Laserfiche WebLink
Proposal for of Site Cleanup Confirmation May 5, 1992 <br /> Southland, 7-Eleven No 20680, 9110 Thomton Road, Stockton, CA 8 <br /> ■ If the PID does not detect any organic vapors on any samples collected from a <br /> boring, one sample collected from varying depths for each such boring will be <br /> analyzed (i e, the same sample interval will not be selected for analysis for each <br />' boring which had no detectable PID readings) <br /> This varying depth scenario is recommended to ensure that the analytical results are <br /> Irepresentative of the vadose zone soils <br /> Samples selected for analysis will be analyzed for STEX and TPH-as-gasoline using EPA Method <br /> 8015/8020, for EDB using EPA Method 504, and for lead using EPA Method 6010/7000 <br /> I3.1.4 Soil Data Review and Evaluation <br /> A cleanup objective of 10 ppm of TPH-as-gasoline was proposed in the March 1991 report and <br /> approved by the SJPH After the laboratory data are collected, the analyses will be reviewed to <br /> determine if the cleanup objective of 10 ppm TPH-as-gasoline has been achieved Groundwater <br /> Technology proposes the following evaluation method to determine attainment of the cleanup <br /> objective <br /> - - - - V <br /> ■ The average of ail-samples is equal to or less than 10 ppm of TPH-as-gasoline, an� <br /> ■ WNp one sample is greater than 100 ppm of TPH-as-gasoline <br /> Tf-Wese conditions are met, the soil cleanup objectives will be determined to have been met <br /> I 3.2 Groundwater Monitoring, Sampling, and Reporting Frequency <br /> A letter has been submitted to-the SJPH requesting a reduction in groundwater monitoring <br /> �requency frommor1thly to quarteriy� Because the monitoring data is used solely for documenting <br /> l water levels and constructing potentiometric surface maps, this reduction is appropriate regardless <br /> of the results of the soil sampling work <br /> If the soil sampling results confirm that the source area soils have been remediated, then <br /> Groundwater Technology proposes that the groundwater sampling frequency be reduced to <br /> semi-annual (twice per year) This frequency would be continued until approval is obtained for site <br /> Iclosure The groundwater monitoring frequency would also be changed to a semi-annual basis <br /> - GROUNDWATER <br /> TECHNOLOGY INC <br />