Chloroform
City of Orange
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.
Testing results - average by year
Year | Average result | Samples taken | Detections | Range of results |
---|---|---|---|---|
2013 | N/A | 0 | 0 | N/A |
2014 | 2.63 ppb | 44 | 13 | ND - 13.7 ppb |
2015 | 4.61 ppb | 51 | 25 | ND - 17.9 ppb |
2016 | 1.30 ppb | 56 | 20 | ND - 10.8 ppb |
2017 | 1.99 ppb | 47 | 24 | ND - 9.40 ppb |
2018 | 2.26 ppb | 44 | 29 | ND - 5.80 ppb |
2019 | 1.86 ppb | 45 | 24 | ND - 8.40 ppb |
ppb = parts per billion
State and national drinking water standards and health guidelines
EWG Health Guideline 0.4 ppb
The EWG Health Guideline of 0.4 ppb for chloroform was proposed in 2018 by the California Office of Environmental Health Hazard Assessment as a one-in-a-million lifetime risk of cancer. Values greater than one-in-a-million cancer risk level can result in increased cancer cases above one in a million people.
ppb = parts per billion
All test results
Date | Lab ID | Result |
---|---|---|
2014-02-12 | 3761-801-1021 | ND |
2014-02-12 | 3761-802-1002 | ND |
2014-02-12 | 3761-803-0912 | 11.0 ppb |
2014-02-12 | 3761-804-0924 | 9.40 ppb |
2014-02-12 | 3761-805-0945 | 6.50 ppb |
2014-02-12 | 3761-806-0936 | 9.40 ppb |
2014-02-12 | 3761-807-0900 | 10.2 ppb |
2014-02-12 | 3761-808-1040 | ND |
2014-03-12 | 4417-034-1155 | ND |
2014-03-13 | 4417-004-0900 | ND |
2014-03-13 | 4417-005-0915 | ND |
2014-03-13 | 4417-009-1230 | ND |
2014-03-13 | 4417-015-1205 | ND |
2014-03-13 | 4417-016-0830 | ND |
2014-03-13 | 4417-018-1000 | ND |
2014-03-13 | 4417-019-1130 | ND |
2014-03-13 | 4417-020-1035 | ND |
2014-03-13 | 4417-021-1115 | ND |
2014-03-13 | 4417-022-1050 | ND |
2014-03-13 | 4417-023-0930 | ND |
2014-03-24 | 4417-003-0925 | ND |
2014-05-13 | 4417-003-0840 | ND |
2014-05-13 | 4417-020-1150 | ND |
2014-05-14 | 4417-015-1255 | ND |
2014-05-14 | 4417-034-0930 | ND |
2014-08-13 | 3761-801-0907 | 8.50 ppb |
2014-08-13 | 3761-802-0853 | 4.90 ppb |
2014-08-13 | 3761-803-0801 | 10.5 ppb |
2014-08-13 | 3761-804-0811 | 12.3 ppb |
2014-08-13 | 3761-805-0838 | 9.90 ppb |
2014-08-13 | 3761-806-0822 | 8.30 ppb |
2014-08-13 | 3761-807-0748 | 13.7 ppb |
2014-08-13 | 3761-808-0920 | 1.30 ppb |
2014-08-27 | 4417-008-1050 | ND |
2014-08-27 | 4417-015-1110 | ND |
2014-08-27 | 4417-020-0950 | ND |
2014-08-27 | 4417-034-0830 | ND |
2014-09-24 | 4417-003-0905 | ND |
2014-10-13 | 4417-003-0820 | ND |
2014-10-13 | 4417-015-1230 | ND |
2014-10-13 | 4417-034-0930 | ND |
2014-10-14 | 4417-020-0935 | ND |
2014-11-19 | 4417-020-1100 | ND |
2014-11-19 | 4417-020-1110 | ND |
2015-02-05 | 3761-801-1037 | 2.10 ppb |
2015-02-05 | 3761-802-1112 | 2.20 ppb |
2015-02-05 | 3761-803-0937 | 10.5 ppb |
2015-02-05 | 3761-804-0945 | 10.00 ppb |
2015-02-05 | 3761-805-1011 | 7.90 ppb |
2015-02-05 | 3761-806-0956 | 11.6 ppb |
2015-02-05 | 3761-807-0921 | 11.1 ppb |
2015-02-05 | 3761-808-1056 | ND |
