Allegheny River Headwaters Watershed Conservation Plan

Allegheny River Headwaters Conservation Plan
Chapter 3. Water Resources
Polluted water discharges into streams and groundwater through mine openings, springs, and seeps.
When the water is exposed to oxygen in the air, the metals precipitate, or drop out of the solution as siltlike
solids, and coat stream bottoms. High levels of iron and aluminum can poison fish and threaten
drinking water supplies (Fripp, Ziemkiqeicx, & Charkavorki, 2000). Siltation from the metals and the
altered pH can affect the survivability of aquatic macroinvertebrates, which form the base of the food
chain, and thus, the basis of a healthy, functioning stream ecosystem.
AMD discharges vary due to geology, hydrology, and flow; therefore, a treatment that works at one
site may not be suitable at another. The goal of an AMD treatment system is to neutralize, isolate,
stabilize, and remove pollutants from the water. This is done by adding alkalinity to increase the pH—
except in discharges that are already alkaline—and then focusing on the capture and removal of metals.
Two treatment methods are used to remediate AMD—active and passive. More detailed information
about mine drainage treatment is available at http://amrclearinghouse.org.
Active treatment of mine drainage uses alkaline chemicals, such as lime, soda, ash, or ammonia, to
decrease acidity and speed up the removal of metals. This method of treatment can be very
expensive, but can work in areas where there is limited land availability for a passive treatment
system.
Passive treatment utilizes a series of ponds or wetlands to collect and treat AMD discharges. Several
sources of AMD can be collected and diverted to the treatment system. Polluted discharge water
slowly flows by the force of gravity through the series of ponds or wetlands, where sediment
particles settle out, metals are oxidized. Organic materials used to line the bottom of the ponds and
limestone that lines the channels connecting the ponds reduce acidity. Because the chemical make-up
and flow of discharges differ, each treatment system requires a specialized strategy to effectively
clean up and improve the water quality. Passive treatment systems are typically limited to areas
where land is available.
Within the headwaters region, AMD impacts are limited to the southern McKean County portion and
primarily within two tributary streams—Scaffold Lick Run and Railroad Run. The entire Scaffold Lick
Run subwatershed—a headwater tributary to Allegheny Portage Creek—is identified as impacting aquatic
life caused by AMD in the 2010 Integrated Water Quality Monitoring and Assessment Report originally
identified in 1998. Railroad Run—a headwater tributary to Potato Creek—was also identified in the 2010
Integrated Water Quality Monitoring and Assessment Report as impacting aquatic life stemming from
AMD. It was initially listed in 2006.
Marcellus Shale Gas Extraction
In order to recover the gas in the Marcellus shale formation, a large volume of water is required,
which becomes contaminated during the extraction through a process called hydrofracking. As a part of
the permitting process for Marcellus shale operations, drilling companies are required to complete a water
management plan for each site. The management plan identifies where the operator intends to obtain and
store the water needed for the drilling process and to ensure it coincides with Act 220—Water Resources
Planning Act (PA DEP, 2010c).
In addition, drilling companies must account for the wastewater that is generated, including how it
will be stored, treated, and/or disposed. Under the Pennsylvania Clean Streams Law, DEP finalized new
regulations to protect Pennsylvania’s water bodies and public drinking water in 2010, by limiting the
amount of total dissolved solids (TDS) that could be discharged into waterways from wastewater of the
natural gas industry (Abdalla, Drohan, Saacke Blunk, & Edson, 2011b). Wastewater fluids that are
recovered must be reused, recycled, or collected and treated at an authorized treatment facility.
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