SITE INFORMATION AND CORRESPONDENCE

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• • Wendy L. Cohen -2- 22 April 1993 water quality. If LOF can demonstrate that land treatment of this section, i.e. , Composite 4, will not result in water quality degradation then the remaining sections also will not degrade water quality. 2. The basis of the proposal should not be the Board's approval of similar operations in the past, which, incidentally, were of much smaller magnitude. Instead, the basis should be its effectiveness in treating the contaminated soils to levels which will not result in water quality degradation. 3. As stated in the general comment above, Attachment 2 should be used to assess the water quality impacts of the contaminated soils. Attachment 3 provides the recommended water quality limits for the petroluem hydrocarbon constituents found at LOF: TPHD - 10 ppb; toluene - 40 ppb; ethylbenzene - 30 ppb; xylene - 20 ppb. These goals must be divided into the highest concentration of each constituent from a waste extraction test (WET) to obtain the necessary environmental attenuation factor that the site must provide for each constituent to prevent water quality degradation. In lieu of WET concentrations, LOF may use the results from Composite 4. However, the Composite 4 concentrations must be divided by 10 to account for the dilution factor during the WET test before determining the attenuation factors. This results in a conservative estimate because it assumes that 1009'. of the constituents are soluble. Thus, ENVIRONMENTAL SOLUBLE CONCENTRATION OF CONSTITUENT IN WASTE (µg/1) ATTENUATION = --------------------------------------------------=-- FACTOR WATER QUALITY LIMIT (µg/1) EAFTPHD = 4,800,000 µg/l + 10 µg/l = 480,000 EAFTotuene = 1,400 ug/l + 40 /tg/l = 35 EAFEthylbenzene = 1,800 mg/l + 30 /tg/l = 60 EAFxylene = 3,900 /tg/l + 20 = 195 LOF must demonstrate, for example through the use of a model such as SESOIL, that the site can provide the attenuation factors which will be obtained using soluble concentrations or as estimated above. Otherwise, a treatment pad must be engineered to protect water quality. 4. With regards to heavy metals, LOF must run a WET on each of the four composites and on the native soils so that a direct comparison can be made. LOF must perform a similar analysis specified in Item 3 for those constituents exceeding their respective background water concentrations or numerical water quality limits. 5. The design parameters of the treatment system must be specified. These include the treatment period, depth of the treatment zone, optimum soil moisture, pH, soil carbon content, fertilizer needs, ground and surface water monitoring, soil and soil-pore water monitoring, drainage controls, and contingency