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Californiaegi <br /> Regional Water Quality Ccontrol Board <br /> .` <br /> Central Valley Region <br /> Steven T.Butler,Chair P.9 I, Gray Davis <br /> Winston H.Hickox 9 p� Governor <br /> Secretaryfor Sacramento Main Office , <br /> Environmental Internet Address: http://www.swrcb.ca.gov/—mgcb5 � t <br /> Protection 3443 Routier Road,Suite A,Sacramento,California 95827-3003 <br /> Phone(916)255-3000•FAX(916)255-3015 <br /> 8 November 1999 <br /> Ms. Katie Hower <br /> Chevron Pipe Line Company <br /> 4000 Executive Parkway, Suite 400 <br /> San Ramon, CA 94583 <br /> SURLAND HOMES PROPERTY, CHEVRON ENVIRONMENTAL MANAGEMENT <br /> COMPANY,TRACY, SAN JOAQUIN COUNTY <br /> I have reviewed the July and October 1999 Quarterly Monitoring Reports (QMRs) for the Surland <br /> Homes Property and your 28 September and 1 November requests to destroy monitoring well (MW) <br /> TW-2 at 2532 Dorset Lane. Chevron Environmental Management Company(CEMC)installed the well <br /> during an investigation of a pipeline leak in this area prior to its development. <br /> The QMRs show detection of sheen at TW-2 and total petroleum hydrocarbons as diesel (TPHd) at <br /> TW-1 (110 µg11) and TW-3 (100 µg/1) when analyses are conducted without silica gel cleanup.Due to <br /> the presence of sheen, Chevron did not collect samples from TW-2, which is upgradient of TW-3, for <br /> laboratory testing. Although the presence of sheen at TW-2 shows that the contaminated soil is leaching <br /> out contaminants into the groundwater, the impact to groundwater (at TW-1 and TW-3) is limited to the <br /> area of soil contamination and approximately less than 100 feet north of this area at TW-1. I understand <br /> that CEMC has provided the Surland Homes Property developer a copy of its soil management plan <br /> (SMP) which describes common sense procedures the developer should follow in case soil <br /> contamination related to crude oil release is encountered. The SMP also directs each property owner to <br /> contact the developer in case they encounter contaminated soil in their property. <br /> Besides TPHd, TW-1 and TW-3 did not contain other petroleum hydrocarbon constituents. These MWs <br /> also did not contain TPHd when their samples were cleaned up with silica gel prior to analysis. The <br /> results show that even without silica gel cleanup, the site is very close to meeting the water quality <br /> objective of 100 µgIl for TPHd. <br /> With regards to closure of TW-2, Ms. Elizabeth Lu of CEMC informed me during our telephone <br /> conversation on 29 October 1999 that the property owner has requested closure of the MW, which was <br /> installed prior to development of the area. Ms.Lu also stated that TW-2 is not needed to establish flow <br /> directions because five years of data at the nearby Dividend Development have shown a consistent <br /> groundwater flow direction to the north. The last two sampling events at Surland have confirmed the (� <br /> northerly flow direction. <br /> California Environmental Protection Agency <br /> ��Recycled Paper <br />