HAA5 Contamination

HAA5 in Illinois Drinking Water

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

239

Cities Tested

Exceeds Limit

% Exceeds Limit

12.7 µg/L

State Avg

▼ 1% vs national

vs National

695

Health Violations

Analysis

HAA5 in Illinois: what the data shows

Illinois has 239 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 239 cities

← ▼ 1% below national rate (better)

National avg

23 of 4420 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	Urbana	17.5 µg/L	No	0	C+
43	North Chicago	17.5 µg/L	No	5	B+
44	Algonquin	17.4 µg/L	No	6	A-
45	North Riverside	17.2 µg/L	No	4	B+
46	Stickney	17.1 µg/L	No	1	B+
47	Midlothian	17.0 µg/L	No	5	A-
48	Waukegan	16.8 µg/L	No	5	B+
49	Plainfield	16.6 µg/L	No	23	B-
50	Mount Vernon	16.6 µg/L	No	2	B+
51	Palos Heights	16.6 µg/L	No	1	A-
52	Rolling Meadows	16.5 µg/L	No	3	A
53	Mount Prospect	16.4 µg/L	No	1	B+
54	Morton Grove	16.2 µg/L	No	2	B-
55	Riverdale	16.2 µg/L	No	6	B+
56	New Lenox	16.2 µg/L	No	7	D+
57	Lincolnwood	15.9 µg/L	No	1	B+
58	Elmhurst	15.8 µg/L	No	2	A-
59	Wheaton	15.8 µg/L	No	2	B-
60	Orland Park	15.8 µg/L	No	0	A-
61	Crestwood	15.8 µg/L	No	0	B
62	Northbrook	15.7 µg/L	No	55	D
63	Decatur	15.6 µg/L	No	28	B
64	Franklin Park	15.6 µg/L	No	5	B
65	Woodridge	15.6 µg/L	No	2	A-
66	Burr Ridge	15.6 µg/L	No	0	A
67	Godfrey	15.5 µg/L	No	22	C+
68	Country Club Hills	15.5 µg/L	No	0	A-
69	Weston	15.3 µg/L	No	6	A
70	Bolingbrook	15.3 µg/L	No	2	A
71	Hoffman Estates	15.2 µg/L	No	7	A+
72	Westmont	15.0 µg/L	No	6	B-
73	Quincy	15.0 µg/L	No	3	B-
74	Zion	14.9 µg/L	No	1	B
75	Alsip	14.9 µg/L	No	2	A-
76	Homewood	14.9 µg/L	No	2	C
77	La Grange	14.9 µg/L	No	1	B
78	Danville	14.8 µg/L	No	24	B
79	Matteson	14.8 µg/L	No	1	B
80	Robbins	14.8 µg/L	No	7	C-
81	Bellwood	14.7 µg/L	No	7	B+
82	Addison	14.6 µg/L	No	0	A
83	Glendale Heights	14.6 µg/L	No	1	A
84	Westchester	14.6 µg/L	No	2	B
85	Darien	14.5 µg/L	No	6	C+
86	Schaumburg	14.5 µg/L	No	17	B+
87	Highland Park	14.5 µg/L	No	2	B+
88	South Holland	14.4 µg/L	No	5	B-
89	Hanover Park	14.4 µg/L	No	3	A
90	Downers Grove	14.4 µg/L	No	2	A
91	Tinley Park	14.3 µg/L	No	0	B+
92	Moline	14.3 µg/L	No	7	C
93	Aurora	14.2 µg/L	No	20	D
94	Centralia	14.0 µg/L	No	2	B
95	Roselle	13.9 µg/L	No	2	A-
96	Hinsdale	13.9 µg/L	No	0	A
97	Wood Dale	13.9 µg/L	No	0	A-
98	Hazel Crest	13.9 µg/L	No	2	B
