WaterVerge

Is Windsor, CO Tap Water Safe to Drink?

Graded D, with 51 unresolved violations on record. See what was cited — and what it means for your tap. What to do next ↓

30K residents served 17 water systems PWSID: CO0162843
Overall Score
48.8 / 100
Violations
51 active
Last Updated
May 2026
Source
Purchased surface water
#179 of 246 in Colorado Top 85% nationally
Local Government
High data confidence
Reviewed by WaterVerge Editorial Team · Last updated May 2026
DGRADE
Water Quality Grade
48.8/100
waterverge.com
D 48.8/100

Windsor, CO — Water Quality Report

Windsor's drinking water received a grade of D (48.8 out of 100), indicating poor water quality. The city's 17 water systems serve approximately 29,623 residents using purchased surface water.

Lead levels were measured at 0.0 ppb (90th percentile), well within EPA limits. PFAS testing under UCMR 5 found no detectable forever chemicals.

The system has 1144 violations on record, including 51 health-based violations. 51 remain unresolved.

Data last updated: May 2026 · Source: EPA SDWIS, UCMR 5
Analysis

What to know about Windsor's water

Windsor ranks #179 out of 246 cities in Colorado for water quality, placing it below average 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 0.14 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 38 violations in the past five years, suggesting a pattern of compliance challenges that residents should monitor closely.

Quality Breakdown

Water quality score

See methodology →
48.8 out of 100 Grade D
A: 90-100
B: 74-89
C: 60-73
F: <50
How is this calculated?
Violations
0/45
F
Historical violation record including health-based and monitoring violations.
Lead & Copper
20/20
A
Lead at 0.0 ppb (90th percentile).
Contaminants
14.8/20
B
No PFAS compounds detected.
Compliance
10/10
A
Monitoring and reporting compliance with EPA regulations.
Source Risk
4/5
B
Water source: Purchased surface water.
Water Safety

Is Windsor, CO water safe to drink?

Concerns Identified

Windsor's drinking water has significant quality concerns based on EPA testing data. With a grade of D (48.8/100), the system has issues across multiple categories. A water filter is recommended for all residents. The city's 17 water systems serve approximately 29,623 residents using surface water (rivers, lakes, or reservoirs).

51
Active Violations
0.0 ppb
Lead (90th %ile)
None
PFAS Detected
7 events
Disaster History

Recent water quality updates for Windsor

A timeline of significant water quality events, violations, and data updates.

Update
Water quality data updated

Latest EPA compliance and testing data incorporated into Windsor's water quality assessment. Grade: D (48.8/100).

Violation
3 drinking water violations recorded

2 health-based. Contaminants: Arsenic, Combined Uranium, Lead and Copper Rule.

Violation
2 drinking water violations recorded

2 health-based. Contaminants: Combined Uranium, Arsenic.

Violation
1 drinking water violation recorded

Contaminants: Public Notice.

Disaster
SEVERE STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES

Federal disaster declaration (FEMA DR-4145). Flood event — may have impacted local water infrastructure.

Disaster
SEVERE STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES

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 Windsor's water supply.

Lead Within Limits
Detected: 0.0 ppb Limit: 15 ppb (EPA Action Level)

Well within EPA limits.

Violation history

Windsor's water system has 1,144 total violations on record, including 51 health-based violations. 51 remain unresolved. 38 violations were issued in the last 5 years.

MCLMROtherMONTTRPT
Most recent violations:
Jan 2026 Arsenic Resolved
Jan 2026 Combined Uranium Resolved
Jan 2026 Lead and Copper Rule Open
Oct 2025 Combined Uranium Resolved
Oct 2025 Arsenic Resolved

Flood & environmental risk

Weld County has experienced 7 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 Riv Ab Boxelder Crk Nr Timnath.

SEVERE STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES
Flood FEMA DR-4145
SEVERE STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES
Flood FEMA DR-3365
HURRICANE KATRINA EVACUATION
Coastal Storm FEMA DR-3224

Where does Windsor's water come from?

Windsor's drinking water comes from surface water (rivers, lakes, or reservoirs), supplied by 17 water systems serving approximately 29,623 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 Riv Ab Boxelder Crk Nr Timnath (river).

What Windsor residents can do

Install a water filter

Recommended: NSF-certified water filter. This addresses the specific contaminants found in Windsor's water.

Request your utility's CCR

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.

Monitor alerts during storms

Windsor'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.

