NCD991278953_19990819_National Starch & Chemical Corp._FRBCERCLA SPD_Final Report for Evaluation of Natural Attenuation OU-4-OCR

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Transmilled Via Federal Express
August 19. 1999
Mr. Jon 8ornholm
Remedial Project Manager
United States Environmental Protection Agency
Region IV
61 Forsyth Street, S. W.
Atlanta, GA 30303-3 I 04
Re: Final Report for National Starch/Evaluation of Natural Attenuation
Operable Unit Four
Cedar Springs Road Plant Site
Salisbury, North Carolina
Project#: 050.61.006 #2
Dear Mr. 8ornholm:
RECEIVED
AUG 261999
SUPEAFUND SECTION
On behalf of National Starch & Chemical Company (NSCC), 8\asland, Bouck & Lee, Inc. (BBL) has
prepared this response to the Final Report for National Starch/Evaluatim1 of Natural Alle11uatio11 (Report)
prepared by the National Risk Management Research Laboratory (NRMRL) and dated March I 6, I 999.
The Report is based upon NRMRL review of the Phase I Natural Degradation 1i·eatability Swczv Report
(NDTS Report) prepared by Envirogen, Inc. (March 28. 1998) and a meeting with representatives of
NRMRL. United States Environmental Protection Agency (USEPA), North Carolina Department of
Environment and Natural Resources (NCDENR). Battelle. NSCC, Envirogen and BBL on December I,
1998 in Raleigh. North Carolina.
In general. we found the Rcpon to be somewhat contradictory to the discussions held during the December
I, I 998 meeting and previous discussions between USEPA, NRMRL, Batte lie, Envirogen and NSCC.
NSCC has extended a considerable amount ofdTort in performing the activities associated "·ith the NOTS
Report to pursue an effective remedy for OU4. It has extended that effort with input from USEPA such
that the Natural Degradation Study ~ould yield the required information in an efficient manner and meet
the requirements of the Record of Decision (ROD) for OU4. We believe that some of the contradictory
information and misunderstandings presented in the Report arc not constructive and do not help USEPA
and NSCC move toward a succcssl'u1 remedial action in OU4. \Ve look forward to discussii1g the issues
presented below with you.
The remainder of this response is presented in four sections:
Chronology of the On-Going Remedial Action lc1r Operable Unit Four (OU4):
a Summary of the Information Discussed at the December I, 1998 Meeting relative to both
the nature of the impacted soil in OU4 and the potential risk related to the impacts:
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Comments on the NRMRL Report; and
a Revised Conceptual Plan for the Phase II NDTS.
Chronology of0U4 Remedial Activities
.-\ chronology ofOU4 Remedial r\cti,·ities follows:
Mr. Jon Bornholm
August I 9. I 999
Page 2 of I 8
Between 1986 and 1988, a Remedial Investigation was performed at the facility. rclati,·c to the
areas of the site which \\ere later designated as OU I and OU2 (the former Trench Area ground-
water and soil impacts: respectively), which identified ground-water. surface water and
sediments in the vicinity of the Northeast Tributary;
as part of the ROD for OU2, signed in 1990, additional investigation activities were prescribed
for the areas which were later designated OUJ (Plant Area ground-water/surface
water/sediment impacts);
a Remedial Investigation was performed between 1991 and 1993 which identified sources and
extent of ground-water impacts in OU3;
in June 1993, a Feasibility Study was submitted which evaluated remedial options for OU3;
as part of the ROD for OU3. signed in 1993, an additional Feasibility Study to evaluate
remedial options for impacted soil (OU4) was required and approved in July 1994;
in October 1994, the ROD for OU4 was signed which selected Natural Degradation and a
contingent soil vapor extraction remedy;
in September 1995, a Unilateral Administrative Order (UAO) to implement the OU4 ROD was
issued;
in October I 995. NSCC submitted its first draft of the NOTS Work Plan to satisfy the
requirements of the ROD and UAO:
the USEPA and NCDENR commented on the October 1995 submittal in November 1995.
December 1995, and March 1996;
the Final NDTS Work Plan was issued in July 1996 and appro,·ed by USEPA in August 1996:
in October 1996 a kick-off nH.:t:ting was held at tile site to discuss and review details or the
NDTS:
between October 19% and December 1997, NSCC performed the NDTS activities. including:
a Laboratory 13iotreatability Study,
installation of soil plots and soil gas monitoring wells:
prt.;cipitation measurement,
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weekly ground-water elevation measurements,
quarterly ground-'.Vater samplins:.
quarterly soil sampling,
weekly soil gas monitoringi
monthly soil gas sampling, and
quarterly soil g.is sampling.
Mr. Jon Bornholm
August 19, I 999
Page 3 of 18
1n January I 998, NSCC submitted a Progress Report on the results or the NDTS with
subsequent regulatory comment in February 1998;
in March 1998, NSCC submitted the Phase I NDTS Report with response to regulatory
comments on the Progress Report;
in May 1998, regulatory comments on the Phase I NDTS Report were issued;
in July 1998, NSCC, USEPA, NRMRL, Battelle and Envirogcn participated in a teleconference
to discuss the regulatory comments;
in July 1998, a response to comments was prepared which incorporated the discussions held
during the teleconference;
in December 1998, a meeting was held to discuss the Phase I NDTS and a plan for moving
forward into Phase II; and
in March 1999, the NRMRL issued the subject Report.
SumnuU)' of the December 1, 1999 Meeting
During the December I, 1999 meeting in Raleigh. North Carolina, we discussed seYeral aspects of the on-
going remedial actions at the Site and the need to integrate the programs to develop a consistent approach
to implementation.
To this end, we presented ideas relative to an integrated Conceptual Model for Impacted Soil in OU4 and
lmracted Ground Water in OU3. This Conceptual ,vlodcl for the Site is summarized as follows:
The geology of the Site includes the presence of an underlying high-angle fractured.
metamorphic bedrock which has weathered in place to produce an oYerlying regolith or fully
weathered saprolitc and a partially-weathered transition zone. The O\·erlying regolith retains
the parent material structure.
The underlying aquifer is impacted by a potential zone of dense non-aqueous phase liquid
(DN/\PL). which is the result or leaking terracotta ripes and miscellaneous spills in the Plant
1\ren as well as the formerly unlined wastewater lagoons. Due to the geologic structure: the
DNA PL may he in residual form within the bedrock and may form a source of impacts to
ground water for an indefinite period of time. To address these impacts. a pump & treat s)1stcm
has been proposed to exercise hydraulic control over the dissolved phase impacts (which also
cncrnnrasses the entirety orOU4).
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Mr. Jon Bornholm
August I 9, 1999
Page 4 of 18
The soil impacts observed in OU4 are residual impacts associated with the OU3 ground-water
issues. Thus, the impacts are primarily obsen·cd in the vicinity of the former terracotta p~pcs
(from Area 2 and from former storm sewers located adjact::nt to Arca 2) anJ former spill areas:
\Vith higher concentrations likely observed in the vicinity of relict high-angle fractures. Some
observed impacts may represent immobile ganglia of residua! DNA PL bound up within relict
high-angle fractures.
The nature and extent of soil impacts presented in the Remedial Investigation (RI) and used
throughout the Remedial Action does 1101 accurately represent the actual conditions. This is
primarily clue to the graphic representation of data from multiple soil horizons in a single
concentration isopleth map. Please see the attached revised figures depicting the understood
extent of impacted soil.
Figure I presents the results of the soil sampling performed in Area 2 during the RI. Eight of
the 20 locations sampled had either no-detection of 1,2-DCA or detections below the
Performance Standard of 169 ug/kg. It is possible that some of the 1,2-DCA detections in the
deeper soil horizons may be residual impacts associated with ground-water conditions in the
area.
Figure 2 presents the results of the soil sampling performed in the Lagoon Area during the RI.
Twenty-one of the 23 sample locations had either no-detection of 1,2-DCA or detections below
the Performance Standard. Soil boring locations that have reported impacts in the deeper soil
arc most likely a result of residual ground-water impacts. The water table in this area is high.
monitoring wells screened in the saprolite in this area have depths to water ranging from 2.67
to 5.61 Ii below ground surface (bgs).
The ROD for OU4 states that there are no unacceptable risks due to direct contact with
impacted soil at the Site. Furthermore, the goal of _the Remedial Action is to prevent the
continued release of constituents to ground water from impacted soil. However, the potcnti,d
presence of DN/\PL in the underlying aquifer present a more constant and higher strength
source of impacts to ground water than the residual material in the soil. The proposed OUJ
Remedial J\ction includes a ground-water extraction system to establish hydraulic control over
the dissolved-phase impacts. including those impacts observed in the vicinity of the soil 111
OU4. Thcrcrore, the impacted soil does not pose a substantial or unmanaged risk.
