Public water system record
Maysville PWS
Serves Maysville, DeKalb County, MO · 1,096 people served
Federal records show 20 health-based violations and 8 monitoring/reporting issues for Maysville PWS in the last ten years. The most serious issue in this window was a Total Trihalomethanes (TTHMs) violation that EPA lists as archived, not resolved.
System profile
Source water
Surface water
ZIP
64469
EPA system ID
MO1010510
- Health-based violations, last 10 years
- 20
- Resolved
- 16
- Unresolved
- 0
- Archived by EPA
- 4
- Any acute record
- Yes
- Monitoring issues, last 10 years
- 8
Key facts
- Maysville PWS draws water from 1 surface water intake and 1 reservoir.
- Highest measured level in the last 10 years: Haloacetic Acids (HAA5), 96.9 µg/L, federal limit 60 µg/L (1.6 times the limit), 2025.
- Most recent formal enforcement: compliance order with a penalty by Missouri, September 2025.
- Record on file since 1993, with 81 health-based violations before October 19, 2016.
- Lead pipe inventory: 2 lead and 8 unknown out of 451 service lines.
Check whether Maysville PWS serves your address
Health-based violations
Since October 2016Violation data reflects EPA records through March 2026. For the most current status, visit the EPA ECHO database.
| Contaminant | Rule family | Start date | Status | Acute |
|---|---|---|---|---|
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 114.4 µg/L, federal limit 80 µg/L (1.4 times the limit)
|
220 | Oct 1, 2025 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Haloacetic Acids (HAA5)
Contaminant limit exceeded
Measured 96.9 µg/L, federal limit 60 µg/L (1.6 times the limit)
|
220 | Oct 1, 2025 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 104.88 µg/L, federal limit 80 µg/L (1.3 times the limit)
|
220 | Jul 1, 2025 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Haloacetic Acids (HAA5)
Contaminant limit exceeded
Measured 78.15 µg/L, federal limit 60 µg/L (1.3 times the limit)
|
220 | Jul 1, 2025 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
No |
|
Interim Enhanced Surface Water Treatment Rule
Treatment technique failure
|
120 | Nov 1, 2024 | Resolved | Yes |
|
Interim Enhanced Surface Water Treatment Rule
Treatment technique failure
|
120 | Oct 1, 2024 | Resolved | Yes |
|
Interim Enhanced Surface Water Treatment Rule
Treatment technique failure
|
120 | Sep 1, 2024 | Resolved | Yes |
|
Surface Water Treatment Rule
Treatment technique failure
|
120 | Sep 1, 2024 | Resolved | No |
|
Interim Enhanced Surface Water Treatment Rule
Treatment technique failure
|
120 | Sep 1, 2024 | Resolved | Yes |
|
Interim Enhanced Surface Water Treatment Rule
Treatment technique failure
|
120 | Aug 1, 2024 | Resolved | Yes |
|
Interim Enhanced Surface Water Treatment Rule
Treatment technique failure
|
120 | Aug 1, 2024 | Resolved | Yes |
|
Surface Water Treatment Rule
Treatment technique failure
|
120 | Aug 1, 2024 | Resolved | No |
|
Chlorite
Contaminant limit exceeded
Measured 1.2 mg/L, federal limit 1 mg/L (1.2 times the limit)
|
210 | Dec 1, 2022 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 94 µg/L, federal limit 80 µg/L (1.2 times the limit)
|
220 | Oct 1, 2017 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 98 µg/L, federal limit 80 µg/L (1.2 times the limit)
|
220 | Jul 1, 2017 | Resolved | No |
|
Haloacetic Acids (HAA5)
Contaminant limit exceeded
Measured 61 µg/L, federal limit 60 µg/L (at or just above the limit)
|
220 | Apr 1, 2017 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 96 µg/L, federal limit 80 µg/L (1.2 times the limit)
|
220 | Apr 1, 2017 | Resolved | No |
|
Haloacetic Acids (HAA5)
Contaminant limit exceeded
Measured 64 µg/L, federal limit 60 µg/L (1.1 times the limit)
|
220 | Jan 1, 2017 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 98 µg/L, federal limit 80 µg/L (1.2 times the limit)
|
220 | Jan 1, 2017 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 92 µg/L, federal limit 80 µg/L (1.2 times the limit)
|
220 | Oct 1, 2016 | Resolved | No |
Monitoring and reporting issues
Since October 2016Missed tests or reports, not contaminants found above a limit.
