Nitrate Contamination

Nitrate in Arizona Drinking Water

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

265

Cities Tested

265

Has Violations

100%

% Has Violations

21.9 violations

State Avg

▼ 0% vs national

vs National

241

Health Violations

Analysis

Nitrate in Arizona: what the data shows

Arizona has 265 cities with nitrate-related violations. The EPA MCL for nitrate is 10 mg/L (measured as nitrogen). The state has 265 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

Arizona

100%

265 of 265 cities

← = Exactly at national rate

National avg

100%

8001 of 8001 cities

City Map

Nitrate data across Arizona

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 Arizona

Highest Nitrate levels (violations)

All Cities

All Arizona cities ranked by nitrate level

#	City	Level	Violations?	Violations	Grade
1	Tucson	545 violations	Yes	150	F
2	Maricopa	252 violations	Yes	228	D
3	Yuma	243 violations	Yes	318	F
4	Buckeye	142 violations	Yes	103	F
5	Bullhead City	120 violations	Yes	57	F
6	Stanfield	119 violations	Yes	215	D+
7	Mesa	118 violations	Yes	3	F
8	Payson	111 violations	Yes	60	F
9	Eloy	111 violations	Yes	64	D
10	Sierra Vista	105 violations	Yes	44	D
11	Prescott	103 violations	Yes	33	F
12	Flagstaff	98 violations	Yes	74	D
13	Scottsdale	91 violations	Yes	22	F
14	Mayer	90 violations	Yes	24	D+
15	Florence	80 violations	Yes	60	F
16	Chandler	73 violations	Yes	32	F
17	Cottonwood	69 violations	Yes	184	D
18	Peoria	68 violations	Yes	13	F
19	Parker	66 violations	Yes	148	F
20	Dolan Springs	64 violations	Yes	12	C+
21	Kingman	63 violations	Yes	110	D
22	Nogales	63 violations	Yes	39	F
23	Catalina	59 violations	Yes	2	D
24	Pinetop	59 violations	Yes	12	D
25	Marana	58 violations	Yes	13	F
26	Globe	58 violations	Yes	46	F
27	Camp Verde	57 violations	Yes	149	D
28	Sun City	56 violations	Yes	1	B
29	Kearny	56 violations	Yes	14	D
30	Phoenix	55 violations	Yes	59	F
31	Gilbert	55 violations	Yes	11	F
32	Apache Junction	55 violations	Yes	18	F
33	Show Low	53 violations	Yes	60	D
34	Douglas	53 violations	Yes	55	D
35	Green Valley	48 violations	Yes	9	D
36	Beaver Dam	47 violations	Yes	14	D
37	Coolidge	47 violations	Yes	18	D+
38	Casa Grande	45 violations	Yes	44	F
39	Sahuarita	45 violations	Yes	19	F
40	Lakeside	45 violations	Yes	15	D+
41	Sedona	42 violations	Yes	174	F
42	Glendale	40 violations	Yes	5	F
43	San Carlos	40 violations	Yes	140	D
44	Wickenburg	38 violations	Yes	21	F
45	Benson	37 violations	Yes	29	D
46	Bonita	36 violations	Yes	4	D
47	Pine	35 violations	Yes	10	F
48	Quartzsite	34 violations	Yes	7	D+
49	Heber	32 violations	Yes	11	F
50	Johnson Ranch	31 violations	Yes	7	D
51	Tonopah	31 violations	Yes	42	D+
52	Litchfield Park	30 violations	Yes	21	F
53	El Mirage	30 violations	Yes	3	D
54	Avondale	29 violations	Yes	13	C+
55	Oro Valley	29 violations	Yes	11	D
56	Chino Valley	29 violations	Yes	48	D+
57	Safford	27 violations	Yes	9	D
58	Tombstone	27 violations	Yes	26	D
59	Ganado	27 violations	Yes	3	D
60	Tempe	26 violations	Yes	3	D+
