE
TCE CONCENTRATIONS
GREATER THAN
150 pi*
100-149ppb
2ft-4t»pb
l-M ppb
NOT DETECTED
Klppbl
NO DATA
AVAILABLE
FIGURE 2
AVERAGE TCE CONCENTRATIONS FROM
1979 THROUGH 1965 IN MONTGOMERY
TOWNSHIP HOUSING DEVELOPHENT
>RHMW RI/FE
-------
tiOtMD
H»TiNTIAL •PUNCH 0» CONTAMIMAtIC
I. miMCITONCHfMICAl NIMAMCM
*niMCl TON OAMM A TiCM
COMrOlMOLMTNIft
ruiMct ION «mro*i
•Nat ntOLL HAND
TMUft AUTOAMOMMIL
TIIACOOA* STATION
• MM. Ft MM CAS
IOMM AND COtMTM V AMIMA1
II. MOMTOOMNNV •MO»*ING Cf MTf II
ti viitAOt mo»f«»
II MlMCITOM VOL M SWA 0
-------
iiOlHO
Q MW*« MOMITOMIMOWfll 1OCA1ION
AMOMUMMM ^
IIMI1I WATIfttllVATIOMIMMIT
ABOVC MIAN ft A LIVIl
WONtOUM INIIMVAt 10 f Tl
UMI MAT ft MMUtl If Nlll.
MOCHT Hill OUAONANOI.I.
MfWJtHMV. OAtIO IHO
KALI
FIGURE 4
SHALLOW WELL WATER ELEVATIONS
ON AUGUST 21,19*7 FOR MTHO/RHHW
SITES
SOURCEi MTHO/RHMW RI/FR
-------
N
UOiMO
Q MM-0 MOMITONMM Witt LOCATION
AMONlMNf*
MMtlt MATIN CLIVATION IN MtT
ACOVf MIAN MA If VII
•60'
• fllZOMtTMICtUllrACICOMTOUft
ICONICKM IMTf HVAL If FTI
UMI MAT ?.t*MNWT« ItMIt*.
MOCMV Milt OUAOMAMOli.
NtN JtMM V. OATtO in*
•c*n
FIGURE 5
DEEP WELL WATEH ELEVATIONS
ON AUGUST 21,1987 FOR
HTHO/RHNW SITES
SOURCE: i MTHTVRHMU
-------
N
UOIHO
^ MM-« MOMITONtNa Will LOCATION
ANONUMMin
lie* til
•eo«
AtOVI Mf AMSf A IIVII
»U COMCTNIC CUMtACI CON TO
(CONTOUR INTINVAl IOMI
_ MNf CTtON or ONOUNO
" WATIH now
> OMOUNOWATf M OIVIOI
tOUKCf:
UCOS MA» » • MIMUTI IINIIt.
MOCH » Mill OUAONAMOll.
NCNNNMV. OATf O 1I7O
tCAli
FIGURE 6
DEEP WELL WATER ELEVATIONS AFTER
5 HOURS OF PUHPINC AT RHHW ON
DICENBER 13,1»«* FOR HTJLD/RHHW SITE
rMD/RH
qni IRPF < MTMO/OMMU ot
-------
LCOCND
Q MONITOHINO WILL LOCATION
** ~ AND NMMCN
AVCNAOC TCC CONCENTRATION Itlt-lttr
M NOT OCTCCTCO
I '»_ti^|
MOTiti
•• TCI CONCf NTHATIOM AMI Mi AM AVIMAOf • Of ALL
OATA Ut7t-tMn fOU OOMf STIC. COMMCMCIAL WATCH
tUTPLV. AND OCIP MONITORING Ml LLS.
>• MTICTWN INMTirON HltTONICAl ANALVIfl VAMIfO
MTWCf M I AND • UO/L.
*• TNI CONCf NTNATIOM ritlM ANI 1HOMM OML V TO AID
Ml f Mi VISUALIZATION Of THt DISTMIMITION Of TCI
ACNOtt THC CITI. TMf CONCIMTNATIONrifLMAMI
IMTIMMO TO IlLMTNATf ANt At MNf Hi IT It fHO-
•AtLI THAT OHOUNO WATCH Of THC IMOICATf O TCI
CONCC«ITNATION HANOI MAT >f CNCOUNTCMCO AT
TNC MCUNT TUNC.
4. ALTHOUOHTHimUMCItBAtCOONAlLHIITOIIICAl
OATA. IT It CONSUTCNT MITH THC MOST Nf CCMT IIM>t
ANAIVTICAL OATA.
SOUHClii' <
usat MAP rtMiMurt tiMit t.
HOCMV MIL OUAOMAMGIC.
v. OATCO itro.
1000
SCAlf
FIGURE 7
,AVERAGE TCE CONCENTRATIONS IN DEEP
MONITORING WELLS AND POTABLE WELL?
FOR RHMW/MTHD SITE3
-------
•OUNONV OF PtUMC
•OUMOftV OF FftlMAflV H.t
LEGEND
MONITORING WELL LOCATION
EXTRACTION WELL
o INJECTION WELL
ACTIVE REMEDIATION
PRIMARY PLUME BOUNDARY
KXX> 2000 FT
SCALE
FIGURE 8
CONCEPTUALIZED LAYOUT OF EXTRACTION
WELLS AND INJECTION WELLS IN
ALTERNATIVE «7 FOR RHHW/HTHD SITES
SOURCE:
MW RI/FS
-------
-8-
or relevant and appropriate regulations (as required by the
Superfund Amendments and Reauthorization Act). Implementation of
this system would include connection of the residence in the
southwest section of the site to public water, sealing of affected
private wells, and flushing the source area by extracting,
treating (air stripping) and reinjecting the treated ground water."
«
No significant changes have been made to this preferred remedy as a
t«bult of the public comment period. **
DESCRIPTION OF ALTERNATIVES
A total of 15 alternatives were developed and evaluated in the RI/FS
(seven alternatives plus several sub-alteratives). These alternatives were
developed in a three stage process consisting of response objective
development, technology review and screening, and assembly of technologies
into a variety of feasible alternatives.
Remedial response objectives generally include the protection of human
health and the environment from existing or potential threats posed by-
contaminated materials. The objectives are used to focus the development
and evaluation of remedial alternatives possible for the site. Response*
objectives are selected in consideration of the site-specific data generated
during the in-field investigations, ARARs, and other response guidance. The
objectives are consistent with NJDEP and USEFA requirements/policies. Since
contamination was generally limited to the ground water, the response
objectives specifically focus on ground water issues.
No single set of federal or state criteria applies to allowable
concentrations in drinking water for all of the contaminants detected in
ground Water at the sites. For this reason, all ARARs and criteria to be
considered have been reviewed and summarized in the final three columns of
Table 3. These columns present the most stringent site-specific ARARs, the
selected site-specific health based goals to be considered, and the
site-specific remedial response objectives.
The area of contamination within the aquifer includes approximately 200
acres and is 100 to 200 feet thick. The area of contamination is further
described by dividing it into a primary plume (TCE concentrations greater
than 100 ppb), and a secondary plume (TCE detected at less than 100 ppb)
(See Figure 7). The maximum TCE concentration detected in the primary plume
is 5,900 ppb (at Princeton Gamma Tech); the mean TCE concentration in this
primary plume is 200 ppb. The secondary plume has a mean concentration of
50 ppb. The objective of the remediation alternatives is to reduce the
entire ground water concentration of TCE to one (1) ppb. One ppb is a New
Jersey maximum concentration limit (MCL) for TCE which is currently
proposed, and is expected to be promulgated in the near future. This level
is being used at these sites in place of the federal MCL of 5 ppb.
Tetrachloroethene and 1,1-dichloroethene will also have a remedial objective
of reducing such concentrations to below 1 ppb and 2 ppb, respectively.
In addition to the remediation of the aquifer, short term actions must
be performed to protect the public health during remediation. Residences
currently using private wells should be provided with an alternate public
-------
-9-
vater supply. While approximately 40 residences are on private veils, all
but one are already part of a water line connection program (September 1987
ROD). The remaining residences should be connected under this program.
In order to prevent future uncontrolled contacts with the ground water,
affected private veils and unused monitor veils should be sealed. The 1987
ROD included sealing of the potable veils for those residences being
connected to the public vater supply. Other residences Save previously
connected to the public supply, these should be sealed. Approximately 60
veils would be affected.
.The possibility of secondary TCE contamination sources down gradient of
Princeton Gamma Tech still remains, but ground vater contamination up
gradient or side gradient of these properties makes any determination
extremely difficult. A monitoring program should be instituted to observe
vhether these locations begin to exhibit evidence of contamination as
regional ground vater conditions improve. As a final consideration, the
vater treatment prior to distribution currently being employed by RHMW
should continue.
A variety of remedial technologies vere evaluated in the FS to.
determine the most feasible methods of remediating the ground vater at the
sites. The technologies vere screened and refined through a preliminary
evaluation. The only technology class eliminated during this preliminary
evaluation vas the in-sltu treatment. Concern regarding the Implementation
of the in-situ treatment technology in the fractured rock aquifer of the
MTHD/RHMW sites vas the primary reason for eliminating this technology.
Several variations vithin the flushing technologies vere retained for
further consideration. These variations either allowed for site remediation
in different time periods or offered different treatment methods.
Seven remedial alternatives vith several sub-alternatives were
Identified to protect human health and the environment from the
contamination at these sites. Table A lists these alternatives, and they
are described below:
Alternative 1 - No Action consists of providing no control measures to
mitigate the contamination or isolate the remaining residence(s) from the
contaminated ground vater. Natural attenuation vould be the only method
used to reduce the levels of contamination. Contaminant levels and
distribution vould be monitored on a regular basis to observe possible
changes that may varrant additional measures (such as delineating secondary
sources or notifying residents). Since contamination vould remain
essentially unremediated, reevaluatlon of the no action response vould be
performed at five-year intervals (as prescribed by SARA) to address whether
changes in site characteristics and to evaluate whether the remedy is
protective of human health and the environment.
