Jefferson County Water Quality
Jefferson County, Kentucky
Water Grade
A
Water Score
86.0
Violations
0
State Rank
#30
of 118 (1 = best)
EPA SDWIS Compliance
Drinking Water Quality
Water Quality Grade
A
Based on EPA compliance history and violation data
Water Score
86/100
Higher = better quality
Health Violations
0
Health-based violations
Violation Rate
0.0%
Systems with violations
Water Advisory: Jefferson County
Water Verdict
Jefferson County receives an excellent water quality assessment with a grade of A and a score of 86.0 out of 100. The water supply meets or exceeds federal safety standards, and residents can generally drink tap water with confidence.
Violation Context
Jefferson County has recorded zero health-based violations, indicating that the water system has met all federal safety standards during the reporting period. The violation rate is zero per 1,000 residents, which is the best possible outcome.
Consumer Guidance
Tap water in Jefferson County is generally safe to drink based on available data. Residents should still review their utility's annual Consumer Confidence Report for transparency on detected contaminants. For long-term peace of mind, request your utility's latest Consumer Confidence Report and consider independent water testing if you have specific health concerns.
Regional Context
Jefferson County has better water quality than the average county in Kentucky. Its water score is 21.8 points higher than the state average, indicating stronger water system performance relative to neighboring counties.
Past 5 years
Water Quality Monitoring
Monitoring Sites
27
Active in the past 5 years
Measurements Recorded
3.4K
3,439 total readings
Most Measured
- Inorganics, Minor, Metals
- Physical
- Biological, Fish
Categories measured most frequently
Data from the EPA Water Quality Portal (WQP), aggregating monitoring records from federal, state, and tribal sources. Each measurement represents a single sample analyzed for a specific characteristic (e.g., E. coli, pH, dissolved oxygen, nitrogen).
Live USGS Streamgage
River & Stream Conditions
Current Discharge
89.4Kcfs
May 14, 6:45 PM UTC
vs Long-Term Average
74%
Below typicalPrimary Streamgage
OHIO RIVER AT LOUISVILLE, KY
- USGS site
- 03294500
- Drainage area
- 91,170 sq mi
- Long-term mean
- 120.6K cfs
One representative streamgage (the one with the largest drainage area in the county). Many counties have multiple gauges — this view summarizes the primary one. The long-term mean is the full-record annual average; "% of typical" compares the latest reading against that average.
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Frequently Asked Questions
What is the water quality in Jefferson County, Kentucky?
Are there any water violations in Jefferson County?
How much water-quality monitoring happens in Jefferson County?
What's happening with rivers in Jefferson County right now?
How does Jefferson County water compare to the Kentucky average?
Is tap water safe to drink in Jefferson County?
Does Jefferson County have clean drinking water?
How does Jefferson County rank for water quality in Kentucky?
Counties with Similar Water Quality
Data Sources
Drinking-water compliance data from the EPA Safe Drinking Water Information System (SDWIS) via the ECHO enforcement database. Scores reflect compliance history and health-based violation counts.
Water-quality monitoring counts from the EPA Water Quality Portal (WQP) — federated USGS, EPA, and state agency sampling records over a rolling 5-year window.
Live streamflow from the USGS National Water Information System (NWIS) — continuous discharge measurements from the largest-drainage gauge in each county, compared against the full-record long-term annual mean.
Disclaimer: This data is informational only. It is not health, legal, or professional advice. For concerns about your specific water supply, contact your local water utility.