Nitrate Contamination

Nitrate in Oklahoma Drinking Water

Ranked by nitrate violation count · Data from EPA SDWIS & UCMR

179

Cities Tested

179

Has Violations

100%

% Has Violations

12.9 violations

State Avg

▼ 0% vs national

vs National

351

Health Violations

Analysis

Nitrate in Oklahoma: what the data shows

Oklahoma has 179 cities with nitrate-related violations. The EPA MCL for nitrate is 10 mg/L (measured as nitrogen). The state has 179 cities with at least one nitrate violation. Nitrate is the most common groundwater contaminant in the United States. It enters water supplies primarily through agricultural fertilizer runoff, septic system leaching, and animal feedlot operations. Rural and agricultural communities face the highest risk. The primary acute health concern is methemoglobinemia ("blue baby syndrome") in infants under six months. Emerging research also links chronic nitrate exposure to thyroid disease, certain cancers, and adverse birth outcomes. Reverse osmosis, ion exchange, and distillation can remove nitrate from drinking water — standard carbon filters do not.

Comparison

Cities exceeding 10 mg/L EPA MCL

Oklahoma

100%

179 of 179 cities

← = Exactly at national rate

National avg

100%

8001 of 8001 cities

City Map

Nitrate data across Oklahoma

Each dot is a city with nitrate violation data. Cities with at least one nitrate-related violation are highlighted. Size reflects population served.

Worst Offenders

Top 10 cities by nitrate level in Oklahoma

Highest Nitrate levels (violations)

