Inflow & Infiltration Program

During smoke testing, a non-toxic, colorless, odorless smoke, similar to a fog machine, fills the wastewater system. By watching where the smoke exits the system, we can find places where stormwater could be getting in such as cleanouts with broken or missing caps, laterals with cracks or holes, downspouts, driveway drains, or window well drains. This gives us a window into the underground connection and leaks we otherwise would not be able to see. Smoke Testing Fact Sheet

Wastewater pipes are accessed at manholes where flow metering equipment is installed. Flow data collected can then be compared to other criteria, like rainfall events, time of day, or water usage, giving us answers to questions like; Does flow increase during wet weather events? Does flow drop in the middle of the night when few people are using water? Is wastewater flow significantly higher than water used?

Dye tests are used to trace individual connections. Non-toxic dye is added to flow from one location and tracked to its next location. This might be used to determine if a sump pump or catchbasin, for example, is connected to the wastewater pipe instead of the stormwater pipe.

CCTV inspections use a manual push camera, or a camera mounted on a remote operated vehicle (ROV) to visually inspect the inside of pipes. The inspections are reviewed to collect information for multiple purposes, such as lateral locations, pipe material and size, or defect types and locations.

Property inspections are done by Halifax Water staff to help private property owners identify sources of I&I. These inspections are planned and booked ahead of time with property owners. Inspections are typically conducted in areas where public sources of I&I have been identified and fixed, but the wastewater system is still at risk for overflows and backups. Property Inspection Fact Sheet