EPA UCMR 5 Data · California

PFAS Drinking-Water Monitoring Results in California

This page summarizes EPA Fifth Unregulated Contaminant Monitoring Rule (UCMR 5, 2023–2025) drinking-water monitoring records linked to ZIP codes in California, as processed for the PFAS Estimator national dataset. Data updated: July 2026.

39.0% of California ZIP codes in this dataset (1076 total)
had at least one regulated PFAS compound detected at or above its applicable EPA threshold (420 of 1076 ZIP codes). Of those, 290 (69.0%) had more than one compound at or above threshold. This dataset includes only ZIP codes with at least one recorded PFAS detection; ZIP codes where all compounds returned non-detect are not represented.

Compounds detected in California

Detection prevalence, exceedance, and concentration by compound, California ZIP codes in the EPA UCMR 5 analytic dataset.
Compound Applicable threshold ZIP codes detected At/above threshold Mean detected Maximum detected
PFOA0.004 µg/L (MCL)318 (29.6% of state)318 (100.0%) — all detections at/above limit by construction0.0109 µg/L0.1883 µg/L
PFOS0.004 µg/L (MCL)388 (36.1% of state)388 (100.0%) — all detections at/above limit by construction0.017 µg/L0.2365 µg/L
PFHxS0.01 µg/L (MCL)416 (38.7% of state)96 (23.1% of detected)0.0096 µg/L0.2502 µg/L
PFNA0.01 µg/L (MCL)34 (3.2% of state)1 (2.9% of detected)0.0069 µg/L0.0102 µg/L
PFBS2.0 µg/L (HI reference)314 (29.2% of state)not calculated¹0.0066 µg/L0.0647 µg/L
Lithium7.36 µg/L (reference, not a regulatory limit)878 (81.6% of state)878 (100.0%) at/above reference53.2917 µg/L474.0 µg/L
PFPeA— (no federal limit)404 (37.5% of state)0.0103 µg/L0.062 µg/L
PFBA— (no federal limit)357 (33.2% of state)0.0095 µg/L0.028 µg/L
PFHpA— (no federal limit)175 (16.3% of state)0.0078 µg/L0.0727 µg/L
6:2 FTS— (no federal limit)5 (0.5% of state)0.0187 µg/L0.0503 µg/L
PFDA— (no federal limit)9 (0.8% of state)0.0037 µg/L0.0056 µg/L

ZIP codes in this dataset (California)

