waterbycounty
Federal water data

County water report

Marion County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Marion County, Florida.

Water grade

C

Water score

56.6

State rank

#38

of 66

Health violations

24

EPA SDWIS, 5-year lookback

Watershed impaired

32.5%

1,273 water bodies assessed

Monitoring sites

319

54,440 recent measurements

Live streamflow

48%

WITHLACOOCHEE RIVER AT US 41 AT DUNNELLON, FL

Water at a glance

Key Water Indicators for Marion County

EPA SDWIS

Safety Grade

C

Score: 56.6 / 100

EPA SDWIS

Active Violations

24

5-year health-based lookback

EPA ATTAINS

Watershed Health

33% impaired

1,273 bodies assessed

USGS NWIS

Streamflow Snapshot

48% of mean

WITHLACOOCHEE RIVER AT US 41 AT DUNNELLON, FL

EPA WQP

Monitoring Sites

319

54,440 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

C

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

56.6/100

Health violations

24

Health-based violations

Violations per 100K served

9.1

Population-normalized SDWIS rate

Editorial analysis

Understanding Marion County’s Water

Drinking Water Quality Overview

EPA SDWIS

Marion County's drinking water earned a C grade, scoring 56.6 out of 100. Over the past five years, EPA SDWIS records 24 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 substantial 32.5% of assessed waterways are impaired (414 of 1,273 water bodies) across Marion County's watersheds. The leading impairment causes are dissolved oxygen and mercury in fish tissue. 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 2026-05-14T14:45:00.000-04:00) puts WITHLACOOCHEE RIVER at 667.0 cfs — well below its long-term average at 48% of mean — low-flow conditions worth noting for water-dependent ecosystems. 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. Marion County has extensive coverage with 319 active monitoring sites with 54,440 recent measurements on record. Predominant monitoring categories include physical and inorganics, minor, metals. 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 Marion County

Water Verdict

Marion County receives a fair water quality assessment with a grade of C and a score of 56.6 out of 100. The water supply meets baseline federal standards, but there may be periods of elevated contaminant levels or infrastructure concerns worth monitoring.

Violation Context

Marion County has recorded 24 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 9.1 violations per 100,000 people served, this rate is high and signals significant water quality management issues.

Consumer Guidance

Tap water in Marion County meets baseline standards but the compliance record shows room for improvement, with a Grade C rating. Marion County's drinking-water compliance score is 56.6 out of 100. The violation rate for Marion County is 9.1 per 100,000 people served. Residents who are immunocompromised, pregnant, or have young children may benefit from using an NSF 53-certified filter. Contacting your local utility for the current Consumer Confidence Report will confirm which specific violations were recorded and whether they have been resolved. Dissolved Oxygen is the leading impairment cause in Marion County's watershed. With 319 active water-quality monitoring sites in Marion County, data coverage is strong. A pipeline streamflow snapshot from the WITHLACOOCHEE RIVER gauge is also available on this page.

Regional Context

Marion County has water quality close to the average county in Florida. Its water score is within 0.6 points of the state average, meaning its overall water system performance is broadly representative of Florida as a whole.

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 Marion County's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    Low dissolved oxygen

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

  • 2

    Mercury (fish tissue)

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

  • 3

    Phosphorus (excess nutrients)

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

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for Marion County

EPA How's My Waterway

Interactive watershed health data for Marion County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Marion County

Consumer Confidence Reports (FL)

Annual water quality reports from utilities in Florida

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

32.5%

414 of 1,273 assessed

Moderate concern

Top Impairment Causes

  • 1

    DISSOLVED OXYGEN

  • 2

    MERCURY IN FISH TISSUE

  • 3

    PHOSPHORUS, TOTAL

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

319

Active in the past 5 years

Measurements Recorded

54K

54,440 total readings

Most Measured

  • Physical
  • Inorganics, Minor, Metals
  • Nutrient

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

667cfs

May 14, 6:45 PM UTC

vs Long-Term Average

48%

Well below typical

Primary Streamgage

WITHLACOOCHEE RIVER AT US 41 AT DUNNELLON, FL

USGS site
02313200
Drainage area
1,960 sq mi
Long-term mean
1,391 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.

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 Marion County: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 →

Improve your water quality at home

Berkey filters remove 99.9%+ of contaminants from tap water.

Shop Berkey →

Sponsored

Test your tap water

Tap Score provides professional mail-in water testing.

Get Tested →

Frequently Asked Questions

What is the water quality in Marion County, Florida?
Marion County, Florida has a drinking-water quality grade of C with a score of 56.6/100, based on EPA SDWIS compliance data. The county has 24 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 Marion County?
Marion County has 24 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 Marion County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 32.5% of Marion County's 1,273 assessed water bodies are classified as impaired (414 impaired). The top reported causes are DISSOLVED OXYGEN, MERCURY IN FISH TISSUE, PHOSPHORUS, TOTAL. 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 Marion County?
EPA's Water Quality Portal records 54,440 measurements from 319 monitoring sites in Marion County over the past five years. The most frequently measured characteristic groups are Physical, Inorganics, Minor, Metals, Nutrient. 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 Marion County right now?
Marion County's primary USGS streamgage on the WITHLACOOCHEE RIVER has a pipeline snapshot of 667 cubic feet per second — 48% of the long-term mean of 1,390.5 cfs. This is well below typical — often a signal of drought stress on source water. For the latest gauge feed, visit waterdata.usgs.gov.
How does Marion County water compare to the Florida average?
Marion County's SDWIS water quality score of 56.6/100 is higher than the Florida state average of 56.0. The average water quality grade across Florida is D, based on data from 66 counties with available SDWIS data.
Is tap water safe to drink in Marion County?
Based on EPA SDWIS data, Marion County has a water quality grade of C (56.6/100). This indicates moderate compliance. Some violations have been recorded but overall standards are maintained. 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 Marion County have so many water violations?
Marion County has 24 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 Marion County rank for water quality in Florida?
Marion County ranks #38 out of 66 counties in Florida by SDWIS water quality score (1 = best). With a score of 56.6/100, 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

Collier County

Florida

C

56.2

Water score

St. Lucie County

Florida

C

56.1

Water score

Martin County

Florida

C

57.8

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

Explore more data for Marion County

Property TaxCost of LivingCrime RateIncomeHealthSchoolsDisaster RiskWeatherCounty Score