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Memo to Greg Vaughn -2- 1 June 1989 (Freon 113) , 1,1 ,1-trichloroethane (TCA) and tetrachloroethylene (PCE) . Each of these constituents were in concentrations an order of magnitude lower than their respective MCL or SAL. Based on these results, the drummed purge water meets drinking water standards and therefore, may be disposed of to land without posing a threat to water quality. The drilling muds and cuttings are not hazardous. However, the reported concentrations of heavy metals were for totals and a determination of a potential threat to water quality is more difficult. In those cases where land disposal is proposed. Future sample analyses of the drilling muds and cuttings should be performed using the Waste Extraction Test using a citrate buffer as described in Section 66700 of Title 22 of the Health and Safety Code. If the total concentration for heavy metals are assumed to be representative of worst case soluble concentrations, then a ten-fold dilution factor is used in the conversion from mg/kg to mg/1 . Using the Designated Methodology an attenuation factor must be considered to determine the potential threat to water quality. If an attenuation factor of 10 is used, then only four constituents (arsenic, barium, chromium and lead) , when compared to the respective Drinking Water Standard (DWS) , are greater than that concentration. However, if an attenuation factor of 100 is used, then all the heavy metal constituents, when compared, are below their respective DWS. (Refer to the attached Table. ) These considerations are also applicable to the VOCs detected in the muds and cuttings. TCE was the only VOC that would not be below the DWS using an attenuation factor of 10 but would be below the DWS using an attenuation factor of 100. If the volumes to be disposed, disposal areas, disposal method, soil/sediment soils at the facility are considered to influence the attenuation, it is my opinion that a one time, short-term application for disposal to land of these muds and cuttings should not pose a threat to water quality. The second document: Drilling Mud, Cuttings, and Development Water Disposal , was submitted by Hargis and Associates and contained three separate proposals for handling the wastes. Hargis has proposed to land dispose on-site of muds and cuttings which have concentrations of VOCs below the STLC or TTLC. However, relatively few VOCs (TCE, vinyl chloride) have an established STLC or TTLC values. Hargis has proposed to land dispose of VOC contaminated muds or cuttings which may be considered to be at designated levels. This proposal is not acceptable. The Hargis proposal is also unacceptable in that they did not include sampling and analyses for heavy metals. Hargis has proposed that muds or cuttings which exceed the STLC or TTLC will be hauled to an appropriate facility for disposal . They also proposed to dispose of any development waters which exceed the MCL or SAL at an appropriate facility. The latter two proposals are acceptable provided those facilities are permitted to accept those types of wastes.