HAA5 Contamination

HAA5 in Mississippi Drinking Water

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

Cities Tested

Exceeds Limit

% Exceeds Limit

9.0 µg/L

State Avg

▲ 1% vs national

vs National

289

Health Violations

Analysis

HAA5 in Mississippi: what the data shows

Mississippi has 61 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 9.0 µg/L — worse 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

Mississippi

1 of 61 cities

→ ▲ 1% above national rate (worse)

National avg

23 of 4420 cities

City Map

HAA5 data across Mississippi

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 Mississippi

Highest HAA5 levels (µg/L)

All Cities

All Mississippi cities ranked by haa5 level

#	City	Level	Exceeds?	Violations	Grade
1	Raymond	66.8 µg/L	Yes	54	D+
2	Clinton	43.1 µg/L	No	12	B
3	Tupelo	38.2 µg/L	No	19	D
4	Jackson	32.9 µg/L	No	75	D
5	Madison	26.2 µg/L	No	2	B
6	Ridgeland	26.2 µg/L	No	21	D+
7	Indianola	23.0 µg/L	No	11	C+
8	Corinth	22.8 µg/L	No	9	D
9	D'Iberville	21.1 µg/L	No	5	C+
10	Natchez	19.2 µg/L	No	11	B+
11	Vicksburg	16.5 µg/L	No	53	D
12	Yazoo City	15.1 µg/L	No	8	D+
13	Greenville	14.9 µg/L	No	46	D
14	Biloxi	12.5 µg/L	No	10	D
15	Canton	12.2 µg/L	No	45	D
16	Flora	12.0 µg/L	No	43	D+
17	Flowood	11.8 µg/L	No	3	B+
18	Clarksdale	11.7 µg/L	No	56	F
19	Gautier	11.5 µg/L	No	4	A-
20	Ocean Springs	11.0 µg/L	No	4	D+
21	Brandon	11.0 µg/L	No	27	D+
22	Pearl	10.3 µg/L	No	5	C
23	Mcneill	7.4 µg/L	No	5	D+
24	Marks	7.3 µg/L	No	5	D+
25	Charleston	6.2 µg/L	No	34	D
26	Gulfport	5.9 µg/L	No	8	D+
27	Picayune	5.5 µg/L	No	5	D+
28	Grenada	4.5 µg/L	No	38	F
29	Hattiesburg	4.5 µg/L	No	25	D
30	Shelby	4.3 µg/L	No	2	C+
31	Weir	4.0 µg/L	No	0	A-
32	Philadelphia	3.7 µg/L	No	6	C-
33	Houlka	2.9 µg/L	No	6	C-
34	Greenwood	2.5 µg/L	No	7	C
35	Meridian	2.0 µg/L	No	5	D+
36	Long Beach	1.8 µg/L	No	2	A-
37	Bailey	1.4 µg/L	No	5	A
38	Starkville	1.3 µg/L	No	16	D
39	Woodville	1.3 µg/L	No	7	D+
40	Pascagoula	1.3 µg/L	No	9	D
41	Pinola	1.3 µg/L	No	6	B
42	Hamilton	1.0 µg/L	No	2	B
43	West Point	0.8 µg/L	No	4	D
44	Water Valley	0.8 µg/L	No	5	D+
45	Oxford	0.8 µg/L	No	22	F
46	Holly Springs	0.7 µg/L	No	3	A-
47	Laurel	0.7 µg/L	No	5	D+
48	Mississippi State	0.6 µg/L	No	2	B+
49	Columbus	0.5 µg/L	No	15	D+
50	Mccomb	0.5 µg/L	No	19	D
51	Hernando	0.5 µg/L	No	11	D+
52	Tylertown	0.5 µg/L	No	0	B+
53	Southaven	0.4 µg/L	No	3	B
54	Cleveland	0.4 µg/L	No	13	B
55	Moss Point	0.3 µg/L	No	8	B
56	Horn Lake	0.3 µg/L	No	5	B
57	Olive Branch	0.1 µg/L	No	8	B-
58	Florence	0.0 µg/L	No	59	D+
59	Saltillo	0.0 µg/L	No	26	D+
60	Aberdeen	0.0 µg/L	No	1	D+
61	Scooba	0.0 µg/L	No	2	B+

FAQ

Frequently asked questions about haa5 in Mississippi

What is HAA5 and why does it appear in Mississippi 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 Mississippi exceed the EPA MCL of 60 µg/L. The state average is 9.0 µg/L.

How can I reduce HAA5 exposure from Mississippi 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 Mississippi cities have the highest HAA5 levels?

The cities with the highest average HAA5 concentrations in Mississippi are: Raymond (66.8 µg/L), Clinton (43.1 µg/L), Tupelo (38.2 µg/L), Jackson (32.9 µg/L), Madison (26.2 µg/L). Note: this data is from UCMR 4 testing (2018–2020) and may not reflect current levels.

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