Posted on January 14, 2019
The Intergovernmental Stormwater Committee has received a $195,000 grant to help pay for dredging the pond at Lakemont Park — the centerpiece project of an ISC plan to reduce the amount of sediment entering area streams by 1.4 million pounds per year, as required by the state Department of Environmental Protection.
The National Fish and Wildlife Federation grant will pay for all “construction,” plus some engineering and design costs — although the total cost is estimated to be about $432,000, according to ISC coordinator Chelsey Ergler and information from NFWF.
In addition to dredging the pond, the project will include construction of three rain gardens, a vegetated permeable pavement parking lot, a rainwater harvest system for reuse of stormwater and a riparian buffer, according to NFWF.
The dredging would restore the original bottom of the pond, according to committee member Tom Levine, an engineer.
The dredging will lead to less sediment in Brush Run below the dam because the pond is now so shallow that it accepts virtually no new sediment from upstream, according to officials.
After dredging, the pond will once again provide a settling basin, they said.
The silt in the pond, which, when dry, would be in the form of powder, is about 4 inches thick on average, according to Levine.
It won’t be hard to tell the difference between the silt and that original bottom, which is dirt and rock, Levine said.
It could take years to get permits for the project, according to Teddie Kreitz of Keller Engineers.
The dredging is considered “maintenance” under the state’s Dam Safety Act, Kreitz said.
But the project will require federal oversight under the Waters of the Nation law, which means Army Corps of Engineers involvement, she said.
Disposal of the dredged material is a major issue.
PennDOT dredged the pond in the mid-1980s, taking out 40,000 cubic yards, Kreitz said.
That’s about 3,300 triaxle dump truck loads, Levine said.
The material was placed on the current site of Logan Town Centre, Kreitz said.
The material taken out this time will need to be tested to determine whether it can be used as clean fill, according to Kreitz.
If it can, the group would seek organizations willing to receive it, according to Kreitz.
The Altoona Water Authority is a potential candidate, as its watersheds include former strip mined land, she said.
Firms like New Enterprise Stone & Lime Co. Inc. might be interested, although it would probably need to be paid, Levine said.
If the material is contaminated and needs to go to a landfill, disposal costs would be much higher, Kreitz said.
The Lakemont project will satisfy about 38 percent of the sediment removal target set by the ISC’s new five-year “permit” from the state Department of Environmental Protection.
It’s not only the largest project proposed by the ISC, but the cheapest, based on cost per pound of sediment removed, Levine has said.
Source: Altoona Mirror
