Laserfiche WebLink
r <br /> 5 Date: April 21,2003 <br /> Quarter: 1 st Quarter,2003 <br /> i <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 Co./Contact Person: URSNernon Elarth <br /> Consultant Project No.: 38466090.00436 <br /> Primary Agency/Regulatory ID No.: San Joaquin County Public Health Services (SJCPHS) _ <br /> Assembly Bili 681 Status: Property owned by Atlantic Richfield Company <br /> WORK PERFORMED THIS QUARTER (First 2003): <br /> 1. Performed quarterly groundwater monitoring and sampling. <br /> 2. Prepared and submitted quarterly groundwater monitoring report. <br /> WORK PROPOSED FOR NEXT QUARTER (Second 2003): <br /> 1. Perform quarterly groundwater monitoring and sampling. <br /> 2. Prepare and submit quarterly groundwater monitoring report. <br /> QUARTERLY RESULTS SUMMARY (First 2003): <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: 10.5- 10.6 feet below ground surface <br /> Groundwater Flow and Gradient: Northwest @ 0.003 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 /> Total petroleum hydrocarbons as gasoline (TPHg), benzene, toluene,ethylbenzene, and total xylenes (BTEX) were <br /> do repor d as below laboratory detection limits in all wells. Methyl tert-butyl ether(MtBE)was detected in MW-2 and <br /> MW-;rat concentrations of 28 and 0.69 micrograms per liter respectively. No other analytes were detected. <br /> 11q 4 Groundwater elevations in site wells increased relative to the previous quarter. The approximate groundwater flow <br /> direction was to the northwest at an average gradient of 0.0031`tlft. <br /> This report is based on data, site conditions, and other information that are generally applicable as of the date of the <br /> report,and the conclusions and recommendations herein are therefore applicable only to that time frame. <br /> K_1J5 BP ARCD105450VQuanerlyll M 0315450 GWNW IQ03.do Page 1 <br />