A by-product of coal-fired power plants, coal combustion residuals (CCR) is one of the largest forms of industrial waste in America, with several million tons of CCR (coal ash) waste generated each year. Because it contains various metals, the EPA has created CCR (coal ash) regulations that create rules for the careful disposal of this waste. This article will cover this distinct form of industrial waste with a focus on disposal regulations that protect the health of individuals and the environment.
What Is CCR (Coal Ash) Waste?
In coal-fired power plants, coal is combusted (or burned) in order to generate electricity. As of 2011, there were 589 coal-fired power plants in the United States, generating 37.4 percent of the total electricity produced in America each year.
While we rely on the energy from coal-fired power plants, there are also certain consequences of burning coal – one of which is CCR (coal ash) waste. CCR (coal ash) waste is a general term for a number of by-products which include:
- Fly Ash – finely ground, powdery form of CCR (coal ash).
- Bottom Ash – course ash particles that gather at the bottom of the coal furnace because they are too large to be carried up the smoke stacks.
- Boiler Slag – molten bottom ash which turns into smooth, glassy pellets.
- Flue Gas Desulfurization Material – a leftover material from the air pollution control equipment that can either be a dry powder or a wet sludge.
CCR (coal ash) waste is not considered a hazardous waste material. That said, it does contain a number of metals including arsenic, lead, mercury, selenium, cadmium and chromium. Safe disposal of CCR (coal ash) is important, and the EPA has set several CCR (coal ash) regulations to keep us safe.
Disposal of CCR (Coal Ash) & CCR (Coal Ash) Regulations
Disposal of CCR (coal ash) can take place in wet impoundments (lagoons) or dry landfills where CCR (coal ash) waste is stored, but two recent events demonstrated that wet impoundments (lagoons) can be particularly risky. The EPA’s CCR (coal ash) regulations have come as the result of these CCR (coal ash) spills, where it was discovered that certain safety procedures must be followed to keep people and the environment safe.
The two events that led to EPA CCR (coal ash) regulations were the Kingston TVA CCR (coal ash) spill in 2008 and the Duke Energy CCR (coal ash) spill in 2014. In both cases, the wet impoundment (lagoon) storage facilities failed, causing water that had CCR (coal ash) dissolved in it to spill out and eventually contaminate rivers. The contaminated waters posed health risks to residents. The events also impacted the environment and wildlife and required costly cleanups.
On October 19, 2015, the EPA established new national standards specifically tailored to address particular risks that the mismanagement of the disposal of CCR (coal ash) can present to human health and the environment. Arrowhead Landfill has long complied with all of the new requirements. These requirements include:
- Siting in suitable, stable locations, e.g. not located close to drinking water sources or waterways.
- Monitoring wells with sampling and analysis, e.g. groundwater monitoring
- Disposal cells above groundwater
- Disposal cells to have composite liner systems
- Leachate collection and disposal systems
- Prevention of airborne CCR (coal ash)
- Storm water management plan
- Closure and post closure plan
When the Arrowhead facility was built nine years ago, the facility was engineered to comply with all the requirements listed above.
It is also worth mentioning that disposal of CCR (coal ash) isn’t the only way to deal with CCR (coal ash) waste. There are also ways to reuse it that provide economic and environmental benefits. In particular, fly ash has been used since the early 1950s in roadways and highways. The fly ash can be used as a partial substitution for cement, and in addition to roads, it can be used for concrete products in construction. The benefits of reuse include lower greenhouse gas emissions, fewer natural resources consumed, reduced disposal of CCR (coal ash), and improved strength of materials. Using CCR (coal ash) in concrete is an example of ‘encapsulated reuse,’ but the EPA is also exploring unencapsulated uses for CCR (coal ash).
CCR (coal ash) waste contains various metals, but is not classified as a hazardous waste by the EPA, and with proper disposal at a highly engineered facility, such as the Arrowhead Landfill, CCR (coal ash) can be disposed of in a way that protects both human health and environmental health.