ARCHIVED REPORTS_XR0005626 - Laserfiche WebLink

Home Browse Search

Third Quarter 1996 Groundwater Monitoring&Remediation Status Report Moore Petroleum, 14800 W Frontage Rd,Manteca,CA November 1, 1996 Page 4 RECOMMENDATIONS The extraction rates, with respect to TPH, as gasoline, and benzene, of the vapor extraction system has been decreasing steadily since the start-up of the unit in January 1995 The extraction rates have decreased to less than one pound per day of TPH, as gasoline, and the system is no longer extracting benzene from the four vapor extraction wells These low extraction rates seem to nndncate that the subject site has most likely reached static levels with respect to soil vapor TPH, as gasoline, concentrations When soul vapors reach these low levels, soil vapor extraction becomes impractical Apex recommends discontinuing the operation of the vapor extraction system due to the significantly decreasing levels of TPH, as gasoline, in the subsurface soils Apex recommends leaving the water treatment system offindefinitely and monitoring the site in a post-remediation monitoring phase Tins monitoring would assess the reaction of the subsurface of the subject site to non-remedial efforts If groundwater contamination is still present after post remedial monitoring, Apex proposes performing a Risk Based Corrective Action (RBCA) assessment to determine whether or not existing groundwater contamination at the subject site is a risk to human health REPORT DIS'TR BUTION Apex submitted copies of this report,in final form,to 1 Ms E Thayer Central Valley Regional Water Control Board 3443 Routier Road, Suite 'A' Sacramento, California 95827-3098 2 Ms M Lagono San Joaquin County Environmental Health Division Post Office Box 2009 Stockton, California 95201 3 Mr Craig Mitchell San Joaquin Valley Unified Air Board 4230 Kiernan Ave , Suite 130 Modesto, California 95356