1. Smoke Testing Information
Saint Paul Public Works - Sewer Utility
Smoke Testing Information

2. Smoke Testing - Purpose
Help Find defects and faulty connections where excess rain water (Inflow) and ground water (Infiltration) can enter the sanitary sewer system…..
Smoke Testing - Purpose
Locate Inflow Sources
Locate Infiltration Sources
Verify System Connectivity for Modeling
Verify Flow Routing & Basin Boundaries
Identify Storm Drain Cross Connections
Locate Illicit Connections
Identify Abandoned Connections
Regain System Capacity
Smoke Testing Information

3. Smoke Testing – Other Benefits to Property Owners
Help identify plumbing defects which can also allow potentially harmful sewer gases to enter a building or home.
Smoke Testing Information

4. What is Inflow & Infiltration (I/I) ?
Inflow is Rain or Clear Water that Directly enters the sanitary system
Infiltration is Ground or Clear Water that Indirectly enters the sanitary system
Smoke Testing Information

5. Sources of Inflow & Infiltration (I/I)
Private Property
Sump Pump
Foundation Drains
Leaking Sewer Services (House Laterals)
Roof Drains (Rain Leaders)
Area Drains
Public Property
Leaking Manholes
Leaking Pipes
Storm & Sanitary
Sewer Cross
Connections
Smoke Testing Information

6. Benefits of Eliminating I/I Sources
Comply with Met Council Rules
In or after 2013 the Met Council will add an annual Demand Charge $3.5 million/ year) to Saint Paul’s Wastewater Treatment Bills if the excessive I/I (surcharge) is not removed from the system
Maintain Health and Safety
For example: reduce risk of sewer back-ups and sinkholes
(Approx. 200 sinkholes/depressions were identified within the City
between 2006 and 2008)
Reduce Infrastructure Wear and Tear
For example: lift stations, sewer pipes
Reduce Wastewater Treatment Costs
Smoke Testing Information

7. Sewer Flow Monitoring During “Dry” and “Wet” Weather Events
Smoke Testing Information

8. Smoke Testing- Process
Simulated smoke will be injected into the sewer system. As a result smoke may be seen coming from manhole covers, storm drains, roof vents, and building foundations.
Each smoke test will last approximately 10 to 30 minutes.
Photographs will be taken to document results.
Residents/Property Owners do not need to be home.
Residents/Property Owners can still use faucets and bathroom facilities.
Smoke Testing Information

9. Smoke Testing- Process
Introduce Smoke
Force Air Into System
Observe Where Smoke Escapes
Smoke Testing Information

10. Smoke Testing- Equipment
High Volume Air Blower
Smoke Testing Information

11. Smoke Material Used
Liquid Smoke
Smoke Testing Information

12. Examples - Manhole Defects Identified
Smoke Testing Information

13. Examples – Leaky Laterals Identified
Smoke Testing Information

14. Ilicit Storm Drain Roof Leaders
Smoke Testing Information

15. Examples – Storm Drain Cross Connections Located
Smoke Testing Information

16. Smoke Testing – Tips for Residents & Property Owners
Tips to prevent smoke from entering your home (complete prior to test)
Run water faucets for a few seconds in unused sinks, tubs, and drains to fill fixture traps.
Pour water into each basement floor drain (at least 1 gallon)
If you have defective plumbing (i.e. no trap), you should consult with a licensed plumber.
If you notice smoke in your home
Do NOT become alarmed.
Open doors and windows to clear smoke.
Please notify the Testing Crew (651)
Simulated smoke will not stain walls or furniture; nor leave a residue.
Consult a licensed plumber in the near future to identify the smoke access area, as the potential exists for sewer gases to enter your
home in the same manner.
Smoke Testing Information

17. Smoke Testing – Safety and Health
There is NO danger of fire or explosion of sewer gas with smoke testing.
St. Paul Police and Fire Departments will be notified of the smoke testing.
If there is an individual in your home or business who has respiratory
and/or mobility limitations please notify the Sewer (651) (prior to testing).
Avoid unnecessary exposure to the simulated smoke. The smoke is not harmful to your health but may cause some coughing. Smoke irritation is temporary and should disappear after exposure has ceased.
A copy of Material Safety Data Sheet (MSDS) for the simulated smoke can be found on Saint Paul’s Home website page ( under the headings of Government/Public Works/ Sewer Utility/ Smoke Testing/ Safety.
Smoke Testing Information

18. Smoke Testing – Communication Steps
Communication Steps (after initial mailing)
Police & Fire Departments will be notified on a regular basis.
Within 3 days of testing Door Hangars will be placed on property front doors.
An automated phone call will be made notifying properties that testing will occur in a few days.
Properties/ Residents who have notified the City as having individuals with respiratory and/or mobility limitations, or pet concerns:
Will be contacted again by the testing contractor identifying a more specific time for which testing will occur.
Properties will be monitored during the time of the test.
Smoke Testing Information

19. Other Information - Sanitary Sewer Services
For information regarding Televising or Repairing Your Sanitary Sewer Service please……
Contact the Sewer Utility Permit (651)
Smoke Testing Information