SITE INFORMATION AND CORRESPONDENCE

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Wendy L. Cohen • 'S' 22 January 1996 Additional Potential Sources of VOCs A survey of VOCs in domestic supply wells in the vicinity of the TDD and All Pure conducted by the Board beginning in November 1991 identified the presence of chloroform and carbon tetrachloride in several domestic wells north of All Pure. Although chloroform concentrations have been below the Proposition 65 level, carbon tetrachloride exceeds the MCL in at least two domestic wells north of All Pure. Additional potential sources of VOCs that have been identified in the area include the TDD, Lyoth Loading Station, and Triple E Produce. Investigations have been conducted at each of these facilities. A plume of tetrachloroethylene and trichlorethylene has originated from the TDD and migrated to the northeast. Although low levels of chloroform are present in the northern portion of TDD, this plume of chloroform is separate from the chloroform at All Pure and that in the domestic wells north of All Pure. No carbon tetrachloride has been detected in any of the TDD wells. All carbon tetrachloride detected in ground water has occurred east of South Banta Road. The Lyoth Loading Station is a former Chevron bulk fuel loading station. Two monitoring wells on the site are screened between 11 and 26 bgs. In the Board's survey, VOCs were not detected in either of these two wells, but because detection limits in one well were elevated due to the presence of high levels of petroleum hydrocarbons, it was not possible to confirm the absence of VOCs in that well. Triple E Produce is a fresh produce processing plant approximately two miles southwest of All Pure. Eight monitoring wells have been installed to monitor the chloroform plume originating from this site. Seven of these wells are screened between 60 and 90 feet bgs. One well is screened between 117 and 137 feet bgs. The chloroform plume has been identified as moving to the northwest, away from TDD, Lyoth Loading Station, and All Pure. Board staff collected samples from these wells in its 1991 survey. Carbon tetrachloride was not detected in any of these monitoring wells during the survey. Summary Activities at the All Pure facility have resulted in soil and ground water contamination with chloroform, carbon tetrachloride, and other chlorinated hydrocarbons. Chloroform is present in the ground water at All Pure in concentrations which exceed the Proposition 65 level. Carbon tetrachloride is present in concentrations which exceed the MCL. The lateral and vertical extent of this contamination have not been Jetermined. Some domestic wells north of the facility have detectable concentrations of chloroform and carbon tetrachloride. Although chloroform in these domestic wells has not exceeded the Proposition 65 level of 10µgll, carbon tetrachloride has exceeded the MCL for drinking water in two of the domestic wells. It does not appear that the chloroform and carbon tetrachloride are coming from the TDD or the Lyoth Loading Station.