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County water report

St. Johns County Water Report

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

Water grade

A

Water score

70.1

State rank

#21

of 66

Health violations

2

EPA SDWIS, 5-year lookback

Watershed impaired

38.1%

687 water bodies assessed

Monitoring sites

221

109,909 recent measurements

Live streamflow

No gauge

DEEP CREEK AT SPUDS, FL

Water at a glance

Key Water Indicators for St. Johns County

EPA SDWIS

Safety Grade

A

Score: 70.1 / 100

EPA SDWIS

Active Violations

2

5-year health-based lookback

EPA ATTAINS

Watershed Health

38% impaired

687 bodies assessed

USGS NWIS

Streamflow Snapshot

No gauge

DEEP CREEK AT SPUDS, FL

EPA WQP

Monitoring Sites

221

109,909 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.

70.1/100

Health violations

2

Health-based violations

Violations per 100K served

0.9

Population-normalized SDWIS rate

Editorial analysis

Understanding St. Johns County’s Water

Drinking Water Quality Overview

EPA SDWIS

St. Johns County earns an A grade for drinking water quality, scoring 70.1 out of 100. Over the past five years, EPA SDWIS records 2 health-based violations — a small cluster that warrants attention.

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 38.1% of assessed waterways are impaired (262 of 687 water bodies) across St. Johns County's watersheds. The leading impairment causes are mercury in fish tissue and iron. 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. St. Johns County has extensive coverage with 221 active monitoring sites with 109,909 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. Johns County

Water Verdict

St. Johns County receives a good water quality assessment with a grade of A and a score of 70.1 out of 100. While the water supply is generally safe, occasional monitoring gaps or minor contaminant detections may occur.

Violation Context

St. Johns County has recorded 2 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 0.9 violations per 100,000 people served, this rate is relatively low compared to many U.S. counties.

Consumer Guidance

Tap water in St. Johns County earns a Grade A overall with a small number of isolated health violations in the recent record. St. Johns County's drinking-water compliance score is 70.1 out of 100. The violation rate for St. Johns County is 0.9 per 100,000 people served. These violations were likely resolved quickly; Grade A reflects a strong multi-year compliance trend. Reviewing the most recent Consumer Confidence Report will show exactly which systems were affected and what corrective action was taken. With 221 active water-quality monitoring sites in St. Johns County, data coverage is strong. Mercury in Fish Tissue is the leading impairment cause in St. Johns County's watershed. A pipeline streamflow snapshot from the DEEP CREEK gauge is also available on this page.

Regional Context

St. Johns County has better water quality than the average county in Florida. Its water score is 14.1 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 St. Johns County's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    Mercury (fish tissue)

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

  • 2

    Iron

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

  • 3

    Low dissolved oxygen

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

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for St. Johns County

EPA How's My Waterway

Interactive watershed health data for St. Johns County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for St. Johns County

Consumer Confidence Reports (FL)

Annual water quality reports from utilities in Florida

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

38.1%

262 of 687 assessed

Moderate concern

Top Impairment Causes

  • 1

    MERCURY IN FISH TISSUE

  • 2

    IRON

  • 3

    DISSOLVED OXYGEN

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

221

Active in the past 5 years

Measurements Recorded

110K

109,909 total readings

Most Measured

  • Physical
  • Nutrient
  • Inorganics, Minor, Metals

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).

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Water Cost Estimate

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3 people  ·  ~225 gal/day

Annual Total

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Monthly

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Water Bill

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Filter Cost

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Safety Grade for St. Johns 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.

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Frequently Asked Questions

What is the water quality in St. Johns County, Florida?
St. Johns County, Florida has a drinking-water quality grade of A with a score of 70.1/100, based on EPA SDWIS compliance data. The county has 2 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. Johns County?
St. Johns County has 2 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. Johns County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 38.1% of St. Johns County's 687 assessed water bodies are classified as impaired (262 impaired). The top reported causes are MERCURY IN FISH TISSUE, IRON, DISSOLVED OXYGEN. 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. Johns County?
EPA's Water Quality Portal records 109,909 measurements from 221 monitoring sites in St. Johns County over the past five years. The most frequently measured characteristic groups are Physical, Nutrient, Inorganics, Minor, Metals. 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.
How does St. Johns County water compare to the Florida average?
St. Johns County's SDWIS water quality score of 70.1/100 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 St. Johns County?
Based on EPA SDWIS data, St. Johns County has a water quality grade of A (70.1/100). 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 St. Johns County have clean drinking water?
St. Johns County has 2 health-based drinking water violations according to EPA records. With a water quality score of 70.1/100 and grade A, the county's drinking water has had some compliance issues but continues to be monitored. 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 St. Johns County rank for water quality in Florida?
St. Johns County ranks #21 out of 66 counties in Florida by SDWIS water quality score (1 = best). With a score of 70.1/100, 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

Leon County

Florida

A

70.1

Water score

Miami-Dade County

Florida

A

70.4

Water score

Walton County

Florida

A

70.4

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.

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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