Fun Fact: Super Bowl Sunday causes a wastewater spike into the Big Dry Creek treatment plant as many families watch the big game at home – and flush the toilet and wash lots of dishes. The Super Bowl and Mother’s Day create the largest peaks of flow into the plant each year.

After leaving your house and traveling through the city’s collection system, Westminster’s wastewater is cleaned at one of two treatment plants. The Big Dry Creek wastewater treatment plant, located in the northeast corner of the city, serves about two thirds of our community and receives wastewater from homes and businesses that are generally north of 92nd Avenue. In the southern part of the city, the city has a partnership with the Metro Wastewater Reclamation District to treat our wastewater on a contractual basis. 

Wastewater must be treated before being released back to local streams in order to maintain public health for everyone living along the Front Range – and it’s the law too. Raw sewage contains harmful bacteria that are toxic to local wildlife and can cause severe illness in humans. The federal Clean Water Act sets water quality standards that every community must meet before releasing treated wastewater back to the environment. Westminster’s permit contains limits on temperature, copper, mercury, E.coli, pH and many other parameters.

At the Big Dry Creek treatment plant, the city doesn’t use any chemicals to clean wastewater, it is entirely a biological treatment process. Special bacteria feed on nutrients in the wastewater and remove them. This treatment process would occur naturally, but much more slowly, so the primary job of the treatment plant operators is to make sure these “bugs” are as happy as can be. This means maintaining the optimal amount of food (wastewater), shelter (warm tanks) and air (lots of extra bubbles) for the bacteria to act like it’s Thanksgiving every day of the year.

The full treatment process creates clean water and biosolids. It takes about 12-18 hours for a gallon of raw sewage to come into the Big Dry Creek treatment plant, get cleaned up and released for another use.
The clean water is released to either Big Dry Creek, or the city’s reclaimed water system that is used for turf grass irrigation. Biosolids are non-toxic materials rich in nitrogen, organic matter and trace nutrients. Westminster uses these biosolids as fertilizer on the city-owned farm near Strasburg, Colo.

A team of talented staff and some big infrastructure enable Westminster to consistently meet the wastewater permit requirements. 

As federal water quality standards become more stringent to protect public health and more residents choose to move to our great city, costs for wastewater collection and treatment are increasing. In spite of recent and future rate increases, wastewater costs are still quite a bargain – it costs less than a penny for each toilet flush to make that water clean again.