Laserfiche WebLink
Harlin Knoll [EH] <br /> From: Nuel Henderson [EH] <br /> Sent: Tuesday, December 14, 2010 8:09 AM <br /> To: Harlin Knoll [EH] <br /> Cc: Adrienne Ellsaesser[EH] <br /> Subject: FW: Shell Station at 2320 N. EI Dorado Street <br /> -----Original Message----- <br /> From: Jim Barton [mailto:jbarton@waterboards.ca.gov] <br /> Sent: Tuesday, December 14, 2010 6:47 AM <br /> To: Nuel Henderson [EH] <br /> Subject: Re: Shell Station at 2320 N. E1 Dorado Street <br /> Hi Nuel, <br /> I conducted a quick review based on GeoTracker documents. I noted there is little PCE/TCE <br /> in soil near the former tanks (only CPT-1 had low levels of PCE, TCE and 1,2-DCA in soil, <br /> while MW-6 had low levels of PCE and TCE also, both at maximum depth) . However, the <br /> maximum groundwater concentrations were on opposite sides of the former tank pit, which <br /> might point to the waste oil tank as a source. Since there was a dry cleaners onsite, and <br /> there is no exact location given for the waste oil tank, there is a possibility that each <br /> one contributed to the PCE/TCE impact to groundwater. Finally, PCE and TCE appear to be <br /> declining in concentrations, so a trend with time to reach WQGs can be established for <br /> those constituents. I concur that the site can be closed as a low risk case with a <br /> stable, declining plume. Thanks. <br /> Jim Barton <br /> James L.L. Barton, P.G. <br /> Engineering Geologist <br /> California Regional Water Quality Control Board Central Valley Region, 11020 Sun Center <br /> Drive, Suite 200, Rancho Cordova, CA 95670 office (916) 464-4615 <br /> fax (916) 464-4704 <br /> To comply with the Governor' s order calling for furloughs, specific staff of the Central <br /> Valley Regional Water Control Board Office and offices of the California Environmental <br /> Protection Agency are required to take three furlough days off every month. I apologize <br /> for any inconvenience this may cause. <br /> >>> "Nuel Henderson [EH] " <nhenderson@sjcehd.com> 12/13/2010 2 :51 PM »> <br /> Jim, <br /> I'm thinking of closing the site at 2320 N. El Dorado Street, Stockton, a Shell site. <br /> TPHg, BTEX and fuel oxys are generally delineated and at moderate to low concentrations. <br /> TPHg is highest in MW-1, and CRA estimates its return to "ESLs" in 12 years. Only benzene <br /> and xylenes in soil exceed ESLs for leaching, but CRA notes that GW impact demonstrates <br /> little active leaching. Impact in MW-1 and MW-2 is not inconsistent with being a part of <br /> the 2315 N. E1 Dorado St site's plume, but CRA did not note this. <br /> CRA estimates dissolved mass at 1.35 pounds TPHg and 0.0044 pounds benzene; soil mass at <br /> 1.2 pounds TPHg and 0.004 pounds benzene. <br /> Problem with site for some time has been PCE and TCE in groundwater, mostly mW-1 and MW-2. <br /> Site had a waste oil tank pulled circa 1984, no recordof its former location available. <br /> 1 <br />