Trichloroacetic acid
Metropolitan Utilities District
Trichloroacetic acid, one of the group of five haloacetic acids regulated by federal standards, is formed when chlorine or other disinfectants are used to treat drinking water. Haloacetic acids and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Click here to read more about disinfection byproducts.
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 | 2.97 ppb | 48 | 48 | 1.26 ppb - 5.71 ppb |
| 2019 | 4.85 ppb | 48 | 48 | 1.75 ppb - 11.3 ppb |
| 2020 | 4.17 ppb | 48 | 48 | 2.77 ppb - 6.10 ppb |
| 2021 | 3.10 ppb | 48 | 48 | 1.84 ppb - 4.32 ppb |
| 2022 | 3.16 ppb | 48 | 48 | 1.30 ppb - 5.70 ppb |
| 2023 | 3.59 ppb | 48 | 48 | 1.96 ppb - 5.22 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 trichloroacetic acid was defined by the California Office of Environmental Health Hazard Assessment's public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against cancer and harm to reproduction and child development.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2018-02-06 | 534078 | 1.26 ppb |
| 2018-02-06 | 534086 | 2.18 ppb |
| 2018-02-06 | 534088 | 1.74 ppb |
| 2018-02-06 | 534083 | 1.68 ppb |
| 2018-02-06 | 534084 | 1.64 ppb |
| 2018-02-06 | 534082 | 1.93 ppb |
| 2018-02-06 | 534085 | 1.65 ppb |
| 2018-02-06 | 534087 | 2.68 ppb |
| 2018-02-06 | 534079 | 2.47 ppb |
| 2018-02-06 | 534077 | 1.37 ppb |
| 2018-02-06 | 534080 | 2.54 ppb |
| 2018-02-06 | 534081 | 2.34 ppb |
| 2018-05-07 | 549803 | 2.20 ppb |
| 2018-05-07 | 549808 | 4.71 ppb |
| 2018-05-07 | 549810 | 4.50 ppb |
| 2018-05-07 | 549802 | 5.33 ppb |
| 2018-05-07 | 549812 | 4.60 ppb |
| 2018-05-07 | 549806 | 3.74 ppb |
| 2018-05-07 | 549805 | 4.40 ppb |
| 2018-05-07 | 549804 | 2.00 ppb |
| 2018-05-07 | 549811 | 4.54 ppb |
| 2018-05-07 | 549809 | 3.72 ppb |
| 2018-05-07 | 549807 | 5.45 ppb |
| 2018-05-07 | 549813 | 5.71 ppb |
| 2018-08-08 | 567012 | 2.54 ppb |
| 2018-08-08 | 567018 | 2.96 ppb |
| 2018-08-08 | 567013 | 2.64 ppb |
| 2018-08-08 | 567014 | 4.42 ppb |
| 2018-08-08 | 567011 | 2.55 ppb |
| 2018-08-08 | 567010 | 2.52 ppb |
| 2018-08-08 | 567008 | 2.84 ppb |
| 2018-08-08 | 567016 | 2.59 ppb |
| 2018-08-08 | 567017 | 2.97 ppb |
| 2018-08-08 | 567015 | 2.70 ppb |
| 2018-08-08 | 567009 | 3.15 ppb |
| 2018-08-08 | 567007 | 5.14 ppb |
| 2018-11-06 | 583372 | 2.66 ppb |
| 2018-11-06 | 583365 | 1.85 ppb |
| 2018-11-06 | 583364 | 2.76 ppb |
| 2018-11-06 | 583370 | 2.79 ppb |
| 2018-11-06 | 583363 | 2.39 ppb |
| 2018-11-06 | 583369 | 1.95 ppb |
| 2018-11-06 | 583371 | 2.86 ppb |
| 2018-11-06 | 583362 | 3.29 ppb |
| 2018-11-06 | 583367 | 2.98 ppb |
| 2018-11-06 | 583366 | 3.19 ppb |
| 2018-11-06 | 583368 | 1.87 ppb |
| 2018-11-06 | 583373 | 2.62 ppb |
| 2019-02-05 | 595235 | 2.46 ppb |
| 2019-02-05 | 595227 | 2.25 ppb |
