EPA UCMR 5 Data · Illinois

PFAS Drinking-Water Monitoring Results in Illinois

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

18.9% of Illinois ZIP codes in this dataset (493 total)
had at least one regulated PFAS compound detected at or above its applicable EPA threshold (93 of 493 ZIP codes). Of those, 24 (25.8%) 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 Illinois

Detection prevalence, exceedance, and concentration by compound, Illinois 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)29 (5.9% of state)29 (100.0%) — all detections at/above limit by construction0.0083 µg/L0.018 µg/L
PFOS0.004 µg/L (MCL)85 (17.2% of state)85 (100.0%) — all detections at/above limit by construction0.0062 µg/L0.017 µg/L
PFHxS0.01 µg/L (MCL)43 (8.7% of state)9 (20.9% of detected)0.0079 µg/L0.0182 µg/L
PFNA0.01 µg/L (MCL)6 (1.2% of state)0 (0.0% of detected)0.0045 µg/L0.0045 µg/L
PFBS2.0 µg/L (HI reference)104 (21.1% of state)not calculated¹0.007 µg/L0.0521 µg/L
Lithium7.36 µg/L (reference, not a regulatory limit)287 (58.2% of state)287 (100.0%) at/above reference30.1638 µg/L230.0 µg/L
PFPeA— (no federal limit)180 (36.5% of state)0.0062 µg/L0.0322 µg/L
PFBA— (no federal limit)326 (66.1% of state)0.0118 µg/L0.2332 µg/L
PFHpA— (no federal limit)6 (1.2% of state)0.0069 µg/L0.0133 µg/L
6:2 FTS— (no federal limit)3 (0.6% of state)0.0057 µg/L0.0063 µg/L

ZIP codes in this dataset (Illinois)

