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EWG's Tap Water Database — 2021 UPDATE

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Perfluorooctane sulfonate (PFOS)

City of Flagstaff

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.

 

22

Samples

0

Samples exceeding legal limit (MCL)

0

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2013ND90ND
2014ND130ND
2015N/A00N/A
2016N/A00N/A
2017N/A00N/A
2018N/A00N/A
2019N/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.

EPA Proposed Maximum Contaminant
Level (MCL) 4 ppt

The proposed legal limit for PFOS is 4 ppt, based on studies on people, including children, showing cancer risk.

ppt = parts per trillion

All test results

Date Lab ID Result
2013-10-23201310240365AMND
2013-10-24201310250061AMND
2013-10-24201310250063AMND
2013-10-24201310250090AMND
2013-10-24201310250083AMND
2013-10-29201310300118AMND
2013-10-29201310300044AMND
2013-10-30201310310165AMND
2013-10-31201311010185AMND
2014-01-29201401300212AMND
2014-01-29201401300194AMND
2014-04-30201405020267AMND
2014-04-30201405020165AMND
2014-04-30201405020259AMND
2014-04-30201405020263AMND
2014-04-30201405020261AMND
2014-04-30201405020163AMND
2014-05-02201405060311AMND
2014-05-29201405300269AMND
2014-06-12201406130296AMND
2014-07-17201407180221AMND
2014-07-17201407180219AMND