Chromium-6 Contamination

Chromium-6 in Texas Drinking Water

Ranked by max chromium-6 detected (µg/L) · UCMR 3 data (2013–2015) · Data from EPA SDWIS & UCMR

247

Cities Tested

247

Detected

100%

% Detected

0.53 µg/L

State Avg

▼ 0% vs national

vs National

900

Health Violations

Analysis

Chromium-6 in Texas: what the data shows

Texas has 247 cities with chromium-6 data from the EPA's UCMR 3 program (2013–2015). Hexavalent chromium (Cr VI) was detected in 247 of those cities. There is currently no federal MCL for chromium-6 — California's 10 µg/L limit is used as a reference. The state average max detected level is 0.53 µg/L. Chromium-6 occurs naturally in some groundwater aquifers but also from industrial discharge, particularly from steel processing, chrome plating, and leather tanning. It is distinct from trivalent chromium (Cr III), which is an essential nutrient at low doses. The National Toxicology Program and IARC classify chromium-6 as a carcinogen via inhalation; the evidence for drinking water carcinogenicity is strong but regulatory action at the federal level remains pending as of 2026. Reverse osmosis systems effectively remove chromium-6 to near-undetectable levels.

Comparison

Cities exceeding No federal MCL (CA: 10 µg/L)

Texas

100%

247 of 247 cities

← = Exactly at national rate

National avg

100%

4005 of 4005 cities

City Map

Chromium-6 data across Texas

Each dot is a city with UCMR 3 chromium-6 data. Detected cities are shown; there is no federal MCL — California's 10 µg/L limit is used as a reference. Size reflects population served.

Worst Offenders

Top 10 cities by chromium-6 level in Texas

Highest Chromium-6 levels (µg/L)

