With wastewater treatment, odors are always a concern. In an effort to address them, we endeavor to not only respond with action when situations arise, but also educate the public on what causes the odor and what mitigation steps are available in controlling them during the treatment process.
Recently, there have been H2S alerts related to wastewater treatment plant operations and seasonal factors, as well as odors associated with digested sludge (biosolids that are the resulting product from the digestion process) in the lagoons at the West County Wastewater District.
Warm, Still Air Can Impact Odors
A reality of the warmer season is that the treatment plant at Canal Blvd sometimes gives off more odors due to increased temperatures, plant age and design, still air (lack of mixing) and other factors. The City has installed H2S monitors near the treatment plant borders and H2S is more prevalent during the late spring and summer months. H2S can evolve at the treatment plant but is also produced by bacteria in sewers and is a byproduct of industrial activities and manufacturing, petroleum refining and transport and can come from marshes and wetlands. We do take measures to minimize the impacts of odors and H2S on our neighbors, investigate complaint calls and H2S alerts from the H2S; that will continue to be our priority.
Digested Sludge and Odor Management
Veolia partners with the City of Richmond and West County Agency to dry digested sludge at West County lagoons prior to ultimate disposal at an appropriate landfill. When wastewater enters the Richmond wastewater treatment plant through the sewer system it is treated, biosolids are produced, treated and carefully monitored to ensure they meet Class B Biosolids requirements. The product that emerges from the digester is referred to as digested sludge or biosolids and it is piped to lagoons approximately five miles from the plant (along the Richmond Parkway). Biosolids are dried until the point where they are ready to be hauled to a landfill.
When the sludge is first pumped to these lagoons, it is treated with a type of deodorant to mitigate odors. In December of last year, we experienced a digester upset for several days at the treatment plant and for a period of time the sludge produced was more odorous than usual. At the time of the digester upset, the sludge took longer to stabilize and the odors took longer than normal to dissipate. The City of Richmond and Veolia Water are rehabilitating Digester #2, a project which is expected to be complete by early October and will reduce the risk of a similar digester upset. In addition to the digester project, operational and monitoring improvements have been implemented to prevent a repeat occurrence.
We recognize that residents living close to these treatment facilities expect to maintain a quality of life that is not impacted by odors and we are committed to doing everything possible to ensure that those expectations are met.
If you have any questions or concerns related to the work we are doing, please contact us at (510) 412-2001.