2015-02-25 | 4417-003-1015 | ND |
2015-02-25 | 4417-005-0840 | ND |
2015-02-25 | 4417-008-1235 | ND |
2015-02-25 | 4417-009-1210 | ND |
2015-02-25 | 4417-016-0925 | ND |
2015-02-25 | 4417-018-0955 | ND |
2015-02-25 | 4417-019-1145 | ND |
2015-02-25 | 4417-021-1110 | ND |
2015-02-25 | 4417-022-1050 | ND |
2015-02-25 | 4417-023-0855 | ND |
2015-03-25 | 4417-017-1110 | ND |
2015-04-28 | 4417-003-0835 | ND |
2015-04-28 | 4417-008-1105 | ND |
2015-04-28 | 4417-015-1025 | ND |
2015-04-28 | 4417-016-0930 | ND |
2015-05-20 | 3761-801-0945 | ND |
2015-05-20 | 3761-802-0933 | ND |
2015-05-20 | 3761-803-0833 | 14.6 ppb |
2015-05-20 | 3761-804-0840 | 13.9 ppb |
2015-05-20 | 3761-805-0918 | 10.5 ppb |
2015-05-20 | 3761-806-0904 | 14.1 ppb |
2015-05-20 | 3761-807-0820 | 11.5 ppb |
2015-05-20 | 3761-808-1003 | ND |
2015-06-17 | 4417-034-1100 | ND |
2015-08-13 | 3761-801-1120 | 5.20 ppb |
2015-08-13 | 3761-802-1100 | 8.10 ppb |
2015-08-13 | 3761-803-1011 | 13.7 ppb |
2015-08-13 | 3761-804-1020 | 17.7 ppb |
2015-08-13 | 3761-805-1050 | 12.4 ppb |
2015-08-13 | 3761-806-1031 | 17.9 ppb |
2015-08-13 | 3761-807-0958 | 13.6 ppb |
2015-08-13 | 3761-808-1130 | ND |
2015-09-01 | 4417-003-1110 | ND |
2015-09-28 | 4417-020-1000 | ND |
2015-11-18 | 3761-801-1102 | ND |
2015-11-18 | 3761-802-1050 | 2.00 ppb |
2015-11-18 | 3761-803-1009 | 3.80 ppb |
2015-11-18 | 3761-804-1018 | 4.20 ppb |
2015-11-18 | 3761-805-1038 | 7.50 ppb |
2015-11-18 | 3761-806-1027 | 4.20 ppb |
2015-11-18 | 3761-807-0958 | 4.80 ppb |
2015-11-18 | 3761-808-1112 | ND |
2015-12-01 | 4417-003-0815 | ND |
2016-01-19 | 4417-016-0910 | ND |
2016-01-19 | 4417-021-0945 | ND |
2016-01-26 | 4417-003-0950 | ND |
2016-01-26 | 4417-009-0925 | ND |
2016-01-26 | 4417-017-1145 | ND |
2016-01-26 | 4417-018-1030 | ND |
2016-01-26 | 4417-019-1220 | ND |
2016-01-26 | 4417-023-1055 | ND |
2016-01-26 | 4417-034-1010 | ND |
2016-02-18 | 3761-801-0930 | ND |
2016-02-18 | 3761-802-0913 | 1.30 ppb |
2016-02-18 | 3761-803-0822 | ND |
2016-02-18 | 3761-804-0833 | ND |
2016-02-18 | 3761-805-0858 | ND |
2016-02-18 | 3761-806-0844 | ND |
2016-02-18 | 3761-807-0812 | 6.10 ppb |
2016-02-18 | 3761-808-0942 | ND |
2016-04-14 | 4417-003-1150 | ND |
2016-04-14 | 4417-015-1110 | ND |
2016-04-14 | 4417-020-1040 | ND |
2016-04-25 | 4417-003-1320 | ND |
2016-04-25 | 4417-008-1405 | ND |
2016-04-25 | 4417-015-1345 | ND |
2016-04-25 | 4417-016-1045 | ND |
2016-04-25 | 4417-034-1000 | ND |
2016-05-18 | 3761-801-1042 | ND |
2016-05-18 | 3761-802-1029 | ND |
2016-05-18 | 3761-803-0922 | 4.20 ppb |
2016-05-18 | 3761-804-0929 | 4.40 ppb |
2016-05-18 | 3761-805-1018 | 1.10 ppb |
2016-05-18 | 3761-806-1000 | 3.90 ppb |
2016-05-18 | 3761-807-0914 | 10.8 ppb |
2016-05-18 | 3761-808-1051 | ND |
2016-06-21 | 4417-008-1035 | ND |
2016-07-13 | 4417-008-1115 | ND |
2016-07-14 | 4417-003-1120 | ND |
2016-07-27 | 4417-049-0850 | ND |
2016-08-17 | 3761-801-0916 | 3.50 ppb |