| 2019-02-05 | 595232 | 2.37 ppb |
| 2019-02-05 | 595226 | 2.44 ppb |
| 2019-02-05 | 595230 | 2.70 ppb |
| 2019-02-05 | 595231 | 2.45 ppb |
| 2019-02-05 | 595224 | 1.75 ppb |
| 2019-02-05 | 595228 | 2.51 ppb |
| 2019-02-05 | 595233 | 2.53 ppb |
| 2019-02-05 | 595229 | 2.53 ppb |
| 2019-02-05 | 595234 | 2.44 ppb |
| 2019-02-05 | 595225 | 1.82 ppb |
| 2019-05-07 | 600558 | 9.93 ppb |
| 2019-05-07 | 600554 | 8.01 ppb |
| 2019-05-07 | 600563 | 11.3 ppb |
| 2019-05-07 | 600555 | 5.93 ppb |
| 2019-05-07 | 600562 | 11.0 ppb |
| 2019-05-07 | 600561 | 9.86 ppb |
| 2019-05-07 | 600553 | 3.04 ppb |
| 2019-05-07 | 600556 | 11.2 ppb |
| 2019-05-07 | 600557 | 9.61 ppb |
| 2019-05-07 | 600559 | 5.66 ppb |
| 2019-05-07 | 600560 | 9.45 ppb |
| 2019-05-07 | 600552 | 3.19 ppb |
| 2019-08-06 | 622441 | 3.49 ppb |
| 2019-08-06 | 622437 | 3.68 ppb |
| 2019-08-06 | 622438 | 3.76 ppb |
| 2019-08-06 | 622445 | 4.11 ppb |
| 2019-08-06 | 622440 | 3.34 ppb |
| 2019-08-06 | 622444 | 4.41 ppb |
| 2019-08-06 | 622446 | 3.33 ppb |
| 2019-08-06 | 622439 | 3.19 ppb |
| 2019-08-06 | 622436 | 3.32 ppb |
| 2019-08-06 | 622447 | 5.50 ppb |
| 2019-08-06 | 622443 | 3.34 ppb |
| 2019-08-06 | 622442 | 6.45 ppb |
| 2019-11-05 | 644368 | 6.77 ppb |
| 2019-11-05 | 644375 | 5.62 ppb |
| 2019-11-05 | 644367 | 4.04 ppb |
| 2019-11-05 | 644369 | 3.90 ppb |
| 2019-11-05 | 644377 | 4.76 ppb |
| 2019-11-05 | 644373 | 3.86 ppb |
| 2019-11-05 | 644366 | 6.63 ppb |
| 2019-11-05 | 644372 | 3.82 ppb |
| 2019-11-05 | 644374 | 5.14 ppb |
| 2019-11-05 | 644371 | 4.45 ppb |
| 2019-11-05 | 644370 | 5.04 ppb |
| 2019-11-05 | 644376 | 4.51 ppb |
| 2020-02-04 | 656180 | 3.91 ppb |
| 2020-02-04 | 656170 | 3.62 ppb |
| 2020-02-04 | 656174 | 3.43 ppb |
| 2020-02-04 | 656175 | 3.56 ppb |
| 2020-02-04 | 656178 | 3.61 ppb |
| 2020-02-04 | 656177 | 3.06 ppb |
| 2020-02-04 | 656181 | 3.60 ppb |
| 2020-02-04 | 656171 | 3.64 ppb |
| 2020-02-04 | 656172 | 3.52 ppb |
| 2020-02-04 | 656176 | 2.77 ppb |
| 2020-02-04 | 656179 | 4.12 ppb |
| 2020-02-04 | 656173 | 3.31 ppb |
| 2020-05-05 | 672086 | 4.46 ppb |
| 2020-05-05 | 672088 | 4.07 ppb |
| 2020-05-05 | 672090 | 3.78 ppb |
| 2020-05-05 | 672092 | 2.93 ppb |
| 2020-05-05 | 672087 | 4.04 ppb |
| 2020-05-05 | 672093 | 3.34 ppb |
| 2020-05-05 | 672095 | 4.66 ppb |
| 2020-05-05 | 672094 | 4.32 ppb |
| 2020-05-05 | 672089 | 4.24 ppb |
| 2020-05-05 | 672096 | 4.36 ppb |
| 2020-05-05 | 672091 | 4.12 ppb |
| 2020-05-05 | 672097 | 4.69 ppb |
| 2020-08-04 | 681784 | 4.57 ppb |
| 2020-08-04 | 681794 | 5.05 ppb |
| 2020-08-04 | 681788 | 5.21 ppb |
| 2020-08-04 | 681792 | 4.21 ppb |
| 2020-08-04 | 681793 | 4.76 ppb |
| 2020-08-04 | 681783 | 4.91 ppb |
| 2020-08-04 | 681790 | 4.64 ppb |
| 2020-08-04 | 681785 | 4.97 ppb |
| 2020-08-04 | 681789 | 4.71 ppb |
