Davenport is moving forward in the long process of replacing critical water control equipment through fiscal year 2029, which will cost the city an estimated $51.4 million.
City Engineer Brian Schadt for Davenport says the pollution control plant digesters were installed in the early 1990s and are now reaching their end of useful life in the plant.
"Your wastewater comes in and our plant treats, Davenport, Bettendorf, Panorama Park in Riverdale. It comes in, it goes through a couple of screening operations. Basically takes anywhere from rags, bottles, anything people flush that they shouldn't be flushing," Schadt said in a phone interview with WVIK on Thursday.
Schadt says the second stage of the water pollution
control process is taking out everything down to cigarette butt size. Followed by sand, grit, et cetera.
"And then it's settled anything organic that can settle out, does that water moves on, where we start introducing aeration, and basically the microorganisms which break down that wastewater from there, it gets filtered out. The water moves on and is disinfected with ultraviolet light and placed back out into the Mississippi River. The sludges are either recycled or returned to keep the bugs happy, essentially, or once we get so much it's actually wasted," Schadt said.
He says that's what goes into the digesters, which is the component that they're working on. Those have heat and mixing and a different type of microorganism. It makes that sludge safe so they can use it in compost, and then it also produces methane.
That methane is used to run electric generation, which powers the plant, and they sell some back to Mid-American.
Schadt says the digesters should cost around $28 million, and the incoming bar screen, which filters out trash, should cost around $5.3 million.
According to Schadt, the city is considering using sewer cash reserves for equipment replacement and considering using equipment replacement funds from sewer fees.
"We're working through getting a consultant right now on board so we can start the design process of the digesters. We'll follow shortly on with the design of the bar screen," Schadt said. "But with those digesters, once we get them involved, there's a design process. We have to go through the Iowa DNR and obtain permits, and then it's going to be a fairly lengthy construction schedule by the time we obtain the parts, the mixers, the electrical needs, things like that."
He says the lead time for equipment replacement has increased since the pandemic started, and it'll take time.
"It's been around for a while. So we definitely have operation and maintenance needs that we've been taking care of through the years, but it serves a large portion of the Iowa side of our community here," Schadt said.
A staff of 31 employees works 24/7, maintaining the efficiency of the water pollution control plant. The plant serves a population of 141,347 and is one of the largest regional treatment facilities in Iowa.
