The Ontario government is nixing plans made by York Region to develop a sewage solution that would ultimately discharge into Lake Simcoe, in favour of a new course of action that would see the waste re-routed to the plant a Dufferin Creek at less than half the project cost.

The government announced on October 25 that it will cancel plans for the Upper York Sewage Solution, which would have directed wastewater from Newmarket, Aurora and East Gwillimbury through a treatment plant and into Lake Simcoe. In its place, it will introduce the Supporting Growth and Housing in York and Durham Act – new legislation that would direct the waste to the Dufferin Creek plant, which is co-owned and operated by York and Dufferin regions.

The decision, it said, was based on recommendations prepared by the York Region Wastewater Advisory Panel. The panel judged expansion of infrastructure at Dufferin Creek to be the most effective option available.

“Expansion of this shared critical wastewater infrastructure for York and Durham Regions is needed to support their significant population housing, and economic growth. Our government is proposing a solution that ensures the most robust wastewater treatment as these communities continue to grow,” said Environment Minister David Piccini. “The Duffin Creek treatment facility is one of the best performing wastewater facilities in the province that ensures the protection, enjoyment and welfare of Lake Ontario, shoreline communities and nearshore areas."

The Duffin Creek treatment facility is one of the top performing wastewater treatment plants in Ontario, achieving world-class standards for high quality treatment, phosphorus control and protective measures for the surrounding environment and watershed, with a capacity to process 630 million litres per day.

The facility currently operates at approximately 50 per cent capacity. The new proposal would add an additional 12 per cent to the current flow levels, meaning it has the capacity to ensure every litre of water the plant receives gets high quality treatment.

Over the past 25 years, governments at all levels have invested more than $850 million in the plant, making it one of the best performing treatment facilities on the Lake Ontario shoreline. Phosphorous limits at the plant are significantly lower than those at other wastewater facilities in Ontario and will continue to be reduced as the facility implements additional upgrades between now and 2030.

In parallel with this initiative, the province says it continues to make multi-million-dollar improvements to wastewater and stormwater infrastructure, investing in the latest technology for real-time wastewater monitoring. In January 2022, it invested $15 million to build, upgrade and rehabilitate storm and wastewater infrastructure in the Lake Ontario basin. This includes optimizing plants, improving local sewer systems and investing in green infrastructure. The Regional Municipality of Durham is receiving $836,590 through this program which will help improve water quality in Lake Ontario.

Ontario also invested $6.3 million in 51 projects to protect and improve Lake Ontario. This includes projects under the Canada-Ontario Agreement Nutrients Annex commitments focused on the Lake Ontario basin and science/monitoring projects. In Durham, this includes monitoring exit loads of phosphorus to Lake Ontario from tributaries, monitoring nutrient and weather event discharges from tributaries, quantifying nutrient loadings and determining internal phosphorus loading in western Lake Ontario coastal wetlands.