SITE INFORMATION AND CORRESPONDENCE

Home Browse Search

Revised Soil and Groundwater Investigation Work Plan Mountain House Development Site#6 July 2007 Soils encountered in the borings were predominantly clays, silts, and sands. Borings advanced on the shoulder of Byron Road encountered clay and gravel fill in the upper 1 to 3 feet that appeared to be road sub-base. Groundwater was observed at the site at depths ranging from 7 to 17 feet bgs. 3. SCOPE OF WORK SAIC will implement the scope of work described in sections 3.1 through 3.5. In general, SAIC will advance up to 27"primary"and four"contingency"borings from which soil and groundwater samples will be collected for laboratory analysis,to delineate the extent of affected soil and groundwater. SAIC will also collect and have analyzed shallow soil samples for a risk assessment. 3.1 PERMITTING,ACCESS,AND SITE SAFETY Before initiating the field investigation, SAIC will perform the following: • Determine the ownership of and obtain access to private properties coincident with the scope of work described herein. • Obtain boring permits from the San Joaquin County Environmental Health Department (SJCEHD). • Obtain an encroachment permit from the Mountain House Community Services District (MHCSD) for borings located in the Byron Road ROW. • Obtain an approved traffic-control plan from the MHCSD. • Prepare a site-specific Health and Safety Plan. • Prepare a site-specific Journey Management Plan. • Conduct a site visit to mark boring locations for Underground Service Alert, which will locate underground facilities in adjacent public ROW. • Subcontract Cruz Brothers Locators, a private utility locator,to identify any potential overhead and underground hazards. 3.2 DWR FILE REVIEW In order to assess the extent of affected soil and groundwater and potential impacts to receptors, SAIC will review DWR files to identify any water wells within 2,000 feet of the site. 3.3 FIELD INVESTIGATION ACTIVITIES SAIC will contract a California-licensed(C-57)driller to operate truck-mounted, GeoProbe direct-push equipment to advance up to 27 primary borings(Figure 3;note,the lettering system A through AA used below will be converted in the field to a consecutive numbering): • SB-A, SB-B, SB-C, and SB-D to investigate the extent of affected media around GP 152. • SB-E to investigate the source,magnitude, and extent of affected media at GP 152. • SB-F, SB-G, and SB-H to investigate the extent of affected media around GP156. • SB-I to investigate the source, magnitude, and extent of affected media at GP 156. • SB-J to investigate the extent of affected media up gradient of GP157 and GP158. • SB-K to investigate the extent of affected media immediately down gradient of GP 157. • SB-L to investigate the extent of affected media immediately down gradient of GP158. • SB-M to investigate the extent of affected media immediately down gradient of GP 160. 3 =- Emr -- .::: M=WJW%i`® From Schee to Solutions