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J Chlordane was not detected above a reporting limit of 20 ug/kg (parts per billion) in either the excavation floor sample (SP 13-A) or in the stockpile sample. The laboratory was able to obtain lower detection limits for DDE and DDT (2 and 6 ug/kg, respectively), and reported concentrations of 2.1 and 8.9�zin SP-13A. However, all three of these detection limits are lower than the 30 ug/kg that were requested by Mr. Infurna in his June 14 1995 letter to Mrs. Snell. At this detection limit, no pesticides would have been detected, and therefore in Table 1 sample SP-13A is shown as ND for chlordane and DDT. n. e initially reported above the 30 u In the sidewall sample, both chlordane and 4,4-DDT were mite y p �g detection limit in SP-14A. Therefore, the duplicate sample (SP-14B) was analyzed to confirm the results. As was the case with the water sample collected in January 1996 (Table 2), analysis of the duplicate sample revealed no contaminants, even at the lower-than-regeusted reporting limits. The results from SP-14B are in agreement with those previously obtained from the nearby borings SP-10 and SP-1 I at a depth of 8 feet, and are considered to be valid. 5.4 CONCLUSIONS AND RECOMAMNDATIONS Random sampling by RESNA Industries in 1993 located an area of soil in which high concentrations of pesticides were reported in one sample. Upgradient Environmental thoroughly investigated the extent of the pesticides by drilling six borings within a radius of five to ten feet around the location of RESNA's boring and six additional randomly-spaced borings in the site vicinity. That investigation identified a small area surrounding boring SP-8 in which low concentrations of the pesticides chlordane and 4,4-DDT were present. This area was remediated by excavating an area measuring approximately 6 x 6 x 7 feet around SP-8 and disposing of the soil as a non-hazardous waste at Altamont Landfill. The source of the pesticide contamination is uncertain. No potential sources of pesticides are evident on the property or from its historical uses. Because DDT has been banned for a number of years, its presence on the property may have been the result of a minor incidental surface release many years ago, or it may have been present in soil that was imported to the site when it was filled, graded, and developed for commercial use around 1980. Nevertheless, in view of the very limited depth, extent, and concentration of the DDT and chlordane, the total volume of these contaminants in the soil must have been very small. As indicated in Section 4.0 above, the detection of 300 ppb chlordane and 420 ppb DDT in sample SP- 14A was not confirmed by analysis of the duplicate sample SP-14B,casting doubt on the validity of the results from SP-14A. Nevertheless, even if the results are valid, they do not exceed the Preliminary Remediation Goals (PRGs) established by the US EPA, Region IX, and Cal/EPA, Department of Toxic Substances Control (DTSC) and therefore no further action is warranted. The PRG for chlordane in soil in areas zoned for residential land use is 0.34 mglkg(or 340 ppb). The PRG for DDT in soil in a residential area is 1.3 mg/kg (or 1300 ppb) (See US Environmental Protection Agency, Region IX, 1995, Region IX Preliminary Remediation Goals, 2d Half 1995, September 1995.) These remediation goals are more stringent than those for commercial or industrial areas. 3