Allen County, Kansas
5 ZIP codes · Avg score 74/100 · Grade B · Updated 2026-06-03
For households in Allen County, the 5 ZIP codes on record show consistently safe tap water.
How Allen County Compares
How Allen County Compares
Allen County scores 10 points above the Kansas state average (64/100) and 6 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Allen County, Kansas
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 14.1 (asthma 10.3%, diabetes 12.5%)
Estimated additional annual cost per homeowner: $894, driven primarily by water_lead
Infrastructure: 0.466% avg pipe failure probability, 100% of ZIPs at high risk
81.4% of homes built before 1978 (lead paint era)
Violation History (2023–2025)
→ Stable trendEPA violation counts by year across Allen County water systems. Health-based shown in red, total in blue.
Peak year: 2023 with 3 violations. Past 5 years: 6 total (6 health-based).
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: $894
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
5,694 housing units in Allen 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 Allen County
Water safety remediation is a moderate expense relative to home values. Most homeowners can address issues through staged improvements over time.
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 Allen 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 Allen County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Allen Company Rwd 8 | 736 | 37 |
| 2 | City of Humboldt, | 1,836 | 28 |
| 3 | Allen Company Rwd 10 | 125 | 19 |
| 4 | WOODSON CO RWD 1 | 1,773 | 19 |
| 5 | City of La Harpe, | 484 | 10 |
18 total water systems serve Allen County.
All ZIP Codes in Allen County
5 ZIP codes tracked in Allen County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 66742 | Gas | 83 | B | 0 | — |
| 2 | 66751 | La Harpe | 83 | B | 1 | $57K |
| 3 | 66748 | Humboldt | 79 | B | 19 (1 health) | $107K |
| 4 | 66755 | Moran | 78 | B | 8 | $133K |
| 5 | 66749 | Iola | 47 | D | 9 (1 health) | $101K |
Recommended Buyer Guides for Allen 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 Water Filters for Lead — Lead above EPA action level in 1 ZIP code
- Best Lead Paint Test Kits — 81.4% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
Deep Dive Reports
Detailed analysis for Allen County, Kansas
Overview
Allen County in Kansas covers 5 ZIP codes with an average Home Safety Score of B (74/100).
4 of 5 ZIP codes have recorded EPA violations. 2 health-based violations have been documented.
← Back to Kansas 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.