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FORMER AMERICAN FOREST PRODUCTS 3.0 Groundwater Closure Summary Report July 2009 URS Project 17322736 Page 3-2 within a I-mile radius of the site. Six water wells operated by the California Water Service Company were reported within a 1-mile radius of the site. All six wells were reported to be screened deeper than 200 feet bgs, which correlates to a deeper, semi-confined aquifer, as opposed to the shallow unconfined aquifer impacted by contaminants at the site. A survey of wells within 2,000 feet of the site was completed in January 2006 (URS, 2006a) (Figure 6). The 2.000-foot radius survey included a search of agency data together with a door-to-door survey of businesses and residences. The 2,000-foot radius survey was updated on July 15-17 2009, and included a search of California Department of Water Resources (DWR)well completion reports, telephone and on- " the-ground inquiries of previously known and potential groundwater users. A Geotracker search was also completed to identify vicinity sites for which well searches may also have been completed.No new wells were identified within 2,000 feet of the Site. The only changes recorded in the DWR records were the destruction of several monitoring wells on the San Joaquin Rural Cemetery at Harding Way and Cemetery Lane, which were installed as part of a leaking underground storage tank investigation. Particular attention was paid to businesses in the Site's downgradient direction to the northeast along El ... Pinal Drive and vicinity. This area is supplied by city water and no supply wells were reported in response to URS' inquiries. The results of the 2,000-foot-radius well survey are presented on Figure 6 and tabulated in Table 3. These results show five water supply wells within 2,000 feet of the site: one domestic water supply well at a residence to the south of the site,three irrigation wells on the San Joaquin Cemetery to the west of the site, and one irrigation well on the Stockton Rural Cemetery to the northwest of the site. All of the identified supply wells are either upgradient or distantly crossgradient to the Site. 3.3 SECOND QUARTER 2009 GROUNDWATER MONITORING This section discusses sampling procedures, analyses, and quality assurance checks undertaken for the most recent groundwater monitoring round conducted in June 2009. Groundwater impacts, including �. those observed through the second quarter of 2009, are discussed in Section 3.4 Groundwater monitoring during the second quarter of 2009 was conducted following the requirements presented in letters from San Joaquin County Environmental Health Department (SJCEHD) dated April 16, 2003. and October 23, 2008. In accordance with the October 2008 letter, sampling is suspended at this time from monitoring wells DMW-1, DMW-3, DMW-4, DMW-7, and DMW-8. Water levels were measured and groundwater samples were collected from site monitoring wells DMW-2, DMW-5, DMW-6, DMW-9, and DMW-11 through DMW-14 on June 6, 200, by URS staff. Well locations are shown on Figure 2, and well construction details are included in Table 1. Field records and chain-of- custody forms are included in Appendix B. Data Validation Summaries and analytical laboratory reports are included in Appendix C. 3.3.1 Field Methods Static water levels were measured from each well"s top of casing (TOC)prior to initiating sampling activities using,an electric water level sounder(Table 2). Prior to sampling, the wells were purged to ensure representativeness of the water samples. Disposable bailers and an electric submersible pump were used for purging. field parameters (temperature, electrical conductivity, pH and turbidity) were monitored during purging, which was continued until field parameters stabilized and a minimum of three casing volumes of groundwater were removed. Purging data were entered on Field Record of Water Sampling Forms(Appendix B). Before and after purging each well the submersible pump was f:r.l4pxocess2 716'Americao Forest+Closure-Sunv '-Report-RCVOt.CIDc