Chloroform
Schriever Water Treatment Service Area
Chloroform, one of the total trihalomethanes (TTHMs), is formed when chlorine or other disinfectants are used to treat drinking water. Chloroform and other disinfection byproducts increase the risk of cancer and may cause problems during pregnancy. Read More.
In addition to tap water disinfection, chloroform pollution in the environment also comes from industrial discharges from pulp and paper mills, and from urban wastewater effluent. Human studies show that chloroform damages the kidneys, liver and central nervous system. In animals, chloroform causes infertility, birth defects and cancer.
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 | 14.7 ppb | 64 | 64 | 9.00 ppb - 19.5 ppb |
| 2019 | 18.9 ppb | 64 | 64 | 14.0 ppb - 25.1 ppb |
| 2020 | 14.2 ppb | 32 | 32 | 10.2 ppb - 18.4 ppb |
| 2021 | 24.3 ppb | 34 | 34 | 3.70 ppb - 52.2 ppb |
| 2022 | 19.9 ppb | 34 | 34 | 7.00 ppb - 48.9 ppb |
| 2023 | 20.4 ppb | 32 | 32 | 6.30 ppb - 40.0 ppb |
ppb = parts per billion
State, National, and Health Guidelines for Drinking Water
EWG Health Guideline: 0.4 ppb
The EWG Health Guideline of 0.4 ppb for chloroform was based on 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 fetal growth and development.
ppb = parts per billion
All test results
| Date | Lab ID | Result |
|---|---|---|
| 2018-03-09 | 35379412001 | 9.20 ppb |
| 2018-03-09 | 35379412002 | 10.9 ppb |
| 2018-03-09 | 35379412003 | 14.3 ppb |
| 2018-03-09 | 35379412004 | 12.1 ppb |
| 2018-03-09 | 35379412005 | 13.4 ppb |
| 2018-03-09 | 35379412006 | 12.7 ppb |
| 2018-03-09 | 35379412007 | 13.6 ppb |
| 2018-03-09 | 35379412008 | 12.3 ppb |
| 2018-03-09 | 35379412001 | 9.20 ppb |
| 2018-03-09 | 35379412002 | 10.9 ppb |
| 2018-03-09 | 35379412003 | 14.3 ppb |
| 2018-03-09 | 35379412004 | 12.1 ppb |
| 2018-03-09 | 35379412005 | 13.4 ppb |
| 2018-03-09 | 35379412006 | 12.7 ppb |
| 2018-03-09 | 35379412007 | 13.6 ppb |
| 2018-03-09 | 35379412008 | 12.3 ppb |
| 2018-06-05 | 35396534001 | 13.5 ppb |
| 2018-06-05 | 35396534002 | 13.2 ppb |
| 2018-06-05 | 35396534003 | 12.3 ppb |
| 2018-06-05 | 35396534004 | 14.1 ppb |
| 2018-06-05 | 35396534005 | 13.8 ppb |
| 2018-06-05 | 35396534006 | 12.5 ppb |
| 2018-06-05 | 35396534007 | 13.4 ppb |
| 2018-06-05 | 35396534008 | 14.5 ppb |
| 2018-06-05 | 35396534001 | 13.5 ppb |
| 2018-06-05 | 35396534002 | 13.2 ppb |
| 2018-06-05 | 35396534003 | 12.3 ppb |
| 2018-06-05 | 35396534004 | 14.1 ppb |
| 2018-06-05 | 35396534005 | 13.8 ppb |
| 2018-06-05 | 35396534006 | 12.5 ppb |
| 2018-06-05 | 35396534007 | 13.4 ppb |
| 2018-06-05 | 35396534008 | 14.5 ppb |
| 2018-09-19 | 35419185001 | 9.00 ppb |
| 2018-09-19 | 35419185002 | 14.4 ppb |
| 2018-09-19 | 35419185003 | 16.7 ppb |
| 2018-09-19 | 35419185004 | 16.5 ppb |
| 2018-09-19 | 35419185005 | 15.8 ppb |
| 2018-09-19 | 35419185006 | 10.3 ppb |
| 2018-09-19 | 35419185007 | 16.1 ppb |
| 2018-09-19 | 35419185008 | 16.6 ppb |
