Smoke Testing FAQs


  1. Why is the City smoke testing?

    “Smoke” testing is a commonly-used method to evaluate sewers, identify failed sanitary sewers, and locate connections between sanitary and storm sewers.  The purpose of smoke testing is to find potential points of inflow and infiltration from storm water or ground water that could lead to high flows during rain events. Smoke testing can also help locate the following:

    • Buildings that have downspout, cellar, yard or basement drains, and sump pumps
    • Points of groundwater or storm  water intrusion into the sewer
    • Any cross connections  between sanitary sewers and storm drains
    • Defective sewer connections that could allow sewer gases into a building

    Sanitary sewer systems are designed to collect residential sewer flows and can be overwhelmed by storm sewer flows infiltrating the system creating problems for residents and the City Operations.

  2. How does smoke testing work?

    This testing is performed by blowing a harmless vapour into a sewer. The “smoke” is not a real smoke, but rather a mist containing a large percentage of moisture. It is highly visible at low concentrations. The smoke is expected to exit from manholes, the sewer stack at the top of your house, catch basins and downspouts.

    The City of Courtenay will deliver notices to buildings within the area of testing and will inform the local fire and police departments of where they will be conducting smoke testing each day.

    Smoke may be seen coming out of the ground, manholes, or sewer stacks and gutters on homes and businesses.  Smoke coming out of the ground may indicate a break or other defect in the sewer line which allows smoke to escape up through the ground.

    For instance, if smoke permeates up through a yard, it indicates breaks in the sewer line. Only enough force to overcome atmospheric pressure is required, and smoke should escape from building sewer stacks.

  3. Can smoke enter my house?

    It is possible, although rare, that smoke could enter a residence through a drain trap which has dried out or some other plumbing defect such as an un-trapped washing machine drain.  Some smoke may enter your home or place of business if the:

    • Vents connected to your building's sewer pipes are inadequate, defective, or improperly installed.
    • Traps under sinks, tubs, basins, showers and other drains are dry, defective, improperly installed, or missing.
    • Pipes, connections and seals of the wastewater drain system in and under your buildings are damaged, defective, have plugs missing, or are improperly installed.
  4. What should I do if smoke gets into the house?

    • Do Not Become Alarmed
    • Open windows to allow ventilation and note the location of the smoke emission; smoke will clear within a few minutes
    • Exit the building and notify smoke testing personnel in the area.
  5. If the smoke vapour is not harmful, why do you recommend evacuating the structure?

    We recommend evacuating as a precautionary measure in case the smoke is due to a real fire rather than a test, and also since smoke in your house from this test indicates other sewer gases may also be entering the building.

  6. If the testing smoke enters my home should I investigate the matter further?

    All residents are advised that if traces of this smoke or its odor enter your house or building, it is an indication that gases and odors from the sewer also may enter. These can be both unpleasant and dangerous, as well as a health risk to the occupants.  The City recommends that you investigate and correct the problem to minimize any potential risks.

  7. What happens if the inspection crews find a faulty sewer or lack of water traps in a home?

    If smoke is seen within a house or structure, our crews will attempt to notify the homeowners of these potential defects. Owners will be responsible for repairs to private property plumbing.

  8. How long will the smoke testing take?

    While crews might be in your area for a few hours, each actual smoke test setup takes approximately 15 minutes to complete. Most houses will only be within the testing area for one or two tests.

  9. What can I do to prepare for smoke testing?

    When you receive notice that smoke testing will take place, you could pour approximately ½ liter of water into your floor drains in basement floors & run a small amount of water into any sink, bathtub or other fixture that may have not been used for a long period of time.

    If there is an individual in your home or business who has respiratory problems and/or mobility limitations, or if you have any additional questions, contact City of Courtenay at 250-338-1525.

  10. Do I have to be home during testing?

    No. Inspection crews will not need to enter your home unless smoke is present and you want them to help identify the defect.  You are not required to allow entry to our crews.

  11. Why can’t you tell me in advance exactly what date my home will be tested?

    This testing cannot be conducted during rainy periods or very windy conditions, so it can sometimes be delayed. Also, other activities in the project may take less time than anticipated, so it can sometimes be sooner than expected.  The schedule may also shift if more or fewer defects than expected are located and need to be documented.

  12. Can the smoke testing activate the smoke alarms?

    Yes, smoke alarms may be activated during smoke testing. If possible, open windows and/or doors for ventilation. If you have any doubts about the origin of the smoke, please notify smoke testing personnel in the area.

  13. Can smoke plug the sewer?

    There is no way smoke can plug the sewer. The smoke is made up of a vaporized substance.

  14. Where does the smoke appear?

    In nearly all cases, smoke will be seen coming from sewer stacks in the roof, building foundations, manhole covers or yard cleanouts. Smoke coming from sewer stacks of homes is a normal occurrence and indicates to the crews that smoke has filled all sewers and the plumbing in the home is working correctly.

    If you have any additional questions please call the City of Courtenay at 250-338-1525.