Is Fort Collins, CO Tap Water Safe to Drink?
Graded D, with 34 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓
46.8/100
waterverge.com Fort Collins, CO — Water Quality Report
Fort Collins's drinking water received a grade of D (46.8 out of 100), indicating poor water quality. The city's 10 water systems serve approximately 303,541 residents using surface water.
Lead levels were measured at 3.9 ppb (90th percentile), well within EPA limits. PFAS testing under UCMR 5 found no detectable forever chemicals.
The system has 121 violations on record, including 6 health-based violations. 34 remain unresolved.
What to know about Fort Collins's water
Fort Collins ranks #188 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.
Hexavalent chromium (chromium-6) was detected at 0.35 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.
The system has seen 39 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.
Water quality score
See methodology →Is Fort Collins, CO water safe to drink?
Fort Collins's drinking water has significant quality concerns based on EPA testing data. With a grade of D (46.8/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 10 water systems serve approximately 303,541 residents using surface water (rivers, lakes, or reservoirs).
Recent water quality updates for Fort Collins
A timeline of significant water quality events, violations, and data updates.
Latest EPA compliance and testing data incorporated into Fort Collins's water quality assessment. Grade: D (46.8/100).
Contaminants: Lead and Copper Rule.
Contaminants: Public Notice, Lead and Copper Rule.
Contaminants: Revised Total Coliform Rule, Surface Water Treatment Rule.
Federal disaster declaration (FEMA DR-4145). Flood event — may have impacted local water infrastructure.
Federal disaster declaration (FEMA DR-3365). Flood event — may have impacted local water infrastructure.
Key contaminant findings
Based on the most recent EPA sampling data for Fort Collins's water supply.
Well within EPA limits.
Violation history
Fort Collins's water system has 121 total violations on record, including 6 health-based violations. 34 remain unresolved. 39 violations were issued in the last 5 years.
Flood & environmental risk
Larimer County has experienced 8 federally declared disasters since 1969. Flooding and severe storms can overwhelm water treatment plants, cause sewage overflows, and introduce agricultural runoff, bacteria, and sediment into drinking water supplies. Local water sources include Cache La Poudre River, Cache La Poudre Riv Ab Boxelder Crk Nr Timnath.
Where does Fort Collins's water come from?
Fort Collins's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 10 water systems serving approximately 303,541 people. Surface water sources are more susceptible to contamination from runoff, industrial discharge, and algal blooms, requiring extensive treatment. Nearby water bodies include Cache La Poudre River (river), Cache La Poudre Riv Ab Boxelder Crk Nr Timnath (river).
What Fort Collins residents can do
Recommended: NSF-certified water filter. This addresses the specific contaminants found in Fort Collins'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.
Run cold water for 30 seconds before drinking, especially in the morning. Lead and copper leach from household plumbing when water sits in pipes.
Fort Collins's area has a history of flooding. After severe weather, watch for boil water advisories from your local utility.
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 Fort Collins
Industrial polluters nearby
Reported releases to surface water by facilities near Fort Collins, ranked by pounds discharged annually.
| Facility | Top chemical | To surface water (lbs/yr) | Distance |
|---|---|---|---|
FORT COLLINS BREWERY FORT COLLINS, CO80524 | — | — | 6.1 mi |
RANCH-WAY FEED MILLS FORT COLLINS, CO80524 | — | — | 2.9 mi |
AVAGO TECHNOLOGIES INC FORT COLLINS COLORADO FORT COLLINS, CO80525 | — | — | 2.8 mi |
WOODWARD INC FORT COLLINS, CO80525 | — | — | 0.4 mi |
HOLCIM WCR INC DRAKE READY MIX PLANT FORT COLLINS, CO80525 | — | — | 2.3 mi |
Source: EPA Toxic Release Inventory (TRI) 2023
Drought conditions
D4 — exceptional droughtLarimer County is currently in D4 (exceptional drought) per the U.S. Drought Monitor (week of May 5, 2026). 30.2% of the county is in D4 (exceptional) drought. 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.
Flood & disaster history
Larimer County has experienced 8 federally declared disasters since 1969. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.
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. | 3.9 | 15 | ppb | Inorganic | Safe |
| 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. | ND | HI | µg/L | PFAS | Not 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)
See how Fort Collins compares by contaminant
Explore where Fort Collins ranks among all Colorado cities for specific contaminants.
Water source & infrastructure
Where Fort Collins's water comes from
Fort Collins'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 303,541 people through 10 water systems.
Water bodies near Fort Collins
Fort Collins is located near 2 notable water bodies. As a surface water system, these water bodies may directly influence the city's drinking water supply.
Water systems serving Fort Collins
| System Name | PWSID | Population | Source |
|---|---|---|---|
| FT COLLINS CITY OF | CO0135291 | 179,901 | SW |
| FT COLLINS LOVELAND WD | CO0135292 | 63,532 | SWP |
| EAST LARIMER COUNTY WD | CO0135233 | 27,944 | SWP |
| CSU MAIN AND WEST HOUSING CAMPUS | CO0235184 | 27,375 | SWP |
| SPRING CANYON WSD | CO0135721 | 2,320 | SWP |
| TIMBER RIDGE MHP | CO0135742 | 1,736 | SWP |
| SKYLINE | CO0135676 | 402 | SWP |
| NUEVA VIDA MOBILE HOME PARK | CO0135600 | 266 | SWP |
| PINEWOOD MOBILE HOME PARK | CO0135611 | 65 | SWP |
| SOLDIER CANYON FILTER PLANT | CO0135718 | — | SW |
How Fort Collins compares
Full Colorado rankings →Fort Collins's score of 46.8/100 is on par with the average of 44/100 among major Colorado cities. It outscores 9 of 10 nearby cities.
Nearby cities
View Colorado rankings →About Fort Collins, CO
Wikipedia →Fort Collins is a home rule city in Larimer County, Colorado, United States, and serves as the county seat and most populous municipality of the county. It is the fourth-most populous city in Colorado with a population of 169,810 at the 2020 census, while the Fort Collins, CO Metropolitan Statistical Area has an estimated 375,000 residents.
Learn more about your water
Guides and resources related to Fort Collins's water quality findings.
Explore water quality across Larimer
Frequently asked questions
Is Fort Collins, CO tap water safe to drink?
Fort Collins's water quality earned a grade of D (46.8/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #188 out of 246 cities tested in Colorado.
What contaminants are in Fort Collins's water?
Lead was measured at 3.9 ppb (90th percentile). No PFAS compounds were detected. 121 violations are on record.
How is Fort Collins'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 Fort Collins?
Based on current data, basic filtration should suffice for additional peace of mind.
Where does Fort Collins's water come from?
Fort Collins's water is sourced from Surface water. The city has 10 water systems serving approximately 303,541 residents.
What health violations has Fort Collins's water system had?
Fort Collins has 6 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. 34 violations remain unresolved.
How does Fort Collins's water compare to other cities?
Fort Collins ranks #188 out of 246 cities in Colorado (better than 24% of state cities) and #13820 out of 15744 cities nationally (12th percentile). The grade of D reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.