Corrective Action Decision Document - Area 12 Fleet Operations Steam Cleaning Discharge Area Nevada Test Site Corrective Action Unit 339 (Nevada Environmental Restoration Project)

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Area 12 Fleet Operations Steam Cleaning Discharge Area Nevada Test Site Corrective Action Unit 339

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CORRECTIVE ACTION DECISION DOCUMENT AREA 12 FLEET OPERATIONS STEAM CLEANING DISCHARGE AREA NEVADA TEST SITE CORRECTIVE ACTION UNIT 339 Environmental Restoration Division and Environmental Protection Division Under Contract No. DE-AC08-96NV11718 DISTRIBUTION of this DOCUMENT is , UH

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This report has been reproduced from the best available copy. DOE and DOE contractors can obtain copies of this report from the Office of Scientific and Technical Information. P.O. Box 62, Oak Ridge, TN 37831, (423) 576-8401. This report is publicly available from the Department of Commerce, National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22161, (703) 487-4650.

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This report was prepared as an account of work sponsored by an agency of the United States Government Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, express or implied, or assumes any legal liabili ty or responsibility for the accuracy, completeness, or usefulness of any information, appa ratus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessar ily state or reflect those of the United States Government or any agency thereof.

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Porttons of this document may be Illegible In electronic Image products. Images are produced from the best available original

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TABLE OF CONTENTS ABBREVIATIONS AND ACRONYMS .......................... Hi 1.2 PURPOSE AND OBJECTIVE.......................................................................... 1 2.0 CORRECTIVE MEASURES STUDY............................................... 6 2.1 BASIS OF EVALUATION.................................................................................................. 6 2.2 IDENTIFICATION OF CLOSURE OPTIONS............................................................... 6 2.3 ANALYSIS OF CLOSURE ALTERNATIVES.......................... 9 3.0 EVALUATION OF PROPOSED CLOSURE ACTIVITIES............................................. 11 3.1 EVALUATION OF GENERAL DECISION FACTORS ............................................. 11 3.1.4 Protection ofHuman Health and the Environment.......................................... 13 3.1.6 Controlling the Sources ofReleases..................................................................... 13 3.1.7 Compliance With Waste Management Standards ...................................... 13 3.1.8 Long-term Reliability and Effectiveness ......................................... 14 3.1.9 Reduction in Toxicity, Mobility or Volume of Waste .............. 14 3.1.10 Short Term Effectiveness ....................................................................................... 14

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3.2 FAVORED CLOSURE ALTERNATIVE........................................................................ 15 4.0 CONCLUSIONS AND RECOMMENDATIONS ............................................ 24 1. SITE LOCATION MAP..................................................................................................................... 2 2. PHASE 2 DRAIN LINE DISCHARGE AREA SAMPLE LOCATIONS AND ANALYTICAL RESULTS............................. .3 3. PHASE 2 FORMER PARKING AREA SAMPLE LOCATIONS AND ANALYTICAL RESULTS ............................................................................................. 4 4. PHASE 1 DRAIN LINE DISCHARGE AREA, DISCOLORED SOIL AREA AND ANALYTICAL RESULTS.......................................................................................... 5 1. CORRECTIVE MEASURES STUDY STANDARDS AND DECISION A. PHASE 2 CHARACTERIZATION REPORT

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ABBREVIATIONS AND ACRONYMS below ground surface Corrective Action Decision Document Corrective Action Site Corrective Action Unit Code of Federal Regulations Corrective Measures Study milligrams per kilogram Nevada Administrative Code Nevada Division of Environmental Protection Nevada Test Site Resource Conservation and Recovery Act Total Petroleum Hydrocarbons Treatment, Storage, and Disposal Facility volatile organic compounds

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This Corrective Action Decision Document (CADD) incorporates the methodology used for evaluating the remedial alternatives completed for a former steam cleaning discharge area at the Nevada Test Site (NTS). The former steam cleaning site is located in Area 12, east of the Fleet Operations Building 12-16. The discharge area has been impacted by Resource Conservation hydrocarbons (as oil) waste. Based upon these findings, resulting from Phase 1 and Phase 2 site investigations, corrective action is required at the site. To determine the appropriate corrective action to be proposed, an evaluation of remedial alternatives was completed. The evaluation was completed using a Corrective Measures Study (CMS). The evaluation is supported by the Nevada Administrative Code (NAC) “A through K” analysis for risk based corrective action. Based on the results of the CMS, the favored closure alternative for the site is plugging the effluent discharge line, removing the sandbagged barrier, completing excavation of VOC impacted soils, and fencing the soil area impacted by TPH, east of the discharge line and west of the soil berm. Management of the “F Listed” VOCs are dictated by RCRA. Due to the small volume of impacted soil, excavation and transportation to a Treatment Storage and Disposal Facility (TSDF) is the most practical method of management. It is anticipated that the TPH (as oil) impacted soils will remain in place based upon; the “A through K” Analysis, concentrations detected (maximum 8,600 milligrams per kilogram), expected natural degradation of the hydrocarbons over time, and the findings of the Phase 2 Investigation that vertical migration has

