Chloroform
Metropolitan District Commission
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 | 40.1 ppb | 51 | 51 | 13.4 ppb - 68.5 ppb |
2015 | 30.7 ppb | 51 | 51 | 11.6 ppb - 53.7 ppb |
2016 | 26.5 ppb | 51 | 51 | 11.6 ppb - 55.8 ppb |
2017 | 31.7 ppb | 51 | 51 | 11.8 ppb - 64.4 ppb |
2018 | 40.6 ppb | 51 | 51 | 14.3 ppb - 83.1 ppb |
2019 | 41.5 ppb | 51 | 51 | 13.2 ppb - 78.7 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 |
---|---|---|
2014-03-03 | BG16768TTHM | 44.0 ppb |
2014-03-03 | BG16770TTHM | 31.0 ppb |
2014-03-04 | BG16773TTHM | 32.0 ppb |
2014-03-04 | BG16775TTHM | 40.0 ppb |
2014-03-05 | BG16778TTHM | 40.0 ppb |
2014-03-05 | BG16780TTHM | 43.0 ppb |
2014-03-05 | BG16782TTHM | 32.0 ppb |
2014-03-05 | BG16784TTHM | 50.0 ppb |
2014-03-06 | BG16787TTHM | 16.0 ppb |
2014-03-06 | BG16789TTHM | 30.0 ppb |
2014-03-07 | BG16792TTHM | 31.0 ppb |
2014-03-07 | BG16794TTHM | 55.0 ppb |
2014-06-09 | AC67729GE | 66.4 ppb |
2014-06-09 | AC67730GE | 68.5 ppb |
2014-06-09 | AC67731GE | 48.1 ppb |
2014-06-09 | AC67732GE | 30.9 ppb |
2014-06-09 | AC67733GE | 49.7 ppb |
2014-06-09 | AC67734GE | 36.0 ppb |
2014-06-09 | AC67735GE | 51.1 ppb |
2014-06-09 | AC67736GE | 33.5 ppb |
2014-06-09 | AC67737GE | 40.5 ppb |
2014-06-09 | AC67738GE | 40.7 ppb |
2014-06-09 | AC67739GE | 16.4 ppb |
2014-06-09 | AC67740GE | 40.2 ppb |
2014-07-18 | AC71437GE | 23.3 ppb |
2014-07-18 | AC71438GE | 23.9 ppb |
2014-07-21 | AC71441GE | 14.9 ppb |
2014-09-08 | AC77253GE | 59.3 ppb |
2014-09-08 | AC77257GE | 23.1 ppb |
2014-09-09 | AC77256GE | 44.3 ppb |
2014-09-09 | AC77258GE | 38.4 ppb |
2014-09-09 | AC77263GE | 63.1 ppb |
2014-09-10 | AC77249GE | 67.4 ppb |
2014-09-10 | AC77254GE | 42.3 ppb |
2014-09-10 | AC77255GE | 62.4 ppb |
2014-09-11 | AC77259GE | 19.3 ppb |
2014-09-11 | AC77260GE | 49.1 ppb |
2014-09-12 | AC77250GE | 64.3 ppb |
2014-09-12 | AC77251GE | 59.0 ppb |
2014-12-01 | AC84506GE | 36.8 ppb |
2014-12-01 | AC84510GE | 43.5 ppb |
2014-12-02 | AC84505GE | 57.7 ppb |
2014-12-02 | AC84509GE | 30.3 ppb |
2014-12-02 | AC84511GE | 30.3 ppb |
2014-12-02 | AC84512GE | 13.4 ppb |
2014-12-03 | AC84502GE | 46.8 ppb |
2014-12-03 | AC84503GE | 36.1 ppb |
2014-12-03 | AC84507GE | 28.2 ppb |
2014-12-03 | AC84508GE | 38.1 ppb |
2014-12-04 | AC84513GE | 38.9 ppb |
2014-12-05 | AC84504GE | 25.7 ppb |
