ARCHIVED REPORTS_XR0007132 - Laserfiche WebLink

Home Browse Search

July 28, 1999 SECOR . Ms Anastasia Duarte-Wilkinson Irlc'>>trdlrr,�rrrll�t{ �,fj�r,�c�tcrl Time Oil Company 2737 West Commodore Way Seattle, WA 98199 SUBJECT: Quarterly Monitoring Report, April _ June 1999 Jackpot Food Mart 14000 East Highway 88 Lockeford, California Ms Duarte-Wilkinson This report presents the results of quarterly groundwater monitoring and sampling conducted at the Jackpot Food Mart at 14000 East Highway, Lockeford, California (the site, see Figure 1) GROUNDWATER MONITORING AND SAMPLING Ten groundwater monitor wells were sampled on April 26, 1999 at the site Monitor wells MW-1 through MW-4 were installed as part of an environmental investigation conducted in December 1994 In July 1996, monitor wells MW-5 through MW-10 were installed as part of an additional environmental site assessment Prior to purging each groundwater monitor well, a water sample was taken and subjective analyses performed 1 he subjective analyses consisted of checking for floating product or a hydrocarbon sheen by lowering a clean teflon bailer down the well and collecting a sample at the groundwater-air interface Wells not containing floating product were purged of approximately 2 to 4 casing volumes of water or until groundwater parameters of pIJ, temperature, and conductivity stabilized as measured by portable meters calibrated to a standard buffer and conductivity standard If the well was slow to recover or purged dry, the water level in the monitor well was allowed to recover to at least 80 percent of its static level before sampling The groundwater samples were then collected by lowering a clean disposable bailer into the well and collecting a representative sample The groundwater samples were slowly transferred to laboratory-cleaned sample containers, sealed with tefloncaps, labeled with the sample number, sample time and date, and immediately placed on ice in an insulated container Each sample was logged onto a chain-of-custody record for subsequent delivery to Excelchem Environmental Labs located in Roseville, California Groundwater samples were analyzed for TPHg, BTEX and MTBE using modified EPA Method 8015, and EPA Method 602 respectively Sample DUP was Submitted as afield duplicate for monitor well MW-1 Groundwater Elevation Data Depth to groundwater was obtained from the existing groundwater monitor wells at the site using a water level indicator graduated to 0 01 foot The depth to groundwater measurement was converted to a groundwater elevation for each well and used to construct a groundwater elevation contour map (Figure 2), and calculate the local groundwater flow direction and hydraulic gradient Groundwater at the site was measured at depths between 64 96 to 77 00 feet below ground surface (bgs) The groundwater potentiometric surface elevation averaged approximately 70 69 feet bgs during this monitoring event The. groundwater elevation has decreased approximately 0 23 feet since the last sampling event in January 1999 The groundwater flow direction during this reporting period is toward the south with a hydraulic O Mme 0011.ckdf rdQ2 99 'ILCOR 0774t717003 July 2b 1999 , J1 ' l fr, ,1. " I , / I � of( 100 41, ,ru,