| 2020-08-04 | 681791 | 4.53 ppb |
| 2020-08-04 | 681787 | 5.27 ppb |
| 2020-08-04 | 681786 | 4.81 ppb |
| 2020-11-10 | 706872 | 6.10 ppb |
| 2020-11-10 | 706877 | 3.95 ppb |
| 2020-11-10 | 706871 | 3.07 ppb |
| 2020-11-10 | 706875 | 3.97 ppb |
| 2020-11-10 | 706867 | 4.26 ppb |
| 2020-11-10 | 706869 | 4.41 ppb |
| 2020-11-10 | 706868 | 4.53 ppb |
| 2020-11-10 | 706866 | 5.57 ppb |
| 2020-11-10 | 706870 | 2.98 ppb |
| 2020-11-10 | 706873 | 4.02 ppb |
| 2020-11-10 | 706874 | 4.17 ppb |
| 2020-11-10 | 706876 | 4.11 ppb |
| 2021-02-02 | 719014 | 2.03 ppb |
| 2021-02-02 | 719008 | 1.88 ppb |
| 2021-02-02 | 719013 | 2.95 ppb |
| 2021-02-02 | 719007 | 1.87 ppb |
| 2021-02-02 | 719004 | 2.79 ppb |
| 2021-02-02 | 719011 | 2.72 ppb |
| 2021-02-02 | 719003 | 2.00 ppb |
| 2021-02-02 | 719005 | 2.87 ppb |
| 2021-02-02 | 719006 | 1.88 ppb |
| 2021-02-02 | 719010 | 2.06 ppb |
| 2021-02-02 | 719009 | 1.88 ppb |
| 2021-02-02 | 719012 | 2.64 ppb |
| 2021-05-04 | 733019 | 3.20 ppb |
| 2021-05-04 | 733020 | 2.25 ppb |
| 2021-05-04 | 733015 | 2.87 ppb |
| 2021-05-04 | 733014 | 2.42 ppb |
| 2021-05-04 | 733021 | 2.39 ppb |
| 2021-05-04 | 733024 | 2.27 ppb |
| 2021-05-04 | 733016 | 3.01 ppb |
| 2021-05-04 | 733017 | 2.02 ppb |
| 2021-05-04 | 733018 | 2.52 ppb |
| 2021-05-04 | 733025 | 2.34 ppb |
| 2021-05-04 | 733022 | 1.84 ppb |
| 2021-05-04 | 733023 | 2.10 ppb |
| 2021-08-04 | 753568 | 3.57 ppb |
| 2021-08-04 | 753569 | 3.80 ppb |
| 2021-08-04 | 753567 | 3.81 ppb |
| 2021-08-04 | 753566 | 3.73 ppb |
| 2021-08-04 | 753563 | 3.61 ppb |
| 2021-08-04 | 753559 | 3.65 ppb |
| 2021-08-04 | 753558 | 3.57 ppb |
| 2021-08-04 | 753564 | 3.68 ppb |
| 2021-08-04 | 753560 | 3.75 ppb |
| 2021-08-04 | 753565 | 3.59 ppb |
| 2021-08-04 | 753562 | 3.82 ppb |
| 2021-08-04 | 753561 | 3.54 ppb |
| 2021-11-03 | 770887 | 4.12 ppb |
| 2021-11-03 | 770888 | 3.93 ppb |
| 2021-11-03 | 770889 | 4.03 ppb |
| 2021-11-03 | 770884 | 3.97 ppb |
| 2021-11-03 | 770878 | 3.93 ppb |
| 2021-11-03 | 770880 | 4.08 ppb |
| 2021-11-03 | 770885 | 3.97 ppb |
| 2021-11-03 | 770879 | 3.97 ppb |
| 2021-11-03 | 770882 | 3.82 ppb |
| 2021-11-03 | 770881 | 3.89 ppb |
| 2021-11-03 | 770883 | 3.81 ppb |
| 2021-11-03 | 770886 | 4.32 ppb |
| 2022-02-23 | 782411 | 2.81 ppb |
| 2022-02-23 | 782410 | 2.77 ppb |
| 2022-02-23 | 782413 | 2.73 ppb |
| 2022-02-23 | 782408 | 2.65 ppb |
| 2022-02-23 | 782409 | 2.53 ppb |
| 2022-02-23 | 782414 | 2.69 ppb |
| 2022-02-23 | 782407 | 2.56 ppb |
| 2022-02-23 | 782417 | 2.57 ppb |
| 2022-02-23 | 782416 | 2.48 ppb |
| 2022-02-23 | 782412 | 2.46 ppb |
| 2022-02-23 | 782415 | 2.49 ppb |
| 2022-02-23 | 782406 | 2.52 ppb |
| 2022-05-03 | 800295 | 1.30 ppb |
| 2022-05-03 | 800294 | 1.30 ppb |
| 2022-05-03 | 800299 | 2.40 ppb |
| 2022-05-03 | 800296 | 2.50 ppb |
| 2022-05-03 | 800301 | 2.20 ppb |
