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Twelve oxygen injection points (IP-1 through IP-12) were installed in June 2007 under the oversight of EarthTech at locations nearby and surrounding monitoring wells MW-8 and MW-14. Nine of the injection points (IP-1 through IP-9) were installed at approximately 25 feet below ground surface (bgs) with 15 feet of 0.020-inch slotted casing from approximately 10 to 25 feet bgs (A-zone), and three injection points (IP-10 through IP-12) were installed at approximately 50 feet bgs with 15 feet of 0.020-inch slotted casing from 35 to 50 feet bgs (B-zone). Between December 17 and 21, 2007, SECOR initiated mobile oxygen injection activities were initiated at the site. Between December 21, 2007 and June 20, 2008, there was a total of twelve oxygen injection events completed on a bi-weekly basis. During each two-day event, oxygen injection into IP-1 through IP-12 was completed using bottled oxygen transported to the site by SECOR. The amount of oxygen injected into each well was 150 ft3 (13.4 pounds) per injection event conducted through April 24, 2008. During the oxygen injection events conducted in May and June 2008, 300 ft3 (26.7 pounds) of oxygen was injected into each well. Approximately 2,964 pounds of oxygen has been injected at the site during the pilot study activities between December 17, 2007 and June 20, 2008. On July 9 through 13, 2009, Stantec oversaw Cascade Drilling Inc. install four off-site oxygen injection wells (IP-14 through IP-17) and oversaw the destruction of seven off-site injection wells (IP-01, IP-04 through IP-09). On July 27 and 28, 2009, Stantec injected 150 cubic feet (13.4 pounds) of oxygen per well into wells IP-11, IP-14, IP-15, IP-16, IP-17 and MW-22 for a combined total of about 80 pounds. Oxygen injections were performed on a bi-weekly schedule between December 17, 2007 and December 28, 2010. An estimated 300 cubic feet (26.8 pounds) of oxygen was injected into wells IP-10, IP-11, IP-14, IP-15, IP-16, IP-17 and MW-22 for a combined historic total of about 9,105 pounds. Oxygen injection activities were voluntarily suspended to evaluate the potential for case closure in December 2010. ATC conducted a Human Health Risk Assessment (HHRA) at the site in July 2011. The HHRA included an evaluation of soil, groundwater, and soil gas analytical results to determine the potential risk to human health and the environment. The findings of the HHRA did not indicate that there were a significant risk to human health and the environment including ecological receptors. 3.0 SCOPE OF WORK The scope of work consists of destroying 19 groundwater monitoring wells (7 on-site and 12 off- site), 6 piezometers (2 on-site and 4 off-site) and 9 remediation wells (3 on-site and 6 off-site) associated with the oxygen injection. All wells will be destroyed by over-drilling. Table 1 summarizes the well construction details and proposed destruction methods. 3.1 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), ATC will prepare a Site-Specific Health and Safety Plan (HASP) prior to the commencement of fieldwork. The