Figure 1- Crew performing smoke testing in a residential area.
Since 2002 the City has embarked on an overall program to evaluate the entire sewage system, and make repairs as they are discovered. Several different operations are used to evaluate the system, which include; internal inspection of pipe using video equipment; visual manhole inspections; flushing and cleaning of the pipes; and smoke testing for illicit connections.
Smoke testing is an easy, cost effective way of locating sewer problems with little disruption to the system or the residents. An additional advantage of this method of investigation is that it will not only test the City maintained mainline, but will also test the integrity of the laterals. This method has been used extensively all over the country for the last 40 years to locate defects in sewer systems.
The smoke testing methods and materials to be used in this project are endorsed by the EPA. Click here to view the MSDS (Material Safety Data Sheet) for smoke candles.
WHEN and WHERE: The project started in late 2012 and will continue through April, 2013. The areas to be tested are in sewage collection system sub-basins 3, 4 7 and 10 as shown in the Figure 2 below.
Figure 2 – City of Folsom Sewer Collection System Sub-Basin Map
Field crews will be in the area gathering preliminary data and providing a two-week notification of all residents in the area prior to performing the actual smoke testing. An additional notice will be placed at your residence within 24 to 48 hours of the actual field work.
HOW: During this phase of the project, inspection crews from the City of Folsom will be conducting the smoke testing project to locate breaks, defects and illegal connections in the sanitary sewer system. This project will require the opening of manholes, which are located in the streets, utility easements and/or alleys. Once opened, a large blower is placed on top of the open manhole which forces a non-toxic smoke into the system. As the smoke is forced through the sewer lines it will be forced from any openings or defects in the system, as shown in Figure 3. The white or gray smoke exiting the system is easily observable by the field crews performing the test, who will log each occurrence. Each of these occurrences will be mapped and analyzed.
Figure 3- Diagram of a smoke testing operation.
- At no time will field crews have to enter your residence. However, should a smoke source be visible on your property, the field crews will likely need to enter the property to investigate and log the source.
- The smoke is NON TOXIC, LEAVES NO RESIDUE, AND CREATES NO FIRE HAZARD. The smoke, which is 50% atmospheric moisture, has a slight odor similar to burning paper and may cause minor throat irritation if inhaled. However, persons with respiratory conditions such as asthma, bronchitis or emphysema should be careful when exposed to smoke of any kind. Should you have any health concerns, please feel free to call the Utilities Department at 355-8365. Click here to view the MSDS ( Material Safety Data Sheet) for smoke candles.
- The smoke should not enter your home or business unless defective plumbing exists or drain traps are dry. Please pour approximately 1 gallon of water down any unused drains in your residence. This will help to prevent smoke from entering your house via seldom used drains. If smoke should enter your house, please notify the smoke testing crews that will be working in the immediate vicinity. Please be advised that if smoke enters your house during this test, it is likely that sewer gases are entering as well. It would be advisable to call a licensed plumber to repair any defective plumbing detected during this project.
- Your presence is not required during the tests, and all public safety authorities have been notified of this event. We would appreciate it if you would mention this notice to your neighbors in case they have not received a notice.
- If you or anyone you know lives in the test area and are concerned about the possibility of smoke entering your property, or should you have any questions concerning this study, please contact the Utilities Department at 355-8365.