The BCWA and Stream Restoration Incorporated (SRI) submitted a PA DEP Growing Greener application to rehabilitate the Richards Passive Treatment system complex. The system consist of three vertical flow ponds (VFP) identified as VFP1, VFP2A and VFP2B, that were constructed in 1999 to treat an abandoned mine discharge from the sealed Egypt Mine, which was discharging to the upper section of Two Lick Creek. A schematic of the project can be seen under the Completed Project heading.
In general, the system has performed well over its 19-year life. Over the last few years, the system has required more frequent maintenance that has been conducted through Stream Restoration Incorporated’s O&M Technical Assistance Program. The last major maintenance event was performed in May 2017. Permeability of the VFP media has decreased to a point that the system is bypassing a large portion of the mine discharge during high flows. In order to rehabilitate the Richards system, the following has been proposed:
- After flowing underneath SR-403, the water will enter a pool to split the flow between Richards 1 and Richards 2 instead of utilizing the existing piping and valve system to balance flows.
- A Terraced Iron Formation (TIF) (aka Oxidation Precipitation Channel) will be used to convey the flow from the pool to each system. The TIF is expected to promote low pH iron removal which should reduce O&M needs and potentially lengthen the life span of the system.
- VFP1 will be replaced by a Jennings-style (mixed media) Vertical Flow Pond (JVFP1) consisting of 2,000 tons of limestone, 370 CY of mushroom compost, and 1,100 CY of woodchips.
- VFP2A & VFP2B will be replaced and reconfigured as one larger Jennings-style (mixed media) Vertical Flow Pond (JVFP2) consisting of 3,350 Tons of limestone, 620 CY of mushroom compost, and 1,860 CY of woodchip. The spent media from three VFPs will be placed and spread evenly in the existing Settling Pond 1 to be used as a low permeability liner and a new outlet pipe will be installed.
- The Settling Pond/Wetland Complex of the Richards 2 system will be reconfigured utilizing PVC Z-piling as directional flow barriers to maximize retention time. The Egypt Mine discharge is one of the largest discharges in the upper section of Two Lick Creek. The PA Fish and Boat Commission classifies the stream as a Trout Stocking Fishery. A reproducing trout population is located below the treatment system.