Chlorate Contamination

Chlorate in Florida Drinking Water

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

151

Cities Tested

131

Over HA

87%

% Over HA

838.5 µg/L

State Avg

▲ 29% vs national

vs National

321

Health Violations

Analysis

Chlorate in Florida: what the data shows

Florida has 151 cities with chlorate data from the EPA's UCMR 3 program (2013–2015). Chlorate exceeded the 210 µg/L EPA lifetime health advisory in 131 of those cities. The state average max detected level is 838.5 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)

Florida

87%

131 of 151 cities

→ ▲ 29% above national rate (worse)

National avg

58%

1812 of 3098 cities

City Map

Chlorate data across Florida

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 Florida

Highest Chlorate levels (µg/L)

All Cities

All Florida cities ranked by chlorate level

#	City	Level	Over HA?	Violations	Grade
1	Orange City	9540.5 µg/L	Over HA	14	C+
2	Ormond Beach	7207.6 µg/L	Over HA	43	D+
3	Clermont	6400.0 µg/L	Over HA	58	F
4	Lakeland	3759.6 µg/L	Over HA	27	D
5	Deltona	2440.0 µg/L	Over HA	19	B+
6	Winter Haven	2400.0 µg/L	Over HA	28	F
7	Fort Myers	2160.0 µg/L	Over HA	5	C+
8	Jacksonville	2000.0 µg/L	Over HA	116	F
9	Lake Mary	1845.6 µg/L	Over HA	1	B
10	Sebring	1700.0 µg/L	Over HA	43	F
11	Longwood	1700.0 µg/L	Over HA	9	F
12	New Port Richey	1657.9 µg/L	Over HA	68	F
13	Maitland	1590.0 µg/L	Over HA	1	B+
14	Okeechobee	1360.0 µg/L	Over HA	150	F
15	Orlando	1357.8 µg/L	Over HA	78	F
16	Edgewater	1340.0 µg/L	Over HA	50	B-
17	Lauderdale Lakes	1300.0 µg/L	Over HA	2	C
18	Port St. Joe	1300.0 µg/L	Over HA	25	C-
19	Wellington	1240.0 µg/L	Over HA	0	A-
20	Port Charlotte	1220.0 µg/L	Over HA	4	B-
21	Pompano Beach	1200.0 µg/L	Over HA	1	F
22	Eustis	1200.0 µg/L	Over HA	16	B-
23	Hobe Sound	1200.0 µg/L	Over HA	23	F
24	Plant City	1190.0 µg/L	Over HA	85	D
25	Weston	1170.0 µg/L	Over HA	2	B-
26	St. Augustine	1121.1 µg/L	Over HA	39	F
27	Kissimmee	1120.0 µg/L	Over HA	26	F
28	Apopka	1120.0 µg/L	Over HA	14	F
29	Vero Beach	1110.0 µg/L	Over HA	7	D
30	Jacksonville	1110.0 µg/L	Over HA	6	A-
31	Coconut Creek	1100.0 µg/L	Over HA	0	C+
32	Pinellas Park	1100.0 µg/L	Over HA	3	B
33	Melbourne	1095.0 µg/L	Over HA	0	A-
34	Haines City	1060.0 µg/L	Over HA	17	F
35	Immokalee	1060.0 µg/L	Over HA	15	B
36	Sarasota	1040.0 µg/L	Over HA	9	C+
37	Boynton Beach	1040.0 µg/L	Over HA	42	F
38	Palm Bay	1000.0 µg/L	Over HA	8	B
39	Homestead	1000.0 µg/L	Over HA	3	C
40	Clearwater	980.0 µg/L	Over HA	14	F
41	Bushnell	980.0 µg/L	Over HA	22	D+
42	Ponte Vedra	962.9 µg/L	Over HA	7	B
43	Middleburg	960.0 µg/L	Over HA	1	A
44	Sunrise	918.0 µg/L	Over HA	1	F
45	Casselberry	910.0 µg/L	Over HA	10	B
46	Davie/Hollywood	890.0 µg/L	Over HA	1	C
47	Wimauma	880.0 µg/L	Over HA	8	B+
48	North Port	872.0 µg/L	Over HA	3	B
49	Sanford	865.2 µg/L	Over HA	8	F
50	Palm Coast	864.9 µg/L	Over HA	6	B+
51	Live Oak	830.0 µg/L	Over HA	23	D
52	Bradenton	817.0 µg/L	Over HA	9	F
53	Winter Springs	789.0 µg/L	Over HA	15	B
54	Coral Springs	780.0 µg/L	Over HA	17	F
55	Lake Worth Beach	772.0 µg/L	Over HA	0	B+
56	Daytona Beach	762.0 µg/L	Over HA	5	A-
57	Palm Springs	760.0 µg/L	Over HA	0	B
58	Pensacola	736.0 µg/L	Over HA	5	C
59	Dunedin	736.0 µg/L	Over HA	4	B-
60	Clewiston	728.0 µg/L	Over HA	14	B+
61	Auburndale	726.0 µg/L	Over HA	5	F
62	West Palm Beach	720.0 µg/L	Over HA	23	C-
63	West Melbourne	720.0 µg/L	Over HA	4	B+
64	Ocoee	703.0 µg/L	Over HA	5	C-
65	Miramar	700.0 µg/L	Over HA	2	F
66	Tarpon Springs	700.0 µg/L	Over HA	3	B+
67	Belleview	683.0 µg/L	Over HA	18	F
