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EWG's Tap Water Database — 2021 UPDATE

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Chloroform

McAllen Public Utility

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

 

207

Samples

0

Samples exceeding legal limit (MCL)

159

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
20141.72 ppb34341.000 ppb - 3.20 ppb
20151.92 ppb3736ND - 4.20 ppb
20161.54 ppb3425ND - 3.30 ppb
20170.582 ppb3417ND - 1.30 ppb
20181.37 ppb3428ND - 2.20 ppb
20190.715 ppb3419ND - 2.00 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
2014-02-27AC449991.10 ppb
2014-02-27AC450361.20 ppb
2014-02-27AC450281.50 ppb
2014-02-27AC450321.10 ppb
2014-02-27AC450291.20 ppb
2014-02-27AC450341.20 ppb
2014-02-27AC450001.60 ppb
2014-02-27AC450301.30 ppb
2014-04-25AC518681.10 ppb
2014-04-25AC518461.20 ppb
2014-04-25AC518401.50 ppb
2014-04-25AC518641.10 ppb
2014-04-25AC518431.000 ppb
2014-04-25AC518501.40 ppb
2014-04-25AC518471.40 ppb
2014-04-25AC518391.10 ppb
2014-08-18AC639873.00 ppb
2014-08-18AC639893.00 ppb
2014-08-18AC641812.50 ppb
2014-08-18AC641212.70 ppb
2014-08-18AC641533.20 ppb
2014-08-18AC641232.30 ppb
2014-08-18AC641542.80 ppb
2014-08-18AC641262.90 ppb
2014-08-18AC641192.40 ppb
2014-08-18AC641583.00 ppb
2014-10-09AC694061.000 ppb
2014-10-09AC694031.70 ppb
2014-10-09AC694021.30 ppb
2014-10-09AC694081.50 ppb
2014-10-09AC693991.60 ppb
2014-10-09AC694071.30 ppb
2014-10-09AC694001.30 ppb
2014-10-09AC694011.10 ppb
2015-03-12AC841691.60 ppb
2015-03-12AC840651.30 ppb
2015-03-12AC840571.50 ppb
2015-03-12AC840601.60 ppb
2015-03-12AC840581.000 ppb
2015-03-12AC84054ND
2015-03-12AC840621.40 ppb
2015-03-12AC840591.50 ppb
2015-03-12AC840461.60 ppb
2015-06-10AC954461.60 ppb
2015-06-10AC953952.40 ppb
2015-06-10AC953991.50 ppb
2015-06-10AC954171.50 ppb
2015-06-10AC953681.60 ppb
2015-06-10AC954143.70 ppb
2015-06-10AC953981.60 ppb
2015-06-10AC953691.40 ppb
2015-06-10AC953962.00 ppb
2015-08-06AD029901.30 ppb
2015-08-06AD029823.50 ppb
2015-08-06AD028864.10 ppb
2015-08-06AD028871.70 ppb
2015-08-06AD029061.10 ppb
2015-08-06AD029042.60 ppb
2015-08-06AD028883.60 ppb
2015-08-06AD029031.10 ppb
2015-08-06AD028941.70 ppb
2015-08-06AD028854.20 ppb
2015-11-18AD140711.10 ppb
2015-11-18AD140052.90 ppb
2015-11-18AD139991.30 ppb
2015-11-18AD139981.30 ppb
2015-11-18AD140061.90 ppb
2015-11-18AD140042.10 ppb
2015-11-18AD140011.30 ppb
2015-11-18AD140162.70 ppb
2015-11-18AD140192.70 ppb
2016-03-23AD300902.20 ppb
2016-03-23AD300871.70 ppb
2016-03-23AD300851.80 ppb
2016-03-23AD300881.60 ppb
2016-03-23AD300911.80 ppb
2016-03-23AD300892.30 ppb
2016-03-23AD300922.10 ppb
2016-03-23AD300862.20 ppb
2016-06-07AD395741.80 ppb
2016-06-07AD395703.30 ppb
2016-06-07AD395752.90 ppb
2016-06-07AD395801.70 ppb
2016-06-07AD395791.80 ppb
2016-06-07AD395722.50 ppb
2016-06-07AD395762.50 ppb
2016-06-07AD395782.80 ppb
