NCD991278953_19900912_National Starch & Chemical Corp._FRBCERCLA ROD_Record of Decision OU-2 1990 - 1991-OCR

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
4WD-NSRB
SEP 1 8 1991
Bruce Nicholson
Superfund Section
REGION IV
345 COURTLAND STREET. N.E.
ATLANTA, GEORGIA 30365
N.C. State Division of Solid Waste Management
P.O. Box 27687
Raleigh, N.C. 27611
Re: Operable Unit #2; Trench Area Soils
·.·,)i:_,;t
'·
National Starch & Chemical Company; Salisbury, N.C.
Dear Mr. Nicholson:
During EPA's review of the Record of Decision for the Second Operable
Unit at National Starch & Chemical Company, an additional risk
characterization of the trench area surface soils was asked to be
done. EPA requested the additional characterization of the trench
area surface soils on October 5, 1990. A sampling plan was approved
in May 1991, and IT Corporation collected six surface soils samples
from the trench area on June 6-7, 1991. The samples were analyzed
for the Target Compound List Volatile and semivolatile compounds by
IT Analytical Services Laboratory. The analytical-results were
provided in the July Monthly Progress Report. The memo discussing
the results was sent to EPA on August 2, 1991 and is attached for
your review. The Risk characterization Report for the trench area
surface soils was received by the EPA on August 26, 1991. This
report is also attached for your review. These reports were
requested to be sent to you by Jill Hickey of the Attorney General's
office during a conference call on September 17, 1991.
At this time these reports are being reviewed by Elmer Akin, Health
Assessment Officer. If you have any questions or comments, please do
not hesitate to call me at 404/347-7791.
Sincerely,
fJ o~
Da~n
Remedial Project Manager
Enclosures
cc: Curt Fehn, EPA
Rich Leahy, EPA
Jill Hickey
·t<i::Gt\VEO
SEP201991
SUPERfllND SECTION
Printed on Recycled Pap':_r
I
r (l] INTERNATIONAL TECHNOLOGY CORPORATION
• • Memorandum
To:
From:
Subject:
Mike Sturdevant Date: August 2, 1991
408668. 70.10
RISK CALCULA ON RESULTS FOR THE TRENCH SURFACE SOILS,
NATIONAL STARCH CHE'MICAL CO.
Please find attached the draft risk assessment results for the trench surface soils data.
The exposure assumptions have been revised to reflect the information from Mr.
Paradowski of NSCC. The exposure duration and frequency were increased over Mr.
Paradowski' s numbers to some extent to be consistent with EPA guidelines that require
risk estimates based on reasonable maximum exposure (RME) scenarios.
The results show all hazard indices below 0.01, and incremental lifetime cancer risk well
below the lxlO ◄ to lxl0·6 risk range (at 2x10·1 to 7xl0"12). I am currently writing the
documentation for the risk assessment, including exposure and volatilization models,
tables of data assumptions, and results. This should be done by early next week.
44-8-85
•
National Starch Chemical Co.
Ol-Aug-91
Trench data
EXPOSURE CALCUALTIONS/RISK CHARACTERIZATION
1. INCIDENTAL INGESTION OF SOIL
constants:
•
------------------------------------------------------------------IR= 50 mg soil/day (adult, commercial;HHEM addendum)
CF= lE-06 (lE-06 kg/mg)
FI= 0.5
EF = 5 days/year (modified from R. Paradowski)
ED= 25 years
BW= 70 kg
AT= 9125 days
ATc= 25550 days
chemical-specific parameters:
CARCINOGENS
Bis(2-ethylhexyl)-
phthalate
NONCARCINOGENS
Acetone
2-Butanone
Benzoic acid
Bis(2-ethylhexyl)-
phthalate
NOTES:
cs (a)
(mg/kg)
6.9
0.069
0.002
0.210
6.9
Intake
(mg/kg/day)
l.21E-08
3.JSE-10
9.78E-12
1.0JE-09
3.JSE-08
Total Hazard
(a) maximum measured in surface soils
(b) 1991 HEAST
(HHEM addendum)
(adult)
( 25 years)
(70 years)
slope factor
(mg/kg/day-1)
or RfD (b)
(mg/kg/day)
0.014
0.1
0.05
4
0.02
Index:
(c) used oral RfDs and slope factors when inhalation
numbers were not available
fd) did not include semi-volatile compounds.
ILCR or
hazard
quotient-
l.69E-10
3.JSE-09
1.96E-10
2.57E-10
l.69E-06
1. 69E-06
•
National Starch Chemical co.
Ol-Aug-91
Trench data
EXPOSURE CALCUALTIONS/RISK CHARACTERIZATION
2. DERMAL CONTACT WITH CHEMICALS IN SOIL
constants:
•
---------------------------------------------------------------------------(le-6mg/kg)
cm2 (adult hands+forearms; EFH) CF=
SA=
AF=
EF =
ED=
FI=
BW=
AT=
ATC=
lE-06
1980
2.77
5
25
0.5
70
9125
25550
mg/cmA2 (clay; HHEM)
days/year(modified from R. Paradowski)
years (HHEM addendum)
kg (adult)
days ( 2 5 years)
days (70 years) ---------------------------------------------------------------------------chemical-specific parameters:
CS ABS
(mg/kg)
absorbed
dose
(mg/kg/day)
slope factor
(mg/kg/day-1)
or RfD (b)
(mg/kg/day)
ILCR or
hazard
quotient
---------------------------------------------------------CARCINOGENS
Bis(2-ethylhexyl)-
phthalate
NON CARCINOGENS
Acetone
2-Butanone
Benzoic acid
Bis(2-ethylhexyl)-
phthalate
NOTES:·
6.9
0.069
0.002
0.210
6.9
0.6 l.59E-06
l 7.41E-08
l 2.15E-09
l 2.25E-07
0.6 4.44E-06
Total Hazard Index:
(a) maximum measured in surface soils
(b) 1991 HEAST
(c)' used oral RfDs and slope factors when inhalation
numbers were not available
(d) did not include semi-volatile compounds.
0.014 2.22E-08
0.1 7.41E-07
0.05 4.29E-08
4 5,6JE-08
0.02 2,22E-04
2.23E-04
. ' . •
National Starch Chemical co.
Ol-Aug-91
Trench data
EXPOSURE CALCUALTIONS/RISK CHARACTERIZATION
3. INHALATION OF AIRBORNE OR VAPOR-PHASE CHEMICALS
·constants: -------------------------------------------------------------------~---------
IR= 2.5 m3/hour (adult male, mod. activity;EFH)
ET= 4 hr/day (modified from R. Paradowski)
EF = 5 days/year .(modified from R. Paradowski)
ED= 25 years (HHEM addendum)
BW= 70 kg (adult)
AT= 9125 days (25 years)
ATc= 25550 days (70 years)
-----------------------------------------------------------------------------
chemical-specific parameters:
apor Phase (d)
NONCARCINOGENS
Acetone
2-Butanone
Fugitive Dust
CARCINOGENS
Bis(2-ethylhexyl)-
CA
(mg/m3)
0.129
0.0013
Intake
(mg/kg/day)
2.52E-04
2.54E-06
phthalate 6.9E-07 4.822477E-10
NON CARCINOGENS
Acetone
2-Butanone
Benzoic acid
Bis(2-ethylhexyl)-
phthalate
NOTES:
6.9E-09
2E-10
2.lE-08
6.9E-07
Total Hazard
fa) maximum measured in surface soils
b) 1991 HEAST
l,350294E-ll
3.913894E-13
4.109589E-ll
1. 350294E-09
Index:
,c) used oral RfDs and slope factors when inhalation
numbers were not available
(d) did not include semi-volatile compounds.
(
slope factor
(mg/kg/day-1)
or RfD (b)
(mg/kg/day)
ILCR or
Hazard
Quotient
0.1 2.52E-03
0.09 2.SJE-05
0.014 6.75E-12
0.1 1. 35E-10
0.09 4.35E-12
4 1. OJE-11
0.02 6.75E-08
2.SSE-03
• rn INTERNATIONAL TECHNOLOGY
CORPORATION
August 21, 1991
Ms. Darcy Duin
Remedial Project Manager
Environmental Protection Agency Region IV
345 Courtland Street, NE
Atlanta, Georgia 30365
•
SUBJECT: Risk Characterization for the Trench Area; Second Operable Unit; National
Starch & Chemical Co. Site Salisbury, Nonh Carolina; IT Project Number
408668.70
Dear Darcy:
Enclosed for your review and approval is the Risk Characterization Report for the trench
area surface soils. This report represents an expanded version of the preliminary risk
calculation provided in the July 1991 Monthly Progress Report.
In order to tie together the work that has been performed in the past and the work required
for the future, a summary chronology of events that lead up to the additional investigation
of the trench area surface soils is provided below.
The trench area soils are considered the Second Operable Unit for the National Starch
Site. The Second Operable Unit Remedial Investigation and Feasibility Study was
completed and approved by EPA in June 1990.
An additional risk characterization of the trench area surface soils was prompted by
Elmer W. Akin's (Health Assessment Officer, EPA) review of the Second Operable
Unit Record of Decision. He determined that additional characterization of the direct
soil exposure pathway was required.
At a meeting between EPA and National Starch on October 5, 1990, Ms. Barbara
Benoy, EPA requested the additional characterization of the trench area surface soils.
National Starch submitted a surface soil sampling plan to EPA by transmittal letter
dated November 12, 1990. National Starch received EPA's verbal approval of the
sampling plan in May 1991.
Regional Otfice
SOU2SS.DOC 312 Directors Dliv_e •Knoxville.Tennessee 37923. 615-690-3211
IT Corporation is a wholly owned subsidiary of International Technology Corporation
Ms. Darcy Duin
August 20, 1991
Page Two
• INTERNI.AL TECHNOLOGY CORPORATION
In accordance with the approved plan, IT collected six surface soil samples from the
trench area on June 6-7, 1991. The samples were analyzed for the Target Compound
List volatile and semivolatile compounds by IT Analytical Services laboratory. The
analytical results were provided in the July Monthly Progress Report.
The results of the enclosed Risk Characterization Report indicate that the chemicals
measured in the trench surface soils do not pose a significant health risk to workers based
on routine maintenance activities (ie. mowing) within the trench area.
The completion of this work should be considered as a completion of Task I and Task II
of the Scope of Work for the Remedial Design and Remedial Action for Operable Unit 2.
The only exception is the filing of a deed restriction, as required under Task I objective
number 3. The remaining tasks (Task III Final Action Report and Task IV Performance
Monitoring) and the filing of a deed restriction will be completed after EPA and National
Starch approve the Consent Decree.
Please provide your comments or acceptance of the report and our understanding of the
SOW requirements by September 13, 1991.
Sincerely,
~~
Michael N. Sturdevant, P.E.
Project Manager
cc: H. Graulich
R. Paradowski
A. Samson
SOU2SS.DOC
•
RISK CHARACTERIZATION FOR TRENCH AREA,
NATIONAL STARCH AND CHEMICAL COMPANY
A risk assessment was performed to determine the current risks associated with potential
direct human exposure to surface soils at the National Starch and Chemical Company
(NSCC) site. This risk assessment follows EPA guidance for performing risk
assessments (EPA 1989a). Aside from the determination of chemicals of concern, the
risk assessment evaluates human exposures to chemicals, summarizes the toxic
characteristics of the chemicals, and provides a quantified human health risk associated
with current site conditions.
1.0 CONTAMINANTS OF CONCERN
Table 1 lists the analytical results for the trench area surface soil sampling. Sample
results were compared to applicable field and laboratory blanks to determine if any
compounds detected may be contaminants introduced during sampling or analysis. The
"five and ten times rule" was applied to the sample results. (EPA, 1989a) For common
laboratory contaminants (methylene chloride, acetone, 2-butanone, toluene and phthalate
esters), data within ten times an associated blank concentration were disregarded. For
all other compounds, data within 5 times the blank concentration was eliminated from
consideration. Methylene chloride was screened out due to its presence in both field and
laboratory blanks. Background levels for the detected organic compounds in site soils
were considered to be zero. Frequency of detection was not considered due to the small
size of the data set. If a compound was detected at least once, it was included. The
sample results that remained after this screening process are presented in Table 2. The
contaminants in the trench surface soils are acetone. 2-butanone, benzoic acid, and bis(2-
ethylhexyl)phthalate.
-1-
• •
2.0 EXPOSURE ASSESSMENT
An exposure assessment was performed to detennine the potential for human receptors,
primarily on-site workers, to be exposed to the above-background concentrations of
chemicals of concern identified in surface soils of the trench area. The exposure
assessment involves identification of potential human receptors, identification of
exposure pathways, and quantification of intakes.
2.1 Site Description
The National Starch and Chemical Company (NSCC) site is located in Rowan County,
North Carolina, approximately five miles south of the City of Salisbury. Salisbury is
located about 40 miles northeast of Charlotte, North Carolina.
The NSCC site, also referred to as the Cedar Springs Road Plant, is approximately 485
acres in size. The disposal area, known as the trench area, is surrounded by heavily
wooded acreage to the north, west, and south. Residential areas are located no less than
1500 feet from the trench area in the northwest and southwest directions. Public access
to the trench area is controlled by posting, fencing, and plant personnel. Figure l shows
the Trench Area and locations of the surface soil samples.
2.2 Identification of Exposure Pathways
Table 3 provides a summary of pathways by which a human receptor may come into
contact with the chemicals found in the surface soils of the trench area. General
exposure assumptions include:
Entry by public is restricted by posting and/or fencing around the
site; and
workers enter the trench area infrequently, primarily for weed
control activities.
The frequency and duration of worker activities m the trench area is based on
information from R.E. Paradowski (1991) of NSCC.
-2-
-
-~----'", ' ·--
~ I \ ( \ r.,o
Figure I. Trench Area and Surface Soil Sampling Locations. (Source: RI Repon, June I 988, IT Corporation, Figure 2-1)
•
•
• •
2.3 Quantification of Exposure
The quantitiative estimate of intake by human receptors involves:
Determining the concentration of each chemical in the
environmental media at the point of assumed human
contact;
identifying applicable exposure models and input parameters; and
quantifying human intake.
Exposure models were identified to address each potential exposure pathway. The
model used to estimate incidental ingestion of soils (EPA, 1989a) is:
where:
I.oil
Cs
IR
CF
FI
EF
ED
BW
AT
=
=
=
=
=
=
=
=
=
I,0il = (Cs)(IR)(CF)(FI)(EF)(ED)/(BW)(A D
intake of sediment/soil (mg/kg-day)
chemical concentration in sediment/soil (mg/kg)
ingestion rate (mg soil/day)
conversion factor (10·• kg/mg)
fraction ingested from contaminated source (unitless)
exposure frequency (days/year)
exposure duration (years)
body weight (kg)
averaging time (days)
The model for dermal contact with chemicals in soil is also presented in EPA (1989a):
where:
AD = (Cs)(CF)(FI)(SA)(AF)(ABS)(EF)(ED)/(BW)(AT)
AD =
SA =
AF =
ABS =
absorbed dose from sediments/soil (mg/kg-day)
skin surface area available for contact (cm2)
soil to skin adherence factor (mg/cm2)
skin absorption factor
Skin absorption factors were determined using the method of McKone (1990).
The model used to determine intake by inhalation of airborne chemicals (EPA 1989a)
is:
I,, = (Ca)(IR)(ET)(EF)(ED)/(BW)(A D
-4-
where:
¼,
Ca
IR
ET
=
=
=
=
•
intake from air (mg/kg-day)
air concentration of chemical (mg/m3)
inhalation rate (m3/hour)
exposure time (hours)
•
Air concentrations were determined for the volatile organic compounds (VOCs) by
modeling vapor flux from the surface soils and subsequent dispersion. Air
concentrations due to fugitive dust releases were estimated for all contaminants using
a dust-loading model. These models are described below.
The specific parameters and assumptions used to model site-specific conditions at the
NSCC site are listed in Table 4.
Volatilization Model
Workers in the trench area could potentially be exposed to vapor-phase chemicals due
to volatilization of organic compounds present in the surface soils. Volatilization and
dispersion models were used to estimate air concentrations of VOCs based on their
concentrations in surface soil. First a VOC flux from soil is calculated, then air
dispersion is modeled for on-site workers. Model assumptions and parameters are
presented in Table 5.
The emission rate for waste at the saturated soil surface was calculated by (GRI, 1988):
where:
Q
Ac
Ka
u
Dp
Sc
p
P.,,,
R
T•
=
=
=
=
=
=
=
=
=
=
(Q) = (Ka)(P -P,.c)/(R)(T.)(Ac)
mass flux (moles/hr)
contaminated area (m2)
air mass-transfer coefficient = 0.0292 (U0·78)(Dp"0·u)(Sc·0·67)
Windspeed (m/hr)
Diameter of waste boundary (m)
Schmidt gas number (unitless)
Vapor pressure of the volatile at the soil surface (atm)
Vapor pressure of the volatile in the atmosphere (atm)
Gas constant (atm · m2/mol · 'K)
Temperature of waste surface CK)
The equation was modified to account for a mixture of volatiles present at less than
saturation amounts by the factor:
(Ci)/(Cs)
-5-
where:
Ci
Cs
=
=
• •
Measured concentration of a given volatile in soil (mg/kg)
Concentration if soil were saturated with a given volatile (111!Ykg)
Cs was calculated by: volatile liquid density {d) · soil porosity (E)
soil density (D)
Dispersion of volatiles into air was estimated using the Nearfield Box Model (GRI,
1988):
where:
Ca
Q
Hb
Wb
Um
=
=
=
=
=
(Ca) = (Q)/(Hb)(Wb)(Um)
Concentration of contaminant in ambient air on site (mg/m3)
Emission rate of contaminant (µg/sec)
Downwind exposure height (m)
Width of contaminated area perpenclicular to wind direction (m)
Average wind speed= 0.22 (U10) In (2.5 Hb) (m/sec)
U10 = Windspeed at 10 m above ground surface (m/sec)
The following assumptions were included in ,the model:
The area of contaminated soil is 5 acres
VOCs are present in a mixture of compounds. The maximum soil
concentration for each compound was used for Ci
The flux from subsurface contaminants is negligible.
