Swank Project:
At the Swank project, flow from an abandoned underground mine averages pH 3.5 with 83 mg/L acidity, 0.6 mg/L Fe and 9.2 mg/L Al at a flow of 175 gal/min. In 2012, the flow was diverted to a 900 ft-long channel descending gently down the hill, and the channel was lined with limestone fragments. At the base of the hill, about half the acidity is neutralized. Although the water is still slightly acid, the cost of the project was only about $38,000. We plan further work at this site.
