Chloroform
CTWC - Shoreline Region-Guilford System
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 |
---|---|---|---|---|
2014 | 16.2 ppb | 29 | 21 | ND - 41.9 ppb |
2015 | 15.6 ppb | 28 | 22 | ND - 38.0 ppb |
2016 | 12.3 ppb | 27 | 22 | ND - 28.0 ppb |
2017 | 17.5 ppb | 26 | 22 | ND - 42.0 ppb |
2018 | 14.5 ppb | 27 | 23 | ND - 44.7 ppb |
2019 | 10.4 ppb | 26 | 21 | ND - 22.6 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 |
---|---|---|
2014-01-29 | 140130CWCBVOC1 | ND |
2014-02-24 | 2223VOC1 | ND |
2014-03-05 | 2672VOC1 | 0.600 ppb |
2014-03-21 | 3482THM | 11.9 ppb |
2014-03-21 | 3483THM | 13.7 ppb |
2014-03-21 | 3484THM | 19.0 ppb |
2014-03-21 | 3485THM | 25.9 ppb |
2014-04-21 | 5353VOC1 | 0.500 ppb |
2014-04-21 | 5354VOC1 | ND |
2014-06-12 | 8366VOC1 | ND |
2014-06-12 | 8367VOC1 | ND |
2014-06-12 | 8370VOC1 | 11.8 ppb |
2014-06-18 | 8760THM | 32.9 ppb |
2014-06-18 | 8761THM | 41.9 ppb |
2014-06-18 | 8764THM | 32.5 ppb |
2014-06-18 | 8765THM | 32.9 ppb |
2014-08-13 | 140915-0128VOC1 | 9.90 ppb |
2014-08-13 | 140915-0129VOC1 | ND |
2014-08-13 | BG93593VOC1 | 9.90 ppb |
2014-08-13 | BG93595VOC1 | ND |
2014-09-15 | BH14101TTHM | 21.0 ppb |
2014-09-15 | BH14102TTHM | 26.0 ppb |
2014-09-15 | BH14103TTHM | 25.0 ppb |
2014-09-15 | BH14104TTHM | 33.0 ppb |
2014-11-03 | BH35439VOC1 | ND |
2014-12-17 | BH54708TTHM | 20.0 ppb |
2014-12-17 | BH54709TTHM | 32.0 ppb |
2014-12-17 | BH54710TTHM | 35.0 ppb |
2014-12-17 | BH54711TTHM | 34.0 ppb |
2015-01-21 | BH65787VOC1 | 7.80 ppb |
2015-02-12 | BH73177VOC1 | 5.50 ppb |
2015-03-09 | BH80664VOC1 | ND |
2015-03-11 | BH82211TTHM | 17.0 ppb |
2015-03-11 | BH82210TTHM | 14.0 ppb |
2015-03-11 | BH82209TTHM | 12.0 ppb |
2015-03-11 | BH82212TTHM | 16.0 ppb |
2015-06-02 | BJ24597VOC1 | 7.90 ppb |
2015-06-02 | BJ24602VOC1 | ND |
2015-06-02 | BJ24619VOC1 | ND |
2015-06-02 | BJ24617VOC1 | ND |
2015-06-03 | BJ25404VOC1 | 1.30 ppb |
2015-06-16 | BJ31718TTHM | 34.0 ppb |
2015-06-16 | BJ31715TTHM | 23.0 ppb |
2015-06-16 | BJ31716TTHM | 32.0 ppb |
2015-06-16 | BJ31717TTHM | 30.0 ppb |
2015-07-27 | BJ63977VOC1 | 6.00 ppb |
2015-07-27 | BJ63961VOC1 | ND |
2015-09-15 | BJ92119TTHM | 24.0 ppb |
2015-09-15 | BJ92122TTHM | 38.0 ppb |
2015-09-15 | BJ92121TTHM | 34.0 ppb |
2015-09-15 | BJ92120TTHM | 33.0 ppb |
2015-10-19 | BK10284VOC1 | ND |
2015-11-03 | BK17717VOC1 | 8.20 ppb |
2015-12-08 | BK34312TTHM | 24.0 ppb |
2015-12-08 | BK34311TTHM | 25.0 ppb |
2015-12-08 | BK34309TTHM | 19.0 ppb |
2015-12-08 | BK34310TTHM | 26.0 ppb |
2016-01-11 | BK50864VOC1 | ND |
2016-01-19 | BK54776VOC1 | 1.000 ppb |
2016-01-19 | BK54777VOC1 | 2.60 ppb |
2016-02-11 | BK64351VOC1 | 6.00 ppb |
2016-03-14 | BK78125VOC1 | 8.50 ppb |
2016-03-15 | BK78696TTHM | 21.0 ppb |
2016-03-15 | BK78697TTHM | 19.0 ppb |
2016-03-15 | BK78692TTHM | 17.0 ppb |
2016-03-15 | BK78693TTHM | 14.0 ppb |
2016-04-11 | BN11374VOC1 | 11.0 ppb |
2016-04-11 | BN11376VOC1 | ND |
2016-06-01 | BN44892VOC1 | ND |
2016-06-01 | BN44876VOC1 | ND |
2016-06-14 | BN54616TTHM | 14.0 ppb |
2016-06-14 | BN54617TTHM | 12.0 ppb |
2016-06-14 | BN54618TTHM | 17.0 ppb |
2016-06-14 | BN54619TTHM | 15.0 ppb |
2016-07-12 | BN71476VOC1 | ND |
2016-07-13 | BN72282VOC1 | 8.30 ppb |
2016-09-14 | BV14928TTHM | 27.0 ppb |
2016-09-14 | BV14929TTHM | 24.0 ppb |