Contaminant Alerts

Top contaminants to know

View all ↓
Lead (90th percentile)
Inorganic / Heavy Metal
Safe
0.0 ppb
EPA Action Level: 15 ppb · 0% of limit
Safe Level
HAA5 (Disinfection Byproducts)
Disinfection Byproduct
Safe
20.9 µg/L
EPA MCL: 60 µg/L · 35% of limit
Within LimitUCMR 4 DataHAA6Br: 2.5 µg/LHAA9: 23.4 µg/L
Chromium-6 (Hexavalent Chromium)
Inorganic
Detected
0.14 µg/L
CA MCL (no federal MCL): 10 µg/L · 1% of limit
DetectedUCMR 3 Data
Strontium
Inorganic
Detected
400.0 µg/L
EPA Health Ref Level: 1,500 µg/L · 27% of limit
DetectedUCMR 3 Data
Manganese
Inorganic
Detected
19.0 µg/L
EPA Secondary MCL: 50 µg/L · 38% of limit
DetectedUCMR 4 Data
Vanadium
Inorganic
Detected
0.53 µg/L
EPA Short-term HA: 21 µg/L · 3% of limit
DetectedUCMR 3 Data
Chlorate
Disinfection Byproduct
Detected
87.0 µg/L
EPA Lifetime HA: 210 µg/L · 41% of limit
DetectedUCMR 3 Data
Molybdenum
Inorganic
Detected
1.70 µg/L
EPA Lifetime HA: 40 µg/L · 4% of limit
DetectedUCMR 3 Data
PFAS Testing

Forever chemicals overview

National PFAS report →
30
Compounds tested
0
Detected
0
Exceed EPA MCL
Compliance Record

Violation summary

1144
Total violations
51
Health-based
51
Active / unresolved
Jan 2026
Most recent violation
Compliance Record

Violations & advisories

1144 Total
51 Active
51 Health-based
1093 Resolved
3 SNC
Violations by category
Synthetic Organic Chemicals
420
Volatile Organic Chemicals
343
Inorganic Chemicals
121
Total Coliform Rule
51
Radionuclides and Revised Rad Rule
39
Jan 2026 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Sep 2025 Active
Public Notice
Other Violation 0
Jul 2025 Active
Consumer Confidence Rule
Other Violation 0
Jan 2025 Active
Public Notice
Other Violation 0
May 2024 Active
Revised Total Coliform Rule
Other Violation 0
Apr 2024 Active
Revised Total Coliform Rule
Other Violation 0
Sep 2023 Active
Revised Total Coliform Rule
Other Violation 0
Jan 2023 Active
Public Notice
Other Violation 0
Dec 2022 Active
Revised Total Coliform Rule
Other Violation 0
Aug 2022 Active
Public Notice
Other Violation 0
Aug 2022 Active
Groundwater Rule
Treatment Technique
Health-Based Health 0
May 2022 Active
Groundwater Rule
Other Violation 0
Nov 2020 Active
Public Notice
Other Violation 0
Jul 2020 Active
E. COLI
Monitoring & Reporting
Monitoring & Reporting 0
Jan 2020 Active
Groundwater Rule
Other Violation 0
Oct 2019 Active
Lead and Copper Rule
Monitoring & Reporting
Monitoring & Reporting 0
Jul 2019 Active
Public Notice
Other Violation 0
Jul 2019 Active
Consumer Confidence Rule
Other Violation 0
Jul 2019 Active
Consumer Confidence Rule
Other Violation 0
Apr 2019 Active
Public Notice
Other Violation 0
Showing 20 of 1144 violations
Industrial pollution

Top industrial polluters within 10 miles of Windsor

Industrial polluters nearby

Reported releases to surface water by facilities near Windsor, ranked by pounds discharged annually.

Total reported releases to surface water: 21,709 lbs

FacilityTop chemicalTo surface water (lbs/yr)Distance
CARESTREAM HEALTH COLORADO
Chemicals · CARESTREAM HEALTH INC
WINDSOR, CO80550
Nitrate compounds (water dissociable; reportable only when in aqueous solution)21,7042.8 mi
LOVELAND PRODUCTS
Chemicals · NUTRIEN US TOPCO LLC
GREELEY, CO80631
Nitrate compounds (water dissociable; reportable only when in aqueous solution)57.2 mi
AVAGO TECHNOLOGIES INC FORT COLLINS COLORADO
Computers and Electronic Products · BROADCOM LTD
FORT COLLINS, CO80525
6.5 mi
WOODWARD INC
Transportation Equipment · WOODWARD INC
FORT COLLINS, CO80525
9.2 mi
HOLCIM WCR INC DRAKE READY MIX PLANT
Nonmetallic Mineral Product · HOLCIM PARTICIPATIONS (US) INC
FORT COLLINS, CO80525
7.5 mi

Source: EPA Toxic Release Inventory (TRI) 2023

Environmental Risk

Drought conditions

D3 — extreme drought

Adams 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.

14
Weeks at D2+ (current streak)
21.7%
Months in D2+ (last 30y)
14
Weeks at D2+ (last 5y)

Source: U.S. Drought Monitor, updated weekly by NDMC, USDA, and NOAA.

Environmental Risk

Flood & disaster history

7
Declared disasters
Sep 2013
Most recent
Flood
Most common type

Weld County has experienced 7 federally declared disasters since 1969. Flooding and severe weather can compromise water treatment infrastructure and introduce contaminants into drinking water supplies.

