Specifications include, but are not limited to: The Town of Fairfax is inviting licensed well drillers to bid on the drilling of two test wells. The Town of Fairfax municipal water system currently relies on one gravel well. The water system is looking to develop a second source of supply and currently has an agreement to drill test wells on a parcel located at the end of Hunt Road (see Figures 1 and 2 at www.fairfax-vt.gov/bids). Several nearby private wells show a potential thin sand/gravel aquifer on top of bedrock (see Figure 3 www.fairfax-vt.gov/bids). The Town will be responsible for site work needed to access the site from its sludge field at the end of Hunt Street. The Town is soliciting costs from Vermont-licensed water well contractors to conduct a test-well drilling program using the dual-rotary drilling method. At two locations at the site (approximately 500 feet apart), the well contractor will utilize a dual-rotary drill rig to advance temporary 6-inch diameter steel casing, and use a diverter to control the discharge of air, water, and cuttings. Sediment samples will be collected by Town’s hydrogeologist. If a promising layer of water-bearing sand and gravel is encountered, a 5-foot length of stainless-steel wire-wrap telescoping well screen (40 to 60 slot) and k-packer will be lowered to the zone of interest. The 6-inch casing will be retracted to expose the well screen to the formation. The well will be developed by air-lifting until the discharge is relatively clear and turbidity is less than 5.0 NTUs. The well contractor will furnish and install a submersible well pump capable of 50 gpm from 80 feet, along the equipment to conduct a 4-hour pumping test (valving, meter, discharge line, etc.). Water-level data and water quality samples will be collected by the Town’s hydrogeologist. After completing the pumping test, and the test well will either be properly abandoned by grouting with cement or bentonite, or a 2-inch PVC observation well will be constructed in the borehole. The 2-inch PVC well will be constructed with a 10-foot length of factory-slotted PVC (20 slot) and solid 2-inch PVC riser to the surface. Sandpack or native collapse around the well screen to two feet above the top of the screen. A two-foot layer of bentonite chips, followed by grouting by tremie pipe to the surface as the 6-inch casing is retracted from the ground. Well contractor will provide and place a 4-inch or 6-inch steel protector pipe over the 2-inch observation well. If no promising sand/gravel layers are encountered during drilling, the borehole will be properly abandoned by grouting the borehole as the 6-inch casing is removed from the ground. All drilling and grouting must be completed in accordance with requirements in the Vermont Water Supply Rule. A Certificate of Liability Insurance, Holds-Harmless Certificate, W9, and a General Service agreement will be required of the selected contractor.
