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Not health advice. Contact your local water utility for concerns.
Data from EPA Water Quality Reports. For official information, contact your water utility or health department.
Water quality data for 4 cities serving 692,247 residents
Jefferson County in Kentucky has an average water quality score of 86/100 (Grade A-) based on analysis of 4 municipal water systems. The county's water systems serve approximately 692,247 residents.
Overall, Jefferson County demonstrates good water quality standards. 3 of 4 cities exceed the county average, with Jeffersontown leading with a score of 89/100.
4 cities ranked by water quality score
| Rank | City | Score | Grade | Population |
|---|---|---|---|---|
| 1 | Jeffersontown Top concern: Haloacetic Acids (18.2% of limit) | 89 | A- | 28,755 |
| 2 | Shively Top concern: Fluoride (14.2% of limit) | 86 | A- | 14,999 |
| 3 | St. Matthews Top concern: Fluoride (13.6% of limit) | 86 | A- | 14,092 |
| 4 | Louisville Top concern: Haloacetic Acids (19.6% of limit) | 84 | B+ | 634,401 |
Top detected contaminants across county water systems
| Contaminant | Avg Level | Max Level | EPA Limit | % of Limit | Cities |
|---|---|---|---|---|---|
| Fluoride | 0.605 mg/L | 0.729 mg/L | 4 mg/L | 15.1% | 4 |
| Haloacetic Acids | 8.659 ug/L | 11.767 ug/L | 60 ug/L | 14.4% | 4 |
| Copper | 0.127 mg/L | 0.158 mg/L | 1.3 mg/L | 9.8% | 4 |
| Nitrate | 0.831 mg/L | 1.264 mg/L | 10 mg/L | 8.3% | 3 |
| Lead | 0.001 mg/L | 0.002 mg/L | 0.015 mg/L | 7.7% | 4 |
| Chromium | 0.008 mg/L | 0.01 mg/L | 0.1 mg/L | 7.5% | 4 |
| Nitrite | 0.073 mg/L | 0.124 mg/L | 1 mg/L | 7.3% | 4 |
| Mercury | 0 mg/L | 0 mg/L | 0.002 mg/L | 6.3% | 4 |
Recent violations across county water systems
Water quality in Jefferson County, Kentucky reflects the region's unique combination of water sources, treatment infrastructure, and environmental factors. Our comprehensive analysis examines 4 municipal water systems serving a combined population of over 692,247 residents.
The county shows strong water quality performance, with scores ranging from 84/100 in Louisville to 89/100 in Jeffersontown. This 5-point spread indicates relatively consistent water quality standards across municipal systems.
The most prevalent contaminants detected across Jefferson County water systems include Fluoride, Haloacetic Acids, Copper. All monitored contaminants remain within acceptable levels relative to EPA Maximum Contaminant Levels (MCLs).
Jefferson County's water quality is generally good. Residents can feel confident in their tap water quality, though those with specific health concerns or sensitivity to certain contaminants may still benefit from filtration. Regular review of your city's annual Consumer Confidence Report is recommended.
Jefferson County has an average water quality score of 86/100 (Grade A-) based on analysis of 4 municipal water systems serving 692,247 residents.
Jeffersontown has the highest water quality score in Jefferson County at 89/100. View the detailed report for Jeffersontown.
Most cities in Jefferson County have water that meets EPA standards. However, a water filter can provide additional protection and improve taste. The need depends on your specific city and any personal health considerations.
Click on any city in the rankings table above to view its detailed water quality report, including contaminant levels, EPA compliance history, and filter recommendations.