Auburn, NY
GeoSpray® Geopolymer Mortar: Penstock Rehabilitation

Project Overview
The City of Auburn, NY currently operates several small hydroelectric facility that uses the water from the Owasco River, just north of the Finger Lakes.  One of these includes the Mill Street Dam Hydropower Facility.  The systems consists of a dam that diverts water during high flow times through a penstock to a small turbine and then back into the river.  The original penstock was made from welded in place steel nearly 100 years ago.  Over time, roads and other structures had been built above the pipe and the steel structure had begun to corrode.  The City of Auburn approached Precision Trenchless, LLC of Schenectady, NY looking for a long term solution to create a new structural penstock, within the current structure.

The existing penstock approximately 165 linear feet in length with a 10% incline to funnel water down to the turbine.  At the entrance to the penstock a flume measuring 12’ 6” wide and nearly 12’ tall was the starting point of the repair,  after the initial 
10 linear feet the pipe necked down to a structure that was approximately 10’ 6” in diameter.  There were several different design conditions, due to significantly varying live load and fill heights. In addition, approximately 80’ into the structure the pipe appeared to have been damaged by a significant impact during previous construction.
Precision proposed Spin Cast Geopolymer Pipe (SCGP) centrifugally lining using Milliken Infrastructure’s GeoSpray geopolymer mortar as a full structural rehabilitation solution.  A professional engineering analysis design ranged between 2” and 2.75” depending upon the diameter and load conditions.

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