New Haven County, Connecticut
80 ZIP codes · Avg score 58/100 · Grade C · Updated 2026-06-03
The systems supplying New Haven County's 80 ZIP codes vary in performance — most meet minimum standards, but violations in select areas are on record.
How New Haven County Compares
How New Haven County Compares
New Haven County scores 7 points below the Connecticut state average (65/100) and 10 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: New Haven County, Connecticut
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Estimated additional annual cost per homeowner: $4,242, driven primarily by sea_level
Infrastructure: 0.379% avg pipe failure probability, 44% of ZIPs at high risk
Violation History (2023–2024)
→ Stable trendEPA violation counts by year across New Haven County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 51 violations. Past 5 years: 58 total (58 health-based).
Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.
Infrastructure Overview
Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.
Compound Risk Breakdown
Estimated additional annual cost per homeowner: $4,242
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Water Safety Affordability
How much it costs to fix water issues relative to home values in New Haven County
Remediation costs are relatively manageable for most homeowners in New Haven County, representing a small fraction of property value.
Remediation includes water filtration, lead abatement, radon mitigation, and flood protection where applicable. Source: Census ACS, EPA SDWIS.
Water Systems with Most Violations
Top 5 systems in New Haven County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Waterbury Water Department | 107,271 | 360 |
| 2 | Yeshiva of Waterbury-durham Campus | 490 | 352 |
| 3 | WALLINGFORD WATER DEPARTMENT | 37,267 | 117 |
| 4 | Northford Glen Condominium Association | 84 | 117 |
| 5 | Regional Water Authority | 418,900 | 107 |
40 total water systems serve New Haven County.
All ZIP Codes in New Haven County
80 ZIP codes tracked in New Haven County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 6501 | New Haven | 70 | B | 0 | — |
| 2 | 6503 | New Haven | 70 | B | 0 | — |
| 3 | 6505 | New Haven | 70 | B | 0 | — |
| 4 | 6506 | New Haven | 70 | B | 0 | — |
| 5 | 6507 | New Haven | 70 | B | 0 | — |
| 6 | 6510 | New Haven | 70 | B | 0 | $496K |
| 7 | 6531 | New Haven | 70 | B | 0 | — |
| 8 | 6540 | New Haven | 70 | B | 0 | — |
| 9 | 6075 | Stafford | 66 | C | 3 (1 health) | — |
| 10 | 6502 | New Haven | 66 | C | 0 | — |
| 11 | 6504 | New Haven | 66 | C | 0 | — |
| 12 | 6508 | New Haven | 66 | C | 0 | — |
| 13 | 6509 | New Haven | 66 | C | 0 | — |
| 14 | 6520 | New Haven | 66 | C | 0 | — |
| 15 | 6521 | New Haven | 66 | C | 0 | — |
| 16 | 6530 | New Haven | 66 | C | 0 | — |
| 17 | 6532 | New Haven | 66 | C | 0 | — |
| 18 | 6533 | New Haven | 66 | C | 0 | — |
| 19 | 6534 | New Haven | 66 | C | 0 | — |
| 20 | 6535 | New Haven | 66 | C | 0 | — |
| 21 | 6536 | New Haven | 66 | C | 0 | — |
| 22 | 6537 | New Haven | 66 | C | 0 | — |
| 23 | 6538 | New Haven | 66 | C | 0 | — |
| 24 | 6712 | Prospect | 66 | C | 7 (1 health) | $351K |
| 25 | 6483 | Seymour | 65 | C | 0 | $345K |
| 26 | 6511 | New Haven | 65 | C | 0 | $313K |
| 27 | 6519 | New Haven | 65 | C | 0 | $248K |
| 28 | 6701 | Waterbury | 65 | C | 22 (2 health) | — |
| 29 | 6702 | Waterbury | 65 | C | 22 (2 health) | — |
