WORK PLANS - Laserfiche WebLink

Home Browse Search

k Stantec September 11, 2009 Page 3 of 6 Reference: Work Plan for Site Closure,Caltrans Shap 10 Maintenance Facility T Stockton,California Joaquin Hydrogeologic Basin. The Basin Plan indicates that groundwater occurring within the San Joaquin ` Hydrogeologic Basin has"designated beneficial" uses for municipal and domestic supply, agricultural supply, and industrial service and supply purposes. t Groundwater at the Site is currently encountered at approximately 43 ft bgs:;,.Groundwater elevations have risen an average 7.88 feet across the Site over the last 4 years. The groundwater flow direction beneath the Site has historically been toward the southeast with an average.hydraulic gradient of 0.002 foot per foot (Stantec, Second Quarter 2009 OM&M Report, dated July 31,2009).." SCOPE OF WORK { p- The proposed scope of work leading to request for closure includes the following and is detailed further 1 below: 1) prepare a Health and Safety Plan (HASP);2) obtain the necessary permits and utility clearances; 3) perform a sensitive receptor survey, confirmation soil borings, and soil vapor investigation; and 4) report of findings and Request for Site Closure. Task 1 —Pre field Activities Stantec will perform the following activities prior to starting any field work: a ❑ Prepare a site-specific HASP to address hazards associated with proposed field activities. The HASP will be reviewed by Stantec and contractor field personnel at'least twice daily during field work. ` The HASP will describe personnel protective equipment (PPE), mandatory safety practices, emergency procedures, hospital map,traffic concerns and job safety analysis (OSA)for tasks being performed_ A copy of the site-specific HASP will be kept on-site at all times during field work. The HASP will be written in accordance with California Department of Industrial Relations, Occupational Safety and Health Administration (Cal-OSHA) and federal regulations (29 CFR 191.0.1.20). ❑ Obtain the necessary permit(§)for the soil borings and soil vapor sampling from the San Joaquin , County EHD. ❑ Stantec will complete a review of available as-built site documents supplied by Caltrans to search for underground utilities in the area of drilling, prior to initiating field work. Stantec will notify L Underground Service Alert(USA)and use a.private utility locator to search for underground lines prior to drilling. Task 2—Field Work Sensitive Receptor,Survey Stantec will complete a visual reconnaissance of surrounding properties using accessible public right-of-way ` within a 2,000-foot radius of the property for signs or aboveground evidence'of agricultural, irrigation or domestic wells, pump houses, evidence of ponds, streams, natural surfacewater, schools, parks or other sensitive receptors. The shallow groundwater aquifer in the vicinity of the Site is not known to be currently used for drinking water. ` Confirmation Soi!_Borings Two confirmation soil borings will be advanced in the area of the former UST location to confirm and document that soil remediation has removed contaminants from Site soils Fi ure-2). Confirmation boring r { 99 locations will be cored and hand augered to 5 ft bgs to inspect for.subsurfacb utilities. The borings will be advanced to a total depth of approximately 50 ft bgs or first-encountered groundwater using a 4-inch hollow �I stem auger, and soil samples will be collected at intervals of 5 feet to.the total depth in each boring. Soil 1AProie0ts\CALTRANSIShop I0120091Ciosureldosure work pian fnt.doo ac