Ethanol plant fined for multiple excessive air emissions

An ethanol plant in north-central Iowa failed to maintain its equipment to limit air pollution and repeatedly emitted harmful chemicals over the course of more than a year, according to the Iowa Department of Natural Resources.

The department recently fined POET Bioprocessing, in Iowa Falls, the maximum administrative penalty of $10,000.

POET, based in South Dakota, has 33 facilities in eight states, according to its website. The company acquired the Iowa Falls site on the southwest edge of town from Flint Hills Resources in June 2021, according to a recent DNR administrative order.

Since then, the company has reported at least 10 instances of excess emissions to the DNR that were a result of its fermentation process.

That process involves yeast converting sugars in corn into ethanol. It emits carbon dioxide and other harmful pollutants.

The DNR alleges that operators of the facility, which produces more than 115 million gallons of ethanol per year, have failed to adequately maintain and operate emissions-control devices, resulting in the excessive releases of acetaldehyde, acrolein, methanol and volatile organic compounds.

“Actual harm to the environment and public health likely occurred due to the amount of pollutants that were emitted,” the DNR order said.

Ethanol has been favored as a fuel that is blended with gasoline because it results in less pollution emissions from vehicles compared with unblended gasoline. The ethanol industry also creates greater demand and higher prices for Iowa corn.

“POET is working with the agency to resolve the issues identified,” the company said of the DNR. “Sustainability is at the core of POET’s mission, and we are dedicated to operating our facilities with excellence.”

The excessive emissions POET reported to the DNR were the result of temporary failures of emissions control equipment, maintenance to the equipment or releases from a safety valve due to high pressures, the DNR order said.

In June 2022, the facility temporarily reduced its production rate in order to bring its emissions into compliance.

Further, the department said POET has postponed DNR-supervised compliance testing when the company knew the test would reveal a violation.

“Postponing the compliance test to avoid a documented violation is considered credible evidence” of a violation, the DNR said in a February 2022 notice.

The recent administrative order was a compromise negotiated between the company and the department. A letter from POET to the DNR in December that was part of the negotiation pushed back against the notion that the company was deliberately blocking the DNR’s oversight when it delayed compliance tests.

“POET Iowa Falls did not attempt to avoid DNR directly observing a noncompliant stack test to avoid a documented violation,” the company said. “POET Iowa Falls personnel attempted to mitigate and minimize an excess emissions event upon discovery. The team evaluated potential solutions and instead of continuing to operate in a potential excess emissions state, expeditiously implemented corrective action to lessen any negative impact on the environment.”

The company has self-reported more than a dozen emissions violations to the DNR in the past year, most recently in January, according to state records.

The DNR order says POET must provide the department with a detailed explanation of excessive emissions in 2021 and 2022 and a plan to prevent similar emissions in the future.

The order requires more frequent emissions testing and precludes the company from delaying compliance tests that are overseen by DNR staff, unless the department agrees to the delay.

The company also agreed to pay the $10,000 fine and consistently maintain its equipment, the order said.