Haloacetic acids (HAA5)
Danbury Water Department
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.
Samples
Samples exceeding legal limit (MCL)
Samples exceeding
health guidelines
Testing results - average by year
| Year | Average result | Samples taken | Detections | Range of results |
|---|---|---|---|---|
| 2018 | 19.0 ppb | 32 | 31 | ND - 29.4 ppb |
| 2019 | 16.1 ppb | 32 | 31 | ND - 39.8 ppb |
| 2020 | 13.9 ppb | 32 | 31 | ND - 26.1 ppb |
| 2021 | 20.3 ppb | 32 | 32 | 1.60 ppb - 41.2 ppb |
| 2022 | 17.4 ppb | 32 | 32 | 1.70 ppb - 37.0 ppb |
| 2023 | 17.2 ppb | 32 | 32 | 3.20 ppb - 44.0 ppb |
ppb = parts per billion
State, National, and Health Guidelines for Drinking Water
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 |
|---|---|---|
| 2018-03-14 | 211585GE | 23.7 ppb |
| 2018-03-14 | 211587GE | 21.2 ppb |
| 2018-03-14 | 211589GE | 25.7 ppb |
| 2018-03-14 | 211591GE | 14.3 ppb |
| 2018-03-14 | 211599GE | 26.7 ppb |
| 2018-03-15 | 211593GE | 19.5 ppb |
| 2018-03-15 | 211595GE | 28.6 ppb |
| 2018-03-15 | 211597GE | 25.1 ppb |
| 2018-06-19 | 215737GE | 19.8 ppb |
| 2018-06-19 | 215739GE | 25.9 ppb |
| 2018-06-19 | 215743GE | 4.40 ppb |
| 2018-06-19 | 215745GE | 21.6 ppb |
| 2018-06-19 | 215751GE | 22.7 ppb |
| 2018-06-20 | 215747GE | 29.4 ppb |
| 2018-06-20 | 215749GE | 16.0 ppb |
| 2018-06-20 | 215741GE | 20.4 ppb |
| 2018-09-14 | DBP 200505484 | 17.4 ppb |
| 2018-09-14 | DBP 200505486 | 26.0 ppb |
| 2018-09-14 | DBP 200505491 | 13.9 ppb |
| 2018-09-14 | DBP 200505493 | 15.1 ppb |
| 2018-09-14 | DBP 200505495 | 16.6 ppb |
| 2018-09-14 | DBP 200505497 | 16.3 ppb |
| 2018-09-14 | DBP 200505499 | 11.2 ppb |
| 2018-09-17 | DBP 200505658 | ND |
| 2018-12-14 | DBP 200516093 | 23.1 ppb |
| 2018-12-14 | DBP 200516094 | 12.5 ppb |
| 2018-12-14 | DBP 200516095 | 17.0 ppb |
| 2018-12-14 | DBP 200516096 | 2.10 ppb |
| 2018-12-14 | DBP 200516097 | 24.3 ppb |
| 2018-12-14 | DBP 200516098 | 16.9 ppb |
| 2018-12-14 | DBP 200516099 | 27.3 ppb |
| 2018-12-14 | DBP 200516100 | 23.7 ppb |
| 2019-03-14 | DBP 200524760 | 21.9 ppb |
| 2019-03-14 | DBP 200524761 | 15.2 ppb |
| 2019-03-14 | DBP 200524762 | 18.1 ppb |
| 2019-03-14 | DBP 200524763 | 15.3 ppb |
| 2019-03-14 | DBP 200524764 | 18.0 ppb |
| 2019-03-14 | DBP 200524765 | 28.5 ppb |
| 2019-03-14 | DBP 200524766 | 28.1 ppb |
| 2019-03-14 | DBP 200524767 | 22.0 ppb |
| 2019-06-20 | DBP 200537265 | 14.4 ppb |
| 2019-06-20 | DBP 200537266 | 16.3 ppb |
| 2019-06-20 | DBP 200537267 | 15.1 ppb |
| 2019-06-20 | DBP 200537268 | 1.10 ppb |
| 2019-06-20 | DBP 200537269 | 17.2 ppb |
| 2019-06-20 | DBP 200537270 | 26.9 ppb |
| 2019-06-20 | DBP 200537271 | 11.9 ppb |
| 2019-06-20 | DBP 200537272 | 19.5 ppb |
| 2019-09-19 | DBP 200549612 | ND |
