Laserfiche WebLink
n r� <br />Date July 8, 2002 <br />isQuarter _ 2Q02 _ _ _ _ <br />9 <br />r <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 010702 <br />Primary Agency/Regulatory ID No San Joaquin County Public Health Services (SJCPHS) <br />Assembly Bill 681 Status Property owned by ARCO <br />WORK PERFORMED THIS QUARTER (Second Quarter - 2002): <br />1 Performed quarterly groundwater monitoring and sampling <br />2 Prepared and subrmtted quarterly groundwater monitoring report including additional figures <br />3 Prepared and submitted "Site Assessment and Aquifer Testing Results" report dated June 6, 2002 <br />4 Continued interim remediation by groundwater batch extraction <br />5 Perform additional offsite assessment <br />WORK PROPOSED FOR NEXT QUARTER (Third Quarter - 2002): <br />1 Perform quarterly groundwater monitoring and sampling <br />2 Prepare and submit quarterly groundwater monitoring report <br />3 Continue interim remediation by batch extraction <br />4 Subnut Problem Assessment Report documenting additional assessment and summary of remedial feasibility <br />testing <br />5 Initiate design and construction of soil vapor extraction and groundwater extraction remedial system <br />QUARTERLY RESULTS SUMMARY <br />Current Phase of Project <br />Frequency of Groundwater Sampling <br />Frequency of Groundwater Monitoring <br />Is Free Product (FP) Present Onsite <br />Current Remediation Techniques <br />Approximate Depth to Groundwater <br />Groundwater Flow and Gradient <br />DISCUSSION: <br />Assessment/Momtoring/Feasibility Testing <br />MW -1 through MW -9, EW -1, DMW-I, and SVE-1 sampled <br />Quarterly <br />Quarterly <br />No <br />Interim remediation (groundwater batch extraction) <br />27-29ft <br />Northeast @ 0 002 ft/ft <br />Total petroleum hydrocarbons as gasoline (TPHg) were reported in five of the twelve wells sampled this quarter at <br />concentrations ranging from 170 ppb (MW -9) to 140,000 ppb (MW -4) Benzene was reported in eight of the twelve <br />wells at concentrations ranging from 12 ppb (MW -9) to 9,900 ppb (EW -1) Methyl tert-butyl ether (MtBE), analyzed <br />using EPA Method 8260B, was reported in eleven of the twelve wells at concentrations ranging from 0 66 ppb (MW -7) <br />to 520,000 ppb (EW -1) 1,2-Dichloroethane (1,2 -DCA) was reported in four of the twelve wells at concentrations <br />ranging from 2 4 ppb (MW -9) to 86 ppb (MW -1) Tert-butyl alcohol (TBA) was reported in six of the twelve wells at <br />