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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

City of Boerne

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

 

138

Samples

0

Samples exceeding legal limit (MCL)

99

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
201414.7 ppb1918ND - 34.4 ppb
201516.2 ppb2720ND - 48.7 ppb
201613.8 ppb2315ND - 32.9 ppb
201712.5 ppb2316ND - 26.2 ppb
201813.4 ppb2315ND - 32.9 ppb
201913.3 ppb2315ND - 33.5 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
2014-02-11AC422220.800 ppb
2014-02-11AC421918.70 ppb
2014-02-11AC421687.80 ppb
2014-02-11AC4217414.5 ppb
2014-02-11AC4217313.7 ppb
2014-04-03AC49258ND
2014-04-03AC4920814.4 ppb
2014-04-03AC492092.60 ppb
2014-04-03AC4921012.0 ppb
2014-04-03AC4921220.0 ppb
2014-07-14AC5951020.0 ppb
2014-07-14AC5961123.7 ppb
2014-07-14AC595787.50 ppb
2014-07-14AC5957913.1 ppb
2014-07-14AC5961626.2 ppb
2014-10-14AC6964527.2 ppb
2014-10-14AC6964013.2 ppb
2014-10-14AC6964319.2 ppb
2014-10-14AC6964134.4 ppb
2015-01-29AC78533ND
2015-01-29AC7846511.9 ppb
2015-01-29AC784449.60 ppb
2015-01-29AC7844311.9 ppb
2015-01-29AC7844915.9 ppb
2015-04-13AC88007ND
2015-04-13AC88003ND
2015-04-13AC8793811.8 ppb
2015-04-13AC8793414.4 ppb
2015-04-13AC8793533.4 ppb
2015-05-11AC9129921.9 ppb
2015-07-23AD00749ND
2015-07-23AD00763ND
2015-07-23AD00779ND
2015-07-23AD0075331.0 ppb
2015-09-11AD0684540.9 ppb
2015-09-11AD068463.80 ppb
2015-09-11AD0684444.0 ppb
2015-09-11AD0684748.7 ppb
2015-11-17AD1377414.0 ppb
2015-11-17AD137773.40 ppb
2015-11-17AD1377037.6 ppb
2015-11-17AD1376913.4 ppb
2015-12-22AD1709125.1 ppb
2015-12-22AD17093ND
2015-12-22AD1709218.5 ppb
2015-12-22AD1709426.5 ppb
2016-02-17AD23965ND
2016-02-17AD2388625.4 ppb
2016-02-17AD23871ND
2016-02-17AD2388816.9 ppb
2016-02-17AD2388727.3 ppb
2016-04-20AD33646ND
2016-04-20AD33644ND
2016-04-20AD3357621.6 ppb
2016-04-20AD33563ND
2016-04-20AD3356223.4 ppb
2016-04-20AD3356624.6 ppb
2016-07-22AD4547421.0 ppb
2016-07-22AD4542627.4 ppb
2016-07-22AD454244.50 ppb
2016-07-22AD4538927.1 ppb
2016-07-22AD4542532.9 ppb
2016-11-02AD56138ND
2016-11-02AD56140ND
2016-11-02AD56150ND
2016-11-02AD5609420.6 ppb
2016-11-02AD560921.20 ppb
2016-11-02AD5609318.9 ppb
2016-11-02AD5609524.4 ppb
2017-01-25AD66830ND
2017-01-25AD66826ND
2017-01-25AD6673219.2 ppb
2017-01-25AD6673117.2 ppb
2017-01-25AD6673019.9 ppb
2017-01-25AD6672922.9 ppb
2017-04-04AD78315ND
2017-04-04AD78327ND
2017-04-04AD78313ND
2017-04-04AD7827023.4 ppb
2017-04-04AD782723.80 ppb
2017-04-04AD7826919.9 ppb
2017-04-04AD7827126.2 ppb
2017-07-17AD89532ND
2017-07-17AD8953412.0 ppb
2017-07-17AD8948220.9 ppb
2017-07-17AD89478ND
2017-07-17AD8947919.7 ppb
2017-07-17AD8948322.4 ppb
2017-11-20AE0534216.3 ppb
2017-11-20AE053412.00 ppb
2017-11-20AE0533920.4 ppb
2017-11-20AE0534021.5 ppb
2018-01-29AE11034ND
2018-01-29AE10984ND
2018-01-29AE1094816.0 ppb
2018-01-29AE10947ND
2018-01-29AE1094511.5 ppb
2018-01-29AE1094621.6 ppb
2018-05-01AE24581ND
2018-05-01AE24583ND
2018-05-01AE24587ND
2018-05-01AE24585ND
2018-05-01AE2452219.2 ppb
2018-05-01AE24521ND
2018-05-01AE245209.70 ppb
2018-05-01AE2452318.4 ppb
2018-08-14AE3694128.0 ppb
2018-08-14AE3688429.3 ppb
2018-08-14AE3685932.9 ppb
2018-08-14AE3687722.1 ppb
2018-08-14AE3687823.3 ppb
2018-11-28AE4716026.7 ppb
2018-11-28AE471612.10 ppb
2018-11-28AE4715916.9 ppb
2018-11-28AE4715830.2 ppb
2019-03-14AE5840023.7 ppb
2019-03-14AE58402ND
2019-03-14AE5839816.2 ppb
2019-03-14AE5840126.1 ppb
2019-06-20AE7145325.7 ppb
2019-06-20AE71454ND
2019-06-20AE7145219.3 ppb
2019-06-20AE7145131.5 ppb
2019-09-17AE8385313.0 ppb
2019-09-17AE8356133.4 ppb
2019-09-17AE8356011.2 ppb
2019-09-17AE8355921.3 ppb
2019-09-17AE8355833.5 ppb
2019-10-02AE85514ND
2019-10-02AE85520ND
2019-10-02AE85522ND
2019-10-02AE85526ND
2019-10-02AE85516ND
2019-10-02AE85524ND
2019-12-09AE9185916.3 ppb
2019-12-09AE918523.50 ppb
2019-12-09AE9185313.8 ppb
2019-12-09AE9187117.6 ppb