pond and bridge landscape


The City of Thornton Wastewater Collection System maintenance staff is charged with protecting the public's health and safety by maintaining the integrity of the new and existing wastewater systems.

Did You Know?

Historians consider the development of sewer systems and wastewater plumbing to be one of the defining qualities of a civilized society.  The City of Thornton Wastewater Collection System consists of approximately 486 miles of infrastructure.

Wastewater Collection Systemtv inspection cropped.png

The City of Thornton Wastewater Collection System maintenance staff is charged with protecting the public's health and safety by maintaining the integrity of the new and existing system. The maintenance team is responsible for monitoring the condition of the wastewater infrastructure through tv inspection for root intrusion, breakage, and infiltration. Washing of sewer lines ensure that lines are free of obstructions.

Wastewater personnel may be seen in public responding to calls or performing routine maintenance wearing additional protective equipment.  This includes protective gowns or white protective coveralls, goggles, masks and gloves.  These are recommended for the protection of our personnel and the citizens we serve.

Sewer taps are scheduled and performed for new development. The City also inspects six sewage lift stations twice per week and emergency generators are exercised weekly to provide reliable operation.

Don't Flush This Stuff!

  • Disinfecting wipes
  • Baby wipes
  • Mop refills
  • Towelettes
  • Paper towels
  • Q-tips
  • Dental floss
  • Diapers

Even if it says 'Flushable,' these items clog your sewer system resulting in an expensive cleaning and possible damage.  Increased power-costs to run a clogged pump and maintenance costs to the city's sewer system are passed on to the consumer in higher sewer rates.  Don't use your toilet as a trash can!  The only thing that should be tossed in the toilet is toilet paper!

Got Grease?

Cooking grease is not a good match for your sanitary sewer system! Some people think that by adding hot water from the kitchen faucet, the grease will just disappear. There is some truth to this. The grease will break down with heat from the hot water, but when it cools down it will solidify in your private sewer service, the city sanitary sewer system, or both. Sewer pipes are sized to accommodate the anticipated maximum flows that can be delivered through the pipe. As fats, oils, and grease cools underground in the sewer pipes, it attaches itself to the pipe walls and lessens the capacity for maximum flow levels. Eventually, the grease can build up enough to nearly or completely block off all sewer flow in an area near you. When that happens, a back-up in your home plumbing can occur or cause a blockage in the city sewer system that can result in a sewer spill from one of thousands of sewer manholes that we maintain. Sewer spills could result in discharging untreated sewer into storm drains, creeks, and waterways in our neighborhoods. Sewer spills impact the environment and the habitat that depends upon clean water to survive.

Through all this, there is hope and an easy way to reduce and eliminate the problems that fats, oils, and grease can cause in the sewer system! It's as easy as using a standard sized food can with the lid completely removed to pour your household cooking grease into. As it cools, it too will start to solidify in the can, much like it would have done had it been washed or flushed down the plumbing drains. When the can gets close to being full, discard the cooled grease can into your garbage. This action alone will help to reduce sewer blockages, sewer spills, help protect our environment, and reduce extra maintenance costs to keep the sewer lines free of grease deposits. You "can" make a difference!

If you have problems or questions about sewer lines, email UtilOperation@ThorntonCo.gov or call Utilities Operations at 720-977-6500.

Wastewater Treatment

Thornton's wastewater is treated at the Metro Wastewater Reclamation District. For more information visit their website at www.metrowastewater.com or call Metro at 303-286-3000.

Important Numbers

  • Report a Sewer Problem - 720-977-6500
  • After Hours Emergencies - 720-977-6500
  • Wastewater Lines Maintenance - 720-977-6500
  • Metro Wastewater - 303-286-3000