Noticing an odor? Here’s how Roseville responds
Nov 9, 2026
An unpleasant odor can disrupt time at home or outdoors. It’s natural to wonder where it’s coming from – and what’s being done about it.
Roseville operates two wastewater treatment plants, Dry Creek and Pleasant Grove. Treating wastewater can produce odors, and we invest in equipment, monitoring and maintenance to reduce them. But our plants aren’t always the source. Your location, nearby activities and weather can also play a role.
“We know odors can be unpleasant. We invest in odor-control equipment, monitor conditions and investigate concerns to understand whether our operations may be contributing and what actions we can take.”
Tracie Mueller, Roseville wastewater utility manager
How we reduce odors
At both Dry Creek and Pleasant Grove wastewater treatment plants, odor-control systems collect and treat odorous air. We invest in upgrades at both plants to help reduce odors in surrounding areas.
Staff also:
- Monitor conditions and potential odor sources
- Maintain and improve equipment
- Adjust maintenance activities when conditions may increase odors
When equipment needs maintenance or replacement, other odor-control systems continue operating, though odors may temporarily be more noticeable.
Why the source isn’t always the plant
Depending on where you are, odors may come from plant operations or other nearby activities, including farming. Agricultural activities near Pleasant Grove are one example. Being near a plant doesn’t necessarily mean it’s the source.
Weather adds to the challenge:
Wind
Can carry odors from other locations.
Calm air
Can allow smells to linger.
Temperature inversions
Act like a lid, trapping cooler air and odors closer to the ground.
Staff consider these conditions when investigating where a smell may have started.
How we investigate – and how you can help
When we receive an odor report, our staff review plant operations, monitoring data and weather conditions to help identify a potential source. If our operations may be contributing, we determine whether adjustments are needed to reduce odors.
Each treatment plant also has four odor sensors that monitor conditions and help us anticipate when odors may be more noticeable. The monitoring system also produces reports every two weeks to help us schedule work when conditions are less likely to cause odors.
Noticing an odor? Let us know.
Report an odor while it’s happening, if possible. Include:
- Where and when you noticed it
- How long it lasted
- What it smelled like and how strong it was
- Whether it was constant or came and went
You don’t need to know the source. Use the City’s online odor report form to tell us what you’re experiencing. Your reports help us investigate concerns and continue improving odor management at our plants.
For more information about Roseville’s wastewater utility, visit roseville.ca.gov/sewer.