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Soil and Groundwater Investigation Report Mountain House Development Site#6 February 25,2010 3. SCOPE OF WORK SAIC-Benham implemented the recommendations presented in the July 2008 SGI R as described in sections 3.1 through 3.3. 3.1 PERMITTING,ACCESS,AND SAFETY To maintain regulatory and legal compliance, protect the health of all involved persons, and prevent accidents, SAIC-Benham: • Completed strategic-planning and project-setup activities, including the site-specific Health and Safety Plan, site-specific Journey Management Plan, and the clearance of subsurface utilities; • Determined the ownership of, and obtained access to,private properties on which borings were proposed; • Conducted a site visit to mark boring locations for Underground Service Alert(USA), notified USA at least 48 hours in advance of field activities, and requested USA to mark underground utilities in adjacent public ROWS; • Subcontracted Cruz Brothers Locators, a private utility locator,to clear the site and proposed boring locations for any potential overhead and underground hazards and/or other potential obstacles; • Obtained soil boring permits from the San Joaquin County Department of Environmental Health; and • Obtained an encroachment permit from the Mountain House Community Services District for borings located on the shoulder of West Byron Road. 3.2 FIELD INVESTIGATION ACTIVITIES To define the extent of affected soil and groundwater at the site, SAIC-Benham advanced 15 soil borings (SB-30 through SB-44) on November 9 through November 18, 2009. An SAIC-Benham field geologist observed PeneCore Drilling (C57 license#906899) advance the soil borings to depths ranging from 20 to 35 feet bgs using a Geoprobe 7822DT direct-push rig. Each boring was hand-cleared to a minimum depth of 8 feet bgs using a hand auger prior to advancement. All field activities were performed under the direction of a California Professional Geologist. The investigation was implemented in accordance with the scope of work, except for the following variations: • A contingency boring (SB-44)was advanced on Assessor's Parcel Number(APN) 209- 150-23 to further define the extent of affected soil in Area 1; and • A private water-supply well (the Foster Well), located on APN 209-150-24, was sampled. Soil borings were logged in accordance with the Unified Soil Classification System(USCS). Soil samples were screened visually for evidence of crude oil and were also screened using a photo-ionization detector(PID)to measure hydrocarbon vapors. Soil and groundwater samples 4 Fmin Science to Solutions