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Californigegional Water Quality Cool Board <br /> Central Valley Region <br /> Karl E. Longley,ScD,P.E.,Chair a <br /> Linda S.Adams Arnold <br /> Secretaryfor 1685 E Street,Fresno,California 93706 Schwarzenegger <br /> Environmental (:// 445-5.waterb •Fax a.gov 445-5910 ��/�' laI Governor <br /> Protection http://www.waterboards.ca.gov/centralvalley I( <br /> 5 June 2009 JUN I I 2o09 <br /> INVIRoNAIc <br /> M. Scott Mansholt �S FASTN <br /> Chevron Environmental Management Company <br /> 6111 Bollinger Canyon Road <br /> Rm 3432 <br /> San Ramon, CA 94583 <br /> REVIEW — 2009 ANNUAL GROUNDWATER MONITORING AND SAMPLING REPORT, <br /> ALDEN PARK, TRACY, SAN JOAQUIN COUNTY <br /> Chevron Environmental Management Company (Chevron) submitted the Annual 2009 <br /> Groundwater Monitoring and Sampling Report (Report) dated 15 April 2009, for the Alden <br /> Park site (Site) in Tracy. The Report was prepared for Chevron by Science Applications <br /> International Corporation (SAIC) and submitted to Central Valley Regional Water Quality <br /> Control Board (Central Valley Water Board) staff for review. <br /> Groundwater sampling and monitoring was conducted in accordance with Monitoring and <br /> Reporting Program (MRP) R5-2006-0812. The Report provides an annual summary of the <br /> 2009 groundwater monitoring analytical results for the former Old Valley Pipeline fuel oil <br /> reservoir site, now occupied by the City of Tracy's Alden Park. Field activities were conducted <br /> in January 2009. <br /> According to SAIC's Report: <br /> • There are 17 monitoring wells associated with the Site. Eight were purged and <br /> sampled and nine contain free product and were not sampled. <br /> • Depth to water, ranged between 11 and 14 feet below ground surface (bgs) with a <br /> north-northwest gradient, consistent with prior information. <br /> • Total petroleum hydrocarbons as diesel (TPHd) at 280 micrograms per liter (Ng/L) was <br /> reported in downgradient monitoring well (MW)-7 and 54 pg/L in crossgradient well <br /> MW-9. Analytical results of samples from the remaining wells were non-detect (ND) for <br /> TPHd, consistent with historical findings. <br /> • Low concentrations of two polynuclear aromatic hydrocarbons (PAHs) at or slightly <br /> above the method detection limits were detected in MW-8. PAHs were ND in the <br /> remaining samples. <br /> • Absorbent socks used in MW-5 and 21 for removal of TPH sheen are monitored <br /> quarterly and replaced as necessary. A replacement sock was installed in MW-5. <br /> California Environmental Protection Agency <br /> 01 Recycled Paper <br />