HAA5 Contamination

HAA5 in Illinois Drinking Water

Ranked by average HAA5 concentration (µg/L) · UCMR 4 data (2018–2020) · Data from EPA SDWIS & UCMR

237

Cities Tested

Exceeds Limit

% Exceeds Limit

12.7 µg/L

State Avg

▼ 1% vs national

vs National

687

Health Violations

Analysis

HAA5 in Illinois: what the data shows

Illinois has 237 cities with HAA5 monitoring data from the EPA's UCMR 4 program (2018–2020). Haloacetic acids (HAA5) form when chlorine-based disinfectants react with natural organic matter in water. The state average is 12.7 µg/L — better than the 15.5 µg/L national average. 1 city exceeds the EPA MCL of 60 µg/L. HAA5 is a group of five chlorinated and brominated acetic acids. Long-term exposure above the MCL is associated with increased cancer risk and adverse reproductive outcomes. The EPA classifies total HAA5 as a probable human carcinogen at elevated concentrations. Activated carbon filtration (especially granular or block carbon) is effective at reducing HAA5. Running water through a refrigerator filter or letting it sit in an open pitcher for 30 minutes also helps, as some HAA5 species are volatile. Boiling does not remove disinfection byproducts and may concentrate them.

Comparison

Cities exceeding 60 µg/L EPA MCL

Illinois

1 of 237 cities

← ▼ 1% below national rate (better)

National avg

23 of 4342 cities

City Map

HAA5 data across Illinois

Each dot is a city with UCMR 4 HAA5 testing data. Cities where average HAA5 exceeded the 60 µg/L EPA MCL are highlighted. Size reflects population served.

Worst Offenders

Top 10 cities by haa5 level in Illinois

Highest HAA5 levels (µg/L)