68	Century	670.0 µg/L	Over HA	1	B-
69	Marco Island	658.0 µg/L	Over HA	5	B-
70	North Miami Beach	652.0 µg/L	Over HA	1	B
71	Titusville	639.0 µg/L	Over HA	1	C
72	Tampa	630.0 µg/L	Over HA	64	F
73	Plantation	628.0 µg/L	Over HA	3	D+
74	Winter Pk/Casselbery	620.0 µg/L	Over HA	0	A-
75	Wildwood	620.0 µg/L	Over HA	2	B-
76	Fort Pierce	607.0 µg/L	Over HA	85	F
77	Ocala	598.5 µg/L	Over HA	91	F
78	South Daytona	580.0 µg/L	Over HA	2	A
79	Hialeah	570.0 µg/L	Over HA	0	B-
80	Jensen Beach	555.0 µg/L	Over HA	75	D
81	St James City	550.0 µg/L	Over HA	0	A
82	Palatka	537.0 µg/L	Over HA	119	F
83	Fleming Island	534.6 µg/L	Over HA	1	A
84	Brooksville	526.0 µg/L	Over HA	41	F
85	Lake Wales	520.0 µg/L	Over HA	56	F
86	Davenport	520.0 µg/L	Over HA	14	F
87	Port Orange	510.5 µg/L	Over HA	2	B-
88	Oviedo	505.0 µg/L	Over HA	12	B-
89	Miami	490.0 µg/L	Over HA	104	F
90	Hallandale Beach	481.0 µg/L	Over HA	2	F
91	North Miami	480.0 µg/L	Over HA	1	B
92	Stuart	478.0 µg/L	Over HA	25	F
93	Oldsmar	470.0 µg/L	Over HA	0	A
94	Cantonment	459.8 µg/L	Over HA	5	B
95	Port St Lucie	440.0 µg/L	Over HA	2	D
96	Margate	430.0 µg/L	Over HA	0	C-
97	Altamonte Springs	430.0 µg/L	Over HA	3	C+
98	Cape Coral	420.0 µg/L	Over HA	1	A
99	Venice	413.1 µg/L	Over HA	0	B+
100	Pembroke Pines	411.0 µg/L	Over HA	8	F
101	Parker	407.6 µg/L	Over HA	7	A-
102	Lecanto	400.0 µg/L	Over HA	2	F
103	Winter Garden	393.0 µg/L	Over HA	4	B
104	Lehigh Acres	380.0 µg/L	Over HA	7	B
105	Palmetto	380.0 µg/L	Over HA	3	B-
106	Callaway	367.0 µg/L	Over HA	3	B+
107	Winter Park	362.0 µg/L	Over HA	6	C+
108	Boca Raton	360.0 µg/L	Over HA	14	B+
109	Mount Dora	356.6 µg/L	Over HA	6	A
110	Odessa	356.0 µg/L	Over HA	8	C+
111	Delray Beach	350.0 µg/L	Over HA	7	C
112	Miami Beach	348.0 µg/L	Over HA	1	C+
113	Panama City	340.0 µg/L	Over HA	6	B-
114	Panama City Beach	340.0 µg/L	Over HA	12	A-
115	Cooper City	330.0 µg/L	Over HA	1	C
116	Lake City	309.0 µg/L	Over HA	112	F
117	Zephyrhills	303.0 µg/L	Over HA	18	F
118	Lynn Haven	302.0 µg/L	Over HA	3	A-
119	Navarre	300.0 µg/L	Over HA	2	B-
120	Cocoa	294.0 µg/L	Over HA	1	A-
121	Tequesta	292.0 µg/L	Over HA	1	B-
122	Bonita Springs	289.0 µg/L	Over HA	8	B
123	Springfield	282.0 µg/L	Over HA	15	C
124	Homosassa	280.0 µg/L	Over HA	2	D
125	Ft Lauderdale	270.0 µg/L	Over HA	12	F
126	Gulfport	262.0 µg/L	Over HA	1	A-
127	Naples	260.0 µg/L	Over HA	42	F
128	Lake Buena Vista	256.0 µg/L	Over HA	0	A
129	Avon Park	256.0 µg/L	Over HA	6	C-
130	Hollywood	248.9 µg/L	Over HA	32	F
131	Hialeah Gardens	241.0 µg/L	Over HA	6	B+
132	Dade City	207.6 µg/L	No	8	F
133	Safety Harbor	202.0 µg/L	No	1	A
134	Trenton	200.0 µg/L	No	8	B+
135	New Smyrna Beach	163.0 µg/L	No	18	B+
136	Opa Locka	157.0 µg/L	No	1	B-
137	Tamarac	147.0 µg/L	No	0	F
138	Alachua	110.0 µg/L	No	6	C+
139	Temple Terrace	92.0 µg/L	No	4	A-
140	North Lauderdale	71.2 µg/L	No	1	F
141	Hudson	71.0 µg/L	No	4	D
142	Sanibel Island	51.0 µg/L	No	0	A-
143	Destin	46.0 µg/L	No	0	A+
144	Lady Lake	44.0 µg/L	No	18	F
145	Tallahassee	33.0 µg/L	No	12	F
146	The Villages	31.0 µg/L	No	1	B
147	Holly Hill	30.0 µg/L	No	0	B+
148	Gainesville	29.0 µg/L	No	8	B
149	Minneola	28.2 µg/L	No	4	B-
150	Milton	24.0 µg/L	No	19	B-
151	Fort Walton Beach	21.1 µg/L	No	4	A

FAQ

Frequently asked questions about chlorate in Florida

Is chlorate in Florida tap water dangerous?

Chlorate has no federal MCL. The EPA lifetime health advisory is 210 µg/L. 131 cities in Florida 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 Florida 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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