The project is located in Cook Forest State Park in Clarion County, PA . Little Hefren Run is a tributary of Toms Run, which runs through Cook Forest State Park and joins with the Clarion River in Cooksburg. Toms Run and most of its lower tributaries are exceptional value cold-water fisheries that support both native and stocked trout populations. The principal exception is Little Hefren Run which, because of mine drainage pollution, was excluded in 1995 from the DEP's exceptional value designation.
In 1998 Hedin Environmental investigated Little Hefren and developed a remediation proposal that was submitted to the Bureau of Watershed Management Section 319 Program. The project was funded and a treatment system was constructed in the autumn of 2000.
The picture shows the settling pond at Little Hefren. The ALD discharges to the pond in the channel. Iron oxidizes and is retained in the pond.
The system was inspected in 2010 and found to be functioning well. The final discharge was pH 7 with very low metal concentrations. Little Hefren is completely restored.