Fugitive Dust Model
Concentrations of contaminants on fugitive dust were estimated using an average dust
loacling of 100 µg/m3 (NCRP, 1984). Concentrations in air were calculated by:
where:
Ca
Cs
DL
CF
=
=
=
=
Ca = (Cs)(DL)(CF)
air concentration (mg/m 3)
soil concentration (mg chemical/kg soil)
dust loacling factor (µg soil/m 3)
unit conversion factor ( I x 10·9 kg/µg)
The results of the exposure modeling effort are presented in Table 6. the highest intake
encountered was for acetone through inhalation of vapor-phase chemicals, at 2.5 x 104
mg/kg-day. All other intakes were two or more orders of magnitude below this level.
-6-
• •
In summary, modeling results show that intake levels for ~II chemicals, all pathways are
low.
3.0 TOXICITY ASSESSMENT
3.1 Carcinogenic Effects
Bis(2-ethylhexyl)phthalate (BEHP) is not known to be carcinogenic in humans; however,
BEHP was found to be carcinogenic in rats and mice (NTP, 1982). Benign and
malignant liver tumors were seen at increased incidence in male and female animals of
both species in the absence of other toxicity. EPA classifies it as Group B2, probable
human carcinogen on the basis of animal studies. EPA has calculated a carcinogenic
slope factor of 1.4 X 10-2 (mg/kg-day)"' via the oral route (EPA, 1991a).
3.2 Noncarcinogenic Effects
BEHP, acetone, 2-butanone, and benzoic acid also show noncarcinogenic effects.
Reference doses (RfDs), uncertainty factors and critical effects or target organs are listed
for these chemicals in Table 7.
4.0 RISK CHARACTERIZATION
Using modeled human intakes and dose-response information, it is possible to estimate
the potential risks associated with the chemicals of concern. Risks are estimated
differently for carcinogens and noncarcinogens. For carcinogenic chemicals, risk is
expressed in terms of the probability of contracting cancer over a lifetime in excess of
the background probability, called the incremental lifetime cancer risk (ILCR). This risk
is estimated using the following formula:
where:
I
SF
=
=
ILCR = (I)(SF)
chemical intake (mg/kg-day)
chemical-specific slope factor (mg/kg-day) ·1
Noncarcinogenic risks are characterized by comparing estimated intakes to allowable
intakes or RfDs. The Hazard Quotient (HQ) is defined:
HQ= I/RID
-7-
where:
I =
RID =
•
chemical intake (mg/kg-day)
reference dose (mg/kg-day)
•
As the HQ approaches unity, concern increases regarding adverse health effects.
HQs were added together for all contaminants for each pathway to arrive at a
cumulative Hazard Index (HI). This approach is conservative because noncarcinogenic
risks are not necessarily additive. Because all pathways involve the same receptor in
the same period of time, risks were also added together for all pathways to determine
overall risks for the trench area.
Risk characterization results for estimated intakes in the trench area are listed in Tables
8 and 9. All of these intake are either below the acceptable risk range for a carcinogen
of 1 x 10"' to 1 x 10·• (EPA, 1990), or have hazard indices much less than one.
5.0 UNCERTAINTIES AND CONCLUSIONS
Uncertainties are introduced at several steps in the risk assessment process, including:
sampling and sample analysis;
selecting chemicals of concern
quantifying exposure-point concentrations, including contaminant fate and
transport modeling
development of toxicity factors
quantification of exposure intakes.
To minimize the effect of uncertainties in the evaluation, each step is biased toward
health-protective (conservative) estimations. The results of the risk assessment are
estimates of potential risk only if all of the conservative assumptions are realized.
Based on the exposure pathways analyzed, it appears that concentrations detected in the
surface soils do not pose a substantial health risk to workers in the trench area.
-8-
• •
Table l. Surface Soil Sampling Results
Trench Area, National Starch and O.cntical Company
Compound (µg/kg) Trip Rinsate DI Water VBLK 2' VBLK 3' VBLK 5' SVBLK'
Blank Blank Blank VB0611 VB06112 VB0612 BLA3374
Methylene chloride 4' 2' 1' NA'
acetone NA
2-butanone NA
toluene 2' 2' NA
total xylcne.s 2' NA
benzoic acid NA NA NA NA
bis(2-ethylhexyl) NA NA NA NA
phthalate
Compound TSS-1 TSS-2 TSS-3 TSS-4 TSS-5 TSS-6 TSS-7 b
Methylene chloride 11 5' 17 9 11 18 5'
acetone 28 69 11' 4' 2'
2-butanone 2'
toluene
total xylenes
benzoic acid 43' 210d 110d 88'
bis(2-ethylhexyl) 750 6900 3700 1000 3400 1400 1400
phthalate
• VBLK 2 applies to sample TSS-1: VBLK 3 applies to samples TSS-2 through TSS-4:
VBLK 5 applies to samples TSS-5 ch.rough TSS-7; SVBLK applies to TSS-1 through TSS-7.
b Field duplicate of TSS-5
• Indicates compound was not detected
d Compound was detected but below quantification limit
• compound not included in this analytical fraction
EPA blank and spike samples, TSS-8 and TSS-9, are not included in this table.
-9-
• •
Table 2. Significant Sample Results for Trench Surface Soil
Trench Area, National Starch and Oi.emical Company
Compound (µg/kg) TSS-1 TSS-2 TSS-3 TSS-4 TSS-5 TSS-6
acetone 28 69 II 4
2-butanone 2
benzoic acid 43 210 llO
bis(2-ethylhexyl)• 750 6900 3700 1000 3400 1400
phthalate
• Field duplicate of TSS-5
b Indicates compound was not detected; or detected concentration was within 10 X the associated blank
concentration for acetone, 2-butanone, or bis(2-ethylhexyl)phthalate, or within 5x the associated blank
concentration for benzoic acid.
-10-
TSS-7 •
2
88
1400
• •
Table 3. Potential Exposure Pathways
Trench Area, National Starch and Chemical Company
Evaluated in
Receptor Exposure Pathway Risk Assessment Reason for Inclusion/Exclusion
On-site Worker Incidental Ingestion of Soil Yes Direct contact with surface soils
may occur
On-site Worker Dermal contact With Soil Yes Direct contact with surface soils
may occur
On-site Worker Inhalation of Fugitive Dust Yes Workers may encounter fugitive
dust from surface soils
On-site Worker Inhalation of Vapor Phase Yes Workers may encounter volatile
Chemicals organics from surface soils
Off-site Resident All Pathways No Access to area is restricted;
transport offsite would be
negligible.
-11-
• •
Table 4. Parameters Used to Describe Exposure to Site-Related Chemicals of Potential Concern
• Trench Area, National Starch and Chemical Company
Concentration of
Exposure Pathway Chemical in
Medium
Incidental Ingestion Maximum
of Soils Concentration
,ermal Contact Maximum
.Vith Soils Concentration
Inhalation of Modeled From
Airborne or Vapor-Maximum
Phase Chemicals Concentration
Exposure Assumptions
· Ingestion rate
(IR)= 50 mg/day
Fraction ingested from
source
(FI) = 0.5
Exposure frequency
(EF) = 5 days/year
Exposure duration
(ED) = 25 years
Body weight (BW) = 70 kg
Averaging time
(AT)= 9,125 days
Averaging time, carcinogens
(ATc) = 25,550 days
Skin surface area
(SA) = 1,980 cm2
Soil adherence factor
(AF)= 2.77 mg/cm2
EF = 5 days/year
ED= 25 years
FI= 0.5
BW = 70 kg
AT= 9,125 days
ATc= 25,550 days
Inhalation rate
(IR) = 2.5 m3 /hr
Exposure time
(ET)= 4 hr/day
EF = 5 days/year
ED= 25 years
BW = 70 kg
AT= 9,125 days
A Tc= 25,550 days
Source
EPA, 1991b
assumed'
based on Paradowski (1991)
EPA, 1991b
EPA, 1991b
EPA, 1989a
EPA, 1989a.
EPA, 1989b .
EPA, 1989a
based on Paradowski (1991)
EPA, 1991b
assumed'
EPA, 1991b
EPA, 1989a
EPA, 1989a
EPA, 1989b
based on Paradowski (1991)
based on Paradowski (1991)
EPA, 1991b
EPA, 1991b
EPA, 1989a
EPA, 1989a.
"assumed that one-half of total soil contact would be from the site, because only 4 hours per day are spent the
trench area.
-12-
• •
Table 5. Volatilization Model Parameters and Assumptions
Trench Area, National Starch and Chemical Company
Parameter Units Value Reference
Mean wind speed m/hr 12,200 for Charlotte, NC;
(Um) GRI, 1988
Diameter of site m 141 calculated from Ac,
boundary (Dp) assuming square
dimensions
Surface area (Ac) m.' 20,000 five acres
Temperature at OK 293 assumed 20 °C
surface (Tp)
Soil porosity (E) unitless 0.05 average for clay;
GRI, 1988
Sciil density (D) g/cm3 1.49 average for clay;
GRI, 1988
Height of box (Hb) m 1.83 assuming a worker
height of 6 feet
Width of box (Wb) m 141 same as Op
Jniversal gas atm·m 8.21 X 10 -S
constant (R) 2/mol•°K
Acetone 2-Butanone
Schmidt number (Sc) unitless 1.7 1.7 GRI, 1988
Molecular weight g/mol 58 72 EPA, 1986
(MW)
Vapor pressure (P) atm 270 77.5 EPA, 1986
Vapor pressure at atm 0 0 assumed .
infinite distance (P;.,)
Liquid density (d) g/cm3 0.788 0.805 Merck Index, 1989
Measured mg/kg 0.069 0.002 analytical results
concentration (Ci)
Saturated mg/kg 123,000 126,000 calculated from Ci,
concentration (Cs) d, E, and D
-13-
• •
Table 6. Results of Exposure Estimates
Trench Area, National Starch and Chemical Company
Concentration at
Receptor Location Estimate Chronic
Exposed (mg/kg-soil) Daily Intake
Population Exposure Pathway Chemical (mg/m3-air) (mg/kg/day)
Noncarcinogens
Workers Ingestion of Soil acetone 0.069 3.4 X 10-lO
2-butanone 0.002 9.8 X 10-12
benzoic acid 0.210 1.ox10-9
bis(2-ethylhexyl)-phthalate 6.9 3.4 X 10-s
Carcinogens
bis(2-ethylhexyl)-phthalate 6.9 1.2 X 10-8-
Noncarcinogens
Workers Dermal Contact acetone 0.069 7.4 X 10-B
With Soil 2-butanone 0.002 2.2 X 10 ·9
benzoic acid 0.210 2.2 X 10 "7
bis(2-ethy lhexy 1)-ph thala te 6.9 4.4 X 10-6
Carcinogens
bis(2-ethylhexyl)-phthalate 6.9 l.6x10·'
Noncarcinogens
Workers Inhalation of Vapor-acetone 0.129 2.5 X 10-•
Phase Chemicals 2-butanone 0.0013 2.5 X 10 "6
Noncarcinogens
Workers Inhalation of acetone 6.9 X ·10 -9 1.4 X 10"11
Fugitive Dust 2-butanone 2.0 X 10-lO 3.9 X 10-13
benzoic acid 2.1 X 10-s 4.1 X 10·11
bis(2-eth y lhexy 1)-p h thala te 6.9 X 10"7 1.4 X 10-9
Carcinogens
bis(2-ethy lhexy 1)-p h thala te 6.9 X 10-7 4.8 X 10-lO
-14-
• •
Table 7. Summary of Noncarcinogenic Health Effects
Trench Area, National Starch and Chemical Company
Chronic RID
Chemical (mg/kg/ day)' Critical Effect or Target Organ' Uncertainty Factor'
Oral
Acetone
2-butanone
benzoic acid
bis(2-ethylhexyl)-phthalate
· Inhalation
2-butanone
'EPA, 1991a
0.1
0.05
4
0.02
0.09
Kidney toxicity
Fetotoxicity
Irritation, Malaise
Liver
Central nervous system
-15-
1000
1000
1
1000
1000
• •
Table 8. Cancer Risks Associated with Potential Exposures
Trench Area, National Starch and Chemical Company
Exposure Pathway
Incidental Ingestion
of Soil
Dermal Contact
with Soil
Inhalation of
Fugitive Dust
Overall Cancer Risk,
all pathways
Chemical
bis(2-ethy lhexy 1)-
p hthala te
bis(2-ethylhexyll-
phthalate
bis(2-ethylhexyll-
phthalate
• Incremental Lifetime Cancer Risk
b used oral slope factor for inhalation pathway
Chronic Daily
Intake (mg/kg-day)
1.2 X 10"6
1.6x10_.
4.8 X 10-lO
-16-
Slope factor
(mg/kg-day) ·1
0.014
0.014
0.014b
ILCR'
1.7 X 10"10
2.2 X 10-s
6.8 X 10"12
2.2 X 10"8
~
Exposure Pathway
Incidental
Ingestion of Soil
Dermal Contact
with Soil
Inhalation of
Vapor-Phase
Chemicals
.nhalation of
Fugitive Dust
• •
Table 9. Hazard Indices Associated with Potential Exposures
Trench Area, National Starch and Chemical Company
Chronic Daily
Intake Reference Dose
Chemical (mg/kg/day) (mg/kg/day)
acetone 3.4 X 10"10 0.1
2-butanone 9.8 X l()·l2 0.05
benzoic acid 1.0 X l()·9 4
bis(2-ethylhexyl)phthalate 3.4 X 10"8 0.02
Total Hazard Index
acetone 7.4 X 10-s 0.1
2-butanone 2.2 X l()·9 0.05
benzoic acid 2.2 X 10"7 4
bis(2-ethylhexyl)phthalate 4.4x10·• 0.02
Total Hazard Index
acetone 2.5 X l()·4 0.1·
2-butanone 2.5 X 10"6 0.09
acetone 1.4 X l()·ll 0.1•
2-butanone 3.9 X 10"13 0.09
benzoic acid 4.1 X l()·ll 4•
bis(2-ethylhexyl)phthalate 1.4 X 10"9 0.02'
Total Hazard Index,
Inhalation
Overall Hazard Index, all
pathways
'used oral RID for inhalation pathway
-17-
Hazard Quotient
3.4 X l()·9
2.0 X 10-to
.2.6 X 10-lO
1.7x10·'
1.7x10""
7.4 X 10"7
4.3 X l() ·S
5.6 X 10"8
2.2 X 10 4
2.2 X l()·4
2.5 X l()·3
2.8 X 10·5
1.4 X 10·10
4.4 X 10·12
1.0 X J0·ll
6.8xlo-•
2.6 X 10"3
2.8x10"3
• •
References
Gas Research Institute (GRI), 1988. Management of Manufactured Gas Plant Sites, Volume III, Risk Assessment.
GRI-87 /0260.3.
McKone, I.E., 1990. Dermal Uptake of Organic Chemical From a Soil Matrix. Risk Analysis, Vol. 10, 407-419.
The Merck Index, 1989. S. Budavari, M.J. O'Neil, A. Smith, P.E. Heckelman, eds. Merck & Co., Inc. Rawway,
NJ.
National Council on Radiation Protection and Measurements (NCRP), 1984. Radiological Assessment: Predicting
the Transport, Bioaccumulation, and Uptake by Man of Radionuclides Released to the Environment. NCRP
Report No. 76.
National Toxicology Program (NTP), 1982. Carcinogenesis bioassay of di-(2-ethylhexyi)phthalate (CAS No. 117-
81-7) in F344 rats and B6C3F, mice (feed study). NTP Tech. Rep. Ser. TR No. 217, NTP, Research Triangle Park,
NC.
Paradowski, R.E., 1991. "Worker Exposure at Trench Area, Cedar Springs Road Plant, National Starch and
Chemical Company". Letter to M. Sturdevant, 25 July 1991. ·
United States Environmental Protection Agency (EPA) 1986. Superfund Public Health Evaluation Manual. EPA
540/1-86/060.
~ited States Environmental Protection Agency (EPA) 1989a. Risk Assessment Guidance for Superfund, Volume
1: Human Health Evaluation Manual (Part A). EPA/540/1-89/002.
United States Environmental Protection Agency (EPA), 1989b. Exposure Factors Handbook. EPA/600/8-89/043.
United States Environmental Protection Agency (EPA) 1990. National Oil and Hazardous Substances Pollution
Contingency Plan (NCP). 40 CFR, July 1, 1990, U.S. Government Printing Office, Washington, D.C.
United States Environmental Protection Agency (EPA), 1991a. Health Effects Assessment Summary Tables,
Annual FY-1991. OERR 9200.6-303(91-1).
United States Environmental Protection Agency (EPA), 1991b. Risk Assessment Guidance for Superfund,
Volume 1: Human Health Evaluation Manual, Supplemental Guidance, "Standard Default Exposure Factors."
-18-
• ~ •
State of North Carolina
Department of Environment, Health, and Natural Resources
Division of Solid Waste Management
P.O. Box 27687 · Raleigh, North Carolina 27611-7687
James G. Martin, Governor
William W. Cobey, Jr., Secretary
Mr. Robert Jourdan, Chief
North Superfund Remedial Branch
EPA Region IV
345 Courtland Street, NE
Atlanta, GA 30365
December 18, 1990
RE: National Starch & Chemical Corporation Superfund Site
Salisbury, North Carolina
Dear Mr. Jourdan:
William L. Meyer
Director
I am writing in response to your letter dated December 11, 1990 regarding potential
damages to natural resources resulting from a release of hazardous substances at the
National Starch & Chemical Corporation Superfund site. The Division of Solid Waste
Management wishes to exercise its right to participate in the investigations at the above
referenced site as well as the negotiations with potentially responsible parties.
