Laserfiche WebLink
California Ronal Water Quality Antrol Board e <br /> Central Valley Region <br /> Robert Schneider Chair <br /> Terry Tamminen - Arnold Schwarzenegger <br /> Secretary for 1^<� Sacramento Main Office Governor <br /> Environmental U u Internet Address: http://www.sw b.ca.gov/rwgcb5 <br /> Protection NO" q 3 Zlop Sun Center D pfi16 Rancho <br /> Cordova,CA 95670-6114 <br /> one(9 <br /> 19 November 200NVIRNNM SERVICES H <br /> PERM I <br /> Mr.Bob Hopkins Mr. Jay Allen <br /> Union Oil Company of California Stone Brothers Management Company <br /> 276 Tank Farm Road,P.O. Box 1069 1024 W.Robinhood Dr. <br /> San Luis Obispo, CA 93406 Stockton,CA 95207 <br /> REPORT REVIEW, CLEANUP AND ABATEMENT ORDER (CAO)NO. 5-00-707, FORMER UNOCAL <br /> STATION #5098 AT 5606 PACIFIC AVENUE,AND FORMER MONTGOMERY WARDS AUTO SERVICE <br /> AT 5400 PACIFICA VENUE,STOC%TON, SAN JOAQUINCOUNTY, <br /> I reviewed the 8 October 2004 MW-1 Redevelopment Report(Report)submitted by GHH Engineering Inc. <br /> (GHH)on behalf of Stone Brothers Management Company. The Report was submitted in response to an incident <br /> reported to me by email from ENSR International Inc. (ENSR) on 26 August 2004. Monitoring well MW-1's <br /> traffic cover was broken, the well cap was missing, and the interior of the well casing was compromised by an oil <br /> emulsion sealant used by a parking lot contractor. On 31 August 2004,ENSR replaced the traffic cover and well <br /> cap, and took a grab groundwater sample from MW-1. Analysis revealed a maximum 2,300 µg/L of Total <br /> Petroleum Hydrocarbons (TPH) as Motor Oil (TPHmo),which compares to the composition of the oil emulsion <br /> sealant's Material Safety Data Sheet(aromatic petroleum oil). The Report states the rehabilitation of MW-1 <br /> occurred on 21 September 2004,when GHH staff swabbed the inside of MW-l's casing to remove the sealant <br /> with a wire brush and an absorbent material,using tri-sodium phosphate soap and a tapwater rinse contained by a <br /> pneumatic well packer installed inside the blank casing above the well screen. GHH redeveloped MW-1 by <br /> removing 10 well casing volumes of groundwater. GHH and ENSR then sampled groundwater for TPH as <br /> gasoline,TPHmo, semi-volatile organic compounds and volatile organic compounds. TPHmo was detected at <br /> concentrations similar to the pre-development grab sample results. The Report recommends conducting a more <br /> vigorous rehabilitation of MW-1, including additional swabbing of the inside of the well casing and overpurging <br /> with a higher capacity well pump. <br /> I concur with the proposal to attempt a second rehabilitation of MW-1, including confirmation groundwater <br /> sampling and analysis of TPHmo by 15 December 2004. Please provide San Joaquin County and myself at least <br /> 3 working days notice prior to conducting the fieldwork. You may contact me at(916)464-4615 if you have <br /> questions. <br /> James L. R.G. <br /> Engineering Geologist <br /> cc: Mr. Mark Owens,UST Cleanup Fund, SWRCB, Sacramento <br /> Mr.Mike hifurna, San Joaquin County Environmental Health Division, Stockton <br /> Ms. Jill Tracy, Esq.,UNOCAL, Brea <br /> Mr. Ben Henningburg, ENSR International, Sacramento <br /> Mr. Gary Hall, GHH Engineering, Auburn, CA <br /> California Environmental Protection Agency <br /> 0d Recycled Paper <br />