Evanston opened its lakefront water plant for tours on Saturday that gave a few dozen residents a chance to see how the facility that’s been pumping filtered water for a century operates.
The most dramatic part of the tour came when Utilities Director Dave Stoneback took a walk along the edge of one of the large filter basins and, over the sound of rushing water, described the process of cleaning out the filter.
“Normally water flows down through the filter media and particles get stuck to the filter media,” Stoneback said. “During a filter wash, water is pumped up through the filter media to remove the debris that attached to the filter media.”
Before that, tour participants got a classroom history lesson on evolution of water service in Evanston — from the first pumping station built shortly after the 1871 Chicago fire, through the addition of filtration and chemical treatment to end epidemics of typhoid and cholera in the early part of the last century, and continued expansion as the city grew and came to serve other suburbs to the west of Evanston.
There were artifacts from the past to look at — including a section of wooden water pipe first used in Evanston and then reused in a village in Alaska.
And a chance to see the massive blue high-lift pumps that send treated water out into the distribution system, supplying water to Evanston, Skokie and the Northwest Water Commission.
At the other end of the process giant green low-lift pumps raise untreated lake water 15 feet into the rapid mix basin where the treatment begins.
Water then flows by gravity through the treatment process to the high lift pumps.
Both sets of pumps are normally powered by electric motors, but have natural gas engines for backup use in the event of a power failure.
Stoneback says Evanston’s plant is the third largest in Illinois, after two much larger plants operated by the City of Chicago. Most other communities along the Lake Michigan shoreline have their own, smaller water treatment plants.