A Midwest US commercial bakery operated an evaporative condenser whose film fill and open basin sat directly above the production area. Yeast, sulfate-reducing bacteria and biofilm had taken over the system, exposing products, ingredients and staff to drift and droplets — including potential Legionella risk. Previous treatment programs had failed to bring it back.
Severe biological contamination in the evaporative condenser — yeast, sulfate-reducing bacteria and entrenched biofilm — in a system whose film fill and open basin sat inside the baking production environment. Drift and aerosol droplets from the system were exposing products, raw ingredients and personnel below.
Multiple prior water treatment programs had failed to achieve biological control. The system had not responded to standard biocide approaches.
The facility faced compounding risks: product recall exposure (FDA/USDA), OSHA regulatory exposure for personnel, and Legionella liability — with the production environment directly beneath the contaminated system.
Conducted biological analysis and biocide effectiveness study to determine which treatment approaches could achieve control given the entrenched contamination profile. Designed monitoring and control program.
Coordinated and executed a planned 3-day weekend shutdown for combined mechanical and chemical cleanup: fully drained the system and vacuumed out approximately 2 feet of accumulated biological material from the basin.
Circulated hydrogen peroxide with dispersant, dual biodispersants, and quaternary ammonium biocide — maintained until ATP readings dropped below 30 RLU throughout the system.
Refilled the system on a safer non-phosphate chemistry program. Coordinated installation of new evaporator panels and wall panels to physically isolate the unit from the production environment, eliminating the drift pathway.
Independent Legionella risk assessment and cooling water program review for commercial facilities, food production, healthcare and institutional buildings. No chemistry sold.