2016-09-14 | BV14930TTHM | 17.0 ppb |
2016-09-14 | BV14931TTHM | 28.0 ppb |
2016-12-15 | BX06134TTHM | 23.0 ppb |
2016-12-15 | BX06135TTHM | 21.0 ppb |
2016-12-15 | BX06136TTHM | 5.70 ppb |
2016-12-15 | BX06137TTHM | 21.0 ppb |
2017-01-17 | BX30298VOC1 | 7.60 ppb |
2017-01-17 | BX30299VOC1 | ND |
2017-01-18 | BX31348VOC1 | 9.30 ppb |
2017-01-30 | BX40966VOC1 | ND |
2017-03-08 | BX82062VOC1 | ND |
2017-03-17 | BX89076TTHM | 17.0 ppb |
2017-03-17 | BX89077TTHM | 16.0 ppb |
2017-03-17 | BX89078TTHM | 14.0 ppb |
2017-03-17 | BX89073TTHM | 12.0 ppb |
2017-06-19 | BY42240TTHM | 25.0 ppb |
2017-06-19 | BY42241TTHM | 42.0 ppb |
2017-06-19 | BY42242TTHM | 35.0 ppb |
2017-06-19 | BY42243TTHM | 31.0 ppb |
2017-06-29 | BY50637VOC1 | 10.00 ppb |
2017-09-14 | BZ02387TTHM | 22.0 ppb |
2017-09-14 | BZ02388TTHM | 34.0 ppb |
2017-09-14 | BZ02389TTHM | 32.0 ppb |
2017-09-14 | BZ02390TTHM | 28.0 ppb |
2017-09-25 | BZ09163VOC1 | 8.40 ppb |
2017-10-24 | BZ27135VOC1 | ND |
2017-10-25 | BZ27134VOC1 | 1.50 ppb |
2017-11-09 | BZ38785VOC1 | 9.80 ppb |
2017-12-14 | BZ60231TTHM | 31.0 ppb |
2017-12-14 | BZ60232TTHM | 29.0 ppb |
2017-12-14 | BZ60233TTHM | 18.0 ppb |
2017-12-14 | BZ60234TTHM | 23.0 ppb |
2018-01-16 | BZ73485VOC1 | 6.80 ppb |
2018-03-15 | CA03073TTHM | 17.0 ppb |
2018-03-15 | CA03074TTHM | 13.0 ppb |
2018-03-15 | CA03075TTHM | 19.0 ppb |
2018-03-15 | CA03076TTHM | 20.0 ppb |
2018-03-30 | CA11464VOC1 | 9.40 ppb |
2018-04-11 | CA18261VOC1 | 7.00 ppb |
2018-06-26 | CA80045TTHM | 31.0 ppb |
2018-06-26 | CA80046TTHM | 28.0 ppb |
2018-06-26 | CA80047TTHM | 23.0 ppb |
2018-06-26 | CA80048TTHM | 19.0 ppb |
2018-07-09 | CA85598VOC1 | ND |
2018-07-17 | CA91979 | 8.40 ppb |
2018-09-12 | DBP 200505042 | 24.8 ppb |
2018-09-12 | DBP 200505043 | 44.7 ppb |
2018-09-12 | DBP 200505044 | 38.2 ppb |
2018-09-12 | DBP 200505047 | 43.7 ppb |
2018-09-13 | VOC1 200505275 | ND |
2018-09-13 | VOC1 200505276 | ND |
2018-09-13 | VOC1 200505266 | ND |
2018-09-19 | VOC1 200506116 | 1.000 ppb |
2018-09-20 | VOC1 200506324 | 0.600 ppb |
2018-10-25 | VOC1 200510568 | 12.3 ppb |
2018-12-17 | DBP 200516235 | 5.50 ppb |
2018-12-17 | DBP 200516237 | 3.70 ppb |
2018-12-17 | DBP 200516238 | 7.40 ppb |
2018-12-17 | DBP 200516239 | 8.70 ppb |
2019-01-30 | VOC1 200520057 | 4.00 ppb |
2019-03-11 | DBP 200524150 | 4.90 ppb |
2019-03-11 | DBP 200524151 | 7.40 ppb |
2019-03-11 | DBP 200524152 | 10.6 ppb |
2019-03-11 | DBP 200524154 | 11.2 ppb |
2019-06-14 | DBP 200536672 | 9.70 ppb |
2019-06-14 | DBP 200536674 | 13.3 ppb |
2019-06-14 | DBP 200536680 | 16.6 ppb |
2019-06-14 | DBP 200536682 | 16.4 ppb |
2019-06-24 | VOC1 200538005 | 7.40 ppb |
2019-07-08 | VOC1 200541172 | 7.30 ppb |
2019-07-08 | VOC1 200539194 | ND |
2019-07-16 | VOC1 200541091 | ND |
2019-07-16 | VOC1 200540648 | 0.800 ppb |
2019-07-16 | VOC1 200540644 | ND |
2019-09-17 | DBP 200549478 | 17.3 ppb |
2019-09-17 | DBP 200549479 | 19.6 ppb |
2019-09-17 | DBP 200549480 | 20.9 ppb |
2019-09-17 | DBP 200549481 | 21.6 ppb |
2019-09-17 | VOC1 200549238 | ND |
2019-09-18 | VOC1 200549465 | ND |
2019-12-10 | DBP 200559642 | 9.70 ppb |
2019-12-10 | DBP 200559643 | 16.1 ppb |
2019-12-10 | DBP 200559644 | 19.6 ppb |
2019-12-10 | DBP 200559645 | 22.6 ppb |
2019-12-10 | VOC1 200559663 | 13.2 ppb |