| 2022-05-03 | 800302 | 4.20 ppb |
| 2022-05-03 | 800297 | 2.50 ppb |
| 2022-05-03 | 800291 | 2.40 ppb |
| 2022-05-03 | 800300 | 2.10 ppb |
| 2022-05-03 | 800293 | 2.70 ppb |
| 2022-05-03 | 800292 | 2.60 ppb |
| 2022-05-03 | 800298 | 3.10 ppb |
| 2022-08-03 | 815782 | 4.65 ppb |
| 2022-08-03 | 815789 | 5.70 ppb |
| 2022-08-03 | 815788 | 4.68 ppb |
| 2022-08-03 | 815791 | 4.33 ppb |
| 2022-08-03 | 815786 | 4.83 ppb |
| 2022-08-03 | 815785 | 3.84 ppb |
| 2022-08-03 | 815784 | 4.35 ppb |
| 2022-08-03 | 815783 | 4.94 ppb |
| 2022-08-03 | 815781 | 4.29 ppb |
| 2022-08-03 | 815792 | 4.32 ppb |
| 2022-08-03 | 815790 | 2.98 ppb |
| 2022-08-03 | 815787 | 4.15 ppb |
| 2022-11-08 | 833750 | 2.34 ppb |
| 2022-11-08 | 833753 | 2.86 ppb |
| 2022-11-08 | 833754 | 2.57 ppb |
| 2022-11-08 | 833743 | 3.07 ppb |
| 2022-11-08 | 833745 | 4.04 ppb |
| 2022-11-08 | 833746 | 3.83 ppb |
| 2022-11-08 | 833747 | 3.15 ppb |
| 2022-11-08 | 833748 | 3.41 ppb |
| 2022-11-08 | 833751 | 3.65 ppb |
| 2022-11-08 | 833749 | 2.42 ppb |
| 2022-11-08 | 833752 | 3.03 ppb |
| 2022-11-08 | 833744 | 3.81 ppb |
| 2023-02-07 | 847408 | 4.04 ppb |
| 2023-02-07 | 847407 | 2.99 ppb |
| 2023-02-07 | 847403 | 2.15 ppb |
| 2023-02-07 | 847406 | 3.17 ppb |
| 2023-02-07 | 847405 | 3.26 ppb |
| 2023-02-07 | 847402 | 2.05 ppb |
| 2023-02-07 | 847409 | 2.58 ppb |
| 2023-02-07 | 847412 | 3.36 ppb |
| 2023-02-07 | 847404 | 3.87 ppb |
| 2023-02-07 | 847413 | 3.66 ppb |
| 2023-02-07 | 847410 | 3.60 ppb |
| 2023-02-07 | 847411 | 3.36 ppb |
| 2023-05-02 | 858531 | 2.43 ppb |
| 2023-05-02 | 858533 | 4.28 ppb |
| 2023-05-02 | 858537 | 2.78 ppb |
| 2023-05-02 | 858532 | 3.61 ppb |
| 2023-05-02 | 858534 | 2.42 ppb |
| 2023-05-02 | 858535 | 4.75 ppb |
| 2023-05-02 | 858528 | 1.96 ppb |
| 2023-05-02 | 858527 | 2.17 ppb |
| 2023-05-02 | 858538 | 3.70 ppb |
| 2023-05-02 | 858536 | 4.54 ppb |
| 2023-05-23 | 868095 | 2.35 ppb |
| 2023-05-23 | 868096 | 3.25 ppb |
| 2023-08-08 | 879873 | 4.26 ppb |
| 2023-08-08 | 879868 | 4.44 ppb |
| 2023-08-08 | 879870 | 3.85 ppb |
| 2023-08-08 | 879869 | 4.51 ppb |
| 2023-08-08 | 879866 | 5.22 ppb |
| 2023-08-08 | 879863 | 4.74 ppb |
| 2023-08-08 | 879872 | 4.38 ppb |
| 2023-08-08 | 879864 | 4.60 ppb |
| 2023-08-08 | 879871 | 3.72 ppb |
| 2023-08-08 | 879862 | 5.05 ppb |
| 2023-08-08 | 879865 | 4.29 ppb |
| 2023-08-08 | 879867 | 4.30 ppb |
| 2023-11-07 | 891411 | 4.28 ppb |
| 2023-11-07 | 891415 | 2.62 ppb |
| 2023-11-07 | 891413 | 3.01 ppb |
| 2023-11-07 | 891414 | 2.99 ppb |
| 2023-11-07 | 891416 | 3.44 ppb |
| 2023-11-07 | 891406 | 3.84 ppb |
| 2023-11-07 | 891405 | 3.79 ppb |
| 2023-11-07 | 891407 | 4.06 ppb |
| 2023-11-07 | 891412 | 2.89 ppb |
| 2023-11-07 | 891410 | 3.65 ppb |
| 2023-11-07 | 891408 | 4.72 ppb |
| 2023-11-07 | 891409 | 3.40 ppb |