Are You Noticing Sewer Odors?  

Sewer odors may come from the plumbing in your home, the 3,000 miles of city sanitary sewers, or the 300 miles of regional sewer pipes that the Milwaukee Metropolitan Sewerage District (MMSD) manages. At MMSD, ​​​we work hard to minimize any odors that may affect our community, but there are times when they may still be noticeable. 

You may detect two main odors near the water reclamation facilities

sewage and the earthy aroma of Milorganite® fertilizer. 

Several factors can increase the smell of sewerage odors in our community, such as the direction of the wind, rainfall, temperature changes, and maintenance work at the water reclamation facilities and regional sewer system.
 

If you smell an odor similar to sulfur, rotten eggs, or natural gas, leave immediately and call WE Energies at 800-261-5325 from another location.

 

If you smell sewage, please Report a Sewer Odor in the form below so we can investigate and notify your municipality. Reporting odors helps to promptly identify and address potential issues and minimize their impact on the community.

Report a Sewer Odor

 

What to Do If You Smell Sewer Odors in Your Home

If you have odor and standing water in your basement, DO NOT go into it. Electricity + Water = Danger.
Visit our “Water in Your Basement?” page for next steps.

If you are experiencing sewer odor and DO NOT have water in your basement, the first step is to check the traps in your plumbing fixtures and basement floor drain to prevent sewer gas odor from getting into your house (see below for the steps).
 

 

What is a Trap?

A trap is a U-shaped plumbing fixture designed to hold water, creating a barrier that prevents sewer gas odors from entering your home. At the same time, it allows wastewater to flow smoothly through your home’s plumbing system, into the local sewer system, and ultimately to the wastewater treatment facility.

Unused toilets and plumbing vent issues can also be sources of sewer gas in your home; a licensed plumber can assist with these concerns. If you check these common problem areas and you still notice odors, please report an odor in the form below, so we can investigate further.
 

How to Check the Trap Under Your Sink

Look under your sink to confirm if a trap was installed. If you see a trap, add water to the drain. If the sink is rarely used, water in the trap can evaporate over time.

The additional water will restore the seal within the trap and should address the odor issue. If your sink does not have a trap,  you may need to call a licensed plumber for assistance. 
 

A graphic that shows how a trap in your pluming fixtures can help prevent sewer odors

How to Check the Trap in Your Basement Floor Drain

Locate your floor drain, commonly found in basements, garages, or utility rooms if your home doesn't have a basement. In finished basements, floor drains might be hidden under carpeting. Some homes may even have multiple floor drains. Identifying where the odor is strongest can help pinpoint the location of the floor drain, especially if you have more than one.

Once you've located the floor drain, check if water is present by shining a flashlight into it. You should see a reflection on the water. If no water is visible, carefully pour water into the drain. The water will fill the trap, allowing water to flow through the drain pipe and creating a seal to block odors from entering your home.

If you have added water to the floor drain and still do not see water sitting in the pipe, you may not have a trap, in which case, you should call a licensed plumber for assistance.

 

 

Report a Sewer Odor to MMSD

We want to hear from you if you notice sewer odors in your community or your home despite properly functioning plumbing traps and basement floor drains. Reporting these odors helps MMSD and your municipality identify and address potential issues, ensuring a healthier and more comfortable environment for everyone.

Thank you for taking the time to notify us of your odor concerns. MMSD may contact you if further information is needed. If you need immediate assistance, please call MMSD at (414) 272-5100.