FIELD DOCUMENTS - Laserfiche WebLink

Home Browse Search

No Further Action Required Request Report US Can—Welty Road September 24, 201 Based on review of the DWR Water Well Drillers reports, four of the identified wells are used for domestic purposes, one well is used for irrigation,one well is used for industrial purposes, and two wells were identified as public-supply wells. The results of the search are provided in Table 2. One of the identified domestic wells appears to correspond to well W-1 (Figure 2; Table 2,well ID#3),which was sampled by ERM-West on March 30, 1995. The well had non-detect results for all of the analyzed constituents, which included TPHg, oil and grease,toluene, ethylbenzene, and total xylenes (ERM-West, 1995; Appendix B.1). The property has been redeveloped since the 1995 sampling event and it is uncertain whether well W-1 is still active. With the exception of the industrial well, all of the other identified wells have screened intervals starting at 120 feet bgs or greater. The areas of affected groundwater at the Site appear confined to the upper water-bearing zones at less than 80 feet bgs. Typically, the crude oil in affected soil is not easily soluble, has a high viscosity, and moves very slowly if at all. Therefore, it is unlikely that any of the wells would become impacted by the shallow affected groundwater related to the Site. The TDS concentrations in groundwater at the Site range from 779 mg/L to 1,280 mg/L, which exceed numerous State of California and federal TDS standards for drinking water as well as agricultural-use criteria. Installation of shallow water-supply wells is unlikely within or in the immediate vicinity of the affected groundwater given its poor quality and likely low yield. Use of the affected groundwater is not anticipated at the Site; consequently, institutional controls are not needed with respect to installation of water- supply wells. No other potential ecological, human, or environmental sensitive receptors are known. 4. Provide a map showing the location of all water supply wells used for municipal, domestic, agricultural, industrial, and other uses within 2,000 feet of the site. Provide well details and distances in a table. Approximate locations of the water-supply wells are shown on Figure 1. A summary of the water-well search results is provided in Table 2. S. Provide scaled site maps of the area impacted showing locations of former and existing tank systems, excavation and sample locations, boring and monitoring well locations, groundwater elevation contours subsurface utilities, buildings, streets, and any nearby surface waters. The locations of current structures, former USTs, former pipelines, excavated areas, and trench and sampling locations are indicated on Figure 2. The Site consists of three areas of affected soil encompassed within a larger area of affected groundwater measuring approximately 1,400 feet by 375 feet, or an area of approximately 12 acres. Groundwater elevation contours were generated as part of groundwater monitoring and sampling activities between 2005 and 2009. The groundwater monitoring and sampling reports are included as Appendix B. Potentiometric surface maps generated during monitoring activities are included as a component of Appendix C. 6. Provide boring logs and cross-sections to show site lithology. Boring logs are provided in the reports included as Appendix B. SAIC has not generated any cross-sections for the Site. 7 SAIE