Odor Control

Being a good neighbor is important to us at MSD. Odor control is just one more way that we strive to keep our customers’ concerns first and foremost, and help make our growing community an even better place in which to live—by working side by side with community residents and leaders.

Drains and pipes that are connected to sewer systems sometimes smell like rotten eggs. Sewer odor, which is caused by hydrogen sulfide, naturally forms when sewage and other materials decompose. Hot, dry weather conditions and other factors contribute to the production of sewer odors. 

While sewer odor is unpleasant, it is not a serious threat to people, animals or plants in the small concentrations that may develop in most homes and commercial buildings. Indoor drains, as well as the sewer system, are designed to prevent sewer odor from escaping.

Inside Your Home

Inside drains typically have water traps that keep sewer odor from seeping out. The curved pipe underneath your bathroom or kitchen sink is an example. When such a trap is filled with water, sewer odor stays inside the pipe.

Adding 3 gallons of freshwater to smelly drains — or to ones that are not used on a daily basis — can prevent sewer odor in your home or business. This should be done regularly during dry weather when the temperature outside exceeds 70 degrees, and in the wintertime when heating decreases the moisture inside buildings. 

Make sure that you check under your sinks for drain pipe leaks. If you are not comfortable doing this yourself, ask a licensed plumber to inspect your pipes for leaks and estimate repairs.

Outside Your Home

The majority of outdoor catch basins feature traps, as well. If you detect sewer odor close to an outside catch basin, please contact MSD’s Customer Relations at 502.540.6000 or CustomerService@LouisvilleMSD.org.

Tell us the precise location of the odor, so that this problem can be corrected quickly. 

MSD’s Odor Control Efforts

MSD invests more than $2 million annually to control odors and address customer concerns. Various treatment processes — including chemical, biological and thermal oxidation technologies — are used to reduce odors from treatment plants and from the sewer collection system.  

MSD contracts with odor specialists to help with the management of odors from the collection system. Professional assistance allows us to monitor hydrogen sulfide levels in the collection system and implement the most effective improvements. This also helps MSD with response to customer concerns regarding odor issues.

We have a goal of “no nuisance conditions” from our Water Quality Treatment Centers. Our Odor Control Master Plan includes scientific identification and quantification of odor sources. Our goal is to identify specific odor sources at our Water Quality Treatment centers and other locations in the wastewater collection system that may cause nuisance conditions and utilize a variety of technologies to control these odors. 

If you experience any nuisance sewer odors, contact us right away at 502.540.6000 or email CustomerRelations@LouisvilleMSD.org. The sooner we hear from you the better chance we have of identifying the source.

Below is a map of our Water Quality Treatment Centers.

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Morris Forman Cedar Creek Derek R. Guthrie Floyds Fork Hite Creek

Odor Control Technologies

View  MSD Odor Control Projects

Odor Brochure

To report a sewage-related odor, please call MSD's Customer Service at 502.540.6000.