Document 0OXqeo3OdoqjNXOEzyo0pgoV

AR226-2584 (BUSS DuPont Engineering May 7,2002 \ ' George R. D asha1 Geologist Division o f Water Resources 1201 Greenbrier Street Charleston, WV 25311-1108 . '' . '' DuPont Enginesrins Battey Mill Plaza - BM0.2? Lancaster pike Si ftte. 141 Wilmington, OE198D5 . Dear Mr, Dasher: ' DuPont appreciates the opportunity to answer questions and respond to comments regarding the February 2002 Si-face Water and Groundwater Monitoring Report for Washington Works Facility ani Local, Letart, and Dry Run Landfills. With this letter we are providing our response to your letter, dated April 29,2002. Listed below are the comments, as identified in your letter, followed by the DuPont response to that comment. G eneral: When w iltyour office be providing us with the proposed locations, etc, fo r the new groundwater monitoring wells at the three landfills? It is our understanding we have requestedfo u r additional wells at the Local Landfill, five a t the Day Run Landfill, and three at the Letart L andfill We have included maps showing the general location (marked hi 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 Run 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 o f ascending order? In other words, the oldest data should be at the top o f the list and the newest data at the bottom. In fa ct, it m ight be appropriate to list the data with the dates in the left column and the wells In the top row, using a separate tablefo r surface and groundwater data. An exam ple would be as such; E. I. flu Pomb Nemours and Company m - m flev.an r n ASH0X8247 EID521407 Mr,Dash# Response to Agency Comments Msy 7,2002 Date Date 1 Date2 Date3 Date4 DateS W eill Data Data Data Data Data Well 2 Data Data Data Date Date Well3 Wed4 Date Data Data Data Data Data Date Data Date ' 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 titan December 2001, where not all o f the monitoring points were sample! on the same date, will no longer be included in these tables'. Dry Run L andfill: The datesfo r Stream Sam pling Point #2 in the Dry Run L andfill Surface Water Table are out o f 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 o f 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 m onitoring weU DRMW-6A omittedfrom the groundwater table? Is this well still being sampled? Table 4.1B o f the February 2002 Surface Water and Groundwater Monitoring Report is a two-page table; data for groundwater monitoring well DRMW-6A is included on the second page o f the table. ASH018248 EXD521408 A M?- Dasher Response So Agency Comments May 7,2002 Why were Stream 1 and Stream 2 omittedfrom the surface water table? Stream SamplingJo in t #1 and Stream Sampling Point #2 are included in Table 4.1A o f the February 2002 Surface Water and Groundwater Monitoring Report. Letart Landfill: .. Why were thefollow ing monitoring point? omittedfrom the report; Lower Pond, North Spring, PZ-1, PZ-2, PZ-S, Route 33 Stream , Stream M ountain Road, Southw est Spring, and Upper Pond? Route 33 Stream is being monitored and is included in Table 3.1A o f 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 B rinker Run and M ud 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 thefollow ing monitoringpoints omittedfrom the report: Outlet-002, Outlet-003, Outlet-101, "R 2", Stream #1, and Stream #2? Outlet-101 is being sampled and is included in Table 2.1A o f the February 2002 monthly 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. Andrew S. Hartten Project Director cet AnnBradley LauraWalter File ASH018249 EID521409