2016-08-17 | 3761-802-0903 | 1.70 ppb |
2016-08-17 | 3761-803-0802 | 5.30 ppb |
2016-08-17 | 3761-804-0810 | 5.00 ppb |
2016-08-17 | 3761-805-0837 | 4.40 ppb |
2016-08-17 | 3761-806-0822 | 4.90 ppb |
2016-08-17 | 3761-807-0750 | 5.90 ppb |
2016-08-17 | 3761-808-0927 | 1.40 ppb |
2016-10-06 | 4417-049-1030 | ND |
2016-10-18 | 4417-003-1030 | ND |
2016-11-16 | 3761-801-0956 | ND |
2016-11-16 | 3761-802-0946 | ND |
2016-11-16 | 3761-803-0901 | 1.70 ppb |
2016-11-16 | 3761-804-0910 | 1.60 ppb |
2016-11-16 | 3761-805-0932 | 1.40 ppb |
2016-11-16 | 3761-806-0922 | 1.40 ppb |
2016-11-16 | 3761-807-0850 | 2.70 ppb |
2016-11-16 | 3761-808-1008 | ND |
2016-12-13 | 4417-022-1015 | ND |
2017-01-11 | 4417-009-1130 | ND |
2017-01-11 | 4417-017-1145 | ND |
2017-01-11 | 4417-018-0840 | ND |
2017-01-11 | 4417-019-1110 | ND |
2017-01-11 | 4417-021-1050 | ND |
2017-01-11 | 4417-022-1020 | ND |
2017-01-11 | 4417-023-1000 | ND |
2017-01-11 | 4417-049-0920 | ND |
2017-01-16 | 4417-003-1120 | ND |
2017-01-16 | 4417-008-1050 | ND |
2017-01-16 | 4417-020-1005 | ND |
2017-02-15 | 3761-801-1009 | 3.00 ppb |
2017-02-15 | 3761-802-0958 | 2.10 ppb |
2017-02-15 | 3761-803-0920 | 1.10 ppb |
2017-02-15 | 3761-804-0926 | ND |
2017-02-15 | 3761-805-0947 | 2.30 ppb |
2017-02-15 | 3761-806-0936 | ND |
2017-02-15 | 3761-807-0911 | 3.90 ppb |
2017-02-15 | 3761-808-1035 | ND |
2017-04-05 | 4417-049-0950 | ND |
2017-04-25 | 4417-016-0840 | ND |
2017-05-10 | 3761-801-0924 | 1.70 ppb |
2017-05-10 | 3761-802-0912 | ND |
2017-05-10 | 3761-803-0808 | ND |
2017-05-10 | 3761-804-0818 | ND |
2017-05-10 | 3761-805-0900 | ND |
2017-05-10 | 3761-806-0830 | ND |
2017-05-10 | 3761-807-0759 | 5.20 ppb |
2017-05-10 | 3761-808-0939 | 1.10 ppb |
2017-05-18 | 4417-016-0855 | ND |
2017-05-18 | 4417-034-0820 | ND |
2017-08-17 | 3761-801-1010 | 5.20 ppb |
2017-08-17 | 3761-802-1000 | 4.00 ppb |
2017-08-17 | 3761-803-0925 | 5.10 ppb |
2017-08-17 | 3761-804-0932 | 5.00 ppb |
2017-08-17 | 3761-805-0950 | 5.60 ppb |
2017-08-17 | 3761-806-0939 | 4.10 ppb |
2017-08-17 | 3761-807-0915 | 8.60 ppb |
2017-08-17 | 3761-808-1020 | 3.90 ppb |
2017-11-29 | 3761-801-1004 | 3.10 ppb |
2017-11-29 | 3761-802-0952 | 9.40 ppb |
2017-11-29 | 3761-803-0909 | 2.80 ppb |
2017-11-29 | 3761-804-0916 | 2.70 ppb |
2017-11-29 | 3761-805-0941 | 3.70 ppb |
2017-11-29 | 3761-806-0927 | 2.80 ppb |
2017-11-29 | 3761-807-0855 | 5.10 ppb |
2017-11-29 | 3761-808-1015 | 1.80 ppb |
2018-02-15 | 3761-801-0957 | 2.30 ppb |
2018-02-15 | 3761-802-0946 | 2.10 ppb |
2018-02-15 | 3761-803-0904 | 2.70 ppb |
2018-02-15 | 3761-804-0911 | 2.50 ppb |
2018-02-15 | 3761-805-0934 | 2.70 ppb |
2018-02-15 | 3761-806-0922 | 2.50 ppb |
2018-02-15 | 3761-807-0850 | 5.40 ppb |
2018-02-15 | 3761-808-1005 | 1.70 ppb |
2018-03-06 | 4417-008-1245 | ND |
2018-03-06 | 4417-009-1220 | ND |
2018-03-06 | 4417-017-1115 | ND |
2018-03-06 | 4417-018-0840 | ND |