13ascd on the results or the Phase I NOTS and the Conceptual Model discussed above, NSCC proposed a
sampling program in the Phase II NDTS. The results or the Phase I NDTS 1·ulfillcd three or the live
requirements specified in the ROD and UAO. including:
demonstrating that natural ckgradation or site constituents is occurring in the saprolitc:
demonstrating that addition of nutrients to the soi! docs not significantly enhance natural
degradation: and
demonstrating where tht..: degradation is occurring in the subsurface.
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i'vlr. Jon Bornholm
August 19, 1999
Page 5 of 18
The purpose of the Phase II NOTS will be to fulfill the remaining requirements of calculating a site-specific
degradation rate and estimating the time frame required to meet the performance standards. To meet these
requirements. NSCC proposed a sampling program consisting of soil sampling from on a Grid (36 sari1plcs)
located in Area 2 on a once per five year basis. 13y pursuing this approach: an appropriate confidence limit
would be achieved in an efficient manner. This was considered appropriate based on the Conceptual i'vloclcl
presented above. which discusses the nature of the impacts to gr0u11d-\\'ater and the time frame over which
the remedial action could be achieved. Due 10 the indefinite period of impacts clue to the potential presence
of DNAPL. the minor contribution due 10 the residual soil impacts will be controlled by the ground-water
remedy.
Comments on the NR.MRL Final Report
The Report provides the following information based upon review of the NOTS Report and our meeting of
December I, 1998:
a discussion of various natural attenuation mechanisms and their applicability to the Site;
a list of suggested analytes to evaluate the various natural attenuation mechanisms; and
a discussion of the proposed sampling plans and a recommended sampling plan.
The following presents our comments on the information presented in the Report.
Comments Regarding Possible Natural Attenuation lvfechanisms
NRMRL lists the following natural attenuation processes as possibly occurring at a given Site:
Anaerobic 13ioclegradation;
Aerobic Biodcgradation;
i\hiotic Chemical Transformation:
Volatilization:
Vapor Transport:
Leaching; and
l'hytorcmcdiation.
NRi'v!RL asserts that the data collected (Laboratory Biotreatability Study. installation of soil plots and soil
gas monitoring wells, precipitation measurement. weekly ground-water cle,·ation measurements, quarterly
ground-,vatcr sampling, quarterly soil sampling, weekly soil gas monitoring. monthly soil gas sampling, and
quarterly soil gas sampling) during thL: Phase I NDTS. which was performed in accordance with the NDTS
Work Plan. neither supports nor excludes any of the listed processes. In the Report, NRl'vlRL neither cites
nor manipulates the large quantity of collected data to support their assertions. rurthcrmorc. NRMRL offers
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Mr. Jon Bornholm
August I 9, I 999
Page 6 of I 8
no explanation for the apparent reversal of their interpretation of the data as discussed in July 1998 and
December 1998.
Anaerobic Biodcgradation
In July 1998 and December 1998, NR,v!RL agreed that the Phase I NOTS data supported anaerobic
biodcgradation. In the Report, NRiv!RL postulates that the concer,trations of daughter products (e.g.,
vinyl chloride) arc the result of volatilization from the aquifer and cites elevated concentrations of
oxygen in the soil gas. To evaluate this concept, we have reviewed the data collected from the
monthly soil gas monitoring (59 samples from the impacted areas and 10 samples from the
background location) and conclude the following:
The average oxygen concentration is 19.4 percent ( 19.4 %) from the background
location. Of the 59 impacted area samples, only 21 samples indicate oxygen
concentrations greater than 19 %, some of which are anomalously high and likely not
representative of site conditions (e.g., 41 % from SGMW-2 in August 1997).
The ground-water quality data included in the NOTS Report indicate that vinyl chloride
(VC) was not detected consistently and that the highest concentration detected was 35
micrograms/liter (ug/L). Assuming equilibrium conditions exist, this concentration
corresponds to a complementary vapor phase concentration of approximately 32
volumetric parts per million (ppmv). The results of the monthly soil gas sampling
indicate that the concentrations of vapor-phase VC range from non detect to 44,000
ppmv. Only 5 of 59 samples indicated concentrations less than 32 ppmv. Only 15 of 59
samples indicated concentrations less than I 00 ppmv. Therefore, the primary source of
VC is impacted vadose zone materials, not the underlying aquifer.
Thus, it can be demonstrated that anaerobic biodcgradation in the vadose zone is occurring because:
there is cviclcncc of oxygen depicted environments in the vadose zone:
concentrations of methane in the soil vapor in impacted areas arc co.nsistcntly greater
than background concentrations; and
soil vapor concentrations of daughter compounds such as VC, which has never been used
at the site and is a daughter product of the anaerobic degradation of 1.2-diehloroethanc.
arc consistently greater than the complementary vapor phase concentration of the
observed aqueous phase impacts.
;\crohic 13iodcgradation
We concur with NRMRL's assessment of the potential aerobic degradation of 1,2-DCA at the site.
However. tlw evidence of anaerobic degradation of 1,2-DC/\ is very strong, indicating that Natural
Degradation is occurring. If aerobic degradation is occurring, it would only improve the rate or
Natural Degradation at the site where aerobic conditions may exist. Further evaluation of potential
aerobic degradation or l ,2-DC/\ is proposed below by sampling for daughter products (chloroacctic
acid).
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Abiotic Transformation
Mr. Jon Bornholm
August 19, 1999
Page 7 of 18
Transformation of l )-DCA to VC occurs ti1rough dehydrohalogenation. which can be an abiutic or
biotic process. NRMRL asserts that the data does not support the existence of an extremely reduced
cm·ironmcnt in the vaclosc zone at the Site cnpabk of supporting the nbiotic process. However, highly
ele,·atcd concentrations of methane in the soil ,·apor (upwards of '100.000 ppmv) indicate that
methanogenesis is likely wking place.
As discussed in numerous documents regarding natural degradation. including the Drc!fi EPA Region
./ Suggested Practices for Ewduation of a Site for Nmural Attenuation (Biological Degradarion) of
C/J!orinmed So/re Ills. the order of reducing conditions. by strength, is as fol lows:
Nitrate Reduction< Ferric Iron Reduction< Sulfate Reduction< Methanogenesis
Thus, the elevated methane concentrations observed are indicative of an extremely reducing condition
in the vadose zone and supportive of abiotic reactions.
Volatilization
Based on the observed concentrations of 1,2-DCA in soil gas, it is apparent that some volatilization
is occurring. However, under equilibrium conditions, 1,2-DCA is expected to be detected at
concentrations commensurate with the observed concentrations in soil and ground water.
Evaluation of the quarterly soil gas quality data collected from soil gas monitoring wells SGMW-7
and SGMW-8, located in the lagoon area, indicate that volatilization and subsequent loss to the
atmosphere is likely not a predominant mechanism for mass loss from the vadose zone. The observed
concentrations of 1,2-DCA in soil gas in the interval 6' to 8' bgs is consistently an order of magnitude
greater than the observed concentrations of 1,2-DCA in the interval 2' to 4' bgs.
To further evaluate potential losses due to volatilization. BBL performed VLEACH (USEPA. 1997)
modeling. VLEAC\-1 modeling presents a conservative estimate of the fate of constituents in soil by
simulating a periodically changing equilibrium condition. In VLEAC\-1. the only mass loss
mechanisms arc leaching from soil to underlying ground water by infiltration and soil gas diffusion
to the overlying atmosphere. Mass loss due to biodegradation is not considered in VLEJ\Cl-1.
presenting n conservative assumption. Additionally, the lower pneumatic conductivity asphalt
matL:rial was not included in the modeling. In the modeling performed, the mass lost cluL: to
volatilization was estimated to be approximately 8% of the source rnnss over a period or 10 years. with
61Xi lost in the first 18 months.
Based on the collected data and the analyses discussed above, volatilization to the atmosphere is not
tonsiclcrcd a significant mass reduction mechanism.
Vapor Phast: Transport
NRMRL asserts that Vapor Phase Transport to the aquifer is a potential mechanism responsible ii,r
natural ckgradation or 1.2-DCJ\ in the vadosc zont:. NRl'vtRL l"urthL:r contends that barometric
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Mr. Jon Bornholm
August I 9, 1999
Page 8 of 18
pumping may amplify the process. We concur that this is a potential mechanism, however, given the
lo\\' pneumatic conductivity of the material \\"C ck1 :1ot bclk\·e that this is a significant mechanism.