61	Paradise Valley	26 violations	Yes	3	C
62	Surprise	25 violations	Yes	18	F
63	White Mountain Lakes	25 violations	Yes	7	D
64	Springerville	25 violations	Yes	16	F
65	Vernon	24 violations	Yes	13	D
66	Humboldt	24 violations	Yes	10	A-
67	Topock	23 violations	Yes	13	C
68	Huachuca City	23 violations	Yes	12	D
69	Star Valley	23 violations	Yes	9	D+
70	Queen Creek	22 violations	Yes	14	D
71	Black Canyon City	22 violations	Yes	16	F
72	Buckeye-Sono	21 violations	Yes	2	B-
73	Hayden	21 violations	Yes	2	D
74	Fountain Hills	20 violations	Yes	21	F
75	Congress	20 violations	Yes	1	B
76	Lake Havasu City	19 violations	Yes	5	D
77	Grand Canyon	19 violations	Yes	11	D
78	Superior	19 violations	Yes	0	C-
79	Round Rock	19 violations	Yes	12	D+
80	Rio Rico	18 violations	Yes	4	C
81	Fort Huachuca	18 violations	Yes	9	F
82	Kayenta	18 violations	Yes	0	D
83	Peach Springs	18 violations	Yes	30	C+
84	Cornville	18 violations	Yes	21	F
85	Somerton	17 violations	Yes	17	D
86	Page	17 violations	Yes	8	F
87	Bisbee	16 violations	Yes	15	F
88	Joseph City	16 violations	Yes	0	C+
89	Fort Mohave	16 violations	Yes	19	D
90	Adaman	16 violations	Yes	9	C-
91	Taylor	15 violations	Yes	1	D
92	Wellton	15 violations	Yes	72	D
93	Tusayan	15 violations	Yes	18	D+
94	Whiteriver	14 violations	Yes	7	D
95	Wittmann	14 violations	Yes	5	D+
96	Three Points	14 violations	Yes	5	D+
97	Oak Creek Canyon	14 violations	Yes	43	D+
98	Concho	13 violations	Yes	17	D
99	Spring Valley	13 violations	Yes	3	A-
100	Supai	13 violations	Yes	11	D+
101	Sun City West	12 violations	Yes	3	B+
102	Winslow	12 violations	Yes	9	D
103	Holbrook	12 violations	Yes	6	F
104	First Mesa Consolidated Villages	12 violations	Yes	74	D
105	Red Mesa	12 violations	Yes	33	D
106	Prescott Valley	11 violations	Yes	6	D
107	Snowflake	11 violations	Yes	1	C+
108	Rimrock	11 violations	Yes	53	C-
109	Duncan	11 violations	Yes	8	F
110	Cave Creek	10 violations	Yes	25	C-
111	Red Rock	10 violations	Yes	1	D+
112	St David	10 violations	Yes	22	D+
113	Hopi High School	10 violations	Yes	46	D+
114	Tacna	10 violations	Yes	63	D
115	White River	10 violations	Yes	20	B-
116	Ak-Chin Village	9 violations	Yes	10	A-
117	Big River	9 violations	Yes	7	D
118	Big River	9 violations	Yes	7	D
119	Bagdad	9 violations	Yes	6	A-
120	Clifton	9 violations	Yes	37	D+
121	Organ Pipe Nm	9 violations	Yes	1	B
122	Miami	8 violations	Yes	1	B
123	Pima	8 violations	Yes	11	F
124	Willcox	8 violations	Yes	7	D
125	Tubac	8 violations	Yes	44	F
126	Middle Verde	8 violations	Yes	22	B-
127	Paulden	8 violations	Yes	3	B
128	Upper Moenkopi	8 violations	Yes	8	B-
129	Linden	8 violations	Yes	3	C-
130	Bacavi	8 violations	Yes	0	B+
131	Pomerene	8 violations	Yes	19	D+
132	Goodyear	7 violations	Yes	3	F
133	Cibecue	7 violations	Yes	4	B-
134	Shungopavi	7 violations	Yes	58	D+
135	Fredonia	7 violations	Yes	1	C-
136	Ehrenberg	7 violations	Yes	5	B
137	Clarkdale	6 violations	Yes	0	B+
138	Sacaton, Sacaton Flats,Upper San Tan, Bl	6 violations	Yes	11	B
139	Eagar	6 violations	Yes	9	C
