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EWG's Tap Water Database — 2021 UPDATE

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Perfluorooctane sulfonate (PFOS)

California American Water Company - Lincoln Oaks

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.

 

64

Samples

0

Samples exceeding legal limit (MCL)

2

Samples exceeding
health guidelines

Testing results - average by year

 
YearAverage resultSamples takenDetectionsRange of results
2014N/A00N/A
2015ND390ND
2016N/A00N/A
2017ND30ND
2018ND10ND
20190.691 ppt212ND - 7.80 ppt

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
2015-02-0228255701ND
2015-02-0228254801ND
2015-02-0328256801ND
2015-02-0328256701ND
2015-02-0428256301ND
2015-02-0428255201ND
2015-02-1028257001ND
2015-02-1028256001ND
2015-02-1228256601ND
2015-02-1228256401ND
2015-02-1728255401ND
2015-02-1728257101ND
2015-02-1928256901ND
2015-02-1928256201ND
2015-02-2428256101ND
2015-02-2528255101ND
2015-02-2728255901ND
2015-05-2728255801ND
2015-06-0929303701ND
2015-06-1729303901ND
2015-08-1030016301ND
2015-08-1030013601ND
2015-08-1030016001ND
2015-08-1030013201ND
2015-08-1130012901ND
2015-08-1130014201ND
2015-08-1130014801ND
2015-08-1130015201ND
2015-08-1330015701ND
2015-08-1330016801ND
2015-08-1330013901ND
2015-08-1829303801ND
2015-08-1830014601ND
2015-08-1830016701ND
2015-08-1930013401ND
2015-08-1930015001ND
2015-08-2430015401ND
2015-08-2530016601ND
2015-12-0730878501ND
2017-11-149590-016-0800ND
2017-11-209590-022-0930ND
2017-11-299590-025-1145ND
2018-03-229590-022-1050ND
2019-11-181225-005-1140ND
2019-11-181225-019-1415ND
2019-11-181225-016-1115ND
2019-11-181225-024-1220ND
2019-11-181225-015-0835ND
2019-11-181225-009-1350ND
2019-11-181225-002-1255ND
2019-11-201225-028-1305ND
2019-11-201225-008-1405ND
2019-11-201225-026-1345ND
2019-11-201225-014-1245ND
2019-11-201225-001-1455ND
2019-11-201225-022-1145ND
2019-11-201225-012-1330ND
2019-11-201225-006-1110ND
2019-11-201225-021-1440ND
2019-11-211225-023-1450ND
2019-11-211225-003-1330ND
2019-11-211225-013-1245ND
2019-11-251225-010-17107.80 ppt
2019-12-121225-010-16006.70 ppt