Sewer System Smoke Testing
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Sewer System Smoke Testing
Purpose & Goals
The City of Longmont performs sewer system "smoke testing" to help locate obstructions and defects in the sanitary sewer system. Specifically, it is a form of inspection that evaluates sewer conditions or connections that could allow storm water to enter into the sanitary sewer. Storm water can cause capacity problems in the sewer and increase wastewater treatment costs, which affects your monthly utility bill.
The information gained from smoke testing contributes to the City’s ability to control costs and maintain a high level of service for the Longmont community.
The Test
Smoke testing involves the introduction of a specially formulated smoke into a local sewer line and pressurizing the system with fans located at manholes to see where smoke comes out. The smoke used in the test is not harmful to humans or pets, creates no fire hazard and is approved by the Environmental Protection Agency.
If the sewer is in good condition, that is, there are no pipe defects or damage, improper storm sewer connections or plumbing defects, then the smoke should only come out through plumbing vents in building roofs, or farther down the line through sanitary sewer manholes. However, if there are defects in the sewer, improper connections, or plumbing defects, smoke may escape at other locations. In those cases, smoke may escape from peculiar places such as pavement cracks, turf areas, rain downspouts on roofs, driveway drains, yard or area drains, window well drains, foundation perimeter drains, defective service pipes, and possibly inside buildings.
If you have any seldom used drains, such as floor drains, please pour water in the drain to fill the trap. which will prevent smoke from entering there. Drain traps should always be filled with water to prevent sewer gases or odors from entering the building. Additionally, many washing machine drain pipes do not have traps. If you suspect your washing machine drain pipe has no trap, tie a damp rag around the drain opening to block smoke from entering your house.
Yes, this vent is designed to vent sewer gases.
The smoke is non-toxic; however, it may cause difficulties with breathing in high concentrations. If someone is not home, it is recommended that you close bathroom doors (and other rooms where you have drains) and open windows if possible while you are away. Do not confine your pets to rooms with drains, sinks or toilets.
Should smoke enter your building, you should contact a member of the smoke testing crew working in your neighborhood. The smoke should not enter your house unless you have defective plumbing or dry drain traps. If this occurs, you should consult your licensed plumber. If any smoke enters your house, the potential, likewise exists for dangerous sewer gases to enter your home or establishment.
Smoke testing is performed Monday-Friday between 8 AM and 5 PM. On days when it is raining, smoke testing is not performed.
At least two weeks prior to testing, a notification letter will be mailed to all property owners and occupants in the test area. It will include staff contact information and the webpage for questions and concerns. City staff will notify Longmont Public Safety seven working days prior to testing. All sensitive businesses such as restaurants will be personally notified by staff/consultant seven working days prior to smoke testing. Finally, five working days prior to smoke testing, door hangers will be distributed to all impacted addresses.
Unfortunately, we are not able to pinpoint the exact time of testing at your address.
Inspection teams will generally consist of one to four people. Each inspector will be wearing an identification badge. Inspections will occur during normal business hours between 8 a.m. and 5 .m. Monday through Friday. Inspection activities should have little to no impact on your daily life and typically will require only a few hours in your area. The information gained from these activities may be used to improve your neighborhood’s sewer services.
The most common cause for smoke entering a home is dry plumbing traps. A trap is required by state plumbing code to prevent sewer gases from entering a home. Water can evaporate from a trap in sinks and other drains that are used infrequently. Other causes for smoke entering the home can be from a bad seal around toilets, washers, or other plumbing deficiencies.