1076 ZIP codes with at least one recorded PFAS detection. Click a ZIP code to view its full compound-level results.

Per-ZIP-code detection summary for California
ZIP code Compounds detected At/above threshold
900011No
900021No
900031No
900041No
900051No
900061No
900071No
900081No
900101No
900111No
900121No
900131No
900141No
900151No
900161No
900171No
900181No
900191No
900201No
900211No
900225Yes (1)
900235Yes (1)
900241No
900251No
900261No
900271No
900281No
900291No
900301No
900311No
900325Yes (1)
900335Yes (1)
900341No
900351No
900361No
900371No
900381No
900391No
900408Yes (2)
900411No
900421No
900431No
900441No
900451No
900461No
900471No
900481No
900491No
900561No
900571No
900588Yes (2)
900591No
900611No
900621No
900635Yes (1)
900641No
900651No
900661No
900671No
900681No
900691No
900711No
900771No
900941No
900951No
902018Yes (2)
902091No
902101No
902111No
902121No
902131No
902204Yes (2)
902214Yes (2)
902221No
902301No
902321No
902408Yes (2)
902418Yes (2)
902427Yes (2)
902451No
902471No
902482No
902491No
902501No
902541No
902557Yes (2)
902601No
902625Yes (2)
902631No
902641No
902651No
902661No
902704Yes (2)
902721No
902741No
902751No
902772No
902781No
902807Yes (2)
902911No
902921No
902931No
903012Yes (1)
903022Yes (1)
903032Yes (1)
903041No
903052Yes (1)
904016Yes (1)
904026Yes (1)
904036Yes (1)
904046Yes (1)
904056Yes (1)
905012No
905022No
905032No
905042No
905052No
906012No
906025Yes (2)
906035Yes (2)
906047Yes (2)
906057Yes (2)
906065Yes (2)
906207Yes (2)
906217Yes (2)
906231No
906305Yes (2)
906317Yes (2)
906387Yes (2)
906397Yes (2)
906409Yes (2)
906508Yes (3)
906608Yes (2)
906708Yes (3)
906805Yes (2)
907018Yes (3)
907033Yes (1)
907042No
907068Yes (3)
907078Yes (3)
907102No
907122Yes (1)
907132Yes (1)
907152Yes (1)
907162Yes (1)
907173Yes (1)
907205Yes (2)
907232No
907311No
907321No
907401No
907423Yes (1)
907431No
907442No
907452No
907462No
907472No
907551No
908011No
908021No
908031No
908041No
908052No
908061No
908071No
908083Yes (1)
908102No
908131No
908141No
908151No
908221No
908311No
908331No
910017Yes (3)
910036Yes (3)
910065Yes (2)
910073Yes (2)
910082Yes (1)
910103Yes (2)
910116Yes (1)
910121No
910165Yes (2)
910206Yes (1)
910401No
910421No
910466Yes (1)
911011No
911031No
911047Yes (3)
911051No
911061No
911072No
911082No
912018Yes (2)
912058Yes (2)
912068Yes (2)
912088Yes (2)
912148Yes (2)
913011No
913021No
913031No
913041No
913061No
913071No
913111No
913161No
913218Yes (2)
913241No
913251No
913261No
913291No
913301No
913311No
913351No
913401No
913421No
913431No
913441No
913451No
913508Yes (2)
913518Yes (2)
913521No
913548Yes (2)
913558Yes (2)
913561No
913601No
913611No
913621No
913641No
913671No
913711No
913771No
913818Yes (2)
913848Yes (2)
913878Yes (2)
913908Yes (2)
914011No
914021No
914031No
914051No
914061No
914111No
914231No
914364No
915012No
915022No
915032No
915045No
915053No
915062No
916011No
916021No
916041No
916051No
916061No
916071No
916081No
917022Yes (2)
917064Yes (2)
917096Yes (2)
917107Yes (2)
917192No
917223Yes (2)
917237Yes (2)
917246Yes (2)
917316Yes (2)
917324Yes (1)
917334Yes (1)
917403Yes (2)
917412Yes (2)
917444No
917454No
917462No
917484No
917502Yes (1)
917545Yes (1)
917553No
917617Yes (2)
917625Yes (2)
917634Yes (1)
917645Yes (2)
917654No
917667Yes (2)
917677Yes (2)
917686Yes (2)
917703No
917716Yes (2)
917732Yes (1)
917751No
917766Yes (2)
917805Yes (2)
917846Yes (2)
917862No
917895Yes (1)
