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Federal water data

County water report

Assumption Parish Water Report

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

Water grade

A

Water score

86.0

State rank

#1

of 63

Health violations

0

EPA SDWIS, 5-year lookback

Watershed impaired

84.7%

118 water bodies assessed

Monitoring sites

25

2,618 recent measurements

Live streamflow

No gauge

Belle River at Hwy 70 near Pierre Part, LA

Water at a glance

Key Water Indicators for Assumption Parish

EPA SDWIS

Safety Grade

A

Score: 86.0 / 100

EPA SDWIS

Active Violations

0

5-year health-based lookback

EPA ATTAINS

Watershed Health

85% impaired

118 bodies assessed

USGS NWIS

Streamflow Snapshot

No gauge

Belle River at Hwy 70 near Pierre Part, LA

EPA WQP

Monitoring Sites

25

2,618 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

A

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

86.0/100

Health violations

0

Health-based violations

Violations per 100K served

0.0

Population-normalized SDWIS rate

Editorial analysis

Understanding Assumption Parish’s Water

Drinking Water Quality Overview

EPA SDWIS

Assumption Parish earns an A grade for drinking water quality, scoring 86.0 out of 100. EPA's Safe Drinking Water Information System (SDWIS) records zero health-based violations over the past five years — a strong compliance signal for a large county.

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 — 84.7% — of assessed waterways are impaired (100 of 118 water bodies) across Assumption Parish's watersheds. The leading impairment causes are enterococcus and dissolved oxygen. Impairment does not mean tap water is unsafe — it measures ambient waterway conditions upstream of treatment, not finished drinking water.

Monitoring Network

EPA WQP

EPA's Water Quality Portal (WQP) aggregates monitoring data from federal, state, and tribal agencies. Assumption Parish has moderate coverage with 25 active monitoring sites with 2,618 recent measurements on record. Predominant monitoring categories include physical and biological, algae, cyanobacteria. 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 Assumption Parish

Water Verdict

Assumption Parish, Louisiana receives an excellent water quality assessment with a grade of A and a score of 86.0 out of 100. The water supply meets or exceeds federal safety standards, and residents can generally drink tap water with confidence. Separately, EPA ATTAINS assessments cover 118 water bodies in the county's watershed, with 84.7% listed as impaired under the Clean Water Act — a source-water measure that is tracked independently of tap-water compliance.

Violation Context

EPA SDWIS records for Assumption Parish, Louisiana show zero health-based violations, indicating that the county's water systems met all federal safety standards during the reporting period. The violation rate is zero per 100,000 people served, which is the best possible outcome. For independent context, 2,618 water-quality monitoring results have been recorded across the county in the EPA Water Quality Portal over the past five years.

Consumer Guidance

The EPA compliance record for Assumption Parish shows no recent health-based violations. No health-based violations have been recorded, placing Assumption Parish in the top tier for drinking-water safety. Assumption Parish's drinking-water compliance score is 86.0 out of 100. As a routine precaution, requesting your utility's annual Consumer Confidence Report each July gives you a full list of detected contaminants and their treatment levels. With 25 active water-quality monitoring sites in Assumption Parish, data coverage is strong. A pipeline streamflow snapshot from the Belle River gauge is also available on this page.

Regional Context

Assumption Parish has better water quality than the average county in Louisiana. Its water score is 55.9 points higher than the state average, indicating stronger water system performance relative to 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 Assumption Parish's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    Enterococcus 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

    Fecal coliform bacteria

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

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for Assumption Parish

EPA How's My Waterway

Interactive watershed health data for Assumption Parish

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Assumption Parish

Consumer Confidence Reports (LA)

Annual water quality reports from utilities in Louisiana

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

84.7%

100 of 118 assessed

High concern

Top Impairment Causes

  • 1

    ENTEROCOCCUS

  • 2

    DISSOLVED OXYGEN

  • 3

    FECAL COLIFORM

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

25

Active in the past 5 years

Measurements Recorded

2.6K

2,618 total readings

Most Measured

  • Physical
  • Biological, Algae, Cyanobacteria
  • Biological, Algae, Phytoplankton

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

927cfs

Oct 1, 8:00 PM UTC

vs Long-Term Average

Long-term average not yet available.

Primary Streamgage

Belle River at Hwy 70 near Pierre Part, LA

USGS site
07381454

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.

Free tool

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 Assumption Parish:C — Moderate

Some violations or watershed impairment detected.

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.

Try the full calculator →

Assumption Parish has good water quality

Learn about water restrictions and conservation in your area.

Water Restrictions →

Frequently Asked Questions

What is the water quality in Assumption Parish, Louisiana?
Assumption Parish, Louisiana has a drinking-water quality grade of A with a score of 86.0/100, based on EPA SDWIS compliance data. The county has 0 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 Assumption Parish?
Assumption Parish has 0 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). Zero violations is an excellent record indicating consistent compliance with federal drinking water standards.
How healthy are the watersheds in Assumption Parish?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 84.7% of Assumption Parish's 118 assessed water bodies are classified as impaired (100 impaired). The top reported causes are ENTEROCOCCUS, DISSOLVED OXYGEN, FECAL COLIFORM. 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 Assumption Parish?
EPA's Water Quality Portal records 2,618 measurements from 25 monitoring sites in Assumption Parish over the past five years. The most frequently measured characteristic groups are Physical, Biological, Algae, Cyanobacteria, Biological, Algae, Phytoplankton. 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 Assumption Parish right now?
Assumption Parish's primary USGS streamgage on the Belle River has a pipeline snapshot of 927 cubic feet per second. Flow is within typical range for this gauge. For the latest gauge feed, visit waterdata.usgs.gov.
How does Assumption Parish water compare to the Louisiana average?
Assumption Parish's SDWIS water quality score of 86.0/100 is higher 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 Assumption Parish?
Based on EPA SDWIS data, Assumption Parish has a water quality grade of A (86.0/100). This indicates good to excellent water quality with strong SDWIS compliance. 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).
Does Assumption Parish have clean drinking water?
Assumption Parish has 0 health-based drinking water violations according to EPA records. With a water quality score of 86.0/100 and grade A, the county's drinking water meets EPA standards with no recorded health violations. Note: drinking-water compliance speaks to the public water system, not necessarily to the watershed itself — check the Watershed Health zone for ATTAINS §303(d) data.
How does Assumption Parish rank for water quality in Louisiana?
Assumption Parish ranks #1 out of 63 counties in Louisiana by SDWIS water quality score (1 = best). With a score of 86.0/100, it falls in the top 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

Lafourche Parish

Louisiana

A

86.0

Water score

St. Bernard Parish

Louisiana

A

86.0

Water score

St. Charles Parish

Louisiana

A

86.0

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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