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EWG's Tap Water Database — 2019 UPDATE

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Perfluorooctane sulfonate (PFOS)

La Crosse Waterworks

Perfluorooctane sulfonate (PFOS) is a member of a group of perfluorinated chemicals used in many consumer products. PFOS and other perfluorinated chemicals can cause serious health effects, including cancer, endocrine disruption, accelerated puberty, liver and immune system damage, and thyroid changes. These chemicals are persistent in the environment and they accumulate in people. Click here to read more about perfluorinated chemicals.

 

26

Samples

0

Samples exceeding legal limit (MCL)

2

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2012N/A00N/A
2013N/A00N/A
20148.77 ppt222ND - 140.0 ppt
2015ND40ND
2016N/A00N/A
2017N/A00N/A

ppt = parts per trillion

State and national drinking water standards and health guidelines

EWG Health Guideline 1 ppt

The EWG Health Guideline of 1 ppt for PFOS was defined by EWG based on studies by Phillipe Grandjean of Harvard University and many other independent researchers who found reduced effectiveness of vaccines and adverse impacts on mammary gland development from exposure to PFOA and PFOS, the two PFAS most widely detected in drinking water. This health guideline applies to the entire class of PFAS detected in water.

ppt = parts per trillion

All test results

Date Lab ID Result
2014-06-09201406100164AMND
2014-06-09201406100167AMND
2014-06-09201406100207AMND
2014-06-09201406100397AMND
2014-06-09201406100209AMND
2014-06-09201406100213AMND
2014-06-10201406110853AM53.0 ppt
2014-06-10201406110967AMND
2014-06-10201406110900AMND
2014-06-10201406110898AMND
2014-06-10201406110893AMND
2014-06-24201406250372AMND
2014-07-23201407240488AMND
2014-12-08201412090550AMND
2014-12-08201412090763AMND
2014-12-08201412090511AMND
2014-12-08201412090769AMND
2014-12-08201412090513AMND
2014-12-08201412090773AM140.0 ppt
2014-12-08201412090588AMND
2014-12-08201412090775AMND
2014-12-09201412100782AMND
2015-05-04201505050286AMND
2015-06-16201506040131AMND
2015-06-16201506040133AMND
2015-06-16201506040135AMND