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k%j KLEINFELDER <br /> The soil cuttings generated from the central borings/monitoring wells may be properly <br /> disposed of with the proposed excavated soil. Soil cuttings generated from the radial <br /> borings and water generated from the well development and sampling can be disposed of <br /> on site. <br /> 4.2 PESTICIDE AREA PS-3 <br /> During the June 1988 and November 1988, soil sampling investigation, surface and <br /> subsurface soil samples were collected from four locations at PS-3. <br /> Low concentrations of organochlorine pesticides were detected in the surface and <br /> subsurface samples from all PS-3 sample locations except for the subsurface sample from <br /> PS-313 which had no detectable concentrations. DDE, DDD, and DDT were detected in <br /> both the surface and subsurface samples. Endosulfan I, endosulfan II, or endosulfan <br /> sulfate were detected in three of the four surface samples and in none of the subsurface <br /> samples. Heptachlor was detected only in one surface sample. Both chlordane isomers <br /> were detected in one of the surface and two of the subsurface samples. The detected <br /> concentrations of DDE, DDD, DDT, heptachlor, and chlordane were significantly below <br /> the California Administrative Code, Title 22 Total Threshold Limit Concentrations <br /> (TTLC) for designation of a hazardous waste. Although endosulfan is listed as a hazardous <br /> material in Title 22, no hazardous waste levels are specified.Ir <br /> Carbamate and urea pesticides were detected in each of the surface samples analyzed from <br /> PS-3 but were not detected in any of the subsurface samples. The highest concentrations <br /> detected were 3,700 ug/kg eptam, 1,100 ug/kg methomyl, and 2,000 ug/kg diuron. There <br /> are no specified concentrations for designation as a hazardous waste in CAC Title 22 for <br /> the carbamate pesticides detected. Eptam is highly volatile and should decrease in <br /> concentration in a relatively short amount of time. Methomyl is the most toxic and has a <br /> rate oral acute Toxicity (LD 50) of 26 mg/kg. <br /> The detected concentrations of organochlorine pesticides did not consistently increase or <br /> decrease with depth, but the carbamate and area pesticide concentrations decrease with <br /> depth and were below detectable limits at 2.5 feet. The organochlorine pesticides are <br /> significantly below the specified CAC Title 22 TTLCs, and there are no specified TTI-Cs <br /> for endosulfans I and II, endosulfan sulfate, and the carbamates. The detection of these <br /> 161-89-107 12 <br />