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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

City of Gonzales Water 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

 

198

Samples

0

Samples exceeding legal limit (MCL)

50

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013N/A00N/A
2014ND380ND
2015ND320ND
2016ND320ND
20170.339 ppb3216ND - 0.760 ppb
20183.73 ppb3216ND - 55.7 ppb
20191.41 ppb3222ND - 15.1 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
2014-02-17201164735ND
2014-02-17201164736ND
2014-02-17201164737ND
2014-02-17201164738ND
2014-02-17201164735ND
2014-02-17201164736ND
2014-02-17201164737ND
2014-02-17201164738ND
2014-05-19204176001ND
2014-05-19204185001ND
2014-05-19204187001ND
2014-05-19204189001ND
2014-05-19204176001ND
2014-05-19204185001ND
2014-05-19204187001ND
2014-05-19204189001ND
2014-05-23AD91786ND
2014-05-23AD91789ND
2014-05-23AD91790ND
2014-05-23AD91786ND
2014-05-23AD91789ND
2014-05-23AD91790ND
2014-08-18208140001ND
2014-08-18208141001ND
2014-08-18208143001ND
2014-08-18208144001ND
2014-08-18208140001ND
2014-08-18208141001ND
2014-08-18208143001ND
2014-08-18208144001ND
2014-11-192012533001ND
2014-11-192012533002ND
2014-11-192012533003ND
2014-11-192012533004ND
2014-11-192012533001ND
2014-11-192012533002ND
2014-11-192012533003ND
2014-11-192012533004ND
2015-02-162016095001ND
2015-02-162016095002ND
2015-02-162016095003ND
2015-02-162016095004ND
2015-02-162016095001ND
2015-02-162016095002ND
2015-02-162016095003ND
2015-02-162016095004ND
2015-05-192020147001ND
2015-05-192020147002ND
2015-05-192020147003ND
2015-05-192020147004ND
2015-05-192020147001ND
2015-05-192020147002ND
2015-05-192020147003ND
2015-05-192020147004ND
2015-08-172024411001ND
2015-08-172024411002ND
2015-08-172024411003ND
2015-08-172024411004ND
2015-08-172024411001ND
2015-08-172024411002ND
2015-08-172024411003ND
2015-08-172024411004ND
2015-11-162028659001ND
2015-11-162028659002ND
2015-11-162028659003ND
2015-11-162028659004ND
2015-11-162028659001ND
2015-11-162028659002ND
2015-11-162028659003ND
2015-11-162028659004ND
2016-02-152032553001ND
2016-02-152032553002ND
2016-02-152032553003ND
2016-02-152032553004ND
2016-02-152032553001ND
2016-02-152032553002ND
2016-02-152032553003ND
2016-02-152032553004ND
2016-05-162036714001ND
2016-05-162036714002ND
2016-05-162036714003ND
2016-05-162036714004ND
2016-05-162036714001ND
2016-05-162036714002ND
2016-05-162036714003ND
2016-05-162036714004ND
2016-08-292041872001ND
2016-08-292041872002ND
2016-08-292041872003ND
2016-08-292041872004ND
2016-08-292041872001ND
2016-08-292041872002ND
2016-08-292041872003ND
2016-08-292041872004ND
2016-11-142045715001ND
2016-11-142045715002ND
2016-11-142045715003ND
2016-11-142045715004ND
2016-11-142045715001ND
2016-11-142045715002ND
2016-11-142045715003ND
2016-11-142045715004ND
2017-02-02352929630030.620 ppb
2017-02-0235292963004ND
2017-02-0235292963005ND
2017-02-02352929630060.650 ppb
2017-02-02352929630030.620 ppb
2017-02-0235292963004ND
2017-02-0235292963005ND
2017-02-02352929630060.650 ppb
2017-05-04353106070090.640 ppb
2017-05-04353106070100.690 ppb
2017-05-0435310607011ND
2017-05-04353106070120.710 ppb
2017-05-04353106070090.640 ppb
2017-05-04353106070100.690 ppb
2017-05-0435310607011ND
2017-05-04353106070120.710 ppb
2017-08-1835331425001ND
2017-08-18353314250020.650 ppb
2017-08-18353314250030.760 ppb
2017-08-18353314250040.710 ppb
2017-08-1835331425001ND
2017-08-18353314250020.650 ppb
2017-08-18353314250030.760 ppb
2017-08-18353314250040.710 ppb
2017-11-0335346242001ND
2017-11-0335346242002ND
2017-11-0335346242003ND
2017-11-0335346242004ND
2017-11-0335346242001ND
2017-11-0335346242002ND
2017-11-0335346242003ND
2017-11-0335346242004ND
2018-02-02353719070010.390 ppb
2018-02-02353719070020.520 ppb
2018-02-02353719070030.540 ppb
2018-02-02353719070040.500 ppb
2018-02-02353719070010.390 ppb
2018-02-02353719070020.520 ppb
2018-02-02353719070030.540 ppb
2018-02-02353719070040.500 ppb
2018-05-1835393231001ND
2018-05-1835393231002ND
2018-05-1835393231003ND
2018-05-183539323100455.7 ppb
2018-05-1835393231001ND
2018-05-1835393231002ND
2018-05-1835393231003ND
2018-05-183539323100455.7 ppb
2018-08-0335408663001ND
2018-08-03354086630020.630 ppb
2018-08-03354086630030.720 ppb
2018-08-03354086630040.700 ppb
2018-08-0335408663001ND
2018-08-03354086630020.630 ppb
2018-08-03354086630030.720 ppb
2018-08-03354086630040.700 ppb
2018-11-0135428204001ND
2018-11-0135428204002ND
2018-11-0135428204003ND
2018-11-0135428204004ND
2018-11-0135428204001ND
2018-11-0135428204002ND
2018-11-0135428204003ND
2018-11-0135428204004ND
2019-02-07354471240010.550 ppb
2019-02-07354471240020.510 ppb
2019-02-07354471240030.690 ppb
2019-02-07354471240040.700 ppb
2019-02-07354471240010.550 ppb
2019-02-07354471240020.510 ppb
2019-02-07354471240030.690 ppb
2019-02-07354471240040.700 ppb
2019-05-08354682870010.360 ppb
2019-05-08354682870020.690 ppb
2019-05-083546828700315.1 ppb
2019-05-0835468287004ND
2019-05-08354682870010.360 ppb
2019-05-08354682870020.690 ppb
2019-05-083546828700315.1 ppb
2019-05-0835468287004ND
2019-08-06354887330011.30 ppb
2019-08-06354887330020.930 ppb
2019-08-06354887330031.10 ppb
2019-08-06354887330040.550 ppb
2019-08-06354887330011.30 ppb
2019-08-06354887330020.930 ppb
2019-08-06354887330031.10 ppb
2019-08-06354887330040.550 ppb
2019-11-0635511100001ND
2019-11-0635511100002ND
2019-11-0635511100003ND
2019-11-0635511100004ND
2019-11-0635511100001ND
2019-11-0635511100002ND
2019-11-0635511100003ND
2019-11-0635511100004ND