Public water system record
Mosby PWS
Serves Mosby, Clay County, MO · 93 people served
Federal records show 21 health-based violations and 11 monitoring/reporting issues for Mosby PWS in the last ten years. The most serious issue in this window was a resolved Total Trihalomethanes (TTHMs) violation.
System profile
- Health-based violations, last 10 years
- 21
- Resolved
- 21
- Unresolved
- 0
- Any acute record
- No
- Monitoring issues, last 10 years
- 11
Key facts
- Mosby PWS buys its water from Kansas City PWS.
- Highest measured level in the last 10 years: Total Trihalomethanes (TTHMs), 109 µg/L, federal limit 80 µg/L (1.4 times the limit), 2020.
- Most recent formal enforcement: compliance order with a penalty by Missouri, June 2020.
- Record on file since 1993, with 4 health-based violations before October 19, 2016.
- Lead pipe inventory: 0 lead and 35 unknown out of 64 service lines.
Check whether Mosby 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 82 µg/L, federal limit 80 µg/L (at or just above the limit)
|
220 | Jan 1, 2025 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 93 µg/L, federal limit 80 µg/L (1.2 times the limit)
|
220 | Apr 1, 2023 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 91 µg/L, federal limit 80 µg/L (1.1 times the limit)
|
220 | Jan 1, 2023 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 95 µg/L, federal limit 80 µg/L (1.2 times the limit)
|
220 | Oct 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 | Jul 1, 2022 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 92 µg/L, federal limit 80 µg/L (1.2 times the limit)
|
220 | Apr 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 | Jan 1, 2022 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 89 µg/L, federal limit 80 µg/L (1.1 times the limit)
|
220 | Oct 1, 2021 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 86 µg/L, federal limit 80 µg/L (1.1 times the limit)
|
220 | Jul 1, 2021 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 89 µg/L, federal limit 80 µg/L (1.1 times the limit)
|
220 | Apr 1, 2021 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 87 µg/L, federal limit 80 µg/L (1.1 times the limit)
|
220 | Jan 1, 2021 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 97 µg/L, federal limit 80 µg/L (1.2 times the limit)
|
220 | Oct 1, 2020 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 104 µg/L, federal limit 80 µg/L (1.3 times the limit)
|
220 | Jul 1, 2020 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 104 µg/L, federal limit 80 µg/L (1.3 times the limit)
|
220 | Apr 1, 2020 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 109 µg/L, federal limit 80 µg/L (1.4 times the limit)
|
220 | Jan 1, 2020 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 106 µg/L, federal limit 80 µg/L (1.3 times the limit)
|
220 | Oct 1, 2019 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 92 µg/L, federal limit 80 µg/L (1.2 times the limit)
|
220 | Jul 1, 2019 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 93 µg/L, federal limit 80 µg/L (1.2 times the limit)
|
220 | Apr 1, 2019 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 91 µg/L, federal limit 80 µg/L (1.1 times the limit)
|
220 | Jan 1, 2019 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 86 µg/L, federal limit 80 µg/L (1.1 times the limit)
|
220 | Oct 1, 2018 | Resolved | No |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 87 µg/L, federal limit 80 µg/L (1.1 times the limit)
|
220 | Jul 1, 2018 | Resolved | No |
Monitoring and reporting issues
Since October 2016Missed tests or reports, not contaminants found above a limit.
| Issue | Start date | Status |
|---|---|---|
|
Revised Total Coliform Rule
Monitoring violation
|
Oct 1, 2025 |
Archived
Violation period ended. EPA no longer counts it toward current compliance, but no fix was formally recorded.
|
|
Public Notice
OTHER
|
Jul 3, 2025 | Resolved |
|
Revised Total Coliform Rule
Monitoring violation
|
Jul 1, 2025 | Resolved |
|
Public Notice
OTHER
|
Oct 22, 2023 | Resolved |
|
Consumer Confidence Rule
OTHER
|
Jul 1, 2023 | Resolved |
|
Consumer Confidence Rule
OTHER
|
Jul 1, 2022 | Resolved |
|
Consumer Confidence Rule
OTHER
|
Jul 1, 2021 | Resolved |
|
Haloacetic Acids (HAA5)
Monitoring and reporting
|
Oct 1, 2020 | Resolved |
|
Total Trihalomethanes (TTHMs)
Monitoring and reporting
|
Oct 1, 2020 | Resolved |
|
Public Notice
OTHER
|
Apr 4, 2019 | Resolved |
|
Public Notice
OTHER
|
Jan 17, 2019 | Resolved |
Full record since 1993
EPA's records for Mosby PWS go back to 1993. Before October 19, 2016 they list 4 health-based violations (1 resolved, 3 archived by EPA without a recorded fix) and 6 monitoring or reporting violations.
| Violations that began in | Health-based | Monitoring and reporting |
|---|---|---|
| 1990s | 1 | 0 |
| 2000s | 0 | 5 |
| 2010 to October 18, 2016 | 3 | 1 |
| October 19, 2016 to 2019 | 6 | 2 |
| 2020s | 15 | 9 |
Most recent health-based violation before October 19, 2016: Total Trihalomethanes (TTHMs), began July 2016, Archived.
Show all 4 health-based violations before October 19, 2016
| Contaminant | Start date | Status |
|---|---|---|
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 87.9 µg/L, federal limit 80 µg/L (1.1 times the limit)
|
Jul 1, 2016 | Archived |
|
Total Trihalomethanes (TTHMs)
Contaminant limit exceeded
Measured 94 µg/L, federal limit 80 µg/L (1.2 times the limit)
|
Apr 1, 2016 | Archived |
|
Groundwater Rule
Treatment technique failure
|
Jul 1, 2010 | Resolved |
|
Total Coliform
Contaminant limit exceeded
|
Apr 1, 1993 | Archived |
Enforcement actions
Missouri regulators took 1 formal enforcement action against Mosby PWS in 2020. The most recent was a compliance order with a penalty in June 2020.
| Date | By | Action | Violations covered |
|---|---|---|---|
| Jun 10, 2020 | Missouri | Compliance order with a penalty | 25 violations (20 health-based): Total Trihalomethanes (TTHMs), Consumer Confidence Rule, Haloacetic Acids (HAA5) |
What the violations mean
Total Trihalomethanes (TTHMs)
21 incidentsDisinfection byproduct levels exceeded the federal limit
Long-term TTHM exposure may increase bladder cancer risk
Where the water comes from
Mosby PWS buys its water from Kansas City PWS. It lists no wells or intakes of its own. It also has an emergency connection to Prathersville PWS.
Buys water from
- Kansas City PWS Kansas City, MO
Emergency or part-time connections to
- Prathersville PWS Excelsior Springs, MO
Annual water quality report
Mosby 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.
Systems serving 500 or fewer people may meet the rule by telling customers the report is available on request, so you may need to ask Mosby PWS for a copy.
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