All Cities

All Texas cities ranked by chromium-6 level

#	City	Level	Detected?	Violations	Grade
1	Kingsville	10.30 µg/L	Detected	45	D+
2	El Paso	8.40 µg/L	Detected	192	F
3	Dayton	7.08 µg/L	Detected	4	D
4	Houston	6.66 µg/L	Detected	929	F
5	Austin	4.01 µg/L	Detected	1288	F
6	Wharton	3.81 µg/L	Detected	1	D
7	Pampa	3.80 µg/L	Detected	7	B
8	Clint	3.67 µg/L	Detected	2	B
9	Levelland	2.77 µg/L	Detected	168	F
10	Borger	2.72 µg/L	Detected	1	C-
11	Amarillo	2.69 µg/L	Detected	26	F
12	El Campo	2.45 µg/L	Detected	19	F
13	Plainview	2.40 µg/L	Detected	25	F
14	Dumas	2.35 µg/L	Detected	6	C+
15	Friona	2.26 µg/L	Detected	10	B
16	Sugar Land	2.10 µg/L	Detected	4	F
17	Lubbock	2.00 µg/L	Detected	1231	F
18	Canyon	1.88 µg/L	Detected	5	F
19	Post	1.88 µg/L	Detected	28	F
20	San Antonio	1.80 µg/L	Detected	25	F
21	Mission	1.67 µg/L	Detected	23	C-
22	Cleveland	1.44 µg/L	Detected	4	C-
23	Horizon City	1.41 µg/L	Detected	1	A
24	Cypress	1.33 µg/L	Detected	624	F
25	Splendora	1.30 µg/L	Detected	4	D
26	Holliday	1.20 µg/L	Detected	4	B+
27	Lockhart	1.10 µg/L	Detected	0	A-
28	Garden Ridge	1.10 µg/L	Detected	0	A-
29	Friendswood	1.01 µg/L	Detected	0	B+
30	Wichita Falls	0.97 µg/L	Detected	823	F
31	Burkburnett	0.97 µg/L	Detected	45	B-
32	Richmond	0.96 µg/L	Detected	3	F
33	Hereford	0.90 µg/L	Detected	13	F
34	Humble	0.88 µg/L	Detected	1	B+
35	Huntsville	0.86 µg/L	Detected	128	F
36	Midland	0.85 µg/L	Detected	231	F
37	Robinson	0.81 µg/L	Detected	2	A-
38	Hurst	0.81 µg/L	Detected	1	A-
39	Eagle Lake	0.81 µg/L	Detected	2	C+
40	Fredericksburg	0.78 µg/L	Detected	129	D
41	Farmers Branch	0.69 µg/L	Detected	0	A-
42	Longview	0.68 µg/L	Detected	20	F
43	The Colony	0.63 µg/L	Detected	2	A-
44	Carrollton	0.62 µg/L	Detected	0	A-
45	Dallas	0.58 µg/L	Detected	102	F
46	Grand Prairie	0.58 µg/L	Detected	10	F
47	Sheppard Afb	0.58 µg/L	Detected	3	A-
48	Denison	0.55 µg/L	Detected	24	F
49	Marion	0.55 µg/L	Detected	2	B-
50	Henderson	0.54 µg/L	Detected	57	F
51	Douglass	0.50 µg/L	Detected	4	B
52	Coupland	0.46 µg/L	Detected	6	C
53	Irving	0.45 µg/L	Detected	9	C
54	Galveston	0.45 µg/L	Detected	2	B+
55	Pleasanton	0.40 µg/L	Detected	7	B+
56	Texarkana	0.40 µg/L	Detected	17	F
57	Coppell	0.39 µg/L	Detected	0	A-
58	Little Elm	0.38 µg/L	Detected	2	C
59	Red Oak	0.37 µg/L	Detected	10	B+
60	Lewisville	0.37 µg/L	Detected	1	C+
61	Temple	0.36 µg/L	Detected	31	C-
62	Vernon	0.36 µg/L	Detected	163	D
63	Diboll	0.36 µg/L	Detected	9	B-
64	Flower Mound	0.35 µg/L	Detected	2	C
65	Stamford	0.35 µg/L	Detected	76	D
66	Seguin	0.35 µg/L	Detected	42	F
67	Addison	0.35 µg/L	Detected	3	C
68	Greenville	0.34 µg/L	Detected	8	C
69	Sunset Valley	0.33 µg/L	Detected	0	A
70	Pearland	0.31 µg/L	Detected	14	F
71	Fate	0.31 µg/L	Detected	0	B
72	Cleburne	0.30 µg/L	Detected	5	C
73	Seabrook	0.30 µg/L	Detected	0	B+
74	San Marcos	0.30 µg/L	Detected	56	C-
75	Stephenville	0.29 µg/L	Detected	39	F
76	West University Place	0.28 µg/L	Detected	2	B+
77	Georgetown	0.28 µg/L	Detected	3	F
78	Hutto	0.28 µg/L	Detected	17	B
79	Duncanville	0.28 µg/L	Detected	5	B+
80	Memphis	0.28 µg/L	Detected	2	B+
81	Zapata	0.27 µg/L	Detected	75	D
82	Baytown	0.27 µg/L	Detected	6	F
83	Tyler	0.26 µg/L	Detected	53	F
84	Lancaster	0.26 µg/L	Detected	5	B-
85	Joshua	0.25 µg/L	Detected	2	C-
86	Stafford	0.25 µg/L	Detected	1	A-
87	Adkins	0.24 µg/L	Detected	2	A-
88	Forney	0.23 µg/L	Detected	10	B-
89	Kilgore	0.23 µg/L	Detected	26	F
90	Seagoville	0.23 µg/L	Detected	7	B
91	Waxahachie	0.22 µg/L	Detected	70	D+
92	Balch Springs	0.22 µg/L	Detected	8	B
93	Uvalde	0.22 µg/L	Detected	0	D
94	Crowley	0.22 µg/L	Detected	2	C+
