Project Background & Challenges

Located in the southeast corner of Iowa at the border of northwest Illinois, Fort Madison is seated right on the Mississippi River. In addition to being famous for their Tri-State Rodeo, Mexican Fiesta, and Annual Lighted Parade, they are also a crucial location for ConAgra’s Packaged Foods and their processing plant. Primarily a canned meat facility with Vienna Sausages being the highest volume of 1.5 million cans in 24 hours; this plant produces many other canned products like chilis, beef stews, potted meat, dried beef in a glass jar, plus other bean products. The lagoon aeration-based wastewater treatment plant used by ConAgra, that also had EDI floating lateral system, was being constrained by the treatment capacity as ConAgra had been increasing production over the years. With their desire to treat BOD₅ and TSS regularly in supporting their environmental goals, anticipating additions to Iowa’s considerably strict wastewater effluent obligations including Nitrates in the future, and DNR request to have redundancy in the aeration system; the plant’s previously positive experience led them to calling EDI and SiteWorks® to take on this multistage aeration project.

The EDI Solution

The site added a DAF (Dissolved Air Floatation) unit (Phase I) to remove suspended solids, fats, oils, and grease from the production waste and an EQ system. For Phase II, the plant added a new round concrete basin which also included EDI Fixed Grid aeration with 372 factory-assembled FlexAir® Pro MiniPanel™ diffuser units – completed in 2021.

This additional “redundant” system allowed taking the old lagoon treatment system offline for an upgrade without hampering production. The final phase (Phase III) was to update the old lagoon system by removing the floating system and installing a new fixed grid system with 260 MiniPanel diffuser units with EDI’s proprietary PTFE-embedded MatrixPlus™ membranes. Each diffuser unit included two diffusers and EDI’s patented Spectrum Diffuser Mount.

Environmental Dynamics International (EDI) offered the FlexAir Pro aeration-mixing system for the ConAgra Fort Madison, IA facility, including all in-basin aeration components. EDI also offered the demolition, installation, and start-up services of the supplied in-basin aeration equipment by SiteWorks™, EDI’s construction division.

Site Construction

The EDI fixed grid system installation in the new ‘redundant’ tank was done within projected timeline. One of the concerns with upgrading the old lagoon was that the concrete basin would most likely be weak. Thus, it was proposed to pour new concrete strips under each lateral of the new system to ensure a good connection to the floor and proper anchoring. The massive amounts of sludge and debris in the bottom of the lagoon took much longer than expected to remove, thus pushing the project back into the cold of December. However, once the tank was drained and cleaned, it was revealed that the concrete was in great condition, and the site was able to save a significant amount of money as well as recover the time lost for sludge removal.

The existing header pipes in the plant would continue to be used for the upgraded Fixed-Grid basin (previous lagoon) as well as the new round basin. Coordination throughout the plant was crucial to install as much as possible in the former-lagoon before coring new outlets into the old header to reduce downtime.

Upgraded System Performance

The new aeration basin and the upgraded lagoon with now a fixed-grid aeration system are capable to treat 800,000 gallons to 1 million gallons per day. With the two fixed-grid systems now in place, the plant can take one basin offline for maintenance in the future without interrupting plant operations. Along with the system redundancy required by DNR, these two aeration systems also prepare the plant to continue to be in compliance with increased production at the plant and new regulations.

Ryan Daly, Manager, Engineering of this plant mentioned:

“Our experience has been good. Just like any project, there are always challenges that come up or things that are not noted and need to be addressed along the way. We had some challenges but were able to get through them very quickly. The team offered solid solutions to issues, and they held themselves accountable for issues on their side, and at the end of the day we turned out a great project.