140	Morenci	6 violations	Yes	15	C-
141	Carefree	6 violations	Yes	0	A-
142	Casa Blanca,Bapchule,Wet Camp,Sacate,Wes	6 violations	Yes	10	A-
143	Hotevilla, Hotevilla/Bacavi Community Sc	6 violations	Yes	1	D+
144	Mammoth	6 violations	Yes	2	C-
145	Keams Canyon	6 violations	Yes	27	B
146	Elfrida	6 violations	Yes	8	D
147	Iyanbito	6 violations	Yes	0	A
148	Iyanbito	6 violations	Yes	0	A
149	Salt River Indian Community	5 violations	Yes	22	B
150	Mohave Valley	5 violations	Yes	14	F
151	Bylas	5 violations	Yes	65	D
152	Stotonic, Goodyear, Gila Butte, Sweetwat	5 violations	Yes	11	B+
153	Bellemont	5 violations	Yes	2	C-
154	Avra Valley	5 violations	Yes	32	B-
155	Sunsites	5 violations	Yes	2	B+
156	Kinlichee	5 violations	Yes	1	C+
157	Seligman	5 violations	Yes	0	A-
158	White Tanks	4 violations	Yes	1	B+
159	Fort Defiance, Window Rock, St. Michaels	4 violations	Yes	22	B-
160	Cordes Lakes	4 violations	Yes	2	B+
161	Vail	4 violations	Yes	9	F
162	Many Farms	4 violations	Yes	1	B-
163	Chilchinbeto	4 violations	Yes	0	B+
164	Nazlini	4 violations	Yes	1	B
165	Red Valley	4 violations	Yes	5	B+
166	Lower Greasewood	4 violations	Yes	9	C+
167	Wildhorse Pass Casino, St. Johns Komatke	3 violations	Yes	12	B+
168	Ajo	3 violations	Yes	0	B-
169	Sells, Big Fields	3 violations	Yes	3	A
170	Saint Johns	3 violations	Yes	7	C+
171	Kaibeto	3 violations	Yes	0	B
172	New Lands (Sanders)	3 violations	Yes	2	A
173	Twin Lakes, Toh-La-Kai, Black Springs Wa	3 violations	Yes	2	A
174	Twin Lakes, Toh-La-Kai, Black Springs Wa	3 violations	Yes	2	A
175	Rock Point	3 violations	Yes	0	B-
176	Tohatchi, Mexican Springs	3 violations	Yes	1	A
177	Tohatchi, Mexican Springs	3 violations	Yes	1	A
178	Gallup, West Of	3 violations	Yes	0	A
179	Gallup, West Of	3 violations	Yes	0	A
180	San Xavier West	3 violations	Yes	3	A-
181	Shonto Junction	3 violations	Yes	1	A
182	Teec Nos Pos	3 violations	Yes	5	B+
183	Alpine	3 violations	Yes	5	B+
184	Nageezi	3 violations	Yes	21	D+
185	Ft. Wingate High School	3 violations	Yes	0	B
186	Ft. Wingate High School	3 violations	Yes	0	B
187	Patagonia	3 violations	Yes	4	C+
188	Nageezi	3 violations	Yes	2	A
189	Naco	3 violations	Yes	4	C-
190	Rough Rock	3 violations	Yes	7	B
191	Pioneer	3 violations	Yes	16	B
192	Upper Cov Wells, Lower Cov Wells, Sikul	3 violations	Yes	3	A
193	Anthem	2 violations	Yes	1	B
194	Chinle, Many Farms, Del Muerto	2 violations	Yes	10	B+
195	Williams	2 violations	Yes	14	D+
196	Sweetwater, Red Mesa	2 violations	Yes	18	C+
197	Clints Well	2 violations	Yes	1	A-
198	Rock Springs	2 violations	Yes	0	A
199	Rock Springs	2 violations	Yes	0	A
200	Inscription House, Broad Mesa West, Dry	2 violations	Yes	1	A
201	Dennehotso	2 violations	Yes	1	B+
202	South Komelic, Choulic, Cold Fields, Top	2 violations	Yes	1	A
203	Kykotsmovi	2 violations	Yes	1	A-
204	Centennial Park	2 violations	Yes	21	B-
205	Tsaile, Dine College	2 violations	Yes	1	A
206	Bourden Ranch Estates	2 violations	Yes	3	B-
207	Vaya Chin, Hickiwan, San Simon Village/S	2 violations	Yes	1	A-
