Perfluorooctane sulfonate (PFOS)

Redmond Water Department

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.

MORE ABOUT THIS CONTAMINANT

Samples

Samples exceeding legal limit (MCL)

Samples exceeding
health guidelines

Testing results - average by year

Year	Average result	Samples taken	Range of results
2014	ND	14	ND
2015	N/A	0	N/A
2016	N/A	0	N/A
2017	N/A	0	N/A
2018	N/A	0	N/A
2019	N/A	0	N/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 Maximum Contaminant
Level (MCL) 4 ppt

ppt = parts per trillion

All test results

Date	Lab ID	Result
2014-03-18	201403190626AM	ND
2014-03-18	201403190601AM	ND
2014-03-18	201403190846AM	ND
2014-03-18	201403190605AM	ND
2014-03-19	201403200285AM	ND
2014-03-19	201403200411AM	ND
2014-03-19	201403200279AM	ND
2014-09-10	201409110583AM	ND
2014-09-10	201409110753AM	ND
2014-09-10	201409110840AM	ND
2014-09-15	201409160629AM	ND
2014-09-15	201409160635AM	ND
2014-09-15	201409160591AM	ND
2014-10-20	201410210247AM	ND