Document JJ1g7GLNGjLOKjQvYYg8rKEge

AR226-2584 OuPoni Ena'ineeritiB BarttYMillPlBZa.Blllg.27 Lancaster Pike 8. ftte. 141 Wilmington.OE 1980S DuPont Engineering May 7.2002 George R. Dasher Geologist Division of Water Resources 1201 Greenbrier Street Charleston, WV 25311-11 OS Dear Mr. Dasher: DuPont appreciates the opportunity to answer questions and respond to comments regarding the February 2002 Siju-faceWater and Groundwatia- Monitoring Report for Washington Works Facility anfl Local, Letart, and Dry Run Landfills. With this letter we are providing our response to your letter, dated April 2$, 2002. Listed below are the comments, as identified in your letter, followed by the DuPont response to that comment. GENERAL: When willyour office be providing us with the proposedlocations, etc, for the new groundwater monitoring wells at the three landfills? It is our understanding we have requested four additional wells at the Local Landfill, five at the Day Run Landfill, and three at the Letart Landfill. We have included maps showing the general location (marked In yellow) -where we -would like these additional wells located. ... .. ..The figures showing the proposed locations for new monitoring wells at the Washington Works facility and the Local, Letart, and Dry Rim Landfills will be included in the C-8 Plume Identification/Groundwater Assessment Work Plan, This document is being finalized and will be submitted following internal review by DuPont. In the groundwater and surface water tables, could the data be made in descending order instead of ascending order! In other words, the oldest data should be at the top of the list and the newest data at the bottom. In fact, it might be appropriate to list the data with the dates in the left column and the wells In the top row, using a separate fable for surface and groundwater data. An example would be as such; E. 1 flu PflRt da Nemours anil Company EN.39M SB. 30001) ASH018247 EID521407 Mr. Dathft Response to Agency Commam Mty7,2002 Date Date! Date 2 Date 3 Date 4 Date 5 Well I Data Data Data Data Data yeB2 Data Data Data Date Data Well 3 Well 4 Date Data Data Data Data Data Data Data Data Data The C-8 tables presented with the Second Quarter 2002 Surface Water and Groundwater Monitoring Report will be reformatted as requested for data collected from December 2001. Historical data older than December 2001, where not all of the monitoring points were sampledon the same date, will no longer be included in these tables'. DRYRUNLANDPILL; The dates fm Stream Sampling Point #1 in the Dry Run Landfill Surface Water Table are put of order. The dates for the Property Boundary sampling point were out of order in Table 4.1A. This has been corrected in Table 4.1A of the March 2002 Surface Water and Groundwater Monitoring Report which is being finalized and will be submitted following internal review by DuPont. Dates for Stream Sampling Point #1 are in order. Why was groundwater monitoring well DRMW-6A omitted from the groundwater table! Is this well stilt being sampled? Table 4.1B of the February 2002 Surface Water and Groundwater Monitoring Report is a two-page table; data for grouodwater monitoring well DRMW-6A is included on the second page of the table. ASH018248 EID521408 Mr- Dasher Respome to Agency ComiiiBits Miiy7,20CS Why were Stream 1 and Stream 2 omitted front the surface water table? Stream SamplingJoint #1 and Stream Sampling Point #2 are included in Table 4.1 A of the February 2002 Surface Water and Ground-water Monitoring Report. LETART LANDFILL: Why were the/allowing monitoring points wittedfront the report: Lower Pond, North Spring, PZ-1, PZ-2, PZ-5, Route 33 Stream, Stream Mountain Road, Southwest Spring, and Upper Pond? Route 33 Stream is being monitored and is included in Table 3.1 A of the February 2002 Surface Water and Groundwater Monitoring Report. The other monitoring points listed above no longer exist because of the construction of the landfill cap. Are Brinker Run and Mud Run being sampled at present? The Route 33 Stream sampling point is located along Brinker Run. Mud Run is not on DuPont property and is not being monitored. LOCAL LANDFILL: Why were the following monitoring points omitted from the report; Outlet-002, Outlet-003, Outlet-191, "JU", Stream #1, and Stream #2? Outlet.. 101 is being sampled and is included in Table 2.1A of the February 2002 moofhiy report. Because the other monitoring points listed above are not Consent Order- or permit-required monitoring points, these locations are not sampled. We hope that these responses adequately address your comments and questions. Please contact me at (302) 992-6820 if you would like to discuss, SSinincceererelyly, , , <A^j/L 4^) Andrew S. Hartten Project Director /'- cc: Ann Bradley Lawa 'Walter FUe ASH018249 EID521409