Is MERCER PWS required to publish a Consumer Confidence Report?

Yes. MERCER PWS is a community water system, and federal rules (40 CFR 141 Subpart O) require every community water system to publish a Consumer Confidence Report each year.

When is MERCER PWS’s next Consumer Confidence Report due?

MERCER PWS’s next Consumer Confidence Report is due by July 1, 2027. The report covers calendar year 2026.

What is a Consumer Confidence Report?

A Consumer Confidence Report (CCR) is the annual drinking water quality report that community water systems must provide to the people they serve. It lists the contaminants detected in the system’s water during the year, where the water comes from, and how the results compare with federal limits. EPA’s revised CCR rule takes effect January 1, 2027, and the first reports in the new format are due July 1, 2027.

MERCER, MO · Mercer County

MERCER PWS Water System

Consumer Confidence Report status

MERCER PWS must publish a Consumer Confidence Report — the annual drinking water quality report covering calendar year 2026 — by July 1, 2027.

As of August 1, 2026, EPA's federal records show no open violations for MERCER PWS.

Data sourced from the EPA ECHO database (SDWA bulk download), last refreshed August 1, 2026. This is a record-keeping and public-information tool — it does not replace Missouri’s official records. Always confirm current status with Missouri before making decisions based on this information.

System facts

System ID (PWSID): MO2010515
System type: Community Water System
Population served: 318
Service connections: 186
Ownership: local government
Water source: groundwater (wells)

MERCER PWS is one of 1,412 community water systems in Missouri in the 500 or fewer people size category, serving 318 people from groundwater.

As of August 1, 2026, its federal record holds 13 entries between 1993 and 2025, all of which EPA lists as closed.

Of the 13, 3 are monitoring and reporting requirements — the category that accounts for about four in five of all violations in EPA's national dataset — rather than findings about the water itself. The record involves the Stage 2 Disinfectants and Disinfection Byproducts Rule, the Surface Water Treatment Rules, and the Public Notice Rule and Revised PN Rule.

Violation history

Maximum Contaminant Level Violation, Average
Health-based
TTHM
October 1, 2025 – December 31, 2025
Archived
Maximum Contaminant Level Violation, Average
Health-based
TTHM
October 1, 2024 – December 31, 2024
Resolved
Maximum Contaminant Level Violation, Average
Health-based
TTHM
April 1, 2024 – June 30, 2024
Resolved
Monitoring and Reporting (DBP)
—
TTHM
July 1, 2023 – September 30, 2023
Resolved
Monitoring and Reporting (DBP)
—
Total Haloacetic Acids (HAA5)
July 1, 2023 – September 30, 2023
Resolved
Public Notification Violation for NPDWR Violation
—
Public Notice
February 1, 2021 – February 10, 2021
Resolved
Maximum Contaminant Level Violation, Average
Health-based
TTHM
October 1, 2020 – December 31, 2020
Resolved
Maximum Contaminant Level Violation, Average
Health-based
TTHM
July 1, 2020 – September 30, 2020
Resolved
Maximum Contaminant Level Violation, Average
Health-based
TTHM
April 1, 2020 – June 30, 2020
Resolved
Initial Tap Sampling for Pb and Cu
—
Lead and Copper Rule
January 1, 1995 – December 31, 1994
Resolved
Treatment Technique (SWTR and GWR)
Health-based
Surface Water Treatment Rule
December 1, 1993 – December 31, 1993
Resolved
Treatment Technique (SWTR and GWR)
Health-based
Surface Water Treatment Rule
August 1, 1993 – August 31, 1993
Resolved
Treatment Technique (SWTR and GWR)
Health-based
Surface Water Treatment Rule
July 1, 1993 – July 31, 1993
Resolved

Archived closed in EPA's records (typically due to age or a data correction)Resolved addressed and confirmed by the state

Period	Violation	Contaminant / rule	Health-based	Status
October 1, 2025 – December 31, 2025	Maximum Contaminant Level Violation, Average	TTHM	Health-based	Archived
October 1, 2024 – December 31, 2024	Maximum Contaminant Level Violation, Average	TTHM	Health-based	Resolved
April 1, 2024 – June 30, 2024	Maximum Contaminant Level Violation, Average	TTHM	Health-based	Resolved
July 1, 2023 – September 30, 2023	Monitoring and Reporting (DBP)	TTHM	—	Resolved
July 1, 2023 – September 30, 2023	Monitoring and Reporting (DBP)	Total Haloacetic Acids (HAA5)	—	Resolved
February 1, 2021 – February 10, 2021	Public Notification Violation for NPDWR Violation	Public Notice	—	Resolved
October 1, 2020 – December 31, 2020	Maximum Contaminant Level Violation, Average	TTHM	Health-based	Resolved
July 1, 2020 – September 30, 2020	Maximum Contaminant Level Violation, Average	TTHM	Health-based	Resolved
April 1, 2020 – June 30, 2020	Maximum Contaminant Level Violation, Average	TTHM	Health-based	Resolved
January 1, 1995 – December 31, 1994	Initial Tap Sampling for Pb and Cu	Lead and Copper Rule	—	Resolved
December 1, 1993 – December 31, 1993	Treatment Technique (SWTR and GWR)	Surface Water Treatment Rule	Health-based	Resolved
August 1, 1993 – August 31, 1993	Treatment Technique (SWTR and GWR)	Surface Water Treatment Rule	Health-based	Resolved
July 1, 1993 – July 31, 1993	Treatment Technique (SWTR and GWR)	Surface Water Treatment Rule	Health-based	Resolved

Archived closed in EPA's records (typically due to age or a data correction)Resolved addressed and confirmed by the state

Enforcement actions

September 23, 2016State Public Notification received549 linked violations

Common questions

Is MERCER PWS required to publish a Consumer Confidence Report?: Yes. MERCER PWS is a community water system, and federal rules (40 CFR 141 Subpart O) require every community water system to publish a Consumer Confidence Report each year.
When is MERCER PWS’s next Consumer Confidence Report due?: MERCER PWS’s next Consumer Confidence Report is due by July 1, 2027. The report covers calendar year 2026.
Does MERCER PWS have any open drinking water violations on record?: As of August 1, 2026, EPA's federal records show no open violations for MERCER PWS.
What is a Consumer Confidence Report?: A Consumer Confidence Report (CCR) is the annual drinking water quality report that community water systems must provide to the people they serve. It lists the contaminants detected in the system’s water during the year, where the water comes from, and how the results compare with federal limits. EPA’s revised CCR rule takes effect January 1, 2027, and the first reports in the new format are due July 1, 2027.

Contact

MEINECKE, TRACY

660-382-4210

MERCER, MO 64661-0000