493 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 Illinois
ZIP code Compounds detected At/above threshold
600021No
600101No
600134No
600142No
600151No
600203Yes (1)
600213No
600301No
600413Yes (1)
600421No
600472No
600481No
600508Yes (2)
600601No
600731No
600813Yes (1)
600871No
600991No
601101No
601121No
601151No
601182No
601191No
601203No
601233No
601243No
601261No
601341No
601351No
601371Yes (1)
601432No
601481Yes (1)
601521No
601561No
601572No
601742No
601752No
601775Yes (1)
601781No
601831No
601851No
601881No
604011No
604037Yes (2)
604042No
604062Yes (2)
604081No
604091No
604106Yes (2)
604111No
604161No
604171No
604231No
604241No
604263Yes (2)
604301Yes (1)
604312No
604321No
604332No
604352No
604361No
604391No
604403No
604415No
604421No
604451No
604463No
604476Yes (2)
604491No
604501No
604521No
604661No
604681No
604704No
604711No
604731No
604751No
604761No
604771No
604813No
604841No
605011No
605024No
605044No
605054No
605064No
605101No
605141No
605381No
605421No
605431No
605443No
605542No
605551No
605581No
605601No
605644No
606571No
609011No
609111No
609361No
609421No
610081No
610117Yes (3)
610321Yes (1)
610371No
610712No
610721Yes (1)
610737Yes (3)
610801No
610811No
611012No
611022No
611037Yes (3)
611072No
611082No
611092No
611117Yes (3)
611142No
611157Yes (3)
612011No
612321No
612401No
612442No
612522No
612541No
612641No
612651No
612701No
612811No
612821No
612841No
612992Yes (1)
613013No
613114No
613134No
613141No
613194No
613214No
613334No
613411No
613421No
613481No
613501No
613541No
613621No
613644No
614015Yes (2)
614105Yes (2)
614141No
614161No
614221No
614253No
614272No
614305Yes (2)
614395Yes (2)
614431No
614485Yes (2)
614535Yes (2)
614543No
614551No
614621No
614693No
615202No
615236Yes (1)
615255Yes (1)
615265Yes (1)
615285Yes (1)
615357Yes (1)
615365Yes (1)
615395Yes (1)
615451No
615467Yes (1)
615475Yes (1)
615501No
615525Yes (1)
615547Yes (1)
615557Yes (1)
615587Yes (1)
615687Yes (1)
615714Yes (1)
616015Yes (1)
616025Yes (1)
616036Yes (1)
616046Yes (2)
616055Yes (1)
616065Yes (1)
616075Yes (1)
616101No
616114Yes (1)
616125Yes (1)
616135Yes (1)
616146Yes (1)
616155Yes (1)
616166Yes (1)
616255Yes (1)
616295Yes (1)
616305Yes (1)
616335Yes (1)
616345Yes (1)
616365Yes (1)
616375Yes (1)
616385Yes (1)
616395Yes (1)
616415Yes (1)
616435Yes (1)
616505Yes (1)
616515Yes (1)
616525Yes (1)
616535Yes (1)
616545Yes (1)
616555Yes (1)
616565Yes (1)
617011No
617041No
617051No
617404No
617481No
617611No
617642No
617761No
618011No
618021No
618031No
618151No
618201No
618211No
618221No
618241No
618251No
618261No
618321No
618431No
618631No
618721No
618731No
618741No
618771No
618801No
619141No
619202No
619281No
619381No
619531No
619561No
619571No
620013No
620023No
620063No
620107Yes (2)
620111No
620122No
620131No
620142No
620185No
620212No
620223No
620248Yes (2)
620256Yes (2)
620262No
620283No
620312No
620321No
620343No
620353No
620361No
620373No
620404No
620451No
620463No
620471No
620523No
620531No
620583No
620593No
620603No
620613No
620621No
620651No
620674No
620701No
620713No
620743No
620751No
620761No
620801No
620831No
620844Yes (2)
620882No
620903No
620941No
620952No
620975Yes (2)
622013No
622023No
622033No
622043No
622053No
622064No
622073No
622083No
622141No
622171No
622181No
622203No
622213No
622223No
622233No
622253No
622263No
622311No
622323No
622334No
622348Yes (3)
622366Yes (1)
622371No
622381No
622396Yes (1)
622406Yes (1)
622414No
622431Yes (1)
622441No
622463No
622493No
622542No
622551No
622561No
622571No
622582Yes (1)
622606Yes (1)
622631No
622641No
622651Yes (1)
622681No
622693No
622711No
622721No
622741No
622753No
622781No
622814No
622843No
622853No
622861No
622931Yes (1)
622944No
622951No
622983No
623012No
623053No
623261No
623381No
623412No
623542No
623551No
623582No
623601No
623611No
623741No
623792No
624011No
624111No
624131No
624141No
624181No
624191No
624201No
624211No
624221No
624241No
624251No
624261No
624281No
624311No
624321No
624332Yes (1)
624341No
624361No
624381No
624401No
624431No
624441No
624451No
624461No
624471No
624481No
624493Yes (1)
624501No
624512Yes (1)
624521No
624543Yes (1)
624581No
624611No
624621No
624631No
624651No
624661No
624671No
624681No
624691No
624731No
624751No
624761No
624791No
624801No
624811No
625101No
625211No
625341No
625461No
625491No
625501No
625531No
625551No
625571No
625651No
625681No
625711No
626011No
626212No
626261No
626281No
626381No
626502No
626564Yes (1)
626852No
626942No
627031No
628011No
628061No
628081No
628101No
628121No
628141No
628151No
628172No
628211No
628241No
628281No
628301No
628311No
628321No
628352No
628381No
628561No
628581No
628591No
628602No
628632Yes (1)
628641No
628671No
628681No
628691No
628711No
628721No
628771No
628791No
628801No
628831No
628881No
628891No
628902No
628931No
628941No
628951No
628961No
628981No
629061No
629071No
629161No
629172No
629181No
629191No
629222No
629301No
629311No
629341No
629352No
629391No
629462No
629481No
629511No
629521No
629541No
629591No
629661No
629671No
629721No
629741No
629771No
629791No
629841No
629871No

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