NCD991278953_19930901_National Starch & Chemical Corp._FRBCERCLA ROD_Draft Record of Decision OU-3-OCR

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,) .,
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IV
345 COURTLAND STREET. N.E.
ATLANTA, GEORGIA 30365
SEP 1 1993
4WD-NCRS
Mr. Bruce Nicholson
North Carolina Department of Environment,
Health and Natural Resources
401 Oberlin Road
Raleigh, NC 27605
RtttUVtHJ
Sfp 02 1993
SUP£RFiJN{ISfC110N
RE: Request to Review Draft Record of Decision for Operable Unit
#3 for the National Starch & Chemicai Company Superfund Site
Dear Mr. Nicholson:
Enclosed for the State of North Carolina Department of Environment,
Health & Natural Resources review and distribution are three copies
of the draft Record of Decision (ROD) for Operable Unit #3 (OU #3)
at the National Starch & Chemical Company (NSCC) site. This ROD
only addresses contaminated groundwater in the "Plant" and lagoon
areas of the facility and the Northeast Tributary. The
contaminated soils in these areas will be addressed in OU #4 ROD.
As with the previous Operable Units, the work conducted during OU
#3 was performed by the potentially responsible party (PRP), NSCC,
and the PRP's contractor, IT Corporation (IT). This ROD is based
on the information provided in the June 1993 Remedial Investigation
(RI) Report, the June 1993 Feasibility Study (FS) Report, and the
July 1993 Proposed Plan Fact Sheet.
The public comment period was to end on August 17, 1993, however
the Agency received a request to extend the public comment period
an additional 30-day. Consequently, the public comment will
conclude on September 16, 1993.
Please note that the page numbering, the titles to some of the
figures and tables, and the Index in this draft ROD may be in
error. For your information, all of the figures and the majority
of the tables were duplicated from either the RI or FS reports.
Also, please note that the cleanup goals for the surface water and
sediment in the Northeast Tributary in Table 23 and other
corresponding tables were left blank. If appropriate, cleanup
goals will be specified after specific information is received G-
WTSU.
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The Superfund Program would like to have this ROD signed by the end
of September 1993, therefore, I would like to have your comments by
Friday, September 17, 1993. If you are unable to submit your
comments to me by this date, it is important that you let me };:now
that you will have comments and when you will be able to transmit
them to me. If I do not hear from you by this date, I will assume
that the State will not have any comments. Thank you in advance
for your time and effort.
If you have any questions, I can be reached at 347-7791.
Sincerely yours,
t.:~::o~
Remedial Project Manager
enclosure
I cc: Michael Kelly, NCDEHNR (w/o encl.)
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RECORD OF DECISION
REMEDIAL ALTERNATIVE SELECTION
OPERABLE UNIT #3
NATIONAL STARCH & CHEMICAL COMPANY SITE
SALISBURY, ROWAN COUNTY
NORTH CAROLINA
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION IV
ATLANTA, GEORGIA
SEPTEMBER 1993 .
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DECLARATION FOR THE
RECORD OF DECISION
SITE NAME AND LOCATION
Chemical Starch & Chemical Company
Cedar Springs Road, Salisbury, Rowan County, North Carolina
STATEMENT OF BASIS AND PURPOSE
This decision document presents the Operable Unit Three Remedial Action for the Chemical
Starch & Chemical Company Superfund Site in Salisbury, North Carolina, chosen in accordance
with the Comprehensive Environmental Response, Compensation, and Liability Act of 1980, as
amended by the Superfund Amendments and Reauthorization Act of 1986 and, to the extent
practicable, the. National Oil and Hazardous Substances Contingency Plan. This decision is
based on the Administrative Record file for this Site.
The State of North Carolina cconcurrs with the selected remedy for Operable Unit Three. State
comments on this Record of Decision, as well as EPA's responses to those comments, can be
found in Appendix A of this document. ·
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this Site, if not addressed by
implementing the response action selected in this Record of Decision, may present an imminent
and substantial endangerment to public health, welfare, or the environment. Presently, no
unacceptable current risks were identified associated with the National Starch & Chemical
Company Site, the principle threat pertains to the future and potential use of the groundwater
beneath and downgradient of the Site and the potential adverse impact contaminated soils will
have on the quality of the groundwater.
DESCRIPTION OF THE SELECTED REMEDY
The selected remedy addresses the elevated concentrations of groundwater contaminants and
restores the aquifer to drinking water quality. The remedial action for the contaminated Site soils
will be addressed in Operable Unit Four.
The selected remedy will permanently remove contaminants in the groundwater through
groundwater extraction and on-site, above-ground treatment with the discharge of the treated
groundwater to be combined with the facility's effluent to the City of Salisbury publicly owned
treatment works. The major components of Operable Unit Three Remedial Action include:
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• Design and implement specified groundwater remediation system. The
groundwater remediation alternative includes extraction wells to remove
contaminated groundwater, an air stripper to remove the VOCs from the extracted
groundwater, control of emissions from the air stripper to the atmosphere through
· vapor-phase carbon adsorption filters, and discharging treated groundwater to the
City of Salisbury POTW system.
• Long-term monitoring of the groundwater.
•
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Implement institutional controls .
Conduct a review of the existing groundwater monitoring system to insure proper
monitoring of both groundwater quality and groundwater flow so that the
effectiveness of the groundwater extraction system can be evaluated. Additional
monitoring wells and/or piezometers will be added to mitigate any deficiencies.
Perform five (5) year CERCLA reviews .
ADDITIONAL SAMPLING AND MONITORING
The installation of additional monitoring wells will be required during the Remedial Design to
further delineate the vertical extent of groundwater contamination in the bedrock. Additional
aquifer tests may also be needed in order to properly design the selected remedy. And in order
to establish a broader database on groundwater quality and groundwater levels, samples and
groundwater level readings will be collected and analyzed. on a regular basis prior to
implementation of the Remedial Action.
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the environment, complies with federal
and state requirements that are legally applicable or relevant and appropriate to the remedial
action, and is cost-effective. This remedy utilizes permanent solutions and alternative treatment
technology to the maximum extent practicable, and satisfies the statutory preference for remedies
that employ treatment that reduces toxicity, mobility, or volume as a principal element. Since this
remedy may result in hazardous substances remaining in the groundwater on-site above the
chemical-specific applicable requirements, a review will be conducted within five years after
commencement of remedial action to ensure that the remedy continues to provide adequate
protection of human health and the environment.
Patrick M. Tobin Date
Acting Regional Administrator
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RECORD OF DECISION
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REMEDIAL ALTERNATIVE SELECTION
OPERABLE UNIT #3
NATIONAL STARCH & CHEMICAL COMPANY SITE
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SALISBURY, ROWAN ~OUNTY
NORTH CAROLINA
PREPARED BY:
U.S. ENVIRONMENTAL PROTECTION AGENCY
REGION IV I .
ATLANTA, GEORGIA -I
SEPTEMBER 1993
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TABLE OF CONTENTS
SECTION PAGE No.
INTRODUCTION .......................................................... 17
SITE LOCATION AND DESCRIPTION .......................................... 17
•. 0 SITE HISTORY ................................ · ........................... 18
4.0 ENFORCEMENT ACTIVITIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
l.o HIGHLIGHTS OF COMMUNITY PARTICIPATION .................................. 21
,.0 SCOPE AND ROLE OF RESPONSE ACTION WITHIN SITE STRATEGY ................ 22
7.0 SUMMARY OF SITE CHARACTERISTICS ....................................... 23
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7.1 SOILS ....................................................... 25
7.2 GROUNDWATER ............................................... 25
7.2.1 SAPROLITE GROUNDWATER ............................... 26
7.2.2 BEDROCK GROUNDWATER ................................ 27
7.3 SURFACE WATER AND SEDIMENT ................................. 37
7.4 HYDROGEOLOGICAL SETTING ...............•.................... 42·
7.5 PATHWAYS AND ROUTES OF EXPOSURE ........................... 45
8.1 CONTAMINANTS OF CONCERN ................................... 49
8.2 EXPOSURE ASSESSMENT ...................... _-. . . . . . . . . . . . . . . . 50
8.3 TOXICITY ASSESSMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52
8.4 RISK CHARACTERIZATION ....................................... 56
8.5 RISK UNCERTAINTY ............................................ 58
8.6 ECOLOGICAL RISK . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
8.7 SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60
APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS . . . . . . . . . . . . . . . . . . 60
9.1 ACTION-SPECIFIC ARARS ....................................... 61
9.2 CHEMICAL-.SPECIFIC ARARS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
9.3 Location-Specific ARARs ......................................... . 65
DESCRIPTION OF ALTERNATIVES .......................................... 65
10.1.1 Alternative GWP1 /GWL 1: No action . . . . . . . . . . . . . . . . . . . . . . . . . . 68
10.1.2 ALTERNATIVE GWP2/GWL2: Long Term Monitoring, Fencing
A Portion Of Northeast Tributary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
10.1.3 ALTERNATIVE GWP3/GWL3: Institutional Controls, Long Term Monitoring,
Fencing
A Portion Of Northeast Tributary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
10.1.4 ALTERNATIVE GWP4A/GWL4A: Groundwater Extraction Through Wells;
Treatment by Air Stripping with Vapor-Phase Carbon Adsorption
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. TABLE OF CONTENTS
SECTION PAGE No.
; and Discharge to POTW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
10.1.5 ALTERNATIVE GWP4B/GWL4B: Groundwater Extraction Wells, Treatment
by
Air Stripping with Fume Incineration; and Discharge to POTW . . . . . . . . . . . . 70
10.2 REMEDIAL ALTERNATIVES TO ADDRESS SURFACE WATER AND SEDIMENT
CONTAMINATION ................................................ 70
10.2.1 ALTERNATIVE SW/SE-1: No Action .......................... 70
10.2.2 ALTERNATIVE SW/SE-2: Long-Term Monitoring ................. 71
11.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES .................... . 71
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11.1 THRESHOLD CRITERIA ........................................ .
11.1.1 Overall Protection of Human Health and the Environment .......... .
11.1.2 Compliance with Applicable or Relevant and Appropriate Requirements .
11.2 PRIMARY BALANCING CRITERIA ................................ .
11.2.1 Long0Term Effectiveness and Permanence ..................... .
11.2.2 Reduction of Mobility, Toxicity, or Volume ...................... .
11.2.3 Short-Term Effectiveness .................................. .
11.2.4 Implementability ........................................ .
11.2.5 Cost ................................................. .
11.3 MODIFYING CRITERIA ......................................... .
11.3.1 State of North Carolina Acceptance .......................... .
11.3.2 Community Acceptance ................................... .
DESCRIPTION OF THE SELECTED REMEDY ................. , . . . . . . . . . . . . . . . . . 77
12.1 PERFORMANCE STANDARDS TO BE ATTAINED ..................... 78
12.2 GROUNDWATER REMEDIATION .................................. 80
12.3 NORTHEAST TRIBUTARY SURFACE WATER/SEDIMENT REMEDIATION ... 82
12.4 MONITOR EXISTING CONDITIONS/ADDITIONAL DATA REQUIREMENTS ... 82
12.4 COST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83
13.0 STATUTORY DETERMINATION ....... : ..................................... 83
13.1 PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT ........... 83
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13.2 COMPLIANCE WITH ARARS ..................................... 84
13.3 COST-EFFECTIVENESS ........................................ 84
13.4 UTILIZATION OF PERMANENT SOLUTIONS AND ALTERNATIVE TREATMENT
TECHNOLOGIES OR RESOURCE TECHNOLOGIES TO THE MAXIMUM EXTENT
PRACTICABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84
13.5 PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT ........... 84
SIGNIFICANT CHANGES .................................................. 84
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LIST OF FIGURES
TITLE PAGE No.
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IGURE 1. SITE LOCATION MAP .................. · ...•.•.•......................... 19
IGURE 2 LOCATION OF FACILITIES THAT COMPRISE OPERABLE UNIT #3 .....•.........•..... · 20
IGURE 3 DISTRIBUTION OF 1,2-DCA IN THE WATER TABLE ZONE OF THE AQUIFER ............. 28
ilGURE 4 DISTRIBUTION OF 1,2-DCA IN THE SAPROLITE ZONE OF THE AQUIFER . . . . . . . . . . . . . . . 29
IGURE 5 SAMPLING LOCATIONS FOR GROUNDWATER (WATER TABLE) VIA WELLPOINTS AND
CONCENTRATIONS OF 1,2-DICHLOROETHANE DETECTED AT EACH WELLPOINT .•....... 32
JIGURE 6 SAMPLING LOCATIONS FOR GROUNDWATER (SAPROLITE ZONE) VIA PUSH-POINT SAMPLER, I TEMPORARY MONITORING WELLS, AND SCREENED WATER SAMPLER AND CORRESPONDING
CONCENTRATIONS OF 1,2-DICHLOROETHANE DETECTED AT EACH LOCATION . . . • . . . . . . 33
FIGURE 8 SURFACE WATER SAMPLING LOCATIONS AND CONCENTRATIONS OF 1,2-DICHLOROETHANE FROM I LAST SAMPLING EFFORT ON THE NORTHEAST TRIBUTARY . . . . . . . . . . . . • . . . . . . . . . . 40
IGURE 9 SEDIMENT SAMPLING LOCATIONS AND CONCENTRATIONS OF 1,2-DICHLOROETHANE FROM LAST
SAMPLING EFFORT ON THE NORTHEAST TRIBUTARY .........•................. 41
IIGURE 10 ORIENTATION OF CROSS-SECTIONAL A-A' . . . . . . . . . . . . . . . • . • . . . . . . • . . • . . . . . . . 43.
IGURE 11 HYDROGEOLOGICAL CROSS-SECTION A-A' . . . . . . . . . . . • . . . . . . . . . . . . • . . . . . . . . . . 44
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IIABLE 1
.,ABLE 2
LIST OF TABLES
TABLE TITLE PAGE No.
RANGE AND FREQUENCY OF DETECTION OF ORGANIC CONTAMINANTS AND INORGANIC
CONSTITUENTS FOUND IN THE ENVIRONMENTAL MEDIA SAMPLED ......••........... 24
FREQUENCY OF DETECTION AND CONCENTRATIONS OF ORGANIC CONTAMINANTS DETECTED IN
GROUNDWATER SAMPLES COLLECTED FROM WELLPOINTS (WATER TABLE) AND PERMANENT
MONITORING WELLS NS-13 AND NS-14 ..........••....................... 30
FREQUENCY OF DETECTION AND CONCENTRATIONS OF VOLATILE ORGANICS DATA FOR
GROUNDWATER SAMPLES COLLECTED FROM PUSH-POINT SAMPLES, TEMPORARY MONITORING
I WELLS, AND SCREENED WATER SAMPLER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
ABLE 4 FREQUENCY OF DETECTION, CONCENTRATIONS DETECTED, AND MOST STRINGENT PROMULGATED
GROUNDWATER STANDARDS FOR CONTAMINANTS DETECTED IN THE SAPROLITE ZONE OF THE I AQUIFERFIGURE 7 CONCENTRATIONS AND ESTIMATED EXTENT OF 1,2-DICHLOROETHANE
CONTAMINATION IN THE BEDROCK ZONE OF THE AQUIFER . . . . . . . . . . . . . . . . . . . . . . . 35
TABLE 5 FREQUENCY OF DETECTION, CONCENTRATIONS DETECTED, AND MOST STRINGENT PROMULGATED
I ~~i1~~~w~~~~ ~~~~~~~~s-~~~ ~-~N-T~~'.N_A_N_T~ -~~T-E~~~~ ~~ :~~ _B_E_D_R~~~ -~~N·E· ~~ ~-H·E 36
TABLE 6 SUMMARY OF DETECTABLE CONCENTRATIONS OF 1,2-DICHLOROETHANE IN SURFACE WATER,
I SEDIMENT, AND SOIL SAMPLING OF THE NORTHEAST TRIBUTARY . . . . . . . . . . . . . . . . . . 38
ABLE 7 CONCENTRATIONS OF ORGANICS AND INORGANICS IN SURFACE WATER AND SEDIMENT FROM
LOCATIONS SW/SE-12 AND SW/SE-13 .................•.................. 39
IABLE 8 CHEMICALS OF POTENTIAL CONCERN ............ , . . . . . . . . . . . . . • . . • . . . . . . . . . . 46
ABLE 9 POTENTIAL CURRENT AND FUTURE EXPOSURE PATHWAYS OF HUMAN EXPOSURE To
CONTAMINANTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48-
jABLE 10 CHEMICALS OF CONCERN POSING RISK ..............•................ -...... 51
■ABLE 11 UPPER CONFIDENCE LIMITS (95%) FOR CHEMICALS AND ASSOCIATED USED TO EVALUATE RISK
CONDITIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
.ABLE 12 PARAMETERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN . 54
.ABLE 13 ESTIMATED POTENTIAL CURRENT/FUTURE CARCINOGENIC/NONCARCINOGENIC RISKS ASSOCIATED .
WITH OU #3 . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . . . . . • • . • . • . . . . . . . . . . • . 55
jABLE 14 SUMMARY OF CARCINOGENIC_ EFFECTS OF CHEMICALS OF POTENTIAL CONCERN . . . . . . . . 57
ABLE 16 ACTION-SPECIFIC AND OTHER CRITERIA To BE CONSIDERED . . • . . • . . . . . . . . . . . . . . . . 62
ABLE 17 CHEMICAL-SPECIFIC AND OTHER CRITERIA To BE CONSIDERED ..................... 63
TABLE 19 LOCATION-SPECIFIC ARARs AND OTHER CRITERIA To BE CONSIDEREDTABLE 20
I SECONDARY SCREENING OF TECHNOLOGIES AND PROCESS OPTIONS FOR GROUNDWATER . . . 67
ABLE 21 SUMMARY OF THE THRESHOLD CRITERIA EVALUATION OF THE ALTERNATIVES ........... 72
TABLE 22 SUMMARY OF PRIMARY BALANCING CRITERIA EVALUATION OF THE ALTERNATIVES . . . . . . . . 75
tBLE 23 PERFORMANCE STANDARDS AND CORRESPONDING RISKS FOR OU #3 . . . . . . . . . . . . . . . . 79
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• ARAR
AWQC
CAA I CERCLA
cm/sec
I CRP
CSF
CWA
I ESD
EPA
FS
GAC
I gpm
HI
HQ
I HRS
LDRs
MCLs
I MCLGs
mg/kg
mph
MW
I NCAC
NCDHR
NCDNRCD
I NCDEHNR
NCGS
NCP
NOAA I NPDES
NPL
O&M
I PAHs
PCBs
POTW
I ppm
PRP
PW
RA I RCRA
RfD
RD
I RI
RME
ROD
I SAR.A.
SOWA
SFFRs
SVOCs
I TAL
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LIST OF ACRONYMS
Applicable or Relevant and Appropriate Federal, State or Local Requirements
Ambient Water Quallty Criteria
Clean Air Act
Comprehensive Environmental Response, Compensation, and Liabillty Act of 1980 -
(Supertund)
centimeters per second
Community Relations Plan
Cancer Slope Factor
Clean Water Act
Explanation of Signtticant Difference
Environmental Protection Agency
Feasibillty Study
Granular Activated Carbon
gallons per minute
Hazard Index
Hazard Quotient
Hazardous Ranking System
Land Disposal Restrictions
Maximum Contaminant Levels
Maximum Contaminant Level Goals
milligrams per kilogram
miles per hour
Monitoring Well
North Carolina Administrative Code
North Carolina Department of Human Resources
North Carolina Department of Natural Resources and Community Development
North Carolina Department of Environment, Health, and Natural Resources
North Carolina General Statute
National Oil and Hazardous Substances Pollution Contingency Plan
National Oceanic and Atmospheric Administration
National Pollution Discharge Elimination System
National Priority List
Operation and Maintenance
Polycyclic Aromatic Hydrocarbons
Polychlorinated Biphenyls
Publicly Owned Treatment Works
parts per million
Potentially Responsible Party
Present Worth
Remedial Action
Resource Conservation and Recovery Act
Reference Dose
Remedial Design
Remedial Investigation
Reasonable Maximum Exposure
Record of Decision
Supertund Amendments and Reauthorization Act of 1986
Safe Drinking Water Act
Submerged Fixed Film Reactors
Semi-volatile Organic Compounds
Target AnalY1e List
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TBC
TCL
TCLP
TMV
ug/kg
ug/1
UV/OX· voes
To Be Considered
Target Compound List
Toxicity Characteristic Leaching Procedure
Toxictty, Mobiltty, or Volume ·
micrograms per kilogram
micrograms per liter
Ultraviolet/Oxidation
Volatile Organic Compounds
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RECORD OF DECISION
SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
OPERABLE UNIT THREE
NATIONAL STARCH & CHEMICAL COMPANY SUPERFUND SITE
SALISBURY, ROWAN COUNTY, NORTH CAROLINA
1.0 INTRODUCTION
The National Starch & Chemical Company Superfund Site (NSCC Site or the "Site") was
proposed for inclusion on the National Priorities List (NPL) in April 1985, re-proposed in June
1988, and finalized on the list in October 1989 with a Hazardous Ranking System (HRS) score
of 46.51. The HRS score was based on the following exposure route scores: exposure via
groundwater pathway -80.46, exposure via surface water pathway -0.00, and exposure via air
pathway -0.00. Currently, the Site is cataloged as Number 257 of the 1,249 Superfund sites
across the country on the NPL.
The Site has been divided into four Operable Units (OU). The area of the NSCC facility
addressed by each operable unit is summarized b_elow:
OU #1 Groundwater in. western portion of the NSCC property
OU #2 Trench Area soils and surface water/sediments in the Northeast Tributary
OU #3 Groundwater under Area 2, the parking lot, and the wastewater treatment lagoons
and the surface water/sediments in the Northeast Tributary
OU #4 Contaminated soils in and around Area 2 and the wastewater treatment lagoons.
The NSCC OU #3 Remedial Investigation and Feasibility Study (RI/FS) is complete. The June
2, 1993 RI Report, conditionally approved by the Agency on July 7, 1993, identified the source,
characterized the nature, and defined the probable extent of the uncontrolled hazardous wastes
in the soil, groundwater, and surface water/sediment in the area addressed by this Operable Unit.
The OU #3 RI Report included a Baseline Risk Assessment. The Baseline Risk Assessment
defined the risk posed by the hazardous wastes present in the area investigated as part of OU
#3. The Proposed Plan Fact Sheet, based on the June 21, 1993 OU #3 FS document, provided
the public a summary of the detailed analysis of the five (5) remedial alternatives for groundwater
remediation and two (2) remedial alternatives for surface water/sediment in the Northeast
Tributary.
This Record of Decision (ROD) has been prepared to summarize the remedial selection process
and to present the selected remedial alternative. OU #4 will focus on the contaminated soils in
Area 2 and around the treatment lagoons.
2.0 SITE LOCATION AND DESCRIPTION
The NSCC Site is located on Cedar Springs Road in Salisbury, Rowan County, North Carolina.
The Site is approximately 5 miles south of the City of Salisbury at latitude 35°37'49" north and
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DRAFT
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NATIONAL Sr>JPi & CHEMICAL CoMPANY SUPERAJNO SITE
DRAFT RECOIi> OF DECISION FOR OPER.481..E UNIT #3
--SEPTB.eER 1, 199ai7:21AM
longitude 80°32'03" west. Figure 1 shows the location of the Site with respect to the City of
Salisbury. The areas of the Site that compose OU #3 are shown in Figure 2. OU #3 includes
the following areas of the NSCC facility: Area 2, the parking lot, the Northeast Tributary, and the
wastewater treatment lagoons. Area 2 consists of the following operations: Area 2 Reactor Room,
the Tank Room, Raw Material Bulk Storage, and the Warehouse. The lagoon area includes three
lagoons which were constructed between 1969-1970 as unlined lagoons. Wastewater was
pumped into Lagoon 2 from 1970 to 1978. In 1978, Lagoon 1 was put into service and Lagoon
3 was lined with concrete. Lagoons 1 and 2 were originally used as settling and evaporation
lagoons. In 1984, Lagoons 1 and 2 were excavated and also lined with concrete. Contaminated
soil excavated from beneath the lagoons was removed and disposed of in an area west of the
plant area. The saturated soil was landfarmed and then used as fill material for expanding the
facility's parking lot. A fourth lagoon was installed in 1992 as part of the treatment system to treat
the contaminated groundwater generated by the OU #1 Remedial Action (RA). In the remainder
of this ROD, the term "Site" refers to the areas investigated as part of OU #3 (i.e., Area 2, the
lagoon area, and the Northeast Tributary) unless otherwise specified.
Land use of the areas immediately adjacent to the NSCC property is a mixture of residential and
industrial developments. An industrial park is located on the east and south sides of the Site.
Another industrial park is located along the southern property line. A mobile home park adjoins
the extreme southwestern corner of the NSCC property. Two housing developments lay to the
north, one of which is adjacent to the facility property. The location of the nearest private, potable
wells is approximately 2,700 feet north of Area #2.
3.0 SITE HISTORY
In September 1968, Proctor Chemical Company purchased the 465-acre tract of land ori Cedar
Springs Road. Within the next year, Proctor Chemical was acquired by NSCC which operated
the facility as a separate subsidiary. Construction of the plant on Cedar Springs Road began in
1970. On January 1, 1983, Proctor Chemical Company was dissolved and its operations merged
with NSCC.
The primary products cit this facility are textile-finishing chemicals and custom specialty chemicals.
Volatile and semi-volatile organic chemicals are used in the production process along with acidic
and alkaline solutions. Acidic and alkaline solutions are also used in the cleaning processes.
The liquid waste stream from the manufacturing processes include reactor and feed line wash and
rinse solutions. This wastewater may include a combination of the following chemicals:
acrylimide, 1,2-dichloroethane (1,2-DCA), methyl isobutyl ketone, methanol, styrene, maleic
anhydride, vinyl toluene, sulphonated polystyrene, epichlorohydrin, octyl alcohol, ethyl alcohol,
allyl alcohol, allyl chloride, sodium hydroxide, and sulfuric acid.
As the result of finding contaminants in groundwater and in the surface water/sediment of the.
Northeast Tributary, the original scope of work specified in the initial 1987 Remedial
Investigation/Feasibility Study Work Plan was expanded. The first Remedial Investigation and
Feasibility Study resulted in OU #1 ROD which was issued by the Agency on September 30,
1988. The OU #1 ROD divided the Site into two Operable Units. The ROD for OU #1 required
the installation of a groundwater interception, extraction, and treatment system in the western
portion of the facility. The contaminants in the groundwater in this area are emanating-from the
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801
Will.
BRIOC
NATIONAL
STARCH SITE
c1WlTS <11-.61;
KANNAPLOIS
DAVIDSON
COUNTY
E. SPDICER 'seF
----CABARRUS COUNTY
SCALE: - -
HICH~
ROCK
LJ,K(
COUNTY
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---0 8 16 MILES
FIGURE 1
LOCATION OF THE NATIONAL STARCH &
CHEMICAL COMPANY SUPERFUND SITE
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AIRPORT ROAD
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500 0 500 1000 ~-250 750
GRAPHIC SCALE: 1 '=500'
-I!!!!! !!!!!!!I
-1---1-
FIGURE 2
LOCATION OF FEATURES ASSOCIATED
WITH OPERABLE UNIT #3
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DRAFT NATIONAi.. STAOO-i & CHEMICAL. CoMPANY SUPERAJND SITE
~ Recom OF DECISION FOO OPEIW3LE UNIT #3
SEPIBeEA 1, 1993/7:21.A.M
-18-
trench area. OU #2 further investigated the contaminated soils in the trench area along with
additional monitoring of the surrounding tributaries. OU #2 ROD was signed on September 28,
1990 and required additional work to identify, characterize, and delineate the contamination being
continuously detected in the Northeast Tributary. This investigation has resulted in the evolution
OU #3 and OU #4.
The Potentially Responsible Party (PRP) has performed OU #1, OU #2, and OU #3 under the
direction and requirements specified in the Administrative Order on Consent (AOC) signed by the
Agency and PRP in December 1986.
4.0 ENFORCEMENT ACTIVITIES
Since there has only been one owner/operator of this property after being developed into an
industrial complex, no "Responsible Party Search" was performed. The PRP for the Site is
National Chemical Starch & Chemical Company (the prior/current owner/operator).
A special notice letter was sent on May 30, 1986 to provide NSCC an opportunity to conduct the
RI/FS. A good faith offer was submitted and negotiations were concluded with NSCC signing an
AOC on December 1, 1986.
