This page summarizes EPA Fifth Unregulated Contaminant Monitoring Rule (UCMR 5, 2023–2025) drinking-water monitoring records linked to ZIP codes in Colorado, as processed for the PFAS Estimator national dataset. Data updated: July 2026.
| Compound | Applicable threshold | ZIP codes detected | At/above threshold | Mean detected | Maximum detected |
|---|---|---|---|---|---|
| PFOA | 0.004 µg/L (MCL) | 40 (16.5% of state) | 40 (100.0%) — all detections at/above limit by construction | 0.0058 µg/L | 0.0105 µg/L |
| PFOS | 0.004 µg/L (MCL) | 18 (7.4% of state) | 18 (100.0%) — all detections at/above limit by construction | 0.0088 µg/L | 0.022 µg/L |
| PFHxS | 0.01 µg/L (MCL) | 19 (7.8% of state) | 4 (21.1% of detected) | 0.0098 µg/L | 0.0284 µg/L |
| PFBS | 2.0 µg/L (HI reference) | 57 (23.5% of state) | not calculated¹ | 0.0074 µg/L | 0.038 µg/L |
| Lithium | 7.36 µg/L (reference, not a regulatory limit) | 232 (95.5% of state) | 232 (100.0%) at/above reference | 24.6651 µg/L | 309.0 µg/L |
| PFPeA | — (no federal limit) | 56 (23.0% of state) | — | 0.0157 µg/L | 0.1089 µg/L |
| PFBA | — (no federal limit) | 51 (21.0% of state) | — | 0.0113 µg/L | 0.042 µg/L |
| PFHpA | — (no federal limit) | 10 (4.1% of state) | — | 0.0037 µg/L | 0.0042 µg/L |
243 ZIP codes with at least one recorded PFAS detection. Click a ZIP code to view its full compound-level results.
| ZIP code | Compounds detected | At/above threshold |
|---|---|---|
| 80002 | 1 | No |
| 80003 | 1 | No |
| 80004 | 1 | No |
| 80005 | 1 | No |
| 80007 | 1 | No |
| 80010 | 4 | No |
| 80011 | 4 | No |
| 80012 | 4 | No |
| 80013 | 4 | No |
| 80014 | 4 | No |
| 80015 | 5 | Yes (1) |
| 80016 | 5 | Yes (1) |
| 80017 | 4 | No |
| 80018 | 4 | No |
| 80019 | 4 | No |
| 80020 | 1 | No |
| 80021 | 1 | No |
| 80022 | 3 | No |
| 80023 | 8 | Yes (2) |
| 80024 | 3 | No |
| 80030 | 1 | No |
| 80031 | 1 | No |
| 80033 | 1 | No |
| 80035 | 1 | No |
| 80036 | 1 | No |
| 80037 | 3 | No |
| 80045 | 4 | No |
| 80102 | 4 | No |
| 80104 | 3 | No |
| 80108 | 5 | Yes (1) |
| 80109 | 3 | No |
| 80110 | 5 | Yes (1) |
| 80111 | 5 | Yes (1) |
| 80112 | 5 | Yes (1) |
| 80113 | 5 | Yes (1) |
| 80118 | 1 | No |
| 80120 | 5 | Yes (1) |
| 80121 | 1 | No |
| 80122 | 1 | No |
| 80123 | 1 | No |
| 80124 | 5 | Yes (1) |
| 80125 | 4 | No |
| 80126 | 4 | No |
| 80127 | 1 | No |
| 80128 | 1 | No |
| 80129 | 4 | No |
| 80130 | 4 | No |
| 80132 | 2 | No |
| 80134 | 5 | Yes (1) |
| 80137 | 4 | No |
| 80138 | 5 | Yes (1) |
| 80202 | 1 | No |
| 80203 | 1 | No |
| 80204 | 1 | No |
| 80205 | 1 | No |
| 80206 | 1 | No |
| 80207 | 1 | No |
| 80209 | 1 | No |
| 80210 | 1 | No |
| 80211 | 1 | No |
| 80212 | 1 | No |
| 80214 | 1 | No |
| 80215 | 3 | No |
| 80216 | 1 | No |
| 80218 | 1 | No |
| 80219 | 1 | No |
| 80220 | 1 | No |
| 80221 | 8 | Yes (2) |
| 80222 | 1 | No |
| 80223 | 1 | No |
| 80224 | 1 | No |
| 80225 | 1 | No |
| 80226 | 1 | No |
| 80227 | 1 | No |
| 80228 | 3 | No |
| 80229 | 8 | Yes (2) |
| 80230 | 1 | No |
| 80231 | 1 | No |
| 80232 | 1 | No |
| 80233 | 8 | Yes (2) |
| 80234 | 1 | No |
| 80235 | 1 | No |
| 80236 | 1 | No |
| 80237 | 1 | No |
| 80238 | 1 | No |
| 80239 | 1 | No |
| 80241 | 8 | Yes (2) |
| 80246 | 1 | No |
