Comments on the Initial Project Description (IPD)

To: Impact Assessment Agency of Canada (IAAC)

Project: Proposed Wesleyville Nuclear Generating Station

*Date: May 4 2026

Organization:Lake Ontario Waterkeeper (a program of Swim Drink Fish Canada)

Statement of Interest

Lake Ontario Waterkeeper (LOW) represents a community of people dedicated to a Lake Ontario that is safe for swimming, drinking, and fishing. As the Wesleyville site sits directly on the northern shore of Lake Ontario, any proposed development represents a significant potential impact on the water quality, aquatic habitat, and the 9 million people who rely on this lake for drinking water.

2. General Objection: Prematurity of the Assessment

Lake Ontario Waterkeeper supports the position that this environmental assessment (EA) is premature. An Impact Assessment cannot be meaningful if the proponent, Ontario Power Generation (OPG), has not defined the fundamental technology being proposed.

The Initial Project Description (IPD) currently lacks details on the specific nuclear technology This technology-neutral approach makes it impossible for the public to evaluate:

Water Intake and Thermal Discharge: Different technologies have vastly different cooling requirements. Without specifics, we cannot assess the risk of "thermal plumes" or the impingement and entrainment of fish populations in Lake Ontario.

 Radioactive Effluent Profiles: Each reactor design carries unique risks regarding the types and volumes of radioactive tritium or other isotopes that may be released into the lake during normal operations or in the event of an accident.

3.  Key Areas of Concern for Lake Ontario

We urge the Agency and the Joint Panel to require OPG to address the following water-specific gaps before proceeding:

 Cumulative Effects on Lake Ontario: The Wesleyville site is situated in an area already stressed by the Darlington and Pickering nuclear stations. We require a cumulative impact study on how a third massive facility will affect the localized aquatic ecosystem, specifically regarding heat pollution and baseline radiation levels in the water column.

 Waste Management and Shoreline Integrity: The long-term storage of nuclear waste at the shoreline poses a generational threat to Lake Ontario. OPG must provide a clear plan for how waste will be shielded from climate-change-induced lake level rises and extreme weather events.

 Emergency Planning for Drinking Water: Lake Ontario provides drinking water for the Greater Toronto Area and beyond. The IPD fails to detail how a severe accident would affect municipal water intakes and what mitigation strategies exist to prevent a total loss of drinking water for millions.

4. Recommended Next Steps

Lake Ontario Waterkeeper recommends that the Agency suspend the progression to the Guidelines phase until OPG provides a supplemental Project Description that:

 1. Identifies a specific technology or a narrow range of technologies.

 2. Provides detailed modeling for water cooling and thermal discharge impacts.

 3. Outlines a comprehensive public engagement strategy that specifically targets downstream water users and shoreline communities.

Conclusion

A project that aims to be "the largest in the world" cannot be reviewed in a vacuum of information. Transparency is the bedrock of the federal *Impact Assessment Act*. We look forward to participating in the upcoming public hearings, provided that the necessary technical data is made available to the public.