2015-03-09 | BH83412TTHM | 41.0 ppb |
2015-03-09 | BH83411TTHM | 32.0 ppb |
2015-03-10 | BH83415TTHM | 30.0 ppb |
2015-03-10 | BH83416TTHM | 46.0 ppb |
2015-03-10 | BH83414TTHM | 19.0 ppb |
2015-03-11 | BH83420TTHM | 25.0 ppb |
2015-03-11 | BH83421TTHM | 42.0 ppb |
2015-03-11 | BH83418TTHM | 37.0 ppb |
2015-03-11 | BH83419TTHM | 36.0 ppb |
2015-03-12 | BH83424TTHM | 25.0 ppb |
2015-03-12 | BH83423TTHM | 13.0 ppb |
2015-03-13 | BH83426TTHM | 20.0 ppb |
2015-06-01 | AC99948GE | 39.4 ppb |
2015-06-01 | AC99952GE | 27.9 ppb |
2015-06-02 | AC99951GE | 25.2 ppb |
2015-06-02 | AC99953GE | 32.6 ppb |
2015-06-02 | AC99947GE | 46.3 ppb |
2015-06-03 | AC99944GE | 53.7 ppb |
2015-06-03 | AC99949GE | 31.9 ppb |
2015-06-03 | AC99950GE | 48.7 ppb |
2015-06-04 | AC99955GE | 38.8 ppb |
2015-06-04 | AC99945GE | 42.0 ppb |
2015-06-04 | AC99954GE | 17.3 ppb |
2015-06-05 | AC99946GE | 22.4 ppb |
2015-06-08 | AC99641GE | 19.3 ppb |
2015-06-08 | AC99645GE | 11.6 ppb |
2015-06-08 | AC99642GE | 16.9 ppb |
2015-09-08 | AD08699GE | 37.7 ppb |
2015-09-08 | AD08704GE | 30.8 ppb |
2015-09-08 | AD08702GE | 32.5 ppb |
2015-09-08 | AD08698GE | 38.5 ppb |
2015-09-09 | AD08695GE | 48.1 ppb |
2015-09-09 | AD08696GE | 43.3 ppb |
2015-09-09 | AD08700GE | 31.1 ppb |
2015-09-09 | AD08701GE | 44.5 ppb |
2015-09-10 | AD08706GE | 39.7 ppb |
2015-09-10 | AD08705GE | 16.2 ppb |
2015-09-11 | AD08703GE | 27.2 ppb |
2015-09-11 | AD08697GE | 29.1 ppb |
2015-11-30 | AD16144GE | 33.9 ppb |
2015-11-30 | AD16140GE | 24.1 ppb |
2015-12-01 | AD16143GE | 15.7 ppb |
2015-12-01 | AD16145GE | 21.0 ppb |
2015-12-01 | AD16139GE | 39.8 ppb |
2015-12-02 | AD16136GE | 33.3 ppb |
2015-12-02 | AD16142GE | 29.7 ppb |
2015-12-02 | AD16137GE | 25.8 ppb |
2015-12-02 | AD16141GE | 18.7 ppb |
2015-12-04 | AD16147GE | 33.8 ppb |
2015-12-04 | AD16146GE | 13.9 ppb |
2015-12-05 | AD16138GE | 15.1 ppb |
2016-02-29 | AD24009GE | 37.7 ppb |
2016-02-29 | AD24010GE | 29.5 ppb |
2016-02-29 | AD24014GE | 35.7 ppb |
2016-02-29 | AD24015GE | 26.7 ppb |
2016-03-01 | AD24013GE | 23.8 ppb |
2016-03-01 | AD24016GE | 11.6 ppb |
2016-03-02 | AD24006GE | 34.1 ppb |
2016-03-02 | AD24007GE | 29.4 ppb |
2016-03-02 | AD24011GE | 26.6 ppb |
2016-03-02 | AD24012GE | 31.7 ppb |
2016-03-03 | AD24017GE | 26.7 ppb |
2016-03-04 | AD24008GE | 21.2 ppb |
