Nitrate Contamination

Nitrate in Oregon Drinking Water

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

198

Cities Tested

198

Has Violations

100%

% Has Violations

12.4 violations

State Avg

▼ 0% vs national

vs National

205

Health Violations

Analysis

Nitrate in Oregon: what the data shows

Oregon has 198 cities with nitrate-related violations. The EPA MCL for nitrate is 10 mg/L (measured as nitrogen). The state has 198 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

Oregon

100%

198 of 198 cities

← = Exactly at national rate

National avg

100%

8001 of 8001 cities

City Map

Nitrate data across Oregon

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 Oregon

Highest Nitrate levels (violations)

All Cities

All Oregon cities ranked by nitrate level

#	City	Level	Violations?	Violations	Grade
1	Newberg	139 violations	Yes	270	F
2	Grants Pass	109 violations	Yes	78	F
3	Salem	103 violations	Yes	108	F
4	Bend	80 violations	Yes	116	F
5	Portland	62 violations	Yes	118	F
6	Klamath Falls	61 violations	Yes	36	F
7	Scappoose	58 violations	Yes	84	F
8	Hermiston	56 violations	Yes	67	F
9	Prineville	55 violations	Yes	56	F
10	Eugene	52 violations	Yes	178	F
11	Sandy	40 violations	Yes	161	F
12	Molalla	38 violations	Yes	75	F
13	The Dalles	37 violations	Yes	54	F
14	Rainier	37 violations	Yes	121	D
15	St Helens	35 violations	Yes	33	F
16	Clackamas	32 violations	Yes	21	D
17	Redmond	29 violations	Yes	35	D
18	Boring	29 violations	Yes	39	D+
19	Seaside	28 violations	Yes	27	F
20	Tillamook	27 violations	Yes	38	F
21	Burns	27 violations	Yes	19	D+
22	Warm Springs	26 violations	Yes	89	F
23	Central Point	25 violations	Yes	68	D
24	Pendleton	25 violations	Yes	43	F
25	Brookings	25 violations	Yes	19	D
26	Roseburg	24 violations	Yes	35	F
27	Woodburn	24 violations	Yes	50	F
28	Enterprise	23 violations	Yes	24	D+
29	Clatskanie	23 violations	Yes	57	D
30	Fairview	22 violations	Yes	20	D
31	Corvallis	21 violations	Yes	38	F
32	Riddle	21 violations	Yes	55	F
33	Medford	20 violations	Yes	44	F
34	Tangent	18 violations	Yes	7	C
35	Ashland	17 violations	Yes	15	D
36	Sheridan	17 violations	Yes	5	D
37	Amity	17 violations	Yes	31	D
38	Stanfield	17 violations	Yes	4	C
39	Westport	17 violations	Yes	32	D+
40	Wamic	16 violations	Yes	10	C-
41	Springfield	15 violations	Yes	19	F
42	Bandon	15 violations	Yes	119	F
43	Gold Beach	15 violations	Yes	3	F
44	Coos Bay	14 violations	Yes	14	D+
45	Wilsonville	14 violations	Yes	10	C+
46	Hood River	14 violations	Yes	13	D+
47	Estacada	14 violations	Yes	119	F
48	Dundee	14 violations	Yes	3	D+
49	Cave Junction	14 violations	Yes	60	D
50	Beaverton	13 violations	Yes	10	F
51	Albany	13 violations	Yes	35	F
52	Milwaukie	13 violations	Yes	1	F
53	La Grande	13 violations	Yes	7	B-
54	Terrebonne	13 violations	Yes	28	D
55	Waldport	13 violations	Yes	25	D
56	Chiloquin	13 violations	Yes	8	D+
57	Pendelton	13 violations	Yes	1	D+
58	Lake Oswego	12 violations	Yes	20	D
59	Keizer	12 violations	Yes	7	C
60	Astoria	12 violations	Yes	45	F
61	Monmouth	12 violations	Yes	18	D
62	Cottage Grove	12 violations	Yes	173	F
63	Rickreall	12 violations	Yes	15	F
64	Welches	12 violations	Yes	47	D+
65	Port Orford	12 violations	Yes	24	D
66	Shady Cove	12 violations	Yes	56	D
67	Newport	11 violations	Yes	29	F
68	Myrtle Point	11 violations	Yes	9	D+
69	Gold Hill	11 violations	Yes	17	D
70	Condon	11 violations	Yes	1	B+
71	West Linn	10 violations	Yes	15	F
72	Coquille	10 violations	Yes	57	F
73	Scio	10 violations	Yes	4	C
74	Canby	9 violations	Yes	21	D
75	Baker City	9 violations	Yes	4	C+
76	Milton-Freewater	9 violations	Yes	12	F
77	Aurora	9 violations	Yes	19	D+
78	Dayton	9 violations	Yes	5	A-
79	Hines	9 violations	Yes	4	A-
80	Lebanon	8 violations	Yes	16	F
81	Sutherlin	8 violations	Yes	6	B
82	Sisters	8 violations	Yes	12	C
83	Jacksonville	8 violations	Yes	10	C+
84	Vernonia	8 violations	Yes	11	D
85	Garibaldi	8 violations	Yes	15	C
86	Otis	8 violations	Yes	28	D
87	Oceanside	8 violations	Yes	6	C
88	Antelope	8 violations	Yes	25	C-
89	Troutdale	7 violations	Yes	2	A-
90	Umatilla	7 violations	Yes	13	D
91	Junction City	7 violations	Yes	14	F
