City of Denver Public Water Systems Water Quality Report

DID YOU KNOW water quality reports, also known as “Consumer Confidence Reports (CCRs),” are annual documents that all public water systems are required to provide to you via mail and online. These reports are supposed to provide important information about the quality of the drinking water delivered over the previous year.

They can be difficult to read or understand. They are often many pages long and contain complex tables and charts. Culligan Water wants to change this and help you MAKE SENSE OF YOUR WATER.

This easy-to-read report will provide you with the following:

Denver’s drinking water system is supplied by a diverse network of reservoirs and treatment plants designed to serve millions of residents throughout the region.

Water is treated at advanced purification facilities using processes such as:

Some treatment facilities also use advanced oxidation and granular activated carbon filtration, helping remove organic compounds and improve overall water quality before the water enters the distribution system.

Denver’s drinking water primarily comes from snowmelt captured in mountain reservoirs across Colorado.

Water supplies originate from multiple river basins, including:

This water is stored in reservoirs such as Strontia Springs, Spinney Mountain, Turquoise, and Dillon, before being treated and delivered through the city’s distribution system.

Seasonal changes in water supply can influence mineral levels, taste, and water hardness throughout the year.

Denver utilities use chloramines as a disinfectant to maintain water safety as it travels through miles of pipes.

Chloramines are a combination of chlorine and ammonia that help protect drinking water from microbial contamination.

While effective for public health protection, chloramines can sometimes create:

Many homeowners install whole-house carbon filtration or reverse osmosis systems to improve taste and remove residual disinfectants.

Denver water contains naturally occurring minerals that come from mountain geology and regional watersheds.

Common mineral characteristics include:

These minerals are not harmful but can influence:

Because of this, many Denver homeowners install water softeners or drinking water filtration systems.

Denver’s drinking water meets state and federal standards, but it can still contain trace levels of certain substances that affect taste, odor, or day-to-day water quality in the home. Below are a few common water quality highlights reported in Denver’s Water Quality Report.

Some contaminants are monitored closely because they can be present at trace levels as part of normal water treatment. Denver reports these results to help track long-term water quality and treatment performance. While the results shown remain below EPA limits, these disinfection byproducts can still be a concern for some households over time.

Yes. Denver’s water is considered slightly hard, with an average hardness of about 113 mg/L as calcium carbonate. Hard water isn’t a health concern, but it can leave mineral buildup on faucets, dishes, and appliances — and it can make soaps and detergents less effective. A water softener helps reduce scaling, improves lather and rinsing, and can help plumbing and water-using appliances run more efficiently over time.

Denver’s report includes an Unregulated Contaminants Monitoring Results (UCMR5) section, and in the results shown, lithium was the only contaminant reported as detected. Over 25 results are listed as detected in that UCMR5 section. Even so, PFAS remain a broader concern across the U.S. as monitoring expands, and many homeowners choose proactive filtration for added peace of mind.

Water quality can vary from neighborhood to neighborhood depending on plumbing age, seasonal water sources, and local infrastructure.

A professional water test can help identify:

Schedule a free water test today to better understand your home’s water quality and treatment options.