| 2018-09-19 | 35419185001 | 9.00 ppb |
| 2018-09-19 | 35419185002 | 14.4 ppb |
| 2018-09-19 | 35419185003 | 16.7 ppb |
| 2018-09-19 | 35419185004 | 16.5 ppb |
| 2018-09-19 | 35419185005 | 15.8 ppb |
| 2018-09-19 | 35419185006 | 10.3 ppb |
| 2018-09-19 | 35419185007 | 16.1 ppb |
| 2018-09-19 | 35419185008 | 16.6 ppb |
| 2018-12-04 | 35435069001 | 15.3 ppb |
| 2018-12-04 | 35435069002 | 18.5 ppb |
| 2018-12-04 | 35435069003 | 19.0 ppb |
| 2018-12-04 | 35435069004 | 19.5 ppb |
| 2018-12-04 | 35435069005 | 19.3 ppb |
| 2018-12-04 | 35435069006 | 18.6 ppb |
| 2018-12-04 | 35435069007 | 19.1 ppb |
| 2018-12-04 | 35435069008 | 19.4 ppb |
| 2018-12-04 | 35435069001 | 15.3 ppb |
| 2018-12-04 | 35435069002 | 18.5 ppb |
| 2018-12-04 | 35435069003 | 19.0 ppb |
| 2018-12-04 | 35435069004 | 19.5 ppb |
| 2018-12-04 | 35435069005 | 19.3 ppb |
| 2018-12-04 | 35435069006 | 18.6 ppb |
| 2018-12-04 | 35435069007 | 19.1 ppb |
| 2018-12-04 | 35435069008 | 19.4 ppb |
| 2019-03-12 | 35454240001 | 14.9 ppb |
| 2019-03-12 | 35454240002 | 14.9 ppb |
| 2019-03-12 | 35454240003 | 15.5 ppb |
| 2019-03-12 | 35454240004 | 15.4 ppb |
| 2019-03-12 | 35454240005 | 16.0 ppb |
| 2019-03-12 | 35454240006 | 14.0 ppb |
| 2019-03-12 | 35454240007 | 15.5 ppb |
| 2019-03-12 | 35454240008 | 16.2 ppb |
| 2019-03-12 | 35454240001 | 14.9 ppb |
| 2019-03-12 | 35454240002 | 14.9 ppb |
| 2019-03-12 | 35454240003 | 15.5 ppb |
| 2019-03-12 | 35454240004 | 15.4 ppb |
| 2019-03-12 | 35454240005 | 16.0 ppb |
| 2019-03-12 | 35454240006 | 14.0 ppb |
| 2019-03-12 | 35454240007 | 15.5 ppb |
| 2019-03-12 | 35454240008 | 16.2 ppb |
| 2019-06-10 | 35474484001 | 17.0 ppb |
| 2019-06-10 | 35474484002 | 22.4 ppb |
| 2019-06-10 | 35474484003 | 22.5 ppb |
| 2019-06-10 | 35474484004 | 22.1 ppb |
| 2019-06-10 | 35474484005 | 22.6 ppb |
| 2019-06-10 | 35474484006 | 24.1 ppb |
| 2019-06-10 | 35474484007 | 21.3 ppb |
| 2019-06-10 | 35474484008 | 20.8 ppb |
| 2019-06-10 | 35474484001 | 17.0 ppb |
| 2019-06-10 | 35474484002 | 22.4 ppb |
| 2019-06-10 | 35474484003 | 22.5 ppb |
| 2019-06-10 | 35474484004 | 22.1 ppb |
| 2019-06-10 | 35474484005 | 22.6 ppb |
| 2019-06-10 | 35474484006 | 24.1 ppb |
| 2019-06-10 | 35474484007 | 21.3 ppb |
| 2019-06-10 | 35474484008 | 20.8 ppb |
| 2019-09-10 | 35496772001 | 14.5 ppb |
| 2019-09-10 | 35496772002 | 17.9 ppb |
| 2019-09-10 | 35496772003 | 25.1 ppb |
| 2019-09-10 | 35496772004 | 21.6 ppb |
| 2019-09-10 | 35496772005 | 23.0 ppb |
| 2019-09-10 | 35496772006 | 18.4 ppb |
| 2019-09-10 | 35496772007 | 20.6 ppb |
| 2019-09-10 | 35496772008 | 19.0 ppb |
| 2019-09-10 | 35496772001 | 14.5 ppb |
| 2019-09-10 | 35496772002 | 17.9 ppb |
| 2019-09-10 | 35496772003 | 25.1 ppb |
| 2019-09-10 | 35496772004 | 21.6 ppb |
| 2019-09-10 | 35496772005 | 23.0 ppb |
| 2019-09-10 | 35496772006 | 18.4 ppb |
| 2019-09-10 | 35496772007 | 20.6 ppb |
| 2019-09-10 | 35496772008 | 19.0 ppb |
| 2019-12-11 | 35518241001 | 16.0 ppb |
