Tolland County, Connecticut
22 ZIP codes · Avg score 64/100 · Grade C · Updated 2026-06-03
Across Tolland County, EPA compliance data for 22 ZIP codes sits at a moderate level — not alarming, but not uniformly clean either.
How Tolland County Compares
How Tolland County Compares
Tolland County scores 1 points below the Connecticut state average (65/100) and 4 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Tolland 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: $1,614, driven primarily by flood
Infrastructure: 0.432% avg pipe failure probability, 56% of ZIPs at high risk
67.6% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↑ Worsening trendEPA violation counts by year across Tolland County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 19 violations. Past 5 years: 37 total (37 health-based). Health-based violations are rising versus the prior 2-year window — worth closer monitoring.
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: $1,614
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
69,803 housing units in Tolland County
Source: U.S. Census Bureau ACS B25034 (Year Structure Built).
Water Safety Affordability
How much it costs to fix water issues relative to home values in Tolland County
Remediation costs are relatively manageable for most homeowners in Tolland 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 Tolland County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Twin Hills Water District | 156 | 35 |
| 2 | Ctwc - Northern Reg-western System | 101,313 | 31 |
| 3 | 890 Boston Turnpike | 60 | 28 |
| 4 | Southridge Park Apartments | 50 | 28 |
| 5 | Cook Drive Association | 49 | 28 |
45 total water systems serve Tolland County.
All ZIP Codes in Tolland County
22 ZIP codes tracked in Tolland County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 6248 | Hebron | 78 | B | 12 (2 health) | $360K |
| 2 | 6250 | Mansfield Center | 78 | B | 1 | $287K |
| 3 | 6237 | Columbia | 77 | B | 2 | $322K |
| 4 | 6238 | Coventry | 76 | B | 7 (4 health) | $318K |
| 5 | 6226 | Willimantic | 74 | B | 3 (1 health) | $181K |
| 6 | 6232 | Andover | 74 | B | 13 (3 health) | $375K |
| 7 | 6071 | Somers | 70 | B | 1 | $379K |
| 8 | 6084 | Tolland | 70 | B | 27 (7 health) | $332K |
| 9 | 6043 | Bolton | 67 | C | 28 (7 health) | $349K |
| 10 | 6279 | Willington | 66 | C | 15 (5 health) | $288K |
| 11 | 6231 | Amston | 63 | C | 0 | $377K |
| 12 | 6246 | Grosvenor Dale | 63 | C | 0 | — |
| 13 | 6251 | Mansfield Depot | 63 | C | 0 | — |
| 14 | 6255 | North Grosvenordale | 63 | C | 0 | $298K |
| 15 | 6076 | Stafford Springs | 61 | C | 3 (1 health) | $247K |
| 16 | 6073 | South Glastonbury | 55 | C | 0 | $529K |
| 17 | 6025 | East Glastonbury | 53 | D | 0 | — |
| 18 | 6072 | Somersville | 53 | D | 0 | — |
| 19 | 6077 | Staffordville | 53 | D | 0 | — |
| 20 | 6265 | South Willington | 53 | D | 0 | — |
| 21 | 6461 | Milford | 50 | D | 0 | $396K |
| 22 | 6460 | Milford | 40 | D | 0 | $373K |
Recommended Buyer Guides for Tolland County
Strictly editorial — no paid placements influence which guides appear; the selection draws on NSF certifications and EPA detection records for water systems serving this county.
- Best Lead Paint Test Kits — 67.6% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
- Best Sump Pumps — Flood is the top compound risk factor
- Best Mold Test Kits — Flood-driven moisture and mold risk
Deep Dive Reports
Detailed analysis for Tolland County, Connecticut
Overview
Tolland County in Connecticut covers 22 ZIP codes with an average Home Safety Score of C (64/100).
11 of 22 ZIP codes have recorded EPA violations. 30 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.