WORK PLANS - Laserfiche WebLink

Home Browse Search

10 February 2009 AGE-NC Project No. 95-0173 Page 7 of 8 3.2.3. Soil Vapor Extraction Well Completion r ��s• ; �y �) If significant hydrocarbon-impact is encountered from soil borings B-11, B-12 or B-13,then each ~hydrocarbon-impacted boring will be _converted. to,,SVE wells'Each SVE well will-be single-completed utilizing 2-inch diameter,schedule 40 polyvinylchloride (PVC)well casing with 20 feet of 0.020-inch slotted well screen between 15 feet and 35 feet bsg. A proposed well construction diagram is depicted in Figure 4. After installing the well casing in the boring,a filter pack material will be slowly emplaced through the augers over the screen interval to approximately two feet above the screened intervals; the filter pack material will consist of a pre-washed, Lapis Luster No. 3 Monterey Sand. A nominal two-foot bentonite seal(bentonite chips)will be placed above the filter pack to minimize the potential for grout penetration into the screened section of the well. The bentonite seal will be formed by pouring bentonite chips into the annulus and allowing the pellets to settle on the filter pack.The bentonite chips will be allowed to hydrate with tap water for a minimum of one-half hour prior to grouting. The remaining annular space will be filled to the ground surface with a cement grout. The grout mixture will consist of Type IM portland neat cement and not more than 6 gallons of water per 94-pound sack of cement. The grout will be placed by pumping through tremmie pipe. A grouting inspection will be scheduled with SJCEFID personnel. 3.2.4. Well Elevation and Coordinate Survey Following completion of well installations,a reference point will be marked on the top of each well head,and surveyed by a California licensed surveying engineer to the nearest 0.01 foot to determine the elevation relative to a surveyed benchmark and to determine GPS coordinates for tracking on the State Water Resources Control Board(SWRCB) GeoTracker database system. 3.2.5. Soil Vapor Extraction Well Network Connections The existing SVE system utilizes a manifold network of two-inch diameter,Schedule 40 PVC piping installed underground from SVE wells VW-1 through VW-7 to the inlet of the SVE remediation system. The SVE remediation system consists of one 4t/2-horsepower,regenerative vacuum blower r and two 1,000-pound carbon canisters. Additional piping would be installed from any newly installed SVE wells to the existing SVE pipe manifold network, segregated by control valves. E , Advanced GeoEnvfronmentaI,Inc. I