208	Gap/Cedar Ridge/Bittersprings,Arizona	2 violations	Yes	0	A
209	Le Chee	2 violations	Yes	3	A
210	Jeddito	2 violations	Yes	12	A
211	Shonto	2 violations	Yes	0	B+
212	Aguila	2 violations	Yes	6	B+
213	Hard Rock, Dinnebeto, Rocky Ridge	2 violations	Yes	2	A
214	Casamero Lake, Borrego Pass, Smith Lake	2 violations	Yes	2	A
215	Casamero Lake, Borrego Pass, Smith Lake	2 violations	Yes	2	A
216	Wilhoit	2 violations	Yes	1	A-
217	Fort Defiance	2 violations	Yes	1	F
218	Circle City	2 violations	Yes	1	B+
219	Crystal, Yazzie Springs, Crystal Junctio	2 violations	Yes	0	A-
220	Crystal, Yazzie Springs, Crystal Junctio	2 violations	Yes	0	A-
221	Yarnell	2 violations	Yes	1	B+
222	San Luis	1 violations	Yes	8	D
223	Tolleson	1 violations	Yes	1	B+
224	Rio Verde	1 violations	Yes	3	B+
225	Pinon, South Pinon, Burnt Corn, Blue Gap	1 violations	Yes	0	A
226	Mariano Lake, Pinedale, Churchrock	1 violations	Yes	4	B+
227	Mariano Lake, Pinedale, Churchrock	1 violations	Yes	4	B+
228	Ganado, Cornfield, Steamboat, Woodspring	1 violations	Yes	4	B+
229	Silverbell	1 violations	Yes	0	A
230	Ash Fork	1 violations	Yes	3	B
231	Bread Springs, Chichiltah	1 violations	Yes	3	A
232	Bread Springs, Chichiltah	1 violations	Yes	3	A
233	Cameron	1 violations	Yes	38	D
234	Sanostee, Tocito, Littlewater, Mittenroc	1 violations	Yes	0	A
235	Sanostee, Tocito, Littlewater, Mittenroc	1 violations	Yes	0	A
236	Aneth	1 violations	Yes	52	D
237	Lukachukai	1 violations	Yes	4	A-
238	Red Rock (South Of Gallup)	1 violations	Yes	4	A
239	Red Rock (South Of Gallup)	1 violations	Yes	4	A
240	Sr Boarding School, Sr Subdivision, Palo	1 violations	Yes	2	A
241	Thoreau West Rural	1 violations	Yes	2	A
242	Thoreau West Rural	1 violations	Yes	2	A
243	Aneth	1 violations	Yes	49	D+
244	Tonalea, Red Lake	1 violations	Yes	1	B+
245	Cottonwood, Tselani	1 violations	Yes	4	A
246	Oljeto	1 violations	Yes	2	A
247	Oljeto	1 violations	Yes	2	A
248	Huerfano	1 violations	Yes	0	A
249	Huerfano	1 violations	Yes	0	A
250	Ojo Encino, North Of	1 violations	Yes	0	A-
251	Ojo Encino, North Of	1 violations	Yes	0	A-
252	Red Mesa	1 violations	Yes	13	B-
253	Klagetoh, South Ganado, Wide Ruins	1 violations	Yes	2	A
254	Toadlena, Two Grey Hills	1 violations	Yes	51	D
255	Toadlena, Two Grey Hills	1 violations	Yes	51	D
256	Tsa Yah Toh	1 violations	Yes	0	A
257	Tsa Yah Toh	1 violations	Yes	0	A
258	Narbona Pass, Sheep Springs	1 violations	Yes	0	A
259	Narbona Pass, Sheep Springs	1 violations	Yes	0	A
260	Sawmill (East And South), Upper Buell Pa	1 violations	Yes	0	A-
261	Standing Rock	1 violations	Yes	0	A-
262	Standing Rock	1 violations	Yes	0	A-
263	Patton Place Estates	1 violations	Yes	0	B+
264	Newcomb	1 violations	Yes	0	A
265	Newcomb	1 violations	Yes	0	A

FAQ

Frequently asked questions about nitrate in Arizona

Is nitrate in Arizona tap water dangerous?

Yes — 265 cities in Arizona 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 Arizona 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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