Hamilton County, Indiana
18 ZIP codes · Avg score 60/100 · Grade C · Updated 2026-06-03
Current EPA records place Hamilton County in the middle tier for drinking water safety, with 18 ZIP codes showing a range of outcomes.
How Hamilton County Compares
How Hamilton County Compares
Hamilton County scores 0 points above the Indiana state average (60/100) and 8 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Hamilton County, Indiana
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 11.1 (asthma 10.3%, diabetes 9.8%)
Estimated additional annual cost per homeowner: $870, driven primarily by flood
Infrastructure: 0.33% avg pipe failure probability, 11% of ZIPs at high risk
37.1% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
↑ Worsening trendEPA violation counts by year across Hamilton County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 16 violations. Past 5 years: 36 total (36 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.
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: $870
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
138,767 housing units in Hamilton 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 Hamilton County
Remediation costs are relatively manageable for most homeowners in Hamilton 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 Hamilton 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 Hamilton County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | CITIZENS WATER - INDIANAPOLIS | 880,345 | 111 |
| 2 | Citizens Water of Westfield, Llc | 61,493 | 101 |
| 3 | Carmel Water Department | 99,927 | 91 |
| 4 | City of Lawrence Utilities | 49,000 | 52 |
| 5 | Citizens Water - Morgan | 5,705 | 52 |
27 total water systems serve Hamilton County.
All ZIP Codes in Hamilton County
18 ZIP codes tracked in Hamilton County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 46030 | Arcadia | 70 | B | 0 | $226K |
| 2 | 46069 | Sheridan | 70 | B | 0 | $243K |
| 3 | 46074 | Westfield | 69 | C | 3 | $400K |
| 4 | 46034 | Cicero | 64 | C | 3 (1 health) | $293K |
| 5 | 46061 | Noblesville | 64 | C | 7 (2 health) | — |
| 6 | 46062 | Noblesville | 63 | C | 7 (2 health) | $351K |
| 7 | 46032 | Carmel | 62 | C | 12 (3 health) | $464K |
| 8 | 46082 | Carmel | 62 | C | 12 (3 health) | — |
| 9 | 46040 | Fortville | 60 | C | 1 | $434K |
| 10 | 46031 | Atlanta | 59 | C | 3 | $178K |
| 11 | 46060 | Noblesville | 58 | C | 7 (2 health) | $292K |
| 12 | 46033 | Carmel | 57 | C | 12 (3 health) | $459K |
| 13 | 46037 | Fishers | 57 | C | 7 (2 health) | $403K |
| 14 | 46038 | Fishers | 57 | C | 7 (2 health) | $302K |
| 15 | 46085 | Fishers | 56 | C | 7 (2 health) | — |
| 16 | 46290 | Indianapolis | 56 | C | 26 (5 health) | $638K |
| 17 | 46056 | Markleville | 53 | D | 0 | $192K |
| 18 | 46280 | Indianapolis | 51 | D | 26 (5 health) | $291K |
Recommended Buyer Guides for Hamilton County
Editorial methodology pairs each documented risk in this county with the buyer category that addresses it, drawing on water-quality detections, housing-stock lead exposure, EPA Radon Zone designation, and FEMA flood and wildfire ratings. NSF-certified options surface where applicable, and products that match the specific contaminant take priority.
- 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
- 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 Hamilton County, Indiana
Overview
Hamilton County in Indiana covers 18 ZIP codes with an average Home Safety Score of C (60/100).
15 of 18 ZIP codes have recorded EPA violations. 32 health-based violations have been documented.
← Back to Indiana 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.