Laserfiche WebLink
San Joaquin County DIRECTOR <br /> o N Donna Heran, REHS <br /> Environmental Health Department <br /> ASSISTANT DIRECTOR <br /> r. ` 600 East Main Street Laurie Cotulla, REHS <br /> All <br /> ( Stockton , California 95202 -3029 PROGRAM COORDINATORS <br /> d17si.I Carl Borgman, REHS <br /> Mike Huggins, REHS, RDI <br /> Website: www.s ' ov. or 1ehd <br /> 9 � � FOR� /9 9 Margaret Lagorlo, REHS <br /> Phone : (209) 468-3420 Robert McClellon, REHS <br /> Fax: (209) 464=0138 Jeff Carruesco, RENS, RDI <br /> Kasey Foley, REHS <br /> September 2, 2008 <br /> VINCE ERARDI <br /> R. M. B. GARAGE (ERARDI VENTURES) <br /> PO BOX 691000 <br /> STOCKTON CA 95269-1000 <br /> RE : R. M . B. GARAGE (ERARDI VENTURES) SITE CODE: 1229 <br /> 715 NORTH HUNTER ST <br /> STOCKTON CA 95269 <br /> The San Joaquin County Environmental Health Department (EHD ) had recommended by <br /> letter dated April 24 , 2006 , that interim remediation be implemented to mitigate impacted <br /> soil and groundwater. By letter dated July 5, 2006 , the EHD approved Additional <br /> Assessment & Interim Remediation Work Plan dated June 12, 2006 , prepared by your <br /> consultant Advanced GeoEnvironmental, Inc. (AGE), a portion of which addressed interim <br /> remediation by Dual Phase Extraction (DPE) . Except for the water discharge line , <br /> construction of the DPE system was completed on January 2, 2008, but the system has <br /> not yet been put into operation . With the high mass of contaminants on your site impacting <br /> groundwater and apparently migrating off-site, it is imperative that the DPE system be put <br /> into operation immediately. Therefore, the EHD directs that the water discharge line be <br /> installed and the remediation system be put into operation by September 31 , 2008 . <br /> The EHD has reviewed Monitoring Well Installation Report — First Quarter 2007 (MWIR) <br /> dated July 10 , 2007 and Quarterly Report — Fourth Quarter 2007 (QMR) dated April 2 , <br /> 2008, prepared by AGE , and has the following comments: <br /> In the QMR and MWIR, AGE recommended conducting additional soil and ground water <br /> investigation to define the vertical extent of the contaminant plume. AGE recommended at <br /> least one additional deep-screened well at a depth between 125 and 150 feet below <br /> surface grade (bsg ) to be installed in the source area , which is the former underground <br /> storage tank (UST) area , and additional monitoring wells screened between approximately <br /> 50 and 60 feet bsg and between 90 and 100 feet bsg . EHD does not concur with AGE's <br /> recommendation for additional corrective action to define the vertical extent of the core of <br /> the contaminant plume at this time. In the source area , groundwater is significantly <br /> impacted in MW-10, which is screened from 50 feet to 60 feet bsg , and in MW-11 , <br /> screened from 88 to 98 feet bsg . However, between the months of March and December <br /> 2007 contaminant concentrations in MW- 11 have been generally dropping ; total petroleum <br /> hydrocarbons quantified as gasoline (TPH-g ) , has declined from 38, 000 micrograms per <br /> liter (ug/1) to 11 , 000 pg/1 . The deepest soil samples collected to date are from the source <br /> area , including CPT-2 at 103 feet bsg and MW-11 at 100 feet bsg, both of which contained <br /> low concentrations of contaminants including 0.014 mg/kg and 0 .22 mg/kg of benzene. <br /> The groundwater contamination may be due to drag down of contaminants during the <br />