Following the signing of OU #1 ROD, the Agency sent a special notice letter to the PRP to initiate
negotiations on a Consent Decree (CD) for implementing the OU #1 Remedial Design/Remedial
Action (RD/RA). However, negotiations on the CD were not successful resulting in the Agency
issuing an Unilateral Administrative Order (UAO) directing NSCC to design and implement the RA -
specified in the OU #1 ROD. The effective date of the UAO was July 27, 1989. Following the
signing of the OU #2 ROD, the Agency sent the PRP another special notice letter in March 1991
to initiate negotiations on a second CD. The CD governing the implementation of the RA required
by OU #2 ROD was signed in August 1991. The OU #2 CD was entered by the Federal Court
on July 20, 1992.
NSCC will be provided an opportunity to conduct the OU #3 RD/RA as specified in this ROD
through the issuance of a third RD/RA special notice letter.
5.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION
Community relations activities for this Site were initiated in 1986, in conjunction with the
development of the RI/FS Work Plan. In developing the August 1986 Community Relations Plan,
the issues and concerns expressed by local citizens from the Site area were compiled and an
overview of these issues and concerns was prepared. A copy of the Community Relations Plan
was placed in the Information Repository located at the Rowan County Public Library. A mailing
list was developed based upon people interviewed, citizens living around the Site, and people
attending the public meetings. The mailing list also includes local, State, and Federal public
servants and elected officials.
Several fact sheets and public meetings were held with respect to OU #1 and OU#2. The
following community relations activities were conducted by the Agency with respect to-OU #3.
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DRAFT NATIONAL ST,iJ¥;H & CHEMICAL COMPANY SUPERRJND SITE
£B.fil RECOID OF DECISION FOR OPERABI.E UNIT #3
SEPIDeER 1, 1993/7:21>.M
-19-
Two fact sheets and the Proposed Plan Fact Sheet were distributed to the public during the OU
#3 RI/FS. The first fact sheet, disseminated in June 1991, provided the community a status
report of activities associated with all three (3) Operable Units. This Fact Sheet provided a brief
history of the Site, a summary of current activities at the Site, a brief overview of the Superfund
program, and a list of contacts for more information. A second Fact Sheet was distributed in June
1993. This fact sheet summarized the findings and conclusions of the OU #3 RI Report which
included the Baseline Risk Assessment, and provided a revised time frame for future activities
at the Site. A flyer was also distributed in June 1993 informing the public of a change in the
Agency's personnel associated with the management of the Site.
The public was informed through the Proposed Plan Fact Sheet and an ad published on July 19,
1993 in The Salisbury Post and The Charlotte Observer newspapers of the August 3, 1993
Proposed Plan Public Meeting. The Proposed Plan Fact Sheet was mailed to the public on July
15, 1993. The basis of the information presented in the Proposed Plan was the June 21, 1993
FS document. A press release reminding the public of the upcoming public meeting was also
issued on July 30, 1993. The Proposed Plan also informed the public that the public comment
period would run from July 19, 1993 to August 17, 1993.
The. goals of the Proposed_ Plan meeting were to review the remedial alternatives developed,
identify the Agency's preferred alternative, present the Agency's rationale for the selection of this
alternative, encourage the public to voice its own opinion with respect to the remedial alternative
reviewed and the alternative selected by the Agency, and inform the public that the public
comment period on the Proposed Plan would conclude on August 17, 1993. The public was also
informed a 30 day extension to the public comment period could be requested and that all
comments received during the public comment period would be addressed in the Responsiveness -
Summary.
On Wednesday, August 11, 1993, the Agency received a request for a 30-day extension to the
public comment period which extended the public comment period to midnight September 16,
1993. A notice was mailed on August 18, 1993 to the addressees on the mailing list informing
them of this extension. An ad was also published in the August 24, 1993 edition of The Salisbury
Post and The Charlotte Observernewspapers informing the public that the public comment period
had been extended to September 16, 1993.
Pursuant to Section 113(K)(2)(B)(i-v) and 117 of CERCLA, all documents associated with the
development of the Proposed Plan and the selection of the remedial alternative specified in this
ROD were made available to the public in the Administrative Record located both in the
Information Repository maintained at the EPA Docket Room in Region IV's office and at the
Rowan County Public Library in Salisbury, North Carolina.
6.0 SCOPE AND ROLE OF RESPONSE ACTION WITHIN SITE STRATEGY
The intent of the remedial action presented in this ROD is to restore the aquifer to drinking water
quality in the eastern portion of the NSCC property. This remedial action involves the extraction
and treatment of the contaminated groundwater at the Site. Remediation of contaminated soils
associated with this area of the NSCC facility will be the focus of OU #4. This is the third of four
RODs contemplated for the Site.
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DRAFT NATIONAL STA!Ui & CHEMICAL CoMPANY SUPERRJND SITE
£.B.fil REC0F{) OF DECISION FOO OPERABLE UNIT #3
SEP'TB.eER 1, 1993/7:21AM
-20-
7.0 SUMMARY OF SITE CHARACTERISTICS
The overall nature and extent of contamination associated with OU #3 is based upon analytical
results of environmental samples collected from surface and subsurface soils, the groundwater,
Northeast Tributary surface water and sediment, and the chemical/physical and
geological/hydrogeological characteristics of the area. Environmental samples were collected
over a period of time and activities. The majority of the samples collected during the OU #3 RI
were screened for volatile organic compounds (VOCs) as the previous Rl's conducted at the
NSCC facility identified voes as the primary contaminants at the Site. A review of the historical
use of chemicals in the manufacturing processes at the Site also supports this appraisal. The
remainder of the samples were analyzed for the entire target compound list (TCL) and target
analyte list (TAL) constituents. The TCL includes voes, semi-volatile organic compounds
(SVOCs), pesticides, and polychlorinated biphenyls (PCBs); the TAL includes inorganics such as
metals and cyanide.
voes, SVOCs, one pesticide, and numerous inorganic analytes were detected in the soils and
groundwater and two VOCs and a number of metals were detected in the surface water/sediment
samples. Based on information reported by NSCC, the waste stream piped to the treatment
lagoons is a RCRA listed waste ( ddefine type of RCRA waste ).
Backgrnund/control samples were collected for groundwater and surface water and sediment.
No background surface or subsurface soils samples were collected for OU #3. Therefore, any
organic contaminant detected in the soils that could not be attributed to cross contamination, was
presumed to be a Site related contaminant. The inorganic analytical data generated for the
upgradient sediment sample (SE-12), collected from the Northeast Tributary, was used for-
comparison for surface and subsurface soils.
Table 1 lists the contaminants detected in each environmental medium sampled as well as the
frequency and range of concentrations detected. As can be seen, no PCBs were detected in any"
of the environmental samples collected. The pesticide detected at the Site was delta-
hexachlorocyclohexane (delta-BHC). It was detected once in the soil and once in the
groundwater at very low concentrations. Pesticides have never been manufactured at this facility.
Cyanide was detected twice in the soil and twice in the groundwater at very low concentrations.
The concentrations of both delta-BHC and cyanide are below health base clean up goals. · Based
on the above information, the following contaminants or group of contaminants will not be
discussed in the following sections: PCBs, pesticides,and cyanide. The following sections
discuss the results and interpretations of the data collected and generated for each environmental
medium investigated as part of OU #3 RI.
Air samples were not collected as part of the OU #3 RI/FS effort. However, the air was monitored
during the RI field work as part of the health and safety effort. Based of the information collected,
the quality of the air at and around the Site is not currently being adversely impacted by the Site.
The PRP also runs routine air sampling in the active portions of the facility as part of their
internal, corporate health and safety procedures. The facility itself is under a State of North
Carolina air permit, Permit Number .!YM\!.
The estimated volume of groundwater impacted is approximately 131 million gallons.
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TABLE 1 RANGE AND FREQUENCY OF DETECTION OF ORGANIC CONTAMINANTS AND
INORGANIC CONSTITUENTS FOUND IN THE ENVIRONMENTAL MEDIA SAMPLED
COMPOUND SOIL GROUNDWATER SURFACE SEDIMENT
WATER
Acetone 22-4,000 (40) 9-4,200 (15) 18-52 (3) 12-63 (7)
Bis{2-chloroethyl)ether 13-32 (2)
Bromodichloromethane 1-220 (7)
2-Butanone 3-42 (30)
Carbon Disulfide 4-8 (3)
Chloroethane 3-35 (6)
Chloroform 2-900 (17) 7-8,900 (2)
Dibromoch_loromethane 3-31 (5)
1,2-Dichloroethane 2-1,600,000 (42) 1-660,000 (30) 2-3,200 (7) 9-1,000 (5)
1, 1-Dichloroethene 1-14 (3)
1,2-Dichloroethene 1-200 (4)
1,2-Dichloropropane 5
Ethylbenzene 9-36 (2)
Methylene Chloride 1-160 (5)
Tetrachloroethene 2 107 (4)
Toluene 1-3,100 (12) 1-120 (3)
1, 1,2-Trichloroethane
Trichloroethane . 11-17 (2) 1-5 (10)
Total Xylenes 2-90 (4)
Vinyl Chloride 32-190 (12) 1-120 (8)
Bis(2-elhylhexyt}phthalate 8
Di-n-butyt Phlhalate 2-17 (3)
Di-n-octyt Phthalate
I
I TABLE 1 RANGE AND FREQUENCY OF DETECTION OF ORGANIC CONTAMINANTS AND
I INORGANIC CONSTITUENTS FOUND IN THE ENVIRONMENTAL MEDIA SAMPLED
COMPOUND SOIL GROUNDWATER SURFACE SEDIMENT
I WATER
Delta-Hexachlorocyclohexane 22 0.16
I Antimony 5, 100-8,2000 (5) 7.6 (1)
I Arsenic 530-2,900 (7) 2.4 1.1-1.9 (2)
Barium 33,300-198,000 28.2-737 (8) 32.1-38.2 (2) . 50.3-88.4 (2)
I (7)
Beryllium 240-680 (7) 1-2.5 (2) 0.49-0.98 (2)
I Chromium 10,000-97,900 12.9-59.6 (6) 35.1-36.5 (2)
(7)
Cobalt 13,700-74,100 47-66.4 (2) 23.6-28 (2)
I (7)
Copper 46,700-161,000 12.4-23.7 (2) 48.4-90.3 (2)
(7)
I Cyanide 2,500-21,900 (2) 12-16 (2) ..
Lead 1,300-9,400 (7) 3.3-3.9 (2) 3,15.1 (2) I Manganese 382,000-1.5-12,000,000 (14) 60-134 (2) 162-1,020,000 (2)
. 2,610,000 (7)
I Mercury 0.05-0.06 (2)
Nickel 4,900-22,900 (7) 23.4-39.6 (3) 10.3-11.6 (2)
I Selenium 0.88
Thallium 2,500-2,600 (2) 0.38
I Vanadium 71,600-379,000
(7)
10.7-272 (11) 14.8-24.4 (2) 146-176 (2)
Zinc 19,700-50,000 22-6,410,000 (4) 10.3-11:4 (2) 23.9-48.5 (2) I (7)
Concentrations for water samples are reported in micrograms per liter {µg/1) or in parts per billion (ppb). g Concentrations for soil/sediment samples are reported in milligrams per kilogram {mg/kg) or in parts per billion {ppb).
Number appearing in parentheses is the frequency of detection.
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DRAFT NATIONAi.. Sr..vni & CHEMICAi.. CoMPNN SUPERRJNO SITE
.Q!!_m AECORO OF DECISION FOR OPEFW31..E UNIT #3
SEPTB.eER 1, 1993/7:21AM
-22-
7.1 SOILS
A total of 107 soil samples were collected to identify the source, characterize the contaminants
present, and delineate the extent of soil contamination. The soil samples were collected from 59
different locations. These soil samples included 11 surface soil samples (0 to 2 feet below the
surface) with the rest being collected between 2 feet below surface to either the water table
interface or auger refusal.
VOCs, SVOCs, one pesticide, and inorganics were detected in the soils. To summarize the
tabulated analytical results for all the soil samples, a total of 14 different voes, one (1) SVOC,
one (1) pesticide, 14 metals, and cyanide was detected. As can be seen in Table 1, the voes
detected most frequently and in the highestconcentrations are acetone, 2-butanone, chloroform,
dibromochloromethane, 1,2-DCA, and toluene (listed alphabetically). A variety of metals were
also detected in the soils. Although these metals occur naturally in soil, elevated concentrations
of 7 metals were detected. The following metals were either detected in onsite soils but not in
the background soil sample or detected onsite at concentrations at least two limes greater than
the background concentration: barium, chromium, cobalt, copper, manganese, nickel, and
vanadium.
In general, the greatest concentrations of organic contaminants were found in two (2) areas. In
the soils underneath Area 2 and north-northeast of the lagoon area. The majority of the elevated
levels of metals were detected in Area 2. Based on the information generated and collected as
part of the OU #3 RI, the following sources of contamination have been identified. In Area 2, the
source of contamination has predominantly been the underground terr-cotta piping. The terra-
cotta piping was used to transported wastewater from the production area to the lagoons as well -·
as control and direct surface water run-off from the plant area to the embankments of the
Northeast Tributary. Currently, NSCC is replacing these buried lines with overhead, stainless
steel pipes. NSCC has also controlled surface water runoff from Area 2 through the use of berms
and sumps. The berms and the grade of the paved surfaces direct the surface runoff into the·
sumps. The surface water runoff .collected in the sumps is then pumped through above ground
pipes to the treatment lagoons. As the underground terra-cotta pipe lines are abandoned, the
ends of each section are pressure grouted to ensure that these pipe lines will no longer act as
conduits. NSCC projects that the installation of the overhead piping arrangement and
abandonmenUgrouling of the underground terra-cotta pipes will be completed in December 1993.
In the lagoon area, the source of contamination was eliminated in 1983 when the PRP lined its
· lagoons with concrete. The contamination being detected currently in the soils and groundwater
in this area is the result of past practices and the residual contamination in the soil.
A more detailed discussion of the contaminants detected in the soils will be incorporated into the
OU #4 ROD.
7.2 GROUNDWATER
The saprolite and bedrock zones of the aquifer have also been adversely impacted by activities
at the Site. Contaminants detected in the groundwater include VOCs, SVOCs, one pesticide,
metals, and cyanide. The pesticide, delta-BHC, was detected in one sapro!ite groundwater
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DRAFT NA.TIONAL STAFCH & CHEMICAL CoMPANY SUPERRJND SITE
~ AECOR:l OF DECISION FOR OPERABt..E UNIT 13
SEPTEt.eER 1, 1993/7:21AM
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sample (NS-42) at 0.16 micrograms per liter (µg/I). Cyanide was detected twice at concentrations
of 16 µg/1 and 12 µg/I at locations NS-13 (a saprolite well) and NS-42, respectively. Table 1
provides a complete list of contaminants detected in the groundwater along with the frequency
of detections and the range of concentrations detected. The greatest concentrations of organic
contaminants in the groundwater were found underneath and north of Area 2 and north of the
lagoon area. In Area 2, contamination can be found throughout the entire aquifer. In the lagoon
area, the highest concentrations detected were in the bedrock zone of the aquifer.
A total of 66 groundwater samples were collected from 52 different locations. All of the
groundwater samples were analyzed for VOCs. Only the groundwater samples collected from
the permanent monitoring wells ·were analyzed for the full analytical analyses. To summarize the
analytical results, a total of 16 different voes, three (3) semi-volatile organic compound (SVOC), .
one (1) pesticide, 14 metals, and cyanide was detected in the groundwater. voes detected in
concentrations that exceed either Federal MCLs or State groundwater quality standards include
(listed alphabetically) acetone, bis(2-chloroethyl)ether, bromodichloromethane, 2-butanone,
chloroform, 1,2-dichloroethane, 1, 1-dichloroethene, cis 1,2-dichloroethene, trans 1,2-
dichloroethene, 1,2-dichloropropane, ethylbenzene, methylene chloride, tetrachloroethene,
toluene, total xylenes, 1, 1,2-trictiloroethane, trichloroethene, and vinyl chloride. The three SVOCs
detected in the groundwater belong to family of organic compounds called phthalates. Numerous
metals were also detected in the groundwater. The inorganics that were detected at
concentrations exceeding two times the concentration found in the background groundwater
samples included: arsenic, barium, beryllium, chromium, cobalt, copper, cyanide, lead,
manganese, nickel, vanadium, and zinc.
Groundwater samples from the water table were collected through a variety of methods. Thirteen .
(13) samples were collected through wellpoints, five (5) groundwater samples were collected
employing a push-point water sampler, twelve (12) groundwater samples were collected from
temporary wells, and nineteen (19) groundwater samples were collected using a screen water
sampler. In addition to collecting groundwater samples from the water table, groundwater
samples were collected from the six (6) saprolite and six (6) bedrock monitoring wells that were
also installed as part of this investigation. The depth of the saprolite wells ranged between 13
to 80 feet. The depth of the bedrock wells ranged in depth of 39 to 135 feet. The depth to the
water table ranged from ground surface at the Northeast Tributary to approximately 33 feet below
ground surface.
The RI did not generate sufficient data to completely define the vertical extent of groundwater
· contamination. It is estimated that the bedrock is fractured to approximately 200 feet below
surface. The deepest bedrock well (NS-41) installed to date in this area of the facility goes to a
depth of 135 feet. The groundwater sample collected from this well showed elevated levels of
voe contamination. Additional information to address this data gap will be collected during the
remedial design (RD).
7.2.1 SAPROLITE GROUNDWATER
Figures 3 and 4 show the distribution of 1,2-DCA at the water table and in the saprolite zone of
the aquifer, respectively. The isopleths shown in Figure 3 are based on the data presented in
Tables 2 and 3. Figures 5 and 6 show the sampling locations and analytical results for-1,2-DCA
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DRAFT
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NATIONAi.. SJAJUi & CHEMICAL CoMPANY SUPERRJNO SITE
CRAFT AECO~ OF DECtSai FOR OPERABLE UNIT #3
SEPTa.eER t, 1993/7:21>.M
for the data presented in Tables 2 and 3, respectively. The isopleths presented in Figure 4 are
based on the data displayed in Table 3 and 4. Figure 4 also shows the locations of the
permanentsaprolite monitoring wells and the corresponding concentrations of 1,2-DeA detected
in each well.
Wellpoints, push-point, temporary wells, and screen water samplers were used to collected
groundwater samples at the water table interface. Table 2 lists the frequency of detection and
the concentrations of voes detected at each wellpoint. Table 3 provides the frequency of
detection and the concentrations of voes found in the groundwater samples collected by means
of the push-point, temporary wells, and screen water samplers. Table 4 provides the frequency
of detection, the concentrations of contaminants detected in the permanent wells installed to
monitor groundwater quality in the saprolite zone of the aquifer, and the promulgated groundwater
standards. The highest concentration and the greatest variety of voes were found in monitoring
well NS-42. voes detected in NS-42 include acetone (31 O µg/1), 2-butanone (240 µg/I), 1,2-DeA
(82,000 µg/I), methylene chloride (160 µg/I), and toluene (220 µg/1).
As can be seen in Figure 4, there are two plumes of contamination in the groundwater in the
saprolite zone. One is emanating from Area 2 and the other one originates in the lagoon area.
Both plumes have migrated approximately 400-500 feet from their source in a northerly direction.
The concentrations detected in the lagoon area are greater in the groundwater than in the
unsaturated soils. This indicates that the contaminants are being flushed out of the unsaturated
soils through the natural processes of precipitation and percolation.
Monitoring well NS-37 had the largest variety of inorganics detected and typically the highest
concentrations of inorganic constituents as well. The metals detected in NS-37 which were twice -
the background concentration were barium (737 µg/1), beryllium (2.5 µg/1), chromium (63.6 µg/1),
cobalt (66.4 µg/1), copper (487 µg/1), manganese (1,500 µg/I), nickel (39.6 µg/1), vanadium (272
µg/1) and zinc (220 µg/I).
7.2.2 BEDROCK GROUNDWATER
Figure 7 shows the distribution of 1,2-DeA in the bedrock zone of the aquifer. This figure also
shows ttie locations of the permanent bedrock monitoring wells and the corresponding
concentrations of 1,2-DeA detected in each well. Table 5 lists the frequency of detection, the
concentrations of contaminants detected in eacli bedrock well, and the promulgated groundwater
standards. The highest total concentration of volatiles and the greatest variety of volatiles were
found in monitoring well NS-40. voes detected in NS-40 included bis(2-chloroethyl)ether (32
µg/1), 1,2-DeA (99,000 µg/I), 1, 1-dichloroethene (5 µg/1), methylene chloride (66 µg/1),
tetrachloroethene (7 µg/1), 1,.1,2-trichloroethane (6 µg/I), total xylenes (11 µg/I), and vinyl chloride
(120 µg/I).
Monitoring well NS-38 had the largest variety of inorganics detected and typically the highest
concentrations as well. The metals detected in NS-38 which were twice the background
concentration were barium (635 µg/1), chromium (13.3 µg/I), cobalt (93.6 µg/1), and manganese
(12,000 µg/1).
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N 250 -
ABANDONED
RAILROAD SPUR
CHAIN LINK FENCE---~
z
\
3J
,,::-,
------,,·, "
:'/ ND ,,
. -: ;'----. -<~::,,----.'·
E 250
LEGEND
NO GAOUNDNATER SCREENING POINT
6 SHOWING 1.2-0CA CONCENTRATION
(ppb)
-..• _
1
_ 1.2-DCACONCENTRATION
t 0000 _/ C~OUA
FIGURE 3
NOTE: Confirmation data
supplemented Dy groul"\dWater
screening data
0 c§
a:
(/)
C!) z ~ (/)
a: c§
UJ
(J
APPROXIMATE SCALE (ft)
1 00 :lOO 300 ~ SCIO
CONCENTRATIONS AND ESTIMATED
EXTENT OF 1,2-DICHLOROETHANE
CONTAMINATION IN THE GROUNDWATER
AT THE WATER TABLE
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1050
750
,so
150
-150 -
-◄50
.750 I
-650
• NS-37
(1 J)
ABANDONED RAILROAD SPUR;-------:-
,,, ' .... ,,, ,,, __ ..
-350 -50
,,,
' I
' I '
250
NS-33
• (ND) I I
550
I I /!
I I
LEGEND
1
• NS-13
(1700)
0
c§ a: en (!l z ii: a.. en a: i3
UJ
t)
1.2·0CA CONCENTRATION
GPNTOUA (ppb)
1,2-0CA CONCENTRATION
(ppb), GROUNDWATER
SAMPLES
SCALE (ft)
FIGURE 4
CONCENTRATIONS AND
ESTIMATED EXTENT OF
1,2-DICHLOROETHANE
CONTAMINATION IN THE
SAPROLITE ZONE OF
THE AQUIFER
-------------------
TABLE 2 FREQUENCY OF DETECTION AND CONCENTRATIONS OF ORGANIC CONTAMINANTS DETECTED IN
GROUNDWATER SAMPLES COLLECTED FROM WELLPOINTS (WATER TABLE) AND PERMANENT MONITORING
WELLS NS-13 AND NS-14
(Samples were only analyzed for VOCs)
FREQUENCY TWP-1A TWP-2 TWP-3 TWP-4 TWP-5 TWP-6 TWP-7 TWP-8
COMPOUND OF (Background)
.DETECTION
VOLATILE ORGANIC COMPOUNDS
Acetone 10/15 I!i'.!;,iw:# iiH~p;ii~ 10 U
Carbon Disulfide 3/15 SU SU SU
Chloroethane 3/15 10 U 10 U 10 U
1,2-Dichloroethane 7/15 10 UJ SU SU SU SU SU
1, 1-Dichloroethene 1/15 SU SU SU SU SU SU SU su·
1,2-Dichloroethene 2/15 SU SU SU SU SU SU SU 10 UJ
1,2-Dichloropropane 1/15 SU SU SU SU SU SU SU SU
Methylene Chloride 3/15 10 U SU SU SU 10 U
Tetrachloroethene 2/15 SU SU SU SU SU SU
Toluene 3/15 SU SU SU SU SU SU
1, 1,2-Trichloroethane 2/15 SU SU SU SU SU SU SU SU
Trichloroethene 2/15 SU SU SU SU SU SU SU SU
Vinyl Chloride 4/15 10 U 10 U 10 U 10 U 10 U 10 U 10 U
--------------------
TABLE 2 FREQUENCY OF DETECTION AND CONCENTRATIONS OF ORGANIC CONTAMINANTS DETECTED IN
GROUNDWATER SAMPLES COLLECTED FROM WELLPOINTS (WATER TABLE) AND PERMANENT MONITORING
WELLS NS-13 AND NS-14
(Samples were only analyzed for VOCs)
COMPOUND FREQUENCY
OF DETECTION
TWP-9 TWP-10
VOLATILE ORGANIC COMPOUNDS
Acetone 10115 10 U
Carbon Disulfide 3115
Chloroethane 3115
1,2-Dichloroethane 7115
1, 1-Dichloroelhene 1115
1,2-Dichloroelhene 2115
1,2-Dichloropropane 1115
Methylene Chloride 3115
Tetrachloroethene 2115·
Toluene 3115
1, 1,2-Trichloroethane 2115
Trichloroethane 2115
Vinyl Chloride 4115
Samples were collected in May 1992.
Co[!f:entrations are in micrograms per liter (µg/1) or parts per billion (ppb).
Shaded area @?\) depicts positive detections.
D -Sample arialyied at secondary dilution.
J -Concentration is estimated.
U -Undetected at the indicated quantitation limit.
UJ -Undetected; the associated quantitation limit is an estimated value.