| Issue | Start date | Status |
|---|---|---|
|
Interim Enhanced Surface Water Treatment Rule
Monitoring and reporting
|
Nov 1, 2025 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
|
Interim Enhanced Surface Water Treatment Rule
Monitoring and reporting
|
Nov 1, 2025 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
|
Surface Water Treatment Rule
Monitoring and reporting
|
Nov 1, 2025 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
|
Lead and Copper Rule
Monitoring and reporting
|
Aug 19, 2025 | Active |
|
Interim Enhanced Surface Water Treatment Rule
Monitoring and reporting
|
Jul 1, 2025 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule
Monitoring and reporting
|
Jul 1, 2025 | Resolved |
|
Surface Water Treatment Rule
Monitoring and reporting
|
Jul 1, 2025 | Resolved |
|
Revised Total Coliform Rule
Monitoring violation
|
Nov 1, 2024 | Resolved |
Full record since 1993
EPA's records for Maysville PWS go back to 1993. Before October 19, 2016 they list 81 health-based violations (61 resolved, 20 archived by EPA without a recorded fix) and 7 monitoring or reporting violations.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 1990s | 4 | 2 |
| 2000s | 32 | 4 |
| 2010 to October 18, 2016 | 45 | 1 |
| October 19, 2016 to 2019 | 6 | 0 |
| 2020s | 13 | 8 |
Most recent health-based violation before October 19, 2016: Total Trihalomethanes (TTHMs), began October 2016, Resolved.
Show all 81 health-based violations before October 19, 2016
| Contaminant | Start date | Status |
|---|---|---|
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 92 µg/L, federal limit 80 µg/L (1.2 times the limit)
|
Oct 1, 2016 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Aug 1, 2016 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Aug 1, 2016 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 91 µg/L, federal limit 80 µg/L (1.1 times the limit)
|
Jul 1, 2016 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Jun 1, 2016 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 94 µg/L, federal limit 80 µg/L (1.2 times the limit)
|
Apr 1, 2016 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Feb 1, 2016 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Sep 1, 2015 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Aug 1, 2015 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Jul 1, 2015 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Jul 1, 2015 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Jun 1, 2015 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 89.8 µg/L, federal limit 80 µg/L (1.1 times the limit)
|
Oct 1, 2014 | Resolved |
|
CARBON, TOTAL
Treatment technique failure
|
Jul 1, 2014 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 100.3 µg/L, federal limit 80 µg/L (1.3 times the limit)
|
Jul 1, 2014 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Jul 1, 2014 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
May 1, 2014 | Resolved |
|
CARBON, TOTAL
Treatment technique failure
|
Apr 1, 2014 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Apr 1, 2014 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Apr 1, 2014 | Resolved |
|
CARBON, TOTAL
Treatment technique failure
|
Jan 1, 2014 | Resolved |
|
CARBON, TOTAL
Treatment technique failure
|
Oct 1, 2013 | Resolved |
|
CARBON, TOTAL
Treatment technique failure
|
Jul 1, 2013 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 104.08 µg/L, federal limit 80 µg/L (1.3 times the limit)
|
Jul 1, 2013 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Jul 1, 2013 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
May 1, 2013 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 90.43 µg/L, federal limit 80 µg/L (1.1 times the limit)
|
Apr 1, 2013 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Apr 1, 2013 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Mar 1, 2013 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 86.77 µg/L, federal limit 80 µg/L (1.1 times the limit)
|
Jan 1, 2013 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Sep 1, 2012 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Aug 1, 2012 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Jun 1, 2012 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
May 1, 2012 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Apr 1, 2012 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Apr 1, 2012 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Dec 1, 2011 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 87.69 µg/L, federal limit 80 µg/L (1.1 times the limit)
|
Oct 1, 2011 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 103.27 µg/L, federal limit 80 µg/L (1.3 times the limit)
|
Jul 1, 2011 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 114.71 µg/L, federal limit 80 µg/L (1.4 times the limit)
|
Apr 1, 2011 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 126.08 µg/L, federal limit 80 µg/L (1.6 times the limit)
|
Jan 1, 2011 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 119.4 µg/L, federal limit 80 µg/L (1.5 times the limit)
|
Oct 1, 2010 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 104.26 µg/L, federal limit 80 µg/L (1.3 times the limit)
|
Jul 1, 2010 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Jun 1, 2010 | Resolved |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 81.36 µg/L, federal limit 80 µg/L (at or just above the limit)
|
Apr 1, 2010 | Resolved |
|
Chlorine dioxide (acute)
Disinfectant residual limit exceeded
Measured 1.5 mg/L, federal limit 0.8 mg/L (1.9 times the limit)
|
Nov 1, 2009 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
Aug 1, 2009 | Resolved |
|
Interim Enhanced Surface Water Treatment Rule (acute)
Treatment technique failure
|
May 1, 2009 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
May 1, 2009 | Resolved |
|
Haloacetic Acids (HAA5)
Contaminant limit exceeded
Measured 64 µg/L, federal limit 60 µg/L (1.1 times the limit)
|
Jan 1, 2009 | Archived |
31 older violations are not listed here. EPA ECHO has the complete list.
