Description: Wetland #1, located along the north side of Fourmile Run is an 8.5 acre wetland treatment system, designed by the PA Department of Environmental Protection in cooperation with the landowner, Wimmer Corporation. Wetland #1 construction involved excavating an existing wetland area created by ten mine drainage discharges. Wetland #1 consists of four cells with internal dikes that cause the water to flow in a serpentine pattern. Construction was completed November 1998. Flow rates have reached nearly 5 times the amount the wetland was designed to handle during high flow conditions, and almost stops flowing during low flow conditions. In order to provide for better treatment performance, Wetland #1 and Wetland #2 were connected via an inverted siphon that carries the effluent from Wetland #1 under Fourmile Run and discharges it into Wetland #2 in July 1999. The water flows from one cell to the next via concrete flow control structures. This structure contains removable stop logs to control flow and the top stop log is equipped with a rectangular weir, which allows for the necessary aeration. Several modifications have been completed to improve effluent water quality. A sludge basin was installed adjacent to Wetland #1 in July 2012 and sludge was removed from Wetland #1 in September 2012. In order to control flow and enhance sludge removal, several internal berms were installed or reinforced. In Fall 2021, several artesian discharges in Cell #2 were captured and a transfer pipeline was installed to move the water anoxically to Wetland #2 for treatment. This new modification also ended the transfer of effluent water from Wetland #1 to Wetland #2 through the inverted siphon. Additional berm work was also competed during this process.