10 U
TWP-11
10 U ·
TWP-12 TWP-13 NS-13 NS-14 ·
10 U
SU
10 U 10 U 10 UJ 10 U
10 UJ SU
SU SU 5 UJ .5 U
SU SU 5 UJ SU
SU SU 5 UJ SU
10 U 10 U SU 5 UJ
SU 5 UJ SU
SU 5 UJ SU
SU 5 UJ SU
SU 5 UJ SU
10 U 10 UJ 10 U
- -·--- - - - -.. --- - - - ----
TABLE 3 FREQUNECY OF DETECTION AND CONCENTRATIONS OF VOLATILE ORGANICS DATA FOR GROUNDV','.ATER SAMPLES
COLLECTED FROM PUSH-POINT SAMPLER, TEMPORARY MONITORING WELLS, AND SCREENED WATER SAMPLER
• (Samples were only analyzed for VOCs)
FREQUENCY GW-1• GW-1A GW-18 GW-2' GW-3 GW-5' GW-SA GW-6
OF DETECTION
SAMPLING DATE 11/20/92 NA 12/4/92 11/20/92 11/21/92 11/21/92 11/23/92 11/19/92
DEPTH TO WATER 8 NA 8 17.8 9.8 6.45 15 6
TABLE (feet)
COMPOUND
VOLATILE ORGANIC COMPOUNDS
GW-6RE
12/16/92
6
1
f-A_ce_t_on_e _______ 4_i3_3 ____ 2_s_,o_o_o _u_· __ 1o_u ___ 1_o_u_J-+_2_s"-o_u_+-_1o_u_-+-_1 o_,o_o_o_u_J-+_1_o_u_J____ · \l~1iiNig@l;l\ii;l
Carbon Disuttide 1/33 12,000 U 5 U 5 U 120 U 5 U 5,000 U 5 U 5 U
Chloroethane 2/33 25,000 U 10 U 10 U 250 U 10 U 10,000 U 10 U 10 U 10 U
Chloroform 1/33 i l~l~P~i~iii 5 U 5 U 120 U 5 U 5,000 U 5 U SU SU
1,2-Dichloroethane 16/33 !ifflQm~iP'H i~l!RQ!Rli 5 U :fili~sroimii SU SU
1,1-Dichloroethene 1/33 12,000 U 120 U 5 U 5,000 U SU SU SU SU SU
1,2-Dichloroethene 1/33 · 12,000 U · 120 U 5 U 5,000 U SU SU SU SU SU
Ethylbenzene 2/33 12,000 U 120 U 5 U 5,000 U 5 u. SU SU
Methylene Chloride 3/33 12,000 U 5 U ;:;g;~ob::i;L SU SU SU SU SU
Tetrachloroethene 2/33 12,000 U 120 U 5 U 5,000 U SU SU SU SU SU
Toluene 3/33 12,000 U 120 U 5,000 U SU SU SU SU SU
Total Xylenes 3/33 12,000 U 120 U 5 U 5,000 U SU SU SU
1, 1,2-Trichloroethane SU SU 120 U . 5 U 5,000 U SU SU SU
Trichloroethene SU SU 120 U 5 U 5,000 U SU SU SU
Vinyl Chloride 10 U. 10 1.1 ,000 U 250 U 10,000 U 10 U 10 U 10 U 10 U
-------------------
TABLE 3 FREQUNECY OF DETECTION AND CONCENTRATIONS OF VOLATILE ORGANICS DATA FOR GROUNDWATER SAMPLES
COLLECTED FROM PUSH-POINT SAMPLER, TEMPORARY MONITORING WELLS, AND SCREENED WATER SAMPLER
(Samples were only analyzed for VOCs) (continued)
GW-7
SAMPLING DATE 11/23/92
D.EPTH TO WATER 9
TABLE (feet)
COMPOUND
VOLATILE ORGANIC COMPOUNDS
Acetone
Carbon Disuttide
Chloroethane
Chloroform
1,2-Dichloroethane
1, 1-Dichloroethene
1,2-Dichloroethene
Ethylbenzene
Methylene Chloride
Tetrachloroethene
Toluene
Total Xylenes
1 , 1 ,2-Trichloroethane
' Trichloroethene
Vinyl Chloride
10 UJ
SU
SU
SU
SU
SU
SU
SU
.10 U
GW-7A
11/24/92
25
10 UJ
SU
10 U
SU
!;i::i1«iip:;gl1;
SU
SU
SU
SU
SU
SU
SU
SU
10 U
GW-8
12/4/92
1
. 10 R
SU
10 U
SU
SU
SU
SU
SU
SU
SU
SU
SU
SU
10 U
GW-BD
12/5/92
1
10 R
SU
10 U
SU
SU
SU
SU
SU
SU
SU
SU
SU
SU
SU
10 U
GW-8B GW-11A"
12/5/92 11/24/92
5 6.5
10 UJ 5,000 UJ
SU 2,500 UJ
10 U 5,000 UJ
SU 2,500 U
SU 2,500 U
5 U 2,500 U
5 U 2,500 U
5 U 2,500 U
SU
SU
SU
SU
10 U
2,500 U
2,500 U
2,500 U
2,500 U
5,000 U
GW-11B
12/3/92
12.5
10 R
SU
10 U
SU
SU
2,500 U
SU
SU
SU
SU
SU
SU
SU
SU
10 U
GW-12
12/6/92
16
10 UJ
SU
10 U
SU
SU
SU
SU
SU
SU
SU
SU
SU
SU
10 U
GW-12A
12/2/92
17
10 R
SU
10 U
SU
SU
SU
SU
SU
SU
SU
SU
SU
SU
SU
10 U
GW-13
11/20/92
4.5
10 UJ
SU
10 U
SU
SU
SU
SU
SU
SU
SU
SU
SU
SU
SU
10 U
-------------------
TABLE 3 FREQUNECY OF DETECTION AND CONCENTRATIONS OF VOLATILE ORGANICS DATA FOR GROUNDWATER SAMPLES
COLLECTED FROM·PUSH-POINT SAMPLER, TEMPORARY MONITORING WELLS, AND SCREENED WATER SAMPLER
{Samples were only analyzed for VOCs) (continued)
GW-14 GW-15
SAMPLING DATE 11/21/92 12/17/92
. DEPTH TO WATER TABLE (feet) 4.5 3
COMPOUND
VOLATILE ORGANIC COMPOUNDS
Acetone 10U 180UJ
Carbon Disuttide
Chloroethane
Chloroform· SU SU
1,2-Dichloroethane liliJggqg;;
1, 1-Dichloroethene SU SU
1,2-Dichloroethene SU SU
Ethylbenzene SU SU
Methylene Chloride SU 11 U
Tetrachloroethene
Toluene SU SU
Total Xylenes SU SU
1, 1 ,2-Trichloroethane
Trichloroet~ene SU SU
Vinyl Chloride ~~titRt!i!;:::;,,
GW-16A
12/2/92
10
10 R
SU
110 U
SU
SU
SU
SU
SU
SU
SU
SU
SU
SU
SU
10 U
GW-17
12/1/92
4
10 R
SU
10 U
SU
Ii ~;~iIPlii
SU
SU
SU
SU
SU
SU
SU
SU
10 U
GW-18 GW-18A GW-19 GW-22 GW-24 GW-25
11/23/92 12/18/92 NA 12/18/92 12/18/92 12/19/92
7.5 7 NA 7 16 11.5
10 UJ
SU 17 U 5 U SU SU SU
10 U 33 U 10 U 10U 10U 10U
SU 17 U 5 U SU SU SU
.
SU . 17 U SU SU SU
SU 17 U SU SU SU SU
SU 17 U SU SU SU SU
SU 17 U SU SU SU SU
SU 17 U SU SU SU SU
SU 17 U SU SU SU SU
SU 17 U · 5 U SU SU SU
SU 17 U SU SU SU SU
SU 17 U SU SU SU SU
SU 17 U SU SU SU SU
10 U 33 U 10 U 10 U 10 U 10 U
--------------------
TABLE 3 FREQUNECY OF DETECTION AND CONCENTRATIONS OF VOLATILE ORGANICS DATA FOR GROUNDWATER SAMPLES
COLLECTED FROM PUSH~POINT SAMPLER, TEMPORARY MONITORING WELLS, AND SCREENED WATER SAMPLER
(Samples were only analyzed for VOCs)
GW-26 GW-27 NS,13
SAMPLING DATE 1/23/93 1/24/93 11/24/92
DEPTH TO WATER TABLE (feet) 14 19 5.44
COMPOUND
VOLATILE ORGANIC COMPOUNDS
Acetone 20 U 21 U 14 U
Carbon DisuHide SU SU SU
Chloroethane 10 U 10 U 10 UJ
Chloroform SU SU SU
.................................. .
1,2-Dichloroethane s_u SU :~ :t;zPXttPi !::ff
1, 1-Dichloroethene SU SU SU
1,2-Dichloroethene SU SU SU
Ethylbenzene SU SU SU
Methylene Chloride 16 U 15 U SU
Tetrachloroethene SU SU SU
Toluene SU SU SU
Total Xylenes SU SU SU
1 , 1 ,2-Trichloroethane SU SU
Trichloroetpene SU SU
Vinyl Chloride 10 U 10 U
Concentrations are in micrograms per liter (µg/1) or pans per billion (ppb). Shaded area (ii) depicts positive detections.
' -Detection limits for V0Cs are elevated; prescreening of sample indicated matrix effects required medium or high level analysis.
NS-14
11/24/92
5.2
12 UJ
SU
10 UJ
5 UJ
5 UJ
5 UJ
SU
5 UJ
5 UJ
5 UJ
5 UJ
5 UJ
5 UJ
SU
10 UJ
D -Concentration reported from secondary dilution. J -Concentration is estimated. NA -Not Available R -Unusable results.
U -Undetected at the indicated quantitation limit. UJ -Undetected; the associated ~uantitation limit us an estimated value.
RE ~ Resampled.
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1.
I
N&50 -
N550 -
N 250
ABANDONED
RAILROAD SPUR
'' '' ''
'' '' ': '' '' : :
'' ''
'' '' : :
" "
ITWP•13 I {2400J)'
755 : :
''
I
TWP•12
(ND)
--------------· , •.•.......••.. TWP•11
(8300J)
' ' : : AREA2
' ' : '
(j)TWP•10
(790J)
' ' . ' : '
TWP•S
@(4800J)
APPROXIMATE SCALE (ft)
0 ,oo 200 300 .OC, 500
:: . :TWP•9
··•··· ··•••·· ···········: .•.•. : : ....•• : : ......•....••• : (SlOOJ) ··(3200) ..•.
N.-50-. .-.. -------------------------------------, .:::::::::::.-, .,-------------
-350 -
, TWP•7@ ~
PARKJNG LOT -(430) (l;TWP•6 : ....... rwi.s@ (ND)
NS•13 (ND) TWP-4
,===; ___ (9_00) ~\ (ND) I~ " I LAGfON ~ TWP•2@ @ TWP~
J L___:_J (ND) (ND)
l~I ~ I E250
-<SO E-350
CHAIN LINK FENCE----------....
E
LEGEND
@ TWP•S
(4800J)
■ NS-14
(ND)
FIGURE 5
TEMPORARY WELL POINT
ANO 1,2-0CA
CONCENTRATION /ppb)
MONITORING WELL
LOCATION ANO 1,2-0CA
CONCENTRATION /ppb)
SAMPLING LOCATIONS FOR
GROUNDWATER (WATER TABLE}
VIA WELLPOINTS AND
CONCENTRATIONS OF
1,2-DICHLOROETHANE DETECTED
AT EACH WELLPOINT
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N a50 -
N 550 -
N 250 -
N-350 -
z LEGEND
6. GROUNOY/A TEA SCREENING GW-16 POINT WITli ,.2-0CA
(420) CONCENTRAT'ON Qn -)
1 NOTE: Confirmation data ~ supplemented by groundwtuer ~ screening data ~~ ~, ~5:. ················/;
ABANDONED RAILROAD SPUR' ______ __,
GW-27
(ND) 6
GW-88"
(ND) ..
GW-18A
(ND) 6GW-18
6 (ND)
GW-7A,-. __ GW-17
,--,-: _-_ :-: :~: :-:-: :--_-_-__ -__ _( 1300) _ ~
6
(48~') \-n'~,,-G~W--1-6-A
------, ,------, : GW-7 GW-6 (ND)
: i : i (200) (ND) GW-16
;: ·: _______________ (420)
'' GW-5A:: GW-5 (30) :':" (98000) 6 GW-15
, ' · (16000)
GW-4A : i GW-4 "
(ND) 4': :(3400) .
:: : : 6GW-14
: : _____ , _____________ : '. _________ (ND)
--------------. ------------------------. -----,----. -. -------------
GW-.1f___ : GW-3 GW-12A
(ND)6 (200) 6 : 6 \ND)
: : / GW-13 GW-25 GW-118 GW-_ll ------·-,; GW-2 6 (ND)
(ND) (ND) 6 (3800) " (51 OO) 6 GW-18 r-----""~ GW-11A 6 24 6 ;, I NS-13 □ [437) GW-1 ~ ~ / (1300) GW(J
6
" . (660000) /" GW-22 \
· " (ND) GW-1A ~--NS-14 (59) ~-~-, (4J)
GW-246 GW-236
(NO) (NO) FIGURE 6
APPROXJMATE SCALE (It)
O 100 200 300 «lO 500
0 ~
~ z a:
Q. rn a:
1§
w u
I I
E--350 E-
. SAMPLING LOCATIONS FOR GROUNDWATER
(SAPROLITE ZONE) VIA PUSH-POINT
SAMPLER, TEMPORARY MONITORING WELL,
AND SCREENED WATER SAMPLER AND
CORRESPONDING CONCENTRATIONS OF
1,2-DICHLOROETHANE DETECTED AT
CHAIN LINK FENCE EACH SAMPLING LOCATION
-------------------
TABLE 4 FREQUENCY OF DETECTION, CONTAMINANTS DETECTED, AND MOST STRINGENT PROMULGATED
STANDARDS FOR CONTAMINANTS DETECTED IN THE SAPROLITE ZONE OF THE AQUIFER
COMPOUND · PROMULGATED FREQUENCY NS-131 . NS-141 NS-33 NS-35 NS-37' NS-39
GROUNDWATER OF DETECTION (Background)
STANDARDS
VOLATILE ORGANIC CoMPOUNDS
Acetone 1/8 14 U 12 UJ 10 U 10 U 10 U
Bromodichloromethane 100 2/8 5U 5 UJ 5U 5U 5U
2-Butanone 1/8 10 U 10 UJ 10 U
Chloroethane 1/8 10 UJ 10 UJ 10 U
Chloroform 0.19 1/8 5 U 5 UJ 5U
1,2-Dichloroethane 0.38 . 5/8 5U
1,2-Dichloroethene ?0(cis)/1 00(trans) 1/8 5 U 5 UJ 5U
Methylene Chloride 5 1/8 5 U 5 UJ 5U
Tetrachloroethene 5 1/8 5 U 5 UJ 5U
Toluene 1,000 1/8 5 U 5 UJ 5U
Total Xylenes 400 1/8 5U 5 UJ 5U
1, 1,2-Trichloroethane 5 3/8 5 UJ 5U
Vinyl Chloride 0.015 1/8 10 UJ 10 U
SEMI-VOLATILE ORGANIC COMPOUNDS
NS-42' NS-43'
l'./~1Q;~;; ;: 1 o u
i:;:~Jt:; 5 U
. (!;;";;#499.;Jii; 10 u
800UJ 10U
400UJ 5U
400 UJ 5U
400 UJ 5U
800 UJ 10 U
Di-n-butylphthalate 1/8 10 U 10 U 10 U 10 U 10 U 10 U .10 U le--------'-------'--------'-----'-------'-----'------'----L---
. PESTICIDESi
Delta-BHC 1/8 0.05 l:J 0.05 U 0.05 U 0.05 U 0.05 U
-------------------
TABLE 4 FREQUENCY OF DETECTION, CONTAMINANTS DETECTED, AND MOST STRINGENT PROMULGATED
STANDARDS FOR CONTAMINANTS DETECTED IN THE SAPROLITE ZONE OF THE AQUIFER
COMPOUND
INORGANICS
PROMULGATED
GROUNDWATER
STANDARDS
FREQUENCY
OF DETECTION
NS-131 NS-141 NS-33
(Background)
NS-35 NS-371 NS-39
Arsenic 50 1/8 2U 2U 2U 2U
Barium 200 8/8
Beryllium 4 2/8
Chromium 50 6/8
Cobalt 2/8
Cyanide 154 2/8
Lead 15b 1/8
Manganese 50 8/8
.Nickel 100 3/8
Vanadium 7/8
Zinc 5,000 2/8 21.1 U 41.7 U 28.1 U
Concentrations are in micrograms per liter (µg/1) or parts per billion (ppb).
Shaded area (; ;J depicts positive detections.
• -Detection ilmits for voes are elevated, due to matrix effects and analyzed under medium or high level.
b -Action Level (EPA, Region IV Established Action Level).
D -Concentration reported from secondary dilution.
J -Concentration is estimated.
NA -Not analyzed.
U -Undetected ·at the indicated quantitation limit.
UJ Undetected; the associated quantitation limit is an estimated value.
NS-421 NS-431
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1050
750
-750 1 -
• NS-24
• NS-38
(1 J)
(Not Sampled)
ABANDONED
RAILROAD SPUR-----......,-
-350 -SO
----s
250
'
NS-34 e (ND)
I I·
550
I/
! I
'LEGEND
• NS-36
(11000)
1.2-0CA CONCENTRATION
. CONTOUR (ppb)
1 ,2-0CA CONCENTRA T10N
(ppb), GROUNDWATER
SAMPLES
APPAOXlMA TE SCALE (tt)
Cl <(
0 a:
Cl)
(!J z
ci: Cl. Cl)
~ w u
flOO 2)0 ,0,0 co .,.,
FIGURE 7
CONCENTRATIONS AND
ESTIMATED EXTENT OF
1,2-DICHLOROETHANE
CONTAMINATION IN THE
BEDROCK ZONE OF THE
AQUIFER
-------------------
TABLE 5 FREQUENCY OF DETECTION, CONCENTRATIONS DETECTED, AND MOST STRIGNENT PROMULGATED
GROUNDWATER STANDARDS FOR CONTAMINANTS DETECTED IN THE BEDROCK ZONE OF THE AQUIFER
COMPOUND
VOLATILE ORGANIC CoMPOUNDS
Acetone
Bis(2;chloroethyl)ether
Chloroform
1,2-Dichloroethane
1, 1-Dichloroethene
Methylene Chloride
Tetrachloroethene
Toluene.
Total Xylenes
1,1,2-Trichloroethane
Trichloroethane
Vinyl Chloride
PROMULGATED
GROUNDWATER
STANDARDS
0.19
0.38
7
5
5
1,000
400
5
2.8
0.015
SEMI-VOLATILE ORGANIC COMPOUNDS
Bis(2-ethylhexyl)phthalate 6
Di-n-butyl Phthalate
Di-q-octyl Phthalate
INORGANICS
Barium 200
Chromium 50
Cobalt
FREQUENCY NS-34 NS-36 NS-38' NS-40 NS-41 NS-44'
OF
DETECTION (Background)
2/6 10 U 10 U 10 U
3/6 10 U
1/6 SU SU
4/6 SU SU
1/6 SU SU 1,200 UD 5 U
2/6 SU SU !if ;;p:715/#Q)/ 1' 5 u
1/6 SU SU 1,200 UD 5 U
1/6 SU SU 1,200 UD 5 U
216 SU 1,200 UD SU
2/6 SU 1,200 UD SU
2/6. SU 1,200 UD SU
2/6 10 U 2,500 UD 10 U
1/6 10 U 10 U 10 U 10 U 10 U
1/6 10 U 10 U 10 U 10 U 10 U
1/6 10 U 10 U 10 U 10 U 10 U
5/6 27.9 U
3/6 10 U
1/6 20 U 20 U '
---------~---------
TABLE 5 FREQUENCY OF DETECTION, CONCENTRATIONS DETECTED, AND MOST STRIGNENT PROMULGATED
GROUNDWATER STANDARDS FOR CONTAMINANTS DETECTED IN THE BEDROCK ZONE OF THE AQUIFER
COMPOUND
Copper
Lead
Manganese
Vanadium
Zinc
PROMULGATED
GROUNDWATER
STANDARDS
1,000
50
5,000
FREQUENCY NS-34 NS-36 NS-38'
OF
DETECTION (Backgnnmd)
2/6
1/6
6/6 1lit1Zlo~/;;
4/6 10 U
2/6 33.7 U
Concentrations are in micrograms per liter (µg/1) or parts per billion (ppb).
Shaded area ('F ) depicts positive detections.
' -Detection'Hiiiits for voes are elevated, due to matrix effects and analyzed under medium or high level.
b -Action Level (EPA, Region IV Established Action Level).
D -Concentration reported from secondary dilution.
J -Concentration is estimated.
U -Undetected at the indicated quantitation limit.
UJ -Undetected; the associated quantitation limit is an estimated value.
N5-40 N5-41 N5-44'
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DRAFT
7.3 SURFACE WATER AND SEDIMENT
-34-
NATIONJJ.. Sr ARCH & CHEMICAL CoMPNN SU PERR/ND SITE
DRAFT RECOR'.> OF DECISION FOR OPEIW3l.E UNIT #3
--5EPT0.flER 1, 1993/7:21AM
A total of 33 surface water and sediment samples have been collected from the Northeast
Tributary. The first samples were collected in March 1987 and the most recent samples were
collected in January 1993. All the samples collected were analyzed for voes. In addition to
being analyzed for voes, two of the samples (SW/SE-12 and SW/SE-13) were also analyzed for
SVOCs and metals. Sampling location SW/SE-12 is the upgradient'background surface
water/sediment sampling location. Each sampling event has shown contamination to be present
in the surface water and sediment of this tributary. To date, only two (2) voes, acetone and 1,2-
DCA, have been detected in this stream. As in the other environmental media samples, metals
were also detected but these metals occur naturally. Two metals were detected at concentrations
at least two times greater than the background concentration. They are manganese in the
surface water and copper in the sediment. It was the continuous detection of 1,2-DCA in this
stream that led to the initiation of OU #3. The objective of OU #3 RI was to identify, characterize,
and delineate the source of contamination continually being detected in the Northeast tributary.
The highest concentration of contaminants were detected in the reach of the tributary that is just
east of the production facility. Table 6 lists each sampling event, the sampling locations, and the
analytical results for 1,2-DCA in the water column and sediment. Table 7 lists the analytical
results for the samples collected at sampling locations SW/SE-12 and SW/SE-13. Figure 8
shows the surface water sampling locations and Figure 9 shows the sediment sampling locations.
These figures also present the analytical results for 1,2:ocA for the last samples collected at
these sampling locations. The highest concentration of 1,2-DCA detected in the surface water
was 3,200 µg/1 in May 1992 at sampling location SW-13 and the highest concentration of 1,2-DCA
detected in the sediment was 7,400 mg/kg in June 1991 at sampling location SE-14. Sampling·
location SW/SE-13 is just downgradient SW/SE-14.
As can be seen in Figures 8 and 9, no contamination was detected upgradient of the Site (SW-
12, SW-12A, and SE-12). The concentration of contamination increases as the stream flows
adjacent to and past Area 2, the production area. The concentrations decrease as the stream
flows away from Area 2.
Surface water and sediment samples were collected on three occasions from the Northeast
Tributary just prior to its leaving the NSCC property. The first samples (sampling location NS-
W2/S2) were collected in June 1987, the second set of samples were collected in July 1990
(sampling location SW/SE-15), and the last time in June 1991 (again, at sampling location SW-
SW-15). As can be seen in Table 6, no contaminants were detected downstream of the plant
prior to the stream leaving NSCC property which indicates that under normal weather conditions,
no contamination is leaving the Site via the Northeast Tributary.
Surface water and sediment samples were also collected to perform an ecological assessment
on this stream. The results of the ecological assessment is discussed in Section 8.6.
The Northeast Tributary is not specifically classified due to the low flow conditions within the
stream, however, it is considered as a Class "C" stream under North Carolina Administrative
Code, Title 15A, Subchapter 2B (NCAC T15A:02B) because the receiving stream of the Northeast
Tributary, Grants Creek, is classified as a Class C stream. A Class C stream is defined as being
suitable for secondary recreation and the "propagation of natural trout and maintenance-of trout".
- - - - - -... ----------- - - - - -
TABLE 6 SUMMARY OF DETECTABLE CONCENTRATIONS OF 1,2-DICHLOROETHANE IN SURFACE
WATER, SEDIMENT, AND SOIL SAMPLING OF THE NORTHEAST TRIBUTARY
Sample Number' March 1987 June 1987 Oct., Nov. 1989 July 1990 June 1991 May 1992 June .1992 January 1993
SW/SE-01 1,400/18b --------------
NS-W1/S1 ·--ND/ND -------- ----
NS-W2/S2 --ND/ND ... ----------
NS-W3/S3 --ND/ND -----------·
NS-W4/S4 --4,400 J/3,400 J -------------
SW/SE-09 ----350/76 160/980 77/23 150 J/9 J ----
SW/SE-10 ----1,200/14 1,600/ND 810/310 1,300 J/610 D ----
SW/SE-11 ----ND/ND ND/ND ND/ND ND/ND ... --
SW-12A --------------ND ...
(Background)
SW/SE-12 -------NS/ND NS/ND 2 J/ND ---ND/ND
(Background)
.
SW/SE-13 ------880/3,400 1,80017,400 3,200 D/290 ---200 J/1,200 D
SW/SE-14 -------1, 700/1,200 1,200/4,200 590 D/1,000 D -· -··
.
SW/SE-15 --------ND/ND ND/ND ... ... ...
SW/SE-16 ----------1,300 DJ/61 ' ---··
S0-01 --------ND -----· --
- - -.. --- - - - ----- - - - ---
TABLE 6 SUMMARY OF DETECTABLE CONCENTRATIONS OF 1,2,0ICHLOROETHANE IN SURFACE
WATER, SEDIMENT, AND SOIL SAMPLING OF THE NORTHEAST TRIBUTARY
Sample Number' March 1987 June 1987 Oct., Nov. 1989 July 1990 June 1991
SO-02 ----... ND --
SO-03 ------ND --
SO-04 ----... ND --
SO-05 ---· --650 --
SO-06 ----... 57 --
SO-07 ... --... ND --
Concentration for surface water samples are in micrograms per liter (µg/1) or parts per billion (ppb)
Concentration for sediment samples are in milligrams per kilogram (mg/kg) or parts per billion (ppb)
a SW/SE: surface water/sediment; NS-W/S: water/sediment (EPA samples); SO: soil
May 1992 . June.1992
... --
---·
... --
----
----
----
b
D
First value represents concentration of 1,2-DCA In surface water/Second value represents concentration of 1,2-DCA in sediment
Concentration reported from secondary dilution
J -Concentration is estimated
ND • Analyzed for but not detected
NS -Not sampled (no water available)
U · Undetected at the indicated quantitation limit
January 1993
-·
--
--
--
--
--
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TABLE 7 CONCENTRATIONS OF ORGANICS AND INORGANICS IN SURFACE WATER
AND SEDIMENT FROM LOCATIONS SW/SE-12 AND SW/SE-13
COMPOUND/ANAL YTE
ORGANICS
Acetone
. 1 ,2-Dichloroethane
IN0RGANICS
Antimony
Arsenic
Barium
Beryllium
Chromium
Cobalt
Copper
Lead
Manganese
Mercury
Nickel
Selenium
Thallium
SW-12
(Background)
10 U
5U
30 U
SW-13
30 U
2U 2U
1 U 1 U
10 U 10 U
20 U 20 U
10 U 10 U
20 U 20 U
2U 2U
2 LiJ 2U
SE-12
(Background)
SE-13
lizi:::1;§?,'Y.'!11i!,\ili:
! ii~!;g~gf iiiii i
0.32 R
0.32 R
Vanadium 1111:11 glll!~!11lli 1~ll1\l3!1111~11111 !il!~,'.!1lfill€ilili;Jl1i lit ;;;a11!§11;,:ii111 If--------------,
Zinc
Samples collected in January 1993.
Shaded area (@'ID depicts posttive detections.
Concentration for surface water samples are in micrograms per ltter (µg/1) or parts per billion (ppb) Concentration for sedimerit samples are in milligrams per kilogram (mg/kg) or parts per billion (ppb) SW -Surface Water Sample
SE -Sediment Sample
D -Concentration reported from secondary dilution.
J -Concentration is estirnated.
R -Unusable results.
U -Undetected at the indicated quantttation limit.
UJ -Undetected; the associated quantttation limit is an estimated value.
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N850 -
N 550
N250 -
-350 -
I -650
ABANDONED
RAILROAD SPUR
'' ', : :
. -----------------------~ :, !"•---------------, ,------
', '' : :
'' '' '' '' '' '' ',
[] (!l ...
:3
LAGOON
1
E-350
, ' : :
'' '' '' '' , ' : :
'' ''
" ! : ':
'' : :
"
AREA2
NS-13 (900)\ I LAGfON I .
/~/
ND
CHAIN LINK FENCE------..___
,
SW-10
(1300J)
' ' : :
E 250
SW-16
(1300J)
E
a: . g
APPROXl~TE SCALE en,
0 100 200 300 ~ "'
LEGEND
... SW-14
(590)
SURFACE WATER
LOCATION ANO 1,2-0CA
CONCENTRATION (ppt>)
■ NS-14
(ND)
FIGURE 8
MONITORING WELL
LOCATION ANO 1,2-0CA
CONCENTRATION (ppt>)
SURFACE WATER SAMPLING
LOCATIONS ALONG THE
NORTHEAST TRIBUTARY AND
ASSOCIATED CONCENTRATIONS
OF 1,2-DICHLOROETHANE
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Na50 -
N550 -
N250 -
z
I
, ,
ABANDONED RAILROAD SPUR ______ _/:'
, ' : : '' '' '' '' : : : :
'' ''
·,, : : , , , ,
'---·------------' ,------------·--: !
AREA 2 , ,
' :
SE-10
(610)
SE'16
(61)
, , SE-13
A.PPROXlMATE SCALE (ft)
I 00 200 300 ~ .,,
' ' ' : _____ , '-------: ___________ -

:

~--.. (~~9) _____ _ ~.:so:---------·_·----------------------------' .:::::.·:.·, ,------------------
SE-14 ..... l PARKING LOT ~
'-·-----·----
-350 -
I~· I LAGOON I LAGfON I 1
I .
-650
E-350
CHAIN LINK FENCE------..._
SE-11
(NO)
E 250
(1000)
LEGEND
.6.SE-13
(290)
FIGURE 9
STREAM SEDtMENT SAMPLE
LOCATION ANO 1,2-0CA
CONCENT!\ATION {ppt))
SEDIMENT SAMPLING LOCATIONS
· ALONG THE NORTHEAST TRIBUTARY
AND ASSOCIATE·□ CONCENTRATIONS
OF 1,2-DICHLOROETHANE
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DRAFT
-39-
NATIONAL Sr AOOH & CHEMICAi... CoMPANY SUPERR./ND SITE
DRAFT RECORl OF Dectsa-1 FOR OPERABLE UNIT #3
-SEPTaeER 1, 1993/7:21AM
Neither sport nor commercial fish species were observed in the surface waters during the
RI field work.
