St. Landry County, Louisiana
15 ZIP codes · Avg score 80/100 · Grade B · Updated 2026-06-04
St. Landry County — 15 ZIP codes, above-average safety grade.
How St. Landry County Compares
How St. Landry County Compares
St. Landry County scores 9 points above the Louisiana state average (71/100) and 12 points above the national average (68/100).
Data: EPA SDWIS Last verified: 2026-06-04
ZIP Code Risk Map
Water Quality Map: St. Landry County, Louisiana
Each dot represents a ZIP code. Color indicates water quality grade. Tap a dot for details.
Key Risk Factors
Health risk index: 16.9 (asthma 11.2%, diabetes 18.1%)
Estimated additional annual cost per homeowner: $4,653, driven primarily by sea_level
Infrastructure: 0.396% avg pipe failure probability, 57% of ZIPs at high risk
70% of homes built before 1978 (lead paint era)
Violation History (2021–2025)
→ Stable trendEPA violation counts by year across St. Landry County water systems. Health-based shown in red, total in blue.
Peak year: 2021 with 19 violations. Past 5 years: 69 total (69 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: $4,653
Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).
Housing Age Distribution
38,405 housing units in St. Landry 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 St. Landry County
Remediation costs are relatively manageable for most homeowners in St. Landry 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 St. Landry 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 St. Landry County ranked by EPA violation count.
| # | Water System | Population | Violations |
|---|---|---|---|
| 1 | Town of Melville Water System | 1,314 | 32 |
| 2 | Midway Water System Inc. | 192 | 32 |
| 3 | Town of Sunset Water System | 4,356 | 22 |
| 4 | Town of Grand Coteau Water System | 1,650 | 22 |
| 5 | Town of Leonville Water System | 9,552 | 17 |
31 total water systems serve St. Landry County.
All ZIP Codes in St. Landry County
15 ZIP codes tracked in St. Landry County.
| # | ZIP Code | City | Safety Score | Grade | Violations | Home Value |
|---|---|---|---|---|---|---|
| 1 | 70551 | Leonville | 98 | A | 1 (1 health) | $114K |
| 2 | 70550 | Lawtell | 94 | A | 1 (1 health) | — |
| 3 | 70571 | Opelousas | 89 | A | 6 (3 health) | — |
| 4 | 70589 | Washington | 89 | A | 1 (1 health) | $106K |
| 5 | 70750 | Krotz Springs | 87 | A | 3 | $113K |
| 6 | 70584 | Sunset | 84 | B | 3 (1 health) | $184K |
| 7 | 70512 | Arnaudville | 80 | B | 3 (2 health) | $135K |
| 8 | 70541 | Grand Coteau | 78 | B | 10 (3 health) | $87K |
| 9 | 70577 | Port Barre | 77 | B | 3 (2 health) | $98K |
| 10 | 70535 | Eunice | 75 | B | 3 (2 health) | $161K |
| 11 | 71353 | Melville | 75 | B | 32 (5 health) | $122K |
| 12 | 71358 | Palmetto | 75 | B | 13 (11 health) | $114K |
| 13 | 70570 | Opelousas | 74 | B | 6 (3 health) | $151K |
| 14 | 70524 | Chataignier | 60 | C | 0 | $93K |
| 15 | 71345 | Lebeau | 60 | C | 0 | — |
Recommended Buyer Guides for St. Landry County
Designed to find the guide that fits the county, not the other way around — the system reads EPA detections, FEMA hazard layers, and CDC lead-exposure markers, then outputs the categories that resolve those specific risks for households here, with NSF-certified products surfaced when the matching contaminant appears in the local monitoring data.
- Best Lead Paint Test Kits — 70% of homes built before 1978
- Best Under-Sink Reverse Osmosis Systems — Multi-contaminant removal at the kitchen tap
Deep Dive Reports
Detailed analysis for St. Landry County, Louisiana
Overview
St. Landry County in Louisiana covers 15 ZIP codes with an average Home Safety Score of B (80/100).
13 of 15 ZIP codes have recorded EPA violations. 35 health-based violations have been documented.
← Back to Louisiana 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.