| 2019-09-19 | DBP 200549613 | 39.8 ppb |
| 2019-09-19 | DBP 200549615 | 1.80 ppb |
| 2019-09-19 | DBP 200549617 | 12.7 ppb |
| 2019-09-19 | DBP 200549618 | 10.2 ppb |
| 2019-10-11 | DBP 200552503 | 15.1 ppb |
| 2019-10-11 | DBP 200552504 | 14.8 ppb |
| 2019-10-11 | DBP 200552505 | 17.5 ppb |
| 2019-12-19 | DBP 200560926 | 12.8 ppb |
| 2019-12-19 | DBP 200560927 | 11.8 ppb |
| 2019-12-19 | DBP 200560929 | 11.8 ppb |
| 2019-12-19 | DBP 200560930 | 21.2 ppb |
| 2019-12-19 | DBP 200560931 | 18.6 ppb |
| 2019-12-19 | DBP 200560932 | 7.00 ppb |
| 2019-12-19 | DBP 200560934 | 15.8 ppb |
| 2019-12-19 | DBP 200560935 | 15.5 ppb |
| 2020-03-19 | DBP 200569976 | 13.1 ppb |
| 2020-03-19 | DBP 200569977 | 11.4 ppb |
| 2020-03-19 | DBP 200569978 | 15.1 ppb |
| 2020-03-19 | DBP 200569979 | 9.20 ppb |
| 2020-03-19 | DBP 200569980 | 17.0 ppb |
| 2020-03-19 | DBP 200569981 | 13.3 ppb |
| 2020-03-19 | DBP 200569982 | 21.4 ppb |
| 2020-03-19 | DBP 200569983 | 17.4 ppb |
| 2020-06-18 | DBP 200579794 | 9.40 ppb |
| 2020-06-18 | DBP 200579795 | 15.1 ppb |
| 2020-06-18 | DBP 200579796 | 13.1 ppb |
| 2020-06-18 | DBP 200579797 | 3.10 ppb |
| 2020-06-18 | DBP 200579798 | 16.9 ppb |
| 2020-06-18 | DBP 200579799 | 15.6 ppb |
| 2020-06-18 | DBP 200579800 | 11.0 ppb |
| 2020-06-18 | DBP 200579801 | 19.1 ppb |
| 2020-09-17 | DBP 200590661 | 3.40 ppb |
| 2020-09-17 | DBP 200590662 | 16.3 ppb |
| 2020-09-17 | DBP 200590663 | ND |
| 2020-09-17 | DBP 200590664 | 9.80 ppb |
| 2020-09-17 | DBP 200590665 | 16.9 ppb |
| 2020-09-17 | DBP 200590666 | 14.5 ppb |
| 2020-09-17 | DBP 200590667 | 8.00 ppb |
| 2020-09-17 | DBP 200590668 | 10.00 ppb |
| 2020-12-18 | DBP 200601598 | 14.5 ppb |
| 2020-12-18 | DBP 200601599 | 12.2 ppb |
| 2020-12-18 | DBP 200601600 | 14.4 ppb |
| 2020-12-18 | DBP 200601601 | 11.8 ppb |
| 2020-12-18 | DBP 200601602 | 18.8 ppb |
| 2020-12-18 | DBP 200601603 | 26.1 ppb |
| 2020-12-18 | DBP 200601604 | 21.4 ppb |
| 2020-12-18 | DBP 200601605 | 25.7 ppb |
| 2021-03-18 | DBP 200610316 | 17.0 ppb |
| 2021-03-18 | DBP 200610317 | 11.0 ppb |
| 2021-03-18 | DBP 200610318 | 11.4 ppb |
| 2021-03-18 | DBP 200610319 | 15.6 ppb |
| 2021-03-18 | DBP 200610320 | 11.8 ppb |
| 2021-03-18 | DBP 200610321 | 22.7 ppb |
| 2021-03-18 | DBP 200610322 | 24.5 ppb |
| 2021-03-18 | DBP 200610323 | 12.0 ppb |
| 2021-06-17 | DBP 200621341 | 18.0 ppb |
| 2021-06-17 | DBP 200621342 | 18.1 ppb |
| 2021-06-17 | DBP 200621343 | 1.60 ppb |
| 2021-06-17 | DBP 200621344 | 20.0 ppb |
| 2021-06-17 | DBP 200621345 | 16.1 ppb |
| 2021-06-17 | DBP 200621346 | 16.4 ppb |
| 2021-06-17 | DBP 200621347 | 18.1 ppb |
| 2021-06-17 | DBP 200621348 | 33.7 ppb |
| 2021-09-14 | 272625 | 35.1 ppb |
| 2021-09-14 | 272617 | 3.50 ppb |
| 2021-09-14 | 272611 | 18.0 ppb |