7.4 HYDROGEOLOGICAL SETTING
The groundwater beneath the NSCC property is designated as Class GA in accordance
with North Carolina's water classification system and Class IIA under USEPA
Groundwater Classification Guidelines (December 1986). The Class GA classifications
means that the groundwater is an existing or potential source of drinking water supply for
humans as specified under North Carolina Administrative Code, Title 15, Subchapter 2L
(NCAC T15:02L). EPA classifies t_he groundwater as Class IIA since the aquifer is
currently being used as a source of drinking water as this aquifer is being used as a
source of drinking water in the vicinity of the NSCC facility.· Therefore, the groundwater
needs to be remediated to a level protective of public health and the environment as
specified in Federal and State regulations governing the quality and use of drinking water.
At the NSCC site, a thick mantle of residual soil eX1ends from the ground surface to the
bedrock. This mantle, the saprolite, is composed of clay-rich residual soils which range
from silty to sandy clays. The saprolite is derived from the intense chemical weathering
of the crystalline bedrock and has retained the structural fabric of the parent materials
below the oxidation profile. These residual soils exhibit increasing amounts of sand size
relict mineral grains below the oxidation horizon and closer to the bedrock. There.
appears to be a complete gradation from saprolite to friable weathered bedrock to
fractured bedrock to sparsely fractured bedrock. The depth to bedrock ranges from 1 o
to 100 feet below ground surface. The deepest bedrock was encountered was in the
vicinity of the Northeast Tributary. Figure 10 shows the orientation of the hydrogeological
cross-section of the Site which is displayed in Figure 11.
Soil fissures near the water table are filled with geothite, presumably derived from the
weathering of the iron-bearing minerals present in the parent rock. There appears to be
no confining layer between the saprolite and bedrock, therefore these two lithologic units
are hydraulically interconnected, and there is little or no impedance between these two
hydraulic systems.
The lithology of the soils underlying the Site was determined from drilling logs. The
thickness of the soil mantle varies across the Site. It appears that Area 2 occupies a
structural high and that the bedrock surface slopes steeply away from this area to the
east and more gently to the north. Rock core records show that the upper 1 o to 15 feet
of bedrock is deeply weathered and friable. Bedrock begins to appear nonfriable and
fresh 15 to 25 feet below the bedrock/saprolite interface. However, fractures continue to
be frequent and fracture surfaces often exhibit oxidation staining to depths of 40 to 100
feet below the bedrock/saprolite interface. Fracture frequency diminishes downward from
the bedrock/saprolite interface. It has been estimated that the bedrock becomes
--·· -·------ ----.. --- - ---
N 0.00.
E-3200 E-2200
NS.15 ...
,ANS.26 ~
~
NS.27
A
AEX-04
PLANT EAST (ft)
E -1200
___ ,, --------------------
CHAIN LINK FENCE FIGURE 10
SCALE 1ft)
0 IDII :ZOO :!1011 '00 600
0 ;::
LEGEND
lOCATDNS WHERE fllfUSAl
SCREENNGSAMPI...E
WAS REACHED
WlHITOAIHG W( I l
Wt1[R[ REAJ5.I\L WAS RCACHEO
BfDflOCI( El£VATON cooao,,a
ORIENTATION AND LOCATION OF
HYDROGEOLOGIC CROSS SECTION
SHOWN IN FIGURE 7
-· - -·-... ,_ ---·--- - --- - - -
...... NS•15 f J
f NS-17 NS-02 I l NS·28
I I
.....
I 000 l .... z j ... ,
I ·.:~~~: I
I 700
000 l
j
500
400 ~~._L_;.r-1--_L__L.~~:___L_~_L__L__L+L_L__L_L,.L_L_,~-?--,.(_L_..LJ.~..L.L-:_L_,L]
2000
A Dist.ice (l'"I) A'
LEOEND
FIGURE 11
500 500 HYDROGEOLOGIC CROSS SECTION A-A'
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DRAFT
-42-
competent approximately 200 feet below ground surface.
NATIONAL SrAEDi & CHEMICAi.. CoMPNff SUPERRJNO SITE
DRAFT RECORD OF DECISION FOR OPERABLE UNIT #3
-SEPTS6ER1, 199317:21~
Water level measurements from the water table/saprolite zone of the aquifer indicate that
hydraulic heads decrease from both the east and west towards the Northeast Tributary
and towards the north along the stream. This data indicates that the Northeast Tributary
acts as a groundwater divide for the saprolite zone of the aquifer and receives
groundwater discharge along its entire reach. This explains the presence of contaminants
being detected in the surface water and sediment of this tributary. Additional data needs
to be collected during the RD to determine where groundwater in the bedrock zone of the
aquifer is discharging.
The hydraulic conductivity oi the saprolite materials and the bedrock ranges from 0;72 to
3.35 feet per day (ft/day) and 0.01 to 1.13 ft/day, respectively. Based of the above
information, the horizontal flow of groundwater in the saprolite was estimated to have a
· · velocity of 80 feet/year (ft/yr) in the lagoon area and 27 ft/yr in Area 2. Additional
information will be collected during the RD to better define the horizontal flow velocity in
the bedrock zone of the aquifer.
7.5 PATHWAYS AND ROUTES OF EXPOSURE
The chemicals of potential concern for each environmental media sampled are listed in
Table 8. This list includes VOCs, SVOCs, and metals. These constituents were.
incorporated into Table 8 because 1) the contaminant detected was above the chemical-
specific applicable or relevant and appropriate requirement (ARAR), 2) the contaminant
was not detected in the upgradient/background sample(s) forth at particular environmental.
media, or 3) the concentration detected on-site was twice the upgradient/background
concentration. The last condition applies particularly to the inorganic constituents.
An exposure pathway is the route or mechanism by which a chemical agent goes from
a source to an individual or population (i.e., the receptor). Each exposure pathway must
include the following:
• A source or mechanism of chemical release to the environment
• A transport medium (e.g., soil, groundwater, air, etc.)
• An exposure point (where a receptor will contact the medium)
• An exposure route (i.e., ingestion, inhalation, or dermal contact).
A pathway is considered complete when all of the above elements are present.
Based on the information collected during the RI, the four transport mechanisms O£Curring
TABLE 8 CHEMICALS OF POTENTIAL CONCERN
CHEMICAUANAL YTE
(Contaminant of
Concern)
Acetone
Bis(2-chloroethyl)ether
Bromodichloromethane
2-Butanone
Carbon Disu~ide
Chloroethane
Chloroform
Dibromochloromethane
1,2-Dichloroethane
1, 1-Dichloroethene
1,2-Dichloroethene
1,2-Dichloropropane
Ethylbenzene
Methylene Chloride
Phenols
Styrene
SURFACE
SOIL
X
X
X
X
SUBSURFACE
SOIL (to 10
feet)
X
X
X
X
X
X
X
SUBSURFACE
SOIL (to Water
Table)
X
X
X
X
X
X
X
GROUNDWATER
X
X
X
X
X
X
X
X
X
SURFACE WATER
OUTSIDE PLANT
OPERATIONS
AREA
X
SURFACE WATER
INSIDE PLANT
OPERATIONS
AREA
X
X
X
SEDIMENT
OUTSIDE PLANT
OPERATIONS
AREA
X
X
X
X
X
X
SEDIMENT
INSIDE PLANT
OPERATIONS
AREA
X
X
X
X
. ----------------~---
TABLE 8 CHEMICALS OF POTENTIAL CONCERN
CHEMICAUANAL YTE SUBSURFACE SUBSURFACE SURFACE WATER SURFACE WATER SEDIMENT SEDIMENT
(Contaminant of SURFACE SOIL (to 10 SOIL (to Water GROUNDWATER OUTSIDE PLANT INSIDE PLANT O_UTSIDE PLANT INSIDE PLANT
Concern) SOIL feet) ·Table) OPERATIONS OPERATIONS OPERATIONS OPERATIONS
AREA AREA AREA AREA
Tetrachloroethene X X X X X
Toluene X X X X X
Total Xylenes X
1, 1,2· Trichloroethane X X
Trichloroethane X X
Vinyl Chloride X X X
Bis(2-ethylhexyl)phthalate X X X
Di-n-butyl Phthalate X
Di-n-octyl Phthalate X
Aluminum X
Antimony X X X
Arsenic X
Barium X
~------------------
TABLE 8 CHEMICALS OF POTENTIAL CONCERN
CHEMICAUANAL YTE . SUBSURFACE SUBSURFACE SURFACE WATER SURFACE WATER SEDIMENT SEDIMENT
(Contaminant of SURFACE SOIL (to 10 SOIL (to Water GROUNDWATER OUTSIDE PLANT INSIDE PLANT OUTSIDE PLANT INSIDE PLANT
Concern) SOIL feet) Table) OPERATIONS OPERATIONS OPERATIONS OPERATIONS
AREA AREA AREA AREA
Beryllium X X X
Cadmium X
Chromium X
Cobalt X X X
Copper X X
Cyanide X X X
Lead X X
Manganese X X X X X
Mercury X
Nickel X X X
Selenium X
Silver X
.
Thallium ·• X X X
Vanadium X X X
Zinc X
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DRAFT
at the NSCC site are:
-44-
NATIOt/Al Sl>Ja-t & CHEMICAL CoMPNff SUPERRJND SITE
DRAFT RECORl OF DECISION FOR OPERABLE UNIT #3
-SEPTBllER 1, 1993/7:21AM
• where soils exhibit high levels of contaminant, infiltration of recharge will form
leachate, which will transport the dissolved contaminants downward to the water
table
• once contaminants have reached the water table, the dissolved contaminants will be
transported with groundwater
• where contaminated groundwater discharges to a surface water body, the
contaminants will mix with the surface water and be transported downstream
• where contaminants in the water exhibit an affinity for partitioning to organic carbon,
some contaminants may become adsorbed to the surface sediment in the receiving
stream and may be transported with stream bedload during flooding. ·
The air pathway was qualitatively evaluated but not quantitatively evaluated as an
exposure pathway for volatilized chemicals and particulate emissions from surface soils
for the following reasons:
1) Much of the Site is covered with either concrete or asphalt;
2) Five VOCs were detected in surface soil; and
3) Each of the VOCs detected were at low concentrations, the highest concentration for
each contaminant detected in the surface soil are listed below:
Contaminant
acetone
2-butanone
chloroform
1,2-DCA
toluene
microgram per kilogram /µg/kg)
3,500
25
2
15
4
Potential current and future exposure pathways under are summarized in Table 9. This
table presents potential routes of exposure, potential receptors, an evaluation of pathway
completeness, and an assessment of exposure potential. As can be seen, there are no
current complete exposure pathways that pose an unacceptable risk to human health or
the environment. Since use of the land surrounding the NSCC facility is a mixture of
residential and commercial, it is possible that the Site may be used as either residential
or commercial area in the future, therefore, both scenarios were evaluated and
incorporated into Table 9.
-·-iiii --- --·-- - - - - - - - - -
TABLE 9
RECEPTOR
CHILDREN
ADULTS
POTENTIAL CURRENT AND FUTURE EXPOSURE PATHWAYS OF HUMAN EXPOSURE TO CONTAMINANTS
MIGRATION/EXPOSURE
PATHWAY
Incidental ingestion of surface soils
Dermal contact with surface soils
Incidental ingestion of subsurface soils
Dermal contact with subsurface soils
Migration of contaminants from soil to
groundwater, creek, and springs. Exposure via
incidental ingestion, drinking water ingestion,
dermal contact at stream and home, inhalation of
voes at stream and home.
Incidental ingestion of surface soils
Dermal contact with surface soils
Incidental ingestion of subsurface soils
Dermal contact with subsurface soils
INCLUDED IN RISK
ASSESSMENT?
CURRENT FUTURE
LAND USE LAND USE
Yes Yes
Yes Yes
No Yes
No Yes
No Yes
No Yes
No Yes
No Yes
No Yes
REASON FOR
INCLUSION/EXCLUSION
Surface soil is currently available for contact by on-site
receptors
Surface soil is currently available for contact by on-site
receptors
Subsurface soil is currently unavailable for contact.
Future development could expose subsurface soil for
future receptors .. Children may ingest significantly more
soil than adults.
Future development could expose subsurface soil for
future receptors
Contaminant may migrate from soil to groundwater
Surface soil is currently available for contact by on-site
receptors
Surface soil is currently available for contact by on-site
receptors
Subsurface soil is currently unavailable for contact.
Future development could expose subsurface soil for
future receptors.
Subsurface soil is currently unavailable for contact.
Future development could expose subsurface soil for
future receptors.
-------------------
TABLE 9
RECEPTOR
CHILDREN·
ADULT
POTENTIAL CURRENT AND FUTURE EXPOSURE PATHWAYS OF HUMAN EXPOSURE TO CONTAMINANTS
MIGRATION/EXPOSURE
PATHWAY
Migration of contaminants from Site to springs;
incidental ingestion of spring water
Migration of contaminants from Site to springs;
dermal contact with sprtng water
Use of groundwater as domestic water source:
ingestion of drinking water
Use of groundwater as domestic water source:
dermal contact with water
Use of groundwater as d_omestic water source:
inhalation of voes from household water use.
Migration of contaminants from Site to springs;
incidental ingestion of and dermal contact with
sprtng water
Use of groundwater as domestic water source:
ingestion of drinking water
Use of groundwater as domestic water source:
dermal contact with water
Use of groundwater as domestic water source:
inhalation of voes from household water use
INCLUDED IN RISK
ASSESSMENT?
CURRENT FUTURE
LAND USE LAND USE
Yes Yes
Yes Yes
No Yes
No Yes
No Yes
No No
No Yes
No Yes
No Yes
REASON FOR
INCLUSION/EXCLUSION
Site-related contaminants are present in the creek as a
result of groundwater discharge. Site-related chemicals
area also likely to be present in the springs near the
creek.
Site-related contaminants are present in the creek as a
result of groundwater discharge. Site-related chemicals
area also likely to be present in the springs near the
creek.
Future development could result in a production well in
this area
Future development could result in a production well in
this area
Future development could result in a production well in
this area
Adults are not expected to play in sprtngs
Future development could result in a production well in
this area
Future development could result in a production well in
this area
Future development could result in a production well in
this area
&!i == == iiiii liiil - - - - - - - - -··-- - - -
TABLE 9
RECEPTOR
CHILDREN
ADULTS
POTENTIAL CURRENT AND FUTURE EXPOSURE PATHWAYS OF HUMAN EXPOSURE TO CONTAMINANTS
MIGRATION/EXPOSURE
PATHWAY
Migration of contaminants from Site to creek;
incidental ingestion of creek sediment
Migration of contaminants from Site to creek;
incidental ingestion of surface water
Migration of contaminants from Site to creek;
dermal contact with sediment
Migration of contaminants from Site to creek;
dermal contact with surface water
Migration of contaminants from Site to creek;
inhalation of contaminants partitioning to air from
surface water
All pathways identified above
INCLUDED IN RISK
ASSESSMENT?
CURRENT
LAND USE
Yes
Yes
Yes
Yes
Yes
No
FUTURE
LAND USE
Yes
Yes
Yes
Yes
Yes
No
REASON FOR
INCLUSION/EXCLUSION
Site-related contaminants are present in creek water and
sediment. Children living in residential area nearby may
play in the creek
Site-rela.ted contaminants are present in creek water and
sediment. Children living in residential area nearby may
play in the creek
Site-related contaminants are present in creek water and
sediment. Children living in residential area nearby may
play in the creek
Site-related contaminants are present in creek water and
sediment. Children living in residential area nearby may
play in the creek
Detected chemicals may volatilize into air
Adults are not expected to swim or play in the creek
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DRAFT
-46-
NATIONAL Slm:tt & CHEMICAL CoMPANY SUPERRJNO Sm;
DRAFT RECORD OF DECISION FOR OPERABLE UNIT #3
-SEPIBeER 1, 1993fl:21AM
In summary, the following pathways were evaluated in the risk assessment:
• Potential current exposure under current land use conditions outside plant operations
area to contaminants in surface water and sediment and springs through incidental
ingestion and dermal contact, and inhalation.
• Potential current exposure under current land use conditions inside plant operations
area to contaminants in surface water and sediment, surface soil, and springs
through incidental ingestion and dermal contact, and inhalation. -
• Potential future exposure under future land use conditions inside plant operations
area to contaminants in surface water and sediment, surface soil, and springs
• Future exposure of onsite residents. to contaminants in the surface water and
sediment, surface soil, subsurface soils, groundwater, and springs through ingestion,
inhalation, and direct contact;
• Future exposure bf potential onsite construction workers to contaminants in soil
(surface and subsurface) through incidental ingestion and direct contact; and to
contaminants in groundwater, surface water, and sediment through direct contact.
8.0 SUMMARY OF SITE RISKS
CERCLA directs the Agency to protect human health and the environment from current
and future exposures.to hazardous substances at Superfund sites. In order to assess the
current and future risks from the NSCC Site, a baseline risk assessment was conducted
in conjunction with the RI. This section of the ROD summaries the findings concerning
the impact to human health and the environment if contaminated media (i.e.,
groundwater) at the Site were not remediated. The baseline risk assessment for OU #3
is incorporated into the June 2, 1993 OU #3 RI Report which can be found in the NSCC
OU #3 Administrative Record.
The following sections will concentrate on the risks posed by contaminants in the
groundwater and surface water and sediment. The risks posed by Site soils will be
summarized in OU #4.
8.1 CONTAMINANTS OF CONCERN
Table 8 provides a comprehensive list of all the contaminants identified as chemicals of
potential concern for all the environmental media sampled at the Site. Identified in the
right hand columns of Table 10 are those Site contaminants that pose a risk above
acceptable levels as identified during the baseline risk assessment encompa~s, It is
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DRAFT
-47-
these contaminants considered during the FS process.
NATION~ SrAA:::tt & CHEMICAL CoMPNff SUPERRJND SITE
~ RECOR'.l OF DecSION FOR OPERABLE UNIT #3
SEPTEMBER 1, 1993/7:21AM
The extent of the plumes are shown in Figures 3, 4, and 7 and the concentrations of
contaminants detected in the groundwater are presented in Tables 2, 3, 4, and 5.
There are residents within a three-mile radius to the Site who obtain drinking water from
private weUs. The nearest private potable wells are approximately 400 feet north of the
NSCC property line. These private potable wells are completed in the bedrock formation.
8.2 EXPOSURE ASSESSMENT
The objective of the exposure assessment is to estimate the type and magnitude of
potential exposures to the chemicals of concern that are present at the Site. The results
of the exposure assessment are combined with chemical-specific toxicity information to
characterize potential risks. The exposure assessment involves the following four (4)
major steps:
• characterization of the physical setting and identification of human receptors
• identification of potential land-use scenarios
• Identification of potential exposure pathways
• quantification of intakes.
The following pathways were evaluated in the risk assessment for each of the
environmental media adversely impacted by Site activities. For soils, they included:
• Incidental ingestion of soil
• Dermal contact with soil.
For groundwater, they included:
• Incidental ingestion of groundwater at springs (current)
• Dermal contact with groundwater ar springs (current)
• Ingestion of groundwater as drinking water (future)
• Dermal contact with groundwater during domestic water use (future)
• Inhalation of volatile chemicals partitioning to the air from groundwater during
domestic water use (use).
For surface water and sediment, they included:
--- - -111!1. - - - - - - ------. -- -
I TABLE 10 CHEMICALS OF CONCERN POSING RISK
CHEMICALS OF CONCERN
Acetone
Bis(2-Chloroethyl)ether
Bromodichloromethane
2-Butanone
Carbon Disulfide
Chloroethane
Chloroform
1,2-Dichloroethane
1, 1-Dichloroethene
1,2-Dichloroethene
1,2-Dichloropropane .
. Ethylbenzene
Methylene Chloride
Phenols
Styrene
Tetrachloroethene
Toluene
. CHEMICALS OF CONCERN
IN MEDIA
Groundwater Soll
X X
X
X X
X X
X
X X
X X
X
X
X
X X
X
X X
X X
Sediment
X
X
X
X
X
X
X
X
X
·x
Surface
Water
X
X
X
X
X
X
CHEMICALS WHICH WILL POSE AS
A RISK
Groundwater Soll 5edlment Surface
Water
X
X
X
X
X X X X
X
X
X
X
X
X
X
-------------------
I TABLE 10 CHEMICALS OF CONCERN POSING RISK
CHEMICALS OF CONCERN
Total Xylenes
1,1,2-Trichloroethane
Trichloroethene
Vinyl chloride
Bis(2-Ethylhexyl)phthalate
Di-n-butyl Phthalate
Di-n-octyl Phthalate
Aluminum.
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
CHEMICALS OF CONCERN
IN MEDIA
Groundwater Soll Sediment Surface
Water
X
X X
X X
X X
X X
x·
X
X
X X X
X X
X
X X X
X X X
X X
CHEMICALS WHICH WILL POSE AS
A RISK
Groundwater Soll Sediment Surface .
Water
X
X
X
X X
X
X
X
X X
-~-----------------
TABLE10 CHEMICALS OF CONCERN POSING RISK
CHEMICALS OF CONCERN CHEMICALS WHICH WILL POSE AS
IN MEDIA A RISK
CHEMICALS OF CONCERN Groundwater Soll Sediment Surface Groundwater Soll Sediment Surface
Water Water
Cobalt X X X
Copper X X X
Cyanide X X X X
Lead X X
Manganese X X X
Mercury X X
Nickel X X X
Selenium X X
Silver X X X
Thallium X X X X
Vanadium X X
Zinc X
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DRAFT
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• Incidental ingestion of creek sediment
• Incidental ingestion of surface water
• Dermal contact with creek sediment
• Dermal contact with surface water
NATIONAL STAR::H & CHEMICAi.. CoMPANY SUPERRJND SITE.
DRAFT AECOPD OF DECISION FOR OPERABl.E UNrr #3
-SEPTB.f!ER 1, 1993/7:21AM
• Inhalation of volatile chemicals partitioning to air from surface water.
Although, the impacted groundwater is not currently being used as a drinking water
source, the aquifer itself is being used as a source of drinking water, therefore, this
resource should be maintained at drinking water quality.
Table 11 provides the reasonable maximum exposure concentrations which were used
in calculating the carcinogenic and noncarcinogenic risks associated with each chemical
of concern. Table 12 lists the specific parameters used to model the site-specific intakes
for OU #3. And Table 13 provides the computed chemical intakes values along with the
calculated risks.
8.3 TOXICITY ASSESSMENT
The toxicity assessment was conducted to further determine the potential hazard posed
by the chemicals of concern for which exposure pathways have been identified. Available
evidence is weighed in regards to the potential of particular contaminants to cause
adverse effects in exposed individuals and to provide, where possible, an estimate of the
relationship between the extent of exposure to a contaminant and the increased likelihood
and/or severity of adverse effects.
Cancer slope factors (CSFs) have been developed by EPA's carcinogenic Assessment
Group for estimating excess lifetime cancer risks associated with exposure to potentially
carcinogenic chemicals. CSFs, which are expressed in units of milligrams/kilogram/day-1
[(mg/kg/dayr1J, are multiplied by the estimated intake of a potential carcinogen, in
(mg/kg/day), to provide an upper-bound estimate of the excess lifetime cancer risk
associated with exposure at that intake level. The term "upper-bound" reflects the
conservative estimate of the risks calculated from the CSF. Use of this approach makes
underestimation of the actual cancer risk highly unlikely. CSFs are derived from the
results of human epidemiological studies or chronic animal bioassays to which animal-to-
human extrapolation and uncertairity factors have been applied.
Reference doses (RiDs) have been developed by EPA for indicating the potential for
adverse health effects from exposure to chemicals exhibiting noncarcinogenic (systemic)
effects. Rps, which are expressed in units of mg/kg/day, are estimates of lifetime daily
-------------------
TABLE 11 UPPER CONFIDENCE LIMITS (95%) FOR CHEMICALS AND ASSOCIATED USED TO EVALUATE RISK CONDITIONS
CHEMICAUANAL YTE
(Contaminant of Concern)
Acetone
Bis(2-chloroethyl)ether
~-Butanone
Carbon Disulfide
Chloroethane
Chloroform
1,2-Dichloroethane
1,2-Dichloroethene
Ethylbenzene
Methylene Chloride
Styrene
Tetrachloroethene
Toluene
Total Xylene's
1,1,2-Trichloroethane
EXPOSURE POINT
CONCENTRATION
FOR GROUNDWATER
(mg/I)
0.04
0.00902
0.00522
0.431
0.0071
0.00603
0.00478
0.0047
0.00478
EXPOSURE POINT
CONCENTRATION
FOR SURFACE
WATER OUTSIDE
· PLANT OPERATIONS
AREA IN NORTHEAST
TRIBUTARY (mg/I)
'1.04
0.00258
EXPOSURE POINT
CONCENTRATION
FOR SURFACE
WATER INSIDE PLANT
OPERATIONS AREA IN
NORTHEAST
TRIBUTARY (mg/I)
0.001
1.26
0.002
EXPOSURE POINT
CONCENTRATION
FOR SEDIMENT
OUTSIDE PLANT
OPERATIONS AREA
IN NORTHEAST
TRIBUTARY (mg/kg).
. 0.044
0.00588
0.98
0.0036
0.00276
0.00783
0.002
0.00247
0.00327
EXPOSURE POINT
CONCENTRATION
FOR SEDIMENT
INSIDE PLANT
OPERATIONS AREA
IN NORTHEAST
TRIBUTARY (mg/kg)
0.066
0.00842
2.55
0.0283
0.002
0.003
- - - --·-- - - - - - - - - - - - -
TABLE 11 UPPER CONFIDENCE LIMITS {95%) FOR CHEMICALS AND ASSOCIATED USED TO EVALUATE RISK CONDITIONS
CHEMICAUANAL YTE
(Contaminant of Concern)
Trichloroethane
Vinyl Chloride
Bis(2-ethylhexyl)phthalate
Di-n-butyl Phthalate
Di-n-octyl Phthalate
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
EXPOSURE POINT
CONCENTRATION
FOR GROUNDWATER
(mg/I)
0.00446
0.011
0.013
0.017
0.002
29.1
0.0185
0.00194
0.257
0.000667
0.00311
0.0414
EXPOSURE POINT
CONCENTRATION
FOR SURFACE
WATER OUTSIDE
PLANT OPERATIONS
AREA IN NORTHEAST
TRIBUTARY (mg/I)
EXPOSURE POINT
CONCENTRATION
FOR SURFACE
WATER INSIDE PLANT
OPERATIONS AREA IN
NORTHEAST
TRIBUTARY (mg/I)
EXPOSURE POINT
CONCENTRATION
FOR SEDIMENT
OUTSIDE PLANT
OPERATIONS AREA
IN NORTHEAST
TRIBUTARY (mg/kg)
0.00247
EXPOSURE POINT
CONCENTRATION
FOR SEDIMENT
INSIDE PLANT
OPERATIONS AREA
IN NORTHEAST
TRIBUTARY (mg/kg)
-------------------
TABLE 11 UPPER CONFIDENCE LIMITS (95%) FOR CHEMICALS AND ASSOCIATED USED To EVALUATE RISK CONDITIONS
EXPOSURE POINT EXPOSURE POINT EXPOSURE POINT EXPOSURE POINT
CONCENTRATION CONCENTRATION CONCENTRATION CONCENTRATION
EXPOSURE POINT FOR SURFACE FOR SURFACE FOR SEDIMENT FOR SEDIMENT
CHEMICAUANAL YTE CONCENTRATION WATER OUTSIDE WATER INSIDE PLANT OUTSIDE PLANT INSIDE PLANT
FOR GROUNDWATER PLANT OPERATIONS OPERATIONS AREA IN OPERATIONS AREA . OPERATIONS AREA
(Contaminant of Concern) (mg/I) AREA IN NORTHEAST NORTHEAST IN NORTHEAST IN NORTHEAST
TRIBUTARY (mg/I) TRIBUTARY (mg/I) TRI.BUTARY (mgil<g) TRIBUTARY (mgil<g)
Cobalt 0.0191 ---------------
Copper 0.301 0.0037 -----------
Cyanide 0.000734 --------------
Lead 0.00394 0.0021 ----. --------
Manganese 2.73 0.213 0.134 -------
Mercury 0.000149 --------------
Nickel 0.0176 ---------------
Selenium 0.00391 ---------------
Silver 0.00319 --------------
Thallium 0.00104 ---------------
Vanadium 0.0759 ---------------
Zinc 1.34 --------------
TABLE 12 PARAMTERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN
Current Land Use
Pathway/
Parameter"
Cs
Age
IR
Fl
CF
EF
ED
BW
AT-Noncancer
Current Conditions
Outside Plant Operations
Area
UCLb or maximum
concentration in sediment
7-16 years
100 mg/day
0.25
1 x 1 o.s kg/mg
143 days/year
1 O years
45 kg
3,650 days
AT-Cancer 25,550 days
Cs i UCL or maximum
concentration in sediment
Future Conditions
Inside Plant Operations
Area.