Alternative 2 - Aquifer Isolation. The September 1987 Record of Decision
for the MTHD site provides for the connection of all affected residences to
public water, and the sealing of their wells. The aquifer isolation
alternative expands upon this past decision by incorporating site knowledge
gained during Phase II sampling. This alternative requires that present
private wells be sealed and future well installations be prohibited in order
-------
-10-
to isolate the aquifer from uncontrolled potable water usage. In addition,
residences within the contaminant plume would be provided with public
water. The Phase II results have identified one additional residence
affected by the contamination plume, located on the eastern edge of Rocky
Hill. This residence was not included under the September 1987 ROD, but
would be addressed in this alternative. The monitoring elements from
Alternative 1 would also be performed as part of the aquifer isolation.
Alternative - - ...» aad Air Si:>lp in the Entire Plume represents an
aggressive aquifer remediation strategy designed to minimize the time
required to clean up the site. In addition to the public water connection
and well sealing components identified in Alternative 2, an aquifer
remediation system would be employed using an estimated 13 extraction wells
consisting of 4 wells within the primary plume and 9 wells located in the
secondary plume within the eastern residential areas. Extracted ground
water would be treated by air stripping. The alternative is further divided
into 3 sub-alternatives, which differ in the possible discharge locations
for the treated ground water (3A - combination of surface water and ground
water discharge; 3B - ground water Injection; 3C - use as a potable water
supply).
Alternative 4 - Pump and Treat with Carbon Adsorption in the Entire Plume is"
identical to Alternative 3 and its sub-alternatives except that activated
carbon adsorption would be the central unit process (4A, 4B and AC
correspond to 3A, 3B and 3C).
Alternative 5 - Pump and Air Strip in the Source Area represents an aquifier
remediation strategy which is designed to focus active remedial efforts in
the most contaminated regions of the aquifer. The ground water secondary
plume would be allowed to remediate itself via natural attenuation, while
Isolation and cleanup of the primary plume is achieved by extraction wells
within the source region. Although extraction wells would not be installed
in the secondary plume, cleanup of this area would be enhanced because any
contribution from the source area would be arrested. Additional enhancement
(i.e. reduction in time to remediate) can also be achieved by reinjection of
the treated water up gradient of this area, which would accelerate the
natural attenuation of the ground water.
Alternative 5 includes the public water connection and well sealing
components of Alternative 2 and an aquifer flushing system using an
estimated 3 extraction wells located in the primary plume within the
commercial areas of Montgomery Township. Extracted ground water would be
treated by air stripping. The alternative is further divided Into 3
sub-alternatives, which differ in the possible discharge locations for the
treated ground water, but incorporate all other elements of Alternative 5
(5A - ground water Injection dovngradlent; SB - ground water injection
upgradient; 5C - use as a potable water supply).
Alternative 6 - Pump and Treat with Carbon Adsorption in the Source Area is
identical to Alternative 5 and its sub-alternatives, except that carbon
adsorption would be the central unit process (6A, 6B and 6C correspond to
5A. 5B and 5C).
Alternative 7 - Pump and Air Stripping In the Source Area with Vicinity
-------
-11-
Injection - During the development of the equipment and piping layout and
costs for Alternative 5, it became evident that another alternative
warranted evaluation. This alternative uses the same 3 primary plume
extraction veils outlined in Alternatives 5 and 6; however. Instead of
incorporating a single centralized treatment unit, individual air strippers
are installed at each pumping location. Discharge from each unit would be
to two injection wells located at nearby points, selected to enhance
flushing within both the primary and secondary plumes. As VI th the other
flushing alternatives, Alternative 7 includes the public water connections
and well sealings of Alternative 2.
SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
The site remediation alternatives described above are evaluated below.
The evaluation discusses the relative advantages/disadvantages of the
alternatives in relation to each of 9 remedial evaluation criteria utilized
in current USEPA guidance (Draft RI/FS Guidance, 3/88; Draft Proposed Plan
and ROD Guidance, 3/88). Table 5 summarizes these criteria. The
evaluations are typically presented in comparison to either Alternative 5B
or Alternative 7, which comprise the elements of the selected remedy.
The Short Term Effectiveness criteria evaluates alternatives in lighC"
of potential impacts during construction, potential impacts to workers and
the community, potential impacts to the environment during implementation,
and time until protection is achieved.
Except for Alternative 1, all alternatives equally protect human health
by connecting affected residences to public water supply.
While all alternatives are expected to eventually result in the ground
water contamination being reduced to acceptable levels, the time for this
cleanup is estimated to vary several fold between the alternatives.
Alternatives that reinject the treated ground water performed significantly|
better than the others, with minimum cleanup time estimates being reduced
from AO years (Alternatives 1, 2, 3C, 4C, 5C, 6C) to less than 7 years)
(Alternatives 3A, 3B, AA, 4B, 5A, 5B, 6A, 6B, 7). Estimated cleanup time
for Alternatives 5A, B and 6A, B are five years, and seven years for
Alternative 7. Those alternatives which do not include reinfection, have
estimated cleanup times of AO years minimum. In summary the short term
effectiveness evaluation indicates a preference for Alternatives 3A, 3B, AA,
AB, 5A, 5B, 6A, 6B, 7 mainly because of the shorter time frames for
achievement of ARARs, and notes shortcomings for Alternatives 1, 2, 3C, AC,
5C, 6C, because of the longer time frames.
Evaluation of Long Term Effectiveness and Permanence yields no
significant variations between the alternatives. The long term
effectiveness and permanence criteria evaluates the magnitude of total
residual risks of untreated waste, adequacy of controls used to manage this
waste and reliability of controls over time. As previously noted,
implementation of all alternatives would result in the eventual reduction of
contaminant levels to the site specific clean-up goals and/or applicable or
relevant and appropriate requirements.
In a similar manner the evaluation of the Reduction of Toxicity,
-------
-12-
Mobility, «nd Volume did not note major differences between the various
alternatives since all should eventually reduce contaminants to acceptable
levels
The Inpleaentability criteria addresses technical and administrative
feasibility as well as the availability of goods and services. Differences
between alternatives only exist..1 vhen considering | administrative
feasibility. The evaluation of the Ajnplementabillty of alternatives notes
that undeveloped land is limit-it* 'across cha siu.s, .uiJ much of the
development is for single family homes. The evaluation further notes that
construction in the eastern region of the sites would potentially impact
both a designated historic district (Rocky Rill), and the flood plain for
the Millstone River, which would necessitate a flood plain assessment.
Added agency coordination would be expftcted because of these factors.
Alternatives 3A, 3B, 3C, 4A, 4B, and 4C all require the construction of
wells and treatment units within both the residential areas and eastern
region of the sites. Alternatives 5A, 5B, 5C, 6A, 6B, 6C, and 7 all limit
construction of extraction wells and treatment systems to undeveloped or
commercially developed areas; although minor impact by subsurface piping and
injection wells located in residential areas would occur. Although'
Altentative 7 necessitates the siting x>f £ treatment systems as opposed to 1
unit for Alternatives 5 and 6, a less extensive piping network would be*
used. Alternatives 1 and 2 have no major construction and are therefore
relatively implementable with respect to land use.
Other factors regarding implementability (I.e. technical feasibility
and availability of goods) do not note significant differences between the
alternatives. In summary, the implementability evaluation indicates a
preference for Alternatives 1, 2, 5A, 5B, 5C, 6A, 6B, 6C and 7 which rated
favorably under the administrative feasibility criteria, and notes
shortcoming for alternatives 3A, 3B, 3C, 4A, 4B, and AC, because of the need
to construct wells within residential/historical/flood plain areas.
Comparative Costs are summarized in Table 4. Review of this table
shows that alternatives incorporating carbon adsorption as the unit process
are significantly more expensive than those that utilize air stripping.
Lacking major differences in effectiveness or implementability these cost
differences favor the air stripping alternatives. In summary the evaluation
of costs notes a preference for alternatives 1, 2, 3A, 3B, 3C, SA, 5B, 5C
and 7 as compared to 4A, 4B, 4C, 6A, 6B, 6C.
Compliance with ARARs has been evaluated by reviewing chemical, action
and location specific ARARs related to the sites or actions. Chemical
specific ARARs, developed in reference to present and potential potable
water usage including the Federal Safe Drinking Water Act and New Jersey
Water Pollution Control Act as amended by Assembly Bill A280 and are
summarized in Table 3. The Federal Water Pollution Control Act and New
Jersey Surface Water Quality Standards are applicable to discharges to the
Millstone River. Action specific ARARs were reviewed typically in reference
to air or. noise concerns and Include the Federal Clean Air Act, New Jersey
Air Quality Standards and New Jersey Noise Control Act. Location specific
ARARs were developed specifically in relation to the cultural sensitivity of
the eastern regions of the sites. The National Historic Preservation Act is
applicable since this area encompasses a historic district, potential
-------
-13-
archeological sites and historic canal regions. In addition, Executive
Order 1193 and 111990, which pertain to floodplains also applies, since the
area Includes a floodplain.
With the exception of Alternative 1, all alternatives are expected to
be in compliance with the ARARs. Review of the location specific ARARs has
resulted in a preference for alternatives which do not call for construction
in the sensitive eastern r-igr'.or. though this preference is '.not considered
overwhelming «auugh .j aij.. ..-._. ...&-. alts-.-i^i::. :s fioo consideration (3A,
3B, 3C, 4A. 4B, 4C).
