On March 1, 2018, the Environmental Protection Agency (EPA) published a proposed rule which would make several changes to the regulation of coal ash waste produced by power plants. Coal ash is a potentially toxic byproduct of burning coal, which is often stored by utilities in on-site pits for years after being produced. Following severe spills in Tennessee and North Carolina where coal ash contaminated nearby rivers, the Obama administration published new regulations in 2015. The Obama-era rule set minimum performance standards for coal ash pits and landfills, requiring certain levels of environmental protection designed to prevent leaks and spills. It also required additional testing, monitoring, and reporting associated with groundwater contamination in the vicinity of stored coal ash. Recent testing required under the 2015 rule showed evidence of groundwater contamination at over 70 sites. The new rule published by the Trump EPA revises the 2015 regulations to allow owners of coal ash storage more time to comply with regulations, allow utilities increased flexibility in locating storage pits and landfills, allow groundwater monitoring to be suspended in certain cases, allow alternative protection standards in certain cases, modify the corrective action required in instances where standards are violated, and allow state officials more discretion in certifying compliance. According to the EPA, the changes are designed to give states additional flexibility in regulatory compliance and reduce compliance costs for utilities by up to $100 million per year. However, environmental NGOs are concerned that the modifications in the Proposed Rule will lead to less stringent monitoring of coal ash storage, less effective corrective measures in the event that problems arise, and continued health impacts on nearby communities.