Water quality in mined and unmined watersheds in East Tennessee

In late 1980 and early 1981 a stream flow monitoring station was installed on each of six small watersheds to evaluate the effects of surface mining on water quality. Three of the watersheds were in the Cumberland Mountains and three were on the Cumberland Plateau of east Tennessee. Both geographic regions had a recently mined, old mined and unmined watershed. Stream flow and concentration levels for 12 water quality parameters, collected every four weeks from 1981 through 198A, were evaluated. Geology, soils and land cover data were also studied.

Analyses were made to determine seasonality of stream water quality, differences due to watershed conditions and changes in stream water quality over the study period. Results showed that there were seasonal variations in water quality and that flow rates were associated with these differences. Significant differences in water quality were found between newly mined and unmined watersheds, with newly mined watersheds generally having higher levels of minerals and greater turbidity. Differences were also found between old mined and unmined watersheds. The Cumberland Mountains unmined watershed had greater concentrations than the old mined one for most of the constituents tested, especially total dissolved solids, lead, magnesium, sodium and calcium. This was apparently due to a road running through the unmined watershed. The two newly mined watersheds showed a significant change in water quality over the study period; the plateau one decreased in stream concentration levels, whereas the mountain watershed levels increased. Two other watersheds showed only marginal changes in water quality.

Stream water quality, as defined by EPA, was adversely affected by surface mining. Age of the mined area was associated with water quality, the older the mined area the better the water quality.