Program Overview

Columbia Water is investing millions in improving and upgrading its water and sewer infrastructure. Smoke testing is an important tool in identifying areas where the sanitary sewer system is leaking and needs to be repaired.

How It Works

Smoke testing is one of several techniques that can identify cracks and illicit connections to the sanitary sewer system. They might come from:

  • Actual cracks in the sewer line
  • Defective sewer connections
  • Illicit cross‐connections with storm drains
  • Building connections without proper traps or plumbing

A section of sewer line is blocked off, and a blower pumps the special smoke into a manhole. Crews look for smoke coming out of the ground, buildings, manholes, stormdrains, and any other places that might indicate a problem with the sewer line. These areas are flagged for further examination and repair.

If the sewer line is in good condition and there are no problems to be fixed, the only places smoke should exit are sewer vent pipes. Any other places that smoke escapes indicate a problem with the sewer system in that area.

Impact on Customers

When City staff or contractors plan to do smoke testing in an area, they will notify customers with door hangers and phone/text/email alerts for people who have signed up.

If you are notified about upcoming smoke testing, make sure to run all of your faucets briefly so water is in all of your traps. If your plumbing is in good working order, this should prevent smoke coming into your building. If smoke does enter your building, there may be something wrong with your plumbing. See Sanitary Sewer Smoke Testing Fact Sheet for more details.

Columbia Water is also notifying customers if smoke testing reveals a problem with their private sewer lateral line. See Understanding Your Sewer Lateral for details.

Is the smoke harmful to people?

No. The “smoke” is not really smoke. It is a non-toxic, non-staining, and odorless mist. Smoke testing using this mist has been endorsed by the U.S. Environmental Protection Agency for more than 20 years as a good way of identifying sewer problems in need of repair.

For most people and pets, this smoke may make you cough but should pose no other hazards. However, individuals with respiratory problems like asthma, emphysema, or other respiratory conditions should avoid direct exposure to the smoke. If someone in your household has a respiratory condition, contact the number on the door hanger to discuss your situation in further detail.

What about pets?

If your pets stay inside during the day, and you are concerned about smoke entering your home, you may want to open your windows. If your pets have a respiratory condition, you may want to make other arrangements for their boarding while the smoke testing occurs.

Is the smoke a fire hazard? Will it set off my fire alarm?

The “smoke” is not a fire hazard. However, it can set off your fire alarm. To dissipate the smoke, open your doors and windows.

If you believe the smoke in your building is from a fire, call 911 immediately.

How does smoke testing work?

A section of sewer line is blocked off, and a blower pumps the special smoke into a manhole. Crews look for smoke coming out of the ground, buildings, manholes, stormdrains, and any other places that might indicate a problem with the sewer line. These areas are flagged for further examination and repair.

If the sewer line is in good condition and there are no problems to be fixed, the only places smoke should exit are sewer vent pipes. Any other places that smoke escapes indicate a problem with the sewer system in that area.

Because the pipe is blocked off at both ends, smoke will only flow into the section of pipe being tested and the plumbing from any buildings hooked into that section. No other sections of the sewer system or connected plumbing will be affected.

What should I expect with the smoke test?

If your plumbing is in good condition and there is water in all of your traps, you should not have smoke enter your house. It may come out of your roof vent. Sometimes sink traps on faucets that have not been used in a while will allow smoke to enter a building.

To prevent this, make sure to run water through all of your faucets for at least 30 seconds before the smoke testing starts.

I filled all of my drain traps, but smoke still entered my building. What should I do?

If you believe the smoke in your building is from a fire, call 911 immediately.

If you believe it is from the smoke testing, this means there is a problem with your plumbing somewhere that could be letting sewer gases inside. This can be caused by:

  • A leak in your plumbing
  • A sewer vent that vents to your attic or inside your building
  • A faulty seal like in your toilet’s wax ring
  • A missing sink or drain trap

If this happens:

  • Open your windows and turn on any ventilation. The smoke should clear within a few minutes.
  • Call the number listed on the door hanger you received notifying you of the smoke testing. The City will address any problems with City lines that may have caused this.
  • You may also want to have someone you trust look at your plumbing. The City is not responsible for problems with private sewer lines that may have caused this.

Does Columbia Water notify people in the area before doing a smoke test?

Yes. The City or its contractor notifies residents and businesses that sanitary sewer work will be going on in their area at least 24 hours before work starts.

Can I get a copy of the Material Safety Data Sheet?

Yes. Contact the number on the notification statement you received to obtain a copy of the MSDS for the sewer testing smoke product used in your area.

I have more questions that were not answered here.

Contact the number on the notification statement you received first. If you need additional help, contact +1 (803) 545-3300.