All Cities

All Illinois cities ranked by haa5 level

#	City	Level	Exceeds?	Violations	Grade
1	Caseyville	90.0 µg/L	Yes	3	B+
2	Dieterich	55.3 µg/L	No	7	F
3	Sparta	42.0 µg/L	No	21	B-
4	O Fallon	41.2 µg/L	No	17	A-
5	Essex	37.9 µg/L	No	14	B-
6	Rock Island	37.3 µg/L	No	5	B-
7	Jerseyville	33.2 µg/L	No	6	A-
8	Nashville	28.1 µg/L	No	27	C-
9	Tuscola	26.6 µg/L	No	0	A
10	West Frankfort	26.6 µg/L	No	6	B+
11	Effingham	25.4 µg/L	No	2	A-
12	Sullivan	25.4 µg/L	No	5	A-
13	Mattoon	25.2 µg/L	No	14	B-
14	Mt Vernon	24.9 µg/L	No	1	A
15	East Moline	24.7 µg/L	No	18	D+
16	Murphysboro	24.2 µg/L	No	8	B
17	Chatham	23.9 µg/L	No	2	A
18	Champaign	23.7 µg/L	No	0	A
19	Litchfield	23.7 µg/L	No	5	D+
20	Granite City	23.6 µg/L	No	0	B+
21	Galesburg	23.6 µg/L	No	1	B
22	Carbondale	23.3 µg/L	No	26	D
23	Kankakee	22.9 µg/L	No	40	F
24	Marion	22.4 µg/L	No	29	D
25	Streator	22.1 µg/L	No	14	A-
26	Springfield	21.8 µg/L	No	3	D
27	Bloomington	21.8 µg/L	No	21	F
28	Fairfield	21.8 µg/L	No	16	D+
29	Jacksonville	21.7 µg/L	No	28	B-
30	Alton	21.7 µg/L	No	1	B
31	Wood River	20.3 µg/L	No	0	B+
32	Lake Forest	20.3 µg/L	No	58	B-
33	Woodstock	19.4 µg/L	No	3	B-
34	Herrin	19.1 µg/L	No	0	C+
35	Naperville	18.8 µg/L	No	0	B+
36	Deerfield	18.8 µg/L	No	4	B
37	Palatine	18.5 µg/L	No	2	B
38	Carlinville	18.4 µg/L	No	74	D
39	Frankfort	18.3 µg/L	No	7	B+
40	East St Louis	17.9 µg/L	No	1	B+
41	Macomb	17.7 µg/L	No	39	D
42	North Chicago	17.5 µg/L	No	5	B+
43	Algonquin	17.4 µg/L	No	6	A-
44	North Riverside	17.2 µg/L	No	4	B+
45	Stickney	17.1 µg/L	No	1	B+
46	Midlothian	17.0 µg/L	No	5	A-
47	Waukegan	16.8 µg/L	No	5	B+
48	Plainfield	16.6 µg/L	No	23	B-
49	Mount Vernon	16.6 µg/L	No	2	B+
50	Palos Heights	16.6 µg/L	No	1	A-
51	Rolling Meadows	16.5 µg/L	No	3	A
52	Mount Prospect	16.4 µg/L	No	1	B+
53	Morton Grove	16.2 µg/L	No	2	B-
54	Riverdale	16.2 µg/L	No	6	B+
55	New Lenox	16.2 µg/L	No	7	D+
56	Lincolnwood	15.9 µg/L	No	1	B+
57	Elmhurst	15.8 µg/L	No	2	A-
58	Wheaton	15.8 µg/L	No	2	B-
59	Orland Park	15.8 µg/L	No	0	A-
60	Crestwood	15.8 µg/L	No	0	B
61	Northbrook	15.7 µg/L	No	55	D
62	Decatur	15.6 µg/L	No	28	B
63	Franklin Park	15.6 µg/L	No	5	B
64	Woodridge	15.6 µg/L	No	2	A-
65	Burr Ridge	15.6 µg/L	No	0	A
66	Godfrey	15.5 µg/L	No	22	C+
67	Country Club Hills	15.5 µg/L	No	0	A-
68	Weston	15.3 µg/L	No	6	A
69	Bolingbrook	15.3 µg/L	No	2	A
70	Hoffman Estates	15.2 µg/L	No	7	A+
71	Westmont	15.0 µg/L	No	6	B-
72	Quincy	15.0 µg/L	No	3	B-
73	Zion	14.9 µg/L	No	1	B
74	Alsip	14.9 µg/L	No	2	A-
75	Homewood	14.9 µg/L	No	2	C
76	La Grange	14.9 µg/L	No	1	B
77	Danville	14.8 µg/L	No	24	B
78	Matteson	14.8 µg/L	No	1	B
79	Robbins	14.8 µg/L	No	7	C-
80	Bellwood	14.7 µg/L	No	7	B+
81	Addison	14.6 µg/L	No	0	A
82	Glendale Heights	14.6 µg/L	No	1	A
83	Westchester	14.6 µg/L	No	2	B
84	Darien	14.5 µg/L	No	6	C+
85	Schaumburg	14.5 µg/L	No	17	B+
86	Highland Park	14.5 µg/L	No	2	B+
87	South Holland	14.4 µg/L	No	5	B-
88	Hanover Park	14.4 µg/L	No	3	A
89	Downers Grove	14.4 µg/L	No	2	A
90	Tinley Park	14.3 µg/L	No	0	B+
