Abandoned Mine Posts

By: Bruce Golden, Regional Coordinator

Did you ever wonder why there’s such a wide range in the chemical make-up of coal mine drainage discharges? It’s because there’s a great diversity in the mining environments in which mine drainage is formed. This multipart series of AMP will explore, on an introductory level, the connection of mine drainage characteristics with the mining environments that created it. It’s not meant to be rigorous, but to mainly get you thinking about the kinds of things that can happen underground which are influential in the
making of polluted water.

Part 1: Introduction

The formation of polluted mine drainage is actually a natural process that has been greatly accelerated due to mining activities. The weathering of the common mineral pyrite, a.k.a. fool’s gold, (and its cousins) is the heart of the process. By weathering of pyrite, we mean that pyrite is exposed to the forces of air and water. A common place to see evidence of a non-coal related example is a road cut where rocks have been stained orange. That orange staining is likely to be a result of small amounts of pyrite being exposed to and reacting with water and oxygen.

Coal seams and surrounding strata commonly contain small percentages of pyrite which, being tucked away safely underground, has little chance of coming into contact with air and water. However, mining of coal exposes vastly greater quantities of pyrite to water and oxygen than would happen without the mining disturbance. If you examine a piece of freshly mined coal, you’re sometimes able to see fragments of pyrite in it, but not always because the pyrite particles may be too small. Even though you may not easily observe the pyrite directly, you can see evidence of its presence by what happens if the coal is left out in the weather. Eventually orange or yellow staining will become evident and the water that passes over it will have acquired some newly dissolved although undesirable constituents.

The water that becomes contaminated by this process goes by several names, which itself can cause some confusion. And since the topic comes up often enough, I’ll
try to make some sense of it here. Here’s at least a partial list of names:

• Acid Mine Drainage – perhaps the most common name. It’s accurate except in the case where local conditions have turned the water alkaline. Even if it’s alkaline, it may still be referred to as Acid Mine Drainage. Go figure.
• Alkaline Mine Drainage – see above.
• Coal Mine Drainage – accurate if the drainage occurs as a result of coal mining. However, other types of mining also can produce the same sort of stuff. And occasionally coal mine drainage isn’t even polluted. (Too bad there’s not more of that!)
• Abandoned Mine Drainage – accurate only if it’s coal mine drainage that originates from mining that occurred prior to the passage of the federal SMCRA legislation in 1977.
• Acid Rock Drainage - refers to drainage from “hard rock” mining, i.e. mining for minerals other than coal, but can also refer to non-mining related discharges (such as with the I99 Sky Top debacle).
• Contaminated Mine Drainage or Polluted Mine Drainage - about the most general terms covering all mining.
• Sulfur Water – a very colloquial term referring to Coal Mine Drainage. Many people believe the orange color in the water is sulfur. While sulfur is almost assuredly present in the form of colorless, odorless sulfate ions , the orange color is due to rust-like compounds of iron. Perhaps the rotten egg smell of hydrogen sulfide gas (H2S) that sometimes accompanies mine drainage (due to bacterial action with sulfate) may reinforce the idea it’s sulfur.
• I’m guessing there are others. Let me know.

So for the rest of this series, I’ll just refer to the polluted water simply as AMD. The “A”, in our case normally means “Abandoned”, just like the “A” in WPCAMR. In the next installment in this series we’ll delve into the chemistry involved in AMD formation. Following that, the underground conditions water may experience on its journey to becoming polluted will be explored.

by Andy McAllister, Watershed Coordinator

Volunteerism has always been a part of the American culture, yet volunteers rarely get the recognition they deserve. The Ohio River Watershed Celebration held last week in Pittsburgh was one of those rare opportunities for watershed associations and environmental groups to celebrate their successes while planning for the future. This week, in an effort to continue celebrating and nurturing that volunteer spirit in all of us, we offer an article from TIME magazine which touts national service as a most promising pathway toward civic health and economic progress.

A Time to Serve by Richard Stengel

Visit Stream Restoration Inc., one of the organizers of the Ohio River Watershed Celebration.

To view a video blog of the 2007 Ohio River Watershed Celebration, visit the PA Environmental Digest.

by Andy McAllister, Watershed Coordinator and Bruce Golden, Regional Coordinator

The editors of Abandoned Mine Posts (AMP) recently caught up with Mark Killar, Director of Watershed Services with the Western Pennsylvania Conservancy and asked about the possibility of trout living in AMD-impacted streams.

AMP: Redstone Creek in Fayette County is a stream that runs orange for many miles from huge abandoned mine discharges, yet we’re aware of reports of rainbow trout being caught there. Could that be? Is it a fluke or are they fish that someone dumped into the creek?
Killar: This kind of scenario has been observed in other streams that receive net alkaline Abandoned Mine Drainage (AMD) from abandoned deep mines. As you may be aware, these discharges often contain high amounts of alkalinity due to the limestone layer located above the flooded portion of the mine(s). Although the discharges look ugly because they contain lots of iron and turn the stream orange, they don’t contain acid or aluminum, the two deadly killers of fish and life in the stream. Because fish aren’t affected that much by iron, they can survive in these net alkaline iron polluted streams.