2016-06-30AD42708ND
2016-08-02AD466592.80 ppb
2016-08-02AD466012.80 ppb
2016-08-02AD46618ND
2016-08-02AD46606ND
2016-08-02AD466352.50 ppb
2016-08-02AD466052.20 ppb
2016-08-02AD46628ND
2016-08-02AD466021.000 ppb
2016-08-02AD466223.00 ppb
2016-10-27AD551261.10 ppb
2016-10-27AD55102ND
2016-10-27AD551101.000 ppb
2016-10-27AD55106ND
2016-10-27AD55109ND
2016-10-27AD551121.000 ppb
2016-10-27AD55107ND
2016-10-27AD55111ND
2017-02-09AD69897ND
2017-02-09AD69899ND
2017-02-09AD69928ND
2017-02-09AD69896ND
2017-02-09AD69895ND
2017-02-09AD69929ND
2017-02-09AD69900ND
2017-02-09AD69930ND
2017-04-19AD801991.30 ppb
2017-04-19AD801411.20 ppb
2017-04-19AD801511.10 ppb
2017-04-19AD801431.10 ppb
2017-04-19AD80139ND
2017-04-19AD801471.10 ppb
2017-04-19AD801461.20 ppb
2017-04-19AD801401.20 ppb
2017-04-19AD801231.10 ppb
2017-07-12AD891071.20 ppb
2017-07-12AD890491.10 ppb
2017-07-12AD89057ND
2017-07-12AD89046ND
2017-07-12AD890481.000 ppb
2017-07-12AD890301.20 ppb
2017-07-12AD89047ND
2017-07-12AD890431.20 ppb
2017-07-12AD890451.30 ppb
2017-10-05AD995321.30 ppb
2017-10-05AD99529ND
2017-10-05AD99531ND
2017-10-05AD99530ND
2017-10-05AD995271.10 ppb
2017-10-05AD99526ND
2017-10-05AD99528ND
2017-10-05AD995251.10 ppb
2018-03-08AE175171.70 ppb
2018-03-08AE174991.70 ppb
2018-03-08AE174892.00 ppb
2018-03-08AE175141.60 ppb
2018-03-08AE175131.50 ppb
2018-03-08AE175181.80 ppb
2018-03-08AE175151.50 ppb
2018-03-08AE175161.60 ppb
2018-05-15AE263441.80 ppb
2018-05-15AE263432.10 ppb
2018-05-15AE263341.90 ppb
2018-05-15AE263451.60 ppb
2018-05-15AE263371.80 ppb
2018-05-15AE263332.00 ppb
2018-05-15AE263292.10 ppb
2018-05-15AE263282.00 ppb
2018-08-15AE372281.10 ppb
2018-08-15AE372061.30 ppb
2018-08-15AE371781.60 ppb
2018-08-15AE371651.50 ppb
2018-08-15AE371681.000 ppb
2018-08-15AE371771.30 ppb
2018-08-15AE371662.10 ppb
2018-08-15AE371761.40 ppb
2018-08-15AE371642.20 ppb
2018-08-15AE371622.10 ppb
2018-11-07AE45594ND
2018-11-07AE455991.10 ppb
2018-11-07AE455911.10 ppb
2018-11-07AE45587ND
2018-11-07AE45595ND
2018-11-07AE45593ND
2018-11-07AE45590ND
2018-11-07AE45592ND
2019-02-14AE547251.10 ppb
2019-02-14AE54733ND
2019-02-14AE54732ND
2019-02-14AE54723ND
2019-02-14AE547341.10 ppb
2019-02-14AE54729ND
2019-02-14AE54735ND
2019-02-14AE547361.10 ppb
2019-05-22AE677031.40 ppb
2019-05-22AE676011.20 ppb
2019-05-22AE676491.50 ppb
2019-05-22AE676021.90 ppb
2019-05-22AE676501.000 ppb
2019-05-22AE676481.40 ppb
2019-05-22AE676532.00 ppb
2019-05-22AE676521.60 ppb
2019-05-22AE676511.40 ppb
2019-09-04AE82073ND
2019-09-30AE85091ND
2019-09-30AE850941.10 ppb
2019-09-30AE850921.20 ppb
2019-09-30AE85067ND
2019-09-30AE85101ND
2019-09-30AE850991.20 ppb
2019-09-30AE850981.10 ppb
2019-09-30AE85068ND
2019-12-04AE91227ND
2019-12-04AE912231.000 ppb
2019-12-04AE912311.000 ppb
2019-12-04AE91229ND
2019-12-04AE91230ND
2019-12-04AE91220ND
2019-12-04AE912261.000 ppb
2019-12-04AE91228ND