Air Quality & Odor Reduction

Odors and pollution are more than a nuisance. That’s why the City of Kalamazoo has been reducing the impact of wastewater treatment and working with businesses to reduce their impact too. We've improved our processes for wastewater treatment to reduce the impact from loading trucks and our treatment processes:

• Envirosuite monitoring was installed in 2019, continusouly monitoring the levels of odor-causing compounds.
• We consulted with odor reduction companies to identify effective additives, including adding peroxide to the primary biosolids tank and using proprietary biosolids odor reduction chemistry.
• We installed five industrial air filters ("carbon scrubbers") to remove hydrogen sulfide.
• We implemented sewer modeling, to better track and identify sources of odors from within the wastewater collection system. 
• Updated septage receiving and handling processes.
• We replaced belt presses with centrifuges to remove more water and create dryer biosolids.
• We realigned the effluent sewer from Graphics Packaging with a new smooth-flow, airtight sewer to prevent any odor causing gases from escaping (watch a video update from October 2024). 
• We installed Just Air for PM2.5, PM10, and NOx monitoring.

The City of Kalamazoo collaborated with EGLE to conduct an air modeling study to use existing Envirosuite data to better predict the location and distribution of potential odors. The Phase 2 study(PDF, 7MB) confirmed that the “Long-term average H2S concentrations above the U.S. EPA RfC of 1.4 ppb from the combination of all emission sources are unlikely to occur outside GPI or KWRP property lines”. Starting in February of 2025 the new sensors will be relocated to enhance emission source attribution.