92	Lakeview	7 violations	Yes	2	D
93	Nehalem	7 violations	Yes	8	D
94	Lyons	7 violations	Yes	8	F
95	Canyon City	7 violations	Yes	2	B-
96	Maupin	7 violations	Yes	12	D
97	Ontario	6 violations	Yes	5	B-
98	Corbett	6 violations	Yes	10	C-
99	Grand Ronde	6 violations	Yes	22	D+
100	Rogue River	6 violations	Yes	7	C
101	Banks	6 violations	Yes	5	B+
102	Elgin	6 violations	Yes	4	A-
103	Glide	6 violations	Yes	1	B+
104	Glendale	6 violations	Yes	42	B
105	Mulino	6 violations	Yes	10	F
106	Sherwood	5 violations	Yes	7	B-
107	Independence	5 violations	Yes	6	B
108	Warrenton	5 violations	Yes	2	B+
109	Winston	5 violations	Yes	9	B
110	Myrtle Creek	5 violations	Yes	55	D+
111	Reedsport	5 violations	Yes	8	C-
112	Philomath	5 violations	Yes	35	B+
113	Harrisburg	5 violations	Yes	37	D
114	Hubbard	5 violations	Yes	30	F
115	Mt. Angel	5 violations	Yes	5	B
116	Gaston	5 violations	Yes	13	D
117	Nyssa	5 violations	Yes	34	B-
118	Manzanita	5 violations	Yes	4	B
119	Harbor	5 violations	Yes	3	B+
120	Brownsville	5 violations	Yes	17	F
121	Yachats	5 violations	Yes	5	D
122	Cloverdale	5 violations	Yes	5	F
123	Merrill	5 violations	Yes	4	A-
124	Wallowa	5 violations	Yes	1	B+
125	Dufur	5 violations	Yes	4	C-
126	Huntington	5 violations	Yes	8	C
127	Oregon City	4 violations	Yes	14	D
128	Talent	4 violations	Yes	3	B-
129	Boardman	4 violations	Yes	0	C+
130	Lafayette	4 violations	Yes	16	C-
131	Aumsville	4 violations	Yes	12	A
132	Jefferson	4 violations	Yes	4	C+
133	Irrigon	4 violations	Yes	2	D
134	Pilot Rock	4 violations	Yes	8	A-
135	Heppner	4 violations	Yes	17	B+
136	Island City	4 violations	Yes	5	D+
137	Oakland	4 violations	Yes	2	D+
138	Falls City	4 violations	Yes	3	B-
139	Pacific City	4 violations	Yes	2	D
140	Malin	4 violations	Yes	9	B
141	Powers	4 violations	Yes	14	B+
142	Arlington	4 violations	Yes	0	A-
143	Hillsboro	3 violations	Yes	7	F
144	Tigard	3 violations	Yes	3	C
145	Silverton	3 violations	Yes	18	C
146	Eagle Point	3 violations	Yes	1	C+
147	Wood Village	3 violations	Yes	9	B
148	Turner	3 violations	Yes	3	B
149	Union	3 violations	Yes	7	A-
150	Columbia City	3 violations	Yes	3	B
151	Vale	3 violations	Yes	45	C
152	Mill City	3 violations	Yes	0	A
153	Ophir	3 violations	Yes	2	B-
154	Bay City	3 violations	Yes	3	B
155	Cascade Locks	3 violations	Yes	3	C
156	Athena	3 violations	Yes	5	A-
157	Donald	3 violations	Yes	14	A
158	Yoncalla	3 violations	Yes	44	C
159	Rhododendron	3 violations	Yes	4	B
160	Parkdale	3 violations	Yes	15	B+
161	Cove	3 violations	Yes	2	A
162	Mount Vernon	3 violations	Yes	3	B+
163	Happy Valley	2 violations	Yes	17	F
164	Forest Grove	2 violations	Yes	2	B+
165	Madras	2 violations	Yes	16	B+
166	Florence	2 violations	Yes	6	A-
167	Veneta	2 violations	Yes	2	A-
168	Carlton	2 violations	Yes	9	B-
169	Canyonville	2 violations	Yes	14	C-
170	Yamhill	2 violations	Yes	53	F
171	Siletz	2 violations	Yes	9	B+
172	Colton	2 violations	Yes	23	D+
173	Joseph	2 violations	Yes	3	B
174	Crescent	2 violations	Yes	3	A
175	Halsey	2 violations	Yes	2	B+
176	Mapleton	2 violations	Yes	70	D
177	Mcminnville	1 violations	Yes	1	B+
178	Lincoln City	1 violations	Yes	1	B+
179	Dallas	1 violations	Yes	4	B-
180	Sweet Home	1 violations	Yes	83	B-
181	Stayton	1 violations	Yes	2	B+
182	Gleneden Beach	1 violations	Yes	2	A-
183	Toledo	1 violations	Yes	0	A
184	Oakridge	1 violations	Yes	5	C+
185	Sublimity	1 violations	Yes	4	A-
186	Gervais	1 violations	Yes	1	A-
187	Willamina	1 violations	Yes	4	A-
188	Lakeside	1 violations	Yes	2	A
189	Netarts	1 violations	Yes	3	B
190	Neskowin	1 violations	Yes	3	B
191	Cannon Beach	1 violations	Yes	3	C+
192	John Day	1 violations	Yes	1	A-
193	Rockaway Beach	1 violations	Yes	15	A-
194	Depoe Bay	1 violations	Yes	5	A-
195	Coburg	1 violations	Yes	6	B+
196	Adair Village	1 violations	Yes	12	C
197	Prairie City	1 violations	Yes	6	B-
198	Echo	1 violations	Yes	3	A-

FAQ

Frequently asked questions about nitrate in Oregon

Is nitrate in Oregon tap water dangerous?

Yes — 198 cities in Oregon 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 Oregon 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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