917906Yes (2)
917917Yes (2)
917924No
918011No
918032No
919013No
919028Yes (2)
919108Yes (2)
919118Yes (2)
919131No
919141No
919151No
919171No
919321No
919351No
919411No
919421No
919451No
919508Yes (2)
919638Yes (4)
919771No
919781No
920031No
920041No
920074Yes (1)
920081No
920091No
920101No
920111No
920142No
920192No
920202No
920212No
920244Yes (1)
920252No
920262No
920271No
920281No
920292No
920371No
920406Yes (1)
920541No
920553No
920561No
920571No
920581No
920594Yes (1)
920641No
920651No
920672No
920691No
920712No
920741No
920752No
920781No
920811No
920825Yes (2)
920831No
920841No
920881No
920912No
920931No
921011No
921021No
921031No
921041No
921051No
921061No
921071No
921081No
921091No
921101No
921111No
921131No
921141No
921151No
921161No
921171No
921181No
921191No
921201No
921211No
921221No
921231No
921241No
921261No
921271No
921281No
921291No
921301No
921311No
921341No
921351No
921361No
921391No
921401No
921451No
921548Yes (2)
921611No
921731No
921791No
921821No
922011No
922101No
922111No
922202No
922251No
922271No
922311No
922331No
922341No
922431No
922491No
922501No
922511No
922521No
922531No
922541No
922571No
922602No
922701No
922741No
922761No
922771No
922831No
922843No
923013Yes (1)
923071No
923081No
923101No
923114Yes (1)
923138Yes (3)
923146Yes (3)
923155Yes (2)
923177Yes (2)
923205Yes (1)
923217Yes (2)
923246Yes (2)
923257Yes (3)
923427Yes (3)
923457Yes (3)
923467Yes (2)
923502Yes (1)
923528Yes (2)
923546Yes (2)
923594Yes (2)
923631No
923734Yes (2)
923744Yes (2)
923754Yes (2)
923767Yes (1)
923776Yes (1)
923828Yes (3)
923851No
923865Yes (2)
923921No
923931No
923941No
923952No
923972No
923994Yes (1)
924014No
924047Yes (2)
924054No
924074No
924086Yes (2)
924107Yes (2)
924114No
924154No
925003Yes (1)
925015Yes (1)
925036Yes (1)
925046Yes (1)
925055Yes (1)
925065Yes (1)
925078Yes (3)
925085Yes (1)
925095No
925134No
925174No
925184No
925302No
925312No
925325No
925431No
925441No
925451No
925481No
925514No
925535Yes (1)
925552No
925574No
925628Yes (2)
925635Yes (2)
925644Yes (2)
925675Yes (2)
925705No
925712No
925721No
925824Yes (2)
925831No
925842No
925852No
925862No
925872No
925908Yes (2)
925918Yes (2)
925928Yes (2)
925933No
925956Yes (2)
925962No
926023No
926033No
926043No
926063No
926092No
926103No
926123No
926143No
926173No
926183No
926193No
926203No
926233No
926242No
926251No
926263No
926273No
926292No
926303No
926372No
926435Yes (2)
926463Yes (1)
926473Yes (1)
926483Yes (1)
926493Yes (1)
926503No
926512No
926532No
926542No
926553Yes (1)
926562No
926573No
926605No
926611No
926623No
926631No
926665Yes (2)
926721No
926731No
926741No
926751No
926763No
926771No
926793No
926833Yes (1)
926881No
926912No
926922No
926941No
927015Yes (2)
927025Yes (2)
927035Yes (2)
927045Yes (2)
927057Yes (3)
927065Yes (2)
927075Yes (2)
927085Yes (2)
927115Yes (2)
927125Yes (2)
927355Yes (2)
927805Yes (1)
927823No
927995Yes (2)
928017Yes (3)
928027Yes (3)
928037Yes (3)
928047Yes (3)
928057Yes (3)
928067Yes (3)
928077Yes (3)
928087Yes (3)
928211No
928233No
928318Yes (2)
928328Yes (2)
928338Yes (2)
928358Yes (2)
928406Yes (2)
928416Yes (2)
928426Yes (2)
928436Yes (2)
928446Yes (2)
928456Yes (2)
928466Yes (2)
928607Yes (3)
928617Yes (3)
928657Yes (3)
928667Yes (3)
928677Yes (3)
928687Yes (3)
928697Yes (3)
928707Yes (2)
928774No
928784No
928796Yes (1)
928804No
928815No
928825Yes (1)
928835No
928853No
928867Yes (2)
928873No
930013No
