PFAS Contamination

PFAS in Colorado Drinking Water

Ranked by number of PFAS compounds detected · Data from EPA SDWIS & UCMR

117

Cities Tested

Exceeds Limit

% Exceeds Limit

1.4 compounds

State Avg

▼ 12% vs national

vs National

206

Health Violations

Analysis

PFAS in Colorado: what the data shows

Colorado has 117 cities with PFAS monitoring data from the EPA's UCMR 5 program. PFAS ("forever chemicals") were detected in 67 of those cities (57%), with some cities exceeding the EPA's 2024 maximum contaminant levels of 4 ppt. The state average is better than the national average. 10 cities exceed the EPA MCL for at least one PFAS compound. PFAS are linked to cancer, immune system disruption, and developmental issues. The 2024 EPA rule requires water systems exceeding the MCL to notify customers and reduce levels by 2029. PFAS data comes from the EPA's Unregulated Contaminant Monitoring Rule 5 (UCMR 5), which required large water systems to test for 29 PFAS compounds between 2023–2025. Not all systems have completed testing — cities without data may still have PFAS present.

Comparison

Cities exceeding EPA MCL (4 ppt each)

Colorado

10 of 117 cities

← ▼ 12% below national rate (better)

National avg

21%

1662 of 7853 cities

City Map

PFAS data across Colorado

Each dot is a city, colored by overall water quality grade. PFAS-tested cities are shown; those exceeding the 4 ppt EPA MCL appear in red. Size reflects population served.

Worst Offenders

Top 10 cities by pfas level in Colorado

Highest PFAS levels (compounds)

