Document Bve8Lgv57NL6R57Vk5vxm5m7w

AR226-2542 EID911356 WASHINGTON W ORKS & EPA an1!i! PLANNING MEETING JUNE26, 1997 i 8I0C0QHSV ONT PERSONNEL Bill Mancini-DuPont CRG-Program Manager Walt Stewart-Site Sr. Environmental Control Consultant Dan Weber-Site Environmental Engineer Mike Lukas-DiiPont CRG-Principal Engineer Andrew Hartten-DuPont CRG-Senior GeoJPM 6I0200HSV E ID 9113S 7  10:00-10:10 Introduction (W a lt/B iil) 10:10-10:40 Review 30 Day Response (Dan) 10:40-11:10 Current Conditions Summary (Dan/Andrew) 11: 10- 11:20 11:20-12:20 12:20- 1:00 Break RFI W.P. Conceptual Approach (Mike/Andrew) Define Path Forward (Ah) E ID 911358 GZ0Z00H SV  To review the required scope and schedule for RFI activities IZ 0ZQOHSV EID911359 CUSSION TOPICS List of SWMUs to be addressed in RFI Current conditions and VI results RFI workplan technical approach and schedule f 2Z0Z00HSV EID911360 I 30-DA Y RESPONSE EC050GHSV EID911361 CURRENT CONDITIONS SUMMARY WOE00HSV EID911362 GEOLOGY & HYDROGEOLOGY \ sso zo o h sv E ID 911363  Simple stratigraphy--Ohio River Terrace Deposits >Fine grained soils near surface and along riverbank Sand and gravel primary site geologic unit and aquifer Overlies Permian age bedrock (shale/ss) 9OK00HSV EID911364 ROGEOLOGY Flow direction controlled by groundwater pumping centers Pumping induces recharge--flow into site from river East Well Field 2000 gpm Ranney Well 800-1000 gpm Lubeck 500-700 gpm 30200HSV EID911365 WASHINGTON WORKS VI RESULTS KEY CONSTITUENTS DETECTED IN GROUNDWATER (by SWMU) Concentration Range (mg/1) RIVERBANK LANDFILL Freon 113 G-8 Tetrachloroethylene Chloroform Arsenic Mercury .081-3.1 .052-7,1 .019-.22 .005-.006 .007-.38 .0005-.028 ANAEROBIC DIGESTION PONDS Freon 113 Methylene Chloride C-8 Barium Lead .015-4.0 ,26-.29 .025-38.0 2.9-3.8 .13-36 BURNING GROUND Carbon Tetrachloride Tetrachloroethylene Trichloroethylene Freon 113 .009-036 .011-.025 027-.32 .Q27-.039 ASH002028 E ID 911366 RFI WORKPLAN TECHNICAL APPROACH t i 620Z00HSV EID91X367 TECHNICAL APPROACH Fully understand hydrogeologic system (i.e., confirm gw capture) Identify key data needs (hydro. & analytical) Meet applicable EPA standard RFI requirements Refine Site Conceptual Model (SCM) 0EGC0OHSV 'E CONCEPTUAL MODEL Present hypothesis to confirm or refute current understanding Supports risk-based decision making i Aids in identifying potential remedial alternatives Focuses RFI activities I lEOZQOHSV E ID 911369 K-BASED DECISION KING Screen VI data against Region III residential RBCs to identify applicable analytical list Development of site-specific RBCs eeozooHsv EID911370 WORKPLAN CHNICAL APPROACH STEP 1-Identify initial data needs (included in workplan) STEP 2-Construct groundwater flow model to fully define hydrogeologic system (identify additional data needs) STEP 3-Refine site conceptual model to confirm or identify final data needs STEP 4-Submit tech, memo to EPA with final RFI data collection points :* STEP 5-Field implementation tCOZOOHSV EID911371 WORKPLAN TABLE OF 'NTENTS Introduction Current Conditions (SWMUs, Geo/Hydro, SCM) RFI Technical Approach Report Preparation References K 0Z00H SV EID911372 WORKPLANENDICES Proj. Management Plan Sampling & Analysis Plan QAPP Data Management Plan HASP Community Relations Plan S0Z0OHSV i E ID 911373 WORKPLAN PA TH f t )WARD :Submittal date September 26,1997 9COZGOHSV E ID 911374