WORK PLANS_CASE 1 - Laserfiche WebLink

Home Browse Search

ChevronTexaco—U.S. Can/Welty Road, Vernalis, CA. Project No. 06-6102-00-5394-101 March 10,2004, 2004 Page 4 of 6 permits,private property access agreements, and traffic-control plan will be submitted to the proper agencies or property owners,if required,for approval prior to field activities. TASK 2—WELL SEARCH AND SURVEY SAIC will conduct a search of DWR files to obtain information on water production wells used for domestic,irrigation,municipal, and/or other uses within a 2,000-foot radius of the site. A copy of the Well Completion Report Release Agreement—Agency Form will be forwarded to the RWQCB for authorization and signature. Following this search SAIC will prepare a table containing the State Well Number, location, and water use(if available), which will be included in the soil and grab groundwater investigation report. TASK 3—FIELD ACTIVITIES Geoprobe-type equipment will be used to advance the six proposed borings and to collect soil and grab groundwater samples. During drilling activities, soil samples will be collected in general accordance with SAIC field procedures and the Second Draft Revised Technical Approach to Site Evaluation and Decision-Making, Old Valley Pipeline Sites(Geomatrix, 2002). Drill cuttings will be drummed on site and will be properly disposed of by ChevronTexaco. During drilling activities, a continuous coring device will be used to collect soil samples. The samples will be field screened using photoionization detection(PID) equipment to detect the presence of residual petroleum in soil. The soil will also be logged in general accordance to the Unified Soil Classification System(USCS) as presented in ASTM 2488-90. Between borings,the down-hole equipment will be cleaned using a Liquinox/water solution to prevent the possibility of cross contamination between consecutive boring locations. The locations of proposed soil borings is shown on Figure 2. Soil borings will be advanced to a target depth of approximately 45 to 50 feet bgs. SAIC will attempt to collect soil samples from the depths that coincide with affected intervals observed in previous borings in accordance with the Second Draft Revised Technical Approach to Site Evaluation and Decision Making, Old Valley Pipeline Sites(Geomatrix, 2002). If soil northeast of GMX-12 appears to be affected by residual petroleum,based on visual and PID readings, SAIC will destroy the borehole according to SJCPHS requirements and advance the contingency boring approximately 200 feet northeast of GMX-12 at the location shown on Figure 2 (SB-18). Based on the analytical results from the November 2003 report, SAIC is planning only one contingency boring to define the lateral extent of affected soil northeast of GMX-12. Following completion of the soil borings, the open borehole will be destroyed according to SJCPHS requirements. Soil samples will be submitted to a California state-certified laboratory,Lancaster Laboratories in Lancaster,Pennsylvania(ELAP#2116),under proper chain-of-custody protocols. Select soil samples submitted will be analyzed for BTEX by EPA Method 8021B,TPHg by EPA Method 8015 modified, TPHc by EPA Method 8015 modified,and PAHs by EPA Method 8270C Select Ion Monitoring(SIM). SAIC will also collect soil samples from each boring for use in a future human health risk assessment (HHRH). These soil samples will be collected from an approximate depth shallower than 10 feet bgs from the proposed soil borings. SAIC will submit one soil sample from the upper 10 feet of borehole at either the 5-foot bgs interval if no impacted soil is observed to the depth of 10 feet bgs,or above groundwater if water is observed shallower than 10 feet bgs. However, if affected soil is observed above 10 feet bgs, SAIC will collect a soil sample for HHRA purposes from the most affected interval. Soil samples collected for the HHRA will be analyzed for the above constituents. However, soil samples collected for HHRA purposes will be analyzed using a detection limit that is sensitive (low) enough to detect concentrations of constituents that are not of human health concern. Therefore, SAIC will request of the laboratory that PAH compounds for soil be analyzed using a detection limit of<5 ug/kg.