Is Denver, CO Tap Water Safe to Drink?
Graded F — but Copper and Manganese were detected above EPA limits. Here's what's in the water and how to remove it. What to do next ↓
39.6/100
waterverge.com Denver, CO — Water Quality Report
Denver's drinking water received a grade of F (39.6 out of 100), indicating failing water quality. The city's 43 water systems serve approximately 1,370,147 residents using surface water.
Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. UCMR 5 testing detected 1 PFAS compound in the water supply.
The system has 1182 violations on record, including 104 health-based violations. 183 remain unresolved.
Latest water news in Denver
Recent reporting on Denver, CO drinking water — boil-water advisories, violations, and infrastructure events.
What to know about Denver's water
Denver ranks #236 out of 246 cities in Colorado for water quality, placing it among the lowest-rated in the state.
The city draws from surface water sources, which are more susceptible to seasonal runoff and agricultural contamination, requiring extensive multi-barrier treatment including coagulation, filtration, and disinfection.
PFAS compounds were detected in testing, though levels remain within current EPA limits. Residents seeking extra precaution may consider an activated carbon or reverse osmosis filter.
Hexavalent chromium (chromium-6) was detected at 0.25 µg/L in UCMR 3 testing. While below California's 10 µg/L limit and with no federal MCL set, residents sensitive to this contaminant may consider reverse osmosis filtration.
As a major metropolitan system serving over 1.4M residents, Denver faces large-scale infrastructure challenges including aging pipes and the complexity of treating water across a vast distribution network.
The system has seen 485 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Denver, CO water safe to drink?
Denver's drinking water has significant quality concerns based on EPA testing data. With a grade of F (39.6/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 43 water systems serve approximately 1,370,147 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Denver
A timeline of significant water quality events, violations, and data updates.
Detected at levels within current EPA limits. PFAS persist indefinitely in the environment.
Latest EPA compliance and testing data incorporated into Denver's water quality assessment. Grade: F (39.6/100).
Contaminants: Lead and Copper Rule.
Contaminants: Revised Total Coliform Rule, Chlorine.
1 health-based. Contaminants: Groundwater Rule, Revised Total Coliform Rule, Chlorine.
Key contaminant findings
Based on the most recent EPA sampling data for Denver's water supply.
Well within EPA limits.
Exceeds EPA action level. Copper can leach from household plumbing — flush taps for 30 seconds before drinking.
Detected but within current EPA limits. PFAS do not break down in the environment and can accumulate in the body over time. An activated carbon filter can reduce exposure.
Violation history
Denver's water system has 1,182 total violations on record, including 104 health-based violations. 183 remain unresolved. 485 violations were issued in the last 5 years.
Where does Denver's water come from?
Denver's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 43 water systems serving approximately 1,370,147 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Lee Gulch (river), Dutch (river), South Platte River Below Union Ave, (river), Little Dry Creek Nr Arapahoe (river), Little Dry Creek Above Englewood (river).
What Denver residents can do
Recommended: Activated carbon or reverse osmosis filter. This addresses the specific contaminants found in Denver's water.
Your water utility is required to publish an annual Consumer Confidence Report (CCR) with detailed testing results. Ask for the latest copy or check your utility's website.
Data: EPA SDWIS, UCMR 5 (PFAS), FEMA, NOAA. Last updated May 2026.
Top contaminants to know
View all ↓Forever chemicals overview
National PFAS report →Violation summary
Violations & advisories
Top industrial polluters within 10 miles of Denver
Industrial polluters nearby
Reported releases to surface water by facilities near Denver, ranked by pounds discharged annually.
