Laserfiche WebLink
ENVIRONMENTAL HEALTH DEPARTMENT <br /> SAN JOAQUIN COUNTY <br /> 2:• �,_.,, .� Unit Supervisors <br /> �. Donna K.Heran,R.E.H.S. <br /> U): 1 Director 304 East Weber Avenue, Third Floor Carl Borgman,R.E.H_S. <br /> Mike Huggins,R.E.H.S.,R.D.I. <br /> Al Olsen,R.E.H.S. Stockton, California 95202-2708 Douglas W. Wilson,R.E.H.S. <br /> • c.. <br /> Program Manager Q�fFo.Ri;. g g Telephone: (209) 468-3420 Margaret Lagorio,R.E.H.S. <br /> Laurie A.Cotulla,R.E.H.S. Robert McClellon,R.E.H.S. <br /> Program Manager Fax: (209) 464-013$ <br /> Mark Barcellos,R.E.H.S. <br /> FEB 0 5 2004 <br /> CARL NAVARRA <br /> 475 BLEWETT ROAD <br /> TRACY CA 95376 <br /> RE: Navarra Property SITE CODE: 1392 <br /> 7500 Eleventh Street <br /> Tracy CA 95376 <br /> San Joaquin County Environmental Health Department (EHD) has received and <br /> reviewed Work Plan for Refined Plume Definition and Management of Floating <br /> Product (WP), dated 26 December 2003, prepared by your consultant The San <br /> Joaquin Company, Inc. (TSJCI). The report included discussions of the historical <br /> use of the site, the site investigation and findings to date with maps showing the <br /> site and surrounding area, a plume map, and cross sections showing the <br /> hydrogeological framework. In addition, TSJC1 has modeled the "floating product" <br /> plume. Floating product is commonly referred to as light nonaqueous phase liquid <br /> (LNAPL) or free product. <br /> Utilizing various modeling techniques and the available, but sparse data, TSJCI <br /> has estimated that between 1,000 and 8,000 gallons of free product can be <br /> recovered from the leading portion of the free product plume. The floating product <br /> plume was estimated to extend approximately 30 feet north of monitoring well <br /> MW-7 and to be approximately <br /> a <br /> yl length Eleventh <br /> also infers that the plume 9th of approximately feet parallel to the <br /> ground water flow direction, with the southern 75 feet of the plume recovered from <br /> the UST excavation due to significant drawdown in the excavation during removal <br /> of free product and ground water. <br /> In the WP, TSJC has proposed to initiate sampling of the domestic wells in the <br /> immediate area and down-gradient of the unauthorized release point; install <br /> additional groundwater monitoring wells, install floating product monitoring wells <br /> and install a cutoff trench to collect the floating product. <br /> EHD approves including sampling the domestic wells in the current ground water <br /> monitoring program. EHD should be informed immediately should any of the <br /> chemicals of concern be detected in any of the domestic wells. Although specific, <br /> written direction commonly is not required, EHD also directs that all ground water <br /> monitoring wells installed as part of this investigation automatically be included for <br />