The Missouri Department of Natural Resources (DNR) is reviewing the City of St. Mary’s proposal for permanent chlorination of the city’s water supply and has asked the city to provide additional information about its plan.
City officials discussed the letter during a work session last Thursday and took it as a sign DNR intended to proceed with the order for permanent chlorination.
City officials had hoped to avoid installing a permanent chlorination system, believing they may have found what was the source of coliform bacteria contamination in the water supply since the city switched to a new water system last year.
The letter, dated July 23 and reportedly received in early August, said the plan must ensure all service connections receive disinfected water after treatment, including the five users who receive their water between the connection from the water provider, Ste. Genevieve County Public Water Supply District, and the standpipe tower.
The letter also asks the city to provide calculations showing the proposed system can achieve “4-log disinfection,” which is the removal of 99.99 percent of viruses through filtration or disinfection, according to a state government website.
The city had 30 days to respond to the letter.
Mayor Carlton Wyatt said he expected the timetable to play out with a permanent chlorination facility being in operation next spring.
Wyatt said it shouldn’t affect rates since the city passed an increase this summer with a chlorination system included in the plan. But he also said DNR could alter the city’s plans and ask it to build a 10,000 gallon retention tank.
Alderman Dennis Bovey said the city would propose having a building constructed by the standpipe tower with an injection pump. He said the chlorine has to be housed in a building and kept at a certain temperature.
Bovey said the city also would build a water line down Cemetery Road to double back and serve those customers who currently receive their water before it reaches the standpipe. The city receives water from the Ste. Genevieve County Public Water Supply District (PWSD) and takes possession of that water from a meter pit before the standpipe.
“Everybody will be getting water from the tower,” Wyatt said.
The city had positive samples for coliform bacteria in December of 2011 as well as January, February and April of 2012. Prior coliform positive samples were taken in March, April and May of 2011 as well.
DNR first informed the city it would have to chlorinate permanently in April. But Bovey, who oversees water and sewer for the city, and other city officials continued to search for the source of contamination and believed an altitude valve in a valve pit near the standpipe may have been the source.
The city received water from PWSD in June that had tested positive for coliform bacteria, delaying its ability to test if it had solved the problem.
“I don’t see why we have to chlorinate, but we do,” Wyatt told the Board of Aldermen during last Thursday’s work session.