18018_Singer Furniture_RCRA Facility Investigation Report_19990203

The following comments are given in regard to Singer Furniture Company's (Singer) July 23,
1998 responses to the Facility Management Branch's (FMB's) May 20, 1998 Notice of Technical
Inadequacy (NOT!) letter regarding Singer's RCRA Facility Investigation Report, dated April 16,
1997. Comments were only given for those responses considered inadequate by the FMB. For
responses not listed, no comment was deemed necessary at this time.
SPECTVIC COMMENTS
Comment to Response !
The laboratory reports must be reviewed by the flv.IB if a risk assessment is to be used at a site.
This is done to ensure that the analytical data meets acceptable quality assurance/quality control
(QNQC) criteria. Si.J'!ger Furniture must provide the analytical data reports to the FMB so that
the FNffi can adequately review any risk assessment submitted for the Singer facility.
Comment to Response 6
All maps must, at the very least, have a north arrow and a scale. All maps that do not have a
north arrow and/or a scale must be revised to include them. It is not sufficient to state the
information in the response to comments without also putting it on the figures.
Comment to Response 12
Pesticides, he1·bicides, and PCBs have been detected and reported in ground water at the Singer
facility at 19 of the 22 wells sampled and in the soil at 16 out of 25 samples analyzed for these
constituents. Many of these data were qualified by your laboratory with a "P" flag. According to
Response 12, the "P" flag indicates that your laboratory was unable to detennine the amowit of a
particular contaminant because the two concentrations obtained from the two different columns
used during the analytical process did not match ·within specific performance criteria. Based on
tltis information, Singer suggests that since the perfonnaoce criteria were not met, the data
shouid not be used to determine the extent of contamination.
The FMB agrees that analytical data that does not meet QNQC criteria should not be used
inappropriately. However, these data are believed to serve a purpose since the laboratory
QA/QC problem was in determining how much contaminant was present, not whether a
contaminant was present or not. At this point the data appear to show that low levels of
pesticide, herbicide, and PCB contamination may exist in the soil and ground water at the Singer
facility. Additional sampling is needed to confirm or deny the existence of these contaminants.
Comment to Response I 3
Ground water contamination in the landfill area has not been adequately defined. Additional
monjtoring wells are needed to define the lateral and vertical e>..'tent of ground water
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contamination. Once contamination has been adequately defined, potential corrective action
measures (if needed) for the landfill can be addressed. ff monitored natural attenuation is chosen
as a corrective measure, natural attenuation roust be proven to be occurring and is sufficient to
remediate the contamination.
Comment to Response 14
As discussed in the January 14, 1998 site meeting, the background sampling locations are
acceptable. Additional sampling is required to show that the contaminants, other than heavy
metals, detected at the background sampling locations are in fact laboratory/method artifacts.
Comment to Response 15
Contamination in environmental media (soil, groundwater, surface water, air, etc.-), based on rhe
definition in Singer's permit, is when a ha.7.Mdous constituent is detected above either naturally
occurring backgrotmd concentrations for naturally occurring constituentS or above practical
quantitation limits for non-naturally occurring constituents. As stated in Singer's Response 15,
"The RFI was designed to establish the nature and extent of contamination ... " The extent of
ground water contamination has not been defined at the site. Benzene and trichloroethene (TCE)
have been detected, above North Carolina Administrative Code (NCAC) 21 ground water
standards, at down-gradient monitoring well CAMU1-4SP during all five sampling events for
which it has been sampled (except for TCE on October 26, 1995). Five out of five sampling
events have detected TCE above 2L standard at down-gradient monitoring well CAMU 1-7SP
(benzene has also been detected in three out of five sampling events). Benzene and TCE were
also detected at down-gradient monitoring well CAMU1-8SP and benzene was detected at down-
gradient monitoring well CAMU1-5SP and background monitoring well BG-2SP. According to
EQM well construction diagrams, the "SP" wells were generally installed about five feet into the
saprolite using a five foot screen with a sand pack that extend a few feet up into the alluvial
aquifor. TI1e analytical and well construction data suggests that the ground water in the saprolite
may be relatively more contaminated than in the alluvium. In addition, these wells are the most
dovv11 grad.ie1it wells at the facility; indicating the lateral and vertical extent of contai.7.ti:nation has
not been defined. Additional monitoring wells are needed ro define the lateral and vertical extef'lt
of grotmd war~r contamination.
Comment to Response l 7
Contamination has been detected in all of the down gradient wells at the site that were installed
in the saprolite. At two locations, CAMU1-4SP (TCE and benzene) and CAMU1-7SP (TCE),
volatile organic compounds have been detected above NCAC 2L standards. One of the wells
(CA1till l-4SP) is located approximately 100 feet from Lower Creek. In addition, numerous
other contaminants have been detected in the ground water at many of the monitoring well
locations, including pesticides, herbicides, or PCBs. Additional monitoring wells are needed to
define the lateral and vertical extent of contamination. If these wells indicates contamination has
reached Lower Creek, then additional investigation may be needed to determine i:he hydraulic
inceraction between ground water and the creek.
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Comment to Responses 18-21
Singer's determination that the site does not pose a risk to human health or the environment was
based on an industrial exposure scenario. A 1isk assessment based on an industrial exposure
scenario requires the use of some mechanism to restrict future land use to that of industrial. At
this time the NC Hazardous Waste Section has 110 mechanism available that can be used to
en.force future land use restrictions. Therefore, all risk assessments submitted to North Carolina's
RCRA program must be based on a residential exposure.
In regard to comment 18 of the NOTI and as stated in this letter, Singer must define the lateral
and vertical extent of contamination at the facility in both soil and ground water.
Comment to Response 22
Due to the lack of any local ordinances banning the installation of drinking water wells and the
fact that both the saprolite and the bedrock are capable of yielding enough water for domesric or
industrial use, Singer must consider future uses of ground water at and surrounding the Singer
facility. Singer must also consider the surface water pathway due to the close proximity of
contamination detected in the ground water to Lower Creek.
GENERAL COMMENTS
The specific comments listed above indicate that additional investigation of the Singer Facility is
needed in order to fully define the lateral and vertical extent of soil and ground water
contamination. 'The RFI report should be revised to reflect the need for the additional
investigation.
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