D
40

Poor Water Quality

Mercer, MO 64661

Mercer County · Population served: 36,518 · Data updated March 2026

Water Systems Serving This Area

🏔
RATHBUN REGIONAL WATER ASSN (RATHBUN)
Surface water · Pop. 33,000
PWSID: IA0400900
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MERCER PWS
Groundwater · Pop. 318
PWSID: MO2010515
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MERCER COUNTY PWSD 1
Surface water · Pop. 3,200
PWSID: MO2024382

Contaminants Detected

ContaminantDetected LevelEPA MCLHealth GuidelineStatus
Lead
13.7
15 ppb 1 ppb Warning

PFAS / Forever Chemicals

1 detected All below limits
CompoundLevelEPA MCLHealth GuidelineStatus
PFBA13.0 pptNo standard500 pptUnregulated

Violation History (Last 5 Years)

38Total (5yr)
15Health-Based
11Major

Water Quality Summary

Understanding Your Water in Mercer

Tap water quality in Mercer, Missouri (64661) receives an overall grade of D (Poor) with a score of 40 out of 100, based on analysis of EPA compliance data, contaminant testing, and violation history. This is 40 points below the Missouri state average of 80. Compared to the national average (75), this area scores significantly lower. The area is served by 3 water systems providing water to approximately 36,518 people, using surface water and groundwater sources. Testing has found elevated levels of Lead that warrant attention. PFAS testing detected 1 compound, all currently below EPA limits. Over the past 5 years, water systems here have accumulated 38 violations, including 15 health-based violations.

Your Score 40/100 D
vs State 40 pts below Missouri avg (80)
vs National 35 pts below national avg (75)

What a Grade D Means

A score of 40/100 signals poor water quality in Mercer, MO. Significant issues have been identified, which may include multiple violations, contaminant levels near or above regulatory limits, or PFAS contamination. We recommend reviewing the detailed contaminant data below, considering a certified water filter, and checking your utility's Consumer Confidence Report for the latest information.

Surface water: sourced from rivers, lakes, or reservoirs
Groundwater: drawn from underground aquifers via wells

Health Information

What These Contaminants Mean for You

⚠️

Lead in Your Water

Lead is a toxic metal that can leach from aging pipes and plumbing fixtures.

Health Effects

Even low levels of lead exposure can cause developmental delays in children, kidney damage, and cardiovascular effects in adults. The EPA action level is 15 ppb, but health experts recommend no safe level of lead in drinking water.

Common Sources

Lead enters water primarily through corrosion of lead service lines, lead solder, and brass fixtures — especially in homes built before 1986.

What You Can Do

If lead is detected above 1 ppb, consider using a certified lead-removal filter (NSF/ANSI 53) for drinking and cooking water. Run cold water for 30 seconds before use if water has been sitting in pipes.

Common Questions

Frequently Asked Questions

Tap water in Mercer, Missouri receives a grade of D (Poor) with a score of 40/100. This indicates significant water quality concerns based on violation history, contaminant levels, or enforcement actions. We recommend reviewing the specific contaminants detected below and considering a certified water filter.

ZIP code 64661 is served by 3 water systems using surface water, groundwater sources, providing water to approximately 36,518 people. Multiple source types mean your water may come from a blend of surface and underground sources.

Lead was detected at 13.7 ppb in Mercer, Missouri. While this is below the EPA action level of 15 ppb, it exceeds the health guideline of 1 ppb recommended by health organizations. Consider a certified lead filter, especially if you have young children.

1 PFAS compound were detected in water serving Mercer, Missouri, but all are currently below EPA limits. While levels are within regulatory standards, some health organizations recommend minimizing any PFAS exposure. Activated carbon or reverse osmosis filters can reduce PFAS levels.

Water systems serving Mercer, Missouri have received 38 violations in the last 5 years, including 15 health-based violations. Violations can range from paperwork issues (monitoring & reporting) to serious health-based violations where contaminant levels exceeded safe limits. Review the violation details above for specifics.

Based on detected contaminants (lead, PFAS), residents in Mercer, Missouri should consider: Reverse osmosis (RO) system — most effective for PFAS, lead, and other contaminants. Always look for filters with NSF/ANSI certification for the specific contaminants you want to remove.

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