Lake County, Indiana
34 ZIP codes · Avg score 65/100 · Grade C · Updated 2026-06-03
For most households in Lake County, the 34 tracked ZIP codes show adequate but uneven water quality.
How Lake County Compares
How Lake County Compares
Lake County scores 5 points above the Indiana state average (60/100) and 3 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Lake County, Indiana
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 14.4 (asthma 11.4%, diabetes 14.9%)
Estimated additional annual cost per homeowner: $2,127, driven primarily by flood
Infrastructure: 0.42% avg pipe failure probability, 63% of ZIPs at high risk
75.9% of homes built before 1978 (lead paint era)
Violation History (2022–2025)
↑ Worsening trendEPA violation counts by year across Lake County water systems. Health-based shown in red, total in blue.
Peak year: 2024 with 6 violations. Past 5 years: 15 total (15 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: $2,127
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
233,635 housing units in Lake 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 Lake County
Remediation costs are relatively manageable for most homeowners in Lake 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 Lake 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 Lake County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Cedar Lake - Robins Nest | 950 | 52 |
| 2 | Indiana American Water - Lowell | 11,908 | 52 |
| 3 | Cedar Lake Water Works | 4,600 | 41 |
| 4 | Indiana American Water - Northwest | 210,510 | 37 |
| 5 | Fairway Regional Water District | 210 | 35 |
28 total water systems serve Lake County.
All ZIP Codes in Lake County
34 ZIP codes tracked in Lake County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 46325 | Hammond | 82 | B | 3 | — |
| 2 | 46327 | Hammond | 82 | B | 3 | $117K |
| 3 | 46411 | Merrillville | 78 | B | 4 (1 health) | — |
| 4 | 46320 | Hammond | 77 | B | 3 | $115K |
| 5 | 46342 | Hobart | 76 | B | 1 | $193K |
| 6 | 46376 | Schneider | 74 | B | 4 (1 health) | $169K |
| 7 | 46308 | Crown Point | 72 | B | 13 | — |
| 8 | 46324 | Hammond | 72 | B | 3 | $142K |
| 9 | 46356 | Lowell | 72 | B | 7 (3 health) | $256K |
| 10 | 46394 | Whiting | 71 | B | 1 | $163K |
| 11 | 46312 | East Chicago | 70 | B | 7 | $92K |
| 12 | 46410 | Merrillville | 69 | C | 4 (1 health) | $192K |
| 13 | 46322 | Highland | 68 | C | 0 | $220K |
| 14 | 46323 | Hammond | 67 | C | 3 | $149K |
| 15 | 46311 | Dyer | 66 | C | 0 | $300K |
| 16 | 46321 | Munster | 65 | C | 3 | $312K |
| 17 | 46375 | Schererville | 64 | C | 11 | $295K |
| 18 | 46373 | Saint John | 63 | C | 0 | $375K |
| 19 | 46393 | Wheeler | 63 | C | 0 | $135K |
| 20 | 46403 | Gary | 63 | C | 0 | $155K |
| 21 | 46404 | Gary | 63 | C | 0 | $88K |
| 22 | 46406 | Gary | 63 | C | 0 | $86K |
| 23 | 46407 | Gary | 63 | C | 0 | $55K |
| 24 | 46307 | Crown Point | 62 | C | 13 | $294K |
| 25 | 46319 | Griffith | 61 | C | 5 | $194K |
| 26 | 46303 | Cedar Lake | 58 | C | 28 (1 health) | $272K |
| 27 | 46368 | Portage | 55 | C | 0 | $214K |
| 28 | 46409 | Gary | 55 | C | 0 | $73K |
| 29 | 46302 | Boone Grove | 53 | D | 0 | — |
| 30 | 46355 | Leroy | 53 | D | 0 | — |
| 31 | 46401 | Gary | 53 | D | 0 | — |
| 32 | 46402 | Gary | 53 | D | 0 | $61K |
| 33 | 46405 | Lake Station | 50 | D | 0 | $124K |
| 34 | 46408 | Gary | 50 | D | 0 | $96K |
Recommended Buyer Guides for Lake County
Eight risk categories drive the selection — PFAS exceedance, lead above EPA action level, pre-1978 housing share, EPA Radon Zone 1, flood-top-risk, wildfire-top-risk, multi-contaminant load, and a baseline fallback — and each category maps to a specific buyer-guide track that surfaces when the county data hits its threshold for that hazard signal.
- Best Lead Paint Test Kits — 75.9% 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 Lake County, Indiana
Overview
Lake County in Indiana covers 34 ZIP codes with an average Home Safety Score of C (65/100).
18 of 34 ZIP codes have recorded EPA violations. 7 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.