Smoke Testing of the Sanitary Sewer System

The City of St. Catharines has retained GEI Consultants Canada Ltd., and 3BP to complete smoke testing in select areas of the city. Smoke testing is a first step to identifying connection points for roof downspouts, catch basins, and other water inlets to the sanitary sewer or storm sewer. This is a proactive approach to confirm that the health of the network as a whole is in good working order with respect to mitigating additional rainwater flow into the sanitary sewer system. This work will not explore any other plumping issues on private properties.

The next phase of smoke testing is scheduled on weekdays  from Tuesday, June 2 to Friday, June 5 from 8:30 a.m. and 4:30 p.m.

Click the date below to view the resident notice and map for where smoke testing will be taking place.

• May 19-25, 2026
• May 25-29, 2026
• May 28 to June 5, 2026

Smoke testing will only be conducted once on City streets, and should be completed within two hours. Residents in areas where smoke testing is scheduled will receive notices ahead of the start of testing for smoke testing. Dates, times and locations will also be posted on this webpage and on the following City social media channels:

• Facebook
• Threads

What is Smoke Testing?

Smoke testing consists of blowing smoke into the sewers and canvassing the area above ground to document locations where smoke is observed (e.g. from catch basins). The smoke used for this test has no odor, is not harmful to your health, and will disappear within minutes.

What do residents need to do?

• Check to see that all plumbing traps under sinks, washing facilities and floor drains have water in them. Pour a few cups of water into your basement floor drains, and any sinks, showers, or other plumbing fixtures before smoke testing starts.
• If smoke enters your home and you experience smoke irritation, please leave the affected area immediately and the irritation will quickly subside.
• If you, or any member of your family have a health condition that you feel we need to be aware of please contact the City’s project manager at 905.980.6963. .

The fire department will be notified of the streets being tested. If you have doubt about the origin of smoke, always contact the fire department at 911, or non-emergency communications line at 905.684.4311 and they will determine if the smoke is related to the testing or if the fire department needs to be dispatched.

Frequently Asked Questions

Is this smoke harmful?
No. If the smoke enters your home, it may make you cough, but it is not harmful to your health and will not harm pets, clothing, draperies or furniture.

What should I do to prepare for smoke testing?
Ensure all plumbing traps have water in them as soon as you receive this notice. To do so, pour a few cups of water down drains, sinks, washing facilities and floor drains. You may also wish to leave a few upstairs windows open a small amount, if you feel safe doing so during the testing period.

Do I need to stay home for the duration of the test?
No, you do not need to be home when testing is being performed.

What is the purpose of smoke testing?
The purpose of the testing is to find potential points where storm water enters sanitary sewers.

What does it mean if smoke enters my house?
It might mean there are deficiencies in the plumbing that may also allow sewer gas to enter your home. The common cause are dry pluming traps that allow smoke to enter.

What should I do if smoke enters my house?
If smoke does enter your home, note the location of the smoke, pour some water down the drain and open windows for ventilation. Contact the Field Inspector, Dyllan Gallant, at 905.984.7957, and he will visit your address.

If smoke gets into the house, how long does it take to dissipate?
The smoke will dissipate in a few minutes. Open windows for ventilation.

What is next?
You will be contacted only if we find something to report or inform you about.
On the day of testing in your area, please contact the Field Inspector, Dyllan Gallant, at 905.984.7957 if needed.