All Cities

All Oklahoma cities ranked by nitrate level

#	City	Level	Violations?	Violations	Grade
1	Okarche	208 violations	Yes	236	F
2	Hollis	150 violations	Yes	148	D+
3	Okeene	111 violations	Yes	114	D+
4	Calumet	108 violations	Yes	117	D
5	Fairview	96 violations	Yes	97	D
6	Tuttle	88 violations	Yes	46	D
7	Crescent	88 violations	Yes	82	C+
8	Granite	88 violations	Yes	91	D+
9	Grandfield	88 violations	Yes	152	D+
10	Hennessey	69 violations	Yes	70	B-
11	Mooreland	67 violations	Yes	59	D+
12	Geary	67 violations	Yes	74	D
13	Woodward	47 violations	Yes	55	D
14	Cordell	46 violations	Yes	46	C+
15	Byron	35 violations	Yes	33	B
16	Edmond	33 violations	Yes	86	F
17	Tipton	33 violations	Yes	136	D
18	Chattanooga	31 violations	Yes	44	D+
19	Carter	30 violations	Yes	28	B+
20	Waynoka	28 violations	Yes	27	A-
21	Canute	26 violations	Yes	23	D+
22	Watonga	25 violations	Yes	27	C+
23	Bison	25 violations	Yes	29	A
24	Gould	24 violations	Yes	28	C-
25	Kremlin	24 violations	Yes	25	F
26	Seiling	23 violations	Yes	23	A-
27	Dill City	22 violations	Yes	24	C-
28	Weatherford	19 violations	Yes	71	D
29	Grove	18 violations	Yes	20	D
30	Mcloud	18 violations	Yes	14	D
31	Duke	18 violations	Yes	46	D
32	Osage	17 violations	Yes	21	D+
33	Goodwell	15 violations	Yes	15	C+
34	Apache	14 violations	Yes	34	C-
35	Norman	13 violations	Yes	52	F
36	Stillwater	11 violations	Yes	72	F
37	Walters	11 violations	Yes	104	D+
38	Hydro	11 violations	Yes	11	C-
39	Oklahoma City	10 violations	Yes	56	F
40	Vian	10 violations	Yes	7	D+
41	Quapaw	10 violations	Yes	9	D
42	Miami	9 violations	Yes	11	D
43	Cherokee	9 violations	Yes	15	B+
44	Boley	9 violations	Yes	6	D+
45	Enid	8 violations	Yes	33	F
46	Cleveland	8 violations	Yes	182	F
47	Tecumseh	8 violations	Yes	142	F
48	Noble	8 violations	Yes	160	D
49	Lexington	8 violations	Yes	16	F
50	Wyandotte	8 violations	Yes	5	D
51	Verden	8 violations	Yes	10	A
52	Elk City	7 violations	Yes	5	D
53	Blair	7 violations	Yes	38	D
54	Afton	7 violations	Yes	89	F
55	Leedey	7 violations	Yes	6	B
56	Tyrone	7 violations	Yes	6	B
57	Vici	7 violations	Yes	6	B+
58	Madill	6 violations	Yes	178	F
59	Okmulgee	6 violations	Yes	262	D
60	Guymon	6 violations	Yes	10	A-
61	Carnegie	6 violations	Yes	9	B
62	Caddo	6 violations	Yes	11	C-
63	Erick	6 violations	Yes	4	D+
64	Laverne	6 violations	Yes	3	C
65	Moore	5 violations	Yes	53	F
66	Ponca City	5 violations	Yes	23	F
67	Locust Grove	5 violations	Yes	103	D
68	Pawnee	5 violations	Yes	276	D
69	Hinton	5 violations	Yes	47	D+
70	Agra	5 violations	Yes	2	B+
71	Garber	5 violations	Yes	39	B-
72	Shidler	5 violations	Yes	145	D
73	Marshall	5 violations	Yes	10	B-
74	Fletcher	5 violations	Yes	7	C
75	Mutual	5 violations	Yes	6	C+
76	Canton	5 violations	Yes	1	B+
77	Washington	5 violations	Yes	8	C
78	Ardmore	4 violations	Yes	188	F
79	Mcalester	4 violations	Yes	670	F
80	Yukon	4 violations	Yes	18	D
81	Tahlequah	4 violations	Yes	56	F
82	Wagoner	4 violations	Yes	141	F
83	Hulbert	4 violations	Yes	117	D
84	Fort Gibson	4 violations	Yes	153	F
85	Mannford	4 violations	Yes	93	B-
86	Commerce	4 violations	Yes	6	B+
87	Barnsdall	4 violations	Yes	448	D
88	Snyder	4 violations	Yes	129	D
89	Fort Cobb	4 violations	Yes	4	A-
90	Lawton	3 violations	Yes	23	F
91	Shawnee	3 violations	Yes	124	D
92	Chickasha	3 violations	Yes	79	F
93	Harrah	3 violations	Yes	61	D
94	Amber	3 violations	Yes	30	D
95	Nichols Hills	3 violations	Yes	21	D
96	Pawhuska	3 violations	Yes	34	D+
97	Stroud	3 violations	Yes	156	D+
98	Mangum	3 violations	Yes	7	C+
99	Fairland	3 violations	Yes	11	D
100	Bowlegs	3 violations	Yes	9	B+
101	Prague	3 violations	Yes	10	D+
102	Goldsby	3 violations	Yes	17	B+
103	Chelsea	3 violations	Yes	10	A-
104	Oilton	3 violations	Yes	4	D+
105	Stuart	3 violations	Yes	96	C-
106	Red Rock	3 violations	Yes	166	D
