Powdered lime is mixed with mine drainage in a large clarifyer. Clapboard Run is located within this watershed. Several large acid mine drainage treatment plants were built and operated in the early 1970's but the operation was discontinued as to costly. Passive Treatment, pioneered by the US Bureau of Mines has proven to be a cost effective way to substantially reduce and sometimes totally eliminate acid mine drainage. Large amounts of treatment space are needed to utilize these techniques.
Aerobic wetlands can remove iron and manganese.
Anaerobic wetlands neutralize acidity through microbial action. There have been some experimental wetlands constructed along the Clarion River which add limestone to the compost substrate of the anaerobic wetlands to increase the alkalinity producing potential of these wetlands and may offer a hope to be able to cut down on their size. Read more about passive wetlands by clicking here .