Crews deliver ash to a fully lined on-site landfill at Duke Energy's L.V. Sutton coal plant in North Carolina in July 2017.
The U.S. Environmental Protection Agency unveiled two proposals Nov. 4 that would ease Obama-era treatment guidelines for waste streams produced by coal-fired power plants and potentially give retiring generators more time to store ash in unlined ponds.
One proposal revises the EPA's 2015 Coal Combustion Residuals, or CCR, rule in response to a federal appeals court ruling, and the other would relax compliance requirements under the 2015 effluent limitation guidelines for coal-fired steam generating units. The EPA said in a news release that it released the proposed rulemakings together because the changes may affect many of the same facilities.
Among its many requirements, the 2015 CCR rule required electric utilities to conduct groundwater testing near surface impoundments, also known as ash ponds, and post the resulting data on public-facing websites. If the underlying groundwater was found to be contaminated with a specific class of potentially toxic pollutants, operators of those sites were required to take corrective action that, in most cases, involved complete closure. In addition, the CCR rule set location restrictions that prohibit coal ash impoundments from being located within five feet of the uppermost aquifer.
However, the U.S. Court of Appeals for the District of Columbia Circuit in August 2018 struck down several parts of the CCR rule as insufficiently protective of public health. The court specifically found that provisions of the 2015 rule allowing unlined and clay-lined surface impoundments to receive coal ash until a leak is detected violate the Resource Conservation and Recovery Act of 1976. It therefore directed the EPA to issue a new rule.
Meanwhile, a March report from environmental groups Earthjustice and the Environmental Integrity Project found that 91% of the 265 coal plants where data was analyzed leaked unsafe levels of coal ash constituents into underlying groundwater.
With its proposed changes to the CCR rule, the EPA would set a new deadline of Aug. 31, 2020, to stop receiving waste and initiate closure of all unlined and formerly clay-lined surface impoundments managing coal ash and impoundments near aquifers or impacting groundwater. The Trump administration previously set a deadline of Oct. 31, 2020, to take such actions.
But the proposal also would establish significant exemptions for storage sites at units with announced retirement dates. Surface impoundments 40 acres or smaller at units with known retirement dates would not have to complete closure until Oct. 17, 2023, while impoundments larger than 40 acres at units with known retirement dates would be given an additional five years to close.
The EPA expects the proposed deadlines to result in net cost savings of $39.5 million annually. Over 500 power generating units at approximately 260 facilities may be impacted by the new rule, according to the agency.
Effluent limitation guidelines
The EPA also proposed Nov. 4 to ease effluent limitation guidelines for two waste streams produced by coal-fired power plants: flue gas desulfurization wastewater and bottom ash transport water.
The guidelines, finalized in 2015, set a national floor for the minimum acceptable level of cleanup technology that can be used to treat six waste streams at coal plants. Of particular relevance here, for the first time, the rule requires coal plant operators to use dry handling or closed-loop wet ash handling systems that produce zero discharges of transport water into nearby waterways. The guidelines also require facility operators to use biological organisms to treat water used to clean out flue gas desulfurization equipment that limits mercury emissions.
In 2017, then-EPA Administrator Scott Pruitt extended the deadline to comply with the Obama-era regulation from Nov. 1, 2018, to Nov. 1, 2020, as the agency reconsidered the rule in response to a request from industry.
Meanwhile, in a move that could further complicate the EPA's Nov. 4 proposal, the U.S. Court of Appeals for the 5th Circuit in April struck down two provisions of the 2015 guidelines as too weak. There, the court concluded that the rule impermissibly set surface impoundments as the "best available technology economically achievable," or BAT, to handle legacy wastewater and a sludge-like waste stream called leachate. The court therefore vacated and remanded the guidelines covering leachate and legacy wastewater.
In contrast to the Obama-era guidelines, the Nov. 4 proposal would not require coal-fired units to implement biological treatment technology for flue gas desulfurization water. Instead, generators would be allowed to rely on chemical treatment technology that helps coal ash and other residuals settle to the bottom of treatment facilities.
The EPA is also proposing to set recycling systems that produce discharges as the BAT for transport water. Unlike closed-loop systems, that technology would allow facilities to discharge a limited amount of wastewater into nearby waterways.
Moreover, the proposed regulation would establish a new subcategory for coal-fired units that plan to close no later than Dec. 31, 2028. Under that exemption, units that plan to retire by that date could continue to use surface impoundments to treat flue gas desulfurization wastewater and bottom ash transport water.
In proposing the exemption, the EPA argued that the 5th Circuit's ruling appeared to allow the agency to select surface impoundments as the basis for best available control technology so long as it cited a statutory factor, such as cost, in its rationale. However, Thomas Cmar, an Earthjustice attorney who successfully argued the 5th Circuit case on behalf of environmental petitioners, disputed that claim.
"The 5th Circuit emphatically held that it is EPA's responsibility to establish standards based on the most effective, modern technologies," Cmar said in a Nov. 4 email. "EPA's continued reliance on unlined ash pits as a 'technology' is directly contrary to the court's ruling that these standards must be strengthened."
The EPA said it will address the 5th Circuit's vacatur in a subsequent action.
'Voluntary incentives program'
Overall, the EPA said it expects the preferred option in its effluent limitation guidelines proposal, which is one of four potential options, to save approximately $175 million annually in pretax compliance costs. The agency also estimated the proposal will yield $137 million annually in social cost savings due to the use of less costly flue gas desulfurization wastewater technologies.
In addition, the proposal would establish what the agency described as a "voluntary incentives program" that envisions some facilities with known retirement dates adopting stricter pollution control technologies than those the EPA has specified as BAT. The program would specifically offer plant operators the certainty of more time — until Dec. 31, 2028 — if they adopt additional controls that achieve more stringent limitations on mercury, arsenic, selenium, nitrate/nitrite, bromide, and total dissolved solids in flue gas desulfurization wastewater.
Under its preferred option, the EPA estimated that 18 plants would participate in the voluntary program, which translates to about 27% of all plants the agency expects to incur flue gas desulfurization compliance costs.
The EPA estimated that participation in the voluntary incentive program would further reduce the pollutants that coal-fired steam generators discharge by approximately 105 million pounds per year compared to maintaining the Obama-era guidelines.
But Betsy Southerland, a former EPA employee who helped write the 2015 effluent limitation guidelines, said the proposal failed to estimate the degree of pollution reduction that would be achieved if the affected plant operators simply chose to follow the agency's own minimum guidelines. "It's simply dishonest," Southerland said in a Nov. 4 interview. "It's a real apples and oranges comparison."
Public comments on both proposals will be due 60 days after their publication in the Federal Register. The EPA said it will also conduct public hearings.