The URL can be used to link to this page

Home My WebLink AboutNCD991278953_19931012_National Starch & Chemical Corp._FRBCERCLA ROD_Distribution of OU-3 Record of Decision and Initiation of OU-4-OCRo· [1 0 D 0 0 0 0 0 0 0 D 0 0 NATIONAL STARCH & CHB1ICAL CORP NPL'SITE DISTRIB.JTION OF OU 3 ROD & INITIAL OU q OCTOBER 1993 :•'!;, .. ,, ':., ~=• : ·~ -:, 'sj ,•~' ,. ,:.:,, ., ,._ ,' • ,f, ; .... ,,;•;>:_'' 0. I I I I I I I I I I I I I I I I I I OCT 12 1993 4WD-NCRS UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION IV 345 COURTLAND STREET, N.E. ATLANTA. GEORGIA 30365 Mr. Alex Samson National Starch & Chemical Company 10 Finderne Avenue Bridgewater, New Jersey 08807 RE: Distribution of Operable Unit #3 Record of Decision and Initiation of Operable Unit #4 Dear Gentlemen: Enclosed is a signed copy· of the Record of Decision (ROD) for Operable Unit ( ciu) #3 which was signed on Thursday, October 7, 1993 .-As specified in the Description of the Selected Remedy of the· DECLARATION and in Section 10. 0 Description of the Selected Remedy, a fourth operable unit is decreed. OU #4 shall focus on the contaminated soils associated with Area 2 and the wastewater treatment lagoon area. As specified in the Agency's August 19, 1993 correspondence, the April 1992 Remedial Investigation/Feasibility Study (RI/FS) Work Plan, approved by the Agency on May 8, 1992, shall govern the OU #4 RI/FS process; the June 2, 1993 OU #3 RI Report, conditionally approved by the Agency on July 7, 1993, shall suffice as the OU #4 RI Report; and all additional data ei_ther collected or generated with respect to these areas of the National Starch and Chemical Company (NSCC) facility since the submittal of the June 2, 1993 RI report shall _be inc:orporated into the OU #4 FS document. The OU #4 FS Report shall focus on remediation alternatives for the contaminated soils in the areas of the Site specified above. All work done as part of OU #4 shall be performed in accordance to the requirements of the December 1986 Administrative Order on Consent. To the extent practical, all relevant information from the June 21, 1993 FS Report shall be transposed into the OU #4 FS Report. As specified in the Agency's comments on the Draft OU #3 FS document, sent to NSCC on May 14, 1993 and June 10, 1993, and in the Agency's August 19, 1993 correspondence referenced above, the principal flaw of the June 1993 OU #3 FS Report is the limited evaluation presented in the text on the "active" remedial technologies to address the contamination in the soil in Area 2 and the wastewater - Print~d on Recycled Paper I I I I I I I I I I I I I I I I I I -2- treatment lagoon area. Defensible, technical rationale needs to be provided in the decision process during the screening, evaluation, and analysis of these alternatives. As stated in previous correspondence, it is not sufficient to state "contaminants in the unsaturated soil are contained in the thin film of water surrounding the soil particles in the unsaturated zone ... therefore •.. immobile". This is not a defensible argument for not evaluating "active" remediation technologies (e.g., soil. venting, soil vapor extraction, etc.). However,· if Site characteristics reduce or render a technology or technologies ineffective, then this justification needs to be incorporated into the FS document to support the elimination of that particular technology or technologies. The OU #4 FS report should also include all the pertinent details on the terra-cotta pipeline abandonment effort and the installation of the above ground piping system (i.e., give yourselves credit were credit is do). At a minimum, the OU #4 FS should include dates, portions of pipe grouted, analytical data for any samples collected, installation of above ground piping, etc. With respect to the information specified above, the Agency is requesting that NSCC perform OU #4. A decision is requested by October 25, 1993. If NSCC elects to perform OU #4, please provide in your response a tentative schedule for completion. As specified in earlier discussions and correspondence, it remains the Agency's opinion that the only field work to be conducted to support this effort was the hydrophobic dye test. This effort was completed the week of September 27, 1993. Therefore, NSCC should be able to submit the draft OU #4 FS document in a relative short timeframe (i.e., near the end of January 1994). If you have any questions, please call me at (404)347-7791. Sincerely yours, Jon K. Bornholm Remedial Project Manager enclosure cc: Hank Graulich, NSCC (w/o encl.) Bruce Nicholson, NCDEHNR (encl.) Ray Paradowski, NSCC (encl.) Michael Sturdevant, IT (encl.) I I I I I I I I I I I I I I I I I I 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 OCTOBER 1993 I I I I I I I I I I I I I I I I I I I DECLARATION FOR THE RIECORD 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 National 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 conditionally concurs with the selected remedy for Operable Unit Three. State comments on this RFi_cord 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 This Operable Unit is the third of four Operable Units for this Site. The first two Operable Units addressed the contamination associated with the Trench Area This Operable Unit and the fourth Operable Unit will address the contamination associated with the active production. area of the National Starch & Chemical Company facility and the wastewater treatment lagoon area This Operable Unit, Operable Unit #3, will permanenUy 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. Operable Unit #4 will address the contaminated soils in this portion of the Site. I I I I I I I I I I I I I I I I I I I The major components of Operable Unit #3 Remedial Action Include: • Design and implementation of the specified groundwater remediation system. The groundwater remediation alternative includes extraction wells to remove contaminated groundwater, an air stripper to remove the volatile organic contaminants 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 publicly owned treatment works system. • Long-term monitoring of the groundwater and surface water and sediment in the Northeast Tributary. • Implementation of a deed restriction on the property as an institutional control. • Review and evaluate 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. • Performance of five (5) year reviews in accordance to Comprehensive Environmental Response, Compensation, and Liability Act of 1980. ADDmONAL SAMPLING AND MONITORING Additional monitoring wells shall be installed 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. ~/YfT~ Patrick M. Tobin {)~'?6:f3 Date Acting Regional Administrator I I I I I I I I I I I I I I I I I I I DECISION SUMMARY RECORD OF DECISION REMEDIAL ALTERNATIVE SELECTION OPERABLE UNIT #3 NATIONAL STARC_H & CHEMICAL COMPANY SITE SALISBURY, ROWAN COUNTY NORTH CAROLINA PREPARED BY: U.S. ENVIRONMENTAL PROTECTION AGENCY REGION IV ATLANTA, GEORGIA OCTOBER 1993 I I TABLE OF CONTENTS I SECTION PAGE No. I 1.0 SITE NAME, LOCATION, AND DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 I I I I I I I I I I I I I I I 2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4.0 SCOPE AND ROLE OF OPERABLE UNIT WITHIN SITE STRATEGY . . . . . . . . . . . . . . . . . . . . 6 5.0 SUMMARY OF SITE CHARACTERISTICS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 5.1 SOILS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 5.2 GROUNDWATER ......................................... : . . . . . . . . . . . . 11 5.2.1 SAPROLITE GROUNDWATER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 5.2.2 BEDROCK GROUNDWATER . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 5.3 SURFACE WATER AND SEDIMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 5.4 HYDROGEOLOGICAL SETTING""'........................................... 34 5.5 PATHWAYS AND ROUTES OF EXPOSURE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 6.0 SUMMARY OF SITE RISKS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 6.1 CONTAMINANTS OF CONCERN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 6.2 EXPOSURE ASSESSMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 6.3 TOXICITY ASSESSMENT . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 6.4 RISK CHARACTERIZATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 6.5 RISK UNCERTAINTY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 6.6 ENVIRONMENTAL RISK................................................. 47 6.7 SUMMARY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 7.0 REMEDIAL ACTION OBJECTIVES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 7.1 APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS (ARARS) . . . . . . . . 61 7.2 ·EXTENT OF CONTAMINATION ....................... ,..................... 62 8.0 DESCRIPTION OF ALTERNATIVES ..............................•.............. 62 8.1 REMEDIAL ALTERNATIVES TO ADDRESS GROUNDWATER CONTAMINATION....... 62 8.1.1 ALTERNATIVE GWP1/GWL1: No action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 8.1.2 ALTERNATIVE GWP2/GWL2: Long Tenn Monitoring and Fencing A Portion Of Northeast Tributary ............................ , . . . . . . . . . 67 8.1.3 ALTERNATIVE GWP3/GWL3: Institutional Controls, Long Term Monitoring, and Fencing A Portion 01 Northeast Tributary . . . . . . . . . . . . . . . . . . . . 67 8.1.4 ALTERNATIVE GWP4A/GWL4A: Groundwater Extraction Through Wells; Treatment by Air Stripping with Vapor-Phase CarbQn Adsorption; and Discharge to POTW . . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . • . . . . . . 68 8.1.5 ALTERNATIVE GWP4B/GWL4B: Groundwater Extraction Wells, Treatment by Air Stripping with Fume Incineration; and Discharge to POTW . . . . . . . 68 I I I I I I I I I I I I I I I I I I I I TABLE OF CONTENTS SECTION PAGE No. 8.2 REMEDIAL ALTERNATIVES TO ADDRESS SURFACE WATER AND SEDIMENT CONTAMINATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 8.2.1 ALTERNATIVE SW/SE-1: No Action . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 8.2.2 ALTERNATIVE SW/SE-2: Long-Term Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . 69 9.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES . . . . . . . . . . . . . . . . . . . . . . . 69 9.1 THRESHOLD CRITERIA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 9.1.1 OVERALL PROTECTION OF HUMAN HEAL TH AND THE ENVIRONMENT . . . . . . . 70 9.1.2 COMPLIANCE WITH APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70 9.2 PRIMARY BALANCING CRITERIA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 9.2.1 LONG-TERM EFFECTIVENESS AND PERMANENCE . . . . . . . . . . . . . . . . . . . . . . 71 9.2.2 REDUCTION OF TOXICITY, MOBILITY, OR VOLUME . . . . . . . . . . . . . . . . . . . . . . 72 9.2.3 SHORT-TERM EFFECTIVENESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 9.2.4 IMPLEMENTABILITY............................................... 72 ... 9.2.5 COST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72 9.3 MODIFYING CRITERIA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 9.3.1 STATE OF NORTH CAROLINA ACCEPTANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 9.3.2 COMMUNITY ACCEPTANCE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 10.0 DESCRIPTION OF THE SELECTED REMEDY . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 10.1 PERFORMANCE STANDARDS TO BE ATTAINED . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 10.2 GROUNDWATER REMEDIATION......................................... 80 10.3 NORTHEAST TRIBUTARY SURFACE WATER/SEDIMENT REMEDIATION . . . . . . . . . . 84 10.4 MONITOR EXISTING CONDITIONS/ADDITIONAL DATA REQUIREMENTS . . . . . . . . . . 84 10.5 COST . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 11.0 STATUTORY DETERMINATION .............................................• 85 11.1 PROTECTION OF HUMAN HEAL TH AND THE ENVIRONMENT . . . . . . . . . . . . . . . . . . . 86 11.2 COMPLIANCE WITH ARARS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 11.3 COST-EFFECTIVENESS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 11.4 UTILIZATION OF PERMANENT SOLUTIONS AND ALTERNATIVE TREATMENT TECHNOLOGIES OR RESOURCE TECHNOLOGIES TO THE MAXIMUM EXTENT PRACTICABLE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 11.5 PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT ......... , .....• , . 86 12.0 SIGNIFICANT CHANGES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87 I I I I I I I I I I I I I I I I I I I APPENDICES APPENDIX A CONCURRENCE LETTER FROM THE STATE OF NORTH CAROLINA AND RESPONSE FROM THE AGENCY APPENDIX B PROPOSED PLAN FACT SHEET APPENDIX C RESPONSIVENESS SUMMARY I I I I I I I I I I I I I I I I I I I FIGURE 1 FIGURE 2 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 FIGURE 9 FIGURE 10 FIGURE 11 LIST OF FIGURES FIGURE TITLE PAGE No. SITE LOCATION MAP . • . . • . . . . . . . . . . . . . . • • . . . . • • . • • . . . . • . • • . • . . 2 LOCATION OF FACILITIES THAT COMPRISE OPERABLE UNIT #3 • . . • . . • . • • • • . 3 DISTRIBUTION OF 1,2-DCA IN THE WATER TABLE ZONE OF THE AQUIFER . . . . 14 DISTRIBUTION OF 1,2-DCA IN THE SAPROLITE ZONE OF THE AQUIFER . . . • . . 15 SAMPLING LOCATIONS FOR GROUNDWATER (WATER TABLE) VIA WELLPOINTS AND CONCENTRATIONS OF 1,2-DICHLOROETHANE DETECTED AT EACH WELLPOINT ....•.....•...•.••.•..•.••..•.•.• 22 SAMPLING LOCATIONS FOR GROUNDWATER (SAPROLITE ZONE) VIA PUSH-POINT SAMPLER, TEMPORARY MONITORING WELLS, AND SCREENED WATER SAMPLER AND CORRESPONDING CONCENTRATIONS OF 1,2-DICHLOROETHANE DETECTED AT EACH LOCATION . • • . • • . . • . • . • . • . 23 CONCENTRATIONS AND ESTIMATED EXTENT OF 1,2-DICHLOROETHANE CONTAMINATION IN THE BEDROCK ZONE OF THE AQUIFER • . • • . • • . . . • . • • . 26 SURFACE WATER SAMl;\,ING LOCATIONS AND CONCENTRATIONS OF 1,2-DICHLOROETHANE FROM L.._ST SAMPLING EFFORT ON THE NORTHEAST TRIBUTARY • • . • • . • • . • • . • • . • • . • • • . • . • • . . • . . . • • . • 32 SEDIMENT SAMPLING LOCATIONS AND CONCENTRATIONS OF 1,2-DICHLOROETHANE FROM LAST SAMPLING EFFORT ON THE NORTHEAST TRIBUTARY . • • . . • . . • . . • • . • • . • • . • • . • . . . • • • • • • • . . 33 ORIENTATION OF HYDROGEOLOGICAL CROSS-SECTIONAL A-A' . . . . . . . . . . . . . 37 HYDROGEOLOGICAL CROSS-SECTION A-A' . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 I I I I I I I I I I I I I I I I I I I TABLE 1 TABLE 2 TABLE 3 TABLE 4 TABLE 5 LIST OF TABLES TABLE TITLE RANGE AND FREQUENCY OF DETECTION OF ORGANIC CONTAMINANTS AND INORGANIC CONSTITUENTS FOUND IN THE PAGE No. ENVIRONMENTAL MEDIA SAMPLED . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 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 ................. 16 FREQUENCY OF DETECTION AND CONCENTRATIONS OF VOLATILE ORGANICS DATA FOR GROUNDWATER SAMPLES COLLECTED FROM PUSH-POINT SAMPLER, TEMPORARY MONITORING WELLS, AND SCREENED WATER SAMPLER ..................................... 18 FREQUENCY OF DETECTION, CONTAMINANTS DETECTED, AND MOST STRINGENT PROMULGATED STANDARDS FOR CONTAMINANTS DETECTED IN THE SAPROi:.'iTE ZONE OF THE AQUIFER . . . . . . . . . . . . . . . . . . . . 24 FREQUENCY OF DETECTION, CONCENTRATIONS DETECTED, AND · MOST STRINGENT PROMULGATED GROUNDWATER STANDARDS FOR CONTAMINANTS DETECTED IN THE BEDROCK ZONE OF THE AQUIFER . . . . . . . . • 27 TABLE 6 SUMMARY OF DETECTABLE CONCENTRATIONS OF 1,2-DICHLOROETHANE IN SURFACE WATER, SEDIMENT, AND SOIL SAMPLING OF THE NORTHEAST TRIBUTARY ................................................. , 29 TABLE 7 CONCENTRATIONS OF ORGANICS AND INORGANICS IN SURFACE WATER AND SEDIMENT FROM LOCATIONS SW/SE-12 AND SW/SE-13 ........ 31 TABLE 8 LIST OF CHEMICALS OF CONCERN IN THE GROUNDWATER POSING RISK AND THE ASSOCIATED UPPER CONFIDENCE LIMITS (95%) EXPOSURE POINT CONCENTRATION . . . . . . . . . . . . . . . . . . . . . . . . . . . • . . . . . 39 TABLE 9 POTENTIAL CURRENT AND FUTURE EXPOSURE PATHWAYS OF HUMAN EXPOSURE TO CONTAMINANTS . . . . . . . . . . . . . . . • . . . . . . . . . . . . . . . . . . . . 40 TABLE 10 PARAMETERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN . . . . . . . . . . . . . . . . . . . . • . • . . . . . . . . . . . . . . • . 48 TABLE 13 SUMMARY OF CANCER RISK AND NONCANCER HI VALUE . . . . . . . . . . . . . . . . . . 60 TABLE 14 REMEDIAL ACTION OBJECTIVES AND ASSOCIATED GENERAL RESPONSE ACTIONS .•.•.•...................•......•.................. 64 TABLE 15 SECONDARY SCREENING OF TECHNOLOGIES AND PROCESS OPTIONS FOR GROUNDWATER ..........................•.•.............. 65 TABLE 16 SUMMARY OF THE THRESHOLD CRITERIA EVALUATION FOR THE ALTERNATIVES .....•.•• ,• • . . . . . . • . . . . . . . . • . • . • . . . . • . . . . . . • . . • . 73 TABLE 17 .APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS •.....•....... 74 TABLE 18 SUMMARY OF PRIMARY BALANCING CRITERIA EVALUATION OF THE ALTERNATIVES , ...... , . . . . . . . . . . . . . . . . . . . . . . • . . . . . . . . • . . . • . . . 76 TABLE 19 PERFORMANCE STANDARDS AND CORRESPONDING RISKS FOR OU #3 ......... 81 I I I AOC ARAR AWQC I CAA CERCLA I cm/sec CD CRP I CSF CWA 1,2-DCA I ESD EPA FS I GAC gpm HI I HQ HRS LDRs I MCLs MCLGs mg/kg I mph MW NCAC NCDEHNR I NCGS NCP ND I NOAA NPDES NPL I NSC NSCC O&M I OU POTW ppb I ppm PQL PRP I PW RA RCRA I I LIST OF ACRONYMS Administrative Order on Consent Applicable · or Relevant and Appropriate Federal, State or Local Requirements Ambient Water Quality Criteria Clean Air Act Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (Superfund) centimeters per second Consent Decree Community Relations Plan Cancer Slope Factor Clean Water Act 1,2-Dichloroethane Explanation of Significant Difference Environmental Protection Agency Feasibility 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 Environment, Health, and Natural Resources North Carolina General Statute National Oil and Hazardous Substances Pollution Contingency Plan Not Detected National Oceanic and Atmospheric Administration National Pollution Discharge Elimination System National Priority List National Starch & Chemical Company National Starch & Chemical Company Operation; and Maintenance Operable Unit Publicly Owned Treatment Works parts per billion parts per million Practical Quantitative Limit Potentially Responsible Party Present Worth Remedial Action Resource Conservation and Recovery Act I I RID RD RI I RME ROD SARA I SOWA SVOCs TAL TBC I TCL TCLP TMV I µg/kg µg/1 voes I I I I I I I I I I I I I Reference Dose Remedial Design Remedial Investigation Reasonable Maximum Exposure Record of Decision Superfund Amendments and Reauthorization Act of 1986 Safe Drinking Water Act Semi-volatile Organic Compounds Target Analyte List To Be Considered Target Compound List Toxicity Characteristic Leaching Procedure Toxicity, Mobility, or Volume micrograms per kilogram micrograms per liter Volatile Organic Compounds - I I I I I I I I I I I I I I I I I I I RECORD OF DECISION SUMMARY OF REMEDIAL ALTERNATIVE SELECTION OPERABLE UNIT THREE NATIONAL STARCH & CHEMICAL COMPANY SUPERFUND SITE SALISBURY, ROWAN COUNTY, NORTH CAROLINA 1.0 SITE NAME, LOCATION. AND DESCRIPTION The National Starch & Chemical Company (NSCC Site or the "Site") 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 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 Operable Unit (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 am••~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 landfanned 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 Record of Decision (ROD), the tenn "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 comer of the NSCC property. Two housing developmenls 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. ' 2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES In September 1968, Proctor Chemical Company purchased the 465-acre tract of land on 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 of 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 I I I I I I I I I I I I I I I I I I I N q,'1e l.,. "o"' ~ ) ' ,, DAVIDSON { COUNTY -70 - \ COUNTY ------7 I l<ANNAPU>IS CABARRUS COUNTY SCALE: - -- -0 8 16 MILES FIGURE 1 LOCATION OF THE NATIONAL STARCH & CHEMICAL COMPANY SUPERFUNO SITE - - + + -= -, •..:'-,I' _, ,,,:-.: -- AIRPORT ROM> ;;-.::.:::;~ -- - -- - , ' ' ' ' ' ' ' ' - , -' .,." '· , ' ,,"" I 500 0 500 1000 ,-._---... -:·· _j 250 750 GRAPHIC SCALE: 1 '=50ll' -- -- -- FIGURE 2 LOCATION OF FEATURES ASSOCIATED WITH OPERABLE UNIT #3 - - I I I I I I I I I I I I I I I I I -4- NATDW. STAID< I Clell:.IL ca,,,..,, Slff!IFUC) S'1E FIEcooc Of DEasol RlR 0PEJwu UIIT 13 rinse solutions. This wastewater may include a combination of the following chemicals: acrylimide, 1,2-dlchloroethane (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/se.diment of the Northeast Tributary, the original scope of work specified in the initial 1987 Remedial Investigation/Feasibility Study (RI/FS) Work Plan was expanded. The first RI/FS resulted in OU #1 ROD which was issued by the Environmental Protection Agency (EPA or 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 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 development of OU #3 and OU #4. The NSCC Superfund 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 4€~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 th~ NPL. National Starch & Chemical Company, 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. Since there has only been one owner/operator of this property after being developed into an industrial complex, no "Responsible Party Search" was performed. National Chemical Starch & Chemical Company has been and remains the owner/operator of the facility. A special notice letter was sent on May 30, 1986 to provide NSCC an opportunity to conduct the first RI/FS. A good faith offer was submitted and negotiations were concluded with NSCC signing an AOC on December 1, 1986. The first RI/FS was completed on June 21, 1988 and September 8, 1998, respectively. The ROD signed on September 30, 1988, divided the Site into two operable units. OU #1 consists of contaminated groundwater and OU #2 consists of trench area soils and surface water/sediment in surrounding tributaries. Following the signl11g of OU #) 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. In support of OU #2, NSCC generated Supplemental RI and FS Reports. These reports were prepared in accordance to the December 1, 1986 AOC. These reports were cornpleted In May 1990 and September 1990, respectively. The Supplemental RI reported continued detections of contaminants in the Northeast Tributary but did not Identify the source of this contamination. I I I I I I I I I I I I g n 0 -5- NATIOIW. STAID< l C-ICM. Coll>ANY Si.ffJIRNJ SITE RE= C6 oeaac,, FOR 0>£1Wll.E UIIT '3 Consequently, the OU #2 ROD divided the Site into a third operable unit. Following the signing of the OU #2 ROD, the Agency sent the PAP another special notice letter in March 1991 to initiate negotiations on a second CD. This CD governed the implementation of the RA required by OU #2 ROD. The CD was signed in August 1991 and was entered by the Federal Court on July 20, 1992. On December 4, 1991, EPA issued written notification to NSCC to conduct a third RI/FS to determine the source, nature, and extent of contamination entering the Northeast Tributary as required by OU #2 ROD. As with the previous RI/FS efforts, OU #3 RI/FS was conducted in accordance to the December 1, 1986 AOC. The OU #3 RI and FS reports were completed on June 2, 1993 and June 21, 1993, respectively. 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. 3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION In 1986, community relations activities for this Site were initiated 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 conceQlS was prepared. A copy of the Community Relations Plan was placed in the lnfonnation Repository located at the Rowan County Public Library in Salisbury. A mailing list was developed based upon people interviewed, citizens living around the Site, and people attending Site related 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. Two fact sheets and the Proposed Plan Fact Sheet were distributed to the public during the OU #3 RVFS. 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 distribuied 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 infonned through the Proposed Plan Fact Sheet and an ad published on July 19, 1993 in The Salisbury Post and The Charlotte OCserver newspapers of the August 3, 1993 Proposed Plan Public Meeting. The Proposed Plan Fad 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 infonned the public that the public comment period would run from July 19, 1993 to August 17, 1993. I I I I I I I I I I I n I 0 D -6- NAraw. STARO< 4 Clelr::.11. COll'AHI' Sl.moRN) S11E REcooo OF DEasioN ~ CiPERAe1£ UIIT 13 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 alternatives reviewed and the remedial alternative selected by the Agency, and infonn the public that the public comment period on the Proposed Plan would conclude on August 17, 1993. The public was also infonned 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 infonning them of this extension. An ad was also published in the August 24, 1993 edition of The Salisbury Post and The Charlotte Observer newspapers infonning the public that the public comment period had been extended to September 16, 1993. Pursuant to Section 113(k)(2)(8)(I-v) and 117 of Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (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 ;:,J, the EPA Docket Room in Region IV's office and at the Rowan County Public Library in Salisbury, North .Carolina. 4.0 SCOPE AND ROLE OF OPERABLE UNIT WITHIN SITE STRATEGY As with many Superfund sites, the problems at the NSCC Site are complex. As a result, EPA organized the work into four operable units. These are: 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. This 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. EPA has already selected remedies for OU #1 in a ROD signed September 30, 1988, and OU #2 in a ROD signed September 30, 1990 (the contaminated groundwater and contaminated soils associated with the Trench Area, respectively). Construction on the OU #1 remedial action phase began in August 1990. OU #2 was initiated on July 20, 1992, the filing date for the CD. OU #2 ROD specified no action for the soils in the Trench Area, long-term monitoring of the soils In the Trench Area, and an Investigation to detennlne the source of contamination being detected In the Northeast Tributary. I I I I I I I I I I I g I D -7- NAJDM. STAAO! l CleiJCM. COll>AHY Si.l>E!RN) Sm; REcalo ~ OEasoN ,a, OPE!wu UtfT '3 The third OU, the subject of this ROD, addresses the contaminated groundwater emanating from Area 2 and treatment lagoon area. The potential use of this contaminated groundwater as potable water results in an unacceptable future risk to human health as EPA's acceptable risk range is exceeded and concentrations are greater than maximum contaminant levels (MCL.s) as established by the Safe Drinking Water Act. The purpose of this response is to prevent current or future exposure to the contaminated groundwater. OU #3 is the third of four operable units contemplated for this Site. 5.0 SUMMARY OF SITE CHARACTERISTICS The NSCe OU #3 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 with the acceptance of the vertical ex1ent of contamination in the bedrock zone of the aquifer. The OU #3 RI Report included a Baseline Risk Assessment. The Baseline Risk Assessment defined the risk posed by-the hazardous contaminants 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) alternatives for groundwater remediation and the two (2) remedial alternatives for addressing the cont,'1/Tlination detected in the surface water/sediment of the Northeast Tributary. 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, surface water and sediment of the Northeast Tributary, 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 (Voes) as the previous Remedial Investigations conducted at the NSee 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 (Tel) and target analyle list (TAL) constituents. The Tel includes VOCs, semi-volatile organic compounds (SVOCs), pesticides, and polychlorinated bipheny1s (PeBs); the TAL includes inorganics such as metals and cyanide. voes, SVOCs, one pesticide, and numerous inorganic analyles were detected in the soils and groundwater and two voes and a number of metals were detected in the surface water/sediment samples. Background/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. I I I I I I I I I I I g 0 D D -8- NAllOHM. STAAC!i l Cl£MIC.ll C<:A.FNtt SUPsRocl SITE REalRD rs; 0EaaoN RJl 0>E!wu UNT '3 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 estimated volume of groundwater impacted is approximately 131 million gallons. -5.1 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. voes, 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 VOCs, one (1) svoe, one (1) pesticide, 14 metals, and cyanide were detected. As can be seen in Table 1, the voes most frequently detected and observed in the highest concentrations were 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 (SE-12) or detected onsite at concentrations at least two times 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 terra-cotta piping which 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 I I I I I I I I I I I I I g I g I D 0 .g. NAT"OIM. ST""°' & C!EMIC,tj_ CoJl,Ntf Sl.mRoll SITE AE<XlRll OF 0EaaoN F<Jl ()>EfWU UIIT '3 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-chloroethyt)elher 13-32 (2) Bromodichlorome1hane 1-220 (7) 2-Butanone 3-42 (30) Car1lon Disulfide 4-8 (3) Chloroe1hane 3-35 (6) Chloroform 2-900 (17) 7-8,900 (2) Dibromochlorome1hane 3-31 (5) 1,2-Dichloroelhane 2-1,600,000 T,12) 1-660,000 (30) 2-3,200 (7) 9-1,000 (5) 1, 1-Dichloroelhene 1-14 (3) 1,2-Dichloroelhene 1-200 (4) 1,2-Dichtoropropane 5 Ethytbenzene 9-36 (2) Melhytene Chloride 1-160 (5) Tetrachloroelhene 2 107 (4) Toluene 1-3,100 (12) 1-120 (3) 1, 1,2-Trichloroelhane Trichtoroelhene 11-17 (2) 1-5 (10) Total Xytenes 2-90 (4) Vinyt Chloride 32-190 (12) 1-120 (8) ;;~'tiiillali!ej.~tJ-~iii1·ii,;;;,;;;i;:;i;l:;ilsf Wtifa:;JM404£\It;~!pffltitti;Ziii1:~;islit'ii::li:; Bis(2-i!thythexyl)phthalate 8 Di-n-butyt Phthalate 2-17 (3) Di-n-octyt Phthalate Delta-Hexachlorocyclohexane 22 0.16 I I I I I I I I I I I I I g g I D D n -10- NATOW. STAAO< l CleiC.M. CC.l«Y Sl.FBIRHJ 5IT'E REc0Ao OF Deaaal FOR CiPawl.E UNT '3 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 Antimony 5, 100-8,2000 (5) 2·30 (3) 7.6 (1) Arsenic 530-2,900 (7) 2.4 1.1-1.9 (2) Barium 33,300-198,000 (7) 28.2-737 (8) 32.1-38.2 (2) 50.3-88.4 (2) Beryllium 240-680 (7) 1-2.5 (2) 0.49-0.98 (2) Chromium 10,000-97,900 (7) 12.9-59.6 (6) 35.1-36.5 (2) Cobalt 13,700-74,100 (7) 47-66.4 (2) 23.6-28 (2) Copper 46,700-161,000 (7) 12.4-23. 7 (2) 48.4-90.3 (2) Cyanide 2,500-21,900 (2) 12-16 (2) Lead 1,300-9,400 ... (7) 3.3-3.9 (2) 3-15.1 (2) Manganese 382,000-2,610,000 (7) 1.5-12,000,000 (14) 60-134 (2) 162-1,020,000 (2) Mercury 0.05-0.06 (2) Nickel 4,900-22,900 (7) 23.4-39.6 (3) 10.3-11.6 (2) Selenium 0.88 Thallium 2,500-2,600 (2) 1-3 (2) 0.38 Vanadium 71,600-379,000 (7) 10.7-272 (11) 14.8-24.4 (2) 146-176 (2) Zinc 19,700-50,000 (7) 22~.,10.000 (4) 10.3-11.4 (2) 23.9-48.5 (2) Concentrations for water samples are reported in micrograms pe1 itter (µg/1) or in parts per billion (ppb). Concentrations for soiVsediment samples are reported in m1C1t>Qrams per kilogram (µg,1(g) or in parts per billion (ppb). Number appearing in parentheses is the frequency of detectl()t1 I I I I I I I I I I I m g n D D 0 -11- NA row. STAAO< l C-CM. ca.,NN ~ SITE REca,o Of 0Easo, A:<\ 0PaaAea.E UIIT '3 bem1s and the grade of the paved surtaces 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 abandonment/grouting of the underground terra-cotta pipes will be completed in December 1993. In the lagoon area, the source of contamination was eliminated in 1984 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. 