95	Rowlett	0.22 µg/L	Detected	0	A-
96	Bonham	0.21 µg/L	Detected	30	B+
97	Converse	0.21 µg/L	Detected	1	A
98	Mesquite	0.20 µg/L	Detected	0	B+
99	Weslaco	0.20 µg/L	Detected	2	C+
100	Glenn Heights	0.19 µg/L	Detected	3	C-
101	Bellmead	0.19 µg/L	Detected	3	B-
102	Sweetwater	0.18 µg/L	Detected	8	B
103	Universal City	0.18 µg/L	Detected	0	B+
104	Richardson	0.18 µg/L	Detected	30	F
105	New Braunfels	0.18 µg/L	Detected	15	D
106	Crockett	0.18 µg/L	Detected	47	F
107	Richland Hills	0.18 µg/L	Detected	2	A-
108	Bellaire	0.18 µg/L	Detected	1	A-
109	Allen	0.17 µg/L	Detected	0	A-
110	Edinburg	0.17 µg/L	Detected	12	C-
111	Desoto	0.17 µg/L	Detected	2	A-
112	Highlands	0.17 µg/L	Detected	14	F
113	Terrell	0.17 µg/L	Detected	21	F
114	Schertz	0.17 µg/L	Detected	0	B+
115	Whitehouse	0.17 µg/L	Detected	12	B+
116	Palestine	0.17 µg/L	Detected	15	C
117	Round Rock	0.16 µg/L	Detected	17	F
118	Marshall	0.16 µg/L	Detected	46	F
119	Cedar Hill	0.16 µg/L	Detected	4	A-
120	Plano	0.16 µg/L	Detected	5	A-
121	Mercedes	0.16 µg/L	Detected	22	F
122	Victoria	0.15 µg/L	Detected	28	F
123	Canyon Lake	0.15 µg/L	Detected	39	F
124	Bastrop	0.15 µg/L	Detected	31	F
125	Garland	0.14 µg/L	Detected	0	A-
126	Eagle Pass	0.14 µg/L	Detected	45	D+
127	Fort Worth	0.14 µg/L	Detected	25	F
128	Frisco	0.14 µg/L	Detected	3	B
129	Beaumont	0.14 µg/L	Detected	42	F
130	Texas City	0.14 µg/L	Detected	4	B
131	Jacksonville	0.14 µg/L	Detected	62	D
132	Grapevine	0.14 µg/L	Detected	0	A-
133	Murphy	0.14 µg/L	Detected	0	B+
134	Comanche	0.14 µg/L	Detected	42	D
135	Athens	0.14 µg/L	Detected	95	F
136	College Station	0.13 µg/L	Detected	2	B-
137	Pflugerville	0.13 µg/L	Detected	19	C+
138	Jbsa Lackland	0.13 µg/L	Detected	4	B+
139	Burleson	0.13 µg/L	Detected	9	B+
140	Wylie	0.13 µg/L	Detected	2	B-
141	Boerne	0.13 µg/L	Detected	24	F
142	Hewitt	0.13 µg/L	Detected	4	A-
143	White Settlement	0.12 µg/L	Detected	13	C+
144	Odessa	0.12 µg/L	Detected	225	F
145	Grandview	0.12 µg/L	Detected	0	B+
146	De Leon	0.12 µg/L	Detected	45	F
147	Bedford	0.12 µg/L	Detected	0	B+
148	Hondo	0.11 µg/L	Detected	1	B+
149	Niederwald	0.11 µg/L	Detected	6	B-
150	Parker	0.11 µg/L	Detected	0	A-
151	Del Rio	0.11 µg/L	Detected	117	F
152	Royse City	0.11 µg/L	Detected	6	C+
153	Hemphill	0.11 µg/L	Detected	115	F
154	Katy	0.11 µg/L	Detected	46	F
155	Nocona	0.11 µg/L	Detected	8	C
156	Deer Park	0.10 µg/L	Detected	2	B+
157	Angleton	0.10 µg/L	Detected	47	F
158	North Richland Hills	0.10 µg/L	Detected	1	B+
159	Kerrville	0.10 µg/L	Detected	131	F
160	Lake Jackson	0.10 µg/L	Detected	6	D
161	Harlingen	0.10 µg/L	Detected	1	C
162	Mckinney	0.10 µg/L	Detected	0	A-
163	Nacogdoches	0.10 µg/L	Detected	17	F
164	Colleyville	0.09 µg/L	Detected	1	B+
165	Keller	0.09 µg/L	Detected	1	B+
166	Sachse	0.09 µg/L	Detected	1	A
167	Freeport	0.08 µg/L	Detected	209	F
168	White Oak	0.08 µg/L	Detected	7	B
169	Corpus Christi	0.08 µg/L	Detected	13	B
170	Kyle	0.08 µg/L	Detected	5	A-
171	The Woodlands	0.08 µg/L	Detected	19	F
172	Dickinson	0.08 µg/L	Detected	8	F
173	Teague	0.08 µg/L	Detected	1	B-
174	Port Isabel	0.08 µg/L	Detected	24	B+
175	Saginaw	0.08 µg/L	Detected	4	A-
176	Rockwall	0.07 µg/L	Detected	4	D
177	Nederland	0.07 µg/L	Detected	28	D
178	Ingleside	0.07 µg/L	Detected	3	D+
179	Taylor	0.07 µg/L	Detected	6	A-
180	Midlothian	0.07 µg/L	Detected	12	B
181	Southlake	0.07 µg/L	Detected	3	B
182	Santa Fe	0.07 µg/L	Detected	25	F
183	Benbrook	0.07 µg/L	Detected	0	B
184	Denton	0.07 µg/L	Detected	3	F
185	Haltom City	0.07 µg/L	Detected	2	B
186	Rosenberg	0.07 µg/L	Detected	1	C-
187	Rio Hondo	0.07 µg/L	Detected	70	F
