Overview:

- Sulfur dioxide pollution from Zug Island's EES Coke Battery has spread as far as southern Louisiana, an air quality expert says in federal court testimony.
- "Every day the facility operates, someone is being impacted," says Lyle Chinkin.
- The testimony came on the third day of the bench trial for the EPA's Clean Air Act lawsuit against EES Coke Battery.

An air quality expert with 40 years of experience testified Wednesday that EES Coke Battery’s excess particulate matter emissions were “one of the largest sources I’ve ever seen.”

The pollution from DTE Energy’s Zug Island subsidiary traveled as far as Maine, Missouri, and the coast of North Carolina, said Lyle Chinkin, an expert in air quality and meteorological analysis and CEO and chief scientist of Sonoma Technology. 

Chinkin testified Wednesday at the bench trial of the Environmental Protection Agency’s Clean Air Act lawsuit over EES Coke Battery’s sulfur dioxide emissions. The U.S. government is seeking $140 million in penalties for environmental violations, and corrective measures.

“Every day the facility operates, someone is being impacted,” Chinkin said. 

Air quality models show Zug Island’s effect

The Clean Air Act requires the EPA to establish National Ambient Air Quality Standards for six key pollutants harmful to health and environment. Chinkin described ambient air as that which the public has no choice but to breathe, giving the example of a UPS driver making deliveries to the island. 

The EPA sets annual PM 2.5 standards at 9 micrograms per cubic meter, and annual sulfur dioxide standards at 75 parts per billion.

Chinkin said he used an AERMOD model to evaluate pollution from EES Coke Battery. It’s a type of computer-generated air quality model that considers the near-field public health impacts of emissions beyond the fenceline of a polluting facility. 

A visualization of an AERMOD model color coded Detroit and Downriver communities to illustrate a spectrum of concentration of sulfur dioxide emissions from EES Coke Battery. 

The low end of the spectrum is 4.3 ppb, and on the high end, more than 100 ppb, Chinkin said. Sulfur dioxide levels everywhere on the map are greater than the EPA’s Significant Impact Level, which is 3 ppb for sulfur dioxide.

The darkest area on the map is near the fenceline of the facility, and registers between 50 to 100 ppb of sulfur dioxide. 

“I’ve been doing this for 40 years. To have a single source violating NAAQS is huge,” Chinkin said. 

The EPA set national ambient air quality standards to protect the public from all air pollution sources, the witness said. He said to have a single source, EES Coke Battery, putting out enough sulfur dioxide to put the area over federal limits, is not something he’s seen much over his career. 

He incorporated self-reported emissions data from the Michigan Air Emissions Reporting System, facility characteristics like combustion stack height and terrain, and National Weather Service data from Detroit Metropolitan Wayne County Airport. 

Chinkin said when he made his models in 2024, he used 2019 data because it was at the midpoint of high and low emissions data from the facility. 

He summarized modeling scenarios — best emission estimates, control-case air quality impacts, and a shutdown case — using emissions data from the combustion stack and flare, and spread out estimated hourly emissions over a year. 

To illustrate the far-reaching impacts of excess PM 2.5 pollution from EES Coke Battery, Chinkin created a CAMx model, a photochemical modeling system for gas and particulate air pollution. 

In one visualization, Chinkin showed U.S. District Judge Gershwin Drain a map from March 22, 2019 depicting concentrations of PM 2.5 spreading from the Zug Island facility to southern Louisiana. The concentrations of PM 2.5 were at 0.05 micrograms per cubic meter. 

“Even though it’s a smaller concentration, it’s impacting a lot more people,” Chinkin said.

MORE ON EPA’s ZUG ISLAND POLLUTION LAWSUIT

Isabelle Tavares covers environmental and public health impacts in Southwest Detroit for Planet Detroit with Report for America. Working in text, film and audio, she is a Dominican-American storyteller who is concerned with identity, generational time, and ecology.