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The Area 12 Fleet Operations site is located in the southeast portion of the Area 12 Camp at the Nevada Test Site (NTS). Closure of Building 12-16 is not included in this evaluation or previous site investigations. The subject area includes a vehicle parking area, which was potentially impacted from surface runoff of a sand/oil interceptor, and the area east of the steam cleaning discharge line located approximately 104 meters (340 feet) from Building 12-16 (Figure 1). This site has been assigned Corrective Action Site (CAS) Number 12-19-01 and is within Corrective Action Unit (CAU) 339. 1.2 PURPOSE AND OBJECTIVE The purpose of this report is to prepare a Corrective Action Decision Document (CADD) based upon the evaluation of remedial options for closure of the Area 12, Building 12-16 Fleet Operations steam cleaning discharge area. The vicinity of the sand/oil interceptor and areas within the effluent discharge area have been impacted by volatile organic compounds (VOCs) and total petroleum hydrocarbons (TPH) as oil. The VOCs and TPH are the constituents of concern (COCs) dictating the closure alternatives for the site. VOCs were identified in three constituents in degreasing solvents previously used at the site (U. S. Department of Energy [DOE], 1996). The Phase 2 sample locations and laboratory analytical results are shown on Figures 2 and 3. The VOCs identified are regulated under the Resource Conservation and Recovery Act (RCRA) and are “F Listed” wastes which require management (40 Code of TPH as oil impacted soils which exceed the Nevada Administrative Code (NAC) Action Level of 100 milligrams per kilogram (mg/kg) were identified predominantly in the discolored areas east of the effluent discharge line. The surficial discolored soil areas and corresponding analytical results, identified in the Phase 1 investigation, are shown on Figure 4. The Phase 2 Investigation identified that the oil hydrocarbons have not migrated to depths greater than 0.9 to 1.2 meters (3.0 to 4.0 feet) below ground surface (bgs). Corrective action is required at the site based upon the findings of the Phase 1 and Phase 2 site investigations. Detailed information of the site history and results of previous characterizations can be found in the Work Plan dated October 1992 (REECo, 1992), the Preliminary Investigation Report dated July 1996 (DOE, 1996), and the Phase 2 Characterization Report dated November 1996

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Analytical Results Reported in mg/kg SANDBAGGED AREA WITH RAINIER MESA ROAD Bechtel Nevada figure 2 PHASE 2 DRAIN LINE DISCHARGE AREA SAMPLE LOCATIONS AND ANALYTICAL RESULTS

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Acetone 0.001 Methylene Chloride 0.003 Analytical Results Reported in mg/kg RAINIER MESA ROAD Bechtel Nevada FIGURE 3 PHASE 2 FORMER PARKING AREA SAMPLE LOCATIONS AND ANALYTICAL RESULTS

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below land surface) microgram per kilogram milligram per kilogram Sandbagged area with RAINIER MESA ROAD Bechtel Nevada figure 4 ™BI",,II.......... ' PHASE I DRAIN LINE DISCHARGE AREA DISCOLORED SOIL AREAS AND ANALYTICAL RESULTS

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2.0 CORRECTIVE MEASURES STUDY 2.1 BASIS OF EVALUATION The objective of the Corrective Measure Study (CMS) is to provide a basis for the selection of the preferred corrective action (which includes the site remediation closure options). The results of the CMS supports closure of the discharge areas by limited soil excavation, plugging of the source point, and limiting access to the site. Corrective action decisions for the closure are based upon a variety of site specific factors and issues which provide the option(s) most suitable for site remediation and closure. The factors and issues considered include: • Level of risk to human health and the environment; • Protection of human health and the environment; • Attainment of media cleanup standards; • Control of the sources of releases; • Compliance with standards for management of the waste; • Long term reliability and effectiveness; • Reduction of toxicity, mobility, or volume of wastes; The last nine issues listed for evaluation are the general decision standards described in Title 40 CFR Part 264.525, proposed Subpart S. These standards are used to address corrective action for solid waste management units (Environmental Protection Agency [EPA], 1990). 2.2 IDENTIFICATION OF CLOSURE OPTIONS As part of the CMS, a number of closure options were evaluated for the site. After preliminary evaluation, a total of nine options were decided upon as viable alternatives for closure or post closure management. The selections were narrowed using the criteria and decision factors listed in Section 2.1. Many of the options can be implemented in conjunction with one another or considered individually. The final options considered for the CMS are as follows: Option 1 -No Action - Under this option, no further action is taken to address closure of the discharge line, sand/oil interceptor, removal of hydrocarbon impacted soils, or removal of the VOC impacted soils. In essence, the site would remain as is, with the COCs being allowed to degrade naturally over an indefinite period of time. In addition, the discharge line and

