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California Regional Water Quality Control Board ;� <br /> `\- Central Valley Region 1 <br /> v Karl E. Longley, ScD, P.E., Chair "�" <br /> Linda S.Adams Arnold <br /> 1665 E Street, Fresno,California 93706 <br /> Secretary/ Phone(559)445-5116•FAX(559)445-5910 Schwarzenegger <br /> Environmental http://wvm.waterboards.ca.gov/centralvalley Governor <br /> Protection <br /> TO: Clay Rodgers FROM: C. Dean Hubbard <br /> Senior Engineering Geologist Engineering Geologist <br /> P. G. No. 57 <br /> SIGNATURE: <br /> Shelton R. Gray <br /> DATE: 19 November 2009 Sen" ngineering Geologist <br /> SIGNATURE. <br /> SUBJECT: CONSIDERATION OF REQUEST FOR NO FURTHER ACTION REQUIRED <br /> DETERMINATION, FORMER LYOTH LOADING STATION AND LYOTH <br /> OFFSITE, SOUTH BANTA ROAD, TRACY, SAN JOAQUIN COUNTY <br /> Rationale: The areas of crude oil affected soil and groundwater have been delineated on the <br /> former Lyoth Loading Station site, including those that extend downgradient to the Lyoth <br /> Offsite property. It is of limited extent within two separate circular areas approximately 50 <br /> feet wide near the center of the former Lyoth facility. A slightly larger elongated portion of <br /> affected soil occurs on this parcel and extends offsite, beneath and generally within the <br /> historical Old Valley Pipeline (OVP) right-of-way and railroad tracks easement at the <br /> northeast property boundary. A smaller oval area of affected soil, less than 100-feet <br /> across, occurs near the western property boundary, extending offsite into the railroad <br /> easement. As indicated on the attached Figure, affected groundwater occurs: a) along a <br /> part of the former facilities' northeast property boundary, b) within the OVP and railroad <br /> easement, and c) offsite to the northeast onto the Lyoth Offsite property. <br /> The maximum vertical extent of crude oil affected soil on the former Lyoth facility is defined <br /> by analytical results of non-detect (ND) for soil samples from depths of between 15 to 25 <br /> feet below ground surface (bgs). The area of impacted groundwater is larger than the area <br /> of affected soil as indicated on the attached Figure. Fuel fingerprint analysis and <br /> laboratory evaluation confirmed the petroleum hydrocarbons present were consistent with <br /> degraded San Joaquin Valley crude oil. <br /> A 1999 Health Risk Assessment (HRA) was completed based on the anticipated future use <br /> of the former Lyoth facility. The HRA findings indicated the total excess cancer risks <br /> determined were within or less than the California Environmental Protection Agency <br /> (Cal/EPA) generally acceptable risk range, indicating there should be no unacceptable <br /> health risk to future residents. The consultant's HRA report concluded that ..."no remedial <br /> action is necessary to make the Site protective of human health under the scenarios <br /> evaluated." The California Office of Environmental Health Hazard Assessment (OEHHA) <br /> staff reviewed the HRA findings. OEHHA staff's review of the HRA addendum in April <br /> 2002 concurred that according to additional inhalation pathway data, the findings were <br /> California Environmental Protection Agency <br /> ORecycled Paper <br />