Benton County, Washington
8 ZIP codes · Avg score 69/100 · Grade C · Updated 2026-06-03
Compared to top-scoring counties, Benton County's 8 ZIP codes land in the middle tier — some meet standards cleanly, others carry documented violations, and the gap between the best and worst areas is wider than average.
How Benton County Compares
How Benton County Compares
Benton County scores 9 points below the Washington state average (78/100) and 1 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-03
ZIP Code Risk Map
Water Quality Map: Benton County, Washington
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 11.7 (asthma 10.8%, diabetes 10.4%)
Estimated additional annual cost per homeowner: $1,478, driven primarily by flood
Infrastructure: 0.32% avg pipe failure probability, 13% of ZIPs at high risk
47.3% of homes built before 1978 (lead paint era)
Violation History (2021–2024)
↑ Worsening trendEPA violation counts by year across Benton County water systems. Health-based shown in red, total in blue.
Peak year: 2023 with 16 violations. Past 5 years: 31 total (31 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: $1,478
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
68,392 housing units in Benton 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 Benton County
Remediation costs are relatively manageable for most homeowners in Benton 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 Benton 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 Benton County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | City of Kennewick | 114,468 | 26 |
| 2 | Summit View Water System | 1,869 | 26 |
| 3 | Bc Water Company | 1,262 | 26 |
| 4 | Badger Mountain Irrigation District | 2,331 | 26 |
| 5 | Community Sewer and Water District | 1,200 | 26 |
21 total water systems serve Benton County.
All ZIP Codes in Benton County
8 ZIP codes tracked in Benton County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 99350 | Prosser | 80 | B | 6 | $289K |
| 2 | 99320 | Benton City | 78 | B | 0 | $300K |
| 3 | 99352 | Richland | 78 | B | 0 | $442K |
| 4 | 99354 | Richland | 78 | B | 0 | $355K |
| 5 | 99353 | West Richland | 72 | B | 7 | $408K |
| 6 | 99336 | Kennewick | 58 | C | 13 (7 health) | $292K |
| 7 | 99338 | Kennewick | 58 | C | 13 (7 health) | $527K |
| 8 | 99346 | Plymouth | 53 | D | 0 | $215K |
Recommended Buyer Guides for Benton County
Editorial-only picks, screened against the EPA detections on file.
- 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 Benton County, Washington
Overview
Benton County in Washington covers 8 ZIP codes with an average Home Safety Score of C (69/100).
4 of 8 ZIP codes have recorded EPA violations. 14 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.