Hamilton Township, Mercer County
Community Relations Coordinator: Mindy Mumford (609) 777-1976
Mercer Rubber Offsite Investigation Fact Sheet
In October 2006, NJDEP conducted soil, sediment, surface and ground
water sampling at the Sayen Gardens in Hamilton Township,Mercer County
in areas of alleged dumping. Subsequent to that sampling, the NJDEP was
informed of additional areas where alleged dumping may have occurred or
contaminated material may have been present. In response to the concern
that there may be additional areas of contamination, and to delineate
contamination detected in October 2006, the NJDEP conducted a second round
of sampling in the Sayen Gardens in March 2007.
The results of the second round of sampling indicate that there
are low-levels of contaminants in the areas sampled at Sayen Gardens.
The contaminants can not be directly related to the Mercer Rubber Plant
and there is no residual evidence of the alleged dumping. The low-level
contaminants do not pose a threat to anyone using the facilities.
The contaminants detected are similar to those found in other
urban/semi-urban developed areas of the state and no further investigation
is necessary at this time. There were no contaminants detected in any
of the ground water or drinking water samples taken and NJDEP and NJDHSS
conclude that the drinking water is safe.
On March 21, 2007, additional soil and sediment sampling took place
in selected areas of Sayen Gardens. Three new locations were sampled and
are designated as follows: “Area Behind the Gazebo,” “Area
at the North End of the Park,” and “Bermed Area Along the
Unnamed Tributary of Miry Run.”
Delineation sampling occurred in the previously sampled areas designated
as “Area North of the Sayen House,” “Area Near the Skating
Pond,” and sediments within the “Unnamed Tributary of Miry
Area North of Sayen House - Contamination was
detected in two surface soil samples collected in October 2006 (S3A and
S4A). The contaminants detected above applicable standards were lead and
one polycyclic aromatic hydrocarbon (PAH), specifically, benzo(a)pyrene.
To delineate this contamination, seven additional soil samples were collected
in March 2007. These samples were collected from within a ten-foot radius
of the original samples and analyzed for lead and PAHs. No contaminants
were detected above applicable standards in any of the samples.
Area near skating pond - Contamination was
detected in one surface soil sample, S9A, collected in October 2006. The
contaminant detected above its applicable standard was lead. To delineate
this contamination, four additional soil samples were collected in March
2007. These samples were collected from within a ten-foot radius of the
original sample and analyzed for lead. Lead was not detected above
its applicable standard in any of the samples.
Skating pond - Low levels of PAHs, metals and
pesticides were detected in sediment and surface water samples collected
in October 2006 at concentrations slightly above the ecologically based
sediment quality criteria used by NJDEP. At that time, the NJDEP determined
that the concentrations of these contaminants were consistent
with what is typically found in water bodies receiving run-off in a developed
environment. Therefore, no additional sampling was conducted in this area.
Unnamed Tributary of Miry Run - Petroleum-type
product was found in one of the surficial sediment samples collected (SED10A)
in October 2006. In March 2007, NJDEP delineated the extent of this product
by collecting sediment samples at five-foot intervals upstream and downstream
of this original location, and visually inspecting the sample for product.
It was determined that the product contaminated area extends five (5)
feet upstream and 15 feet downstream of SED10A, totaling 20 feet of product
Sediment and surface water samples were collected from along the entire
length of this unnamed tributary of Miry Run in October 2006. Low
levels of PAHs, metals and pesticides were detected at concentrations
slightly above the ecologically based sediment quality criteria used by
NJDEP. The NJDEP determined that the concentrations of these contaminants
were consistent with what is typically found in water bodies receiving
run-off in a developed environment. Therefore, no additional sediment
and surface water sampling was conducted in this area for these contaminants.
New Areas Sampled
Area Behind Gazebo - This area is located
behind (west) the Sayen House. One soil boring location was sampled; one
shallow and one deep soil sample were collected. Both samples were analyzed
for Target Compound List (TCL) Base Neutral/Acid Extractable (BN/AE) compounds
and lead. No contaminants were detected above applicable standards
in either of the samples.
Area Near North End of Park - This area is
located north of the “Area North of Sayen House,” near the
park boundary near Percy West Drive. One surface soil sample was collected
and analyzed for TCL BN/AE compounds and lead. A deeper sample was not
collected, as this area was flooded at the time of the sampling. The
only contaminant detected above applicable standards in this sample was
Bermed Area along Unnamed Tributary of Miry Run - The unnamed tributary of Miry Run was reportedly historically dredged
and the dredged materials placed along the eastern side of the tributary,
forming the present day bank/berm. Because the tributary sediments contained
low-levels of metals and PAHs, it was determined that sampling of the
berm was appropriate. Samples were collected from three locations, corresponding
to original sediment/surface water locations 6A, 8A, and 10A. Samples
were collected at two depths at each location - one shallow sample and
one sample from immediately above the ground water table; the actual depth
of the deeper sample varied depending on the depth to ground water (3.0
feet below grade to 7.0 feet below grade). The samples were analyzed for
TCL BN/AE compounds and Target Analyte List (TAL) metals. PAH
contaminants were detected in two of the shallow samples.
The data indicate that some areas of Sayen Gardens continue
to have levels of contaminants above the most restrictive soil clean up
criteria. These include the area north of the Sayen House; area near skating
pond; unnamed tributary of Miry Run; area near the north end of the park;
and the bermed area along the unnamed tributary of Miry Run. However,
these levels are consistent with what could be expected for a developed
The levels of PAH compounds and lead, although over the criteria,
do not pose a risk to park visitors or neighbors living near the park.
A public health concern may exist only if there are consistent contacts
with the materials. The materials of concern are not located in areas
where visitors or neighbors have regular and consistent contact. The only
exception is the petroleum-type product found in the brook. In the coming
months, the NJDEP will remove this product from the brook and eliminate
any exposure concerns.
There were no contaminants detected in any of the ground water
or drinking water samples taken. NJDEP and NJDHSS conclude that the drinking
water is safe and the contaminants do not present a health risk.
For more information please contact Lynette Lurig, NJDEP Community Relations Coordinator at (609) 633-1314.
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