Why Davenport Wants to Protect Its Wastewater Treatment Plant

Sep 17, 2019

This year's Mississippi River flood was the worst on record in the Quad Cities. 

A broken levee in downtown Davenport got the most publicity, but as Zach Wilson reports, as Davenport's Flood Task Force prepares for future floods, protecting the wastewater treatment plant is the top priority.


During the spring flood, Davenport Public Works employees had to work long and hard to make sure the sewage plant ran smoothly. 

Davenport owns and operates the facility, but it also serves Bettendorf, Riverdale, and Panorama Park. That means 140,000 people rely on it at home, work, and school. 

The plant removes waste from sewage water and then puts the clean water back into the Mississippi River.  

A whiteboard at Davenport's wastewater treatment plant explaining what the plant does.
Credit Zach Wilson, WVIK News

Water Pollution Control Plant Manager Dan Miers explained that the multi-step process includes microorganisms breaking down the waste in a special tank. Gravity is also part of that process; the holding tanks are lined up to filter and drain the wastewater naturally, with each one slightly below the last in elevation. 

The problem is the elevation of the Davenport wastewater treatment plant. It's only slightly higher than the Mississippi River. 

Miers says if the river gets too high, the holding tanks might be inundated, along with several buildings at the plant.

"We got to about 22.7 feet of flood water out in the river. We were probably about a foot and a half from the buildings being inundated here at the plant. We would have had to have done some protection measures and gotten the employees out."

The water was high enough that roads to the plant were flooded and impassable. But sewage treatment is an essential public service, and Davenport had to keep it running.

"We had the employees locked in the facility for about eight days because there was no access in or out of the plant. So they stayed here and operated the plant, and we maintained operations the entire time."

Talk about going above and beyond the call of duty.

The plant's employees slept in cots and ate meals in a makeshift kitchen. Miers was ready if the river rose even higher.

"I have a plan set out. If we get to 23 feet we start activating cleaning up our basement and getting things higher: we start preparing. In preparation, once we get to 23.5, we're gonna say, 'alright now we need to prepare for 24 feet.' We're gonna go ahead and work towards shutting down the plant and getting employees out of here."

In the Illinois Quad Cities, Greg Pyles manages Moline's wastewater treatment plant on the Rock River. He says they also have concerns.

"Flooding is a huge issue along with the environmental conditions that we're in. And, the wastewater is coming one way or another and you don't want that water to enter the receiving stream, it's a public health hazard."

Now that river flooding happens in the Quad Cities more frequently, cities are under pressure to increase protection of their sewage treatment plants, especially in Davenport.

One of the Davenport plant's "clarifiers."
Credit Zach Wilson, WVIK News

The question is, how? How much will it cost, and where will the money come from?

Davenport City Engineer Brian Schadt says there isn't a clear solution, and city officials have only just started thinking about it.

"I wish I had a good answer for that right now. There's no real good one answer. We really need to look at this from an engineering perspective and treatment perspective, make sure we have the ample contact time through each part of the plant, then be able to remove that treated flow and get it out."

In the meantime, Schadt says Davenport will study what preventative measures other plants around the country have put in place, and work with consultants to determine the best course of action.