Description: The Potts Run Passive Treatment System was constructed in 2018-2019 to treat two sources of acid mine drainage—the Oak Twin discharge and the No. 3 discharge. The No. 3 discharge flows from an abandoned deep mine adit while the Oak Twin discharge is the effluent of a rock drain installed as part of a surface mine reclamation project. The treatment system consists of two vertical flow ponds (VFPs) arranged in parallel that discharge to a settling pond which discharges to an unnamed tributary to Potts Run. To ensure that the system provides decades of effective treatment at minimal cost, a regular operation and maintenance (O&M) program should be implemented so that problems are corrected before they impact system performance or become expensive to fix. This O&M plan provides guidance for inspection, operation and maintenance of the passive treatment system. https://www.tu.org/magazine/conservation/mine-drainage-cleanup-in-pennsylvania-perseverance-pays-off-in-the-potts-run-watershed/