UCL or maximum
concentration in sediment
7-16years
100 mg/day
0.25
1 X 10-6 kg/mg
143 days/year
10 years
45 kg
3,650 days
. 25,550 days
· UCL or maximum
concentration in sediment
Future Land Use
Reasonable Maximum
Exposure
UCL or maximum
concentration in sediment
1-12 years
140 mg/day
0.5
1 x 1 o.s kg/mg
286 days/year
12 years
22.5 kg
4,380 days
25,550 days
UCL or maximum
concentration in sediment
Reference(s)/
Justification
Assumption (See \ext)
Based on ingestion of 200 mg/day to age 6
and 100 mg/day after that (EPA, 1991 b)
Assumption (See text)
See text. Assume 2x current EF for future
Corresponds to age exposed
Average for years exposed EPA (Region IV
Guidance)
365 x ED
365 x 70 yr lifetime
-· - - - -·-- - -·-· -·--·------
TABLE 12 PARAMTERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN
Pathway/
Parameter"
Age
SA
AF
ABS
CF
EF
ED
BW
AT-Noncancer
AT-Cancer
Cw
Age
Current Land Use Future Land Use
Current Conditions Future Conditions
Outside Plant Operations Inside Plant Operations Reasonable Maximum
Area Area Exposure
7-16 years 7-16 years 1-12 years
3,400 cm2/event 3,400 cm 2/event 2,200 cm2/event
0.2 mg/kg 0.2 mg/kg 0.2 mg/kg
0.01 Organics 0.01 Organics 0.01 Organics
0.001 lnorganics 0.001 lnorganics 0.001 lnorganics
1.0 x 1 O:° kg/mg 1.0 X 10-6 kg/mg 1.0 x 10-6 kg/mg
143 events/year 143 events/year 286 events/year
10 years 1 O years 12 years
45 kg 45 kg 22.5 kg
3.650 days 3,650 days . 4,380 days
25,550 days 25,550 days 25,550 days
UCL or maximum UCL or maximum UCL or maximum
concentration in surface water concentration in surface water concentration in surface water
7-16 years 7-16 years 1-12years
Reference(s)/
Justification
Assumption (See text)
Average surface area of arms, hands, legs, ·
and feet for years exposed (EPA, 1992a)
EPA Region IV Guidance
EPA Region IV Guidance
See text. Assume 2x current EF for future
Corresponds to age exposed
Average for years exposed (EPA Region IV
Guidance)
365 x ED
365 x 70 yr lifetime
Assumption (See text)
- - -.. - - --·-- - -·-- --··-- -
TABLE 12 PARAMTERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN
Current Land Use
Pathway/
Parameter"
IR
Fl
ET
EF
ED
BW
Current Conditions
Outside Plant Operations
Area
25 ml/hr
1 (unitless)
1 hr/day
143 days/year
10 years
45 kg
AT-Noncancer 3,650 days
AT-Cancer 25,550 days
Cw UCL or maximum
concentration in surface water
Age 7-16 years
SA 3,400 cm2
CF 0.001 Ucm3
PC Chemical specific cm/hr
Future Conditions
Inside Plant Operations
Area ·
25 ml/hr
1 (unitless)
1 hr/day
143 days/year
1 O years
45 kg
3,650 days·
25,550 days
UCL or maximum
concentration in surface water
7-16 years
3,400 cm2
0.001 Ucm3
Chemical specific cm/hr
Future Land Use
Reasonable Maximum
Exposure
25 ml/hr
1 (unitless)
1 hr/day
286 days/year
12 years
22.5 kg
4,380 days
25,550 days
UCL or maximum
concentration in ·surface water
1-12years
2,200 cm 2
0.001 Ucm3
Chemical specific cm/hr
Reference(s)/
Justification
50% of swimming ingestion (EPA, 1991 b)
Assumption
50% of swimming time (EPA, 1991b)
See text. Assume 2x current EF for future
Corresponds to age exposed
Average for years exposed (EPA Region IV
Guidance)
365 x ED
365 x 70 yr lifetime
Assumption (See text)
Average arms, hands, legs, feet for years
exposed (EPA, 1992a)
EPA, 1992a
- - - - - - - - - - --· - ---.. -.. -
TABLE 12 PARAMTERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN .
Current Land Use
Pathway/
Parameter"
ET
EF
ED
BW
AT-Noncancer
Current Conditions
Outside Plant Operations
Area
2 hr/day
143 days/year
10 years
45 kg
3,650 days
AT-Cancer 25,550 days
Ca Calculated from UCL or
maximum concentration in
surface water
.
Age 7-16 years
IR 3.2 m3/hr
ET 2 hr/day
EF 143 days/year
ED 10 years
Future Conditions
Inside Plant Operations
Area
2 hr/day
143 days/year
10 years
45 kg
3,650 days
25,550 days
Calculated from UCL or
maximum concentration in
surface water
7-16 years
3.2 m3/hr
2 hr/day
143 days/year
10 years
Future Land Use
Reasonable Maximum
Exposure
2 hr/day
266 days/year
12 years
22.5 kg
4,360 days
25,550 days
Calculated from UCL or
maximum concentration in
surface water
1-2 years
3.2 m3/hr
2 hr/day
266 days/year
12 years
Rn•e•nncn(s" VI l'C'I C' JI
Justification
EPA, 1990b
See text. Assume 2x current EF for future
Corresponds to age exposed
Average for years exposed (EPA Region IV
Guidance)
365 x ED
365 x 70 yr lifetime
Calculated values in
Assumption (See text)
For moderate activity at age 10 (EPA,
1990b)
See text. Assume 2x current EF for future.
- - - - - -·-- - --· - -. - - - -. - -
TABLE 12 PARAMTERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN
Current Land Use Future Land Use
Current Conditions Future Conditions
Pathway/ Outside Plant Operations Inside Plant Operations Reasonable Maximum Reference(s)/
Parameter" Area Area Exposure Justification
BW 45 kg 45 kg 22.5 kg Average for years exposed (EPA Region IV
Guidance)
AT-Noncancer 3,650 days 3,650 days 4,380 days 365 x ED
AT-Cancer 25,550 days 25,550 days 25,550 days 365 x 70 yr lifetime
Cw UCL or maximum
concentration in groundwater
Age 0-30 years Assumption (See text)
IR 2 Uday Upperbound estimates EPA, 1991b
Fl 1 unitless 100% of drinking water is assumed to come
from contaminated area (EPA, 1991 b)
EF 350 days/year See text
ED 30 years 90% upperbound of time lived in one place
(EPA, 1991 b)
BW 70 kg Standard default for adult exposure (EPA,
1991 b)
I AT-Noncancer 10,950 days 365 x ED
AT-Cancer 25,550 days 365 x 70 yr lifetime
- - - - - - - - - - - - - - - -----
TABLE 12 PARAMTERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN
Pathway/
Parameter'
Cw
Age
SA
CF
PC
ET
EF
ED
BW
AT-Noncancer
AT-Cancer
Current Land Use
Current Conditions
Outside Plant Operations
Area
Future Conditions
Inside Plant Operations
Area
Future Land Use
Reasonable Maximum
Exposure
UCL or maximum
concentration in groundwater
0-30 years
21,500 cm2
0.001 Ucm3
Chemical-specific cm/hr
0.2 hour/day
350 days/year
30 years
70 kg
10,950 days
25,550 days
Reference(s)/
Justification
Assumption (See text)
Average of whole body for years exposed
(EPA, 1992a)
EPA, 1992a
EPA, 1991b
See text
Corresponds to age exposed
Standard default for adult exposure (EPA,
1990a)
365 x ED
365 x 70 yr lifetime
- - - - -- ---··----- - - - -·-.
TABLE 12 PARAMTERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN
Current Land Use
Current Conditions
Pathway/ Outside Plant Operations
Parameter' Area
Ca
Age
IR
ET
Shower
Indoors
EF
ED
BW
AT-Noncancer
AT-Cancer
Cw i
Future Conditions
Inside Plant Operations
Area
Future Land Use
Reasonable Maximum
Exposure
Calculated from UCL or
maximum concentration in
groundwater
0-30 years
0.63 m3/hr
0.2 hour/day
16 hour/day
350 days/year
30 years
70 kg
10,950 days
25,550 days
UCL or. maximum
concentration in groundwater
Reference(s)/
Justification
Calculated values
Assumption (See text)
Average (EPA, 1991 b)
Upperbound estimate (EPA, 1991b)
Upperbound estimate (EPA, 1991b)
See text
Upperbound estimate (EPA, 1991 b)
Standard default for adult exposures (EPA,
1990a)
365 x ED
365 x 70 yr lifetime
-1!!!11 ---- - - - - - --------- -
TABLE 12 PARAMTERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN
Pathway/
Parameter"
Age
IR
Fl
EF
ED
BW
AT-Noncancer
AT-Cancer
Cw
Age
SA
CF '
PC
Current Land Use
Current Conditions
Outside Plant Operations
Area
Future Conditions
Inside Plant Operations
Area
Future Land Use
Reasonable Maximum
Exposure
1-12 years
2 Uday
1 Unitless
350 days/year
12 years
22.5 kg
4,380 days
25,550 days
UCL or maximum
concentration in groundwater
1-12 years
8,900
0.001 Ucm3
Chemical-specific cm/hr .
Reference(s)/
Justification
Assumed
Assumed same ingestion rate as adults
100% of drinking water is assumed to come
from contaminated area (EPA, 1991b)
See text
Corresponds to age exposed
Average years exposed (EPA, 1990b)
ED x 365 days/year
70 year lifetime x 365 days/year
Assumed
Average for whole body
(EPA, 1992a)
EPA, 1992a
-------------------
TABLE 12 PARAMTERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN
Pathway/
Parameter"
ET
EF
ED
BW
AT-Noncancer
AT-Cancer
Ca
Age
IR
ET
Shower
Indoors
EF
Current Land Use
Current Conditions
Outside Plant Operations
Area
Future Conditions
Inside Plant Operations
Area
Future Land Use
Reasonable Maximum ·
Exposure
0.2 hour/day
350 days/year
12 years
22.5 kg
4,380 days
25,550 days
Calculated from UCL or
maximum concentration in
groundwater
1-12years
0.63 m3thr
0.2 hour/day
16 hours/day
350 days/year
Reference(s)/
Justification
EPA, 1991b
See text
Corresponds to age exposed
Average for years exposed
(EPA, 1990b)
ED x 365 days/year
70-year lifetime x 365 days/year
Calculated value
Assumed
Assumed same inhalation rate as adults
Upperbound estimate (EPA, 1991b)
Upperbound estimate (EPA, 1991b)
See text
-· - - - - - - - ----· - - - - - - - -
TABLE 12 PARAMTERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN
Pathway/
Parameter"
ED
BW
AT-Noncancer
AT-Cancer
Current Land Use
Current Conditions
Outside Plant Operations
Area
Future Conditions
. Inside Plant Operations
Area
Cw UCL or maximum UCL or maximum
concentration in surface water concentration in surface water
Age 7-16 years 7-16years
IR 25 ml/hr 25 ml/hr
Fl 1 unitless 1 unitless .
ET 0.5 hr/day 0.5 hr/day
EF 71 days/year 71 days/year .
ED 10 years 1 O years .
BW 45 kg 45 kg
AT-Noncancer 3,650 days 3,650 days '
AT-Cancer 25,550 days 25,550 days
Future Land Use
Reasonable Maximum
Exposure
12 years
22.5 kg
4,380 days
25,550 days
UCL or maximum
concentration in surface water
1-12 years
25 ml/hr
1 unitless
0.5 hr/day
143 days/year
12 years
22.5 kg
4,38d days
25,550 days
Reference(s)/
Justification
Corresponds to age exposed
Average for years exposed (EPA, 1990b)
ED x 365 days/year
70-year lifetime x 365 days/year
Assumption (See text)
50% of swimming ingestion (EPA, 1991b)
Assumption
50% of swimming time (EPA, 1991 b)
See text. Assume 2x current EF for future
Corresponds to age exposed
Average for years exposed (EPA, 1990a)
365 x ED
365 x 70 yr lifetime
•
-------------------
TABLE 12 PARAMTERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN
Pathway/
Parameter"
Cw
Age
SA
CF
PC
ET
EF
ED
BW
AT-Noncancer
Current Land Use
Current Conditions
Outside Plant Operations
Area
.
Future Conditions
Inside Plant Operations
Area
Future Land Use
Reasonable Maximum
Exposure
UCL or maximum UCL or maximum UCL or maximum
concentration in surface water concentration in surface water concentration in surface water
7-16 years 7-16years 1-12years
3,400 cm2 3,400 cm2 2,200 cm 2
0.001 Ucm3 0.001 Ucm3 0.001 Ucm3
Chemical-specific cm/hr Chemical specific cm/hr Chemical specific cm/hr
1 hr/day 1 hr/day 1 hr/day
71 days/year 71 days/year 143 days/year
10 years 10 years 10 years
45 kg 45 kg 22.5 kg
3,650 days 3,650 days 4,380 days
AT-Cancer 25,550 days 25,550 days 25,550 days
Reference(s)/
Justification
Assumption {See text)
Average arms, hands, legs, feet for years
exposed {EPA, 1990a)
EPA, 1992a
EPA, 1991b
See text. Assume 2x current EF for future
Corresponds to age exposed
Average for years exposed {EPA, 1990a)
365 x ED .
365 x 70 yr lifetime
-------------------
a
b
-
TABLE 12 PARAMTERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN
Current Land Use Future Land Use
Current Conditions Future Conditions
Pathway/ Outside Plant Operations Inside Plant Operations Reasonable Maximum Reference(s)/
Parameter' Area Area Exposure Justification
Ca. Calculated from UCL or Calculated from UCL or Calculated from UCL or Calculated values
maximum concentration in maximum concentration in maximum concentration in
surface water surface water surface water
Age 7-16years 7-16 years 1-2 years. Assumption (See text)
IR 3.2 m3thr 3.2 m3/hr 3.2 m3/hr For moderate activity at age 10 (EPA,
1990b)
ET 1 hr/day 1 hr/day 1 hr/day Less time in springs than in tributary
EF 143 days/year 143 days/year 286 days/year See text. Assume 2x current EF for future.
.
ED . 1 O years 1 O years 12 years
BW 45 kg 45 kg 22.5 kg Average for years·exposed (U.S. EPA
Region IV Guidance)
AT-Noncancer 3,650 days 3,650 days 4,380 days 365 x ED
AT-Cancer 25,550 days 25,550 days 25,550 days 365 x 70 yr lifetime
Parameters are ·Cx = concentration in media "x"; IR = ingestion rate or inhalation rate (with volatiles); Fl = fraction ingested from source; EF =
exposure frequency; ED= exposure duration; BW =bodyweight; AT-Noncancer = average time for noncarcinogens; AT-Cancer= averaging time
for carcinogens; SA = surface area exposed; AF = adherence factor; ABS-= absorption factor; CF = conversion factor; ET = exposure time; PC
= permeability constant.
UCLJUpper 95% confidence limit
-------------------
TABLE 12 PARAMTERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN
Pathway/
Parameter"
Current Land Use
Current Conditions
Outside Plant Operations
Area
Future Conditions
lriside Plant Operations
Area
Future land Use
Reasonable Maximum
Exposure
Reference(s)/
Justification
I g;rm;r~mmfflllitilllt~E!!l~t!nBI II I~ ii
Cw UCL or maximum UCL or maximum UCL or maximum
concentration in sur!ace water concentration in surface water concentration in surface water
Age 7-16 years 7-16 years 1-12 years Assumption (See text}
SA 3,400 cm2 3,400 cm2 2,200 cm 2 Average arms, hands, legs, feetfor years
exposed (EPA, 1990a}
CF 0.001 Ucm 3 0.001 Ucm 3 0.001 Ucm3
PC Chemical-specific cm/hr Chemical specific cm/hr Chemical specific cm/hr EPA, 1992a
ET 1 hr/day 1 hr/day 1 hr/day EPA, 1991b
EF 71 days/year 71 days/year 143 days/year See text. Assume 2x current EF for future
ED 10 years 1 O years 10 years Corresponds to age exposed
BW 45 kg 45 kg 22.5 kg Average for years exposed (EPA, 1990a}
AT-Noncancer 3,650 days 3,650 days 4,380 days 365 x ED .
AT-Cancer 25,550 days 25,550 days 25,550 days 365 x 70 yr lifetime
- - - - - - -.. - - -·---· --· - ---
a
b
TABLE 12 PARAMTERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN
Current Land Use Future Land Use
Current Conditions Future Conditions
Pathway/ Outside Plant Operations Inside Plant Operations Reasonable Maximum Reference(s)/
Parameter' Area Area Exposure Justification
Ca Calculated from UCL or Calculated from UCL or Calculated from UCL or Calculated values
maximum concentration in maximum concentration in · maximum concentration in
surface water surface water surface water
Age 7-16 years 7-16 years 1-2 years Assumption (See text)
IR 3.2 m3/hr 3.2 m3/hr 3.2 m3/hr For moderate activity at age 10 (EPA,
1990b)
ET 1 hr/day 1 hr/day 1 hr/day Less time in springs than in tributary
EF 143 days/year 143 days/year 286 days/year See text. Assume 2x current EF for future.
ED 1 O years 10 years 12 years
BW 45 kg 45 kg 22.5 kg Average for years exposed (U.S. EPA
Region IV Guidance)
AT-Noncancer 3,650 days 3,650 days 4,380 days 365 x ED
AT-Cancer 25,550 days 25,550 days 25,550 days 365 x 70 yr lifetime
Parameters are C, = concentration in media "x";· IR = ingestion rate or inhalation rate (with volatiles); Fl = fraction ingested from source; EF =
exposure frequency; ED= exposure duration; BW =bodyweight; AT-Noncancer = average time for noncarcinogens; AT-Cancer= averaging time
for carcinogens; SA = surface area exposed; AF = adherence factor; ABS = absorption factor; CF = conversion factor; ET = exposure time; PC
= permeability constant.
UCL-Upper 95% confidence limit
- - - - - - - -.· - - ---- - - - - - -
TABLE 13 ESTIMATED POTENTIAL FUTURE LAND USE HAZARD ASSOCIATED WITH NONCARCINOGENS
POTENTIALLY DERMALLY DERMAL INGESTED INHALED INHALATION
EXPOSED ABSORBED CONTACT DOSE INGESTION · DOSE OF voes
POPULATION CHEMICAL DOSE HQ (mg/kg/day) HQ (mg/kg/day) HQ
(mg/kg/day)
Silver 1.88 X 10'7 7.51 X 10-4 8.73 X 10·5 1.75 X 10'2 NA NA
• •' Tetrachloroethene 1.35 X 10'5 1.50 X 10·3 1.31 X 104 1.31x10·2 · NA . NA
Thallium 6.14 X 10'8 2.05 X 10·2 2.86 X 10 5 4.76 X 10-1 NA NA
Total Xylenes 2.21 X 10'5 1.11 X 10·5 1.29 X 10·4 6.44 X 10·5 NA NA
,1 T richloroethene 4.20 X 10-6 7.78 X 104 1.22 X 104 2.03 X 10·2 NA NA
Vanadium 4:47 X 10-6 1.28 X 10·2 2.08 X 10·3 2.97 X 10-1 NA NA
Zinc 7.87 X 10·5 4.24 X 10·3 3.66 X 10'2 1.22 X 10-1 NA NA
)
Total HQ 7.81 X 10-1. 1.83 X 10° 9.86 X 10·7
Total Media HI . 1.91x101
Child Resident Carbon disulfide 9.19x10·7 1.02x 10-5 2.18 X 10·7 2.18 X 10·5 4.52 X 10·5 1.51 X 10·3
Manganese (water) 5.13 X 10-6 2.05x 10 2 2.92 X 10·5 5.83 X 10·3 NA NA
· Methylene chloride 3.45 X 10·7 5.75 X 10-6 4.35 X 10'7 7.26 X 10·5 9.05 X 10·5 1.01x10 5
Total HQ 2.05 X 10'2 5.84 X 10·3 1.52 X 10·3
Total Media HI 2.79 X 10 2
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DRAFT
-53-
NATIONAi.. STAFCH & ClsEMICAI.. COMP.INY SUPERRJNO SITE
DRAFT RECD~ OF DECISION FOR O?£RA8l.E Umr #3
-SEPTB.EEA 1, 1993/7:21..w
exposure levels for humans, including sensitive individuals, which will result in no adverse
health effects. Estimated intakes of chemicals from environmental media (i.e., the
amount of chemical ingested from contaminated drinking water) can be compared to the
A.O. A.Os are derived from human epidemiological studies or animal studies to which
uncertainty factors have been applied (i.e., to account for the use of animal data to
predict effects on humans). These uncertainty factors help ensure that the R,Ds will not
underestimate the potential for adverse noncarcinogenic effects to occur.
The Agency has derived CSFs and A.Os for the contaminants of concern at the Site for
use in determining the upper-bound level of cancer risk and non-cancer hazard from
exposure to a given level of contamination. These values are provided in Table 14.
8.4 RISK CHARACTERIZATION
The risk characterization step of the baseline risk assessment process integrates the
toxicity and exposure assessments into quantitative and qualitative expressions of risk.
The output of this process is a characterization of the site-related potential
noncarcinogenic and carcinogenic health effects.
Potential concern for noncarcinogenic effects of a single contaminant in a single medium
is expressed as the hazard quotient (HQ) (or the ratio of the estimated intake derived
from the contaminant concentration 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 population may be reasonably exposed, the Hazard Index (HI) can be
generated. The HI provides a useful reference point for gauging the potential significance
of multiple contaminant exposures within a single medium or across media. The Hqs and
His for the exposure pathways (current and future) identified at the Site are listed in Table
13.
The HQ is calculated as follows:
· Non-cancer HQ = CDI/A1D, where:
COi = Chronic Daily Intake
A.O = reference dose; and
COi and R,D are expressed in the same units and represent the same exposure
period (i.e., chronic, subchronic, or short-term).
For carcinogens, risk are estimated as the incremental probability of an individual
developing cancer over a life-time as a result of exposure to the carcinogen. Excess life-
time cancer risk is calculated from the following equation:
I
I TABLE14 SUMMARY OF CARCINOGENIC EFFECTS OF CHEMICALS OF POTENTIAL CONCERN
I INHALATION ORAL CSF EPA GASTROINTESTINAL
CHEMICAL CSF (mg/kg/day}"1 GROUP ABSORPTION
(mg/kg/day)"1 FACTOR a
I
• Acetone ND ND Db 0.9 I Bis(2-Chloroethyl)ether 1.2x10ob 1.1x10ob B2 b 0.9
I Bromodichloromethane ND 6.2 X 10'2 b B2 b 0.9
2-Butanone ND ND ND 0.9
I Carbon Disuttide ND ND ND 0.9
Chloroethane ND ND NA 0.9
I Chloroform .8.1 X 10·2 b 6.1 X 10'3 b B2 b 1.0
Dibromochloromethane ND 8.4 X 10·2 b Cb 0.9
I 1,2-Dichloroethane 9.1X10'2 b 9.1x10·2 b B2 b 0.9
1, 1-Dichloroethene 1.75x10·'b 6.1 X 10'1 b Cb 0.93
I 1,2-Dichloroethene ND C ND ND 0.9
6.8 X 10·2 d B2 d 1,2-Dichloropropane ND 0.9
I Ethylbenzene ND ND Db 0.9
Methylene Chloride 1.7 X 10'3 b 7.5 X 10'3 b B2 b 1.0
I Styrene ND 0 ND 0 ND 0.9
Tetrachloroethene 2.0 X 10'3 8 5.2 X 10'2 8 C -B2 ° 0.9
I Toluene ND ND Db 1.0
Total Xylenes ND ND Db 1.0
I 1, 1,2-Trichloroethane 5.7 X 10'2 b 5.7 X 10·2 b Cb 0.9
Trichloroethane 6.0 X 10'3 8 1.1 X 10'2 8 C -B2 ° 0.9
I Vinyl Chloride 3.0 X 10'1 d 1.9x10°d Ad 0.9
I Bis(2-Ethylhexyl)phthalate ND 1.4 X 10'2 b B2 b 0.9
I Di-n-butyl Phthalate ND ND Db 0.9
Di-n-octyl Phthalate ND ND NA 0.9
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I • -=
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I TABLE 14 SUMMARY OF CARCINOGENIC EFFECTS OF CHEMICALS OF POTENTIAL CONCERN
I INHALATION ORAL CSF EPA GASTROINTESTINAL
CHEMICAL CSF (mg/kg/day)"1 GROUP ABSORPTION
(mg/kg/day)"1 FACTOR a
I Delta-BHC ND ND Ob 0.9
,I Aluminum ND ND NA 0.05
I Antimony ND ND NA 0.05
Arsenic 0 1.5x10•1 b 1.75 X 10ob Ab 0.98
I Barium ND ND NA 0.1
Beryllium 8.4X10'b 4.3 X 10° b B2 b 0.001
I Cadmium 6.3 X 10° b ND B1 b 0.06
Chromium VI 1 4.2X10'1 b ND Ab 0.05
I Cobalt ND ND NA 0.05
Copper ND ND NA 0.5
I Cyanide ND ND Ob 0.05
Lead ND ND B2 b 0.1
I Manganese ND ND Ob 0.05
Mercury ND ND Ob 0.15
I Nickel 8.4 X 10'1 b ND Ab 0.05
Selenium Ob ND ND 0.6
I Silver ND ND Ob 0.05
Thallium ND ND Ob 0.05
I Vanadium ND ND NA 0.05
/ Zinc ND ND NA 0.5
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SUMMARY OF NONCANCER TOXIC EFFECTS OF CHEMICALS OF POTENTIAL CONCERN
CHEMICAL
Bis(2-C hloroethyl)ether
Bromodichloromethane
2-Butanone
Carbon Disuttide
Chloroethane
Dibromochloromethane
1,2-Dichloroethane
1, 1-Dichloroethene
1,2-Dichloroethene0
1,2-Dichloropropane
Ethylbenzene
Methylene Chloride
Tetrachloroethene
INHALATION
RfCh
(mg/kg/day)
· ND
ND
3 X 10·1 m
· 3 X 10·3 d
.ND
ND
ND
ND
ND'
ND
1 X 10•>m
3x10-'m
9 X 10·1 m
ND
3 X 10·1 m
ND
1 X 1 o·l m .
ORAL RfDh_
(mg/kg/day)
ND
2 X 10•2m
5 X 10.,m
10 X 10-lm
ND
1 X 10•2m
2 X 10•2m
ND
9 X 10•3m
1 X 10·2d
ND
1 X 10·1 m
6x10•2m
6 X 10·1 m
2 X 10·1 m
1 X 10•2m
2 X 10·1 m
~ -=
CRITICAL EFFECT
AND
TARGET ORGAN1
(Inhalation; oral)
NA; liver, kidney
damage
NA; NA
NA; renal
cytomegaly
Central nervous
system; fetotoxicity
Fetal toxicity; fetal
toxicity, malformation
NA; NA
NA; fatty cyst on
liver, liver lesions
NA; hepatic lesions
NA;NA
NAq; hepatic lesions
NA; decreased
hematocrtt and
hemoglobin
NA;NA
Developmental
toxicity;
hepatotoxicity and
nephrotoxicity
NA; liver toxictty
NA;NA
NA; RSC and liver
effects
NA; hepatotoxicity
CNS effects, eyes
and nose irrnation;
changes in liver,
kidney weight
UNCERTAINTY
FACTOR1
(Inhalation; oral}
NA; 1000
NA;NA
NA; 1000
1000; 1000 ·
1000; 100
NA; NA
NA; 1000
NA; 1000
NA;NA
NA; J 000
NA; 3000
NA; NA
300; 1000
100; 1_00
NA;NA
NA; 1000
NA; 1000
100; 1000
GASTROINTESTINAL
ABSORPTION
FACTOR1
0.9
0.9
0.9
0.9
0.9
1.0
0.9
0.9
0.93
0.9
0.9
0.9
1.0
0.9
0.9
0.9
1.0
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·TABLE 14 SUMMARY OF NONCANCER TOXIC EFFECTS OF CHEMICALS OF POTENTIAL CONCERN
INHALATION ORAL R!Dh CRITICAL EFFECT UNCERTAINTY GASTROINTESTINAL
CHEMICAL R!Ch (mg/kg/day) AND FACTOR1 ABSORPTION
(mg/kg/day) TARGET ORGAN1 (Inhalation; oral) FACTOR1
(Inhalation; oral)
Total Xylenes ND 2 X 10°m NA; hyperactivity, 100; 100 1.0
decreased body
weight
1, 1,2-Trichloroethane ND 4 X 1Q•3m NA; clinical NA; 1000 0.9
chemistry alterations
Trichloroethene ND 6 X 10·3P NA; NA NA; NA 0.9
NA NA; increased liver 0.9
and kidney weight,
nephrotoxicity
Di-n-butyl Phthalate ND 1 X 10"1 m NA; whole body NA; 1000 0.9
ND 3x10°P NA; NR' 0.05
ND 4 X 10"'m NA; blood glucose, NA; 1000 0.05
cholesterol
ND 3 X 10-4m NA; ·NA;3 0.98
hyperpigmentation,
keratosis
1 X 10"'d 7 X 10•2m Fetotoxicity; 1000;3 0.1
increased blood
pressure
ND 5 X 10•3m NA; ND NA; 100 0.001
Cadmium (water) ND 5 X 10"'m NA; proteinuria, NA; 10 0.06
renal damage
Cadmium (food) ND 1 X 10"3 m NA; renal damage NA; 10 0.06
ND 5x10"3m Nasal mucosa 300;500 0.05
atrophy; ND
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I TABLE14 SUMMARY OF NONCANCER TOXIC EFFECTS OF CHEMICALS OF POTENTIAL CONCERN
I INHALATION ORAL RfDh CRITICAL EFFECT UNCERTAINTY GASTROINTESTINAL
CHEMICAL R!Ch (mg/kg/day) AND FACTOR1 ABSORPTION
(mg/kg/day) TARGET ORGAN1 (Inhalation; oral)· FACTOR1
I (Inhalation; oral)
Cobalt 3 X 10·7 p 6 X 10·2P Respiratory tract; NA;NA 0.05
. blood
I Copper ND ND NA;NA NA;NA 0.5
t
Cyanide ND 2 X 10•2m NA; reduced weight NA; 100 0.05
gain, thyroid and
myelin effects
I Lead ND ND NA; NA NA;NA 0:1
Manganese (water) 1 X 10~m 5 X 10·3 m Respiratory; CNS 300; 1 0.05
I Manganese (food) 1 X 10~m 1.4x10-'m Respiratory; CNS 300; 1 0.05
Mercury g·x 10-sd 3 X 1ff'd Neurotoxiclty; kidney 30; 1000 0.15
.1
effects
Nickel ND 2 X 10"2 m NA; decreased body NA; 300 -0.05
& organ weights
I Selenium ND 5 X 10·3 m NA; selenosis NA; 3 0.6
Silver ND 6 X 10-sm NA; argyria NA; 3 0.05
l Thallium' ND 6 X 10•5m NA; increased NA; 3000 0.05
SGOT and serum
I LDH levels, alopecia
Vanadium ND 7x10·3d_ NA; none observed NA; 100 0.05
t
Zinc ND 3 X 10°1 m NA; anemia NA; 10 0.5
' The oral CSF is divided by the gastrointestinal absorption factor (GAF) to estimate a dermal SF. i.e., a SF based on absorbed, rather tnan ingested (or
I exposure) dose, see Section 6.4.3 tor description of derivation of GAF.
