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Remedial Strategy for Perchlorate-bearing Commingled Plumes at an Explosives Test Facility EPA Technical Support Project Meeting October 21, 2004 Speaker: Vic Madrid Lawrence Livermore National Laboratory Environmental Restoration Division UCRL-PRES-207684 This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48. Slide 2 Site 300 location map Location Map Site 300 Courtesy Kevin Mayer, US EPA, Region 9 Slide 3 Site 300 Raw Chemicals High explosives RDX or cyclonite: C 3 H 6 N 6 O 6 HMX or octogen: C 4 H 8 N 8 O 8 Potassium perchlorate: KClO 4 Ammonium perchlorate: NH 4 ClO 4 Mock Explosives: Ba(NO 3 ) 2 Nitric acid: HNO 3 Radionuclides Tritium: 3 H Depleted uranium ( 235 U/ 238 U < 0.007) Solvents & heat exchange fluids TCE Silicon oil (TKEBS/TBOS) Slide 4 Site 300 Technical Operations HE Processing Facility Clarifier & Cloth Filter Open burn treatment facility Unlined lagoon HE Solid Waste Dry well Floor drain Septic system Open air detonation on firing table Device shipped offsite Raw Materials HE Liquid Waste Test Device Firing table gravel & shot debris disposed in unlined landfills Slide 5 Site 300 Technical Operations HE Processing Facility Clarifier & Cloth Filter Open burn treatment facility Unlined lagoon HE Solid Waste Dry well Floor drain Septic system Device shipped offsite Raw Materials HE Liquid Waste Test Device Environmental Test Facility TCE used as heat exchange fluid Slide 6 Data from CERCLA investigations 1,000+ boreholes ~ 70% continuously cored > 50% geophysical logs up to 550 ft depth 600+ ground water monitor wells 15 years of ground water monitoring data hydrographs covering drought to El Nio conditions broad range of chemical data including isotopes Slide 7 Site 300s commingled plumes 8 Operable Units 12 commingled plumes Low levels of perchlorate detected in nearly all plumes Slide 8 Summary of perchlorate data From 1965 to 1975 about 2 tons of perchlorate were used at Site 300 Perchlorate monitoring began in January 1998 at the request of the RWQCB 2,520 ground water samples have been collected from 380 monitor wells and analyzed for perchlorate at 4 g/L detection limit 730 perchlorate detections in 122 monitor wells Maximum result = 65 g/L detected down gradient of a landfill pit The most widespread perchlorate contamination is located beneath the HE Process Area where it is commingled with VOCs, RDX, & elevated nitrate. In the northern part of Site 300 perchlorate is commingled with tritium, depleted uranium, and elevated nitrate. Slide 9 Major geologic structures Slide 10 Pit 7 complex tritium plume Slide 11 Extent of pit inundation by shallow ground water during 1998 El Nio Dec 97Feb 98Mar 98 Apr 98May 98 Jul 98 Slide 12 Hydrogeologic Cross-section through the landfill pits Pit 7 Pit 5 Pit 7 Pit 5 Slide 13 Extent of depleted uranium in ground water Bedrock aquifer Alluvial aquifer Pit 3 Pit 5 Pit 7 Slide 14 11 14 8 Perchlorate detections in Pit 7 area Slide 15 Proposed remedial alternatives for perchlorate-bearing commingled plume Funnel & gate PRB Hydraulic Diversion Multi-component remedial alternatives to remove depleted uranium and perchlorate, prevent pit inundation, & recycle tritium 1) Hydraulic diversion system 2) In situ (PRB) using cow bone char or apetite & ion exchange resin 3) Ex situ (funnel & gate) using cow bone char or apetite & ion exchange resin 4) Recirculation of tritium-bearing effluent for ex-situ option in situ ex situ Draft Final Pit 7 Remedial Investigation/Feasibility for the Pit 7 Complex at Lawrence Livermore National Laboratory Site 300, December, 2004 UCRL-AR-202492-DR Slide 16 Tnbs 2 Aquifer Conceptual Model B832 Cyn HE Process Area GSA 650 600 550 Unconfined Confined Discharge to alluvial aquifer Extent of Saturation GW Elevation Contours Recharge A A Slide 17 Tnbs 2 TCE (g/L) 50 20510 30 40 TCE g/L 5 10 20 30 40 50 10000 feet Former W-S Well 6 Mass Est. = 13 kg TCE source Slide 18 Tnbs 2 RDX (g/L) 45 1 90 45 10 TCE g/L 5 25 50 75 50 25 5 RDX g/L 100 Mass Est. = 3 kg RDX source 10000 feet 50 25 5 5 50 Slide 19 Tnbs 2 NO 3 - (mg/L) 10 10000 feet Mass Est. = 100,000 kg Possible nitrate source 45 60 90 Slide 20 Nitrate (mg/L) along cross-section A-A 97 120 130 100 70 90 80 35 15 62 58 ND 12 3.6 ND 86 - >100 mg/L 65 - 85 mg/L 51 - 65 mg/L 31 - 50 mg/L 11 - 30 mg/L ND- 10 mg/L Slide 21 Dissolved O 2 (mg/L) along cross-section A-A 4.6 4.1 7.6 5.8 7.2 0.8 0.2 Perchlorate (g/L) along cross-section A-A ND > 8 g/L 4 - 8 ND < 4 ND 5.8 9.8 9.2 ND 9.2 ND 8.7 5.7 11 ND Slide 26 Ongoing ground water cleanup activities Currently operating 13 ground water treatment facilities 7 facilities treating perchlorate 2 new facilities planned for FY05 will treat perchlorate Slide 27 Key question Given large-scale, dilute, multiple constituent plumes in low-yield aquifers, how do we develop cost-effective strategies for ground water extraction and treatment using available remedial technology and effluent disposal options? Slide 28 Treatment options COC Destruction Removal VOCs & RDX GAC ClO 4 - & NO 3 - Bioreactor Ion exchange Phytoremediation Slide 29 Effluent disposal Method Advantage Disadvantage Air misting - nitrate utilization by - wetland creation indigenous grasses Subsurface - hydraulic control - maintenance Injection- preserve resource Surface - low cost- compliance issues Discharge- low maintenance Slide 30 Does GAC remove perchlorate? W-817-03 GAC_1 GAC_2 GAC_3 GAC_1 influent GAC_2 influent GAC_3 influent effluent TCE = 14-29 g/L RDX = 5-10 g/L ClO 4 - = 17-33 g/L NO 3 - = 70-90 mg/L W-817-03 ClO 4 - break through Slide 31 GAC profiling results Treated 50,000 gallons @ 1-2 gpm flow rate using solar-powered GAC treatment unit ClO 4 - breakthrough after 20,000 gallons Effluent @ perchlorate breakthrough GAC Profile TCE =