The Contractor shall procure, fabricate and deliver all materials, equipment, and supervision required to install a new drinking water well and abandon an existing drinking water well in accordance with all applicable federal, state and local codes. A. Abandon existing 12-inch production well 10-05 a. Remove pump, associated equipment, and well house from 10-05. Set equipment aside for possible reuse. b. Excavate and disconnect underground utilities (power and water line) at pitless junction. c. Conduct downhole geophysical logging of 10-05 using gamma, resistivity, and caliper logging methods to determine the condition of the borehole, identify any voids and/or obstructions, estimate backfill material volume, and determine the depth and thickness of the shale confining unit that separates the Upper Saginaw Sandstone (USS) aquifer from the Lower Saginaw Sandstone (LSS) aquifer. d. Remove any obstructions that would interfere with the proper plugging of the well. e. Plug the well with neat cement using tremie methods from the bottom of the well to approximately 3 ft below ground surface (bgs). Extensive fractures, gravel, or cavernous zones identified by the geophysical logging may be plugged using concrete grout (Portland cement, sand, and water mixture) or other MDEQ approved methods. f. Inspect the plugged well approximately 48 hours after grouting for settling. If greater than 20 ft of settling has occurred, grout remaining well annulus to approximately 3 ft bgs using tremi methods described above. If less than 20 ft of settling has occurred, backfill the well annulus with a bentonite grout slurry or hydrated bentonite chips to approximately 3 ft bgs. g. Remove surface pad and soil around well casing to a depth of 3 ft bgs. h. Cut casing approximately 3 ft bgs, backfill remaining void with soil to grade, and restore area around well to pre-abandonment conditions to the extent possible. i. Complete a well abandonment report and submit to MDEQ, the Ingham County Health Department and BWL. B. Install 14-inch Replacement Well a. MDEQ has allowed BWL to drill the well, sample and then apply for permit. Contractor to contact MDEQ for verification. b. Drill a 5 inch diameter test well into the upper shale confining unit to a depth of approximately 400 ft bgs using direct circulation mud rotary methods. (Depth of test well may change depending on existing surface or downhole geophysical data available in the vicinity of the replacement well and/or determinations made in the field from the drilling returns by the driller or qualified field representative.) c. Supply and install approximately 125 ft of 5 inch plastic casing into test well. Grout the boring annulus at the base of the casing. d. Establish pumping characteristics to test well. Perform capacity test and determine suitability for permanent production well in area in consultation with BWL engineer. e. Drill a 14 inch diameter test well into the upper shale confining unit to a depth of approximately 400 ft bgs using direct circulation mud rotary methods. Supply and install approximately 125 ft of 14-inch steel casing and grout the boring annulus by tremi methods to approximately 6 ft bgs. Allow grout to cure for at least 24 hours. f. Complete as an open borehole well. g. Air-develop well with drill rig to surge open portion of borehole and remove accumulated sediments. h. Demobilize. C. Place 10-0 x 5-0 x 10 thick slab with (2) mats of 6x6 w1.4 x w1.4 welded wire fabric. Contractor shall cast around well pipe and main, while maintaining isolation through the use of isolation joint material. Contractor shall follow specifications for concrete as found in Section IV Reinforced Concrete. Final layout and location of slab to be approved by BWL Engineer. D. Supply and install drop pipe, head piece, (2) 90 degree elbows and spool piece. Drop pipe shall be 6-inch to a depth of 300 feet plus or minus 10 feet and discharge. Drop pipe shall be 6 domestic ERW pipe-threaded and couple SP6 abrasive blast-one coat devoe 201 primer-one coat devoe barrust 235 applied to the exterior only. Spool piece shall be minimum 24 long. E. Supply and install pump and motor and associated discharge piping. Pump shall be: National Pump submersible size M8HC (9stage) pump with bowl rate 350 gpm at 300 tdh, all bronze construction with 1770 rpm, 8 motor bracket and 6 discharge or approved alternate. Well pump motor shall be 50 HP, 3 Phase and 1800 rpm. Pump and motor submittals to be approved by BWL before purchase. F. Connect pump and motor to electrical supply in well cabinet. G. Disinfect well and place in service. Furnish materials, equipment, and labor required to start up and perform a documented functional test of the system as specified. Contractor shall provide a final report documenting and verifying performance and any deficiencies not corrected. Miscellaneous work items not specifically covered, but required for completion of Work. Contractor shall submit, prior to materials arriving on site, a Material Safety Data Sheet (MSDS) for all chemicals, liquids, solutions, or compounds that will be used, for approval by the Engineer. Those substances found to be hazardous shall not be stored on site. The Engineer will provide a list of any suspect substances and will work with the Contractor to ensure that a plan is established to ensure that none accidentally comes in contact with any drinking water source. The BWL will work directly with and manage the Contractor. BWL will be responsible for the following: Obtain all necessary permits Provide notification to public utilities Provide access to the work locations Provide locations of both test and production wells Transmission main connection Installation of 480 volt power supply to well house Water quality testing Well Cabinet No additional specifications were given.