Please contact Lee Crosby (919 /733-2801) or Jill Hickey, Assistant Attorney General
with the NC Department of Justice (919/733-8352), so that we may discuss how our
activities might best be coordinated.
We look forward to working with you and your staff.
cc: Barbara Benoy
Reuben Bussey, ORC
Curt Fehn
Sincerely,
rJ~c1~~
William L. Meyer
• [ iHiCl~IVi:O
UNITED STATES ENVIRONMENTAL PROTECTION /<GEN'CYE0fTHES(CR.CTMIY
DEC J 1 19!10
345COU::L:~:NSTIRVEET, N.E ~EC 13 t99o
ATLANTA. GEORGIA 30365 frl~iil'-1:fAtr!T HEALTH
AND tjfTU~AL R£SOlfflCES
4WD-NSRB
William W. Cobey, Jr., secretary
Dept. of Environmental Health & Natural Resources
P.O. Box 27687
Raleigh, North Carolina 27611
Re: National Starch & Chemical Corporation Superfund Site,
Salisbury, North Carolina
Dear Mr. Cobey:
DEC 26 1990
The United States Environmental Protection Agency (EPA) has documented
the release or threatened release of hazardous substances, pollutants or
contaminants at the National Starch & Chemical Corporation Superfund
Site (NSCC), located in Salisbury, North Carolina.
Sections 104(b,c), 12l(f), 122(j), 126, and other sections of the
Comprehensive Environmental Response, Compensation and Liability Act of
1980 (CERCLA), as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA), clarify and define the respective
roles of EPA and Federal, State, and Tribal Natural Resource Trustees.
Specifically, those sections of CERCLA require EPA to notify the
appropriate Trustees of potential natural resource damages emanating
from a release or threatened release of hazardous substances,
pollutants, or contaminants and to coordinate with the Trustees in
assessments, investigations, planning and negotiations in reference to
the release.
Pursuant to Sections 104(b)(2), 104(c)(2), lOS(a), 12l(f), and
12l(f)(l)(f), EPA hereby notifies the Natural Resource Trustee of the
State of North Carolina of potential damages to natural resources that
may be under your jurisdiction resulting from a release under
investigation at the NSCC Superfund Site. The investigation(s)
(Remedial Investigation/Feasibility Studies] for this Site were
initiated in December 1986. These studies resulted in a Record of
Decision (ROD) for groundwater cleanup; the groundwater ROD was signed
in 1988. Construction of the groundwater extraction system began in
August 1990. A second ROD, concerning the trench area soils, was signed
in September of 1990. This letter specifically notifies you of the ROD
issued for Operable Unit 2, trench area soils. A copy of the NSCC
Operable Unit 2 ROD is enclosed.
• •
The Agency also seeks to coordinate investigations of the Site and
negotiations with the potentially responsible parties to voluntarily
conduct the Remedial Design/Remedial Action. However, please note
that Congress has mandated certain limited time frames under Section
122(e) for negotiations with potentially responsible parties.
Therefore, it is important that your Agency contact EPA as soon as
possible should you wish to coordinate and/or participate in the
anticipated negotiations.
Please contact Barbara Benoy, the Remedial Project Manager for the
Site, at 404/347-7791 or Reuben Bussey, the Regional attorney for the
Site, at 404/347-2641. Thia will provide EPA with the maximum
benefit of your expertise and unique perspective. Thank you for your
attention to this matter.
Enclosure
cc: Reuben Bussey, ORC
• •
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IV
345 COURTLAND STREET, N.E.
ATLANTA, GEORGIA 30365
DEC 1 1 1990
4WD-NSRB
William Myer, Director
Solid Waste Management section
Dept. of Environmental Health & Natural Resources
P.O. Box 2091
Raleigh, North Carolina 27603
Re: National Starch & Chemical Corporation Superfund Site,
Salisbury, North Carolina
Dear Mr. Myer:
Dfc 13
The United States Environmental Protection Agency (EPA) has documented
the release or threatened release of hazardous substances, pollutants or
contaminants at the National Starch & Chemical Corporation Superfund
Site (NSCC), located in Salisbury, North Carolina.
sections 104(b,c), 12l(f), 122(j), 126, and other sections of the
Comprehensive Environmental Response, Compensation and Liability Act of
1980 (CERCLA), as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA), clarify and define the respective
roles of EPA and Federal, State, and Tribal Natural Resource Trustees.
Specifically, those sections of CERCLA require EPA to notify the
appropriate Trustees of potential natural resource damages emanating
from a release or threatened release of hazardous substances,
pollutants, or contaminants and to coordinate with the Trustees in
assessments, investigations, planning and negotiations in reference to
the release.
Pursuant to Sections 104(b)(2), 104(c)(2), lOS(a), 12l(f), and
12l(f)(l)(f), EPA hereby notifies the Natural Resource Trustee of the
state of North Carolina of potential damages to natural resources that
may be under your jurisdiction resulting from a release under
investigation at the NSCC Superfund Site. The investigation(s)
[Remedial Investigation/Feasibility Studies] for this Site were
initiated in December 1986. These studies resulted in a Record of
Decision (ROD) for groundwater cleanup; the groundwater ROD was signed
in 1988. Construction of the groundwater extraction system began in
August 1990. A second ROD, concerning the trench area soils, was signed
in September of 1990. This letter specifically notifies you of the ROD
issued for Operable Unit 2, trench area soils. A copy of the NSCC
Operable Unit 2 ROD is enclosed.
1990
•
The Agency also seeks to coordinate investigations of the Site and
negotiations with the potentially responsible partiks to voluntarily
conduct the Remedial Design/Remedial Action. Howevkr, please note
that Congress has mandated certain limited time frariles under Section
122(e) for negotiations with potentially responsibl~ parties.
Therefore, it is important that your Agency contactiEPA as soon as
possible should you wish to coordinate and/or participate in the
anticipated negotiations. I
Please contact Barbara Benoy, the Remedial Project Manager for the
Site, at 404/347-7791 or Reuben Bussey, the Regional attorney for the
Site, at 404/347-2641. This will provide EPA with the maximum ,
benefit of your expertise and unique perspective. Thank you for your
attention to this matter.
Sincerely
M!4f.1-.:t.. .. o,
Waste Management Division
Enclosure
cc: Reuben Bussey, ORC
15: 513 EPA REG I OH I ~1 OCA/OPA • Florid,,
Aoonr.,y
~EPA . I . .
Environmental News
002
1,1w:..issippi
Nor ii I Carolina
so:111, GJ1otin:i.
(t.04) 347-300'1
EPA SELECTS REMEDY FOR CLEANUP OF1 CONTAMINATED SOILS AT THE NATIONAL STARCH & CHEMICAL CORPORATION SUPERFUND SITE, IN SALISBURY, N'
1
c
· · The U.S. EnJ ironmental Protection Agency (EPA) announced today. that the Record .of Decision (ROD)' has · been :stgned for,.tl1~ qleanup of contaminated·· soils at :the National . .Starch.& C.hemi.cal Ci:iiporation (NSCC) Superfund site .in :salisbury, ''NC .. . .. . . '. ,.··. ', .. ,.' ..•. ·. . .·' I .· ,'• .. ·· '' .. .. ' . . . • . The. site is located on the outskirts of the city Ii.mi ts. of Salisbury .•... NationaL.Starch & Chemical Co. ij · a ·manufacturer of ·' · specialty chemicals for the textile and furniture industries, deposited liquid waste in unlined trenches 'en the site. It was proposed for inclusion on the National Priorities List in April 1985, The ROD outlines EPA' s selected remedy1 for cleanup of the trench area soils. The trench area soils are loca'ted in an area of the site • I that was used by NSCC for disposal of reaction vessel wash waters between 1971 and 1978, The selected remedy! calls for natural soil flushing. This remedy constitutes a "No Further Action." remedy. The process will allow for rainfall to percolate into the trench area, infiltrating the groundwater and ultimately[being extracted through a groundwater pump and treat system. The selected remedy is consistent with one selected in December 1988 for decontamination of groundwater at the site, · I Conatruction of the extraction system and treatment facility is currently underway. Further investigation will be conducted on the Northeast tributary to determine the source of surface water contamination.
The ROD ia avnilable for public review at the Rowan County Public Library, 201 West Fisher Street, Salisbury, NC, -0-November 26, 1990[ CONTACTr Cynthia Peurifoy, Community Relations, [phone] Charlis Thompson, Press Office, [phone]
I
I
' 1-
• /~:~<:.~/~~-;:~;~.
/~ _,:, ' :"I _-;t.--,
/3 ):ii,;t~.::.,. ~\ hs ··;,,J 1~--03
'\:~::11··" f-" ~.,;:,;~ .. :. -::~~--~/
State of North Carolin'a
•
Department of Environment, Health, antj Natural Resources
, Division of Solid Waste Management
P.O. Box 27687 · Raleigh, North Caroliha 27611-7687 I
James G. Manin: Governor
William W. Cobey, .Ir., Secretary
Ms. Barbara Benoy
Remedial Project Manager
U.S. EPA Region IV
Waste Management Division
345 Courtland Street N.E.
Atlanta, GA 30365
October 23, 1990
I Subj: National Starch and Chemical Corporation NPL Site
Salisbury, Rowan County, NC
Dear Ms. Benoy:
William L. Meyer
Director
As we have discussed and commented on in our conditional
concurrence on the ROD for Operable Unit #2, the State of North
Carolina supports EPA' s decision to address surface water
contamination at the subject site by initiating Operable Unit #3.
The NC Division of Solid Waste Management ~ould like to reiterate
this position and ·make additional comme!nt reghrding Operable
Unit #3. i I
Because of repeated sampling events which show that the creek
is contaminated with 1, 2-dichloroethane ( Dc'A) , the1 State of North . ' Carolina finds that the, no action alternative for Operable Unit #3
is unacceptable. The State views · this conta'mination as a
potentially serious situation which I requirfes additional
investigation as to its source. · Sampling result~ show that the
surface water contains up to 1700 ug/liter 0CA. This is 340 times
greate~ than the· the maximum contaminant leVel (Mei) of 5 ug/liter
(promulgated 1987). This is also 4,500 ti~es gre~
1
ter than the NC
Groundwater Standard (NCAC Tl5:02L .0202) of 0.38 ug/liter.
Exceeding the groundwater standard is palrticularly significant
given the fact that a suspected source of the DCAI in the surface
water is groundwater discharge to the creek.I If the surface water
in the creek is so heavily contaminated, then it isllikely that the
ground water which is discharging to the I creek is at least as
contaminated as the surface water, and prob~bly more so.
Therefore, it ~s the State's position that the grou~dwater adjacent
to the creek must be investigated to determine whether groundwater
standards have been violated.
Benoy Letter
10/23/90
page 2
1•
I
I
. . f I . . . In addition to sur ace water contamination, the sediment
contains up to 3,400 ug/Kg DCA. Creekside ~oils ak deep as 3 feet
contain up to 1,700 ug/Kg and soils at a i inche~ to 1 foot deep
contain 630 ug/Kg. This data confirms the ~resenc~ of DCA in media
that can continue to be a source of surface lwater c!ontamination.
We note that the highest level of DCA in the surfac!e water from the
November 1989 sampling event was 1,200 ug/~iter ~nd in 1990 this
maximum level was 1,700 ug/liter·. Although \this does not
necessarily show a trend, it is entirely ·possible, that the level
of DCA in the creek is increasing. Therefo~e, to leave the source
uninvestigated would be, in our opinion, n6t onlylcontrary to the
intent of CERCLA but also environmentally irresponsible.
Therefore, it is our position that any CEReLA cleanup of the site
by the PRP is incomplete until the surface water bontamination is
addressed.
Sincerely,
... ~-J.-~w
William L. Meyer
WM/BN/let/nsop3
• •
Record of D~cision
National Starch & Chemi<tal Cprp. Site
Salisbury, North C'arolirna ·
U.S. Environmental Protection Agency
Region IV
Atlanta, Georgia
I
September 1990
• •
DBCLARATIOR l!'OR TBB RECORD OF DECISION
Site Name fpd Location
National Starch and Chemical Corporation
Salisbury, Rowan County, North Carolina
Statement of Basis and Purpose
Thie decision document represents the selected remedial action for
Operable Unit Number 2 at the National Starch and Chemical
Corporation Site developed in accordance with th~ Compreh~nsive ' ' Environmental Response, Compensation, and Liability Act of 1980
(CERCLA), as amended by the Superfund Amendments\and Reauthorization
Act of 1986 (SARA) 42 u. S. C. Section 9601 et. seq., and\to the
extent practicable, the National Oil and Hazardo~s Substances
Pollution contingency Plan (NCP), 40 CFR Part 301. I
This decision is based upon the contents of the Administrative Record
for the National Starch Chemical Corporation sit~. I
The State of North Carolina conditionally,concur1 on the selected
remedy.
Description of the Selected Remedy
This remedy addresses the remediation of residual subsurface soil
contamination. The United States Environmental Protectioh Agency has
selected no (further) action for the Second Operable Unit(
specifically the soils contained in the •trench area•. Monitoring
of the trench area soils will be conducted on a quarterly\basis to
verify that no unacceptable exposures to risks posed by conditions at
the site occur in the future.
Declaration Statement
The selection of a no remedial action alternative is protective of
' I human health and the environment based on the following criteria:
. i I
0
0
0
Th• Record of Decision for Operable Unit 1, September 30,
1988, presents the remedy selection for \the grouridwater
wllieh mitigate• the principal threat posed by th~
' I caataminated groundwater at the site. The only route of I I migration for the •trench area• soils would be into the
contaminated aquifer. I I
The natural infiltration of precipitation will work with the I I selected groundwater remedy effectively flushing residual • I I soil contamination into the groundwater capture zone. I I soils will be conducted on a quarterly Monitoring of the
/"'"'~
i
I I
I
I
'-. I
• •
o The risk assessment evaluated all potential ekposure pathways
I '
relevant to human exposure. No public health threat exists directly
il ' l I I
from th••• ao a. The remedy for the potentLa exposure from
groundwater has been addressed within the first bperable hnit Record
of Decision. . I I
Since this remedy will result in hazardous substances remaining
on-site, a review will be conducted within five Years aft~r
commencement of remedial action to insure that the remedy\continues
to provide adequate protection of human health arid the envir~nment.
'~ I C, lj j -'-'--::xr::wlC-
reer c. Tidwell
Regional Administrator
7
ii
• •
SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION
I
I
NATIONAL STARCH AND CHEMICAL CORPORATION
SALISBURY, NORTH CAROLINA!
PREPARED BY:
U.S. ENVIRONMENTAL PROTECTION
REGION IV
ATLANTA, GEORGIA
I AGENCY
I I
I
I
•
TABLE OF CONTENTS
Site Location and Description
Site History and Enforcement Analysis
Community Relations Activities
Scope and Role of Operable Unit 2 Resource
Site Characteristics
Trench Area Soils
surface Water and Sediments
Summary of Site Risks
contaminants of Concern
Exposure Assessment
Toxicity Assessment
Risk Characterization
Description of the No Action Alternative
Costing Information
Explanation of Significant Differences
1 •
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'
i
I
I
I
I
Actioj
'
l
4
6
6
7
7
lO
10
11
11
13
13
16
17
18
FIGURE
1
2
3
•
LIST OF FIGURES
Site Vicinity Map
National Starch Site
Soil Borings Locations
•
2
3
5
l
2
3
4
5
•
LIST OF TABLES
Organic Analysis Results
from Boring Samples
Inorganic Analysis Results
from Boring Samples
Groundwater Contaminants of Conc·ern
with Highest Concentrations Detected
in Groundwater, Subsurface Soil
and TCLP Leachates of SUbourface Soil
Site-related Carcinogens of
Potential Concern
Site-related Noncarcinogens of
Potential Concern
APPENDIX A -RESPONSIVENESS SUMMARY
APPENDIX B -LETTER FROM SUPPORT AGENCY
r •
I
I
8
9
12
14
15
• I•
DECISION SUMMARY FOR THE RECORD OFII DECISION
OPERABLE UNIT NUMBER 2
NATIONAL STARCH AND CHEMICAL CORPORATION
SITE LOCATION AND DESCRIPTION
The National Starch and Chemical Company (NSCC) site is located in
Rowan county, North Carolina, approximately fivelmiles sohth of the
City of Salisbury (Figure l). Salisbury is located about 40 miles
northeast of Charlotte, North Carolina. \
I The NSCC site, also referred to as the Cedar Spr~ngs Road Plant, is
approximately 465 acres in size. The disposal area, known as the
trench area, is surrounded by heavily wooded acreage to the north,
west, and south. The chemical plant is located in the ea~tern
portion of the site property. Residential areaslare located no less I I than 1500 feet from the trench area in the northwest and southwest
directions. I I
Land use of the area immediately adjacent to thel site consists of a
' I mixture of residential and industrial developments (Figure 2).
According to 1986 statistics, Rowan County cover~ 517 squ~re miles in
area and has a population of 104,678. The popul~tion of the City of
I Salisbury was 23,931 as of 1986. Groundwater islthe sourfe of
drinking water supplies for the community1 the City of Salisbury
• I supplies residents located to the north, east, and south of the
site. Other nearby residents are supplied by sm~ll community wells.
