SITE INFORMATION AND CORRESPONDENCE

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Mr. Verrill Norwood -3- 6 August 1996 Task 4 - Laboratory Analysis All Pure proposes to analyze the soils samples for volatile organic compounds (VOCs), but does not state the analytical method to be used. The toxicity characteristic leaching procedure (TCLP) should be used on the soil samples to be analyzed for VOCs. This method uses a zero headspace extractor to allow accurate assessment of leachable VOCs in a waste. The TCLP extraction solution should be deionized water. The analytical method used should be able to achieve detection limits no greater than the water quality limits listed in the attached Volatile Organic Contaminants Found in Ground Water at Class III Landfills. The analyses requested for general minerals, pH, electrical conductivity (EC), and total dissolved solids (TDS) are necessary since nitrates, chloride, EC, and TDS are known to be elevated in the ground water in the area of the ponds. It is necessary to determine the potential of the soils to further impact ground water quality with regard to these parameters. The TCLP with deionized water should also be used on soil samples to be analyzed for these parameters. The standard protocols for analysis of water for these parameters should be conducted on the extract from the TCLP. All Pure should propose the analytical methods to be used on the extract from the TCLP for VOCs, general minerals, pH, EC, and TDS. Detection limits for VOCs should be stated. Task 5 - Report All Pure proposes to submit a report describing the sampling procedures and analytical results following receipt of the analytical results. The report is proposed to include a description of the methods and construction schedule to achieve closure of the surface impoundments. Closure is proposed to be accomplished by backfilling with clean compacted native soil and grading to prevent ponding of surface water over the closed impoundments and divert runoff to the south. The report on soil sampling should include the proposed disposal method and/or remediation method for all contaminated soils and the source of soil to be used as backfill. Laboratory analyses may be required for the fill soils before backfilling. The report should also include cleanup levels to be achieved in the ponds, an estimate of volume of soils to be excavated, removed, or remediated, a grading plan, and proposals for confirmation sampling and soil compaction. Chapter 15 requirements for closure of the surface impoundments will not apply if no contaminants remain in the soil. The schedule to be included in the report must include schedules for submittal of a closure report and construction of any building over the impoundment areas. The closure report must report the date of closure of each pond, the volume of soil excavated, removed, or remediated, all analytical results for soils removed or remediated and all confirmation samples, percent compaction of the soils, and the final grading plot. Closure of the impoundments must be under the direct supervision of a registered civil engineer or certified engineering geologist. The responsible engineer or geologist must sign the report and include his or her stamp with expiration date if an engineer, or registration number if a geologist.