99	Oak Forest	13.8 µg/L	No	0	B+
100	Bensenville	13.8 µg/L	No	4	A
101	Elmwood Park	13.8 µg/L	No	3	B+
102	Buffalo Grove	13.6 µg/L	No	1	A
103	Hickory Hills	13.6 µg/L	No	1	A
104	Wheeling	13.6 µg/L	No	5	A+
105	Elk Grove	13.6 µg/L	No	2	A-
106	Waterloo	13.6 µg/L	No	1	C
107	Berwyn	13.5 µg/L	No	3	A-
108	Mokena	13.4 µg/L	No	2	A
109	Justice	13.3 µg/L	No	0	A-
110	Taylorville	13.3 µg/L	No	0	A-
111	Oak Park	13.2 µg/L	No	2	A
112	Glenview	13.2 µg/L	No	3	B+
113	Chicago Ridge	13.2 µg/L	No	1	A-
114	Lombard	13.2 µg/L	No	1	A-
115	Palos Hills	13.2 µg/L	No	3	A
116	Glen Ellyn	13.1 µg/L	No	0	A-
117	Carol Stream	13.1 µg/L	No	1	A-
118	Niles	13.1 µg/L	No	3	B
119	Washington	13.0 µg/L	No	5	C
120	Forest Park	13.0 µg/L	No	2	A-
121	Evergreen Park	12.9 µg/L	No	0	B+
122	Villa Park	12.9 µg/L	No	2	A
123	River Grove	12.5 µg/L	No	3	A-
124	Worth	12.5 µg/L	No	3	A
125	Burbank (South Stickney)	12.5 µg/L	No	7	B+
126	Streamwood	12.5 µg/L	No	2	A-
127	Evanston	12.4 µg/L	No	1	A+
128	Arlington Heights	12.4 µg/L	No	1	B-
129	Blue Island	12.3 µg/L	No	19	C
130	Bridgeview	12.3 µg/L	No	0	A-
131	Markham	12.3 µg/L	No	7	B
132	Oak Lawn	12.2 µg/L	No	2	B
133	Pontiac	12.1 µg/L	No	10	C
134	Schiller Park	12.0 µg/L	No	7	A-
135	Chicago	11.9 µg/L	No	68	F
136	Lincoln	11.9 µg/L	No	8	F
137	La Grange Park	11.8 µg/L	No	2	A
138	River Forest	11.8 µg/L	No	1	B+
139	Skokie	11.8 µg/L	No	9	C-
140	Summit	11.3 µg/L	No	1	B+
141	Oak Brook	11.3 µg/L	No	8	D
142	Mchenry	11.3 µg/L	No	57	F
143	Freeport	11.3 µg/L	No	19	B-
144	Dolton	11.2 µg/L	No	2	C
145	Elgin	11.1 µg/L	No	9	C-
146	Lisle	11.1 µg/L	No	2	A-
147	Des Plaines	11.0 µg/L	No	0	B+
148	Brookfield	10.8 µg/L	No	0	A-
149	North Lake	10.8 µg/L	No	1	B+
150	Park Ridge	10.7 µg/L	No	1	B
151	Maywood	10.6 µg/L	No	3	C+
152	Bartlett	10.4 µg/L	No	49	B-
153	Cicero	9.7 µg/L	No	3	B
154	Peoria	9.6 µg/L	No	5	D+
155	Harvey	9.6 µg/L	No	1	B
156	Melrose Park	9.3 µg/L	No	6	C
157	Crystal Lake	9.1 µg/L	No	4	A-
158	Winnetka	9.1 µg/L	No	0	A
159	Lyons	8.7 µg/L	No	7	A-
160	Norridge	8.6 µg/L	No	0	A-
161	Wilmette	8.5 µg/L	No	0	A
162	Morton	8.2 µg/L	No	13	B-
163	Normal	8.1 µg/L	No	3	D+
164	Rantoul	7.5 µg/L	No	54	D
165	Round Lake Beach	7.3 µg/L	No	3	B+
166	Beardstown	7.1 µg/L	No	1	A
167	Lindenhurst	6.9 µg/L	No	0	B+
168	Wauconda	6.9 µg/L	No	3	A
169	Canton	6.8 µg/L	No	7	B+
