Coal Ash Reuse
Coal combustion residuals, comonly known as coal ash, can be reused in different products and materials. The beneficial use of coal ash is the reuse of coal ash in a product to replace virgin raw materials removed from the earth, thus conserving natural resources. EPA encourages the beneficial use of coal ash in an appropriate and protective manner, because this practice can produce positive environmental, economic, and product benefits such as:
- reduced use of virgin resources,
- lower greenhouse gas emissions,
- reduced cost of coal ash disposal, and
- improved strength and durability of materials.
While the beneficial use of coal ash has these potential benefits, the environmental impacts associated with their use should also be considered. The most recent available data from responses to an American Coal Ash Association (ACAA) survey of electric utilities shows that in 2012, at least 39 million tons of coal ash were beneficially used.
Encapsulated Reuse
The encapsulated uses of coal combustion residuals (CCR) are where coal ash is bound in a product, such as in wallboard, concrete, roofing materials, and bricks. There are important benefits to the environment and the economy from the use of coal ash in encapsulated form. The two largest encapsulated uses reported by the ACAA are fly ash used in "concrete/concrete products/grout" (11.8 million tons) and flue gas desulfurization (FGD) material gypsum used in "gypsum panel products" (7.6 million tons), making up nearly 50 percent of the total amount of coal ash that is beneficially used.
EPA developed a methodology for evaluating encapsulated beneficial uses of CCR. This methodology supports beneficial use decisions by allowing the user to determine whether releases from an encapsulated beneficial use of coal ash is comparable to or lower than those from analogous products made without coal ash, or are at or below relevant regulatory and health-based benchmarks, during use.
Methodology for Evaluating Encapsulated Beneficial Uses of Coal Combustion Residuals
EPA used the methodology to evaluate the potential environmental impacts associated from fly ash used as a direct substitute for portland cement in concrete, and from FGD gypsum used as a replacement for mined gypsum in wallboard. EPA’s evaluation concluded that the beneficial use of encapsulated CCR in concrete and wallboard is appropriate because they are either comparable to analogous products or below the relevant benchmarks.
Coal Combustion Residual Beneficial Use Evaluation: Fly Ash Concrete and FGD Gypsum Wallboard
Beneficial Use Frequently Asked Questions
Unencapsulated Reuse
Unencapsulated uses of coal ash are those where coal ash is used in a loose or unbound particulate or sludge form. EPA plans to develop a conceptual model for unencapsulated beneficial uses of coal ash in 2015.
How are beneficial uses of coal ash currently regulated?
Currently, state environmental agencies are primarily responsible for regulating beneficial use. Beneficial use of coal combustion residuals is currently excluded from federal regulation under EPA's May 2000 regulatory determination that the Bevill amendment applies to such uses. Under the Resource Conservation and Recovery Act, federal action could be taken if there were a finding of imminent or substantial endangerment in a specific circumstance.
The final CCR disposal rule reaffirms EPA's Bevill determination for beneficial used, and provides a definition of beneficial use to distinguish between beneficial use and disposal. This rule does not affect beneficial use applications started before the effective date of the rule; only applications to be started after the effective date of the rule need to determine if they comply with the criteria contained in the final rule distinguishing between beneficial use and disposal.