Haloacetic acids (HAA5)

Rancho California Water District

Haloacetic acids are formed when disinfectants such as chlorine are added to tap water. The group of five haloacetic acids regulated by federal standards includes monochloroacetic acid, dichloroacetic acid, trichloroacetic acid, monobromoacetic acid and dibromoacetic acid. Read More.

Haloacetic acids are harmful during pregnancy and may increase the risk of cancer. Haloacetic acids are� genotoxic, which means that they induce mutations and DNA damage. Multiple studies by the National Toxicology Program have demonstrated the cancer-causing properties of individual haloacetic acids in laboratory animals. The Department of Health and Human Services is currently considering listing di- or tri-haloacetic acids for possible inclusion in its comprehensive Report on Carcinogens.

Click here to read more about disinfection byproducts.

MORE ABOUT THIS CONTAMINANT

120

Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Detections	Range of results
2014	10.4 ppb	16	14	ND - 41.0 ppb
2015	7.09 ppb	24	17	ND - 27.0 ppb
2016	N/A	0	0	N/A
2017	6.01 ppb	32	28	ND - 15.0 ppb
2018	5.18 ppb	32	24	ND - 12.0 ppb
2019	3.29 ppb	16	13	ND - 6.10 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.1 ppb

The EWG Health Guideline of 0.1 ppb for the group of five haloacetic acids, or HAA5, was defined in a peer-reviewed scientific study by EWG and represents a one-in-a-million lifetime cancer risk level. This health guideline protects against cancer.

EPA Maximum Contaminant
Level (MCL) 60 ppb

The legal limit for the group of five haloacetic acids (HAA5), established in 1998, was based on the need for residual disinfectant levels in water served to customers and the cost of treatment. This limit does not fully protect against the risk of cancer and harm to the developing fetus due to exposure to haloacetic acids.

