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St. Landry Parish Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for St. Landry Parish, Louisiana.

Water grade

F

Water score

23.7

State rank

#30

of 63

Health violations

108

EPA SDWIS, 5-year lookback

Watershed impaired

85.7%

84 water bodies assessed

Monitoring sites

44

7,778 recent measurements

Live streamflow

116%

BAYOU TECHE @ ARNAUDVILLE, LA

Water at a glance

Key Water Indicators for St. Landry Parish

EPA SDWIS

Safety Grade

F

Score: 23.7 / 100

EPA SDWIS

Active Violations

108

5-year health-based lookback

EPA ATTAINS

Watershed Health

86% impaired

84 bodies assessed

USGS NWIS

Streamflow Snapshot

116% of mean

BAYOU TECHE @ ARNAUDVILLE, LA

EPA WQP

Monitoring Sites

44

7,778 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

F

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

23.7/100

Health violations

108

Health-based violations

Violations per 100K served

97.0

Population-normalized SDWIS rate

Editorial analysis

Understanding St. Landry Parish’s Water

Drinking Water Quality Overview

EPA SDWIS

St. Landry Parish's water systems carry a failing grade, scoring 23.7 out of 100. Over the past five years, EPA SDWIS records 108 health-based violations — a pattern that public water utilities are required to disclose and correct.

Watershed Conditions

EPA ATTAINS

Under the Clean Water Act §303(d), EPA ATTAINS tracks whether waterways meet quality standards for drinking, recreation, and aquatic life (reporting cycle: 2022). A large majority — 85.7% — of assessed waterways are impaired (72 of 84 water bodies) across St. Landry Parish's watersheds. The leading impairment causes are fecal coliform and dissolved oxygen. Impairment does not mean tap water is unsafe — it measures ambient waterway conditions upstream of treatment, not finished drinking water.

River & Streamflow Status

USGS NWIS

USGS NWIS gauge data (as of 2005-09-30T23:27:00.000-05:00) puts BAYOU TECHE @ ARNAUDVILLE, LA at 1.2k cfs — flowing above its historical average at 116% of mean. Streamflow is a leading indicator of drought stress, sediment load, and dilution capacity: low flows concentrate pollutants and warm water temperatures, stressing aquatic life and, in surface-water-dependent systems, the source water quality for treatment plants.

Monitoring Network

EPA WQP

EPA's Water Quality Portal (WQP) aggregates monitoring data from federal, state, and tribal agencies. St. Landry Parish has moderate coverage with 44 active monitoring sites with 7,778 recent measurements on record. Predominant monitoring categories include physical and nutrient. More monitoring sites generally indicate greater scientific attention to local water conditions — and provide the baseline data that regulators use to set future impairment listings.

Editorial advisory

What the data suggests for St. Landry Parish

Water Verdict

St. Landry Parish, Louisiana receives a poor water quality assessment with a grade of F and a score of 23.7 out of 100. The water supply has documented quality issues. Residents are strongly encouraged to use filtered or bottled water for drinking and to stay informed about utility improvement plans. Separately, EPA ATTAINS assessments cover 84 water bodies in the county's watershed, with 85.7% listed as impaired under the Clean Water Act — a source-water measure that is tracked independently of tap-water compliance. At the most recent USGS reading, local streamflow was running above its historical mean at 115.6%.

Violation Context

EPA SDWIS records for St. Landry Parish, Louisiana show 108 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 97.0 violations per 100,000 people served, this rate is high and signals significant water quality management issues. For independent context, 7,778 water-quality monitoring results have been recorded across the county in the EPA Water Quality Portal over the past five years.