IRIS (U.S. EPA, t993) ·
• ND= Not determined .
' Source: 1992 HEAST, including July 1992 and November 1992 Supplements.
I U.S. EPA, 1992, "May 13, 1992 Risk Assessment Teleconference tor Superfund Meeting Notes."
. Value given is tor Chromium VI, assuming all chromium found is Chromium VI. ·
9 Value tor nickel refinery dust. i The reference concentration or reference dose is tne dose below which no adverse effects are likely to be seen (EPA, 1991c and 1992c). 'I Determined by the EPA (1991c, 1992c). .
· The oral R+D is multiplied by tne Gastrointestinal Absorption Factor (GAF). · · .
k NA = Not applicable. · f Source: IRIS.
Values given are tor 1,2-cis-dichloroethene. · · ·
P From the Environmental Criteria and Assessment Office of tne U.S. EPA, Cincinnati, Ohio.
I By analogy to thallium sulfate, adjusting tor differences in molecular weight.
.. NR = Not reported.
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DRAFT
Risk= COi x SF, where:
-55-
NATKlNAl STA~ II, CHEMICAL COMPN-4Y SUPERRJNO SITE
~ REC0FO OF DECISION FOA OPERABLE UNIT #3
SEPTEJ.EER 1, 199317:21 AM
Risk= a unit less probability (e.g., 2 x 10·5) of an individual developing cancer; COi = chronic daily intake averaged over 70 years (mg/kg-day); and SF= slope-factor, expressed as (mg/kg-day)"1
Excess lifetime cancer risks are determined by multiplying the intake level with the cancer potency factor. These risks are probabilities that are generally expressed in scientific notation (i.e., 1 x 10-6 or 1 E-6). An excess lifetime cancer risk of 1 E-6 indicates that, as a plausible upper-bound, an individual has a one in one million chance of developing cancer as a result of site-related exposure to a carcinogen over a 70-year lifetime under the specific exposure conditions at a site.
EPA has set an acceptable carcinogenic risk range of 1 E-4 to 1 E-6, but prefers that remediation of Superfund sites achieve a residual cancer risk no greater than 1 E-6. However, depending upon site factors, a risk of 1 E-4, may be considered protective.
The carcinogenic upper-bound risk for each of the exposure pathways (current and future) identified at the Site are summarized in Table 15. The accumulative future risk and hazard index posed by the groundwater at the Site is 2 x 10-3 and 60 for a child, respectively.
8.5 RISK UNCERTAINTY
There is a generally recognized uncertainty in human risk values developed from experimental data. This is primarily due to the uncertainty of extrapolation in the areas of (1) high to low dose exposure and (2) animal data to values that are protective of human health. The Site specific uncertainty is mainly in the degree of accuracy of the exposure assumptions.
The risk assessment is aimed at providing a conservative estimate of risk for the Site. A number of uncertainty and assumptions made throughout the risk assessment are likely to result in an overall overestimation rather than an underestimation of risk. The exposure scenarios also involve a number of uncertainties. Consumption of 2 liters of contaminated drinking water per day for 350 days a year represents the upper bound of potential exposure and has been used because site-specific data were not available. This may be an overestimation of the actual exposure that may occur in the future. The scenario assumes that an adult is consistently being exposed to the same concentrations for 30 years. The daily intake by ingestion is reported as being equal to the daily intake by ingestion; the use of this assumption yields an almost equal risk for the inhalation scenario. Dermal absorption of vapor phase chemicals is considered to be lower than inhalation intakes in many instances and is not considered in this risk assessment.
I
I I TABLE 15 SUMMARY OF CANCER RISK (ILCR) AND N0NCANCER HI VALUEa
I Current Land Use
Receptor/
Current Conditionb Future Condition° Future Land Used ILCR or HI
I
Child/lLCR 8 X 10·5 1 X 104 4 X 104
I Child/HI 6 X 10·2 4 X 10·2 1 X 10-1
Adult/lLCR NA NA NA I Adult/HI NA NA NA
I Child/lLCR 4 X 10·9 9 X 10·9 ·1 X 10·7
I Child/HI 5 X 10·7 6 X 10-7 6 X 10-6
Adult/lLCR NA NA NA
,1 Adult/HI NA NA NA
I Child/lLCR 2 X 10-5 2 X 10-5 1 X 104
Child/HI 1 X 10·2 1 X 10·2 3 X iQ·2
I Adult/lLCR NA. NA NA.
Adult/HI NA NA NA I
I Child/lLCR NA NA 2 x 10·3
,, Child/HI NA NA 6 X 101
I Adult/lLCR NA NA 2 X 10·3
Adult/HI NA NA 2 X 101
I a Values presented are the sum for all exposure pathways associated with the environmental
medium.
b Outside the plant area; the fence successfully precludes access to the plant area. I C Inside the plant area; the fence around the plant area is not functional.·
d The NSCC property is available for residential use.
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DRAFT
-57-
NATIONAL ST AR:::H & CHEMICAL CoMP.v« SUPERR.INO SITE
~ RECOF{) OF 0ECISON FOR 0Pl:RA8lf Ui,m #3
SEPIB.eEA 1, 199l/7:21AM
As a result of the uncertainties and assumptions described above, the risk assessment
is a conservative analysis intended to indicate the potential for adverse impacts to occur
and not an absolute estimate of risk to humans or a specific population.
8.6 ECOLOGICAL RISK
Exposure of aquatic and benthic organisms may be exposed via both surface water and
sediment. An ecological assessment was conducted during Phase I of the RI for OU #3
to determine if there were any effects of 1,2-DCA on the benthic communities inhabiting
the Northeast Tributary. During Phase II of the OU #3 RI, chronic toxicity testing was
performed on surface water and sediment samples to further examine ecological
impairments noted by the rapid assessment protocol. Chemical, ecological, and
toxicological investigations conducted at the Northeast Tributary found ecological impacts
in areas of the Northeast Tributary exhibiting elevated levels of 1,2-DCA in surface water
or sediments. However, it could not be concluded that 1,2-DCA was the sole cause of
this impact in view of the naturally-limiting factors associated with a headwater stream of
this type.
8.7 SUMMARY
Actual or threatened releases of hazardous substances from this Site, if not addressed
by implementing the response action selected in this Record of Decision, may present an
imminent and substantial endangerment to public health, welfare, or the environment.
Presently, no unacceptable current risks were identified associated with the NSCC Site.
The unacceptable risks connected with the Site are associated with the potential future
use of the groundwater as a potable source of water. This is due to the presence of
contaminants at concentrations above EPA's MCLs for drinking water and the State of
North Carolina groundwater quality standards. These contaminants will be remediated
during the remedial action phase.
Presently, no substantive link can be made between the presence of 1,2-DCA in the
Northeast Tributary and limited biodiversity in this stream as the area of the stream
impacted by the Site is approximately 1,500 feet from the head-water of this stream.
9.0 APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
Section 7.0 defined the extent and characterized the contamination and the environmental
setting of OU #3. Section 8.0 highlighted the human health and environmental risks
posed by the Site. This Section examines and specifies the performance standards (i.e.,
cleanup levels) for the contaminants in the groundwater and surface water/sediment
associated with OU #3.
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DRAFT
-58-
NATION,1,L STAF0-1 & CHEMICAi.. COMPANY SUPERRJNO SITE
DRAFT AECOR'.l OF DECISION FOR 0PERABI.E UNIT #3
SEPTEJ,EER 1, 1993/7:21,1,1,1
Section 121 (D) of CERCLA, as amended by SARA, requires that remedial actions comply
with requirements or standards set forth under Federal or State environmental laws. The
applicable or relevant and appropriate requirements (ARARs)' that must be complied with
are those that are action-specific, chemical-specific, or location-specific at the Site. Thus,
ARARs are used to determine the appropriate extent of Site cleanup, to scope and
formulate remedial action alternatives, and to govern the implementation and operation
of the selected action.
"To Be Considered" (TBCs) criteria are non-promulgated, non-enforceable advisories, or
guidelines issued by federal or state governments (e.g., reference does, carcinogenic
potency factors, Ambient Water Quality Criterion) that may be useful for developing
remedial action alternatives or for determining what is protective to human health and the
environment.
This section examines the performance criteria associated with the· contaminants
identified during the OU #3 RI/FS and the environmental media contaminated.
9.1 ACTION-SPECIFIC ARARS
Action-specific requirements are technology-based and establish performance, design,
or other similar action-specific controls or regulations on activities related to the
management of hazardous substances or pollutants. Table 16 lists all potential
.action-specific ARARs.
9.2 CHEMICAL-SPECIFIC ARARS
Chemical-specific ARARs are concentration limits established by government agencies
for a number of contaminants in the environment. Chemical-specific ARARs can also be
derived in the Risk Assessment. Table 17 lists all of the potential chemical-specific
ARARs which may be pertinent at NSCC OU #3. Discussed below is each environmental
medium investigated during OU #3 RI and the associated chemical-specific ARARs.
As declared previous, the groundwater at the NSCC Site is designated as Class GA by
the State and Class II by EPA and _the surface water in the Northeast Tributary is
classified as Class C by the State. The Safe Drinking Water Act (SOWA) and North
Carolina Administrative Code, Title 15, Subchapter 2L (NCAC T15:02L.0202) establish
MCLs and non-zero maximum contaminant level goals (MCLGs) for numerous organic
and inorganic constituents. For contaminants that do not have either a federal or state ·
cleanup level, risk-based remediation goal numbers were calculated. The most stringent
state or federal performance standards (cleanup levels) to be obtained at the NSCC OU
#3 Site, in the groundwater and surface water/sediment in the Northeast Tributary, are
shown in Table 18. This table also specifies the source for the stated cleanup goal.
-· ---· -------- - -------
TABLE 16 ACTION-SPECIFIC ARARS AND OTHER CRITERIA TO BE CONSIDERED
Action Requirement(s) Prerequisite(s) Citation Comments A" RAR" TBC0
Air Stripping RCRA standards for control of emissions of RCRA hazardous waste 40 CFR Subparts AA & 1111 The standard requires reduction lrom GWP4A
volatile organics. 115A NCAC 13A0009(o)I ·production accumulator vessels" and leak GWL4A
detection and repair programs. Product GWP4B
accumulator vessels include air strippers. GWL4B
Container Storage Containers of hazardous waste must be: RCRA hazardous waste (listed or 40 CFR 264.171 These requirements are applicable or GWP4A
(On Stte) characteristic) held for a temporary 115A NCAC 13A00090II relevant and appropriate for any GWL4A
• Maintained to good condnion period before treatment, disposal, 40 CFR 264.172 contaminated soil or groundwater or GWP4B . Compatible wtth hazardous waste to be or storage elsewhere. (40 CFR I15A NCAC 13A00090)1 treatment system waste that might be GWL4B
stored 264.10) in a container (i.e., any 40 CFR 264.173 containerized and stored on stte prior to
·: • Closed during storage (except to add or portable device in which a material 115A NCAC 13A00090)1 treatment or final disposal. Groundwater
remove waste) is stored, transported, disposed of, or soil containing a listed waste must be
or handled). managed as if ~ were a hazardous waste
so long as n contains the listed waste.
Inspect container storage areas weekly lor ' 40 CFR 264.174
deterioration. I15A NCAC 13A00090)1
Place containers on sloped, crack-free base, 40 CFR 264.175
and protect lrom contact wnh accumulated . l15A NCAC 13A0009U)I
liquid. Provide containment system wnh a
capacny of 10 percent of the volume of
containers of free liquids.
Remove spilled or leaked waste in a timely
manner to prevent overflow of the containment
system.
Keep containers of ignttable or reactive waste 40 CFR 264.176
at least 50 feet from the facimy's property line. l15A NCAC 13A00090)1
Container Storage Keep 1ncompatille materials separate. 40 CFR 264.177 GWP4A
(On Sne) -Separate incompatille materials stored near l15A NCAC 13A00090)I GWL4A
(Continued) each other by a dike or other barrier. GWP4B
GWL4B
At closure, remove all hazardous waste and 40 CFR 264.178
residues from the containment system, and I15A NC,AC 13A0009U)I
decontaminate or remove all containers, liners.
----------- - -------
TABLE 16 ACTION-SPECIFIC ARARs AND OTHER CRITERIA i:o BE CONSIDERED
Action Requirement(s) Prerequisite(s) Citation Comments A" RAR0 TBC0
Storage of banned wastes must be in 40. CFA 268.50
accordance with 40 CFA 268. When such l15A NCAC 13A0012(d)I
storage occurs beyond one year, the own-
er/operator bears the burden-of proving that
such storage is solely for the purpose of
accumulating sufficient quanttties to aRow for
proper recovery, treatment, and disposal.
Groundwater Well Any non-waste material (e.g., groundwater or Non-waste material containing listed AGRA 'contained in' principle GWP4A
Development, soil) that contains a hazardous waste must be hazardous waste GWL4A
•: Testing, and managed as if n were a hazardous waste. GWP4B
Sampling GWL4B
All Off-Sne Shipment The off-sne shipment of hazardous waste Generating sne to shi> waste off-40 CFA 262, N.C.: GWP4A
Requirements for requires that all AGRA and DOT requirements site. 115A NCAC 13A000n . Generator must keep inspecfon GWL4A
Hazardous Waste for manifesting and shipping papers as 40 CFR 263, records for 3 years. GWP4B
Per RCRA and DOT needed, marf<ing, labeling, placarding, and p 5A NCAC 13A00081 GWL4B
Regulations Will Be special requirements based or type of carriage 49 CFR 171 through 179 D, F, H, & I on NC manifest must be
Met by the OU-2 (i.e., rail, aircraft, public highway, etc.) be met. filled out.
Sne (Generator) and
Transporter
Sloon Water Operations as defined in the regulations that Discharge of storm water from 40 CFA 122 All
Discharges discharge storm water from ns facility must industrial facilnies and large
periorm sampling, and comply wnh water construction snes (greater than five
quality standards, and effluent limnations set acres in area).
by Best Achievable Technology (BAT).
Incineration . Analyze the waste feed RCRA hazardous waste incineration 40 CFR 264 Subpart 0 Those alternatives that propose fume GWP4A . Destruction effectiveness p5A NCAC 13A0009(q)I incineration would be subject to these GWL4A . Monnoring . requirements GWP4B
GWL4B
-- - -- ------- - - -- ----
TABLE 16 ACTION-SPECIFIC ARARS AND OTHER CRITERIA TO BE CONSIDERED
Action Requirement(s) Prerequisite(s) Citation Comments A" RARb TBC0
Closure with No General performance standard requires Applicable to land.tiased unit con-40 CFR 264.111 All
Post-Closure Cara elimination of need for further maintenance taining hazardous waste. Applica-j15A NCAC 13A0009(h)I
{e.g., Clean Closure) and control; aliminatiQn.of post-closure escape bla to RCRA hazardous waste
ol hazardous waste, hazardous constituents, {listed or characteristic) placed at
leachate, contamina!'!(i run-off, or hazardous site after the affective data ol the
waste decomposition products. requirements, or placed into anolh-
er unn. Not applicable to material
treated, stored, or disposed only
before Iha affective data of the
requirements, of ii treated in_-sltu, or
'· consolidated within area of con-
lamination. Designed for cleanup
that will not require long-tenn
management. Designed for claa-
nup to haafth.tiased standards.
Disposal or dacont""!ination of equjlmenl, May apply to piping and container 40 CFR 264.178
and structures. or tank liners and hazardous waste l15A NCAC 13A00090JI
residues. 40 CFR 264.197
Removal or decontamination of all waste I15A NCAC 13A0009~J]
residues, contaminated containment system
components {e.g., liners, dikes), and
structures and equipment contaminated with
waste.
Treatment Design and operating standards for all T raatment of hazardous wastes in 40 CFR 264 (Subpart X) The substantive portions of these GWP4A
hazardous waste treatment units including units and regulated elsewhere l15A NCAC 13A0009(I1] requirements will be relevant and GWL4A
miscellaneous units {long tann retrievable under RCRA (e.g., air strippers). 40 CFR 264.273 appropriate to the construction, operation, GWP4B
storage, thennal treatment other than in-j15A NCAC 13A0009(nl] maintenance, and closure of any mis-GWL4B
cineration, open burning, open detonation, 40 CFR 264.343-345 cellaneous treatment unit (a treatment unit
chemical physical, and biological treatment l15A NCAC 13A0009(ql] that is not elsewhere regulated) con-
. units using other lhci!l tanks, surface im-. 40 CFR 265 (Subpart P) · structed on the OU #3 site for treatment
poundments, or land·lreatment unns) require j15A NCAC 13A0010(pl] and/or disposal of hazardous sne wastes.
new miscellaneous unns to satisly
environmental pertonnance standards by
protection of groundwater, surtace water, and '
air qualny, and by limning surface and sub-
surtaca migration.
-· -- -- - ----- ------ --
TABLE 16 ACTION-SPECIFIC ARARS AND OTHER CRITERIA TO BE CONSIDERED
Action Requirement(s) Prerequisite(s) Citation Comments A" RARb TBC0
T raatment of wastes subject to ban on land Treatment of LOR waste 40 CFR 268.43 -Table CCW The substantive portions of th858
disposal must attain levels. achievable by best 115ANCAC 13A.0012(cJI · requirements are to be considered in the
demonstrated available treatment technologias disposal of any OU #3 sne wastes that is
(BDA D for each hazardous consttluent in a restricted hazardous waste.
each fisted waste. .
1,2-IJCA (U077) non-wast~ater 7.2 mg'1<g
total
Discharge to P0TW Comply wtlh all condnions of permn. Wastewater generated Cfy of Salisbury Water A copy of permn is included in Append~ F. GWP4A
' Resources Division Industrial GWL4A
Wastewater D~charge Permn GWP4B .. SIW Permn # NCS002-T GWL4B
Underground lnjec-Hazardous waste to be injected is subject to 40 CFR 268.2
lion of Wastes and land ban regulations. Treated groundwater
Treated that m88ts the definnion of hazardous waste
Groundwater and is to be injeded also is subjed to land
ban regulations.
Groundwater Mon, Groundwater monitoring at new or existing Creation of a new disposal unit, 40 CFR, Subpart F All
toring RCRA disposal unns. remedial adions at an existing 15A NCAC 13A.0009(g)
RCRA unn or d~posal of RCRA
hazardous waste.
RCRA T raatment, A regulated RCRA TSDF must submn an Regulated RCRA TSDF. 40 CFR 270.10 through 270.65 Though NPL sites are exempt from the All
Storage, and application for a permn (including both Parts A permitting process, all substantive
Disposal Facilfy and B). requirements of the permnting process
(TSDF) Permitting must be met
Operation of Air Registration of Air Pollution Sources. Emission of air pollution. 15A NCAC 2D.0202 "The director may require the owner or GWP3A
Pollution Source (Air operator of a source of air polluti9n to GWP3B
Stripper) -register that source: Must submn a "G" GWL3A
sh88t GWL3B
Toxic Emission Toxic Air Pollutant Guidelines. Emission of Ethylene Dichloride 15A NCAC 2D.1100
(Chemical: Ethylene (EDC)
Dichloride)
Toxic Emission Permn Requirements for Toxic Air Pollutants. Emission of EIJC 15A NCAC 2H.0610 De minimis for permitting requirements for
(Chemical: Ethylene EIJC is 260 lb/yr. NSCC emitted
Dichloride) approximately 58,956 b/yr. Permn will be
required.
- - -- -- - - - -- - - ---·-- -
TABLE 16 ACTION-SPECIFIC ARARs AND OTHER CRITERIA TO BE CONSIDERED
Action Requirement(s) Prerequisite(s) Citation Comments A" RARb TBC0
Toxic Emission Applicabilny-2H.0610(a) North Carolina Toxic Air A toxics review is required for ·existing
(Chemical: Ethylene Pollutant Control Regulations, A facilities that begin permrtted ccnstruction
Dichloride) Summary of the Requirements, on a new source of~ amount of ~
July 31, 1991. l5ted toxic pollutant after April 30, 1990.'
Th5 will require ccmputer air dispersion
modeling for a predicted maximum annual
average ccncentration at the property line
to ccmpare wnh the acceptable ambient
limns (Ml) ol 3.8 µgtm".
•. Emitting in Prevention of Significant Deterioration (PSD) Emitting in Rowan County which is CM Section 107 Proposed new and modified sources in
..
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Attainment or Review designated attainment or unclassifi-
Unclassifiable Area able for all regulated pollutants.
for any Criteria
Pollutant (EDC)
• Applicable Requirements for Alternatives as noted.
• Relevant and Appropriate Requirements for Alternatives as noted.
° Criteria To Be Considered for Alternatives as noted.
Rowan County are potentially subject to
PSD review. NSCC is classified as an
existing major stationary source. Addition
of air stripper is a modification, therefore,
must check for significant emissions
increase of any pollutant subject to regu-
lation under CM (i.e., VOCs). PSD de
minimis = 40 tpy increase; ccmpare th5 to
projected EDC emissions after air stripper
addition to determine if PSO review is re-
quired.
Note: All parenthetical citations are from North Carolina Hazardous Waste Management Regulations, North Carolina Administrative Code, Title 15A, Chapter
13 -Solid Waste Management, Subchapter 13A -Hazardous Waste Management.
- - - --· . - -_, - - - - - - --- -
~
,1
TABLE 17 POTENTIAL CHEMICAL-SPECIFIC ARARS FOR GROUNDWATER
STANDARD REQUIREMENT,
CRITERIA, OR LIMITATION
Resource Conservation and
Recovery Act (RCRA), as amended
RCRA Groundwater Protection
Safe Drinking Water Act (SOWA)
National Primary Drinking Water
Standards
Maximum Contaminant Level
Goals (MCLGs)
Clean Water Act (CWA)
Water Quality Criteria
Comprehensive Environmental
Response, Compensation, and
Liability Act of 1980 (CERCLA)
Clean Air Act (CAA)
National Primary and Secondary
Ambient Air Quality Standards
CITATION DESCRIPTION
42 u.s.c §§ 6905, 6912,
6924,6925
40 CFR Part 264 Provides lor groundwater protection standards,
general monitoring requirements, and technical
requirements.
40 u.s.c § 300
40 CFR Part 141 Establishes health-based standards for public
water systems (MCLs).
Publication L. N!. 99-399, Establishes drinking water quality goals set at
100 Stat. 642 (1986) levels of no known or anticipated adverse health
effects.
33 u.s.c § 1251-1376
40 CFR Part 131 Sets criteria for water quality based on toxicity to
aquatic organisms and human health.
42 U.S.C § 9601 et. seq. Provides for response to hazardous substances
released into the environment and the cleanup of
inactive hazardous waste disposal sites.
40 U.S.C § 1857
40 CFR Part 50 Sets primary and secondary air standards at levels
C to protect public health and public welfare. ..
APPLICABLE/
RELEVANT AND
APPROPRIATE
No/Yes
Yes/Yes
Yes/Yes
No/Yes
Yes/Yes
Yes/Yes
CoMMENT
The RCRA MCLs are relevant and appropriate for
groundwater at the Site.
The MCLs for organic and inorganic contaminants
are applicable to the groundwater contaminated by
the Site since it is a potential drinking water source.
Proposed MCLGs for organic and inorganic
contaminants are applicable to the groundwater
used for drinking water.
The AWQC for organic and inorganic contaminants
are relevant and appropriate.
Applicable to OU #3.
May be relevant or appropriate if onsite treatment
units are part of remedial actions .
- - - - - - - - - - - - --a-- - - -
..
11
TABLE 17 POTENTIAL CHEMICAL-SPECIFIC ARARS FOR GROUNDWATER
STANDARD REQUIREMENT,
CRITERIA, OR LIMITATION
National Emissions Standards
for Hazardous Air Pollutants
(NESHAPs)
North carolina Drinking Water and
Groundwater Standards
CITATION
40 CFR Part 61
tSA NCAC Chapter 2L
DESCRIPTION
Provides emissions standard for hazardous air
pollutant lor which no ambient air quality standard
exists. ·
Regulates water systems within the state that
supply drinking water that may affect the public
health.
Establishes groundwater classification and water
quality standards. Applicable to groundwater at
the Site.
APPLICABLE/
RELEVANT AND
APPROPRIATE
Yes/Yes
No/Yes
COMMENT
May be relevant or appropriate if onsite treatment
units are part of remedial actions.
Provides the state with the authority needed to
assume primary enforcement responsibility under
the federal act.
Guidelines lor allowable levels ol toxic organic and
inorganic compounds in groundwater used for
drinking water. Applicable to groundwater at the
Site.
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DRAFT
-15-
CCMP.-HY SUPE?.FUNO SITE
~ RECORD OF DECISION
OPERABLE UNIT 13
AUGUST 30, 19S3/3:23PM
numbers were calculated. The most stringent state or federal performance standards (cleanup
levels) to be obtained at the NSCC OU #3 Site, in the groundwater and surface water/sediment
in the Northeast Tributary, are shown in Table 18. This table also specifies the source for the
stated cleanup goal.
9.1.3 Location-Specific ARARs
Location-specific ARARs are design requirements or activity restrictions based on the
geographical and/or physical positions of the Site and its surrounding area. These requirements
and/or restrictions can be stipulated by federal, state, or local governments. Table 19 lists the
location-specific ARARs that apply at the NSCC OU #3 Site.
10.0 DESCRIPTION OF ALTERNATIVES
Due to an insufficient evaluation of soil remediation technologies in the June 21, 1993 FS
document, this ROD will only address the remediation of groundw_ater and surface
water/sediment. Soil remediation in Area 2 and lagoon area will be addressed in OU #4.
