Coal Ash after Hurricane Florence

The Tar River where it begins to form the Rocky Mount Reservoir near NC 58.

October 1, 2018 | Margaret Huffman

Dr. Eric Edwards
Dr. Roger von Haefen
Dr. Sara Sutherland

Department of Agricultural and Resource Economics
North Carolina State University

Hurricane Florence has caused significant impacts across North Carolina. As the flood waters begin to recede, breaches and flooding at some coal ash waste ponds have North Carolinians concerned about potential environmental and health effects. This information sheet provides a brief overview of the coal ash problem and potential solutions going forward.

What is Coal Ash?

Before it is burned to produce electricity, coal is pulverized into a fine dust. When the dust is burned, it leaves residual particles, analogous in a home fireplace to the leftover ashes and residues left on the ground, on the bricks and in the chimney. When the ash and residuals are removed, they become industrial waste that needs to be stored. Coal ash may contain pollutants including heavy metals like mercury, arsenic, and lead. Because coal-fired power plants require large amounts of water for cooling, they are often located near rivers. Coal ash is typically stored on-site in open-air pits. Even after the plants are retired, a site containing coal-ash continues to house potential contaminants. In North Carolina, these sites are monitored by the Department of Environmental Quality.

Coal Ash in North Carolina

There are 33 open-air coal ash pits at 14 facilities in North Carolina. In February 2014, a storm pipe break caused a coal ash pond at the Dan River Steam Station to spill 39,000 tons of coal ash over a 70-mile stretch of the river. Only around 10% of the discharged waste from the Dan River spill was ultimately recovered using hydraulic dredging to vacuum the ash from the stream bed. The spill significantly affected the appearance of the Dan River and harmed local tourism. In 2015 Duke Energy pled guilty to nine Clean Water Act violations and paid $102 million in fines and restitution for illegal discharges. The U.S. Department of the Interior is currently working with Duke Energy, the owner of the plant, to assess the natural resource damages from the spill and restore the river to its pre-spill conditions. The Dan River spill was the third largest coal ash spill in U.S. history.

Environment and Health Effects of Coal Ash

Coal ash is a potential environmental contaminant and carcinogen. While coal ash dust is most harmful as an airborne pollutant, the first-ever documented cases of occupational cancer occurred in the chimney sweeps of England (circa 1775) through direct prolonged skin contact to coal soot. Absent direct inhalation or contact, the environmental and health consequences of spills and leaks from coal ash containment facilities are not well documented. The EPA regulates coal ash due to its heavy metal content and numerous documented instances where these metals (especially arsenic) leached out of unlined or inadequately clay-lined landfills and ponds. From a human health standpoint, the primary concern from coal ash is drinking water contamination. Local drinking water utilities are required to test for these contaminants and provide a Consumer Confidence Report to their customers.[1] Contamination of ecosystems, fish, and even agriculture have also been raised as areas of concern.

Hurricane Florence

Two Duke Energy coal ash facilities were compromised in North Carolina as a result of Hurricane Florence. Duke Energy has confirmed that there were numerous breaches in containment ponds at its Sutton facility near Wilmington. The Sutton Coal Plant was retired in 2013, but the site continues to have two coal ash pits and a cooling pond which sit adjacent to the Cape Fear River. A coal ash landfill on the site also appeared to be leaking in a separate incident. In addition, three coal ash pits at the retired Lee Station coal facility near Goldsboro were inundated with floodwaters. Duke Energy and a nonprofit environmental group have released conflicting results of water quality tests on the Neuse River near Lee Station. It is strongly contested at this point whether coal ash was released at any of the North Carolina facilities, and what the environmental or health impacts will be. The North Carolina Department of Environmental Quality is monitoring both the Neuse and Cape Fear Rivers, but water quality test results are not yet available. Reputable local and national newspapers are often the best source for current information on coal ash spills and water quality.

Policy Responses to the Coal Ash Problem

North Carolina’s Coal Ash Management Act of 2014 required Duke Energy to close all 33 coal ash pits by 2029. Whether the 110 million tons of coal ash in those pits should be stabilized on site or moved to lined landfills was left to state regulators to determine on a case-by-case basis. The original law, however, did mandate that coal ash at the Dan River and Sutton plants be moved to lined landfills. At the federal level, the EPA passed new rules in 2015 requiring all landfills and surface impoundments actively receiving coal ash to be lined and adhere to minimum standards. Existing unlined facilities were required to cease receiving coal ash and eventually close. In July 2018, the EPA relaxed the 2015 rules to give companies more time to close their ponds and increase state flexibility in certifying whether facilities that store coal ash are adequate. One key area of dispute is the location of permanent coal ash storage facilities. Because plants are often collocated near rivers, ponds and landfills are often in floodplains. However, moving coal ash to higher ground requires significant expense and the transportation of the contaminated dust via trucks over local roads and highways. One solution, which is low-cost and environmentally beneficial, is to recycle the coal ash. Encapsulated reuse, where the ash cannot escape into the surrounding environment, includes the use of coal ash in cement and drywall products. Unencapsulated use for road-fill and embankments also offers a potential solution, one that was used in North Carolina at the Ashville Airport, saving $12 million. Both types of reuse are regulated by the EPA to ensure contaminants do not leach into the environment.