5.2 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 voes, svoes, one pesticide, metals, and cyanide. The pesticide, delta-BHC, was detected in one saprolite groundwater sample (NS-42) at 0.16 micrograms per liter (µg/1). Cyanide was detected twice at concentrations of 16 µg/I 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 61 groundwater samples were collected from 52 different locations. All of the groundwater samples were analyzed for VOCs. Only groundwater samples collected from permanent monitoring wells were analyzed for the full analytical analyses. To summarize the analytical results, a total of 16 different voes, three (3) SVOCs, one (1) pesticide, 14 metals, and cyanide were 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, chlorofom1, 1,2-<iichloroethane, 1, 1- dichloroethene, 1,2-<iichloroethene (cis-and trans-), 1,2-<iichloropropane, ethylbenzene, methylene chloride, tetrachloroethene, toluene, total xylenes, 1, 1,2-trlchloroethane, 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 lnorganics that were detected at concentrations exceeding two limes 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 I I I I I n D I I I I I I I I I I 0 I -12- NATXJHM. STAAO< l C!o&11. Co/l>Ntt SI.FEMJc) 5rrE RECORO OF DEaaal ~ CffJwu UIIT '3 also installed as part of this investigation. The depth of the saproiite 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 sur1ace at the Northeast Tributary to approximately 33 feet below · ground surface. The RI did not generate sufficient data to completely define the vertical ex1ent 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 RD. 5.2.1 SAPROLrTE GROUNDWATER Figures 3 and 4 show the distribution of 1,2-DeA at the water table and in the saproiite 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-DeA 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 permanent saprolite monitoring well~"and the corresponding concentrations of 1,2-DeA detected in each well. · Wellpoints, push-point, temporary wells, and screen water samplers were used to collect 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 most stringent promulgated groundwater standard, the frequency of detection, and the concentrations of contaminants detected in the permanent wells installed to monitor groundwater quality in the saprolite zone of the aquifer. The highest concentration and the greatest variety of voes were found in monitoring well NS-42. voes detected in NS-42 include acetone (310 µg/1), 2-butanone (240 µg/1), 1,2-oeA (82,000 µg/1), 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 saproiite 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 lnorganics 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/I), manganese (1,500 µg/I), nickel (39.6 µg/1), vanadium (272 µg/1) and zinc (220 µg/1). I I I I I I I I I I I I I I I I I I I -13- 5.2.2 BEDROCK GROUNDWATER NATIOl<M. STAAC>f l Clei&oL ca.,..,, -..., SITE RealRo OF llEa9oN A:11 CIPERAII.E UNT '3 Figure 7 shows the distribution of 1,2-oeA in the bedrock zone of the aquifer. This flgure·aIso shows the locations of the permanent bedrock monitoring wells and the corresponding concentrations of 1,2-DeA detected in each well. Table 5 lists the most stringent promulgated groundwater standards, the frequency of detection, and the concentrations of contaminants detected in each bedrock well. 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/I), 1,2-DeA (99,000 µg/1), 1, 1-dichloroethene (5 µg/1), methylene chloride (66 µg/I), tetrachloroethene (7 µg/I), 1, 1,2-trichloroethane (6 µg/1), total xylenes ( 11 µg/1), 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/1), cobalt (93.6 µg/1), and manganese (12,000 µg/I). 5.3 SURFACE WATER AND SEDIMENT A total of 33 surface water and se:•!liment 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 svoes and metals. Sampling location SW/SE-12 is the upgradlent/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- oeA, 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-DeA 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 was 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 analy1ical results for 1,2-DeA in the water column and sediment. Table 7 lists the analy1ical 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 analy1ical results for 1,2-oeA for the last samples collected at these sampling locations. The highest concentration of 1,2-DeA 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-DeA detected In the sediment was 7,400 µg/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 upgradlent 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. I I I I I I I I I I I I I I I I I I I N 850 - \ ':> ~ LEGEND NO ClROUNOWATER ~ 00M L. SHClW'NG 1.2-0CA CONCEN'TRAllON ~I · . _ . . 1.2-DCA CONCENTRATION 1 0000 _/ . CONTOUR NOTE: Confirmation oata 1UPCM,l•11a:t l:,y Qr0UndW'ater ICfNf'llr'IQ 0ata 3J" "4J --····--···::c: ; ABANDONED RAILROAD SPUR.----~.-.,' N5 , . , NO c,NO " NB : _a•':···-· N sso -r-----~Z='---:_:---;-'-,,:"., "~1 a;;oo;;;-,_,,_, ,4~sooo~·...,_ ·S:,i:,::N:;;o:;-7 ;;:::::::::::::::}:::~7: r~ '~cf • '._ : :, I: : 100 .. : .'., 1000: I s-.1,oooi> :: ............ ~ . ,_ : \~30 I 9-sooo" tsooo ' ' '·-..... N 200 - APPOOXIMA TE SCALE (ft) 1 00 200 JOC 400 500 :3400c,. FIGURE 3 CHAIN LINK FENCE---~ CONCENTRATIONS AND ESTIMATED EXTENT OF 1,2·DICHLOROETHANE CONTAMINATION IN THE GROUNDWATER AT THE WATER TABLE I I I I I I I I I I I I I I I I I I I 750 - 450 - ,so - -750 t .... • NS-37 (1J) ABANDONED-----<► RAILROAD SPUR '' '' '' '' '' '' '' '' '' '' □ -350 -50 , ' ' ' I I \ \ 1 I I I , NS-33 • (ND) I ,.. S50 1 1.2-0CA CONCENTRATlON CONTOUR~) • 1 ,2-0CA CONCENm,< TlON NS-13 ~). GAOl-"OWATER ( 1700) SAMPLES ~ a: en Cl z if 11. en ~ w (J SCAI.E(!1) ___ ..,_ FIGURE 4. CONCENTRATIONS AND ESTIMATED EXTENT OF 1,2-DICHLOROETHANE. CONTAMINATION .IN THE SAPROLITE ZONE OF THE AQUIFER -------------allt.nJIL.,-..co.!IIIL,Jlle - ,, AEcoRo Of OECISIOH FOR OPERABLE lJNrr t3 -16- 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 VOLATILE ORGANIC COMPOUNDS Acetone 10/15 cart>on Disulfide 3/15 Chlo roe thane 3/15 1,2-0ichloroethane 7/15 1, 1-Dichloroelhene 1/15 1,2-Dichloroelhene 2/15 1,2-Dichloropropane 1/15 Methylene Chloride 3/15 Tetrachloroelhene 2/15 Toluene 3/15 1, 1,2-Trichloroethane 2/15 Trtchloroelhene 2/15 Vi1yl Chloride 4115 TWP-1A (Background) 5U 10 U 10 UJ 5U 5U 5U 10 U 5U 5U SU SU 10 U TWP-2 5U 10 U 5U 5U 5U 5U 5U 5U 5U SU SU 10 U TWP-3 TWP-4 TWP-5 TWP-6 TWP-7 TWP-8 lllf2g!; 10 U SU 10 U 10 U 10 U SU SU 5U 5U SU SU SU 5U SU 5U SU SU 5U 5U SU 10 UJ SU SU SU 5U 5U SU SU 5U 5U 10 U SU SU SU 5U 5U SU SU SU 5U 5U 5U SU SU SU 5 U 5 U 5U SU SU SU 5 U 5 U 10 U 10 U 10 U 10 U -------------------NATIOHAl STARCH & CtEMICAL CoMPANY SUPERFLN> SITE REcoRJl OF DECISION FOO ClPERASLE UNIT '3 -17- 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 VOLATILE ORGANC CoUPOUNDS Acetone 10/15 carbon Disulfide 3/15 Chloroethane 3/15 1.2-Dichloroethane 7/15 1, 1-Dichloroethene 1/15 1.2-Dichloroethene 2/15 1.2-Dichloropropane 1/15 Melhytene Chloride 3/15 Tetrachloroethene 2/15 Toluene 3/15 1, 1,2-Trichloroelhane 2/15 Tric:hloroelhene 2/15 Vnyt Chloride 4/15 Samples W918 collec1ed In May 1992. lWP-9 lWP-10 10 U SU SU ConcentratiOns are In micrograms per iter (µg/1) or parts per bilUon (ppb). Shaded area en n depicts positive detections. D -Sample analyzed at secondary dilution. J -Concentration is estimated. U -lkldetected at the indicated quantitation imlt. UJ -Undetected; the associated quantitation limlt is an estimated value. TWP-11 TWP-12 TWP-13 NS-13 NS-14 10 U SU 10 U 10 UJ SU SU SU 5 UJ SU SU SU 5 UJ SU SU SU 5 UJ SU 10 U SU 5 UJ SU SU 5 UJ SU SU SU 5 UJ SU SU SU 5 UJ SU SU 5 UJ SU 10 UJ 10 U ---------------~~~~ REcoAo OF OEaSKlN FOA ClP£RABLE lJIIT 13 -18- TABLE 3 FREQUENCY OF DETECTION AND CONCENTRATIONS OF VOLATILE ORGANICS DATA FOR GROUNDWATER SAMPLES COLLECTED FROM PUSH-POINT SAMPLER, TEMPORARY MONITORING WELLS, AND SCREENED WATER SAMPLER (Samples ware only analyzed for VOCs) COMPOUND FREQUENCY OF DETECTION SAMPLING DATE DEPTH TO WATER TABLE (feet) VOUTILE ORGANIC CoMPOUNDS Acetone Carbon Disulfide Chloroethane Chloroform 1,2-Dichloroethane 1, 1-Dlchloroethene 1,2-Dlchloroethene Ethylbenzene Methylene Chloride T etrachloroethene Toluene Total Xytenes 1, 1,2-Trlchloroethane Trlchloroethene Vinyl Chloride 4/33 1/33 2/33 1/33 16/33 1/33 1/33 2/33 3133 2/33 3133 3133. 4/33 1/33 2/33 GW-1° GW-1A GW-1B 11/20/92 NA 12/4/92 8 NA 8 25,000 U 10 U 10 UJ 12,000 U SU SU 25,000 U 10 U 10 U SU 12,000 u 5 u 5 u 12,000 u 5 u 5 u 12,000 u 5 u 5 u 12,000 u 5 u 5 u 12,000 u 5 u 5 u 12,000 u 5 u 5 u 12,000 u 5 u 5 u 12,000 u 5 u 5 u 12,000 u 5 u 5 u 25,000 u 10 u 10 u GW-2" 11/20/92 17.8 250 U • 120 U 250 U 120 U 120 u 120 u 120 u :~1;;~~~~~i~~:f t~l~: 120 u 120 u 120 u 120 u 120 u 250 u GW-3 11/21/92 9.8 10 U SU 10 U SU SU SU SU SU SU GW-S" 11/21/92 6.45 10,000 UJ 5,000 U 10,000 U 5,000 U 5,000 U 5,000 U 5,000 U 1!1tw~~;i;tfr 5 U 5,000 U SU 5,000 U SU 5,000 U SU 5,000 U 10,000 U 10 U GW-SA 11/23/92 15 10 UJ SU 10 U SU SU SU SU SU SU SU SU SU SU 10 U GW-6 11/19/92 6 10 U SU SU SU SU SU SU SU SU SU· 10 U GW-6RE 12/16/92 6 SU 10 U SU SU SU SU SU SU SU SU SU 10 U iiii liiiii -------------NA-,~-51».,. fEcoAo OF DEasloN FOR CffR..aE lNT 13 -19- TABLE 3 FREQUENCY 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) COMPOUND SAMPLING DATE DEPTH TO WATER TABLE (feet) GW-7 11/23/92 9 GW-7A 11/24/92 25 VOLATILE ORGANIC CollPOUNDS Acetone 10 UJ 10 UJ Carbon DisuHide SU SU Chloroethane 10 U Chlorofonn SU SU 1,2-Dichloroethane 1, 1-Dichloroethene 1,2-Dichloroethene Ethylbenzene SU SU Methylene Chloride SU SU Tetrachloroethene SU SU ,1-T_ot_a_l _Xy:...le_n_e_s ___ --iFJl ... ■11t1fl@ S U 1,1,2-Trtchloroethane SU SU Trichloroethane S U S U Vinyl Chloride 10 U 10 U GW-8 12/4/92 1 10 R SU 10 U SU SU SU SU SU SU SU SU 10 U GW-8D 12/5/92 1 10 R SU 10 U SU SU SU SU SU SU SU SU SU SU SU 10 U 12/5/92 5 • 10 UJ SU 10 U SU SU SU SU SU SU SU SU SU SU SU 10 U GW-11A" 11/24/92 6.5 5,000 UJ 2,500 UJ 5,000 UJ 2,500 U 2,500 U 2,500 U 2,SOO U 2,SOO U 2,SOO U 2,SOO U 2,SOO U 2,SOO U S,000 U GW-11B GW-12 12/3/92 12/6/92 12.5 16 10 R 10 UJ SU SU 10 U 10 U SU SU SU --2,500 U SU SU SU SU SU SU SU SU SU SU SU SU SU SU SU SU SU 10 U 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 liii iiii - - ----- -- ------NATIOHAL STARCH & CtEMICAI. iliiwPANY 5oPEilFu«l SITT RECORD Of DECISION FOA CloERABI.E lNT 13 -20- TABLE 3 FREQUENCY 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) COMPOUND GW-13 GW-14 GW-15 GW-16A GW-17 GW-18 GW-18A GW-19 .. SAMPLING DATE 11/20/92 11/21/92 12/17/92 12/2/92 12/1/92 11/23/92 12/18/92 NA DEPTH TO WATER TABLE (feet) 4.5 4.5 3 10 4 7.5 7 NA VOLATILE ORGANIC CouPOUNDS Acetone 10 UJ 10 U 180 UJ 10 R 10 R 10 UJ 10 U Carbon DisuHide 5 u 5 u 5 u 4 5 u SU SU 17 U 5 u Chloroethane 10 u 10 u 110 U 10 U 10 U 33 U 10 U Chloroform 5 u SU 5 u s u 5 u 5 u 17 U SU 1,2-Dichloroethane 5 u 5 u 16,000 D // 5 u 11.~a1, SU 17 U :iili~!ili!iji]fiiiiiiilift~f .,::>.::: 1, 1-Dichloroethene 5 u 5 u 5 u 5 u SU SU 17 U 5 u 1,2-Dichloroethene 5 u 5 u s u SU SU SU 17 U SU Ethylbenzene s u s u s u SU s u SU 17 U SU Methylene Chloride s u SU 11 u SU 5 u 5 u 17 U SU Tetrachloroethene SU SU SU SU SU 17U SU Toluene SU SU SU SU SU SU 17U SU Total Xylenes SU SU SU SU SU SU 17 U SU 1, 1,2-Trtchloroethane SU s u :~~lliff~:ij:~If1:fi/~/i~ 5 u SU 17 U SU Trtchloroethene SU SU s u SU s u SU 17 U 5 u Vinyl Chloride 10 U 10 U 10 U 10 u 10 U 33U-10 U &iii iiii iiii -- - - - - - - - - - -NA-T--•IC.II.IILSU>-SrrE AEcoAo Of OeaSION FOR OPERABLE UNI 113 ·21· TABLE 3 FREQUENCY 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) COMPOUND GW-22 GW-24 GW-25 GW-26 GW-27 NS-13 NS-14 SAMPLING DATE 12/18/92 12/18/92 12/19/92 1/23/93 1/24/93 11/24/92 11/24/92 DEPTH TO WATER TABLE (feet) 7 16 11.5 14 19 5.44 5.2 VOLATIL£ ORGANIC CollPOUNDS Acetone 10 U 10 U 20 U 21 u 14 U 12 UJ Carbon DisuHide SU SU SU 1 SU SU SU SU Chloroethane 10 U 10 U 10 U 10 U 10 U 10 UJ 10 UJ Chlorofonn SU SU SU SU SU SU 5 UJ 1,2-0lchloroethane SU SU SU SU SU <) 1l?@IP:!ll!i S UJ 1, 1-0ichloroethene SU SU SU SU SU SU 5 UJ 1,2-0ichloroethene SU SU SU SU SU SU SU Ethylbenzene SU SU SU SU SU SU 5 UJ Methylene Chlortde 5 U · SU SU 16 U 15 U SU S UJ Tetrachloroethene SU SU SU SU SU SU 5 UJ Toluene SU SU SU SU SU SU 5 UJ Total Xy1enes SU SU SU SU SU SU 5 UJ 1, 1 ,2-Trlchloroethane SU SU SU 5 u. ~~ 5 UJ Trichloroethane SU SU SU SU SU SU Vlnyl Chloride 10 U 10 U 10 U 10 U 10 U 10 UJ Concentrations are In micrograms per rrter (µwl) or parts per billion (ppb). Shaded area ( HD depicts positive detections. • -Detection limits for V0Cs are elevated; prescreening of sample indicated matrix effects required medium or high level analysis. D • Concentration reported from secondary dilution. J -Concentration is estimated. NA -Not Availabie R -Unusabie results. RE -Resampled. U -Undetected at the indicated quantitation limit. UJ -Undetected; the associated quantitation limit us an estimated value. I I I I I I I I I I I I I I I I I I I N &50 - NS50 - N2>0 - llWP-13 I lillQQ,!)J I ABANDONED RAILROAD SPUR------;► '' '' '' '' '' '' : : '' '' '' " ' ' ' ' :•-----······----,--·-----------lWP-11 AREA2 (8300J) ,. , : lWP-9 ii) lWP-10 (790J) lWP-8 lj) (4800J) • APPROXIMATE SCALE (ft') ... "" ... "' ' ' ' : _____ : : _______ '···-----··-···: (6100J) ··(3200) .... '"-"'·-···--···-··········---··--·····-···--, ,c,::c,, :-··-··--· --··-·-·-. --i lWP-7 (i) ~ PAAIONG LDT -(430) *lWP-6 : _______ lW~-5 (jl (ND) NS-13 (ND) lWP-4 E] (900) ~\ (ND) lWP-2@ lj) lWP-3 (ND) (ND) L---..c::::;--.--=====:!....:=I ~ I E-350 ~ / E2,0 E LEGEND (jl lWP-8 (4800J) ■ NS-14 (ND) FIGURE 5 TEMPORARY WELJ.. POINT ANO 1.2-0CA CONCE"""" 00N =1 MONITORNG 'NEU. LOCATION ANO 1.2-0CA CONCE""""OON -I SAMPLING LOCATIONS FOR GROUNDWATER (WATER TABLE) VIA WELLPOINTS AND CONCENTRATIONS OF 1,2-DICHLOROETHANE DETECTED AT EACH WELLPOINT I I I I I I I I I I I I I I I I I I I N &50 - N 550 - N 250 - N-350 - -650 '- LEGEND t:,. GAOI.H)WATER SCREE1..a GW -16 !'OM" wm< 1.2-0CA (420) CONCENmATlON (ln -l 1 NOTE. Conffrmat10n aata (P. ... ....,.. , • I tad Cly grounawa• 'l{,f\ "i~'.'. ·················/;-- ABANDONED.---------RAILROAD SPUR GW-8B.:. (ND) GW-18A (ND) 6GW-18 c,. (ND) GW-27 (ND) c,. GW-7A,.-. __ GW· 17"""'(:;7----- --.--.. -.-.. -.. -.. -.-.. -.. -.~_..._(1_~00) _" " (48~) GW-7 GW-6 (200) (ND) u GW-16A (ND) GW-SA:: (30) ~ : .·····•·•····· GW-5 GW-15 (98000) 6 ( 16000) :GW-4 t:,. ,' GW-4A:: (ND) '\': :(3400) c,. GW-14 T' i~~· it····:;;J·2:,· GW-25 GW-11B GW•11 ········;,· GW-2 c,. (ND) (ND) (ND) 6 (3BOO) 6 (5100) ---...-~--'6~ GW-1B GW-11A 6 (24\A , . I NS-13 □ 0430000) ~r'~ ; 11300) GW(;_,,26 t:,. (~~ I ::. I 6 GW-22 \ 6 (ND) GW-1A NS-14 (5Q) '---~---, (4J) GW-246 GW-236 (ND) (ND) FIGURE 6 APPRQJOMATc SCAl£ (It) 0 , 00 200 )00 oll>O SCIO 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 1,2-0ICHLOROETHANE DETECTED AT EACH SAMPLING LOCATION CHAIN LINK FENCE lal liiliiiii iiii iiii -----------NAnONALSTNlCl!·'""""--AHYSlJ>ERRNlSrrE REcoRo Of llEaSION FOR ClPEIW!l£ lJNT 13 -24- 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-3'r NS-39 Ns-421 Ns-43• GROUNDWATER OF DETECTION STANDARDS VOLATILE ORGANIC COMPOUNDS Acetone,, 1/8 14U 12UJ Bromodichloromethane 100 2/8 5 U 5 UJ (Bacllgraund) 10 U SU 10 U 10 U 1 o uJ 111111'~Jg~mI11 1 o u 5U SU !i'i\~qj;~! 5 U 2-Butanone 1/8 10 U 10 UJ 10 U 10 U 10 U Ii;;g~~;l;; 10 U I 10 U 1t--c_h1o_roet_h_an_e ___ +------t----110 ____ 1_o_u_J--11--1_o_u_J-+----10 u 10 u 000 UJ 10 u Chloroform 0.19 1/8 5 U 5 UJ isu7 5 U 400 UJ 5 U 10 U SU 1t-1,2_-D_ich_1oro_et_h_an_e_-+ __ o_.3_8 _----1r----s,_0 __ rl!=tl=l»=·•···•·•·=••••g.1=J=ll+-_s _uJ_r-----E-t~l~ii""'•• i=•••11z=:boo=····•·•··=;oa='.\=It---5-u-., 1 1,2-Dichloroethene 70 (cisi1rans) 1/8 5 U 5 UJ ~ 5 U 400 UJ 5 U SU SU Methylene Chloride 5 1/8 5 U 5 UJ 5 U 5 U 6 U i;Jif.flib'Jit'.pzj 5 U SU T etr~loroethene 5 1 /8 5 U 5 UJ Toluene 1,000 1/8 Total Xylenes 400 1 /8 1,1,2-Trk:hloroethane 5 3/8 Vinyl Chloride 0.015 1/8 SEID-VOLATILE ORGANIC COIIPOulllS 01-n-butyl Phthalate PEsTlcml:S Detta-BHC 1/8 1/8 5 U 5 UJ SU SW 10 U 10W 10 U 10 U 0.05 U 0.05 U SU SU 5U 5U SU SU SU 400W SU SU 400UJ SU 10 U 10 U 10 U 800W 10 U 10 U 10 U 10 U 0.05 U 0.05 U 0.05 U -------------------NA~T~WICAI. ~ &.. SITE -25- TABLE 4 FREQUENCY OF DETECTION, CONTAMINANTS DETECTED, AND MOST STRINGENT PROMULGATED STANDARDS FOR CONTAMINANTS DETECTED IN THE SAPROLITE ZONE OF THE AQUIFER COMPOUND INoRGANICS Arsenic Barium Beryllium Chromium Cobalt Cyanide Lead Manganese Nickel Vanadium Zinc PROMULGATED FREQUENCY NS-131 GROUNDWATER OF DETECTION STANDARDS 50 1/8 200 8/8 4 2/8 50 6/8 2/8 15" 50 8/8 100 318 7/8 5,000 2/8 2U NS-141 NS-33 NS-35 NS-37' NS-39 (Background) 2 U 2 U Concentrations are In micrograms per liter (µg/1) or parts per billion (ppb). Shaded area (ii /) depicts posltlve detections. • -Detection limits 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 quantitatlon limit. UJ -Undetected; the associated quantltatlon limit Is an estimated value. REooRD Of OEaSION RJA OPERABLE LINT '3 NS-421 NS-43' 10 U 2U I I I I I I I I I I I I I I I I I I I 1050 - 750 - •so 150 - .750 I .... • NS-24 • NS-38 (1 J) (No1 Sampled) ABANDONED RAILROAD SPUR _____ __,_ □ I .... -50 I ' --::::::::::::::::::::: ..,../LE_ 1 _G_EN_O ____ --j 1 ----s 250 ' • NS-W (ND) NS-34 e (ND) I I 550 • NS-36 (11000) 1 .2-0CA CONCENTRATION CONTOUR~) 1.2.QCA C0NCENTRA TION (pptl), GROUNDWATER SAMPLES Ai>PAOXIMATE SCALE ~ Cl ~ en (.!l z cf Cl. en ~ w u FIGURE 7 CONCENTRATIONS AND ESTIMATED EXTENT OF 1,2-DICHLOROETHANE CONTAMINATION IN THE BEDROCK ZONE OF THE AQUIFER - - ---- -----27----- ----_,_ NATIONAL ~TARCH'"l"cii'MICAL COMPANY 5uPERR.N> &TE RECORD OF DEaSKlN FOR OPERABLE lJNrr 13 TABLE 5 FREQUENCY OF DETECTION, CONCENTRATIONS DETECTED, AND MOST STRINGENT 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-T richloroethane Trichloroethane Vinyl Chloride PROMULGATED GROUNDWATER STANDARDS 0.19 0.38 7 5 5 1,000 400 5 2.8 0.015 Sall-VOLATILE ORGANIC COMPOUNDS Bis(2-ethylhexyl)phthalate 6 Di-n-butyl Phthalate Di-n-octyl Phthalate FREQUENCY N5-34 NS-36 Ns-38' N5-40 N5-41 N5-44' OF DETECTION (Backgrol.lld) 2/6 10 U 3/6 10 U 1/6 1,200 UD 5 U 4/6 SU llli.~211! s u 1/6 SU SU 1,200 UD 5 U 2/6 SU SU ;lilt~7'Qµi>!lll! s u 1/6 SU SU 1,200UD SU 1/6 SU SU 1,200 UD 5 U 2/6 SU 1,200 UD 5 U 2/6 SU 1,200 UD 5 U 2/6 SU 1,200UD SU 2/6 10 U 2,500 UD 10 U 1/6 10U 10 U 10 U 10 U 10 U 1/6 10 U 10 U 10 U 10U 10U 1/6 10 U 10 U 10 U 10 U 10 U -------------------NATIOHAl STNICli I CIEUICAI. CoWPAHY SUPslANl SITE RECOAO Of OEaSION FOA 0..RM!l£ I.INT 13 -28- TABLE 5 FREQUENCY OF DETECTION, CONCENTRATIONS DETECTED, AND MOST STRINGENT PROMULGATED GROUNDWATER STANDARDS FOR CONTAMINANTS DETECTED IN THE BEDROCK ZONE OF THE AQUIFER COMPOUND INORGANIC$ Barium Chromium Cobalt Copper Lead Manganese Vanadium Zinc PROMULGATED GROUNDWATER STANDARDS 200 50 1,000 15' 50 5,000 FREQUENCY N5-34 N5-36 N5-38' OF DETECTION (eactignn.rld) 5/6 3/6 10 U 1/6 20 U 2/6 10 U 1/6 2U 6/6 4/6 2/6 Concentrations are in micrograms per liter (µg/1) or parts per billion (ppb). Shaded area (ii':?) depicts positive detections. • -Detectiori:Iimits for VOCs 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. W -Undetected; the associated quantitation limit is an estimated value. N5-40 N5-41 N5-44' 14.3 U 2U 14 U 33 U -------------------N . .iiiiiw:1;rAACH""i"eii'MICAl ~ SUl'ERFlHl SITE AEcoRo Of DEasloN FOR ClPERAet£ lNT il3 -29- 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 1,400/18. ---· -· -· -· -· -· NS-W1/S1 -ND/ND -· -· ---· -· -- NS-W2/S2 -· ND/ND -· -· -· -· -· -· NS-W3/S3 -· ND/ND -· -·d -· -· -· -· 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 Jn,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 -· --· .-• S0-02 ---· ND -· -· -· - ---------------~~-~ -30- 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 S0-03 ------ND -- S0-04 -----ND -- S0-05 -----650 -- S0-06 ------57 -- S0-07 -----ND4 -- Concentration for surface water samples are in micrograms per liter (µg/1) or parts per billion (ppb) Concentration for sediment samples are in micrograms per kilogram (µg/kg) or parts per billion (ppb) • SW/SE: surface water/sediment; NS-WIS water/sediment (EPA samples); SO: soil AEcooo OF OEaSION FOR 0PERAB1£ UN1 13 May 1992 June 1992 January 1993 ------ -- ---- ------- ------ ------ b First value represents conc:entrabOn or 1.2-DCA in surface water/Second value represents concentration of 1,2-DCA in sediment D -Concentration reported from secoodaty dllutlon J -Concentration Is estimated ND -Analyzed for bu1 not detected NS -Not sampled (no water available) U -Undetected at the Indicated quantitation limit I I I I I I I I I I I I I I I I I I I -31- NAT0<,11. STARO< l CleilC.ll ~"" SlJ>aRN) 5m; RE00RD Of llEaaoN R:11 CFE-. UNT '3 TABLE 7 CONCENTRATIONS OF ORGANICS AND INORGANIC$ IN SURFACE WATER AND SEDIMENT FROM LOCATIONS SW/SE-12 AND SW/SE-13 COMPOUND/ANAL YTE ORGANICS Acetone 1 ,2-Dichloroethane IN0RGANICS Antimony SW-12 (Background) 10 U SU 30 U SW-13 30 U SE-12 (Background) SE-13 ~;;;;;-!'.igfafaiii ;;;·;1;)?® 6;;:::: 4.9 UJ Arsenic 2U Barium 2U :--~~ ·;. ~--:>1::v: ·<:<· ··.: ·r: , ·_·:,··i:)\1l~i::J/:"::_;:>\::·: ::~t~1~1~~a-~1,11ilim1@t :0:rfi~~~~~~r.~~0t~:Jr Beryllium 1 u 1 u iFS~ii;:;;:;;: .,:x:;Qi~#9?J• .. >5 Chromium ,,, 1 o u 1 o u ;ti;:::ii~~~§H:::}f ;2:\@;;j)r::111 Cobalt 20 u 20 u :li~t.Es:1;gi%1,~f.}.\}.1-! $j(f%~f:1~;~_:.~:~f®;,_,.; Copper 10 U 10 U :.t_;jf(:/0;,~~i\(}f;~,: ~fl?frf?~~S-::::::: .. ::<~-j 11-.....:....:--------t-----t----===iiiim Lead 2 U 2 U !\i~~l~#.!i!if ~~[f {IJJf {~ Manganese Mercury 0.2 U 0.2 U Nickel 20 U 20 U Selenium 2U 2U Thallium Vanadium Zinc Samples collected In January 1993. Shaded area Ct) depicts positive detections. Concentration for surface water samples are in micrograms per liter (µg/1) or parts per billion (ppb) Concentration for sediment samples are in micrograms per kilogram (µg/kg) or parts per billion (ppb) SW -Surface Water Sample SE -Sediment Sample D -Concentration reported from secondary dilution. J -Concentration Is estimated. R -Unusable results. U -Undetected at the indicated quantltation limH. UJ -Undetected; the associated quantHation limH is an estimated value. I I I I I I I I I I I I I I I I I I I N850 - ABANDONED RAJLAOAO SPUR '' '' ' ,------ '' '' '' '' " " '' '' '' '' SW-12 (2J) CHAIN LINK FENCE----___:..,__ AREA2 SW-10 (1300J) E250 SW-13 APPROXIMATE SCAi..E (ft) 0 ,oo 200 ,00 «xi "' .6.SW-14 (590) SURFACE WATER LOCATION ANO 1,2-0CA CONCENT>IATION '-1 ■ NS-14 (NO) FIGURE 8 MOMTORING WELL LOCATION ANO 1,2-0CA CONCENTl<ATION '-1 SURFACE WATER SAMPLING LOCATIONS ALONG THE NORTHEAST TRIBUTARY AND ASSOCIATED CONCENTRATIONS OF 1,2-DICHLOROETHANE I I I I I I I I I I I I I I I I I I I I N&50 - ABANDONED RAILROAD SPUR ___ ___,► N550 - '---------------- N250 - '' '' AREA2 ·-. --. -. --... --~~ :~---::::: ~ -~---_ ---... --. ---------------. --, PARl<ING LOT _____.,.; LAGOON 1 E-350 I LAGfON I CHAIN LINK FENCE-----..:C- SE-12 (NO) E 250 SE-10 (610) SE-16 (61) 0 1 00 200 JOO .00 SOO SE-13 .. (?!l<l) _____ _ SE-14 (1000) LEGEND A SE-13 (290) FIGURE 9 STREAM SEDIMENT SAMPLE LOCATION AHO 1,2-C>CA CONCENTIIATION -I SEDIMENT SAMPLING LOCATIONS ALONG THE NORTHEAST TRIBUTARY AND ASSOCIATED CONCENTRATIONS OF 1,2-DICHLOROETHANE I I I I I I I I I I I I I I I I I I I -34- NA T1llHM. ST""°' l CIEIIICM. COOPN<t SlfflRN) SiTE Re<XRl OF llEaaoN ~ Cl>awlJ; lJlfT '3 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 the 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 toxicity tests as part of the environmental assessment of this stream. The results of the environmental exposure assessment are discussed in Section 6.6. 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 28 (NCAC 15A-2B.02) 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". Neither sport nor commercial fish species were observed in the surface waters during the RI field work. ~ 5.4 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 15-2L.02). EPA classifies the groundwater as Class IIA since the aquifer is currently 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 extends from the ground surface to the bedrock. This mantle, the saprolite, is composed of day-rich residual soils which range from silty to sandy clays. The saprolite is derived from the intense chemical weathering of the crystailine bedrock and has retained the structural fabric of the parent niaterials below the oxidation profile. These residual soils exhibit increasing amounts of sand-sized relict mineral grains below the oxidation horizon and closer to the bedrock. There appears to be a complete gradation from saprolite/friable weathered bedrock, to fractured bedrock/sparsely fractured bedrock. The depth to bedrock ranges from 1 0 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 zones. I I I I I I I I I I I I I •• I -35- NA110NM. STAAO< l CIEM&11. CC.lltf 9.fflF.JC) Srre REalRo CJ' DEaaclo FOR~ U1fT 13 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 0 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 competent approximately 200 feet below ground surface. 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 of 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 th!'~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. 5.5 PATHWAYS AND ROUTES OF EXPOSURE The chemicals of concern for groundwater are listed in the Table 8. This list Includes VOCs, a SVOC, and metals. Contaminants were included in Table 8 if the results of the risk assessment indicated that the contaminant might pose a significant current or future risk or contribute to a risk which is significant. The criteria for including contaminants in this table was a carcinogenic risk level within or above the acceptable range (i.e .. 1 E-4 to 1 E-6) or a hazard quotient greater than 0.1. Contaminants were also included if they exceeded either State or Federal applicable or relevant and appropriate requirements. 1,2-DCA ,s the only the chemical of concern detected in the surface water. 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. I I I I I I I I I I I I I I I I I I I -36- NArow. STAAO< l C!EMl'.:.ll ca.,.,,, Sl.FeRAHl SITE l'cca,o a' OEClaao RJO C"8wu UIIT '3 Based on the information collected during the RI, the four transport mechanisms occurring at the NSCC site are: • • • 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 voes were detected in surface soil; and 3) Each of the voes 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 human exposure pathways 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. 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. ------------------- N 1300 - ~ " Q), g ,;Ji> 28 EX-01 ~ NS-21..t. 0 A z N IB ~ = o.. NJOO-.t,.NS-26 c-::, N0.00-ljl-03 NS-27 .... ..t.EX-04 8 & N-700 ) I l E-3200 E ·2200 E-1200 PLANT EAST (It) NS-15 .... .. :ill. :: ;•----- ~ :: :: V. :: : : 0 ., •• ,, ., s ' :: : · ~~· SCALI' 1111 l£GENO ■ I.DCATDNS WHEN' llllf\JSM_ SBA2-2 ..-. ... ~ ... ..,.,,.., NS-14 ~wtu WHUlf llff\.lSM •..S l'l(ACfttO r- llfOMJD. Elft'ATION 0 """""" ;:: FIGURE 10 ORIENTATION AND LOCATION OF HYDROGEOLOGIC CROSS SECTION SHOWN IN FIGURE 7 ------------------- NO<III ..... J f NS-17 ..... I ..... I I ..,.,, I -I .... I ~ .... I . .. : ,f'lnC',h~::.: ... I - 000 I I ... A A' I.EOENO FIGURE 11 500 500 HYDROGEOLOGIC CROSS SECTION A-A' I I I I I I I I I I I I I I I I I I I -39- NAraw. ST...,. & CIEIIICM. ca,,.,,, SU>aRolJ SITE REc0Ro <»' 0Eaaoo RlA CiPawl..E UlrT 13 TABLE 8 LIST OF CHEMICALS OF CONCERN IN THE GROUNDWATER POSING RISK AND THE ASSOCIATED UPPER CONFIDENCE LIMITS (95%) EXPOSURE POINT CONCENTRATION CONTAMINANTS OF CONCERN IN THE GROUNDWATER Acetone Bis 2-Chloroeth I ether Chloroform 1,2-Dichloroethane 1, 1-Dichloroethene 1,2-Dichloroethene cis and trans 1 2-Dichloro r ane Meth lene Chloride Tetrachloroethene 1,1,2-Trichloroethane Trichloroethene Vinyl Chloride Antimon Arsenic Barium Be Ilium Cadmium Chromium Man anese Thallium Vanadium Zinc EXPOSURE POINT CONCENTRATION FOR CONTAMINANTS DETECTED IN GROUNDWATER (mg/I) NA 0.04 0.00522 0.431 0.0071 NA NA 0.00603 0.00478 0.00478 0.00446 0.011 0.0185 0.00194 0.257 0.000667 0.00311 0.0414 2.73 0.00104 0.0759 1.34 NA -Chemical was not carried through the risk assessment but is listed as a contaminant of concern because it exceeds either State and/or Federal groundwater standards in some monitoring wells. -------------------NAnotW. STARCH & cii'w'ICAL CoWPN('{ SUPERFI.ND SITE P.CORO Of DECISION FOR ClPERAl!I.E UNIT '3 -40- TABLE 9 POTENTIAL CURRENT AND FUTURE EXPOSURE PATHWAYS OF HUMAN EXPOSURE TO CONTAMINANTS RECEPTOR CHILDREN ADULTS CHILDREN MIGRATION/EXPOSURE PATHWAY Incidental ingestion of surtace soils Dermal contact with surface sous Incidental ingestion of subsurtace soils Dennal contacl "'111 "-'>5<61.ial SOds lolgiaDui, ul oorca,rw,a,,u trom SOIi '> ~-a88k. and spnngs. Exposu-e v,a flCIClanlal •,geslOI•. dnnmg walef "'118stion, demlal contact at stream and home, llhalabon of voes at stteam and home. Incidental ingestion of surtace soils Dermal contact with surface sous Incidental Ingestion of subsurface soils Dermal contact with subslmce soils Migration of contaminants from Site to springs; Incidental ingestion of spring water INCLUDED IN RISK ASSESSMENT? CURRENT FUTURE LAND USE LAND USE Yes Yes Yes Yes No 4 Yes No Yes No Yes No Yes No Yes No Yes No Yes Yes Yes REASON FOR INCLUSION/EXCLUSION Surface soil is currendy available for contact by on-site rece tors Surface soil is currendy available for contact by on-site rece tors Subsurface soil is currently unavailable for contact. Future development could expose subsurtace soil for Mure receptors. Children may ingest significandy more soil than adults. Future development could expose subsurtace soil for Mure rece tors Contaminant may migrate from soil to groundwater Surface sou is currendy available for contact by on-site rece tors Surface sou is currendy available for contact by on-site rece ors Subsurface sou is currently imvailable for contact. Future development could expose subsurface soil for . Mure race tors. Subsurface soH is currently imvailable for contact. Future development could expose subsurface soil for future race tors. Site-related contaminants are prasent in the creek as a result of groundwater discharqe. Site-related chemicals area also likely to be present 111 the springs near the Cl88k. -------------------NATIONAi. STARCH & C>EWICAI. COWPAHY SUPEAA.NO 5rre l'EOORo OF DECISION FOR Ol>ERABL£ UNIT 13 -41- I TABLE 9 POTENTIAL CURRENT AND FUTURE EXPOSURE PATHWAYS OF HUMAN ExPosuRE To CONTAMINANTS RECEPTOR ADULT CHILDREN MIGRATION/EXPOSURE PATHWAY Migration of contaminants from Site to springs; dennal contact with spring water Use of groundwater as domestic water source: inoestion of drinking water Use of groundwater as domestic water source: dennal contact with water Use of groundwater as domestic water source: inhalation of voes from household water use Migration of contaminants from Site to springs; . incidental ingestion of and dennal contact with sorino water Use of groundwater as domestic water source: inoestion of drinkino water Use of groundwater as domestic water source: dennal contact with water Use of groundwater as domestic water source: inhalation of voes from household water use Mi~n of contaminants from Site to creek; incidental ingestion of creek sediment Migration of contaminants from Site to creek; inadental Ingestion of surface water Migration of contaminants from Site to creek; dennal contact with sediment INCLUDED IN RISK ASSESSMENT? CURRENT FUTURE LAND USE LAND USE Yes Yes No Yes No ~ Yes No Yes No No No Yes No Yes No Yes Yes Yes Yes Yes Yes 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 ,n the springs near the creek. Future development could result in a production weU in this area Future development could result in a production weU in this area Future development could result in a production well in this area Adults are not expected to play in springs Future development could result in a production weU in this area Future development could result in a production wen in this area Future development could result in a production wen in this area Site-related contaminants are present in creek water and .sediment Children iving in residential area nearby may lll;iv in the creek Site-related contaminants are present in creek water and sediment Children iving in residential area nearby may nbv in the creek Stte-related contaminants are present in creek water and sediment Children tiving in residential area nearby may play in the creek ------NATIONAi. STARCH & C>EMICAL COMPANY 5uPEAfLNIJ SHE REcoRn Of DECISION FOR OPERABLE llNT 13 -42- I TABLE 9 POTENTIAL CURRENT AND FUTURE EXPOSURE PATHWAYS OF HUMAN EXPOSURE TO CONTAMINANTS I INCLUDED IN RISK MIGRATION/EXPOSURE ASSESSMENT? REASON FOR RECEPTOR PATHWAY CURRENT FUTURE INCLUSION/EXCLUSION LAND USE LAND USE Migration of contaminants from Site to creek; dennal contact with surface water Yes Yes Site-related contaminants are present in creek water and sediment Children living in residential area nearby may olav in the creek Migration of contaminants from Site to creek; Yes Yes Detected chemicals may volatilize into air Inhalation of contaminants partitioning to air from surface water ADULTS All pathways identified above No f No Adults are not expected to swim or play in the creek I I I I I I I I I I I I I I I I I I -43- NAraw. STAID< l Cl&ICM. ca.,,.,, SlJ>EaFuc> SITT -Of DEaaao Fa, CPewl.E IJlfT '3 • 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 of 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. 