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Smoke Testing

Periodically, Cayucos Sanitary District staff performs routine smoke testing in areas of the Cayucos community to evaluate the sewer infrastructure in that neighborhood. The goal of smoke testing is to identify areas of the sewer system that are functioning improperly, damaged, or are otherwise contributing to inflow and infiltration, which Cayucos’ sewer system is not designed to accommodate. By maintaining the structural integrity of our sewage collection system, we are able to provide quality, reliable sewer service, while minimizing energy consumption and treatment costs.

How it Works 

May contain: artwork of a house, pipes, bathroom, underground
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  • District staff isolates a portion of the sewer mainline pipe. 
  • A smoke machine is placed on top of a manhole located within the isolated section and begins blowing non-toxic, odorless smoke into the sewer system. 
  • District staff carefully observes the test section and evaluates each building within it in search of irregular signs of smoke. 
  • If your plumbing is adequate and your p-traps are full, smoke will not enter your building via drains. If irregular smoke is spotted emitting from your property (usually from the ground outside of the building), staff will document the source and nature of the problem and you will be notified in writing as to how to correct the defect. 
  • As the property owner, your responsibility is limited to defects identified within your sewer lateral and/or plumbing.  

How to Prepare

May contain: person, plumbing, and smoke pipe
  • You do not need to be home for the test to take place. 
  • If you have not used the drains in the lowest level of your building in the past week, we recommend running water down those drains for about 10 seconds at any time prior to the commencement of the smoke test. This will help ensure that your p-trap is full and will help prevent smoke from entering your building. You need not worry if it would be inconvenient to access your home and run water prior to the commencement of the smoke tests; running water is simply a preventative measure for your comfort.
  • If smoke does enter your home, don't be alarmed; the smoke is non-toxic and will not harm pets or sleeping people. However, this is an indicator that dangerous sewer gas has the potential to enter your building. Contact us right away at (805) 995-3290.