Long-Term Odor Reduction Remedy at Dubuque Water & Resource Recovery Center Starts Next Week 

MAY 10, 2024

The City of Dubuque Water and Resource Recovery Center (WRRC) will begin the 6-8 week process of removing stored waste from the facility the week of May 13, 2024. This process could result in a short-term increase in strong odors but is expected to produce long-term benefits because the stored waste has been the source of strong odor emissions that have impacted residents throughout the community.  

An error by a private contractor during a routine inspection at the WRRC late last fall resulted in inoperable equipment for an extended period. Without the use of the equipment, two of the facility’s four anaerobic digesters went “dormant” and could no longer accept and treat waste. To maintain operations and adhere to permit limitations, the City was forced to divert waste from the normal treatment process and, instead, temporarily store it in the open-air (uncovered) excess flow tanks that allow odor-producing gases to readily escape into the atmosphere. The odor from these tanks caused significant odors from the WRRC to impact parts of the community. 

The first step to address the short-term odor issue was to bring the anaerobic digesters back “online” within normal operational parameters. That was achieved on April 2, and waste handling returned to normal operations at the WRRC at that time.   

To eliminate the odor for good, the 1.7 million gallons of waste stored at the WRRC must be removed from the temporary storage tanks. The process will involve mixing the waste, pumping it into trucks, and hauling it to other treatment facilities in the region. The estimated time to remove all the waste and clean the temporary storage tanks is 6-8 weeks. It will require over 300 truckloads to haul the waste away for disposal. 

The process of identifying potential disposal options first required testing, analyzing, characterizing, and quantifying the waste. Strategies for treatment and disposal involved either treating the waste at the WRRC, hauling it to an offsite treatment facility, or a combination of the two. While the WRRC can treat some of the waste, it can only accommodate a limited amount which would require several months to deal with all the excess waste. Therefore, efforts focused on identifying offsite disposal alternatives in accordance with applicable environmental regulations.  

Removing the odorous stored waste is separate from the City’s ongoing wastewater odor reduction efforts. A study is currently underway that involves identifying where hydrogen sulfide (the most common odor-producing compound involved in wastewater treatment) is most prevalent in the facility’s treatment system, then adding chemical dosing to the system to effectively reduce hydrogen sulfide while not hindering the overall effectiveness of the treatment process. For additional details on this issue, please visit www.cityofdubuque.org/odorcontrol.

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MEDIA CONTACT
Deron Muehring, Water & Resource Recovery Center Director
DMuehrin@cityofdubuque.org, 563.589.4177