QUINCY — The city of Quincy backtracked on its initial response to a report regarding the 2015 Legionnaires’ outbreak at the Illinois Veterans Home.

The report from a group of researchers at Virginia Tech hypothesized that temporary changes made to the city’s water distribution system created favorable conditions that allowed Legionella bacteria growth throughout the system. The report, funded by the state of Illinois, specifically noted there were no legal violations.

Jeffrey Conte, director of utilities and engineering, who initially denied that the city temporarily switched from its primary disinfectants before the outbreak at the Illinois Veterans Home, said he was mistaken when he made that comment. He had reviewed plant operations data from 2014.

He confirmed that in January 2015, the plant moved to chlorine, which is a stronger disinfectant.

“We were concerned about the pathogen kill at low water temperatures,” Conte said. “Because of that we applied for the permit, we got the permit, we switched over on the first of January, and then we did use that until the water was warm again in the summer time and went back to chloramine, because of the disinfection byproducts rule.”

After plant improvements, the plant switched to chlorine permanently in November 2015.

“At the time, the reason we did switch back was because the stronger chlorine produces more disinfection byproducts, which are also regulated,” Conte said. “Now the improvements we made to the treatment plant allowed us to get rid of the precursors to the disinfection byproducts, so that we were comfortable by November 2015 that we could meet both the disinfection byproducts rules and get better pathogen kill with free chlorine.”

The report believes that the July 13, 2015, storm that knocked down hundreds of trees and cut power to a majority of the city increased raw water turbidity in the Mississippi River and resulted in lower total chlorine residuals entering the municipal distribution system.

The first case at the Veterans Home was identified Aug. 6, 2015, with an outbreak confirmed on Aug. 21, 2015, when the second case was diagnosed.

At least 13 people died, and dozens more were sickened from a Legionnaires’ disease outbreak at the Illinois Veterans Home that year. Other outbreaks were reported in 2016, 2017 and 2018.

Four community-based cases were reported in 2015.

Conte stood by his comments regarding phosphate use and disinfectant residuals in the water.

The report said phosphate for corrosion control was discontinued temporarily and could have released more lead into the water system, citing an increase in children testing positive for heightened blood lead levels in June 2015, though it noted similar spikes in monitoring data in Adams County in previous years.

Conte said the city used very low doses of phosphate to prevent lime scale building up on the filter media. It was discontinued temporarily for a plant upgrade.

The city started added more phosphate in 2017 after some tests showed increased lead levels, though Conte said the levels were in compliance.

Conte said repeated testing of the city’s water distribution system has turned up no positive tests for Legionella, and that water entering the Veterans Home campus tests for chlorine.

The Virginia Tech report suggests that anytime changes are made in water treatment of distribution system operation, increased monitoring of water samples needs to be implemented, along with monitoring for Legionella, increased flushing and better communication between utilities and their customers.

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