Deep tunnel CSO projects are high risk projects as 9-figure decisions are often made based on limited geotechnical investigation. Even small inaccuracies in this data have resulted in change orders in the tens of millions of dollars.
Retaining 7NT to perform the drilling is a low/no cost way of insuring against this risk.
For little or no additional cost, the owner can hire the best drilling firm and reduce the substantial risk associated with inaccurate data gathering.
7NT’s track record on CSO tunneling projects includes the following:
- DRTC project in Indianapolis set world records for mining in a day, a week and a month.
- DRTC project in Indianapolis is $80 million under budget, while the remaining 18 miles of the Indianapolis system are currently projected to come in $70 million under engineer’s estimate.
- South Hartford Conveyance Tunnel had multiple bids come in $30 million to $50 million under engineer’s estimate.