ARCHIVED REPORTS_XR0007200 - Laserfiche WebLink

Home Browse Search

U-Haul#709-50 . Stockton,Cahfomia MS 0 Environmental Technology Inc ' December 4, 1997 Mr Mike Infuma San Joaquin County Public Health Services Environmental Health Division 304 East Weber Avenue,Third Floor Stockton, CA 95202 Subject Groundwater Monitoring Report U-Haul#709-50 2701 N Wilson Way Stockton, California SOTA Project No 94HW021 ' Dear Mr Infurna ' On behalf of U-Haul International, Inc (UHI), SOTA Environmental Technology, Inc (SOTA) has conducted groundwater monitoring activities for the subject site The objective of our monitoring activities was to evaluate the impact to groundwater resulting from an unauthorized release of gasoline at the subject site This letter-report describes our monitoring activities and presents a summary of our findings and opinions regarding current groundwater conditions at the site On September 26, 1997, SOTA personnel conducted groundwater monitoring activities for seven ' on-site wells (MW-1 through MW-6 and MW-8) and one off-site well (MW-7), shown in Figure 1 (attached) Prior to well purging and sampling, the depth to groundwater was measured and each well inspected using a clear bailer for the presence of free-phase product Visual evidence of free- product was not observed in any of the wells during this monitoring event September 1997 groundwater level measurements were observed to range from 2 01 to 2 14 feet higher than the September 1996 measurements Based on the September 1997 measurements, the groundwater gradient is generally 0 003 feettfoot with a southerly flow direction, which is consistent with previous observations The groundwater elevation data for this monitoring event and previous events are summarized in Table 1, attached The current groundwater gradient and flow direction are depicted in Figure 2 Following groundwater level measurements, each monitonng well was purged of at least four well casing volumes of water using a submersible pump, until field measurements indicated stabilized conditions of pH, temperature and conductivity The submersible pump was decontaminated between uses by flushing with a solution of phosphate-free detergent followed by clean tap water ' Purge water and decontamination fluids generated during the groundwater sampling activities were placed in DOT-rated 55-gallon steel drums, and placed in a secure area on-site pending disposal Groundwater levels were subsequently allowed to recover to at least 90% of static conditions prior to sampling Groundwater samples were collected from each well using dedicated disposable polyethylene bailers, transferred to laboratory-supplied 40-n-d VOA vials with the bottom-emptying device, appropriately labeled and stored in a cooler with ice for transport ' 16980 Via Tazon, Suite 130 3625 N 16th Street, Suite 117 _ San Diego, CA 92127-1633 Phoenix, AZ 85016 619 485 8100 FAX 619 485 0812 602 265 8554 FAX 602 265 8457 E-mail sotaine0pacbell net E-mail sota0primenet com