OCWA piloting technology to reduce phosphorus in wastewater effluent

June 2, 2021

Elevated levels of phosphorus have long been an issue in many of the Great Lakes, particularly Lake Erie.

Phosphorus is an essential plant nutrient. However, when levels are too high, they can contribute to the formation of harmful blue green algae blooms that can lead to large-scale environmental problems.

OCWA is committed to protecting the health of the Great Lakes, from which many communities in this province source their drinking water. We support the key actions in the Canada-Ontario Lake Erie Action Plan to reduce phosphorus loadings to the western and central basins of Lake Erie by 40 per cent by 2025, by promoting adoption of innovative technology to reduce and recover phosphorous in municipal wastewater treatment and collection systems.

OCWA brought in partners, funding 

Our focus is on helping municipal clients find solutions to reduce the amount of phosphorus and other damaging nutrients from entering local water sources through wastewater effluent. While plant upgrades are sometimes necessary, our goal is to optimize existing wastewater facilities through process and technical changes whenever possible.

OCWA is working with clients like the Town of Kingsville, in southwestern Ontario, where we are piloting an innovative phosphorus reduction technology (RE300) at the local wastewater treatment facility. OCWA brought in Bishop Water as a project partner and helped the Town apply to the Ministry of the Environment, Conservation & Parks for funding through the Great Lakes funding program. The Ministry also provided technical advice.

Conventional chemicals costly

The Lakeshore West Water Pollution Control Plant (WPCP) in Kingsville discharges to the western basin of Lake Erie and consistently meets the facility’s total phosphorus effluent limit. However, the number of greenhouses in the area is growing and will generate more phosphorus for the WPCP to remove from wastewater.

There are several downsides to using higher amounts of conventional iron- or aluminum-based chemicals to remove phosphorus. It is costly, it could negatively affect the treatment process, and it results in excessive amounts of chemical sludge. Additional sludge production also means higher haulage costs and could require expansion or an upgrade of the plant’s solid and/or liquid treatment processes.

No plant upgrades required

Wanting to avoid the issues associated with heavier usage of conventional chemicals, OCWA and the Town worked together to explore other phosphorous removal options.

It was determined that a rare earth-based chemical composed of lanthanum and cerium called RE300 was the best solution for the Town. In use at more than 50 treatment plans in the United States, RE300 does not cause effluent toxicity and can be used with existing chemical dosing equipment – so there is no need to expand or upgrade infrastructure.

“We’re very pleased with OCWA’s work to bring forward this innovative phosphorus reduction technology for us to pilot,” says Andrew Plancke, Kingsville’s Director of Infrastructure & Engineering. “Phosphorus loading has been a focus for the Town because of the rising number of new greenhouses in the area. OCWA was very proactive, working with the MECP and the technology provider to develop and secure 100% funding to conduct a demonstration project. If the project is a success, RE300 would replace conventional ferric chloride and offset the need for expensive capital upgrades for the Town.”

Multiple benefits

There are other benefits. Unlike iron- and aluminum-based phosphorus removal chemicals, RE300 requires a lower dose. It does not produce as much chemical sludge, it improves sludge dewatering and it does not consume alkalinity or lower pH like other coagulants.

The RE300 pilot project began in early March and will run for a period of 12 months, with technical support from both OCWA and Bishop Water.

If the pilot is successful, RE300 could be a cost-effective option for Ontario municipalities to use in reducing phosphorus loadings and meeting effluent limit targets.

Is your municipality experiencing issues related to phosphorus loading? Contact your local OCWA representative to discuss a solution that is right for your needs.