Research opportunity | Transforming Sewer Ventilation: A Collaborative Path to the Ventilation Management Model (VMM)

Sewer Ventilation Reckoning

Sewer systems in Australia have long prioritised ventilation strategies to disperse odours, particularly hydrogen sulfide, which triggers public complaints and requires immediate operational fixes. Emerging evidence from multiple studies now shows these same approaches—often involving forced extraction or passive venting—trap moisture, create ideal conditions for microbially induced corrosion (MIC), and release significant methane and other greenhouse gases generated in anaerobic wastewater environments.

The shift matters urgently because sewer infrastructure across the country, much of it ageing, faces compounding pressures from urban growth, climate variability, and stricter emissions accounting. Corrosion shortens pipe and manhole lifespans dramatically, forcing utilities into expensive reactive repairs or premature replacements. At the same time, methane escaping from sewers contributes to Scope 1 emissions that utilities must now report and reduce under Australia's Net Zero by 2050 framework.

The proposed Ventilation Management Model (VMM) seeks to move beyond odour-centric thinking toward holistic airflow management that balances drying of pipe walls to inhibit corrosion, controlled venting to minimise gas buildup, and data-driven prediction of risks. This would leverage advances in real-time sensors and digital twin simulations, building on prior fragmented work at universities and utilities. The timing aligns with the Cooperative Research Centres Projects (CRC-P) funding round, which offers matching grants and requires industry collaboration—here led by WaterRA and Melbourne Water—to turn research into deployable tools before asset failures escalate further.

Tensions exist between short-term odour management demands (driven by community and regulatory pressure) and longer-term goals of asset longevity and decarbonisation. Over-ventilating solves smells fast but worsens corrosion and emissions; under-ventilating risks safety incidents from toxic gas accumulation. Utilities also grapple with uneven adoption of monitoring technology, as current systems struggle to capture intermittent H₂S peaks reliably. Without a unified model, decisions remain siloed, perpetuating high costs estimated in the hundreds of millions annually industry-wide.

Recent incidents, including sewage spills and persistent odour complaints in Perth, underscore the fragility of existing approaches amid growing urban density and infrastructure strain.