170	East Peoria	6.7 µg/L	No	133	F
171	Dixon	6.7 µg/L	No	57	C
172	Calumet City	6.6 µg/L	No	3	C-
173	Lake In The Hills	6.6 µg/L	No	4	A-
174	Troy	6.6 µg/L	No	3	A-
175	Chicago Heights	6.6 µg/L	No	0	B+
176	Charleston	6.3 µg/L	No	10	C+
177	Plano	6.3 µg/L	No	0	B+
178	Lansing	6.3 µg/L	No	2	B
179	Loves Park	6.3 µg/L	No	35	B
180	Round Lake	6.3 µg/L	No	3	A-
181	South Elgin	6.3 µg/L	No	28	C
182	Mundelein	5.9 µg/L	No	22	F
183	Saint Charles	5.8 µg/L	No	3	B+
184	Glen Carbon	5.7 µg/L	No	0	B
185	Carpentersville	5.7 µg/L	No	0	B+
186	Edwardsville	5.6 µg/L	No	18	D+
187	Warrenville	5.4 µg/L	No	0	B+
188	Batavia	5.4 µg/L	No	33	B+
189	Yorkville	5.3 µg/L	No	83	C+
190	Cary	5.2 µg/L	No	11	A-
191	Robinson	5.2 µg/L	No	0	A-
192	Grays Lake	5.0 µg/L	No	6	A
193	Bethalto	4.8 µg/L	No	0	A-
194	Dallas City	4.7 µg/L	No	1	B+
195	Lockport	4.6 µg/L	No	20	F
196	Morris	4.6 µg/L	No	74	F
197	Libertyville	4.3 µg/L	No	14	C
198	Gurnee	4.3 µg/L	No	4	A
199	Barry	4.2 µg/L	No	3	B+
200	Collinsville	3.9 µg/L	No	12	C-
201	Machesney Park	3.9 µg/L	No	4	B
202	Vernon Hills	3.9 µg/L	No	4	B+
203	Park Forest	3.8 µg/L	No	2	A
204	Rockford	3.5 µg/L	No	43	F
205	Huntley	3.5 µg/L	No	15	A
206	Lake Zurich	3.5 µg/L	No	35	B+
207	Romeoville	3.3 µg/L	No	17	A-
208	West Chicago	3.2 µg/L	No	22	A
209	Crest Hill	3.1 µg/L	No	12	F
210	Sycamore	3.0 µg/L	No	31	A-
211	De Kalb	2.9 µg/L	No	7	B+
212	Coal Valley	2.9 µg/L	No	12	F
213	Geneva	2.8 µg/L	No	67	B-
214	South Beloit	2.8 µg/L	No	3	A-
215	Odell	2.7 µg/L	No	14	A
216	Polo	2.7 µg/L	No	2	A
217	Pekin	2.5 µg/L	No	1	D+
218	Barrington	2.5 µg/L	No	3	B+
219	Poplar Grove	2.4 µg/L	No	8	C+
220	Peru	2.1 µg/L	No	92	F
221	Coleta	2.0 µg/L	No	1	A-
222	Pecatonica	1.8 µg/L	No	1	A-
223	Sugar Grove	1.6 µg/L	No	7	A-
224	Antioch	1.6 µg/L	No	6	C-
225	Ottawa	1.4 µg/L	No	62	F
226	Byron	1.3 µg/L	No	1	C+
227	Aledo	1.1 µg/L	No	6	A+
228	Kewanee	1.0 µg/L	No	34	B
229	Carbon Cliff	0.9 µg/L	No	12	B+
230	Minooka	0.9 µg/L	No	6	A-
231	Chillicothe	0.8 µg/L	No	11	D+
232	Shorewood	0.7 µg/L	No	4	A-
233	Warren	0.6 µg/L	No	0	B+
234	Richton Park	0.5 µg/L	No	5	F
235	Prairie Du Rochr	0.4 µg/L	No	1	B-
236	Lemont	0.1 µg/L	No	26	D
237	Joliet	0.0 µg/L	No	131	F
238	Oswego	0.0 µg/L	No	24	A-
239	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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