The highest concentration of 1,2-OCA in the ground water reported in the NDTS Report is 220
milligrams/Liter (mg/L). Assuming equilibrium conditions, this corresponds to a complementary
vapor phase concentration of approximately I :.000 ppmv. Only 30 of' the 59 monthly soil gas
samples indicated concentrations in excess of 12.000 ppm,·. Thus, approximately 50% of the samples
indicate that vapor-phase transport from the \'ad0se zone to the aquifer is not occurring.
As discussed in Contributions to Our Knowledge of the Aeration of Soil (Buckingham, 1904), the
barometric and soil gas pressure fluctuations can be estimated. If one assumes free communication
of pressure between the soil air and the outside air, as the outside air pressure increases the soil
pressure must also increase by the same amount. Therefore, since the pore space of the soil remains
constant, outside air enters the pore space vacated by the compressed soil air. In the northern
latitudes, diurnal barometric pressure fluctuations are influenced more by the daily heating and
cooling cycle rather than gravitational effects. The daily fluctuations in barometric pressure resulting
from the thermal effects seldom exceed 3 millibar (mbar). (Effects of Atmospheric Pressure on Gas
Transport in the Vadose Zone, Massman and Farrier, 1992) Assuming the daily pressure fluctuation
is 3 mbar and the depth of-the vadose zone is 13 feet (in the area of monitoring well NS-46)
atmospheric air will enter 0.42 inches into the soil. Therefore, barometric pumping is not considered
to be a substantial contributing factor.
Leaching
NRMRL states that the test plots became saturated and that the pumping required to remove water
from the vadose zone was not discussed in the NOTS Report. This issue is discussed in detail in the
following locations in the NOTS Report:
Section 3, Page 3-1. Fourth Paragraph of the NOTS Report;
the response to Comment# 2 on the January 1998 Progress Report located on Page R-16
at the beginning of the NDTS Rcpon: and
the response to Comment# 12 on the NDTS Report located on Page 15 of the July 16,
1998 correspondence from Envirogen. Inc.
An accumulation of water was observed at the top of the test plots subsequent to precipitation events
of greater than approximately one hall"inch. The accumulated water was bailed l"rom the top ol"the
test plots alter the rain stopped. It is both highly unlikely (and not supported by the moisture content
data included in the NDTS Report) that saturation of the soil in the test plot occurred due to these
minor events given the nature of the geology (clay). Please note that standard practice in pcrformiag
hydraulic conductivity testing on clays in triaxial cells requires 48 hours of applied heads much
greater than one half inch to achieve saturation. Furthermore. the addition of moisture to Test Plots
2 anu 3 did not signilicantly alter the observed degradation. Thus leaching is not likely to be as
important a mechanism as degradation.
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Phytoremediation
Mr. Jon Bornholm
August 19, I 999
Page 9 of 18
The impacted soil in the \·icinity of the La~oon Area is present at depths or:.+ to 18 feet bgs nnc! are at their greatest in the vicinity of the "atcr table. As discussed previouslv, these are likely due to the former unlined lagoons/terracotta pipe and/or associated with the ground-water conditions. In either case, these sources are located at a depth below the frost line. The on!,· vegetation present in the vicinity of the Lagoon Area is grass. The root zone for grass \vould not extend to a depth where significant mass reduction would be observed by plant uptake. Funher evaluation of potential phytoremediation is not warranted.
Commenrs Regarding Suggested Ana!ytes
The Report provides a I ist of suggested analytes for evaluating various natural degradation processes at the site. As discussed below on a point-by-point basis, many of these analytes are included in the Phase I NOTS and others are readily available in site-related documents (of the 23 analytes suggested by NRMRL, IO were included in the Phase I NOTS and 2 have been described in other site-relat_ed documents). The following presents our comments on the suggestions on an analyte-by-analyte basis .
.L Electron Donors
Section 5 of the Phase I NOTS Report presents the results of99 soil samples collected from the test plots at the site and analyzed for VOCs and total organic carbon (TOC). The results indicate that potential electron donors include acetone, toluene, and TOC.
NRMRL recom,nends sampling for hydrogen gas (1-1,[g]) which is identified as an electron donor. H,[g) is not an electron donor, but is a byproduct of fermentative microorganisms that decompose natural and anthropogenic organic compounds during reductive dechlorination (Technical Protocol for Evaluation of Chlorinated Solvents in Ground Water, USEPA, 1998). The Phase I NOTS did not include analysis for H,[g] in the soil gas samples. Other indicators of dechlorination (e.g., elevated concentrations of chloride ion, methane_ VC) identified during the Phase I NOTS suggest that H,[g) is probably present in the vadosc zone.
NSCC proposes that a limited Hz[g) evaluation be perlonnccl for confirmation. Soil gas samples will be collected from the four existing soil gas monitoring wells to provide hydrogen gas information from,both impacted and unimpactccl areas.
7 = Competing Electron Acceptors
Section 5 of the NOTS Report presents the results oflJl) soil s:nnplcs and I _()60 soil gas (832 \\'cckly. 208 monthly and 20 quarterly) samples collected at the site. As part of the analytical work done on the samples. indicators or competing electron acceptors were evaluated in the soil nnd soil gas. These indicators include nitrate: sulfate, iron and methane.
The data docs not indicate decreased concentrations of nitrate or sulfotc in the impacted areas. The results or iron analyses indicate slightly clevnted concentrations in the impacted area. Increased dissolved iron concentrations can be indicative or anaerobic degradation ol'vinyl chloride. The n:sults ol"methanc analyses identify elevated concentrations which arc indicative o!'methanogcncsis and a
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ivlr. Jon Bornholm
August 19, 1999
Page IO of 18
strongly reducing environment. Methanogenesis generally occurs after oxygen, nitrate, and sulfate have been depleted in the treatment zone, thus indicating that alternate electron acceptors do not appear to be hindering the methanogenic proc~35cs in thl: treatment zon~.
BBL proposes no additional sampling for co,r,peting electron acceptors.
Daughter Product (Reducti\-e Dcchlori11Z1tio11) Conccntrntions
Section 5 of' the NOTS Report presents the results of 99 soil samples and 228 soil gas samples collected from the site. analyzed for a number of daughter products. including chlorocthane. VC, cthcnc. and ethane. The soil samples indicated sporadic detections of VC at generally elevated detection limits. The results of the soil gas anal,·ses indicate elevated concentrations of VC, ethcne. ch loroethane, ethane and methane.
The concentrations ofVC and ethene are greater than the concentrations of ethane. This indicates that dehydrohalogcnation of 1,2-DCA is likely the source of VC and that reductive dchalogcnation of VC is I ikely the source of ethene. Reductive dehalogenation of 1,2-DCA may be occurring, resulting in transformation of 1,2-DCA to chloroethane and from chlorethanc to ethane. The rate of reductive
dehalogenation may be fast, resulting in the less frequent detections of chloroethane. The elevated concentrations of methane are indicative of anaerobic degradation of 12-DCA as it is the daughter product of the transformation of ethene and ethane.
BBL proposes no additional sampling for reductive dechlorination daughter products.
:L Chloride Ion
Chloride Ion data from 99 soil samples arc presented in Section 5 of the Phase I NDTS Report. Please note that chloride was not detected in the background samples, but was detected in all samples
collected from the impacted areas. This is a strong indication that dechlorination of 1,2-DCA and associated daughter compounds is occurring in the vadose zone and yielding chloride.
13131., proposes no additional sampling for chloride ion.
The results of 1,060 soil gas samples for Carbon Dio,idc are presented in Section 5 of the Phase I NDTS Report. The avt:ragc CO~ concentration in the soil gas samples from the soil gas monitoring wells located in the impacted soil plots is 2.57 % by volume. The average CO~ concentration in the soil gas sampks from the soil gas monitoring wells located in the background soil plot is 3.23 % by volume. These results do not indicate oxidatiYc degradation.
1313L proposes no additional sampling for carbon dioxide.
6. Breakdown (Oxidative Dcgradation/J\crobic Biodegradation) Products
BBL proposes limited additional sampling to evaluate the presence nfO.\i<lmive Dcgradation/;\ernbic
niodegradation breakdown rroducts.
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ivlr. Jon Bornholm
August I 9, I 999
Page 11 of 18
Additional soil samples will be collected from the soil test plots and will be analyzed for chloroacetic
acid. which is an intermediate compound in the aerobic degradation pathway of 1.2-DCA. The ~rnalytical laboratory l'dicrobial Insights. located in Rockford. Tennessee: will follow a m·ethod tu detect chloroacetic acid at le\'els similar to the USEPA-approved method for analysis ofchloroacctic
acid. Attachment A is the Standard Operating Procedure for the method th,1t will be employed.
