Keokuk Municipal Waterworks is confident the upgrade of the filter system at the water plant will improve the quality of drinking water without significantly hiking water rates.
General Manager Andrea Rogers said the plant has been gradually shifting from a sand-filter system to a system of plastic membrane filters. She described the membranes as similar to "camping straws, taking out the really, really small stuff."
Rogers said the water that Keokuk residents drink every day comes directly from the Mississippi River so it is a lengthy process to prepare the water for daily consumption. She said the water is softened to remove “the grit” found in the river before it is treated with chemicals and carbonated.
Rogers said one of the final steps in the process is the filter system that will be upgraded. She said the filters help address turbidity, which is the amount of material in water.
“The lower the turbidity, the better the water is,” said Rogers. “By drinking water standards, it has to be a 0.3 turbidity to leave the plant. Our sand filters usually get down to a 0.1. These membrane filters usually get it down to a 0.05.”
Rogers said the average resident will not notice a difference in the taste, even with the improved filtering process.
Rogers said the $6 million project will include an upgrade of one existing membrane filter and the addition of two new membrane filters. She said that would allow the plant to fully shift away from the sand-filter system, which would essentially be used as a back-up system moving forward.
Rogers said Keokuk Municipal Waterworks will not have to do a special rate hike to pay for the upgrade. She said monthly water rates have been increasing by roughly 4% every other year for quite some time.
Rogers said the last increase was in July 2018 and the next is scheduled for July 2020 with nothing planned in-between. She said a roughly 4% increase would be less than $2/month to the average user.
Rogers said service interruptions are not anticipated during the upgrade, which should get underway later this year. She said the project will take several years to complete.