I I
Several unnamed tributaries traverse the site and flow into the
Grants Creek system. One tributary flows along ~he frontlof the
plant paralleling Cedar Springs Road and leaves the property to the
north. A small intermittent stream forms the so~thwesterh site
' I boundary. A third small stream is indicated on the USGS quadrangle
map in the northwest quadrant of the site. Grants Creek forms the
western boundary of the property and continues flowing in a northerly
direction. I I
I There is no designated North Carolina State Significant Habitat,
agricultural land, or historic landmark site potJntially 6r directly
affected by the site. There are no endangered species oricritical
habitats within proximity of the site. There are no identified
> I coastal or fre■h-water wetlands within an area of influence of the
site. I
I The geologic tramework of Rowan Coun,;:y forms two:distinct aquifers.
The first i ■ a shallow aquifer created by the saprolite. The second
. is a bedrock aquifer formed of crystalline rocks.1 These two aquifers
are interconected with clay-rich saprolite. Water yieldirig
properties are variable. Wells drilled within t~e bedrock aquifer
generally have higher yields than those in the sJprolite ~quifer and
average approximately 40 to 50 gallons per minutJ.
I
I
I
• Cedar Springs Road Plant
•
Figure 1
Site Vicinity Map
• • Site History and Enforcement Analysis
The NSCC ■it• is located on the outskirts of the!salisbury city limits.
Edward Proctor of Salisbury founded the Proctor ~hemical ~ompany in 1938. rn
September 1968, Proctor Chemical com~any purchased the 465-acre Cedar Springs • I I Road property. Within the next year, Proctor Chemical was acquired by
National Starch and operated as a separate subsi4iary. C~nstruction of the
Cedar Springs Road plant began in 1970. On January 1, 1983, Proctor Chemical . I Company was dissolved and its operations merged Wieh National Starch. The
National Starch facility is primarily a manufactJring pladt for textile
finishing chemicals and custom specialty chemica~s.
I
I
From 1971 to 1978, the NSCC conducted on site disposal of approximately
350,000 gallons of reaction vessel wash water int'o trenches which were
• ' I reported to be approximately 200 to 300 feet long and 8 feet deep. The wash
water consisted predominantly of salt brines, sullfuric ac~d solutions, and
solvents and is classified as 0002 waste with cor'rosive piaperties and a pH~
2. These trenches were constructed within a 5-adre tract iof the western
section of the site property. The trench area i~ shown on Figure 3.
Liquid effluent from the plant production area fJowed intd the easternmost I I pretreatment holding lagoon, which was unlined, and then was pumped to an
active trench in the trench area. Each trench w~s used uritil liquid no
longer readily percolated into the ground. At that ti.me, the trench was
backfilled and seeded, and a new trench was constructed.
' I
In 1976, NSCC installed eight monitoring wells around the site to determine
I if the trenching operations had impacted groundwater quality. Four of these
monitoring wells were installed adjacent to or within the \trench area._
Sampling results revealed that shallow groundwater immediately within and
adjacent to the trench area was contaminated. I~ June 19'7i7, sampling and
analysis conducted by the State of North Carolina: verified NSCC's results.
The State subsequently requested that NSCC cease 1on site Jaste disposal in
the trench area. I
The NSCC site was proprosed for inclusion on the National Priorties List
(NPL) in April 1985 with EPA assuming lead resporisibility for the site.
Negotiations to allow NSCC to conduct the Remedial Investi:gation/Feasibility
I ' ' Study (RI FS) activities were concluded with the signature of an I I Administrative Order on Consent on December l, 1986. These activities
resulted in the issuance of the first Record of D~cision iROD) during
September 1988. : I -~ I The first MD addressed groundwater remediation at the site under Operable
Unit l. Tliit ROD ■pacified that soil contaminatiori in the ;trench area be
'further inveat:igated to determine whether the are~ continued to be a major
source of groundwater contamination. The first R~D also r~quired that
· analytical monitoring continue on cor .. taminated surface wat1er and sediments to
further delineate the source. \ I
The final Remedial Design for groundwater remediation under Operable Unit l
has been approved by EPA. Construction began in August 1990 which
constitutes the initial Remedial Action (RA).
-4-
• 1.
i
At EPA's direction, a Supplemental RI/FS was con1ucted for Operable Unit 2.
The trench area was the focal point of the inves71gation.[ Subsurface soils
were sampled from ten boreholes drilled in the trench area. The boreholes
were continuously sampled using split spoons, be9inning at the surface and
extending to a depth of 30 feet or to the satura~ed zone,jwhichever was
encountered first. Field screening was conducts~ in the ~inal selection of
the samples submitted for laboratory analysis. In additiOn, Toxicity
Characterisics Leaching Procedure (TCLP) analyses were cariducted on
severalborehole samples using both a standard and a rainw~ter solution
(collected in the trench) to determine certain site-specific leachability
characteristics of the soils. \ I
The Supplemental RI also included ad·::litional monitoring of the surface water
and sediments in what is known as the northeast tributaryJ This tributary I I was sampled in October and November ~f 1989 and again in July of 1990.
Results of this tributary sampling confirmed surface wateJ and sediment
contamination. Therefore, the northeast tributa~y will bJ addressed under a
third operable unit. \ I
This decision document presents the remedial se1Jction for the residual soil
contamination in the trench area at ~he NSCC sit~.
COMMUNITY RELATIONS ACTIVITIES
EPA's community relation efforts for the NSCC ha~e been ongoing since 1986.
' I Communication with the community has included the development of several site
specific fact sheets as well as four public meetings to d•te. Specifically
for Operable Unit 2, the Supplemental RI/E'S and P,roposed ~lan Fact Sheet were
distributed to the public during July 1990. The Second Operable Unit
Administrative Record was made available at the Rowan Courity Library during
the Public Comment Period. Public Comment was hel1d f J 11 30 1990 t
August 29, 1990. ] rom ul y '
0
All comments made to the Agency concerning the Pr~posed Plan and the site in
general have been compiled and addressed in the R8eponsive1ness Summary which
is attached to this Record of Decision as Appendir A. I
SCOPE AND ROLE OF OPERABLE UNIT 2 RESPONSE ACTIONj I
The scope of this response action is to address ahy soil contamination in the
I trench area aa a source control Operable Unit. The first Operable Unit
action waa decided with the issuance of a ROD on September! 30, 1988. This
ROD requirell the development of a groundwater int~rception and extraction
system to la installed downgradient of the contaminant plume. Pretreatment
for the extracted groundwater includes air stripping, filt~ation through
.activated carbon, metals removal, and treatment through th~ company's
existing lagoon system. Discharge will be to the\Salisbury Publically Owned
Treatment Works (POTW). A contingency for an alternate diScharge point was
included in the ROD if permit requirements for the POTW cahnot be met.
Monitoring of the surface waters on the site are also required under the
first ROD. I I
Objectives of Operable Unit 2 are to: ensure thatlcleanup standards for the
site are developed for all appropriate media, (i.e., subsutface soils and
-6-I
• ' ' I
I •
g roundwater), implement a cleanup alternative that is . I protective of human I health and the environment, and select a remedy 1
1
that
in a coat ~tactive manner.
meets the above criteria
SITE CIIARACTlll\ISTICS
The NSCC site was characterized during the init~al RI/FS under a
comprehensive site-wide investigati<)n. Based ori the results of this initial
RI, the trench area was determined ta be the only signif~cant area from past
disposal practices that could be considered a rE!maining ~ource area to
groundwater contamination. The first ROD requi~ed that the trench area be
further investigated to identify tho degree of Source coritribution. This
decision document is limited to the characteristics as o8served in the trench
area soils and is based on the Supplemental RI. I The trerich area is not
considered the source of contamination to the tr'ibutary.
i
I
TRENCH AREA SOILS
The Supplemental RI characterized the trench area subsurface soils with the
installation of 10 boreholes. Figure 3 provides' the bor~hole locations.
Results of the organic analysis are shown on Ta8le l. S~gnificant levels of
l,2-dichloroethane, 2-butanone, l,2-dichloropropane, 4-m~thyl-2-pentanone,
toluene, ethylbenzene and xylenes wore identifi~d in the !trench area
subsurface soils. Antimony and arsenic were the inorganfc constituents
identitied at elevated levels; theoe two contlllriinanta W<ire detected at
elevated levels in only one location. Tabulated inorgan~c data are presented
in Table 2. i I
Based on the data developed from both the initia.l and supplemental Ris, the
subsurface soil contamination has boen observed 'from 5 feet below land I I surface down to the water table. The top 5 feet is believed to be clean soil
which was backfilled into trenches as they were deactivated. Maximum
concentrations were observed approximately 18 fe~t below lland. surface. There
is no current complete route of exposure specifically from these soils, i.e.,
no dermal exposure potential. Migration pathway! is isola'.ted to leaching into
the groundwater. I
The trench area is known to be the original source of the groundwater I I contamination based on historical di.sposal practices. The supplemental RI
was designed to measure the effectiveness of the' natural 'soil flushing by
percolating raintall through the aoil contaminants as wel:l as determining the
actual con~amtna"t concentrations remaining in the trench! area subsurface
aoils. Tlle;llupplemental RI was conducted to chafacterize\ the remaining
contaminatiiln in the subsurface soils in the trench area specifically to
, f~ • I determine U· ramadiation of the soils was necessary. Results of the I I Supplemental RI indicate that the natural leaching process has resulted in
reducing the levels of the soils contamination. 1Thia ia based on the
magnitude of the contamination currently in the 9roundwat~r compared to the
residual levels of the contamination left in theisoil. Ih fact, several of
the contaminants of concern identified in the first ROD w~re not detected
I ' within the trench area soils during the supplemental RI field work.
: I
The Supplemental RI determined that the most notable contaminant
concentrations of trench area soils were approxilriately 18 feet below the land
-7-I
I
Table l NATIONAL STARCH: ORGANIC ANALYSIS RESULTS FROM SOIL BORING SAMPLES COLLECTED NOVEMBER 1989
fAUl J (oa,o..N)
l lSf .... Sl,Ur,CU
Q.¥Nl1UHON
~ wa 11 1111 -~•cs
Mitt, ICM clll•t Ide
CJllorelof■
J ........
■i_.lcllloroaettw,nc
•-■Hhr 1-J-pcnl &RCMM: ···--1111,.1bcn1cnc
)1•1\1(}14111 I oaGAH1q
•-•lhrlPM-1
' .....
IUHOIC ■cle
-~~l_tr~!._H_!~ftJ'_l~!~h-__
ll1tJ-cl11W'IM■rll,tlltMIUI ..... ,
•
•• MIil .... ,._ oVC) ~I N.•HS
ltt-11 ..... ..... .... ..... -· ..... ...." --..._. ... H ...., . ...... ...... ..... ltt-14 lt1-lt , ........ I ltt-111 IU6A11 u,u,,.,.111 .... ...... ll•H· , ... u-11-n· u-u· .... -11-20· n-11· 11-,0· J••. ll-M' zo-n· u-u· a1.DOl1 DI )04
ca • I I "' I "' ' .. ' " .. " ,, " • • ' •• ... I I " ' "' ' ... ... ,,. , .. " .... " ... " •
' " ' " ... ... IN.ON ,, .... ·-· , .... ., .. noo1
"' " ' ' " •
... . .. . ..
' u ... , .. , ..
' ' ' ' ' ,, .. ... !1 -' " ' .. ... ' ., .. .. ..
' • ' 11 .... -,, ..
""
. -----------_':_" ____ .:.:..... _ ______ -~---_ ---~-__ •• ___ UIK ______ ··--·-
clJIO clJII ... )to JU 160
,1110 419 ... ·-, ..
' -' ...
dJM UIJH cano caJto caJ90 c1UM cdJJO HO••••M»ooooono
' , ..
........... , .. ··-
.. • .. .. .. .. .. ... .. .. .. ... .. ..
• ttt .. chl••DINl· ... ICM
J-MIIITl.,.._I
acAOI" alcoMI
----,----------------------------------------~----
lllt 1-ct110,oe1brl •••• , u ....
'
..
• Qu,aRlllell .. 11■111 ., .... re,,ouc• ,., NII • .,..,c, di.M ,. lllclf ·••IPllltr .... llutllc ll■IU lfC •• ,11,olt on IM CCIIIIIUIU ., .,..., ...
•
lt:i,Qllt:d con<cn11u1a.n 11 Ocl-lhC ....... , .... .,. 11■11.
d (.-OURd II., .. p1ucn1 In Ille 1,1:1o1,io1, ...... U1r UIPUICllplrd ~u 1, IM ,,o tlhnt. concrAIIUIOlli,
(._ourtd raccrckd ci1llbntlon ungr ol ln,111arnl but elthln lnUuarnt IIAur ungr,
Table 2 NATIONAL STARCH: INORGANIC ANALYSIS RESULTS FROM SOIL BORING SAMPLES COLLECTED NOVEMBER 1989
.... 9DIIHG Uil) SA-"'f N.aMIS (CNN:CftlUI 1-1 UC IA -O/lt IPClal !
SMIN.tO INIIIV.U , ... UN> SIAUCt 1ft)
.-i-11 ..,_,,
h■Gtl .U..l't'II Dl.UCJION ..... ..... • ,,
l 111 .. IUtC:H l 1a11S -----" ---·· _,, _,, _,, _,. _,, (aH-1'1 (IH-111 11"64U I.UWMJU ......... , .. ._.. •••• 11-,,· 1►11" •-••· ic-u· ... ,.. )4-JI • 21-11· J-4. ll-n· n-u· Joi-JI' UOOH ..... . ..... • ., .. ,_ N.tN •--JJ .... >•--"--
.. __
" -.. ... .. -.. ... .. . .. ... ' ... .. . .. .. • < < ........... .. • • ,.,,-1c .. .. '.' .. , ... " ' ,,. H.e .. " .. , "' "' , .. .. • '" ,., .. ' ' ' • ' ... < < < ' ' •.. ,. ..... ... • •• . .. • ' • • • • • • . ' •• . '
<••·-• 1 J • , .. ' ' ' . ' ' ' ' ' ' ' Celch• ... . ... "' ... ... m .... .... ,., . m ... JUO u,o JISO ... "'
CIU-1119 .. u " " " • " ' ..
c .... ,, " " •• • " .. " " ,. .. .. " •• ,_, .. .. .. .. •• .. " " .. .. ... .. .. , .. .. ,._ .. -" -.. ... ... , .. "· -46.0CNI •• ... ....... " ... ... , .. "· ... " . .. ' ' .. ... , .. " " ' ' .... ... J. 7 .. , •• . ' ' ' '., . ' .. , , .. ' . • ' ' ' ' --·"· ... .... ·-... m .... ,, .. , ... .... ,., .. .. HJO JSIO ,s.o ' .. .......... ... .., ... Jle.■ ... m ... ... Ill ___ )19 61& _____ '" -·-· UI ______ S ' ' .. ----)------
--------~--------------·---· ------... , ...... ... ■.H I.OS I.H .... . ..
NIO.•I • , . ,. " ' • " " " • • ' ,., ......... , , .. ... '" ...
' ' ' ' ' ' < ' ' ' ' -·-.. , .. "' .. "' "' "' .,,. ... .. .. "' IHI ,. -Illa ......... n,---n--m---111---,,.----111---..,---,u~----.11 m " ... "
""' .. ' aJ. J ... .... ., .. .... ..., ... , .. ., _, ... .. ... ' •• " "
ti DIIHllon 11■111 •I , ... uc4 tol 1011 , ... tel ... lo IIMII Vtlllt1•U11-,. Dcl■cllon 11■111 UC avt1ll1•1c on Ille CUllflulu ol •rwl)'III .
• --IMIIUIU , .. , ... 1c: c~• 0111 -·· ... MUClc• In ........... .
N,11 NOi •HIICIIIJIC.
• I
surface and were found in much lower concentrations than expected. It
' I appears that residual soil contamination is effe~tively leaching into the
groundwater., aoil concentrations are consequentlY being r~duced. Any
' I remedial actions involving removal or treatment of these subsurface soils
I will introduce additional risks to the environment or human health, by the I excavation or construction concerns inherent to any further action.
To support the potential for natural soil flushihg to be lonsidered as a
viable remedial option in conjunction with the groundwatek extraction system,
two vadoee zone models were applied to the studyldata. The first objective
was to determine an acceptable concentration of a contamihant in soil; the
second objective was to predict the time required to achi~ve this acceptable
concentration. Pre-established groundwater cleariup critekia (Operable Unit 1
ROD, 1988), were considered the upward limit forlcontamin~nt concentrations
I ' in groundwater. Soil concentrations were then back-calculated using the
soil/water equilibrium relationship. Modeling d~ta and ihformation are
provided in Appendix B, 1 I
The modeling approach was based on conservative ~ssumptions and was also used
to predict the leachate concentration over time.: The pa~ition coefficients
were calculated based on site-specific results of the TCLP analysis. The
' I model predicts that most compounds will leach into the groundwater within 5
years. 1,2-dichloroethane is predicted to take ~uch long~r (approximately 22
years), Preliminary estimates show that the groundwater kemediation effort
may take 20 to JO years before meeting the cleanup criteria throughout the I plume. I
Surface Water and Sediments
Surface water/sediment sampling was conducted du~ing both the first and
supplemental Ris, The actual source of this contamination has not been . I I determined. It has been concluded that the trench area soils are not the
source. This Second Operable Unit presents the selected temedy for the
trench area soils. '. I .