| 30 | 6706 | Waterbury | 65 | C | 22 (2 health) | $171K |
| 31 | 6710 | Waterbury | 65 | C | 22 (2 health) | $220K |
| 32 | 6721 | Waterbury | 65 | C | 22 (2 health) | — |
| 33 | 6762 | Middlebury | 65 | C | 1 | $452K |
| 34 | 6770 | Naugatuck | 65 | C | 0 | $242K |
| 35 | 6454 | Meriden | 61 | C | 5 (1 health) | — |
| 36 | 6716 | Wolcott | 61 | C | 7 (1 health) | $299K |
| 37 | 6478 | Oxford | 60 | C | 1 | $455K |
| 38 | 6493 | Wallingford | 60 | C | 24 (2 health) | — |
| 39 | 6494 | Wallingford | 60 | C | 24 (2 health) | — |
| 40 | 6495 | Wallingford | 60 | C | 24 (2 health) | — |
| 41 | 6513 | New Haven | 60 | C | 0 | $227K |
| 42 | 6515 | New Haven | 60 | C | 0 | $284K |
| 43 | 6703 | Waterbury | 60 | C | 22 (2 health) | — |
| 44 | 6704 | Waterbury | 60 | C | 22 (2 health) | $179K |
| 45 | 6705 | Waterbury | 60 | C | 22 (2 health) | $178K |
| 46 | 6708 | Waterbury | 60 | C | 22 (2 health) | $197K |
| 47 | 6720 | Waterbury | 60 | C | 22 (2 health) | — |
| 48 | 6722 | Waterbury | 60 | C | 22 (2 health) | — |
| 49 | 6723 | Waterbury | 60 | C | 22 (2 health) | — |
| 50 | 6724 | Waterbury | 60 | C | 22 (2 health) | — |
| 51 | 6725 | Waterbury | 60 | C | 22 (2 health) | — |
| 52 | 6726 | Waterbury | 60 | C | 22 (2 health) | — |
| 53 | 6749 | Waterbury | 60 | C | 22 (2 health) | — |
| 54 | 6450 | Meriden | 56 | C | 5 (1 health) | $220K |
| 55 | 6451 | Meriden | 56 | C | 5 (1 health) | $223K |
| 56 | 6405 | Branford | 55 | C | 1 | $388K |
| 57 | 6437 | Guilford | 55 | C | 1 | $491K |
| 58 | 6443 | Madison | 55 | C | 0 | $535K |
| 59 | 6471 | North Branford | 55 | C | 21 (2 health) | $365K |
| 60 | 6492 | Wallingford | 55 | C | 24 (2 health) | $328K |
| 61 | 6401 | Ansonia | 53 | D | 0 | $268K |
| 62 | 6403 | Beacon Falls | 53 | D | 0 | $324K |
| 63 | 6524 | Bethany | 53 | D | 18 | $419K |
| 64 | 6488 | Southbury | 51 | D | 10 | $382K |
| 65 | 6516 | West Haven | 51 | D | 3 (1 health) | $265K |
| 66 | 6408 | Cheshire | 50 | D | 16 (1 health) | — |
| 67 | 6411 | Cheshire | 50 | D | 16 (1 health) | — |
| 68 | 6410 | Cheshire | 48 | D | 16 (1 health) | $419K |
| 69 | 6472 | Northford | 45 | D | 0 | $372K |
| 70 | 6517 | Hamden | 45 | D | 0 | $313K |
| 71 | 6477 | Orange | 42 | D | 1 | $467K |
| 72 | 6473 | North Haven | 40 | D | 0 | $360K |
| 73 | 6487 | South Britain | 40 | D | 0 | — |
| 74 | 6514 | Hamden | 40 | D | 0 | $250K |
| 75 | 6525 | Woodbridge | 40 | D | 0 | $546K |
| 76 | 6878 | Riverside | 40 | D | 0 | $1899K |
| 77 | 6518 | Hamden | 35 | F | 0 | $308K |
| 78 | 6820 | Darien | 35 | F | 0 | $1728K |
| 79 | 6870 | Old Greenwich | 35 | F | 0 | $1579K |
| 80 | 6512 | East Haven | 30 | F | 0 | $265K |
Recommended Buyer Guides for New Haven County
Editorial-only picks, screened against the EPA detections on file.
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best Radon Test Kits — EPA Radon Zone 1 (highest risk) dominant in county
Deep Dive Reports
Detailed analysis for New Haven County, Connecticut
Overview
New Haven County in Connecticut covers 80 ZIP codes with an average Home Safety Score of C (58/100).
38 of 80 ZIP codes have recorded EPA violations. 52 health-based violations have been documented.
← Back to Connecticut water quality report
Data Sources
- Water quality: EPA Safe Drinking Water Information System (SDWIS)
- Home values: U.S. Census Bureau ACS (median estimates by ZCTA)
Updated daily.