Enforcement actions
Missouri regulators took 4 formal enforcement actions against Maysville PWS and issued 4 boil water orders between 2011 and 2025. The most recent was a compliance order with a penalty in September 2025.
| Date | By | Action | Violations covered |
|---|---|---|---|
| Sep 11, 2025 | Missouri | Compliance order with a penalty | 6 violations: Interim Enhanced Surface Water Treatment Rule, Surface Water Treatment Rule |
| Aug 28, 2024 | Missouri | Boil water order | 1 violation |
| Feb 20, 2018 | Missouri | Compliance order with a penalty | 13 violations (13 health-based): Interim Enhanced Surface Water Treatment Rule, Total Trihalomethanes (TTHMs), Haloacetic Acids (HAA5) |
| Oct 31, 2017 | Missouri | Compliance order with a penalty | 7 violations (7 health-based): Total Trihalomethanes (TTHMs), Haloacetic Acids (HAA5) |
| Aug 23, 2016 | Missouri | Boil water order | 1 violation (1 health-based): Interim Enhanced Surface Water Treatment Rule |
| Jul 7, 2015 | Missouri | Boil water order | 1 violation (1 health-based): Interim Enhanced Surface Water Treatment Rule |
| Apr 11, 2014 | Missouri | Boil water order | 1 violation (1 health-based): Interim Enhanced Surface Water Treatment Rule |
| Aug 10, 2011 | Missouri | Compliance order with a penalty | 86 violations (79 health-based): Interim Enhanced Surface Water Treatment Rule, Chlorine dioxide, Total Trihalomethanes (TTHMs), Total Coliform, Surface Water Treatment Rule |
What the violations mean
Total Trihalomethanes (TTHMs)
7 incidentsDisinfection byproduct levels exceeded the federal limit
Long-term TTHM exposure may increase bladder cancer risk
Interim Enhanced Surface Water Treatment Rule
6 incidentsThe system did not meet a filtration or treatment requirement for surface water
Inadequate treatment of surface water can let pathogens such as Cryptosporidium and Giardia through
Haloacetic Acids (HAA5)
4 incidentsHaloacetic acid byproducts exceeded the federal limit
Long-term exposure to HAAs may increase cancer risk
Surface Water Treatment Rule
2 incidentsThe system did not complete a treatment step or action that the Surface Water Treatment Rule requires (a treatment technique violation).
The utility had to notify customers about each of these violations.
Chlorite
1 incidentTest results for Chlorite were above the federal limit (a maximum contaminant level violation).
The utility had to notify customers about this violation.
Where the water comes from
Maysville PWS draws water from 1 surface water intake and 1 reservoir.
Annual water quality report
Maysville PWS must give its customers an annual water quality report (Consumer Confidence Report) by July 1, with the levels its tests found in the previous year.
Where the state allows it, systems serving fewer than 10,000 people may publish the report in a local newspaper or news site instead of mailing it, and must provide a copy on request.
Find a posted report with EPA's Consumer Confidence Report search
Testing your own water
To test the water at your tap, or a private well this record does not cover, use a laboratory certified for drinking water by Missouri.
Certified drinking water labs by state EPA guidance for private wells