Smoke / Dye Testing

Sanitary Sewer Smoke Testing

Smoke testing is one of the most cost-effective methods your utility can use to locate breaks and defects in the public sewer system (sewer mains, service laterals, cross or illegal connections). The smoke is an indication of inflow and infiltration (I&I) that can enter a sewer system during a rain event. This reduces the capacity at the sewer plant, increases treatment costs and can lead to overburdening of the sanitary system, possibly leading to overflows and backups. Duke’s is a leader in quality smoke testing with millions of feet of smoke testing completed across America. Our turnkey approach ensures proper notification to all emergency personnel and residents, safe execution of field work and analysis that offers rehabilitation solutions for your system.

Did You Receive A Door Notice?

If you received a pink door tag from Dukes indicating that your utility will be sewer smoke testing in your area, there are things that you can do to prepare. Please consult our FAQ section below for more information. If you would rather have one of our representatives contact you, please visit our CONTACT US page or call 888-655-4085 between the hours of 7am and 4pm CT.

How Smoke Testing Works

Blowers are placed in adjoining manholes and a non-toxic liquid smoke is forced through the blowers into the sanitary or storm sewer. Defects in the pipe or manhole structures will create a pathway for the smoke to escape thereby identifying the location of the defect.

Smoke Testing Page 011122

Frequently Asked Questions

Most utilities undergo sewer smoke testing to identify possible defects within the sanitary sewer system that may contribute stormwater to the system. This storm water increases demand on the sewer system and Wastewater Treatment Plant capacity and treatment costs to residents. Smoke testing is an effective means of identifying large defects that are capable of allowing large volumes of storm water to enter a system during a rain event. 

Your utility may choose to undergo smoke testing for a variety of reasons. Some utilities choose to smoke test to meet regulatory requirements to reduce excess stormwater from entering a sanitary sewer system. Others may proactively deploy smoke testing to identify possible capacity constraints and defects in order to determine best ways to rehabilitate the system. Others may smoke test as part of normal operational plans to maintain system performance.

Once you receive your door tag, you can help your utility prepare for the smoke testing by doing the following:

  • Pour water down every unused or underused drain in your building. Please be mindful of drains located in laundry rooms, utility rooms, basement bathrooms or garages.  We recommend pouring 1/2 – 1 gallon of water down these drains to create a barrier in the “P-Trap” which will prevent smoke from entering your home.
  • If you have pets, we recommend moving them to an interior room of the house for the test.

*Please note, you may pour water down your drains anytime prior to the test. You do not have to pour water down your drains on the day of the test*

No, you do not need to be home for the test. If you have any pets or special needs, please contact us at 888-655-4085 or through our CONTACT US page.

If you have any pets or persons within the building who may have special needs, please contact us prior to the dates on your pink door tag at 888-655-4085 or through our CONTACT US page. We will advise you on steps you can take to prepare and extra notice we can provide to you on the day of the test. Please inform us if you have any of the following situations:

  • A person who will be alone and is an invalid or sleeping during the test
  • Any individuals with respiratory problems who will be in the building
  • Elderly persons who will be alone and might be alarmed or confused if they see smoke.

If smoke should enter your building during the test, it probably means that there are defects in the interior plumbing that could allow sewer gas to enter. Note the location of the smoke and call us at 888-655-4085 to report the defect. Most utilities are not responsible for private plumbing defects but our technical support team can assist with identifying if the defect is the result of faulty plumbing and provide assistance on determining proper next steps you can take. Before calling, open doors and windows to ventilate any smoke that enters the building. The smoke used during a test is non-flammable and non-toxic. Opening your windows allows the smoke to vent. Once the test is completed, smoke will dissipate within a matter of minutes. If you believe the smoke in your home to be unrelated to the sanitary sewer smoke testing, please call 911 or your local emergency management. Your local police and fire departments have been notified of the testing in your area.

If you see smoke in the yard, that is the sign of a sewer defect and our inspection crews will be surveying the area during the test to note the defect and take pictures.

No. The smoke has no odor, is non-toxic, non-staining, does not create a fire hazard and will dissipate in a few minutes.

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