6.0 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 risks posed by Site soils will be summarized in OU #4. 6.1 CONTAMINANTS OF CONCERN Table 8 provides a comprehensive list of all 1110 contaminants identified as chemicals of concern in the groundwater at the Site. The contar-/iinants and concentrations of these contaminants detected in the groundwater are the major contributors to the significant risk for this Operable Unit. The following sections will concentrate on the risks posed by contaminants listed in Table 8. 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 wells. 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. I I I I I I I NATIONM. STAID< & CleiCM. ca,,,,.,, Sl.FEaR.NJ Sn. REalRD OF lleaao, RJI 0PeAAa.E UIIT '3 -44- 6.2 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 infonnation 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 • Denna! contact with soil. I For groundwater, they included: I I I I I I I I I I I • Incidental ingestion of groundwater at springs (current) • Denna! contact with groundwater ar springs (current) • Ingestion of groundwater as drinking water (future) • Denna! contact with groundwater during domestic water use (future) • Inhalation of volatile chemicals partitioning to the air from groundwater during domestic water use. Table 8 provides the reasonable maximum exposure concentrations which were used in calculating the carcinogenic and noncarcinogenic risks associated with each chemical of concern in the groundwater. The surface water and sediment pathways were evaluated for a current and future trespasser (age 7-16 years) and a future child resident (age 1-12 years) for Incidental Ingestion, dennal · absorption and Inhalation exposure to chemicals of potential concern In these media The exposure frequency and duration for the trespasser scenario were 143 days per year and 1 O years, and 286 days per year and 12 years for the resident scenario. The body weight was 45 kilograms for the trespasser and 22.5 kilograms for the resident. The exposure duration was the same for exposure to spring water; the frequency of exposure was 71 days per year for the trespasser and 143 days· per year for the child resident. As stated previously, the contaminants and concentrations of these contaminants detected In the groundwater are the major contributors to the significant risk for this Operable Unit and the only chemical of concern in the surface water is 1,2-DCA. Although, the Impacted groundwater Is not currently being used as a drinking water source, the aquifer itself is being used as a source of I I I I I I I I I I I I I I I I I 'I -45- NA TJCH". ST""°' & C!EMcM. Caol'NN Sl..oE!RNl 5m REcl:Al OF 0Eaaa, R:11 OPe1W1LE UIIT '3 drinking water; therefore, this resource should be maintained at drinking water quality. Table 10 lists the specific parameters used to model the site-specific groundwater intakes for OU #3. The exposure point concentrations for surface water outside the plant operations area and inside the plant operations area in the Northeast Tributary are 1.04 milligrams per liter (mgl1) and 1.26 mgl1. 6.3 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-' [(mg/kg/day)''], 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 uncertainty factors have been applied. Reference doses (R,Os) have been developed by EPA for indicating the potential for adverse health effects from exposure to chemicals exhibiting noncarcinogenic (systemic) effects. R,Ds, which are expressed in units of mg/kg/day, are estimates of lifetime daily 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 R,O. R,Ds 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,Os will not underestimate the potential for adverse noncarcinogenlc effects to occur. The Agency has derived CSFs and R,Os for the contaminants of concern at the Site for use in determining the upper-bound level of cancer nsk and non-cancer hazard from exposure to a given level of contamination. These values are provided in Table 11. 6.4 RISK CHARACTERIZATION The risk characterization step of the baseline risk assessment process Integrates the toxicity and exposure assessments into quantitative and qualitaUve expressions of risk. The output of this process is a characterization of the site-related potential noncarcinogenic and carcinogenic health effects. Potential concern for noncarclnogenic 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 I I I I I I I I I I I I I I I I I I I -46- NA row. STAIIO< l C>&ICM. ca.,..,, SU>alRH) Sm; AEcalD OF ilEaaoN R:lR Q>awu UlfT '3 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 12. The HQ is calculated as follows: Non-cancer HQ = CDI/R,D, where: COi = Chronic Daily Intake R,D = 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. Table 12 provides the computed chemical intakes values along with the calculated risks. Excess life-time cancer risk is calculated from the following equation: Risk= COi X SF, where: 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)"' 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 .. 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; however, depending upon site factors, a risk of 1 E-4, may be considered protective. Where the cumulative carcinogenic site risk to an individual is less than 1 E-4 and the noncarcinogenic HQ is less than 1, a RA is generally not warranted. If an RA is initiated at a Superfund site, then the Agency strives to achieve a residual cancer risk of no greater than 1 E-6. The carcinogenic upper-bound risk for each of the exposure pathways {current and future) identified at the Site are summarized in Table 13. The cumulative future risk and hazard index posed by the groundwater at the Site is 2 x 10·3 and 60 for a child, respectively; The only chemical that exceeded EPA's risk range In surface water and spring water was 1,2-DCA. 6.5 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. Other major I I I I I I I I I I I I I I I I I I I -47- NA"°""-STAAO< & CHEWCAI. CoolPAHY S!A>EAAMO SITE REmul CF Droso, FOR CIPEIW!l.E UIIT '3 uncertainties of the NSCC OU #3 human health baseline risk assessment are: uncertainties associated with predicting future land use, uncertainties associated with estimating chemicai concentrations at receptor locations, uncertainties with the toxicity assessment, and uncertainties associated with assumptions used in the exposure models. Use of upperbound estimates tends to overestimate exposure and the effect of more than one upperbound parameter tends to produce an conservative estimate. The assumption that future exposure concentrations will be equal to current concentrations increases uncertainty because environmental concentrations appear to vary over time. And the assumption that residences will be constructed on the plant operations area under the future land-use scenario also adds to the uncertainty. Models used to predict exposure concentrations have inherit uncertainties associated with them. These uncertainties are associated with predicting the movement of the contaminants and the receptors as well as the assumptions made (e.g., skin surface area, soil adherence factors, and absorption coefficients for soil and water). 6.6 ENVIRONMENTAL RISK The ecological risk assessment for OU #3 evaluated risks to the aquatic and benthic (bottom- dwelling) organisms in the Northeast Tributary. These organisms can be exposed to site-related contaminants in surface water and/or sediment. The main ecological contaminant of concern in this tributary is 1,2-DCA. To determine if there were any effects of 1,2-DCA on the benthic communities inhabiting the Northeast Tributary, a Rapid Bioassessment Protocol was used to conduct an ecological field assessment during Phase I of the RI for OU #3. Results indicated that tributary segments with historically elevated 1,2-DCA levels (adjacent to the plant operations area) were devoid of sensitive macrobenthic species and exhibited generally lower taxa richness and abundance than the reference station. However, the benthic assemblages were not dominated by taxa known to be tolerant of chemical stress. This portion of the Northeast Tributary is located near the stream's headwater area. In view of the naturally-limiting factors associated with a headwater stream of this type, ecological impacts resulting from the presence of 1,2-DCA in the Northeast Tributary could not be determined. During Phase II of the OU #3 RI, chronic toxicity tests were perfonmed on surface water and sediment samples to further examine the ecological impairments noted during the field assessment. Surface water tests were conducted using fathead minnows and water fleas, while amphipods and water fleas were used for whole sediment tests. The measurement endpoints (survival, growth, or reproduction) did not differ significantly between site samples (containing elevated levels of 1,2-DCA) and reference or laboratory samples (containing little or no 1,2-DCA). These test results initially suggested that ecological impainments observed in the Northeast Tributary resulted from natural stresses rather than the presence of 1,2-DCA or other chemicai contaminants. However, chemical analysis of surface water samples collected at the same time and locations as those for the toxicity tests indicated that the level of 1,2-DCA In the sample collected adjacent to the Site (200 ug/1, estimated value) had decreased below historic levels for that area (800-3200 ug/1) and was below the screening level (2000 ug/1) thought to be potentially toxic to aquatic organisms. -------------------NATIONAL STARCH & CI-EMICAL CoMPANY SUPERFI.MD SHE TABLE 10 Pathway/ Parameter- cw Age IR Fl EF ED BW AT-Noncancer AT-Cancer RECORD Of DECISION FOR ClPERABl.f UNIT 13 -48- PARAMETERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN Current Land Use Current Conditions Outside Plant Operations Area Future Conditions Inside Plant Operations Area Future Land Use (Resident) Reasonable Maximum Exposure UCL or maximum con~ntration in groundwater 0-30 years 2 Uday 1 unitless 350 days/year 30 years 70 kg 10,950 days 25,550 days Reference(s)/ Justification Assumption (See text) Upperbound estimates EPA, 1991b 100% of drinking water is assumed to come from contaminated area (EPA, 1991 b) See text 90% upperbound of time lived in one place (EPA, 1991 b) Standard default for adult exposure (EPA, 1991 b) 365 x ED 365 x 70 yr lifetime -------------------NATIONAL 5TARciiT"CfEMICAl.1xi'iiPANY SUPE!lflNl SHE TABLE10 Pathway/ Parameter- cw Age SA CF PC ET EF ED BW AT-Noncancer AT-Cancer REcooo Of DECISION FOR OPEIW!LE UNIT 13 -49- PARAMETERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN Current Land Use Current Conditions Outside Plant Operations Area Future Conditions Inside Plant Operations Area Future Land Use (Resident) Reasonable Maximum Exposure UCL or maximum contentration in groundwater 0-30 years 21,500 cm2 0.001 Ucm3 Chemical-specific cm/hr 0.2 hour/day 350 day&'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 -------------------NATI~TARCH Tii£U1CAL coiiPAijy SUPEllflNO SITE TABLE 10 Pathway/ Parameter" Ca Age IR ET Shower Indoors EF ED BW AT-Noncancer AT-Cancer RECORD OF DECISION FOR 0PE"'8lf iJHIT 13 -50- PARAMETERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN Current Land Use Current Conditions Outside Plant Operations Area Future Conditions Inside Plant Operations Area Future Land Use (Resident) Reasonable Maximum Exposure Calculated from UCL or maP.imum 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 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 ------------------- TABLE 10 Pathway/ Parameter" Cw Age IR Fl EF ED BW AT-Noncancer AT-Cancer NATIONAL STARCH & CI-EMJCAL COMPANY SUPERFl.tm SITE RECORD OF DECISION FOR OPERABLE UNIT 13 -51- PARAMETERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN Current Land Use Current Conditions Ou1side Plant Operations Area Future Conditions Inside Plant Operations Area Future Land Use (Chilid Resident) Reasonable Maximum Exposure . UCL or maximum • concentration in groundwater 1-12 years 2 Uday 1 Unitless 350 days/year 12 years 22.5 kg 4,380 days 25,550 days Reference(s)/ Justification Assumed Assumed same ingestion rate as adults 100% of drinking water is assumed to come from contaminated area (EPA, 1991 b) See text Corresponds to age exposed Average years exposed (EPA, 1990b) ED x 365 days/year 70 year lifetime x 365 days/year ------------------- TABLE10 Pathway/ Parameter' Cw Age SA CF PC ET EF ED BW AT-Noncancer AT-Cancer -52- NATIONAL STARCH & CtUUCAL CoMPAHY SUPERFLtm SHE RECORD Of DECISION FOR OPERABlf UNIT 13 PARAMETERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN Current Land Use Current Conditions Outside Plant Operations Area Future Conditions Inside Plant Operations Area Future Land Use (Chilid Resident) Reasonable Maximum Exposure 8 UCL or maximum concentration in groundwater 1-12 years 8,900 0.001 Ucm 3 Chemical-specific cm/hr 0.2 hour/day 350 days/year 12 years 22.5 kg 4,380 days 25,550 days Reference(s)/ Justification Assumed Average for whole body (EPA, 1992a) EPA, 1992a 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 --------------------------NATIONAL STARCH & CI-EMICAL COMPANY SUPERFL.WD SHE RECORD OF OECISMlN FOR OPERABlE UNIT t3 -53- TABLE 10 PARAMETERS USED To DESCRIBE EXPOSURES To SITE-RELATED CHEMICALS OF CONCERN Pathway/ Parameter" Ca Age IR ET Shower Indoors 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 (Chilid Resident) Reasonable Maximum Exposure C?Jculated from UCL or maximum concentration in groundwater 1-12years 0.63 m3/hr 0.2 hour/day 16 hours/day 350 days/year 12 years 22.5 kg 4,380 days 25,550 days Reference(s)/ Justification Calculated value Assumed Assumed same inhalation rate as adults Upperbound estimate (EPA, 1991 b) Upperbound estimate (EPA, 1991 b) See text Corresponds to age exposed Average for years exposed (EPA, 1990b) ED x 365 days/year 70-year lifetime x 365 days/year • 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 = penmeability constant. • UCL-Upper 95% confidence limit NA mNM. STARO< & C-IC.ll C<M'IHr 5u>EaRHJ Sm I RE<xlRD '1' ilEosoo F<>1 Ol>EIWU UlfT S -54- I TABLE 11 SUMMARY OF NONCANCER TOXIC EFFECTS OF CHEMICALS OF POTENTIAL CONCERN I INHALATION ORAL RIDd CRITICAL EFFECT UNCERTAINTY GASTROINTESTINAL CHEMICAL RICd (mg/kg/day) AND FACTOR' ABSORPTION (mg/kg/day) TARGET ORGAN' (Inhalation; oral) FACTOR' I (Inhalation; oral) I Acetone ND 1 X 10'1 h NA; liver, kidney NA; 1000 0.9 damage I Bis(2-Chloroethyl)ether ND ND NA;NA NA;NA 0.9 1 X 10·2h Chloroform ND NA; fatty cyst on NA; 1000 1.0 I liver, liver lesions 1,2-Dichloroethane ND ND NA; NA NA;NA 0.9 I 1, 1-Dichloroethene ND• 9 X 10•3h NAm; hepatic lesions NA; 1000 0.93 1,2-Dichloroethene' ND 1 X 10·2b NA; decreased NA; 3000 0.9 -hematocril and I hemoglobin 1,2-Dichloropropane 1 X 10•3h ND ·NA;NA NA;NA 0.9 I Methylene Chloride 9 X 10·1 h 6 X 10•2h NA; liver toxicity 100; 100 1.0 Tetrachloroethene ND 1 X 10·2h NA; hepatotoxicily NA; 1000 0.9 I 1, 1,2-Trichloroethane ND 4 X 10•3h NA; clinical NA; 1000 0.9 chemistry alterations I Trichloroethane ND 6x10•3k NA; NA NA;NA 0.9 Vinyl Chloride ND ND NA; NA NA;NA 0.9 I I I Antimony ND 4 X 10◄h NA; blood glucose, NA; 1000 0.05 cholesterol I Arsenic ND 3 X 10◄h NA; NA;3 0.98 hyperpigmentation, keratosis I Barium 1 X 10◄b 7x10•2h Fetotoxicity; 1000;3 0.1 increased blood I pressure Beryllium ND 5x10·3h NA; ND NA; 100 0.001 I -55- NAOOIW. STAAO< & CIEMICAI. CoiPIIN SlJPE1'F\Hl Sm REcOfm a Droso, Fe,, ~ UIIT « I I I I I I I I I TABLE 11 SUMMARY OF NONCANCER TOXIC EFFECTS OF CHEMICALS OF POTENTIAL CONCERN INHALATION ORAL RIDd CRITICAL EFFECT UNCERTAINTY GASTROINTESTINAL CHEMICAL RICd (mg/kg/day) AND FACTOR• ABSORPTION (mg/kg/day) TARGET ORGAN° (Inhalation; oral) FACTOR' (Inhalation; oral) Cadmium (water) .. ND 5 X 10"h NA; proteinuria, NA;.10 0.06 renal damage Cadmium (food) ND 1 X 10•3h NA; renal damage NA; 10 0.06 Chromium VI' ND 5 X 10·3h Nasal mucosa 300; 500 0.05 atrophy; ND Manganese (water) 1 X 10" h 5 X 10•3h Respiratory; CNS 300; 1 0.05 Manganese (food) 1 X 10" h 1.4 X t0·1 h Respiratory; CNS 300; 1 · 0.05 Thallium' ND 6x1Q·5h NA; increased NA; 3000 0.05 SGOT and serum ~ LOH levels, alopecia Vanadium ND 7 X 10·3b NA; none observed NA; 100 0.05 Zinc ND 3 X 10·1 h NA; anemia NA; 10 0.5 I • ND = Not determined b Source: 1992 HEAST, including July 1992 and November 1992 Supplements. I ' Value given is for Chromium VI, assuming all chromium found is Chromium VI. d The reference concentration or reference dose is the dose below which no adverse effects are likely to be seen (EPA, 1991c and 1992c). • Determined by the EPA (1991c, 1992c). 1 1 The oral R+D is multiplied by the Gastrointestinal Absorption Factor !GAF) g NA = Not applicable. h Source: IRIS. i Values given are for 1,2-cis-dichloroethene. I k From the Environmental Crrteria and Assessment Office of the u S EP4. Cincinnati, Ohio. m By analogy to thallium suttate, adjusting for differences in molecular •e,gnt. I I I I I I I ------------------- -56- TABLE 12 ESTIMATED POTENTIAL FUTURE LAND USE RISK FROM CARCINOGENS POTENTIALLY EXPOSED POPULATION Chlld Resident Adult Resident CHEMICAL 1, 1,2-Trichloroethane 1,2-Dichloroethane Arsenic Beryllium Bis(2-chloroethyl)ether Bis(2-ethylhexyl)phthalate Chloroform Methylene chloride Tetrachloroethene T richloroethene Vinyl chloride Total RISK Total Media 1,1,2-Trichloroethane 1,2-Dichloroethane DERMALLY ABSORBED DOSE (mg/kg/day) 5.22 X 10-ll 1.09x10 .. 2.52x 10./l 8.67 X 10·9 1.09 X 10-l; 5.58x 10-l; 6.04 X 10·7 3.53 X 10·7 2.98 X 10-l; 9.27 X 10·7 1.20 X 10-7 1.01 X 10·7 2.12 X 10-< DERMAL CONTACT RISK 3.31 X 10·9 1.10 X 10-5 4.50x 10./l 3.73 X 10"5 1.34 X 10-l; 8.68 X 10-ll 3.68 X 10·9 2.65 X 10·9 1.72 X 10·7 1.13 X 10-ll 9.05 X 10·9 5.00 X 10-5 6.42 X 10"9 2.14x 10-5 , INGESTED DOSE (mg/kg/day) 6.99 X 10-5 6.29 X 10·3 2.83 X 10-5 9.75 X 10-l; 5.84 X 10-< 1.90 X 10-< 7.62 X 10-5 8.82 X 10-5 6.98 X 10·5 6.51 X 10-5 1.60 X 10-< 5.61 X 10-5 5.05 X 10·3 INGESTION RISK 3.98x 10-l; 5.72 X 10-< 4.96 X 10-5 4.19 X 10-5 6.43 X 10-4 2.66 X 10-l; 4.65 X 10·7 6.61 X 10·7 3.63 X 10-l; 7.16 X 10·7 3.04 X 10-< 1.62 X 10·3 3.20x 10-l; 4.60 X 10-< NATIONAl STAACH & CI-EW.ICAL COMPANY SUPERFltlO SITE RECORD OF DECISKlN FOR OPERABLE UNIT 13 INHALED DOSE (mg/kg/day) 9.01 X 10-l; 1.52 X 10·3 NA NA 1.74 X 10-l; NA 1.36 X 10·5 1.42 X 10-5 1.62 X 10-5 1.42 X 10-5 3.82 X 10-5 7.24 X 10-ll 1.22 X 10·3 INHALATION OF voes RISK 5.13 X 10·7 1.38 X 10-4 NA NA 2.09 X 10-l; NA 1.10 X 10-l; 2.41 X 10-ll 3.25 X 10-ll 8.50 X 10-ll 1.15 X 10"' 1.53 X 10-< 1.83 X 10-3 4.12x10·1 1.11x10 .. ------------------- -57- TABLE 12 ESTIMATED POTENTIAL FUTURE LAND USE RISK FROM CARCINOGENS POTENTIALLY DERMALLY DERMAL INGESTED EXPOSED ABSORBED CONTACT DOSE POPULATION CHEMICAL DOSE RISK (mg/kg/day) (mg/kg/day) Arsenic 4.89 X 10" 8.74 X 1 0" 2.28 X 10·5 Beryllium 1.68 X 10" 7.24 X 10·5 7.83 X 10-6 Bis(2-chloroethyl)ether 2.12 X 10-6 2.59 X 10-6 4.70x 10 .. ' Bis(2-ethylhexyl)phthalate 1.08 X 10·5 1.68 X 10'7 1.53 X 10_, Chloroform 1.17 X 10-6 7.15 X 10·9 6.12 X 10·5 Methylene chloride 6.86 X 10·7 5.14 X 10·9 7.09 X 10·5 Tetrachloroethene 5.79 X 10-6 3.35 X 10·7 5.61 X 10·5 Trichloroethane 1.80 X 10-6 2.20 X 10" 5.23x 105 Vinyl chloride 2.33 X 10·7 1.76 X 10" 1.29 X 10_, Total RISK 9.71 X 10'5 Total Media INGESTION RISK 3.98 X 10·5 3.37 X 10·5 5.17x 10., 2.14x 10-s 3.74 X 10·7 5.31 X 10·7 2.92 X 10-6 5.76 X 10·7 2.45 X 10_, 1.30 X 10·3 NATIONAL STAACH & C~WICAL COMPANY SUPERRJrfO SHE REcoRD OF OEaSION FOR DPERA8LE UNIT 13 INHALED INHALATION DOSE OF voes (mg/kg/day) RISK NA NA NA NA 1.40 X 10-6 1.68 X 10" NA NA 1.09 X 10·5 8.86 X 10·7 1.14x10 5 1.94 X 10" 1.30 X 10·5 2.61 X 10" 1.14 X 10·5 6.83 X 10" 3.07 X 10·5 9.21 X 10" 1.23 X 10_, 1.52 X 10-3 -------------------NATIONAl STAACH & C1£MICAL C:OMPANY SUPERFLNO SITE RECORD Of DECISION FOR OPERABLE UNIT 13 -58- TABLE 12 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) 1111;r,!l~ll.~9t;~nlll~I! I II Chlld Resident 1, 1,2-Trichloroethane 3.05 X 10·7 8.46 X 10·5 4.08 X 10 .. 1.02 X 1 o-' NA NA 1,2-Dichloroethane 1.05 X 10·5 1.17 X 10·3 d 6.05 X 10-4 6.05 X 10-2 NA NA Aluminum 2.21 X 10·3 1.47 X 10·2 2.48 X 10° 8.27 X 10 1 NA NA Antimony 1.40 X 10-6 7.00 X 10·2 1.57 X 10-3 3.94 X 10° NA NA Arsenic 1.47 X 10·7 5.00 X 10 .. 1.65 X 10-4 5.51 X 1 O-' NA NA Barium 1.95 X 10-5 2.79 X 10·3 2.19 X 10·2 3.13 X 10·' NA NA Cadmium (water) 1.98 X 10•7 6.60 X 10-3 2.65 X 10-4 5.30 X 1 o-' NA NA Chromium 3.14 X 10-6 1.26 X 10·2 3.53 X 10·3 7.05 X 10-' NA NA Manganese (water) 2.07 X 10-4 8.29 X 10-' 2.33 X 1 o-' 4.66 X 101 NA NA Thallium 7.91 X 10-6 2.64 X 10·2 8.88 X 1 o-s 1.48 X 10° NA NA Vanadium 5.76 X 10-6 1.65 X 10·2 6.47 X 10·3 9.24 X 10-' NA NA Zinc 1.01 X 10-4 5.47 X 10·3 1.14 X 1 o-' 3.80 X 1 o-' NA NA Total HQ 1.01 X 10° 5.69 X 10' 7.67 X 10-6 Total Media HI 5.79 X 101 Adult Resident 1,1,2-Trichloroethane 2.37 X 10•7 6.57 X 10-s 1.31 X 10-4 3.27 X 10·2 NA NA 1,2-Dichloroethane 8.15 X 10-6 9.06 X 10-4 1.94 X 10 .. 1.94 X 10·2 NA NA ------------------- -59- TABLE 12 ESTIMATED POTENTIAL FUTURE LAND USE HAZARD ASSOCIATED WITH NONCARCINOGENS POTENTIALLY DERMALLY DERMAL INGESTED EXPOSED ABSORBED CONTACT DOSE INGESTION POPULATION CHEMICAL DOSE HQ (mg/kg/day) HQ (mg/kg/day) Aluminum 1.71 X 10·3 1.14x 10·2 7.97 X 10"1 2.66 X 10'1 Antimony 1.09 X 10-6 5.44 X 10·2 5.06 X 10-4 1.26 X 10° Arsenic 1.14x10·1 3.88 X 10-4 • 5.31 X 10·5 1.77x10'1 Barium 1.51 X 10·5 2.16 X 10·3 7.04 X 10·3 1.01 X 10'1 Cadmium (water) 1.54 X 10·7 5.13 X 10 3 8.52 X 10·5 1.70 X 10'1 Chromium 2.44 X 10-6 9.75 X 10·3 . 1.13 X 10·3 2.27 X 10'1 Manganese (water) 1.61 X 10-4 6.44 X 10'1 7.49 X 10·2 1.50 X 101 Thallium 6.14x 10.s 2.05 X 10"2 2.86 X 10·5 4.76x 10'1 Vanadium 4.47 X 10-6 1.28 X 10-2 2.08 X 10·3 2.97 X 10'1 Zinc 7.87 X 10'5 4.24 X 10"3 3.66 X 10·2 1.22 X 10'1 . Total HQ 7.81 X 10'1 1.83 X 10° Total Media HI NATIONAL STARCH & CI-EMICAL CoMPAHY SUPERfLtm SITE RECORD Of OEaSION FOR OPERABLE UNIT '3 INHALED INHALATION DOSE OF voes (mg/kg/day) HQ NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA NA 9.86 X 10·7 1.91 X 101 I I I I I I I I I I I I I I I I I I I -60- NAOON.11. STAAO< l CHEMIC.II. COWPAHY 5'..l>ERP.Hl Sm RE<olUl Of Dea"°" FOO ClPEFWLE UNT 13 TABLE 13 SUMMARY OF CANCER RISK AND N0NCANCER HI VALUEa Current Land Use Child/RISK BX 10·5 1 X 10◄ 4 X 10◄ Child/HI 6 X 10·2 4 X 10·2 1 X 10·1 Adult/RISK NA NA NA Adult/HI NA NA NA Child/RISK 4 X 10.g 9 X 10.g 1 X 10·7 Child/HI 6 X 10·7 6 X 10-8 Adult/RISK NA NA NA Adult/HI NA NA NA Child/RISK 2 X 10·5 2 X 10-s 1 X 10◄ Child/HI l_i 1 X 10·2 1 X 10"2 3 X 10-.2 Adult/RISK NA NA NA Adult/HI NA NA NA Child/RISK NA NA 2 X 10-3 Child/HI NA NA 6 X 101 Adult/RISK NA NA . Adult/HI NA NA 2 X 101 a Values presented are the sum for all exposure pathways associated with the environmental medium. b Outside the plant area; the fence successfully predudes access to the plant area. 0 Inside the plant area; the fence around the plant area is not functional. d The NSCC property is available for residential use. I I I I I I I I I I D I I I I I I I I ·61 • 6.7 SUMMARY NAllOIW. STAAO< l CHBl""'-C,.,.N<r SlffRF\HlSrrE REaJ10 ~ DEoSCII Fal ClP£RAa£ UIIT 13 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 beneath and downgradient of the Site as a potable source of water and the potential adverse impact contaminated soils will have on groundwater quality. The unacceptable, future risk 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 has been made between the presence of 1,2-DCA in the Northeast Tributary and the 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. However, the RI report did conclude that the source of 1,2-DCA in the Northeast Tributary is the contaminated groundwater in the saprolite zone of the aquifer discharging into this stream. Since very high concentrations of 1,2·DCA (660,000 µg/1) have been found in the groundwater, the potential for discharge of groundwater contaminants above levels of ecological concern is possible. Hence it is necessary to institute long-term monitoring of,.!he Northeast Tributary. 7.0 REMEDIAL ACTION OBJECTIVES. Section 5.0 defined the extent and characterized the contamination and the environmental setting of OU #3. Section 6.0 highlighted the human health and environmental risks posed by the Site. This Section specifies the remedial action objectives to protect human health and the environment by preventing exposure to the contaminants in the groundwater and surface water/sediment associated with OU #3. The specific remedial action objectives and general response actions for the environmental media adversely impacted by the Site addressed in this ROD are listed in Table 14. 7.1 APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS (ARARS) Section 121 (d) of CERCLA, as amended by SARA, requires that remedial actions comply with requirements· or standards set forth under Federal and State environmental laws. The requirements that must be complied with are those laws that are applicable or relevant and appropriate (ARAR) to the (1) remedial action(s), (2) location, and (3) media-specific contaminations at the Site. Applicable requirements defined In 40 C.F .R. § 300.400(9)(1) are those requirements applicable to the release or RA contemplated based upon an objective determination of whether the requirements specifically addresses a hazardous substance, pollutant, contaminant, RA, location, or other circumstance found at a CERCLA site. These requirements would have to be met under any circumstance. Relevant and appropriate requirements defined in 40 C.F.R. § 300.400(9)(2) are those requirements that address problems or situations sufficiently similar to the I I I I I I I I I a I I I I I I I I I -62- NArow. STAAO< & C""'CAL ca,,,,.,, SlffRru<l SITE AEcoRo CJ' OEaSIOH ~ ClP£1WU UNIT 13 circumstances of the release or removal action contemplated, and whether the requirement is well suited to the Site. The action-, chemical-, and location-specific ARARs for the selected remedial alternative are listed in Table 17. 7.2 EXTENT OF CONTAMINATION The extent and volume of contaminated soils will be addressed in OU #4 ROD. Figures 3, 4, and 7 delineate the estimated periphery of the plumes in the groundwater associated with OU #3. These plume estimates are based on contamination levels detected in the groundwater as well as where there were no detections of contaminants in the groundwater. Calculations were performed to estimated the volume of groundwater which needs to be remediated. By using an estimated surface area of 748,481 square feet, a saturated aquifer thickness of 26 feet in the saprolite and 100 feet in the bedrock, and an aquifer porosity of 35 percent in the saprolite and 5 percent in the bedrock, the quantity of contaminated groundwater in one pore volume of the aquifer was estimated to be 131 million gallons. 8.0 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 15 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 15 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. 8.1 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·. I I I I I I I I g I I I I I I I I I I Alternative GWP1/GWL 1: Alternative GWP2/GWL2: Alternative GWP3/GWL3: Alternative GWP4NGWL4A: Alternative GWP4B/GWL4B: -63- No action NA110HM. STARCH & CIEIIICM. ColPNl'I Si.ff!RNl SITE RErooo Of DroSOI FOR 0.SIW!lf UlfT 13 Long-Term Monitoring with Fencing A Portion of Northeast Tributary Institutional Controls with Fencing A Portion of Northeast ' Tributary 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." 8.1.1 ALTERNATIVE GWP1/GW~a1: 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 ... 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, operation and maintenance (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. I I 1\ I I\ 1\ 1\ I I 1\ I 11 B I I \ I \ I I I I I I I -64- NAOOl<M. STAAC!< l CHEll&li. Ga.FNN &.ffAAHl Srre AEallID c:,; lleasoo FOO OPawl.E UMIT 113 TABLE14 REMEDIAL ACTION OBJECTIVES AND ASSOCIATED GENERAL RESPONSE ACTIONS MEDIUM REMEDIAL ACTION OBJECTIVE GENERAL RESPONSE ACTION Groundwater For Human Health: Prevent ingestion of No Action water having levels of 1,2-DCA resulting in lnstltutional Control cancer risks exceeding the 10◄ to 1 o-s risk Containment range. Containment/Treatment Collection/Discharge For Environmental Protection: None, Collection/TreatmenVDischarge groundwater concentrations have not conclusively been found to represent an environmental hazard. Surface Water For Human Health: None, surface water is No Action not a drinking water source. Existing Monitoring concentrations oii,2-DCA are below Ambient Water Quality Criteria. For Environmental Protection: None, surface water concentrations have not conclusively been found to represent an environmental hazard. Sediment For Human Health: Prevent direct contact No Action with sediments having levels of 1,2-DCA Monitoring resulting in cancer risks exceeding the 10"' to 10 .. risk range. For Environmental Protection: None. .. -, ------- - - - -- ---liiiill - - - - - -·•-- ____ ---Generel----------- RNpOn .. Action Technology Type ,.._, H lt'A --H -- Proc:ee• Option H lt'A I H OWi Rwlill1kw.;, I Cc.ullw.•• H Ylllllcll ___ H EJdl-slm,1opcllol,_ ~-~ Ylllllcll ::t.::-~ ~=~ : . ~--I l -1-l . • &~EPd••Wlla I l -Div, T,_ I ~-ColocllonlOlodw====~~~~ 1£ ~-: l Or>6l4I 'I C I t !,!zPOTW I l ~ I "L--'""=-=:::-:e-=-=Dlolwpo=eK!.--' • Con,.do.lllEJnclion-I ~ -I- &1 • ...ie.u_,_ I ~ ... -.0r111n T,_ I .. ,. I 1 -T-I ~ c.ban I -· 111-I ~ I .~ ~ a-bllT,_ ~ I , ~..........._OlJ..1 P111blilll1a11Jlo,.-■ ~ T-111 ---I ------------------- lnatnutlonel lmplernentablllty ....... - .......... ....... - ....,.,..__ ___ __.., ..... ,.,t,1 .........-----Ollllally 1, .. ,e ,_ -ClfflalllJ ,, ... ,aid! ....... ii tu ............. - e...,11, .... , •. Jth 111.-, ..... ,, ......... lni!CMIIMTW■ducw ...,..___~ ...,..__ -Dllllmdly Effectlvellffe In Meeting PRQe Nol ElledMO • W••-T_ lo_ PAGI v..,_ v..,_ Nol-lDreon.,....k#Ms v..,_ v..,_ .....,....,e-... TABLE 15 SECOND SCREENING OF TECHNOLOGIES AND PROCESS OPTIONS FOR GROUNDWATER Coat .__ i.-1o-... ......,,High --llgh .... ....,,_ M 1 _,,, ... II I ...,llgh ... 9 •toHIIJh .. ! ... High 11!!!!!1 !!II =---- - - - - --1!!!1!11 lliiil -- - -___ .1!!!!!!1.-General RHpon8' .-_ -----•Actlon-------rachnology Type Cln-SII• 1~ 1 Off-Se .. , _______ _,, • Procaa Opllon Ruined ' L I 1-l ProcaaaOptlon n..