930023No
930033No
930043No
930053No
930063No
930073No
930105Yes (2)
930123Yes (1)
930131No
930151No
930201No
930211No
930221No
930231No
930241No
930301No
930331No
930351No
930361No
930411No
930601No
930611No
930631No
930651No
931011No
931031No
931051No
931081No
931091No
931102No
931112No
931172No
932151No
932411No
932423Yes (2)
932474Yes (2)
932578Yes (2)
932745Yes (2)
932775Yes (2)
932915Yes (2)
932925Yes (2)
933018Yes (2)
933047Yes (2)
933057Yes (2)
933067Yes (2)
933077Yes (2)
933088Yes (2)
933098Yes (2)
933118Yes (2)
933125Yes (1)
933138Yes (2)
933148Yes (2)
934011No
934028Yes (2)
934051No
934206Yes (2)
934226Yes (2)
934233Yes (2)
934271No
934341No
934361No
934371No
934411No
934441No
934467Yes (1)
934481No
934491No
934541No
934551No
934581No
934601No
934632No
934653No
935011No
935051No
935231No
935241No
935341No
935351No
935361No
935391No
935461No
935506Yes (1)
935513No
935522No
935551No
935561No
935601No
935617Yes (2)
935841No
935861No
936042No
936101Yes (1)
936119Yes (2)
936129Yes (2)
936144Yes (1)
936199Yes (2)
936221No
936251No
936351No
936441No
936507Yes (2)
936573Yes (2)
936601No
937018Yes (3)
937028Yes (3)
937038Yes (3)
937048Yes (3)
937058Yes (3)
937068Yes (3)
937108Yes (3)
937118Yes (3)
937208Yes (3)
937218Yes (3)
937228Yes (3)
937238Yes (3)
937258Yes (3)
937268Yes (3)
937279Yes (3)
937288Yes (3)
937308Yes (3)
937405Yes (1)
939011No
939051No
939061No
939071No
939081No
939218Yes (2)
939238Yes (2)
939248Yes (2)
939261No
939271No
939301No
939331No
939408Yes (2)
939438Yes (2)
939448Yes (2)
939508Yes (2)
939538Yes (2)
939558Yes (2)
939601No
940056Yes (2)
940141No
940151No
940221No
940241No
940351No
940391No
940402No
940412No
940421No
940431No
940661No
940801No
940861No
940871No
941296Yes (1)
943061No
945011No
945021No
945051No
945061No
945071No
945102No
945131No
945153Yes (2)
945231No
945251No
945261No
945281No
945301No
945351No
945411No
945421No
945441No
945451No
945461No
945471No
945491No
945506Yes (2)
945516Yes (2)
945521No
945531No
945561No
945611No
945631No
945641No
945651No
945667Yes (3)
945681No
945691No
945711No
945721No
945741No
945771No
945781No
945791No
945801No
945821No
945831No
945887Yes (3)
945951No
945961No
945971No
945981No
946011No
946021No
946031No
946051No
946061No
946071No
946081No
946091No
946101No
946111No
946121No
946131No
946181No
946191No
946211No
947021No
947031No
947041No
947051No
947061No
947071No
947081No
947091No
947101No
947201No
948011No
948031No
948041No
948051No
948061No
949241No
949284Yes (1)
949311No
950031No
950052No
950062No
950072No
950083Yes (1)
950101No
950121No
950143Yes (1)
950182No
950196Yes (2)
950207Yes (2)
950232Yes (1)
950303Yes (1)
950323Yes (1)
950333Yes (1)
950374Yes (1)
950391No
950431No
950503Yes (1)
950512No
950521No
950541No
950551No
950561No
950601No
950621No
950641No
950663No
950703Yes (1)
950731No
950766Yes (2)
950776Yes (2)
951103Yes (1)
951114Yes (1)
951123Yes (1)
951133Yes (1)
951163Yes (1)
951173Yes (1)
951183Yes (1)
951194Yes (1)
951204Yes (1)
951213Yes (1)
951223Yes (1)
951234Yes (1)
951243Yes (1)
951253Yes (1)
951263Yes (1)
951273Yes (1)
951283Yes (1)
951293Yes (1)
951303Yes (1)
951313Yes (1)
951323Yes (1)
951333Yes (1)
951341No
951351No
951364Yes (1)
951384Yes (1)
951394Yes (1)
951483Yes (1)
952021Yes (1)
952031Yes (1)
952041Yes (1)
952051Yes (1)
952061Yes (1)
952071Yes (1)
952091Yes (1)
952101Yes (1)
952111Yes (1)
952121Yes (1)
952151Yes (1)
