Community Water System · PWS CO0103005
Aurora City Of
Operator location Aurora, Colorado - larger served population (> 3,309) at 533,407 people served; 18 SDWIS violations on record from surface water sources.
- 533,407
- People served (this PWS) Larger third of systems
- 18
- EPA violations (this PWS) Lower third of systems
- 4
- Health-based (this PWS) Middle third by health-based share
- 4 PFAS
- UCMR5 (this PWS) Middle third of PFAS-detected systems
Aurora City Of standing, low SDWIS violation third
533,407 people served (SDWIS) - larger served population (> 3,309). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 22% is middle-third health share (≤ 23%). UCMR5: middle-third PFAS panel (≤ 4 compounds). Population rank #62 of 29,740 among systems serving 500+.
The verdict
Aurora City Of is in the lower third by violation count (18; lower-third violation load (≤ 21 violations)). A low count does not mean the system is unmonitored - monitoring and reporting violations still appear in SDWIS. Population served is large (533,407; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is 22% (middle-third health share (≤ 23%)). UCMR5 detected 4 PFAS compounds (middle-third PFAS panel (≤ 4 compounds)).
- #62 of 29,740
- Population · /systems
- #2 of 551
- Population · CO
- 18
- Total EPA violations on record
- 22%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
4 PFAS "forever chemicals" detected in testing under EPA's UCMR5 monitoring program.
Based on EPA SDWIS violation history and UCMR5 PFAS testing only, not water taste, odor, infrastructure age, or contaminants outside the federally tracked set.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 91,821
- County
- Arapahoe
- School/Daycare
- No
- MCL Violations
- 4
- Monitoring Violations
- 13
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| TTHM | MR | 5 | 2016 |
| Total Haloacetic Acids (HAA5) | MR | 5 | 2016 |
| Coliform (TCR) | MCL | 4 | 2011 |
| Interim Enhanced Surface Water Treatment Rule | MR | 3 | 2011 |
Violation Count vs. the National Corpus
Aurora City Of has 18 recorded EPA violations, 29% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 70% carry more. 22% of this system's own violations are health-based (4 of 18), and it ranks #62 of 29,740 by population served among that same cohort.
EPA violations vs. the national water-system corpus
Public water systems serving 500+ people (EPA SDWIS)
18 Lower than most fewer violations than 70% of 29,740 water systems
the national water-system corpus, bucketed by value
Each bar is a band; taller bars hold more water systems. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source EPA SDWIS · 2026-05-15
How many violations vs. how serious, among peer systems
Aurora City Of plotted against 29 peer public water systems (500+ people served), by total violation count (x) and the share of those violations that are health-based (y). The crosshair sits at this sample's own median on each axis. A high violation count does not automatically mean a serious record: most monitoring and reporting violations are minor, not health-based.
Violation volume vs. health-based share
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 4 of 348 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| PFHpS | 9/11/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMPA | 9/11/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| NMeFOSAA | 9/11/2023 | <6.00 ppt | 6.00 ppt | Not Detected |
| NEtFOSAA | 9/11/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTrDA | 9/11/2023 | <7.00 ppt | 7.00 ppt | Not Detected |
| 8:2 FTS | 9/11/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFPeA | 9/11/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 9/11/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 9/11/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeS | 9/11/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| ADONA | 9/11/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFTA | 9/11/2023 | <8.00 ppt | 8.00 ppt | Not Detected |
| NFDHA | 9/11/2023 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFHxA | 9/11/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 9/11/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 9/11/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxS | 9/11/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFNA | 9/11/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOS | 9/11/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFOA | 9/11/2023 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFBA | 9/11/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFDoA | 9/11/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| 6:2 FTS | 9/11/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFUnA | 9/11/2023 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 9/11/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| 9Cl-PF3ONS | 9/11/2023 | <2.00 ppt | 2.00 ppt | Not Detected |
| 4:2 FTS | 9/11/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| HFPO-DA | 9/11/2023 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFDA | 9/11/2023 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOS | 8/5/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFNA | 8/5/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHxS | 8/5/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 8/5/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 8/5/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| NMeFOSAA | 8/5/2024 | <6.00 ppt | 6.00 ppt | Not Detected |
| NEtFOSAA | 8/5/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTA | 8/5/2024 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFPeA | 8/5/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFTrDA | 8/5/2024 | <7.00 ppt | 7.00 ppt | Not Detected |
| PFMBA | 8/5/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpS | 8/5/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeS | 8/5/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFEESA | 8/5/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOA | 8/5/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFMPA | 8/5/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| 8:2 FTS | 8/5/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 8/5/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 6:2 FTS | 8/5/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFHxA | 8/5/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| NFDHA | 8/5/2024 | <20.00 ppt | 20.00 ppt | Not Detected |
Population served record for Aurora City Of
EPA SDWIS lists 533,407 people served and 91,821 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.
Sources: EPA SDWIS · Colorado Department of Public Health and Environment, Water Quality Control
Nationwide peers
18 violations · 533,407 served: nearest cross-state SDWIS matches.
Cross-state systems with similarly light violation ledgers
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
- Cheyenne Arapaho Concho EPA Region 6 — Tribal Water Systems 18violations
- Assiniboine & Sioux Rural Water System EPA Region 8 — Tribal Water Systems 18violations
- Poplar, City Of EPA Region 8 — Tribal Water Systems 18violations
- Torreon-Ojo Encino East - NTUA EPA Region 9 — Tribal Water Systems 18violations
Cross-state systems with similar served population
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with Aurora City Of
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Colorado compares on the same EPA violation measures. Colorado systems
- Check whether PFAS was detected at this system under UCMR5 testing. PFAS guide
- Find and compare another public water system by name or PWSID. Search systems
EPA SDWIS and UCMR5 figures are informational only, not a substitute for a certified lab test of your own tap water.
Every figure on PlainWater is rendered directly from EPA SDWIS drinking-water data, no number is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.