| 2019-12-11 | 35518241002 | 17.4 ppb |
| 2019-12-11 | 35518241003 | 19.6 ppb |
| 2019-12-11 | 35518241004 | 18.2 ppb |
| 2019-12-11 | 35518241005 | 19.3 ppb |
| 2019-12-11 | 35518241006 | 22.0 ppb |
| 2019-12-11 | 35518241007 | 18.3 ppb |
| 2019-12-11 | 35518241008 | 17.2 ppb |
| 2019-12-11 | 35518241001 | 16.0 ppb |
| 2019-12-11 | 35518241002 | 17.4 ppb |
| 2019-12-11 | 35518241003 | 19.6 ppb |
| 2019-12-11 | 35518241004 | 18.2 ppb |
| 2019-12-11 | 35518241005 | 19.3 ppb |
| 2019-12-11 | 35518241006 | 22.0 ppb |
| 2019-12-11 | 35518241007 | 18.3 ppb |
| 2019-12-11 | 35518241008 | 17.2 ppb |
| 2020-03-12 | 35537425001 | 13.9 ppb |
| 2020-03-12 | 35537425002 | 14.0 ppb |
| 2020-03-12 | 35537425003 | 14.4 ppb |
| 2020-03-12 | 35537425004 | 13.8 ppb |
| 2020-03-12 | 35537425005 | 14.2 ppb |
| 2020-03-12 | 35537425006 | 17.8 ppb |
| 2020-03-12 | 35537425007 | 14.2 ppb |
| 2020-03-12 | 35537425008 | 13.9 ppb |
| 2020-06-12 | 35556393001 | 14.7 ppb |
| 2020-06-12 | 35556393002 | 16.7 ppb |
| 2020-06-12 | 35556393003 | 18.1 ppb |
| 2020-06-12 | 35556393004 | 16.9 ppb |
| 2020-06-12 | 35556393005 | 17.0 ppb |
| 2020-06-12 | 35556393006 | 18.4 ppb |
| 2020-06-12 | 35556393007 | 17.5 ppb |
| 2020-06-12 | 35556393008 | 16.8 ppb |
| 2020-09-17 | 35578893001 | 13.2 ppb |
| 2020-09-17 | 35578893002 | 13.3 ppb |
| 2020-09-17 | 35578893003 | 13.6 ppb |
| 2020-09-17 | 35578893004 | 14.6 ppb |
| 2020-09-17 | 35578893005 | 13.1 ppb |
| 2020-09-17 | 35578893006 | 15.8 ppb |
| 2020-09-17 | 35578893007 | 15.2 ppb |
| 2020-09-17 | 35578893008 | 15.6 ppb |
| 2020-12-17 | 35600000001 | 10.2 ppb |
| 2020-12-17 | 35600000002 | 10.9 ppb |
| 2020-12-17 | 35600000003 | 12.1 ppb |
| 2020-12-17 | 35600000004 | 10.3 ppb |
| 2020-12-17 | 35600000005 | 11.2 ppb |
| 2020-12-17 | 35600000006 | 12.0 ppb |
| 2020-12-17 | 35600000007 | 11.2 ppb |
| 2020-12-17 | 35600000008 | 10.3 ppb |
| 2021-03-05 | 35617074001 | 3.70 ppb |
| 2021-03-05 | 35617074002 | 10.8 ppb |
| 2021-03-05 | 35617074003 | 11.4 ppb |
| 2021-03-05 | 35617074004 | 11.7 ppb |
| 2021-03-05 | 35617074005 | 10.9 ppb |
| 2021-03-05 | 35617074006 | 11.2 ppb |
| 2021-03-05 | 35617074007 | 13.0 ppb |
| 2021-03-05 | 35617074008 | 11.6 ppb |
| 2021-06-10 | 35640075001 | 17.1 ppb |
| 2021-06-10 | 35640075002 | 18.1 ppb |
| 2021-06-10 | 35640075003 | 18.3 ppb |
| 2021-06-10 | 35640075004 | 19.0 ppb |
| 2021-06-10 | 35640075005 | 18.9 ppb |
| 2021-06-10 | 35640075006 | 18.7 ppb |
| 2021-06-10 | 35640075007 | 18.2 ppb |
| 2021-06-10 | 35640075008 | 18.7 ppb |
| 2021-09-16 | 35664177001 | 24.9 ppb |
| 2021-09-16 | 35664177002 | 48.4 ppb |
| 2021-09-16 | 35664177003 | 31.9 ppb |
| 2021-09-16 | 35664177004 | 39.5 ppb |
| 2021-09-30 | 35669021001 | 36.7 ppb |
| 2021-10-29 | 35675828001 | 27.9 ppb |
| 2021-10-29 | 35675828002 | 43.2 ppb |
| 2021-10-29 | 35675828003 | 37.6 ppb |
| 2021-10-29 | 35675828004 | 48.2 ppb |
| 2021-10-29 | 35675828005 | 27.6 ppb |
| 2021-12-02 | 35681497001 | 10.9 ppb |