2018-03-06 | 4417-019-1135 | ND |
2018-03-06 | 4417-020-1015 | ND |
2018-03-06 | 4417-021-1055 | ND |
2018-03-06 | 4417-022-1040 | ND |
2018-03-06 | 4417-023-0950 | ND |
2018-05-09 | 4417-016-1005 | ND |
2018-05-09 | 4417-034-0910 | ND |
2018-05-09 | 4417-049-1050 | ND |
2018-05-16 | 3761-801-0940 | 2.40 ppb |
2018-05-16 | 3761-802-0927 | ND |
2018-05-16 | 3761-803-0852 | 4.20 ppb |
2018-05-16 | 3761-804-0857 | 1.000 ppb |
2018-05-16 | 3761-805-0918 | 1.40 ppb |
2018-05-16 | 3761-806-0904 | ND |
2018-05-16 | 3761-807-0844 | 5.80 ppb |
2018-05-16 | 3761-808-0948 | 2.00 ppb |
2018-08-15 | 3761-801-0949 | 5.30 ppb |
2018-08-15 | 3761-802-0940 | 3.70 ppb |
2018-08-15 | 3761-803-0902 | 5.60 ppb |
2018-08-15 | 3761-804-0911 | 5.20 ppb |
2018-08-15 | 3761-805-0929 | 4.90 ppb |
2018-08-15 | 3761-806-0915 | 5.70 ppb |
2018-08-15 | 3761-807-0854 | 5.70 ppb |
2018-08-15 | 3761-808-0958 | 4.10 ppb |
2018-11-15 | 3761-801-1114 | 3.00 ppb |
2018-11-15 | 3761-802-1105 | 1.30 ppb |
2018-11-15 | 3761-803-1034 | 3.50 ppb |
2018-11-15 | 3761-804-1039 | 3.60 ppb |
2018-11-15 | 3761-805-1054 | 1.40 ppb |
2018-11-15 | 3761-806-1045 | 3.50 ppb |
2018-11-15 | 3761-807-1027 | 4.10 ppb |
2018-11-15 | 3761-808-1122 | ND |
2019-01-14 | 4417-008-1035 | ND |
2019-01-14 | 4417-009-0950 | ND |
2019-01-14 | 4417-019-0915 | ND |
2019-01-14 | 4417-023-0840 | ND |
2019-02-20 | 3761-801-1040 | ND |
2019-02-20 | 3761-802-1031 | 1.40 ppb |
2019-02-20 | 3761-803-0958 | 2.10 ppb |
2019-02-20 | 3761-804-1003 | ND |
2019-02-20 | 3761-805-1020 | 1.60 ppb |
2019-02-20 | 3761-806-1011 | ND |
2019-02-20 | 3761-807-0951 | 3.70 ppb |
2019-02-20 | 3761-808-1047 | 1.40 ppb |
2019-04-22 | 4417-016-0910 | ND |
2019-04-22 | 4417-021-1010 | ND |
2019-04-22 | 4417-034-1200 | ND |
2019-04-22 | 4417-049-0935 | ND |
2019-04-23 | 4417-017-1135 | ND |
2019-05-15 | 4417-017-1030 | ND |
2019-05-15 | 4417-022-1145 | ND |
2019-05-15 | 3761-801-1009 | 1.10 ppb |
2019-05-15 | 3761-802-1000 | ND |
2019-05-15 | 3761-803-0928 | 3.90 ppb |
2019-05-15 | 3761-804-0934 | 3.80 ppb |
2019-05-15 | 3761-805-0951 | 3.50 ppb |
2019-05-15 | 3761-806-0941 | 3.60 ppb |
2019-05-15 | 3761-807-0917 | 8.40 ppb |
2019-05-15 | 3761-808-1016 | ND |
2019-06-18 | 4417-020-0940 | ND |
2019-08-14 | 3761-801-1010 | ND |
2019-08-14 | 3761-802-1001 | 1.40 ppb |
2019-08-14 | 3761-803-0925 | 5.50 ppb |
2019-08-14 | 3761-804-0932 | 4.60 ppb |
2019-08-14 | 3761-805-0949 | 4.40 ppb |
2019-08-14 | 3761-806-0940 | 3.60 ppb |
2019-08-14 | 3761-807-0917 | 6.10 ppb |
2019-08-14 | 3761-808-1017 | ND |
2019-11-05 | 4417-018-1135 | ND |
2019-11-22 | 3761-801-0926 | 2.50 ppb |
2019-11-22 | 3761-802-0917 | 1.60 ppb |
2019-11-22 | 3761-803-0844 | 3.40 ppb |
2019-11-22 | 3761-804-0850 | 4.10 ppb |
2019-11-22 | 3761-805-0907 | 4.80 ppb |
2019-11-22 | 3761-806-0857 | ND |
2019-11-22 | 3761-807-0838 | 4.40 ppb |
2019-11-22 | 3761-808-0933 | 2.70 ppb |