Document M4QXy4dZgZ1obBLmdYqLGpN2M

AR226-2537 UNITED STATES ENVIRONMENTAL PROTECTION AGENCY Region III 841 Chestnut Building Philadelphia, Pennsylvania 19107 6NV1R6NMENTAI owes In Reply Refer To; (3HW52) CERTIFIED MAIL RETUEILJRECEIPT REQUESTED 8EP 3 0 1991 PIAMT nig COPY l0 NOT RIMOVt W. M. stewart E.I du Font de Nemours and Company, P.O. Box 1217 Parkersburg, WV 26102 Inc. Res Washington Works WVD 04 587 5291 ^.z^ Dear Mr, stewart: The Environmental Protection Agency (EPA) has completed the review of the second draft of the RCRA Verification Investigation (VI) Work Plan submitted December 14, 1990 by Du Font for their Washington Works Plant. The VI Work Plan hasi substanttvely met the VI Work Plan requirementsi of the RCRA permit issued to Du Font on December 13, 198S and EPA conditionally approves the Work Plan subject to the following requirements: I. Unit A-l, Du Pont Road Landfill The leaehate sampling program is accepted as proposed. The groundwater sampling program ie accepted as proposed. in addition, Du Font must conduct surficial soil sampling (o- 2 feet) as called for in permit condition II.B.l.b.(1)(a)(i). These saaples muat be tested for the parameters listed in Table 18 of the RCRA permit. Use the appropriate soil sampling plan developed for other solid waste management units; such plan may be modified as necessary tor this unit. For figure 2 of the Work Plan; Currently the scale of this map is l"=300. The map scale must be changed to express the scale PriHtf M Rie-fcttil Pisptr CF033537 EID482263 either as a fraction, be included. ex. 1;24,000, or the units for the 300 must II. unit A-2, River Bank Landfill Soil, groundwater, and leachate sampling plans are accepted as proposed. III. Unit B-4, Anaerobic Digestion Ponds the Ths plan for soil and groundwater ponds is acceptable as proposed. samples to be taken outside For the cores taken inside the ponds; samples must be taken every 5 feet (starting 0"2 feet below the level of backfill), where soil characteristics change, and taken until groundwater is encountered. Groundwater samples must be taken in Table 18. from each boring and tested for the parameters listed IV. Unit c-6, Polyacetal Product Incinerator For this unite, it is sufficient to sample one upwind and one downwind soil sample at the specified locations. In addition the sampling parameter list for this unit must include the metals burned in this unit, specifically, cadmium, chroiaimtt, lead, and selenium. V. Unit F-ll, Injection Wells This Bubmigsion and plan are accepted as proposed. VI. unit H-13, Burning Grounds The number and location of the soil borings are approved but soil samples must be taken every 5 feet, where soil characteri sties change, and until groundwater is encountered. VII. Trigger levels for a RCR& Facility Investigation if a The Permittee must conduct a RCRA facility Investigation (RFI) release of a hazardous waste or hazardous constituents from a SWMU to groundwater, surface water, soil or sediment exceeds; I. The Practical Quantitatlon Limit (PQL) where the PQL is at or below the health-based the lowest concentrations level (available upon of analytes that can request). PQLs are be reliably deter- CB-033538 EID482264 mined within specified limits o precision and accuracy by SW-846 fTest Methods for Evaluation Solid Wastes; Physical/Chemical Methods) methods under routine laboratory operating conditions. Should the PQL not be practical, the Permittee must justify the use of a higher number. This justification must be in the Verification Investigation Report. 2. The method detection limit where the PQL is greater than the health-based limit, VIII. QA/QC E.J. review of Clugston of EPA's the second draft Annapolis Laboratory has of Du Font's QA/QC plan. completed the The plan is approved subject to the reviewer's comments which are enclosed and the following comments; If groundwater monitoring wells are pumped dry during the well evacuation, sampling must be performed within two hours, not the 24 hours specified in Appendix B of the VI Work Plan? and Where groundwater samples tor metal analyses are taken, both filtered and unfiltered samples shall be taken and analyzed. IX. Effect of public Water Supply Wells From investigations already performed, it is obvious that the public supply wells have a significant impact on the groundwater flow at the site. Therefore, provide available data on the those wells such as size, depth, screened interval, pumping rates, etc* X. Data Management and Models All raw data must be kept in an easily retrievable form for the duration of the HSWA permit and provided to EPA upon request. it EPA recognizes the legitimacy of using computer models to determine the extent o or risk associated with contamination. However, approval of any conclusions of this study which are based on computer models necessitates that EPA have access to the same models. Du Font must provide the name and distributor for any commercially available package and make the necessary arrangements for EPA access a custom designed package is used. CT033539 EID482265 XI. Schedule Within 180 days of receipt o this approval of this VI work Plan or by April 6, 1S92, Du Font shall execute the Plan and submit the VI Report to EPA for approval. Du Font shall also submit the VI Report to WVDMR. Acceptance of the above conditions may be addressed by submitting revised pages and/or a supplement to the VI Work Plan within 30 calendar days of receipt of this letter. Should exception be taken to all or part of the above conditions, a written statement of the grounds tor the exception shall be submitted within 15 days from receipt of this letter. XII. other comments The supplement to the VI Work Plan must include a proposed schedule for field and sampling activities* WVDHR and EPA Bust be notified of any changes in this schedule at least 14 calendar days in advance, you should have any questions, please do not hesitate to if in contact John J. Humphries at (215) 597-0320 or Mary F. Beck at (2155 597-7239. enclosure cci <3*S. Atwal (WVDMR) ' /' ^/ 7b^e^^r^t^L/.<A'-<li(e^n, chief RCKA Programs Branch CF033S40 EID482266