Wastewater Smoke Testing

About the Fall 2018 Smoke Testing

City staff are preparing to smoke test sanitary sewer lines in northeast and northwest Sioux Center to help find and prevent costly sewer issues. 

The City has contracted with Bolton & Menk to assist in performing this work October 17 and 18. 

Crews will release a nontoxic smoke into the sewers, and the smoke will show leaks, breaks, or faulty connections in the lines.

Breaks or faulty connections can allow clean water into the sanitary sewer system, which can overflow it in a significant storm, and result in significant treatment costs to the City and the residents. 

Finding and sealing breaks helps us reduce the likelihood of these events. Reducing clean water in the sanitary sewer system reduces the amount of sewage treated, lowering costs for our community.


Smoke Map2

Preparing Your Home for the Test

If you live in the area where testing will take place, you should have received a mailing regarding this testing.

The nontoxic smoke from the test could enter your home through floor drains and unused toilets, sinks or showers. While all drains have water traps to prevent fumes from entering homes, floor drains can dry up. 

Make sure the drains in your residence have water in them so they can prevent smoke from entering. Pour a bucket of water down floor, sink or shower drains or down any toilets that haven’t been used in a month. 

The smoke used in the test is nontoxic and won’t stain curtains or any other fabric. However, the smoke may cause some coughing and can be an irritant to people or pets with respiratory conditions. The City recommends that people with these types of health concerns notify us during testing.  


Call Josh Pope (Bolton & Menk) at 712-580-5075 or the City of Sioux Center at 712-722-0761 if:

  • You or someone in your home has mobility limitations, respiratory conditions or other health concerns that may be aggravated by exposure to the smoke.
  • There is a daycare or nursing home operated on your property.

Safety is the first priority - call 911 if you see smoke that you are not certain is the result of City smoke testing.  

How Is Smoke Testing Done?

Smoke is blown into sewer systems and creates visual indicators where leaks or breaks exist.Sewer smoke testing

It involves opening of manholes in the streets and public utility easements. The test takes 5 minutes. 

A special non-toxic smoke is used in these tests. The smoke is manufactured for this purpose, leaves no residuals or stains, and has no effect on plant or animal life. The smoke has a distinctive, but not unpleasant odor. Visibility and odor last only a few minutes where there is adequate ventilation.

Call Josh Pope (Bolton & Menk) at 712-580-5075 or Zeke Ellis (City of Sioux Center) at 722-0761 if:

  • You or someone in your home has mobility limitations, respiratory conditions or other health concerns that may be aggravated by exposure to the smoke.
  • There is a daycare or nursing home operated on your property.

Safety is the first priority - call 911 if you see smoke that you are not certain is the result of City smoke testing.  

What is the purpose of testing?

  • To find the source of an inflow or infiltration problem.
  • To find leaks and incorrect connections to sewer lines.
  • To find abandoned sewer lines not previously surveyed.

Because the plumbing appliances in your house or building are connected to the sanitary sewer system, some smoke may enter your home or place of business if the:

  • Vents connected to your building’s sewer pipes are inadequate, defective, or improperly installed.
  • Traps under sinks, tubs, basins, showers and other drains are dry (not used often), defective, improperly installed, or missing.
  • Pipes, connections and seals of the wastewater drain system in and under your buildings are damaged, defective, have plugs missing, or are improperly installed.

What do I do if smoke enters my house?

If traces of this smoke or its odor enter your house or building, it is an indication that gases and odors from the sewer also may enter. Sewer gasses can be both unpleasant and dangerous, as well as a health risk to the occupants. If smoke does enter your home that means there is a defect in your plumbing and you should contact a plumber to resolve the problem.  You may also contact a member of the smoke testing crew working in your area. The crew member may be able to help and check with you as to where the smoke has entered your building. Location, identification and correction of the source of smoke that enters your building is urgently advised.

The information gained from this testing will be used to improve your sewer services and may reduce the eventual cost to utility customers. Should you have any questions please contact Josh Pope at 712-580-5075.

Frequently Asked Questions about Smoke Testing

1. Why does the City perform smoke tests?
A. The City performs smoke tests to determine if there are any incorrect connections to or defects within the sanitary sewer system. A defect could allow storm water in to the sanitary sewer system raising the cost of wastewater treatment and potentially causing sewer backups.

2. I or a family member has a respiratory problem. What should I do during a smoke test?
A. Very rarely does smoke enter a home, but it would be best if you could sit outside for the duration of the smoke test which is approximately 5 minutes. If you cannot sit outside open the windows of your home and shut your bathroom doors. Also let the City smoke test crew member who knocks on your door know you have a respiratory condition.

3. I work during the day and have inside animals. What do I do during a smoke test?
A.  Very rarely does smoke enter a home, but if you do have to leave your animals inside make sure you leave windows open. On the rare occasion when smoke does enter the home it is usually a defect in the bathroom, so do not lock animals in the bathroom. Shut bathroom doors and leave the bathroom window open.

4. Is smoke harmful to my animals?
A. In most cases no. But if your animal has a respiratory condition the smoke could irritate it.

5. Is smoke harmful to my plants?
A. No, the smoke is not harmful to indoor or outdoor plants.

6. Why would smoke enter my resident or business?
A. A plumbing defect or unused sinks, showers or drains is how smoke would enter a home or business. The most frequent cause of smoke in a resident or business is a bad wax ring on the toilet. Unused sinks, showers or drains should have water placed in them to fill up the p-traps. A p-trap is a standard plumbing fitting used on all sinks, showers or drains so sewer gases and sewer odor won’t enter your home.

 7. Should I be concerned if smoke enters my home or business?
A. Yes, this means that sewer gases or odors can also enter your home or business.

8. What should I do if smoke enters my home or business?
A. Open your windows and call a professional plumber.

9. How long does the smoke test last?
A. Approximately 5 minutes.

10. I have a sump pump connected to my sewer lateral under the house will that be affected during the smoke test?
A. Yes, sump pumps are illegal connections to the sanitary sewer system. If you have a sump pump connected to the sanitary sewer system you should disconnect it. If your sewer lateral becomes fully or partially plugged and your sump pump turns on, the water could be pumped into your home through a shower or tub causing tremendous damage.