Evaluation of Overall Protection summarizes how the alternative
eliminates, reduces or controls existing and potential risks to human health
and the environment through treatment, engineering controls and/or
institutional controls. Other than Alternatives 1 and 2 all alternatives
would provide protection to human health and the environment. As discussed
under the short-term effectiveness, the remedies differ in the overall time
for remediation. Alternatives 3C, 4C, 5C, 6C may Involve institutional-
controls over a longer period of time since their estimated cleanup _times
are longer than for Alternatives 3A, 3B, 4A. 4B, 5A, SB, 6A, 6B, 7. Under'
all alternatives except Alternative 1, the existing risk to human health
would be mitigated by providing an alternate water supply to all affected*
residences. (Note: Following implementation of the September 1987 ROD, all
residences within the MTHD site will be connected to available alternative
water supplies). . -
This summary evaluation results in a preference for Alternatives 3A,
3B, 4A, 4B, 5A, 5B, 6A, 6B, 7 since overall protection to human health would
be achieved with a shorter time period for institutional controls (i.e.
alternate water supply) necessary than for 1, 2, 3C, AC, 5C, 6C.
State Acceptance has been noted for the preferred alternative
(Alternative 7 with acceptability of combining some treatment units if
overwhelming land use concerns arise). The ground water is considered by
the state to be unsuitable as a private potable water supply, and as such
Alternative 1 is opposed. A preference for a timely and effective aquifer
remediation results in a general reservation for Alternatives 2, 3C, 4C, 5C,
6C which all have excessive cleanup times.
Community Acceptance has been noted for the preferred alternative
provided that concerns regarding the prevention of air and noise pollution
associated with air stripping units be addressed. The community has
Identified this concern as the Inadvertent trading of one pollution type
(ground water) for others (air and noise). A responsiveness summary is
attached to address and respond to community concerns.
THE SELECTED REMEDY
After careful review and evaluation of the alternatives presented in
the feasibility study to achieve the best balance of all Devaluation
criteria, NJDEP and USEPA presented a composite_of Alternatives'SB and 7 to
the public as the preferred remedy for ~ffie Montgomery Township Housing
Development and Rocky Hill Municipal Well Field sites. Alternative 5B and 7
best satisfy the evaluation criteria in that they have relatively short
-------
remediation time frames to achieve ARARs and are most administratively
feasible and cost effective vhen compared to the remaining alternatives.
The input received during the public comment period, consisting
primarily of questions and statements transmitted at the public meeting held
on Kay 12, 1988, is presented In the attached Responsiveness Summary.
Public comments received encompassed a vide range of issues but did not
necessitate .".ny major changes in the remedial approach taketo at the site.
Accordingly, the prefaced alternative was selected as a permanent solution
for the site. Some activities will be performed during the initial phases
of the remedial design process and prior to implementation of the selected
remedial alternative. Components of the selected alternative are described
as follows:
1) Extraction of the contaminated ground water through pumping followed by
on-site treatment and relnjectlon of the treated vater back into the
underlying aquifer. The ground water vill be treated to achieve
federal and state cleanup standards;
An aquifer remediation system vill be installed to actively flush the
primary plume. The less contaminated ground vater in the secondary"
plume limits vill be permitted to attenuate through natural means,
although enhanced flushing vill accelerate the remediation process.
The conceptualized system consists of three extraction veils, each
pumping at 350 gpm, individual air stripping units to reduce
contaminant levels from 200 ppb to 1.0 ppb, and two reinjection veils
per extraction veil. Figure 8 shovs the conceptualized locations of
these veils. As previously noted, this system vill be refined and
modified, if necessary, during design.
2) Connection of any remaining affected residences to the public vater
supply;
. Provision of public vater vould be made to residences within the
contamination area, not already connected as part of the September 1987
ROD. This is believed to involve one residence, though a questionnaire
vould be distributed to potentially affected residents prior to
implementation. Implementation of this activity vould occur separately
from other remedial activities, so as not to cause unnecessary delay.
3) Sealing of private vater supply and monitoring veils vlthin the
contaminant plume;
. An estimated 60 private vater supply veils and monitor veils vould be
sealed in the site area. Well sealing is being conducted to assure
that the contaminated aquifer is not being utilized for potable
purposes during remediation.
4) Implementation of a ground vater sampling program to monitor the
effectiveness of the cleanup;
. It vill be necessary to sample and analyze the rav vater from each
-------
-15-
extraction veil and the treated effluent several times during the year
to monitor the treatment efficiency of the system and to monitor the
extracted groundwater quality. Details of the monitoring program will
be developed during the design.
Prior to implementation of the selected remedy, a design would be
conducted which would include: a pump test with analytical sampling of the
pumped water, a bench scale treatability s?udy o* t>^. •3.l?;«.«d V st ^er
system, and a ground water model of the planned extraction and injen.ion
system. The goals of these activities include the determination of
extraction veil number locations and capacities, Injection well number
locations and capacities, air stripper sizing, pretreatment or post
treatment requirements (if any), and the possible need for short term carbon
adsorption on the exhaust from some air strippers.
STATUTORY DETERMINATIONS
The selected remedy provides for restoring the contaminated ground
water to acceptable levels, and assuring that contact with the ground water*
is limited while remediation is underway. This remedy has been additionally
determined in the RI/FS to be a cost effective means of achieving the*
necessary remedial objectives. This remedy is therefore protective of human
health and the environment, attains federal and state requirements that are
applicable or relevant and appropriate for this action, and is cost
effective and utilizes alternatives treatment technologies to the maximum
extent practicable. The preference for treatment to reduce the mobility,
toxlclty or volume of the hazardous substance is also met by the selected
alternative. The selected alternative is therefore in compliance with
Section 121 of SARA.
Protectiveness is being attained by providing well sealing and water
connections to eliminate present risks, and restoring the aquifer to
eliminate future risks. ARARs are all being met by the selected remedy,
both with respect to present and future site conditions. The identification
of ARARs vas done as part of the comparative analysis of the alternatives,
and will, therefore not be repeated here.
Since the selected remedy utilizes air stripping versus carbon
adsorption, and natural attenuation to the greatest extent practical, it is
the most cost effective means of achieving the site objectives. The remedy
provides the best balance among the 9 evaluation criteria by utilizing an
alternative treatment technology to remediate the contaminant plume in a
reasonable time frame. There are no short-term effects during the
remediation. Institutional controls vill be in place during the restoration
period and all affected residences vill be hooked up to an alternative vater
supply to eliminate the existing risks at the site.
The selected remedy results in the attainment of remedial response
objectives through treatment and natural attenuation. The remedy therefore
satisfies the preference for the reduction of toxicity, mobility and volume
of site contaminants.
-------
TABLE 1
COMPOUNDS DETECTED IN RESIDENTIAL AND MONITORING WELLS AT
MONTGOMERY TOWNSHIP HOUSING DEVELOPMENT AND ROCKY HILL
MUNICIPAL WELLFIELD SITES DURING THE REMEDIAL INVESTIGATION
oicAHtes
1,1,1-trichlorotthant*
1.1-dichloroethant*
1.1-dichoroethene*
1,2-dichlorMthent*
acetone*
bis<2-ethylhexyl )phthalat*
broaod i ch 1 ororne than*
chlordant
chloroform*
di-n-butylphthalatt
diethylphthalatt
tthylbenient
Mthylene chloride*
n-ni trosodiphenylamiint
phenols
pyrene
tet rach (oroethont*
toluene
trichlorMthont*
MCTALS ANO MISC. COMPOUNDS
aluminum
antimony
arsenic
barium
beryllium
cadmium
calcium
chromium
cobalt
copper
cyanide
iron
lead
Mgnesium
manganese
mercury
nickel
potassium
silver
•odium
thallium
vanadium
tine
plu
mm
cone.
•DJUTOtlW
WILLS
(ppb)
2
19
MO
37
80
58
MO
1.3
19
MO
MO
MO
IS
MD
43
3.4
S3
1.2
4SO
(PP»
140
0.11
0.186
2.3
0.01?
0.007
2230
0.406
0.098
0.581
MD
165
0.786
193
6.4
0.0004
0.34
S4.4
0.024
82
MO
0.2
1
M
I.
WAKE
WILLS
(ppb)
37
8.4
44
17
12
MO
MO
0.74
MD
HO
4.2
S.3
18
MD
S4
mo
24
MO
340
(PP"»
0.19
MD
0.04
0.3
MO
0.01
334
0.12
0.081
0.2
0.1
3.8
2.2
74
0.3
0.0002
0.07
1.9
0.18
58
0.004
43
0.21
pl
•
cone
an* i Tonne
WILLS
(ppb)
4.9
S.4
MO
7.8
13.8
13.3
MD
0.52
4.1
10
MD
H)
4.7
MD
15.3
9.7
9.2
4.9
102
(PP»
19
0.04
0.018
0.4
0.005
0.005
202
0.06
0.03
0.09
MO
25
0.09
29
1.1
0.0002
0.07
8.7
0.01
20
MD
0.05
0.17
ume
tan
•OTAJLC
WELLS
(ppb)
5.7
4.9
5.9
5.0
8.6
' MO
MD
0.5
•0
MO
9.8
5.0
4.7
MO
12.2
MD
s.s
MD
38.6
(PP"»
0.120
MD
.010
.120
.005
.005
49.0
.014
.010
.060
.010
.220
.090
14.0
.030
0001
0.020
1.7
0.017
13.0
0.010
1.2
0.070
background bi
eanc.(b) «
(ppb)
3.25
S
5
5
22
17
S
0.5
S
10
3
5
8.3
2.6
10
10
S
S
5
(PP»
23.4
0.06
0.0041.
