The Montour Run Watershed Association will begin construction in the next few months on a new $1,119,089 private-public passive abandoned mine water treatment system project in the Montour Run Watershed adjacent to Mahoney Road in North Fayette Township in western Allegheny County.

The purpose of the system is to treat abandoned mine drainage flowing to Milk Run, which is a tributary of Montour Run.  Milk Run flows parallel to Mahoney Road and has been polluted for nearly a century. 

The discharge, known as MKR3, is the single largest source of acidity and aluminum in the Montour Run watershed.

This mine drainage has been flowing from an old, abandoned, underground coal mine into Milk Run since the early 1900s. 

Sulfur, typically pyrite, in and around the Pittsburgh number 8 coal seam oxidizes when exposed to air in the mine.  When the oxidized sulfur comes into contact with ground water, it creates dissolved iron and sulfuric acid. 

The acid dissolves additional minerals, including aluminum, found in the clay strata underlying the coal seam.   When the mine drainage that contains dissolved aluminum is mixed with alkaline or higher pH water, the aluminum precipitates out as a white substance, giving the stream a milky appearance.

The Montour Run Watershed Association has been working with government agencies and officials, private companies and environmental advocacy groups on the new passive treatment system for several years. 

The project is funded by a Range Resources reclamation in-lieu of penalty project ($949,089), the U.S. Office of Surface Mining ($150,000) and the Foundation for Pennsylvania Watersheds ($20,000). 

The Department of Environmental Protection; the Allegheny County Conservation District; the not-for-profit Stream Restorations, Inc.;  Independence Conservancy; landowners Continental Communities, LLC and Great Rentals, LLC; and the Washington County Conservation District have also been instrumental in seeing the project come to fruition. 

BioMost, Inc., a design-build firm that specializes in passive treatment systems and has constructed other facilities within the Montour Run Watershed, is the MRWA’s  contractor that designed and permitted the system and will build the Milk Run treatment system in 2018. 

Extensive design and permitting activities have been taking place since 2015 on the project.  In the late fall of 2017, BioMost received the last of the necessary permits to begin construction.

Groundbreaking will take place when the weather breaks in the spring, most likely in March. 

The passive system will require no electricity, no pumps and no operator.  The design uses natural limestone and gravity to treat the water. 

Once completed, the system will restore one mile of stream and improve Montour Run for miles by removing an estimated 72,000 pounds of acid and 7,000 pounds of aluminum per year.

The Montour Run Watershed Association will monitor the system and if necessary, see that corrective actions are taken.  The funding from Range Resources mentioned above includes designated operation and maintenance funds of $191,000 to ensure the system remains effective for decades to come. 

For more information on the Montour Run watershed and other MRWA projects, visit the Montour Run Watershed Association website.

[Posted: Jan. 24, 2018]

1/29/2018