Chromium-6 Contamination

Chromium-6 in North Carolina Drinking Water

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

110

Cities Tested

110

Detected

100%

% Detected

0.32 µg/L

State Avg

▼ 0% vs national

vs National

362

Health Violations

Analysis

Chromium-6 in North Carolina: what the data shows

North Carolina has 110 cities with chromium-6 data from the EPA's UCMR 3 program (2013–2015). Hexavalent chromium (Cr VI) was detected in 110 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 0.32 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)

North Carolina

100%

110 of 110 cities

← = Exactly at national rate

National avg

100%

4005 of 4005 cities

City Map

Chromium-6 data across North Carolina

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 North Carolina

Highest Chromium-6 levels (µg/L)

All Cities

All North Carolina cities ranked by chromium-6 level

#	City	Level	Detected?	Violations	Grade
1	Raleigh	11.00 µg/L	Detected	241	F
2	Statesville	4.90 µg/L	Detected	37	F
3	Fayetteville	1.90 µg/L	Detected	392	F
4	Nashville	0.95 µg/L	Detected	36	F
5	Pinehurst	0.69 µg/L	Detected	5	C-
6	Elizabeth City	0.46 µg/L	Detected	2	A-
7	Henderson	0.46 µg/L	Detected	25	F
8	Harrisburg	0.45 µg/L	Detected	28	F
9	Concord	0.43 µg/L	Detected	37	F
10	Butner	0.41 µg/L	Detected	25	B
11	Warrenton	0.40 µg/L	Detected	5	B
12	Oak Island	0.35 µg/L	Detected	1	B
13	Hudson	0.32 µg/L	Detected	2	A-
14	Kings Mountain	0.30 µg/L	Detected	5	B
15	Lawndale	0.28 µg/L	Detected	1	B-
16	Rockingham	0.27 µg/L	Detected	15	C
17	Asheboro	0.27 µg/L	Detected	8	F
18	Deep Run	0.27 µg/L	Detected	0	B+
19	Mount Airy	0.25 µg/L	Detected	0	B
20	Greenville	0.23 µg/L	Detected	7	C-
21	Raeford	0.23 µg/L	Detected	16	F
22	Lexington	0.22 µg/L	Detected	14	B-
23	Lincolnton	0.22 µg/L	Detected	0	D+
24	Leland	0.21 µg/L	Detected	11	C
25	Rutherfordton	0.21 µg/L	Detected	7	B-
26	Monroe	0.20 µg/L	Detected	10	B-
27	Rocky Mount	0.19 µg/L	Detected	17	C
28	Kinston	0.19 µg/L	Detected	4	C-
29	Albemarle	0.19 µg/L	Detected	46	C-
30	Reidsville	0.19 µg/L	Detected	36	F
31	Hickory	0.18 µg/L	Detected	11	F
32	Pinebluff	0.18 µg/L	Detected	32	D+
33	Forest City	0.18 µg/L	Detected	1	B-
34	Conover	0.18 µg/L	Detected	6	F
35	Longview	0.18 µg/L	Detected	0	A-
36	Greensboro	0.17 µg/L	Detected	29	F
37	Taylorsville	0.17 µg/L	Detected	7	B
38	Miller Creek	0.17 µg/L	Detected	1	B+
39	Mayodan	0.17 µg/L	Detected	1	B+
40	Granite Falls	0.16 µg/L	Detected	4	B+
41	Wilson Mills	0.16 µg/L	Detected	3	B-
42	Clayton	0.16 µg/L	Detected	50	D
43	Denver	0.16 µg/L	Detected	10	C-
44	Newport	0.16 µg/L	Detected	31	F
45	Clemmons	0.15 µg/L	Detected	0	A-
46	Mt Holly	0.15 µg/L	Detected	1	A-
47	Laurinburg	0.14 µg/L	Detected	0	C
48	Mt Gilead	0.14 µg/L	Detected	18	F
