— — Multiple mechanical failures Wednesday at a controversial Town of Tonawanda coke factory led to the release of untreated smoke containing high amounts of toxic chemicals into the atmosphere, according to a statement from the EPA.

Tonawanda Coke, which for months has been at the center of a battle over air pollution in the town, was cited for having multiple malfunctions to its “exhauster” — a piece of equipment that forces the smoke produced in the coking process into a containment system for treatment. The EPA said in its release that both the primary and secondary exhausters failed Wednesday morning. A third exhauster was known to be inoperable, as well, according to the EPA.

Erin Heaney, spokeswoman for the Clean Air Coalition, said she was glad to see a quick response to the breakdown by regulatory agencies.

“There are supposed to be two backups and neither worked,” Heaney said. “This shows (Tonawanda Coke) is not doing their due diligence.”

The process of making coke, one of the necessary components in forging steel, produces smoke that contains high amounts of various chemicals including ammonia and benzene, a known carcinogen. The plant is supposed to trap that smoke and treat it to reduce levels of the harmful chemicals before releasing controlled amounts into the atmosphere.

On Wednesday, that mechanical system failed. As a result, EPA says “raw coke oven gas generated at the facility’s battery of coke ovens (was sent) through a small stack and into the air.”

The EPA said steps are being taken to fix the exhaust systems and “the plant is slowly returning to normal operations.”

Residents may notice black smoke coming from one of the plant’s stacks as a result of the problem, according to the EPA.

Heaney said workers at the nearby Tonawanda wastewater facility observed smoke and three large flames coming from the battery around 11 a.m.

Tonawanda Coke has been at the center of a controversy since an air quality study completed in 2009 found benzene levels surrounding the plant at 75 times legal levels. Town residents in the surrounding neighborhood have long complained of noxious odors and higher-than-normal incidents of cancer that they attribute to the plant’s emissions.

Late last year the plant’s environmental control manager, West Seneca resident Mark L. Kamholz, was arrested on a federal indictment charging him with violating, among other laws, the Clean Air Act. Kamholz faces a court date later this month.

Tonawanda Coke owner JD Crane has maintained that his facility operates within legal limits for benzene emission and attributes the increased levels to the abundance of industrial facilities in the area and vehicle exhaust from cars idling at the nearby Grand Island toll barrier.

The EPA’s statement on Wednesday’s incident did not include information on what if any punishment the plant will face.