drone image of jones island wastewater treatment plant

Jones Island Odor 

Jones Island Water Reclamation Facility Odor Assessment, Modeling, and Capital Improvement Plan

Project Description

MMSD cleans billions of gallons of wastewater every year at two reclamation facilities that serve 1.1 million people in 28 communities. The Jones Island Water Reclamation Facility is located near the Milwaukee central business district and adjacent to the Milwaukee Harbor, situated underneath the Hoan Bridge.  The Jones Island Water Reclamation Facility has been managing our wastewater every day since 1925, now up to 390 million gallons a day, and sometimes that process smells bad. Although many odors are contained within the facility, some odors naturally drift to surrounding areas, especially during hot weather conditions.

In 2017, complaints of unpleasant odors from nearby neighborhoods increased.  A 2018 “Odor Source Evaluation Recommendations” memorandum identified nine primary odor suspects, and MMSD’s 2050 Facilities Plan identified over $55 million of potential capital investments that may be necessary to reduce these odors.

In response to the complaints, MMSD has taken initial steps to address odors through operational changes and by installing activated carbon filters, which adsorb and remove odors, on a pair of sludge blending tanks and in the thickening building. The purpose of this project is to create a comprehensive and sustainable odor reduction plan. Through the use of air dispersion modeling, which models how odors travel through the air in different weather conditions, MMSD will prioritize odor source management strategies. The modeling will be based on odor samples and complaint locations to ensure MMSD is responsive to past complaints.

Milwaukee Water Reclamation Odors

There are two distinct odors you may notice from the Jones Island Water Reclamation Facility – sewage and Milorganite. Sewage smells like, well the stuff that goes down the sewer. The sewage smell is often reported as smelling like chemicals, decay, or sulfur (rotten eggs). Milorganite, the fertilizer made from heat-dried sewage sludge, has a musty, earthy smell. If you think you are smelling either one of these odors please contact us. Every odor complaint is logged and tracked, and plant operations makes it their goal to respond and identify the issue.

Odor Sources at Jones Island

Different parts of the wastewater treatment process create different odors. The graphic below shows some of the top areas of wastewater treatment where nuisance odors have been identified to date. To see a video of the wastewater treatment process click here.

To report a smell please call 414-225-2256 for a response or if you don’t require a response fill out the Reporting an Odor Form.

Project Goals:

  • Create a plan to improve the quality of life throughout the community relative to Jones Island Water Reclamation Facility odors.
  • Assess how climate change will affect odors.
  • Incorporate social, environmental, and financial sustainable practices.
  • Recommend solutions to manage odors for the next 20 years.


Summer 2020 – Sampling and modeling; gather community input

Fall/Winter 2020 - Analyze results and draft improvement plan

Fall/Winter 2020 – Community meetings

Spring/Summer 2021- Final report and recommendations

Get Involved

If you think you are smelling an odor from the Jones Island Water Reclamation Facility, please call 414-225-2256 for an immediate response. MMSD staff will go out to investigate the smell and record the odor complaint. If you do not need a response but would like to report an odor complaint that will be included in the study, please fill out the Reporting an Odor Form. MMSD will conduct stakeholder and public outreach activities throughout the entirety of the project to provide information, obtain project input and feedback.

Stay tuned to this website and MMSD social media platforms (Twitter, Instagram, Facebook) for upcoming events.

Project Comment Form:

If you have questions about the project please fill out the form below.

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