Catfish Run along Brownsville Road
Catfish Run is culverted for hundreds of feet under a small commercial area along Brownsville Rd immediately after exiting South Park. There is an acid mine drainage(AMD) seep in this area from old mining activity.
Here we see Catfish Run exiting the culvert. The odd, milky water is common where an AMD flow enters a non-polluted flow. The pH of AMD can be very low(3.0-4.0). Heavy metals, such as iron and aluminum, remain in solution at these pH levels. When the AMD combines with the clean flow the pH increases and the heavy metals precipitate out of solution. This precipitate gives the water a milky appearance.
Heavy metals in solution are very toxic to fish and other aquatic organisms. The precipitate eventually settles to the stream bottom and also makes life difficult for benthic organisms