0.232
0.0038
0.005
34.6
0.014
0.023
0.053
'
19.4
0.039
19.1
1.15
0.0002
0.04
3.94
0.036
11.1
0.033
0.16
tckground
Man
onc.(b)
(Mb)
•OL
•OL
•OL
•OL
11.1
10.5
•OL
•01
•OL
•OL
•OL
•pi
•OL
IP. I
•OL
4.7
•OL
4.8
(PP»>
S.I
0.010
0.008
0.1
0.004
•OL
15.1
0.009
0.022
0.037
.
4.5
0.013
1.4
0.3
•OL
0.034
2.4
0.014
8.0
0.027
0.1
a. plow MI. and van* art calculated fro* II data for ail residential veils
and all annitorlnQ well* except MW-60,MW-110,MW-11S,MW-130,NW-13S,MU-150.
b. Uekjround MX.and Mans are calculated from It data for tht designated
background wella NW.60,W*110.NW11S.MW-130,MM3S,MU-1SO.
c. In calcultfnf the Man conentratlona. the contract detection Malt for each
individual compound was used for all values reported as not detected; therefore,
all Mans are conservatively high estiMtea. If the Milsus detected value reported
»os below the Mthod detection liait. It is possible for the Man to aicead the Mai
• indicates compounds for taMch values were re-calculated to include
the result* of additional sailing perforsad in April and August, 1987.
SOURCE] MTHD/RHMW RI/FS
-------
TABLE 2
COMPARISON OF SITE DATA FOR INDICATOR CHEMICALS
WITH GROUND WATER REMEDIAL RESPONSE OBJECTIVES
SUBSTANCE
Trichloroethene
Tetrachloroethent
Chlordane
1,1-dlchtoroethen*
Arsenic
••Hi*
Beryl llua
ChroMlua
Lead
Nickel
Silver
RESPONSE
OBJECTIVE
(ug/l)
1.0
1.0
0.5
2.0
SO
1000
5.0
SO
SO
3SO
50
MONITORING UELL DATA
0 OETECTEOX
MAXIMUM MEAN «. ANALYZED
. (ug/l) (ug/l) (a)
650
53
1.3
NO
186 (b)
Z300
17
406
786
340
24
102.S
9.2
0.52
NO
17.8
396.7
5.2
57
85.9
72.6
10.9
23VU
13X44
1X44
0\44
9\19
19\19
12M9
12\19
12\19
6\19
S\19
OCCURENCES
ABOVE
OBJECTIVE
23
4
1
0
1 (b)
2 (0
3 (d)
4 (d)
2 (0
0
0
MAXIMUM
(ug/l)
340
26
0.76
U
39
306
MO
117
2170
71
180
POTABLE UELL DATA
MEAN f OETECTEDV
(ug/l) « ANALYZED
38.6
5.5
0.5
5.9
10.6
116.2
NO
13.6
94.5
22.3
17.2
26X42
8\42
1X*2
1X*2
13X36
36X36
0X36
33X36
29X36
32X36
21X36
OCCURENCES
ABOVE
OBJECTIVE
26
8
1
1
0
0
0
0
4
0
1
(•) Background wells ere not Included In this deta.
(b) Not detected in duplicate sample taken fro* sane well.
(c) Exceeded objective* In sarnies 30 and 30 duplicate. Monitoring well
30 fro* which these saoples were collected was a poorly installed well
and data fro* this well is highly questionable.
(d) Exceeded objectives in samples 3D. 3D duplicate, and 3S. Monitoring wells
30 and 3$ from which these sanples were collected were poorly installed wells
and data from these wells is highly questionable.
NO Not detected
SOURCE I MTHD/RHMW RI/FS
-------
State of JUto
DEPARTMENT OF ENVIRONMENTAL PROTECTION
DIVISION OF HAZARDOUS SITE MITIGATION
401 E. State St., CN 413, Trenton, NJ. 08625-0413
(609) 984-2902
Anthony J. Fero
Director
MONTGOMERY TOWNSHIP HOUSING DEVELOPMENT
AND ROCKY HILL MUNICIPAL WELLFIELD
SUPERFUND SITES
MONTGOMERY TOWNSHIP AND ROCKY HILL BOROUGH
SOMERSET COUNTY
NEW JERSEY
RESPONSIVENESS SUMMARY
This community relations Responsiveness Summary, prepared as part of the
Record of Decision (ROD), is divided into the following sections:
I. OVERVIEW
This section discusses the New Jersey Department of Environmental
Protection's (NJDEP) and the United States Environmental Protection
Agency's (USEPA) preferred alternative for remedial action and likely
public reaction to this alternative.
II. BACKGROUND ON COMMUNITY INVOLVEMENT AND CONCERNS
This section provides a brief history of community interest in the
Montgomery Township Housing Development/Rocky Hill Municipal
Wellfield (MTHD/RHMW) Superfund sites and identifies key
community issues. A chronology of community relations activities
conducted by the NJDEP and USEPA prior to and during the Remedial
Investigation/Feasibility Study (RI/FS) is included.
III. SUMMARY OF MAJOR QUESTIONS AND COMMENTS RECEIVED DURING THE PUBLIC
COMMENT PERIOD AND NJDEP'S RESPONSES
This is a summary of major questions and comments regarding the
results of the RI/FS directed to NJDEP during the public comment
period. This section also addresses major concerns expressed
throughout the RI/FS phase. NJDEP's/USEPA's responses are included
in this section.
IV. REMAINING CONCERNS
This describes the remaining community concerns of which NJDEP and
USEPA should be aware in conducting the Remedial Design and Remedial
Actions at the MTHD/RHMW sites.
New Jersey is an Equal Opportunity Employer
Recycled Paper
-------
-2-
ATTACHMENTS:
A. Agendas and Fact Sheets distributed at the 1/14/86, 7/29/87 and
5/12/88 Public Meetings.
B. List of speakers at the 5/12/88 Public Meeting.
C. Letters sent to NJDEP during the public comment period (April 25,
1988 - May 31, 1988). /
D. Public notices and press releases concerning the 1/14/86, 7/29/87
and 5/12/88 Public Meetings, and an informational flyer.
E. New Jersey State Department of Health Stream or Wastevater
Analysis Field Information Data Sheets.
F. Proposed Remedial Action Plan (PRAP).
I. OVERVIEW
The remedial alternative presented in this Record of Decision
represents a final remedial solution for the RHMW/MTHD sites. It
addresses ground water contamination in the underlying aquifer.
The specific components of the remedial action are as follows:
- Extraction of the contaminated ground water through pumping
followed by on-site treatment and reinjection of the treated
water back into the underlying aquifer. The ground water will be
. treated to achieve federal and state cleanup standards;
- Connection of any remaining affected residences to the public
water supply;
Sealing of private water supply and monitoring wells within the
contaminant plume; and
Implementation of a ground water sampling program to monitor the
effectiveness of the cleanup.
Based on comments received during the public comment period, Montgomery
Township officials and residents are concerned about the placement of
the pump and treatment units as well as the air emissions and potential
noise pollution associated with these units. The Borough of Rocky Hill
has expressed concern regarding payment for costs incurred in the
installation and operation of the Borough's water supply treatment
system.
These concerns have been addressed both at the May 12, 1988 public
meeting and within this Responsiveness Summary.
-------
-3-
II. BACKGROUND ON COMMUNITY INVOLVEMENT AND CONCERNS
Concern over the quality of potable water from the Rocky Hill well
first developed as a result of a Rutgers University study in 1979
which indicated high levels of trichloroethene (TCE) at this
municipal facility. The Rocky Hill findings triggered a subsequent
sampling program for the neighboring Montgomery Township Housing
Development.
Residents of both Montgomery Township and the Borough of Rocky Hill
expressed concerns early on regarding the water quality and the
economic implications associated with this problem. This included Rocky
Hill residents' dissatisfaction with the taste and higher cost of the
water supplied by the Elizabethtown Water Company. Borough officials
addressed these concerns and acted to protect public health by
installing air stripping units which effectively treat the water supply
so that it meets potable standards.
In Montgomery Township, the Health Department took an early lead in
initiating the testing of private wells for contaminants, alerting the
community to possible problems and organizing Township meetings. In
1980, a citizens' committee was formed in Montgomery Township. This'
committee sent a petition to the Township requesting a clean water
supply for all the residents. The group also produced newsletters,
coordinated meetings, helped organize a sampling program and gathered
information about the water problems in their area. This
organization's activities apparently diminished over the next three
years. Three of the committee leaders relocated, while only two or
three families from the development attended an update meeting in May
of 1983. The Montgomery Township Health Department, the USEPA and the
NJDEP do not have records of any recent activities sponsored by this
citizens' committee.
Other organized bodies involved in these issues have included: The
Montgomery Township Board of Health, the Montgomery Township
Environmental Commission and the Association to Improve Montgomery
Township.
Montgomery Township officials arranged for the Elizabethtown Water
Company to extend service into the MTHD beginning in 1981. At
present, roughly one-half of the residences have been connected to this
supply. A September 1987 Operable Unit Record of Decision addressed
this issue.
Other community concerns not addressed in this 1988 Responsiveness
Summary were addressed in detail in the September 1987 Operable Unit
Record of Decision.
-------
-4-
Chronology of Major Community Relations Activities
Community Relations activities conducted at the MTHD/RHMV sites to date
include the following:
A Community Relations Plan was prepared (June, 1985).
Municipal officials were contacted to advise them of a contract award
to conduct the Rl/FS for the MTHD/RHMV sites (August, 1985).
An informational flyer was distributed to homes in the MTHD regarding
the RI/FS and planned activities (November, 1985).
