WORK PLANS - Laserfiche WebLink

Home Browse Search

• • LFR Inc. Health and Safety LFR will prepare a site-specific Health and Safety Plan (HSP) prior to commencing field activities. The activities conducted under LFR's direction at the site will be in compliance with applicable Occupational Safety and Health Administration regulations, particularly those in Title 8 California Code of Regulations 5192, and other applicable federal, state, and local laws, regulations, and statutes. A copy of the HSP will be kept on-site during scheduled field activities. 3.2 Installation of Groundwater Monitoring Wells A California C-57-licensed contractor will install the groundwater monitoring wells under the supervision of LFR staff working under the direction of an LFR Professional Geologist. The boreholes for each proposed monitoring well will be advanced using sonic drilling methods. Due to the nature of the sonic drilling methods, soil samples will be collected continuously for lithologic description. After the boring has been advanced to the desired depth, the groundwater monitoring well will be constructed using 2-inch-diameter, polyvinyl chloride (PVC) casing. The well screen will be 0.010-inch-slotted PVC casing. The length of the well screen will be based on the thickness of the water-yielding sediment encountered. Based on the screen intervals from surrounding B- and C-zone interval groundwater monitoring wells, it is anticipated that the screened interval will be approximately 5 to 10 feet in length. Blank PVC casing will be installed from the top of the screened interval to the ground surface. After the well casing has been placed inside the drill casing, the well annulus materials (sand, bentonite, and grout) will be added. The well annulus opposite the screened interval will be filled with clean Number 2/12 Monterey sand to a height of approximately 2 feet above the top of the well screen. A minimum of 3 feet of bentonite chips will be placed and hydrated above the sand pack to isolate the screened interval from material above and to prevent the entrance of grout into the sand pack. After the bentonite seal has hydrated, a cement-bentonite grout mix will then be placed in the annular space above the bentonite seal to the ground surface to seal the remainder of the borehole from the possible infiltration of surface water. The style of protective wellhead covers (e.g., stovepipe, flush-mounted, etc.) will be determined per the request of the current property owner and installed in concrete at each monitoring well. The SJCEHD will be notified before the wells are sealed so that a field inspector can witness this activity. After the well is completed, the top-of-casing elevation will be surveyed to the nearest 0.01 foot and tied into the elevations of the existing wells at the site by a licensed surveyor. wpStockton-2009 B_C Zone Well Imoill_FINAL.doc Page 3