Laserfiche WebLink
Metadata
Document management portal powered by Laserfiche WebLink 9 © 1998-2015 Laserfiche. All rights reserved.
Date: ,Tune 20,2005 <br /> Quarter: 2' Quarter,2005 <br /> • <br /> ARCO QUARTERLY GROUNDWATER MONITORING REPORT <br /> Facility No.: 5450 <br /> Address: 1617 West Fremont Street, Stockton, CA <br /> ARCO Environmental Engineer: Paul Supple <br /> Consulting CodContact Person: URS/Jeffrey Brooks <br /> Consultant Project No.: 38466523.OA143 <br /> Primary Agency/Regulatory 1D No.: San Joaquin County Environmental Health Department <br /> Assembly Bill 681 Status: Property owned by Atlantic Richfield Company <br /> WORK PERFORMED THIS QUARTER (Second 2005): <br /> 1. Performed quarterly groundwater monitoring and sampling. <br />� I <br /> 2. Prepared and submitted quarterly groundwater monitoring report. <br /> WORK PROPOSED FOR NEXT QUARTER (Third 2005): <br /> 1. Perform quarterly groundwater monitoring and sampling. <br /> 2. Prepare and submit quarterly groundwater monitoring report. <br /> QUARTERLY RESULTS SUMMARY (Second 2005): <br /> Current Phase of Project: Monitoring <br /> Frequency of Groundwater Sampling: MW-2 through MW-4 sampled quarterly <br /> Frequency of Groundwater Monitoring: Quarterly <br /> Is Free Product(FP) Present Onsite: No <br /> Current Remediation Techniques: Natural attenuation <br /> Approximate Depth to Groundwater: 9.40—9.60 feet below ground surface(bgs) <br /> Groundwater Flow and Gradient: Northwest @ 0.005 feet/foot(ft/ft) <br /> ANALYTICAL DATA REVIEW: <br /> Based on the review of the analytical and hardcopy data(chain-of-custody records,blanks,dilutions, holding times, <br /> LCS/LCSD results, MS/MSD results, and surrogate recoveries), the data are acceptable as reported by the <br /> laboratory. <br /> DISCUSSION: <br /> Methyl tent-butyl ether (MtBE) was the only analyte detected above laboratory reporting limits in the groundwater <br /> sample collected from site monitoring well MW-2 this quarter. The MtBE concentration in MW-2 is consistent with <br /> historical detections at this location.No other analytes were detected above laboratory reporting limits. <br /> Groundwater elevations in site wells decreased relative to the previous quarter. The approximate groundwater flow <br /> direction across the site was toward the northwest at an average hydraulic gradient of 0.005 ft/ft. <br /> i <br /> K.\Wproces\15 6P ARCM5450\Quaner1y%2005\2 QTR 0515450 GWMR 2005.doc Page 1 <br />