Septic Systems
Smoke Testing :: Exterior Smoke Testing

Before Smoke testing can take place local police and fire agencies must be notified, as well as any potential residential or industrial connections to the line being tested.

Exterior smoke testing is best used to detect:

  • Inflow sources such as storm sewer inter-connections
  • Point source inflow leaks in drainage paths or ponding areas
  • Roof leaders
  • Area drains
  • Foundation drains
  • Abandoned building sewer laterals

Exterior smoke testing is known to be a relatively inexpensive and quick method of detecting inflow/infiltration sources in sewer systems. Using a gas driven fan, a safe and non toxic petroleum distillate (liquid smoke) is forced into the storm or sanitary sewer system. Lighter than air liquid smoke passes through the storm or sanitary system and rises through any openings that exist within the system. Smoke testing is the most cost effective and efficient way to locate infiltration and exfiltration problems in sewer systems. It is used to find leaks, inflow sources and most restrictive conditions within the sewer lines. Smoke testing helps identify plumbing problems or leaks in buildings. Sewer gases can cause health problems for occupants. Smoke testing is also an extremely good method for tracking piping systems and other mapping purposes. The system configuration is also proven by locating hidden manholes and identifying any new construction that has not been updated on drawings.

Smoke testing involves forcing smoke-filled air through a sewer line and into the sewer system. The smoke under pressure will fill the main line plus any connection lines or leaks. The smoke is non-toxic and only enough force to overcome atmospheric pressure is required to adequately fill the system, thus forcing the smoke through any connecting lines, and will come out at any opening. As long as openings exist for the smoke to flow, smoke tests are effective, regardless of surface characteristics, soil make-up and depth of sewer lines. Whether in a municipal mainline sewer, residential or industrial system, breaks or illegal taps in the sewer line will allow the smoke to escape and surface through the ground or pipe work quickly revealing the source of the problem. Smoke testing can be used for locating illegal connections, cross connections or leaks in a sealed system. Illegal or improper cross connections can add up to trouble in sanitary or storm sewers. Leaks can be found using smoke testing simply by filling the pipeline with smoke, for long enough, that the smoke saturates the ground and comes to the surface. As long as openings exist for the smoke to follow, smoke tests are effective, regardless of surface type, soil type and depth of the lines.

Exterior Smoke Testing Smoke Blower Leak Detection Test of Sanitary Municipal Sewer Lines

Smoke testing sewer systems was introduced in the early 1960's as a method of identifying areas where extraneous water was entering sanitary sewer systems. Today, smoke testing is known to be a proven method of effectively identifying inflow (storm/ground water entry into sanitary sewer), connected roof and basement drains, yard drains, illegal taps, and storm sewer cross connections.

Atlantic Water Investigations Limited offers smoke testing, an extremely tangible process in which storm water cross connections are visual immediately upon testing. Although the concept is simple, it takes careful planning and an experienced firm in order to implement a successful smoke testing program. The result is a visual confirmation of smoke in a storm water system, evidence that rain water has been entering the sanitary sewer system. Safe, non-toxic smoke is generated and blown into sanitary sewer systems under very low pressure. The smoke will enter the sanitary system as well as cross connected storm water sources such as roof leaders and perimeter drains. Reducing inflow and infiltration saves costs from treating groundwater at wastewater treatment plants. The Environmental Protection Agency has instructed municipalities to eliminate inflow and infiltration into sewer systems. Smoke testing sewer systems is an effective way to accomplish this goal.

Smoke testing is accomplished by isolating a section of sewer line and introducing smoke into the line utilizing a smoke blower and smoke-generating device. (Important: Notify all local authorities and citizens before conducting smoke tests! Cherne provides guidelines for properly preparing and announcing to the community that a smoke test will be conducted.) Client responsible to isolate lines with pipe plugs if required before test. Lines plugged before testing can fill up with sewer and have the probability of sewer backup flooding residences. We conduct the test without plugging up the lines. Then smoke is introduced into the sewer system. The clients test crew then checks buildings, roof vents, the street, and other areas that potentially could be a source of extraneous water and records those locations for corrective follow-up.

Our smoke blower is available for either traditional "smoke bombs" or liquid smoke fluid. Available with a 5.5 horsepower Honda engine, our unit generates up to 3769 cubic feet per minute of airflow to quickly introduce smoke into the sewer system. Cherne's blowers are made of lightweight cast aluminum and feature a 1/2" foam cell gasket to insure a leak-free seal on manholes and minimize vibration. The traditional smoke blower has a smoke bomb box holder, whereas the liquid smoke blower is supplied with a pressurized tank, hose and all components necessary to conduct the smoke test.