Jefferson County’s air quality is much better since the 2013 closure of the Doe Run Co. lead smelter in Herculaneum — so much so that the Missouri Department of Natural Resources ruled Thursday that the area should be redesignated as compliant with national pollution standards for sulfur dioxide emissions.
The unanimous ruling at the DNR’s Air Conservation Commission meeting in Jefferson City was met with criticism from some who worry that there are insufficient measures in place to ensure the local Clean Air Act compliance extends into the future.
“Once you’ve managed to improve that, you need a plan in place to ensure those gains aren’t lost,” said Ken Miller, an environmental scientist with the Washington University Interdisciplinary Environmental Clinic, which has tracked the issue on behalf of the Sierra Club.
The area is home to Ameren’s coal-fired Rush Island Energy Center, which emits 97 percent of the nonattainment zone’s sulfur dioxide. In comments leading up to Thursday’s decision, others at the Interdisciplinary Environmental Clinic argued that a designation of compliance would effectively use the smelter’s closure to “let Ameren off the hook for reducing their emissions.”
The St. Louis-based utility’s fleet of coal plants in the region includes Labadie Energy Center — the largest coal plant in the country that has not installed expensive “scrubbing” technology to reduce sulfur dioxide emissions. Its plants at Rush Island and Meramec do not have scrubbing equipment either.
Miller said he doesn’t necessarily expect Ameren’s local sulfur dioxide emissions to increase, but suggests that the plan discussed Thursday does not provide teeth for enforcement, if they were to spike for any reason.
“The question is what could DNR or (the Environmental Protection Agency) do about it if that happened to be the case? The answer is not a whole heck of a lot,” said Miller, noting that allowable limits are several times greater than the plants’ current emission levels. “What it sort of ignores is the fact that you have three Ameren plants (in the vicinity) that contribute sulfur dioxide to the nonattainment area.”
The DNR, however, justified the redesignation by reasoning that the closure of the Herculaneum lead smelter constitutes a “permanent and enforceable” improvement for air quality.
“This permanent and enforceable reduction in the emissions is the key,” said Darcy Bybee, air quality planning section chief at DNR, at Thursday’s meeting.
Ameren said the decision was “the right step,” according to Steve Whitworth, its senior director of environmental policy and analysis.
He said sulfur dioxide emissions at Rush Island have declined steadily over time and would likely continue to do so.
“I expect they’ll remain flat to declining,” Whitworth said.
Even with nearby coal plants such as Meramec slated to retire in 2022, Whitworth said the utility’s aim is to transition generation to new sources — including renewables — rather than shifting back to other coal plants, such as Rush Island.
“We’ll continue to reduce emissions and transition our fleet as time moves forward,” Whitworth said.
The decision from DNR came more than two months after initially expected. The meeting included the group’s newest member, Kevin Rosenbohm, appointed by Gov. Eric Greitens on Wednesday. There are two vacant seats remaining on the commission.
The commission’s proposed action still requires approval from officials at the EPA before being finalized.