Perfluorooctane sulfonate (PFOS)
Status: No national drinking water standard exists
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.
2012-2017:
27
states detected
200
utilities detected
11 million
people served
26
states over health guideline
175
utilities over health guideline
9.9 million
people served over health guideline
Health concerns for PFOS
Cancer
Harm to the immune system
Hormone disruption
Harm to fetal growth and child development
Harm to the liver
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
States reporting PFOS in drinking water
UTILITIES REPORTING ABOVE HEALTH GUIDELINES | UTILITIES WITH CONTAMINATION | ||||||
---|---|---|---|---|---|---|---|
State | Utilities | People Served | Utilities | People Served | |||
Florida | 26 | 3,147,966 | 26 | 3,147,966 | |||
California | 20 | 2,031,706 | 20 | 2,031,706 | |||
New York | 10 | 1,182,675 | 19 | 1,204,643 | |||
New Jersey | 8 | 884,136 | 10 | 1,103,566 | |||
Ohio | 8 | 349,931 | 8 | 349,931 | |||
North Carolina | 5 | 319,091 | 6 | 334,379 | |||
Delaware | 1 | 301,000 | 1 | 301,000 | |||
Alabama | 23 | 306,528 | 22 | 298,656 | |||
Wisconsin | 1 | 53,000 | 6 | 291,297 | |||
Arizona | 6 | 266,863 | 6 | 266,863 | |||
Pennsylvania | 7 | 199,941 | 7 | 199,941 | |||
Texas | 18 | 178,722 | 16 | 177,519 | |||
Michigan | 4 | 164,729 | 4 | 164,729 | |||
Massachusetts | 7 | 147,638 | 7 | 147,638 | |||
Alaska | 0 | 0 | 7 | 115,049 | |||
Minnesota | 2 | 40,938 | 3 | 105,288 | |||
New Hampshire | 7 | 62,797 | 9 | 88,752 | |||
Georgia | 3 | 75,208 | 3 | 75,208 | |||
Rhode Island | 6 | 39,154 | 7 | 62,018 | |||
Colorado | 3 | 59,000 | 3 | 59,000 | |||
Maine | 2 | 45,465 | 2 | 45,465 | |||
Illinois | 2 | 27,393 | 2 | 27,393 | |||
Washington | 1 | 22,926 | 1 | 22,926 | |||
Indiana | 1 | 16,800 | 1 | 16,800 | |||
West Virginia | 1 | 15,652 | 1 | 15,652 | |||
Kentucky | 1 | 3,713 | 1 | 3,713 | |||
Tennessee | 2 | 3,312 | 2 | 3,312 |
Filtering technologies that reduce PFOS

Activated Carbon

Reverse Osmosis
Utilities with the highest amounts of PFOS, 2012-2017
Utility | Location | Tests | Average level | People served |
---|---|---|---|---|
Ayer DPW Water Division | Ayer, MA | 6 of 6 | 33,833.3 ppt | 7,427 |
Devens Massdevelopment* | Devens, MA | 8 of 9 | 33,666.7 ppt | 6,500 |
Mashpee Water District* | Mashpee, MA | 2 of 17 | 5,294.1 ppt | 34,257 |
Hudson Water Supply | Hudson, MA | 6 of 12 | 2,791.7 ppt | 18,954 |
Hyannis Water System | Hyannis, MA | 11 of 18 | 1,100.8 ppt | 35,000 |
Pawling Water District #1 | Pawling, NY | 4 of 16 | 270.8 ppt | 100 |
Pawling Village* | Pawling, NY | 4 of 16 | 270.8 ppt | 2,200 |
Oatman Water Company | Scottsdale, AZ | 2 of 2 | 265.0 ppt | 129 |
Security Waster District | Colorado Springs, CO | 35 of 38 | 169.7 ppt | 19,000 |
City of Stuart - Water Plant | Stuart, FL | 2 of 2 | 160.0 ppt | 19,000 |
Issaquah Water System | Issaquah, WA | 3 of 9 | 158.8 ppt | 22,926 |
Newburgh City | Newburgh, NY | 4 of 4 | 150.0 ppt | 28,000 |
Oakdale* | Oakdale, MN | 66 of 146 | 124.2 ppt | 27,378 |