Table 20 inventories those technologies that passed the initial screening for remediating the
contaminated groundwater and surface water/sediment at OU #3. In the initial screening, process
options and entire technologies were eliminated from consideration if they are difficult to
implement due to Site constraints or contaminant characteristics, or if the technology has not
been proven to effectively control the contaminants of ·concern. Table 20 also presents the
results of the final screening of the groundwater remediation technologies. Effectiveness,
implementability, and relative capital and operation and maintenance costs are the criteria used
for evaluating the technologies and process options in the final screening. The process options
that were retained for further evaluation are boxed in by a bold line. This table provides the
rationale as to why certain technologies were not retained for the detailed comparison .
. The five (5) groundwater remediation alternatives retained to address the estimated 131 million
gallons of contaminated groundwater and the two (2) surface water/sediment remediation
alternatives are described below.
10.1 REMEDIAL ALTERNATIVES TO ADDRESS GROUNDWATER CONTAMINATION
Although the groundwater alternatives for addressing contaminated groundwater for Area 2 and
the lagoon area were considered separately in the FS, they were combined in this ROD. Area
2 alternatives are identified by "P" for the "Plant" and the alternatives dealing with the
contaminated groundwater associated with the lagoon area are identified by "L" for "Lagoon
Area".
. _ .....
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I TABLE 18 OU #3 GROUNDWATER AND SURFACE WATER/SEDIMENT PERFORMANCE STANDARDS
I RANGE AND FEDERAL STATE SELECTED
FREQUENCY ( ) ESTABLISHED ESTABLISHED PERFORMANCE SOURCE OF
CONTAMINANT OF DETECTION PERFORMANCE PERFORMANCE STANDARD PERFORMANCE
I CONCENTRATIONS STANDARD STANDARD (CLEANUP GOAL) STANDARD
IN (µG/L) (MCL) (µGIL) (µGIL) (µGil)
GROUNDWATER
I Acetone (15) OU #1
Bis(2-C hloroethyl)ether 13-32 (2) OU #1
I Bromodichloromethane 1 (1) 1001'1 MCL1'1
Chloroform 7-8,900 (2) 1001'1 0.19 CRQUState~1
I 1,2-Dichloroethane 1-660,000 (30) 5 0.38 CRQUState~1
1, 1-Dichloroethene 1-14 (3) 7 7 MCUState
I cis 1,2-Dichloroethene 70 70'
trans 1,2-Dichloroethene 100 70 State
I 1,2-Dichloropropane 5 (1) 5 0.56 CRQL/State~1
Ethylbenzene 9-36. (2) 700 29 State
I Methylene Chloride 1-160 (5) 5
Tetrachloroethene 1-7 ( 4) 5 0.7 CRQL/State~1
I Toluene 1-120 (3) 1,000 1,000 MCL/State
Total Xylenes 2-90 (4) 10,000 400(530') State I 1, 1,2-Trichloroethane 1-5 (10) 5 MCL
Trichloroethene 1-5 (4) 5 2.8 State .
28-12,000 (14) 50
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I TABLE 18 OU #3 GROUNDWATER AND SURFACE WATER/SEDIMENT PERFORMANCE STANDARDS
I RANGE AND FEDERAL STATE SELECTED
FREQUENCY ( ) ESTABLISHED ESTABLISHED PERFORMANCE SOURCE OF
CONTAMINANT OF DETECTION PERFORMANCE PERFORMANCE STANDARD PERFORMANCE
I CONCENTRATIONS STANDARD STANDARD (CLEANUP GOAL) STANDARD ·
IN (µGil) (MCL) (µGil) (µGil) (µGIL)
I SURFACE WATER
I Acetone
1,2-Dichloroethane
I
SEDIMENT
I VOLATILE ORGANIC COMPOUNDS
Acetone
I 1,2-Dichloroethane
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I µg/I --Micrograms per Liter
MCL --Maximum Concentration Limit as Spec~ied in the Safe Drinking Water Act
OU1 --Performance Standard Developed in September 30, 1988 Operable Unit #1 Record Of Decision
I 1'1 --Based on MCL for Trihalomethanes
CRQL --Contract Required Quantltation Limit .
State~1 --Where the Maximum Allowable Concentration Of A Substance Is Less Than The Limit Of Detectability (15 A NCAC
I 2L.0202(b)(1) ·
State --State Groundwater Quallty Standards (NCAC 15-2L.0202)
, ' --Interim State Being Proposed
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DRAFT
9.3 Location-Specific ARARs
-62-
NATIONAL STAFCH & CHEMICAL COMP~Y SUPERA.NO Srre
DRAFT RECORD OF DECISION FOR OPERN!I.J: UNIT 13
-SEPTBEER1, 199317:21AM
Location-specific ARARs are design requirements or activity restrictions based on the geographical and/or physical positions of the Site and its surrounding area. These requirements and/or restrictions can be stipulated by federal, state, or local governments. Table 19 lists the location-specific ARARs that apply at the NSCC OU #3 Site.
10.0 DESCRIPTION OF ALTERNATIVES
Due to an insufficient evaluation of soil remediation technologies in the June 21, 1993 FS document, this ROD will only address the remediation of groundwater and surface water/sediment. Soil remediation in Area 2 and lagoon area will be addressed in OU #4.
Table 20 inventories _those technologies that passed the initial screening for remediating the contaminated groundwater and surface water/sediment at OU #3. In the initial screening, process options and entire technologies were eliminated from consideration if they are difficult to implement due to Site constraints or contaminant characteristics, or if the technology has not been proven to effectively control the contaminants.of concern. Table 20 also presents the results of the final screening of the groundwater remediation
technologies. Effectiveness, implementability, and relative capital and operation and maintenance costs are the criteria used tor evaluating the technologies and process options in the final screening. The process options that were retained for further evaluation are boxed in by a bold line. This table provides the rationale as to why certain technologies were not retained for the detailed comparison.
The five (5) groundwater remediation alternatives retained to address the estimated 131 million gallons of contaminated groundwater and the two (2) surface water/sediment
remediation alternatives are described below.
10.1 REMEDIAL ALTERNATIVES TO ADDRESS GROUNDWATER CONTAMINATION
Although the groundwater alternatives for addressing contaminated groundwater for Area 2 and the lagoon area were considered separately in the. FS, they were combined in this ROD. Area 2 alternatives are identified by "P" for the "Plant" and the alternatives dealing with the contaminated groundwater associated·with the lagoon area are identified by "L" for "Lagoon Area".
Alternative GWP1/GWL 1:
Alternative GWP2/GWL2:
Alternative GWP3/GWL3:
No action
Long-Term Monitoring with Fencing A Portion of
Northeast Tributary
Institution.al Controls with Fencing A Portion of
Northeast Tributary
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r_A~, .. 19 LOCATION-SPECIFIC ARARS AND OTHER CRITERIA TO BE CONSIDERED
LOCATION REQUIREMENT($) PREREQUISITE($) CITATION
Hazardous waste site Actions to limit worker exposure to Construction, operations and 29 CFR 1910.120
hazardous wastes or hazardous maintenance, or other activities
substances, including training and with potential worker exposure.
monitoring.
Wetland Action to minimize the destruction, Wetland as defined by Executive Executive Order 11990, Protection
loss, degradation of wetlands. Order 11990, Section 7 and U.S. of Wetlands (40 CFR 6, Appendix
Action to prohibit discharge of Army Corps of Engineers A). Clean Water Action Section
dredged or fill material into regulations. 404, 40 CFR Part 230, 33 CFR
wetland without permit. 320-330 .
Area affecting stream or river Action to protect fish or wildlife. Diversion, channeling, or other Fish and Wildlife Coordination Act
activity that modifies a stream or (16 USC 661 et seq.); 40 CFR
river and affects fish or wildlife. 6.302
Wild and scenic rivers Action to determine if project will Any river, and the bordering or Wild and Scenic Rivers Act (16
affect the free-flowing adjacent land, designated as "wild USC 1271 et seq., Section 7(a),
characteristics, scenic, or natural and scenic or recreational.· 36 CFR297.4, 40 CFR 6.302(e)
values of a designated river.
COMMENTS A" RARb TBCC
All
No wetlands are known
to exist on the OU #3
site.
No diversions or
modifications of the
Northeast Tributary are
planned at the OU #3
site.
No wild and scenic or
recreational streams or
rivers are known to exist
within the OU #3 site.
-------------------
TABLE19 LOCATION-SPECIFIC ARARS AND OTHER CRITERIA TO BE CONSIDERED
LOCATION REQUIREMENT($) PREREQUISITE($) CITATION COMMENTS A" RAR 0 TBC0
Wilderness area Area must be administered in Any unit of the National Wildlife Wilderness Act (16 USC 668dd et No designated wilderness
such a manner as will leave it Range System .§gQJ 50 CFR 27, 35.5 areas exist within the OU
unimpaired as wilderness and to #3 site.
preserve its wildness. The
following are not allowed in a
,··· wilderness area: ;
• Commercial enterprises
• Pennanentroads,exceptas
necessary to administer the
area , • Motor vehicles
ti • Motorized equipment
• Motor boats
• Aircraft
• Mechanized transport
• Structures or buildings
Historic project owned or Action to preserve historic· Property included in or eligible for National Historic Preservation Act, No historic properties
controlled by federal agency property; planning of action to the National Register of Historic Section 106 (16 USC 470 et seq.); exist on the OU #3 site
minimize hann to National Historic Places 36 CFR Part 800
Landmarks
Within 1 OO•year floodplain Facility must be designed, RCRA hazardous waste, 40 CFR 264.18(bl The OU #3 site is not in
. constructed, operated, and treatment, storage, or disposal. a 100-year floodplain.
maintained to avoid washout. .
Within floodplain Action to avoid adverse effects, Action that will occur in a Executive Order 11988, Protection Not applicable for OU #3
. . minimize potential harm, restore floodplain, i.e., lowlands, and of Floodplains (40 CFR 6, site
I and preserve natural and relatively flat areas adjoining Appendix Al, Fish and Wildlife
beneficial values. inland and coastal waters and Coordination Act (16 USC 661 gt
other flood-prone areas. .§gQJ; 40 CFR 6.302
'
TABLE 19 LOCATION-SPECIFIC ARARS AND OTHER CRITERIA TO BE CONSIDERED
LOCATION REQUIREMENT($) PREREQUISITE($)
Within area where action may Action to recover and preserve Alternation of terrain that threatens
cause irreparable han11, loss, artifacts. significant scientific, prehistoric,
or destruction of significant historic, or archaeological data.
artifacts
Critical habitat upcn which Action to conserve endangered Deten11ination of presence of
endangered species or species or threatened species, endangered species or threatened
threatened species depends including consultation with the species
Department of the Interior
•'
• Applicable Requirements for Alternatives as noted.
• Relevant and Appropriate Requirements for Alternatives as noted.
° Criteria To Be Considered for Alternatives as noted.
CITATION
National Archaeological and
Historical Preservation Act (16
USC Section 469); 36 CFR Part
65
Endangered Species Act of 1973
(16 USC 1531 et seq.); 50 CFR
Part 200, 50 CFR Part 402, Fish
and Wildlife Coordination Act (16
USC 661 et seq.); 33 CFR 320-
330
COMMENTS A" RARb TBC0
No artifacts have been
found in OU #3
No endangered species
are known to exist on the
OU #3 site.
t
I
General
Reaponee
Action
NoAdlon
lmlllublll Conlrol
~
ConlalnmonVTrulmonl
.
. .
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IColedlorv°T
Technology Type Process Option ..
H WA H WA
H ---1--1 Deod-lona I
H Vollk:al -Aow ConlrolH EdnldlonllrNdlon -
~~ Vollk:al-AowConlrolH
In SluT-monl ==w• :
1-ll Con-lonal EldnlcllonWelo I
I -Ion . 1 ---I .. -Drain ~-TIWICh I
' In-I
On-610 J .
l1 1n~ I
• ~: r-PCffW I
~ On-6lo ---I
I Con--lon-I
~ -H
I EnhanoodEldnldlonWelo I
l -Drain TrwMlh I
I N, I
~ ...-r-~ . Carbon I
61■-n I
~ I
a..ricolTr....,_ H
' --~ I
~ 1 ~-~1 PnilnNll:ment ~eml
l Trealmonl -Blor-I
0
lnslhutlonal
lmplernent11bllhy
E&allylnl>lomonl-
~ .. ,:i1eua1lable
...... ,.,table
Nol....,..._,._lof_
ln,plo.1••---Dlfflcuty
~--• Dlfflcuty
~-lllflklJlly
ln ..... ,a,..,._
Nol ....... iled "" -
~ •1,pl,N1•~-• All El•-• -Bo~ e..ra,.,,.,..,_.._
.,,_IIM Taal■ .....
ln,plo■1••--Dlfflcully
~-Dlfflcuty
-,_ -Effectiveness
In Meeting PRGa
Nol Ellocllvo
SlttlllY Ellocllvo
Nol Ellocllve • Wmw -
TnNltmenl lo Meet PRGI
Ellocllvo
-Ell9cllvo
Nol Effective • W9!9' -
Troalmonl lo Moel PRGo
Vsy Ellocllvo
Vsy Ellocllvo
Vsy Ellocllvo
Vsy Ellocllvo
Ellocllve
Ellocllve
!kl_, Ellocllv--
Modondoly Ellodlvo
ModondolyEllodlvo
Coat
UM
UM
Low lo Modarllfe
~High
~High
Low 10 Modenlle
UM
-atolyHgh
Mtd.:.aw,t-lgt'I
Hgh
Hgh
High
_ _,High
_ _,High
TABLE 20 SECOND SCREENING OF TECHNOLOGIES AND PROCESS OPTIONS FOR GROUNDWATER
-----llil ,. ,_ ;---·-----.. -·-General
Reaponlk lnatltutlonal Ettectlveneaa Action Technology Type Proceaa Option lmplernentablllty In Meeting PRGa Coat
~ .,_ in.,--wllh Modonde Ollllallly Ellllc:llvo Low 10 Moderate
Clr>Sllo~
ln)ecllon ...... , .. ,&able Ellllc:llvo Law I~•---~ ~: r".IIVPOTW I 1n1>1a..--wllh -Olffltully Ellllc:llvo --·►tlgh ~-SUrlaooW-~ I. in'l>ianwOablo wlh Olffltully Eftadtve -Hl11
._ ________ -"""-Opllon Roi-
•: .,
,1 .
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DRAFT
Alternative GWP4A/GWL4A:
Alternative GWP4B/GWL4B:
NATIONAL STAF01 & CHEMICAL COMPANY SUPEARJ~D SITE
~ RECORD OF DECISION FOR 01'!:RABU: Umr 13
SEPTBeER 1, 1993/7:21.lM -65-
Groundwater Extraction, Air Stripping, Vapor-Phase Carbon Adsorption, Discharge to Publicly Owned Treatment Works (POTW) (i.e., local sewer system)
Groundwater Extraction, Air Stripping, Fume Incineration,
Discharge to POTW
The point of compliance for all the groundwater alternatives listed above for OU #3 is defined as throughout the entire plume of contamination in accordance to 40 CFR 300.430(a)(1 )(iii)(F) which states "EPA expects to return usable ground waters to their beneficial uses wherever practicable, within a timeframe that is reasonable given the particular circumstances of the site. When restoration of ground water to beneficial uses. is not practicable, EPA expects to prevent further migration of the plume, prevent exposure to the contaminated ground water and evaluate further risk reduction." ·
10.1.1 Alternative GWP1/GWL 1: No action
The No Action alternative is included, as required by CERCLA, to establish a baseline for comparing the benefits achieved by the other groundwater remediation alternatives. Under these alternatives, no cleanup activities would be implemented to remediate the groundwater adversely impacted by past Site activities (i.e., the Site is left "as is"). Because these alternatives do not entail contaminant removal or destruction, hazardous materials would remain on Site requiring a review of the Site remedy every five years in accordance with CERCLA Section 121(c). The implementation of this remedy could begin immediately and would have no negative impact on future remedial actions .
A slight reduction in the levels of contamination may occur over time through natural processes; however, the levels in the groundwater would remain above the groundwater cleanup goals for up to 70 years. Although there is no current unacceptable risk associated with the contaminated. groundwater, this situation would change immediately if a potable well was installed near the Site. The reason there is no current risk is because nobody in the vicinity of the adversely impacted groundwater is using this groundwater as a source of drinking water. However, if a potable well was installed in or near the plume, the risk would increase to 2 x 10·3 • Since this alternative does not involve any treatment or other remedial action, the reduction in the toxicity, mobility, or volume (TMV) of the contaminated groundwater at the Site would result from natural processes.
There are no capital costs associated with this alternative; however, O&M costs would be incurred for conducting the five year reviews. This review includes monitoring the groundwater under the Site once every five years as well for a period of 30 years.
Capital Costs:
Annual O&M Costs:
Total PW Costs for 30 Years:
Time to Design:
Construction Time:·
Duration to Achieve Clean-up:
$ 0
$ 22,000
$ 227,000
None
None
Over 30 years
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DRAFT NATlONAL STA~ & CHEMICAL COMP...« SUPERRJNO SITE
CRAFT RECOFO OF DECISION FOR OPERABLE UNrr #3
-66-
10.1.2 ALTERNATIVE GWP2/GWL2: Long Term Monitoring, Fencing
A Portion Of Northeast Tributary
SEl"TBtoeER 1, 1993/7'21 ,1,1,1
This alternative is analogous to Alternative GWP1/GWL 1, except under Alternative GWP2/GWL2 additional monitoring wells would be installed, groundwater monitoring data would be collected
annually instead of once every five years, and a portion of the Northeast Tributary would be fenced.
Capital Costs:
Annual O&M Costs:
Total PW Costs for 30 Years:
Time to Design:
Construction Time:
Duration to Achieve Clean-up:
$ 178,000
$ 138,000
$1,479,000
None
None
Over 30 years
10.1.3 ALTERNATIVE GWP3/GWL3: lnstltutlonal Controls, Long Term Monitoring, Fencing
A Portion Of Northeast Tributary
This alternative is identical to Alternative GWP2/GWL2, except Alterative GWP3/GWL3 includes institutional controls. No remediation activities would be conducted for groundwater. The additional costs are associated with preparing and filing deed restriction(s) and implementing the other institutional controls. The specific institutional controls to be implemented include: using
deed restrictions to control the installation of new wells on both the plant property and adjacent
property; track plume migration; and install fencing around the Northeast Tributary to limit access to contaminated surface water and sediment. ·
This alternative provides no reduction in TMV of the contaminants, however, it can reduce or
eliminate direct exposure pathways and the resultant risk to the public. As part of this alternative, the groundwater would be monitored on a yearly basis. As EPA may not have the authority to implement these institutional controls, the responsibility rests with the State of North Carolina to ensure the institutional controls are in place, are reliable, and will remain in place after initiation of O&M. Therefore, the responsibility for implementing and enforcing institutional controls· falls on the State of North Carolina. Groundwater monitoring and the five year CERCLA review would
be conducted for 30 years.
Capital Costs:
Annual O&M Costs:
· Total PW Costs for 30 Years:
Time to Design:
Construction Time:
Duration to Achieve Clean-up:
$ 198,000
. $ 138,000
$1,500,000
None
None
Over 30 years
10.1.4 ALTERNATIVE GWP4A/GWL4A: Groundwater Extraction Through Wells;
Treatment by Air Stripping with Vapor-Phase Carbon Adsorption
; and Discharge to POTW
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DRAFT NATIONAL Sr.l..FCH & CHEMICAi. COMPANY SUPERAJND SITE
~ RECOR:> OF DECISION FOR O1'1:R.ABLE UNIT "3
SEPTSeEA 1, 1993/7:21AM
-67-
This alternative includes extracting groundwater by means of extraction wells downgradient of both areas, Area 2 and the lagoon area; volatile organics removal through air stripping; control of emissions to the atmosphere from the air stripper through vapor-phase carbon adsorption; and combined discharge with treated groundwater from OU-1 to the Salisbury publicly owned treatment works (POTW). The treated effluent must meet permit limits set by the Salisbury POTW. Spent activated carbon would be changed out and sent. to a commercial regeneration/recycling facility, destroyed through incineration, or disposed in an appropriately regulated landfill. The five year review CERCLA requirement would apply to this alternative.
Capital Costs:
Annual O&M Costs:
Total PW Costs for 30 Years:
Time to Design:
Construction Time:
Duration to Achieve Clean-up:
$1,437,000
$ 740,000
$5,792,000
1 year
6 months
15 to 30 years
10.1.5 ALTERNATIVE GWP4B/GWL4B: Groundwater Extraction Wells, Treatment by Air Stripping with Fume Incineration: and Discharge to POTW
This alternative is identical to Alternative GWP4A, except that the control of emissions to the atmosphere from the air stripper would be accomplished through fume incineration.
Capital Costs:
Annual O&M Costs:
Total PW Costs for 30 Years:
Time to Design:
Construction Time:
Duration to Achieve Clean-up:
$1,679,000
$ 659,000
$5,270,000
1 year
6 months
1 5 to 30 years
10.2 REMEDIAL ALTERNATIVES TO ADDRESS SURFACE WATER AND SEDIMENT
CONTAMINATION
10.2.1 ALTERNATIVE SW/SE-1: No Action
No further activities would be conducted on surface water or the sediment in the Northeast Tributary. As with Alternative GWP1/GWL 1, this stream would be left "as is". Samples would be collected and analyzed every five years as part of the five year review CERCLA requirement which would apply to this alternative.
Capital Costs:
Annual O&M Costs:
. Total PW Costs for 30 Years:
Time to Design:
Construction Time:
Duration to Achieve Clean-up:
..
$ 0
$ 16,000
$151,000
None
None
Over 30 years
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DRAFT
-68-
10.2.2 ALTERNATIVE SW/SE-2: Long-Term Monitoring
NATIONAL ST.-.~ & CHB,41CAL C0MPAHY SUPERRJNO SITE
DRAFT RECOR) OF OeCSl()N FOR 0P£R.i&.E UNrr #3
·sePIDeeR 1, 199317:21AAA
This alternative is similar to Alternative SW/SE-1, except under Alternative SW/SE-2, surface water and sediment samples would be collected from the Northeast Tributary annually instead of once every five years.
Capital Costs:
Annual O&M Costs:
Total PW Costs for 30 Years:
Time to Design:
Construction Time:
Duration to Achieve Clean-up:
$ 0
$ 92,000
$867,000
None
None
Over 30 years
11.0 'suMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES
Section 10.0 describes the remedial alternatives that were evaluated in the detailed analysis of alternatives set forth in the June 21, 1993 OU #3 Feasibility Study Report. This section summarizes the detailed evaluation of these remedial alternatives in accordance with the nine (9) criteria specified in the NCP, 40 CFR Section 300.430(e)(9){iii). This section summarizes the comparison of the groundwater and surface water/sediment remedial alternatives; the soils remedial alternative will be addressed under OU #4.
11.1 THRESHOLD CRITERIA
In order for an alternative to be eligible for selection, it must be protective of both human health and the environment and comply with ARARs; however, the requirement to comply with ARARs · can be waived in accordance to 40 CFR Section 300.430(1)(1 )(ii)(C). Table 21 summarizes the evaluation of the five (5) groundwater and two (2) surface water/sediment remedial alternatives · with respect to the threshold criteria.
11.1.1 Overall Protection of Human Health and the Environment
This criterion assesses the alternatives_ to determine whether they can adequately protect human health and the environment from unacceptable risks posed by the contamination at the Site. This assessment considers both the short-term and long-term time frames.
Under current conditions, the groundwater does not pose an unacceptable risk to human health or the environment. And in contemplating future use scenarios· for the Site in the Risk Assessment, the scenario that typically results in manifesting the greatest risk, using contaminated groundwater as potable water, the overall risk posed by the Site was 2 x 10·3_
Alternatives GWP2/GWL2, GWP3/GWL3, GWP4A/GWL4A, and ·GWP48/GWL48, provide adequate protection for human health by preventing ingestion of potentially contaminated groundwater and surface water. Alternatives GWP4A/GWL4A and GWP4B/GWL48 would afford the greatest protection to human health because it would substantially reduce the contamination
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TABLE 21 SUMMARY OF THE THRESHOLD CRITERIA EVALUATION FOR THE
ALTERNATIVES
GWP1/GWL 1: No Action
GWP2/GWL2: Long Term
Monitoring; Fence Portion of
Northeast Tributary
GWP3/GWL3: Institutional Controls;
Long Term Monitoring; Fence
Portion of Northeast Tributary
GWP4A/GWL4A: Groundwater
Extraction; Treatment Via Air
Stripping.and Vapor-Phase
Adsorption; Discharge to POTW
GWP4B/GWL4B: Groundwater
Extraction; Treatment Via Air
Stripping and Fume Incineration;
Discharge to POTW
SW/SE-1: No Action
SW/SE-2: Long-Term Monitoring
. _ ....
Does not eliminate any exposure
pathways or reduce the level of risk.
Does not eliminate any exposure
pathways, reduces potential risk of
exposure to contaminated surtace
water/sediment by fencing stream.
Contamination would continue to
discharge into Northeast Tributary.
Potential offsite contaminant migration
would not be eliminated. Institutional
controls would eliminate risk posed by
using contaminated groundwater as
potable water. Contamination would
continue to discharge into Northeast
Tributary.
Offsite contaminant migration would be
eliminated. Eliminates potential risk of
ingestion, inhalation, and dermal
absorption. Eliminates contamination
entering Northeast Tributary.
Offsite coritaminant migration would be
eliminated. Eliminates potential risk of
ingestion, inhalation, and dermal
absorption. Eliminates contamination
entering Northeast Tributary.
Protective of human health but may not
be protective of the environment.
Protective of human health but may not
be protective of the environment.
Not in compliance
Not in compliance
Not in compliance
In compliance ·
In compliance
No Federal or State
ARARs for contaminants
detected in stream.
No Federal or State
ARARs for contaminants
detected in stream.
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DRAFT
-70-
N,1,TIONAI.. STAR:>! & CHEMICAi.. COMP.l#Y SUPERRJNO SITE
DRAFT REC0fll OF DECISION FOR OPER>&f UNrr #3
--SEPTB,llER 1, 1993/7:21AM
in the groundwater and prevent the potential for exposure through use of existing or future off site
wells. Alternatives GWP4A/GWL4A and GWP4B/GWL48 would also remediate the surface water
and sediment, which would eliminate the potential for exposure via ingestion of these media.
These alternatives protect the environment by removing contaminants from groundwater,
controlling the extent of groundwater contamination, and reducing the contamination in the
tributary and downstream surface waters. Alternative GWP3/GWL3 would not be as protective
of the environment because contamination would continue to migrate into the tributary through
groundwater discharge. Neither Alternatives GWP1 /GWL 1 nor GWP2/GWL2 would provide
protection for either human health or the environment.· Natural degradation/attenuation of
contaminants in the subsurface is not anticipated to prevent the potential migration of
contaminants off site, although such processes may reduce the amount and concentration of
contaminants which would eventually leave the Site.
Under present conditions, both Alternatives SW/SE-1 and SW/SE-2 would be protective of human
health, but may not be protective of the environment. If higher concentrations are discharged into
the stream along with the groundwater, then both alternatives may not be protective of human or
the environment.
11.1.2 Compliance with Applicable or Relevant and Appropriate Requirements
This criterion assesses the alternatives to determine whether they attain ARARs under federal
and state environmental laws, or provide justification for waiving an ARAR. Section 9.0 defines
the three types of ARARs: action-specific, chemical-specific, and location-specific. Site specific
ARARs are identified below.
MCLs and State groundwater quality standards are ARARs for Site groundwater. By leaving
contaminants above MCLs in the groundwater, Alternatives GWP1/GWL 1, GWP2/GWL2, and
GWP3/GWL3 would not comply with these ARARs. Therefore, these alternatives would not
achieve the requirements of the NCP. Alternatives GWP4A/GWL4A and GWL4B/GWL4B would
obtain performance standards for groundwater (MCLs and North Carolina Groundwater
Standards), surface water and sediment at the point of compliance. These alternatives would
also comply with action-and location-specific ARARs related to the construction and operation
of the groundwater extraction, treatment, and discharge systems to be installed under these
Alternatives. The discharge to the POTW and air emission associated with Alternatives
GWP4A/GWL4A and GWL4B/GWL4B will also satisfy all appropriate ARARs. The disposal of
any sludge or. spent activated carbon created by the groundwater treatment system will also
comply with the appropriate ARARs.
There are no Federal or State ARARs for the contaminants detected in the surface water or
sediment originating from the Site.
11.2 PRIMARY BALANCING CRITERIA
These criteria are used to evaluate the overall effectiveness of a particular remedial alternative.