91	Moline	14.3 µg/L	No	7	C
92	Aurora	14.2 µg/L	No	20	D
93	Centralia	14.0 µg/L	No	2	B
94	Roselle	13.9 µg/L	No	2	A-
95	Hinsdale	13.9 µg/L	No	0	A
96	Wood Dale	13.9 µg/L	No	0	A-
97	Hazel Crest	13.9 µg/L	No	2	B
98	Oak Forest	13.8 µg/L	No	0	B+
99	Bensenville	13.8 µg/L	No	4	A
100	Elmwood Park	13.8 µg/L	No	3	B+
101	Buffalo Grove	13.6 µg/L	No	1	A
102	Hickory Hills	13.6 µg/L	No	1	A
103	Wheeling	13.6 µg/L	No	5	A+
104	Elk Grove	13.6 µg/L	No	2	A-
105	Waterloo	13.6 µg/L	No	1	C
106	Berwyn	13.5 µg/L	No	3	A-
107	Mokena	13.4 µg/L	No	2	A
108	Justice	13.3 µg/L	No	0	A-
109	Taylorville	13.3 µg/L	No	0	A-
110	Oak Park	13.2 µg/L	No	2	A
111	Glenview	13.2 µg/L	No	3	B+
112	Chicago Ridge	13.2 µg/L	No	1	A-
113	Lombard	13.2 µg/L	No	1	A-
114	Palos Hills	13.2 µg/L	No	3	A
115	Glen Ellyn	13.1 µg/L	No	0	A-
116	Carol Stream	13.1 µg/L	No	1	A-
117	Niles	13.1 µg/L	No	3	B
118	Washington	13.0 µg/L	No	5	C
119	Forest Park	13.0 µg/L	No	2	A-
120	Evergreen Park	12.9 µg/L	No	0	B+
121	Villa Park	12.9 µg/L	No	2	A
122	River Grove	12.5 µg/L	No	3	A-
123	Worth	12.5 µg/L	No	3	A
124	Burbank (South Stickney)	12.5 µg/L	No	7	B+
125	Streamwood	12.5 µg/L	No	2	A-
126	Evanston	12.4 µg/L	No	1	A+
127	Arlington Heights	12.4 µg/L	No	1	B-
128	Blue Island	12.3 µg/L	No	19	C
129	Bridgeview	12.3 µg/L	No	0	A-
130	Markham	12.3 µg/L	No	7	B
131	Oak Lawn	12.2 µg/L	No	2	B
132	Pontiac	12.1 µg/L	No	10	C
133	Schiller Park	12.0 µg/L	No	7	A-
134	Chicago	11.9 µg/L	No	68	F
135	Lincoln	11.9 µg/L	No	8	F
136	La Grange Park	11.8 µg/L	No	2	A
137	River Forest	11.8 µg/L	No	1	B+
138	Skokie	11.8 µg/L	No	9	C-
139	Summit	11.3 µg/L	No	1	B+
140	Oak Brook	11.3 µg/L	No	8	D
141	Mchenry	11.3 µg/L	No	57	F
142	Freeport	11.3 µg/L	No	19	B-
143	Dolton	11.2 µg/L	No	2	C
144	Elgin	11.1 µg/L	No	9	C-
145	Lisle	11.1 µg/L	No	2	A-
146	Des Plaines	11.0 µg/L	No	0	B+
147	Brookfield	10.8 µg/L	No	0	A-
148	North Lake	10.8 µg/L	No	1	B+
149	Park Ridge	10.7 µg/L	No	1	B
150	Maywood	10.6 µg/L	No	3	C+
151	Bartlett	10.4 µg/L	No	49	B-
152	Cicero	9.7 µg/L	No	3	B
153	Peoria	9.6 µg/L	No	5	C-
154	Harvey	9.6 µg/L	No	1	B
155	Melrose Park	9.3 µg/L	No	6	C
156	Crystal Lake	9.1 µg/L	No	4	A-
157	Winnetka	9.1 µg/L	No	0	A
158	Lyons	8.7 µg/L	No	7	A-
159	Norridge	8.6 µg/L	No	0	A-
160	Wilmette	8.5 µg/L	No	0	A
161	Morton	8.2 µg/L	No	13	B-
162	Normal	8.1 µg/L	No	3	D+
163	Rantoul	7.5 µg/L	No	54	D
164	Round Lake Beach	7.3 µg/L	No	3	B+
165	Beardstown	7.1 µg/L	No	1	A
166	Lindenhurst	6.9 µg/L	No	0	B+
167	Wauconda	6.9 µg/L	No	3	A
168	Canton	6.8 µg/L	No	7	B+
169	East Peoria	6.7 µg/L	No	133	F
170	Dixon	6.7 µg/L	No	57	C
171	Calumet City	6.6 µg/L	No	3	C-
172	Lake In The Hills	6.6 µg/L	No	4	A-
173	Troy	6.6 µg/L	No	3	A-
174	Chicago Heights	6.6 µg/L	No	0	B+
175	Charleston	6.3 µg/L	No	10	C+
176	Plano	6.3 µg/L	No	0	B+
177	Lansing	6.3 µg/L	No	2	B
178	Loves Park	6.3 µg/L	No	35	B
179	Round Lake	6.3 µg/L	No	3	A-
180	South Elgin	6.3 µg/L	No	28	C
181	Mundelein	5.9 µg/L	No	22	F
182	Saint Charles	5.8 µg/L	No	3	B+
