Nitrate Contamination

Nitrate in Arizona Drinking Water

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

244

Cities Tested

244

Has Violations

100%

% Has Violations

21.6 violations

State Avg

▼ 0% vs national

vs National

221

Health Violations

Analysis

Nitrate in Arizona: what the data shows

Arizona has 244 cities with nitrate-related violations. The EPA MCL for nitrate is 10 mg/L (measured as nitrogen). The state has 244 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%

244 of 244 cities

← = Exactly at national rate

National avg

100%

7727 of 7727 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	Mesa	118 violations	Yes	3	F
7	Payson	111 violations	Yes	60	F
8	Eloy	111 violations	Yes	64	D
9	Sierra Vista	105 violations	Yes	44	D
10	Prescott	103 violations	Yes	33	F
11	Flagstaff	98 violations	Yes	74	D
12	Scottsdale	91 violations	Yes	22	F
13	Florence	80 violations	Yes	60	F
14	Chandler	73 violations	Yes	32	F
15	Cottonwood	69 violations	Yes	184	D
16	Peoria	68 violations	Yes	13	F
17	Parker	66 violations	Yes	148	F
18	Dolan Springs	64 violations	Yes	12	C+
19	Kingman	63 violations	Yes	110	D
20	Nogales	63 violations	Yes	39	F
21	Catalina	59 violations	Yes	2	D
22	Pinetop	59 violations	Yes	12	D
23	Marana	58 violations	Yes	13	F
24	Globe	58 violations	Yes	46	F
25	Camp Verde	57 violations	Yes	149	D
26	Sun City	56 violations	Yes	1	B
27	Kearny	56 violations	Yes	14	D
28	Phoenix	55 violations	Yes	59	F
29	Gilbert	55 violations	Yes	11	F
30	Apache Junction	55 violations	Yes	18	F
31	Show Low	53 violations	Yes	60	D
32	Douglas	53 violations	Yes	55	D
33	Green Valley	48 violations	Yes	9	D
34	Sahuarita	45 violations	Yes	19	F
35	Lakeside	45 violations	Yes	15	D+
36	Sedona	42 violations	Yes	174	F
37	San Carlos	40 violations	Yes	140	D
38	Glendale	40 violations	Yes	5	F
39	Wickenburg	38 violations	Yes	21	F
40	Benson	37 violations	Yes	29	D
41	Bonita	36 violations	Yes	4	D
42	Pine	35 violations	Yes	10	F
43	Quartzsite	34 violations	Yes	7	D+
44	Heber	32 violations	Yes	11	F
45	Johnson Ranch	31 violations	Yes	7	D
46	Litchfield Park	30 violations	Yes	21	F
47	El Mirage	30 violations	Yes	3	D
48	Avondale	29 violations	Yes	13	C+
49	Oro Valley	29 violations	Yes	11	D
50	Chino Valley	29 violations	Yes	48	D+
51	Safford	27 violations	Yes	9	D
52	Tombstone	27 violations	Yes	26	D
53	Ganado	27 violations	Yes	3	D
54	Tempe	26 violations	Yes	3	D+
55	Paradise Valley	26 violations	Yes	3	C
56	Surprise	25 violations	Yes	18	F
57	White Mountain Lakes	25 violations	Yes	7	D
58	Springerville	25 violations	Yes	16	F
59	Humboldt	24 violations	Yes	10	A-
60	Topock	23 violations	Yes	13	C
61	Huachuca City	23 violations	Yes	12	D
62	Queen Creek	22 violations	Yes	14	D
63	Black Canyon City	22 violations	Yes	16	F
64	Buckeye-Sono	21 violations	Yes	2	B-
65	Hayden	21 violations	Yes	2	D
66	Fountain Hills	20 violations	Yes	21	F
67	Congress	20 violations	Yes	1	B
68	Lake Havasu City	19 violations	Yes	5	D
69	Grand Canyon	19 violations	Yes	11	D
70	Superior	19 violations	Yes	0	C-
71	Round Rock	19 violations	Yes	12	D+
72	Rio Rico	18 violations	Yes	4	C
73	Fort Huachuca	18 violations	Yes	9	F
74	Peach Springs	18 violations	Yes	30	C+
75	Cornville	18 violations	Yes	21	F
76	Kayenta	18 violations	Yes	0	D
77	Somerton	17 violations	Yes	17	D
78	Page	17 violations	Yes	8	F
79	Bisbee	16 violations	Yes	15	F
80	Joseph City	16 violations	Yes	0	C+
81	Adaman	16 violations	Yes	9	C-
82	Taylor	15 violations	Yes	1	D
83	Wellton	15 violations	Yes	72	D
84	Tusayan	15 violations	Yes	18	D+
85	Whiteriver	14 violations	Yes	7	D
86	Spring Valley	13 violations	Yes	3	A-
