Understanding Coal Ash and the New Final Rule

For years, the safe disposal of coal combustion residuals (CCRs) or “coal ash” from coal-fired electric power plants has been a contentious subject among industry, environmentalists, and the public. In December 2014, the U.S. Environmental Protection Agency (EPA) published a final rule for dealing with the problem. This article discusses coal ash, its past, and how the new rule will change how it is managed in the future.

The makeup of coal ash:  Coal ash is essentially the byproduct of the combustion of coal at power plants that contains contaminants like mercury, cadmium, and arsenic associated with cancer and various other serious human health effects. Coal ash is disposed of in wet form in large surface impoundments and in dry form in landfills, and the EPA says there are several different types of materials produced in the processes, including:

• Fly Ash is produced from burning finely ground coal in a boiler and is a very fine, powdery material composed mostly of silica;

• Bottom Ash is made up of the coarse angular ash particles that are too large to be carried up the smoke stacks, and this ash remains in the bottom of the coal furnace;

• Boiler Slag is molten bottom ash from slag tap and cyclone type furnaces that turns into smooth glassy pellets after cooling with water; and

• Flue Gas Desulfurization Material (FGD) is the material leftover from the process of reducing sulfur dioxide emissions from a coal-fired boiler. It can be a wet calcium sulfite or calcium sulfate sludge or a dry, powered mixture of sulfites and sulfates.

The volume of U.S. coal ash produced and disposed of annually. According to the EPA, coal ash “is one of the largest industrial waste streams generated in the United States. In 2012, more than 470 coal-fired electric utilities burned over 800 million tons of coal, generating approximately 110 million tons of CCRs in 47 states and Puerto Rico.” In addition, the EPA says, “In 2012, approximately 40 percent of the CCRs generated were beneficially used, with the remaining 60 percent disposed in surface impoundments and landfills. Of that 60 percent, approximately 80 percent was disposed in on-site disposal units.” More than 310 active on-site landfills now receive coal ash with the average size of more than 120 acres and an average depth of over 40 feet. An additional 735-plus active on-site surface impoundments that average more than 50 acres in size with an average depth of 20 feet are also in use.

The impetus for the new rule: Although coal ash has been a product of electricity generation for decades, a 2008 coal ash spill in Kingston, Tennessee, brought the problem of safe management to the national forefront. According to the EPA, the incident occurred at the Tennessee Valley Authority (TVA) power plant when an ash disposal cell failed, releasing “an estimated 5.4 million cubic yards of fly ash to the Emory and Clinch Rivers and surrounding areas. The release extended over approximately 300 acres outside the ash storage area.”  When released, the EPA says the initial “wave” of water and ash “destroyed three homes, disrupted electrical power, ruptured a natural gas line in a neighborhood located adjacent to the plant, covered a railway and roadways in the area, and necessitated the evacuation of a nearby neighborhood.”

How the EPA evaluated coal ash storage and disposal nationwide. EPA’s Coal Ash Surface Impoundment Integrity Assessment Program assessed all of the nation’s aboveground coal ash surface impoundments, which was more than 500 units at more than 200 power plants. By its conclusion in 2012, the program was “one of the largest targeted field assessments ever conducted by EPA.”

The structural integrity reports produced were “completed by contractors who are experts in the area of dam integrity … and are signed and stamped by a professional engineer.” Each coal impoundment report provided a hazard potential rating of less than low, low, significant, or high, which the EPA says was “not related to the stability of the impoundments but to the potential for harm should the impoundment fail, and the EPA requested operators “implement the recommendations in the reports and provide plans for taking action.”

Coal ash will not be considered a hazardous waste. The final requirements for coal ash disposal were established for nonhazardous waste under Subtitle D of the Resource Conservation and Recovery Act (RCRA), rather than under Subtitle C that covers hazardous waste. As one result, under RCRA, the EPA is not authorized to issue federal permits for nonhazardous waste disposal of coal ash.

The role of RCRA-authorized states. According to the EPA, under Subtitle D, “the state and local governments are the primary planning, permitting, regulating, implementing, and enforcement agencies for management and disposal of … non-hazardous solid wastes.” The EPA is thus “strongly encouraging” states to adopt at least the minimum criteria in their regulations and notes that many states already have adopted requirements that exceed the new federal requirements and the final rule does not preclude authorized states from establishing more stringent regulations in the future. The EPA is also encouraging states to revise their Solid Waste Management Plans (SWMPs) and to submit these revisions to the EPA for approval, however, EPA approval of a SWMP revision does not mean that the state program operates “in lieu of” the federal program, as the EPA has no authority under RCRA to make such a determination.

Structural integrity requirements to reduce the risk of catastrophic failure. Beginning 6 months to 2 years after the rule is published, structural integrity design criteria will be implemented and will require several periodic structural integrity assessments. Examples include:

• Structural stability assessments by a qualified professional engineer,

• Safety factor assessments to document that the unit achieves minimum engineering factors of safety,

• Hazard potential classification assessments to assess the damage that would occur if there was a failure of the surface impoundment, and

• Weekly inspections of the unit and monthly monitoring of unit instrumentation.

In addition, certain surface impoundments must develop a detailed emergency action plan, including the actions to be taken to protect communities.

Groundwater protection requirements. Poor construction and management of coal ash disposal units have been connected to groundwater contamination and the new rule provides several requirements to address the problem, including:

• Groundwater monitoring and corrective action (beginning 30 months after rule publication);

• Closure of unlined surface impoundments that are polluting groundwater;

• Location restrictions for new surface impoundments and landfills so that they cannot be built in sensitive areas such as wetlands and earthquake zones (beginning 18 months after rule publication);

• Liner design requirements for new surface impoundments, landfills, and expansions (documentation required 18 months after rule publication);

• Closure of units failing to meet engineering and structural standards or that are located too close to a source of drinking water; and

• Proper closure of all surface impoundments and landfills that will no longer receive coal ash.

Day-to-day operating criteria requirements. Beginning 6 months after rule publication, the new requirements will include:

• Air criteria for all units to manage fugitive dust, log citizen complaints, and submit an annual report;

• Run-on and run-off controls for landfills to minimize impacts from water coming into the unit and to protect against releases to surface waters; and

• Hydrologic and hydraulic capacity requirements for surface impoundments to help prevent overtopping of the unit or erosion of the materials used to construct the surface impoundment.

Recordkeeping, Notification, and Internet Posting: Beginning 6 months after rule publication, all unit owners/operators must:

• Record compliance with final rule requirements (i.e., annual groundwater monitoring results, corrective action reports, fugitive dust control plans, and closure completion notifications) in the facility’s operating record;

• Notify the state of decisions; and

• Maintain a publicly available website of compliance information to promote state and citizen engagement in implementation.

For more information or assistance with your Environmental and Health & Safety regulatory compliance needs, contact Ralph Carito at Total Environmental & safety, LLC (Total) at rcarito@TotalEnviron.com or 908-442-8599.