NJDEP held a briefing for municipal officials (November 14, 1985).
Notices were sent to those listed on the Contacts list of the Community
Relations Plan and press releases were sent to the media announcing the
January 14, 1986 public meeting (December 1985).
A public meeting was held at the Montgomery Township Municipal Building
to discuss the initiation of the RI/FS. Approximately 35 people
attended Including citizens, local officials and media representatives.
(January 14, 1986).
The Operable Unit MTHD RI/FS report was placed in repository for
public review and comment at five locations: the Montgomery Township
Municipal Building, the Mary Jacobs Library in Rocky Hill, the
Somerset County Library Main Branch, NJDEP in Trenton and USEPA in New
York. The public comment period was from July 15, 1987 to August 14,
1987.
Notices were sent to those listed on the Contacts list of the Community
Relations Plan and press releases were sent to the media announcing the
remedial action alternatives and the July 29, 1987 public meeting (July
1987).
A public meeting was held at the Montgomery Township Municipal Building
to discuss the completion of the Operable Unit RI/FS for Private
Potable Veils. Approximately 35 people attended including citizens,
local officials and media representatives (July 29, 1987).
The MTHD/RHMV RI/FS report and Proposed Remedial Action Plan
(PRAP) was placed in repositories for public review and comment at
five locations: the Montgomery Township Municipal Building, the Mary
Jacobs Library in Rocky Hill, the Somerset County Library Main
Branch, the NJDEP in Trenton and the USEPA in New York. The public
comment period was from April 25, 1988 to May 31, 1988.
A Notice was sent to those listed on the Contacts list of the Community
Relations Plan and a press release was sent to the media announcing the
May 12, 1988 public meeting and the availability of the PRAP (April
1988).
-------
NJDEP held a briefing for municipal officials (May 12, 1988).
A public meeting was held at the Montgomery Township Municipal Building
to discuss the completion of the RI/FS for the MTHD/RHMW sites.
Approximately 30 people attended including citizens, local officials
and media representatives (May 12, 1988).
Telephone contact and written correspondence was maintained between
NJDEP and municipal officials and the press (ongoing throughout Rl/FS).
III. SUMMARY OF MAJOR QUESTIONS/AND COMMENTS RECEIVED DURING THE PUBLIC
COMMENT PERIOD AND NJDEP'S RESPONSES
In April 1988, the Remedial Investigation/Feasibility Study (RI/FS) and
the Proposed Remedial Action Plan (PRAP) were placed in the following
repositories for review: Somerset County Library, North Bridge St. &
Voge Ave; Mary Jacobs Library, 64 Washington Street, Rocky Hill;
Montgomery Township Municipal Building; NJDEP, 401 East State Street,
Trenton; and USEPA Emergency & Remedial Response Division, 26 Federal
Plaza, New York.
On May 12, 1988 NJDEP held a public meeting to present the results of_
the RI/FS and to receive comments/questions. (See attachment A: agenda
and fact sheet distributed at the meeting.) The meeting was held at
the Montgomery Township Municipal Building. Notification of the public
meeting and the availability of the RI/FS reports and the PRAP was
accomplished through press releases and direct mailing of notices to
contacts listed in the Community Relations Plan including local, state
and federal officials, as well as identified concerned citizens.
Approximately 30 people attended including citizens, local officials
and .media representatives and five people commented during the meeting
(see Attachment B). NJDEP also held a briefing for municipal officials
prior to the public meeting on May 12, 1988.
The public comment period was originally scheduled from April 25, 1988
through May 23, 1988 but was extended to May 31, 1988 at the request of
a former commercial property owner in the area. In addition to the
comments made during the public meeting and briefing, four letters were
received by NJDEP (see Attachment C).
Following is a summary, organized by subject, of all major questions/
comments received by NJDEP at the public meeting, briefing and during the
comment period. Major subjects include:
Payment of costs to the Borough of Rocky Hill.
Consideration of technologies for the prevention of air and noise
pollution associated with air stripping units;
Concerns associated with the placement of the pump and treat units;
-------
. Comments contained in the report, "Evaluation of Remedial
Investigation/Feasibility Study of Montgomery Township Housing
Development and Rocky Hill Municipal Vellfield #2 Somerset County,
New Jersey"; and
. Comments submitted to NJDEP by Geraghty & Miller on behalf of
Princeton Gamma Tech (PGT).
Payment of Costs to the Borough of Rocky Hill
1. The Borough of Rocky Hill expressed concern regarding payment for costs
incurred in the installation and operation of the Borough's water
supply treatment system.
Response: While the RI/FS evaluated the response action taken by the
Borough of Rocky Hill to the contamination and concluded that it was
appropriate, determination of whether federal funds would be provided
for this action has not been made at this time.
Consideration of Technologies for the Prevention of Air and Noise Pollution
1. Montgomery Township Officials expressed a preference for the carbon
adsorption alternative or the use of carbon adsorption equipment on the
air stripping unit(s) as a means of minimizing noise and air pollution.
In addition the municipality requested that they be involved with the
location and design of the selected alternative early on and that the
public have input into Remedial Design Phase decisions (see Attachment
C).
Response: As part of the development of a response to this question,
NJDEP/USEPA have further evaluated the air emissions from the system
recommended by NJDEP/USEPA. The results of this evaluation appear
below:
The air stripper system identified in the RI/FS as Alternative 5B was
used as the basis in this evaluation. This system treats ground water
contaminated with a concentration of 200 parts per billion (ppb)
TCE at a flow rate of 1,050 gallons per minute (GPM). TCE would
be displaced into an air stream being introduced at a rate of 50 parts
air to one part of water, or 7,000 cubic feet per minute (CFM).
Further assumptions for the calculations of ground-level concentrations
and impacts are the following: stack height - 20 ft., stack velocity
1,000 feet per minute (FPM), and duration of operation - 10 years.
The resulting ground-level concentration has been estimated at 6.3
ppb as a maximum concentration, with an average concentration of 0.63
ppb. The potential for odor concern can be identified by comparing
the maximum concentration (6.3 ppb) with the odor threshold
identified for TCE (50,000 ppb), and the result is that the odor
threshold has not been exceeded. The probability for increased cancer
risk from exposure to the average concentration (0.63 ppb) is about
one in ten million (0.12x10 ), which is well below the typically
applied negligible risk of one in one million (1.0x10 ).
-------
-7-
The above evaluation indicates that neither health, nor odor concerns
are expected from implementation of the remedy. In addition, the air
and water quality will be monitored in a manner prescribed in the
Design Phase. As previously stated in the Rl/FS, the need for carbon
adsorption on the air stream would be determined once more accurate
expectations of ground water flow, TCE concentrations and resulting
air emissions are developed during Design.
Noise concerns will be addressed in the Design Phase by proper
equipment selection, sizing and location. The likelihood of noise
problems from a well designed system is minor, as can be exhibited by
the similar (although somewhat smaller) treatment unit currently in
operation at Rocky Hill Well field.
NJDEP will keep the Township informed during the Design Phase. A
briefing will be held for municipal officials and a fact sheet and
press release will be issued. This will further help to assure that
the community's concerns are addressed; NJDEP requests that the
Township initiate contacts with NJDEP as the need arises. NJDEP's
Bureau of Community Relations can be contacted at (609) 984-3081.
2. The Township Health Officer had several questions regarding air •
pollution: Who will conduct air monitoring? How often will monitoring
and stack testing be done? Who will pay for the monitoring? The
Health Officer further requested that the results be sent to the Health
Department.
Response; NJDEP or the NJDEP contractor will conduct air monitoring
as part of standard Operations and Maintenance procedures. The
sampling results will be sent to the Township Health Department.
NJDEP's Division of Environmental Quality will assist in developing a
sampling program, including a schedule for sampling. Operations and
Maintenance tasks are publicly funded by the state and federal
governments unless agreements can be reached with a responsible party
to fund this work.
Concerns Associated with the Placement of the Pump and Treat Units
1. A resident requested a copy of the diagrams used by the consultant to
demonstrate the proposed location of the pump and treat units.
Response: The resident was informed that the diagrams used at the
public meeting are part of the RI/FS reports which are available for
public review in local repositories. In addition, the Township Health
Officer has a copy of the RI/FS reports.
Comments contained in the report, "Evaluation of Remedial Investigation/
Feasibility Study of Montgomery Township Housing Development and Rocky Hill
Municipal Vellfield #2 Somerset County. New Jersey", submitted to NJDEP by
Groundwater Technology. Inc. on behalf of EG & G. Inc. (See Attachment C)
-------
(EG & G, Inc. engaged the services of Groundwater Technologies, Inc.
to prepare comments on the RI/FS and PRAP. EG & G is the current
owner of Princeton Applied Research, Inc. (PAR), who occupied the
current PGT facility during a period reportedly from 1966 through
1971. Summaries of the comments are presented below, and their
associated responses follow, in order.
Inventory of Potential Sources:
1. The inventory of potentially responsible parties is not complete since
it fails to identify or discus* the following:
a. Princeton North Shopping Center which includes a six-bay Goodyear
auto service store (Princeton Tires), a print shop (Triangle
Reproduction) and a dry cleaners (Mrs. B's Dry Cleaning and
Laundry);
b. Princeton Gamma Tech facility on the west side of Route 206;
c. Current Thul's Auto Supply store on Route 518 west of Route 206;
d. G. M. Printing, and
s \
e. Princeton Research Printers.
Response; Princeton North Shopping Center (which includes the current
Goodyear and Triangle Reproduction facilities) was constructed in 1973
or 1974, and has been connected to the available sewer system since
that date. Available information notes that the dry cleaner in the
shopping center did not dry clean on the premises until just recently.
