The DuPage Water Commission, which has its headquarters in Elmhurst, is the largest wholesale provider of Lake Michigan water in the state.
Daily Herald file
Residents of suburban communities receiving Lake Michigan water directly or indirectly from Chicago might see a change in the way the water looks.
A change in the city’s water treatment process that began last week should ultimately result in a long-term benefit to consumers, but could cause a temporary “discoloration” of water, authorities say.
Chicago water department officials said there is a slim chance of seeing the discoloration, which most likely will appear as cloudiness. They also emphasize there will be no change in water quality. It remains safe to drink, bathe in and cook with.
In a move affecting more than 120 suburban communities, Chicago is switching from using blended phosphates to orthophosphates.
Phosphates form a protective barrier between plumbing fixtures and water, preventing metals, including lead, from leaching into the water supply, according to a statement from Mount Prospect.
The use of orthophosphates should further reduce lead levels in drinking water for people with lead service lines or plumbing components containing lead, the village states.
Patrick Schwer, Chicago’s director of water quality surveillance, said the change also will control corrosion of galvanized pipe or cast iron pipe.
But Schwer warned people might see minor discoloration during the transition period.
“We’re just cognizant that when we make water chemistry changes, things that we do not expect can potentially happen,” he said. “So I’ve been very transparent to all of our suburbs and to all our folks here, just to keep vigilance on any potential issues that might be popping up. We want to make sure that people have confidence in the water.”
The transition is expected to take several months, officials said.
“There may be a bit of cloudiness. That is my understanding from discussions with the city,” said Chris Bostick, manager of water operations for the DuPage Water Commission.
The water remains safe, despite the temporary aesthetic change, officials note.
Bostick recalled what happened when communities made the switch from well water, which is high in iron content, to Lake Michigan water in the 1990s.
“The pipes had a lot of iron inside,” he said. “A lot of that iron content would break off from the mains.”
In that instance, municipalities had to flush their water mains to remove the flaked off iron particles.
Some communities like Mount Prospect have advised residents to contact their public works departments if they see an actual change in the color of the water, as that may indicate another issue.
Chicago sells directly to such communities as Des Plaines, Park Ridge, Rosemont and the DuPage Water Commission, which is the largest wholesale provider of Lake Michigan water in the state and provides drinking water to most of DuPage County.
Additional information about Chicago’s transition to orthophosphate treatment can be found on the city of Chicago’s website.