Total reported releases to surface water: 693 lbs
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
SUNCOR ENERGY COMMERCE CITY REFINERY COMMERCE CITY, CO80022 | Ammonia | 630 | 4.5 mi |
NESTLE PURINA PETCARE CO DENVER, CO80216 | Manganese And Manganese Compounds | 61 | 4.3 mi |
BAND IT IDEX INC DENVER, CO80216 | Nickel | 2 | 3.1 mi |
US MIX DENVER, CO80223 | Lead And Lead Compounds | 0 | 7.1 mi |
OWENS CORNING ROOFING & ASPHALT LLC DENVER, CO80216 | Polycyclic aromatic compounds | 0 | 6.1 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Superfund sites within 10 miles of Denver
Superfund sites nearby
Federally tracked hazardous-waste sites on the EPA National Priorities List. Proximity does not necessarily indicate tap-water contamination — the connection depends on hydrology and treatment.
- CHEMICAL SALES CO4.5 mi
- VASQUEZ BOULEVARD AND I 704.6 mi
- ROCKY MOUNTAIN ARSENAL USARMY5.4 mi
- BRODERICK WOOD PRODUCTS6.9 mi
- DENVER RADIUM SITE7.3 mi
Source: EPA Superfund National Priorities List
Drought conditions
D3 — extreme droughtAdams County is currently in D3 (extreme drought) per the U.S. Drought Monitor (week of May 5, 2026). Drought can elevate disinfection-byproduct (TTHM/HAA5) levels and taste/odor issues as utilities draw from lower reservoirs.
Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.
Recommended water filters
Based on contaminants detected in Denver's water supply, we recommend the following filter types.
Full contaminants report
| Contaminant | Detected Level | EPA Limit | Unit | Category | Status |
|---|---|---|---|---|---|
| Lead (90th percentile) LeadHeavy Metal A toxic heavy metal that can leach into drinking water from older pipes, solder, and fixtures. No amount of lead in water is considered safe. Health EffectsBrain and nervous system damage in children, kidney damage, high blood pressure, and reproductive problems in adults. EPA Limit15 ppb action level Common SourcesCorrosion of lead pipes, lead solder, brass faucets, and household plumbing. | 0.0 | 15 | ppb | Inorganic | Safe |
| Copper (90th percentile) CopperInorganic A metal that enters drinking water mainly through corrosion of copper plumbing. Small amounts are essential for health, but excess levels are harmful. Health EffectsGastrointestinal distress (nausea, vomiting, diarrhea) at short-term high levels; liver and kidney damage from long-term exposure. EPA Limit1.3 mg/L action level Common SourcesCorrosion of copper household plumbing, erosion of natural deposits. | 11.06 | 1.3 | mg/L | Inorganic | Over Limit |
| 11Cl-PF3OUdS | ND | HI | µg/L | PFAS | Not Detected |
| 4:2 FTS | ND | HI | µg/L | PFAS | Not Detected |
| 6:2 FTS 6:2 FTSPFAS A fluorotelomer sulfonate commonly found at sites contaminated with aqueous film-forming foam (AFFF) used in firefighting. Health EffectsPotential liver toxicity and endocrine disruption. Less studied but identified as a contaminant of concern. EPA LimitNo individual MCL (not yet regulated) Common SourcesFirefighting foam (AFFF), airports, military bases, and industrial facilities. | ND | HI | µg/L | PFAS | Not Detected |
| 8:2 FTS | ND | HI | µg/L | PFAS | Not Detected |
| 9Cl-PF3ONS | ND | HI | µg/L | PFAS | Not Detected |
| ADONA | ND | HI | µg/L | PFAS | Not Detected |
| HFPO-DA HFPO-DA (GenX)PFAS A replacement for PFOA in manufacturing, marketed as safer but still a persistent "forever chemical." Also known as GenX. Health EffectsLiver and kidney effects, reproductive toxicity, immune system effects, and potential cancer risk. EPA Limit10 ppt MCL Common SourcesFluoropolymer manufacturing (used as PFOA replacement), industrial wastewater discharge. | ND | 0.01 | µg/L | PFAS | Not Detected |
