Chlorate Contamination

Chlorate in Alabama Drinking Water

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

Cities Tested

Over HA

61%

% Over HA

483.7 µg/L

State Avg

▲ 2% vs national

vs National

250

Health Violations

Analysis

Chlorate in Alabama: what the data shows

Alabama has 75 cities with chlorate data from the EPA's UCMR 3 program (2013–2015). Chlorate exceeded the 210 µg/L EPA lifetime health advisory in 46 of those cities. The state average max detected level is 483.7 µg/L. Chlorate is a disinfection byproduct that forms when chlorine dioxide or hypochlorite solutions are used to disinfect drinking water. It is most common in systems that use chlorine dioxide for taste-and-odor control or that store hypochlorite for extended periods. There is no federal MCL — the EPA lifetime health advisory is 210 µg/L. Chlorate can interfere with thyroid function by blocking iodide uptake, an effect of particular concern for pregnant women, infants, and people with thyroid conditions. Reverse osmosis and ion exchange (anion-specific) are effective at removing chlorate; standard activated carbon filters provide only modest reduction.

Comparison

Cities exceeding 210 µg/L EPA lifetime HA (no MCL)

Alabama

61%

46 of 75 cities

→ ▲ 2% above national rate (worse)

National avg

59%

1866 of 3166 cities

City Map

Chlorate data across Alabama

Each dot is a city with UCMR 3 chlorate testing data. Cities where chlorate exceeds the 210 µg/L EPA lifetime health advisory are highlighted. Size reflects population served.

Worst Offenders

Top 10 cities by chlorate level in Alabama

Highest Chlorate levels (µg/L)

All Cities

All Alabama cities ranked by chlorate level

#	City	Level	Over HA?	Violations	Grade
1	Fort Payne	2600.0 µg/L	Over HA	3	C+
2	Russellville	1600.0 µg/L	Over HA	1	B+
3	Bessemer	1300.0 µg/L	Over HA	3	B-
4	Phenix City	1200.0 µg/L	Over HA	4	C+
5	Valley	1200.0 µg/L	Over HA	1	B
6	Tuscumbia	1166.0 µg/L	Over HA	11	D+
7	Jasper	1100.0 µg/L	Over HA	9	B+
8	Sheffield	1100.0 µg/L	Over HA	2	B+
9	Tuscaloosa	1000.0 µg/L	Over HA	3	A-
10	Alexander City	960.0 µg/L	Over HA	6	B+
11	Montgomery	935.0 µg/L	Over HA	1	A-
12	Lanett	930.0 µg/L	Over HA	2	B+
13	Smiths	920.0 µg/L	Over HA	0	B+
14	Vinemont	870.0 µg/L	Over HA	1	A
15	Helena	850.0 µg/L	Over HA	0	A
16	Alabaster	830.0 µg/L	Over HA	2	A-
17	Decatur	820.0 µg/L	Over HA	1	B+
18	Guntersville	790.0 µg/L	Over HA	1	B+
19	Muscle Shoals	760.0 µg/L	Over HA	4	A-
20	Mt Hope	760.0 µg/L	Over HA	2	B+
21	Northport	670.0 µg/L	Over HA	3	A-
22	Rainsville	660.0 µg/L	Over HA	3	B
23	Florence	620.0 µg/L	Over HA	7	D
24	Double Springs	591.5 µg/L	Over HA	7	A-
25	Opelika	590.0 µg/L	Over HA	8	B
26	Townley	590.0 µg/L	Over HA	2	A
27	Cullman	580.0 µg/L	Over HA	3	B+
28	Auburn	570.0 µg/L	Over HA	1	A-
29	Columbiana	560.0 µg/L	Over HA	2	B
30	Gulf Shores	560.0 µg/L	Over HA	1	A
31	Haleyville	550.0 µg/L	Over HA	2	A-
32	Citronelle	520.0 µg/L	Over HA	2	D
33	Prichard	480.0 µg/L	Over HA	13	C+
34	Loachapoka	479.0 µg/L	Over HA	2	A-
35	Allgood	418.0 µg/L	Over HA	2	A
36	Elmore	400.0 µg/L	Over HA	1	A-
37	Birmingham	380.0 µg/L	Over HA	1	A-
38	Huntsville	380.0 µg/L	Over HA	0	C+
39	Clanton	370.0 µg/L	Over HA	5	A-
40	Madison	361.0 µg/L	Over HA	0	B+
41	Douglas	360.0 µg/L	Over HA	1	A-
42	Oneonta	252.0 µg/L	Over HA	3	A
43	Daphne	250.0 µg/L	Over HA	9	D
44	Redstone Arsenal	250.0 µg/L	Over HA	24	B
45	Sylacauga	250.0 µg/L	Over HA	2	A-
46	Pell City	248.0 µg/L	Over HA	3	B+
47	Oxford	210.0 µg/L	No	2	B+
48	Marion	202.0 µg/L	No	5	B+
49	Mobile	170.0 µg/L	No	2	A-
50	Odenville	163.0 µg/L	No	0	B+
51	Wetumpka	160.0 µg/L	No	1	A-
52	Hartselle	139.0 µg/L	No	6	A
53	Scottsboro	130.0 µg/L	No	11	C+
54	Cleveland	130.0 µg/L	No	5	B
55	Somerville	117.0 µg/L	No	6	A
56	Albertville	110.0 µg/L	No	0	B
57	Boaz	110.0 µg/L	No	4	B+
58	Pelham	108.0 µg/L	No	2	A-
59	Trussville	90.0 µg/L	No	0	A-
60	Mulga	80.5 µg/L	No	3	B
61	Orange Beach	76.0 µg/L	No	1	C-
62	Bay Minette	63.0 µg/L	No	1	D
63	Arab	58.0 µg/L	No	0	A+
64	Rainbow City	58.0 µg/L	No	1	A
65	Sardis	55.0 µg/L	No	0	A
66	Ozark	53.2 µg/L	No	1	B
67	Leeds	50.7 µg/L	No	3	A-
68	Dothan	49.9 µg/L	No	1	B
69	Kennedy	43.8 µg/L	No	0	A-
70	Southside	43.0 µg/L	No	0	B+
71	Heflin	38.4 µg/L	No	5	D+
72	Thorsby	38.0 µg/L	No	0	A
73	Carrollton	38.0 µg/L	No	4	B-
74	Theodore	31.0 µg/L	No	5	C
75	Alexandria	28.0 µg/L	No	1	A+

FAQ

Frequently asked questions about chlorate in Alabama

Is chlorate in Alabama tap water dangerous?

Chlorate has no federal MCL. The EPA lifetime health advisory is 210 µg/L. 46 cities in Alabama exceed this level. Chlorate can interfere with thyroid iodide uptake, which is a particular concern for infants, pregnant women, and people with hypothyroidism.

Where does chlorate in Alabama water come from?

Chlorate is a byproduct of chlorine-based disinfectants — particularly chlorine dioxide and hypochlorite (bleach) solutions. Levels tend to be higher in systems that use chlorine dioxide for taste-and-odor treatment or store sodium hypochlorite at high concentrations or for long periods. Levels vary seasonally with disinfectant use.

How can I reduce chlorate exposure?

Reverse osmosis is the most effective home treatment for chlorate, typically removing 80–95%. Anion exchange systems also work but require regeneration. Standard activated carbon filters provide only limited chlorate reduction. Boiling does NOT remove chlorate.

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