Section 319
               NONPOINT SOORGE  PROGRAM SOGGESS  STORY
 Addressing Abandoned Mine Discharges Allows Stream to Recover
Waterbodies  Improved   Elevated metal loads and low pH levels in acid mine
                                  drainage (AMD) from abandoned coal mines had
 degraded water quality in Pennsylvania's Little Coon  Run. As a result, the Pennsylvania
 Department of Environmental Protection (DEP) placed four segments of the stream (totaling
 5.12 miles) on the state's 2004 Clean Water Act (CWA) section 303(d) list of impaired
 waters. Implementing passive AMD treatment systems  and plugging an abandoned
 gas well improved water quality. Little Coon Run  now meets state water quality criteria;
 consequently, DEP intends to remove all four segments of Little Coon Run from the 2012
 CWA section 303(d) list of impaired waters.
 Problem
 Little Coon Run flows north through Clarion County
 and discharges into Coon Creek, which in turn
 empties into the Tionesta Reservoir in northwestern
 Pennsylvania's Forest County (Figure 1). Surface
 and subsurface coal-mining activities took place
 in this region between the 1940s and 1960s.
 Improperly reclaimed coal-mining areas in the
 watershed left minerals such as iron-sulfide (pyrite)
 exposed to the elements. Pyrite chemically reacts
 with water (provided by rain, stormwater runoff or
 groundwater) and produces acidic (low-pH) water,
 which can enter local waterbodies.

 For decades AMD has impaired Little Coon Run's
 aquatic life designated use because of low pH and
 elevated manganese, iron and aluminum loads.
 Low pH and elevated metal loads place stress
 on aquatic organisms, sometimes to the point
 at which the organisms perish and the streams
 become lifeless. In August 1999 a Pennsylvania
 DEP biologist performed a Statewide Surface
 Water Assessment Program Survey at the mouth
 of Little Coon Run, which identified AMD-related
 impairments (low pH and elevated metal loads) and
 a lack of pollution-intolerant macroinvertebrates.
 As a result, the Pennsylvania DEP placed four
 segments of Little Coon Run on the state's 2004
 CWA section 303(d) list of impaired waters for
 low pH and high levels of manganese. To meet
 the state's standards, the pH must stay above
 6.0 standard units and manganese concentrations
 may not exceed  1.00 milligram per liter (mg/L).
          Little Coon
          Run Watershed
Figure 1. Little Coon Run is in northwestern
Pennsylvania.
Project Highlights
AMD sources are typically addressed through a
variety of remediation approaches. For example,
the alkalinity of the polluted streams is increased to
neutralize the acidity of the water and reduce metal
loads, enabling aquatic organisms to return. Each
site, however, can be unique; while one metal might
be a problem at one site, another might be a bigger
problem at another site. To restore AMD-impaired
streams, efforts are usually directed  toward
reducing the metal loads and neutralizing pH by
adding alkalinity to the discharge.

Pennsylvania's Growing Greener Program funded
a Watershed Assessment and Restoration Plan on
Little Coon Run in 2003. Three discharges were
identified as the most significant sources of AMD

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Figure 2. Remediation projects to address AMD have significantly
improved the water quality in Little Coon  Run.

             in the watershed and were targeted for treatment.
             Two of the discharges were abandoned gas wells
             that were best suited for being plugged. The
             third source, on State Game Lands  #24, required
             construction of a passive treatment system
             consisting of an anoxic limestone drain, a settling
             pond and a constructed wetland. Because the
             passive AMD treatment sites need  to be inspected
             periodically, the project included constructing nearly
             a mile of permanent access road. The well plugging
             and passive system were completed in 2007.
             Results
             According to the restoration project's final report,
             sample results from the mouth of Little Coon Run
             demonstrate significantly improved water quality
             (Figure 2). In 2001, before the restoration projects
             were completed, the average pH was 4.5 standard
             units. The average pH at the same location in 2008
             was 6.2, and the final reading in September of that
             year was 7.0 standard units, which meets state
             water quality standards for attaining the designated
             use of aquatic life.

             Metal concentrations have also shown significant
             improvement. The largest decrease was in
             manganese, which dropped 70 percent between
             2001  and 2008; aluminum declined 26 percent.
             Iron and aluminum concentrations had begun
Figure 3. Biologists found this mottled sculpin, a pollutant-
intolerant fish species, near the mouth of Little Coon Run.

to decline before the treatment projects were
completed and were already attaining water
quality standards in 2001. Monitoring data
collected in September 2008 showed manganese
levels of 0.22 mg/L, which are well below the state
standard  of 1.00 mg/L.

In addition, fish collected in a recent (2010) survey
indicate water quality has improved as a result of
remediation efforts. For example, the 2010 survey
found a mottled sculpin (Figure 3), a pollution-
intolerant species that is not frequently found in
streams with elevated levels of pollutants.
Partners and Funding
Partners involved in the restoration of Little
Coon Run include Pennsylvania DEP's Bureau of
Abandoned Mine Reclamation, Pennsylvania Game
Commission, Farmington Township, Western
Pennsylvania Coalition for Abandoned Mine
Reclamation and Hedin Environmental. The projects
were funded by Pennsylvania DEP's Growing
Greener Program ($40,000 for the watershed
assessment) and the Office of Surface Mining's
Appalachian Clean Streams Program (more than
$400,000 for constructing the passive treatment
system and plugging the wells). Farmington
Township provides ongoing operation and
maintenance of the passive treatment system.
I
                  U.S. Environmental Protection Agency
                  Office of Water
                  Washington, DC

                  EPA841-F-11-001W
                  March 2011
For additional information contact:
Joe Kelly
Pennsylvania Department of
  Environmental Protection
717-783-2404
Joseph kel@state. pa. us

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