Horsham Water&sewer Authority* | Horsham, PA | 169 of 395 | 97.2 ppt | 25,000 |
Rome* | Rome, GA | 4 of 4 | 95.0 ppt | 45,586 |
Wright-Patterson AFB Area A PWS | Wright Patterson Afb, OH | 4 of 8 | 85.0 ppt | 16,551 |
Artesian Water Company* | Newark, DE | 4 of 39 | 77.9 ppt | 301,000 |
Warminster Municipal Authority* | Warminster, PA | 10 of 38 | 72.8 ppt | 40,000 |
Ocala Palms (consec.) | Ocala, FL | 2 of 2 | 50.5 ppt | 100 |
City of Ocala* | Ocala, FL | 2 of 2 | 50.5 ppt | 50,924 |
City of North Miami* | North Miami, FL | 2 of 2 | 50.0 ppt | 80,000 |
Oakland Association Inc. | Oakland, RI | 3 of 5 | 48.9 ppt | 175 |
FKAA J. Robert Dean Water Treatment Plant | Florida City, FL | 2 of 2 | 48.5 ppt | 73,090 |
Warrington Twp Water&sew Dept | Warrington, PA | 3 of 17 | 48.4 ppt | 18,400 |
Town Creek Water System | Town Creek, AL | 2 of 4 | 45.0 ppt | 1,635 |
West Morgan-East Lawrence Water Authority* | Decatur, AL | 2 of 4 | 45.0 ppt | 26,130 |
Trinity Water Works System | Trinity, AL | 2 of 4 | 45.0 ppt | 2,475 |
Camp Pendleton (South) | Camp Pendleton, CA | 15 of 97 | 41.7 ppt | 39,400 |
United Water Pennsylvania | Harrisburg, PA | 1 of 9 | 40.3 ppt | 97,645 |
Addison Water Works* | Addison, AL | 4 of 8 | 40.0 ppt | 2,544 |
V.A.W. Water System, Inc* | Vinemont, AL | 4 of 8 | 40.0 ppt | 29,985 |
Whorton Bend Water and Fire Pro Authority | Gadsden, AL | 3 of 4 | 35.0 ppt | 1,890 |
Gadsden Water Works and Sewer Board* | Gadsden, AL | 3 of 4 | 35.0 ppt | 44,637 |
Highland Water Authority | Gadsden, AL | 3 of 4 | 35.0 ppt | 5,271 |
Northeast Etowah County Water Co-op | Gadsden, AL | 3 of 4 | 35.0 ppt | 4,176 |
Widefield WSD* | Colorado Springs, CO | 6 of 17 | 34.6 ppt | 19,000 |
Montebello Land & Water Company | Montebello, CA | 4 of 6 | 34.3 ppt | 32,219 |
Liberty Water Lpsco* | Avondale, AZ | 2 of 12 | 34.2 ppt | 45,298 |
Sanford Water District | Sanford, ME | 2 of 16 | 33.8 ppt | 14,025 |
Atlantic City Municipal Utilities Authority | Atlantic City, NJ | 5 of 7 | 32.9 ppt | 152,415 |
City of Martinsburg* | Martinsburg, WV | 3 of 8 | 29.9 ppt | 15,652 |
Yorba Linda Water District | Yorba Linda, CA | 14 of 18 | 29.8 ppt | 77,513 |
California American Water Company - Suburban | Sacramento, CA | 18 of 96 | 29.3 ppt | 111,768 |
City of Miami Beach | Miami Beach, FL | 1 of 2 | 29.0 ppt | 95,000 |
Pendleton County Water District #1/south | Falmouth, KY | 2 of 4 | 27.1 ppt | 3,713 |
Freeport | Freeport, IL | 2 of 7 | 26.7 ppt | 26,443 |
City of Greensboro* | Greensboro, NC | 3 of 8 | 24.8 ppt | 277,080 |
City of Lauderhill | Lauderhill, FL | 1 of 2 | 24.5 ppt | 55,000 |
Dover Water Department | Dover, NH | 2 of 6 | 23.2 ppt | 28,000 |
Plainfield Township | Grand Rapids, MI | 3 of 5 | 22.7 ppt | 40,891 |
* This water utility supplies finished drinking water to at least one other water utility. The purchasing utility is not required to test for or report Perfluorooctane sulfonate (PFOS), but it likely has the contaminant in its water supply.
