ARCHIVED REPORTS_XR0005601 - Laserfiche WebLink

Home Browse Search

Geo Inc Page 3 Solo&Groundwater Investigation Report ' Ted Peters- AS r • Project No 701 2 April 20,2001 Since only selected soil sample collected were submitted for laboratory analysts, a screening process was done to gather additional information through field observation noting the ' following ■ sediment type, especially grain size and clay content ■ moisture content ' ■ visible evidence of contamination, i e , color change due to reduction of iron or discoloration from hydrocarbons and other pollutants ■ readings above background on a organic vapor meter (OVM) The OVM is a portable photo ionization detector that uses a 10 0 eV lamp to detect compounds with ionization potential below 10 0 eV (hydrocarbon range) Details on the geology encountered during the completion of the sampling event as well as the field observations are included in Section 3 3, Geology and Field Observations 2.1.2 Soil Laboratory Analyses Based on field screening observations, two soil samples from each borehole were submitted to Sherwood Labs (State Certified Laboratory #1400) for analysis of • benzene, toluene, ethylbenzene and xylene (BTEX by EPA method 602) • gasoline range petroleum hydrocarbons (TPH-G by EPA method 8015(m)) ' . • diesel range petroleum hydrocarbons (TEPH-D by EPA method 8015(m)) • Methyl-tert Butyl Ether(MTBE) (by EPA method 602) ' The detection limits for these compounds are listed below A Chain of Custody was completed for all samples collected and tracked to ensure sample integrity etecti( emitsBTEX TPITT; - Soi 17(µg/Kg , 2.2 Monitoring Well Installation The monitoring wells were constructed using 2 0-inch diameter PVC casing with flush threads The screened intervals extended from approximately 5 20 feet below grade ' surface (bgs) Groundwater was encountered at approximately 8 feet bgs A #12 sand filter pack surrounded and extended 0 - 1 feet above the 0 020 inch screened interval and was topped by a 1 5 —2 5 feet bentonite chip transition seal installed on top of the filter pack and hydrated A surface seal was achieved by pouring neat cement on top of the transition seal The wells were secured with locking watertight caps encased in flush mounted traffic rated well boxes ' On March 27, 2001, Don Light of Del Tech mobilized to the site to develop the new monitoring wells (using mechanical surging and pumping methods) until a clear stream of water was obtained On March 29, 2001, Don Light returned to the site to purge and collect groundwater samples from the two new monitoring wells All development and purge water was containerized in 55-gallon DOT approved containers and stored on site until its disposition can be arranged