| 2021-09-14 | 272613 | 28.9 ppb |
| 2021-09-15 | 272615 | 32.8 ppb |
| 2021-09-15 | 272619 | 20.9 ppb |
| 2021-09-15 | 272621 | 25.2 ppb |
| 2021-09-15 | 272623 | 16.6 ppb |
| 2021-12-13 | 277827X | 28.0 ppb |
| 2021-12-14 | 277829X | 5.20 ppb |
| 2021-12-14 | 277833X | 35.0 ppb |
| 2021-12-14 | 277835X | 32.0 ppb |
| 2021-12-14 | 277837X | 41.2 ppb |
| 2021-12-14 | 277823X | 19.7 ppb |
| 2021-12-14 | 277825X | 21.5 ppb |
| 2021-12-14 | 277831 | 18.6 ppb |
| 2022-03-08 | 281777 | 37.0 ppb |
| 2022-03-08 | 281772 | 22.5 ppb |
| 2022-03-08 | 281773 | 18.0 ppb |
| 2022-03-08 | 281775 | 14.5 ppb |
| 2022-03-09 | 281774 | 22.0 ppb |
| 2022-03-09 | 281778 | 29.4 ppb |
| 2022-03-10 | 281779 | 30.0 ppb |
| 2022-03-10 | 281776 | 25.4 ppb |
| 2022-06-14 | 288303 | 18.8 ppb |
| 2022-06-14 | 288305 | 30.0 ppb |
| 2022-06-14 | 288297 | 4.50 ppb |
| 2022-06-14 | 288299 | 17.6 ppb |
| 2022-06-15 | 288301 | 34.0 ppb |
| 2022-06-15 | 288291 | 17.8 ppb |
| 2022-06-15 | 288293 | 19.5 ppb |
| 2022-06-15 | 288295 | 18.6 ppb |
| 2022-09-14 | 296290 | 17.7 ppb |
| 2022-09-15 | 296292 | 12.6 ppb |
| 2022-09-15 | 296294 | 1.70 ppb |
| 2022-09-15 | 296296 | 10.7 ppb |
| 2022-09-15 | 296298 | 11.0 ppb |
| 2022-09-15 | 296300 | 1.80 ppb |
| 2022-09-15 | 296302 | 16.3 ppb |
| 2022-09-15 | 296308 | 5.00 ppb |
| 2022-12-13 | 303028 | 16.2 ppb |
| 2022-12-13 | 303031 | 13.2 ppb |
| 2022-12-13 | 303035 | 21.6 ppb |
| 2022-12-13 | 303037 | 19.6 ppb |
| 2022-12-13 | 303039 | 14.4 ppb |
| 2022-12-14 | 303033 | 13.5 ppb |
| 2022-12-15 | 303024 | 8.60 ppb |
| 2022-12-15 | 303026 | 12.3 ppb |
| 2023-03-06 | 307813 | 11.5 ppb |
| 2023-03-07 | 307811 | 20.8 ppb |
| 2023-03-07 | 307812 | 9.70 ppb |
| 2023-03-07 | 307817 | 18.3 ppb |
| 2023-03-07 | 307818 | 11.1 ppb |
| 2023-03-07 | 307814 | 10.1 ppb |
| 2023-03-07 | 307816 | 20.5 ppb |
| 2023-03-08 | 307815 | 12.4 ppb |
| 2023-06-06 | N3F0423-01 | 24.1 ppb |
| 2023-06-06 | N3F0423-03 | 24.0 ppb |
| 2023-06-06 | N3F0423-06 | 44.0 ppb |
| 2023-06-06 | N3F0423-08 | 21.6 ppb |
| 2023-06-07 | N3F0423-07 | 19.8 ppb |
| 2023-06-07 | N3F0423-04 | 3.20 ppb |
| 2023-06-07 | N3F0423-02 | 22.0 ppb |
| 2023-06-08 | N3F0423-05 | 20.2 ppb |
| 2023-09-12 | CO99982 | 6.10 ppb |
| 2023-09-12 | CO99983 | 19.7 ppb |
| 2023-09-12 | CO99989 | 19.3 ppb |
| 2023-09-13 | CO99986 | 15.0 ppb |
| 2023-09-13 | CO99987 | 14.2 ppb |
| 2023-09-13 | CO99988 | 8.50 ppb |
| 2023-09-14 | CO99984 | 18.2 ppb |
| 2023-09-14 | CO99985 | 4.40 ppb |
| 2023-12-11 | CP68213 | 19.2 ppb |
| 2023-12-12 | CP68214 | 6.70 ppb |
| 2023-12-12 | CP68216 | 30.5 ppb |
| 2023-12-12 | CP68217 | 22.4 ppb |
| 2023-12-12 | CP68218 | 21.6 ppb |
| 2023-12-12 | CP68211 | 20.1 ppb |
| 2023-12-12 | CP68212 | 16.6 ppb |
| 2023-12-13 | CP68215 | 14.3 ppb |