Is Denver water safe to drink?

Yes, and Denver Water reports it meets or beats federal standards. Safe is not the same as good, though. Here is what is actually in it: hardness, chloramine, and the lead service line question.

Short answer: yes. Denver Water treats its water to meet federal and state standards and publishes the test results every year. It is not a Flint situation and it never has been.

But “safe” and “good” are different questions, and most people asking this one actually want to know about three specific things. So here they are, with the numbers.

1. The taste and smell: chloramine

Denver Water disinfects with chloramine, chlorine combined with ammonia. So do Aurora, Thornton, Westminster and Castle Rock.

Chloramine is used because it stays stable far longer in the pipes than free chlorine does, which keeps water protected all the way to the last house on the line. The trade-off lands in your kitchen:

• It does not gas off if you leave a pitcher in the fridge.
• Boiling does not remove it.
• Cheap carbon filters underperform on it, because it needs much more contact time than free chlorine.

If the smell bothers you most in the shower, that is normal. Hot water and steam release it into the air. It also means an under-sink filter cannot fix that particular complaint: the water has to be treated where it enters the house. More on chloramine and what removes it.

2. The hardness: Denver Water doesn’t publish a number

This surprises people, and it is worth knowing before you let anyone quote you a figure for “Denver’s hardness.”

Denver Water’s own hardness page gives a classification rather than a measurement:

Denver’s water can be classified as soft to moderately hard.

It adds three things that matter more than a single number:

• The water is slightly harder in winter, when waterways and reservoirs freeze and the water picks up more minerals, and softer from late spring through fall, when runoff dilutes them.
• The southern collection system is moderately hard; the northern system is somewhat soft.
• For scale, the USGS calls anything under 60 mg/L soft, and 121 to 180 mg/L hard.

So if a salesperson tells you Denver runs 12 grains per gallon, ask where the number came from. Several filtration company sites publish Denver hardness figures that contradict each other and the utility. Ours comes from a titration test at your kitchen tap, on the day, with the result written down.

For context, the neighbors who do publish numbers: Thornton averages about 200 mg/L (11.7 gpg) and Pueblo about 180 mg/L (10.5 gpg). Hardness for every Front Range city.

3. Lead: the real issue, and it is not the water leaving the plant

This is the part worth reading carefully, because it is the one genuine health question in Denver, and the answer is about your plumbing, not the supply.

Water leaves Denver Water’s treatment plants lead-free. Lead gets picked up on the way to your tap, from a lead service line (the pipe connecting the main to your house) or from lead solder and older fixtures inside the house.

What Denver Water is doing about it:

• It runs a Lead Reduction Program launched in January 2020, a 15-year effort to replace every lead service line in its system at no direct cost to the customer.
• It estimates 60,000 to 64,000 properties may have one. More than 15,000 were replaced in the program’s first three years.
• The program exists under an EPA variance that lets Denver Water raise pH and alkalinity instead of adding orthophosphate. In 2022 the EPA said the replacement program “has been shown to be more effective than orthophosphate treatment.”
• Customers who may have a lead line get a free filter pitcher certified to remove lead, with cartridges mailed to them, and are told to use it for drinking, cooking and mixing infant formula until the line is replaced and for six months afterward.

So if you are in an older Denver home: check your status with Denver Water first. If you are in the program, you already have a filter, and it is the right tool for now.

Where we come in, honestly: when that program ends for your address, the pitcher stops arriving. A 10-cup pitcher that needs a new cartridge every month is also a chore, which is why plenty of people replace it with an under-sink system. If lead is your specific concern, the answer is not a whole-house softener. It is reverse osmosis at the kitchen sink, and ideally a certified lab test before and after so you have the number in writing.

What about PFAS?

Colorado has real PFAS stories, and they are geographically specific:

• Fountain, Security and Widefield in El Paso County dealt with PFAS from firefighting foam at Peterson. Those systems installed treatment: Fountain brought carbon online in 2018, Security’s ion exchange plant in 2021.
• Commerce City and South Adams County have PFAS in wells traced to the Suncor refinery area, and the district is building a treatment plant.

For Denver Water customers this is not the headline issue, and Boulder’s 2025 report found no detectable levels of the six regulated PFAS. If you want certainty for your own address, that is a lab panel question, not a marketing question.

So do you need anything?

Here is the decision, minus the sales pitch:

Read it yourself

You do not have to take our word for any of this. Denver Water publishes its annual water quality report, and it is the single best source on your own supply. Look for hardness (in mg/L, divide by 17.1 for grains per gallon), the disinfectant residual, and your treatment plant.