COUNTY REPORT LA

St. Martin County, Louisiana

3 ZIP codes · Avg score 69/100 · Grade C · Updated 2026-06-04

While St. Martin County avoids the worst tiers, a portion of its 3 ZIP codes have logged violations.

How St. Martin County Compares

St. Martin County69/100
Louisiana avg71/100
National avg68/100

How St. Martin County Compares

C
County Grade
69/100
Avg Safety Score
3
ZIP Codes
8
Water Systems

St. Martin County scores 2 points below the Louisiana state average (71/100) and 1 points above the national average (68/100).

Data: EPA SDWIS Last verified: 2026-06-04

C
County Grade
69
Avg Safety Score
3
ZIP Codes
Best ZIP: 70521 (94/100)
Lowest ZIP: 70582 (42/100)
$150K
Median Home Value
$2,100
Avg Remediation (140% of home value)

Key Risk Factors

Health risk index: 16.1 (asthma 10.5%, diabetes 15.5%)

Estimated additional annual cost per homeowner: $5,253, driven primarily by sea_level

Infrastructure: 0.293% avg pipe failure probability

55% of homes built before 1978 (lead paint era)

Violation History (2021–2024)

→ Stable trend

EPA violation counts by year across St. Martin County water systems. Health-based shown in red, total in blue.

2021
4 (4 health)
2022
7 (7 health)
2024
1 (1 health)

Peak year: 2022 with 7 violations. Past 5 years: 12 total (12 health-based).

Source: EPA SDWIS historical violations. Data may lag 6–12 months for the most recent year.

County Health Indicators vs National Average

Asthma 10.5% (national: 8.9%)
Diabetes 15.5% (national: 10.5%)
Obesity 45.3% (national: 32.4%)

Black markers indicate national averages. Source: CDC PLACES, Census ACS.

Infrastructure Overview

1977
Median Build Year
55%
Pre-1978 Housing
29%
Pipe Failure Probability
0%
ZIPs at High Infra Risk
Moderate
Lead Pipe Risk

Sources: Census ACS (housing age), EPA SDWIS (infrastructure risk model), state bridge inspection data.

Compound Risk Breakdown

Estimated additional annual cost per homeowner: $5,253

Sea Level Rise $3,000/yr
Flood $1,933/yr
Energy Code Gap $270/yr

Bar widths proportional to share of total annual risk cost. Source: compound risk model (FEMA, EPA, USGS).

Housing Age Distribution

20,689 housing units in St. Martin County

Pre-1940 4%
1940–1959 13%
1960–1979 28%
1980–1999 28%
2000+ 27%

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. Martin County

$150K
Median Home Value
$2,100
Est. Remediation Cost
1.4%
of Home Value
Remediation as % of home value low burden

Remediation costs are relatively manageable for most homeowners in St. Martin 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. Martin County residents

Asthma 10.5% (US avg: 8.9%)
Diabetes 15.5% (US avg: 11%)
Obesity 45.3% (US avg: 32.4%)

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. Martin County ranked by EPA violation count.

# Water System Population Violations
1 Cecilia Water Corporation 12,249 9
2 City of Breaux Bridge Water System 8,754 8
3 Henderson Nina Water System Inc. 5,136 8
4 United Water System 4,446 8
5 Town of Arnaudville Water System 3,957 8

8 total water systems serve St. Martin County.

All ZIP Codes in St. Martin County

3 ZIP codes tracked in St. Martin County.

# ZIP Code City Safety Score Grade Violations Home Value
1 70521 Cecilia 94 A 1 (1 health)
2 70517 Breaux Bridge 71 B 8 (3 health) $152K
3 70582 Saint Martinville 42 D 0 $149K

Recommended Buyer Guides for St. Martin County

Independent picks. EPA-grounded. Matched here.

Overview

St. Martin County in Louisiana covers 3 ZIP codes with an average Home Safety Score of C (69/100).

2 of 3 ZIP codes have recorded EPA violations. 4 health-based violations have been documented.

← Back to Louisiana water quality report

Data Sources

Updated daily.

Frequently Asked Questions

Is water safe in St. Martin County?
St. Martin County receives a grade of C. Some ZIP codes have recorded violations and residents in affected areas may want to test their water.
How many water systems serve St. Martin County?
St. Martin County is served by 8 public water systems that supply drinking water to residents across 3 ZIP codes.
What is the biggest environmental risk in St. Martin County?
The primary environmental risk factor in St. Martin County is sea_level. This contributes to an estimated additional annual cost of $5,253 per homeowner.
How old are homes in St. Martin County?
The median home build year in St. Martin County is 1977. 55% of homes were built before 1978, which means they may contain lead-based paint and older plumbing materials.
How does St. Martin County compare to Louisiana?
St. Martin County has an average water safety score of 69/100, which is below the Louisiana state average of 71/100.

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