952191Yes (1)
952221No
952231No
952311Yes (1)
952406Yes (2)
952426Yes (2)
952471No
952511No
952585Yes (2)
953018Yes (3)
953041No
953052Yes (1)
953077Yes (2)
953221No
953271No
953303Yes (1)
953363Yes (2)
953373Yes (2)
953381No
953403Yes (3)
953413Yes (3)
953483Yes (3)
953507Yes (2)
953517Yes (2)
953547Yes (2)
953557Yes (2)
953567Yes (2)
953577Yes (2)
953587Yes (2)
953601No
953631No
953653Yes (1)
953664Yes (2)
953681No
953703No
953761No
954011No
954031No
954041No
954051No
954071No
954091No
954223No
954336Yes (2)
954411No
954426Yes (2)
954483No
954511No
954531No
954581No
954641No
954671No
954721No
954766Yes (2)
954828Yes (2)
954971No
955011No
955031No
955371No
956088Yes (3)
956102No
956131No
956161No
956181No
956191No
956201No
956215No
956231No
956246Yes (2)
956262No
956285No
956461No
956482Yes (1)
956511No
956528Yes (3)
956556Yes (3)
956608Yes (3)
956611No
956621No
956671No
956706Yes (3)
956711Yes (1)
956721No
956738Yes (3)
956781No
956821No
956841No
956875Yes (2)
956885Yes (2)
956922Yes (1)
956942No
956951No
957091No
957261No
957352Yes (1)
957461No
957471No
957576Yes (2)
957588Yes (3)
957621No
957761No
958118Yes (3)
958148Yes (3)
958158Yes (3)
958168Yes (3)
958178Yes (3)
958188Yes (3)
958198Yes (3)
958208Yes (3)
958218Yes (3)
958228Yes (3)
958238Yes (3)
958248Yes (3)
958258Yes (3)
958268Yes (3)
958276Yes (3)
958288Yes (3)
958298Yes (3)
958306Yes (2)
958318Yes (3)
958328Yes (3)
958338Yes (3)
958348Yes (3)
958358Yes (3)
958388Yes (3)
958418Yes (3)
958425No
958435No
958648Yes (3)
959266Yes (3)
959286Yes (3)
959321No
959485Yes (2)
959516Yes (3)
959531No
959636Yes (3)
959653Yes (1)
959662No
959711No
959736Yes (3)
959871No
959881No
960017Yes (2)
960027Yes (2)
960037Yes (2)
960081No
960191No
960211No
960242Yes (1)
960621No
960731No
960803Yes (1)
960877Yes (2)
960932Yes (1)
961301No
961451No
961508Yes (2)
961588Yes (2)
961613Yes (1)

Methodology & limitations

Results are based on EPA UCMR 5 monitoring data (2023–2025), linked to ZIP codes via Public Water System Identifier. Non-detections are not present in this analytic dataset. For each compound and ZIP code, the highest observed concentration across the monitoring period is retained; this characterizes the upper bound of observed drinking-water concentrations, not a long-term average or an individual exposure estimate. A single water system may serve multiple ZIP codes, so the same monitoring record can appear for more than one ZIP in this table. ZIP-code assignment reflects water-system service area geography and does not establish individual household exposure. Private wells are not represented unless served by a monitored public water system. PFOA and PFOS are reported by detection prevalence because the UCMR 5 reporting limit equals their federal MCL. A full PFBS Hazard Index is not calculated because co-located, same-event multi-compound readings are not retained in this dataset. Lithium has no federal Maximum Contaminant Level; 7.36 µg/L is an evidence-based reference concentration from a prospective cohort study, not a regulatory threshold.

Related links

PFAS Estimator homepage & national ZIP lookup
Full national methodology, limitations, and dataset documentation
All states & territories index

Data from the EPA Unregulated Contaminant Monitoring Rule (UCMR 5), 2023–2025. Detection does not indicate a health risk. Not medical advice. Data updated: July 2026. · EPA Source