In stream dynamics of acid mine drainage and untreated sewage

Both acid mine drainage (AMD) and untreated sewage are serious water quality issues faced by poor, rural communities both within the United States and worldwide. In Appalachia, it is common for these water quality issues to coincide. The aim of this study was to investigate the interaction between AMD and untreated sewage in stream. The study area, Murray City, Ohio, was conflicted, blocking construction of a mine water treatment system to maintain sewage ‘treatment’ by the AMD. Data collected over 5 months from Snow Fork Creek in Murray City, Ohio, show that during low flow, high net acidity portions of a water year, the acidity is sufficient to limit fecal indicator bacteria populations below regulatory limits. During high flow, low net acidity portions of the water year, bacterial populations thrive above the regulatory limits until a point where dilution by water of good quality leads to a decrease in fecal indicator bacteria concentrations to near the regulatory limit of 126 CFU/100 mL for primary contact recreation. This study shows that AMD limits the survival of fecal indicator bacteria and suggests that traditional fecal indicator bacteria are insufficient for detecting untreated sewage in acidic streams despite both visual and olfactory evidence.