| lithium LithiumInorganic A naturally occurring alkali metal found in groundwater. Monitored under UCMR 5 to assess occurrence in drinking water. Health EffectsKidney effects at high doses. Low-level exposure effects under study; some research suggests neurological effects. EPA LimitNo MCL (monitoring only under UCMR 5) Common SourcesNatural mineral deposits, geothermal water, and industrial discharge. | 10.800 | HI | µg/L | PFAS | Detected |
| NEtFOSAA | ND | HI | µg/L | PFAS | Not Detected |
| NFDHA | ND | HI | µg/L | PFAS | Not Detected |
| NMeFOSAA | ND | HI | µg/L | PFAS | Not Detected |
| PFBA PFBAPFAS One of the shortest-chain PFAS compounds. Very mobile in water and difficult to remove with standard filtration. Health EffectsThyroid effects, potential developmental toxicity. Shorter half-life in body than long-chain PFAS. EPA LimitNo individual MCL (not yet regulated) Common SourcesDegradation of longer-chain PFAS, industrial discharge, and firefighting foam. | ND | HI | µg/L | PFAS | Not Detected |
| PFBS PFBSPFAS A short-chain PFAS used as a replacement for PFOS. While it clears the body faster than long-chain PFAS, it still persists in the environment. Health EffectsThyroid effects, reproductive and developmental toxicity, kidney effects. EPA LimitPart of Hazard Index (1.0) Common SourcesIndustrial discharge, firefighting foam, and as a replacement chemical in manufacturing. | ND | HI | µg/L | PFAS | Not Detected |
| PFDA | ND | HI | µg/L | PFAS | Not Detected |
| PFDoA | ND | HI | µg/L | PFAS | Not Detected |
| PFEESA | ND | HI | µg/L | PFAS | Not Detected |
| PFHpA PFHpAPFAS A medium-chain PFAS compound found in various environmental samples. Less studied than PFOA/PFOS but still considered a contaminant of concern. Health EffectsLiver effects, potential developmental toxicity, and endocrine disruption. EPA LimitPart of Hazard Index (1.0) Common SourcesDegradation of longer-chain PFAS, industrial discharge, and contaminated water sources. | ND | HI | µg/L | PFAS | Not Detected |
| PFHpS | ND | HI | µg/L | PFAS | Not Detected |
| PFHxA PFHxAPFAS A short-chain PFAS replacement chemical widely used after manufacturers phased out longer-chain PFAS. Very commonly detected in water. Health EffectsLiver and kidney effects, potential thyroid disruption. Considered less toxic than long-chain PFAS but still persistent. EPA LimitNo individual MCL (not yet regulated) Common SourcesIndustrial processes, firefighting foam (AFFF), food packaging, and textile treatment. | ND | HI | µg/L | PFAS | Not Detected |
| PFHxS PFHxSPFAS A medium-chain PFAS found in firefighting foam and consumer products. It has a long half-life in the human body, similar to long-chain PFAS. Health EffectsImmune system effects, thyroid disruption, and potential reproductive and developmental harm. EPA LimitPart of Hazard Index (1.0) Common SourcesFirefighting foam (AFFF), waterproof textiles, food packaging, and industrial discharge. | ND | HI | µg/L | PFAS | Not Detected |
| PFMBA | ND | HI | µg/L | PFAS | Not Detected |
| PFMPA | ND | HI | µg/L | PFAS | Not Detected |
| PFNA PFNAPFAS A long-chain PFAS compound used in manufacturing fluoropolymers. It bioaccumulates in the body and is very persistent in the environment. Health EffectsDevelopmental effects, liver toxicity, immune suppression, and potential cancer risk. EPA LimitPart of Hazard Index (1.0) Common SourcesFluoropolymer manufacturing, industrial emissions, and contaminated water sources. | ND | HI | µg/L | PFAS | Not Detected |