7. Oxvaen
Section 5 of the Phase I NDTS Report presents the results of 1,060 soil gas samples collectecl at the
site. The results of the oxygen evaluation indicate depleted oxygen concentrations in impacted areas.
This is consistent with an environment suitable for anaerobic biodcgradation.
l3BL proposes no additional sampling for oxygen.
-8.., Carbon Isotope
Carbon isotopic compositions can be used to compare isotopic fractionation in CO2 between impacted
and unimpacted areas. The CO, in impacted areas would be expected to be depicted in 13C as biogcnic CO, introduces relatively light carbon. The CO, in the soil atmosphere has a typical relative difference of 20 13C parts per thousand. Carbon isotope fractionalization of CO, in the soil gas samples was not performed during the Phase I NDTS.
BBL proposes a limited carbon isotope analysis to resolve this data gap. Existing gas chromatograms
with appreciable levels of carbon dioxide collected during previous soil sampling events will be selected and sent to an analytical laboratory experienced in carbon isotope fractionation. Additional
soil gas sampling may be necessary if the laboratory is unable to use the existing chromatograms for
the carbon isotope fractionation.
DCA Degraders
The presence of documented DCA degraders would provide indirect evidence of metabolic potential
ror DCA biodcgradation. During the Phase I NDTS, species of microorganisms were identified in the Phase I 131Orcport prepared by Blue Planet Technologies. Bacterial species identified include: Pscudomonas, Micrococcus, Bacillus, and Coryncbactcrium. A Pscudomonas species has bL:cn
reported to transform DC;\ (Partial Rapid Metabolism of 1,2-Dichloroethanc by Methylosinus
Trichosporioum O13-Jb. Riebeth. ct al.. 1992). The BIOrcports in their entirety arc located in Appendix A oCthc Phase I NDTS.
1313L proposes no additional sampling lor DCA degraders.
111. Plant Disclwro{;
/\s discussed above. the only vegetation in the vicinity of the vadosc zone impacts is grass and is not likely to be a signilicant mechanism in natural degradation. Further evaluation ofphyton.:mcdiation
is not warr;:intcd.
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lL Plant Tissue Analvsis
Pkasc SCl: the response for item I 0.
12. Source Characterization
ivlr. Jon Bornhoirn
August 19, I 999
Page 12 of 18
VC. chloroethane. ethene and ethane were never used at the site. As discussed in the Phase I NOTS,
these constituents arc not a source of impacts, but arc the result of degradation of 1.2-DCA. BBL
proposes no additional source charncterization.
.Ll... Surface Emission Rate
As discussed in the earlier response regarding volatilization, the estimated quantity of mass lost is
expected to be insignificant. The site is an active manufacturing facility with permitted air emissions
of 1,2-DCA. The permitted emission of 1,2-DCA is 40,141.5 pounds per year from the process areas
and the ground-water pre-treatment facility. It would be difficult to measure 1,2-DCA emissions from
the ground surface and differentiate from other permitted emissions sources.
BBL proposes no additional investigation of surface emission rate.
.l.:L Helium Tracer Tests
To evaluate the use of helium tracer tests to estimate vapor transport rates, BBL conducted a literature
search of 257 databases. Three records related to helium tracer tests in the vadose zone were
identified. In "Factors Controlling the Concentration of Methane and Other Volatiles in Groundwater
and Soil-Gas around a Waste Site" by C. Barber, G.B. Davis, D. Briegel and J.K. Ward (Journal of
Cm11m11im1111 f-/ydrology, 5: 155-169, 1990), the authors reported significant mass balance errors with
the use of helium. The authors attributed the mass balance error to losses lo the atmosphere. This loss
lo atmosphere can be attributed to the density difference (helium is lighter than air). 1,2-DCA has a
vapor density of 4.04 grams per liter, thus it is denser than air.
A 1-lclium Tracer Test is not proposed. It would not yield information suitable for developing a vapor-
phase transport rate clue to the inherent dirliculties noted in the literature and the physical differences
between the tracer and the constituent of concern.
Q Downgradicnt DCA Concentrations
Soil sampling, data presented in the Remedial Investigation Rcpo11, nnd included in the Phase I NOTS
Report, indicates that the extent oi' soil impacts in the do"ngrndienl areas arc deep (adjacent to the
water table). of lesser crn11..:entratio11. and within the area of irnpactcd ground water. Thus.
dnwngradicnt impacts arc more likely due to migration of constituents in the ground water than vapor
rhasc transport.
13131_ proposes no additional clowngradienl soil sampling for DCA.
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lQ. Water Table Fluctuations
Mr. Jon Bornholm
August I 9, 1999
Page 13 of I 8
Ground-water elevation data is presented in Section 5 of the Phase I NOTS Rcpo11. The data indicate
that the ground-water elevation in response to precipitati(~ll. The ma~imurn observed fluctu:!ticn was
3.6i feet between April 199i and October 1997 in monitoring well NS-39, located near the crest of
the topographic divide separating the ground-water compartments of the Unnamed Tributnry and the
Northeast Tributary. The minimum observed fluctuation was 0.5 feet between September I 997 and
December I 997 in monitoring well NS-36, located roughly adjacent to the Northeast Tributary.
The Final Design Report for OU3 (BBL, January I 999) presents the results of a 72-hour pumping test
performed in OU3. As part of the pumping test, a data-logger was installed in a background well
located near the crest of the topographic divide (NS-28). The data collected l'rom the background well
indicates that the short-term fluctuation is 011 the order of 0. I feet. This background fluctuation
corresponded with an atmospheric pressure fluctuation of I 6 millibars.
These results are consistent with the conceptual hydrogeologic model for the Piedmont. The
conceptual hydrogeologic model describes water table fluctuations as primarily a function of
precipitation, with larger fluctuations expected near ground-water divides and smaller fluctuations
near discharge features. The bulk of the impacted areas in OU4 lie in an intermediate position.
BBL proposes no additional investigation of water table fluctuations.
.lL Barometric and Soil Gas Pressure Fluctuations
As discussed in the previous section on Vapor Transpo11 Rates, the depth of influence is not estimated
to be significant. Thus the effect of barometric pressure fluctuations is not anticipated to be a
significant factor in the exchange of atmospheric air and soil gas, which would add oxygen or remove
vapor-phase 1,2-DCA.
BBL proposes no additional investigation of soil gas pressure fluctuations.
l.lL Surface Infiltration
Based on the ground-water llow modeling performed for the site, the estimated recharge rate over the
plant area is 4 inches per year and 12 inches per year in the unpaved areas. Please note that this
represents 10 % and 30 '¾i. respectively. of the yearly precipitation which is available for leaching
impacts from the vadosc zone to the ground water.
13131., proposes no additional investigation of surface inriltration.
12., Vertical Moisture Profiles
During the Phase I NDTS moisture content samples were collected in the four soil plots from a
shallow zone (typically 4 to 6 l"cet below ground surfoee) and a deep zone (typically 6 In 8 l"cet below
ground surface). Moisture contents between the two zones did not vary substantially. The moisture
content of the deep samples were slightly less than that of the shallow samples.
;. ,'I•.',,,'/.
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BBL proposes no additional investigation of vertical moisture profiles.
20. Site Characterization
Mr. Jon Bornholm
August 19, 1999
Page 14 of I 8
Please refer to the figures discussed above and attached to this correspondence for information
regarding the extent of asphalt cover.
21. Rainfall Data
Rainfall data for the site is presented in Section 5 of the Phase I NOTS Report. Additional regional
rainfall data is presented in Attachment A.
BBL proposes no additional collection of rainfall data.
22. Soil Gas DCA Concentrations
The results of I 00 Monthly and Quarterly Soil Gas Samples indicating 1,2-_DCA concentrations are
presented in Section 5 of the Phase I NOTS Report.
BBL proposes no additional collection of soil gas 1,2-DCA data.
23. Identify When Lagoon is Submerged
The lagoons were lined in 1984. The lagoons serve as the wastewater pre-treatment system for the
facility which operates continuously. The lagoons arc continuously submerged, but are not connected
with the underlying material. Therefore, the lagoons do not act as a mechanism for leaching of
residual impacts in the vadose zone.
Comments Regarding Sugges!ed Sampling Design
The Report provides the following information in its evaluation of the sampling design proposed by NSCC
in tht.: December I, 1999 meeting and various other potential sampling designs:
a critique of the sampling design proposed by NSCC:
a discussion of various general sampling designs: and
a proposal for a sampling design considered appropriate for the project.
