The general description of work includes: 1. Mobilization of drilling equipment to the site. 2. Surface Casing Installation: drill a minimum 34-inch diameter borehole, install 30-inch diameter surface casing to 39 feet (minimum 1.5-inch thick annular cement grout seal). 3. Setup Sound Abatement Wall 4. Drilling. a. Drill a maximum 17½-inch diameter pilot borehole from beneath surface casing to approximately 1,000 feet bls or as directed by CONSULTANT. b. Geophysical logging: Conduct geophysical logging consisting of a caliper, electric, gamma ray, and sonic log in the boring (Geophysical logging company subcontracted by CONTRACTOR). c. Zonal water quality sampling and hydraulic testing: Collect five (5) to seven (7) zonal groundwater samples at depth intervals as determined by the CONSULTANT. d. CONSULTANT to develop final well design based on pilot hole analysis including depth, wellscreen setting(s), aperture size of louvered perforations and grade size of filter pack within 72 hours following zonal groundwater sampling. 5. Ream Drilling: a. Drill a 24-inch diameter borehole from beneath surface casing to a depth as indicated on the final well design. b. Geophysical logging: Conduct geophysical logging consisting of a caliper log on the completed boring (geophysical logging company subcontracted to CONTRACTOR). 6. Well installation: Casing and Screen per Final Well Design a. Casing: 16⅝-inch, high strength low allow steel (HSLA) 0.312-inch wall thickness per final well design. b. Screen: 16⅝-inch, HSLA steel, 0.312-inch wall thickness, louvered perforations, “Ful Flo” pattern as manufactured by the Roscoe Moss Company, Los Angeles, California per final well design. c. Sump: 16⅝-inch, HSLA steel casing, 0.312-inch wall thickness per final well design. d. Install centralizers at 80-foot intervals on screen and casing. Centralizers shall be manufactured with HSLA steel...
