PFAS Analyte · UCMR 5
PFOS
Perfluorooctane sulfonic acid
Detection Rate — PFOS
896 of 6,146 monitored systems
3,032 detections across 39,261 total samples
States with Most PFOS Detections
Water Systems with Most PFOS Detections
Systems ranked by number of samples detected above the minimum reporting limit. Detection count reflects monitoring frequency, not concentration level.
City of Fresno
CA1010007 · CA · 545,716 served
Brookwood Comm Wtr System
NC0326127 · NC · 15,380 served
Ridgewood Water
NJ0251001 · NJ · 61,700 served
Cliffdale West
NC0326332 · NC · 15,220 served
Northampton Bucks Co Mun Auth
PA1090089 · PA · 36,750 served
Emerald Coast Utilities Authority (ecua)
FL1170525 · FL · 242,172 served
Town of Payson
AZ0404032 · AZ · 17,682 served
Cws - Bakersfield
CA1510003 · CA · 267,881 served
Aqua Pa Main System
PA1460073 · PA · 822,600 served
Town of Harrisburg
NC0113025 · NC · 20,549 served
Ambler Boro Water Dept
PA1460020 · PA · 20,000 served
Cal-water Service Co.-chico
CA0410002 · CA · 114,925 served
City of Vancouver
WA5391200 · WA · 373,047 served
City of Modesto
CA5010010 · CA · 218,771 served
Pico Rivera - City, Water Dept.
CA1910042 · CA · 40,600 served
All records are from official EPA UCMR 5 monitoring data. Detection counts reflect the number of samples where the analyte was reported above the minimum reporting limit (MRL). They are not compliance determinations and do not imply a health violation. The EPA MCL for PFOS is 4 ppt under the PFAS National Primary Drinking Water Regulation (April 2024).
PFOS at a Glance
Note
Individual MCL of 4 ppt finalized April 2024.