Stormwater infiltration into a commercial or domestic sewer network can pose serious risks to both public health and the structural integrity of assets. On a larger scale, this often happens when stormwater enters a sewer system through low gully traps, broken pipes, illegal connections, or unsealed utility holes. The phenomenon is commonly referred to as Inflow and Infiltration (I&I).
Early detection is essential to avoid costly damage and environmental impacts. Here’s how to identify the signs of I&I and what to do about it.
Stormwater infiltration is often hidden from view, but there are several tell-tale signs to look out for:
Pump overuse: Your wastewater pump runs for unusually long periods, especially during or after rainfall.
Increased flow during storms: A significant rise in wastewater flow occurs during storm events due to inflow from gully traps, roofs, or illegal connections.
Unexpected surges in dry weather: Inflow increases during dry weather conditions compared to previous months, suggesting infiltration rather than surface water input.
Sewer overflows: Overflow events in the sewer network can indicate excess water is entering the system.
These signs can confirm that there is a problem, but identifying the source of infiltration requires more detailed investigation.
1. Private Property Inspections
Visual inspections of gully traps, stormwater connections, and the sewer network can help detect obvious defects or illegal connections.
2. CCTV Sewer Inspections
Professional camera inspections provide a clear view inside sewer pipes to pinpoint damage, cracks, or areas that may require rehabilitation, replacement, or pipe relining.
3. Manhole Inspections
Manholes are inspected for evidence of root intrusion, broken joints, or design failures that could be allowing stormwater in.
4. Smoke Testing
One of the most effective and non-invasive techniques for identifying I&I sources, smoke testing uses a fog machine to blow harmless, non-toxic smoke into the sewer system. If smoke escapes through the ground, stormwater pipes, or other surface openings, it’s a strong indicator of a break or illegal connection.
Yes. At PPS, we use a non-residual thermal fog that is completely safe, odourless, and contains no carbon monoxide. This makes the process safe for both residents and the environment.
Once the testing is complete, we’ll provide a comprehensive report, including photos and documentation of any illegal or faulty connections. This ensures you have a clear understanding of what needs to be addressed.
Stormwater infiltration is more than just a plumbing issue—it can lead to environmental damage, higher utility costs, and compromised infrastructure. If you suspect an issue, early detection is key. With advanced techniques like CCTV inspections and smoke testing, PPS can help you uncover the source quickly and safely—before small issues become big problems.
Think you might have stormwater entering your sewer system?
Contact PPS today for a professional assessment.