2015 Abandoned Mine Land Reclamation Award Winners
OSMRE first recognized outstanding abandoned mine land reclamation and exemplary reclamation techniques in 1992, when it started the annual Abandoned Mine Land Reclamation Awards Program. The program mirrors one of the objectives of the Surface Mining Control and Reclamation Act of 1977 to ensure that land mined for coal would be restored to beneficial use as part of the mining process, and that lands abandoned without reclamation prior to the law would be reclaimed.
OSMRE Western Region Director David Berry presented the awards at the annual conference of the National Association of Abandoned Mine Land Programs in Santa Fe, New Mexico September 27-30, 2015, during the AML Awards Banquet.
2015 Abandoned Mine Land Reclamation Awards Presentation Video
(Links to individual winner segments appear below)
The winners of the 2015 Abandoned Mine Reclamation Awards.
Appalachian Regional Award Winner: Simpson Northeast Coal Refuse Fire Fell Township, Lackawanna County, PA
The judges selected the Simpson Northeast project for its involvement in a high-priority site that required a quick turn-around. The design team worked very quickly to start and finish the project and made sure to utilize various engineering methods to control water runoff and work around the freezing temperatures. The project was high-profile and was well received by the community. The design team utilized OSMRE resources to tackle a problem they didn't have specific experience in.
A fire burning and the fuel, just a quarter mile from a major river, goes back to late 1800s underground mining, and some surface mining into the 1960s. Reports of local brushfires went back months. At first the size of the fire fooled the state’s AML specialists. Their first estimate measured the steam and smoke covered surface area at about 120 by 120 feet, more than 100 feet high, with four acres of potential fuel for the fire. They estimated they would need to move about 50 thousand cubic yards of refuse to extinguish the flames. In retrospect, that number was wildly optimistic. The nearby river was an easy way to get water to extinguish the fire but was also a high quality cold water fishery. Project managers estimated they would need in excess of 20-thousand gallons of water from the river each day. That number was wildly optimistic.
When work began in January 2014, the temperature at some burn areas exceeded 1200 degrees, indicating a large fire that apparently had smoldered for a long time. Crews put a 500 gallon per minute water stream at each work station as heavy equipment exposed the hot material in a six foot deep trench. Then, just a few days later, brutal cold kicked in, with temperatures hovering in the single digits for nearly a month, freezing the water lines. The cold required 24 hour a day pumping to free the lines, and that led to expanding the site from four, then seven, then to seventeen acres in size. Crews built check dams and settling ponds to capture and control the runoff, and when possible to reuse the water.
By April, the state realized killing the flames would take longer than expected, and called reporters in, which allowed the team to tell its story directly to the public. By the time the fire was extinguished 111 days later, workers had moved more than 285 thousand cubic yards of refuse, or six times the amount first estimated. The teams had pumped and recycled more than 156 million gallons of water from the river, or more than eight times originally estimated. Over the next two months, the state reclaimed the site. Teams regraded the burn area to match those unaffected by the fire, then seeded, fertilized, and mulched, and also included limestone to help prevent acid mine drainage. Many of the techniques the team used are now part of an OSMRE course on how to manage similar fires.
After almost six months of efforts, the project was complete. And with those efforts come the 2015 Appalachian Region Award for the Pennsylvania Department of Environmental Protection.
Mid-Continent Regional Award Winner: AML Site 2052 Minnehaha Slurry, Sullivan County, Indiana
The judges chose to honor the Minnehaha Slurry site for tackling unique engineering challenges to consolidate existing slurry material into a smaller area and stabilization of the project levee through traditional earthwork and non-traditional approaches. The use of a passive bioreactor was a great use of new technologies. Geomorphic design was also included in the project and the post construction contours very well executed.
One of the most worrisome threats in coal country is the inadvertent release of what is known as slurry – the byproduct when coal is processed and washed before it is taken away. What is left behind is a mix of coal fines, chemicals, and water that flows like molasses and threatens anything downstream with pollution. The most immediate problem for this project was repairing a weakened impoundment levee dating back to the early 1900s. The 60 acre impoundment sat near a creek first diverted and created by the coal company, a tributary to a major river. However, the impoundment was structurally unstable because of how it was built. After that slurry pond became full – this was fifty years ago – they took coarse material, gob, and raised it up another 10, 15 feet. A sudden failure would have sent a huge discharge downstream that likely would have damaged property and injured or killed people – the very thing the AML fund is designed to address. Gob material, consisting of coal and spoils, was exposed in the tailing ponds, and that contributed to ongoing acid mine drainage into the nearby creek. The highly acidic water also penetrated the levee holding back the sludgy mix – making a breach a distinct possibility. If the levee was breached the levee, the slurry would have flowed into Mud Creek and it would have been very difficult to stop.
Project managers had three goals in mind for the site: repair the levee, reclaim the coal, and fix the acid mine drainage. The biggest obstacle to doing all three was geography; a cramped, small site that would hamper moving heavy equipment around. So, project engineers chose to take the cramped layout and use it for their own purpose. They needed room to create a bioreactor. To clear some land, they pumped more than six million gallons of acidic water out of the levee, treated it, and then placed the cleaned water in the nearby creek. From there, they took the slurry and stacked it away from the levee. They removed coarse material from the dam and replaced it with more dense soil, strengthening the levee and making it less likely to breach.
