In the event of the development of the large oil shale reserves of Colorado, Utah, and Wyoming, one of the main environmental concerns will be disposal of retorted-oil shale which will be generated in greater volume than the original volume oI the mined oil shale. Investigators have found that leachates of retorted-oil shale are alkaline and have large concentrations of dissolved solids, molybdenum, boron, and fluoride (STOLLENWERK & RUNNELS 1981). STOLLENWERK & RUNNELS (1981) concluded that drainage from waste shale piles could have deleterious effects on the water quality of streams in northwestern Colorado.