The full-day field trip will visit two treatment systems in Pennsylvania that demonstrate passive Mn and Fe removal and resource recovery. The Greene system was installed in 2015 to treat 100 gpm (23 m³/h) of acidic water containing 45 mg/L Fe, 3 mg/L Al, and 31 mg/L Mn. The system consists of aerobic ponds that remove most of the Fe, followed by four drainable oxic limestone beds that raise the pH and remove Mn. The site has an effluent permit that limits Mn to 2.0 mg/L (monthly average). The final effluent from the system averaged < 1 mg/L Mn. The tour will focus on the drainable limestone beds. Routine and major maintenance requirements of the system will be discussed. A flushing event will be observed. The second stop is the Lowber system, which was installed in 2006 to treat 1850 gpm (420 m³/h) of alkaline water containing 50–80 mg/L Fe. The system consists of six ponds followed by a constructed wetland and the final effluent averages 1 mg/L Fe. The system collects approximately 1 t/d of iron oxide solids, which requires regular maintenance. Infrastructure has been installed to facilitate sludge pumping and placement of large geotubes for iron oxide recovery. The tour will include a walk through the processing system, stacked iron oxide and three recently filled geotubes. The sale of iron oxide as a pigment will be discussed.