Sep 2013
SEVERE STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES
Flood FEMA #4145
Sep 2013
SEVERE STORMS, FLOODING, LANDSLIDES, AND MUDSLIDES
Flood FEMA #3365
Sep 2005
HURRICANE KATRINA EVACUATION
Coastal Storm FEMA #3224
Aug 1997
SEVERE STORMS, HEAVY RAIN, FLASH FLOODS, FLOODING, MUDSLIDES
Flood FEMA #1186
Aug 1976
SEVERE STORMS & FLASH FLOODING
Flood FEMA #517
May 1973
HEAVY RAINS, SNOWMELT AND FLOODING
Flood FEMA #385

Full contaminants report

Contaminant Detected Level EPA Limit Unit Category Status
Lead (90th percentile) 0.0 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 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 ND 0.01 µg/L PFAS Not Detected
lithium 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 ND HI µg/L PFAS Not Detected
PFBS 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 ND HI µg/L PFAS Not Detected
PFHpS ND HI µg/L PFAS Not Detected
PFHxA ND HI µg/L PFAS Not Detected
PFHxS ND HI µg/L PFAS Not Detected
PFMBA ND HI µg/L PFAS Not Detected
PFMPA ND HI µg/L PFAS Not Detected
PFNA ND HI µg/L PFAS Not Detected
PFOA ND 0.004 µg/L PFAS Not Detected
PFOS ND 0.004 µg/L PFAS Not Detected
PFPeA 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
Data source: EPA SDWIS, UCMR 5, local utility CCR.

Lead level trend (90th percentile)

EPA action level: 15 ppb
Lead has decreased by 0.5 ppb from 1992 (1.0 ppb) to 2025 (0.5 ppb).
Infrastructure

Water source & infrastructure

Primary Source
Purchased Surface Water
Operator
Local Government
Population Served
29,623
Water Systems
17
Source breakdown
Purchased Surface Water
10
Groundwater
4
Purchased Groundwater
2
Surface Water
1
Water Source

Where Windsor's water comes from

Purchased Surface Water

Windsor'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 29,623 people through 17 water systems.

Local Hydrology

Water bodies near Windsor

Windsor is located near 1 notable water body. As a surface water system, these water bodies may directly influence the city's drinking water supply.

Cache La Poudre Riv Ab Boxelder Crk Nr Timnath
river
Infrastructure

Water systems serving Windsor

System Name PWSID Population Source
WINDSOR TOWN OF CO0162843 23,500 SWP
BOULDER MEADOWS MHP CO0107179 1,657 SWP
CLOVERLEAF COLORADO LLC CO0135184 1,007 SWP
HICKORY VILLAGE CO0135343 816 SWP
SMITH CREEK CROSSING CO0125716 518 GWP
RIVERVIEW CG CO0235676 450 SW
SUNSET WD CO0135726 425 SWP
PIONEER MOBILE HOME PARK CO0116610 250 SWP
ALPENSEE WD CO0159119 168 GW
CREEKSIDE SOUTH ESTATES METRO DISTRICT CO0101188 160 GW
GROVER TOWN OF CO0162322 154 GW
STORM KING MHP CO0123724 135 SWP
INLAND HOUSE CONDOMINIUM ASSOCIATION MI0003362 90 GW
DERBY VILLAGE MOBILE HOME PARK CO0101201 81 GWP
SATANK WA CO0123726 80 SWP
BRIGHTON VILLAGE LLC CO0101030 77 SWP
NORTHSIDE VILLAGE MHP CO0101553 55 SWP
Regional Comparison

How Windsor compares

Full Colorado rankings →

Windsor's score of 48.8/100 is on par with the average of 45/100 among major Colorado cities. It outscores 9 of 10 nearby cities.

Windsor (this city)
48.8
Denver
39.6
Aurora
38.1
Lakewood
36.9
Colorado avg
45
City Profile

About Windsor, CO

Wikipedia →

Windsor is a home rule municipality in Larimer and Weld counties in the U.S. state of Colorado. According to the 2020 census, the population of the town was 32,716. Windsor is located in the Northern Colorado region.

Economic Profile
$121,754
Median Income
$532,770
Median Home Value
$1,659/mo
Median Rent
4.9%
Unemployment
Community
41.3
Median Age
505
People / sq mi
50.9%
College Educated
78.5%
Homeownership
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Frequently asked questions

Is Windsor, CO tap water safe to drink?

Windsor's water quality earned a grade of D (48.8/100). Significant issues have been found. A water filter is strongly recommended. The city ranks #179 out of 246 cities tested in Colorado.

What contaminants are in Windsor's water?

Lead was measured at 0.0 ppb (90th percentile). No PFAS compounds were detected. 1144 violations are on record.

How is Windsor'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 Windsor?

Based on current data, basic filtration should suffice for additional peace of mind.

Where does Windsor's water come from?

Windsor's water is sourced from Purchased surface water. The city has 17 water systems serving approximately 29,623 residents.

What health violations has Windsor's water system had?

Windsor has 51 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. 51 violations remain unresolved.

How does Windsor's water compare to other cities?

Windsor ranks #179 out of 246 cities in Colorado (better than 27% of state cities) and #13401 out of 15744 cities nationally (15th percentile). The grade of D reflects the combined assessment of violation history, lead and copper levels, PFAS contamination, and regulatory compliance.