Smoke Testing FAQ

During the testing process, a harmless, non-toxic artificial smoke is injected into sections of the sewer system to see where it surfaces. In a properly functioning system, the smoke will exit through places such as manholes and plumbing vents on rooftops.

If there are leaks or improper connections, the smoke will find the defected area and escape through the break.

It is not unusual to see plumes of smoke rising from peculiar places, such as cracks in the street or in residential yards during smoke testing. This is normal during smoke testing and helps crews identify areas that need further investigation or repair.

Before this work begins, residents should pour water into floor drains, sinks, tubs, showers, and toilets, especially those that are rarely used.

The water contained in the plumbing traps create a seal that helps prevent the harmless test smoke from entering the home.

Areas that are used infrequently, such as basement floor drains, utility rooms, garages, or secondary bathrooms, are most likely to have dry drains. It’s important to ensure you pour water into these drains.

A sanitary sewer system is designed to carry wastewater to a treatment facility.

Smoke testing is one of the most safe and effective ways to assess the condition of our sewage infrastructure to ensure we continue maintaining a reliable system.

It helps us to identify and locate any existing issues within a sewer pipeline so repairs can be made, if defects are found.

During testing, you may notice white smoke coming from roof vents, escaping from manholes or catch basins, rising from the ground, residential lawns, green spaces, or street cracks.

These are normal signs that testing is underway and do not indicate a fire.

No. The smoke used during testing is non-toxic, non-staining product commonly used for sewer system inspections.

It is safe for people, pets, plants, clothing, furnishings, and property, and it does not create a fire hazard.

It is uncommon for smoke to enter homes. In homes with properly functioning plumbing, smoke should remain within the sewer system and exit through roof vents and manholes.

In the uncommon event that smoke enters your home, it is often due to a dry drain or another plumbing issue that may otherwise go unnoticed. The testing can help identify these conditions and provide an opportunity to correct them.

*See next question to know what to do if smoke does enter your home.

Smoke should not enter a home with properly functioning plumbing.

In the uncommon event that smoke enters your home, simply open windows and doors to allow ventilation; the smoke is harmless and will dissipate quickly. Contact Ed Power at 709.735.0151 so the source can be investigated.

Smoke entering a house is often caused by a dry drain trap or a plumbing issue that may otherwise go unnoticed. The testing can help identify these conditions, which also helps prevent sewer odours from entering under normal circumstances.

Yes. In the uncommon event that smoke enters your home, it may activate your smoke alarm.

If your alarm sounds during the smoke testing, first ensure there are no signs of fire. Do not assume it is related to testing. 

If the alarm was clearly activated by smoke testing and you are certain there is no fire, simply open windows and doors to ventilate the area. The smoke is harmless and will dissipate quickly.

Contact Ed Power at 709.735.0151 so the source can be investigated.

No. Residents do not need to be home while smoke testing is being conducted. The work is performed from the outside, and no one will need to enter your home.

No, there is no need for any concern. The smoke used during testing is harmless to pets.

In homes with properly functioning plumbing and with all drain traps sealed, smoke should not enter the home. However, you can place your pet in an area of your home that has no plumbing or leave windows slightly opened for good ventilation.

One of the most important things you can do to prevent this from potentially happening, is to pour water into floor drains, sinks, tubs, showers, and toilets, especially those that are rarely used.

*See question #2. How should residents prepare their homes?

Smoke coming from roof vents is normal and expected during testing. You may also see smoke coming from the ground, cracks in the street, catch basins, or residential yards. This is not unusual and is not a cause for concern.

Smoke seen in these locations help to identify areas that may require further investigation as part of the condition assessment. The location where smoke is visible is not always the location of a potential defect, as smoke can travel a distance underground before reaching the surface.

Residents do not need to leave their homes or avoid the area if smoke is seen outside. The smoke is harmless and will dissipate quickly.

If defects are identified through smoke testing, we will assess the findings and undertake any necessary repairs as part of our ongoing infrastructure maintenance program.