Description
The North Dakota Public Service Commission is seeking a qualified contractor to reclaim an abandoned underground lignite‑coal mine near New Salem. The work requires vertical drilling, installation of PVC casing, placement of groundwater monitoring wells, and injection of a cementitious Controlled Low‑Strength Material (CLSM) to fill mine voids. The contractor must also provide traffic control, site clean‑up, and comply with extensive safety, environmental, and Buy‑America requirements.
• Drill approx. 35,000 ft of vertical boreholes (4¾‑7½ in dia, up to 240 ft deep).
• Install 10,000 ft of 3‑in ID PVC pipe in boreholes intersecting mine voids.
• Construct three groundwater monitoring wells (≈220 ft deep) ≥ 21 days before drilling.
• Inject ~1,000 cu yd of CLSM, meeting ASTM C94 strength and slump specifications.
• Provide traffic‑control measures, site restoration, and detailed daily reporting (drill logs, CLSM injection logs).
• Maintain performance and payment bonds equal to 100 % of the contract amount and a 5 % bid bond.