Menu

EWG's Tap Water Database — 2021 UPDATE

Donate

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.

Click here to read more about disinfection byproducts.

MORE ABOUT THIS CONTAMINANT

 

163

Samples

0

Samples exceeding legal limit (MCL)

131

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
201416.2 ppb2921ND - 41.9 ppb
201515.6 ppb2822ND - 38.0 ppb
201612.3 ppb2722ND - 28.0 ppb
201717.5 ppb2622ND - 42.0 ppb
201814.5 ppb2723ND - 44.7 ppb
201910.4 ppb2621ND - 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
2014-01-29140130CWCBVOC1ND
2014-02-242223VOC1ND
2014-03-052672VOC10.600 ppb
2014-03-213482THM11.9 ppb
2014-03-213483THM13.7 ppb
2014-03-213484THM19.0 ppb
2014-03-213485THM25.9 ppb
2014-04-215353VOC10.500 ppb
2014-04-215354VOC1ND
2014-06-128366VOC1ND
2014-06-128367VOC1ND
2014-06-128370VOC111.8 ppb
2014-06-188760THM32.9 ppb
2014-06-188761THM41.9 ppb
2014-06-188764THM32.5 ppb
2014-06-188765THM32.9 ppb
2014-08-13140915-0128VOC19.90 ppb
2014-08-13140915-0129VOC1ND
2014-08-13BG93593VOC19.90 ppb
2014-08-13BG93595VOC1ND
2014-09-15BH14101TTHM21.0 ppb
2014-09-15BH14102TTHM26.0 ppb
2014-09-15BH14103TTHM25.0 ppb
2014-09-15BH14104TTHM33.0 ppb
2014-11-03BH35439VOC1ND
2014-12-17BH54708TTHM20.0 ppb
2014-12-17BH54709TTHM32.0 ppb
2014-12-17BH54710TTHM35.0 ppb
2014-12-17BH54711TTHM34.0 ppb
2015-01-21BH65787VOC17.80 ppb
2015-02-12BH73177VOC15.50 ppb
2015-03-09BH80664VOC1ND
2015-03-11BH82211TTHM17.0 ppb
2015-03-11BH82210TTHM14.0 ppb
2015-03-11BH82209TTHM12.0 ppb
2015-03-11BH82212TTHM16.0 ppb
2015-06-02BJ24597VOC17.90 ppb
2015-06-02BJ24602VOC1ND
2015-06-02BJ24619VOC1ND
2015-06-02BJ24617VOC1ND
2015-06-03BJ25404VOC11.30 ppb
2015-06-16BJ31718TTHM34.0 ppb
2015-06-16BJ31715TTHM23.0 ppb
2015-06-16BJ31716TTHM32.0 ppb
2015-06-16BJ31717TTHM30.0 ppb
2015-07-27BJ63977VOC16.00 ppb
2015-07-27BJ63961VOC1ND
2015-09-15BJ92119TTHM24.0 ppb
2015-09-15BJ92122TTHM38.0 ppb
2015-09-15BJ92121TTHM34.0 ppb
2015-09-15BJ92120TTHM33.0 ppb
2015-10-19BK10284VOC1ND
2015-11-03BK17717VOC18.20 ppb
2015-12-08BK34312TTHM24.0 ppb
2015-12-08BK34311TTHM25.0 ppb
2015-12-08BK34309TTHM19.0 ppb
2015-12-08BK34310TTHM26.0 ppb
2016-01-11BK50864VOC1ND
2016-01-19BK54776VOC11.000 ppb
2016-01-19BK54777VOC12.60 ppb
2016-02-11BK64351VOC16.00 ppb
2016-03-14BK78125VOC18.50 ppb
2016-03-15BK78696TTHM21.0 ppb
2016-03-15BK78697TTHM19.0 ppb
2016-03-15BK78692TTHM17.0 ppb
2016-03-15BK78693TTHM14.0 ppb
2016-04-11BN11374VOC111.0 ppb
2016-04-11BN11376VOC1ND
2016-06-01BN44892VOC1ND
2016-06-01BN44876VOC1ND
2016-06-14BN54616TTHM14.0 ppb
2016-06-14BN54617TTHM12.0 ppb
2016-06-14BN54618TTHM17.0 ppb
2016-06-14BN54619TTHM15.0 ppb
2016-07-12BN71476VOC1ND