I
' I Continual monitoring of the surface water system~ known as the northeast
tributary, is required by the first ROD, until a'source of contamination can
be defined. Further investigation of this system will bejcontinued under a
third Operable Unit to ultimately select an appropriate remedy. ' I
summary of Site Riska I
I I
CERCLA.dirats that the Agency must protect human health and the environment I from cur~ and potential exposure to hazardous,substanc~s at the site. The
risk asse1'_,t conducted during the initial RI 'i'oncludedlthat the principal
risk presented from the NSCC site was the potential for human consumption of ' contaminated groundwater. Likewise, the principal risk posed from the
trench area soils is also the potential for hwnari consumption of contaminated
groundwater since the only route of migration of land/or e~posure to the
contaminated subsurface soils is infiltration to!groundwater. The following
section summarizes the Agency's finding concernidg the ri~ks from exposure to
groundwater r~lated to this site and discusses the contaminated soil as a
source of exposure. l [
-10-I
• •
Contaminants of Concern
Eleven carc1nogmns and fourteen non-carcinogens have been identified in the
groundwater at this site. The toxicity, mobilitY and persistence
characteristics of these substances at the site do not wakrant the exclusion
' of any of these· substances from consideration as, chemicals of concern at the
site. The contaminants of concern for groundwater at thi~ site are listed in
Table 3. This table also shows the highest conc~ntration~ of these
substances in groundwater and in the soil sampleB collect~d at the site.
Also the TCLP results for the three soil samples;collected at the 12 to 18
ft. level are shown. The maximum concentrationsl from a r~inwater and
standard leachate are shown. This table also -shows the highest
concentrations of these substances in groundwatek and in the soil samples
collected at the site. The maximum concertrationS from a hainwater and
standard leachate are shown. The results of sampling fro~ the supplemental
RI indicate levels of contaminants of concern in'. the soil[ of the trench area·
are of minimal significance relative to the concentrations currently existing ' in groundwater. Since the groundwater pump and treat system is designed to
I capture the highly contaminated groundwater as well as lesser contaminated
groundwater originating by the leaching of rainfall through the residual
I ' soils in the trench area, no excavation of the source is deemed necessary.
Therefore, no contaminants of concern were identified for soil.
I
Exposure Assessment
Groundwater in the area is a current source of dfinking w~ter; it is
classified as Class IIA based on the Agency's Gr9undwater1c1asaification
Strategy. A 1988 survey of existing off-site water supply wells revealed a
total of l,539 homes within a 3-mile radius of the site. These wells are
outside the limits of the city water lines and could poteritially use the
groundwater for drinking and other domestic purposes. Th~ closest well is
located 2,200 feet northeast of the site. : I
In developing the hypothetical exposure scenarios for groundwater at this
site, it was assumed that nearby residents would~be expos~d to water
contaminated at the highest concentrations found:on site.\ Thia is a
reasonable assumption baaed on the facts that residences are located almost
directly along the site boundaries in the direction of apparent groundwater
flow, and because the data indicate chat the grotindwater plume is advancing
rapidly. The potential routes of hwnan exposure.relativeito the groundwater
include water used for drinking and other domestic purposes.
. : I Contamin~ -r• identified in soil sample taken to a depth of 30 ft.
However, a trench-area sample taken ilt the 0-2 ft. depth showed low levels of
only thr-organic contaminants, i.e. methylene chloride, !acetone and
bis(2-ethylhexyl) phthalate. This finding .of minimal contamination is
·consistent with the understanding that trenched areas (8 ft. deep) had been
back filled_ with clean soil. Only the top 1 to 2, feet of !surface soil is
considered as a direct-exposure soil source. The'refore exposure through soil
ingestion, inhalation and dermal contact could be possible to the three
organic contaminants. The more extensive contami:nation of the subsurface
soil would be of concern as a source of exposure 'through 9roundwater use.
i I
I
-11-
lllghest
•
TABLE 3
' Groundwater contaminants o~ Concern with
Concentrations Detected in Gro,undwater, Subsurface
and TCLP Leachates of Subsur:face soul {ppb).
Soil
CARCINOGENS
MAXIMUM
WATER CONCa
,
1
MAXIMUM SOIL
CONCf
MAXIMUM TCLP
CONCb,c
Arsenic
Benzene
Bis(2-chloroethyl)ether
Bromodichloromethane
chloroform
1,2-dichloroethane
l,l-dichloroethylene
Methylene chlorode
1,1,2-trichloroethane
Trichloroethylene
Vinyl chloride
NON-CARCINOGENS
Actone
Barium
Beryllium
Cadmium
Chromium (VI)
l,2-dichlorpropane
Ethyl benzene
Manganese
Nickel
4-nitrophenol
Selenium
Toluene
Xylenes (mixed)
Zinc
·~ t
310
8
14,000
7
49
350,000
ll
8
ll
10
90
89,000
2,290
120
114
554
29,000
1,500
l,400,000
5,190
13,000
274
6,000
3,800
14,900
I ' I
44,00?
ND
33,000
' ND
~ 100,0?
ND ' 7l ' ~
ND ' ND
31,000
190,000
809
3,000
27,009
100,ooq
1,1oq
964,ooq
23,000
' ND ' ND
30,ooq
11,ooq
99,200
I
a Data from Public Health Evaluation in FS Report, seJtember, 1988.
2
810
l
150
760
19
33
5900
30
62
95
7l
b I I Data from supplemental RI report for Second Operable Unit, May 1990. All
maximum values occurred in samples taken a: 10 feet ior below.
C Only samples collected at 12-18 ft. below surface were subjected to TCLP
analysis. i I
'
• •
Toxicity Assessment
cancer potacy tactors (CPFs) have been developed by EPA's Carcinogenic
' I assessment Qroup for estimating excess lifetime cancer risks associated with
I ' expsoure to potentially carcinogenic chemicals. CPFs, which are expressed in I I units of (mg/kg/day)-1, are multiplied by the estimated iptake of a potential
carcinogen, in mg/kg-day, to provide an upper-bo~d estimate of the excess
lifetime cancer risk associated with exposure atjthe inta~e level. The term
"upper bound" reflects the conservative estirnate·of the risks calculated from
the CPF. Use of this approach makes underestimation of the actual cancer
risk highly unlikely. Cancer potency factors ar~ darivedlfrom the results of
human epidemiological studies or chronic animal bioaseays to which
animal-to-human extrapolation and uncertainty fa~tors have been applied. The
Agency considers individual excess cancer risk f~om expos~re to contaminants
at superfund site to be protective if they fall ~ithin a io-4 to 10-6
range, i.e. 1:10,000 to l:l,000,000. The 10-6 risk levellis the desired
level for single carcinogens; the sum of site upPerbound Cancer risk should
not exceed 10-4 I
i Reference doses (RfDs) have been developed by EPA for
potential for adverse health affects from exposure to
' I indicating the
chariticals exhibiting
I noncarcinogenic effect. RfOs, which are expressed in units of mg/kg-day, are
' I estimates of lifetime daily exposure levels for humans, including sensitive
' I individuals. Estimated intakes of chemicals from environmental media (e.g.,
the amount of a chemical ingested from contaminated drinking water) can ba
compared to the RfD. RfDs are derived from human epidemiological studies or
animal studies to which uncertainty factoras have been applied (e.g. to
account for the use of animal data to predict affects on humane.) These
uncertainty factors help ensure that the RfDs will not underestimate the
potential for adveroa noncarcinoganic affects to
1
occur. I
i I The CPPs for the ll carcinogens and the RfDs for'tha 14 non-carcinogens
selected as the groundwater contamin4nts of concern are shown in Tables 4 and
5. I I
Risk Characterization I
, I Excaas litatima cancer risks are determined yb multiplying the intake level
with the cancer potency tactor. These risks are 'probabilitiaa that are
generally expreesad in aciantific notation (e.g., l x 10-i or lE-6). An
excess lit-riak ct l x 10-6 indicates that, a'.a a plausible upper bound,
an indiv~-haa a one in a million chance of d~valoping\cancer as a result
of sita-re¥ted exposure ~o a carcinogen over a 70-year lifetime under the
specific --,oeura conditions at a site. '
1
I
.Potential concern tor noncarcinogenic effects of ,a single1contaminant in a
single medium is axpraasad as the hazard quotian~ (HQ) (or the ratio of the
estimated intake derived from the contaminant concantraticin in a given medium
to the contaminant's reference dose). By adding :the HQs for all contaminants
within a medium or across all media to which a given popu~ation may
reasonably ba exposed, the Hazard Index (HI) can be generated. The HI
provides a useful reference point for gauging the potenti~l significance of
multiple contaminant exposures with a single madi'um or actoss media.
-13-
COMPOUND
1,2-dichloroethane
bis{2-chloroethyl)ether
acsenic
vinyl chloride
1.1-dichluroethylcue
chlu.-oform
1.1,2-trichloroclhanc
bromuJ ich I or-omc Lha11c
benzene
tricl1loroetl1ylc11c
methylene chloride
TAJII.E 4
_ SITE-RELATEIJ t:AR!:INIJGENS OF POTENTIAL CONt:ERN AT TUE
NATIONAi. STAR!:11 ANIJ CUl,MlCAI, CORPORAT LON SI n;
SAl.lSKURY, NORTH CAROl.lNA
HadJ11wa
Observed
Coocerntration
(ug/1)
350,000
14,000
310
90
11
49
I 1
7
8
10
8
Estimated
Worse Case
lntake8
(mg/kg/day)
l .OOE+ol
4.00E-01
8.86E-03
2.57F.-03
3. 14E-04
1 • 40E-UJ
3.14E-04
Z.OOE-04
Z.Z9E-U4
Z.86E-U4
2.Z9E-04
t:Pt'b
(mg/kg/day)-1
9. IUE+OZ
I. IIU-:➔OU
1.50E+OU
2. )OE-100
5.80E-01
8. IOE-02
5. rm-oz
8. l(ll-:-02
5.2UE-02
1. IOE-02
7. 5E-0)
Worst Case
f.xcess
Cancer
IUskc
9. 1 UE-0 I t,. 40E-0 I
I. DE-02
'.,.'II E-0]
I .821•:-04
I. UE-11
1 .sm:-os
I .62E-W,
I • I '11•:-0'.,
J. 11, E-0(,
I • 7 1 E-06
lluaber
Exceedinl\
Detect 1011
1.lmiLd
18
7
I) -,
I ,,
z
z
--------~---_-_--_-_-_-__ -_-_-_-_-_-_-_-_-__ -_-_--_-~-------.----~ ------~---~=-~=~------------------------
3The estimated worst case iocake does not represent any real exposure scenario at lite :;iLt.!. II. i:; hascJ 011 • a 70 kg person drinking 2 liters of water per-day for their entire life from the monitoring well containing ___ _
the~maxi.mum-ob_s_e-rve~d-c-00.ceOCratlon OJaChemi.cal-.-TlliStiypothefica-1 exposure sccnar-io is usc<l ~-;:.'..mi~ -
ative toxicity based on the inherent toxicity an<l the maximum detected concentration of each chemical. Th h;
assumption assists in identifying those carcinogens that have the greatest potential to pose a hazard with
frequent exposure over a number of years.
bcpf or Cancer Potency Factors were obtaiued fc-um the Super fund Vul,l ic Ilea I.th l~valual iu11 Ma1111al, EPA l')Hb.
cworst case excess cancer risk is derived from the equation l!:CR = CPF X Uose = estimated worst case intake.
<l111Jicatcs Lhc number of smap]es out of ]H Lhat cxc.:cctl the analytical detect io11 I imil lor 111,-11 d11:1oical.
COltPOUNIJ
1.2-dichloropropanc
manganese
l1-11 i l ruphenol
acetone
nickel
cadmium
xylene (mixed)
beryllium
chromium (as Cr VI)
selenium
zinc
bar iuf!I
to] uc1:c
ethyl bl!nzc11c
'1'11111.~: 5
S IT1':-R1':I.A1'1•:JI UIINCI\KC I NOl;ENS llF POTENT 1111. CONCERN /IT TIIE
NAT lON/\1. ST.\KCII /\Nil Clll':H ICAI. COllPIJKI\TI IJN SI TE
HAXIHUH
08SERV1':D
CONCENTRATlONS
(ug/1)
29,000
1,380,000
13,000
89,000
5190
114
3800
120
554
274
14900
2290
6000
1500
SIii. ISIIUKY, NORTH CAROi.i NII
ESTIHll"l"I">
WURST CASI•:
1.NTIIKl•:a
(mg/kg/day)
R.Z'IE-111
:I. 91, EH> I
·1. / 11•:-0 I
2. ~l1EHlll
I. 411~:-0 I
3. 2(,E-0J
l.09E-OI
3.1,JE-OJ
I • 511E-02
7. IIJE-0:1
11 • 2f1 E-111
(,. 51, E-02
I • / I l•:-o I
4.2'1E-OZ
AIC
or Rfl>
(mg/ kg/ da1)_::: I
l.71E-04
2. 21lE-0 I
1. oo~:-oz
l .00E-01
I. OOE-02
2. 90E-Ol1
·I .OUE-02
5.00E-011
5.0UE-UJ
] • 0llE-0"1
2. lllE-01
.5. 1111\-02
J.OllE-01
l.OOE-01
WOHST t:M;1-:
111\Z/\l<ll
INlll·:xh
/11\/,'j • '•
I 7'J. 2
:II.I
15. ,,
14. II
I I • 2
10.9
r,. 9
·1. Z
:J • ,,
/. o
I.]
o.6
u _1,
SIJUll(;i,;c
HCI.G
IIEA
d
Kf 11
IIEI\
'""' IIEI\
Kfll
II E/\
IIE/1
IIE/1
111-:11
KI ll
11rn
"1"J'he cst.:imated wor!:.t case intake does ool represent any ,·cal cxpoHtffC Hcc11.-u·io al: tlw :-;it,•. It i~, L;1:;c1l 1111 ;1
10 kg-ve-rSOn-drinklng-i fi.t-ers-of waier -pc.---,-tay-ro.-· tt,C-iT-Cnt-iic -fit'~ -1:nml l1t~-IDuttit,;rf11)~ -~c1T coutainiu•~
the maximum ol>servcd concentration of a chemical.. 'L'his hypothetical cxpusur-e .sccnar-iu ii; 11!a~d tu .-auk ,·claL ivc
toxicity l>ased on the inherent toxicity anti the maximum detected conccutr-ation of each chcmic;1I. This potc11Lial
assists in identifying those nonca1""ciougcn:-. that have the greatest potent i a I lo po~;c a haza r-,1 w i lh f rcc111c11l
exposure-over-a-number-of--years .------------------------
buazard Index 1s derived from the equation: Ill Uose/Kcference Uosc, wl1crc: Ill = laaz.anl i1ulcx,
llosc = c.slimatcd wor~,L ca!iC i11t;1k1'.
Kcfer-euce <lose = acceptable i11l.;d,1•
for ch["oni1· cxpof;111·1·
CJIEA = llealth Effects Assessment document 1u·cpa.-c<l l,y Environmental CriteC"ia a11<l As.sc.ssmcul Offi1..::c, EPA 11n-v1
Kfl> = Reference Uusc fC"um SPllat, EPA llJH(,
MCl.l; = Maximum Lontawinaut Level Coal, (El'J\ l~HU))
d1h'.1·ived hy w,i111•. Ilic Hl"J for phenol a11J w;i11g an additiuual safely faclo,-tu ,uhlrt~!;:; llw k11ow11 liir,lu-1· ;w11t1:
lox.i,:ily ol l1-11itr·11pl1t!llO).
•
I
• •I I
The carcinogenic _upperbound risks and the non-ca.t'cinogeniC Hazard rndex
values tor the 25 groundwater contaminants of concern are!shown in Tables 9
and 10. The risk numbers are based 1:-,n exposure to the mclJfimum concentrations
detected for ~ach chemical during the RI investigation. ~he potential risk
posed by th••• chemicals from ground water contamination is being addressed
in the remedy for operable unit one (OU#l). The :risk sunuiiary of this ROD for
operable unit unit two has included a discussion ·.of the risk from groundwater
for two t"easons: (l) it was not adequately discuSsed in the ROD for OUf:l and
' its inclusion here provides a more accessible record and (2) it provides
important background information for the no-actiOn remedylpropoeed for OUt2,
the soil source.
The data indicate that all remaining site contaminants arl in the saturated
zone or in the deep soil just above -:he surficial aquifer, Although minimal
data were collected to confirm this ,:1.ssumption, all site history information
I
indicate that no contamination exists in the top·2-S ft. of soil. The three
I
contaminants detected in the top 2 ft.. of soil discussed under the Exposure
I
Assessment Section were well below levels of concern. Therefore, the direct
soil exposure pathways are not relevant for this ; site. I
Groundwater contamination from deep soil leaching appearslto be the only
exposure pathway to remaining site contaminants and this Pathway is being
addressed under OUtl. The groundwater and deep ~oil datalindicate that the
primary contaminants (volatile and semivolatile compounds) are moving into
the groundwater and that maximum concentrations have likely already reached
' ' the surficial aquifer. It is likely that disturbance of the soil source of
these contaminants could result in an increase h8alth risk by creating new
I
direct exposure pathways to workers and perhaps to the c~unity. Therefore,
a no action remedy is believed to be the course that would create the least
' I risk from the soil source while the remedy identified under OUtl achieves
groundwater protection. :
DESCRIPTION OF THE NO ACTION ALTERNATIVE I
I
The no-action alternative would leave contaminated soils in place. This will
allow for the naturally occurring leaching or cl~aning of 1the soil in
conjunction with groundwater remediation. Leachate from the residual soil
contamination would be extracted and treated by the groundwater extraction
system. Infiltration to groundwater is the only,route oflmigration and
subsequent exposure potential. ' j
I
A deed reauiction would be filed identifying the areas of contamination.
The deed ratriction will prevent property transfers to urtinformed purchasers
and will l!lti.t furture utilization of the property. Thea~ restrictions are
easily impl-nted by processing the restrictions throughla local attorney
and the Rowan County or City of Salisbury Register of Deeds.
