B
74

US Water Score: B

Farmington, MO 63640

Saint Francois County · Population served: 18,217 · Data updated July 2026

Service-area evidence: EPA service-area records associate the listed system with this ZIP. Boundaries may still overlap or change.

Water Systems Serving This Area

🌊
FARMINGTON PWS
Groundwater · Pop. 18,217
PWSID: MO4010270
🏔
THOMAS HILL PWSD 1
Surface water · Pop. 11,250
PWSID: MO2024504
🌊
FARMINGTON CORRECTIONAL CENTER
Groundwater · Pop. 3,500
PWSID: MO4069041
🌊
PILOT KNOB RURAL WD 1 N & S
Groundwater · Pop. 839
PWSID: MO4020601
🌊
PILOT KNOB RURAL WD 1 DOE RUN AREA
Groundwater · Pop. 507
PWSID: MO4021451

Contaminants Detected

ContaminantDetected LevelEPA MCLHealth GuidelineStatus
Lead
7.7
15 ppb 1 ppb Warning

PFAS / Forever Chemicals

3 detected Below comparison values

UCMR5 occurrence results are screening information, not a finding of regulatory compliance or noncompliance. PFAS rules and compliance dates are evolving.

CompoundLevelEPA MCLHealth GuidelineStatus
PFBA9.3 pptNo standard500 pptNo federal MCL shown
PFHxS4.8 ppt10 ppt10 pptBelow comparison value
PFPeA3.8 pptNo standardNo federal MCL shown

Violation History (Last 5 Years)

24Total (5yr)
5Health-Based
5Major

Water Quality Summary

Understanding Your Water in Farmington

Tap water quality in Farmington, Missouri (63640) receives an overall grade of B (Moderate-low record-based concern) with a score of 74 out of 100, based on analysis of EPA compliance data, contaminant testing, and violation history. This is 15 points below the Missouri state average of 89. The area is served by 7 water systems providing water to approximately 18,217 people, using groundwater and surface water sources. Testing has found elevated levels of Lead that warrant attention. PFAS testing detected 3 compounds, all below the EPA final MCL values used for comparison. Over the past 5 years, water systems here have accumulated 24 violations, including 5 health-based violations.

Your Score 74/100 B
vs State 15 pts below Missouri avg (89)
vs National 1 pts below national avg (75)

What a Grade B Means

A score of 74/100 means Farmington, MO performs well in the US Water Score model, with only minor system-level concerns. Residents should still review their utility's Consumer Confidence Report for official compliance information and household-specific context.

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

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

Based on public water-system records, Farmington, Missouri receives an internal US Water Score grade of B (Moderate-low record-based concern) with a score of 74/100. This indicates relatively few system-level concerns in our model, but it is not an EPA safety rating and does not guarantee tap conditions inside individual homes.

ZIP code 63640 is served by 7 water systems using groundwater, surface water sources, providing water to approximately 18,217 people. Multiple source types mean your water may come from a blend of surface and underground sources.

Lead was reported at 7.7 ppb in public-system records for Farmington, Missouri. This is below the currently applicable EPA action level of 15 ppb, but may be above more protective health guidance; EPA's future LCRI action level is 10 ppb. Household plumbing can materially change tap-level exposure, so consider certified filtration and individual tap testing, especially where children are present.

3 PFAS compounds were detected in water serving Farmington, Missouri, with reported values below the EPA final MCL values used by this site. This comparison is informational: federal compliance timelines and the status of some PFAS standards are still evolving. Activated carbon or reverse osmosis filters can reduce some PFAS when appropriately certified and maintained.

Water systems serving Farmington, Missouri have received 24 violations in the last 5 years, including 5 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 Farmington, 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.

Explore Nearby

Water Quality in Nearby ZIP Codes