A joint venture of Triad and Midwest Mole was the lowest among eight bidders for the Market Street Drainage Tunnel for the Charleston (S.C.) Water System. Triad/Midwest Mole’s bid was $13,779,000. The second bid was $16,378,600 and the highest bid was $25,950,000.
This 10-ft diameter stormwater tunnel will stretch 4,000 ft, and includes a 25-ft access shaft and three 54-in. drilled drops. Depths range from 80 ft to 140 ft below surface. The engineeer’s cost estimate was approximately $18 million. The construction schedule is 18 months.