AMP: So, some discharges aren’t as toxic as others? Is it possible that some of these discharges could actually help fish populations?
Killar: Well, one thing that helps out trout in particular is the 50 degree water temperature of the mine water. Especially at low stream flows, the mine discharges have a positive effect on the stream by keeping the water temperature down because they often can make up a significant portion of the stream flow when the streams are usually flowing low. Cooler water means the stream can hold more oxygen, which the trout like and need. Besides that, people wouldn’t normally think there are trout in the orange water so they don’t fish there and the trout get a chance to grow.

AMP: You said that “fish aren’t affected that much by iron”. Does that mean we should simply not be concerned about water that’s just polluted by iron then?
Killar: A study was done on Sewickley Creek some years ago (which also has several large alkaline deep mine discharges on it) and to the surprise of the person doing the study several nice brown trout turned up in a little orange tributary to the stream. It was a very small stream that looked ugly as heck, but again, didn’t have acid or aluminum being dumped into it from the mine discharge. Upon further study, it turned out the fish only had minnows in their stomachs and no aquatic insects, which makes sense in that the heavy coating of iron on the bottom of the stream significantly reduces the number of aquatic insects because it smothers out their habitat. The big question is “What the heck are the minnows eating to keep them alive?” One theory is they come from the smaller unpolluted tributaries or are washed into the unpolluted sections from upstream. A similar situation happened on Loyalhanna Creek near Latrobe where again large net alkaline deep mine discharges polluted it and turned the stream orange. One local fisherman had a secret spot he would fish (in the orange portion of the stream) and would catch some pretty large fish. Again, it was likely that few fisherman would consider fishing in that portion of the stream so the fish had lots of time to grow big.

Visit the Western Pennsylvania Conservancy’s website for information about conservation activities in your area.

For a listing of watershed groups in Western Pennsylvania, visit http://amrclearinghouse.org/Sub/organizations/WesternPennsylvania.htm

Note from the Editors: The staff of WPCAMR are always looking for interesting stories to share with our readers. On a recent visit to Huntingdon County, WPCAMR’s Watershed Coordinator Andy McAllister, spent some time with Huntingdon County Conservation District (HCCD) Manager, Andy Patterson andWatershed Specialist, Bob Whittaker and learned how HCCD has been thinking outside the box when it comes to mine drainage treatment: treating acidic seeps while upgrading dirt and gravel roads. Bob Whittaker submitted this article for Abandoned Mine Posts and we are happy to share it with you.

A Stream On The Rebound

by Robert Whittaker, Watershed Specialist, Huntingdon Conservation District

If you would ask a resident of the Broad Top (an area on the border of Huntingdon and Bedford counties) where you could find a good trout stream in the area, they would probably say, “Not here!” Little do they know, located within the heart of this old mine land, a native Brook Trout population is on the rebound.

Miller Run a tributary of Shoup’s Run, has undergone an “environmental makeover” over the last six years. With the cooperation of the Department of Environmental Protection, the Environmental Protection Agency, Pa Game Commission, and the Huntingdon County Conservation District, the Shoup’s Run Watershed Association is seeing positive results from years of planning and construction within the watershed.

Over the last six years Miller Run has seen quite a bit of change: two limestone sand dosing areas, an acid mine land project complete with a large storm water retention basin, and one limestone bed with one more to be completed this summer. All of these practices are meant to treat the acid mine drainage occurring in that watershed.

However, the watershed group was looking to do more. That was when we started looking at the road surfaces. Continuing for over one mile alongside Miller Run is a state game lands access road which historically was built from and maintained with mine spoil. With every rain event, a little bit of that mine spoil and its acidic runoff would make its way into the stream, depressing the pH levels and making it harder for the trout to survive. Finding a way to treat that runoff became the focus.

With the cooperation of the Penn State Dirt and Gravel Roads Program we had a plan developed to not only address runoff, but also address erosional problems along this 7,000 feet of road surface. The plan consisted of two phases. The first phase addressed unstable road ditches and acidic seeps along this stretch of road. The second phase consisted of placing 2,600 tons of high calcium carbonate limestone on the road surface that years ago had been previously constructed of mine spoil

During the summer months, Miller Run has very little water so the year-round seeps, in spite of their acidity, are vital to the resident trout. Previous analyses have shown that the water from these acidic seeps fortunately is very low in metals. By simply providing high quality limestone and sufficient contact time in the roadside ditches, we’ve been able to treat the acidity before that water enters the stream. Chemical analysis of the seep water before treatment shows zero alkalinity and very low pH. Water samples of the treated water taken at the end of the limestone ditches reveal that the system is indeed working, with recent data showing a remarkable alkalinity of 40 mg/L and a neutral pH of 7.0.

The ditches weren’t the only target. We also focused on treating the acidity at the outlet of the culvert pipes. In some cases there was just not enough space to overexcavate the ditches to fill them with limestone. In those cases, we designed infiltration boxes to be placed at the outlet of the culverts. The infiltration box is essentially an excavated area containing two sizes of limestone. The larger limestone size provides erosion protection, while the smaller size limestone provides alkalinity to neutralize the acid water coming from the seeps. These structures are designed to allow water coming out of the culvert during low flows, to be stored in the infiltration box. Once the holding capacity is met, the water spills out of the end of the box and to the creek. Although during high flow the water may fill the box and escape treatment but the box will still provide erosion protection benefits at the outlet of the culvert. The boxes are indeed functioning, producing the much-needed alkalinity or Miller Run while providing erosion control as the water from the ditch outlets to the stream.

This project was jointly funded through EPA/DEP 319 program and through the Penn State Dirt and Gravel Road Program.