ppb = parts per billion

All test results

Date	Lab ID	Result
2014-02-11	4790-801-1023	2.30 ppb
2014-02-11	4790-802-0841	21.0 ppb
2014-02-11	4790-803-0815	5.20 ppb
2014-02-11	4790-804-1056	ND
2014-02-11	4790-805-0922	7.50 ppb
2014-02-11	4790-806-1007	5.30 ppb
2014-02-11	4790-807-1039	ND
2014-02-11	4790-808-0934	5.50 ppb
2014-05-05	4790-801-0927	34.0 ppb
2014-05-05	4790-802-1115	41.0 ppb
2014-05-05	4790-803-1047	23.0 ppb
2014-05-05	4790-804-1006	2.50 ppb
2014-05-05	4790-805-1205	3.90 ppb
2014-05-05	4790-806-0912	3.00 ppb
2014-05-05	4790-807-0945	7.40 ppb
2014-05-05	4790-808-1150	4.10 ppb
2015-02-11	4790-801-0915	8.10 ppb
2015-02-11	4790-802-1043	6.80 ppb
2015-02-11	4790-803-1028	8.00 ppb
2015-02-11	4790-804-0955	ND
2015-02-11	4790-805-1105	5.40 ppb
2015-02-11	4790-806-0903	7.90 ppb
2015-02-11	4790-807-0935	7.60 ppb
2015-02-11	4790-808-1116	4.30 ppb
2015-05-12	4790-801-1006	9.80 ppb
2015-05-12	4790-802-1144	16.0 ppb
2015-05-12	4790-803-1122	ND
2015-05-12	4790-804-1047	ND
2015-05-12	4790-805-1213	ND
2015-05-12	4790-806-0954	ND
2015-05-12	4790-807-1022	ND
2015-05-12	4790-808-1243	ND
2015-08-04	4790-801-1424	27.0 ppb
2015-08-04	4790-802-0921	21.0 ppb
2015-08-04	4790-803-0848	15.0 ppb
2015-08-04	4790-804-1545	2.00 ppb
2015-08-04	4790-805-1102	4.80 ppb
2015-08-04	4790-806-1405	3.40 ppb
2015-08-04	4790-807-1444	20.0 ppb
2015-08-04	4790-808-1127	3.00 ppb
2017-02-28	4790-801-1129	6.20 ppb
2017-02-28	4790-802-0946	8.50 ppb
2017-02-28	4790-803-1251	ND
2017-02-28	4790-804-1212	9.00 ppb
2017-02-28	4790-805-1017	12.0 ppb
2017-02-28	4790-806-1115	8.00 ppb
2017-02-28	4790-807-1146	7.90 ppb
2017-02-28	4790-808-1031	6.20 ppb
2017-06-09	4790-801-0820	5.70 ppb
2017-06-09	4790-802-0958	15.0 ppb
2017-06-09	4790-803-0943	6.50 ppb
2017-06-09	4790-804-0910	5.80 ppb
2017-06-09	4790-805-1020	9.30 ppb
2017-06-09	4790-806-0807	8.10 ppb
2017-06-09	4790-807-0835	12.0 ppb
2017-06-09	4790-808-1030	8.90 ppb
2017-08-10	4790-801-0853	6.00 ppb
2017-08-10	4790-802-1038	4.60 ppb
2017-08-10	4790-803-1021	4.70 ppb
2017-08-10	4790-804-0950	ND
2017-08-10	4790-805-1105	2.10 ppb
2017-08-10	4790-806-0840	5.00 ppb
2017-08-10	4790-807-0919	6.00 ppb
2017-08-10	4790-808-1118	3.00 ppb
2017-11-30	4790-801-1128	6.00 ppb
2017-11-30	4790-802-1033	ND
2017-11-30	4790-803-1049	3.20 ppb
2017-11-30	4790-804-1209	ND
2017-11-30	4790-805-0948	6.20 ppb
2017-11-30	4790-806-1114	7.30 ppb
2017-11-30	4790-807-1147	6.70 ppb
2017-11-30	4790-808-1004	2.30 ppb
2018-02-01	4790-801-0930	12.0 ppb
2018-02-01	4790-802-1152	7.00 ppb
2018-02-01	4790-803-1101	9.30 ppb
2018-02-01	4790-804-1009	9.00 ppb
2018-02-01	4790-805-1230	7.30 ppb
2018-02-01	4790-806-0916	9.40 ppb
2018-02-01	4790-807-0945	12.0 ppb
2018-02-01	4790-808-1304	7.50 ppb
2018-05-02	4790-801-0954	5.90 ppb
2018-05-02	4790-802-1215	5.90 ppb
2018-05-02	4790-803-1149	5.10 ppb
2018-05-02	4790-804-1105	8.50 ppb
2018-05-02	4790-805-1251	5.10 ppb
2018-05-02	4790-806-0925	6.40 ppb
2018-05-02	4790-807-1014	7.30 ppb
2018-05-02	4790-808-1307	2.50 ppb
2018-08-20	4790-801-0927	7.60 ppb
2018-08-20	4790-802-1143	6.80 ppb
2018-08-20	4790-803-1117	6.00 ppb
2018-08-20	4790-804-1010	6.60 ppb
2018-08-20	4790-805-1209	ND
2018-08-20	4790-806-0910	2.10 ppb
2018-08-20	4790-807-0946	7.60 ppb
2018-08-20	4790-808-1236	ND
2018-11-20	4790-801-0900	ND
2018-11-20	4790-802-0945	ND
2018-11-20	4790-803-0910	ND
2018-11-20	4790-804-1015	5.30 ppb
2018-11-20	4790-805-1100	3.40 ppb
2018-11-20	4790-806-0815	ND
2018-11-20	4790-807-0930	ND
2018-11-20	4790-808-1035	ND
2019-02-07	4790-801-1055	4.00 ppb
2019-02-07	4790-802-0830	ND
2019-02-07	4790-803-1245	ND
2019-02-07	4790-804-1200	2.80 ppb
2019-02-07	4790-805-0915	4.50 ppb
2019-02-07	4790-806-1030	3.10 ppb
2019-02-07	4790-807-1130	3.40 ppb
2019-02-07	4790-808-0945	2.70 ppb
2019-05-28	4790-801-0900	3.90 ppb
2019-05-28	4790-802-1305	4.60 ppb
2019-05-28	4790-803-1050	ND
2019-05-28	4790-804-1000	6.10 ppb
2019-05-28	4790-805-1140	6.00 ppb
2019-05-28	4790-806-0830	4.80 ppb
2019-05-28	4790-807-0930	3.60 ppb
2019-05-28	4790-808-1210	3.10 ppb