At the same time, the engineers moved more than 70 thousand cubic yards of substrate to create the bioreactor; a combination of 17,000 tons of agricultural lime, 2400 tons of compost, 4000 tons of wood chips, and 5000 tons of hay and straw, all designed to act as a natural filter. The bioreactor takes in water from the stream that drains the slurry and also from a nearby gob pile. Water coming in is highly acidic. Water going out is almost completely alkaline, and the iron and manganese concentrations are much lower. And the impact of this project also spilled over to an active mining site. Peabody Mining allowed the AML team to store substrate materials on Peabody’s permitted area while construction was going on. Peabody also benefited, and so did the environment, when the company saved money by using the same contractor as the AML project to treat another acidic area. Finally, the team finished the site using geomorphic techniques to make the site not only functional but aesthetically pleasing.
The judges cited the use of the bioreactor as an emerging technology, the consolidation of the slurry into a smaller site, and the geomorphic design in awarding the Mid-Continent AML Award to the Indiana Department of Natural Resources.
Small Project Award Winner: Lightner/Boston Coal Mine Erosion Control Project, Durango, Colorado
The judges chose the Durango, Colorado project for its involvement, cooperation and input between several agencies, particularly Colorado and New Mexico, in order to achieve success. The project included the input of community members and the local college which helps spread the word about AML programs. The project also focused on detailed re-vegetation that was more labor intensive but ultimately created microclimates for vegetation, and therefore wildlife, to thrive.
The challenge for the Small Project Award winner was almost the opposite of our first two awardees. Instead of having to deal with an overabundance of water and acid mine drainage, this project winner faced ongoing problems with erosion due to a desert environment and change in the drainage patterns.
Project managers described this site as a legacy of the economic lifeblood of the surrounding community – a place that still contains stone houses and mining equipment from the early 1900s. So, one of the goals of fixing the emerging erosion problem was to preserve the historic nature while also introducing native vegetation. Mined between 1901 and 1926, the site held more than 4000 cubic feet of coal waste – the byproduct of more than a million tons produced there. In 1992, the state built a bioreactor onsite, which reduced the acidity from some water escaping. But previous work to fill old mine openings had also directed drainage away from the mine workings, and the acid flow was almost completely stopped. Except, that is, when rain events happened, causing erosion, which exposed coal wastes as far as 15 to 20 feet down, with little vegetation to stabilize the area.
To remedy the problem, project managers adopted innovative dry land reclamation techniques from the New Mexico AML program –but shifted them from large scale acre by acre revegetation to small scale, work done by the square foot – a necessity because of the fragile desert environment and to keep the historic nature of the site. After characterizing the soils, project managers brought students in from a local college and from the Southwest Conservation Corps to learn about the place, and supply some of the needed work. That work included amending the soils with 2 and a half tons of biochar, four tons per acre of beer mash and wood chip compost, primarily applied using rakes and shovels. The teams – using volunteers from all around the area – built berms and installed more than 11 thousand feet of straw wattles by hand. That provided small areas for planting 20-thousand live plants, including pine, mahogany, oak and sagebrush.
Done at a cost of less than $300,000, the site today is almost completely recovered, and erosion is almost nonexistent. Which is why the judges chose the Colorado Division of Reclamation Mine and Safety as the Small Project Award Winner for 2015.
National Award Winner: Lake Valley Mine Safeguard Projects, Lake Valley, Sierra Country, New Mexico
The judges chose the Lake Valley project for very challenging conditions due to the large number of dangerous mine openings, the presence of weak subsurface soil and rock, and the presence of deteriorated cribbing and near-surface underground workings. The project team utilized creative technical solutions to address the issues on the site. Toroid tire plugs were a very innovative use of new technology utilizing material that would normally be a waste product, and geosynthetically confined soil was an affordable engineering technique that provided a reliable closure solution.
A project that utilized international resources, innovative closure techniques and focused on protecting bats is the National Award winner claimed the judges’ votes because of all those attributes and also the long term effort needed to finish the project.
At one time, the area was home to one of the most dubious mining claims in American history, a time in which two worldly marketers convinced thousands of people to converge in 1881 to try to find silver in the desert dirt. A time that came crashing down in 1893 when Congress demonetized silver and many left without their fortune. In the early 1900’s mining returned, but not for silver. Instead, manganese and flux materials were needed for wartime production. That ended in 1955. Left behind was a maze of mine openings and a ghost town comprised of just a few small buildings, a two room schoolhouse that now serves as a museum, and just two people who volunteer to manage the historic property. That, and dozens of mine openings that pose a threat for anyone who might go near them.
The team identified 297 hazardous mine openings scattered over a two mile area, many in just a half square mile. A biologist identified significant bat maternity and hibernation use, primarily housing a species of concern. But the biggest challenge facing the team was geology. A study indicated variable soil conditions and relatively low strength. While some of the mines went as deep as 100 feet, the openings themselves were within a few feet of the surface, meaning they were subject to collapse. After investigating the use of more traditional techniques to close some of those openings, the AML team realized some would require different treatment.
In some areas, engineers used tried and true techniques to close the mines – backfilling, blasting, and polyurethane foam plugs. And they created bat gates to ensure access. But at 15 locations, the team selected a new low-cost method to plug the openings. With traditional techniques off the table the team turned to using toroid tire plugging. In this method, engineers used old earthmoving equipment tires to shore up the entrances. In this technique, tires are built both vertically and horizontally into support structures. Their durability provides a long-term - hundreds of years solution; their flexibility allows for movement needed when the earth shifts. And the cost is negligible since the tires are no longer usable on equipment. At this, the Feature 4 Carolina opening, engineers needed to close a 16 by 20 foot wide area, but still provide for cave access. They stacked the tires into a floor and beam support system, and then included a six foot wide corrugated steel pipe as a doorway for bats.
The project managers say this is the first time the tire plugging method was used in the United States. It is the signature moment for this project that also provided significant protection for bats. The project also preserved the historic nature of the site, and increased the safety of those who might visit there. Which is why the judges chose the New Mexico Abandoned Mine Land Program as the National Award winner for 2015.