The Slippery Rock Watershed Coalition provided updates on projects to rehab two passive mine drainage treatment systems that are more than 20 years old in Butler County in their most recent newsletter.
Ferris Treatment Complex
The Ferris Passive Treatment Complex, pictured in the photos below, was originally designed and constructed by the Pennsylvania Department of Environmental Protection Knox District Mining Office in 1997 to treat AMD from an old deep mine in the coal mining ghost town of Ferris.
The complex consists of two passive systems referred to as the SR85/86 (aka VK system) and the SR87/88 (aka JP system). Over the last nearly 25 years, a variety of maintenance and rehab work has been completed.
Water monitoring conducted during the 2015 Passive Treatment Snapshot found the first pond of the SR85/86 system overflowing and all the water bypassing the system.
Maintenance completed at the system in 2017 indicated that the first vertical flow pond treatment media was completely deteriorated and in need of replacement.
A temporary fix was put in place to bypass the first pond to provide at least partial treatment.
Much to our surprise, water monitoring conducted during the 2020 Passive Treatment System snapshot have demonstrated that the system is still performing fairly well even without a fully functioning system.
See the table below to see the Raw untreated water (SR86) and final effluent (VK2). There was no water flowing into the SR87/88 system at the time so no samples could be collected.
The SR85/86 passive system which will be rehabilitated as part of the Growing Greener and OSM funded “Slippery Rock Passive Treatment Rehab & Maintenance” Project. Design work is currently under way with the hopes of construction to be completed this summer.
SR81 Treatment Complex
Another treatment system that will be included as part of the Growing Greener and OSM funded “Slippery Rock Passive Treatment Rehab & Maintenance” Project is the SR81 treatment system.
Construction of the SR81 passive system was completed in 2002 making the system almost 20 years old. The system, which was designed by BioMost, Inc and constructed by Amerikohl Mining, consists of an Anoxic Limestone Drain, a settling pond and constructed wetland.
The system discharges into a naturally existing wetland before finally flowing into Slippery Rock Creek.
The system had been designed to treat 60 gallons per minute, but during construction, the contractor accidentally broke into the old abandoned underground mine which dramatically increased the flow for the entire life of the system.
Even though the average flow rate has been about 3 times what it was designed for, the system has done a rather good job of treating the water.
As can be seen in the table below, water monitoring conducted during the 2020 Passive Treatment System snapshot demonstrated that the system is still performing well even though it is almost 20 years old and overwhelmed the entire time.
The flow rate could not be measured because water within the ponds had become backed up covering the pipe.
As part of the grant, the treatment system will be expanded, increasing the size of the ALD and the settling area of settling pond and wetlands. Design and permitting is expected to begin this year.
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Federal Program Reauthorization
Work like this could not be funded without federal Abandoned Mine Reclamation Program funding. The Program is due to expire in September. Read more here.
For more information on programs, initiatives, upcoming events and how you can get involved, visit the Slippery Rock Watershed Coalition website.
(Photo: Ferris Treatment System)
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[Posted: March 26, 2021] PA Environment Digest
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