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interceptor would not be addressed. This option is viable for this site based upon evaluation of the site risks, however, due to the presence of “F Listed” wastes in the near surface soil, the YOC impacted soils require management under RCRA standards. Option 2 - Removal of the Steam Cleaning Effluent Discharge Line - This involves the removal of approximately 104 meters (340 feet) of the clay line which extends from the interceptor to the effluent discharge point. Associated excavated soils will also require segregation, characterization, and disposal. In conjunction with other options this could be used as part of a closure alternative. Independently this option does not address the identified impacted soils associated with the site. Option 3 - Removal of the Sand/Oil Interceptor - This involves the characterization, content removal, cleaning, and excavation of the sand/oil interceptor. Surrounding soils excavated would also require segregation, characterization, and disposal. The location of the sand/oil interceptor is shown on Figure 1. In conjunction with other options this could be used as part of a closure alternative. Independently this option does not address the identified impacted soils associated with the overspill or effluent discharge areas of the site. Option 4 - Partial Plupsins of the Discharge Line and Removal of the Sandbas Barrier - This involves plugging the discharge line with Sulfaset Cement (or equivalent) to a minimum of 0.9 meters (3.0 feet). In addition, the sandbag barrier would be removed from around the discharge line. Soil from the sandbag berm would be used for site grading and backfill. In conjunction with other options this could be used as part of a closure alternative. Independently this option does not address the impacted soils associated with the site. Option 5 - Excavation/Disposal ofthe Oil Impacted Soils Exceedins NAC Action Levels - This involves large scale excavation and disposal of all impacted areas with TPH exceeding the NAC Action Level to an average depth of approximately 0.9 meters (3.0 feet). Confirmation soil samples are required to verily that cleanup was achieved. After confirmation results are received and verified, the excavation area will be backfilled. Figure 4 identifies the discolored soil areas east of the effluent discharge line where TPH concentrations exceeded the NAC Action Level. The discolored area comprises the majority of the release area that requires excavation using this In conjunction with other options this could be used as part of a closure alternative. Independently, this option does not address the required management of the VOC impacted soils,

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the sand/oil interceptor, or the discharge line associated with the site. In addition, based upon the concentrations detected, the extent of migration identified, the depth to groundwater, and the removal of the impacted areas would not provide a significant benefit to human health or the This involves the excavation and disposal of areas with RCRA “F Listed” waste. Excavation will be completed to an average depth of approximately 0.9 meters (3.0 feet). Confirmation soil samples will also be required to verity that cleanup was achieved. Cleanup will be based on nondetectable concentrations of the "F Listed" VOCs reported by the laboratory. The maximum laboratory detection levels are dictated by U. S. EPA Method 8240B, Revision 2 (EPA, 1994). In conjunction with other options this could be used as part of a closure alternative. Independently this option does not address the hydrocarbon impacted soils, sand/oil interceptor or the discharge line associated with the site. Option 7 - Post Closure Inspection - This involves inspection for potential migration of contaminants or discharge. Inspection would be required for up to ten years. This may be a regulatory requirement if the discharge sources and impacted soils remain in place or if limited closure activities occur. In conjunction with other options this could be used as part of a closure alternative. Due to the presence of “F Listed” wastes identified, this option alone would not meet the requirements of Option 8 - Fencing and Demarcation ofEffluent Discharge Area - This involves demarcation around the sand/oil interceptor and around the perimeter of the effluent discharge area. Fencing will consist of “T-Posts” with cable wiring. Signs will be placed to indicate that the area is impacted by the identified COCs. This will prevent disturbance of the area and allow for natural degradation of the COCs. This option could be used as part of a closure alternative in conjunction with other options. Independently it does not address the closure of the sand/oil interceptor or effluent discharge line, or removal of the impacted soils. Option 9 - Bioventing to Remediate COCs in Place - This requires the installation of numerous shallow bioventing and monitoring wells; designing and installing a venting system using conventional or alternate energy sources; continuing venting for up to 10 years with periodic off gas monitoring for oxygen, carbon dioxide, and methane; monitoring and reporting on a quarterly basis for 10 years; and confirmatory sampling upon completion of remedial activities.

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Due to title type of site specific COCs, the concentrations detected, the evaluation of the “A through K” analysis, the depth of migration, the restrictions of the site geology, and the costs in comparison to the benefits added, this is not a viable option for consideration. 2.3 ANALYSIS OF CLOSURE ALTERNATIVES The following closure alternatives were developed using one or more of the options presented in Section 2.2. Based upon a review of each of the options, the following alternatives have been developed based upon; the risk evaluation (“A through K” Analysis) for the protection of human health and the environment, control of the sources of the releases, long term effectiveness, implementability, and estimated cost to complete in relation to the other alternatives under Under this alternative, no further action is taken to address closure of the discharge line, sand/oil interceptor, …