Laserfiche WebLink
E C O R <br /> Date: January 29, 2003 <br /> Quarter: 4Q02 <br /> i <br /> ARCO QUARTERLY GROUNDWATER MONITORING REPORT <br /> Facility No.: 4932 Address: 16 E. Harding Way, Stockton, CA <br /> ARCO Environmental Engineer: Paul Supple <br /> Consulting Co./Contact Person: SECOR/Rusty Benkosky <br /> Consultant Project No.: 77BP.54932.02.0336 <br /> Il Primary Agency/Regulatory ID No.: San Joaquin County Public Health Services (SJCPHS)_ <br /> Assembiy Bill 681 Status: Property owned by ARCO <br /> WORK PERFORMED THIS QUARTER (Fourth Quarter - 2002): <br /> 1. Performed quarterly groundwater monitoring and sampling. <br /> 2. Prepared and submitted quarterly groundwater monitoring report including additional figures. <br /> 3. Initiated design and began permitting soil vapor extraction and groundwater extraction remedial <br /> system. <br /> WORK PROPOSED FOR NEXT QUARTER (First Quarter - 2003): <br /> 1. Perform quarterly groundwater monitoring and sampling. <br /> 2. Prepare and submit quarterly groundwater monitoring report including additional figures. <br /> 4. Initiate construction of soil vapor extraction and groundwater extraction remedial system. <br /> QUARTERLY RESULTS SUMMARY <br /> Current Phase of Project: Assessment/Monitoring/Feasibility Testing <br /> Frequency of Groundwater MW-1 through MW-11, EW-1, EW-2, EW-6, DMW-1 <br /> through DMW-3 and SVE-1 Sampled quarterly - <br /> Frequency of Groundwater Quarterly <br /> Is Free Product (FP) Present Onsite: No <br /> Current Remediation Techniques: Interim remediation discontinued October 2002 <br /> Approximate Depth to Groundwater: 30 Y2-32 Y2 ft <br /> Groundwater Flow and Gradient: Shallow- Northeast 0 0.003 ft/ft <br /> Deep—Northeast @ 0.003 ft/ft <br /> DISCUSSION: <br /> Total petroleum hydrocarbons as gasoline (TPHg) were reported in nine of the sixteen wells sampled this <br /> Quarter at concentrations ranging from 120 ppb (MW-9) to 140,000 ppb (MW-4). Benzene was reported in <br /> eight of the sixteen wells at concentrations ranging from 0.75 ppb (MW-9) to 6,300 ppb (MW-4). Methyl <br /> Cert-butyl ether (MtBE), analyzed using EPA Method 8260B, was reported in thirteen of the sixteen wells at <br /> concentrations ranging from 0.66 ppb (MW-8) to 90,000 ppb (EW-2). 1,2-Dichloroethane (1,2-DCA) was <br /> reported in seven of the wells at concentrations ranging from 0.85 ppb (MW-7) to 350 ppb (MW-4). Tert- <br /> . butyl alcohol (TBA) was reported in two of the sixteen wells at concentrations of 2,500 ppb (MW-6) and <br /> 3,600 ppb (EW-2). Tort-amyl methyl ether (TAME) was detected in three wells at concentrations ranging <br /> from 64 ppb (MW-4) to120 ppb (EW-2). Di-isopropyl ether (DIPE) was detected in one well (DMW-1) at a <br /> concentration of 1.3 ppb. Ethylene dibromide (EDB) and ethyl tort butyl ether (ETBE) were not detected this <br /> ;WRC0149321QMRs12002140MR02.doc -2- <br />