The Mills River Watershed

Five sites including one site on the North Fork of the Mills River, one site on the South Fork of the Mills River, one site on Brandy Branch, and two sites on the Mills River

Much like the Green River watershed, the Mills River watershed shows few water quality problems and is one of the finest water resources in the county. The North Fork Mills River and the Mills River at Davenport Bridge and at Hooper Lane all show excellent water quality, the South Fork Mills River rates good, and Brandy Branch rates average. However, like Clear Creek, there appear to be problems on the Mills River that do not show up on analysis of the parameters tested. The downstream area of the Mills River is also listed as impaired by the state of North Carolina based on testing of benthic organisms. The reason for the difference in results is probably the same as that for Clear Creek. Toxic substances such as pesticides are difficult and expensive to analyze, but when benthic organisms cannot survive, but other chemical testing indicates no major water quality problems, pesticides may be the cause. Fortunately, it is relatively easy to remove the toxic threats to the stream and recovery is rapid if this is done, particularly if the stream is otherwise in good condition. As the Mills River is a drinking water supply, removing the potential sources of toxic pollutants is imperative. The other potential water quality that may face the Mills River watershed in the near future is the rapid development of the area. Extensive buffer zones along the waterways in this watershed will be necessary to keep pollutants from entering the stream and will be well worth the reduced cost of removing pollutants from the water supply.

The South Fork Mills River normally also exhibits excellent water quality. It rates slightly lower than the other Mills River sites because of some serious sedimentation and nutrient loading that occurred in the early part of 1998. The problem has not recurred since that time. Brandy Branch shows significantly poorer water quality than the other sites analyzed in this watershed. Although it is rated average, the state also shows this stream on its impaired waterways list. VWIN analysis has shown this stream to have unusually elevated nitrogen concentrations and conductivity levels that are atypical for this watershed. While this stream has not been analyzed long enough to conduct trend analyses, the data thus far seem to indicate that nitrogen concentrations peak in winter and decline in summer. This often indicates runoff from livestock holding areas as a possible source. While wastewater from the VanWingerden Greenhouse Company has also been considered a potential source, the company has switched in the past year to a recirculating water system and little waste is produced. Analysis of samples at different points in the stream will be necessary to try to locate the source of pollutants.