Public Drinking Water Violations in Mountaintop Coal Mining Areas of West Virginia, USA

Mountaintop coal mining (MTM) has adverse impacts on surface and ground water quality. Instances of domestic well water contamination from mining activities have been documented, but possible mining impacts on public water treatment systems are unknown. We analyzed the US Environmental Protection Agency's Safe Drinking Water Information System to examine the number and type of public water treatment violations in West Virginia for the years 2001-2009. Violations were compared between three groups of water treatment facilities: those in counties with mountaintop coal mining (n = 161 facilities), coal mining other than mountaintop mining (n = 184 facilities), and with no coal mining (n = 137 facilities). Adjusting statistically for system size and water source, there were 73.0 violations per system in MTM areas, 16.7 violations per system in other mining areas, and 10.2 violations per system in non-mining areas (F = 7.21, df = 7, 475, p < 0.0001). Excess violations in MTM counties were most often related to failure to conduct required sampling for organic compounds. Complete sampling and reporting of public drinking water quality in MTM areas is needed.