ARCHIVED REPORTS_XR0007372 CASE 2

Home Browse Search

3.0 PURPOSE AND SCOPE OF SERVICES The investigation outlined in this report was pnmanly designed as a limited program of sampling and chemical testing of groundwater samples at the above-mentioned site Mr Harlan Knoll of the San Joaquin County Environmental Health Department requested in May 1999 that this investigation be performed as a prerequisite to obtaunng site closure The program was designed to help further assess the lateral and vertical Wdent of diesel fuel constituents in the groundwater onsite Specifically,these tasks included • Purging and sampling three groundwater monitoring wells, Chemcally testing groundwater samples by a California state-certified analytical laboratory,and • Preparation a report siimmanz g the subsurface investigation with findings, conclusions and recommendations ions 4.0 INVESTIGATION AND LABORATORY METHODS 4.1 FIELD PROCEDURES Site activities were conducted under the supervision of a State of California Registered Geologist having five or more years of professional expenence in groundwater hydrology The field operations were supervised by a qualified Geologist designated by the supervising Registered Geologist Field operations personnel were trained in accordance with 29 CFR 1910 (404iour OSHA health and safety training) Untrained field operations personnel or visitors were not allowed on the site during field operations 4.2 GROUNDWATER MONITORING WELLS 4.2.1 Water Level Measurement Three nm Aonng wells were sampled during this quarterly monitoring and sampling round The locations of the nwnaring wells are presented on Figure 2 The procedure for sampling the monitoring wells consisted of intially measuring the depth to the groundwater surface in each well utilizing a decontarrunated Sohnst Model 101 flat tape electrical water-level meter Groundwater surface depth was detemuned to the nearest 0 01 foot and referenced to the top of casing for each well Groundwater elevations were determined from an arbitrary datum of 37 feet,the approximate surfs=elevation of the site based on the U S Geological Survey Lodi North 7 5-minute Quadrangle map dated 1967 (photorevtsed 1980) Table 4-1 lists the date of the sounding and the groundwater surface elevations Before use and pnor to subsequent measurematts in each well,the measuring equipment was decontammated AT&T—Lodi,Quarterly Groundwater Monitoring Report No 3 NATC ATC Protect No 75 75128 0001 November 14,2001 Page 2 of 7