The trench disposal area itself does not present
1
a directlhealth risk. As
previously stated, the risk posed is through the migration from soils into
groundwater; subsequent contaminated groundwater 1consumption poses the
principal site threat. Therefore, access restriCtion to this area is not
required. It should be noted that the trench area lies well within the NSCC
property.
-16-
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The primary conc~rn at the NSCC site is groundwater cont~ination. The only
manner in which the soils contamination can manifest its8lf is through ' ' leaching 14G the groundwater syste1n. The groundwater r'medy was presented
in the t~Oporll.ble Unit ROD in 1988. The groundwater,plume is to be
controlled--and treated to prevent releases off the site Property; therefore,
any potential exposure pathway will be mitigated. By allowing the natural
attenuation of the soil, contamination (over time) will be reduced because of
' ' biodegradation, leaching, and volatilization of 1contaminants. I
Any residual contaminants in the unsaturated zo~e will b~ leached naturally
by precipitation infiltration and then captured within t~e groundwater
extraction system for ultimate treatment and diBposal. Contaminant transport
modeling, as presented in the Supplemental RI, predictedlthat most compounds
will leach into the groundwater within the projected time frame for
groundwater remediation, i.e. 20 to 30 years. This leaching process will
actually be inhanced by the groundwater extractfon systeJ. This alternative,
in conjunction with groundwater remediation, provides an 1leffective method to
treat soil and groundwater contaminilnts. :
'
Additional Remedial Alternatives addressing the ;trench area soils were
developed in both the initial and Supplemental FSs. These documents and all
' relative data are contained within the Administ~ative Record.
I Costing Information I
I The capital costs asaocitated with the no action alternative are the attorney
fees for processing the deed restrictions. The operation and maintenance
' ' costs associated with this alternative are for resampling and evaluating the
reduction of contaminants in the soil every five years. !
Capital Costs
Deed restriction, lawyer fees
Subtotal $1,000
Operation and Maintenance costs
Soil sampling every five years $150,DOO
(30 years, pr■■ent worth)
Sul:ltotal $150,000
Presen1 ½ ,~:Plf • $1,000 + $150,000
PW• $151,000
I I
I
I $1,000
I I In summary, the trench area subsurface soil has been adequately addressed to
concludes that the contaminants existing in the soil willl leach over time
into percolating rainfall. The leachate will th~n becom~ captured by the , I groundwater extraction system and tx·eated in the on-site pretreatment
system. ,
1
-17-
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A conservative modeling approach was used to predict the lachate
concentration over time. The partition coefficients were !calculated based on
site-spec:U'ic results of leachate (TCLP) analysis. Also, 1the highest known
concentration of each compound was uaed in the model to account for
uncertainti-in the data set. Even with this conservatiJe approach, the ' model predicts that most compounds will leach into the grOundwater with 5
years. 1,2-dichloroethane, (DCA), ia predicted t'o take 22 years before a safe
level is reached (in groundwater). Preliminary e;stimatee lshow that the
groundwater remediation effort may take 20 to 30 'years before meeting the
' I cleanup criteria throughout the plume. The~efore, the remedial alternative of
natural soil flushing (or no further action) as described lin the original and
supplemental FS is the recommended approach. '
: ' In addition, soil samples should be c:ollected for monitori!ng purposes no less
frequently than every 5 years to verify that soil remediation is progressing.
At a minimum, analysis will consist of volatile organic c6mpounds. . I
EXPLANATION OF SIGNIFICANT DIFFERENCES
The selected remedy as presented in this decision
significant or otherwise, from the proposed plan.I
-18-
docwnenJ has no differences,
• .,...,-~"'STAii~~,~ .-"",/ ~·;"'"'> ~ ....
!/Jr"' 'r: .i :'"t ,.,, ~\
'" 'J))i·'f~'" ~-~~ ;:--,, i ):~ : -~ ~
\V,.., ,111 '.' . t::f \~ .. .,.., •. /.:,.<j ~,·,:·.:.~::~~:·>~·
State of North Carolina
•
Department of Environment, Health, and Natural\Resources
Division of Solid Waste Management
P.O. Box 27687 · Raleigh, North Carolina 27611-7687
James G. Martin, Governor
William W. Cobey, Jr., Secretary
t I
I
William L. Meyer
Director
September 24, 1990
Mr. Greer C. Tidwell
Regional Administrator
U.S. EPA Region IV
345 Courtland Street
Atlanta, GA 30365 I
I
RE:
I Conditional Concurrence with the Record of Decision (Operable Unit #2)
National Starch and Chemical Company NPL Sitei 1·
Salisbury, Rowan County, NC '
Dear Mf.Tidwell: • I
i
North Carolina appreciates the opportunity to tomment 6n the attached Draft
Record of Decision (ROD) for the subject site, and we look forward to working with EPA
on the final resolution of the problems at this site. The '.state con~urs with the ROD for
Operable Unit #2 subject to the following comments, cond_itions, or exceptions listed below. . : . I
1.
2.
' I
Contamination in the northeast tributary i~ not addr~ssed in the ROD for
Operable Unit #2. Because repeated sampling evehts show the tributary
sediments and water to be contaminated, it! is impedtive that this creek be
remediated. It is our understanding that an Operable Unit #3 will be created
to specifically address contamination in the jriortheastltributary.
The proposed plan to allow natural s~il flushi~g to remediate the
contamination is understandable given the level~ and depth of the
contaminants, however subsurface samples ;should bd taken periodically to
monitor declining soil concentrations. It is underst6od that groundwater ·
extraction/treatment will be continued until:groundwiter cleanup goals have
been met. The current contaminated subsJrface soil [may prolong the time
period for groundwater extraction, therefore we would advise that a more
thorough analysis of the benefits of soil vapilr extractibn and soil flushing be
conducted.
• ei
I
Mr. Greer C. Tidwell
26 September 1990
Page 2
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3.
4.
State concurrence in the Draft Record of D'.ecision anb Remedial Alternative
Selection is based solely upon the information contain~d in the attached Draft
' ' Record of Decision and Remedial Alternative Selection. Should the State
receive new or additional information 'which si~nificantly affects the ·
conclusions or remedy selection contained: in the Draft Record of Decision
and Remedial Alternative Selection, it I may modify or withdraw this ' concurrence, effective immediately, upon written notice to EPA Region IV.
Such notice shall contain a statement of the reasbn or reasons for the
modification or withdrawal of State concu~rence. i
State concurrence in this Draft Record of Decision and Remedial Action
Alternative Selection in no way binds the ~tate to corcur in future decisions
or commits the State to participate in future activities regarding this site
including but not limited, to remedial design selectioi or State participation,
financial or otherwise, in the clean up of the site. The\ State reserves the right
to review, comment and make independent assessments of all future work
relating to this site. : 1
i · I ·
In addition to the comments on the ROD for Operable Unit #2, the State has
concerns about the overall Remedial Plan at the site whi~h concerri the remedial plans for
the groundwater which is now in place. ' I
1.
2.
3.
I
.The ROD for Operable Unit #1 states that the pretieated groundwater will
be discharged to the National Starch Wastewater lagoon for further treatment.
After review, we feel this violates RCRA rules becaJse the lagoon does not
meet RCRA minimum technical requirements (i.e., there is no double liner,
no leachate collection system, nor 4 monitoring welld). It is imperative that
this be corrected before implementing the [remedial plan. . I
The air stripper operation must confor/n to the j Air Toxics Standards
promulgated in May 1990 (NCAC Title 15A, Chapter 2, Section .0610).
Community and State concerns dictate that!risk assesJments be conducted on
the treated water discharges and air enjissions from the site. The air
emissions risks should be assessed at the, property l1ine and added to the
ambient baseline risk. The total risk should not exceed the 1 x 10·6 level.
Likewise for surface water, the risk assessment should i:onsider the risks posed
by 1llJ sources discharging to High Rock Lake. Thei risk from the site plus
risks from other dischargers should not exceed the 1 Ix 10·6 level.
i I
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I
Mr. Greer C. Tidwell
26 September 1990
Page 3
• •
Again, the State appreciates the opportunity to co~ment on the Draft ROD, and we
look forward to working with you on this site in the futur,e. !
WLM/acr
cc: George Everett
Respectfilly yours,!
i I I
/,f I I ' / v_!~;j~~.
William L. Meyer I
I
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State of North Carolina ,
Department of Environment, Health, and Natural Resources
Division of Solid Waste Management I
P.O. Box 27687 · Raleigh, North Carolina 27611-7687 . I .
James G. Martin, Governor
William W. Cobey, Jr., Secretary
HEHORANDUH
TO, Lee Crosby, Chief
Superfund Section
September 20, 1990
FROH, ' _ _Jf{Jf Jerome H. Rhodes, Ch1elf'
Hazardous Waste Section
RE: National Starch and Chemical Company Sitei
Salisbury, Rowan County, North Carolina
ARAR Review
William L. Meyer
Director
The Hazardous Waste Section has reviewed this document
found that there is no conflict with RCRA regulations.
review several small errors were found which EPA might
for ARAR's and has
Howe~er, during the
'
LOCATION
Cover Letter
Site History
Site Charac-
teristics
Trench Area
Soils
Table 3-1
want to correct.
I
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' I As was already noted with a question mark, the National Starch
Company Site is in Salisbury, Rowan,County, hot Morrisville,
Wake County. ; I
!
Paragraph 5, Line 6, Word 10 should be 11 decikion11 •
I
I
Paragraph 1, Line 5, Word 4 should be "trench".
I
Paragraph 1, Line 8, Word 3 should be I 11 elevated11 •
I
Paragraph 3, Sentence 3. The word "specifically" should be
removed as "specific remediation", which appears later in the
sentence, is sufficient to get the point across. , I
At the top of the table, Concentrations in ug/kl should be
"ug/1".
9/20/90
JHR/DJO/mb/# here
'
i I • •i
UNITED STATES ENVIRONMENTAL PR,OTECTIO(-l AGENCY
REGION IV
34SCOURTLANOSTREET
ATLANTA, GEORGIA 303«55
4WD-NSRB
Mr. Jack Butler
North Carolina Department of Environmental Health and
Natural Resources
401 Oberlin Road
Raleigh, North Carolina 27602-2091
Re:
7
National Starch and Chemical Company Site
-N01:!!'imd J 1 o, Wake '191:iflt.y, North Carolina
$-31 i'5.l:unj I "Rc,Wa,-, C,,~ ~)I Pf RF/IND SECTION
Dear Mr. Butler: I
Enclosed is a copy of the Draft Record of Decision (ROD) ,on the
subject site. Please review the ROD and provide; comments' to me in
writing no later than COB on Friday,· September 21, 1990. j Since a
signed ROD is scheduled for September 30, 1990, I appreci_ate your
anticipated cooperation in expediting this review. If yo1u will be
unable to review the ROD by the requested deadline, pleas'e let me
know as soon as possible. Do not hesitate to contact mys1elf or Curt
' I Fehn if you have any questions concerning this matter. Ij can be
contacted at 404/347-7791. ,
/,~-
r ;·---( Barbara H. • Benoy
Remedial Project
Was'te Management
Manager
Division
cc: Bill Meyer, NC-DEHNR
Lee Crosby, NC-DEHNR
Bruce Nicholson, NC-DEHNR
I
DECLARATION FOR THE RECORD OF DECISION
Site Name and Location
National Starch and Chemical Corporation
Salisbury, Rowan County, North Carolina
Statement of Basis and Purpose
' e!
I
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, I This decision document represents the selected remedial action for
the National Starch and Che~ical Corporation Site develop~d in
accordance with the Comprehensive Environmental Response, l
Compensation, and Liability Act of 1980 (CERCLA); as amended by the
I Superfund Amendments and Reauthorization Act of 1986 (SARA) 42 U. S.
c. Section 9601 et. seq., and to the extent' practicable, i:he National
' I Oil and Hazardous Substances Pollution Cont'ingency Plan (NCP), 40 CFR
i Part 300.
.This decision is
for the National
' i based upon the contents of the Administrative
starch Chemical Corporation sit~. ! Record
The United States Environmental Protection Agency and the State of
North Carolina concur on the selected remedy.
Description of the Selected Remedy ,
This remedy addresses.the remediation of residual subsurflce soil
contamination. The United States Environmental Protectio~ Agency has
selected no (further) action for the Second Operable Unit/
specifically the soils contained in the "trench area". Mdnitoring
of the trench area soils will be conducted no les's frequeritly than
every 5 years to verify that no unacceptable expoi5ures to 1
1
risks posed
by conditions at the site occur in the future.
! '
I Declaration Statement
The no remedial action selection is protective of\ human
the environment based on the following criteria:
I
he,alth
I
and
0
0
I
The Record of Decision for Operable Unit
1
1, Septelmber 30,
. , I 1988, presents the remedy selection for the groundwater
which'mitigates the principal threat posed by the~
contaminated groundwater at the site. The only route of
' I migration for the "trench area" soils would be into the
' ' contaminated aquifer. '
The natural infiltration of precipitation will walk with the
selected groundwater remedy
soil contamination into the
I
effectively flushing ~esidual
I groundwater capture zone. , I
I '
I ' I I
I
• •
0 Monitoring
than every
I of the soils will be conducted no les~ frequently
0
5 years. I I
The risk assessment evaluated all potential expo~ure
pathways relevant to human exposure. No public ~ealth
threat exists directly from these soils.: The remedy for
potential exposure from groundwater has :been actdlessed
within the first operable unit Record of DecisioJ.
I
Greer C. Tidwell
Regional Administrator
Date
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the
•
DECISION SUMMARY FOR THE RECORD OF ,DECISION I
NATIONAL STARCH AND CHEMICAL CORPORATION I
I
SITE LOCATION AND DESCRIPTION '
', ' 1 1 d ' The National starch and Chemical Company (NSCC) site is ocate in
Rowan County, North Carolina, approximately five 'miles soJth of the
city of Salisbury (Figure 1). Salisbury is locatied about 140 miles
i northeast of Charlotte, North Carolina.
I
The NSCC site, also referred to as the Cedar SpriPgs
approximately 465 acres in size. The disposal area,
Road 1Plant, is
knowii as the -
' trench area, is surrounded by heavily wooded acreage to the north, ' west, and ·south. The chemical plant is located in the eastern
portion of the site property. Residential areas are locat1ed no less
than 1500 feet from the trench area in the northwest and s6uthwest
directions. l
Land use of the areas immediately adjacent to the site is a mixture
of residential and industrial developments (Figure 2). Achording to
1986 statistics, Rowan County covers 517 square miles in akea and has
' a population of 104,678. The population of the city of Salisbury as
of 1986, was 23,931. Groundwater is the, source of drinking water
supplies for the community; the city of Salisburylsuppliesiresidents
located to the north, east, and south of the site. Other nearby
' I residents are supplied by small community wells.
Several unnamed tributaries traverse the site and :flow intJ the
' Grants Creek system. One flows along the front of-the plar:it
paralleling Cedar Springs Road and leaves the proPerty to the north.
A small intermittent stream forms the southwestern' site bo~ndary. A
third small_ stream is indicated on the USGS quadra,ngle map lin the
northwest quadrant of the site. Grants Creek forms the western
boundary of the property and continues flowing in 'a northeily
dirt?ction. , I
:
There is no designated North Carolina State Significant Habitat,
agricultural land, nor historic landmark site potentially o'r directly
affected by the site. There are no endangered species or c1ritical
habitats within proximity of the site. There are no identi'fied
coastal or fresh-water wetlands within an area of ~nfluence1I of the
site.
I
The geologic framework of Rowan County forms two distinct aquifers.
The first is a shallow aqui~er created by the sapr61ite. T~e second
is a bedrock aquifer formed of crystalline rocks. 1These twb aquifers
are int~rconected ~ith clay-rich s~prolit~ .. Water:yieldingj
properties are variable. Wells drilled within the ibedrock aquifer
generally have higher yields than those in the saprolite aq~ifer and
average approximately 40 to 50 gallons per minute. 1 I
I
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•
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N
I
•
• Cedar Springs Road Plant
.-;>· ft~:.l,
/'\-..,,:"-~
'.•~:,...,.__,<a
ci911rc I
Vicinity Mar
Cedar Sri-in~JS Hoad Pli111I.
CON\CUR I N';"ERVAL
FIGURE ~ f;t A
-3-
10 FEEi II
i ' I I
I
SCALE: l'' = 2000' L---vo I :.'.J c.H : l f;,,, / 1.j IHDUSTRIAL/COVJ-IERCIAL
I
I l"-XX<'.<! RESIDENTIAL
I
FIGURE 2F.2., ;,:-!",' '
INDUSTRIAL/COMMERCIAL AND RESIDENTIAL USE AROUND
NATIONAL STARCH AND CHEMICAL CORPORATION SITE • I
' i f~\ r:}, Ji~. F~'''f' m INTERN.ATIONAL
:'., .• i i c\ • \, · , TECENCLOGY
COR?0?---~4~ION
C-C I
•
Site History and Enforcement Analysis
The NSCC site is located on the outskirts of the'.SalisburY city limits.