183	Glen Carbon	5.7 µg/L	No	0	B
184	Carpentersville	5.7 µg/L	No	0	B+
185	Edwardsville	5.6 µg/L	No	18	D+
186	Warrenville	5.4 µg/L	No	0	B+
187	Batavia	5.4 µg/L	No	33	B+
188	Yorkville	5.3 µg/L	No	83	C+
189	Cary	5.2 µg/L	No	11	A-
190	Robinson	5.2 µg/L	No	0	A-
191	Grays Lake	5.0 µg/L	No	6	A
192	Bethalto	4.8 µg/L	No	0	A-
193	Dallas City	4.7 µg/L	No	1	B+
194	Lockport	4.6 µg/L	No	20	F
195	Morris	4.6 µg/L	No	74	F
196	Libertyville	4.3 µg/L	No	14	C
197	Gurnee	4.3 µg/L	No	4	A
198	Barry	4.2 µg/L	No	3	B+
199	Collinsville	3.9 µg/L	No	12	C-
200	Machesney Park	3.9 µg/L	No	4	B
201	Park Forest	3.8 µg/L	No	2	A
202	Rockford	3.5 µg/L	No	43	F
203	Huntley	3.5 µg/L	No	15	A
204	Lake Zurich	3.5 µg/L	No	35	B+
205	Romeoville	3.3 µg/L	No	17	A-
206	West Chicago	3.2 µg/L	No	22	A
207	Crest Hill	3.1 µg/L	No	12	F
208	Sycamore	3.0 µg/L	No	31	A-
209	De Kalb	2.9 µg/L	No	7	B+
210	Coal Valley	2.9 µg/L	No	12	F
211	Geneva	2.8 µg/L	No	67	B-
212	South Beloit	2.8 µg/L	No	3	A-
213	Odell	2.7 µg/L	No	14	A
214	Polo	2.7 µg/L	No	2	A
215	Barrington	2.5 µg/L	No	3	B+
216	Pekin	2.5 µg/L	No	1	D+
217	Poplar Grove	2.4 µg/L	No	8	C+
218	Peru	2.1 µg/L	No	92	F
219	Coleta	2.0 µg/L	No	1	A-
220	Pecatonica	1.8 µg/L	No	1	A-
221	Sugar Grove	1.6 µg/L	No	7	A-
222	Antioch	1.6 µg/L	No	6	C-
223	Ottawa	1.4 µg/L	No	62	F
224	Byron	1.3 µg/L	No	1	C+
225	Aledo	1.1 µg/L	No	6	A+
226	Kewanee	1.0 µg/L	No	34	B
227	Carbon Cliff	0.9 µg/L	No	12	B+
228	Minooka	0.9 µg/L	No	6	A-
229	Chillicothe	0.8 µg/L	No	11	D+
230	Shorewood	0.7 µg/L	No	4	A-
231	Warren	0.6 µg/L	No	0	B+
232	Richton Park	0.5 µg/L	No	5	F
233	Prairie Du Rochr	0.4 µg/L	No	1	B-
234	Lemont	0.1 µg/L	No	26	D
235	Joliet	0.0 µg/L	No	131	F
236	Oswego	0.0 µg/L	No	24	A-
237	North Aurora	0.0 µg/L	No	27	A-

FAQ

Frequently asked questions about haa5 in Illinois

What is HAA5 and why does it appear in Illinois tap water?

HAA5 (haloacetic acids) are disinfection byproducts that form when chlorine reacts with naturally occurring organic matter in source water. They are a normal byproduct of the disinfection process that makes water safe to drink. 1 cities in Illinois exceed the EPA MCL of 60 µg/L. The state average is 12.7 µg/L.

How can I reduce HAA5 exposure from Illinois drinking water?

Activated carbon filters (granular or block) effectively reduce HAA5. Refrigerator filters and under-sink carbon systems are convenient options. Unlike lead or PFAS, HAA5 levels can also be reduced by letting water stand in an open container, as some species evaporate. Boiling does NOT remove HAA5 and can concentrate them by reducing water volume.

Which Illinois cities have the highest HAA5 levels?

The cities with the highest average HAA5 concentrations in Illinois are: Caseyville (90.0 µg/L), Dieterich (55.3 µg/L), Sparta (42.0 µg/L), O Fallon (41.2 µg/L), Essex (37.9 µg/L). Note: this data is from UCMR 4 testing (2018–2020) and may not reflect current levels.

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