-. I -I ~POlW I --I lnatltutlonal lmplllrnentabllhy ...... ,.,11:11 ~·-·-wlli Dllculy -------- Ettectlveneaa In lleallng PRQa Ellldlve TABLE 15 SECOND SCREENING OF TECHNOLOGIES AND PROCESS OPTIONS FOR GROUNDWATER ..... -.. lfdl I I I I I 11 I I I\ 1\ I 1\ I m\ I I I I I I I I I I I I \ I I I \ I I I I I I I I I I I I I I I I I I I I I I I I 1. I I I I Capital Costs: Annual O&M Costs: Total PW Costs for 30 Years: Time to Design: Construction Time: Duration to Achieve Clean-up: -67- $ 0 $ 22.000 $ 227,000 None None Over 30 years NA TIONAl ST AArn & CHBIICM. ca,,,.,,, SU'ERRHl SITE AEC0A0 Of OroOON ,a, 0>awu U..r '3 8.1.2 ALTERNATIVE GWP2/GWL2: Long Term Monitoring and Fencing A Portion Of Northeast Tributary 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. Extending the existing fence line to inclose additional portions of the Northeast Tributary is a precautionary action to reduce the future likelihood of exposing children to unacceptable levels of contaminants in the Northeast Tributary via dermal albsorption, · ingestion, and/or inhalation. As stated in Section 6.0, the current levels of contaminants in the Northeast Tributary do not pose an unacceptable risk. However, under this alternative, the contaminated groundwater is not actively remediated which could lead to higher levels of contaminants entering the Northeast Tributary along with the r;!oundwater. This increase in concentrations of contaminants entering the stream may result in unacceptable exposure concentrations in either water column or sediment or both. 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 8.1.3 ALTERNATIVE GWP3/GWL3: Institutional Controls. Long Term Monitoring, and 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 restrictlon(s) and implementing any other institutional controls. The specific institutional controls to be implemented include: using deed restrictions to control the installation of new wells on plant 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 year1y basis. As EPA may not have the authority to implement these institutional controls, the responsibility rests on the PAP ensure the institutional controls are in place, are reliable, and will remain in place after initiation of O&M. Groundwater monitoring and the five year CERCLA review would be conducted for 30 years. I 11 ,1 I II 1I I Ii I 1I; I I ' ,1 I II 11 ii I 1\ 1I 11 ' II 1I I I\ I Capital Costs: Annual O&M Costs: Total PW Costs for 30 Years: Time to Design: Construction Time: Duration to Achieve Clean-up: -68- $ 198,000 $ 138,000 $1,500,000 None None Over 30 years NAOOIW. STAACH I CHEIICIL co,,,.,,, SU>ERAHl SITE Recaul Cl' DEoSION RlR Q>efWl£ Ull'T '3 8.1.4 ALTERNATIVE GWP4A/GWL4A: Groundwater Extraction Through Wells; Treatment by Air Stripping with Vapor-Phase Carbon Adsorption; and Discharge to POTW 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 8.1.5 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 15 to 30 years I I ' 11 I Ii 11 •i I 11 I I I I 11 1\ •\ 11 I I! I -69- NAT10NM. STAAO< & CMSIK:.11. ColFAHY 5u>ERRHJ SITE RE<:ooo a DEasoH FOA Q,ERA81£ Uon '3 8.2 REMEDIAL ALTERNATIVES TO ADDRESS SURFACE WATER AND SEDIMENT CONTAMINATION 8.2.1 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 8.2.2 ALTERNATIVE SW/SE-2: Long-Term Monitoring 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 9.0 SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES Section 8.0 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 (9j 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. 9.1 TliRESHOLD 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(f)(1)(ii)(C). Table 16 summarizes the I Ii I 11 ,1 I •1 Ii 1! ! II ' I I I 1, I 11 11 I I! •I -70- NAllOflN. STAAO< & CMEWICI< Coll>-&.,,.RAJI() SITE ReCIJRn CE DeaSION FOR OPERASLE UPfT 13 evaluation of the five (5) groundwater and two (2) surface water/sediment remedial alternatives with respect to the threshold criteria. 9.1.1 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, GWP4NGWL4A, and GWP4B/GWL4B, provide adequate protection for human health by preventing ingestion of potentially contaminated groundwater and surface water. Alternatives GWP4NGWL4A and GWP4B/GWL4B would afford the greatest protection to human health because it would substantially reduce the contamination in the groundwater and prevent the potential for exposure through use of existing or future off site wells. Alternatives GWP4NGWL4~and GWP4B/GWL4B would indirectly remediate the surface water and sediment, since the groundwater remediation would decrease the potential for contaminants to reach the tributary via groundwater discharge. Both of these alternatives 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/GWL1 nor GWP2/GWL2 would provide protection for human health. 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 SWISE • 1 and SW/SE-2 would be protective of human health, but may not be protective of the environment. tt higher concentrations are discharged into the stream along with the groundwater, then ootn alternatives may not be protective of human or the environment. 9.1.2 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 tor waiving an ARAR. Site specific ARARs are identified in Table 17. MCLs and State groundwater quality standards are ARARs for Site groundwater. By leaving contaminants above these standards in the groundwater, Alternatives GWP1/GWL1, GWP2/GWL2, and GWP3/GWL3 would not comply with these ARARs. Therefore, these I I 11 I 11 ! I\ 1\ ' 11 I 11 I 1: 1 I\ I I I I 1I I 11 I 11 I 11 I 11 I RI I I -71- NATO<AL STAAO< 'C>EIICJ< ca.,,.,, SUPERruCJ srre RE<alO ~ Dea .... RJR Q>eRABI.£ UIIT '3 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. However, the long-term monitoring requirement associated with SW/SE-2, if done inconjunction with remediation of the groundwater, would serve to verify that groundwater contaminants are not migrating into the tributary at levels of concern for human health or the environment. 9.2 PRIMARY BALANCING CRITERIA These criteria are used to evaluate the overall effectiveness of a particular remedial alternative. This evaluation is summarized in T'lble 18. 9.2.1 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 /GWL1 and GWP2/GWL2 is questionable, because of the time it would require for "Nature" to clean "ltselr. 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 and prevent them from migrating into the surface water and sediment of the· tributary via groundwater discharge. 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. I I I I I I I I I I I I I I I I I I I -72- NA"'""-STAAO< l C!EWICIL COMPAHY SU>ERRHl Sm AE00RD Cl' llEasoH FOO OPERAIU UlfT 113 9.2.2 REDUCTION OF TOXICITY, MOBILITY, 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/GWL4B 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 voes in the tributary; however, neither of these alternatives would result in the destruction of the VOCs. These contaminants would transfer from the tributary to the atmosphere through the process of volatilization. 9.2.3 SHORT-TERM EFFECTIVENESS This criterion assesses the short-term impact of an alternative to human health and the environment. The impact during ... !!1e 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. 9.2.4 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. 9.2.5 COST This criterion assesses the cost of an alternative in tem,s 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 I I I I I I I I I I I I I I I I -73- NA TXlNAI. STARCH & Cle!C.11. co.,,,,, SloERR.N) SITE RE<:aUl Cl' 0Ea90N FOR 0Pawu UlfT 13 TABLE 16 SUMMARY OF THE THRESHOLD CRITERIA EVALUATION FOR THE ALTERNATIVES GWP1 /GWL 1: No Action GWP2JGWL2: ~ong Term Monitoring; Fence Portion of Northeast Tributary GWP3/GWL3: lnstltutional Controls; Long Term Monitoring; Fence Portion of Northeast Tributary GWP4A/GWL4A: Groundwater Extraction; Treatment Via Air Stripping and Vapor-Phase Adsorption; Discharge to POTW GWP48/GWL48: 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 surface water/sediment by fencing stream. Contamination would continue to discharge into Northeast Tributary. Potential off-site contaminant migration ~ould not be eliminated. lnstltutional controls would eliminate risk posed by using contaminated groundwater as potable water. Contamination would continue to discharge into Northeast Tributary. Off-site contaminant migration would be eliminated. Eliminates potential risk of ingestion, inhalation, and dermal absorption. Eliminates contamination entering Northeast Tributary. Off-site contaminant 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. ------------------- -74- TABLE 17 APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS STANDARD REQUIREMENT, CRITERIA, 0A LIIIITATION GROUNDWATER Sale Drinking Water Ad National P!inary Drinking Waler Standards Maximum Contaminanl Level Goals SURFACE WATER Clean Waler Ad Ambient Waler Quality Crileria (AWOC) National polhant Discharge Bimilalion Sys1em (NPDES) National Prelraabnent Program Waler Quality Management Plana (WOMP} CITATION DESCRIPTION 42 U.S.C § 300 Eslablishes standards lor drinking water 40 CFR Part 141, Soopart B Eslablishes healh-based slandards tor pct/ic waler systems maximum contamilant levels (MCLs) 40 CFR Part 141, Soopart F Eslablishes dri1king waler quality goals sec at levels of no known or anlicpated adverse healh effects 33 u.s.c. §§ 1311, 1313, 1317 Defiles laws responsille for protection of Iha integrly of Iha nalions waters 40 CFR Part 131 Sais ai1eria lor water quality based on loxicity lo aqualic organisms and human health 40 CFR Part 122, Soopart C Defnes charge lirnils tor pollutanis; use ol besl available technology economically achievable for toxic pollutanls discharged to surtace waters 40 CFR Part 403 Sais imils tor discharge to POTWs 40 CFR Part 130 Sais ai1eria for water quality based on toxicity to aqualic organisms and human health; discharge must comply with EPA-approved WQMP APPLICABLE/RELEVANT AND APPROPRIATE No/Yes No/Yes No/Yes Yes/Yes No/Yes Yes,No Yes,No No/Yes NATIONAL STARCH & C1£MICAL C.0MPANY SUPERA.111O SITE RECORD OF DECISION FOR ()IERABLE UNIT 13 CoilMENTS The MCLs tor organic and inorganic contaminants musl be addressed as Iha groundwaler is a being used a source for drinking waler MCLGs are appropriate al lhis Site as l is a source of drinking water The AWOC lor organic and i1organic contaminants are relevant and appropriate Discharge from facilities must comply with NPDES regulalions Pretreatment regulalions must be met tt wastewater ii discharged lo a POTW Criteria avalable tor water and fish coosumption; tt wasler water is discharged to a waterway, l musl be in accool wih a WQMP 81 a!1 11111 .. 111111a lilliiiil _. iiiil ----------- -75- TABLE 17 APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS STANDARD REQUIREMENT, CRITERIA, OR LIIIIT ATION AIR Clean Air Ad CITATION 40 u.s.c. §§ 1857, 7409, 7411, 7412 National Prinary and 40 CFR Part 50 Secondary Ambient Ai' Qualily Standards National Emissions Standards 40 CFR Part 61 for Hazardous Air Pollutants (NESHAPs) GROUNDWATER, SURFACE WATER, Atl4 NOl1h Can,lila IJriru,g W-111d l£AC I lie 1 !>A. Cllipl• 2. Groundwa!8' Standarda ~-21. NOl1h Carolila Waler pollution NCAC Title 15A, Chap!., 2, Control Regulations ~er2H Nooh Caroma Ail Pollution Control NCAC Title 15A, Chapter 2, Requirements ~er2D DISPOSAL· DISCHARGE To SURFACE WATERiPOTW NOl1h Caroli\a Surface Waler NCAC Title 15A, Chapter 2, Qualily Standards ~8'28 NOl1h Carolila Waler Pollution NCAC Title 15A, Chapter 2, Control Regulations ~8f2H NOl1h Caroma Ail Pollution Control NCAC Title 15A, Chapter 2, Requirements ~8f20,2H DESCRIPTION Identifies laws responsble fllf protedion of the nations air qualay Sets primary and secondary air standards al levels to proted plblic healh and pttific welfare Provides emissioos standard fllf hazanloular pollutants for which oo ambient air qualny standard exists Ellal>llshos gsoundwal8' clas58s and regulates ...... qualny standanls Establishes permit procedures and condnions fllf wastewaler discharges Establishes emission lrnns fllf air polkJtants Surface water qualay standards Regulates surtace wa!8f discharges and discharges to POTWs Air polkltion control and ar qualily and emissions standards APPLICABLE/RELEVANT AND APPROPRIATE YOSJNo YOSJNo Yes,No Yes,No Yes.No YOSJNo Yes.No Yes.No Yes.No NATIONAL STARCH & Ct-EWICAL COMPANY SUPERFLtm SHE RECORD OF DECISION FOR OPERABLE lJNIT 13 CollllEHTS Applicable for on-sne trea!ment units having air emissions Applicable for on-sne trea!ment unns wnh hazardoos emissk>OS The guidelines for allowable levels of toxic organic and inorganic contaminants are applicable as the groundwal8' is used as a drinking wal8' source Musi be oo~ied wah tt wastowaler is discharged to surtace wal8f Air regulations must be oomplied wnh tt trea!manl r8Sllls ri air emissions Standards must be maintained alter discharge of trea!ed wa!8f Must be oo~ied Wlh tt discharged to aur1aoa water °' POTW is ,-aary Musi be oonside<ed tt trealment results in ar emissions ------------------- -76- TABLE 18 SUMMARY OF PRIMARY BALANCING CRITERIA EVALUATION OF THE ALTERNATIVES GWP1/GWL1: No Action GWP2/GWL2: Long- Tenn Monil0ring; Fence Portion of Northeast Tributary GWP3/GWL3: Institutional Controls; Long-Tenn Monitoring; Fence Portion of Northeast Tributary Does not meet ARARs. Length of service unknown (not permanent). Ongoing monitoring of groundwater contaminan1 levels would be conducted 10 assess contaminants migration. ARARs are not met at the Site. length of service unknown (not pennanent). Fence would reduce potential of exposure 10 contaminated surface water/sediment Ongoing monitoring of groundwater contaminant levels would be conducted 10 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 10 contaminated surface water/sediment None. except natural attenuation. None, except natural attenuation. None, except natural attenuation. None. None. None. None. None. None. NATIONAL STARCH & Ct-EMICAL CoUPA.NY SUPERftMO SITE RECORD Of OECISK>N FOR OPERABl..f UNIT 13 0 227 0 1,479 0 1,500 ---1!!!!!!11 11B --1111111 liiiiil liill ---------NATIONAL STARCH & Ct£MJCAl COMPANY SUPERAMO SITE RECORD OF DECISION FOR OPERABLE UNIT 13 -77- TABLE 18 SUMMARY OF PRIMARY BALANCING CRITERIA EVALUATION OF THE ALTERNATIVES •111111~ GWP4A/GWL4A:· Groundwater Extraction; Treabnent Via Air Stripping and Vapor-Phase Adsorption; Discharge to POTW GWP4B/GWL4B: Groundwater Extraction; Treabnent Via Air Stripping and Fume Incineration; Discharge to POTW SW/SE-1: No Action SW/SE-2: Long-Tenn Monitoring Pennanent remedy. ARARs are met. Pennanent remedy. ARARs are met. Under current conditions human health may be protected but possibly not the environment. Under current conditions human health may be protected but possibly not the environment. Eliminates TMV of contaminants and potential for off-site migration. Greatest degree of risk reduction for ingestion, inhalation, and dennal absorption. Eliminates TMV of contaminants and potential for off-site migration. Greatest degree of risk reduction for ingestion, inhalation, and dennal absorption. Would increase mobility of contaminants, however, through volatilization toxicity and volume of contaminants in the waler column would be reduced. Would increase mobility of contaminants, however, through volatilization toxicity and volume of contaminants in the water column would be reduced. Potential release of voes during extraction well installation and treabnent system operation. Noise nuisance due to operation of drilling equipment. d Potential release of voes during extraction well installation and treabnent system operation. Noise nuisance due to operation of drilling equipment. None. None. Design of extraction, 12 months to design 5,792 treabnent, discharge, and 6 months to oonstruct monitoring systems. Air stripping of voes to meet POTW pretreabnent requirements. Treatment of air stripping off-gases will be required during start-up. Design of extraction, 12 months to design 5,270 treabnent discharge, and 6 months to construct monitoring systems. Air stripping of voes to meet POTW pretreabnenl requirements. Treatment of air stripping off-gases will be required during start-up. None. None. 151 None. None. 867 I I I I I I I I I I D I I I I I I I NATlOHM. STAAO< l CHBI""-Cols>>Kr SU>ERRHJ 5m AE<nm c, ilEaso< Ria ClP6WU Ulfl '3 -78- required to be deposited at the present time at a given interest rate to yield the total amount necessary to pay for Initial construction costs 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 8. Alternative GWP1/GWL1 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 Adsorption/POTW Discharge: $5,792,000 Alternative GWP48/GWL4B Groundwater Extraction/Air Stripping/ Fume lncineration/POTW Discharge : Alternative SW/SE-1 Alternative SW/SE-2 9.3 MODIFYING CRITERIA No i;..:tion Long-Term Monitoring $5,270,000 $ 151,000 $ 867,000 State and community acceptance are modifying criteria that shall be considered in selecting the remedial action. 9.3.1 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 conditionally concurs with the selected remedy as described in Section 10. The State's correspondence providing conditional concurrence, along with the specific. conditions, and the Agency's response to the stipulated conditions can be found in Appendix A. 9.3.2 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, 1993. The public comment period on the Proposed Plan began July 19, 1993 and closed on September 16, 1993. Written comments were received from the City of Salisbury and NSCC during the public comment period. The questions asked during the August 3, 1993 public meeting and the Agency's I I I I I I I I I I I I I ·1 I I I I I -79- NAIIOHN. STARD< l CHEMICM. COWl>AHY SU'EAAHJ SITE REcau) OF ilroSIOH """ Cll>E!WII.E U ..-r '3 response to the written comments are summarized in the Responsiveness Summary, Appendix A. Since no input was received from the community at large, it is infeasible to assess the community's acceptance of the proposed remedy. 10.0 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 a deed restriction as the institutional control. Long-term monitoring of the groundwater and the surface water/sediment in the Northeast Tributary. • Design and implementation of a groundwater remediation system. The selected groundwater remediation alternative consists of a groundwater extraction system consisting of 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 Ire~ 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 alsoJncludes fencing a portion of the Northeast Tributary. However, since the groundwater extraction system will reduce and then eliminate contamination migrating into the Northeast Tributary, ~ will not be necessary to install this fence. This condition will be evaluated 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. 10.1 PERFORMANCE STANDARDS TO BE ATTAINED Table 17 lists the action-specific, chemical-specific, and location-specific Site specific ARARs. Performance standards include any applicable or relevant and appropriate standards/ requirements, cleanup levels, or remediation levels to be achieved by the remedial action. The surface water and groundwater performance standards to be met/attained by the NSCC OU #3 RA are listed in Table 19. I I I I I I I I I I n D I I I I I I I -80- NA OONAL SrAROi & C>EWCJl ca.,"" 5LmRo«J SrrE AEalRo ~ llEoSIOII FOO ClPawLE UIIT '3 Table 19 provides the remediation goals to be achieved at this Site along with the range and frequency of detection for the listed contaminants. 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 8, 9, 10, 11, 12, and 13. 10.2 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 by removal of contaminated groundwater through extraction wells until the performance standards specified in Table 19 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) extr&cting 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 will 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 contamina!ion. 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 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 estimated volume of groundwater adversely impacted by past Site activities is 131 million gallons. 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 any or all of the monitoring points duiiiig.irnplementation, the contingency measures and goals described in this section may replace the selected remedy and goals for these portions of the plume. ------------------- -81- TABLE 19 PERFORMANCE STANDARDS AND CORRESPONDING RISKS FOR OU #3 CHEMICAL OF CONCERN GROUNDWATER Bis( 2-Chloroelhyt)ether Chlorofonn 1,2-0i~thane 1, 1-llichloroelhene 1.2-Dichloroelhene (ciSMUlS) 1.2-Dichloropropane Methylene Chloride Tetrachloroelhene 1, 1,2-T richloroethane Trichloroethane V11yt Chloride RANGE AND FREQUENCY ( ) OF. DETECTION ,, (µg/1) · 13-32 (2) Hl,900 (2) t~.000 (30) 1-t ◄ (3) 1-200 (4) 5 (1) 1-160 (5) 1-7 (4) 1-5 (10) 1-5 (4) 1-120 (8) PERFORMANCE STANDARDS (CLEANUP GOALS) PERFORMANCE STANDARD (µg/1) 5 7 70 5 5 2.8 POINT OF COMPLIANCE The Entire Plume of Contaminated Groundwater BASIS OF STANDARD State CRQUState (b) CROUState (b) CROUState(b) MCUState MCUState CROUState(b) MCUState CROUState(b) CROUState(b) State CROUState(b) NATIOKAL STARCH & CHEWICAL COMPANY SUPERFLWD SITE RECORD OF DECISION FOR 0PERABI.E UNIT 13 CORRESPONDING RISK LEVELS CHEMICAL-SPECIFIC AME RISK CANCER(a) NON-CANCER(a) 1E-4 NA 2E-7 NA 2E-6 NA 1E-4 NA NA 0.2 2E-6 NA 1E-6 NA 1E-6 0.003 2E-6 0.006 9E-7 0.01 SE-5 NA ------------------- -82- TABLE 19 PERFORMANCE STANDARDS AND CORRESPONDING RISKS FOR OU #3 CHEMICAL OF CONCERN Antimony Chromium Manganese Thallium Zinc SURFACE WATER 1,2-Dichloroethane RANGE AND FREQUENCY ( ) OF DETECTION (µg/1) 2-30 (3) 12.9-59.6 (6) 28-12,000 (14) 1-3 (2) 22~.410,000 (4) 2-4,400 (19) µg/1 --micrograms per liter PERFORMANCE STANDARDS (CLEANUP GOALS) PERFORMANCE STANDARD (µg/1) 6 50 50 2 2,100 2,000 POINT OF COMPLIANCE BASIS OF STANDARD MCL State State MCL State Northeast Tri>u1a,y EPA, Region IV Chronic on NSCC Property Screening Value MCL --Maximum Concentration Limit as Specified in the Safe Drinking Water Act NATIONAL STARCH & CHEWICAL COMPANY SUPERFLNO SITE RECORD OF DECISION FOR OPERABLE UNIT '3 CORRESPONDING RISK LEVELS CHEMICAL-SPECIFIC AME RISK NA 0.4 NA 0.3 NA 0.3 NA 0.9 NA 0.2 NA NA (al --The risk levels are based on a 2 liter daily consumption rate by a 70 kilogram individual. CRQUState!b) --Where the Maximum Allowable Concentration Of A Substance Is Less Than The Limit Of Detectability (NCAC 15-2L.0202(b)(1)) and where CRQL is the Contract Required Quantitalion Limit State --State Groundwater Quality Standards (NCAC 15-2L.0202) I I I I I I I I I D I I I I I I I I I -83- NATONM. STAAO< & CHBIICll COMl>AHY SU>ERAJNl SITT AR:oon Cf Oeasa, FOR CIPEIW!LE UlfT '3 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. 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 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 gradient 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 remedial technologies for groundwater restoration. I I I I I I I I I I I I I I I I I I I -84- NATlONAL STAR<:>< l C>eolCM. CcM!,Ntt SlJ>EHruc) 5rrE AEalAo a DEOSIOH FUR Clolc-. UNIT 13 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 listed in Table 17. 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. 10.3 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 paired surface water and sediment samples at a minimum of four (4) sampling locations. These samples shall be analyzed for TCL voes. After the groundwater extraction system becomes operational and the levels of contamination in the Northeast Tributary obtain the performance standards specified in Table 19 for two consecutive sampling events, the number of sa~,1pling points and the sampling frequency may be reduced. 10.4 MONITOR EXISTING CONDmONS/ADDmONAL 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 collected. 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 19 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 10.0, 10.1 and 10.2 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 groundwater sample collected. This sampling effort will continue until the groundwater remediation system is I I I I I I I • • I I I I I I I I I I -85- NATIClNo'< STAAC!< l C1£11""'-CoiPIHr SU'ERAH> SIT'e RE0JR0 ~ OEOsa, F<>l 0Pawu UIIT 13 functional and the monitoring procedures specified in the Operation and Maintenance Manual are implemented. Analytical Monitoring Well Sampling Samples Are To To Be Sampled Frequency Be Analyzed For Simroli!e Wells NS-13 Annually voes, T AL metals NS-14 Annually voes NS-33 Annually voes NS-35 Biannually voes, T AL 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, T AL metals NS-41 Annually .. voes NS-44 Annually voes 10.5 COST The total present worth costs for the selected alternatives is Alternative GWP3/GWL3: Alternative GWP4A/GWL4A: Alternative SW/SE-2: TOTAL PRESENT WORTH COST The break down of this cost is specified below. $1,500,000 $5,792,000 $ 867,000 $8,159,000 Procedure To Be Used 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 Methods 8240 + 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 11.0 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 I I I I I I I I I I I I ·t I I I I -86- NAOOHM. STARCH & CHBIIC.II. Ccu>NN SCoERRHl SITE REcooo Of ilEoSION RJa OPawl.E UIIT 13 health and the environment, is cost-effective, utilizes permanent solutions to the maximum extent practicable, and satisfies the statutory preference for remedies involving treabnent technologies. 11.1 PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT 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. 11.2 COMPLIANCE WITH ARARS The selected remedy will be designed to meet all Federal or more stringent State environmental laws. A complete list of the ARARs which are to be attained is included in Table 17. No waivers of Federal or State requirements are anticipated for OU #3. 11.3 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. 11.4 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 treabnent can be practicably utilized for this action. Of the alternatives that are protective of human 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 treabnent; short-term effectiveness, implementability, and cost; State and community acceptance; and the statutory preference for treatment as a principal element. 11.5 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-9as 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. I I I I I I I I I I I I I II I I I I -87- 12.0 SIGNIFICANT CHANGES NAllOIW. ST-'""'< & CIEIIIC.M. r:a,,,,,, SU'lcRRJII) Srre REcoRo CX' ilEOSO< F<>< ClP<IWU U..-r '3 CERCLA Section 11 ?(b) requires an explanation of any significant changes from the preferred alternative originally presented in the Proposed Plan (Appendix 8). 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 July 15, 1993. 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 tor the implementation of an active groundwater ex1raction system. The groundwater extraction system will reduce and then eliminate the contaminants entering into the surface water and sediment of the Northeast Tributary, thereby eliminating the need tor 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 10. The Proposed Plan reported the total present worth costs tor Alternatives GWP4A, GWL4A, GWP4B, and GWL4B to be $2,222,000, $3,570,000, $2,274,000, and $2,996,000, respectively. These costs, obtained from the June 21, 1993 OU #3 FS report, were based on obtaining the cleanup goals at the point of compliance specified in said document. The FS proposed obtaining a groundwater cleanup goal of 5.0 µg/1 tor 1,2-DCA at the periphery of the plume. However, the use of 5.0 µg/1 as a cleanup goal tor 1,2-DCA and the selection of the periphery of the plume at point of compliance are in error. Tne most stringent promulgated cleanup level for 1,2-DCA can be found in the State's groundwater quality standards and is described in Section 10.1 as 1.0 µg/1. The point of compliance, as described in Section 8.1, is throughout the entire plume. By changing these two conditions, the estimated remediation timeframe is lengthened which results in a different O&M cost for Alternatives GWP4A, GWL4A, GWP48, and GWL48. The total present worth costs for Alternative GWP4A/GWL4A becomes approximately $107,000 less than the total present worth costs tor Alternative GWP4B/GWL4B. Since both alternatives achieve the same degree of protection and treatment, Alternative GWP4A/GWL4A is selected because it is more cost effective. Also, refer to Comment #9 in the Responsiveness Summary (Appendix C). I I I I I I I I I I n I I I ·1 I I I I APPENDIX A 'CONCURRENCE LETTER FROM THE STATE OF NORTH CAROLINA AND RESPONSE FROM THE AGENCY - I I I I ····• .. ; ; ~: l :. ,:~ .. ;..;..,;.-, ·.: I I D I I I I I I I I I I I State of North Carolina Department of Environment, Health, and Natural Resources 512 North Salisbury Street • Raleigh, North Carolina 27604 James B. Hunt, Jr., Governor Jonathan B. Hawes, Secretary r 23, 1993 ·Mr.Curt Fehn, Chief-·· NC Remedial Section U.S. EPA Region IV 345 Courtland Street, N.E. Atlanta, GA 30365 Subj: Conditional Concurrence with the Record of Decision National Starch and Chemiciil Company NPL Site Salisbury, Rowan County, NC Dear Mr. Fehn: The Division of Solid Waste Management (DSWM) has completed review of the attached Draft Record of Decision and concurs with the selected remedy subject to the following conditions. 1. 2. The NC Groundwater Standard for trans 1,2-dichloroethene is 70 ug/1 not 100 ug/1 as shown in the Draft ROD. The Performance Standard for this contaminant in Table 21 (page 109 of the Draft ROD) u well as the groundwater standard data in Table 4 (page 24 of the Draft ROD) should be corrected accordingly. New State Groundwater Standards ( 15A NCAC 2L ,0202) have been approved by the NC Environmental Management Cammi.won and the Rules Review Committee. The new standards will take effect October 1, 1993. For acetone the new standard is 700 ug/1, and for xylene the new ttaodar.t is 530 ug/L These new standards are based on the latest health information and represent the best science. Furthermore, these are the "taodartts that have bcca approved and will be In effect during the remedial efforts. Therefore, the Division of Solid Waste Management requests that the performance standards presently In the Draft ROD be modified to reflect the new NC Groundwater Standards. PO Box XT687. ~. Noni, C.mlina 27611-7687 lei,.....,. 919-n3-498<4 Fax# 919-nl-0>13 An Equal Opportunity Alftnnanw ,..,_ Em"'°""' I I I I I . _: .. I I I I I I I B Mr. Curt Fehn 22 September 1993 Page 2 3. 