2016-05-30 | AD32107GE | 25.9 ppb |
2016-05-30 | AD32112GE | 26.4 ppb |
2016-05-31 | AD32110GE | 21.8 ppb |
2016-05-31 | AD32111GE | 28.3 ppb |
2016-05-31 | AD32106GE | 31.4 ppb |
2016-06-01 | AD32108GE | 22.7 ppb |
2016-06-01 | AD32109GE | 33.5 ppb |
2016-06-01 | AD32103GE | 42.2 ppb |
2016-06-01 | AD32104GE | 28.3 ppb |
2016-06-02 | AD32113GE | 13.5 ppb |
2016-06-02 | AD32114GE | 28.4 ppb |
2016-06-03 | AD32105GE | 22.1 ppb |
2016-06-15 | AD32724GE | 20.3 ppb |
2016-06-15 | AD32723GE | 14.2 ppb |
2016-06-16 | AD32722GE | 11.7 ppb |
2016-09-12 | AD41850GE | 26.0 ppb |
2016-09-12 | AD41846GE | 37.5 ppb |
2016-09-13 | AD41849GE | 26.4 ppb |
2016-09-13 | AD41851GE | 27.4 ppb |
2016-09-13 | AD41845GE | 55.8 ppb |
2016-09-14 | AD41842GE | 43.1 ppb |
2016-09-14 | AD41843GE | 39.5 ppb |
2016-09-14 | AD41847GE | 24.7 ppb |
2016-09-14 | AD41848GE | 33.5 ppb |
2016-09-15 | AD41852GE | 21.6 ppb |
2016-09-15 | AD41853GE | 34.9 ppb |
2016-09-16 | AD41844GE | 19.7 ppb |
2016-12-05 | AD49844GE | 19.8 ppb |
2016-12-05 | AD49848GE | 22.6 ppb |
2016-12-06 | AD49849GE | 17.4 ppb |
2016-12-06 | AD49843GE | 35.6 ppb |
2016-12-06 | AD49847GE | 14.6 ppb |
2016-12-07 | AD49845GE | 19.9 ppb |
2016-12-07 | AD49846GE | 23.5 ppb |
2016-12-07 | AD49840GE | 26.7 ppb |
2016-12-07 | AD49841GE | 20.3 ppb |
2016-12-08 | AD49850GE | 13.8 ppb |
2016-12-09 | AD49842GE | 13.1 ppb |
2016-12-09 | AD49851GE | 26.8 ppb |
2017-03-06 | AD57222GE | 24.8 ppb |
2017-03-06 | AD57226GE | 21.0 ppb |
2017-03-07 | AD57227GE | 23.0 ppb |
2017-03-07 | AD57221GE | 35.9 ppb |
2017-03-07 | AD57225GE | 17.8 ppb |
2017-03-08 | AD57223GE | 25.0 ppb |
2017-03-08 | AD57224GE | 27.8 ppb |
2017-03-08 | AD57218GE | 27.9 ppb |
2017-03-08 | AD57219GE | 24.1 ppb |
2017-03-09 | AD57228GE | 12.7 ppb |
2017-03-09 | AD57229GE | 23.7 ppb |
2017-03-10 | AD57220GE | 15.2 ppb |
2017-06-12 | AD65857GE | 37.0 ppb |
2017-06-12 | AD65861GE | 26.6 ppb |
2017-06-13 | AD65862GE | 28.7 ppb |
2017-06-13 | AD65856GE | 38.1 ppb |
2017-06-14 | AD65853GE | 40.9 ppb |
2017-06-14 | AD65854GE | 35.9 ppb |
2017-06-14 | AD65858GE | 25.7 ppb |
2017-06-14 | AD65859GE | 31.7 ppb |
2017-06-15 | AD65860GE | 27.3 ppb |
2017-06-15 | AD65863GE | 16.9 ppb |
2017-06-15 | AD65864GE | 31.6 ppb |
2017-06-16 | AD65855GE | 25.8 ppb |
2017-06-26 | AD66733GE | 17.1 ppb |