107	Tulsa	2 violations	Yes	6	D
108	Claremore	2 violations	Yes	153	F
109	Midwest City	2 violations	Yes	11	B+
110	Collinsville	2 violations	Yes	24	C+
111	Broken Bow	2 violations	Yes	122	F
112	Sulphur	2 violations	Yes	2	A-
113	Hastings	2 violations	Yes	63	D+
114	Oologah	2 violations	Yes	32	B-
115	Perry	2 violations	Yes	129	D
116	Okemah	2 violations	Yes	71	D
117	Earlsboro	2 violations	Yes	4	C+
118	Kingfisher	2 violations	Yes	38	D
119	Elgin	2 violations	Yes	13	D+
120	Big Cabin	2 violations	Yes	39	D+
121	Tonkawa	2 violations	Yes	6	B-
122	Roland	2 violations	Yes	39	A-
123	Stigler	2 violations	Yes	30	B
124	Perkins	2 violations	Yes	1	D
125	Cookson	2 violations	Yes	102	D
126	Welch	2 violations	Yes	81	D+
127	Hooker	2 violations	Yes	0	A-
128	Fairfax	2 violations	Yes	254	D
129	Medford	2 violations	Yes	9	C-
130	Boise City	2 violations	Yes	2	D+
131	Red Oak	2 violations	Yes	116	D
132	Hendrix	2 violations	Yes	5	D
133	Marland	2 violations	Yes	10	D+
134	Bernice	2 violations	Yes	6	C
135	Bartlesville	1 violations	Yes	217	F
136	Durant	1 violations	Yes	104	D
137	Del City	1 violations	Yes	12	F
138	Mustang	1 violations	Yes	9	C+
139	Skiatook	1 violations	Yes	72	B-
140	Eufaula	1 violations	Yes	374	F
141	Mounds	1 violations	Yes	219	D+
142	Cushing	1 violations	Yes	1	A-
143	Ochelata	1 violations	Yes	41	D
144	Atoka	1 violations	Yes	269	D+
145	Idabel	1 violations	Yes	123	D
146	Alva	1 violations	Yes	6	B-
147	Cache	1 violations	Yes	64	F
148	Porum	1 violations	Yes	45	B-
149	Westville	1 violations	Yes	23	D
150	Wynnewood	1 violations	Yes	85	D
151	Sayre	1 violations	Yes	2	A
152	Choctaw	1 violations	Yes	3	F
153	Jay	1 violations	Yes	87	D
154	Chandler	1 violations	Yes	150	D
155	Blanchard	1 violations	Yes	12	D
156	Wayne	1 violations	Yes	28	C
157	Disney	1 violations	Yes	22	B
158	Kansas	1 violations	Yes	7	D
159	Colbert	1 violations	Yes	4	C+
160	Ratliff City	1 violations	Yes	45	F
161	Haskell	1 violations	Yes	109	D
162	Wilson	1 violations	Yes	4	B+
163	Salina	1 violations	Yes	68	B+
164	Buffalo	1 violations	Yes	16	D+
165	Beggs	1 violations	Yes	176	D
166	Custer City	1 violations	Yes	2	B
167	Rush Springs	1 violations	Yes	5	A
168	Shattuck	1 violations	Yes	11	B
169	Pond Creek	1 violations	Yes	3	C+
170	Braggs	1 violations	Yes	2	B+
171	Weleetka	1 violations	Yes	187	D
172	Kiowa	1 violations	Yes	197	D
173	Sterling	1 violations	Yes	9	A-
174	Carney	1 violations	Yes	14	A-
175	Paoli	1 violations	Yes	7	C+
176	Coleman	1 violations	Yes	3	B+
177	Bokchito	1 violations	Yes	4	A
178	Forgan	1 violations	Yes	4	B
179	Achille	1 violations	Yes	2	A-

FAQ

Frequently asked questions about nitrate in Oklahoma

Is nitrate in Oklahoma tap water dangerous?

Yes — 179 cities in Oklahoma have nitrate-related violations. The EPA MCL is 10 mg/L. Nitrate is especially dangerous for infants under six months, where it can cause methemoglobinemia ("blue baby syndrome"). Adults face lower acute risk, but chronic exposure is linked to thyroid disease and certain cancers.

How can I remove nitrate from my drinking water?

Reverse osmosis, ion exchange, and distillation are effective at removing nitrate. Standard carbon filters (including most pitcher and faucet-mount filters) do NOT remove nitrate. If you rely on a private well in an agricultural area, have your water tested annually for nitrate.

What causes high nitrate levels in Oklahoma water?

Nitrate contamination comes primarily from agricultural fertilizer runoff, septic system leaching, and animal feedlot operations. Rural communities near intensive farming are most at risk. Shallow wells are particularly vulnerable. Heavy rainfall can spike nitrate levels as it washes fertilizer into groundwater and surface water supplies.

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