Edward Proctor of Salisbury founded the Proctor qhemical fompany in 1938. In
September 1968, Proctor Chemical Company purchased the 465-acre Cedar Springs
Road property. Within the next year, Proctor Chemical was acquired by
I National Starch and operated as a separate subsidiary. Construction of the
Cedar Springs Road plant began in 1970. On January 1, 1983, Proctor Chemical • I Company was dissolved and its operations merged with National Starch. The
National Starch facility is primarily a rnanufact~ring plant for textile
finishing chemicals and custom specialty chemicals. \
From 1971 to 1978, the NSCC conducted onsite disposal of 1pproxim~tely
350,000 gallons of reaction vessel wash water :into trenchJs which were
reported to be approximately 200 to 300 feet long and 8 f~et deep. The wash
water consisted predominantly of salt brines, sulfuric ac+d solutions, and
solvents and is classified as D002 waste with corrosive pioperties and a pH<
2. These trenches were constructed within a 5-acre tractlof the western •
section of the site property. The trench area is· shown of Figure \ ~ ' I ~~-~
I
Liquid effluent from the plant production area fl:owed into the easternmost
pretreatment holding lagoon, which was unlined, and then Was pumped to an
active trench in the trench area. Each trench wa1s used uritil liquid no
longer readily percolated into the grourld. At that time, ithe trench was
backfilled and seeded, and a new trench was constructed. i
In 197?, NSCC installed eight monitoring wells ar~und the !site to determine
if the trenching operations had impacted groundwater gual~ty. Four of these
monitoring wells were installed adjacent to or within the 'trench area.
Sampling results revealed that shallow groundwater immedi~tely within and
adjacent to the trench area was contaminated. In: June 19i.7, sampling and
analysis conducted by the state of North Carolina verified NSCC's results.
The state subsequently requested that NS.CC cease ~:msite wa'.ste disposal in the
trench area. !
I The NSCC site was proprosed for inclusion on the National •Priorties List
(NPL) in April 1985 with EPA assuming lead responsibility for the site.
Negotiations to allow NSCC to conduct the Remedial Investi1gation Feasibility
Study (RI/FS) activities were concluded with the Signature'. of an
' Administrative ORder on Consent on December 1, 1986. These activities
resulted in the i'ssuance of the first Record of Decsion (RbD) for the site.
. ' I The first ROD addressed groundwater remediation at the sit~ under Operable
Unit 1. The ROD specified that residual soil contamination in the trench
area be further investigated to determine whether,the areal continued to be a
major source of groundwater contamination. The first ROD k1s0 required that
analytical monitoring continue on contaminated ~uiface watkr and sediments to
further delineate the potential source.
The Remedial Design for groundwater remdiation un4er Operaple Unit 1
approved and finalized by EPA. Construction began August 1990 which
I I initiated the Remedial Action, (RA).
I
I I
has been
I
FIC'..'RE
' I
LOCATIO\~\ I
I
I
!
•
' I At EPA's direction, a Supplemental RI/FS was conducted for Operable Unit 2. ' The trench area was the focal point of the investigation.\ Subsurface soil
were sampled from ten boreholes drilled in the tiench are~. The boreholes
were continuously sampled using split spoons, beginning a~ the surface and
extending to a depth of 30 feet or to. the saturated zone, '.whichever was
encoutered first. Field screening was conducted 'in the final selection of
the samples submitted for laboratory analysis. In additicin, TCLP analyses
were conducted on several borehole samples using both a standard solution and
rainwater collected at the site in the trench are'a to det~rmine certain I leachability characteristics of the soils. I
I
The Suplemental RI also included additional monitOring of jthe sur~ace wate_r
and sediments in what is known as the northest tributary.! This tributary was
sampled in October and November of 1989 and again1 in July 1of 1990. This
decision document presents the remedial selection1 for the 1residual soil
contamination in the trench area at the Nsc·c site. I I
' COMMUNITY RELATIONS ACTIVITIES 1
I
EPA's community relations outreach fer the NSCC has been cpnducted since 1986
with the development of a Community Relations Plan. Communication with the
community has included the development of several site speCific fact sheets
as well as four public meetings to date. Specifically fort Operable Unit 2,
the Supplemental RI/FS and Proposed Plan Fact Sheet were distributed to the . ' public during July 1990. The Second Operable Unit Administrative Record was
made available at the Rowan County Library during the Public Comment Period.
' ' Public Comment was held from July 30, 1990 to Aug~st 29, 1~90.
' I All comments made to the Agency concerning the PrOposed Pl~n and the site in
general have been compiled and addressed in the Responsiveness Summary which
is attached to this Record of Decision as Appendix, A
SCOPE AND ROLE OF OPERABLE UNIT 2 RESPONSE ACTION
I
The· scope of this response action is to address anY soil c~ntamination in the
trench area as a source control Operable Unit. The first Operable Unit
action was decided with the issuance of a ROD on September \30, 1988. This
ROD required the development of a groundwater interception land extraction
system to be installed downgradient of the contaminant plume. Pretreatment
' for the extracted groundwater includes air stripping, filtration through
activated carbon, metals removal, and treatment thi-ough the1 company's
existing lagoon system. Discharge will be to the Salisbury\ Publically Owned
Treatment Works (POTW). A contingency for an alternate discharge point was
' ' included in the ROD if permits requirements for the POTW cannot be met. ' Monitoring of the surface waters on the site are also required under the
first ROD. !
Objectives of Operable Unit 2 are to: ensure that cleanup standards for the
site are developed for all appropriate media, implement a cleanup alternative
that is protective of human health and the environffient, and 1 select a remedy
that meets the above criteria in a cost effective manner. I
• •
SITE CHARACTERISTICS
I
I
I
I
I
I
The NSCC site was characterized during the initial RI and[FS under a
comprehensive site-wide investigation. Based on 'the results of this initial
RI, the trench area was determined to be the only'. signifi6ant area from past
disposal practices that could be considered a sou'rce area.1 The first ROD
required that the treanch area be further investigated to \identify the degree
of source contribution. This decision document is lirniteq to the
characteristics as observed in the trench area soils and b_ased on the
Supplemental RI. Results of continued monitoring of surfa,ce water and the
re~pective sediments are presented in part to establish th_at the trench area
is not considered the source of contamination to the trib~~ary.
i
TRENCH AREA SOILS
The Supplemental RI characterized the trench area 1subsurfabe soils with the
installation of .. 10 .. , boreholes. Figure 4 prbvides the borehole _.,.,., •••• ~ I locations. Resultes of the organic analysis are _shown on Table
Significant levels of 1,2-dichloroethane, 2-butanone, 1,2-dichloropropane;
4-methyl-2-pentanone, toluene, ethylbenzene and xylenes we~e identified in
the trench area subsurface soils. Antimopy and arsenic we~e the inorganic
constituents identified at elevated· levels; these
1
two contaminants were
detected at elevatyed levels in only one location. Tabulated inorganic data
are presented in Table ,;)__
' I Based on the data deve~oped from both the initial and suppI
1
emental Ris, the
subsurface soil contani.'inat"ion has been observed from 5 feet below land
' I surface down to the water table. The top 5 feet is believe1d to be clean soil
which was backfilled into trenches as they were deactivated,-Maximum
concentrations were observed approximately 18 feet,below land surface. There
• I is no current complete route of exposure specifically from these soils, i.e.,
no dermal exposure potential. Migration pathway is isolate~ to leaching into
the groundwater. ]
• I The trench area is known to be the original source of the groundwater
I contamination based on historical disposal practices. The Supplemental RI
was designed to measure the effectiveness of the natural soil flushing by
' percolating rainfall of the soil contaminants as well as determining the
actual contaminant concentrations remaining in the '.trench a~ea subsurface
I soils. The Supplemental RI was conducted to characterize the remaining
contamination in the subsurface soils in the trench area specifically to
determine if specific remediation of the soils was necessarY. Results of the
Supplemental RI indicate that natural leaching of the soils \has resulted in
notably reducing the levels of the contaminants of Concern. ' In fact, several
of the contaminants of concern were not detected within the :trench area soils
during the supplemental RI field work. ;
I
The Supplemental RI d~termined that the most notable concent'rations of trench
area soils were approximately 18 feet below the land surface'. and were found
in much lower concentrations than expected. It appears thatl residual soil
contamination is effectively leaching into the groundwater; soil
concentrations are consequently being reduced. Any'remedial1 actions
involving removal or treatment of these subsurface Soils wili introduce , I
I
I
TABLE 3 NATIONAL STARCH: ORGANIC ANALYSIS RESULTS FROM BORING SAMPLES COLLECTED NOVEMBER 1989
TAIC!T Co.J>O..Nl
llST Sl.eSTANCfS
QJANTtUTICW
VOi.A.TiU OIIGANICS
ACctone
CHbon DI su!Y~·dc
Chlorolor•
I. 2-d I Ch lo roe lh..lnc
llroaod I ch I Of Oat I h.lnc
1, l-dlchloroproplnc
11,oaoror ■
, -•et l1y I -1 -ocn I a none
To l uenc
fthylbcnicne
Tot,;i I Xylcncs
SfMtVOt.A.111 f OIIGANICS
,-a.ethylphcnol
11cnzolc icld
n-Nl I 101odlphcny la■lnch
Phcno I
He Ji Ch lo1obut1dl enc
1--thylphenol
.llenzyl.ll(Ohol -----~
11 l I ( l-chlorocl hy I )ether
• l lAITS P>l .... 06 P>/1-07 6H-Oa aH-09
0-1· 10-11. U-1'' 10-11 ·
"' b
" 1
"' I 1 "
"' '
"'
' ' 2700
1700
' ' " "'
IOOC
~cd210· cd110 dlbO J'iO 110 7b0
Jl.OOOg
SOil IIOIIH,G M-0 SAAIPlf ,..,__.,n,s 1conccntr11 Ions ire In ug/ko (opbJJ
SAtl.PlfD INTfRVAL flOM U.lsO SUllfACf (fl)
&H-0911 &H-0911-RE
11-ll. ll• I).
" ,.
I I "' , "
"' "' '"
"' ,.,
' "
"' '"
"'
1100
' HOO 1700
cdJ 10 .
'70 1,10
811-11 ett-12
DU' DU'
W-10 !.H-11 t.H-1 l 8H-') Slt-1' Btl-15 (811-16) (SH-17)
ta-10· 11-20. l&-:28. 21-)0" 1-,. ll-30" 20-22· H-21'
I I "' I " " " ' • I 0 ' "' '" " .ooo " '" ' " 1
°'' " . 000 ,boo ' !i,oo9 llOO a,oo9
' " " '
'" ' ' " °'' 1 " 1 " "'
70C BOC HOC
----1~oc
dJbO cd1'l0 cd270 cd170 Cd110 c<ll'lO cdJ'iO cd170 7b0 )bO b10 HO )bO UO '70 710
' ' )bO l!iO
' '"
-,
"
QIUnllUllon 11•111 uc 001 reported lor 1011 UOl(IICI due 10 lhclr vul.1blllty. "PPllc,1btc tl•ltS HC ,1v1llabtc on !11c CeftlllCIIU ol An.1lySII.
--1ndlc,1e1 org,nlc co.pounds th,11 .. ere 1101 dclccled.
~cpor!ed concenlr.1,IIOn II belo., lhc quar1tl11tlon ll•II.
Co.pound 11,110 p1e1cnt In the L1bo1.11ory blink. The 1upc11crlp1cd m.-.ber 11 the lab bl1nl conccnt1.1tlon.
C01011>01Jnd c•cccdcd c.1llbr11lon ,,nuc or lnr.rrua,:111 lmt .. lthln hHl<ta<:nl llnc.11 r,nge.
Arulyte HI found In the blink H •ell H the llll(}IC
U Co-vound .i.n, ly1cd ., ,1 IC(Oll<IHY di lut Ion 1iCIOI
" oc1ec1et1 ,11 d!phcnyla•lnc.
NA NOi ;,ppl !cable.
Rt Rcc.lflCtlon.
11:INSATf RAL.--Al[I:
IOCOOJ7 ooo,
"' ' "' " •
"
' '
twllDUI
"'
"'
"' • "'
"'
"' ...
"'
"'
"'
"'
"'
"'
TABLE 3-6: NATIONAL STARCH: INORGANIC ANALYSIS RESULTS FROM SOIL BORING SAMPLES COLLECTED NOVEMBER 1989
S0ll • IHMIING ArsD SAJoi,Plf N..W.llfllS 1conccn1r;,tlon1 "' In •g/lq (ppal l
S,u,.PLEO INTfll:VAl ""' U.t,,() SUl.fACf ff n
THG!J ANAL YH DE HCT ION
• l ISi S'-"STAN:::fS l UUTS """' &H-07 6H--OI IIH-09 6t1-098 8.11-1 0 l!Jl-1 I llll-12 &H-D !li-14 IIH-15
o-•. 10-IJ' n-u· 10-ll. ·-10' 1,-n· 111-20· ]4-21' Ja-JO, 1-•. n-n·
Aluo1m• ,. '" " 000 "· ,00 " . 200 "· ,oo " '" ". 500 JO 700 " '" ,, 700 50 '" b C C Ant taony " b '
Ar scntc .. ' .. '.'
IIHh• 21. J '" 70.9 " " ' '" '" '" '" 4]. 9 '" C C C C lleryltlt.• 0.' 0.' 0 .• • 0.' 0 ' 0., 0. 0.' 0.'
(i[a(i,a 0., 0 ' .. '.' C C C C C C.1lclu. "' lHO ,,. "' "' "' 60]0 ]60~ lllO "' "' Chroa/uo " " " " " " ' Cobi I I " " " " " " " " ,. " Copper ., " " " " " ., " ,. " "' 110n " 000 " '" .. . ◄00 "· ,00 " JOO " 000 .. '" " '" "· '" "· "' ". JOO
C IU(! . . ' ' , ... ' .. ' ' ,., ' • ' ' . . ,
C C ..,_gncs fuo ,,. H50 !BOO "' "' 10,0 B40 1800 1190 ,., ]1,]Q
..,_nl)-,IOCIC m .. ' '" 219. 0 "' '" "' "' "' "' "' .1tcrcu1 y 0, o .OJ 0. 05 --0. OJ 0 " -0 " Nlclc I ,0 ,0 " " " POI I 111 La '" "' C C C C C C C C C 50dli... " '" '" ,. "' m rn 15~0 , .. " " vu-.dh• m " "' '" "' 1 n '" 122---119--151--,, --------------
--zinc---------46. l ◄1. 1 56. a H.4 H.◄ bl>. 'ii 66. 2 50. 2 " ' " "
D<ctcctlon 11•111 001 reported lor loll Ulll'.IICI due 10 lhclr vuh,blllly. OCICCllon 11•111 He .1v.1ll.1blc on the Ccrttllu.lcs ol Ar\.alyJIS.
--lndlCl!cl lnorg.1ntc c<>apound1 th1t •ere not detected ln thl I uaplc.
v,otuc orc.icr 111,n ln111~n1 dccat/on li ■lt_ bul lcn 111,n contr.1ct 1cqulrcd qu,1,ntltUlo11 11•11.
NA t,,ot A.ppl lc.,,b(c.
6U-1 \ 11,H-, 2
"" ""
(Mi-16) (6H-17) tlNSATf IAJ,.,.ATEI
10-n· ]4-21' 1(1(0039 01304
C " JOO " '" "
C '" 96. 1 ' C o., 0 ' ' ..
2120 J270 7 1'0 C ..,
"
" ,0 ., ,0' " " '" " "' C '" " ' .. ' ' C C 2'70 2510 1 lbO '" C "' , .. ' "
" C '" '" C C "' IUO 10, 'il00 lllO , __ ---"' ..
66 _ a 56 .6 " C
"
IAl~ATU
h'llOIH •
C l
C "'
,.
C .,
C •
C l • -----·
"
•
additional risks to the environment or human health, by the excavation or
construction concerns inherent to any further action.
To support the potential for natural soil flushing to be considered as a
viable remedial option in conjunction with the groundwater extraction system,
two vadose zone models were applied to the study data. T~e first objective
was to determine an acceptable concentration of a contamiriant in soil; the
second objective was to predict the time required to achie've this acceptable
concentration. Pre-established groundwater cleanup criterta (Operable Unit 1
ROD, 1988), were considered the upward limit for contamina'nt cOncentrations
in groundwater. Soil concentrations were then back-calcul'ated using the
soil/water equilibrium relationship. Modeling data and in'formatiqn are
provided in Appendix B. I
Surface Water/Sediment
' Surface water/sediment sampling was conducted during both t~e first and
supplemental Ris. The actual source of this contamination!has not been
determined. It has been concluded that the tiench area soils are not the·
source. This Second Operable Unit piesents the selected r8medy for the
trench area soils. \
Contamination of the latest data generated from sampling adtivities on the
surface water system is provided on Tables 3i-v1.v'?t.-,k~ith coiresponding
sampling location shown on Figure ~. As requifed by th~ First Operable
Unit ROD, continued monitoring of the tributary will be co~ducted until
sufficient· data is obtained to identify a source. 1
TABLE }-,'>i: NATIONAL STARCH: ORGANIC ANALYSIS RESULTS FROM SURFACE. WATER SAMPLES COLLECTED OCTOBER 1989
"'-
TARGET Cc:»4PCX.HW
LI ST SUBSTANCES
OUANTITATION
VOLATILE ORGANICS
Methylene chloride
Acetone
1,2-dichtoroethene (total)
Chloroform
1,2-dichloroethane
2-butanooe
1, 1,1-trichloroethane
Bromodichloromethane
Trichlorethene
Tetrachloroethene
1, 1 , 2, 2-tet rach _t oroethiine
Toluene
Ethyl benzffie
SEMIVOLATJLE ORGANJCS
o i -n-but"yl phtha-late
Bis(2-ethylhexyl)phthalate
Hexechlorobut&diene
LIHITS8 SIJ-01
01267
SU-02
01263
120
SU-03
01269
SURFACE UATER AND SAMPLE NUMBERS
SU-05
01251
su-06
01261
210
SU-07
01271
(Concentrations are in ug/kl (ppb))
OUP
SU-08 SU-09 SU-10 SU-11 SU-11A SU-12
01279 01265 01255 01275 D1276 01273
350 1200
TRIP TRIP
TU-15 TU·15A
01281 D1259
0 a~ntltBtior'f':11mlts are not reported for surface water sn,rples due to their variability.
b
Applicable limits are available on the Certificates of Analysis.