87	Supai	13 violations	Yes	11	D+
88	Sun City West	12 violations	Yes	3	B+
89	Winslow	12 violations	Yes	9	D
90	Holbrook	12 violations	Yes	6	F
91	First Mesa Consolidated Villages	12 violations	Yes	74	D
92	Red Mesa	12 violations	Yes	33	D
93	Snowflake	11 violations	Yes	1	C+
94	Duncan	11 violations	Yes	8	F
95	Prescott Valley	11 violations	Yes	6	D
96	Cave Creek	10 violations	Yes	25	C-
97	Red Rock	10 violations	Yes	1	D+
98	St David	10 violations	Yes	22	D+
99	Hopi High School	10 violations	Yes	46	D+
100	White River	10 violations	Yes	20	B-
101	Tacna	10 violations	Yes	63	D
102	Ak-Chin Village	9 violations	Yes	10	A-
103	Big River	9 violations	Yes	7	D
104	Big River	9 violations	Yes	7	D
105	Bagdad	9 violations	Yes	6	A-
106	Clifton	9 violations	Yes	37	D+
107	Organ Pipe Nm	9 violations	Yes	1	B
108	Miami	8 violations	Yes	1	B
109	Pima	8 violations	Yes	11	F
110	Willcox	8 violations	Yes	7	D
111	Middle Verde	8 violations	Yes	22	B-
112	Paulden	8 violations	Yes	3	B
113	Upper Moenkopi	8 violations	Yes	8	B-
114	Bacavi	8 violations	Yes	0	B+
115	Pomerene	8 violations	Yes	19	D+
116	Linden	8 violations	Yes	3	C-
117	Goodyear	7 violations	Yes	3	F
118	Cibecue	7 violations	Yes	4	B-
119	Shungopavi	7 violations	Yes	58	D+
120	Fredonia	7 violations	Yes	1	C-
121	Ehrenberg	7 violations	Yes	5	B
122	Sacaton, Sacaton Flats,Upper San Tan, Bl	6 violations	Yes	11	B
123	Clarkdale	6 violations	Yes	0	B+
124	Eagar	6 violations	Yes	9	C
125	Morenci	6 violations	Yes	15	C-
126	Carefree	6 violations	Yes	0	A-
127	Casa Blanca,Bapchule,Wet Camp,Sacate,Wes	6 violations	Yes	10	A-
128	Hotevilla, Hotevilla/Bacavi Community Sc	6 violations	Yes	1	D+
129	Mammoth	6 violations	Yes	2	C-
130	Keams Canyon	6 violations	Yes	27	B
131	Elfrida	6 violations	Yes	8	D
132	Iyanbito	6 violations	Yes	0	A
133	Iyanbito	6 violations	Yes	0	A
134	Salt River Indian Community	5 violations	Yes	22	B
135	Mohave Valley	5 violations	Yes	14	F
136	Bylas	5 violations	Yes	65	D
137	Stotonic, Goodyear, Gila Butte, Sweetwat	5 violations	Yes	11	B+
138	Bellemont	5 violations	Yes	2	C-
139	Sunsites	5 violations	Yes	2	B+
140	Avra Valley	5 violations	Yes	32	B-
141	Kinlichee	5 violations	Yes	1	C+
142	Seligman	5 violations	Yes	0	A-
143	White Tanks	4 violations	Yes	1	B+
144	Fort Defiance, Window Rock, St. Michaels	4 violations	Yes	22	B-
145	Cordes Lakes	4 violations	Yes	2	B+
146	Many Farms	4 violations	Yes	1	B-
147	Chilchinbeto	4 violations	Yes	0	B+
148	Nazlini	4 violations	Yes	1	B
149	Lower Greasewood	4 violations	Yes	9	C+
150	Wildhorse Pass Casino, St. Johns Komatke	3 violations	Yes	12	B+
151	Sells, Big Fields	3 violations	Yes	3	A
152	Saint Johns	3 violations	Yes	7	C+
153	Ajo	3 violations	Yes	0	B-
154	New Lands (Sanders)	3 violations	Yes	2	A
155	Twin Lakes, Toh-La-Kai, Black Springs Wa	3 violations	Yes	2	A
156	Twin Lakes, Toh-La-Kai, Black Springs Wa	3 violations	Yes	2	A
157	Tohatchi, Mexican Springs	3 violations	Yes	1	A
158	Tohatchi, Mexican Springs	3 violations	Yes	1	A
159	Gallup, West Of	3 violations	Yes	0	A
160	Gallup, West Of	3 violations	Yes	0	A
161	San Xavier West	3 violations	Yes	3	A-
162	Shonto Junction	3 violations	Yes	1	A
163	Alpine	3 violations	Yes	5	B+
164	Ft. Wingate High School	3 violations	Yes	0	B
165	Ft. Wingate High School	3 violations	Yes	0	B
166	Patagonia	3 violations	Yes	4	C+
167	Nageezi	3 violations	Yes	2	A
168	Nageezi	3 violations	Yes	21	D+
169	Rock Point	3 violations	Yes	0	B-
170	Naco	3 violations	Yes	4	C-
171	Pioneer	3 violations	Yes	16	B
172	Upper Cov Wells, Lower Cov Wells, Sikul	3 violations	Yes	3	A
173	Anthem	2 violations	Yes	1	B
