Walla Walla County, Washington
9 ZIP codes · Avg score 67/100 · Grade C · Updated 2026-07-19
ZipCheckup grade for Walla Walla: C.
A mixed picture - some signals here are worth your attention.
In recent monitoring cycles, Walla Walla County's 9 ZIP codes show a split record - several have documented water safety violations.
How Walla Walla County Compares
How Walla Walla County Compares
Walla Walla County scores 11 points below the Washington state average (78/100) and 1 points below the national average (68/100).
Data: EPA SDWIS Last verified: 2026-07-19
ZIP Code Risk Map
Water Quality Map: Walla Walla County, Washington
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 12.1 (asthma 11%, diabetes 10.6%)
Estimated additional annual cost per homeowner: $1,458, driven primarily by flood
Infrastructure: 0.418% avg pipe failure probability, 44% of ZIPs at high risk
58.3% of homes built before 1978 (lead paint era)
Violation History (2022–2025)
↓ Improving trendEPA violation counts by year across Walla Walla County water systems. Health-based shown in red, total in blue.
Peak year: 2023 with 4 violations. Past 5 years: 8 total (8 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: $1,458
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
36,635 housing units in Walla Walla 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 Walla Walla County
Remediation costs are relatively manageable for most homeowners in Walla Walla 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 Walla Walla County residents
Black markers = national averages. Red = above national avg. Green = below. Source: CDC PLACES, Census ACS.
Water systems serving Walla Walla County
8 community water systems serving Walla Walla County.
- C
- C
- C
- C
- C
- B
Show all 8 water systems
- C
- C
20 total water systems serve Walla Walla County.
Systems with the most violations in Walla Walla County
4 water systems with recorded EPA violations.
- C
- D
- C
- C
All ZIP Codes in Walla Walla County
9 ZIP codes tracked in Walla Walla County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 99324 | College Place | 77 | B | 12 | $339K |
| 2 | 99348 | Prescott | 75 | B | 0 | $204K |
| 3 | 99361 | Waitsburg | 73 | B | 0 | $291K |
| 4 | 99323 | Burbank | 71 | B | 13 | $359K |
| 5 | 99362 | Walla Walla | 69 | C | 10 | $398K |
| 6 | 99329 | Dixie | 63 | C | 0 | $278K |
| 7 | 99360 | Touchet | 63 | C | 0 | $492K |
| 8 | 99337 | Kennewick | 58 | C | 13 (7 health) | $357K |
| 9 | 99363 | Wallula | 53 | D | 0 | $207K |
Recommended Buyer Guides for Walla Walla 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 — 58.3% 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 Walla Walla County, Washington
Overview
Walla Walla County in Washington covers 9 ZIP codes with an average Home Safety Score of C (67/100).
4 of 9 ZIP codes have recorded EPA violations. 7 health-based violations have been documented.
← Back to Washington 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.