Denver’s drinking water comes from Denver Water (EPA system CO0116001), which draws surface water from a river, lake or reservoir and treats it before distribution for about 1,287,000 people. EPA’s records associate 10 sizeable community systems with Denver; Denver Water is the main one, and it is the system this page examines in depth. This page translates that system’s official EPA record — lead and copper results, violation history, and what the data does and does not say — into plain English.
This page is built entirely from the U.S. EPA’s Safe Drinking Water Information System (SDWIS), the same records state regulators use. We did not test Denver’s water, and system-level data describes the utility’s water as a whole — not what comes out of one specific home’s tap. Where the record is silent, we say so rather than guess.
Key takeaways
- Denver Water supplies Denver (Surface water); it serves about 1,287,000 people across its service area.
- Denver Water’s most recent reported 90th-percentile lead result is 3.6 ppb, below the EPA action level of 15 ppb.
- No health-based violations in the last 10 years of EPA records for Denver Water.
- EPA does not track hardness. If you’re shopping for a softener, test first and size from a real grains-per-gallon number.
The water system serving Denver
Denver Water is the community water system the EPA associates with Denver, Colorado. It reports a population served of about 1,287,000.
| System | EPA ID | People served | Source water | Role |
|---|---|---|---|---|
| Denver Water | CO0116001 | 1,287,000 | Surface water | Main system |
| Crestview Wsd | CO0101040 | 23,756 | Purchased surface water | Also serves the area |
| Cherry Creek Valley Wsd | CO0116175 | 22,000 | Purchased surface water | Also serves the area |
| North Washington Street Wsd | CO0101105 | 14,500 | Purchased surface water | Also serves the area |
| High View Wd | CO0130344 | 4,000 | Purchased surface water | Also serves the area |
| Advenir French Quarter | CO0116104 | 3,447 | Purchased surface water | Also serves the area · wholesale supplier |
EPA’s records associate 23 further systems with the Denver area beyond the ones above — neighbourhood districts, subdivisions and mobile-home parks among them. If your water bill names a different system, that name — not the city name — is the record to check.
Not sure which system serves your address? Run your ZIP code through our What’s In My Water? lookup — it resolves the systems EPA lists for your ZIP and shows the same records in full.
Lead and copper
Lead: Denver Water’s most recent reported 90th-percentile lead result is 3.6 ppb, below the EPA action level of 15 ppb.
Read those numbers carefully: a 90th percentile is a system-wide statistic from a sample of homes, not a test of your tap. Lead in drinking water comes mostly from a home’s own plumbing — service lines, solder and fixtures — so two houses on the same street can test very differently. Homes built before 1986 carry the highest risk, whatever the system average says.
Violation history — the last 10 years
EPA records show no health-based violations for Denver Water in the last 10 years. Health-based violations are the serious kind: a contaminant over its legal limit, a skipped treatment step, or a disinfectant level above its maximum.
Separately, EPA lists 34 monitoring/reporting items for this system in the last 5 years — missed or late tests and paperwork. Those are compliance-process findings, not contamination findings, and we keep them in their own bucket on purpose.
What this means for your home
System data sets the background; your home’s plumbing writes the foreground. In practice:
- Lead is a plumbing question, not a system alarm, here. The system’s own result is low, so the remaining risk sits in your home’s pipes and fixtures. A filter certified to NSF/ANSI 53 for lead is cheap insurance for older homes; our water filter guides explain the certifications without the marketing.
- Taste and smell: surface-water systems disinfect with chlorine or chloramine, which is most of what people taste. A basic carbon filter (NSF/ANSI 42) handles it; our chloramine vs chlorine explainer helps you tell which one your water has.
- Hardness is not in this record — by design. The EPA doesn’t track it, so nobody can honestly tell you your grains-per-gallon from this page. Scale on fixtures and shower doors is a hint, not a measurement. Test (strips are a start; a lab test is better — see how to test your water at home), then size any softener with our softener sizing calculator and the softener hub.
- On a private well instead of city water? None of this system’s record applies to your tap — start with our well water hub for the test-first approach.
Water quality in nearby cities
New York, NY · Los Angeles, CA · Houston, TX
This guide is one of our per-city water reports — see the full list on the Water Quality hub, alongside our contaminant explainers and testing guides.
Frequently asked questions
Is Denver water safe to drink?
On the evidence in its EPA record, yes: Denver Water has no health-based violations in the last 10 years, and its most recent 90th-percentile lead result was 3.6 ppb, below the EPA action level of 15 ppb. Health-based violations are the serious category — the contamination and treatment failures — so a clean 10-year record is the strongest signal the federal data offers. Two honest limits: EPA data describes the system as a whole, not your tap, and lead in particular usually comes from a home’s own plumbing — a certified home test is the only way to know your exact water.
Where does Denver get its drinking water?
Denver Water is the community water system the EPA associates with Denver. It draws surface water from a river, lake or reservoir and treats it before distribution and serves about 1,287,000 people across its service area (EPA system ID CO0116001). 9 other sizeable systems also report serving parts of Denver — they are listed in the table above.
What is the lead level in Denver’s water?
Denver Water’s most recent reported 90th-percentile lead result is 3.6 ppb, below the EPA action level of 15 ppb. That figure is a system statistic from sampled homes, not a test of your tap — your own plumbing decides your exposure, and a certified home test is the only way to know it.
Has Denver’s water system had violations?
No health-based violations appear for Denver Water in the last 10 years of EPA records. It does carry 34 monitoring/reporting items in the last 5 years — paperwork findings, not contamination.
Do I need a water filter in Denver?
Nothing in Denver Water’s EPA record points to a problem you must filter for. Most households here who filter do it for taste (a simple carbon filter) or for lead insurance in older plumbing (NSF/ANSI 53). If you shop, match the certification to the job — and measure hardness before considering a softener.
Source: U.S. EPA SDWIS via Envirofacts, retrieved November 11, 2026. System-level data describes the utility’s water, not any individual tap. If your water bill names a different system, that system’s record is the one that applies to you.