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Federal water data

County water report

Coal County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Coal County, Oklahoma.

Water grade

F

Water score

3.5

State rank

#55

of 77

Health violations

44

EPA SDWIS, 5-year lookback

Watershed impaired

100.0%

1 water bodies assessed

Monitoring sites

8

3,508 recent measurements

Live streamflow

No gauge

Primary USGS station not mapped

Water at a glance

Key Water Indicators for Coal County

EPA SDWIS

Safety Grade

F

Score: 3.5 / 100

EPA SDWIS

Active Violations

44

5-year health-based lookback

EPA ATTAINS

Watershed Health

100% impaired

1 bodies assessed

USGS NWIS

Streamflow Snapshot

No gauge

Primary USGS gauge not mapped

EPA WQP

Monitoring Sites

8

3,508 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.

3.5/100

Health violations

44

Health-based violations

Violations per 100K served

1096.4

Population-normalized SDWIS rate

Editorial analysis

Understanding Coal County’s Water

Drinking Water Quality Overview

EPA SDWIS

Coal County's water systems carry a failing grade, scoring 3.5 out of 100. Over the past five years, EPA SDWIS records 44 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 — 100.0% — of assessed waterways are impaired (1 of 1 water bodies) across Coal County's watersheds. The leading impairment causes are mercury and turbidity. 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. Coal County has limited coverage with 8 active monitoring sites with 3,508 recent measurements on record. Predominant monitoring categories include physical and biological, algae, phytoplankton. 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 Coal County

Water Verdict

Coal County receives a poor water quality assessment with a grade of F and a score of 3.5 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.

Violation Context

Coal County has recorded 44 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 1096.4 violations per 100,000 people served, this rate is high and signals significant water quality management issues.

Consumer Guidance

Coal County has a Grade F compliance record with 44 health-based violations — among the highest levels in the country. Coal County's drinking-water compliance score is 3.5 out of 100. 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 Oklahoma Department of Environmental Quality or Health can expedite utility compliance action. Mercury is the leading impairment cause in Coal County's watershed. There are 8 active water-quality monitoring sites in Coal County.

Regional Context

Coal County has poorer water quality than the average county in Oklahoma. Its water score is 12.3 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 Coal County's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    Mercury

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

  • 2

    High turbidity

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

  • 3

    Copper

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

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for Coal County

EPA How's My Waterway

Interactive watershed health data for Coal County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Coal County

Consumer Confidence Reports (OK)

Annual water quality reports from utilities in Oklahoma

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

100.0%

1 of 1 assessed

High concern

Top Impairment Causes

  • 1

    MERCURY

  • 2

    TURBIDITY

  • 3

    COPPER

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

8

Active in the past 5 years

Measurements Recorded

3.5K

3,508 total readings

Most Measured

  • Physical
  • Biological, Algae, Phytoplankton
  • 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).

Free tool

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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 Coal County: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 Coal County, Oklahoma?
Coal County, Oklahoma has a drinking-water quality grade of F with a score of 3.5/100, based on EPA SDWIS compliance data. The county has 44 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 Coal County?
Coal County has 44 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 Coal County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 100.0% of Coal County's 1 assessed water bodies are classified as impaired (1 impaired). The top reported causes are MERCURY, TURBIDITY, COPPER. 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 Coal County?
EPA's Water Quality Portal records 3,508 measurements from 8 monitoring sites in Coal County over the past five years. The most frequently measured characteristic groups are Physical, Biological, Algae, Phytoplankton, 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.
How does Coal County water compare to the Oklahoma average?
Coal County's SDWIS water quality score of 3.5/100 is lower than the Oklahoma state average of 15.8. The average water quality grade across Oklahoma is F, based on data from 77 counties with available SDWIS data.
Is tap water safe to drink in Coal County?
Based on EPA SDWIS data, Coal County has a water quality grade of F (3.5/100). 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 Coal County have so many water violations?
Coal County has 44 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 Coal County rank for water quality in Oklahoma?
Coal County ranks #55 out of 77 counties in Oklahoma by SDWIS water quality score (1 = best). With a score of 3.5/100, it falls in the bottom 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

Lincoln County

Oklahoma

F

3.3

Water score

Caddo County

Oklahoma

F

3.8

Water score

Le Flore County

Oklahoma

F

3.2

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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