Laserfiche WebLink
PUBLIC HEALTH SERVICES � <br /> SAN JOAQUIN COUNTY <br /> JOGI KHANNA M.D.,M.P.H. <br /> Health Officer <br /> Cq �P <br /> P.O. Box 2009 . (1601 East Hazelton Avenue) • Stockton, California 95201 c'koRN <br /> MAR 12 1991 (209) 468-3400 <br /> RICK SILK C�p� <br /> UNOCAL CORP <br /> P 0 BOX 5155 <br /> SAN RAMON CA 94583 <br /> RE: UNOCAL SS #32859 IN REPLY REFER TO SITE CODE: 1213 <br /> 1665 Pacific Ave, Stockton <br /> We have reviewed the December, 1990 Report of Subsurface Environmental Investigation prepared by <br /> Applied Geosystems. <br /> Our conclusions differ from your consultant only in that residual contaminants remaining in boring locations <br /> KB3 and KB5 do pose a significant threat to groundwater. <br /> The site was originally impacted with petroleum hydrocarbons in an approximate 4000 cubic yard area. The <br /> excavation activity in spring of 1988 effectively removed approximately 1300-1400 cubic yards of <br /> contaminated soil in the tank pit area. The remaining 2600-2700 cubic yards encompasses the former <br /> islands and pipeline areas bounded by KB3, B3/MW3, B2/MW2, and KB5. <br /> The analytical results from the above referenced soil borings were applied to the risk appraisals of the LUFT <br /> Manual'. The conclusion is that the residual petroleum hydrocarbons remaining at depths of 20-25 feet <br /> below grade threaten water quality, which may be evidenced by the continued increase in hydrocarbons <br /> detected in MW#2. <br /> A Problem Assessment Report(PAR) should be prepared to include the recommendations from the December <br /> 1990 Applied Geosystem's report and suggested remediation addressing soil and groundwater cleanup. The <br /> PAR will be due in our office and Central Valley Regional Water Quality Control Board no later than June <br /> 3, 1991. <br /> If you have any questions contact Diane Hinson, Supervising RENS, of my staff at (209) 468-3452. <br /> Jogi Khanna, lk M.P.H. <br /> Health Of G%'���� <br /> curie A. CoCf)la, REHS, Program Manager <br /> Environmental Health Division <br /> LAC/DH:nr <br /> c: CVRWQCB <br /> c: Applied Geosystems - Eloise Frick <br /> 4191 Power Inn Road, Ste D & E, Sacramento, CA 95826 <br /> 'Reference, LUFT Manual, October 1989; General Risk Appraisal, <br /> Environmental Fate Worksheet (PHS/EHD) , and Site Closure Evaluation <br /> (PHS/EHD) <br /> A Division of San Joaquin County Health Care Services <br />