Factors affecting water quality from strip-mined sites

This project analyzed the parameters that influence the quality of water from strip-mined sites. An instrumented watershed near Beckley, W. Va., provided data on precipitation, stream flow, and water quaIity, both before and during mining operations. This data was analyzed to derive linear relationships between a water-quality parameter and such variables as temperature, current and antecedent precipitation, and the extent of the area disturbed by mining. Mathematical formulae representing sulfate and calcium concentration, alkalinity, turbidity, conductance, and discharge were used in the study. A correlation analysis also was made among the various water-quality parameters.

A formula for each water-quality parameter was derived for each of three different conditions: (1) before mining; (2) during mining for the disturbed area alone, and (3) during mining for the entire watershed. The coefficients in the formulae then were refined for minimum error.

As is reported in the findings, the coefficients indicate that temperature is not an important water-quality consideration except in the case of alkalinity. The coefficients of the antecedent precipitation terms indicate that, in most cases, surface runoff is the basic mechanism by which the substances affecting water quality are conveyed from the disturbed area into a receiving stream. The findings provide data that can be used in the future for predicting water-quality impacts from strip mining operations at particular sites in the study area.