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Sanitary Sewer Smoke Testing
Smoke testing is performed periodically as part of Gwinnett County Department of Water Resources’ ongoing sanitary sewer inspection program. Smoke testing helps to identify areas where stormwater or ground water is entering the sanitary sewer system. Stormwater connections to the sewer system cause an unnecessary load on the wastewater treatment plants, and could potentially cause sanitary sewer backups.
Smoke Testing Safety
During the test, a non-toxic smoke is forced into the sewer lines in your neighborhood. This smoke leaves no residuals or stains and has no harmful effects on plants or animals.
Testing Notification
A door hanger explaining this testing will be delivered to each property at least 24 hours prior to testing in the neighborhood.

A Gwinnett County Department of Water Resources’ contractor will perform the smoke testing. Crew members will wear uniforms and photo identification badges, and will drive vehicles identified with the contractor’s name.  The crew members will not request entry into your home, but will be available in the neighborhood to assist you if you have any questions about the process.

Signs will also be placed in the right-of-way of the streets to identify smoke testing areas and the scheduled date of testing.

However, this type of testing cannot be conducted during rainy periods or windy conditions, so they can sometimes be delayed after the first door hanger notice is placed.


Frequently Asked Questions
Each day Gwinnett County will notify the local fire and police departments as to where they will be conducting sewer system smoke testing.

Q.         What is the purpose of smoke testing?
A.         Smoke testing is performed to find possible defects in the sewer system and illegal connections to the sewer system such as storm drains or roof drains. Smoke testing can help locate faulty pipes and sewer connections which can allow storm water or ground water to enter the sewer system, increasing the risk of sewer overflows and driving up wastewater treatment costs.


Q.         Is the smoke used for testing the sewer system harmful?
A.         No. It is not harmful to you, your pets or your plants, and it will not harm clothing, drapes, or furniture. If there are individuals in your home who have respiratory problems and are immobile, please notify us at 678.376.7000 prior to testing.


Q.         What should I do to prevent smoke from getting into my house?
A.         Make sure all your sinks, showers, bathtubs, toilets and other drains have had water run through them recently. Simply flush toilets and pour one quart of water into all drains. Make sure you check drains rarely used such as floor drains in basements or garages and bathrooms rarely used. This will ensure that the traps in the pipes contain water, which will help prevent smoke from flowing into your home.


Q.         If smoke gets into my home, how long will it take for the smoke to dissipate?
A.         It depends upon how much smoke enters the building. Open windows to provide ventilation and allow the smoke to dissipate more quickly.


Q.         I’m not going to be home during smoke testing and have pets in the house, what should I do?
A.         If you have proper plumbing connections and all of the traps in your pipes have water in them, smoke should not enter your home. If some smoke from the test does enter your home, it is not harmful to pets, people, or plants. 


Q.         Can the smoke testing activate the smoke alarms?
A.         Yes, smoke alarms may be activated during smoke testing. If smoke from the testing enters your home, open windows and/or doors for ventilation as appropriate to clear the smoke.


Q.         If my drains are filled and I still have smoke coming into my house, what should I do?
A.         This may indicate that your internal plumbing is not working properly. You should consider calling a plumber, but repairs to your internal plumbing are at your discretion. 


Q.         How are County crews recognizable in the field?
A.         Gwinnett County personnel are uniformed, carry identification badges, and are in County marked vehicles. Contractors for the County are uniformed and also drive vehicles with their company name and carry a Contractor identification letter. Although you are free to ask these field crews questions, they should not ask to enter your home.