| PFOA PFOAPFAS A long-chain PFAS ("forever chemical") once widely used in nonstick coatings and firefighting foam. It persists in the body and environment for years. Health EffectsLinked to kidney and testicular cancer, thyroid disease, elevated cholesterol, and reproductive issues. EPA Limit4.0 ppt MCL Common SourcesIndustrial discharge, firefighting foam (AFFF), nonstick cookware manufacturing, and contaminated groundwater. | ND | 0.004 | µg/L | PFAS | Not Detected |
| PFOS PFOSPFAS A long-chain PFAS compound historically used in stain-resistant coatings and firefighting foam. One of the most studied and persistent PFAS chemicals. Health EffectsLiver damage, immune system suppression, thyroid disruption, increased cholesterol, and potential cancer risk. EPA Limit4.0 ppt MCL Common SourcesFirefighting foam (AFFF), industrial sites, stain-resistant fabric treatments, and contaminated groundwater. | ND | 0.004 | µg/L | PFAS | Not Detected |
| PFPeA PFPeAPFAS A short-chain PFAS compound commonly detected in drinking water. One of the most frequently found PFAS in UCMR 5 monitoring. Health EffectsLess studied than PFOA/PFOS. Potential liver and thyroid effects. Research is ongoing. EPA LimitNo individual MCL (not yet regulated) Common SourcesIndustrial discharge, firefighting foam degradation, and consumer products. | ND | HI | µg/L | PFAS | Not Detected |
| PFPeS | ND | HI | µg/L | PFAS | Not Detected |
| PFTA | ND | HI | µg/L | PFAS | Not Detected |
| PFTrDA | ND | HI | µg/L | PFAS | Not Detected |
| PFUnA | ND | HI | µg/L | PFAS | Not Detected |
Lead level trend (90th percentile)
Copper level trend (90th percentile)
See how Denver compares by contaminant
Explore where Denver ranks among all Colorado cities for specific contaminants.
Water source & infrastructure
Where Denver's water comes from
Denver's drinking water comes primarily from surface water sources such as rivers, lakes, or reservoirs.
Surface water systems require multi-stage treatment including coagulation, sedimentation, filtration, and disinfection to meet EPA Safe Drinking Water Act standards.
These sources can be impacted by seasonal changes, stormwater runoff, upstream agriculture, and industrial discharge.
The system is operated by local government ownership and serves approximately 1,370,147 people through 43 water systems.
Water bodies near Denver
Denver is located near 5 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.
Water systems serving Denver
| System Name | PWSID | Population | Source |
|---|---|---|---|
| DENVER WATER BOARD | CO0116001 | 1,287,000 | SW |
| CRESTVIEW WSD | CO0101040 | 23,756 | SWP |
| CHERRY CREEK VALLEY WSD | CO0116175 | 22,000 | SWP |
| NORTH WASHINGTON STREET WSD | CO0101105 | 14,500 | SWP |
| ADVENIR FRENCH QUARTER | CO0116104 | 3,447 | SWP |
| NORTH PECOS WSD | CO0116553 | 2,500 | SWP |
| EASTERN ADAMS CO MD | CO0101234 | 2,485 | GW |
| WEST OLIVE ESTATES | MI0040614 | 1,850 | GW |
| NORTH LINCOLN WSD | CO0116552 | 1,000 | SWP |
| NORTHWEST PINES MOBILE HOME COMMUNITY | TX1011032 | 990 | GW |
| PINEWOOD ON THE LAKE MHP | MI0040464 | 950 | GW |
| CRANBERRY LAKE MHC | MI0040382 | 820 | GW |
| MCDONALD FARMS ENTERPRISES INC | CO0207500 | 772 | SWP |
| YANKEE SPRINGS MEADOWS | MI0040585 | 710 | GW |
| MASON MANOR | MI0040197 | 630 | GW |
| DUTCH HILLS | MI0040116 | 620 | GW |
| FOUR SEASONS MOBILE HOME PARK | GA1130010 | 600 | GW |
| RAINTREE ESTATES | TX0200390 | 489 | GW |
| GROVELAND MANOR | MI0040384 | 435 | GW |
| HOLLY HILLS MHC | MI0040665 | 435 | GW |
| ALEDO MOBILE HOME PARK | TX1840041 | 423 | GW |
| LAMPLIGHTER MOBILE HOME PARK | CO0122467 | 420 | SWP |
| CANTERBURY ESTATES MHP | MI0040617 | 350 | GW |
| CAPITAL CROSSINGS | MI0040675 | 345 | GW |
| OLD ORCHARD ESTATES | MI0040156 | 296 | GW |
| MEADOW STREAMS ESTATES | MI0040061 | 293 | GW |
