Residents of Pennsylvania are most likely familiar with hearing the phrase, “don’t drink the water,” when visiting one of Pennsylvania’s many rivers. This is because most of the state’s water supply has been poisoned from being exposed to hazardous materials from abandoned mines. One of the most notable examples of this is pollution in Big Run Stream, located in Jennings Environmental Center.
Wil Taylor, the Center Manager of Jennings Environmental Education Center, explained that a mine opened in Jennings in the 1920s and was used until the 1940s. When the mines shut down, they the employees left the facility as it was. At the time, this was a common and legal practice.
When the government became more environmentally motivated in 1970, legislation was passed to clean up selected abandoned mine sites. Jennings was selected to be one of the sites that would be cleaned.
So in 1977, Operation Scarlift reclaimed the site by removing the buildings, cleaning the litter, and sealing the mine shut.
In 1984 there was a large-scale flood caused by a storm. The mine seal failed causing toxic mine drainage to overflow into the park and Big Run Stream which is a tributary to Slippery Rock Creek. The creek is important to the area because it contains a cold-water fishery.
The park manager had three options to choose in order to deal with the situation. The first would be to ignore it, and let Big Run become a dead stream. The second option was to try to reseal the mine, which could have forced the water to pop out at a different location. The last option was to try to treat the water with a passive treatment.
A passive treatment system uses natural biological and chemical processes in order to treat and clean water.
Active treatment is also a frequently used option in Pennsylvania. Taylor stated that although it is an effective and instantaneous way to clean water, it is expensive and requires the use dangerous chemicals that create byproducts that need to be disposed of.
In 1987, an aerobic wetland was built in Jennings as a basic type of passive treatment system. Although it did help to populate the area with grass, it was ineffective at treating the water.
“It brought important people together with the common goal addressing the abandoned mine drainage,” Taylor explained. “Abandoned mine drainage is the number one polluter of streams in Pennsylvania It’s impacting over 5,000 miles of streams, so it was a problem that people wanted to address. So, this was one of the first places that people actually got together and tried to come up with legitimate working ways to do that.”
In 1992, the Jennings management tried a different type of passive treatment, which was also ineffective.
“Although it didn’t work, it was very worthwhile,” Taylor said. “A third system was [built] in 1997, and it works very well. The only reason why it works is because of the information that was gained from the first two systems. So these weren’t a waste of money or time, the third system worked because of the first two.”
Mine drainage is when water and oxygen comes into contact with a mineral known as pyrite, it produces sulfuric acid. This makes the water acidic with a pH of about 3.5. To put that in perspective, vinegar has a pH of about 3. This drainage contains other harmful substances such as iron, aluminum, sulfite, nickel and cadmium. Taylor noted that aluminum is especially harmful to vegetation.
There are three steps in order to treat mine drainage. The first step is to neutralize the water to make it less acidic. Because the water is originally acidic, it will appear to be clear because all of the minerals are dissolved and suspended within the water. In order to neutralize the water, it is mixed with limestone. The acidic water absorbs the limestone and becomes more alkaline and less acidic.
After being neutralized, the water must be oxidized. This is done by adding vegetation to the water and by creating waterfalls. By adding oxygen to the water, the minerals will separate from the water and become solids. Because the minerals will now be solid, the water will appear to be an orange or red color.
The final step is to filter the water, which is done by allowing the contents of the water to settle to the bottom of a designated wetland.
After being filtered, the pH of the water raises from 3.5 to a much healthier pH of 7. All aluminum and almost all of the iron is removed by the end of the filtration cycle.
“We have basically stopped the flow of mine drainage into Big Run,” Taylor stated. “I’m not going to say [Big Run] is unimpacted, but it is much better than it was and it is certainly not having a negative effect on Slippery Rock Creek anymore.”
There are an estimated 300 passive treatment systems in Pennsylvania with 18 treating water from Slippery Rock Creek.
“Most of those systems were built in the middle of nowhere,” Taylor explained. “Here, we can learn from our system. If we have an issue, we can correct it. We have people that are monitoring water quality on a weekly basis. In those other systems, that’s not the case.”
With that being said, the passive system in Jennings is permanent. The system was designed to have a 10 to 12 year lifespan, and over last summer they realized that the amount of water coming into the system was much greater than the amount of water leaving the system.
The problem was that the limestone turned into a clay-like substance. So the old limestone was moved to the side of the system, and a new mixture of limestone, bulking agents, woodchips and mushroom compost.
Funding for the project came from three main sources. The $60,000 price tag was divided into thirds and paid by the Burrough of State Parks, Western Pa. Coalition for Abandoned Mine Reclamation, and the Pa. Foundation for Watersheds. The Office of Surface Mining donated another $10,000 to finish up the project.
“Directly, this treatment has no effect of the Slippery Rock borough,” Taylor explained. “Slippery Rock isn’t getting their water anywhere near where this water is coming from. Indirectly, the impact is huge. The lessons learned here and the technologies developed were expanded into to the watershed. If not for water consumption, streams that haven’t had fish in a hundred years, now have fish in them again.”