4 • DSWM concurrence on this Record of Decision and the selected remedy for the site is based solely on the information contained in the attached Draft Record of Decision. Should DSWM receive new or additional information which significantly affects the conclusions or remedy selection contained In the Record of Decision, it may modify or withdraw this concurrence with written notice to EPA Region IV. DSWM concurrence on this Record of Decision in no way binds the State to concur In future decisions or commits the State to participate, financially or otherwise, in the clean up of the site. The State reserves the right to review, comment. and make Independent assessments of all future work relating to this site. The DSWM appreciates the opportunity to comment on the Revised Draft Record of Decision for the subject site, and we look forward to working with EPA on the final remedy. H you have any questions concerning these comments please contact Bruce Nicholson or me at (919)733-2801. bin \let\nsou3con cc: Michael Kelly Bruce Nicholson Jon Bomholm "' Sincerely, Jack Butler, PE Environmental Engineering Supervisor Superfund Section I Attachment I I I I I I I UNITED STATES ENVIRONMENTAL PROTECTION AGENCY REGION IV 345 COURTLAND STREET. N.E. ATLANTA. GEORGIA 30365 I SEP 2 4 1993 I I I I I I I I I I I I C I I I 4WD-NCRS Mr. Jack Butler, PE Environmental Engineering Supervisor Superfund section Division of Solid Waste Management North Carolina Department of Environment, Health, and Natural Resources P.O. Box 27687 Raleigh, North Carolina 27611-7687 RE: conditional Concurrence on Operable Unit #3 Record of Decision for the National starch & Chemical company Superfund Site from North Carolina Division of Solid Waste Management Dear Mr. Butler: EPA-Region IV appreciates the Di;_;.ision of Solid Waste Management, North Carolina Department of Environment, Health, and Natural Resources's concurrence on the Record of Decision (ROD) for Operable Unit #3 at the National Starch & Chemical Company superfund Site located in Salisbury, North Carolina. For the record, EPA would like to respond to your se·ptember 23, 1993 conditional concurrence letter. Your letter, along with this response, will be included in Appendix A of the ROD. These letters should stand as official documentation that EPA-Region IV and Division of Solid Waste Management have agreed on the preferred alternatives at this point in time. For your information, the Agency has incorporated the States' s groundwater standard of 70.0 µg/1 for trans-1,2-dichloroethene in all the appropriate tables. The Agency has also incorporated 700 µg/1 as the performance standard for acetone in the ROD. Please contact me at ( 404) 3457-7791 if you have any questions or comments regarding this matter. sincerely yours, j,iz6owJ~ Jon K. Bornholm Remedial Project Manager cc: Curt Fehn, EPA Bruce Nicholson, NCDEHNR Printed on Recycled Paper I I I I I I I APPENDIX B I PROPOSED PLAN FACT SHEET ... I I n I I I I I I I I "'""'I .... " w1•w I··-·-----I .. ,...., .. I ,.......,1 -··--· ~ ~~j I Region, GROUNDWATER REMEDIATION FOR OPERABLE UNIT #3 FOR THE NATIONAL STARCH & CHEMICAL COMPANY SUPERFUND SITE. I I I I I I I I I I I I I I I I I Salisbury, Rowan County, North Carolina July 1993 INTRODUCTION This Proposed Plan identifies the preferred options for addressing the comaminated groundwater and surtace water/sediment associated with Operable Unit #3 at the National Starch & Chemical Company Superfund Sile in Salisbury, NOl1h Carolina. The tern, 'Operable Unir is used when individual actions are taken as a part of an overall site cleanup. A number of operable units can be used in the course of a site cleanup. ( Terms in bold lacs print are defined in a glossary locafBd at the end of this publication.) This document has been prepared and is being issued by lhe U.S. Environmental Protection AgeN;y (EPA), the lead Agency for !,ite activities, and the NOl1h Carolina Department of Environment. Health and Natural Resources (NCDEHNR), lhe support agency. EPA, in consultation with NCDEHNR, direcled and oversaw the Remedlal Investigation and Ftaslblllty Study, and will select a remedy for Operable Unil #3 only alter lhe public comment period has ended and all information submitted ID EPA during this time has been reviewed and consiclered. EPA is issuing this Proposed Plan as part of its public participation responsibiities in accordance with Section 117(a) of lhe Comprehensive Environmental Response, Compensadon, and Liability Act (CERCLA), also known as Superfund. This document summarizes information that is explained in greater detai in the Remedial Investigation Report. lhe Feasibiity Sb.Jdy Report, and other documents contained in the lnfonnatton Repos1t0Iy/Amnlnlstratlve Record for lhis Sile. EPA and lhe Stale encourage the public to review these document~.ID better understand lhe Site and lhe Supemm activities that have been conducted. The Administrative Record is available lor publlc review locally al lhe Rowan Public Libraly at 201 West FISher Strae1, Salisbury' North Carolina. EPA, in consultation with NCDEHNR, may modify lhe pref81Ted alternative or select anothel response action presented in this Plan and the Remedial Investigation and lhe Feasibiity Sb.Jdy Reports based on new information and/or publlc comments. Therefore, the public is encouraged to review and comment on all alternatives identified here. A fourth Operable Unit will be developed ID addnlss the contaminated soils and source of contamination at the Site in the near fub.Jre. THIS PROPOSED Pl.AN 1. Includes a brief background of the Site and the principal findings of Operable Uri! '3 Sile Remedial Investigation; 2. Presents lhe remeclal (cleaA4>) alemalives lor the Sile considered by EPA; 3. Outlines the crtlillta used by EPA to recommend a remedial altemal111 lor use at the Site; 4. Provides a SIJllfflary of the analysis of the remedial alternatives: 5. Presents EPA's rationale fol ils p,elminary selection of the prelelTed remedial altemaJNes; and 6. Explails the opporvitles lor the pubic to commenl on the remedial ahBmalives. PUBLIC MEETING: DATE: August 3, 1993 LOCATION: Agrlcuttural Extension Ctnter 27XI Old Concord Road Salisbury, North ClroBna · TIIIE: 7:00 PII • 9:00 PII PUBLIC COIIIIENT PERIOD: July 19, 1993. August 17, 1993 I I I I I I I I I In D I I I .. u. ,.,~,.,,~ °"'DC NATIONAL STARCH SITt: -~ Cl,11-.,0SON COUl(!'I' - ---c:Zi;RUSCQUl(!'I' ... 11 500 10110 250 750 GRAPHIC SCAI.E, l'•SOO' ? T N Figuce l \ ·~~---, . ?', ~, ' ~/;<:~ , .. , . , . , / _,, ,' ,,·,,:' _, I I I I I I I I I I I I I I I I I I I SITE BACKGROUND The National Starch & Chemical Company (NSCC) faciity occupies 465 acres on Cedar Springs Road on the outskirts of Salisbury, Nor1h caroina (refer to Figure 1). Presen1fy, land use immediately adjacent to the Site is a mirue of residential and nduslrial developments. East and south of the Site are industrial par1<s consisting primarily of ight industrial operations. The west and nor1h sides of the NSCC property are bordered by residential developments. Refer to the F,gure 2 for Site location. A surface stream, referred to as the Northeast Tributary, etosses the NSCC property parallel to Cedar Spring Road and passes within 50 yards of the manufae1Urilg area of the facility (refer 10 Figure 2'/. Surface water runoff from the eastern side of the faciity discharges into this ributary. The focus of the Operable Unit #3 Remedial Investigation was to determine the source, nature, and extent of · the contamination entering this stream. Primarily, NSCC manufacturas textile-finishing chemicals and custom specialty chemicals. VolaUla and seml-volaUla organic chemfcals are used in the production process along with acidic and alkaline solutions. Acidic and alkaline solutions are also used in the cleaning processes. The waste stream from the manufae1Urilg process includes wash and rinse solutions. ~ ............ , .. .. -·-··· ,, I :! Ji Ii : ,, :11 tJi~EJ Operable Unit #3 focused on the areas of the faciwty referred to as ma 2 and the waslewater treatment lagoons (refer to Figure 3). Area 2 consists of the folfowi1g operations: ma 2 Reactor Room, the Tri Room, Raw Material Bulk Storage, and the Warehouse. The 1aQ0on area n:tJdes ttvee lagoons. A lou1h laQ0on was nstaled in 1992 for pretreatment of contaminated grt>IR!water as part of lhe Operable Unit #1 Remedial Action (RA). As the result of finding ~inants in groundwater and in the surface water/sediment of the Nor1heast Tributary, the onginal scope of wol1I specified in lhe initial Remedial lnvestigatiorvFeasibiity Study WOik Plan has been expanded twice. r:-.; :irst Remedial Investigation and Feasibility Study resulted in the first Record of Decision (ROD) to be issued by the ~ on September 30, 1988 for the NSCC Superf\r,d site. The frdngs of Operable Unit #2 Remedial lnvestigatiM'Feasibility Study led to the second Record of Decision, rendered by the ~ on September 30, 1990. As in Operable Unit #1 and Operable Unit #2, lhe work performed for Operable Unit #3 is being pe!formed by National Starch & Chemical Co!poration, the Potentially Responsible Party (PRP). The engineemg contractor hired by the PRP to concu:t Operable Unit #3 wori< is fT Corporation. The NSCC site was proposed for inclusion on the NaUonal Priorities List in April 1985 and finalized on the lisl in October 1989. The Site had a Hazardous Ranking System score of 46.51. Only Sites with a Hazanlous Rankilg System score of 28.5 01' hqler are 819ble ID be placed on the National Priorities List. SCOPE AND ROLE Of OPERABLE UNIT wmtll SrTE STIIATEGY As ~lh many ~ sites, the NSCC site is complex. Consecµ!nUy, EPA dvided the work Into ttvee manageable components caDedKOperable Units (OU). These operable ll1IS are:· OU-1 • Grwidwater in western portion of the NSCC property OU-2 • Trench Area soils · and surface water/sedinents in the · Northeast Triluta/y ~--· ncaaaa · Sl'l"I .. ,oa. ......U air! tl OU-3 • Grouldwaa/wface water/sedinents in lhe a,eas of Area 2, the lagoons, and lhe Northeast Trtuta,y twaa&I: tDITf fl DfltwU. nual • caa:icu. CDDU!' IWWWWWWW IIft 3 I I I I I I I I I I I I I I I I I I RESULTS OF THE REMEDIAL INVES11GA110N FOR OU-3 TlY8e envirmnental meda {soils, grooodwater, and Sima! water/sediment) have been adversely impacted by contamination origilalrig from lhe NSCC plant and from past chemical hanling ard cisposal practia,s of lhe facility. The primary contaminar( at lhe Siil is 1,2-<llchloroetllane (1,2-DCA). This contaminanl is known as a chlorinaled organic compound !hat 'IOlatiizes readily and is classified as a probable human carcinogen. A carcinogen is any substance !hat can cause or contribute ID lhe development of cancer. Other organic chemicals W8l8 also delectad. The chemicals of concsm at lhe Sits are {ISied alphabetically): acelDne, bis (2-chloroethyl} ether, bis (2- elhythexyl) phthalalB, 2-llutanone, cadmil.111, carbon disulfide, chloroform, chloroelhane, delta-8HC, 1,2- dicNoroelhene, ci-il-butyl phthalalB, ci-n«t)i phthalale, ethyl benzene, methylene chloride, styrene, tetrachloroethene, toluene, 1, 1,2-trichloroethane, trichloroelhene, Yilyt chloride and IDtal xylene. The folowilg inotganics wen, also del8cted: alU!lirun, rimony, arsenic, bari.rn, bel)'tlun, clromun, cobaJt. copper, cyaride, lead, manganese, men:uy, nickel, selen1111, thalium, vanadium, andzilc. The OU-3 soil investigation has generaled ample information 1o characterize lhe contamination, de1e1mine lhe soura1, and defile lhe eXBll of contamination in lhe Yldose soi zone. The vadose zone is comprised of sai>uface soil !hat is not saluraled wilh waler. The inl8r1ace be'-1 lhe vadose zone and lhe sallraled zone is commony refelred ID as Ille water tallll. F01118en cifferenl YOlatie orgalic coml)Olllds, one sem~'l'Olatle orgalic compol.fld, ard one pesticide Mre delected in lhe vadose sois. The p,inary SOlml of contamination in A/88 2 Mre bwied, leaking leml-cotta pipilg used ID ranspolt wasl8 Slreams flOm lhe ~ area ID lhe treatment lagoons. The S0llt8 of lhe contaminants delectad in lhe lagoon area is lhe soi ltlder. and aroood lhe lagoons wtich -a contaminated prior ID lhe lagoons beilg lned with concrelll. OU-3 defiled lhe nalu'e of~ contamination {lhe contaminatis present and lhei' concenr.llions} but adcitional wOllc is needed ID complelBly defire lhe eX111nt of groU1dwater contamination, especialy in lhe bedrock zone of lhe aqlifw. The aiµter is SLCcivided inlD 1wo illlElrCOM9Cled zones, lhe shallow zone ard lhe bedrock zone. Bot, of lhese zones have been adYersely inpacllld by activities at lhe NSCC plant. Sixteen different YOlatile orgarjc compolllds and foll' semi-volatile organic compounds -e delected in lhe groundwater. Grot.na#atsr in lhe shaJow zone in lhe 1/icinity of lhe lagoons is flowing at an approximalB speed of 80 leet per 'f8a/. This rale slows ID approximalely 27 feet per year just east of lhe lagoon area. The hig-,est concentrations of contamination delected in lhe Northeast Trilutary were follld just east of lhe plant. The levels of lhese 'IOlatie organics decrease downstream as lhese contaminants 'IOlatiize into lhe atmo~. Two samples, one Sllface water and one seciment, wen, c;ojiecWJd from lhe Nor1heast Trtuta,y just prior ID lhe stream leavilg lhe NSCC property and flowing l.llder Airport Road. No contaminants were delBCled in lhese sample& whch indicalBs lhat lhe ikeihood of contamination leavilg lhe Sile via Sllface water/sediment is mirimal. n. apparen1 S0lJ'C8 of lhe organics in tns stream is lhe discharge of contaminaled l1'0lJ'l(lwalll inl0 lhe Slream. lnotganics W8l8 delllcted in al llwee of lhe enwonmental mecia sampled {sois, i,0111dwa18r, and Sllface wa18r and seciment). All of lhe metals delllcted are natua11y OCCUTi1g and lhe variation in concenlralions delected does not indicate lhe Sits is releasing inorganic contaminants int> lhe enworvnent. L.enoi:t ■..,.l"•a• ==-( (r==-·-=-·-·· ---1-'" ~_-, ..::.L.___----Se.pr-o I I 't. CC I ay) n . .,._, ,I Fr-e.ctured waet.her-ed Bedr"oclc S-dr-'OClc 4 I I I I I I I I I I I I • I I I I I I SUIIIIARY OF SITE RISKS A task of !he Remedial investigatio~easibilily Study is ID analyze and estimate !he tunan health and enworvnental p,-oblems that C0lid resut W !he soil, groundwater, and surface water/sediment contamination is not cleaned up. This analysis is call a Baseline Risk Assessment. in calculating risks ID a pol)!Aation W no remedial action is ta.ken, EPA evaluates !he reasonable maximum exposure levels for current and lutul8 exposure scenarios 10 Site contaminants. Scenarios were developed for residents living on or near to the Site as weU as lot" employees working on the Sile. in conducting this assessment. EPA focuses on the adverse human heallh effects that could result from long-tenn daily, dilect exposure as a result of ingestion, inhalation, or dennal contact ID carcinogenic chemicals (cancer causing) as wea as the adverse heallh effects that could result from long-term exposure 10 raH:arcinogenic chemicals insent at the Sits. EPA considers a long-term resident beginning as a young child being exposed daily tor 30 years 10 be a reasonable maximum exposure scenario for future exposure 10 the NSCC sits. A goal of the ftqerq is 10 reduce the risk posed by a Superfund Site 10 lewer lhan one person out ol 10,000 being at risk of developing cancer. This is the minimum risk !he Aoeocy will allow, typically the Pqaocy aspires tt,•;;e even more p,-olective and strives ID lower the risk so that at a minimum, only one person out of one milion may be adversely impacted by the contamination lollld at a Superfund Site. EPA has concluded that !here are no major current risks ID human heallh at the Site. Exposure pathways evaluated i1 the Risk Assessment were ingestion, irtlalation, and dilect contact to contaminants i1 the soil, grcxlldwater, and surface water/sediment The only reason grOllldwater does not pose a current risk is because the contamination in !he groundwater has not migrated beyond the property boundary and consequen11y, has not impact any private, potable wel. There are no potable wels located on Sits .. However, there are tlv8e unacceptable futur9 carcinogenic risks associated wilh the contamination at the Sits. The first scenario resulting in an IIIICCeptable future risk is having residents iving i1 homes bl.ti on or near the Sits and using the groundwater as potable waler. Another unacceptable future risk is the expoSln of a ctild ID SI.Vface water, sediment. and spring water. The third INCCl!ptable future risk involves exposing ildividuals 10 contaminated subsurface soil. . The future residential use ol the grollldwater would also result in an unacceptable future risk due ID the p,'&sence of noncarcinogeric ctiemicals in the grollldwater. A semi-quantitative assessment of the Northeast Trilutary was also conducted as part of the RiskMsessment. Tl1s envirorvnental assessment included chemical, ecological, and toxicological in'l8stigations of the su1ace waler and sediment colec1ed from !he Nol1lleast Tributary. The data oenerated by !he envil'OIYT18ntal assessment lollld adverse ecological inlpacts in areas of the stream where elevated levels ol 1,2-0CA were detsded. However, the assessment could not conclude that the contaminants originating from the Site, primarily 1.2-DCA. are the sole cause of !tis impact. There is a strong indication that !he nallrally~imiting factors of the stream itself results in !he dininished runbers of benthic (bottom-dNeling) organisms in this section of !he Northeast Tributary. REIIEDIAL ACTION OBJECTIVES Remedial action objectives (RAOs) were developed based on !he results of the Risk Assessment. an examinabon of potential Applicable Ol Relevant and Appropriate Requirements (ARARs), and ltlreats to groundwater and the Northeast Tribulary. Adioo-, location-, and chemicaJ-specific ARARs were examined. Chemical-specific ARARs tor groundwater include maxlroom concentraUon levels (MCLs) as specified in !he Safe Drinking Water Act and North Caroina Grwidwater Standards. in summary, the Remedial Action Objectives are: FOR GROUNDWATER For Human Heallh: Prevent ingestion of water having concentrations of 1,2-DCA resulting in cancer risks above acceptable limits. For Envirorvnental Protection: None, groundwater concentrations have not been found to rep,-esent an e11YV01V118ntal hazard. FOR SURFACE WATER For Human Heallh: None, surface water is not a drinking water SOIIC8. For Environmental Protection: No,.,, surface water concentrations have not been identified as the sole cause tor the imited benthic populations. FOR SEDIMENT For Human Heallh: Prevent direct contact wilh sediments having levels of 1,2-0CA resulting in cancer risks above acceptable .limits. For Enwonmental Protection: None. The objective of a rerneciation is m obtain smgent heallh risk levels. For grOllldwater, al chemical-specific ARAAs, which include MCl.s and Iha Nortl Clrolila Grol.ndwater Standards, wil be achieved where Iha specified concentration is leclncaly detectable. The estinated volume of contami1atsd i,ollldwater recµring remediation is 131 milion gallons. I I I I I I D I I I I I I I I I I I I F0< l110le rnonnalion about the P.emedial Action Ctijec1r,vs and altemati'l8s fer Iha NSCC OU-3 site, please refer ID Iha June 21, 1993, Feasoity Study docunent and other docunents available for review at the Aanirisrati'l8 Record localed at the Rowan N:lic Library. SUDIIIARY Of REIIEDIAL Al.lcRNATIYES The following section provides a summary of the altamatives developed n the Feasibility Study (FS) Report. The prinary objective of the Feasibility Study was m detennne and evaluate alternatives for cleaning up Iha Si1B. Descriptions of the clean-up alternatives are summarized below. The Report contains a more detailed evalualiolvdescriplion of each altamative. The cost information provided below for each altamative represents estimated IDtal present worth (PW) of each altemati'/8. Total present worth was calcuallld by combining the capital cost plus the present worth of the annual operating and maintenance (O&M) costs. Capital cost includes COllSlrucllon, engineeri1g and desi~. equipment, and site development. Operating costs were calculated for activities that continue after completiam of construction, such as routine operation and mailtenance of trealment equipment, and IJ1)Uldwater momoring. The present worth of an altemali'/8 is the amount of capital required ID be deposited at the present time at';. given interest rate ID yield the IDtal am01111 necessary m pay for initial canstruction costs and we expenditures, includilg operation and maintenance and~ AUre replacement of capital equipment. REMEDIAL ALTERNATIVES TO ADDRESS GROUNDWATER CONTAMINATION The groundwater remedial al1Bma1M!s for adltessilg contaminated QIWldwater were COl'QClered separately for Area 2 and Iha lagoon area. Area 2 alternatiws are identified by 'P" for the Plant and Ille aJtemalM!s deaJilg with Ille contaminated IJ1)ll1dwater associated with the lagoon area are identified by 'l'. ALTERNATIVESGWP1 ANDGWL1: NoAcno# Capital Costs: AmuaJ O&M Costa: Total PW Costs for 30 Years: Tlll18 ID Design: Consiuctian Tlll18: Duation m Adiew Clean-l.p: S 0 S 22,000 S 227,000 None None <Mr-30years CERCLA r8Cµl8S Iha! the 'Na Action' a118ma1ive be evaluated at 8V8IY ~ Site ID eslalilsh a baselile for compartsan. Na h.ftlllW acti'lities WOlid be C0l1CM:l8d wlf1 regard m the IJ1)ll1dwater beneath the Sita llldar this alternalM! Q.e., the Site ii left 'as 151 Because these altemalives do not entail contamilari removal or destrudlan, a rea o1 the ramedy WOlid be C0l1CM:l8d mry 1\18 years 6 in accordance with CERCLA Section 121(c). Operatw,g costs are based on concu::tilg tis review every fi'l8 years which includes momoring Iha IJ1)Uldwater lllder the Site once 8V8fY five years for a period of 30 years. ALTERNATIVES GWP2 AND GWl.2: LONG TERII lloNITOIIIHG, FEIICMl A Pollno# OF NoR7HEAsr TIUIIITARY Capital Costs: AmuaJ O&M Casts: Total PW Casts for 30 Years: Time ID Design: Constuction Time: Dir.Ilion m Adwi'/8 Clean-up: S 178,000 S 138,000 $1,479,000 None None Over 30 years These alanatives are siniar ID Altemati'18s GWP1 and GWL 1, except llldar Altamatives GWP2/GWl.2 additional momoring wells woud be instaled, IJ1)Uldwater morilDmg data WOlid t:,e colecled arn.aly instBad of once e-.ery fi'l8 years, and a portion of the Northeast Tributary would be fenced. ALTERNATIVES GWP3 AND GWL3: IIISmvnoNAL CONT1IOI.S, FEJalG A Polrrloll OF NoimEAsT TlliBuTARr Capital Casts: AmuaJ O&M Casts: Total PW Costs lor 30 Years: Tlll18 ID Design: Consiuctian Tlll18: Dlr.llion m Actwi'/8 Clean-up: $ 198,000 S 138,000 $1,500,000 Nore None Over 30 years These altemalives tor IJ1)Uldwater conlamination n Area 2 and the lagoon area are identical ID Alilmalives GWP2 and GWl.2, except AfaalM! GWP31GWl.3 i'ldudes institutional contlOls. Na ramedalion activtties WOlid be corWCl8d for i,Ollldwater. The additional costs are associated with preparing and ling deed resvicUon(s) and inplementing the other institutional coni'Ols. The specific institutional C0IWOls ID be implemented include: USllll deed resrlctians m cont101 Ille inslallatlon of new wells on both the plant prope,ty and ~ property; !rack pune mi!,ation; and nstall fencilg ar0l.lld the Nor1heasl Tributary ID limit access m cantaminUld sufaca water and secimn. A 'pune· is the dischalge of a conlamilari from a i;ven point of OfV/1 n water or ai. lor examl)le, smoke from a smokestack. These al1Bmalives provide no reduction in voune, mobility or IDxicily of the contaminants, howe'l8r, they can recb:e 0< elinilata clrecl expaue pathways and Ille resutant risk m Ille pii)llc. As pwt of these all8matlvea, the i,ollldwater WOlid be manilDrad an a yuty basil. As EPA may not ha'/8 Ille IUh0rity ID inplemn these ins1Uiona1 controls, · Ille responsibilty rests wilh the Slata of N011h Carolna ID 81151n the ilSlltutianal conrois n in place, 818 rellallle, and will ramail n place ala n1iatian of O&M. llwefole, the responsolty for inplementlng and enloldng inshJlional C0lll10ls falls on the Stale of Norll C8roli1a. Grolnlwal8r moriloltng and 1\18 ya CERCLA 11views WOlid be I I I I R I I I I I I I I I I I I I conducted fOf 30 years. The O&M cost is fOf bolh Area 2 and the lagoon area. ALTERNATIVE GWP4A: GROUMJWATER Em1Acno11 THROUGH WEllS NID TIIEATIENT BY AIR SrlllPPflG W1T1I VAPOII-PHAsE CARIOII ADsoRPnoll Capital Costs: Annual O&M Costs: Total PW Costs to< 30 Years: Time to Design: Consb'uction Time: Duration ID Achieve Clean-up: $ 648,000 S 306,000 $2,222,000 t year 6 monlhs 15 to 30 years This alternative includes extacting gro\lldwater by means of extraction wells downgradient of Area 2; volatile 0lgallics removal through ai' stripping; control of emissions ID the abnosphere from lhe ai' SUq)8r lll'ough Yapor1)hase carbon adsorption; and comtined discharge v,;111 treated grounct.Yater from OU-1 ID the Salisluy publicly owned treabllent works (POTW). The treated effluent must meet permit limits set by Iha Salisluy POTW. Spent activated carbon would be changed out and sent ID a commercial regeneration/recycling laciUty. The five year review CERCL.A requirement would apply ID lhis alternative. ALTERNATIVE GWLAA: GIIOIMDWATER E1:,7IN:TIOII WEI.LS, TIIEATIENT BY AIR ST-,a W1T1I VAPOfl.l'HASE CARBOII AosQRPTIOI/ Capital Costs: AnnuaJ O&M Costs: Total PW Costs to< 30 Years: Time ID De591: Conslruction Tlll18: Duration ID Actieve Clean-up: $ 789,000 . S 434,000 $3,570,000 1 year 6 months 20 years This alternative is identical ID Alternative GWP4A except this alternative addresses contaminated !1l)ll'dwater associated wilh the lagoon ania. ALTERNATIVE GWP4B: GIIOIM1WATER EmlAcnoll WElLS, TIIEATIENT BY AIR STRa : fCl wrTH FLltE IIICINERATIO#. Capital Costs: AnnuaJ O&M Costs: Total PW Costs for 30 Years: Time ID De591: ConslructionTlll18: Dir.Ilion ID Achieve Clea/H4>: S 766,000 S 299,000 $2,274,000 1 year 6 months 15 ID 30 years This altemative is identical ID Alternative GWP4A. except that the control of emissions i) lhe atrnosphele from lhe air stripper WOlid be accompished llrough fllne ncineration. ALTERNATIVE GWLAB: GIIOIIIDlrATER Em!Acno11 WEUs, TIIEATIENT BY AIR Snu I U.G WITH Fla II/ClltEIIATIO# 7 Capital Costs: Amua1 O&M Costs: Total PW Costs to< 30 Years: Time ID 08591: Conslruction Time: D\l'alion ID Actieve Clean-up: $ 913,000 $ 360.000 $2,996,000 1 year 6 months 20 years This alternative is identical ID Alilma1iYe GWP4B except to< this alternative adci'esses contaminated grollldwater associated "Mth Iha lagoon area. ALTERNATIVE GWP4C: GROUl«!WATER EmlACnOII WEI.LS, TREATIENT BY I.JOUD-l'HAsE CAIIBOII ADsollPTIOII Capital Costs: AnnuaJ O&M Costs: Total PW Costs fO( 30 Years: Tlll18 ID Oesq1: Conslruction Time: Duration ID Actieve Clean-up: $ 788,000 $ 432.000 $4,305,000 1 year 6 months 15 ID 30 years This alternative includes extacting i,il\lldwater by means of extraction wells downgradient of Area 2; volatile organics removal through liquid-phase carbon adsorption and combined cischarge 'Mlh treated glOllldwater from OU-1 cischarge ID Iha Salisluy POTW. The treated effluent must meet permit limits set by Ille Salisluy POTW. Spent activated carton woud be regenerated. The five year review CERCL.A raqurement would apply ID ll'is altemative. ALTERNATIVE GWLAC: GIIOIMDWATER Em1Acno11 WEI.LS, TIIEATIENT BY~ CAIIBOII ADsoRPTIOII Capital Costs: AmJal O&M Costs: Total PW Costs to< 30 Years: Time ID 08591: Consruclion T11118: DIiation ID Actieve Clean-up: S 987,000 S 941,000 $8,375,000 1 year 6 monlhs 20 years nu alanative is idenllcal Ill Allamahl GWP4C except lhis .,.,itdve adliasses ~ter associated Mtl 1111 lagoon ania. ALTERNATIVE GWL5A: GIIOIIIDWATER EmlACTIOII lrEUI, TIIEATIE.NT IY AIR Snw, .... ..m, VAPOfl.l'HASE c-AasolFTl0II, /#SIii• BmlFHFDl•'ICW REoulRIIG GIIOIM1WATER II/JECTIOI/ OF MmltENTS capital Coats: Arnl3I O&M Costs: Totll PW Costs a 30 Years: Tlll18 ID Oesq1: Consl:uctlon Time: Dlntion ID Achieve Clea/H4>: $1,093,000 S 798,000 S7,4n.OOO 1 year 6monlla 15 ID 30 years This all8rmtive includes exnctlng gl1U1dwalar by means of eXlrac:llclr wels locaJad ~ ol the lagoons; YOlalile orgarics removal llrough air mtpping; control of I I I I I I B I I I I I I I I I I I I emissions to lhe aunosphele from lhe at stripper ttrougt, vapor-j)hase C3lbon adsorption: combinng a por1ion of Ille dischargedgrOllldwalerwilhtrealedgroundwatsrlrom OU-1 for cischarging to lhe Salsbury POTW, polishing Ille remaining portion of 118 gr011ldwa1Br by ar stripping to clearup goals before rjedlllg lhe trea18d grw-,dwa1Br along wilh nutrients in1D Ille contaminated a18a to promo1B In-situ biodegrada1ion of lhe contlminants. 'n-situ' means to keep in place ~.e., lhe traatment is c:onduClad in its original place). The treated effluent being cischarged to lhe Salsbury POTW mus1 meet permn imits set by lhe Salisluy POTW. Spent activated cartion would be regenerated. The five year review CERCLA requirement would apply to Iris alternative. ALTERNATIVE GWLSB: GIIOIMDWATER EXTRACTION Wru.s, TREA TIIENT BY All STAll'PIHG wm, FIJIIE INCINERA noN, IN-SrTU BIOREIIEDIA TION REOVIRING GROU/ONATER INJECTIOII OF MmilENTII Capital Costs: Annual O&M Costs: Total PW Costs for 30 Years: Time to Design: Conslruclion Time: Dura1ion to Acnew Clean-up: $1,365,000 S 733,000 $7,000,000 1 year 6 monlhs 15 to 30 years This altematiw is sinilar to Altemati\18 GWI.SA except control of emissions of lhe vapor coming from !he first air stripper would be accomplished ~ lhe use of a lune incineration. ALTERNATIVE GWL5C: G,.,_ATER EmlACTJON TliROUGH WEI.LS, TREATIIENT BY LloUr>PHAsE CARBO# ADSORPTION, IN-51TU 8/0REIIEDIATION REQUIRING GROUIONATER IHJEcTIOII OF MmllENT8 Capital Costs: Annual O&M CoSls: Total PW Costs for 30 Years: Time 1D Design: Conslruction rme: Dlla1ion to Acne\18 Clean-up: $1,216,000 $ 1,631.000 $13,853,000 1 year 6 months 15 to 30 years This altematiw ilcludas exncung gr0llldwa1Br by means of extraction web IDcad downgladleri of Ille lagoons; volatile orgarics rllllOV8I lmilql lcµd-phase C3lbon adsorption; combini1g a portion ol 118 discharge wllh trealBd groundwater from OU-1 far clschargi1g to Ille Salisbury POTW; lhe remaimg portion of 118 natlld gr011ldwatsr would be ~ a1ong will rurients, back no 118 COn1aminaEd a/8a ID promote in-WI blocle!,adalion of 118 contaminanls. The treated ellk81I being lischarged to 118 Salisluy POTW will meet perml limits set by lhe POTW. Spent actiYalBd carbon would be changad cM.C and 18111 to a commen:ial rege11era1ion laciily. The li¥e year mtew CERCLA ~ would apply. The naiad effluent must meet permi limb set by 118 POIW. The 11Ya year review CERCI.A recp8ll18l1t woud apply to tis allelnatiw. 8 REIIEDW. ALTERNATIVES TO ADDAESS SURFACE WATER AND SEDIIIENT CONTAIIINATlON ALTERNATIVE SW1iSD1: No AcnO# Capital Costs: Annual O&M CoSls: Total PW Costs for 30 Years: Time ID Design: Cons1r1Jction Time: Duration to Achieve Clean-up: $ 0 S 16,000 $151,000 None None Over 30 years No flrtlBI' activities woud be c:onduClad on su1ace watsr or lhe sediment in lhe Nc~~:351 Tributary. As wllh Alternative GWPI/GW1.1, lhis S1ream woud be left ·as is'. Samples would be colect8d and analyzed e\/8f'f live years as part of lhe live year review CERCLA ~ent which aw!Y to this altemalMt. ALTERNATIVE SW2r.:l02: I.DNG-TERll lloWTORMG Capital Costs: Annual O&M Costs: Toti! PW Costs for 30 Years: Time to Design: Conslruction Time: Dl.fa1ion to Acne\18 Clean-up: $ 0 S 92,000 $867,000 None None Over 30 years This altematiw is sinilar ID Altemati\18 SW1/SD1, except l6lder Allemali\18 SW2/S02, Sllface water and sediment samples woud be coled8d from Ille Nor1heasl Trb.rtary arroally insl8ad of once e\/8f'f lw years. CHI I EHIA FOR EV ALUATlfG REIIEDW. ALTERNATIVES EPA's selection ol lhe preferl8d ~ altemall\18 for lhe NSCC OU-3 sita, as described in this Proposed Plan, is Ille resut of a comprehensive evaluation and screening process. The Feasibility Study far 118 Siil was concilc1Bd to identily and analyze 118 allemali,ea considenld for .,adlnssing contamination at Ille Site. The Feasibilty Study and other docunents for lhe NSCC OU-3 site desaibe, in detal, lhe allemali\181 considerad, as wel as Ille process and ailBlia EPA used to narrow Ille lisl to potllnaal remeclal al1ematill8s to address Ille Sits contaminalion. As slated previously, all of lhese docunents are avaiable for pullic mtew in Ille inlorma1ion repository/uniristrati\18 record. Allelnali'l8S GWNC, GWl.4C, GWl5A. GWL5B, and GWLSC were not retailed far 118 detailed analysis because the om alanahel,woud ac1iM 118 same de!Pee of prollletion tor tunan healtl and lle:81M1a111118111 blaal a SlilstantiaJtf k1wer cost •· Tf2 · l;:-ij_: .~_.t. EPA always 1W lhe lol1owi1g mi crllarta.,10 evalualll allamalwes identified in 118 Feasllllly 8'idy. TIie remecial allamd'l8 l8lectad far a ~ site must aclie\/8 Ille I I I I I I I I I I D I I I R I I I two threshold crilelia as well as attain Iha best balance among Iha live evaluation criteria. The rine criteria are as follows: THRESHOLD CRITERIA 1. Overall protec11on of hlll18n health and tile environment The degree to which each alternative eliminates, reduces, or controls tlv'eats to public health and Iha envi1'01VT1ent through treatment, engineering melhods or institutional controls. 2. Compliance With Applicable Of Relevant and Appropriate Requirements {ARARs): The alternatives are evaluated for compliance with all state and federal enviroMlertal and public heallh laws and requirements lhat apply or are relevant and appropriate t> Iha &ii& conditions. EVALUATING CRITERIA 3. Cost: The benefits of inplemenling a particular remedial alternative are weighed against Iha cost of implementation. <Asts include Iha capital (up-front) cost of implementing an alternative over Iha long term, and Iha net p,asent _., of bolh capital and operation and maillenance costs. '! .... 4. lmplementablllty: EPA considers lhe teclvlical feasibility (e.g., how difficuh lhe alternative is ti construct and operate) and adminiSlrative ease (e.g., lhe amcx111 of coordination with other goverrvnent agencies lhal is needed) of a remedy, including Iha availabiMty of necessary materials and 58!Vices. 