Colorado is home to some of the most celebrated water sources in the country. Snowmelt from the Rocky Mountains feeds reservoirs and rivers that supply millions of residents across the Front Range and beyond. Municipal water utilities throughout the state treat this water to meet or exceed federal drinking water standards before it reaches your home. But the question "Is my tap water safe?" is more nuanced than a simple yes or no. Here is what Colorado residents should understand about their tap water.
Blog
Is Colorado Tap Water Safe to Drink? What You Need to Know
Understanding municipal water treatment, federal standards, and the variables that affect what reaches your glass.
Get Our Free Water Quality Guide
Download our comprehensive guide to understanding your home water quality in Colorado.
How Colorado Municipal Water Is Treated
Every public water system in Colorado is required to follow treatment protocols established by the U.S. Environmental Protection Agency (EPA) under the Safe Drinking Water Act. The typical process begins with coagulation and flocculation, followed by sedimentation, filtration through sand, gravel, or activated carbon, and finally disinfection with chlorine or chloramine.
Major utilities like Denver Water, Aurora Water, and Colorado Springs Utilities publish annual Consumer Confidence Reports detailing the results of thousands of tests conducted throughout the year. These reports are publicly available and provide a snapshot of what was detected in the treated water supply.
What the EPA Regulates -- and What It Does Not
The EPA currently regulates over 90 contaminants in public drinking water, setting enforceable Maximum Contaminant Levels (MCLs) for substances such as lead, arsenic, nitrates, and disinfection byproducts.
However, hundreds of other substances remain unregulated. The EPA maintains a Contaminant Candidate List (CCL) of chemicals and microorganisms that are known or anticipated to occur in public water systems but do not yet have enforceable standards. Emerging contaminants such as PFAS, pharmaceutical residues, and microplastics fall into this category.
In 2024, the EPA finalized the first-ever national drinking water standard for several PFAS compounds, marking a significant step toward regulating these persistent chemicals.
The Journey from Treatment Plant to Your Tap
Even when water leaves the treatment plant in compliance with all federal and state standards, it still travels through miles of underground distribution mains, a service line connecting the main to your home, and your home's internal plumbing before reaching your faucet.
Each stage introduces variables. Aging distribution pipes can contribute trace metals or sediment. Service lines made of lead, galvanized steel, or other older materials may affect water quality at the point of entry. Water that sits in pipes overnight can accumulate higher concentrations of dissolved metals, which is why first-draw water can differ from water that has been running.
Colorado-Specific Considerations
Much of Colorado’s water originates as snowmelt, which is naturally soft and low in minerals. However, as water is transported, stored, and treated, its mineral content can change. The characteristics of your local source water directly influence the treatment approach and the final quality at your tap.
Communities on the Eastern Plains that rely on groundwater sources often have harder water with higher concentrations of calcium and magnesium. These areas may also see different trace mineral profiles compared to Front Range surface water supplies, making local testing especially relevant.
Wildfire activity, which has increased in recent years, can affect source water quality. Ash and debris from burned watersheds can introduce elevated levels of manganese, dissolved organic carbon, and sediment into reservoirs, requiring utilities to adjust their treatment processes in response.
Colorado’s rapid population growth has led to significant infrastructure expansion. New developments connect to modern distribution systems, while older neighborhoods may rely on infrastructure that is decades old. This means water quality at the tap can vary meaningfully even within the same city.
What You Can Do
1
Read Your CCR
Review your utility’s annual Consumer Confidence Report to learn what is being detected at the treatment level. These are publicly available on your utility’s website.
2
Check Plumbing Age
Consider the age and material of your home’s plumbing. Homes built before 1986 may have lead solder, and older service lines can affect what reaches your tap.
3
Get a Home Analysis
A home water analysis can measure hardness, pH, chlorine levels, TDS, and the presence of specific metals at your actual point of use -- data your city report does not cover.
4
Flush Your Tap
Run your cold water tap for 30 seconds to two minutes before drinking or cooking, especially first thing in the morning. This flushes stagnant water from your pipes.
Disclaimer: The Water Awareness Foundation is an independent educational organization. We are not affiliated with any government agency, water utility, or regulatory body. The information in this article is for educational purposes only and should not be interpreted as medical or legal advice.
Curious About Your Tap Water?
A home water analysis can reveal what your city report does not cover. No obligation, no pressure.