In general. we concur with NRMRL's assessment of the NSCCs original proposed sampling program. The
proposed program would be effective in evaluating the rate of degradation in the vicinity of the sampling
grid. while other portions of the site may not be as extensively studied. However, the objective of the Phase
II program is to develop a site-specific degradation rate and an estimate of the time frame for remediation.
The objective of a long-term monitoring program would be to gauge the effr:ctiveness of the site-speci ric rate
by comparing observed results over time frame cstimatccl for remediation.
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Mr. Jon Bornholm
August ! 9, I 999
Page 15 of 18
It must be noted that the location of the proposed 32 foot by 24 foot plot was chosen to be coincident with the area of highest observed concentrations. Furthermore, as discussed in the December I. 1999 meeting and earlier in this correspondence, the actual area of impacted vadose zone is unlikely to be as extensive as depicted in previous submittals. By developing a site-specific degradation rate in the vicinity of the area of highest 1,2-DCA concentrations, we are being conser\'ativc. 13y implementing a long term monitoring program, we can judge the effectiveness of the remediation on areas which exhibit lesser concentrations.
The NRMRL-proposed sampling plan developed for the project is not site-specific enough to be implemented at the site. The site is a continuously operating manufacturing facility (7 days per week, 24 hours per day). Furthermore, the areas of impacts are generally in close proximity to operating areas. By overlaying a grid on the site, it is apparent that approximately 85% to 90% of the coverage is inaccessible for sampling due to the presence of buildings, tanks and electrical equipment.
Revised Conceptual Phase II NOTS Sampling Plan
To address NRMRL comments on the proposed Phase II NDTS Sampling Plan, we have revised the plan to include random sampling from two gridded areas on the site. The revised plan will monitor the impacted areas and provide data to develop a site-specific degradation rate. The proposed sampling will be performed on an annual basis for five years at which time a site-specific degradation rate will be calculated. The plan consists of more extensive sampling on a grid from Area 2 than in the Lagoon Area. The specific plan for
each area is described in the following sections.
AREA 2
The sampling grid for Area 2 is shown in Figure 3. The grid covers the area to the north and east of the plant building and is composed of242 blocks with spacing of 40 ft by 40 ft and 20 ft by 20 ft. This area was selected for additional sampling based on the distribution of the maximum 1,2-DCA
concentrations in previous sampling events~ locations of non-detects, and previously unsamplcd
locations. Approximately 150,000 ft' of Arca 2 will be covered by the proposed grids.
The liner grid spacing (20 ft by 20 ft) is present in the vicinity of sample location SI3A2-20 (the former waste-water line to the northwest of the building) and along the locations of the former terra
cotta pipes to the cast of the building. The finer grid is selected for these areas based ow the
substantially higher 1,2-DCA concentrations detected in samples SBA2-0 I, SBA2-06, SBi\2-08,
SBi\2-09, S13A2-l 9, and SBi\2-20. These areas arc covered with the liner grid to bias the random
sampling to the impacted and potentially impacted areas.
In ;\rea 2, both random and biased samples will be collected annually over the grid for live years.
Biased samples will be collected from five soil boring locations sampled during the RI at the depth
interval where the highest 1,2-DC;\ concentration was recorded. The following table lists the live
locations to be sampled.
• /l O I ,') , • t: / ,.
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Sample Depth 1,2-DCA
(ft Bgs) (ug/kg)
SBA2-06 5.5 29,000
SBA2-08 19.5 1.300 EJ
SBA2-09 13.5 53,000 D
SBA2-16 3.5 540 D
SBA2-20 5.5 1,600,000 D
Notes
"E" qunllficr indicates concentration exceeded the calibration range
'T' qualifier indicates t:stirnatcd concentration less than the detection limit
.. D .. qualifier indicates concentration from diluted run sample
Mr. Jon Bornholm
August 19, ! 999
Page 16 of 18
In addition, ten grid blocks will be selected for random sampling. Two locations within each block
will be randomly selected. At the selected locations, a Geoprobe sampler will be advanced into the
soil and split-spoon samples will be collected continuously from the ground surface to the water table.
Photo Ionization Detector (PIO) readings will be collected from each split spoon. Soil from the
interval with the highest PIO reading will be sent to the analytical laboratory to be analyzed for 1,2-
DCA. These sampling results will be used to develop a mass estimate of 1,2-DCA over the gridded
area. Geostatistical methods may be utilized to account for extreme concentration values of 1,2-DCA.
In the four subsequent annual sampling events, locations where 1,2-DCA was not detected will be
eliminated from the sampling program. Additional sample locations will be selected to replace the
eliminated sample locations. At a minimum, five additional grid blocks will be randomly selected
each year. Two locations within each block will be randomly selected for sampling. Locations where
1,2-DCA was detected will be resamplcd the following year. Rcsarnpling at these locations will occur
within a three-foot radius of the previous soil boring location. Figure 4 presents a decision tree
graphically depicting this process.
This sampling program will provide a time series of 1,2-DCA concentrations at the repeated soil
sampling locations. These series of concentrations will be used to estimate local 1,2-DCA degradation
rates. Yearly 1,2-DCA mass estimates over the sampling grid will be used to estimate a site-wide I)-
DCA degradation rate. The sampling program will also provide information on the variability of the
1,2-DCA impacts on several scales:
•
•
illlmediatc -the repeated sampling or the same location (within feet, as close as is
feasible with the chosen sampli_ng,cquipmcnt) will provide information on tile variability
of 1.2-DCA impacts on the order of feet;
local -the paired sampling within each randomly-selected grid box will provide
information of the variability of 1,2-DCi\ impact on the order of tens of feel (20 n by
20 ft in the small grid boxes and 40 ti by 40 ft in the large grid boxes); and
site-wick -sampling over the grid will provide information on the site-wide variability
of the 1,2-DCi\ impacts.
• I\ , ' t /) " , • / ,', .•: ', , ; I 0• /l / I ;I
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Mr. Jon Bornholm
August I 9, 1999
Page 17 of 18
An additional benefit of the sampling program will be the identification of areas without 1,2-DCA
impacts. By sampling and eliminating these locations yearly, at the end of the program a greater areal
extent of the site will be sampled.
LAGOON AREA
A number of soil samples collected from soil borings installed below the water table in the Lagoon
Arca may have overstated the extent of impacts in this area. Depth to ground water measurements
collected from saprolite monitoring wells in the area range from 2.67 ft bgs to 5.61 ft bgs. 1,2-DCA
concentrations above the Performance Standard were reported at depths greater than 7 ft bgs (soil
boring SBLA-18, 7.5 ft Bgs, 1,2-DCA concentration 19,000 ug/kg and soil boring SBLA-06, 9.5 ft
bgs, 1,2-DCA concentration 180 ug/kg). These samples were most likely collected from the saturated
zone where soil quality is affected by impacted ground water. The concentration of 1,2-DCA in
ground water in this area is 110,000 Dug/Lat monitoring well NS-40. The only other soil borings
with reported 1,2-DCA concentrations above the Performance Standard of 169 ug/kg are SBLA-13
(! 1.5 ft Bgs, 1,2-DCA concentration 16,000 ug/kg) and SBLA-14 (3.5 ft Bgs, 1,2-DCA concentration
290 ug/kg). From the previous soil sampling results in the Lagoon Area, only four soil samples out
of 44 had a 1,2-DCA concentration above the Performance Standard.
Based on the results of the previous soil sampling in the Lagoon Area, limited additional sampling
is proposed in this area. Biased samples will be collected at the two locations where 1,2-DCA was
identified at concentrations above the Performance Standard. Biased samples will be collected from
these two locations sampled during the RI at the depth interval where the highest 1,2-DCA
concentration was recorded. The following table lists the two locations to be sampled.
Sample Depth 1.2-DCA
(ft bgs) Concentration
(uglkg)
SBLA-13 11.5 16.000
SBLA-14 3.5 290
These two locations will be sampled for five years, each year sampling within a three-foot radius of
the previous sampling location. At the end of five years, a local 1,2-DCA degradation rate will he
estimated using the data collected.
All grid points selected for sampling will be surveyed by a North Carolina licensed surveyor and soil
samples will be collected using a GcoprohcTM_ All soil sampling will follow procedures as described
in the US EPA Region IV EISOPQAM. Soil samples will he analyzed for Volatile Organic Compounds
by method SW-846 8260B.
The proposed sampling for Arca 2 and the Lagoon Arca will provide information on areas with high
and low 1,2-DCi\ concentrations to develop a site-specific degradation rate.
