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EWG's Tap Water Database — 2021 UPDATE

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Total trihalomethanes (TTHMs)

Freeport

Trihalomethanes are cancer-causing contaminants that form during water treatment with chlorine and other disinfectants. The total trihalomethanes group includes four chemicals: chloroform, bromodichloromethane, dibromochloromethane and bromoform. Read More.

Studies conducted in the U.S. and Europe have found that drinking tap water that carries disinfection byproducts increases the risk of developing bladder cancer. In animal studies, all trihalomethanes cause liver, kidney and intestinal tumors. Some human epidemiological studies also reported an association between disinfection byproducts and an increased risk of problems during pregnancy, including spontaneous miscarriage, cardiovascular defects, neural tube defects and low birth weight.

The health guideline of 0.15 parts per billion, or ppb, for the group of four trihalomethanes, or THM4/TTHM, was defined in a peer-reviewed scientific study by EWG and represents a one-in-one-million lifetime cancer risk level.

Click here to read more about disinfection byproducts.

MORE ABOUT THIS CONTAMINANT

 

235

Samples

0

Samples exceeding legal limit (MCL)

2

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014ND350ND
2015ND390ND
2016ND420ND
2017ND430ND
20180.0189 ppb441ND - 0.830 ppb
20190.0156 ppb321ND - 0.500 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 0.15 ppb

The health guideline of 0.15 parts per billion, or ppb, for the group of four trihalomethanes, or THM4/TTHM, was defined in a peer-reviewed scientific study by EWG and represents a one-in-one-million lifetime cancer risk level.

EPA Maximum Contaminant
Level (MCL) 80 ppb

The legal limit for the group of four trihalomethanes, established in 1998, was based on the need for residual disinfectant levels in water served to customers and the cost of treatment. This limit does not fully protect against the risk of cancer due to exposure to trihalomethanes.

