Description: A passive system was installed originally in 2007 consisting of a inflow pond, Vertical Flow Pond, Outflow (Settling) pond, and a wetland. The inflow iron concentration was very high, and Fe accumulated in the VFP. In 2009, 2 oxidation Ponds were added for low pH iron removal. This was moderately successful in reducing the Fe, but it was still a problem. In 2010, a slag bed was installed near the outflow pond. This worked for a year or so, but the alkalinity then dropped off. In 2014 the system was extensively renovated - old compost removed, some limestone added and 2 ft of new compost mixed with limestone added. The performance improved greatly but iron still accumulated and caused overflow at high flow. In 2018 the iron was removed with a suction pump. We'll see how that goes.