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Mr. Jon Bornholm
August 19, 1999
Page 18 of 18
We look forward to discussing the revised Conceptual Phase 11 NOTS Sampling Plan presented above, as well as any other questions or comments you may ha\·e regarding this response letter. Please contact either me at [phone] or Angela Dahl at [phone] to schedule a meeting or conference call.
Sincerely,
BLASI.AND, BOUCK & LEE, INC.
4----
Michael P. Fleischner, P.E.
Senior Project Engineer
MPF/cml
219917CJ7.WPI)
cc: Mr. Douglas Cregar, National Starch & Chemical Company
Mr. Alex Samson, National Starch & Chemical Company
Ms. Angela Dahl, National Starch & Chemical Company
Mr. Richard Franklin, National Starch & Chemical Company
Mr. Raymond Paradowski, National Starch & Chemical Company
Mr. Joseph 1-lochreiter, Blasland, Bouck & Lee, Inc.
Mr. David Lipson, Blasland, Bouck & Lee, Inc.
Ms. Catherine Yewdall, Blasland, Bouck & Lee, Inc.
I \
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I
SBA2-07
\ \ \ \ \
\ \\ \
\ \ \
\ \ \ \ \ \
DEPTH SCREEN
9.5 ND
19.5 ND
LAB I I \
\
110U \.. -410D
740D 21.5 ND
I ..,. ,I_
~\ SBA2-05
DEPTH SCREEN LAB
I ~~ l
I ~\
'----I
9.5 ND NA
16.6 ND NA
21.5 ND 7U
\
SBA2-1 9
DEPTH SCREEN LAB
13. 5 156 3, 700
17.5 . 1,393 NA
I ,,/ SBA 2-11
DEPTH SCREEN LAB
I ---------
5.5 ND 3J
7.5 ND 2J \
.,.. 'eNS-0319.11 I 3-l----~_S_B_A_2_-~20 ____ ---I
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DEPTH SCREEN LAB
5.5 169,000 1,600,000D
7.5 27,980 290,000D
19.5 17,310 NA
I ? \ ,___ __ SB_A_2_-1_0_-----1
\ r' DEPTH SCREEN LAB
7.5 I ND 2J
\ SBA2-12
DEPTH SCREEN LAB
7.5 211 NA
9.5 298 NA
11. 5 63 670U
\
\
\
A NSC01 LWC L Cf"J'"-•,SRE~ "'4ES.• •.2.• 'f-oST• •PATT• p sm PCP/CL I A\JGVST lJ, 19'i9 CRA ei2-SO, WON 050/05061006\0S()61CCl ow._
SBA2-08
DEPTH SCREEN LAB
1.5 ND 380D
3.5 55 330
19.5 2,249 1,300EJ
SBA2-14
DEPTH SCREEN LAB
7.5 ND NA
SBA2-13
DEPTH SCREEN
9.5 [ ND
.._ < \ \_ -
J_ -.... '-::::.-
-~ -:< -,,,.,. ,,,.,.SBA2
'o//, \ \I I \ I\ \ \ ~ '--'--I ....._ \. _____
,r -----:i r -SBA2-15 --. "\
SCREEN LAB
----
SBA2-16
ND 6J / --.,,------1)
SCREEN LAB SBA2-06
14 540D DEPTH SCREEN LAB
,......--.,,,=-------------------1 5. 5 13,591 29,000 ~\\, --~~-)\ SBA2-04 9.5 4,064 4,100
DEPTH SCREEN LAB 18. 5 725 95 " ..,.. ~----1 1.5 15,738 NA '-, 1-----....__---1-------1
'-<. 3.5 14,506 17,000
13 NA NS-43 I-17.5 I .... "--------~ SBA2-01
DEPTH SCREEN LAB NS-44 '""' ~ ~--------~ 3.5 697 34,000
~)' SBA2-17
~~::-\-, ---7-D_E_P_T_H_S_C_R_EE_N_L_A_B ........ ...,./.-----------,
17 3.5 ND NA SBA2-02
jl DEPTH SCREEN LAB
1.5 ND 26
2,298.7 83,000
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SBA2-03
DEPTH SCREEN LAB
448 240
13.5 334 NA
17.6 81 I NA
SBA2-18
SCREEN LAB
ND 4J
'-. -............._
--...._
\ '-
'
I
)
LEGEND
j. SOIL BORING LOCATION
e MONITORING v.£LL LOCATION
---ACTIVE PROCESS SEWER LINES (UNDERGROUND)
---ACTIVE TRENCH
---ABANDONED TERRA-COTTA PROCESS SEWER
LINES (UNDERGROUND)
---ABANDONED TERRA-COTTA STORM SEl't£R LINE
f 3.4) DEPTH OF WATER (FEET BELOW GROUND SURFACE)
ND NOT DETECTED
NA NOT ANAL VZED
J THE REPORTED VALUE IS AN ESTIMATED
CONCENTRATION BELOW DETECTION LIMIT
E RESULT EXCEEDED CALIBRATION CURVE
DEPTH MEASURED IN FEET BELOW GROUND SURFACE
SCREEN 1.2-DCA FIELD SCREENING CONCENTRATION (ppb)
LAB 1,2-DCA LABORATORY CONCENTRATION (ppb)
NOTE:
CONCENTRATIONS SHO'MII IN BOLD INDICATE 1,2-DCA
CONCENTRATION WAS BELOW ROD PERFORMANCE STANDARD
(167 ug/\<g) IN TI-iE FIELD SCREENING AND LABORATORY
SAMPLES, OR BELOW PERFORMANCE STANDARD IN THE FIELD
SCREENING SAMPLE AND WAS NOT ANALYZED IN THE
LABORATORY.
SOURCES:
-~OIL SAMPLE LOCATIONS TAKED FROM A MAP ENTITL~
DISTRIBUTION OF 1,2-DCA IN SOIL SAMPLES, AREA 2 .
PREPARED BY INTERNATIONAL TECHNOLOGY CORP.
DA TE UNKNOWN.
-MAP ENTITLED "SITE MAP' PREPARED FOR NATIONAL STARCH
AND CHEMICAL COMPANY BY INTERNATIONAL TECHNOLOGY
CORPORATION, KNOX"1LL£, TENN., DATED 5/18/93.
-MONITORING 'M:LL SURVEY BY SCHULENBE,RGER SURVEYING
COMPANY, SALISBURY. N.C .• DATED 1/21 /97
-MONITORING 'M:LL SURVEY BY TAYLOR 'M:ISMAN & TAYLOR,
RALEIGH N.C., DATED 3/98
100' 100'
SCAL£ IN FEET
NATIONAL STARCH AND CHEMICAL COMPANY
CEDAR SPRINGS ROAD PLANT, SALISBURY, NORTH CAROLINA
EVALUATION OF NATURAL ATTENUATION
FOR OPERABLE UN IT FOUR
1,2-DCA SOIL SAMPLING
RESULTS FOR AREA 2
BB I
FIGURE L Bl.ASL.AND, BOUCK & LEE, INC.
engineers & scientists 1
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SBLA-04 ~-1-----r-------,---i DEPTH SCREEN LAB
