ST. LOUIS — A federal appeals court on Friday upheld a judge’s 2019 ruling that ordered Ameren Missouri to install pollution controls at its Rush Island power plant south of Festus, a decision likely to force the St. Louis-based electric utility to rethink its long-term plans or spend hundreds of millions retrofitting a 1970s-era coal plant.
The utility did win a partial victory, though. The U.S. Court of Appeals for the Eighth Circuit rejected one portion of the district court’s ruling, which ordered Ameren to also install pollution controls at another coal plant to make up for the harmful sulfur dioxide emissions that environmental regulators said Rush Island had emitted.
The ruling is the latest in a lawsuit filed at the request of the U.S. Environmental Protection Agency over a decade ago accusing Ameren of violating the Clean Air Act by making upgrades to its Rush Island plant that increased sulfur dioxide emissions without proper permits. The government’s lawsuit accused Ameren of installing new equipment in 2007 and 2010 that allowed Rush Island to burn more coal and thus emit more sulfur dioxide.
The case plodded through the court system until 2019, when U.S. District Judge Rodney Sippel ordered Ameren to install sulfur dioxide control equipment, commonly known as scrubbers, at its Rush Island plant. In addition, he ordered Ameren to install another type of sulfur dioxide pollution control at Labadie, one of the largest coal plants in the country, to make up for the harm from Rush Island’s excess pollution.
Sulfur dioxide, a byproduct of coal combustion, causes heart and lung issues blamed for tens of thousands of deaths in the U.S. each year. While scrubbers are commonly used on many coal plants across the country, Ameren has instead relied on low-sulfur coal from Wyoming to meet many pollution rules. Still, scrubbers can reduce sulfur dioxide by some 95%, far more than the reductions achieved from burning low-sulfur coal.
Only one of Ameren’s plants, Sioux in St. Charles County, has scrubbers. Those cost ratepayers some $600 million to install in 2010, and the project was a prime driver of a rate increase the following year. Ameren argued in its appeal that the cost of the pollution controls mandated in Sippel’s ruling could exceed $2 billion.
Friday’s decision largely affirmed Sippel’s ruling but said the district court couldn’t order pollution controls at Labadie as a penalty for violations at Rush Island.
“Because Ameren committed no violation of the (Clean Air Act) at its Labadie plant, the district court lacked authority to authorize injunctive relief as to it,” the court wrote.
It sent that portion of the case back to the district court, but the decision means Ameren may finally have to install scrubbers at Rush Island, which, at 45 years old, is its newest coal plant.
Neither the utility nor environmental groups were pleased by the appellate court’s ruling.
“It is disappointing Ameren will not have to make up for the excessive pollution that spewed from its Rush Island coal plant by adding pollution controls to its Labadie coal plant as well,” Andy Knott, interim central region director for Sierra Club’s Beyond Coal campaign, said in a statement. “Thankfully, there will be some justice in this case. (Ameren CEO) Warner Baxter could choose to do the right thing for the common good and accelerate the closure of the Labadie coal plant considering it is the largest coal plant in the United States that lacks modern pollution controls.”
Ameren said it was “disappointed” in the court’s decision and noted that air quality monitors near Rush Island meet federal and state standards.
“It is premature to speculate on next steps at this time while we review and assess the judgment,” a company spokesman said. “Looking forward, we can say Ameren remains committed to achieving net-zero carbon emissions by 2050 while maintaining the reliability and affordability that customers have come to expect.”
As the cost of renewables has come down, Ameren has ramped up construction of wind and solar energy and in September pledged to be carbon neutral by 2050. It plans to retire its oldest coal plant, Meramec in south St. Louis County, next year and its Sioux plant at the end of the decade. But it still planned to operate Rush Island until 2039.
The appeals court ruling, however, has raised questions about Rush Island’s financial viability given the hundreds of millions new pollution controls would cost. It’s unknown how much of the expense state regulators will allow the utility to pass on to ratepayers for a construction project that would likely take years. Ameren might instead look at other power generation investments or the timeline for shuttering its coal plants.
Originally posted at 3 p.m. Friday, Aug. 21, 2021