Consumer Guidance

St. Landry Parish has a Grade F compliance record with 108 health-based violations — among the highest levels in the country. St. Landry Parish's drinking-water compliance score is 23.7 out of 100. The violation rate for St. Landry Parish is 97.0 per 100,000 people served. Residents are strongly advised to use a certified NSF 58 reverse-osmosis filter or bottled water for all drinking and cooking until violations are corrected. Contacting the Louisiana Department of Environmental Quality or Health can expedite utility compliance action. Fecal Coliform is the leading impairment cause in St. Landry Parish's watershed. With 44 active water-quality monitoring sites in St. Landry Parish, data coverage is strong. A pipeline streamflow snapshot from the BAYOU TECHE @ ARNAUDVILLE, LA gauge is also available on this page.

Regional Context

St. Landry Parish has poorer water quality than the average county in Louisiana. Its water score is 6.4 points lower than the state average, suggesting more challenges with contamination control or infrastructure than neighboring counties.

Advisory text summarizes county-level public records and is not a replacement for your utility's current Consumer Confidence Report or direct local notices.

Contaminants & Resources

Key issues flagged in St. Landry Parish's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    Fecal coliform bacteria

    Impairment cause per EPA Clean Water Act §303(d) assessment

  • 2

    Low dissolved oxygen

    Impairment cause per EPA Clean Water Act §303(d) assessment

  • 3

    High turbidity

    Impairment cause per EPA Clean Water Act §303(d) assessment

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for St. Landry Parish

EPA How's My Waterway

Interactive watershed health data for St. Landry Parish

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for St. Landry Parish

Consumer Confidence Reports (LA)

Annual water quality reports from utilities in Louisiana

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

85.7%

72 of 84 assessed

High concern

Top Impairment Causes

  • 1

    FECAL COLIFORM

  • 2

    DISSOLVED OXYGEN

  • 3

    TURBIDITY

Source: EPA ATTAINS · Reporting cycle 2022

Impairment is determined under the Clean Water Act §303(d): a water body is impaired when it fails to meet state-defined quality standards for designated uses (drinking, recreation, aquatic life). Assessment coverage varies by state; counties without assessed water bodies are not shown.

Past 5 years

Water Quality Monitoring

Monitoring Sites

44

Active in the past 5 years

Measurements Recorded

7.8K

7,778 total readings

Most Measured

  • Physical
  • Nutrient
  • Microbiological

Categories measured most frequently

Data from the EPA Water Quality Portal (WQP), aggregating monitoring records from federal, state, and tribal sources. Each measurement represents a single sample analyzed for a specific characteristic (e.g., E. coli, pH, dissolved oxygen, nitrogen).

Live USGS Streamgage

River & Stream Conditions

Current Discharge

1,210cfs

Oct 1, 4:27 AM UTC

vs Long-Term Average

116%

Above typical

Primary Streamgage

BAYOU TECHE @ ARNAUDVILLE, LA

USGS site
07385500
Drainage area
1,530 sq mi
Long-term mean
1,047 cfs

One representative streamgage (the one with the largest drainage area in the county). Many counties have multiple gauges; this view summarizes the primary one. The long-term mean is the full-record annual average; the percent-of-typical value compares the latest reading against that average.

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Estimate Your Water Costs

Water Cost Estimate

3

3 people  ·  ~225 gal/day

Annual Total

$558

Monthly

$47

Water Bill

$558/yr

Filter Cost

$0/yr

Safety Grade for St. Landry Parish:F — Failing

High violation count or severe watershed conditions.

Estimates use the national average residential water rate ($0.0068/gal, EPA/AWWA 2023) and EPA WaterSense per-person consumption baseline (75 gal/person/day). Actual bills vary by utility, usage tier, and local infrastructure fees. For informational purposes only.