1.5 ND 6U
3.5 ND 7U
.--<'. 5.6 ND NA
11.6 ND 36U
'-
,r _.....:..---_ _)~
SBLA-24
7.5 ND 3J
SBLA-16
SBLA-23
DEPTH SCREEN LAB
3 .5 ND 1 6U
\ NS-12 '--.._.,Y . ,., I \ \ '---__,,.\ \
SBLA-22 SB!.__
' DEPTH SCREEN LAB 1------=-.~;..=,..,
D /__,,. 5.5 N 5J .,,,. ,........_
/ --\ \ ~\' \,,~ DEPTH SCREEN LAB
SBLA-07
7.5 ND 6U
9.5 ND 36 SBLA-20
DEPTH SCREEN LAB
3.5 ND NA
SBLA-06 7.5 ND NA
~
~ \ DEPTH SCREEN LAB ~........,,.....-,,,,.=---+-,,-
7.5 ND 7U ........
SBLA-19
SBLA-11
DEPTH SCREEN
13.5 ND
LAB ~ \J I , 3J '-(__.,..,
15.5 ND NA SBLA-10
17.5 7.9 7 DEPTH SCREEN LAB
~ I 7.5 ND 13
I \\! I
/f"--., A\ ( "'
I "-11.5 ND NA
17.5 ND 7U
SBLA-01
DEPTH SCREEN
3.5 ND
LAB 9, 50
5.5 ND 49
7.5 ND 65 SBLA-18
\/, DEPTH SCREEN LAB
J' 3.5 89 NA
SBLA-02 5.5 ND NA
DEPTH SCREEN
1.6 ND
3.5 ND
LAB
2J
7U
\\ \ "' '\
'--
5.5 ND 7U SBLA-09
'"\_, -DEPTH SCREEN LAB
1.5 ND NA
SBLA-03 3.5 ND 2J
DEPTH SCREEN
3.6 ND
LAB
7U \
5.5 ND
7.5 71
7U
23
I I
\
SBLA-08
DEPTH SCREEN LAB
1.5 ND 3J
3.5 ND NA --j--X'---'1'-¥----~\
•
LEGEND
SOIL BORING LOCATION
MONITORING WELL LOCATION
---ACTIVE PROCESS SEWER LINES (UNDERGROUND}
ACTIVE TRENCH
---ABANDONED TERRA-COTTA PROCESS SEWER
LINES (UNDERGROUND}
---ABANDONED TERRA-COTTA STORM SEWER LINE
12.851
ND
NA
u
DEPTH
SCREEN
LAB
NOTE:
DEPTH or WATER (FEET BELOW GROUND SURFACE}
NOT DETECTED
NOT ANAL YlED
THE REPORTED VALUE IS AN ESTI"-IATED
CONCENTRATION BELOW DETECTION LIMIT
1,2-DCA WAS NOT DETECTED AT THE INDICATED
CONCENTRATION
MEASURED IN FEET BELOW GROUND SURFACE
1,2-DCA FlELD SCREENING CONCENTRATION (ppb)
1,2-DCA LABORATORY CONCENTRATION (ppb)
CONCENTRATIONS SHOWN IN IOU> INDICATE 1,2-DCA
CONCENTRATION WAS BELOW ROD PERFORMANCE STANDARD
(167 ug/kg) IN THE FIELID SCREENING AND LABORATORY
SAMPLES, OR BELOW PERFORMANCE STANDARD IN THE FIELID
SCREENING SAMPLE AND WAS NOT ANAL VZED IN THE
LABORATORY.
SOURCES:
-:;;8'1h~1i~~LJNL8f~~f~irclA1~E~cfi~0fAJPttf. f~llP
PREPARED BY INTERNATIONAL TECHNOLOGY CORP.
DA TE UNKNOWN.
-MAP ENTITLED "SITE MAP' PREPARED FOR NATIONAL STARCH AND CHEMICAL COMPANY BY INTERNATIONAL TECHNOLOGY
CORPORATION, KNOXVILLE, TENN., DATED 5/18/93.
-MONITORING Y.£LL SURVEY BY SCHUI.ENBERGER SURVEYING
(,OMPANY, SALISBURY, N.C., DATED 1/21/97
DEPTH SCREEN
.__;..,-~
-,,.---xc---X >-----+-------<---~
1-----+-----~-:-B--L..;.~....;.._s~--v--v-v---,__5_.5 ____ N_D ___ e_u___, l-
1 ,A~ 3.5 ND -MONITORING Y.£LL SURVEY BY TAYLOR Y.£ISMAN & TAYLOR,
RALEIGH N.C., DATED 3/9B
.
SBLA-17
NA ~~~~\_\ \\\-~< -. \
-.. \ \ \ , \ NATIONAL STARCH AND CHEMICAL COMPANY --' -.. \ , CEDAR SPRINGS ROAD PLANT, SALISBURY, NORTH CAROLINA
.,------. ....__ '---'l"l, ~ " \...., -...... EVALUATION OF NATU RAL ATTENUATION
~ -., -.. ~ ~ -....... FOR OPERABLE UNIT FOUR ' \..,__ t ' "-~ ........ -f l------..:.....=..:...:........:=...:....::.:...::....:==--=~:__:_-=-=-:...:........:-----1
~ 5.6 ND
I I I I
I I
100' 100' 200'
SCALE IN FEET
DEPTH I SCREEN I LAB DEPTH [ SCREEN I LAB \
\ '---
'-.. ......... , \ ~ 1-~ , ......... '--vJ 1,2-DCA SOIL SAMPLING
--"-~ , RESULTS FOR LAGOON AREA ~ ~ " --......... 3 I ND I NA 4 I ND NA ........
------......... \ ~ BBL BLASI.AHO, BOUCK & l[E, INC. I
engineers & scientists
FIGURE
2
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• NS-24
I AUGUST T9. 1t99 CRA-t:!-5(1' ,Q.j
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LEGEND
SOIL BORING LOCATION
MONITORING v.£ll LOCATION
---ACTIVE PROCESS SEv.£R LINES (UNDERGROUND)
ACTIVE TRENCH
---ABANDONED lERRA-COTTA PROCESS SEWER
LINES {UNDERGROUND)
---ABANDONED lERRA-COTTA STORM SEv.£R LINE
---GRID LINE
SOURCES:
"Oil SAMPLE LOCATIONS TAKED FROM A MAP ENTITL~ -.,DISTRIBUTION OF 1,2-DCA IN SOIL SAMPLES, AREA 2 .
PREPARED BY INTERNATIONAL "TECHNOLOGY CORP.
DAlE UNKNOWN.
MAP ENTITLED ·sI1E MAP' PREPARED FOR NATIONAL STARCH -AND CHEMICAL COMPANY BY INlERNATIONAL "TECHNOLOGY
CORPORATION, KNOXVILLE, lENN., DATED 5/18/93.
-MONITORING WELL SURVEY BY SCHULENBERGER SURVEYING COMPANY, SALISBURY, N.C., DATED 1/21/97
MONITORING WELL SURVEY BY TAYLOR v.£ISMAN & TAYLOR,
RALEIGH N.C., DAlED 3/98
,.,. 50' 100'
SCALE IN FEET
NATIONAL STARCH AND CHEMICAL COMPANY
CEDAR SPRINGS ROAD PLANT, SALISBURY, NORTH CAROLINA
EVALUATION OF NATURAL ATTENUATION
FOR OPERABLE UNIT FOUR
SOIL SAMPLING PLAN
FOR AREA 2
/ BBL 81.ASLANO, BOUCK & L£[, INC. I engineers & scientists
FIGURE
3
-------------------Figure 4
Area 2 Soil Sampling Plan
Operable Unit 4
Cedar Springs Road Plant Site
Salisbury, North Carolina
YEAR ONE
Collect 5 Biased Soil
Samples and 10 Pairs of
Random Soil Samples
YEARS TWO
THROUGH FIVE
Eliminate any Locations
That Had Non-Detect
Concentrations of 1,2-DCA
!
Select Additional Pairs
of Random Samples to
Replace Eliminated
Locations (A Minimum of 5'
1
Collect Soil Samples
From Previous Locations
Not Eliminated and Newly
Selected Random Locations
YEAR FIVE
Using All Collected
Data, Geostatistical and
Regression Techniques
Estimate Site-Wide and
Local Degradation Rates
BBL
BlASLAND. BOUCK & LEE. INC. -08/9-,-------------------------------------------englneen & scientists
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DETERMINATION OF HALOACETIC ACIDS
IN DRINKING \VATER BY ION EXCHANGE LIQUID-SOLID EXTRACTION AND
GAS CHROMATOGRAPHY WITH A MASS SELECTIVE DETECTOR
This is a liquid-solid extraction method and is designed as a simplified alternative to the
liquid-liquid extraction approach of Method 552 for the haloacetic acids.
t. Scope and Application
Analyte
Monochloroacetic Acid
Dichloroacetic Acid
Trichloroacetic Acid
Monobromoacetic Acid
Bromochloroacetic Acid ·
Dibromoacetic Acid
Chemical Abstract Services
Registry Number
79-11-8
79-43-6
76-03-9
79-08-3
5589-96-3
631-64-1
I 2. Summary of Method
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2.1 A 100-ml volume of sample is adjusted to pH 5.0 and extracted with a
preconditioned miniature anion exchange column. The analytes are eluted with
small aliquots of acidic methanol and esterified directly in the medium after the
addition of a small volume of methyl-tert-butyl ether (MTBE) as a co-solvent. The
methyl esters are partitioned into the MTBE phase and identified and measured by
capillary column gas chromatograph coupled to a Mass Selective Detector.
3. Interferences
The acid forms of the analytes are strong organic acids that react readily with alkaline
substances, and can be lost during sample preparation. Glassware must be acid rinsed with
I :9 hydrochloric acid:water prior to use to avoid analyte losses due to absorption.
3.1 Organic acids and phenols, especially chlorinated compounds, are the most direct
potential interference with the determination. The procedure includes a methanol
wash step after the acid analytes are absorbed on the column. This step eliminates the
potential for interference from neutral or basic, polar organic compounds present in the
sample.
