Seminole County, Florida
31 ZIP codes · Avg score 77/100 · Grade B · Updated 2026-06-03
Seminole County's tap water quality puts it in the upper tier nationally; the 31 ZIP codes here record few health-based violations.
How Seminole County Compares
How Seminole County Compares
Seminole County scores 4 points above the Florida state average (73/100) and 9 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Seminole County, Florida
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 11.6 (asthma 9.1%, diabetes 11.4%)
Estimated additional annual cost per homeowner: $5,056, driven primarily by sea_level
Infrastructure: 0.29% avg pipe failure probability, 4% of ZIPs at high risk
51.8% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↓ Improving trendEPA violation counts by year across Seminole County water systems. Health-based shown in red, total in blue.
Peak year: 2023 with 34 violations. Past 5 years: 79 total (79 health-based). Health-based violations are declining versus the prior 2-year window.
Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.
County Health Indicators vs National Average
Black markers indicate national averages. Source: CDC PLACES, Census ACS.
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: $5,056
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
229,256 housing units in Seminole 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 Seminole County
Remediation costs are relatively manageable for most homeowners in Seminole 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.
Health Outcomes vs National Average
CDC PLACES data for Seminole County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water Systems with Most Violations
Top 5 systems in Seminole County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Sanlando (3 Wtps) | 36,953 | 477 |
| 2 | Altamonte Springs Water Department (2 Wps) | 51,000 | 332 |
| 3 | Longwood, City of (2 Wps) | 23,237 | 312 |
| 4 | Seven Springs | 32,834 | 304 |
| 5 | Florida Governmental Utility Authority | 32,296 | 304 |
38 total water systems serve Seminole County.
All ZIP Codes in Seminole County
31 ZIP codes tracked in Seminole County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 32795 | Lake Mary | 97 | A | 1 | — |
| 2 | 32719 | Winter Springs | 95 | A | 3 | — |
| 3 | 32718 | Casselberry | 94 | A | 4 | — |
| 4 | 32752 | Longwood | 93 | A | 76 (2 health) | — |
| 5 | 32762 | Oviedo | 93 | A | 5 (2 health) | — |
| 6 | 32791 | Longwood | 93 | A | 76 (2 health) | — |
| 7 | 32730 | Casselberry | 90 | A | 4 | $285K |
| 8 | 32772 | Sanford | 90 | A | 37 (4 health) | — |
| 9 | 32715 | Altamonte Springs | 89 | A | 43 (5 health) | — |
| 10 | 32716 | Altamonte Springs | 89 | A | 43 (5 health) | — |
| 11 | 32746 | Lake Mary | 88 | A | 1 | $420K |
| 12 | 32708 | Winter Springs | 81 | B | 3 | $353K |
| 13 | 32707 | Casselberry | 80 | B | 4 | $305K |
| 14 | 32750 | Longwood | 80 | B | 76 (2 health) | $351K |
| 15 | 32766 | Oviedo | 80 | B | 5 (2 health) | $530K |
| 16 | 32779 | Longwood | 80 | B | 76 (2 health) | $459K |
| 17 | 32773 | Sanford | 78 | B | 37 (4 health) | $260K |
| 18 | 32701 | Altamonte Springs | 77 | B | 43 (5 health) | $258K |
| 19 | 32714 | Altamonte Springs | 77 | B | 43 (5 health) | $292K |
| 20 | 32765 | Oviedo | 75 | B | 5 (2 health) | $419K |
| 21 | 32747 | Lake Monroe | 73 | B | 0 | — |
| 22 | 32771 | Sanford | 73 | B | 37 (4 health) | $333K |
| 23 | 32792 | Winter Park | 72 | B | 18 (7 health) | $344K |
| 24 | 32745 | Mid Florida | 66 | C | 0 | — |
| 25 | 32732 | Geneva | 55 | C | 19 (11 health) | $467K |
| 26 | 33001 | Long Key | 55 | C | 0 | $603K |
| 27 | 33051 | Key Colony Beach | 55 | C | 0 | $835K |
| 28 | 33070 | Tavernier | 55 | C | 0 | $695K |
| 29 | 33036 | Islamorada | 50 | D | 0 | $996K |
| 30 | 33037 | Key Largo | 50 | D | 0 | $661K |
| 31 | 33050 | Marathon | 50 | D | 0 | $706K |
Recommended Buyer Guides for Seminole 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 — 51.8% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
Deep Dive Reports
Detailed analysis for Seminole County, Florida
Overview
Seminole County in Florida covers 31 ZIP codes with an average Home Safety Score of B (77/100).
23 of 31 ZIP codes have recorded EPA violations. 64 health-based violations have been documented.
← Back to Florida 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.