Utility | Location | Tests | Average level | People served |
---|---|---|---|---|
Mashpee Water District* | Mashpee, MA | 2 of 17 | 5,294.1 ppt | 34,257 |
Hudson Water Supply | Hudson, MA | 6 of 12 | 2,791.7 ppt | 18,954 |
Hyannis Water System | Hyannis, MA | 11 of 18 | 1,100.8 ppt | 35,000 |
Security Waster District | Colorado Springs, CO | 35 of 38 | 169.7 ppt | 19,000 |
City of Stuart - Water Plant | Stuart, FL | 2 of 2 | 160.0 ppt | 19,000 |
Issaquah Water System | Issaquah, WA | 3 of 9 | 158.8 ppt | 22,926 |
Newburgh City | Newburgh, NY | 4 of 4 | 150.0 ppt | 28,000 |
Oakdale* | Oakdale, MN | 66 of 146 | 124.2 ppt | 27,378 |
Horsham Water&sewer Authority* | Horsham, PA | 169 of 395 | 97.2 ppt | 25,000 |
Rome* | Rome, GA | 4 of 4 | 95.0 ppt | 45,586 |
Wright-Patterson AFB Area A PWS | Wright Patterson Afb, OH | 4 of 8 | 85.0 ppt | 16,551 |
Artesian Water Company* | Newark, DE | 4 of 39 | 77.9 ppt | 301,000 |
Warminster Municipal Authority* | Warminster, PA | 10 of 38 | 72.8 ppt | 40,000 |
City of Ocala* | Ocala, FL | 2 of 2 | 50.5 ppt | 50,924 |
City of North Miami* | North Miami, FL | 2 of 2 | 50.0 ppt | 80,000 |
FKAA J. Robert Dean Water Treatment Plant | Florida City, FL | 2 of 2 | 48.5 ppt | 73,090 |
Warrington Twp Water&sew Dept | Warrington, PA | 3 of 17 | 48.4 ppt | 18,400 |
West Morgan-East Lawrence Water Authority* | Decatur, AL | 2 of 4 | 45.0 ppt | 26,130 |
Camp Pendleton (South) | Camp Pendleton, CA | 15 of 97 | 41.7 ppt | 39,400 |
United Water Pennsylvania | Harrisburg, PA | 1 of 9 | 40.3 ppt | 97,645 |
V.A.W. Water System, Inc* | Vinemont, AL | 4 of 8 | 40.0 ppt | 29,985 |
Gadsden Water Works and Sewer Board* | Gadsden, AL | 3 of 4 | 35.0 ppt | 44,637 |
Widefield WSD* | Colorado Springs, CO | 6 of 17 | 34.6 ppt | 19,000 |
Montebello Land & Water Company | Montebello, CA | 4 of 6 | 34.3 ppt | 32,219 |
Liberty Water Lpsco* | Avondale, AZ | 2 of 12 | 34.2 ppt | 45,298 |
Sanford Water District | Sanford, ME | 2 of 16 | 33.8 ppt | 14,025 |
Atlantic City Municipal Utilities Authority | Atlantic City, NJ | 5 of 7 | 32.9 ppt | 152,415 |
City of Martinsburg* | Martinsburg, WV | 3 of 8 | 29.9 ppt | 15,652 |
Yorba Linda Water District | Yorba Linda, CA | 14 of 18 | 29.8 ppt | 77,513 |
California American Water Company - Suburban | Sacramento, CA | 18 of 96 | 29.3 ppt | 111,768 |
City of Miami Beach | Miami Beach, FL | 1 of 2 | 29.0 ppt | 95,000 |
Freeport | Freeport, IL | 2 of 7 | 26.7 ppt | 26,443 |
City of Greensboro* | Greensboro, NC | 3 of 8 | 24.8 ppt | 277,080 |
City of Lauderhill | Lauderhill, FL | 1 of 2 | 24.5 ppt | 55,000 |
Dover Water Department | Dover, NH | 2 of 6 | 23.2 ppt | 28,000 |
Plainfield Township | Grand Rapids, MI | 3 of 5 | 22.7 ppt | 40,891 |
Westfield Water Department | Westfield, MA | 3 of 13 | 22.6 ppt | 42,000 |
Bemidji | Bemidji, MN | 4 of 19 | 20.5 ppt | 13,560 |
City of Tempe | Tempe, AZ | 6 of 24 | 19.7 ppt | 165,000 |
Dyer Water Department | Dyer, IN | 1 of 4 | 19.6 ppt | 16,800 |
Emerald Coast Utilities Authority* | Pensacola, FL | 5 of 52 | 19.2 ppt | 249,872 |
City of Fountain | Fountain, CO | 4 of 12 | 18.3 ppt | 21,000 |
Chatsworth | Chatsworth, GA | 4 of 12 | 17.4 ppt | 28,262 |
City of Lathrop | Lathrop, CA | 2 of 8 | 16.8 ppt | 12,427 |
Liberty Utilities - Bellflower - Norwalk | Downey, CA | 4 of 12 | 16.2 ppt | 72,884 |
Montgomery County Water Services* | Kettering, OH | 1 of 4 | 15.3 ppt | 96,498 |
Rainbow City Utilities Board* | Rainbow City, AL | 1 of 4 | 15.0 ppt | 11,748 |
City of Anaheim | Anaheim, CA | 11 of 38 | 14.4 ppt | 450,000 |
West Lawrence Water Co-op* | Moulton, AL | 2 of 12 | 14.2 ppt | 14,562 |
City of Zephyrhills* | Zephyrhills, FL | 2 of 17 | 13.9 ppt | 21,823 |
* This water utility supplies finished drinking water to at least one other water utility. The purchasing utility is not required to test for or report Perfluorooctane sulfonate (PFOS), but it likely has the contaminant in its water supply.