OUR SERVICES
Cross-Contamination Testing
We use smoke testing, dye tracing and CCTV inspection to locate cross-connections between sewer and stormwater systems — before they become an environmental liability.
SERVICE OVERVIEW
Cross-Contamination Testing
Cross-contamination happens when sewer and stormwater systems are wrongly connected — allowing pollution to flow into rivers and the environment, or contaminants to enter systems that should be clean.
Absolute GPR uses smoke testing, dye tracing and CCTV inspection to find these cross-connections, so you can correct them, protect water quality and stay on the right side of environmental compliance.
Why It Matters
Why Cross-Connections Are a Problem
The wrong connection is buried and invisible — until you test for it. But the consequences aren’t invisible at all.
A stormwater drain wrongly plumbed into the sewer overloads treatment works during rain events, causing bypasses and spills that pollute receiving watercourses.
A sewer wrongly connected to stormwater discharges raw effluent directly into the environment — creating a public health risk and serious regulatory exposure.
Both are common in older or poorly documented networks and both remain invisible until symptoms appear or a formal test is carried out.
OUR METHODS
How We Test for Cross-Contamination
We combine methods for certainty. Together they build clear evidence of what’s connected to what — and where the fix is needed.
Smoke Testings
Safe, non-toxic smoke is pushed through one network under low pressure. Where it emerges in the other system, or at the surface, it reveals a physical connection or defect that shouldn’t be there.
Dye Tracing
Coloured, water-safe tracer dye is introduced into a suspected connection point and followed as it travels through the system — confirming the flow path and direction of contamination.
CCTV Inspection
Once a cross-connection is identified, robotic camera inspection lets us see it directly — confirming its exact location, confirming the pipe condition and providing a recorded visual for compliance documentation.
Scope of Investigation
What We Investigate
Sewer-to-Stormwater Cross-Connections
Stormwater-to-Sewer Cross-Connections
Illegal or Misdirected Connections
Sources of Pollution & Infiltration
Suspected Contamination Pathways
WHO WE SERVE
Who It's For
Municipalities & Water Authorities
Protecting receiving watercourses from illegal discharges and managing the overload cross-connections place on treatment infrastructure.
Environmental & Compliance Teams
Investigating pollution incidents, confirming contamination pathways and building the evidence needed for enforcement or remediation.
Developers & Industrial Sites
Confirming that drainage connections are correctly separated and compliant before handover, development approval or occupancy certification.
Common Questions
Frequently Asked Questions
What is a cross-connection?
A cross-connection is where two systems that should be separate — typically sewer and stormwater — are wrongly joined, letting flow pass from one to the other. It causes pollution, overloads infrastructure and creates regulatory liability for the property or authority responsible.
How do you prove a cross-connection exists?
We use a combination of smoke testing, dye tracing and CCTV inspection to physically demonstrate the connection and locate it precisely — giving you clear, documented evidence for remediation, compliance and regulatory reporting.
EXPLORE MORE
Related Services
Condition assessment works best when combined with targeted investigation and monitoring.
Smoke Testing
The primary tool for locating where sewer and stormwater are physically linked across a network.
Sewer & Stormwater Assessment
Comprehensive condition assessment alongside connection testing to understand the full state of the network.
CCTV Pipeline Inspection
Robotic camera inspection to visually confirm and document cross-connections found through smoke or dye testing.
Find the Connection. Fix the Problem. Stay Compliant.
Talk to our team about cross-contamination testing on your network — we’ll confirm the method and scope to get you the evidence you need.