Laserfiche WebLink
S E C 0 R <br /> 7-Eleven Store #20632 <br /> Quarterly Groundwater Monitoring Report (4Q2005) <br /> • January 20, 2006 <br /> Page 3 <br /> indicator. Dissolved oxygen concentrations were also measured in each well using a YSI <br /> Model 550A dissolved oxygen meter equipped with a down hole sensor. <br /> Well purging and sampling equipment was thoroughly cleaned prior to purging and <br /> sampling each well. The sampling procedure for each well included measuring the water <br /> level and checking for the presence of liquid-phase hydrocarbons (LPH), using either an <br /> electronic indicator and a clear Teflon® bailer or an oil-water interface probe. Wells not <br /> containing LPH were purged of approximately three casing volumes of water (or to dryness) <br /> using a submersible pump or bailer. The equipment and purging methods used for the <br /> current sampling event are noted on the field data sheets in Attachment A. During purging, <br /> temperature, pH, and electrical conductivity were monitored. After purging, water levels <br /> were allowed to recover to 80% of the original levels prior to collection of the water sample. <br /> Groundwater samples were collected using a disposable Teflon® bailer, placed into <br /> appropriate Environmental Protection Agency (EPA) approved containers, labeled, logged <br /> onto chain-of-custody documents, and transported on ice to a California state-certified <br /> laboratory. Copies of the field notes are presented in Attachment A. <br /> GROUNDWATER SAMPLE ANALYSES AND RESULTS <br /> The groundwater samples collected from MW-1, MW-2, MW-3, MW-4R, MW-5, MW-6, and <br /> MW-7 were analyzed for the presence of TPHg; benzene, toluene, ethylbenzene, and total <br /> xylenes (BTEX); and fuel oxygenates MtBE, tert-butyl alcohol (TBA), diisopropyl ether <br /> (DIPE), ethyl-tert-butyl ether (EtBE), and tert-amyl-methyl ether (TAME) by EPA Method <br /> 82606. The certified laboratory analytical report and chain-of-custody documentation are <br /> presented as Attachment B. <br /> Groundwater analytical results are presented on Figure 3, and are summarized in Tables 1 <br /> and 2. <br /> PURGE AND RINSATE WATER DISPOSAL <br /> Water generated during well sampling and equipment cleaning was pumped into a SECOR <br /> truck-mounted water tank. The water was transferred into properly labeled 55-gallon drums <br /> and stored on-site. The drummed non-hazardous petroleum hydrocarbon contaminated <br /> water is transported quarterly by Belshire Environmental to DeMenno Kerdoon in Compton, <br /> California, for disposal. <br /> i <br /> 20632 05-4Q Report.doc S1=COR International Incorporated <br />