The City and County of Denver is working to improve and rehabilitate storm and sanitary (wastewater) mainlines citywide. Wastewater mainlines are usually located in streets or alleys. Some of these systems are more than 100 years old.
A sanitary mainline is a large pipe where the water from residential appliances (dishwashers, washing machines, sinks, toilets, showers and bathtubs) flows after it leaves a home or business. A storm mainline collects stormwater that is generated by water (from storm events, snow melt or other sources) running across the surface of impervious surfaces, such as streets, sidewalks, parking lots, and roof tops.
The process uses a polymer resin lining to preserve the integrity of wastewater systems, preventing failures in older lines and minimizing any leakage into soil or waterways. This method is also less invasive to neighborhoods compared to open cut projects around the City. Each main can be lined in a single day, allowing crews to complete work on a street with minimal traffic or access impacts.
To check progress on neighborhood lining projects, see the current project list below.
If your basement’s bathroom or laundry room has a pump that sends your sanitary flows up to your first-floor sanitary pipes, you do not need to contact us. Please refrain from using these and your other sanitary facilities (laundry, bath, dishwasher, etc.) on the day of the lining.
The mailer that was sent out in advance of the project didn’t make it clear that we are only concerned with foundation sump pumps. If your foundation sump pump empties out the side of your house, this is not a concern for our project. If your foundation sump pump is piped inside your house to a sanitary drain — typically a sink or laundry drain — please inform the contractor.
This page includes links to current lining projects with maps of the sanitary mains that have been selected for this project. Some mains are located in alleys at the rear side of your lot. If you are unable to determine if your main will be lined, please contact the project manager listed on the neighborhood page.
No. A resin-lined bag is inserted in one manhole and fed to the next. It is then inflated, heated, and as a result, hardened. Once hardened, openings are cut in the liner to allow you to continue using your sanitary services as usual.
On the day your main is lined, we ask that you refrain from using your sanitary services (typically from 8:00 a.m. to 4:00 p.m.).
There will be minor traffic reconfiguration as well, but the contractor will likely do several hundred feet per day, so your daily travel should only be impacted for a few days.
There may also be an odor in the air due to the curing process.
A mailer will be sent out several months before construction, and a door hanger will be provided a day or two prior to construction with tips to help minimize odors indoors at your house/business.
Don’t be concerned; there may be a chemical odor present during the lining process. The best way to limit the odor level is to ensure that all floor drains and P-traps have water in them. This can be done by pouring a few cups of water in all floor drains and seldom-used sinks, drains, toilets, etc. Talk to the contractor when they arrive on your street if you have questions about how to manage this. It is also helpful to open windows and use ceiling or box fans to move the air out of the building or home.
The total project will take up to 7 months, but each main will be lined in a single day.
If your main is being lined, we do ask that you refrain from bathing, washing clothes, etc. on the day that your main is being lined. The next day, the contractor will be lining another main, and you can use your bathrooms, sinks, etc. just like any other day.
We are aware that some businesses (laundromats, diners, hotels, etc.) have to use their sanitary services throughout the day. Special accommodations, such as bypass pumping and night-lining, can be made in these instances. Please contact the project manager for your neighborhood.
An orange door hanger will be placed on your front door when your service has been restored.