Some community members have noticed an unpleasant odor in parts of Independence over the past few weeks. This smell is coming from the city’s wastewater treatment lagoons and is the result of a seasonal lagoon “turnover” event.
Here’s what’s happening:
Wastewater lagoons rely on natural biological processes to break down organic material (called biosolids). Under normal conditions, these materials settle and decompose gradually. However, a combination of temperature conditions and stagnant air can cause a lagoon to “turn over,” allowing remaining biosolids to rise to the surface, particularly in Lagoon 1, as shown in the photo. 
When these biosolids reach the surface, they can release gases such as hydrogen sulfide, which is responsible for the sulfur-like odor some residents are noticing.
Over the past few years, the city has removed a significant amount of accumulated biosolids from the lagoons, greatly reducing long-term odor issues. That said, some material remains and must continue to naturally break down as part of the treatment process.
As weather patterns shift and wind returns, the biological activity stabilizes, and the odor should dissipate naturally.
City staff are actively monitoring lagoon conditions and appreciate the community’s patience. We understand that odors can be unpleasant, and we’re committed to long-term improvements while continuing to operate a safe and effective wastewater treatment system.