5. Short-term effectiveness: The length of time needed ti implement each all&mative is considered, and EPA assesses lhe risks Iha! may· . be posed ti wor1<ers and nearby residents dumg construction and implementalicin: 6. Long-term effectiveness: rte altematives are evaluated based on !heir abiity to maintain reliable prolection of pidc health and lhe envi1'01VT1ent over time once lhe deaR.11) goals have been met 7. Reductton al contaminant toxicity, mobUIIY, and votume: · EPA evafuales each alternative based on how It recb:es (1) hi harmlu natin of lhe contamilanls, (2) !heir allifly ti move tf'rolql lhe enviormenl. and (3) Iha volume or amcx111 of contamination at Iha site. · MODIFYING CRITERIA 8. State acceptance: EPA lllqUllsts stale comments on the Remedial Investigation and Feasibifily Study rapol1a, u wall u hi Proposed Plan. and must talra rm> consideralion whether Iha 9 state C0l1CIIS wilh, opposes, or has nc comment on EPA's p,alen'ed alternative. 9. Community acceptance: To 8llSll8 lhat Iha public has an adequate Oppornr,ity ti provide input. EPA holds a Pldc comment period and considers and responds to all comments received from tie commurity prior ti Iha filal seleclion of a remedial action. EVALUA110N OF ALTERNATlVES The following summary profiles lhe performance of Iha preferred altemaives ii terms of Iha nine evaluation criteria noting how rt compares il lhe other alternatives under consideration. The comparative analysis tor Iha groundwater remediation all&rnatives is as foDows: GROUNDWATER REMEDIATION The lollowing alternatives were suqecled to detailed analysis for migration control: AttemaUve GWP1: No action with regard 10 Iha groll1dwater in Area 2 AJ1emaUv1 GWP2: 1.ong-T8ml Groundwater Monitoring of in Area 2 wilh Fenci,g A Portion of Northeast Trillutary AJ1ema11ve GWP3: lnstiflllional Corwols with regard ID Iha groll1dwater in Area 2 with Fencing A Portion of Northeast T rillutary Altamallvt GWP4A: Groundwater Extraction Tl'rough Wells ~ of Area 2 and Treatment By f,,Jr SIJWing with Vapor-Phase Carbon Adsorption wilh Combined Discharge 10 Iha Saisblly POTW AJtemaUve GWP4B: Gl'Ollldwater Extraction TIYough Wells ~ of Area 2 and Trea1ment By f,,jr Strwing With Fume Incineration wilh Combn!d Discharge 10 lhe Saisblly POTW AJtemaUve GWL 1: No Action with regard to Iha grou-,dwater in lhe lagoon area 'Ill mdv"t GWl.2: Long-Tenn Groundwater Moritoring of in lhe lagoon area with Fencing A Pol1ion of Northeast Trtlulary ♦II mdVI GWL3: lnslibltional Conrols with regard m Iha grou-,dwater in lhe lagoon area will Fencing A Portion ol Northeast Trilulary . • ' A111m111Y1 GWUA: G-oundwal8r Extraction TIYough Wells Oowl93(1ent ol lhe Lagoon Area'-' and Treatment By /'6 Strlppilg with Vapor-Phase Carbon Adsorption will Combined Oischal ge ii Ille Salswy POTW I I I I I I I I B I n I I I n I I I 0 AltamaUvt GWLAB: Grouidwaler Ex1raction TlYougn Wells Downgradient ol hi Lagoon Alea and Trealment By Air StJiWing Willl F\1118 nciieration with Combined Discharge to hi Saisluy POTW Overall Protection: Altamah9a GWP2, GWL2, GWP3, GWl.3, GWP4A, GWL4A, GWP4B, and GWl.48 provide . adequate protection for tunan heallll by p,e~ ingestion of polSntialy contaminated pr,dwalef' and surface water. Altematives GWP4A, GWP48, GWL4A, and GWl.48 would afford hi grea1est protection ID tunan heallll because ~ would substantially reduce the contamination in the groundwater and prevent the potential for expoSU/8 ttvough use of existing °' fuM! rff sits wels. Alternatives GWP4A, GWP4B, GWL4A, and GWl.48 would also remedia1e the surface water and sediment, which would eliminate the po1ential for exposure via ingestion of these media. These altemalives protect Iha enviromlent by removing contaminants from pr,dwalef', contoling Iha extent of groundwater contamination, and reducing the contamination in 1h11 ribu1ary and downstream simce wal!irs. Neither All!irnatives GWP3 nor GWl.3 would protect the enviromient because contamination would contirue 10 migrate inlD the lribu1ary h'ougn grooodwater discharge. None of 1h11 Al1ernatives GWP1, GWl.1, GWP2, 0< GWL2 wil provide protection for either tunan heal1ll °' 1h11 environment Natural degradation/attenuation of contaminants in the ~ is not anticipated to"'prevent the potential migration of contaminants off sits, altho\ql such processes may reduce tle am0llll and concentration of contaminants. Compliance with ARARs: All8malives GWP4A, GWP48, GWL4A, and GWL48 would ob1ain perfonnance standalds for pr,dwater (MCLs and North Caroma Groilldwatsr Standalds), surface water and seoment at tle point of compliance. These alternatives would also comply willl location-and action-specific ARARs related ID 1118 discharge to 1h11 POTW and ai" emission conro1a. Alternatives GWP1, GWL 1, GWP2, GWL2, GWP3, and GWl.3 a,a not expectad to meet performance standalds at 1118 point of compiance, however, Alternatives GWP3 and GWl.3 would comply willl Iha location-specific ARAR relnd ID operations at a hazardous waste site. -Long-tenn E118ctiYeneg and Pennanence: Allematives GWP4A, GWP48, GWlAA, and GWl.48 WOlid provide an effective and permanent allion for pr,dwater, surface water, and sediment because 1118 chemicals of concern would be removed from hi pr,dwaler and deA"Oyed. The raliabil\y ol lhese allai llidlY9i la his;!. Theall afternaUY9t would not pose a tunan heall1 · °' enviromlental risk at Iha poi1t ol compiance nl no treatment resi<ilala WOlid be left on Sa. Altamalves GWP3 and GWl.3 would pl8Y9l'II potential lJbl8 risk by p,eY9nting the lnslallation al li'ndng waifs in any areas exceecing MCLs 0< North Carolina Giwlqwalar Standards. Altemativea GWP1, GWL 1, GWP2, and GWL2 wi1 not be prolactive ol tunan heallh and hi 8IMl1ml8l1I in Iha long tann because these altemalives do not remove, nat. or 10 isola1e subslrlace contamination. Ave-~ CfRCU manda~ reviews ri be reqind for al of 1118 alanatives. Reduction of Toxicity, Moblty °' Valme: Altematives GWP4A, GWP48, GWL4A, and GWl.4B would reduce hi toxicity and YOklne ol conlamination in pr,dwaler tl'l0lqi removal and treatmn. They would aso reduce 1118 IDxicity and 'IOl\1118 of contamination in uface water nl sedmelt. Allernatives GWP1, GWl.1, GWP2. GWL2, GWP3, and GWl.3 do not chctly reduce IDxicity, molliity, °' 'IOU1l8 of groundwater, surface waler °' sediment contamination. Short-tenn Effectiveness: All of the alternatives can be implemented without ~ficant risk to the commlrily °' on-sits WO!lu!rs and without adverse 81M10Mlental impacts. Implementability: None of Iha al1ernatives pose significant concerns regarding inlplementation. Cost Tollll p,esent WOr1h costs (based on 30 years) tor 1118 groundwater allef'natives are p,esented_ below: AltamaUvas GWP11GWL 1 • No action: $227,000 AltamaUvas GWP2/GWL2 · Long-Term Monitoring willl Fencing A PO<tion of Nor1heast Tribuary: $1,479,000 AltamaUvas GWP3/GWL3 -lnstiUllional Controls willl Fencing A PO<tion of Nor1heast Tribuary: $1,500,000 All8ma1lv8 GWP<tA • Grouldwalsr Extrac:tion/Ai" Slrippirv'/apor-Phase carbon Adsorption/POTW Discharge: $2,222,000 AltamaUve GWP4B · Grouldwater Extrac:tion/Ai" Slrippi~e lnc:inerallorvPOTW Discharge : $2,274,000 AltamaUvt GWL4A · Groilldwatsr Extrac:tion/Ai" Strippirv'/apor-Phase carbon Adsotption/POTW Discharge: $3,570,000 AltamadVI GWL48 · GroUldwaler Extraction/Ai" Stripping/Fume lncineration/POTW Discharge: $2,996,000 SURFACE WATER/SEDIMENT The following allamaliY9s ftll' SI~ fD detailed analysis for Sllface waler nl sediment 1'811181idon: Altamadve SW1/SD1: No Action Altamadve SW2ISD2: Long-Tenn Moril0r'ilg Overall PTOtection: lklder pr881I co,dtions, bolll AltematiY9a SW1/S01 nl SW21S02WOlidbe prOl8ctiYe of lunan heallh, tu may not t,e p,OleCho of lie envilonmelt. I I I I I 0 B I I n R R I I I I I I It higher concenvations ot contlminanls are <ischarged mi the stniam from hi grooodwaler, lhen neih!r attema!M! may be l)'Otecti'le of tunan health no, the envirom,ent Compliance with ARARs: There are no Federal or Stale ARARs tor the contaminants detected in the surface water or sediment. Long-lenn Effectiveness and Pennanence: Under CUIT8l1I conditions, Alternatives SW1/SD1 and SW2/S02, woud be prolective of human health but possibly not the envirOIV118f1t It higher concentrations of contaminants begin discharging inlD the bibutary, none of these allematives may be prolective of human health. Reduction of Toxicity, Mobility or Volume: Both Alternatives SW1/S01 and SW2/SD2 could lead ID a reduction of 'IOlatile contaminan1s in the tribulary, however, neihr of these alternatives woud resut in the tleSlruclion of the 'IOlatile contaminants. These contaminants woud be transferred from the tributary ID the atmosphere llvough the l)'OC8SS of volatilization. Short-tenn Effectiveness: All of the alternatives can be implemented without significant risk '> the commriy or on-site wor11ers and without adverse 111Mronmental impacts . .,. 11 lmplemerttabolity: None of the ii111l<naDves pose siglficanl concems regarding inplementation. Cost Total p,-esent 'Mll1l COSIS (based on 30 years) tor the suface water/sediment altematives are presenllld below: Altema11ve SW1/SD1 -No Action: $151,000 Altema11ve SW2/SD2 · l.on!J-Tenn Momlmg: $867,000 State Acceptance: The NCOEHNR has relliewed and provided EPA with comments on the repor1S and data from the RI and the FS. The NCOEHNR has also reviewed tis l)'Oposed plan and EPA's prefemld alternative and presen11y cona.rs with EPA's selection. Community Acceptance: Cornmooty acceptance ot the preferred alternative wil be evalualed alter hi pubiic comment period ends and a response to each comment wil be included In a Responsiveness SUmnwy whidl will be a part of the Record af Decision (ROD) tor the Site. I m m I I I I I I I I I I I I I I I I EPA'S PREFERRED ALTERNATIVE After conducting a detailed analysis of all the feasible cleanup alternatives based on the criteria described in the previous sections, EPA is prnposing a cleanup plan to address groundwater, surface water, and sediment contamination at the Site. The EPA preferred alternatives are: GROUNDWATER REMEDIATION ALTERNATIVES GWP3B AND GWL3B: Long-Term Monitori~lnstitutional Controls; ALTERNATIVE · GWP4B: Groundwater Extraction Through Wells and Treatment By Air Stripping with Fume Incineration; and ALTERNATIVE GWL4B: Groundwater Extraction Through Wells and Treatment By Air Stripping with Fume Incineration and Combine Treated Groundwater with Groundwater from OU- 1 for Discharge to the Salisbury POTW At a cost of $1,500,000, $2,279,000, and $2,996,000 . ... SURFACE WAl'ER/SEDIIIENT ALTERNATIVE SW2/SD2: Long-Term Monitoring Cost: $867,000 An active groundwater remediation alternative would reduce the levels of contamination in both the surface water and sediment as the source of this contamination is the discharge of contaminated groundwater along the section of the Northeast Tributary. OVERALL TOTAL PRESENT WORTH COST OF $7,637,000 Based on current information, these alternatives~ to p.-ovide the best balance of trade-offs with respect to the nine criteria that EPA uses to evaluate alternatives. EPA believes the preferred alternative will satisfy the statutory requirement of Section 121 (b) of CERCLA. 42 USC 9621 (b), which provides that the selected alternative be p1 Otllehe cl human health and the environment, comply with ARARs, be cost effective, and utilize permanent solutions and treatments to the maximum extent practicable. The selection of the above alternatives is preliminary and could change in response to public comments. 12 I I I B I D I I I I I I I I I I I I I COIIIIUtfiY PARTlCPA 110N EPA has developed a commlJlily relations program as mandated by Congress ll1der SupelMd ID respond ID citizen's concerns and needs tor infonnation, and ID enable residents and public officials ID participala in lhe decision-making process. Pwc involvement activities ll1deltaken at Supemr,d sites consist of interviews with local residents and elected olficials, a commi.nly relations plan for each site, lad sheets, avaiabiily sessions, pullic meetings, IM)iic comment periods, ,-spaper advertisements, sile visits, and Technical AssiSlance Grants, and ariy other actions needed ID keep lhe commi.nty mined and il'Mllved. · EPA is conducting a 30-day publlc C0lllll8III period from July 19, 1993 to August 17, 1993, ID provide an Ol)l)Ol11.r,ily tor IM)iic involvement in selecting the linaJ clearup method tor tis Site. Public input on all alternatives, and on the infonnalion that SUl)pOrtS the alternatives is an important contribution ID the remedy selection process. During lhis comment period, lhe public is invited ID attend a public meeting on August 3, 1993, at the AQricutural Extension Center Auditori1111, 2727 Old Concold Road, Salistuy, North Carolina begirrilg at 700 p.m. at which EPA wil present the Remedial lnvestigationt Feasibiily Sludy and Proposed Plan describing the preferred alternative for treatment of lhe contaminated ~!Br at the National Starch & Chemical Company Superfund Site and ID answer any questions. Because tis Proposed Plan Fad Sheet provides only a summary description of the dearup alternatives being considered, the public is enco1nged ID consult the infoonation repository for a more detailed explanation. During this 30-<lay period, the public is invited ID review all site-related documents housed at the infonnalion repository located at the Rowan County Public Ubraly, 201 West Front Street, Salisbuy, North Carolina and offer comments ID EPA either orafty at the public meeting which wil be recorded by a COIII repor1er or in written lorm <img lhis tine period. The actual l9fl18CiaJ action could be cifferent from the preferred al18mative, depending upon new information or slatements EPA may raceive as a reSlit of public comments. H you prefer ID submtt written comments, please mail them postmarlied no lalBr than micnght August 17, 1993 to: 0/aM Blmtt NC CDIJllllllllly Rll6tlons COOrrllMtDr -U.S.£P A, Region 4 Natlh RllmedJII Sl.f»ttund Bnnch 345 COUlflllnd StrNt, NE Afllllll, GA 30365 All comments wil be reviewed and a response prepared in making the lnal determination ol the most awopriate allemative for cleanu!l,1reatment of hi Site. EPA's final choice of a remedy wil be issued in a RecOld of Decision (ROD). A document called a Aesponslv-SUmnary Sll!lmarizing EPA's response ID al IM)ilc comments wil also be issued with the ROO. Once the ROD is signed by lhe ~ Aannstrator it wil become part of hi AannstralMI Record (located at hi Ubraly) which contai1s all documents used by EPA in making a final detennination of the best deaR.ip,1raatment tor the Sile. Once the ROD has been approved, EPA wil begin negotiations with hi Polentlally Respanslbll Partlel (PRPI) ID allow tlem hi Opporllnly ID design, implement and absolb al costs of the remedy determred in the ROD in accordance with EPA guidance and prolDCol. tt negotiations do not reslit in a selllelrMn, EPA may conduct the remedial activity using Supemr,d Trust manes, and sue tor reintxnement of its costs with the assislance of hi llepamlent of Justice. Or EPA may issue a ll1ialllral acinilistrative order 01' dil8ctly file suit ID ton:e the PRPs ID concaict hi ramedial activity. Once an ~ has been reached, hi design of lhe selected remedy wil be developed and implementation of the remedy can begin. The ~ actions are the standard procedlles utiized caJing the Supemr,d process. As part of the ~ ~. EPA provides affected commlrities by a Supemr,d site with the Opporllnly ID apply tor a Tecmical Assistance Granl(TAG). Tlis i,ant ol 14> ID $50,000 enables the i,014> ID lire a tedYical advisor Ol'consutanl ID assist them in interpreting or commenting on site fi1cings and proposed remedial action plans. For 11101'8 informallon conceml11g ttu s,ant ~. please contact .... ,_,,.,, l'lttol\ Coordinator NC Taal Asslsll/lcf Gf111111 Wllfl lllnlgllfllltlt DMBlon U.S.£P .A., Rig/on 4 345 COUlltand StrNt, NE AftMll,GA30356 (404} 347-az:u 13 I I I I I I I I I I I I I I I I I I I r ~ INFORIIATION REPOSITORY LOCATION: Rowan Counly Public Library 201 Wesl Fisher Slreet Sallstuy, Nort11 C111,1111 28144 Phone: (704) 633-5578 Hours: llonday • Friday 8:00 un. · 9:00 p.m. Slbnay 9:00 un. · 5:00 p.m. I I FOR MORE INFORMATION .a.BOOT SITE ACTMTIES, PLEASE CONTACT: llr. Jon Bomhom, Remedial Profed ll■iagar or 11s. Diana Barrell, NC Comnnty Re1at1ons CoordhdDr North ~ Remedlal Brlncb Wlltl llaiagema1 Division U.S. Enmlruaal Ptubic:tb'I Aen;y, Raglan IV 345 Cow1land SlneC, NE Alllnll,Gl30365 ToD FrN No.: 1-800-435-8233 GLOSSARY OF TEAIIS USED It TitlS FACT SHEET Aquifer: NI ~ geological fonnation, °' ~ ol fonnalionl, C0nlairing usable amOllllS of ~ Iha! can 514)1)1y weDs and springs. Adnnlslntlve Rlt:atd: A tie which is maillanld and C0l1lainl al nam,a,n used by lhe lead agency III make ils decision on Iha selec;on ol a metlOd Ill be uliized Ill clean l¢'eal COi ani-., • a ~ lila. Ttia lie is held in hi inlDnnalion repository tor pubic review. Appllcable or lWIVIIII 11111 ~ Rllqullwmms (ARARs): Thi lldiwal and Slalll ~ hit a selecllld remedy must allain. Thesa ~ may vasy 1111ong sillls and vaialA A,,111...s. ,,..,_ Rlat 411NHlfflt A means of estimatilg Iha am0U1I ol damagi a~ lila coud ra1JS11 Ill l'unall twalh and hi enwonment. <lljeclws ol a risk assessment are 111: help determine hi need tor adlon; help delannin8 Iha leWlla ol chemicals Iha! can remain on hi sila after ~ and stil prolliel healtl and hi 8l1lliromlent; and provide a basis for compar'o,g cillerent ~ maflod&. 14 I I I a n I I I I I I I I I I I I I I Carcinogen: Any substance that can cause or con1ribute ID lhe production of cancer: canceri)'Oducing. Compre/lfns/ve Environmental RespollSf, Compensation 111d Llab/1/ly Act (CERCL.A): A federal law passed in 1980 and modified in 1986 by 1118 Superfund Amendments and Reau1horizalion NJ. (SARA). The Ads craated a special tax paid by producers of various chemicals and oi products lhat goes into a Trust Fund, commonly known as Superll.nd. These Ads ~ EPA lhe au1holity to iffiestigate and clean up abandoned or \JlCOOU'olled hazaroous wasle sites utiizilg money from 1118 Superll.nd Trust or by taking legal action ID force parties responsible for lhe contamination ID pay for and clean ~ lhe siil. Groundwater: Water found benea1h lhe ear1h's surtace that fills pores belWeen materials such as sand, soi, or gravel (usually in aquifers) which is often used for supplying wells and springs. Because groundwater is a major source of drinking watsr lhere is growing concern over areas where agricultural and industrial pollutan1S or substances are getting into groundwatsr. Hazardous Ranlclng System (HRS): The principle screening w used by EPA to evaluate risks ID public health and 1he envirorvne111 associated with hazardous waste sitss. The HRS calculates a score based on lhe potential of hazardous substances spreading from lhe sits 1hrough 1he air, surface water. or groundwater and on olher factors such as nearby population. This score is lhe prvnary factor in deciding ij 1he site should be on lhe National Priorities Lisi and. ij so, what rarwng ~ should have comparad to olher sites on lhe 1st Information Repository: A file containing accurate up-to~te llfomlation, lec:lvlical reports, reference docunents, information about lhe Technical Assistance Grant. and any olher matsrials per1inell1 to lhe sits. This file is usually located in a public building such as a library, city hall or school. that is accessible for local residents. Mu/mum Contaninant Lavels /MCI.SJ: The maximum permissible level of a contaminant in water delivered to any user of a public water systsm. MCLs are enforceable Slandards. National Po/lutam Discharge Elimination Syst;'-'.1 (NPOES/: A provision of 1118 Clean Water NJ. which prohibi1S lhe discharge of pollutan1S into waters ol 1118 inked Stales unless a special permit is issued by EPA, a Slate or (where delegatsd} a tribal goverrvne111 on an Indian reservation allowing a con1rolled discharge of liquid al1llr it has llldergone 118atment. National Prlolftles List (NPL/: EPA's list of lhe most serious uncontrolled or abandoned hazaroous was1e sites identified lor possible long-tsrm remedial action under Superfund. A site must be on 1he NPL to receive money from 1118 Trust Fund for remedial action. The list is based prvnarily on lhe score a site receives from lhe Hazard Rarwng Systsm (HRS). EPA is requred to updalll lhe NPL at least once a yea,. Po18ntlally Responsible Parties (PRPs/: Af1y individual or company • including owners, operators, transponers, or generators • potsntially responsible lor, or oonttluting to, 1118 contamination problems at a Superfund site. Whenever possible, EPA requires PAPS, through administrative and legal actions, ID dean up hazaroous waste siles PAPS have contaminated. Remedial lnvestlgatloNFeasJ/JIUty Study {RWS/:The Remedial Investigation is an in-<lepth, ex1ensive sampling and analytical study to galher data necessary to determnt lhe na1ure and exlent of contamination at a Superflnl site;_, establish criteria for cleaning up 1118 she; a de~lion and analysis of 1he potential cleanup allematives lor remedial actions; and support 1118 tecmcal and cost analyses of lhe al1ematives. The FeasibiUty study also usually recommends setedion of a cost-i!ffective altamalive. Record of Decision (ROO/: A IU)lic docunent 1hat amounces and explains which metlod has been selected by 1118 Agere, _, be used at a SupelUld sill to clean ~ 1118-contaminalion. Responsiveness Sllmmaty: A SLmmary of oral and written public comments received by EPA dlmg a public commell1 period and EPA's responses ID those comments. The responsiveness summary is a key part of lhe Record of Decision. Slml•Volatlll Orgllllc Compocnds (SVOCsJ: ~ng chemical compotllds that, at a rataUvely low 1Bmpera1ure, fklctuale between a vapor Sla1e (a gas) and a liquid stale. Vo/atl/1 Orr,llllc COfffKJC/11(/s (VOCS/: Any orga,ic compollld 1hat evaporates readily into 1118 ai' at room 1Bmpera1ure. Water Tab/« The level below which 1118 soil or rock is salllated wi1h water, somlines rafelTed ID as 1118 upper Sl.fface 11118 salllated zone. The level of grol.lldwater. 15 I I I R D I I I I I I I I I I I I ,-------------------------- MAILING UST ADDmONS If you Ill not._,, an cu IIIIIID~ 11st 1111d lfllUld llb ID be pllCld an the llllt ID receive lutln kdomlldan on the Ndonlll Sllrdl I a•U Con...-,y ~ SIii, pl-~ ttu fonn 111d m.m ID 01W lllmll, Cormuity Rolatlonl CoonllnllDr II the above lddrlsl: NAME-·----------------------------- ADDRESS-· ----------------------------i CITY, STATE, ZIP CODE: _______________________ _ I I : PHONE NUMBER·--------------------------! I l ------------------ U.S. Emlim1w._. Prat tke AQeflOY M,l~-.11.E. Allal1ll,0..,..- Nord,.....,_ .......... _ Dllno8onlcl,Calmunllyll-.c-d. __ ,,..,.....,,.... ...,_ I g I I D ·n I APPENDIX C I RESPONSIVENESS SUMMARY .,,, I I I I I •• I I I I I I I I I I I I I I I I I I I I I I I I RESPONSIVENESS SUMMARY FOR THE PROPOSED REMEDIAL ACTION FOR OPERABLE UNIT #3 NATIONAL STARCH & CHEMICAL COMPANY SUPERFUND SITE SALISBURY, ROWAN COUNTY, NORTH CAROLINA Based on Public Comment Period July 19 through September 16, 1993 Which Includes August 3, 1993 Public Meeting Held In Agricultural Extension Center, Salisbury, North Carolina Prepared by: U.S. Environmental Protection Agency, Region IV September 1993 · I I I I I I I I I I I I I I I I I I I RESPONSIVENESS SUMMARY OPERABLE UNIT #3 PROPOSED PLAN NATIONAL STARCH & CHEMICAL COMPANY SUPERFUND SITE TABLE OF CONTENTS SECTION PAGE No. 1.0 OVERVIEW ..................................................... . 2.0 BACKGROUND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 3.0 SUMMARY OF MAJOR ISSUES/CONCERNS/QUESTIONS/STATEMENTS VOICED DURING PROPOSED PLAN PUBLIC MEETING AND RESPONSES . . . . . 3 ,.,. 3.1 SOIL REMEDIATION ALTt:RNATIVES............................... 4 3.2 AREA OF SOIL CONTAMINATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3.3 MIGRATION OF CONTAMINATION................................. 4 4.0 SUMMARY OF MAJOR ISSUES/CONCERNS/QUESTIONS/STATEMENTS VOICED DURING PUBLIC COMMENT PERIOD . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 4.1 CONCERN ABOUT DISCHARGING INTO THE CITY OF SALISBURY SEWER SYSTEM . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 4.2 ESTABLISHMENT OF A FOURTH OPERABLE UNIT . . . . . . . . . . . . . . . . . . . . 5 4.3 ESTABLISHMENT OF A POINT OF COMPLIANCE WITH ENFORCEABLE INSTITUTIONAL CONTROLS . . . . . . . . . . . . . . . . . . . . . . . . 7 4.4 ESTABLISHMENT OF A SITE CLEANUP LEVEL FOR 1,2-DICHLOROETHANE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 4.4 SELECTION OF THE MOST COST EFFECTIVE REMEDIAL ALTERNATIVE ................................................ 11 ATTACHMENTS Attachment A -Transcript of Public Meeting I I I n I I I I I I I I I I I I I I I I RESPONSIVENESS SUMMARY OPERABLE UNIT #3 PROPOSED PLAN NATIONAL STARCH & CHEMICAL COMPANY SUPERFUND SITE 1.0 OVERVIEW The development of this Responsiveness Summary is in accordance to the requirement set forth in 40 CFR 300.430(f)(3)(i)(F). This community relations Responsiveness Summary is divided into the following sections: Section 2.0 BACKGROUND This section discusses the Environmental Protection Agency's preferred alternative for remedial action, provides a brief history of community interest, and highlights the concerns raised during the remedial planning for Operable Unit #3 (OU #3 or OU3) at the National Starch & Chemical Company (NSCC or NSC) Superfund Site. Section 3.0 SUMMARY OF MAJQR ISSUES/CONCERNS/QUESTIONS/STATEMENTS VOICED DURING PROPOSED PLAN PUBLIC MEETING This section provides a summary of issues/concerns and questions/comments voiced by the local community and responded to by the Agency during the Proposed Plan public meeting. "Local community" may include local homeowners, businesses, the municipality, and not infrequently, potentially responsible parties. Section 4.0 SUMMARY OF MAJOR ISSUES/CONCERNS/QUESTIONS/STATEMENTS VOICED DURING PUBLIC COMMENT PERIOD This section provides a comprehensive response to all significant written comments received by the Agency and is comprised primarily of the specific legal and technical questions raised during the public comment period. 2.0 BACKGROUND The Environmental Protection Agency (EPA) conveyed its preferred remedial alternative for OU #3 NSCC Superfund Site, located in Salisbury, North Carolina in the Proposed Plan Fact Sheet mailed to the public on July 15, 1993, and through an ad in The Salisbury Post and The Charlotte Observer newspapers. The ads were published in the July 19, 1993 edition of these two newspapers. A press release reminding the public of the forthcoming meeting was issued on July 30, 1993. The public meeting was held on August 3, 1993 at the Agricultural Extension Center in Salisbury, North Carolina. The purpose of the meeting was to present and discuss the findings of the OU #3 Remedial Investigation/Feasibility Study (RI/FS), to apprise meeting participants of EPA's preferred remedial alternative for OU #3, to respond to any questions or address any I I n n I I I I I I I I I I I I I I A-2 OU #3 National Starch & Chemical Company Responsiveness Summary concerns expressed during the public meeting, and to take their comments and make them a part of the official record. A copy of the transcript from the August 3 public meeting was placed in the Information Repository for public reading. The Proposed Plan Fact Sheet, the newspaper ad, and the press release all informed the public that the 30-day public comment period would run from July 19 to August 17, 1993. However, a request was made for a 30-day extension to the public comment period. Consequently, the public comment period was extended to September 16, 1993. No remedial alternative was presented for soils as this environmental medium will be addressed in the forthcoming Operable Unit #4. The alternative presented for addressing the contaminated groundwater included Alternatives . GWP3B/GWL3B and GWP4B/GWL4B: This alternative permanently removes the contaminants in the groundwater through groundwater ex1raction and on-site treatment through an air stripper with controls on air emissions. The treated groundwater will be discharged into the City of Salisbury's sewer system. The following activities are involved in this alternative: • Contaminated groundwater will be extracted from within and at the periphery of the plumes emanating from the Area 2 and the treatment lagoon area via ex1raction wells and piped to an on-site, above-ground tr.s-atment process; • · Treatment will consist of air stripping to achieve concentrations to meet discharge requirements set forth by the City of Salisbury wastewater treatment system; Long-term monitoring of the underlying aquifer; and Implementation of a deed restriction on the NSCC property as an institutional control. The alternative presented for addressing the contamination detected in the surface water and sediment of the Northeast Tributary was SW/SE-2. This alternative requires long-term monitoring of the stream as the proposed groundwater remediation system will reduce and eventually eliminate the contamination discharging into the stream along with the groundwater. The Risk Assessment indicates that neither the soils nor groundwater pose an unacceptable risk to either human health or the environment under present conditions; however, these contaminated environmental media could pose as an unacceptable future risk to both human health or the environment. In addition, the remediation of the groundwater is warranted as the levels of 1,2-· dichloroethane and a number of other chemicals are above applicable or relevant and appropriate requirements (ARARs) established for these contaminants in the groundwater. For these contaminants, the cleanup goals selected were Safe Drinking Water Maximum Concentration Levels, State of North Carolina groundwater quality standards, and risk based concentrations. Community interest and concern about the NSCC Site has fluctuated from moderate to high over the past two decades. Awareness of and concern about the NSCC "Plant·, not the Superfund related hazardous wastes, were very high in the communities which are adjacent to and nearby the "Plant". NSCC received considerable news media attention when it's Lumber Street Plant, which is also located in Salisbury, North Carolina, experienced an explosion which destroyed a section of the plant. In 1984, at the NSCC Cedar Springs Road Plant where the Superfund Site I I I I I I I I I I I I I I I I I I A-3 OU #3 National Starch & Chemical Company Responsiveness Sunvnary is located, a production process reportedly boiled over releasing a vapor cloud containing acetic acid. The vapor cloud reportedly injured vegetation for up to 1.5 miles from the plant. A 1985 newspaper article indicated there were mixed feelings in the communities surrounding the plant. Some of the residents believe that NSCC is a responsible company with an excellent record and that NSCC will work with EPA and cleanup the dump. Other residents were concerned about the ettects on their health and believe their community has borne the brunt of living near to NSCC. As stated above, the community has maintained a high level of awareness and concern regarding NSCC as a result of the incidents reported in the media. The following provides details on the accumulative community relations ettorts conducted by the Agency. A Community Relations Plan identifying a positive public outreach strategy was completed in September 1986. As part of this initiative, Information Repositories including the Administrative Record, were established at the Rowan County Public Library and in EPA, Region IV Information Center in Atlanta, Georgia to house the Administrative Record for the Site. The Information Repository and Administrative Record are available for public review during normal working hours. Fact sheets and public meetings were the primary vehicles for disseminating information to the public. EPA sponsored a number of public meetings and released several fact sheets to keep the public apprised of current activities, to help the community understand the Superfund program and the public's role in the process, and to share information regarding the direction and technical objectives of data collection activities at the Site. Only a few individuals from the community attended the Proposed Plan public meeting. In addition to these individuals, one representative from the news media, representatives from NSCC, and representatives from various government agencies also attended the meeting. 