| 80247 | 1 | No |
| 80249 | 1 | No |
| 80260 | 8 | Yes (2) |
| 80264 | 1 | No |
| 80265 | 1 | No |
| 80293 | 1 | No |
| 80294 | 1 | No |
| 80306 | 3 | No |
| 80314 | 6 | Yes (2) |
| 80401 | 3 | No |
| 80402 | 1 | No |
| 80403 | 1 | No |
| 80419 | 1 | No |
| 80422 | 1 | No |
| 80435 | 6 | Yes (3) |
| 80452 | 1 | No |
| 80465 | 2 | No |
| 80482 | 1 | No |
| 80497 | 3 | No |
| 80498 | 3 | No |
| 80503 | 1 | Yes (1) |
| 80504 | 1 | Yes (1) |
| 80510 | 1 | No |
| 80512 | 1 | No |
| 80513 | 2 | Yes (1) |
| 80521 | 1 | No |
| 80523 | 1 | No |
| 80524 | 1 | No |
| 80525 | 1 | No |
| 80528 | 1 | No |
| 80534 | 2 | Yes (1) |
| 80535 | 1 | No |
| 80537 | 1 | Yes (1) |
| 80538 | 1 | Yes (1) |
| 80542 | 1 | Yes (1) |
| 80543 | 2 | Yes (1) |
| 80546 | 1 | No |
| 80547 | 1 | No |
| 80549 | 1 | No |
| 80550 | 2 | Yes (1) |
| 80601 | 7 | Yes (2) |
| 80602 | 8 | Yes (2) |
| 80603 | 6 | Yes (1) |
| 80610 | 1 | No |
| 80612 | 1 | No |
| 80615 | 1 | No |
| 80620 | 1 | No |
| 80622 | 1 | No |
| 80624 | 1 | No |
| 80631 | 1 | No |
| 80634 | 1 | No |
| 80640 | 7 | Yes (2) |
| 80642 | 1 | No |
| 80646 | 1 | No |
| 80648 | 1 | No |
| 80649 | 1 | No |
| 80650 | 1 | No |
| 80651 | 1 | Yes (1) |
| 80653 | 1 | No |
| 80654 | 1 | No |
| 80701 | 1 | No |
| 80705 | 1 | No |
| 80723 | 1 | No |
| 80733 | 1 | No |
| 80742 | 1 | No |
| 80750 | 1 | No |
| 80751 | 1 | No |
| 80759 | 1 | No |
| 80807 | 1 | No |
| 80809 | 1 | No |
| 80817 | 7 | Yes (3) |
| 80828 | 1 | No |
| 80829 | 1 | No |
| 80831 | 1 | No |
| 80863 | 1 | No |
| 80903 | 1 | No |
| 80904 | 1 | No |
| 80905 | 1 | No |
| 80906 | 4 | No |
| 80907 | 1 | No |
| 80908 | 1 | No |
| 80909 | 1 | No |
| 80910 | 1 | No |
| 80911 | 7 | Yes (3) |
| 80913 | 1 | No |
| 80914 | 1 | No |
| 80915 | 4 | Yes (1) |
| 80916 | 1 | No |
| 80917 | 1 | No |
| 80918 | 1 | No |
| 80919 | 1 | No |
| 80920 | 1 | No |
| 80921 | 1 | No |
| 80922 | 4 | Yes (1) |
| 80923 | 1 | No |
| 80924 | 1 | No |
| 80925 | 7 | Yes (3) |
| 80926 | 1 | No |
| 80927 | 1 | No |
| 80928 | 4 | Yes (1) |
| 80929 | 1 | No |
| 80938 | 1 | No |
| 80939 | 4 | Yes (1) |
| 80951 | 4 | Yes (1) |
| 81001 | 1 | No |
| 81003 | 1 | No |
| 81004 | 1 | No |
| 81006 | 1 | No |
| 81007 | 1 | No |
| 81008 | 1 | No |
| 81022 | 1 | No |
| 81050 | 1 | No |
| 81052 | 3 | No |
| 81067 | 4 | Yes (1) |
| 81101 | 1 | No |
| 81130 | 1 | No |
| 81147 | 1 | No |
| 81201 | 1 | No |
| 81212 | 1 | No |
| 81230 | 3 | Yes (1) |
| 81301 | 1 | No |
| 81303 | 1 | No |
| 81320 | 1 | No |
| 81321 | 1 | No |
| 81323 | 1 | No |
| 81324 | 1 | No |
| 81327 | 1 | No |
| 81328 | 1 | No |
| 81335 | 1 | No |
| 81401 | 2 | No |
| 81403 | 2 | No |
| 81416 | 2 | No |
| 81425 | 1 | No |
| 81427 | 1 | No |
| 81432 | 1 | No |
| 81435 | 2 | Yes (1) |
| 81503 | 1 | No |
| 81504 | 1 | No |
| 81505 | 1 | No |
| 81506 | 1 | No |
| 81520 | 1 | No |
| 81521 | 1 | No |
| 81526 | 1 | No |
| 81527 | 1 | No |
| 81620 | 1 | No |
| 81623 | 1 | No |
| 81625 | 1 | No |
| 81626 | 1 | No |
| 81632 | 1 | No |
| 81635 | 1 | No |
| 81636 | 1 | No |
| 81637 | 1 | No |
| 81639 | 1 | No |
| 81650 | 1 | No |
| 81657 | 1 | No |
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.
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