49	Windsor	0.14 µg/L	Detected	7	A-
50	Highlands	0.14 µg/L	Detected	25	F
51	Jacksonville	0.14 µg/L	Detected	22	F
52	Camp Lejeune	0.14 µg/L	Detected	10	A-
53	Gastonia	0.13 µg/L	Detected	102	F
54	Salisbury	0.13 µg/L	Detected	27	F
55	Lilesville	0.13 µg/L	Detected	16	D
56	Roxboro	0.13 µg/L	Detected	9	A-
57	Charlotte	0.12 µg/L	Detected	47	F
58	Fuquay-Varina	0.12 µg/L	Detected	34	F
59	Roanoke Rapids	0.12 µg/L	Detected	17	B
60	Tarboro	0.12 µg/L	Detected	49	F
61	Erwin	0.12 µg/L	Detected	0	B+
62	N Wilkesboro	0.11 µg/L	Detected	4	B+
63	Wilmington	0.11 µg/L	Detected	22	F
64	Wilson	0.11 µg/L	Detected	7	C+
65	Kannapolis	0.11 µg/L	Detected	16	C-
66	Sanford	0.11 µg/L	Detected	31	F
67	Maple	0.11 µg/L	Detected	4	B+
68	Newton	0.11 µg/L	Detected	15	F
69	Cherry Point	0.11 µg/L	Detected	3	A-
70	Elkin	0.11 µg/L	Detected	1	B+
71	High Point	0.10 µg/L	Detected	2	B-
72	Mocksville	0.10 µg/L	Detected	19	C
73	Smithfield	0.10 µg/L	Detected	9	C+
74	Washington	0.10 µg/L	Detected	2	B+
75	King	0.10 µg/L	Detected	12	B+
76	Havelock	0.10 µg/L	Detected	20	B+
77	Holly Springs	0.09 µg/L	Detected	8	C-
78	Shelby	0.09 µg/L	Detected	2	A
79	Hiddenite	0.09 µg/L	Detected	3	A-
80	Bellarthur	0.09 µg/L	Detected	3	B-
81	Hamlet	0.09 µg/L	Detected	20	F
82	Kill Devil Hill	0.09 µg/L	Detected	1	A-
83	Lumberton	0.08 µg/L	Detected	2	B
84	Eden	0.08 µg/L	Detected	10	C
85	Asheville	0.08 µg/L	Detected	12	F
86	Goldsboro	0.08 µg/L	Detected	11	F
87	Mebane	0.08 µg/L	Detected	10	B+
88	Blowing Rock	0.08 µg/L	Detected	7	C
89	Burlington	0.08 µg/L	Detected	33	F
90	Valdese	0.07 µg/L	Detected	0	B+
91	Apex	0.07 µg/L	Detected	40	F
92	Boone	0.07 µg/L	Detected	33	F
93	Thomasville	0.07 µg/L	Detected	0	A-
94	Elizabethtown	0.07 µg/L	Detected	1	B+
95	Harkers Island	0.07 µg/L	Detected	5	A-
96	Maxton	0.07 µg/L	Detected	12	C
97	Lillington	0.06 µg/L	Detected	4	B-
98	Carrboro	0.06 µg/L	Detected	0	A
99	Burgaw	0.06 µg/L	Detected	21	F
100	Mooresville	0.06 µg/L	Detected	22	F
101	New Bern	0.05 µg/L	Detected	4	B+
102	Cary	0.05 µg/L	Detected	9	F
103	Morganton	0.05 µg/L	Detected	2	B+
104	Hillsborough	0.05 µg/L	Detected	9	C-
105	Durham	0.05 µg/L	Detected	94	F
106	Kenansville	0.05 µg/L	Detected	2	B
107	Clinton	0.04 µg/L	Detected	3	B+
108	Carolina Beach	0.04 µg/L	Detected	5	D
109	Waynesville	0.04 µg/L	Detected	5	C+
110	Hendersonville	0.03 µg/L	Detected	36	F

FAQ

Frequently asked questions about chromium-6 in North Carolina

Is chromium-6 in North Carolina 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. 110 cities in North Carolina 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 North Carolina 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 North Carolina?

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).

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