Phosphorus Filter

Tom Kehler, fishery biologist at the U.S. Fish and Wildlife Service's Northeast Fishery Center in Lamar, Pennsylvania, checks the flow rate of water leaving a phosphorus filter column. The USGS has pioneered a new use for acid mine drainage residuals that are currently a disposal challenge, using the residuals in plastic columns like the ones pictured to filter phosphorus from agricultural and municipal wastewaters.  The Northeast Fishery Center helped the USGS test the concept, and currently filters more than 1000 gallons per day.