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EWG's Tap Water Database — 2019 UPDATE

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Selenium

City of Houston

Selenium is an essential element in diets. But too much selenium can decrease thyroid hormone production and cause hair loss, skin lesions and brittle fingernails.

 

108

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012ND50ND
2013ND120ND
20141.37 ppb183ND - 11.1 ppb
20150.235 ppb171ND - 4.00 ppb
20162.29 ppb2911ND - 9.40 ppb
20171.68 ppb278ND - 10.00 ppb

ppb = parts per billion

State and national drinking water standards and health guidelines

EWG Health Guideline 30 ppb

The EWG Health Guideline of 30 ppb for selenium was defined by the California Office of Environmental Health Hazard Assessment as a public health goal, the level of a drinking water contaminant that does not pose a significant health risk. This health guideline protects against hair loss and nail damage.

EPA Maximum Contaminant
Level (MCL) 50 ppb

The legal limit for selenium, established in 1991, was based on human epidemiological studies of populations exposed to naturally occurring selenium in drinking water. This limit does not include any additional consideration of children’s health.

ppb = parts per billion

All test results

Date Lab ID Result
2012-01-31AB79460ND
2012-02-01AB79700ND
2012-04-10AB86381ND
2012-05-23AB90843ND
2012-07-24AB96031ND
2013-02-25AC11513ND
2013-03-11AC12855ND
2013-06-13AC21981ND
2013-06-13AC21980ND
2013-08-08AC27162ND
2013-08-08AC27158ND
2013-08-08AC27161ND
2013-08-08AC27157ND
2013-08-08AC27160ND
2013-09-24AC31092ND
2013-09-25AC31269ND
2013-10-29AC33587ND
2014-02-03AC41009ND
2014-03-14AC47093ND
2014-03-14AC47094ND
2014-03-14AC47095ND
2014-04-16AC50780ND
2014-04-16AC50781ND
2014-04-17AC51021ND
2014-06-03AC55768ND
2014-06-03AC55769ND
2014-07-15AC59675ND
2014-07-15AC59674ND
2014-07-16AC59810ND
2014-08-14AC63644ND
2014-10-08AC6915111.1 ppb
2014-10-09AC69343ND
2014-10-09AC69342ND
2014-12-18AC754216.80 ppb
2014-12-18AC754246.70 ppb
2015-03-04AC82828ND
2015-03-05AC82837ND
2015-06-04AC945694.00 ppb
2015-06-04AC94568ND
2015-06-04AC94567ND
2015-06-04AC94566ND
2015-06-04AC94565ND
2015-07-21AD00317ND
2015-07-21AD00315ND
2015-07-21AD00316ND
2015-07-21AD00322ND
2015-07-21AD00320ND
2015-09-17AD07499ND
2015-10-22AD11442ND
2015-10-22AD11445ND
2015-10-22AD11444ND
2015-11-12AD13300ND
2016-02-18AD241985.30 ppb
2016-02-18AD242069.20 ppb
2016-02-18AD241897.60 ppb
2016-02-18AD242075.50 ppb
2016-02-18AD24197ND
2016-02-18AD24205ND
2016-03-03AD26825ND
2016-03-16AD28983ND
2016-03-16AD28979ND
2016-03-17AD29296ND
2016-03-17AD29295ND
2016-03-23AD300574.90 ppb
2016-03-23AD30059ND
2016-03-23AD30063ND
2016-03-23AD30058ND
2016-06-08AD396874.70 ppb
2016-06-08AD396869.40 ppb
2016-06-16AD408814.20 ppb
2016-06-16AD40876ND
2016-09-20AD50273ND
2016-09-20AD50274ND
2016-09-21AD50631ND
2016-10-06AD526203.60 ppb
2016-10-06AD526216.30 ppb
2016-10-06AD52624ND
2016-11-18AD58725ND
2016-11-21AD58729ND
2016-11-21AD587305.70 ppb
2016-11-21AD58728ND
2017-01-26AD670454.30 ppb
2017-01-26AD670547.90 ppb
2017-02-28AD72383ND
2017-02-28AD72381ND
2017-03-01AD72708ND
2017-03-01AD72707ND
2017-03-02AD73025ND
2017-03-02AD73018ND
2017-03-28AD77082ND
2017-03-28AD770836.10 ppb
2017-03-28AD770816.30 ppb
2017-03-28AD770804.20 ppb
2017-03-29AD77389ND
2017-03-29AD77385ND
2017-04-26AD811063.20 ppb
2017-04-27AD81406ND
2017-04-27AD814073.30 ppb
2017-07-06AD88418ND
2017-07-06AD88419ND
2017-07-06AD88420ND
2017-07-25AD90485ND
2017-09-11AD95398ND
2017-09-11AD95394ND
2017-09-26AD9795410.00 ppb
2017-09-26AD97959ND
2017-09-26AD97955ND
2017-11-07AE03784ND