Laserfiche WebLink
Metadata
Document management portal powered by Laserfiche WebLink 9 © 1998-2015 Laserfiche. All rights reserved.
• Former Beacon Station No 12419 July 31,2003 <br /> Stockton, California Groundwater Monitoring_Report <br /> aromatic compounds benzene, toluene, ethylbenzene and total xylenes (BTEX), and the fuel <br /> oxygenates methyl-tert-butyl ether (MTBE), dusopropyl ether (DIPE), ethyl-butyl ether <br /> (ETBE), tert-amyl methyl ether (TAME), tert-butanol (TBA), methanol and ethanol, and the <br /> lead scavenger compounds 1,2-d ichloro ethane (DCA) and 1,2-dibromoethane (EDB) by <br /> Environmental Protection Agency (EPA) Method 8260B <br /> Groundwater Monitoring Results <br /> Depth-to-groundwater measurements were subtracted from the surveyed TQC elevations to <br /> calculate groundwater elevations Groundwater elevation data were used to construct the <br /> Groundwater Contour Map, as shown on Figure 2 The groundwater flow direction was <br /> variable across the site but generally trended to the north-northwest Groundwater gradient <br /> magnitudes range from approximately 0 001 to 0 002 L, <br /> Groundwater analytical results are summarized in Table 1 Benzene concentration data from <br /> this sampling event were used to construct the Benzene Isoconcentration Map, as shown on <br /> Figure 3 Copies of the laboratory data sheets and COC documents are included as <br /> Attachment C <br /> GeoTracker Electronic Data Deliverables <br /> The analytical electronic data deliverable (EDD) is uploaded by Kiff The groundwater well <br /> • measurement file EDD (GEO_WELL) for this quarterly monitoring event has been uploaded <br /> by Horizon The GEO_WELL file upload confirmation sheet is contained in Attachment E <br /> Recommendations <br /> Horizon has submitted a Remedial Action Plan (RAP) to the San Joaquin Country <br /> Environmental Health Department (SJCEHD) which describes the proposed remedial system <br /> installations The proposed remediation system plans are complete and Horizon is in the <br /> process of selecting a contractor and obtaining the necessary permits from the San Joaquin <br /> County Building Department <br /> It was proposed in the Fourth Quarter 2002 Report that the sampling frequency of monitoring <br /> wells MW-7, MW-11, air sparge well AS-2 and AS-3 be decreased to a semi-annual (first and <br /> third quarters) schedule, and monitoring wells MWA through MW-5 and air sparge ASA be <br /> decreased to an annual schedule (first quarter) The remaining monitoring wells MW-6 and <br /> MW-8 through MW-10 would continue to be sampled on a quarterly schedule The <br /> groundwater samples will be analyzed for all site analytes (TPHg, BTEX, the seven fuel <br /> oxygenates, DCA and EDB) for the first quarter For the second through fourth quarters the <br /> groundwater samples will be analyzed only for TPHg, BTEX and MTBE Horizon will <br /> implement the modified quarterly sampling program for third quarter 2003 <br /> i <br /> 419gmrQ243 <br /> Project No 141946 2 HORIZON ENVIRONMENTAL INC. <br />