Laserfiche WebLink
Former Beacon Station No. 12474 <br /> Stockton.California August 4,2003 <br /> ' Quarterly Groundwater Monitoring Report <br /> located in Davis, California. The samples were analyzed for total petroleum hydrocarbons <br /> as gasoline (TPHg), the volatile aromatic compounds benzene, toluene, ethylbenzene and <br /> total xylenes (BTEX), and the fuel oxygenate methyl-t-butyl ether (MTBE) by! <br /> Environmental Protection Agency(EPA) Method 8260B. <br /> Results <br /> Depth-to-groundwater measurements were subtracted from the surveyed TOC elevations to <br /> calculate groundwater elevations. Groundwater elevation data, as summarized in Table 1, <br /> were used to construct the Groundwater Contour Map shown on Figure 2. The groundwater <br /> flow is toward the west with an average gradient of approximately 0.004 foot/foot. <br /> Groundwater analytical results are summarized in Table 1. Benzene concentration data from <br /> this sampling event were used to construct a Benzene lsoconcentration Map shown on <br /> Figure 3. Analytical reports and chain-of-custody:documents are contained in Attachment . <br /> C. Historical groundwater level and analytical data collected prior to 1998 are summarized <br /> in Tables i and 2 in Attachment D. <br /> Geo-Tracker Electronic Data Deliverables <br /> The analytical electronic data deliverable (EDD) is uploaded by Kiff. The groundwater well <br /> measurement file EDD for this quarterly monitoring event was uploaded by Horizon. The <br /> GEO_WELL upload confirmation sheet for this quarter is contained in Attachment E. <br /> Recommendations <br /> Horizon proposed modifications to the quarterly monitoring program in the Fourth Quarter <br /> 2002 report. Approval of the modifications are pending. On March 5, 2003, Horizon <br /> submitted a report and a work plan addendum containing results of an additional ' <br /> groundwater investigation, and a proposal for additional wells to evaluate the extent of <br /> petroleum hydrocarbon impacts. Approval of this proposal is pending. <br /> Report Distribution <br /> We recommend a copy of this report be forwarded to: <br /> Mr. Gordon Boggs Mr. Francy Naderzad <br /> CRWQCB - Central Valley Region 748 Pollard Road <br /> 3443 Routier Road, Suite A ,. Los Gatos, California 95032 <br /> Sacramento, California 95827-3098 <br /> f <br /> 474gmr02Q3.doc <br /> 1474.46 2 HORIZON ENVIRONMENTAL INC. <br />