What It Takes To Treat Your Water

Every drop matters – and when we say that, we mean it literally. The water that arrives to each of our customers has been filtered and treated with one thing in mind: quality. From reservoirs to Thornton’s treatment facilities to our infrastructure, maintaining the quality of your water is the most important step of the process.

The city of Thornton is required to report on water quality every year and must maintain compliance with the Colorado Department of Public Health and Environment (CDPHE) and Environmental Protection Agency (EPA) water rules.

Check out the video below to learn about the importance of water quality and how we achieve it.

Where Does Thornton’s Water Come From? And Why Does It Have To Be Treated? 

Thornton uses water from multiple watersheds – the area that flows into that common body of water – including the Upper South Platte River and Clear Creek headwaters.

In 2028, we will add a high-quality water source to this list by sourcing from the Cache la Poudre River. In the 1980s, Thornton purchased water rights in the Water Supply and Storage Company, which diverts water from the Poudre River. The 70-mile Thornton Water Project pipeline will bring high-quality water from these reservoirs to our community. Learn more in our Thornton Water Project Waterblogged post!

Having water from multiple watersheds allows our Water Quality team to test, treat, and combine water from various sources to reliably deliver the best water possible. But your water isn’t simply mixed and sent to your door – first, it undergoes a state-of-the-industry treatment process.

Have you ever seen a family of ducks swimming in a reservoir? Or when a big rainstorm causes dirty runoff from the streets or sidewalks? Nobody wants to drink that. We don’t control what happens with nature, and we certainly can’t predict it. Our priority is removing unwanted particles and germs from our source water so your drinking water is clean and safe when it reaches you.

Some of the contaminants that may be harmful to our health that we work every day to remove include:

• Microbial contaminants, including bacteria and viruses from wildlife, livestock, and wastewater treatment effluent. Remember that cute family of ducks we mentioned earlier?
• Salts, metals, or other inorganic contaminants present due to urban storm runoff, mining, and more. In other words, we need to remove anything that would not have been there otherwise without humans.
• PFAS – per- and polyfluoroalkyl substances – are thousands of manufactured chemicals used in consumer products since the 1940s that have been found to carry the possibility of health-related effects. Earlier this year, the EPA released a new drinking water regulation for six PFAS compounds, and we are proud to say Thornton is already proactively meeting the new limits – five years ahead of schedule! Temporary measures, such as source water blending and additional water treatment chemical doses, helped reach this goal while we pursue longer-term strategies to maintain compliance when PFAS concentrations are expected to be higher.

Our Water Treatment Facilities

First, we have the Wes Brown Water Treatment Plant. This facility processes up to 50 million gallons of water per day using ultrafiltration (UF) technology to remove contaminants from source water.

Water at this facility first receives chemicals to clarify the water, which allows any particles to sink to the bottom. This creates “clarified water,” which is carried to the next step. The clarified water is channeled through UF membranes, where it is treated on an even smaller scale, removing pathogens, viruses, and bacteria. Finally, the water is carried to the pump station for a final round of disinfection.

Second, we have the Thornton Water Treatment Plant – the newest member of our water quality family! Treating Thornton’s water since 2020, this facility processes up to 20 million gallons of water daily and is key to improving the taste and smell of your water.

The first step is adding coagulants, which cause small particles and microorganisms to separate from the raw water. The coagulants help unwanted particles and microorganisms, called “floc,” to stick together and grow larger as large paddles mix the water. Then, the “floc” is separated by gravity from the clean water in the sedimentation basins. Next, ozone is added to the clean water to break down organic compounds before it travels to the heart of the plant: biofilters. These organic compounds are filtered out with Granular Activated Carbon (GAC) and fine sand, causing contaminants, bacteria, and metals that squeaked by in the previous steps to be filtered out for good. Lastly, a low dose of chlorine is added to meet Colorado’s water quality standards as the treated water travels through 668 miles of pipe.

To learn more about our treatment facilities, visit the city of Thornton’s Water Treatment webpage.

Explaining Water Hardness, Taste and Smell

Water Hardness

Hard water is caused by high concentrations of mineral deposits in the water supply and can vary depending on the time of year – especially depending on current drought conditions. The minerals that cause water hardness are OK to drink. In fact, the World Health Organization said water is an excellent source of calcium and magnesium! Thornton’s water hardness is in the normal range for water in the western U.S. If you’re frequently cleaning off mineral buildup, try using a 1:1 mixture of water and white vinegar. This solution works well for cleaning fixtures or soaking dishes to remove mineral deposits. Hand-drying fixtures and dishes can also help reduce these deposits.

Taste & Smell

Natural elements, minerals, and nutrients influence water’s taste and smell. Naturally occurring algae in water storage reservoirs produce compounds that can be detected by our noses and tastebuds in very low amounts. Thornton tests for these compounds weekly and optimizes treatment to keep levels in check. Taste and smell can also change depending on the time of year. Visit our Taste & Smell Waterblogged Post to soak up more facts about the natural components in our water and how they’re filtered out during treatment.

Have a Thirst for Knowledge?

To say that water can be complicated between chemistry, infrastructure, filtration, and more is an understatement. If you’re interested in learning more, check out the current Water Quality Report on the city of Thornton’s website. In the meantime, we’ll continue to guarantee that every drop of water – again, literally – that reaches you, your residence, and your families meets standards for safety and quality.