3.0 SUMMARY OF MAJOR ISSUES/CONCERNS/QUESTIONS/STATEMENTS VOICED DURING PROPOSED PLAN PUBLIC MEETING AND RESPONSES This section summarizes the major issues and concerns expressed during the Proposed Plan public meeting. Only four questions were asked during the public meeting. They related to: • Why was soil remediation alternatives left out of the Proposed Plan? Area of soil contamination? • In what direction is the contamination migrating and has the contamination migrated off the NSCC property? A recount of the questions summarized above and the Agency's response can be found on pages 32-36 of the transcript of the Proposed Plan public meeting (Attachment A). Summarized below are significant questions asked during the Proposed Plan public meeting: I I I I I I I I I I I I I I I I I I I A-4 3.1 SOIL REMEDIATION ALTERNATIVES OU #3 National Starch & Chemical Company Responsiveness Summary -Q: What's wrong with the soil that you have to go back to the operation? A: It's not what's wrong. NSCC needs to perform a more thorough evaluation of the soil alternatives. 3.2 AREA OF SOIL CONTAMINATION Q: Where's the soil now? A: An overhead was used to show the extent of soil contamination. 3.3 MIGRATION OF CONTAMINATION Q: Has any of the contamination left the soil yet? Left the property? A: To the best of our knowledge, no. Q: Something in the paper about it traveling north; is that true? A: .,Its tending to follow the stream which flow in a northerly direction. 4.0 SUMMARY OF MAJOR ISSUES/CONCERNS/QUESTIONS/STATEMENTS VOICED DURING PUBLIC COMMENT PERIOD This section summarizes the major issues and concerns expressed during the Proposed Plan public comment period. The major issues and concerns on the proposed remedy for OU #3 NSCC Site can be grouped into five areas: • Discharge into the City of Salisbury sewer system; • Establishment of a Fourth Operable Unit; • Establishment of a Point of Compliance with Enforceable Institutional Controls; • Establishment of a Site Cleanup Level for 1,2-0ichloroethane; and • Selection of the Most Cost Effective Remedial Alternative. Below is each written comment received and the Agency's corresponding response in italicized print. The comments below have been transcribed verbatim from the written set of comments the Agency received. I • I a I I I I I I I I I I I I I I I A-5 OU #3 National Stardi & Chemical Company Responsiveness Sunvnary 4.1 CONCERN ABOUT DISCHARGING INTO THE CITY OF SALISBURY SEWER SYSTEM COMMENT #1: This industrial user is subject to categorical OCPSF organics limits, and is usually in compliance with our local limits for those compounds. However, the application of supplementary limits to the discharge -fume toxicity, explosivity, and human health criteria -could result in some limits being so restrictive that this discharger may be unable to consistently meet those limits. If this occurs, the potential exists that the remediation project could be halted until the system is redesigned to meet the more stringent limits. The City requests that the EPA Superfund Branch work and communicate with the NPDES Permit Branch in an effort to develop and implement limits based on more practical, alternative ways of assuring both worker safety and collection system integrity. We feel that the existing methods may produce limits which are unrealistic when compared to OCPSF limits or local limits derived by traditional headworks methods. We request your assistance in resolving this compliance issue. RESPONSE: Currently, IT Corporation which is NSCC's contractor, does not believe it will be necessary to revise NSCC's existing discharge permit. However, in the event after closer examination of all the data, it becomes apparent that the discharge permit to the City of Salisbury sewer system will need to be revised due to the additional loading created by the groundwater extraction system for OU #3, then all entities involved, the Agency, North Carolina Department of Environment, Health & Natural Resources (NCDEHNR), the City of Salisbury, the potentially responsible party (PRP), and the PRP's contractor will need to work together to develop and implement limits based on practical, alternative ways of assuring both worker safety and collection system integrity. A determination on whether or not the existing discharge permit will need to be revised cannot be made until the Remedial Design stage at which time the actual loading rates and volumes can be calculated. 4.2 ESTABLISHMENT OF A FOURTH OPERABLE UNIT COMMENT #2: For the reasons expressed in the enclosed comments of IT, we do not believe that it is necessary to establish a Fourth Operable Unit. NSC has agreed to perform the DNAPL test suggested by EPA and the State. We are prepared to perform this test immediately following EPA's approval so that the results will be available prior to issuance of the ROD. Thus, if the tests do not show the presence of DNAPLs, we do not think a Fourth Operable Unit to address soils should be required. At a minimum, we think it is premature to establish a Fourth Operable Unit unless and until such time as continued groundwater monitoring results indicate that concentrations of contaminants do not significantly decrease. We suggest that the ROD be written so as to require a Fourth Operable Unit at a later date, only if necessary, following the analyses of sufficient groundwater monitoring I I I D n I I I I I I I I I I I I I I A-6 OU #3 National Starch & Chemical Company Responsiveness Summary results that would allow a determination of the effectiveness of a no action soil alternative. RESPONSE: The need for a fourth operable unit was a mutually agreed upon decision between the Agency and NCDEHNR. The decision was based upon the fact that the June 21, 1993 FS report did not provide sufficient supporting and defendable technical rationale for the elimination of soil remediation technologies that could permanently remove the residual contamination from the soil. Therefore, OU #4 FS will need to more thoroughly evaluate soil remediation technologies providing sufficient rationale for the elimination and/or retention of appropriate technologies that can address the soil contamination at the Site. Another concern which was highlighted during the review of the draft Proposed Plan focused on the potential presence of either a free-phase or residual dense non-aqueous phase liquid (DNAPL) in the soil in Area 2. The primary contaminant at the NSCC site is 1,2-dichloroethane (1,2-DCA) which is a chemical that can exist as a DNAPL. The presence of a ONAPL in either the soils or aquifer can control the ultimate success or failure of remediation at a hazardous waste site. The testing procedures and findings of the hydrophobic dye test conducted on September 22-23, 1993 shall be incorporated in the OU #4 FS document. Currently, the Agency does not foresee the need for any additional field work to be conducted as part of OU #4; hence, the June 2, 1993 RI report should suffice as the OU #4 RI report. COMMENT #3: We disagree with the EPA for the need of another Operable Unit. Based on the investigative data that has been collected the source of contamination of the subsurface soils is well defined. In fact, the EPA has stated in the Proposed Plan that "The OU3 soil investigation has generated ample information to characterize the contamination, determine the source, and define the extent of contamination in the vadose soil zone." The EPA and the NCDEHNR have both expressed their concerns about the presence of dense nonaqueous phase liquid (DNAPL), which they have used as the basis for the establishment of OU4. The agencies want the OU3 FS expanded to include more active remedial actions for the soil because they suspect that DNAPL may be present in the soil and if the DNAPL continues to release from the soil to the groundwater the groundwater" remediation will not succeed in cleaning up the aquifer. The data that has been collected to date does not indicate that DNAPLs are present, but direct testing has not been performed to refute their concern. The NCDEHNR has recommended a field screening test using hydrophobic dye to make the determination of the presence or absence of DNAPLS, which NSCC has agreed to perform. The testing procedure along with the proposed borehole location is provided as Attachment A. (This attachment has not been I I I D I I I I I 'I I I I I I I I I A-7 OU #3 National Starch & Chemical Company Responsiveness SUnvnary incorporated into the Responsiveness Summary.) We feel that if the test results show an absence of DNAPL there truly is no need for another operable. unit. We continue to recommend long-term monitoring of the groundwater to determine if no action is sufficient for the subsurface soils. If increased concentrations of contaminants or no substantial decrease in concentrations of contaminants are noted after 5 years of active groundwater remediation then other remedial options may have to be considered. RESPONSE: As denoted in the Response to Comment# 2 above, it is the lack of supporting technical rationale in the June 21, 1993 FS report for the elimination/retention of the soil remediation technologies that is actually driving the need for revising this document in OU #4. In other words, the OU #3 FS report failed to meet the requirement set forth in Section 121 CERCLA. This section states, EPA shall "conduct an assessment of ... alternative treatment technologies, that in whole, or in part will result in a permanent. .. significantly decrease in the toxicity, mobility ... ". The FS report failed to discuss alternative treatment technologies for soil. The FS report discussed only institutional controls and long-term monitoring. If a DNAPL is found to exist on-site, the Agency has found through experience that it is more advantageous to remove the DNAPL directly rather than rely on a pump and treat technology to remove the DNAPL. If necessary, the OU #4 FS report will need to address this issue. 4.3 ESTABLISHMENT OF A POINT OF COMPLIANCE WITH ENFORCEABLE INSTITUTIONAL CONTROLS COMMENT #4: EPA should establish a point of compliance for remediation of the contaminated plume that is, at a minimum, at the plume periphery rather than throughout the plume. That the NCP permits a remedy to incorporate a point of compliance that is a distance away from the source of groundwater contamination is not disputed by EPA. This issue was raised recently in a lawsuit brought by various states against EPA challenging EPA's use of the NCP in CERCLA. Ohio v. EPA, 39 ERG 2065, US Ct App, DC (1993). There, the Plaintiff states argued that in the preamble to the NCP EPA acknowledges that, while "remediation levels should generally be attained throughout the contaminated· plume, or at and beyond the edge of the waste management area ... an alternative point of compliance may also be protective of public health and the environment under site-specific circumstances." (underlines added) 40 C.F .R. 300.430(f)(S)(iii)(A). EPA did not challenge the states' interpretation of the NCP in this regard. Rather, EPA's response was that" ... alternatives must in any case be protective of public health and the environment." Ohio v. EPA, supra at p. 2080. It is thus clear from the language of the NCP, and from EPA's interpretation of the NCP in the Ohio case, that it is permissible to set a point of compliance at the property boundary, the plume periphery, or any other alternate point so long as it is protective of public health and the environment. I I I I I n I I I I I I I I I I I I I A-8 OU #3 Natiooal Slaron & Chemical Company Responsiveness Sunvnary The NCP threshold criteria of overall protection of public health and the environment is met at this site by setting such alternative point of compliance at the plume periphery, especially when combined with institutional controls. NSC is certainly agreeable to having a deed restriction recorded against the site indicating that the plume of contaminated groundwater is not suitable for drinking and prohibiting such use in perpetuity. Such deed restriction would run with the land and would thus legally prevent drinking water wells from being established in or near the plume. Moreover, NSC is willing to support the adoption by the City of Salisbury of an ordinance that would also prohibit such use of the groundwater unless it is demonstrated to meet drinking water standards. Such undertakings on the part of NSC could be incorporated into an enforceable Consent Decree in which NSC would agree to notify EPA and the State of North Carolina in the event it ever sold the site to a third party. Stipulated penalties could also be incorporated into the Consent Decree to ensure the enforceability of such institutional controls. It is doubtful that a site cleanup level of 5 ppb (and certainly of 1 ppb) for 1,2-dichloroethane ("DCA") throughout the entire plume could ever be met. Establishing an alternate point of compliance of the plume periphery, along with the institutional controls mentioned above, or other institutional controls which NSC would be wiIi'ing to consider, meets the threshold NCP requirement of overall protection of the environment and is consistent with EPA's interpretation of the NCP as articulated most recently in Ohio v. EPA, supra. RESPONSE: 40 CFR 300.430(a)(1)(iii)(F) 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.· And in accordance to Section 5.2.1 of EPA's Guidance on Remedial Actions for Contaminated Ground Water at Superfund Sites (EPA/540/G-88/003), The area of attainment defines the area over which cleanup levels will be achieved in the ground water: It encompasses the area outside the boundary of any waste remaining in place and up to the boundary of the contaminant plume.· Furthermore, it states that " ... if the source is removed. the entire plume is within the area of attainment.· Based on the above assertions. the Agency elected that the entire plume be the point of compliance. COMMENT #5 The proposed plan did not discuss a compliance point nor do the agencies accept the concept of a compliance point for CERCLA, when it is commonly used under RCRA. However, the agencies have no problem associating various laws, acts, regulations to determine cleanup standards (i.e. ARARS). The final rule, 40 CFR 300.430 (f)(S)(iii)(A), provides the following statement "performance shall be measured at appropriate locations in the groundwater .. .". The groundwater plume is considered the waste management area, therefore the point of compliance should be at the edge of the plume. I I I I D I I I I I I I I I I I I I A-9 OU #3 National $larch & Chemical Company Responsiveness Sunvnary The groundwater plume boundary has been well defined as depicted in figures in the RI/FS documents. The area of groundwater contamination is well within the property boundaries, which offers the agency with a large buffer zone between the compliance point and the nearest receptors. An integral part of the establishment of compliance points is the implementation of institutional controls. Institutional controls are required at this site in order to prevent future human exposure to contaminants remaining within the waste management area (i.e. groundwater plume upgradient of the compliance points). The agencies have expressed concern over their inability to enforce institutional controls. There are many options available to the agencies such as: deed restrictions, local ordinances, fencing, etc. The enforcement terms of for these controls can be identified as part of a consent decree, administrative order, contract, etc. National Starch should make a recommendation to the agency. RESPONSE: The Agency maintains that the point of compliance will be throughout the entire plume of contamination. Refer to the response for Comment #4 for the supporting rationale. 4.4 ESTABLISHMENT OF A SITE CLEANUP LEVEL FOR 1,2-DICHLOROETHANE COMMENT #6: As discussed in the enclosed comments of IT, the site cleanup level for DCA should be set at 5 ppb (at the point of compliance, as discussed above) which is the federal primary drinking water standard. Such level satisfies the NCP criteria of overall protection of public health and the environment. The State of North Carolina drinking water standard of .38 ppb, while relevant, is not appropriate based on problems with the accuracy of detecting concentrations of DCA at that level and it is not applicable to the contaminated groundwater plume here since such groundwater is not the source of drinking water supplies. EPA has proposed a level of 1 ppb for Operable Unit Three in recognition of the problem of accurately detecting DCA at levels of .38 ppb. However, EPA has previously determined that the practical quantitative limit ("PQL") (defined as the lowest level that can be reliably achieved within specified limits of precision and accuracy) is 5 ppb for all volatile organic compounds except vinyl chloride. Federal Register, Vol. 52, No. 130, July 6, 1987. We do not believe there is any basis for establishing a level of 1 ppb for DCA as an ARAR at this site. To the extent that any level other than the federal drinking water standard is deemed by EPA to be an ARAR, we believe such ARAR should be waived and we accordingly request such a waiver. We do not believe that a level of 1 ppb of DCA can be demonstrated by EPA to be applicable to the conditions at this site, nor is it technically achievable since it is below the PQL as detennined by EPA. RESPONSE: 40 CFR 300.400(g)(4) states, "Only those state standards that are promulgated, are identified by the State in a timely manner, and are more stringent than federal requirements may be applicable or relevant and appropriate". The state • I I I I n I I I I I I I I I I A -10 OU #3 National Slatel1 & Chemical Company Responsiveness Summary groundwater quality standard for 1,2-DCA is 0.38 µgl1 as specified in North Carolina Administrative Code (NCAC) 15-2L.0202(g). However, NCAC 15- 2L.0202(b)(1) allows the state groundwater quality standard to be raised to the detectable concentration. Consequently, the Agency raised the groundwater performance standard for 1,2-DCA from 0.38 µgl1 to 1.0 µgl1 as 1.0 µgit is the detection limit for 1,2-DCA under the drinking water analytical protocols, EPA method 524.2. Based on the Superfund Analytical Methods for Low Concentrations Water for Organic Analysis for the Contract Laboratiry Program, dated June 1991, the quantitation limit for 1,2-DCA is set at 1 µgit. 40 CFR 300.430(f)(1 )(ii)(C) provides the grounds for invoking a waiver. Based on the Agency's evaluation on the request for a waiver to the State's groundwater quality standard (NCAC 15-2L.0202), the Agency concluded that the request does not satisfy any of the specified grounds for invoking a waiver. COMMENT #7: The federal MCL for 1,2-DCA is 5 ppb. The NCDEHNR groundwater standard for 1,2-DCA is 0.38 ppb. IT has presented arguments in the past against using the state standard based on the impracticability of accurately measuring the concentration of 1,2-DCA at that level. Based on this argument, EPA has now proposed a cleanup standard of 1 .0 ppb. However, this is in conflict with the evaluation that was conducted by the EPA for the establishment of the MCL. For the establishment of MCLs the EPA assesses a range of factors such as: the availability and performance of Best Available Technology (BAT), the cost of these technologies, the availability and reliability of analytical results, and the resulting health risk (for carcinogens 10-4 to 10-6 is the acceptable range). As part of the assessment for proposing the MCL for 1,2-DCA, the EPA determined that "the costs associated with the additional removals, i.e., from 0.005 mg/I to 0.001 mg/I, are not warranted", therefore, the MCL was established at 5 ppb (Federal Register, Vol. 52, No. 130, July 6, 1987). The EPA proposed cleanup standards are established for drinking water supplies. National Starch plans to implement deed restrictions and possibly have the City of Salisbury establish an ordinance so that the installation of drinking water wells within the plume area will not be allowed. Based on the arguments presented, we feel that the cleanup level for 1,2-DCA should be 5 ppb. RESPONSE: Although the argument set forth in this comment is straightforward, it does not address the ultimate reason why the Agency selected a performance (clean-up) standard of 1 microgram per titer (µg/1) or 1 part per billion (ppb) for 1,2-DCA. To have selected anything else (i.e., the maximum contaminant level (MCL) for 1,2-DCA) as requested by this comment would have resulted in this Record of Decision (ROD) in being out of compliance with the law. 40 CFR 300.400(g)(4) states, "Only those state standards that are promulgated, are identified by the State in a timely manner, and are more stringent than federal requirements may I I I I I I I I I I I I I I I I D I A -11 OU #3 National Starch & Chemical Company Responsiveness Sunvnary be applicable or relevant and appropriate". The state groundwater quality standard for 1,2-DCA is 0.38 µgt7 as specified in NCAC 15-2L.0202(g). However, NCAC 15-2L.0202(b)(1) allows the state groundwater quality standard to be raised to the detectable concentration. Consequently, the Agency raised the groundwater performance standard for 1,2-DCA from 0.38 µgt1 to 1.0 µg/1 as 1. 0 µgll is the detection limit for 1,2-DCA under the drinking water analytical protocols, EPA method 524.2. 4.4 SELECTION OF THE MOST COST EFFECTIVE REMEDIAL ALTERNATIVE COMMENT #8: For the reasons discussed by IT, we believe that vapor-phase carbon adsorption should be selected by EPA as the preferred remedial alternative based on cost-effectiveness. RESPONSE: Both the vapor-phase carbon adsorption technology and the fume incinerator technology achieve the same degree of protection and treatment of the emissions from the air stripper. As directed by 40 CFR 300.430(f)(1 )(ii)(D), the Agency should select the most cost effective alternative. Based on the information provided in Comment #9, the Agency concurs with the request stated in this comment and has selected vapor-carbon adsorption as the choice of treating the emission generated by the air stripper. COMMENT #9: Upon further review of the cost estimates provided in the FS it became apparent that the O&M costs for vapor-phase carbon adsorption did not take into account the reduction in groundwater concentrations over time. Using the results of the contaminant fate and transport model (FS Appendix D) the depletion rates tor 1,2-DCA were estimated. Using the depletion rates and starting with an assumed average concentration of 55,000 ppb of 1,2-DCA in groundwater, the estimated vapor-phase carbon usage was calculated. The cost was then estimated based on the total amount of carbon required for 15 years of treatment. Therefore, the revised estimate for Alterative GWL3A Lagoon Area Groundwater (Extraction, Air Stripping, Vapor-Phase Carbon) is $2,612,000 and the revised estimate for Alterative GWP3A Plant Area Groundwater (Extraction, Air Stripping, Vapor-Phase Carbon) is $1,814,000. The combined total is approximately $480,000 less than was reported in the FS cost estimate for the same Alternatives and is approximately $107,000 less than the combined total for the same alternatives using fume incineration. Therefore, we recommend that the agency select vapor-phase carbon adsorption over fume incineration. RESPONSE: The Agency appreciates the above information and as specified in the response to Comment #8, concurs with the request to change the treatment technology for the emissions from the air stripper from fume incinerator to vapor-phase carbon adsorption. I I I I I I I ATTACHMENT A m TRANSCRIPT OF PUBLIC MEETING .,. I I I I m I I m g I I I I I I I I I I I g I g I • I I I I I NATIONAL STARCH AND CHEMICAL COMPANY SUPERFUND SITE GROUNDWATER REMEDIATION FOR OPERABLE UNIT NUMBER 3 7:00 P.M. August 3, 1993 Salisbury, North Carolina PROPOSED PLAN PUBLIC MEETING <C~arlotte <Court Lporttng, 3lnr. Joel i!lffir, !lox llli2g ([I,arlott,. ::i:-orth <C=ilina 28220 (704) 373-03-!7 Joli Jm (800) .[i5-g4z4 I I I I I I I D R I I I I I I I I I Ms. Diane Barrett Community Relations Coordinator United States Environmental Protection Agency Region IV 345 Courtland Street, Northeast Atlanta, Georgia 30365 Mr. Jon Bornholm Remedial Project Manager Superfund Remedial Branch Mr. Winston Smith Groundwater Expert * * * * * * * * ... Comments by Ms. Barrett Comments by Mr. Bornholm Public comments * * * * * * * * Pages 4 - 9 9 -32 32 -33 2 I I I I I I n I I I I I I I I I I I I This is the proposed plan public meeting for the National Starch and Chemical Company Superfund Site in Salisbury, North Carolina, conducted before Shannon s. McGilberry, Certified Verbatim Reporter and Notary Public, at the Agricultural Extension Center, 2727 Old Concord Road, Salisbury, North Carolina, on August 3, 1993, beginning at 7:00 P. M, .,.. I I I I I I I n I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 MS. BARRETT: Well, I want to welcome you tonight. My name is Diane Barrett; I'm the Community Relations Coordinator for the State of North Carolina for our Superfund sites in this State. Tonight's meeting is to present to the public the proposed alternatives for treating groundwater at this site, at the National Starch and Chemical Company Superfund Site. I'd like to introduce to you our other people from Atlanta. Mr. Jon Bornholm, Jon please stand. He is the remedial project manager for this site and then Mr. Winston Smith; he is our groundwater expert. I hope each of you have availed yourselves of the literature out 'front as you came in as well as signing up. This literature will give you a lot of information about what we're talking about tonight, so that will help y'all make a well informed decision on what we're doing here. The public comment period for this particular proposed plan began on July the 19th and will end at midnight August the 17th. This is also a required meeting by our circle of law and we have a court reporter here and she will be taking the transcript from this meeting. So when it comes to our public comment period, if you would please ~tand and give your name so that she I I I I I I I I I a n ·1 I R I I n I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 can get it for the record, we would appreciate it. I wanted to give you just a brief run_down of the community relations activities that have happe .. ,d so far at this site. First of all, let me ask how many of you have L~en to one of these meetings before regarding this particular site and are familiar with Superfund? Are y'all familiar with Superfund? Okay. First of all, at any site after it's first discovered, and this site was investigated and the proposed in the national priorities list and then finalized in October of 1989, and the national priorities list made this site eligible to be funded for remedial design work through our Superfund money. The Superfund money is a tax that is levied against chemical and oil producing companies and the monies there are put in a fund, and as the Superfund work progresses and we get into the remedial design and action stages of a process, the monies are used to conduct the activities if there are not viable people to pay for the work. When we first began, after the site was first listed on the national priorities list, the agency conducted in~erviews here in the community to find I I I I I I I I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 0 out what the community concerns were and then we prepared what we call our --a community relations plan that addressed the concerns of the communities and how we would endeavor to keep them informed. Now, we do that through such things as fact sheets, news articles, telephone calls, we have a one-eight-hundred number, for your convenience, to call us. It is listed in the fact sheet. We also have set up a repository which houses all of the documents that have been developed that give us reports on making our decisions on how to conduct the remedial design activities for the site and making a selection of which alternatives to use. This repository is in the Rowan County Public Library in downtown Salisbury. When we first started our interviews, a mailing list was also developed at the time, and then from each meeting thereafter, the names of those who attended have been added to our mailing list so that we can make sure that those interested do receive information. On September the 4th, 1985, the first meeting was conducted here and that there were about sixty people, I th:i.nk, that attended that meeting, and I I 1 2 I 3 I 4 5 I 6 7 I 8 9 n 10 I 11 12 I 13 14 I 15 I 16 17 I 18 19 I 20 I 21 22 I 23 24 I 25 I I I that was just the beginning of meetings. At that time, too, the remedial investigation began and that identifi the nature and extent of the contamination. This particular meeting covers groundwater at the site. As part of the remedial investigation, a risk assessment is conducted and this evaluates and identifies any risks posed by specific chemicals. There are six fact sheets out there in the entrance way covering various contaminants of concern. The major contaminant of concern, though, is what we call 1,2-DCA, which is DichlQ_roethane. This is a major contaminant of concern that we're addressing. After remedial investigation is conducted, that sometimes can last a year to two years because extensive sampling and analytical work is done, and sometimes we may have to go out a second time to gather mor.e data if we feel like we have not been able to get enough at the time. Then the feasibility study begins. This goes through various alternatives that can be utilized to treat the contaminants that are at the site, and this also supports all of our responses to the contaminants and the concerns that are listed in our investiga_tion. I I I I I n I I I I I I I I I I I I I 1 2 3 4 5 6 3 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 After the feasibility study has been completed, we are at the point where we are now, with the proposed plan fact sheet and our public meeting. These meetings, or this period, carries a thirty-day public comment period and if requested, it can be extended another thirty days. Once this is completed, when the comment period ends, a remedy will be selected. That remedy is selected based on all the documentation that we have received, plus all public comments that we get from the public. A record of decision is recorcTed and announcing the selection that has been made for treatment of the contamination at the site. An announcement will appear in an area newspaper informing the public of the selection as well as a regular decision fact sheet will be prepared giving more detail into the alternative that was selected so that it gives the public a better understanding of what's going on. Hopefully tonight, too, through Jon's explanation of everything that you'll have a good understanding of what we're proposing, but we've got some good slides. This is .the Superfund process. Any time I I I I I I n I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 throughout that process community relations are conducted and down below is a list of the various activities that we undertake in keeping our public informed. There is a technical assistance branch that is offered at each Superfund site for the affected community, and that technical assistance branch allows the community to organize into a nonprofit unit and then to contract to have a consultant come in and help them understand and decipher all the technical explanations and help them have a more active part in the decision makin~ process regarding the site. Right now, looking at this chart, we are at step five, the