This evaluation is summarized in Table 22.
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DRAFT NATIONAL $TAR:;H & CHB,UCAI. COMPANY SUPERRJND SITE
DRAFT AECOI'{) OF DECISION ~ 0PERA8l..f UNIT #3
SEPTB.l!EA 1, 1993/7:21.w
-71-
11.2.1 Long-Term Effectiveness and Permanence
This criterion assesses the long-term effectiveness and permanence an alternative will afford as well as the degree of certainty to which the alternative will prove successful.
Under Alternatives GWP1/GWL 1, GWP2/GWL2, and GWP3/GWL3 groundwater contamination would not be actively remediated; therefore these alternatives cannot be considered to be permanent or effective remedial solutions as these alternatives do not remove, treat, or isolate subsurface contamination. The long-term effectiveness of Alternatives GWP1 /GWL 1 and GWP2/GWL2 is questionable, because of the time it would require for "Nature" to clean "Itself". These remedies would rely on the natural attenuation and the flowing groundwater to eventually remove all the contaminants that have entered the groundwater at the Site. Alternative GWP3/GWL3 would prevent potential future risk by preventing the installation of drinking wells in any areas exceeding MCLs or North Carolina Groundwater Standards. Alternatives GWP4A/GWL4A and GWP4B/GWL4B would provide an effective and permanent solution for groundwater, surface water, and sediment because the chemicals of concern would be removed from the groundwater and destroyed. The reliability of Alternatives 'GWP4A/GWL4A and . GWP4B/GWL4B is high and these alternatives would not pose a human health or environmental risk at the point of compliance and no treatment residuals would be left on Site. Five-year CERCLA mandated reviews will be required for all of the alternatives.
Under current conditions, both Alternatives SW/SE-1 and SW/SE-2 would be protective of human health, but may not be protective of the environment. If higher concentrations of contaminants begin discharging into the tributary, then neither of these alternatives may be protective of human or the environment.
11.2.2 Reduction of Mobility, Toxicity, or Volume
This criterion assesses the degree to which the alternative employs recycling or treatment to reduce the .TMV of the contaminants present at the Site.
Alternatives GWP4A/GWL4A and GWP4B/GWL48 would reduce the toxicity and volume of contamination in groundwater through removal and treatment. They would also reduce the toxicity and volume of contamination in surface water and sediment. The groundwater treatment processes associated with these two alternatives would completely comply with the statutory preference for alternatives that reduce toxicity of contaminants. Alternatives GWP1/GWL 1, GWP2/GWL2, and GWP3/GWL3 do not directly reduce toxicity, mobility, or volume of groundwater, surface water or sediment contamination.
Alternatives SW/SE-1 and SW/SE-2 could lead to a reduction of VOCs in the tributary, however, neither of these alternatives would result in the destruction of the voes. These contaminants would transfer from.the tributary to the atmosphere through the process of volatilization.
l
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..
ti
SUMMARY OF PRIMARY BALANCING CRITERIA EVALUATION OF THE ALTERNATIVES
GWP1/GWL1: No
Action
GWP2/GWL2: Long-
Tenn Monitoring;
Fence Portion of
Northeast Tributary
GWP3/GWL3:
Institutional Controls;
Long-Tenn Monitoring;
Fence Portion of
Northeast Tributary
Does no1 mee1 ARARs. Length of
service unknown (no1 permanen1).
Ongoing monitoring of groundwater
contaminant leveis would be
. conducted to assess contaminants
migration. ARARs are not met at
the Site. Length of service
unknown (not pennanent). Fence
would reduce potential of exposure
to contaminated surface
water/sediment.
Ongoing monitoring of groundwater
contaminant levels would be
conducted to assess contaminants
migration. ARARs are not met at
the Site. Effectiveness is
depended on enforcement of
institutional controls. Length of
service unknown (not permanent).
Fence would reduce potential of
exposure to contaminated surface
water/sediment.
GWP4A/GWL4A: · Pennanent remedy.
Groundwater ARARs are met.
Extraction; Treatment
Via Air Stripping and
Vapor-Phase
Adsorption; Discharge
to POTW
None, except natural
attenuation.
None, except natural
attenuation.
None, except natural
attenuation.
Eliminates TMV of
contaminants and potential
for off-site migration.
Greatest degree of risk
reduction for ingestion,
inhalation, and dennal
absorption.
None.
None.
None.
Potential release of voes
during extraction well
installation and treatment
system operation. Noise
nuisance due to operation
of drilling equipment.
None.
None.
None.
Design of extraction,
. treatment, discharge, and
monitoring systems. Air
stripping of voes to meet
POTW pretreatment
requirements. Treatment of
air stripping off-gases will
be required during start-up.
0
0
0
12 months to design
6 months to construct
227
1,479
1,500
5,792
- - - - - - - - - - - -----
SUMMARY OF PRIMARY BALANCING CRITERIA EVALUATION OF THE ALTERNATIVES
. GWP48/GWL4B: .
Groundwater
Extraction; Treatment
Via Air Stripping and
Fume Incineration;
Discharge to POTW
Permanent remedy .
ARARs are met.
Eliminates TMV of
contaminants and pctential
tor off-site migration.
Greatest degree of risk
reduction for ingestion,
inhalation, and dermal
absorption.
Potential release of voes
during extraction well
installation and treatment
system operation. Noise
nuisance due to operation
of drilling equipment.
Design of extraction,
treatment, discharge, and
monitoring systems. Air.
stripping of voes to meet
POTW pretreatment
requirements. Treatment of
air stripping off-gases will
be required during start-up .
- --· -
12 months to design
6 months to construct
5,270
.. ll========4===========l='========le=========l=========Jc=======l======:I
,1
)
SW/SE-1: No Action
SW/SE-2: Long-Term
Monitoring
Under current conditions human
health may be protected but
pcssibly not the environment.
Under current conditions human
health may be protected but
pcssibly not the environment.
Would increase mobility of None.
contaminants, however,
through volatilization toxicity
and volume of
contaminants in the water
column would be reduced.
Would increase mobility of None.
contaminants, however,
through volatilization toxicity
and volume of
contaminants in the water
column would be reduced.
None. None. 151
None. None. 867
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DRAFT
-73-
NATIONAL ST,1,fOi & CHEMICAL CC-MP.11.Y SUPERFUND SITE
CRAFT RECOfll OF DECISION FOO O?£RAat...E UNrr #3
--. SE?Ts.eER 1, 1993/7"21..IM
11.2.3 Short-Term Effectiveness
This criterion assesses the short-term. impact of an alternative to human healt_h and the
environment. The impact during the actual implementation of the remedial action is usually
centered under this criterion.
All of the alternatives for both groundwater and surface water/sediment can be implemented
without significant risk to the community or on-site workers and without adverse environmental
impacts.
11.2.4 Implementability
This criterion assesses the ease or difficulty of implementing the alternative in terms of technical
and administrative feasibility and the availability of services and materials.
None of the alternatives for both groundwater and surface water/sediment pose significant
concerns regarding implementation. The design of the treatment systems for Alternatives
GWP4A/GWL4A and GWP4B/GWL4B cannot be completed until the discharge requirements are
defined by the Salisbury POTW. This will occur during the RD.
11.2.5 Cost
This criterion assesses the cost of an alternative in terms of total present worth cost (PW). Total
PW was calculated by combining the capital cost plus the PW of the annual O&M costs. Capital
cost includes engineering and design, mobilization, Site development, equipment, construction,
demobilization, utilities, and sampling/analyses. Operating costs were calculated for activities that
continue after completion of construction, such as routine operation and maintenance of treatment
equipment, and groundwater monitoring. The PW of an alternative is the amount of capital
required to be deposited at the present time at a given interest rate to yield the total amount
necessary to pay for initial construction cos!s and future expenditures, including O&M and future
replacement of capital equipment.
More detailed information on the development of the total present worth costs for each alternative
can be found in Section 10.
Alternative GWP 1 /GWL 1
Alternative GWP2/GWL2
Alternative GWP3/GWL3
No Action
Long-Term Monitoring, Fence Portion of
Northeast Tributary:
Institutional Controls, Long-Term Monitoring,
Fence Portion of Northeast Tributary:
Alternative GWP4A/GWL4A Groundwater Extraction/Air Stripping/
$ 227,000
$1,479,000
$1,500,000
Vapor-Phase Carbon Adsorplion/POTW Discharge: $5,792,000
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DRAFT
NATIONAL STA/Ui & CHEMICAL COMPANY SUPERAJNO SITE
~ RECOFO OF DECISION FOR 0P€R"'8lf UNfT "3
SEPTBE!ER 1, 199:v?:21>M -74-
Alternative GWP4B/GWL4B Groundwater Extraction/Air Stripping/ Fume lncineration/POTW Discharge : $5,270,000
$ 151,000
$ 867,000
Alternative SW/SE-1
Alternative SW/SE-2
No Action
Long-Term Monitoring
11.3 MODIFYING CRITERIA
State and community acceptance are modifying criteria that shall be considered in selecting the remedial action.
11.3.1 State of North Carolina Acceptance
The State of North Carolina has reviewed and provided EPA with comments· on the reports and data from the RI and the FS. NCDEHNR has also reviewed the Proposed Plan and EPA's preferred alternative and cccondltlonally concurs with the selected remedy as described in Section 12.
11.3.2 Community Acceptance
The Proposed Plan Fact Sheet was distributed to interested residents, to local newspapers and radio and TV stations, and to local, State, and Federal officials on July 15, 1993. The Proposed Plan public meeting was held in the evening of August 3, 1992. The public comment period on the Proposed Plan began July 19, 1993 and closed on September 16, 1992.
Written comments were received from the City of SSalisbury and the PPRp during the public comment period. The questions asked during the June 11, 1992 public meeting and the Agency's response to the written comments are summarized in the Responsiveness Summary, Appendix A.· SSSince no input was received from the community at large, it is infeasible to assess the ccommunity's aacceptance of the proposed remedy.
12.0 DESCRIPTION OF THE SELECTED REMEDY
As stated previously, the soil remediation alternative will be addressed in OU #4. Alternative GWP3/GWL3 and GWP4B/GWL4B was selected for groundwater and SW/SE-2 for the surface water/sediment in the Northeast Tributary. Briefly, the selected remedy for this Site is:
• Implement institutional controls .
Long-term monitoring of the groundwater.
Design and implementation of the groundwater remediation. The selected groundwater remediation alternative consists of a groundwater· extraction system consisting of
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DRAFT N,,_TIONAI.. ST,,_i:oi I!, CHEMICAi.. COMP.I.'« SUPERFUNO SITE
DRAFT AECOFll OF DECISION FOA O?fR,i&f UNIT '3
SEPTBeEA 1, 1993/7:21 ~
-75-
extraction wells, an air stripping process to remove the VOCs, control of emissions from
the air stripper to the atmosphere through vapor-phase carbon adsorption filters, and
combining the effluent with the treated groundwater from OU #1 and the facility's operation
effluent to be discharged to the City of Salisbury POTW system.
• Delineate the vertical extent of groundwater contamination in the bedrock.
More accurately evaluate the direction and speed of the flow of groundwater in the
bedrock.
Conduct a review of the existing groundwater monitoring system to insure proper
monitoring of both groundwater quality and groundwater flow so that the effectiveness of
the groundwater extraction system can be evaluated. Additional monitoring wells and/or
piezometers will be added to mitigate any deficiencies.
Alternative GWP3/GWL3 also includes fencing a portion of the Northeast Tributary.
However, since the groundwater extraction system will reduce and then eliminate
contamination migrating into the Northeast Tributary, it will not be necessary to install this
fence. This condition will be evaluate in the 5 year CERCLA review.
This remedy will reduce the levels of contamination in the groundwater to below their Federal
MCLs and State groundwater quality standards. ·
12.1 PERFORMANCE STANDARDS TO BE ATTAINED
Performance standards include any applicable or relevant and appropriate
standards/requirements, cleanup levels, or remediation levels to be achieved by the remedial
action. The performance standards to be met/attained by the NSCC OU #3 RA include the . . following tables and Table 23:
• action-specific ARARs are inventoried in Table 6,
chemical-specific ARARs are inventoried in Table 7, and
location-specific ARARs are inventoried in Table 9.
Table 23 provides the remediation goals to be achieved at this Site. This table also lists the risk
level associated with each remediation goal. These risks are based on the reasonable maximum
exposure (RME) levels and summarizes the information provided in Tables 11, 12, 13, 14, and
15.
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TABLE 23 PERFORMANCE STANDARDS AND CORRESPONDING RISKS FOR OU #3
PERFORMANCE STANDARDS (CLEANUP GOALS)
CHEMICAL OF
CONCERN
GROUNDWATER
Acetone
Bis(2-Chloroelhyl)ether
Bromodichloromethane
Chlorolorm
1,2-Dichloroethane
1, 1-Dichloroethene
cis 1,2-Dichloroethene
trans 1,2-Dichloroethene
1,2-Dichloropropane
Ethylbenzene
Methylene Chloride
Tetrachloroethene
Toluene
Total Xylenes
1, 1,2-Trichloroethane
Trichloroethene
Vinyl Chloride
PERFORMANCE
STANDARD
(µGIL)
3,500
5
100
7
70
70
29
5_
1,000
400
5
2.8
POINT OF
COMPLIANCE
The Entire
Plume of
Contaminated
Groundwater
BASIS OF
STANDARD
OU #1
OU#1
CRQUState1'1
CRQUStateM
MCUState
State
CRQUState~1
State
CROUState1'1
MCUState
Sate
MCL
State
CRQUState~1
CORRESPONDING RISK LEVELS
CHEMICAL-SPECIFIC RME RISK
CANCER NON-CANCER
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TABLE 23 PERFORMANCE STANDARDS AND CORRESPONDING RISKS FOR OU #3
PERFORMANCE STANDARDS (CLEANUP GOALS) CORRESPONDING RISK LEVELS
Acetone
1,2-Dichloroethane
I SEDIMENT
VOLATILE ORGANIC COMPOUNDS
Acetone
1,2-Dichloroethane
µg/I --Micrograms per Liter
MCL --Maximum Concentration Limit as Specified in the Safe Drinking Water Act OU #1 --Performance Standard Developed in September 30, 1988 Operable Unit #1 Record Of Decision l•I --Based on MCL for Trihalomeilianes
CRQL --Contract Required Quantitation Limit State~I --Where the Maximum Allowable Concentration 01 A Substance Is Less Than The Limit Of Detectability (15 A NCAC 2L.0202(b)(1) State --State Groundwater Quality Standards (NCAC 15-2L.0202)
• --Interim State Being Proposed
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·DRAFT NATIONAi.. STA~ & CHEMICAi.. COMP.+,NY SUPERRJND SITE
CRAFT Reco~ OF OECIS()N FOR OPERABI..E UNIT '3
SEPTB.flER 1, 1993/7·21 AAI
-77-
12.2 GROUNDWATER REMEDIATION
The groundwater remediation alternatives selected for the OU #3 at the NSCC Site are ·
GWP3/GWL3 and GWP4B/GWL4B -Institutional Controls, Long-term Monitoring, Groundwater
Extraction and Physical Treatment (Air Stripping) with Control of Air Emissions Via Vapor-Phase
Carbon Adsorption Filters, and Discharge to POTW. A description of the selected remedial
alternative follows.
The contaminated aquifer will be remediated until the performance standards specified in Table
23 are achieved. Figures 3, 4, and 7 delineates the estimated periphery of the plumes
emanating from OU #3. The extracted groundwater from Area 2 and the lagoon area will be
combined for treatment. · Following treatment of the extracted groundwater, the groundwater will
be discharged into the sewer system along with the rest of the NSCC influent to the City of •
Salisbury POTW.
It is anticipated that four (4) extracting wells, two (2) installed in the saprolite and 2 into the
bedrock, downgradient of Area 2 and six (6) extraction wells, three (3) installed in the saprolite
and 3 into the bedrock, downgradient of the lagoon area will be required. The Area 2 bedrock
and saprolite extraction wells would have an estimated combined flow of 15 gallons per minute
(gpm) and 10 gpm, respectively. The lagoon area bedrock and saprolite extraction wells would
have an estimated combined flow of 6 gpm and 30 gpm, respectively. At these pumping rates,
it is anticipated that these wells will achieve and maintain a sufficient drawdown in the underlying
aquifer to contain and remove the plumes of contamination. The extraction wells will be located
within and near the sources of contamination. The extracted groundwater will be treated in an
above-ground, on-site air stripper. The actual number, placement, pumping rate of each
extraction well, the size of the air stripping unit, and the size of the vapor-phase activated carbon
adsorption units need will be determined in the RD. The air stripper will be designed to achieve
the pretreatment requirements which will be determined by the City of Salisbury POTW. The only
anticipated by-product to be generated by the groundwater treatment process described above
is spent activated carbon. The activated carbon may be regenerated, destroyed, or disposed of
in an appropriately regulated landfill. The most cost effective option for dealing with the spent
activated carbon will be implemented.
The goal of this remedial action is to restore the groundwater to its beneficial use, as defined in
Section 7.4. Based on information obtained during the RI, and the analysis of all of the remedial
alternatives, EPA and the State of North Carolina believe that the selected remedy may be able
to achieve this goal.
Groundwater contamination may be especially persistent in the immediate vicinity of the
contaminants' source where concentrations are relatively high. The ability to achieve cleanup
goals at all points throughout the area of attainment, or plume, cannot be determined until the
extraction system has been implemented, modified as necessary, and plume response monitored
over time. If the selected remedy cannot meet the specified performance standards, at all of the ·
monitoring points during implementation, the contingency measures and goals described in this
section may replace the selected remedy and goals for these portions of the plume.
Such contingency measures will, at a minimum, prevent further migration of the plume and
include a combination of containment technologies and institutional controls. These measures
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DRAFT
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N.-.TIONAL STA!Ui & CHEMICAL CciMPM'Y $UPERAJNO SITE
DRAFT RECOFII OF DECISION FOil OPERABlf UNIT #J
SEPTSeER 1, 1993/7:2\AM
are considered to be protective of human health and the environment, and are technically practicable under the corresponding circumstances.
The selected remedy will include groundwater extraction for an estimated period of 30 years, during which time the system's performance will be carefully monitored on a regular basis and adjusted as warranted by the performance data collected during operation. Modifications may include any or all of the followings:
a) at individual wells where cleanup goals have been attained, pumping may be discontinued;
b) alternating pumping at wells to eliminate stagnation points
c) pulse pumping to allow aquifer equilibration and encourage adsorbed contaminants to partition into groundwater;
d) installation of additional extraction wells to facilitate or accelerate cleanup of the contaminant plume.
To ensure that cleanup continues to be maintained, the aquifer will be monitored at those wells where pumping has ceased on an occurrence of every 2 years following discontinuation of groundwater extraction.
If it is determined, on the basis of the preceding criteria and the system performance data, that certain portions of the aquifer cannot be restored to their beneficial use, all of the following measures involving long-term management may occur, for an indefinite period of. time, as a modification of the existing system:
a) engineering controls such as physical barriers, or long-term g~adient control provided by low level pumping, as contaminant measure;
b) chemical-specific ARARs may be waived for the cleanup of those portions of the aquifer based on the technical impracticability of achieving further contaminant reduction;
c) institutional controls may be provided/maintained to restrict access to those portions of the aquifer which remain above remediation goals;
d) continued monitoring of specified wells; and/or
e) periodic reevaluation of ~emedial technologies for groundwater restoration.
The decision to invoke any or all of these measures may be made during a periodic review of the remedial action, which will occur at 5 year intervals in accordance with CERCLA Section 121 (c).
The RA shall comply with all ARARs (see Section 9). The presence of contamination in the groundwater will require deed restrictions to document their presence and could limit future use of the area known to be affected by the contaminated groundwater.
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DRAFT NATIONAL Sl.&.A:>t & CHEMICAL COMPJNY SUPERAJNO SITE
DRAFT RECO!tl OF 0ECtSJOO ~ OPl:RABU: UNIT #3
SEPTBol!ER 1, 199lf7:21 AM
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12.3 NORTHEAST TRIBUTARY SURFACE WATER/SEDIMENT REMEDIATION
It is anticipated that the groundwater remediation alternative described above will initially reduce and then eliminate contamination in the Northeast Tributary as the source of this contamination is the contaminated groundwater discharging into the stream. Alternative SW/SE-2 requires long-term monitoring of the water column and sediment to insure that the groundwater remediation is reducing the levels of contamination in the Northeast Tributary.
Initially, each annual sampling effort will collect a minimum of four (4) surface water and 4 sediment samples collected at the same location. These samples shall be analyzed for TCL VOCs. After the groundwater extraction system becomes operational and the levels of contamination in the Northeast Tributary obtain the performance standards specified in Table 23 for two consecutive sampling events, the number of sampling points and the sampling frequency may be reduced.
12.4 MONITOR EXISTING CONDITIONS/ADDITIONAL DATA REQUIREMENTS
In addition to the work described above, this ROD and the RD will also have to address a number of data gaps.
Since the RI was not able to completely delineate the extent of the groundwater contamination
in the bedrock zone of the aquifer, additional monitoring wells will need to be installed during the RD. It is anticipated that at least two (2) bedrock monitoring wells are needed to better portray the vertical extent of contamination as well as delineate the depth to which bedrock is fractured. To determine to what depth the bedrock is fractured, bedrock cores will need to be coUected. The analytical data generated from the samples collected from these bedrock wells should provide sufficient information to determine if contaminants have migrated to this depth. The placement
of these and any other additional monitoring wells will be made after a review and evaluation of the existing groundwater monitoring system. This review is to insure that the groundwater
monitoring system will provide adequate information· to assess the long-term quality of the groundwater and to demonstrate the effectiveness of the groundwater extraction system. This review effort may also require the. need for additional groundwater modeling and aquifer testing. If a contaminant is found above its groundwater remediation standard specified in Table 23 in the deeper .regions of the bedrock, then the groundwater extraction system shall be extended to include this lower region of the bedrock zone of the aquifer and all the requirements specified in Sections 12.0, 12.1 and 12.2 of this ROD will apply.
In order to help establish a broader data base on groundwater quality additional groundwater samples will be collected and analyzed. Below are listed the wells to be sampled, how frequently these wells are to be sampled, and the chemical analyses to be performed on each sample groundwater collected. This sampling effort will continue until the groundwater remediation
system is functional and the monitoring procedures specified in either the Operation and Maintenance Manual are implemented.
Monitoring Well
To Be Sampled
Sampling
Frequency
Samples Are To
Be Analyzed For'
Analytical
Procedure
To Be Used
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DRAFT
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Sa12rolile Wells
NS-13 Annually voes, TAL metals NS-14 Annually voes
• NS-33 Annually voes
NS-35 Biannually voes, TAL metals NS-37 Annually voes NS-39 Annually voes
NS-42 Biannually voes, TAL metals NS-43 Annually voes
Bedrock Wells
NS-34 Annually voes
NS-36 Biannually voes, TAL metals NS-38 Annually voes
NS-40 Biannually voes, TAL metals
NS-41 Annually voes
NS-44 Annually voes
12.4 COST
The total present worth costs for the selected alternatives is
Alternative GWP3/GWL3:
Alternative GWP4A/GWL4A:
Alternative SW/SE-2:
$1,500,000
$5,792,000
$ 867,000
$8,159,000
The break down of this cost is specified below.
N.-,TIONAI.. STA.!Vi & CHEMICAL CQMpNjy SUPERAJNO SITE
~ RECOJ:{) OF DECISION FOO 0PERABI..E UNf'l' #3
SEPlBl!ER 1. 1993/7:21>M
EPA Methods 8240 + 6010
EPA Method 8240
EPA Method 8240
EPA Methods 8240 + 6010
EPA Method 8240
EPA Method 8240
EPA Methods 8240 + 6010
EPA Method 8240
EPA Method 8240
EPA Methods8240 + 6010
EPA Method 8240
EPA Methods 8240 + 6010
EPA Method 8240
EPA Method 8240
The present worth cost components of the institutional controls, long-term monitoring, groundwater extraction, air stripping, emissions control of off-gas via vapor-phase activated carbon filtration, and discharging to the local POTW are:
TOTAL CONSTRUCTION COSTS
TOTAL PW O&M COSTS (at annual PW O&M Costs of $878,000) TOTAL PRESENT WORTH COST
13.0 STATUTORY DETERMINATION
$1,635,000
$6,524,000
$8,159.000
Based on available information, the selected remedy satisfies the requirements of Section 121 of CERCLA, as amended by SARA, and the NCP. The remedy provides protection of human health and the environment, is cost-effective, utilizes permanent solutions to the maximum extent practicable, and satisfies the statutory preference for remedies involving treatment technologies.
13.1 PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
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DRAFT
-81-
NATION.A.L STAFOI & CHB,OCAL COMPANY SUPERRJND Sm:
~ RECORJ OF DECISION FOi, OPERABLE UNIT #;3
SEl"TEM!ER \, 1993/7'2\AM
The selected remedy will permanently treat the groundwater. Dermal, ingestion, and inhalation contact with Site contaminants will be eliminated and risks posed by continued groundwater contamination will be abated.
13.2 COMPLIANCE WITH ARARS
The selected remedy will be designed to meet all Federal or more stringent State environmental laws. A complete discussion of the ARARs which are to be attained is included in Section 9. This section also describes the TBC requirements. No waivers of Federal or State requirements are anticipated for OU #3.
13.3 COST-EFFECTIVENESS
The selected groundwater remediation technologies are more cost-effective. than the other acceptable alternatives considered. The selected remedy will provide greater benefit for the cost because it permanently removes the contaminants from the impacted aquifer.
13.4 UTILIZATION OF PERMANENT SOLUTIONS AND ALTERNATIVE TREATMENT TECHNOLOGIES OR RESOURCE TECHNOLOGIES TO THE MAXIMUM EXTENT PRACTICABLE
The selected remedy represents the maximum extent to which permanent solutions and treatment can be practicably utilized for this action. Of the alternatives that are protective of hu.man health and the environment and comply with ARARs, EPA and the State have determined that the selected remedy provides the best balance of trade-offs in terms of: long-term effectiveness and permanence; reduction in mobility, toxicity, or volume achieved through treatment; short-term effectiveness, implementability, and cost; State and community acceptance; and the statutory preference for treatment as a principal element.
13.5 PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
The preference for the treatment of contaminated groundwater is satisfied by the use of the groundwater extraction system, the air stripper to remove volatile contaminants from the groundwater, and control of the air stripper off-gas via vapor-phase activated carbon adsorption at the Site. Further treatment of the discharged groundwater will be achieved at the POTW. The principal threats at the Site will be eliminated by use of these treatment technologies.
14.0 SIGNIFICANT CHANGES
CERCLA Section 11 ?(b) requires an explanation of any significant changes from the preferred alternative originally presented in the Proposed Plan (Appendix B). Below are the specific changes made in the ROD as well as the supporting rationale for making those changes. The Proposed Plan was disseminated to the public on June 8, 1992.
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DRAFT
-82-
N.-,TIONAL STAFCH & CHEMICAL CoMPANY SUPEA~D Sm:
DRAFT REC0FI> OF DECISION FOR OPEfW!lf UNrr 13
--SEPTB.eER 1, 199317:21 AM
Alternative GWP3/GWL3 included installing a fence around a portion of the Northeast Tributary as it assumed that no remediation of the groundwater would occur. However, the selected remedy does call for the implementation of an active groundwater extraction system. The groundwater extraction system should reduce and then eliminate the contaminants entering into the surface water and sediment of the Northeast Tributary, thereby eliminating the need for this fence. This is the reason why .the installation of the fence around a portion of the Northeast Tributary has been excluded from the selected remedy as described in Section 12.
The Proposed Plan reported the total PW costs !cir Alternatives GWP4A, GWL4A, GWP4B, and GWL4B as 2,222,000, 3,570,000, 2,274,000, and 2,996,000, respectively. These costs, obtained from the June 21, 1993 Feasibility Study Report for OU #3 at the National Starch & Chemical Company Superfund Site, was based on obtaining the cleanup goals at the point of compliance specified is said document. The FS proposed groundwater clean goals above promulgated State and/or Federal standards. Because this ROD incorporates the lower promulgated standards, the duration of the pump and treat scenario increased significantly resulting in a change in cost in the . air stripper off-gas treatment technology.
Consequently, the total PW cost for Alternative GWP4A/GWL4A became $mmmmmmm and the total PW cost for Alternative GWP4B/GWL4B became $mmmmmmm. Since both alternatives achieve the same degree of treatment, Alternative GWP4A/GWL4A was selected because it is more cost effective.