ARCHIVED REPORTS_XR0004059 - Laserfiche WebLink

Home Browse Search

Ms. Linda Turkatte June 11, 1996 Page 4 feet above mean sea level(msl)from Texaco survey data. Well elevation data and calculated groundwater ' elevation data are included in Table 1. Groundwater monitoring well MW-1 was developed and-sampled on February 7, 1995. The well was developed by alternately bailing and surging. Well development continued until the groundwater was reasonably free of sediment. Ten casing volumes of water were removed during well development. During well development, measurements and observations of pH, electrical conductivity,temperature, color,and turbidity were recorded and are included on a Groundwater Sample Field Data Sheet(Attachment B). Following well development,SECOR collected a groundwater sample from the monitoring well MW-1 for chemical analysis. Prior to.sampling the well was allowed to recover to 80%of the initial water level prior to development. The groundwater sample was collected using a disposable PVC bailer and decanted.directly into laboratory-supplied sample containers.. Each of the sample containers was labeled, sealed in:plastic bags, and placed in an ice-filled.cooler. The sample was submitted to Superior,along with a completed chain-of-custody record and was analyzed for TPHg and BTEX by EPA;Methods 8015,modified and 8020,. respectively. Decontamination, and Material Containment To minimize the potential for cross-contamination,soil sampling and groundwater development,equipment were washed in a dilute trisodium phosphate (TSF') solution, rinsed in fresh water, and final rinsed:with distilled water or steam cleaned between each drilling or sampling location. Because groundwater,samples were collected with pre-cleaned dedicated bailers,decontamination between•groundwater sampling locations was not required. Downhole drilling equipment was steam-cleaned between'each borehole location in`a designated area prepared to contain rinsate. The water-level indicator was rinsed with deionized water between well,soundings to prevent cross-contamination. Soil cuttings generated during field activities were stockpiled on and covered with visqueen on-site pending appropriate.disposal. All water generated during well development, sampling, and decontamination was temporarily stored in 55-gallon drums at an on-site location pending appropriate disposal-. SUBSURFACE CONDITIONS Evaluation of subsurface conditions for this Site investigation is based on data collected from the four boreholes advanced in the vicinity of the former Site USTs(MW-1,VE-1, SB-1 and SB-2), soil chemical data collected during UST removal activities in February 1994; and from three Texaco groundwater monitoring wells(MW-6,MW-8,and MW-14)located on or adjacent to the Site(Figure 3). Groundwater quality data was collected for well MW-1 by SECOR on February 7, 1996 and for wells MW-6,MW-8, and MW-14 by Blaine Tech on February 27, 1996. HASUMDRILL.RYT 50090-011-02