public comment period, and we really request your comments. This is your site; you live here, we don't, and we need to know what really affects you and we would appreciate your comments. I want to turn the meeting over now to Jon Bornholm who will go through the alternatives that have been proposed in the fact sheet. Thank you for your attention. MR. BORNHOLM: Thanks, Diane. Just a brief word about myself. I've been a Remedial Project Manager for the Superfund program since 1984. I conducted the 1988 public meeting here in I I 1 2 I 3 I 4 5 I 6 7 a 8 I 9 10 I 11 12 I 13 I 14 15 I 16 17 I 18 I 19 20 I 21 22 I 23 24 I 25 I I I 1 ' .u Salisbury on the first operable unit in lieu of my colleague who was on maternity leave. Hopefully everybody picked i.:p a handout that looks like this; it's about twenty pages long. This is basically all the overheads I'll be going through tonight. Some of them I'll read through quickly because you have a copy of them here and you can look at them more in detail at your own leisure. But first of all, what I'd like to do first is just go through the history of the site just so that everybody is brought up to date as to where we' re= at today. The first figure that shows is the approximate location of the site in Salisbury, and moving into the background of the site. It was first owned by Proctor Chemical which was then been acquired by the present owner, National Starch & Chemical Company, who continue to operate the plant today. It is an active facility. As Diane alluded to before, the site was proposed.on the National Priorities List in 1985. It was reproposed in 1988 and was finalized on the list in 1989. Sites that score below a hazardous ranking score of 28.5 are not added to the list, the National.Priorities List. Everything above I I I I n I I I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 28.5 is eligible to be placed on the National Priorities List and the individual scores for the ranking process basically the surface water pathway and air pathway at the time of assessment scored zero and the groundwater pathway was what scored and resulted in the site being put on the National Priorities List. The first operable unit began in 1986 with the National Starch and Chemical Company signing a administrative order on consent with the Agency, basically agreeing to do the work that we estab~ished for them to do and the rest of the information pertains to the work done as part of operable unit number 1. The remedial investigation looked at the air, the surface water, the ground water, as well as the soils. The proposed plan fact sheet was distributed to the public and we held our public meeting. Back then the public comment period was only three weeks long. Since that time the Superfund law has been revised to a four-week period or thirty days with a potential extension of an additional thirty days at the request of the public. That record of decision was signed on September 30th, 1988 for operable uni~ one. And I'll --there's another I I I I I D I I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 figure that's kind of details where all these operable units are on the site. Operable unit two was initiated back in '89. Basically what the first record of decision did was it identified the --the information said that the groundwater and soil was contaminated, but the Agency wasn't comfortable with the information with respect to the soils contaminated, so the Agency directed the potential responsible parties to go back and do an additional investigation which on operable unit two consists of. Again, we had a~proposed plan fact sheet that was issued to the public. We had our public meeting and then the record decision was signed in September of 1990. As an operable unit number --as in the record decision for operable unit one, this record decision for operable unit two also required additional work by the potentially responsible parties and this became operable unit three. And basically wher~ we're at right now with regard to operable unit three, the work was basically started in 1991 with the remedial investigation being concluded in March of this year, at least the field work was. The proposed plan was dis1;ributed on Ju,ly. Tonight is the I I m I I I I m I I I I I I I I I I I 1 2 3 4 5 6 _7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 public meeting for that proposed plan and then the public commentary is --it began, as Diane said, on July 19th. Operable unit three consists of two areas. The plant area, which is the active facility itself, which consists of area number 2, which includes the reactor room, the tank room, the raw materials bulk storage room, and the warehouse, and as well as the buried terracotta pipe lines from the reactor room to their treatment lagoons. And that the second area of investigation as part of op~rable unit number 3, were the lagoons themselves. I'm going to try to put it all together for you. This figure --operable unit number 1 deals with groundwater flowing in this direction. So down here, which is basically off this figure, groundwater contaminated this area and is being dealt with by operable unit number 1. Operable unit number 2 basically deals with the contaminated soils in the trench area, and then operable unit three, which is what we are talking about tonight, here is area number 2 which is the actual plant, and here is the lagoons. Okay. T_he remedial investigation, again, I I m I I I _p I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 looked at soils, groundwater, surface water and sediment. As far as the soils, basically we tried to define three things in the remedial investigation for each environmental media. We tried to characterize the contamination, what contaminants are out there and at what concentration. We tried to define where that contamination is coming from and then how far has it migrated from the source. Basically what we found is that we had fourteen different volatile organics in the soils, with 1,2-DCA, or 1,2- Dichl~roethane being the main contaminant at the site. As far as the source, the lagoons were unlined prior to 1983. After that time they were excavated and lined with concrete liners, so they were acting as a source prior to 1983 and then the terracotta piping or pipelines coming from the treatment --or the active facility leading to the treatment lagoons is the other source on the site. And then as far as the extent, basically what the data shows is that it has basically stayed close to where the source evolved. There was some migration but all contaminants remain on site. And then try to put it in a figure, these are the concentrations of 1,2-Dichloroethane in and around I I I m ~1 D ' I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 area number 2, which is right here (indicating on document), and arranges the concentration range, the highest concentration was one million six hundred thousand parts per billion down to non- detect. And again, these lines out here show the range of concentrations and then move further away from the source, the levels of concentration decrease to non-detect. And then as far as the lagoon.area, again, this figure is based on concentrations of 1,2- Dichloroethane. Again, we have a little hot spot right ~ere, per se, and then as we move away from that area, the levels decrease again down to non- detect; and that's soils. The other --and then when we look at acetone we tried to put the concentration of acetone on a figure again. We have the same general area of location of contamination near the lagoon right here (indicating on document), as we did with 1,2- Dichloroethane and basically the same for area number 2 and this area, and then in this area. where 1,2-Dichloroethane encompassed this whole area. As far as groundwater, again, we had those three object~ves: one, to characterize what was I I I I I I 0 I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 in the groundwater, the types of contaminants and their concentrations. Number 2, to find out the source of where that contamination was coming from and then also to define the extent of contamination. How far has that contamination migrated. In the groundwater we found sixteen different volatile organics. Again, the major compounds were 1,2-Dichloroethane and acetone. As you would assume, the source for soils would be the same source for groundwater and that was the lagoons prior to being lined and the terracotta pipe~~ne. As part of the remedial investigation we al~o tried to define the geology of the soils so we could determine which way groundwater is flowing, how quickly it is flowing and what this thing shows is a cross section of the geology of the site, (indicating on document) here being the northeast trlbutary, the plant area being approximately right in this area, and below the plant we have what is called saprolite, which is weathered bedrock, basically typical soils for this area. Down underneath the bedrock, underneath the saprolite we have fractured bedrock, and.then below the fractured bedrock we I I I • I I D I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 have constant bedrock, which basically there's no fractures and there's no groundwater flowing through that area. To try to put this all in some type of meaning and try to define the concentrations and the extent of contamination. Again, as I mentioned, the primary contaminant is 1,2- Dichloroethane, so most of these figures are based on the concentrations we found at the site of 1,2- Dichloroethane. Okay. As with the soils, again, we have basically two hot spots on the site. One that'._:, near the lagoon area and the second one is within the area number 2, which is the active facility. Groundwater is predominantly moving towards the northeast tributary in this direction (indicating on document). And this figure basically shows the concentration of 1,2- Dichloroethane at the water table. Okay. This figure, again, is based on concentrations of 1,2-Dichloroethane in the groundwater and the saprolite, which is below the water table, and again, it's basically showing the same thing. We have a high concentration of contaminants in both the lagoon area and the plant area. I I I I g g I n I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Then the third figure is the range of concentration in the bedrock zone, the fractured bedrock zone. Again concentrations are again -- the higher concentrations are again right in those areas where the lagoons and the plant are. The important thing, which I should have mentioned on all these figures, is that we do have delineation or a definition of the extent of the plume, which is defined by these dotted lines and basically the information is showing that the contaminants in the groundwater are not migrating off tbe property. That's an important consideration .. Then the last environmental media that was investigated for this operable unit was the surface water and sediment in the northeast tributary. We only found two organics, two volatile organics there. Again, 1,2- Dichloroethane and acetone. The source is the groundwater, the contaminated groundwater, is discharging into that stream and it extends just downgradient of the plant area itself. And basically the next two figures define the extent of contamination in that stream with the concentration.s being the numbers in parenthesis, I I I I I I I I I I I I I I I I I I .I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 with the flow and the stream going this way. Again, there were no detections of these contaminants upstream of the plant, that's what the "ND'' stands for, non-detect. Then as you get parallel to the plant, you get detection, concentrations of contaminants. As you move downstream, again, those concentrations fall off until you eventually reach non-detect. During one sampling event at the site, samples reflected along the entire reach of the stream down to the property boundary and at that partic:.,lar point no detections were --no contaminants were detected leaving the site. That's --this map basically is for surface water and then this figure is for sediment, which basically follows the same pattern. Upgradient we have non-detect, just parallel to the site we have some detections, and then as you move down gradient, the concentrations decrease until you reach non-detect. We tried to lump this all together as to contaminants detected, the total list of contaminants detected, is this first table here, table 1-1. It lists all the organics that we've detected and.which environmental media they were I I I I I I I I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 detected in, soil, groundwater, surface water or sediment. The first numbers basically are-the ranges and then the numbers in parenthesis are the frequency of detection. How frequently did they - -were those contaminants detected. And again, let me just point out 1,2-Dichloroethane and acetone were the two primary contaminants at the site. Okay. Using all this information, we go into a risk assessment. In order for there to be a risk, two pieces of the puzzle have to be present. One, ~here has to be a pathway. Although you might have a contaminant here, if you have no pathway from that source to a population or something, there cannot be a risk because there's no exposure. And then the second piece of that puzzle is the chemical has to have some toxicity associated with it. If you have a source of water, water is not toxic, although it is a pathway, it wouldn't cause risks because water in itself does not have any toxicity associated with it. And not to try to confuse the issue, basically when we talk about risks, we use numbers. We .use --in our --in the EPA we use I I I I I I I I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 the term ''unacceptable risk," and that is when the risk is greater than one times ten to the minus fourth or one of ten thousand people may be adversely affected by contaminants. And then if it's a noncarcinogenic chemical we use a hazard what's called a hazard index and if the hazard index is greater than one, then that contaminant in itself poses an unacceptable risk. Not that I'm going to go through this, but basically, the important issue here that I want to point out is one, the site does not pose a current risk ~o the public health. There are future unacceptable risks associated with the site and these are based on scenarios developed by the Agency. And there are three scenarios that would present an unacceptable risk to human health. First would be if a site was developed as a residential area and those folks would build their own wells and use the groundwater under the site. That would pose an unacceptable risk and these would be the numbers associated with that risk. The other --another risk would be a child playing in surface water, sediment or spring. Then the third one would be exposure to subsurface soils. If you're building a foundation, gardening or I I I I I I R I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 • something --the gardening would be --you'd have to dig real deep though, the soils, that would pose an unacceptable risk. But the main point is, that I want to point out is that there is no current risk posed by the site based on our information collected to date by the contaminants present in the soil or the groundwater. The groundwater does not pose a risk because there's no pathways to date, meaning that there are no people using that contaminated groundwater for probable use, for drinking water. ~~d as far as --another part of the risk assessment is environmental risks. Basically, what this --the key here is that it's basically inconclusive to date, because the headwaters of the northeast creek are just above the property. There's not much environment for the bionic organisms to survive in, so they conclusive --it could not be proven conclusively that the discharge of 1,2-Dichloroethane into the stream along with the groundwater is causing an environmental --an adverse environmental effect. The next table lists what the Agency has identified as performance standards or our clean up goals to b~ obtained by ,the groundwater I I I I I I I I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 remediation. There are several changes here, they are in the handouts, so let me point those.out. One, I believe the State has proposed seven hundred and I believe that's up for comment right now and it has not been promulgated. If it's not promulgated by the time that this record decision is signed then the clean up goal will be thirty- five hundred because that is the value that's promulgated today. Another change, I believe, there's a typo, is Tetrachloroethane. The State standard is point seven. I think it says seven in the t.::mdout that you have. Because the quantitation limits or analytical methods, that moves up to one, that's the lowest level that we can detect on parts per billion. And I think this 70 here is also a proposed State clean up goal out for public comment and this 70, I think, is missing and that is already promulgated, that's already been established as a State clean up goal .. What the law, Superfund Law, requires us to do is to select the most stringent clean up goals. So basically what I tried to do, is I tried to list the federal clean up goals here, the State clean up goals here, and whichever is the smallest number, the m_ost stringent clean up standard is I I I I g I D I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 the one that's listed in the shaded area and that will be the one that will be included into ·the record decision as the clean up goal or performance standard. And then the other difference is the addition of that number, which again is the proposed State clean up. It's a rarity when they go up in concentration rather than going --rather than decreasing. And then this is the last half of that table. As you may notice, this table has fewer compounds than that table 1-1, that lists all the conta1Jinants that were detected. Basically the reason is that the other contaminants did not pose a risk. These are the contaminants that were detected on site that posed an unacceptable risk. And as far as --as far as the surface water, we really don't have any established clean-up goals that are written into laws. We use what is called "TBC's," to be considered. They're not enforceable by any law or any faction, but the goal is to achieve a level of two hundred thousand micrograms per liter in the surface water, and that should be three thousand, I believe, a little typo there, with range concentrations from two to three thousan~, so we're just above that goal I I I I I Ii I I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 .:: .J here. Basically that's the end result of the remedial investigation, with all that information. Using that information we go on to the feasibility studies. Basically, all the feasibility study is is a screening process going step-wise, looking at the cookbook range of remedial alternatives or techniques that we could use at the site and then through a process of screening that we narrow that list down to a shorter list that we take into a detailed analysis. 5"0 the first step of the process is to eliminate all those techniques that just won't work at the site. Then following that we use the second step which is the screening process and we use three criterias to evaluate those remaining technologies to eliminate those that aren't worthy of passing through the process. And the next couple of slides basically just show the cook this is basically the cookbook list of all the technologies that were initially considered and the shaded areas are those that were rejected, and then one more page to that entire table. And then in the right hand column under "Comments" is the rationale for rejecting the technologies. That's I I I I I I I I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 the first screening; if the technology just is not implementable at the site, it gets thrown out. The second step of that screening process is a little bit more detailed. Again, we are looking at the three criteria, institutional implementability, effectiveness and cost. And in this table the ones that are --the blocks that are encircled in bold are the ones that were kept. Again, the rationale as to why each of these alternatives are either kept or rejected is stated under the criteria. .'.nd then once we get through that screening process we develop our remedial alternatives. The first step is to combine appropriate technologies into remedial alternatives to address the contaminants in each of the environmental media that are of concern. In this instance we are looking at groundwater and surface water. And then, again, we use the same three criteria to look at the remedial alternatives to evaluate them. And those alternatives that survive, those remedial alternatives, that survive that screening then go through a detail evaluation using these nine criteria. To date, only seven criteria have been used. ~he public comment period incorporates I I I I I I I I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 these last two, the State acceptance, as well as the community acceptance, and that's the primary reason why we're here tonight. All of these -- the special criteria and the evaluating criteria have already been done and that was done in part by the feasibility study efforts. And then the modifying criteria is basically the result of the public comment period. And then to just briefly review those remedial alternatives that basicaliy survived the process of elimination. This lists the alterr~tives that we are required by law to carry through the whole evaluation process, the no action alternatives. That gives us a baseline to evaluate the other alternatives from it. Basically, what a no action alternative is you don't do anything with the site. Then let me point out why there --the •p• stands for the plant and the "L'' stands for the lagoon area. The second alternative we are looking at long-term monitoring as well as fencing portions of the northeast tributary where we had elevated levels of contaminants in the surface water and sediment. The third alternative would be long-term I I l 2 I 3 I 4 5 I 6 7 I 8 I 9 10 I 11 12 I 13 I 14 15 I 16 17 I 18 19 I 20 I 21 22 I 23 24 I 25 I I I monitoring, implementing institutional controls, and then, again, fencing that portion of the northeast tributary where elevated levels of contaminants were detected, that were already outside the fenced area. That's already --the fence is already in existence. Alternative number 4, 4-A, --okay; all the fours are basically the same. It's extracting groundwater through extraction wells, and the only difference between A and Bis the type of treatment for the extracted groundwater. 'lnder A the water will be treated through a air stripper. I have some pictures of that just to help you picture what an air stripper is, and then the contaminated exhaust corning off the air stripper would be treated through a vapor incinerator with the treated groundwater being discharged through the local sewer system. Then under alternative B, again, we're using air stripping as our primary treatment. Excuse me --A is --alternative 4-A deals with air stripping and using carbon absorption which means the off gas coming from the air stripper to remove the contaminants out of that air stream prior to being discha~ged to the environment, with the I I I I I I I I I I I I· I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 groundwater discharging --with the treated groundwater being discharged to the local sewer system. Then alternative 4-B uses the fume incinerator and the activated carbon to treat the exhaust gas coming from the air stripper. As far as the surface water, the first alternative is no action, the second one is long- term monitoring. Basically, it's our opinion that by treating the groundwater we will be addressing the contaminants that are migrating into the surface stream along with the contaminated grounawater, so when we stop the migration of the contaminated groundwater at that stream, we will remediate the stream as well. The next page lists what EPA has identified as our preferred alternatives. Basically it's long-term monitoring along with institutional controls along with groundwater extraction using air stripping as the primary treatment, using fume incinerators to treat the off gas coming off the air stripper and then discharging all the treated groundwater to the local sewer system along with the rest of the discharge at the existing site that goes to the Salisbury treatment plant and then as far as the surface water, just long-term I I I I I I I I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 30 monitoring, continue to sample, to provide the data necessary to assure that the stream is being remediated by the groundwater remediation system. Then the last page basically lists conversations between us and the State. We were uncomfortable with the evaluation that was done for the soils part of the site, so we have we are going to request that the National Starch and their contractors revisit that, which will result in a fourth operable unit, which will mean another public meeting, which will just discuss the soil remediation aspect of the site, and hopefully that will occur within about four months, estimated time frame. Just for some pictures of what an air stripper is, (displaying photographs) these pictures were taken at another Superfund site called Chemtronics. It is in Swannanoa, North Carolina. Basically, this is a picture of the computer system that runs the whole groundwater extraction system. Okay. This basically is the extraction well, drilled down to the bedrock. It has pressure sensors in it. It has meters to measure the flow and this is ~11 fed back into the computer system I I I I I I I I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10. 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 3 L so that the computer can turn the pump on and off as necessary. Okay. This is the house --this is the building that was built on site to house the treatment system. The blue stack sticking out is the air stripper. Okay. The first apparatus that the groundwater discharges into once it gets pumped out of the ground is called an equalization tank and this is a picture of one. Basically, it allows basically the purpose of it is to have the main bfStem see a constant flow of of water flowing through it. Okay. This is the base of the air stripper. Air is blown into the bottom and the water is pumped to the top and allowed to trickle down as the air is flowing up forcing the volatile organics out with the water. Okay Following the air stripper is the water, groundwater, is pumped through these canisters which contain activated carbon. Basically, it polishes the water to ensure that all the contaminants have been removed, and then from this point it's discharged into the Buncombe County sewer system. There's one more. Here we go. And then this is a picture of what a fume incinerator I I 1 I 2 3 I 4 5 I 6 7 I 8 I 9 10 I 11 12 I 13 I 14 15 I 16 17 I 18 I 19 20 I 21 22 I 23 I 24 25 I I I looks like. That's all I have for pictures of these. 32 Basically that's the end of my presentation. Because we have a court reporter and because this is for the record, if you have any comments or questions, please state your name and you need anything else? (WHEREUPON, the reporter indicated negatively.) MR. BORNHOLM: Please state your name before you make your comment or ask your question. I'll open lt up to you. Do you have any questions or comments? MS. BARRETT: Jon must have really informed you mighty well, to not have any questions. MR. YOUNG: I'm Wes Young. What's wrong with the soil that you have to go back to the operation MR. BORNHOLM: It's not what's wrong. The alternatives that were looked at and the feasibility studies, in our opinion, did not go far enough and we want them to do a further evaluation of the remedial alternatives that may be available to address the soil contamination at the site. It's our opinio~ that sufficient data I I I I I I I I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 JJ already exists but basically ours will be a really an effort of more evaluation of the technologies available. MR, YOUNG: Where's the soil now? MR, BORNHOLM: The soil is --this shows both areas (indicating on document). This is the figure that delineates the distribution of acetone in the soils. There's a hot spot of contamination in this area which is near the lagoon area and basically in this area at the facility. This area that's shaded here is the plant itself which is on a con~ete foundation and then the area between here, over here, and over here is all paved, driveways. Basically, the contaminated soil is down under the facility itself. And then as far as this area is concerned, the levels of contaminants in the groundwater are higher than the levels in the soil which basically indicates that through natural --the process of natural percolation of rain, snow through the soil, it's carrying that contaminant to the groundwater and it's our feeling that with the groundwater pump and treat system will catch that contamination as it migrates into the groundwater, at least for _this area in here. That's the I I I I I I I I I I I I I I I I .1 ,, I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 initial idea. Any other questions or comments? MR. BEAR: Does any of the contamination left the soil yet? Left the property? MR, BORNHOLM: To the best of our knowledge, no. Could you state your name please for the record? MR, BEAR: Odell Bear. MR, BORNHOLM: To the best of our knowledge, no. Based on all the information from operable units one, two and the work done as far as operable unit three, no contamination has left the site.= MR, BEAR:· Something was in the paper about it traveling north; is that true? MR. WINSTON: Its tending to follow the stream. It's tending to follow the stream in a northerly direction. MR, BORNHOLM: Which flows in a northerly direction. MR, WINSTON: It hasn't gotten off the site, off the property. MR, BORNHOLM: (Indicating on document) This is the figure for groundwater and saprolite area and there is a well down here with a concentration of one --I ~hink it's one parts per billion, I I I I I I I I I I I I I I I I I I I 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 35 which is right at our detection levels, that we can't detect below that, per se. And then ·the paired well with that, which is in bedrock has the same concentration. Again, that's right at the quantitation limits of our current technology for detecting contaminants, so one day that could be zero and one day that could be one, depending on the --how finicky the machines are. So basically, what that's showing us is that the contaminants have not left the site via groundwater, through the groundwater. MS. BARRETT: Are there any more questions before we conclude our meeting? Okay. Well, we thank you very much for your attention and for corning and the meeting is adjourned. MR. BORNHOLM: Thank you. (WHEREUPON, the meeting was concluded at 8:00 P. M.) I m 0 m I I I I I I I I I I I l I I I STATE OF NORTH CAROLINA COUNTY OF MECKLENBURG 36 I, Shannon S. McGilberry, Certified Verbatim Reporter and Notary Public, do hereby certify that foregoing public meeting in the referenced matter was taken by me and transcribed under my supervision and that the foregoing thirty-six (36) pages constitute a verbatim transcription of same. I do further certify that I am not of counsel for or in the employment of any of the parties to this action, nor do'1 have any interest in the result thereof. IN WITNESS WHEREOF, I have hereunto subscribed my name, this 16th day of August, 1993. My Commission Expires: August 16, 1993 Shannon S. McGilberry Certified Verbatim Reporter Notary Public PLEASE NOTE that unless otherwise specifically requested in writing, the tape for this transcript will be retained for thirty days from the date of this certificate.