2017-06-26 | AD66734GE | 11.8 ppb |
2017-06-27 | AD66735GE | 14.2 ppb |
2017-09-12 | AD74745GE | 64.4 ppb |
2017-09-12 | AD74746GE | 48.9 ppb |
2017-09-12 | AD74749GE | 30.7 ppb |
2017-09-12 | AD74750GE | 40.6 ppb |
2017-09-12 | AD74751GE | 34.2 ppb |
2017-09-13 | AD74742GE | 43.8 ppb |
2017-09-13 | AD74743GE | 49.6 ppb |
2017-09-13 | AD74747GE | 34.6 ppb |
2017-09-13 | AD74748GE | 51.9 ppb |
2017-09-14 | AD74752GE | 17.5 ppb |
2017-09-14 | AD74753GE | 48.2 ppb |
2017-09-15 | AD74744GE | 28.6 ppb |
2017-12-04 | AD82362GE | 41.5 ppb |
2017-12-04 | AD82366GE | 27.8 ppb |
2017-12-05 | AD82367GE | 31.7 ppb |
2017-12-05 | AD82361GE | 54.6 ppb |
2017-12-05 | AD82365GE | 29.8 ppb |
2017-12-06 | AD82358GE | 48.3 ppb |
2017-12-06 | AD82359GE | 41.4 ppb |
2017-12-06 | AD82363GE | 36.3 ppb |
2017-12-06 | AD82364GE | 45.6 ppb |
2017-12-07 | AD82368GE | 12.3 ppb |
2017-12-07 | AD82369GE | 36.9 ppb |
2017-12-08 | AD82360GE | 28.8 ppb |
2018-03-05 | AD89784GE | 38.0 ppb |
2018-03-05 | AD89780GE | 38.1 ppb |
2018-03-06 | AD89781GE | 34.8 ppb |
2018-03-06 | AD89782GE | 39.2 ppb |
2018-03-06 | AD89783GE | 27.5 ppb |
2018-03-06 | AD89785GE | 32.5 ppb |
2018-03-06 | AD89776GE | 41.7 ppb |
2018-03-06 | AD89777GE | 38.4 ppb |
2018-03-06 | AD89779GE | 52.1 ppb |
2018-03-08 | AD89786GE | 15.7 ppb |
2018-03-08 | AD89787GE | 26.6 ppb |
2018-03-09 | AD89778GE | 26.6 ppb |
2018-06-11 | AD98391GE | 42.0 ppb |
2018-06-11 | AD98395GE | 31.8 ppb |
2018-06-12 | AD98396GE | 35.4 ppb |
2018-06-12 | AD98390GE | 61.8 ppb |
2018-06-12 | AD98394GE | 31.1 ppb |
2018-06-13 | AD98387GE | 54.7 ppb |
2018-06-13 | AD98388GE | 42.0 ppb |
2018-06-13 | AD98392GE | 32.3 ppb |
2018-06-13 | AD98393GE | 40.0 ppb |
2018-06-14 | AD98397GE | 18.1 ppb |
2018-06-14 | AD98398GE | 37.8 ppb |
2018-06-15 | AD98389GE | 28.0 ppb |
2018-07-16 | AE00911GE | 21.5 ppb |
2018-07-16 | AE00927GE | 14.3 ppb |
2018-07-16 | AE00912GE | 15.0 ppb |
2018-09-05 | AE06391GE | 56.2 ppb |
2018-09-05 | AE06392GE | 49.4 ppb |
2018-09-05 | AE06396GE | 36.9 ppb |
2018-09-05 | AE06397GE | 44.8 ppb |
2018-09-06 | AE06399GE | 40.1 ppb |
2018-09-06 | AE06400GE | 36.6 ppb |
2018-09-06 | AE06401GE | 20.7 ppb |
2018-09-06 | AE06402GE | 47.5 ppb |
2018-09-06 | AE06394GE | 50.7 ppb |
2018-09-07 | AE06395GE | 48.5 ppb |
2018-09-07 | AE06398GE | 40.8 ppb |