188	Forest Hill	0.06 µg/L	Detected	7	A-
189	Waco	0.06 µg/L	Detected	53	F
190	League City	0.06 µg/L	Detected	67	F
191	Mcallen	0.06 µg/L	Detected	0	A
192	Port Neches	0.06 µg/L	Detected	6	B+
193	Livingston	0.06 µg/L	Detected	398	F
194	Abilene	0.06 µg/L	Detected	46	F
195	Lufkin	0.06 µg/L	Detected	167	F
196	Fort Stockton	0.06 µg/L	Detected	54	D
197	Brownsville	0.06 µg/L	Detected	5	C+
198	Trophy Club	0.06 µg/L	Detected	0	A+
199	Springtown	0.06 µg/L	Detected	71	D
200	West Columbia	0.06 µg/L	Detected	2	C+
201	Groves	0.06 µg/L	Detected	5	B+
202	Granbury	0.05 µg/L	Detected	28	F
203	Kempner	0.05 µg/L	Detected	19	B-
204	Porter	0.05 µg/L	Detected	58	F
205	San Benito	0.05 µg/L	Detected	16	B+
206	Pharr	0.05 µg/L	Detected	0	A-
207	Watauga	0.05 µg/L	Detected	4	A-
208	La Porte	0.05 µg/L	Detected	0	B+
209	Arlington	0.05 µg/L	Detected	5	D+
210	Euless	0.05 µg/L	Detected	1	A-
211	Galena Park	0.05 µg/L	Detected	4	B-
212	Alice	0.05 µg/L	Detected	103	F
213	Jasper	0.05 µg/L	Detected	77	F
214	Conroe	0.05 µg/L	Detected	54	F
215	Portland	0.05 µg/L	Detected	2	B+
216	Brenham	0.05 µg/L	Detected	20	F
217	Rockport	0.05 µg/L	Detected	20	B-
218	Menard	0.05 µg/L	Detected	1	A-
219	Mc Gregor	0.05 µg/L	Detected	5	C-
220	Sulphur Springs	0.05 µg/L	Detected	18	C
221	La Marque	0.05 µg/L	Detected	3	B
222	Bryan	0.05 µg/L	Detected	11	D
223	Belton	0.04 µg/L	Detected	22	F
224	Blue Ridge	0.04 µg/L	Detected	1	B
225	Pasadena	0.04 µg/L	Detected	0	B-
226	Donna	0.04 µg/L	Detected	6	B
227	Wills Point	0.04 µg/L	Detected	27	C-
228	Harker Heights	0.04 µg/L	Detected	19	B-
229	Mount Pleasant	0.04 µg/L	Detected	2	A-
230	Fort Hood	0.04 µg/L	Detected	3	A-
231	Vidor	0.04 µg/L	Detected	250	F
232	Three Rivers	0.04 µg/L	Detected	19	B+
233	Highland Village	0.04 µg/L	Detected	3	A-
234	Montague	0.04 µg/L	Detected	5	D
235	San Angelo	0.04 µg/L	Detected	40	F
236	Lake Dallas	0.04 µg/L	Detected	2	B-
237	Mabank	0.04 µg/L	Detected	66	D
238	Big Spring	0.04 µg/L	Detected	48	F
239	Sherman	0.03 µg/L	Detected	2	B+
240	Elsa	0.03 µg/L	Detected	5	B-
241	Somerville	0.03 µg/L	Detected	17	C-
242	Gilmer	0.03 µg/L	Detected	7	C
243	Como	0.03 µg/L	Detected	1	B+
244	Brownwood	0.03 µg/L	Detected	12	A-
245	Ennis	0.03 µg/L	Detected	2	A-
246	Corinth	0.03 µg/L	Detected	2	A-
247	Alvin	0.03 µg/L	Detected	37	F

FAQ

Frequently asked questions about chromium-6 in Texas

Is chromium-6 in Texas tap water dangerous?

Chromium-6 (hexavalent chromium) is a potential human carcinogen. There is currently no federal MCL — California's 10 µg/L limit is the most protective US standard. 247 cities in Texas had detectable chromium-6 in UCMR 3 testing (2013–2015). Reverse osmosis is the most effective removal method.

Where does chromium-6 come from in Texas water?

Chromium-6 enters water supplies from two main sources: natural weathering of chromium-containing rock formations (especially in the Southwest and parts of the Midwest) and industrial discharge from steel mills, chrome plating, and coal ash sites. Groundwater systems are more commonly affected by natural sources, while surface water systems near industrial areas face pollution-related risks.

How can I filter chromium-6 from my water in Texas?

Reverse osmosis (RO) systems are the most effective, removing over 95% of chromium-6. Some high-quality activated alumina or anion exchange filters also provide significant reduction. Standard carbon filters and pitcher filters are generally NOT effective against chromium-6. Look for filters certified by NSF International against NSF/ANSI 58 (for RO systems).

More contaminants