Most of the water that you drink in Westminster starts at the Continental Divide, travels down Clear Creek and ends up in Standley Lake. From Standley Lake, the water is piped to one of the city’s two water treatment plants: the Semper Water Treatment Facility (near Pierce Street and 90th Drive) or the Northwest Water Treatment Facility (near Wadsworth Parkway and 104th Avenue).  These two facilities treat all of Westminster’s drinking water.

The treatment process begins with the initial chemical assessment of the water coming into the facility from the lake. Since the quality of water changes constantly based on conditions in Standley Lake, it is critical that the process is monitored 24/7 by on-site staff. Certified treatment operators continuously adjust and balance treatment options to provide consistent quality in the finished water that comes out of your faucet. 

Here’s how the process works:

• Chemicals are added during water treatment to remove impurities from the lake water and optimize the treatment process. 
• The chemicals react with the impurities to form larger particles during the flocculation stage of the treatment process. 
• These larger, heavier particles settle out of the water during the sedimentation stage and are filtered out during the filtration stage. 
• Ammonia and chlorine are carefully added during the disinfection stage in just the right concentrations to make sure the water is free of harmful bacteria by the time it gets to your home. 

It takes 31 employees to treat the water in Standley Lake for delivery to residents and businesses in Westminster. Many of these folks work 24/7/365 to ensure that you receive safe and clean water, while making sure that we meet and exceed state and federal drinking water regulations. 

How much water does Westminster actually need in a day?  It depends on the day, and especially on the season. In the winter, we treat about 10 million gallons each day, primarily for what customers are using inside their homes and businesses. In the peak of the summer, Westminster treats up to 40 million gallons a day. Why the difference? In a word: irrigation. In the summer, up to three quarters of what our customers use is for landscape irrigation. Since our treatment plants need to be able to provide that amount of water in the summer, the plants must be large enough to meet that “peak” demand on the highest water use day of the year.

Providing high quality water reliably to everyone in Westminster is a huge responsibility. It also comes at a cost. The rate increases adopted by City Council for 2017 and 2018 are funding the operations and maintenance that these two plants, and the entire water system, require to maintain this level of service to you. This also includes the wastewater system.

You have told us that you highly value this service, and it is with great pride that Westminster employees work to provide safe, clean and good-tasting water to you. 

Learn more about our water treatment facilities and where your water comes from.