ppb = parts per billion

All test results

Date Lab ID Result
2014-02-261402E45-001-POCSND
2014-02-261402E45-004-POCSND
2014-02-261402E45-008-POCSND
2014-02-261402E45-002-POCSND
2014-02-261402E45-005-POCSND
2014-02-261402E45-003-POCSND
2014-02-261402E45-006-POCSND
2014-02-261402E45-007-POCSND
2014-04-021404165-006-POCSND
2014-04-021404165-007-POCSND
2014-04-021404165-001-POCSND
2014-04-021404165-008-POCSND
2014-04-021404165-003-POCSND
2014-04-021404165-005-POCSND
2014-04-021404165-004-POCSND
2014-04-021404165-002-POCSND
2014-09-101409756-004-POCSND
2014-09-101409756-005-POCSND
2014-09-101409756-002-POCSND
2014-09-101409756-001-POCSND
2014-09-101409756-003-POCSND
2014-09-101409756-008-POCSND
2014-09-101409756-006-POCSND
2014-09-101409756-007-POCSND
2014-10-141410928-001-POCSND
2014-10-301410K14-001-POCSND
2014-12-121412948-006-POCSND
2014-12-121412948-003-POCSND
2014-12-121412948-001-POCSND
2014-12-121412948-007-POCSND
2014-12-121412948-002-POCSND
2014-12-121412948-004-POCSND
2014-12-121412948-005-POCSND
2014-12-181412D94-001-POCSND
2014-12-181412D96-001-POCSND
2015-01-201501B45-001-POCSND
2015-01-201501B48-001-POCSND
2015-02-101502609-002-POCSND
2015-02-101502609-001-POCSND
2015-03-111503723-005-POCSND
2015-03-111503723-004-POCSND
2015-03-111503723-002-POCSND
2015-03-111503723-001-POCSND
2015-03-111503723-003-POCSND
2015-03-111503723-007-POCSND
2015-03-111503723-006-POCSND
2015-03-181503C64-001-POCSND
2015-03-181503C64-002-POCSND
2015-04-141504A96-004-POCSND
2015-04-141504A96-007-POCSND
2015-04-141504A96-008-POCSND
2015-04-141504A96-002-POCSND
2015-04-141504A96-003-POCSND
2015-04-141504A96-009-POCSND
2015-04-151504A96-001-POCSND
2015-04-151504A96-006-POCSND
2015-04-151504A96-005-POCSND
2015-07-201507D49-007-POCSND
2015-07-201507D49-004-POCSND
2015-07-201507D49-003-POCSND
2015-07-201507D49-008-POCSND
2015-07-201507D49-006-POCSND
2015-07-201507D49-009-POCSND
2015-10-211510G28-001-POCSND
2015-10-211510G28-003-POCSND
2015-10-211510G28-002-POCSND
2015-10-211510G28-006-POCSND
2015-10-211510G28-009-POCSND
2015-10-211510G28-007-POCSND
2015-10-211510G28-005-POCSND
2015-10-211510G28-011-POCSND
2015-10-211510G28-008-POCSND
2015-10-211510G28-010-POCSND
2015-10-211510G28-004-POCSND
2016-02-011607A22-006ND
2016-03-021603153-001ND
2016-03-021603153-002-POCSND
2016-03-0216003153-005-POCND
2016-03-021603153-002ND
2016-03-021603153-006ND
2016-03-021603153-003-POCSND
2016-03-021603153-004-POCND
2016-03-171603E70-002ND
2016-03-171603E70-001-POCND
2016-03-171603E70-003-POCSND
2016-03-171603E70-003ND
2016-05-111605971-010ND
2016-05-111605971-006ND
2016-05-111605971-002ND
2016-05-111605971-003ND
2016-05-111605971-001ND
2016-05-111605971-004ND
2016-05-111605971-007ND
2016-05-111607I26-001-POCSND
2016-05-111605971-009ND
2016-05-111605971-008ND
2016-07-131607A22-004ND
2016-07-131607A22-001ND
2016-07-131607A22-002ND
2016-07-131607A22-003ND
2016-07-131607A22-007ND
2016-07-131607A22-005ND
2016-07-13 1607A22-009ND
2016-07-131607A22-008ND
2016-09-221609J39-001-POCSND
2016-10-06701368008ND
2016-10-06701368017ND
2016-10-06701368032ND
2016-10-06701368020ND
2016-10-06701368023ND
2016-10-06701368002ND
2016-10-06701368014ND
2016-10-06701368029ND
2016-10-06701368011ND
2016-10-06701368026ND
2016-10-06701368005ND
2017-03-087012890008ND
2017-03-087012890004ND
2017-03-087012890010ND
2017-03-087012890009ND
2017-03-087012890001ND
2017-03-087012890006ND
2017-03-087012890005ND
2017-03-087012890011ND
2017-03-087012890002ND
2017-03-087012890007ND
2017-03-087012890003ND
2017-05-257019669006-POCSND
2017-05-257019669007-POCSND
2017-05-257019669005-POCSND
2017-05-257019669008-POCSND
2017-05-257019669010-POCSND
2017-05-257019669011-POCSND
2017-05-257019669009-POCSND
2017-05-257019669003-POCSND
2017-05-257019669004-POCSND
2017-05-257019669001-POCSND
2017-05-257019669002-POCSND
2017-08-297028485001ND
2017-08-297028485007ND
2017-08-297028485005ND
2017-08-297028485009ND
2017-08-297028485004ND
2017-08-297028485002ND
2017-08-297028485008ND
2017-08-297028485006ND
2017-08-297028485010ND
2017-09-147029977001-POCSND
2017-10-057032081002ND
2017-10-057032081001ND
2017-10-057032081003ND
2017-10-057032081004ND
2017-10-197033528004-POCSND
2017-10-197033528005-POCSND
2017-10-197033528007-POCSND
2017-10-197033528002-POCSND
2017-10-197033528006-POCSND
2017-10-197033528001-POCSND
2017-10-197033528003-POCSND
2018-03-067044635003ND
2018-03-067044635009ND
2018-03-067044635001ND
2018-03-067044635004ND
2018-03-067044635007ND
2018-03-067044635008ND
2018-03-067044635006ND
2018-03-067044635002ND
2018-03-067044635005ND
2018-03-297046647002ND
2018-04-247049440001-POCSND
2018-04-247049440002-POCSND
2018-04-247049440008ND
2018-04-247049440005-POCSND
2018-04-247049440004-POCSND
2018-04-247049440009-POCSND
2018-04-247049440006-POCSND
2018-04-247049440007-POCSND
2018-04-247049440003-POCSND
2018-05-117051431001-POCSND
2018-06-127054639001-POCSND
2018-07-317059905009-POCSND
2018-07-317059905008ND
2018-07-317059905005-POCSND
2018-07-317059905006-POCSND
2018-07-317059905004ND
2018-07-317059905011-POCSND
2018-07-317059905010-POCSND
2018-07-317059905001-POCSND
2018-07-317059905002-POCSND
2018-07-317059905003-POCSND
2018-07-317059905007-POCSND
2018-09-1170644040020.830 ppb
2018-09-117064404001ND
2018-11-277072124004-POCSND
2018-11-277072124008-POCSND
2018-11-277072124005-POCSND
2018-11-277072124010-POCSND
2018-11-277072124009-POCSND
2018-11-277072124007-POCSND
2018-11-277072124001-POCSND
2018-11-277072124002-POCSND
2018-11-277072124006-POCSND
2018-11-277072124003-POCSND
2019-01-317078033009ND
2019-01-317078033003ND
2019-01-317078033008ND
2019-01-317078033006ND
2019-01-317078033007ND
2019-01-317078033001ND
2019-01-317078033002ND
2019-01-317078033005ND
2019-01-317078033004ND
2019-01-317078033010ND
2019-06-047091996003ND
2019-06-047091996006-POCSND
2019-06-047091996004-POCSND
2019-06-047091996009-POCSND
2019-06-047091996005ND
2019-06-047091996002-POCSND
2019-06-047091996001-POCSND
2019-06-047091996008-POCSND
2019-06-047091996007-POCSND
2019-06-047091996010-POCSND
2019-09-10701043760010.500 ppb
2019-09-1070104376002ND
2019-10-2470109658003ND
2019-10-2470109658008ND
2019-10-2470109658004ND
2019-10-2470109658005ND
2019-10-2470109658002ND
2019-10-2470109658006ND
2019-10-2470109658010ND
2019-10-2470109658009ND
2019-10-2470109658007ND
2019-10-2470109658001ND