by Jack Caldwell
FORESTRY AND WETLAND POST-MINING LAND USE
Four papers describe the performance of wetlands and forests at reclaimed mines. Issue discussed include the role of soil compaction in revegetation success, soil carbon content stock distributions patterns on mined grassland, and growth directly on mine spoils unamended by topsoil. On the basis of these papers one must conclude that rehabilitation of disturbed mine lands is feasible and contributory to acid drainage control. [2502, 721, 1976, 45, and 12]
To control acid drainage at the abandoned Brukunga Pyrite Mine, South Australia, the tailings impoundment has been revegetated, a diversion drain constructed, treatment plant upgrades undertaken, and plans formulated to move and cap waste rock piles.  These works have and will reduced annual costs to about $7 million (Australian Dollars) per year.
Large databases on the quality of and impact from acid drainage as a basis for further decision making and possible action are reported in four papers:
- On the basis of measurements of flow from over 140 abandoned underground coal mines in Pennsylvania, the relationship between pH, SO4-2, and dissolved metals is established. 
- In the Boulder River, Montana and the Animas, Colorado watershed the US Geological Survey collected water quality data from abandoned hard rock mines 
- Water quality data from one flooded and one free-draining coal mine-pool in Pennsylvania established the mechanism controlling long-term water quality changes 
- Comparison of flow quality between 1968 and 2000 from 150 underground mines in West Virginia establish quality improvements from the majority of mines .
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To fully understand the nature and extent of acid drainage, read the papers on lessons learned. The most interesting, to my mind, is that  which tells what happened at twenty-five mines, with names going from A to Z-X being omitted due to "extreme political sensitivity." For the rest the tales span forty years of successes and failures at the Seneca Mine in Colorado  to the use of covers and treatment systems at the Savage River Mine in Tasmania .
Of particular personal interest is the story of the Greens Creek, Alaska dry-stack tailings disposal system operation and performance.  I spent two beautiful summers in the early eighties on Admiralty Island locating a site for the tailings and completing geotechnical characterization of the site now used with great success. Well I recall the agony of trying to decide where to place the tailings and how to place them. I am glad the right decisions were taken-this is another testament to the fact that you can mine successfully and protect the environment even in the most beautiful and challenging places.
I also lingered long over a paper  on control of flow into and out of the Grootvlei Mine in South Africa. I was born and brought up in those places shown in the maps in the paper: Brakpan, East Geduld, Grootvlei, Blesbokspruit, Rowhill, Cowles Dam, Modderbee, and Modderfontein Oos. There is no doubt the place is an environmental mess, but we kids knew no better and rode our bikes everywhere allowed and forbidden. It is good to see cleanup in progress. The miracle is that is still recall my father and his friends fretting over the impending closure of the Grootvlei Mine in the early 1960s-so much for integrated mine planning.
Similar conclusions could be reached by others, no doubt, on the basis of the case histories about the Bahia de Ite, Peru , the tailings deposit at Chanaral, Chile , and other sites. For example, the Jundee Mine in Australia proves that if you can find a site with little acid generating rock and a dry climate, you won't have much in the way of water quality impact in the long-term . And the Kidston Gold Mine, Queensland, case history proves that with the right cover, you can control infiltration to acid generating materials .
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