Smoke Testing

Smoke testing is a standard practice used by wastewater utilities to locate points where rainwater and groundwater can enter pipes, leading to high flows in downstream pipes, lift stations and treatment plants during storm events.  

The test consists of RCM Utilities crew members systematically placing a blower, or fan, on manholes. The blower pushes non-toxic smoke through sewer pipes. Any location where smoke is identified during the test, except plumbing vent stacks, is a potential location where rainwater or groundwater can enter the sewer system. These locations are documented on maps and with pictures so that SJCUD personnel can return and eliminate these sources of rainwater and groundwater from entering the system.

The smoke is:

• Non-toxic
• Non-staining
• Non-flammable

The smoke should not enter the building but can if plumbing drains are dry or if piping in or under the house is defective. If smoke enters the building, you should leave the home until the smoke dissipates (approximately 15 minutes) and notify the work crew of the issue so the fault can be identified. 

* Any person with respiratory conditions such as emphysema or asthma should avoid exposure to the smoke. 

Smoke testing is the most cost-effective method for utilities to find sources of surface water inflow. Fast and easy to do, smoke testing produces immediate results that can be acted on quickly.  Smoke testing also helps identify plumbing leaks in buildings; sewer gases can cause health problems for building occupants.

Common points of sewer inflow include:

• Abandoned Sewer Lines
• Cross Connected Storm Lines
• Leaking Manholes
• Broken Laterals
• Roof Downspouts
• Yard Drains

Prior to beginning the smoke testing, SJCUD will give door-to-door notices to all homes and buildings on the streets to be smoke tested at least 24 to 48 hours in advance. Police and fire departments will be notified daily of work areas.

While crews might be in your area for a few hours, each actual smoke test setup takes approximately 10 minutes to complete. Most houses will only be within the testing area for one or two tests.

RCM Utilities personnel are uniformed and carry identification badges. Crew members operate from vehicles with proper signage for ease of recognition.

You will receive a door-hanger notification 24 to 48 hours prior to smoke testing in your area. When you receive notice, you need to prepare ALL drains (such as floor drains, garage sinks, etc.) by filling the p-traps with water:

• Run faucets for 60 seconds
• Fill floor drains with approx. 1 gallon of water
• Flush toilets

Since plumbing fixtures in your home or business are connected to the sanitary sewer system, there is potential for the smoke to enter the building if the drains are dry or not connected properly. This happens particularly under the following circumstances:

• The vents connected to your building’s sewer pipes are defective or improperly installed
• The traps under sinks, tubs, basins, showers and other drains are dry, defective or improperly installed
• The pipes, connections or seals in the wastewater drain system in and/or under your building are damaged, defective, have plugs missing or improperly installed

Finding these faults and correcting them is important to prevent sewer gases from entering the building. Sewer gases can cause health problems for building occupants. Corrections of such defects on private property are the responsibility of the property owner. A licensed plumber should be consulted to ensure the proper corrections are made.

Do not become alarmed. The smoke should not enter your building but, if it does, it will have a distinct odor similar to burning newspaper and will dissipate in approximately 15 minutes.  Exposure can be reduced by opening doors and windows until the smoke clears the building. Exit the building and notify smoke testing personnel in the area so the fault can be identified.

Corrections of defects on private property are the responsibility of the property owner. A licensed plumber should be consulted to ensure the proper corrections are made.

Homeowners do not need to be home while the smoke test is being performed. Inspection crews will not need to enter your home. You are not required to allow entry to our crews.

Field inspectors will be documenting the testing, taking photos and measuring distances so that the defects may be found at a later date and repaired.

If you must leave your pets unattended, proper ventilation should be provided in the event smoke enters the house. House pets will react in a manner similar to a prudent person and leave the smoky area.  Pets quartered in confined areas with no ventilation or exit available should be provided alternative arrangements during the testing.

SJCUD will notify residents who need to make corrections. Most corrections can be easy fixes, such as disconnecting a downspout from the ground and letting the water flow above ground away from the home. Corrections of such defects on private property are the responsibility of the property owner.