No -phase II RI field efforts were focused on the PGT/Route 206
facility because an early site visit noted that the nature of the
facility's operation was mainly offices, and no contamination was found
in either Monitor well (MW-6) or MW-10.
Thul's Auto Supply was located on Route 206 during the late 70's
(while the contamination was already evident in RHMV). Sampling was
performed at the Route 206 property, although sampling was not
performed where Thul's relocated to Route 518.
G.M. Printing is connected to the Montgomery Shopping Center septic
system. This system was sampled during the RI.
1377 Route 206 is also known as Princeton Chemical Research, which is
the name of a previous owner. Samples of water, soil and septic tanks
have been collected, the results of which are available in the RI/FS
reports.
Ground Water Flow Direction:
2. No discussion is presented to support the implication that the RI/FS
RKMV #2 pump test conditions and historic production conditions
produced comparable directions of ground water flow, despite the
availability of a procedure to evaluate the drawdown of
intermittently pumped wells.
-------
Response; Pumping at a capacity greater than the daily pumping rate
accentuates the aquifer properties; it does not change them. Although
other pumping test procedures are available, the procedures used in
this test were designed to collect the maximum amount of data in the
minimum time period.
Baseline Contamination:
3. The RI should have investigated all possible septic fields for TCE
contamination and other chlorinated volatile organic compounds to
pr.operly establish baseline conditions.
Response: Fifteen septic fields were investigated in the RI (13
'SF' samples and SB-13, SB-16). In addition seven septic tank
samples were collected. This is considered to be appropriate for the
site. Several background monitor wells were installed to identify
baseline groundwater conditions. The RI has addressed all compounds of
concern at the site. TCE was used as an indicator chemical and TCA
was not, based in part on frequency of detection. The following table
illustrates this point:
Number of Detections of TCA and TCE
Phase I Phase I Phase II Phase II
Monitor Wells Potable Veils Monitor Wells Potable Wells
TCA 0 10 1
TCE ~9 21 15 5
Limitations:
4. The statement of limitation in the RI employs several unsubstantiated
assertions to support the assumption that the Brunswick Formation meets
the classical definitions of unconfined and semi-confined aquifers
despite the existence of data indicating otherwise.
Response: Although the presence of fractures results in anisotropic
aquifer characteristics, the flow characteristics in any given
direction are more typical of porous media conditions rather than
channel flow conditions. This conclusion has been substantiated in the
RI.
RI/FS Timetable:
5. The date on the Feasibility Study Volume 2 (March 1988) precedes the
date on the Remedial Investigation Volume 1 (April 1988), suggesting
that the identification of the source area is biased.
Response; The different dates on the two report covers is from an
error in report production. Both the RI and FS were completed in April
1988. RI development began well before the FS, but the submittal for
public comment was deferred to coincide with FS release.
-------
Anecdotal Information:
6. Unsubstantiated anecdotal information regarding TCE usage appears to
be extensively relied upon to draw conclusions regarding the source
area. In addition, the narrative of Potential Sources of Contamination
highlights multiple potential sources for TCE but does not explain
why these potential source areas were not investigated further.
Response; The comment refers to Chapter 3 of the RI, which is entitled
"Site Background Information". Unconfirmed results and findings were
included in the chapter to serve as the basis for the site
investigation. The findings of the RI, not unsubstantiated
information, were primarily used for development of the conclusions
stated in the report.
The comment further notes that additional data is needed to support
eliminating these facilities. The task of virtually eliminating any
possibility of secondary contamination is difficult, especially when an
identified upgradient source contributes contamination. This was not
within the scope of the RI.
Veil Installation and Sampling:
7. It appears that a significant number of wells were not adequately
designed for the scope of the project. (Ten of the thirty wells
installed for the RI could not be sampled during the first round
because they were dry). Furthermore, the excessively wide temperature
range (5°C to 23.0 C ) of ground water samples taken for the two
sampling rounds suggests that either the thermometer used may have been
faulty, not enough time was allowed for the thermometer to reach
equilibrium, or that the wells were inadequately purged to provide a
representative sample. At a minimum, the significant temperature range
should have been discussed and justified.
Response: The well construction program was developed to monitor two
ground water regions. The first region was the overburden and heavily
weathered bedrock, and the second was the competent bedrock. Early in
drilling it became evident that some of the shallow boreholes were
dry, though the use of mud-rotary drilling techniques made precise
determination difficult. The choices remained to either: 1) drill
slightly deeper until a water filled well was expected (possibly by
using the water depth of the corresponding deep well as a guide), 2)
abandon dry boreholes, or complete the wells as originally planned,
since some dry wells were expected to fill with water either after
development (water jetting was used) or during a wetter season. The
idea of completing a deeper well would have resulted in a well which
would not satisfy the objectives of the shallow wells, probably getting
most water from the competent bedrock. The decision proved to be sound
since many 'dry1 boreholes produced water upon development, and other
wells which were dry in round one sampling later contained water.
-------
Regarding the temperature range of the samples, the cause was not
identified. It can be noted however, that inadequate well purging has
been ruled out as the cause for these variations. Monitor wells were
all purged of 3 to 5 well casing volumes of water prior to sampling,
except for a couple of shallow wells which were very slow to recover
with water. These wells were purged till dry and allowed to recover.
Domestic wells were purged by running the tap for an excess of 30
minutes.
Pump Test:
8. The absence of significant drawdown in the shallow wells indicates
that the six-hour pump test was not of sufficient duration since the
well logs indicate that the deep/shallow pairs actually monitor the
same ground water system.
It also appears that the choice of data points was based solely on
those points falling in a straight line, without consideration of the
hydrologic characteristics which they represent.
In addition, a drastic increase in drawdown occurred at 110 minutes
in all wells, yet pumping did not continue past 360 minutes. This.
steepening of drawdown curve could represent a sudden dewatering of
fractures or encroachment on an impervious boundary.
Finally, according to the pump test data, ground water (and any
accompanying contamination) should be expected to move toward RHMV #2
from a greater distance in a northeast-southeast direction.
Hydrogeologic characteristics of the area should therefore inhibit
(but not necessarily prevent) the movement of ground water flow from
PGT to RHMW 02.
Response: While it is agreed that the duration of the pumping test
could have been longer than six hours, it is obvious from the results
that the shallow and deep ground water zones monitored are in poor
hydraulic connection.
Curve matching of pumping test data is the science of obtaining a
closest fit (best match) to a type curve produced by field data. The
NJDEP & USEPA believe this procedure to be correct. A relatively poor
hydraulic connection, as indicated by the pump test, has been noted in
the RI.
Nature and Quality of Ground Water Data:
9. Given the extensively fractured nature of the aquifer, it must be
assumed that the shallow and deep zones are in hydraulic communication
at each pair of monitoring wells, offering man-made pathways for deep
infiltration of shallow contaminants, driven by existing vertical
gradients (Table 5-1). Thus, ground water samples from these
monitoring wells must be regarded as composite samples with possible
man-made impacts, and water quality data cannot be interpreted with
reference to its alleged vertical position. Furthermore, since round
two sampling took approximately seven weeks to complete, data may not
be internally consistent and comparable.
-------
-12-
Response: Since the shallow monitor wells and deep monitor wells were
not installed in the sane borehole, it is not necessary to assume the
shallow and deep monitor wells are in hydraulic connection with each
other. Although it is possible that the wells monitor the same zone,
it is also quite probable that properly installed monitor wells can
evaluate specific zones of interest. Data suggests (water levels
analyses) that individual zones are being monitored by the wells.
Ground Water Divide:
10. Based on standard accepted pumping test criteria of 72 hours drawdown
and 48 hours of recovery, a 14-hour recovery period is considered
Insufficient time for complete recovery of a pumping well prior to
starting the actual pump test (RI page 5-3). Therefore conclusions
drawn from the RHMW #2 pump test data should be considered suspect.
In addition, the RI does not address the possibility that Intermittent
pumping could easily affect the location of the inferred on-site ground
water divide due to the relatively flat piezometric surface.
Response: The use of RHMW as the pump test well placed operational
limits on the pump test duration. This test was still preferred as-
compared to a typical pump test, which would have been operated for the
standard accepted duration, but would have utilized a much smaller flow
rate as part of its standard accepted design.
Regarding the variations between the pump test duration and actual
pumping condition, it must be noted that the pump test was designed to
obtain aquifer flow constants, and not just ground water contours. The
pump test was therefore designed to place a maximum stress upon the
aquifer (within operational limits of the wellfield) in order to
obtain the best possible information. Typical ground water contours
are noted to be variable between those for pumping and non-pumping
conditions.
Analytical Data:
11. It is an inappropriate conclusion that a 20 ppb difference for a
selected compound (between MW-7 and MW-4) be used to identify the
source area, based on two rounds of sampling approximately eight months
apart. Due to the inherent impurities and composition variations,
chlorinated solvent analyses of trends should have, at a minimum, been
based on the total chlorinated volatile organic compounds, including
tentatively identified compounds. In addition, ECRA wells MW-3 and
MW-4 on the hydraulically upgradient side of PGT showed elevated
levels of 1,2-dichloroethene suggesting that there are other sources
upgradient of PGT.
Response; The RI report conclusions were not based on a ratio in TCE
concentration of less than 1.5:1 between onsite and offsite condition
(relative to the PGT property). Conclusions are based on several
factors including hydrologic conditions and onsite TCE
concentrations reported by PGT in excess of 4,900 ppb, which is
closer to 10 times greater than offsite conditions (the minimum noted
ratio of average concentration was between results for PGT's MW-1
to and MW-4D, which is about 5.5:1).
