Odor complaints are potential indicators of deeper infrastructure issues

As anyone in the world of wastewater management knows, harmful gases and volatile organic compounds (VOCs) produced during the treatment of wastewater can create foul odors that pose health risks for employees and are unpleasant for surrounding communities. These smells can also signal serious problems happening within the facility itself.

In many cases, odor acts as the canary in the coal mine for corrosion. It’s often the first, and most noticeable, sign of deeper infrastructure issues. If you can smell it, there’s a strong chance that corrosive gases and VOCs are already attacking electrical systems and other critical assets. While corrosion itself remains invisible in its early stages, odor becomes the alarm bell that operators and neighbors detect first.

The formation of VOCs and corrosive gases is inevitable in wastewater treatment, but how facilities manage them makes all the difference – for community relations, employee health and protection of valuable infrastructure. Odor complaints shouldn’t be dismissed as a public relations problem, rather, they should be recognized as indicators of deeper operational challenges. And in that sense, corrosion monitoring isn’t just about asset protection - it’s an objective, data-driven way to validate what your senses are already telling you.

What do odor complaints often reveal?

Odor intensity can fluctuate seasonally due to the ebb and flow of temperature, humidity and cloud cover. Typically, as different solids break down during treatment, “off-gassing” occurs, the release of VOC’s and other compounds into the air. Facilities who are committed to minimizing nuisance odors will install “scrubbers” to remove these gases before venting air back into the atmosphere.

The two most common corrosive gases generated at wastewater treatment facilities are hydrogen sulfide and sulfur dioxide/trioxide. If left unscrubbed, the presence of these acid gases will damage electrical systems, circuit boards and metal infrastructure within the facility.

Historically, odor control strategies have focused on external emissions, the air that leaves the facility into the surrounding communities, rather than the air that circulates internally where workers and sensitive equipment are present.

If equipment failures become frequent or severe, it may indicate a need for additional scrubbers or corrosion control measures inside control rooms and switchgear areas.

The science behind the smell

Acid gases are corrosive because in the presence of moisture, like a humid wastewater management environment, they form strong acids that attack metal surfaces. Over time, this process strips ions from metal atoms, gradually weakening circuit boards, control panels and other infrastructure. To make matters more complex, sulfur-bearing gases can even corrode silver contacts without the presence of moisture. If left untreated, the corrosion can creep over the circuit board and lead to short circuits and eventually, facility shutdowns.

Activated carbon media, an incredibly absorbent material typically made from coconut shell or coal, is widely used in scrubbers and deep-bed filtration systems to absorb these gases. As air passes through the media, harmful compounds are captured, mitigating both odor and corrosion risk. However, media eventually becomes saturated and must be replaced. For large vessels, the typical lifespan is around one year. While each facility will have different needs, generally, the only component that changes here is how close the facility is to the surrounding community, requiring more of the carbon media to scrub the air.

Improper installation or handling of the carbon media can lead to out-gassing, which may cause health issues for employees. Ensuring proper preparation and installation is critical for effective odor and corrosion control.

Operational, regulatory and reputational risks

Ignoring or delaying action on odor complaints can create significant risks for wastewater utilities. From an operational standpoint, unchecked corrosion may lead to unexpected shutdowns of critical systems, higher maintenance costs and shortened asset lifespans. Employee health can be affected as well, resulting in poor work performance or an increase in absences, which can negatively affect the daily management of facilities. Regulatory agencies may issue fines or compliance orders if corrosion or gas emissions exceed permitted levels, which can be expensive and time-consuming to resolve.

There’s also a reputational aspect. Persistent odor complaints can create community frustration, negative media coverage and damage relationships with local leaders. Over time, this can reduce public trust and make it harder to gain approval or funding for future projects. Taken altogether, these risks demonstrate why proactively addressing odor and corrosion isn’t just good practice, it’s essential for long-term operational and financial sustainability.

From reactive to proactive

In many facilities, odor complaints are manually logged through direct calls, emails and social media complaints. Sometimes these issues can be brought up by homeowner associations or at public meetings. The challenge is that human senses vary. What one person thinks is a very strong smell, another person may not notice at all. Relying solely on subjective complaints can result in gaps in detection and delayed action.

Regardless of how the complaint is logged, there are some facilities that only address odor after receiving complaints – replacing their carbon media or repairing equipment reactively. But a proactive approach has significant advantages for your facility and surrounding community: longer equipment life, fewer unplanned shutdowns, improved compliance and better budgeting accuracy.

By continuously monitoring corrosion and gas levels, facilities can identify when assets are at risk before failure occurs. This allows managers to schedule maintenance and media replacement proactively, protecting electrical systems and extending the equipment lifespans. In financial terms, investing in proactive monitoring and corrosion control is often more cost-effective than emergency repairs or equipment replacement.

Proactive corrosion monitoring helps justify budget requests by providing objective data about asset condition, transforming general odor complaints into a measurable sign of risk.

Technologies and best practices

One way to log this information in a more objective way is with a simple tool called corrosion coupons, which Freudenberg Filtration uses when touring or auditing a facility. These small metal strips are meant to be placed in vulnerable areas and will change color over time as they oxidize. When a coupon darkens significantly, it signals high corrosion activity and a need to replace or upgrade a facility’s protective measures.

For real-time protection, there are more advanced systems that continuously track air quality in control rooms and other critical spaces. These systems measure corrosivity, temperature, humidity and pressure to help prevent equipment damage.

Freudenberg also pioneered the original honeycomb carbon module, designed to increase contact area and efficiency. These calcined (heat-treated) honeycomb media maintain structural integrity even in hot climates, meaning they can avoid any softening and breakdown that would otherwise occur.

Choosing the right equipment for a facility is not just about price, it is about partnering with a company that truly understands the needs of each unique facility – like average temperature, humidity and community proximity – to deliver application-driven solutions that protect infrastructure and safeguard employee health.

Conclusion

In modern life, most people rarely think about how their tap water reaches them inside their house, or what happens after it goes back down the drain. Yet wastewater management facilities, and the professionals who operate them, play a critical role in our society, not only for providing water for daily living, but making sure the spent water is safely processed and returned back into the ecosystem.

Odorous gases and corrosion can threaten that work by harming workers and damaging essential equipment. By proactively monitoring corrosion and investing in proper scrubbing technologies, facilities can protect assets, ensure regulatory compliance and reduce costs over time.

Odor complaints are not just about comfort, they are early indicators of deeper issues. Addressing them proactively helps secure operations today and preserves infrastructure for tomorrow. Remember: do not ignore what your nose already knows.