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Frequently Asked Questions

What is the water quality in St. Landry Parish, Louisiana?
St. Landry Parish, Louisiana has a drinking-water quality grade of F with a score of 23.7/100, based on EPA SDWIS compliance data. The county has 108 health-based drinking water violations over the past 5 years. Watershed health, monitoring records, and streamflow snapshots are reported separately on this page.
Are there any water violations in St. Landry Parish?
St. Landry Parish has 108 health-based drinking water violations recorded by the EPA over the past 5 years. Health-based violations indicate instances where contaminant levels exceeded EPA Maximum Contaminant Levels (MCLs). Violations may have been resolved — check with your local water utility for current status.
How healthy are the watersheds in St. Landry Parish?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 85.7% of St. Landry Parish's 84 assessed water bodies are classified as impaired (72 impaired). The top reported causes are FECAL COLIFORM, DISSOLVED OXYGEN, TURBIDITY. Impairment means the water body fails to meet state quality standards for at least one designated use — drinking water source, recreation, aquatic life, or fish consumption. Note: watershed impairment doesn't always translate to tap-water issues; treatment plants can remove most regulated contaminants.
How much water-quality monitoring happens in St. Landry Parish?
EPA's Water Quality Portal records 7,778 measurements from 44 monitoring sites in St. Landry Parish over the past five years. The most frequently measured characteristic groups are Physical, Nutrient, Microbiological. Each measurement is a single sample analyzed for one characteristic (E. coli, pH, dissolved oxygen, etc.). High monitoring density means more scientific evidence behind any reported signal — it does not by itself indicate water quality.
What's happening with rivers in St. Landry Parish right now?
St. Landry Parish's primary USGS streamgage on the BAYOU TECHE @ ARNAUDVILLE, LA has a pipeline snapshot of 1,210 cubic feet per second — 116% of the long-term mean of 1,046.61 cfs. Flow is within typical range for this gauge. For the latest gauge feed, visit waterdata.usgs.gov.
How does St. Landry Parish water compare to the Louisiana average?
St. Landry Parish's SDWIS water quality score of 23.7/100 is lower than the Louisiana state average of 30.1. The average water quality grade across Louisiana is F, based on data from 63 counties with available SDWIS data.
Is tap water safe to drink in St. Landry Parish?
Based on EPA SDWIS data, St. Landry Parish has a water quality grade of F (23.7/100). This indicates below-average compliance with significant violations. Residents may want to consider home water filtration or independent testing. The grade speaks to the public water system, not the watershed — for watershed-level concerns, see the Watershed Health zone. For the most up-to-date information, contact your local water utility or review your Consumer Confidence Report (CCR).
Why does St. Landry Parish have so many water violations?
St. Landry Parish has 108 health-based drinking water violations on record from the EPA SDWIS database. A higher violation count can result from aging infrastructure, underfunded water utilities, agricultural runoff contamination, or industrial pollution. Counties with more water systems may also see more violations simply due to scale. Residents concerned about water quality should consider independent water testing and home filtration systems.
How does St. Landry Parish rank for water quality in Louisiana?
St. Landry Parish ranks #30 out of 63 counties in Louisiana by SDWIS water quality score (1 = best). With a score of 23.7/100, it falls in the middle third of counties statewide. The ranking reflects EPA SDWIS compliance only — not watershed impairment, monitoring density, or streamflow, which are tracked separately on this page.

Counties with Similar Water Quality

Caddo Parish

Louisiana

F

23.8

Water score

St. Helena Parish

Louisiana

F

23.8

Water score

St. James Parish

Louisiana

F

23.4

Water score

Data Sources

Drinking-water compliance data from the EPA Safe Drinking Water Information System (SDWIS) via the ECHO enforcement database. Scores reflect compliance history and health-based violation counts.

Watershed health and impaired-waterway data from the EPA ATTAINS Clean Water Act §303(d) assessments, state-reported and EPA-finalized.

Water-quality monitoring counts from the EPA Water Quality Portal (WQP), federated USGS, EPA, and state agency sampling records over a rolling 5-year window.

Live streamflow from the USGS National Water Information System (NWIS), continuous discharge measurements from the largest-drainage gauge in each county, compared against the full-record long-term annual mean.

Disclaimer: This data is informational only. It is not health, legal, or professional advice. For concerns about your specific water supply, contact your local water utility.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor

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