Colorado Water Report Card: Worst Water Systems
The most contaminated public water systems in Colorado, ranked by PFAS levels, lead, and EPA violations from official EPA data.
Quick Answer
Widefield Wsd has the highest PFAS in Colorado at 140.6 ppt (35x the EPA limit). Us Department Of The Army Fort Carson has the highest lead at 10.4 ppb. The tables below rank the worst systems in each category so you can see how your water compares.
Highest PFAS Levels in Colorado
Public water systems in Colorado with the highest peak PFAS ("forever chemical") reading in EPA UCMR5 testing (2023-2025). The EPA enforceable limit for PFOA and PFOS is 4 ppt.
| # | Water System | Location | Peak PFAS (ppt) | Compounds | vs 4 ppt limit |
|---|---|---|---|---|---|
| 1 | Widefield Wsd | – | 140.6 | 8 | 35x |
| 2 | Fountain City Of | – | 76.7 | 3 | 19x |
| 3 | Security Wsd | – | 63.6 | 3 | 16x |
| 4 | Stratmoor Hills Wsd | – | 42 | 4 | 11x |
| 5 | Todd Creek Village Md | – | 38 | 6 | 10x |
| 6 | Chipeta Wd | – | 29.5 | 1 | 7x |
| 7 | Snake River Wd | – | 22 | 7 | 6x |
| 8 | Cherokee Md | – | 19.8 | 4 | 5x |
| 9 | Parker Wsd | – | 14 | 5 | 4x |
| 10 | Brighton City Of | – | 13.8 | 7 | 3x |
| 11 | Thornton City Of | – | 12.6 | 7 | 3x |
| 12 | Grand County Water No 1 | – | 11.8 | 1 | 3x |
Highest Lead Levels in Colorado
Community water systems in Colorado with the highest 90th-percentile lead result under the EPA Lead and Copper Rule. The EPA action level is 15 ppb; there is no safe level of lead for children.
| # | Water System | Location | Lead 90th-pctile (ppb) | vs 15 ppb |
|---|---|---|---|---|
| 1 | Us Department Of The Army Fort Carson | Fort Carson · 48,000 served | 10.4 | within |
| 2 | Inverness Wsd | Englewood · 8,140 served | 9.9 | within |
| 3 | Csu Main And West Housing Campus | Fort Collins · 27,375 served | 8 | within |
| 4 | Wray City Of | Wray · 2,342 served | 5 | within |
| 5 | Front Range | Broomfield · 1,620 served | 4 | within |
| 6 | Arapahoe Cnty Wwwa | Centennial · 31,000 served | 3.8 | within |
| 7 | Meridian Md | Englewood · 23,415 served | 2 | within |
| 8 | Yuma City Of | Yuma · 4,049 served | 1.2 | within |
| 9 | Cimarron Village | Wheat Ridge · 1,010 served | 0 | within |
| 10 | Paint Brush Hills | Falcon · 4,994 served | 0 | within |
How This Report Card Is Built
PFAS rankings use EPA UCMR5 monitoring (2023-2025), showing each system's peak detection above the 4 ppt EPA limit. Lead rankings use the EPA Lead and Copper Rule 90th-percentile tap results. Violation counts come from the EPA Safe Drinking Water Information System (SDWIS) and count health-based violations. Lead and violation lists are limited to community water systems serving 1,000 or more people. Figures are the most severe on record and do not necessarily reflect current treated water.
Frequently Asked Questions
What is the most PFAS-contaminated water system in Colorado?
In EPA UCMR5 testing (2023-2025), Widefield Wsd had the highest recorded PFAS level in Colorado at 140.6 ppt - about 35x the EPA's 4 ppt limit for PFOA and PFOS.
Which Colorado water system has the highest lead levels?
Us Department Of The Army Fort Carson in Fort Carson had the highest 90th-percentile lead result in Colorado under the EPA Lead and Copper Rule at 10.4 ppb (within the 15 ppb action level).
Where does the Colorado water report card data come from?
PFAS figures come from EPA UCMR5 monitoring (2023-2025), lead from the EPA Lead and Copper Rule 90th-percentile tap results, and violations from EPA SDWIS health-based violation records. Figures are the most severe on record and do not necessarily reflect current treated water. Check your exact address at knowyourexposure.com.
What Colorado Residents Should Do
- Look up your exact address at knowyourexposure.com for your system's data
- See the full Colorado water quality overview
- If your system is listed, a certified filter (reverse osmosis for PFAS, NSF-53 for lead) reduces exposure at the tap. See the best water filters.