Demchak, J., Morrow, T., Skousen, J., Donovan, J. J., & Rose, A. W. (2001). Treatment of acid mine drainage by four vertical flow wetlands in Pennsylvania Evolution and remediation of acid-sulfate groundwater systems at reclaimed mine-sites. Geochemistry – Exploration, Environment, Analysis, 1(1), 71–80.
Abstract: Acid mine drainage (AMD) is a serious problem in many watersheds where coal is mined. Passive treatments, such as wetlands and anoxic limestone drains (ALDs), have been developed, but these technologies show varying treatment efficiencies. A new passive treatment technique is a vertical flow wetland or successive alkalinity producing system (SAPS). Four SAPS in Pennsylvania were studied to determine changes in water chemistry from inflow to outflow. The Howe Bridge SAPS removed about 130 mg l (super -1) (40%) of the inflow acidity concentration and about 100 mg l (super -1) (60%) iron (Fe). The Filson 1 SAPS removed 68 mg l (super -1) (26%) acidity, 20 mg l (super -1) (83%) Fe and 6 mg l (super -1) (35%) aluminium (Al). The Sommerville SAPS removed 112 mg l (super -1) (31%) acidity, exported Fe, and removed 13 mg l (super -1) (30%) Al. The McKinley SAPS removed 54 mg l (super -1) (91%) acidity and 5 mg l (super -1) (90%) Fe. Acid removal rates at our four sites were 17 (HB), 52 (Filson1), 18 (Sommerville) and 11 (McKinley) g of acid per m (super 2) of surface wetland area per day (g/m (super 2) d (super -1) ). Calcium (Ca) concentrations in the SAPS effluents were increased between 8 and 57 mg l (super -1) at these sites. Equilibrators, which were inserted into compost layers to evaluate redox conditions at our sites, showed that reducing conditions were generally found at 60 cm compost depths and oxidized conditions were found at 30 cm compost depths. Deeply oxidized zones substantiated observations that channel flow was occurring through some parts of the compost. The Howe Bridge site has not declined in treatment efficiency over a six year treatment life. The SAPS construction costs were equal to about seven years of NaOH chemical treatment costs and 30 years of lime treatment costs. So, if the SAPS treatment longevity is seven years or greater and comparable effluent water quality was achieved, the SAPS construction was cost effective compared to NaOH chemical treatment. Construction recommendations for SAPS include a minimum of 50 cm of compost thickness, periodic replacement or addition of fresh compost material, and increasing the number of drainage pipes underlying the limestone.
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Yernberg, W. R. (2000). Improvements seen in acid-mine-drainage technology. Min. Eng., 52(9), 67–70.
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Hellier, W. W., Giovannitti, E. F., & Slack, P. T. (1994). Best professional judgement analysis for constructed wetlands as a best available technology for the treatment of post-mining groundwater seeps. In Special Publication – United States. Bureau of Mines, Report: BUMINES-SP-06A-94 (pp. 60–69). Proceedings of the International land reclamation and mine drainage conference and Third international conference on The abatement of acidic drainage; Volume 1 of 4; Mine drainage.
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Sanders, F., Rahe, J., Pastor, D., & Anderson, R. (1999). Wetlands treat mine runoff. Civil Engineering, 69(1), 53–55.
Abstract: In the late 1890s, silver, lead and zinc deposits were discovered along the headwaters of the Blackfoot River, northeast of Missoula, Mont. Settlers began mining the metals in earnest, and eventually the mines became known as the Upper Blackfoot Mining Complex (UBMC). Many of the mines were operated long enough to supply metals for World War II weaponry, but after the war the mines were abandoned, and by the 1960s, their orange-tainted runoff began to concern both passersby and state officials. In 1991, the state contacted the current owners of several of those mines-including the Mike Horse and the Anaconda-to negotiate a voluntary cleanup. The American Smelting and Refining Co. (ASARCO) and the Atlantic Richfield Co. (ARCO) agreed to remediate the sites' metal-enriched, moderately to severely acidic drainage, which was discharging into the upper Blackfoot River. As part of effort to reclaim the Mike Horse and Anaconda mines, engineers with McCulley, Frick and Gilman Inc. (MFG), Boulder, Colo., developed an integrated, passive wetland treatment system that will take several years to reach full treatment capacity in the high-elevation environment, but will last for decades. (Constructed and restored wetlands have also been part of the remediation of other UBMC mines, such as the Carbonate and Paymaster mines.) The Mike Horse and Anaconda system, designed to meet National Pollutant Discharge Elimination Systems (NPDES) restrictions, concentrates primarily on zinc and iron and, to a lesser extent, on copper, lead and other metals.
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Reisinger, R. W., & Gusek, J. (1999). Mitigation of water contamination at the historic Ferris-Haggarty Mine, Wyoming. Min. Eng., 51(8), 49–53.
Abstract: An historic underground copper mine in Wyoming is discharging neutral but copper-laden water into a pristine creek. The EPA-deferred site qualifies for reclamation by the Wyoming Abandoned Mine Land (AML) program. The cleanup goal is to restore the discharge so that the creek can eventually support a trout fishery. Hydrological and geochemical investigations underground have suggested two sources of mine water: one clean and the other containing copper. Results of bench- and pilot-scale tests support the viability of using low-cost passive treatment techniques to reduce copper concentrations in the near-freezing mine discharge.
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