Community Water System · PWS MS0230001
City of Bay St Louis
Operator location Bay St Louis, Mississippi - larger served population (> 3,309) at 9,284 people served; 735 SDWIS violations on record from groundwater sources.
- 9,284
- People served (this PWS)
- 735
- EPA violations (this PWS)
- 25
- Health-based (this PWS)
- No PFAS
- UCMR5 (this PWS)
City of Bay St Louis standing, high SDWIS violation third
9,284 people served (SDWIS) - larger served population (> 3,309). Corpus terciles use 29,740 systems serving 500+ (the sitemap cohort). Health-based share 3% is middle-third health share (≤ 23%). UCMR5: UCMR5 tested, none detected. Population rank #5,009 of 29,740 among systems serving 500+.
The verdict
City of Bay St Louis sits in the upper third of the sitemap cohort by violation count (735), so the tables below sample a dense compliance trail rather than a near-clean ledger. Population served is large (9,284; larger served population (> 3,309)), so household exposure scale sits behind the violation mix. Health-based share is 3% (middle-third health share (≤ 23%)). UCMR5 tested this system and reported no PFAS above the minimum reporting level.
- #5,009 of 29,740
- Population · /systems
- #71 of 837
- Population · MS
- 735
- Total EPA violations on record
- 3%
- Health-based (MCL / treatment failure)
Population ordinals match the sitemap cohort (systems serving 500+, population_served DESC). See methodology · corpus placement.
System Details
- System Type
- Community
- Owner Type
- Local
- Connections
- 3,847
- County
- Hancock
- School/Daycare
- No
- MCL Violations
- 25
- Monitoring Violations
- 682
- Treatment Tech Violations
- 0
Violation History
Contaminant violations recorded by EPA.
| Contaminant | Category | Count | Latest |
|---|---|---|---|
| Combined Uranium | MR | 208 | 2012 |
| Radium-228 | MR | 156 | 2012 |
| Radium-226 | MR | 146 | 2012 |
| Gross Alpha, Excl. Radon and U | MR | 84 | 2008 |
| Combined Radium (-226 and -228) | MR | 84 | 2008 |
| TTHM | MCL | 20 | 2024 |
| Public Notice | Other | 9 | 2024 |
| Consumer Confidence Rule | Other | 6 | 2023 |
| Coliform (TCR) | MCL | 5 | 1993 |
| Chlorine | MR | 4 | 2018 |
Violation Count vs. the National Corpus
City of Bay St Louis has 735 recorded EPA violations, 98% of the 29,740 public water systems serving 500+ people nationwide carry fewer, and 2% carry more. 3% of this system's own violations are health-based (25 of 735), and it ranks #5,009 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)
735 Higher than most more violations than 98% 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
PFAS Testing Results (UCMR5)
Results from EPA's Fifth Unregulated Contaminant Monitoring Rule. 0 of 232 samples detected PFAS.
| Contaminant | Date | Result | MRL | Status |
|---|---|---|---|---|
| HFPO-DA | 2/28/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFOS | 2/28/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| 9Cl-PF3ONS | 2/28/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 2/28/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFDoA | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFDA | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOA | 2/28/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| ADONA | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHpA | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFBS | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| NMeFOSAA | 2/28/2024 | <6.00 ppt | 6.00 ppt | Not Detected |
| NEtFOSAA | 2/28/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFTA | 2/28/2024 | <8.00 ppt | 8.00 ppt | Not Detected |
| PFBA | 2/28/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| NFDHA | 2/28/2024 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFTrDA | 2/28/2024 | <7.00 ppt | 7.00 ppt | Not Detected |
| PFPeS | 2/28/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFNA | 2/28/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFUnA | 2/28/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| 6:2 FTS | 2/28/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFHpS | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxS | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFEESA | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFHxA | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFPeA | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMPA | 2/28/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| 8:2 FTS | 2/28/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| 4:2 FTS | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| NMeFOSAA | 2/28/2024 | <6.00 ppt | 6.00 ppt | Not Detected |
| PFEESA | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 8:2 FTS | 2/28/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFMPA | 2/28/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFPeA | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFMBA | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| NFDHA | 2/28/2024 | <20.00 ppt | 20.00 ppt | Not Detected |
| PFPeS | 2/28/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
| PFHpS | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFTA | 2/28/2024 | <8.00 ppt | 8.00 ppt | Not Detected |
| 6:2 FTS | 2/28/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| NEtFOSAA | 2/28/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFDA | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFTrDA | 2/28/2024 | <7.00 ppt | 7.00 ppt | Not Detected |
| HFPO-DA | 2/28/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| ADONA | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| 9Cl-PF3ONS | 2/28/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| 11Cl-PF3OUdS | 2/28/2024 | <5.00 ppt | 5.00 ppt | Not Detected |
| PFUnA | 2/28/2024 | <2.00 ppt | 2.00 ppt | Not Detected |
| PFDoA | 2/28/2024 | <3.00 ppt | 3.00 ppt | Not Detected |
| PFOA | 2/28/2024 | <4.00 ppt | 4.00 ppt | Not Detected |
Population served record for City of Bay St Louis
EPA SDWIS lists 9,284 people served and 3,847 connections for this PWS, confirm the service-area footprint on the federal report before comparing to municipal census totals.
Sources: EPA SDWIS
Nationwide peers
735 violations · 9,284 served: nearest cross-state SDWIS matches.
Cross-state systems with comparable violation load
Nearest cross-state community systems (500+ served) by total SDWIS violations on record.
Cross-state systems with similar served population
Nearest cross-state systems by EPA SDWIS population_served (same 500+ sitemap gate).
What to do with City of Bay St Louis
Use this system's EPA-reported record as a starting filter, not a final verdict.
- See how every tracked system in Mississippi compares on the same EPA violation measures. Mississippi 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.