Our Projects

The challenge. Kennett's three-cell aerated lagoon couldn't reliably meet Missouri's tighter ammonia limits in cold weather, when nitrifying bacteria slow down.

The upgrade. The Kennett Board of Public Works upgraded the plant to a 1.4 MGD design flow (1.8 MGD peak). Lagoon effluent now goes through a moving bed biofilm reactor (MBBR) stage, then disk filtration and UV disinfection. The new treatment train was required under the state permit from January 2021.

Compliance on the coldest day, not on average. Nitrifying bacteria slow sharply in cold water, and near freezing they nearly stall. Monthly averages can hide that dip, but fish downstream feel every day's ammonia. That's why water quality limits are set on a daily basis: the "D" in TMDL stands for daily.

CARMON FBX™'s role. The MBBR stage is outfitted with CARMON FBX™, designed to raise the water temperature from 0 °C to 5 °C at the full 1.4 MGD design flow. That's about 1.3 MW of heat, supplied by a natural gas boiler. The MBBR carriers scrub the heat transfer surfaces as they move, so the exchanger stays clean in lagoon effluent without chemical cleaning or shutdowns.

Results. The municipality meets its nitrogen numbers.

Project team. Owner: Kennett Board of Public Works. Design engineers: Bartlett & West, Triplepoint Environmental. Contractor: Zoellner Construction.  CARMON FBX™ technology and heating/exchange equipment: EcoVia Corporation.