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�� Carc�/no4 November 3,2014 ATC Glover Well Destruction Report Sbaping the Future Other than the drainage ditch located along the south edge of the site, there are no flood control basins or spreading basins, or lined or unlined canals shown on available maps or identified during site reconnaissance within 2,000 feet of the site. Any surface spills that were able to leave the site to the south would encounter the ditch and flow toward the channelized creek to the west. Unlike the creek, the drainage ditch near the site does not contain standing water year-round. Storm sewers and improperly sealed sanitary sewers can extend the range at which a surface spill may impact municipal facilities such as wastewater treatment plants. The distances usually involved, related water handling machinery and resulting aeration, and conditions that promote biological digestion of organic wastes at the destination tend to reduce potential impact in all but the most catastrophic of surface releases. Such facilities are also carefully monitored for irregularities, and are typically notified if large spills occur that could affect them. As such, only wastewater treatment facilities within the normal radius of concern are considered sensitive receptors. The water treatment facilities for Tracy are located approximately two miles north-northwest of the site, and are not considered sensitive relative to the site. 2.0 SCOPE OF WORK The scope of work consisted of destroying all nine monitoring wells and five remediation wells, MW-1 through MW-9, AS-1 and AS-2, and SVE-1 through SVE-3(Figure 2). All remediation wells and monitoring wells MW-1 through MW-5, MW-7 and MW-8 were destroyed by over drilling each well to total depth using a hollow-stem auger drill rig followed by grouting with neat Portland using tremie from total depth to the surface. Monitoring wells MW-6 and MVV-9 were approved to be pressure grouted in place due to proximity to subsurface structures. `_ , ,( d-g . 2.1 Site Health and Safety Plan As required by the Occupational Safety and Health Administration (OSHA) Standard "Hazardous Waste Operations and Emergency Response" guidelines (29 CFR 1910.120), and by California Occupational Safety and Health Administration (Cal-OSHA) "Hazardous Waste Operations and Emergency Response" guidelines (CCR Title 8, Section 5192), Cardno prepared a Site-Specific Health and Safety Plan (HASP) prior to the commencement of fieldwork. The Site-Specific HASP was reviewed and signed by all field staff and contractors before beginning field operations at the site. 2.2 Permitting Cardno obtained approval for the well destruction from SJCEHD on August 11, 2014. A copy of the permit is included as Attachment 1. —� 2.3 Subsurface Utility Clearance Prior to field activities, Cardno marked all proposed drilling locations in accordance with the Underground Service Alert (USA) guidelines, and notified USA North of upcoming subsurface activities so existing underground utilities in the area of proposed work could be located and avoided. Cardno also contracted a private utility locator to confirm the locations of the underground utilities in the vicinity of the work and attempt to identify any other subsurface conflicts. Obstructions were found near MW-6 and MW-9- 4