-------
-13-
QA/QC Issues:
12. On the table labeled Round One Monitoring Veil Samples Tentatively
Identified Compounds, the location of MW-4S is identified as
"Polycell" and should be listed as "airport".
The absence of a lock (contrary to NJDEP regulation) on MV-16 and the
integrity of data is of particular concern since it is between
monitoring wells MW-7S, MW-7D, and MW-4D, which have had elevated
concentrations of contaminants, while monitoring well MW-16 has not.
Response: The comment regarding table headings is correct; the
tentatively Identified compounds noted for MW-4S actually apply to
MV-4S "airport". The lock on MV-16 was broken several months after
the sample was collected during a water level survey by NJDEP and
Geraghty & Miller. The lock has since been replaced.
Comments Submitted to NJDEP by Geraghty & Miller on behalf of Princeton
Gamma Tech (PGT)
PGT engaged the services of Arent, Fox, Kintner, Plotkin & Kahn
(Arent et al.) to prepare comments on the Rl/FS and PRAP. Arent et
al. additionally hired Geraghty & Miller, Inc. (G & M) and Roy F.
Veston, Inc. to present comments.
The comments were numerous and diverse as indicated by their extensive
volume, although three major issues are noted within these comments. These
major issues are as follows:
Concern was expressed that portions of the RI were not adequately
performed. Examples of inadequacies included a lack of details in the
background search, and lack of a soil gas survey.
PGT noted that other possible source areas exist and expressed
concern that these areas were not eliminated as potential sources.
Preference was noted for Alternative #2, which consisted of providing
water connections, but not flushing the aquifer.
As a response to the first major issue, it must be noted that the background
search, and the scope of the site investigation at these sites are already
relatively extensive. The presentation of additional background
information, or the recommendation that another one of the myriad of
investigative techniques be utilized does not alter the results of the RI.
Specifically, this information does not detract from the findings that
relatively high concentrations of TCE are present in a location which
could impact the ground water of both RHMV and MTHD.
Regarding the second issue, significant efforts were made to identify and
characterize all potential sources within the study area. NJDEP recognizes
the fact that these efforts do not virtually eliminate the possibility that
any given location is a contamination source. To accomplish this task would
amount to conducting a major field investigation at every property in the
study area, which is not required to meet the objectives of the study.
-------
The third issue oust be based on the comparison of the benefits of a more
expedient cleanup and the disadvantages of increased costs. Review of the
costs and cleanup times of the different alternatives presented in the RI/FS
resulted in a marked preference on the part of NJDEP and USEPA for
alternatives utilizing a limited aquifer flushing scheme.
MTHD Contamination:
1. The estimates of maximum rate q£ ground water flow found in the RI
prove that PGT could not have' contaminated the ground water under
MTHD. Shallow ground watez flow from PGT Is in a northwest or
west-northwest direction away from the MTHD. In addition, available
data indicate that deep ground water flow from PGT would be in the
southeast direction also away from the MTHD. Further, there is no
explanation as to why PGT's ECRA water-level analyses were excluded
from the RI/FS whereas the chemical Analyses are included (at Vol. 3,
Appendix 1).
Response; Several homes in the MTHD are currently supplied by
municipal water. Prior to connection to the municipal water supply,•
the homes were supplied by privately owned individual wells. The
comment fails to address the impact of the pumping of the individual*
wells on the ground water flow direction and flow rate. Additionally,
although the ground water flow component at the PGT facility is
predicted (by PGT consultants) to be to the northwest, the regional
ground water flow component is to the northeast as evidenced by
fracture trace analyses and ground water flow contours as stated in the
RI/FS report. The northeast orientation of the primary fracture
system, coupled with the pumping of all the MTHD individual
residential wells, could have potentially induced ground water flow
toward the MTHD greater than what is currently evidenced beneath the
PGT facility.
The water level information collected by PGT under the ECRA program
was not included in the appendix since it was not referenced in the
RI. This data was not referenced for the following reasons:
It was preliminary and only part of ongoing PGT activities regarding
water levels.
As noted above, it did not present information beyond that presented in
the regional study of the RI.
Minor discrepancies were noted in the reported well casing elevations,
which would have required resolution prior to inclusion in the report.
RHMW Contamination:
2. PGT could not have contaminated the RHMW for the following reasons:
a. Contaminated shallow ground water under PGT flows naturally away
from the RHMW (G & M Assessments, Figures 1 and 7; pages
2,11-12);
-------
•15-
b. Pumping action does not draw the contaminated water to the RHMV
(RI at 5-5 and 6-3) and;
c. Wells between PGT and the RHMV were not contaminated (RI at
5-29 Table 5-7).
Response: No conclusion has been reached stating that PGT
contaminated the ground water entering either RHMV or MTHD. The
conclusions presented in the RI/FS report note that the property is a
primary source area for contamination to the sites. Among other
factors presented in the report, the results used in forming this
conclusion include a water level in Monitor Veil MV-7D of 3 to 4 feet
below that in MV-75, a water level in (MV-7D) and RHMV of 5 to 60
feet below that in MW-7D, and the presence of ground water TCE
contamination in PGT's MV-1 in concentrations typically 20 times
greater than that in RHMV. The general downward water flow, the
location of the PGT property upgradient of any contaminated offsite
location, and the presence of on-site TCE in concentrations well
above those found offsite is typical across the entire RHMV/MTHD
site.
The presence of TCE in MV-9D, MW-9S and the PGT production well
only serves to further support the above conclusions, since the only
identified upgradient source of contamination to these wells is the
PGT property. The variations in shallow well elevations are
negligibly minor when compared to the differences found both within the
on-site well pair, and across the site as a whole.
Deficiencies of RI/FS:
3. Public participation was not timely invited.
Response; In accordance with the requirements of the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA), and
the Superfund Amendments Reauthorization Act (SARA), NJDEP conducted an
extensive community relations program. The major community relations
activities conducted at the MTHD/RHMV sites to date are outlined
earlier in this Responsiveness Summary under the Chronology of
Community Relations Activities. PGT received a hand-delivered
informational flyer describing planned RI/FS activities in November
1985.
4. Vhy did NJDEP's Consultant, Voodward-Clyde Consultants (VCC), not
use the resources of USEPA's Denver facility for sophisticated
analyses of aerial photographs and also make use of the 1961 and 1974
aerial photographs considered by G & M? What indications of disturbed
areas did VCC find on the aerial photographs it considered? How did
its findings influence decisions to sample or not to sample?
-------
Response; The degree to which aerial photographs were used in this
RI/FS is considered to be appropriate by NJDEP/USEPA. Although aerial
photos can be a useful supplement to a ground water investigation,
primary data collection should be relied upon as the principal
investigative technique. The fact that the 6 & H aerial photo review
found no significant new information further supports this.
Spray Waste Irrigation Area:
5. What is the location of the tank farm referenced on the RI (at 3*10)
and the spray waste irrigation area? Is the disturbed area identified
by G & M (Figure 4) the tank farm and/or the irrigation area? Finally,
why were soil samples taken and monitoring wells installed outside the
disturbed area identified by 6 & M and no samples taken or analyses
conducted in the tank farm or spray waste irrigation areas?
Response: The waste discharge area behind the property once operated
by Princeton Chemical Research (PCR) has been identified as the patch
of white sand clearly evident in aerial photos. This area is the
location of SB-2. The tank farm at the PCR facility is the
rectangular area of graded land immediately behind the building. Soil
boring SB-3 is in this location.
6. We request access to the entire file of NJDEP's investigations of 1377
Route 206, since only selected portions appear to be included in the
RI/FS.
Response; Available results regarding the 1377 Route 206 property are
included in the RI report. The RI compiled the limited historical data
currently available, and augmented -it with six soil borings, a pair of
monitor wells and a septic sample. PGT's request for file access
should be coordinated through the NJDEP Division of Hazardous Waste
Management.
Residential Septic Sampling System:
7. Why did WCC not sample residential septic systems in the MTHD or in
Rocky Hill Borough?
Response; Residential septic systems were sampled as part of the
RI/FS. Only one residential septic tank sample was collected (Tank
4). Septic field borings were typically used in the residential
locations instead of tank samples (SF-1, SF-2, SF-3, SF-4) in
an attempt obtain evidence of past discharge.
Potentially Responsible Parties:
8. The Fifth Dimension was not identified as a potential responsible party
(PRP), and its old septic system was not sampled. Field samplings
were not attempted at Fifth Dimension or the disturbed area to the east
of it, and a monitoring well was not placed directly between Fifth
Dimension and the RHMW.
-------
Response: The background investigation and earlier Remedial Action
Master Plan did not identify the former Fifth Dimension facility as a
potential source of ICE contamination. Information suggesting their
contribution has only recently been made available by PGT.
The site investigation used several wells upgradient of JtHMW to help
identify potential sources from outside of the study area. These
wells, which were all uncontaminated, include MW-6, MW-10, MV-11,
MW-14, MV-15. MW-10 is located 500 feet north in a line between
the Fifth Dimension location and RHMV; it is actually between the
facility and PGT and is somewhat downgradlent of the location.
Another well located more downgradient of the location (static
conditions) is MW-13, which also is not contaminated. It should be
noted that possible contribution from this or any location has not been
virtually eliminated as a result of the RI.
9. Why was Nemes omitted as a PRP and its old septic system not
sampled?
Response: Because of a lack of an apparent cause, no sampling or
investigation was conducted at this property as part of the RI. Please
note the introductory response to general issues raised by 6 & M on
behalf of PGT earlier in this Responsiveness Summary.