| GARDEN MEADOWS | CO0101300 | 250 | SWP |
| COUNTRY ACRES MHP (LA SALLE COUNTY) | IL0995365 | 222 | GW |
| UNION PACIFIC RAILROAD CO.-KEENE WATER | CA1500371 | 208 | GWP |
| TIMBERLAND MHC | OK4005573 | 200 | GW |
| CRESTWOOD ESTATES | CO0101187 | 140 | GW |
| MEADOWOOD VILLAGE MHP | CO0103506 | 125 | SWP |
| FOXHILL MD | CO0118285 | 123 | GW |
| PLEASANT VIEW ESTATES | CO0130604 | 122 | SWP |
| COUNTRY HOMES LAND CO | CO0103186 | 100 | SWP |
| PINON PINES PROPERTY LLC | CO0108050 | 100 | GW |
| CASTLECOMB WATER SYSTEM | TX1330163 | 93 | GW |
| EXCELL LAWSON VILLAGE | CO0110025 | 90 | GW |
| DEEP CREEK CREEDE HAVEN | CO0140600 | 86 | GW |
| VALLEY VISTA ESTATES | CO0101800 | 51 | GW |
| VALLI HI MHP | CO0110045 | 50 | GW |
| HARVEST ESTATES (FORMERLY BILLS MHP) | IL0915165 | 40 | GW |
| DEEP CREEK MOUNTAIN VALLEY ESTATES | CO0140187 | 31 | GW |
How Denver compares
Full Colorado rankings →Denver's score of 39.6/100 is below the average of 45/100 among major Colorado cities. It outscores 4 of 10 nearby cities. 6 of 10 nearby cities score higher.
Nearby cities
View Colorado rankings →Compare Denver water quality
Head-to-head reports vs other large US cities — grades, lead, PFAS, and Superfund / TRI proximity.
- Denver vs Columbus, OH
- Denver vs San Diego, CA
- Denver vs Cleveland, OH
- Denver vs Dallas, TX
- Denver vs Oakland, CA
About Denver, CO
Wikipedia →Denver is the capital and most populous city of the U.S. state of Colorado. Officially a consolidated city and county, it is located in the South Platte River valley on the western edge of the High Plains, and is just east of the Front Range of the Rocky Mountains (Rockies). Denver is the 19th-most populous city in the United States and the fifth-most populous state capital, with a population of 715,522 at the 2020 census. The ten-county Denver metropolitan area, with over 3.05 million residents, is the 19th-largest metropolitan area in the country and functions as the economic and cultural center of the broader Front Range Urban Corridor.
Learn more about your water
Guides and resources related to Denver's water quality findings.
Explore water quality across Denver
Frequently asked questions
Is Denver, CO tap water safe to drink?
Denver's water quality earned a grade of F (39.6/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #236 out of 246 cities tested in Colorado.
What contaminants are in Denver's water?
Lead was measured at 0.0 ppb (90th percentile). 1 PFAS compound was detected. 1182 violations are on record.
How is Denver's water quality grade calculated?
The grade is based on four factors: violation history (40%), lead and copper levels (25%), PFAS contamination (25%), and regulatory compliance (10%). The score is also adjusted based on how complete the available data is. See our methodology page for full details.
Do I need a water filter in Denver?
PFAS compounds have been detected. A filter with activated carbon can help reduce exposure.
Where does Denver's water come from?
Denver's water is sourced from Surface water. The city has 43 water systems serving approximately 1,370,147 residents.
What health violations has Denver's water system had?
Denver has 104 health-based violations on record. The most recent violation was recorded in January 2026. Health-based violations mean the water exceeded EPA maximum contaminant levels (MCLs) for a regulated substance. 183 violations remain unresolved.
How does Denver's water compare to other cities?
Denver ranks #236 out of 246 cities in Colorado (better than 4% of state cities) and #15228 out of 15744 cities nationally (3th percentile). The grade of F reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.