2016-07-13BN72282VOC18.30 ppb
2016-09-14BV14928TTHM27.0 ppb
2016-09-14BV14929TTHM24.0 ppb
2016-09-14BV14930TTHM17.0 ppb
2016-09-14BV14931TTHM28.0 ppb
2016-12-15BX06134TTHM23.0 ppb
2016-12-15BX06135TTHM21.0 ppb
2016-12-15BX06136TTHM5.70 ppb
2016-12-15BX06137TTHM21.0 ppb
2017-01-17BX30298VOC17.60 ppb
2017-01-17BX30299VOC1ND
2017-01-18BX31348VOC19.30 ppb
2017-01-30BX40966VOC1ND
2017-03-08BX82062VOC1ND
2017-03-17BX89076TTHM17.0 ppb
2017-03-17BX89077TTHM16.0 ppb
2017-03-17BX89078TTHM14.0 ppb
2017-03-17BX89073TTHM12.0 ppb
2017-06-19BY42240TTHM25.0 ppb
2017-06-19BY42241TTHM42.0 ppb
2017-06-19BY42242TTHM35.0 ppb
2017-06-19BY42243TTHM31.0 ppb
2017-06-29BY50637VOC110.00 ppb
2017-09-14BZ02387TTHM22.0 ppb
2017-09-14BZ02388TTHM34.0 ppb
2017-09-14BZ02389TTHM32.0 ppb
2017-09-14BZ02390TTHM28.0 ppb
2017-09-25BZ09163VOC18.40 ppb
2017-10-24BZ27135VOC1ND
2017-10-25BZ27134VOC11.50 ppb
2017-11-09BZ38785VOC19.80 ppb
2017-12-14BZ60231TTHM31.0 ppb
2017-12-14BZ60232TTHM29.0 ppb
2017-12-14BZ60233TTHM18.0 ppb
2017-12-14BZ60234TTHM23.0 ppb
2018-01-16BZ73485VOC16.80 ppb
2018-03-15CA03073TTHM17.0 ppb
2018-03-15CA03074TTHM13.0 ppb
2018-03-15CA03075TTHM19.0 ppb
2018-03-15CA03076TTHM20.0 ppb
2018-03-30CA11464VOC19.40 ppb
2018-04-11CA18261VOC17.00 ppb
2018-06-26CA80045TTHM31.0 ppb
2018-06-26CA80046TTHM28.0 ppb
2018-06-26CA80047TTHM23.0 ppb
2018-06-26CA80048TTHM19.0 ppb
2018-07-09CA85598VOC1ND
2018-07-17CA919798.40 ppb
2018-09-12DBP 20050504224.8 ppb
2018-09-12DBP 20050504344.7 ppb
2018-09-12DBP 20050504438.2 ppb
2018-09-12DBP 20050504743.7 ppb
2018-09-13VOC1 200505275ND
2018-09-13VOC1 200505276ND
2018-09-13VOC1 200505266ND
2018-09-19VOC1 2005061161.000 ppb
2018-09-20VOC1 2005063240.600 ppb
2018-10-25VOC1 20051056812.3 ppb
2018-12-17DBP 2005162355.50 ppb
2018-12-17DBP 2005162373.70 ppb
2018-12-17DBP 2005162387.40 ppb
2018-12-17DBP 2005162398.70 ppb
2019-01-30VOC1 2005200574.00 ppb
2019-03-11DBP 2005241504.90 ppb
2019-03-11DBP 2005241517.40 ppb
2019-03-11DBP 20052415210.6 ppb
2019-03-11DBP 20052415411.2 ppb
2019-06-14DBP 2005366729.70 ppb
2019-06-14DBP 20053667413.3 ppb
2019-06-14DBP 20053668016.6 ppb
2019-06-14DBP 20053668216.4 ppb
2019-06-24VOC1 2005380057.40 ppb
2019-07-08VOC1 2005411727.30 ppb
2019-07-08VOC1 200539194ND
2019-07-16VOC1 200541091ND
2019-07-16VOC1 2005406480.800 ppb
2019-07-16VOC1 200540644ND
2019-09-17DBP 20054947817.3 ppb
2019-09-17DBP 20054947919.6 ppb
2019-09-17DBP 20054948020.9 ppb
2019-09-17DBP 20054948121.6 ppb
2019-09-17VOC1 200549238ND
2019-09-18VOC1 200549465ND
2019-12-10DBP 2005596429.70 ppb
2019-12-10DBP 20055964316.1 ppb
2019-12-10DBP 20055964419.6 ppb
2019-12-10DBP 20055964522.6 ppb
2019-12-10VOC1 20055966313.2 ppb