City of Thunder Bay Leaking Pipes Class Action

Roy O’Connor LLP has issued a proposed class action lawsuit against the City of Thunder Bay for damage alleged to be caused to pipes and plumbing systems following the City’s introduction of sodium hydroxide into the municipal water supply. The damage alleged includes what are described as “pinhole leaks” in the plumbing, the significant costs to repair the leaks, and the resulting damage from the leaks.

The proposed class action seeks compensation totaling $350,000,000 to cover the thousand or tens of thousands of residents, businesses and other operations whose pipes and plumbing systems were damaged or, are at risk of damage and failure, by the City’s introduction of sodium hydroxide into the water supply years ago. Following complaints and concerns being raised, the City discontinued the use of sodium hydroxide earlier this year.

The Plaintiff’s statement of claim alleges that, among other things, the City owed legal duties to the proposed class members (including individuals, businesses and other organizations supplied with water from the City) to ensure that the water supply did not unnecessarily corrode their pipes and plumbing systems. The statement of claim alleges that the City breached those duties through the introduction and use of sodium hydroxide into the water supply. The statement of claim further alleges that the City had more reasonable, prudent and appropriate alternatives (other than the introduction of sodium hydroxide) that were readily available to address any concerns that the City had about the potential leaching of lead in plumbing systems in a subset of local properties. The Plaintiff’s allegations have yet to be proven in Court.

Next Steps

The Plaintiff is moving for the certification of this action as a class proceeding.

A Class Action Case Management Judge has been appointed to oversee this action.

The City of Thunder Bay has appointed legal counsel and served a Notice of Intent to Defend.

The Plaintiff served her motion record in support of certification on February 18, 2022. The City of Thunder Bay is served its responding record in August, 2022. In March 2023 the hearing of the certification motion was adjourned. The hearing of the certification motion is now scheduled to proceed on June 14 and, if necessary, June 15, 2023 at 10:00 am.

While the hearing is proceeding by Zoom and is open to the public, it is still an official proceeding of the Ontario Superior Court of Justice and similar rules that apply to attending an in-person hearing apply to a Zoom hearing. To watch the hearing:

  • 1. Please log into the Zoom stream below by 9:45 am on Wednesday, June 14, 2023;
  • 2. Please log in with your real name and make sure that your camera and microphone are turned off; and,
  • 3. Please do not record the hearing as it is a criminal offence to record a Superior Court hearing in Ontario.

To Join the Zoom Hearing:
Click Here for Zoom Hearing Link
Meeting ID: 610 2410 7135
Passcode: 703715

Additional updates will be posted on this site as the case develops.

Register For More Information

If you believe that you may be a class member in this proceeding and wish to receive information from time to time about the status of the lawsuit, you may request such information by filling in the form found at: The Registration Page

More Information

For more information please contact James Katsuras at:


Phone: 416-362-1989
Toll Free: 1-888-303-5033

About Roy O’Connor LLP

Roy O’Connor LLP - Roy O’Connor LLP has been recognized in peer reviews as one of Canada’s leading boutique litigation firms and leading litigators in class actions. Among other things, Roy O’Connor is Benchmark Canada's (a guide to Canada's leading litigators) three-time winner of its award for Plaintiff’s Firm of the Year in Canada (2013, 2015 and 2017). For more information about Roy O’Connor, its lawyers and their experience please see our main site.‎