All Cities

All Colorado cities ranked by pfas level

#	City	Level	Exceeds?	Violations	Grade
1	Colorado Springs	10 compounds	Yes	117	F
2	Thornton	9 compounds	Yes	3	F
3	Parker	8 compounds	Yes	4	F
4	Brighton	8 compounds	Yes	18	F
5	Keystone	7 compounds	Yes	1	C
6	Centennial	6 compounds	Yes	18	F
7	Englewood	6 compounds	No	33	D
8	Aurora	5 compounds	No	22	F
9	Highlands Ranch	5 compounds	No	0	B-
10	Greenwood Village	5 compounds	No	24	F
11	Castle Pines	5 compounds	No	0	B+
12	Lochbuie	5 compounds	No	1	A-
13	Lakewood	4 compounds	No	28	F
14	Commerce City	4 compounds	No	0	A
15	Fountain	4 compounds	No	4	F
16	Gunnison	4 compounds	Yes	14	C
17	Rocky Ford	4 compounds	Yes	325	F
18	Castle Rock	3 compounds	No	20	F
19	Silverthorne	3 compounds	No	3	D+
20	Lamar	3 compounds	No	14	B-
21	Montrose	2 compounds	No	7	F
22	Berthoud	2 compounds	Yes	8	C+
23	Monument	2 compounds	No	23	F
24	Morrison	2 compounds	No	12	C+
25	Redvale	2 compounds	Yes	0	D
26	Delta	2 compounds	No	1	A-
27	Denver	1 compounds	No	104	F
28	Westminster	1 compounds	No	1	D
29	Arvada	1 compounds	No	1	B+
30	Greeley	1 compounds	No	16	F
31	Pueblo	1 compounds	No	15	F
32	Littleton	1 compounds	No	16	F
33	Golden	1 compounds	No	18	B-
34	Vail	1 compounds	No	0	A
35	Northglenn	1 compounds	No	0	A+
36	Fort Carson	1 compounds	No	0	A-
37	Durango	1 compounds	No	112	F
38	Canon City	1 compounds	No	4	B+
39	Clifton	1 compounds	No	2	A
40	Pueblo West	1 compounds	No	5	B-
41	Fort Morgan	1 compounds	No	5	A-
42	Falcon	1 compounds	No	1	D
43	Wellington	1 compounds	No	4	B-
44	Lucerne	1 compounds	No	0	B+
45	Dolores	1 compounds	No	1	B
46	Sterling	1 compounds	No	29	C-
47	Black Hawk	1 compounds	No	0	A-
48	Peyton	1 compounds	No	2	B-
49	Alamosa	1 compounds	No	44	D
50	Pagosa Springs	1 compounds	No	25	F
51	Federal Heights	1 compounds	No	0	B+
52	Rifle	1 compounds	No	64	D
53	La Junta	1 compounds	No	245	F
54	Cortez	1 compounds	No	7	D
55	Craig	1 compounds	No	0	B
56	Woodland	1 compounds	No	1	B-
57	Carbondale	1 compounds	No	77	F
58	Limon	1 compounds	No	3	A-
59	Salida	1 compounds	No	2	D
60	Hillrose	1 compounds	No	15	B+
61	Larkspur	1 compounds	No	11	D+
62	Administrative Contact	1 compounds	No	9	F
63	Yuma	1 compounds	No	12	C+
64	Hayden	1 compounds	No	6	D
65	Burlington	1 compounds	No	84	C-
66	Creede	1 compounds	No	0	B
67	Edwards	1 compounds	No	43	C
68	Fort Collins	0 compounds	No	6	D
69	Boulder	0 compounds	No	15	F
70	Grand Junction	0 compounds	No	4	B
71	Broomfield	0 compounds	No	5	B
72	Longmont	0 compounds	No	2	A-
73	Loveland	0 compounds	No	50	F
74	Erie	0 compounds	No	1	A
75	Aspen	0 compounds	No	2	D
76	Lafayette	0 compounds	No	19	F
77	Steamboat Springs	0 compounds	No	57	F
78	Windsor	0 compounds	No	51	D
79	Breckenridge	0 compounds	No	4	B+
80	Firestone	0 compounds	No	0	A-
81	Johnstown	0 compounds	No	6	B
82	Estes Park	0 compounds	No	49	D
83	Louisville	0 compounds	No	2	A-
84	Evans	0 compounds	No	0	B+
85	Niwot	0 compounds	No	1	A
86	Superior	0 compounds	No	5	A
87	Frederick	0 compounds	No	1	B-
88	Evergreen	0 compounds	No	57	F
89	Usaf Academy	0 compounds	No	3	A
90	Glenwood Springs	0 compounds	No	17	F
91	Gypsum	0 compounds	No	1	A+
92	Fort Lupton	0 compounds	No	35	D
93	Trinidad	0 compounds	No	12	D
94	Winter Park	0 compounds	No	7	D
95	Severance	0 compounds	No	0	A
96	Idaho Springs	0 compounds	No	28	B
97	Milliken	0 compounds	No	0	B
98	Telluride	0 compounds	No	21	D
99	Basalt	0 compounds	No	6	D
100	Florence	0 compounds	No	2	C+
101	Leadville	0 compounds	No	3	D
102	Eagle	0 compounds	No	4	C+
103	Eaton	0 compounds	No	1	B-
104	Manitou Springs	0 compounds	No	4	A
105	Dacono	0 compounds	No	2	A-
106	Buena Vista	0 compounds	No	13	F
107	Snowmass Village	0 compounds	No	2	B-
108	New Castle	0 compounds	No	3	A-
109	Copper Mountain	0 compounds	No	1	B+
110	Granby	0 compounds	No	9	C-
111	Frisco	0 compounds	No	7	F
112	Monte Vista	0 compounds	No	10	D+
113	La Porte	0 compounds	No	3	A-
114	Central City	0 compounds	No	1	A-
115	Hudson	0 compounds	No	12	D
116	Crawford	0 compounds	No	31	F
117	Antonito	0 compounds	No	17	F

FAQ

Frequently asked questions about pfas in Colorado

Does Colorado tap water contain PFAS?

PFAS were detected in 67 of 117 Colorado cities tested under EPA's UCMR 5 program. 10 cities exceed the 2024 EPA MCL of 4 ppt for individual PFAS compounds.

How can I remove PFAS from my drinking water in Colorado?

Reverse osmosis (RO) systems are the most effective at removing PFAS, typically removing 90%+ of compounds. High-quality activated carbon block filters (NSF 58-certified for RO, or NSF 53 for solid carbon) also provide significant reduction. Standard pitcher filters vary widely in PFAS removal.

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