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4. Safety
4.1 The toxicity or carcinogenicity of each reagent used in this method has not been
precisely defined. From this viewpoint, exposure to these chemicals must be
minimized. The laboratory is responsible for maintaining a current awareness file of
OSHA regulations regarding the safe handling of the chemicals specified in this
method. A reference file of material data handling sheets should also be made available
to all personnel in the chemical analysis.
5. Equipment and Supplies
A. PASTEUR PIPETS, Glass disposable
B. pH METER -Wide range with the capability of accurate pH measurements at pH
5 ± 0.5.
C. 15-ml amber colored bottles with Teflon-lined screw caps.
D. LIQUID-SOLID EXTRACTION VACUUM MANIFOLD -Available from a
number of suppliers.
E. LSE CARTRIDGES (1ml) AND FRITS -Also available from a number of
suppliers.
F. 75-ml RESERVOIRS PLUS ADAPTERS -Available from J.T. Baker, Cat. No.
7120-03 and Cat. No. 7122-00
G. GRADUATED CONICAL CENTIRIFUGE TUBES WITH TEFLON-LINED
SCREW CAPS (15 mis).
H. SCREW CAP CULTURE TUBES -Suggested size 13 x I 00 nm.
I. BLOCK HEATER-Capable of holding screw cap culture tubes.
J. VORTEX MIXER
6. Reagents and Standards
A. NANO PURE H20
B. METHANOL-Pesticide quality or equivalent.
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7.
C.
D.
E.
F.
METHYL-TERT-BUTYL ETHER -Nanograde, redistilled in glass if necessary.
Ethers must be demonstrated to be free of peroxides. One test kit (EM Quant Test
Strips), is available from EM Science, Gibbstown, NJ. Procedures for removing
peroxides from the ether are provided with the test strips. Ethers must be periodically
tested (at least monthly) for peroxide formation during use. Any reliable test kit may
be used.
SODIUM SULFATE -(ACS) granular, anhydrous. Heat in a shallow tray at 400°C
for a minimum of 4 hours to remove phthalates and other interfering organic
substances. Alternatively, extract with methylene chloride in a Soxhlet apparatus for
48 hours.
SODIUM HYDROXIDE (NaOH), IN -Dissolve 4g ACS grade reagent water in a
100 mL volumetric flask and dilute to the line.
1,2,3 -TRICHLOROPROP ANE, 99+% --For use as the internal standard.
G. 2-BROMOPROPIONIC ACID -For use as a surrogate compound.
H. 10% Na2SO4 / H2O (BY WEIGHT) SOLUTION -Dissolve !0g Na2SO4 in 90g
reagent water.
I. 10% H2SO~eOH SOLUTION -prepare a solution containing 10ml H2SO4 in 90ml
methanol.
1.· IM HCl/MeOH -Prepare a solution containing 8.25 ml HCL (ACS grade) with 91.75
ml methanol.
K. AG-I-XS ANION EXCHANGE RESIN -Rinse resin with three consecutive 500ml
aliquots of deionized water and store in deionized water. Available from Biorad,
Richmond, CA.
L. ACETONE -ACS reagent grade or equivalent.
M. AMMONIUM CHLORIDE -ACS reagent grade or equivalent.
N. SODIUM SULFITE-ACS reagent grade or equivalent.
Stock Standard Solutions
A. Ahaltyes and Surrogates (Table I) -Prepare at I to 5 mg/ml in MTBE
B. Internal Standard Fortifying Solution -Prepare a solution of 1,2,3-
trichloropropane at I mg/ml by adding 36 µI of the neat material (Sect. 7.6) to
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c.
50ml of MTBE. From this stock standard solution, prepare a primary dilution
standard at 10 mg/L by the addition of 1 ml to 100ml MTBE.
Surrogate Standard Fortifying Solution -Prepare a surrogate stock standard
solution of 2-bromopropanoic acid at a concentration of 1 mg/ml by accurately
weighing approximately 10mg of 2-bromopropanoic acid, transferring it to a 1 O-
m! volumetric, and diluting to the mark with MTBE. Prepare a primary dilution
standard at a concentration of 2.5 µg/ml by diluting 250 µI of the stock standard
to 100 mis with methanol.
8. Sample Collection, Preservation and Storage
A.
B.
C.
D.
E.
Grab samples must be collected in accordance with conventional sampling
practices (9) using amber glass containers with TFE-lined screw caps and
capacities in excess of 100 ml.
Prior to shipment to the field, to combine residual chlorine, add crystalline
ammonium chloride (NH.iCl) to the sample container in an amount to produce a
concentration of lOOmg/1 in the sample. Alternatively, add 1.0 ml of a 10 mg/ml
aqueous solution of NH4Cl to the sample bottle for each 100 ml of sample bottle
capacity immediately prior to sample collection. Granular ammonium chloride
may also be added directly to the sample bottle.
After collecting the sample in the bottle containing the dechlorination reagent,
seal the bottle and agitate for I min. ·
Samples must be iced or refrigerated at 4 °C and maintained at these conditions
way from light until extraction. Holding studies performed to date have
suggested that, in samples dechlorinated with NH4Cl, the analytes are stable for
up to 28 days. Since stability may be matrix dependent, the analyst should verify
that the prescribed preservation technique is suitable for the samples under study.
Extract concentrates (Sect. 11.3.6) should be stored at 4°C or less, away from
light in glass vials with Teflon-lined caps. Extracts should be analyzed within 48
hours following preparation.
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9. Procedure
Preparation and Conditioning of Extraction Columns
A. Preparation -Place 1 ml liquid-solid extraction cartridges onto the vacuum
manifold. Place frits into the tubes and push down to place them flat on the
bottom. Add the AG-l-X8 resin solution dropwise to the tubes with a Pasteur
pi pet until there is a solid layer of resin 10mm in height. Add reagent water and
apply vacuum to settle out the suspended resin particles. Do not allow the resin
to go dry. At this point extraction of samples can begin or the columns can be
stored for later use by maintaining the resin under water and sealing the top with
aluminum foil.
B. Conditioning -Attach adapters and 75ml reservoirs to the liquid-solid extraction
cartridges. To condition the columns, add to the reservoirs and pass the following
series of solvents in 10ml aliquots through the resin under vacuum: methanol,
reagent water, I M HCI/MeOH, reagent water, 1 M NaOH, and reagent water.
The conditioning solvents should pass through the resin bed to dry and the sample
should be added (Sect.11.2.3) immediately after the last reagent water aliquot.
10. Sample Extraction and Elution
A. Remove the samples from storage and allow them to equilibrate to room
temperature.
B. Adjust the pH of a I 00ml sample to 5 ± 0.5 using 1:2 H2SO4 water and check the
pH with a pH meter or narrow range pH paper.
C. Add 250µ1 of the surrogate primary dilution standard (Sect. 7.15.3) to each
sample.
D. Transfer the I 00ml sample to the reservoir and apply a vacuum to extract the
sample at the rate of -2ml/min.
Once the sample has completely passed through the column add IO mis MeOH to
dry the resin, add 4 mis I 0% H2SO4/methanol to the column and elute at the rate
of approximately 1.51111/min. Tum off the vacuum and remove the culture tubes
containing the elutants.
11. Solvent Partition
A. Add 2.5 ml MTBE to each elutant and agitate in the vortex mixer at a low setting
for about 5 seconds.
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B. Place the capped culture tubes in the heating block (Sect. 6.13) at 50°C and
maintain for I hour. At this stage, quantitative methylation of all method analytes
is attained.
C. I. J Remove the culture tubes from the heating block and add to each tube J 0ml
of I 0% by weight of sodium sulfate in reagent water (Sect. 7 .8). Agitate
each solution for 5-10 seconds in the vortex mixer at a high setting.
C.1.2 Allow the phases to separate for approximately 5 minutes. Transfer the
upper MTBE layer to a 15ml graduated conical centrifuge tube (Sect. 6.1 I)
with a pasteur pipet. Repeat the extraction two more times with
approximately !ml MTBE each time. Combine the MTBE sample extracts
in the graduated centrifuge tube.
C.1.3 Add 200µ1 of the internal standard fortifying solution (Sect. 7.15.2) to each
extract and add MTBE to each to a final volume of 5ml.
C. l .4 Transfer a portion of each extract to a vial and analyze using GC/MS. A
duplicate vial should be filled from excess extract. Analyze the samples as
soon as possible. The sample extract may be stored up to 48 hours if kept at
4°C or less, away from light in glass vials with Teflon-lined caps.
6