Analytical Assurance:
10. What analytical assurance did VCC or NJDEP secure that the TCA
reported in the Montgomery Township Shopping Center's septic system as
of 2/11/80 was not TCE (Veston Letter at 5)7
Response; Two septic fields, two septic tanks and three monitor wells
were sampled on this property as part of the RI. Historical samples
were also reviewed. The area identified as disturbed soil north of the
facility appears to be mounded material generated during construction
of the shopping center.
The comment also questioned data quality, and suggested (by reference
to the Veston letter) that the full data package be included as part
of the RI. Data packages were not included as a means of keeping the
report size to a minimum. Data for this site encompassed approximately
25,000 pages, which is excessive for inclusion in the report.
Analytical assurances for sample data are secured by preparation and
review of the following information:
1) Quality Assurance Project Management Plan;
2) Field Sampling Plan;
3) Field Sampling Audits by NJDEP;
-------
4) Data packages prepared in accordance with NJDEP Tier I
deliverable requirements;
5) Audits of data packages by the Bureau of Environmental
Measurements and Quality Assurance - Office of Quality
Assurance.
In general, the work conducted by Woodward Clyde and their
laboratory has been acceptable to NJDEP and USEPA.
Regarding the identification of TCA in the Montgomery Shopping Center
septic tank, the results were obtained from the lab data sheet (and not
the RAMP) and no further confirmation was employed since the
Information was used to a limited extent.
Soil Gas Surveys:
11. Why were cost effective soil gas surveys of vicinity properties not
conducted (Veston Letter)?
Response: Neither a soil-gas survey nor other similar field survey
techniques were employed at these sites. Combined use of monitor wells"
and source borings was used instead.
Other Contaminants:
12. The RI/FS fails to consider and pursue data which indicate that there
are sources of both TCE and other contaminants in the area which are
not associated with PGT.
Response; All RI sample results identified in concentrations greater
than the typically applied response objectives (such as drinking water
regulations or soil action levels) have been discussed in the Rl/FS.
Please refer to section 4.2, Evaluation of Cleanup Criteria, within the
FS for an example of this discussion.
History of PRP Sites:
13. The RI/FS failed to investigate some PRP sites and did not disclose
the history of others.
Response; Chapter 2 (Introduction) and Chapter 3 (Site Background
Information) of the RI/FS reports, as well as Appendices A and B,
provide a summary of the background information. More detailed
historical information is present in the two Remedial Action Master
Plans and the Background Report.
The comment also refers to a previous letter from Arent et al.
(Attachment C) that noted an error in the reporting of septic tank
contamination at PGT. The attached data sheets (Attachment E)
indicate that two samples were collected at this location, unlike the
RI which presents the data as a single sampling event.
-------
The RI attempted to find the source(s) of contamination, not the
individual(s) responsible for this contamination. Historical
information was used for the development of the field investigation,
not for responsibility assignment.
The possibility of secondary contribution will be addressed in the
monitoring program being incorporated as part of the remedy.
TCE Migration:
14. Has the TCE migrated from its source?
Response; While a portion of the TCE has migrated from the source,
shallow ground water contamination is still evident at the primary
source area. The conclusions of the RAMPs regarding TCE migration
were based on information available at the time (1983-4). The
conclusions of the RI/FS include significant additional information
which has failed to support the Issues of the comment.
Counterpumping:
15. Counterpumping is unjustified because of the geology of the site and
the numerous unidentified sources of Volatile Organic Compounds (VOC)
which may presently be contaminating the ground water.
Response: The possibility of secondary contribution will be addressed
in the monitoring program being incorporated as part of the remedy.
Public Health Rationale:
16. The public health rationale of the FS underlying the PRAP does not
make sense.
Response: The Public Health Assessment contained in the RI/FS report
was performed in a manner consistent with USEPA guidance (USEPA, 1986)
and satisfies all applicable or relevant and appropriate requirements
as designated by SARA.
TCE Sources:
17. Since WCC failed to identify the TCE source, WCC is in no
position to design a rational FS, beyond the measures already mandated
and undertaken plus Aquifer Isolation and Monitoring, Alternative 2.
Response; The primary source area was identified as the current PGT
property. It is correct that only low concentrations of TCE have
been found in one septic tank sample. No soil samples were
contaminated with TCE. The FS is nonetheless acceptable.
Precedence for Alternative 2:
18. There is precedence for Alternative 2 reflected in at least three
Records of Decisions which addressed situations similar to the MTHD
and RHMW contamination. These RODs appear to be the appropriate
-------
models for addressing the concern at the MTHD and the RHMW
Superfund sites particularly since the installation of air stripping at
the RHMW in 1983 and the 1987 ROD for the MTHD have already
addressed and eliminated any public health concerns.
Response; Section 4.2 within the FS identifies the remedial response
objectives for the MTHD/RHMW sites and discusses the formulation of
the site specific remediation criteria for ground water, soils and
surface waters. /
Remedial response objectives address the protection of public health,
welfare, and the environment from existing or potential threats posed
by contaminated materials. The objectives are used to focus the
development and evaluation of all the site specific remedial
alternatives possible. Response- objectives are selected in
consideration of the site specific data generated during the field
investigations, the applicable or relevant and appropriate requirements
(ARARs), and other response guidance. The objectives developed for
(MTHD/RHMW) are consistent with USEPA requirements/policies.
Costs of Response:
«•
s \
19. Given the serious flaws of the RI/FS set forth in the above comments
and in the attachments, we do not concede that the costs of preparing
the WCC Rl/FS may properly be considered "costs of response" under
CERCLA or the New Jersey Spill Act.
Response; The RI/FS has been conducted in accordance with CERCLA, and
is therefore an appropriate cost.
6 & M Assessment and Weston Letter:
\
20. Since the Rocky Hill Municipal Well (RHMW) represents one of the
Superfund sites, at a minimum, several water samples should have been
obtained from this well during the RI for an analysis of Priority
Pollutant constituents plus 40 peaks.
/
Response; Water quality samples are collected by the Township as part
of their operation. Some of these results are included in the RI.
21. During the December 13, 1986 pump test, time-dependent water samples
should have been analyzed to assess TCE variations with the
enlargement of the capture zone for the RHMW over the duration of the
pumping test.
Response; This was not done. However, analytical samples of water
were collected after treatment as part of the NJDEP discharge
requirements.
22. The well inventory (description of well construction details) for
domestic wells in the MTHD and other wells in the study area is
inadequate in terms of domestic and production well locations and
pertinent well construction details.
Response: Well logs are included in the interim report (on file)
which provide some additional information.
-------
23. The number and location of water-level measurement points (monitoring
wells) that form the basis of the RI at the MTHD is insufficient for
an assessment of shallow ground water flow conditions in this area.
Response; The hydrologic investigation is considered adequate and
appropriate by NJDEP and USEPA.
24. The deep monitoring wells are cased in the bedrock over almost the
entire thickness of the Brunswick Aquifer to the depth the wells were
drilled. This does not allow for an assessment of ground water flow
conditions in the deeper portions of the Brunswick Aquifer. In
addition, well depths are highly variable (85 to 250 feet), further
complicating an assessment of deeper flow conditions.
Response: The investigative methodology is considered appropriate
mostly based upon the fact that natural flow is predominately within
vertical fractures.
25. Given the VCC pumping test results and their statement that "the
facility for contaminant migration would be greatest along strike"
(RI, Page 3-6), it is surprising that the VCC study did not
concentrate on studying potential sources that lie along formation"
strike in proximity to RHMW.
Response; The investigation maintained an effort to investigate
potential sources of contamination to MTHD/RHMW sites without
concentrating along the strike. While the ground water flow is
greatest along the strike, flow perpendicular to the strike is also
expected.
26. The Public Health Assessment (PHA) did not address the No Action and
Aquifer Isolation alternatives in any detail. The Aquifer Isolation
Alternative warrants consideration.
Response; The PHA was based upon a No Action scenario. The Aquifer
Isolation Alternative has been considered throughout the RI/FS Study.
The Alternative, however, was not as effective at achieving the site
objectives as the selected alternative.
27. How was the "perceived likelihood of finding non-volatiles in a given
boring" evaluated (RI at p. 4-5)7
Response: Selection of samples for analysis was based upon the
following instructions presented to WCC:
Hierarchy for deciding which samples are to be sent to the lab are as
follows (in descending preference).
a) High OVA reading
b) Visible contamination
c) Bottom of Boring (Water-Table)
d) 2-4 feet depth
-------
28. The statement (RI at p. 6-7) referring to "the plume" as having
achieved "steady state" is inaccurate. The TCE concentrations are
erratic with time, and no other data are presented to indicate that any
"plume" has achieved steady state.
Response: In context, the statement in question refers Jto a lack of
significant trends. Variations in samples at a given location are
recognized.
i
\V. -.REMAINING CONCERNS
Many of the Issues addressed in this Responsiveness Summary will continue to
be of concern to the community. Montgomery Township officials have
requested that they be kept up-to-date on Remedial Design activities,
including a briefing during this phase, and have also requested an
opportunity to provide input into the Design. Honoring of this request
should help to further alleviate some of the above concerns, including those
of noise and air pollution and placement of the pump and treat units.
The concerns regarding the sealing of private wells and connections to the
public water supply system for the MTHD are generally being addressed*
under the September 1987 Operable Unit Record of Decision.
The issue of payments for past water line connections in MTHD is
continuing to be .addressed by NJDEP and USEPA under applicable laws and
regulations. --,...« ,
•'•> ••.' - •• .
Although NJDEP and USEPA have been able to identify a primary source of the
contamination, a responsible party (ies) has not been named. Should
payment to the communities for past actions be precluded by applicable laws
and regulations, then _the question of reimbursement for past costs may
remain unanswered until a responsible party(ies) is identified, at which
time the communities may choose to pursue reimbursement from the responsible
party(ies).
------- |