| 2021-12-02 | 35681497002 | 24.7 ppb |
| 2021-12-02 | 35681497003 | 23.5 ppb |
| 2021-12-02 | 35681497004 | 25.4 ppb |
| 2021-12-02 | 35681497005 | 36.4 ppb |
| 2021-12-02 | 35681497006 | 33.0 ppb |
| 2021-12-02 | 35681497007 | 52.2 ppb |
| 2021-12-02 | 35681497008 | 22.5 ppb |
| 2022-03-11 | 35703403001 | 10.6 ppb |
| 2022-03-11 | 35703403002 | 9.60 ppb |
| 2022-03-11 | 35703403003 | 22.8 ppb |
| 2022-03-11 | 35703403004 | 23.3 ppb |
| 2022-03-11 | 35703403005 | 22.4 ppb |
| 2022-03-11 | 35703403006 | 23.8 ppb |
| 2022-03-11 | 35703403007 | 11.6 ppb |
| 2022-03-11 | 35703403008 | 15.1 ppb |
| 2022-03-17 | 35704970001 | 11.7 ppb |
| 2022-03-17 | 35704970002 | 15.6 ppb |
| 2022-06-15 | 35727612001 | 13.9 ppb |
| 2022-06-15 | 35727612002 | 14.1 ppb |
| 2022-06-15 | 35727612003 | 13.6 ppb |
| 2022-06-15 | 35727612004 | 29.1 ppb |
| 2022-06-15 | 35727612005 | 34.3 ppb |
| 2022-06-15 | 35727612006 | 33.3 ppb |
| 2022-06-15 | 35727612007 | 32.3 ppb |
| 2022-06-15 | 35727612008 | 17.4 ppb |
| 2022-09-08 | 35745433001 | 10.7 ppb |
| 2022-09-08 | 35745433002 | 11.7 ppb |
| 2022-09-08 | 35745433003 | 10.5 ppb |
| 2022-09-08 | 35745433004 | 35.2 ppb |
| 2022-09-08 | 35745433005 | 36.7 ppb |
| 2022-09-08 | 35745433006 | 34.9 ppb |
| 2022-09-08 | 35745433007 | 48.9 ppb |
| 2022-09-08 | 35745433008 | 11.9 ppb |
| 2022-12-08 | 35765453001 | 7.00 ppb |
| 2022-12-08 | 35765453002 | 9.30 ppb |
| 2022-12-08 | 35765453003 | 9.20 ppb |
| 2022-12-08 | 35765453004 | 21.4 ppb |
| 2022-12-08 | 35765453005 | 21.7 ppb |
| 2022-12-08 | 35765453006 | 20.9 ppb |
| 2022-12-08 | 35765453007 | 20.6 ppb |
| 2022-12-08 | 35765453008 | 10.00 ppb |
| 2023-03-02 | 35783375001 | 10.5 ppb |
| 2023-03-02 | 35783375002 | 12.5 ppb |
| 2023-03-02 | 35783375003 | 12.9 ppb |
| 2023-03-02 | 35783375004 | 26.1 ppb |
| 2023-03-02 | 35783375005 | 30.9 ppb |
| 2023-03-02 | 35783375006 | 34.8 ppb |
| 2023-03-02 | 35783375007 | 28.7 ppb |
| 2023-03-02 | 35783375008 | 13.0 ppb |
| 2023-06-14 | 35806771001 | 16.5 ppb |
| 2023-06-14 | 35806771002 | 18.1 ppb |
| 2023-06-14 | 35806771003 | 19.8 ppb |
| 2023-06-14 | 35806771004 | 38.5 ppb |
| 2023-06-14 | 35806771005 | 40.0 ppb |
| 2023-06-14 | 35806771006 | 38.3 ppb |
| 2023-06-14 | 35806771007 | 36.0 ppb |
| 2023-06-14 | 35806771008 | 19.1 ppb |
| 2023-09-12 | 35827662001 | 12.1 ppb |
| 2023-09-12 | 35827662002 | 13.2 ppb |
| 2023-09-12 | 35827662003 | 13.0 ppb |
| 2023-09-12 | 35827662004 | 27.3 ppb |
| 2023-09-12 | 35827662005 | 35.2 ppb |
| 2023-09-12 | 35827662006 | 34.6 ppb |
| 2023-09-12 | 35827662007 | 36.9 ppb |
| 2023-09-12 | 35827662008 | 14.6 ppb |
| 2023-12-15 | 35849368001 | 8.10 ppb |
| 2023-12-15 | 35849368002 | 6.30 ppb |
| 2023-12-15 | 35849368003 | 8.20 ppb |
| 2023-12-15 | 35849368004 | 10.5 ppb |
| 2023-12-15 | 35849368005 | 10.1 ppb |
| 2023-12-15 | 35849368006 | 9.00 ppb |
| 2023-12-15 | 35849368007 | 8.80 ppb |
| 2023-12-15 | 35849368008 | 9.90 ppb |