A contractor for the Altoona Water Authority is fixing a leaky outlet pipe that allowed contaminated Kittanning Run to leak into the Kittanning Point Reservoir near Horseshoe Curve.
Normally, the contaminated water bypasses Kittanning Point and two reservoirs downstream.
To address the problem until repairs could be made, authority workers lowered the reservoir to create “holding” capacity, authority General Manager Mark Perry said.
This prevented the acid mine drainage water from flowing immediately out of the reservoir and into the Impounding Dam Reservoir below it and then into the intakes of the Horseshoe Curve Water Treatment Plant.
Instead, water from Glen White Run, which feeds the reservoir system, diluted the Kittanning Run water in the upper reservoir, before it rose enough to flow over the spillway and head downstream, Perry said.
Fortunately, a recent rainstorm accelerated the dilution in Kittanning Point, he said.
The authority discovered the problem in connection with a tile replacement project in a section of the bypass channel a half mile downstream.
It was a problem that had apparently been discovered, then solved in stopgap fashion by a previous generation of authority employees, using a fix that recently came apart when workers drove equipment in the channel over the outlet pipe’s entry grate, according to Perry.
That broke loose a crust of concrete just below the channel that had sealed off a 24-inch iron ductile pipe leading to the reservoir.
Workers from Allison Park Contractors in Gibsonia, aided by authority employees, inserted a sleeve of plastic piping inside the corroded ductile iron outlet pipe to make the repair.
It wasn’t clear Friday how much the Allison Park work will cost, as the repair project will be based on cost of material and time taken, Perry said.
Mirror Staff Writer William Kibler is at 814-949-7038.