The U.S. Environmental Protection Agency has proposed barring six coal-fired power plants in various states—a combined 11 GW—from disposing coal ash into unlined surface impoundments. The agency, however, also proposed to provide disposal extensions if the coal plants are needed to maintain grid reliability.
The EPA’s proposed determinations, issued on Jan. 25, fall under its Coal Combustion Residuals (CCR) Part B final rule, which it published in November 2020 as a revision to its CCR regulations under Part 257, Subpart D. The rule essentially finalized a two-step process for coal facilities with clay-lined surface impoundments to demonstrate to the agency that “based on groundwater data and the design of a particular surface impoundment, the operation of the unit has and will continue to ensure there is no reasonable probability of adverse effects to human health and the environment,” the EPA said. The plants had until Dec. 14, 2020, to submit applications, and approved facilities were given until Nov. 30, 2021, to conduct alternative liner demonstrations.
The agency ultimately received eight alternate liner demonstration applications from eight facilities with a combined 17 CCR surface impoundments. While seven facilities ultimately completed their applications, Arizona Electric Power Cooperative’s 204-MW Apache Generating Station withdrew its application.
But on Jan. 25, the EPA proposed to deny all six remaining completed applications, citing a failure to comply with CCR regulations. Among reasons the EPA cited for its proposed denials were “a failure to prove groundwater is monitored to detect and characterize any elevated levels of contaminants coming from the coal ash surface impoundment” and “evidence of potential releases from the impoundments and insufficient information to support claims that the contamination is from sources other than the impoundments.” The agency also pointed to “inadequate documentation for the design and performance of the impoundment liners” and a “failure to meet all location restrictions.”
The six coal plants include DTE Electric’s 1.3-GW Belle River Power Plant and 3.3-GW Monroe Power Plant in Michigan; Rainbow Energy Center’s 1.2-GW Coal Creek Station in North Dakota; KeyCon Operating’s 2-GW Conemaugh Generating Station in Pennsylvania; Salt River Project’s (SRP’s) 821-MW Coronado Generating Station in Arizona; and Luminant Generation’s 2.4-GW Martin Lake Steam Electric Station in Texas.
“If EPA finalizes these denials, the facilities will have to either stop sending waste to these unlined impoundments or submit applications to EPA for extensions to the deadline for unlined coal ash surface impoundments to stop receiving waste,” the agency said on Wednesday. The plants will have four months from the date of a finalized ineligibility determination to apply for an alternative closure deadline. If unable to submit an alternative closure deadline, the plants must cease waste receipt at impoundments within 135 days of the EPA’s final decision.
However, in “the significant interest of maintaining grid reliability,” the EPA on Wednesday also proposed a process for the facilities “to seek additional time, if needed to address demonstrated grid reliability issues.” This process will rely “in part on reliability assessments from the relevant regional transmission organizations, ensuring a reliable supply of electricity while protecting public health,” the agency said.
The plants all serve crucial power corridors. DTE’s Belle River and Monroe plants and Rainbow Energy’s Coal Creek serve in power-strapped zones within the Midcontinent Independent System Operator, providing a combined 5.9 GW to the grid operator. Conemaugh serves in PJM Interconnection, and Martin Lake serves in the Electric Reliability Council of Texas. While Coronado is part of SRP, an independent power cooperative and does not serve a regional transmission organization, the EPA suggested the Department of Energy’s Office of Electricity will aid the EPA in evaluating Coronado’s reliability claims.
It is unclear how the determinations will affect plant operations. According to the Energy Information Administration, DTE is slated to retire the Belle River plant 2028 and is mulling the closure of Monroe that same year, while SRP plans to retire Coronado in 2032.
The EPA set up separate dockets for each case and plans to collect comments between Feb. 8, 2023, and March 10, 2023.
—Sonal Patel is a POWER senior associate editor (@sonalcpatel, @POWERmagazine).