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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 607,347 residents
New Haven County in Connecticut has an average water quality score of 87/100 (Grade B) based on analysis of 4 municipal water systems. The county's water systems serve approximately 607,347 residents.
Overall, New Haven County demonstrates good water quality standards. 2 of 4 cities exceed the county average, with Naugatuck leading with a score of 100/100.
4 cities ranked by water quality score
| Rank | City | Score | Grade | Population |
|---|---|---|---|---|
| 1 | Naugatuck | 100 | A | 22,735 |
| 2 | Waterbury Biggest deduction: 2 monitoring/reporting violations in the last 5 years (−2 pts) | 98 | A | 107,271 |
| 3 | New Haven Biggest deduction: PFOA detected at up to 7.1 ppt in UCMR5 sampling (2024-06-11), at or above EPA's 4 ppt MCL (−10 pts) | 76 | C | 418,900 |
| 4 | Meriden Biggest deduction: PFOA detected at up to 6.1 ppt in UCMR5 sampling (2024-04-30), at or above EPA's 4 ppt MCL (−10 pts) | 73 | C | 58,441 |
Real EPA readings across county water systems (lead: latest 90th percentile; PFAS: UCMR5 2023–2026; others: 2012–2019 averages)
| Contaminant | Avg Level | Max Level | EPA Limit | % of Limit | Cities |
|---|---|---|---|---|---|
| PFAS (PFOA/PFOS max, UCMR5) | 5.05 ppt | 10.7 ppt | 4 ppt | 126.3% | 4 |
| TTHM (2012–2019 avg) | 44.097 ug/L | 49.261 ug/L | 80 ug/L | 55.1% | 4 |
| HAA5 (2012–2019 avg) | 28.02 ug/L | 39.931 ug/L | 60 ug/L | 46.7% | 4 |
| Fluoride (2012–2019 avg) | 0.76 mg/L | 0.848 mg/L | 4 mg/L | 19% | 4 |
| Radium (2012–2019 avg) | 0.52 pCi/L | 1.135 pCi/L | 5 pCi/L | 10.4% | 4 |
| Nitrate (2012–2019 avg) | 0.769 mg/L | 1.159 mg/L | 10 mg/L | 7.7% | 4 |
| Lead (90th percentile) | 1 ppb | 4 ppb | 15 ppb | 6.7% | 4 |
| Uranium (2012–2019 avg) | 0.154 ug/L | 0.497 ug/L | 30 ug/L | 0.5% | 4 |
Recent violations across county water systems
Health-based: MCL exceeded — Maximum Contaminant Level Violation, Average - Total Haloacetic Acids (HAA5)
12/31/2017
Other — Consumer Confidence Report Complete Failure to Report - Consumer Confidence Rule
6/30/2025
Other — Consumer Confidence Report Complete Failure to Report - Consumer Confidence Rule
6/30/2024
Showing 10 of 19 recent violations
Water quality in New Haven County, Connecticut 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 607,347 residents.
The county shows strong water quality performance, with scores ranging from 73/100 in Meriden to 100/100 in Naugatuck. This 27-point spread indicates significant variation in water quality across the county, suggesting different water sources or treatment approaches.
The most prevalent contaminants detected across New Haven County water systems include PFAS (PFOA/PFOS max, UCMR5), TTHM (2012–2019 avg), HAA5 (2012–2019 avg). At least one reading averages above 50% of its EPA limit across the county's systems, worth attention from residents and utilities.
New Haven 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.
New Haven County has an average water quality score of 87/100 (Grade B) based on analysis of 4 municipal water systems serving 607,347 residents.
Naugatuck has the highest water quality score in New Haven County at 100/100. View the detailed report for Naugatuck.
Most cities in New Haven 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.