Mannheim Water Treatment Plant Upgrades to Sidestream Injection

The Mannheim Water Treatment Plant (WTP), part of the Waterloo Region water system, treats water from the Grand River and provides 20–25% of the drinking water for the district.

The treatment process uses ozone to primarily remove taste, odor, and color compounds. The ozone also effectively breaks down previously injected polymers and improves UV transmittance (UVT). The ozonation step is followed by granular activated carbon filtration, UV and chlorination. The resulting disinfected water is then mixed with groundwater from nearby wells and stored or distributed to residents.

The existing ozone dissolution system installed at Mannheim utilized fine bubble diffusers (FBD). Due to the system’s inefficiency, the plant was limited in its ability to apply the desired levels of ozone to the water because ambient ozone alarms would occur when the applied ozone dose was increased past a certain point—forcing the plant to shut down and all personnel to evacuate the filter/ozone area until the ozone sufficiently dissipated.