--lnclicates organic c~s that were not detected.
C Reported concentration
~A Not applicable.
is below the quantitation limit.
P•a• 1 of 1
RINSATE
DU-16
D1260
30
34
5
5
•
NA.
NA
NA
,:_/
TABLE 3';:2-: NATIONAL STARCH: INORGANIC ANALYSIS RESULTS FROM SURFACE WATER SAMPLES COLLECTED NOVEMBER 1989
T ARGE.T, ANAL YTE
LIST SUBSTANCES
Alll'Aint..n
Antimony
Arsenic
Bariun
Beryl l iun
Cadniun.
Calciun
Chromiun
Cobalt
Copper
Iron
l•ad
Magnes iun
Manganese
Mercury
Nickel
Potassiun
Seleniun
Silver
Sodiun
Thalliun
-vinadiun
Zinc
0ETECTIQ!j
LIMITS8 S11-01
01299
149
b
35
9720
14
100012c
3480
130
-1600
7350
339
SW-02
01292
566
35
10,000
20
26
111012
3950
140
1810.
5890
SURFACE ~ATER AND SAMPLE NUMBERS
S11-03 SW-04
01293 01297
65 104
30 34
20,500 9540
14 15
35912 103012
9310 3640
63 142
1230
9620 5640
SW-05
01298
274
47
8900
10
79812
3980
86
5110
SW-06
01296
224
72
8980
13
454012
4220
930
4220
(Concentrations are in ppb)
SW-07
01294
78
31
24,800
18
43612
11,200
100
11,200
SW-08
01295
116
22
13,700
.13
40712
6210
44
6760
SW-09
01301
113
26
13,200
81912
6660
185
OUP
SW-09A
01302
430
29
14,200
26
123012
· 7160
193.
SW-10
01300
418
26
11,400
208012
5950
566
SW-11
. 01303
7040
61
7830
17
24
20,600
4010
766
1 ~9q_o _ 1_2.~00 ___ 17,600_ --3630 --------------------~ ------
46
969 319 429 239 329 409 329 379 479 499 41
• Detection limits not reported for surface water st11rples due to the Variability.
b Detection li~its are available on the Certificates
--Indicates inorganic corrpot..o:::ls that were not detected.
C C orrpot..o:::I i s a l so pres en t in the laboratory blank. The superscript nurbcr is the lab blank concentration.
--------
of Analysis.
•
• - ---
,·
CJ ·;o
:t,~J
-ft
' ~Jt'i
TABLE 3~,:''f: NATIONAL STARCH: ORGANIC ANALY?IS RESULTS FROM SEDIMENT SAMPLES COLLECTED OCTOBER 1989
~
TAR GET COHPOUND
LI ST SUBSTANCES
VOLATILE ORGANICS
Methylene chloride
Acetone
0UAMTITATION
LIHITS8 SE·D1
D1268
1,2-dichloroethene (total)
Chloroform
1,2-dichloroethane
2·butanone
1, 1, 1-trichloroethane
Bromodichloromethane
Trichlorethef'le
Tetrachloroethene
1, 1,2,2-tetrachtoroethane
Toluene
Ethyl benzene
SEHIVOLATILE ORGAMJCS
SE·D2
D1264
SE-03
D1270
SE-04
D1250
SEDIMENT AND SAJ1PLE NUHBERS (Concentrations are in ug/kg (ppb))
SE-OS
01252
112
40
SE-06 SE-07 SE-08 SE-09
D1262 D1272 D1280 D1266
102
24
76
SE-10
D1256
102
41
12
14
SE· 11
01277
SE·11A
01278
102c
49
SE· 12
01274
132
24
Page 1 of 1
TRIP TRIP RIMSATE
T~·1S T~·15A 0~·16
01281 01259 01260
30
34
5
s
•
o·f-n·butylphthalate
Bis(2-ethylhexyl)phthalate
Hexachlorobut&diene
150c
400120c 540 120 780120 390120c 310120c 520120 780120c 660 120 290120c 520120
160c
510120c
250c MA
720120c 980120 MA ••• 100<
8 Ouantitation limits are not reported for soil soo-ples due to their variability. Applicable limits are available on the Certificates of Analysis.
b --Indicates organic corrpourds that were not detected.
Reported concentration is below the quantitation limit.
d COfl"PO\-Kld Is elso present In the leboretory ble~k. The superscripted ntJTbcr is the leb blenk concentrotion.
C
NA Not applicable.
MA
0
TABLE lc:-4: NATIONAL STARCH: INORGANIC ANALYSIS RESULTS FROM SEDIMENT SAMPLES COLLECTED OCTOBER 1989
TARGET ANALYTE DETECTION
LIST SUBSTANCES LIMITS• SE-01
D12611
SE-02
D1264
A.lunlnc.n 3190 2900
Antimony b
Arsenf c 0.3 0.5
Bariun ~ 32.1 23.9
Beryl l iun 0.2
Caciniun
Celciun 389 381
Chromiun 9 14
Cobat t 5 5
Copper 7 6
Iron 67801.4c 66501.4
Leod 2.0 1.9
Hagnesfun 497 579·
Manganese 253 145
Mercury
Mickel 4
Potassfun
Seleniun
Sit ver
Sodiun 33 37
ThB(CilJ'n .----
Van&dillft 18 18
Zinc 32.8 22.9
SEDIMENT AND SAMPLE NUMBERS (Concentrations are in ppn)
SE-03
D1270
6480
1.6
26.7
0.2
1280
62
13
14
24,7001.4
8
935
296
78
82
118
SE-04
D1250
12,300
72.0
0.4
1620
29
12
27
18 2001.4 • 6.1
2400
265
8
.. 74
66
40.4
SE-05
D1252
7270
1.1
52.8
0.1
1060
37
12
14
18,7001 ·4
4.0
965
271
5
146169
49 -
58
20.8
SE-06
D1262
9380
0.7
73
0.2
883
39
15
20
24,8001.4
7.6
1000
360
6
· 33
88
77
SE-07
D1272
61100
1.2
28.5
1110
30
13
13
18,5001.4
11.6
1110
311
5
60
45.9
SE-08
D1280
11,000
0.9
51.8
0.2
1900
41
18
21
24,6001.4
10.0
1240
444
7
122
88
58. 1
SE-09
D1266
9970
44.5
2380
39
8
29
74601.4
4.4
9'57
·113
6
131
89.2
SE· 10
D1256
9790
0.9
50.1
0. 1
794
35
21
20
23,4001·4
10.9
342
1520
5
45
84
23.6
SE· 11
D1277
15,600
0.6
79.4
4;5
2270
35
19
42
25,1001•4
9.0
901
293
12
104
99
8490
8 Detection limits not reportM for soil sarrples due to the variability. Detection limits ere available on the Certificates of Analysis.
b -· Indicates inorganic corrpcx.nds that were not detected.
c Corrpotnd is also present in the laboratory blank. The superscript nurber is the lab blank concentration.
SE·11A
D1278
10,300
0.8
70.8
0.3
1970
26
16
35
20,3oo'-4
7.7
747
259
10
56
82
80.2
SE-12
D1274
28,100
65.1
D.7
1150
51
38
42
57,9001.4
20.0
616
1680
·0.08
•
12 • 221169
56
154
129
C ' l
• •
I
' I
~u~ >4tv,C,<_ . ~7du(c
y:}11 ✓;,ifJ!c,rL ~/ /ll~J{t~fizJ ·· j
. /) 4, ? .. () 4-<~ i~/'; I
"YC·'/l_e,, / I ~) -1-V
' ' I .
• •
. I
Comparing the groundwater contaminants of concern and the.respective cleanup
criteria (First Operable Unit ROD, Sept. 1988), with the borehole results of
the Supplemental RI, several contaminants of concern were'not detected in the
organic analysis of the trench subsurface soils., Results :of the trench area
soils indicate levels of inorganic constituents which are representative of
background conditions.
Surface Water and Sediments
Continual monitoring of the surface water system, known a~ the northeast
tributary, is required by the first ROD, until a source of contamination can
be defined. Further investigation of this system will continue uI}der the --·
first Operable Unit ROD, as defined, until sufficient dat~ are available to
seleCt an appropriate remedy. Results of the JulY i~90 s~rface water and
sediment sampling effort are presented in Tableef __ 7,_ __ _
Summary of Site Risks
CERCLA directs that the Agency must protect human health ~nd the environment
from current and potential exposure to hazardous kubstances at the site. The
risk assessment conducted during the initial RI concluded that the principal
risk presented from the NSCC site w·as the potential for hllman consumption of
contaminated groundwater. Likewise, the principai" risk posed from the
trench area soils is also the potential for human consumpt\on of contaminated
groundwater since the only route of migration and/or exposure of these soils
is infiltration to groundwater. The following sectio~ summarized the
Agency's finding concerning the risks from exposure to groundwater related to
this site. '
I Eleven carcinogens and fourteen non-carcinogens hi3.ve been ,identified in the
groundwater at this site. The toxicity, mobility and persistence
characteristics of these substances at the site d9 not war'rant the exclusion
of any of these substances from consideration as shemicals; of concern ~t,...the
site. The substances of concern for this site are listed 'in Table (4· ,{ .
This table also presents the highest detected on-Site leve~s for these
substances, as well as other related health inforffiation. 1.
Exposure Assessment
I Groundwater in the area is a current source of drinking water; it is
classified as Class IIA based on the Agency's Gro~ndwater Classification
Strategy. A 1988 survey of existing off-site water supply:wells revealed a
total of 1,539. homes within a 3-mile radius of the site. These wells are
I outside the limits of the city water lines and could potentially use the
groundwater for drinking and other domestic purposes. The closest well is
I located 2,200 feet northeast of the site.
I ' ,
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TABLE t { •
HAZARDOUS SUBSTANCES FOUND IN THE GROUNDWATER
AT THE NATIONAL STARCH SITE
HIGHEST CONC, 10-6 EXCESS I
CARCINOGENS FOUND ON SITE CANCER RISK
Arsenic 310 ppb 0.02 ppb
Benzene 8 ppb '1. 2 ppb
Bis(2-chloroethyl) ether 14,000 ppb 0.03 ppb
Bromodichloromethane 7 ppb 0.43 ppb
Chloroform 49 ppb 0.43 ppb
1,2-dichloroethane 350,000 ppb 0. 38 ppb
1,1-dichloroethylene 11 ppb 0.06 ppb
Methylene chloride 8 ppb 5,.0 ppb I
1,1,2-trichloroethane 11 ppb 0.59 ppb
I
Trichloroethylene 10 ppb 3.0 ppb
Vinyl chloride 90 ppb 0.02 ppb
HIGHEST CONC. CONC. EQUIV. I
NON CARCINOGENS FOUND ON SITE TO RfD OR ACI I
Acetone 89,000 ppb 3,500 ppb
Barium 2,290 ppb 1,800 ppb
Beryllium 120 ppb 17.5 ppb
Cadmium 114 ppb 10 ppb
Chromium 554 ppb 1175 ppb
1,2-dichloropropane 29,000 ppb 6 ppb
Ethyl benzene 1,500 ppb 3,500 ppb
Manganese 1,400,000 ppb 7,700 ppb
Nickel 5,190 ppb 350 ppb
4-nitrophenol 13,000 ppb 350 ppb
Seleniun:i 274 ppb 105 ppb
Toluene 6,000 ppb 2,000 ppb
Xylenes 3,800 ppb 350 ppb
Zinc 14,900 ppb 7,350 ppb
* = Proposed Maximum Contarnina'nt Level Goal (MCLG)
-20-
CURRENT
MCL
10 ppb
5 ppb
none
none
none
5 ppb
7 ppb
none
none
5 ppb
2 ppb
CURRENT
MCL
none
1,000 ppb
none
10 ppb
50 ppb
6 ppb *
680 ppb *
none
none
none
10 ppb
2,000 ppb *
440 ppb *
none
• •
I
. In developing the hypothetical exposure scenarios for grou_ndwater at this
site, it was assumed that nearby residents would be exposed to water
contaminated at the highest concentrations found on site. 1 This is a
reasonable assumption based on the facts that residences a:re located almost
directly along the site boundaries in the direction of app,arent groundwater
flow, and because the data indicate that the groundwater plume is advancing
rapidly.
The potential routes of human·exposure relative to the groundwater include
water used for drinking and other domestic purposes.
Toxicity Assessment
Both carcinogens and non-carcinogens were identified in the groundwater. For
carcinogens, Table X lists the concentration for each substance which
is equivalent to a 10-6 risk. The Agenc~ cOnsiders individual excess
cancer risks in the range of 10-4 to 10-a·s protective; hOwever, the
10-6 risk level is used as the point of departure for setting cleanup
levels at Superfund sites. A 10-6 level is particularly appropriate as a
point of departure at this site given the number of carcinogens that nearby
residents may be exposed to from the site.
For non-carcinogens, this concentration which would be equivalent to either
the reference dose (RfD) or the acceptable chronic intake (ACI). The RfD
and ACI are levels to which humans can b~ exposed to on a 9aily basis without
adverse effect. Exposures which exceed concentrations equfvalent to these
RfDs and ACis would be considered an unacceptab'ie risk at this site.
summary of Risk Characterization
Given the proximity of the residents to the site bOundary (Particularly those
residences in the King's Forest Subdivision and the Little Acres Trailer
Court) and the rapid advancement of the groundwater plume, the risks from
current and potential exposure to contaminated groundwater from this site
would be unacceptable without groundwater remediation incluOing plume ' interception. !
Public health will not be at risk unless the soil is excavated or additional
contaminants froffi the soil migrate into the groundwater and\the contaminant
plume migrates past the property line at levels in excess of ARARs.
Groundwater will be controlled so that ARARs throughout the 1 plume will be
achieved.
• •
DESCRIPTION OF THE NO ACTION ALTERNATIVE
The no-action alternative would leave contaminated soils fn place. This will
allow for the naturally occurring leaching or cleaning of 1the soil in
conjunction with groundwater remediation. Leacha~e from t'he residual soil
contamination would be extracted and treated by the ground.water extraction
system. Infiltration to groundwater is the only route of migration and
subsequent exposure potential. A deed restriction would be filed identifying
the areas of contamination.
The deed restriction will prevent property transfers to uninformed purchasers
and will limit furture utilization of the property. These1 restrictions ar~
easily implemented by processing the restrictions through -'a local attorney
and the Rowan County or City of Salisbury Register of Deeds.
I
The trench disposal area itself does' not present a direct realth risk. As
previously stated, the risk posed is through the migration from soils into
groundwater; subsequent contaminated groundwater consumpti6n poses the
principal site threat. Therefore, access restricfion to tris area is not-
required. It should be noted that the trench area lies well within the NSCC
property.
The primary concern at the NSCC site is groundwater contamination. The only
manner in which the soils contamination can manifest itself is through
leaching into the groundwater system. The groundwater rem~dy was presented
in the first Operable Unit ROD in 1988. The groundwater plume is to be
controlled and treated to prevent releases off the site p~operty; therefore,
any potential ~xposure pathway will be mitigated. By alloWing the natural
attenuation of the soil Contamination (iver time) will be reduced because of
biodegradation, leaching, and volatilization of ccintaminants.
Any residual contaminants in the unsaturated zone will be leached naturally
by precipitaion infiltration and then captured within the groundwater
extraction system for ultimate treatment and disposal. Contaminant transport
modeling, as presented in the Supplemental RI, predicted t~at most compounds
will leach into the groundwater within the project'ed time frame for
' groundwater remediation, i.e. 20 to 30 years. This leachi~g process will b~
actually be inhanced by the groundwater extraction system. I This alternative,
in conjunction with groundwater remedation, provid,es an ef~ective method to
treat soil and groundwater contaminants.
Additional Remedial Alternatives addressing the trench area soils were
developed in both the initial and Supplemental Fss·. These 'documents and all
relative data are contained within the Administrative Record.
-----.
• •
Costing Information
' The capital costs associtated with the no action alternative are the attorney
fees for processing the deed restrictions. The operation:ands_ mintenance
costs associated with this alternative are for resampling and evaluation the
reduction of contaminants in the soil every five years.
Capital Costs
Deed restriction, lawyer fees
Operation and Maintenance Costs
Soil sampling every five yeats
(30 years, present worth)
Present Worth
Subtotal
·Subtotal
PW=
PW
$1,000
$1,000
i
$150,000
$150,000
$1,000 + $150,000
'
$15Jl,OOO
' '
In summary, the trench area subsurface soil has been adeqJately addressed to
concluded that the contaminate existing in the soil will teach over time into
percolating rainfall. The leachate will then become captu.red by the
groundwater extraction system and treated in the on-site pretreatment system.
A conservative modeling approach was used to predict the leachate
I concentration over time. The partition coefficients were :calculated based on
site-specific results of leachate (TCLP) analysis. Also, :the highest
concentration of each compound modeled was used to account for uncertainties
in the data set. Even with this conservative approach, th,e model predicts
that most compounds will leach into the groundwater with 5, years.
1,2-dichloroethane, (DCA), is predicted to take 22 years before a safe level
is reached in the soil that will not impact the groundwate:r. Preliminary
estimates show that the groundwater remediation effort may' take 20 to 30 years
before meeting the cleanup criteria throughout the plume. Therefore, the
remedial alternative of natural soil flushing as described; in the original and
Supplemental FS is the recommended approach.
In addition, soil samples should be collected for monitori:ng purposed no less
frequent than every 5 years to verify that soil remediatio.n is progressing.
At a minimum, analysis will consist of volatile organic coffipounds.
EXPLANATION OF SIGNIFICANT DIFFERENCES
The selected remedy as presented in this decision
significant or otherwise, from the proposed plan.
. I
document has no differences,
• •
A
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