2018-09-07 | AE06393GE | 30.2 ppb |
2018-12-03 | AE14329GE | 83.1 ppb |
2018-12-03 | AE14330GE | 65.3 ppb |
2018-12-03 | AE14334GE | 40.7 ppb |
2018-12-04 | AE14333GE | 47.6 ppb |
2018-12-04 | AE14335GE | 56.0 ppb |
2018-12-05 | AE14326GE | 64.1 ppb |
2018-12-05 | AE14327GE | 61.6 ppb |
2018-12-05 | AE14331GE | 65.5 ppb |
2018-12-05 | AE14332GE | 63.3 ppb |
2018-12-06 | AE14336GE | 17.7 ppb |
2018-12-06 | AE14337GE | 45.0 ppb |
2018-12-07 | AE14328GE | 40.6 ppb |
2019-03-11 | AE22328GE | 36.7 ppb |
2019-03-11 | AE22324GE | 51.1 ppb |
2019-03-12 | AE22327GE | 39.3 ppb |
2019-03-12 | AE22329GE | 50.6 ppb |
2019-03-12 | AE22323GE | 61.0 ppb |
2019-03-13 | AE22320GE | 54.9 ppb |
2019-03-13 | AE22321GE | 50.8 ppb |
2019-03-13 | AE22325GE | 54.7 ppb |
2019-03-13 | AE22326GE | 51.6 ppb |
2019-03-14 | AE22330GE | 16.7 ppb |
2019-03-14 | AE22331GE | 29.3 ppb |
2019-03-15 | AE22322GE | 35.0 ppb |
2019-06-03 | AE30192GE | 52.9 ppb |
2019-06-03 | AE30196GE | 43.5 ppb |
2019-06-04 | AE30191GE | 78.7 ppb |
2019-06-04 | AE30195GE | 45.2 ppb |
2019-06-04 | AE30197GE | 46.6 ppb |
2019-06-05 | AE30193GE | 46.1 ppb |
2019-06-05 | AE30194GE | 53.5 ppb |
2019-06-05 | AE30188GE | 62.0 ppb |
2019-06-05 | AE30189GE | 57.8 ppb |
2019-06-05 | AE29314GE | 29.2 ppb |
2019-06-05 | AE29313GE | 16.4 ppb |
2019-06-05 | AE29315GE | 31.4 ppb |
2019-06-06 | AE30198GE | 23.2 ppb |
2019-06-06 | AE30199GE | 46.0 ppb |
2019-06-07 | AE30190GE | 34.2 ppb |
2019-09-09 | AE38255GE | 49.3 ppb |
2019-09-09 | AE38259GE | 34.2 ppb |
2019-09-10 | AE38260GE | 38.1 ppb |
2019-09-10 | AE38254GE | 49.8 ppb |
2019-09-10 | AE38258GE | 69.5 ppb |
2019-09-11 | AE38256GE | 39.1 ppb |
2019-09-11 | AE38257GE | 52.2 ppb |
2019-09-11 | AE38251GE | 56.8 ppb |
2019-09-11 | AE38252GE | 33.8 ppb |
2019-09-12 | AE38261GE | 23.5 ppb |
2019-09-12 | AE38262GE | 52.6 ppb |
2019-09-13 | AE38253GE | 33.4 ppb |
2019-12-02 | AE45714GE | 30.6 ppb |
2019-12-02 | AE45710GE | 33.0 ppb |
2019-12-03 | AE45709GE | 42.3 ppb |
2019-12-03 | AE45715GE | 29.0 ppb |
2019-12-03 | AE45713GE | 24.6 ppb |
2019-12-04 | AE45711GE | 34.3 ppb |
2019-12-04 | AE45712GE | 46.5 ppb |
2019-12-04 | AE45706GE | 39.3 ppb |
2019-12-04 | AE45707GE | 33.4 ppb |
2019-12-05 | AE45716GE | 13.2 ppb |
2019-12-05 | AE45717GE | 42.5 ppb |
2019-12-06 | AE45708GE | 19.4 ppb |