Laserfiche WebLink
r <br /> Case Closure Summary Page 2 <br /> Le«_...ig Underground Fuel Storage Tank Progr <br /> III Release and Site Characterization Information (continued) <br /> Maximum Documented Contaminant Concentrations - - Before and After Cleanup <br /> Contaminant Soil (ppm) Water (ppm) Contaminant Soil (ppm) Water (ppm) <br /> Before After Befores After Before After Before After <br /> TPH (Gas) 30' <14 3.1 <.0050 Ethyl I enzene .65' <.0054 <.0005 <.0005 <br /> TPH (Diesel) 3202 <54 <.005 <.0050 Xylene .613 <.0054 .190 <.0005 <br /> Benzene 004' <.00540075 <.0005 Oil Z3< Grease <br /> Toluene .17' <,005" .0031 <.0005 Heavy Metals <br /> Lead .105 .105 <br /> Comments: A petroleum hydrocarbon sheen was observed floating on the groundwater that infiltrated the tank pit at the <br /> time of tank removal (319189). Soil sample notations made for identification: 1. 15.5NE-17NW (Dup) on 10/25189. 2. #1 <br /> East South End on 319/89. 3. 15.5NE-17NW on 10/25189. 4. Tank Pit Re-Excavation on 11112193. 5. 17SE-16SW on <br /> 10/25/89 6. Excavation pit on 11112/93. 7. Monitoring well samples on 2123/96. A total of 1,988 cubic yards of <br /> contaminated soil was removed in October 1989 (388 yd3) and November 1993 (1,600 yds3) . The contaminated soil was <br />' aerated and used for backfill on site. 54,000 gallons of contaminated groundwater was pumped from the 1993 excavation <br /> pit and disposed at the City of Stockton Wastewater treatment facility. Post remediation monitoring verified that <br /> groundwater contamination was no longer evidenced. <br /> IV. Closure <br /> Does completed corrective action protect existing beneficial uses per the Regional Board <br /> Basin Plan? Yes. <br /> Does completed corrective action protect potential ieneficial uses per the Regional Board <br /> Basin Plan? Yes. <br /> Does corrective action protect public health for current land use? Yes. <br /> Site management requirements: None. <br /> Should corrective action be reviewed if land use changes? No. <br /> Monitoring wells decommissioned: (Yes) Number Decommissioned: (4) Number retained: (0) <br /> List enforcement actions taken: NOR sent 6/30/93 . <br /> List enforcement actions rescinded: None. <br /> V. Local Agency Representative Data <br /> Name: Donna eran Title: Director of Environmental Health <br /> Signature: Date: -3 )— <br /> VI. Central Valley Regional Water Quality Control Bard (RB) Notification <br /> Date Submitted to RB: 6/17/96 Respionse Date: 7/18/96 <br /> RB Staff: J. Brathovde Response: Concurrence with no further action <br /> Title: Assoc Eng Geologist required. <br /> VII. Additional• Comments, Data, etc. <br /> Jeanne Homsey, Registered PE #47410, with Smith Envilronmental stated that excavation, natural <br /> biodegradation and aeration successfully remediatedlthe contaminated soil and that the <br /> groundwater that was contaminated has also been remediated by extraction and natural <br /> biodegradation. <br /> is ocument an t o related a e retained y the lead agency as part of the official <br /> site file. (08124193) Exhibit N Page 2 of 2 <br /> MMICLOSURE1601VEN.SWB <br />