The notice of violation was issued against the treatment plant for failing to conduct the daily checks of "scrubber solution pH and reduction and oxidation capacity" on May 12, a failure that was reported by the city to the Department of Health; intermittently exceeding the hydrogen sulfide emissions concentration permit limit of 0.25 parts per million at the odor control systems; exceeding the H2S emissions permit limit of 0.025 parts per million at the fence line intermittently; and for simultaneously taking both the "primary and headworks odor control systems out of service" on June 6.

The treatment plant provides primary and secondary treatment of municipal wastewater. One of the main air pollutants emitted from the plant is H2S, a gaseous compound formed by the decomposition of organic matter, which has an odor of rotten eggs, according to the Department of Health.