Environmental Remediation

Hudson Falls Tunnel Drain Collection System

McMahon & Mann was engaged by Ecology and Environment Engineering, P.C. to provide geotechnical engineering consultation to the NYSDEC on a project designed to collect polychlorinated by-phenols from the rock formation beneath the Hudson River. The potentially responsible party designed a collection system consisting of a vertical shaft along the banks of the Hudson River, a series of tunnels extending from the shaft beneath the river and vertical drains extending from the tunnel crown into the rock formation containing the dense non-aqueous phase liquids laden with polychlorinated by-phenols. One of the tunnels shown in the original design plans extended beneath a concrete dam that impounds the Hudson River for power generation at an adjacent plant.

Location

Hudson Falls, New York

Client

Ecology & Environment Engineering, P.C. and New York State Department of Environmental Conservation

Date

2008

McMahon & Mann was engaged by E&E to provide geotechnical engineering consultation to the NYSDEC on a project designed to collect polychlorinated by-phenols from the rock formation beneath the Hudson River. The potentially responsible party designed a collection system consisting of a vertical shaft along the banks of the Hudson River, a series of tunnels extending from the shaft beneath the river and vertical drains extending from the tunnel crown into the rock formation containing the dense non-aqueous phase liquids laden with polychlorinated by-phenols. One of the tunnels shown in the original design plans extended beneath a concrete dam that impounds the Hudson River for power generation at an adjacent plant.

McMahon & Mann reviewed the drawings, specifications and instrumentation plans proposed by the potentially responsible party and offered our advice to the NYSDEC regarding the feasibility of the plans and the effect of the tunnel on the overlying dam structure. During construction, we observed the blasting events and rock excavation, reviewed the blast vibration and rock instrumentation data and provided our opinions to E&E and the NYSDEC on geotechnical engineering issues.