Who Owns the Sewer Service Line?

The sewer service line is owned and maintained by the property owner. Sewer service is defined as the length of the pipe between the house/business and the sewer main line, which is usually located in the street, easement, or alley.

Reporting a Problem

If you are experiencing sluggish drains or a sewer backup in your house or business, there could be a blockage in your service line or in the main sewer line. The City can check this to determine where the problem may be occurring and what action needs to be taken. Contact our Water Utilities Monday through Friday, 8 am – 5 pm. After hours, please call Longmont Police Dispatch, and they will notify a utility technician to respond to your call.

• The nature of the problem, such as sewer odor, sewer backing up, slow running drains, etc.
• Your Name
• Your Address
• Your Phone Number

The City of Longmont will send a crew out to investigate the problem and clean the main sewer line, if plugged. If a problem is found in our main line causing damage to your property through your service line, a claim should be sent through the City’s Risk Management Office at (303) 651-8435.

If you believe your sewer line is clogged or sewage backs up into your basement or crawl space only when you run water in your home or business, the problem is most likely in your service line system, and you may need to call a plumber to repair it. Plugged sewer lines are most frequently caused by tree roots, grease accumulation, or structural problems. Property owners are responsible for clean up and repair for problems originating in the service line system, including repairing damage to the street or driveway, if necessary.

Preventing Sewer Line Problems

Property owners can aid in preventing clogged sewer lines by not putting grease and greasy food scraps down the sink or garbage disposal. Grease and meat drippings should be collected in a disposal container and thrown in the trash. Any other greasy leftovers (such as bones, meat trimming, etc.) should be thrown into the trash.

In addition, the City performs sewer system “smoke testing” to help locate obstructions and defects in the sanitary sewer system to evaluate sewer conditions or connections that could allow storm water to enter into the sanitary sewer. Storm water can cause capacity problems in the sewer and increase wastewater treatment costs, which affects your monthly utility bill.

The information gained from smoke testing contributes to the City’s ability to control costs and maintain a high level of service for the Longmont community. Visit the Sewer System Smoke Testing webpage for more information.

Fat Trappers are used to collect fry pan grease for disposal to trash. Learn how to get your FREE Fat Trapper.

Never dispose of the following in down your drains or toilets:

• Antifreeze
• Motor oil
• Paint thinner and other solvents
• Oil-based paints (in any quantity, including clean-up waste)
• Latex-based paints
• Pesticides, Herbicides
• Pharmaceuticals or Over the Counter Medication

Learn more about how to dispose of these and other household hazardous waste.

Other items to never flush down your toilet:

• Wet Wipes or “Flushable” Wipes
• Sanitary Items
• Tissues and Paper Towels
• Rags
• Cotton Swabs
• Diapers
• Dental Floss
• Bandage
• Cigarettes / Cigar Tips
• Cat Litter
• Makeup remover pads
• Anything that is not Toilet Paper or Human Waste

Property owners and tenants should become familiar with the general layout of their plumbing systems, and especially the location of your sewer “clean out” outlet. The outlet cover is usually located in the yard and allows easy access to the more distant stretches of the private sewer line so blockages may be removed. A plumber can help locate sewer cleanouts, if you have any.

Commercial property owners should check their grease interceptors/traps and sand traps. Make sure they are cleaned on a regular basis and that records of the inspections are kept.

Roots in Sewer Service Line Notification

The City of Longmont completes periodic inspections of the sewer main line. During these inspections, crews may observe roots coming from of the sewer service line into the main line. When this occurs and the problem is severe enough, the City will attempt to notify the property owner regarding the roots in the sewer service line. This will allow the property owner to take action before a sewer backup occurs on their property as well as decrease any backup issues in the City’s sewer main line.

It is recommended for the property owner to remove the roots at the property owner’s earliest convenience to decrease the roots growth in the sewer line. The property owner may complete the repairs to remove the roots themselves or hire a plumber. The City does not provide a list of plumbers who can provide this service.

2025 Sewer Line Rehabilitation Projects

The City of Longmont has contracted with C&L Water Solutions, Inc. to rehabilitate the sewer main in the several areas south of 9th Avenue. These sewer main rehabilitations will consist mainly of trenchless methods (no digging required). 

During the actual time of sewer rehabilitation in your immediate area, you will be notified and residents should not use their water to prevent any backups in your home. Activities to avoid include showering, laundry, washing dishes, and flushing toilets. C&L Water Solutions, Inc. is not responsible for any backups due to water use during construction time. If water is used during the work hours, a sewer backup may not be noticed immediately but can still occur a day or two later, even after the sewer service is reinstated. Please be aware of the consequences of water use during this time.

This work is expected to begin in early July and last through December.