174	Chinle, Many Farms, Del Muerto	2 violations	Yes	10	B+
175	Williams	2 violations	Yes	14	D+
176	Sweetwater, Red Mesa	2 violations	Yes	18	C+
177	Clints Well	2 violations	Yes	1	A-
178	Rock Springs	2 violations	Yes	0	A
179	Rock Springs	2 violations	Yes	0	A
180	Inscription House, Broad Mesa West, Dry	2 violations	Yes	1	A
181	South Komelic, Choulic, Cold Fields, Top	2 violations	Yes	1	A
182	Kykotsmovi	2 violations	Yes	1	A-
183	Centennial Park	2 violations	Yes	21	B-
184	Tsaile, Dine College	2 violations	Yes	1	A
185	Bourden Ranch Estates	2 violations	Yes	3	B-
186	Vaya Chin, Hickiwan, San Simon Village/S	2 violations	Yes	1	A-
187	Gap/Cedar Ridge/Bittersprings,Arizona	2 violations	Yes	0	A
188	Le Chee	2 violations	Yes	3	A
189	Jeddito	2 violations	Yes	12	A
190	Aguila	2 violations	Yes	6	B+
191	Hard Rock, Dinnebeto, Rocky Ridge	2 violations	Yes	2	A
192	Casamero Lake, Borrego Pass, Smith Lake	2 violations	Yes	2	A
193	Casamero Lake, Borrego Pass, Smith Lake	2 violations	Yes	2	A
194	Wilhoit	2 violations	Yes	1	A-
195	Fort Defiance	2 violations	Yes	1	F
196	Circle City	2 violations	Yes	1	B+
197	Crystal, Yazzie Springs, Crystal Junctio	2 violations	Yes	0	A-
198	Crystal, Yazzie Springs, Crystal Junctio	2 violations	Yes	0	A-
199	Shonto	2 violations	Yes	0	B+
200	Yarnell	2 violations	Yes	1	B+
201	San Luis	1 violations	Yes	8	D
202	Tolleson	1 violations	Yes	1	B+
203	Rio Verde	1 violations	Yes	3	B+
204	Pinon, South Pinon, Burnt Corn, Blue Gap	1 violations	Yes	0	A
205	Mariano Lake, Pinedale, Churchrock	1 violations	Yes	4	B+
206	Mariano Lake, Pinedale, Churchrock	1 violations	Yes	4	B+
207	Ganado, Cornfield, Steamboat, Woodspring	1 violations	Yes	4	B+
208	Silverbell	1 violations	Yes	0	A
209	Ash Fork	1 violations	Yes	3	B
210	Bread Springs, Chichiltah	1 violations	Yes	3	A
211	Bread Springs, Chichiltah	1 violations	Yes	3	A
212	Sanostee, Tocito, Littlewater, Mittenroc	1 violations	Yes	0	A
213	Sanostee, Tocito, Littlewater, Mittenroc	1 violations	Yes	0	A
214	Lukachukai	1 violations	Yes	4	A-
215	Red Rock (South Of Gallup)	1 violations	Yes	4	A
216	Red Rock (South Of Gallup)	1 violations	Yes	4	A
217	Sr Boarding School, Sr Subdivision, Palo	1 violations	Yes	2	A
218	Thoreau West Rural	1 violations	Yes	2	A
219	Thoreau West Rural	1 violations	Yes	2	A
220	Aneth	1 violations	Yes	49	D+
221	Aneth	1 violations	Yes	52	D
222	Cottonwood, Tselani	1 violations	Yes	4	A
223	Oljeto	1 violations	Yes	2	A
224	Oljeto	1 violations	Yes	2	A
225	Cameron	1 violations	Yes	38	D
226	Tonalea, Red Lake	1 violations	Yes	1	B+
227	Huerfano	1 violations	Yes	0	A
228	Huerfano	1 violations	Yes	0	A
229	Ojo Encino, North Of	1 violations	Yes	0	A-
230	Ojo Encino, North Of	1 violations	Yes	0	A-
231	Red Mesa	1 violations	Yes	13	B-
232	Klagetoh, South Ganado, Wide Ruins	1 violations	Yes	2	A
233	Toadlena, Two Grey Hills	1 violations	Yes	51	D
234	Toadlena, Two Grey Hills	1 violations	Yes	51	D
235	Tsa Yah Toh	1 violations	Yes	0	A
236	Tsa Yah Toh	1 violations	Yes	0	A
237	Narbona Pass, Sheep Springs	1 violations	Yes	0	A
238	Narbona Pass, Sheep Springs	1 violations	Yes	0	A
239	Sawmill (East And South), Upper Buell Pa	1 violations	Yes	0	A-
240	Standing Rock	1 violations	Yes	0	A-
241	Standing Rock	1 violations	Yes	0	A-
242	Patton Place Estates	1 violations	Yes	0	B+
243	Newcomb	1 violations	Yes	0	A
244	Newcomb	1 violations	Yes	0	A

FAQ

Frequently asked questions about nitrate in Arizona

Is nitrate in Arizona tap water dangerous?

Yes — 244 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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