ARCHIVED REPORTS_WELL INSTALL AND QUARTERLY GROUNDWATER MONITORING REPORT 2008

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Well Installation and Quarterly Groundwater Monitoring Report Second Quarter 2008 1950 West Fremont Street,Stockton, California 2.4 SAMPLE HANDLING AND ANALYSIS All groundwater samples were sealed in their appropriate containers, labeled with a unique identifier, placed in a cooler with ice, and shipped to the analytical laboratories under chain-of-custody (COC) protocol. Groundwater samples were submitted to the following state-certified laboratories for analyses: • Maxxam Analytics, Inc. (Maxxam) located in Waterloo, Ontario, Canada for MDMA analyses with ultra-low detection limits. Groundwater samples submitted for NDMA analysis were collected into unpreserved 1-liter amber bottles. ' • TestAmerica Laboratories, Inc. Pleasanton (TestAmerica) located in Pleasanton, California for dissolved CAM 17 metals (500-mL poly bottle preserved with nitric acid), volatile organic compounds (VOCs) (40-mL VOAs preserved with HCl) and semi-volatile organic compounds (SVOCs) (unpreserved 1-liter amber bottles)analyses. ' Copies of CDCs for the groundwater samples are provided in Appendix D. 2.5 SLUG TESTING Slug testing was performed on the new wells. These tests consisted of both slug-in tests (also known as slug tests or falling head slug tests) and slug-out tests (also known as bail tests or rising head slug tests). The tests were performed to determine the hydraulic conductivity of the geologic materials of the screened interval of the well. The hydraulic conductivity results are utilized in the development of groundwater velocities for the site. ' Testing was performed using a solid PVC displacement object (slug), 1.5 inches in diameter and 5.7 feet in length. This size of slug created a water-level change of approximately 3 feet within the well casing. This magnitude of water-level change was deemed sufficient to stress the aquifer and obtain reliable results. Water level change data were collected using a self-contained, factory calibrated, data-logging pressure transducer called a Mini-Troll Pro®. The water in the well was displaced by lowering the slug rapidly, creating a water level rise. The water level then gradually fell to its original level. Once the ' water level had recovered completely, the slug was removed rapidly and the water level dropped. The gradual recovery to static or nearly static conditions was recorded. The datalogger data were downloaded in the field and transmitted, along with the field data sheets, for analysis. Project 102790 6 July 2008