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County water report

Hardin County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Hardin County, Illinois.

Water grade

F

Water score

34.2

State rank

#68

of 102

Health violations

2

EPA SDWIS, 5-year lookback

Watershed impaired

32.6%

135 water bodies assessed

Monitoring sites

3

994 recent measurements

Live streamflow

No gauge

Primary USGS station not mapped

Water at a glance

Key Water Indicators for Hardin County

EPA SDWIS

Safety Grade

F

Score: 34.2 / 100

EPA SDWIS

Active Violations

2

5-year health-based lookback

EPA ATTAINS

Watershed Health

33% impaired

135 bodies assessed

USGS NWIS

Streamflow Snapshot

No gauge

Primary USGS gauge not mapped

EPA WQP

Monitoring Sites

3

994 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.

34.2/100

Health violations

2

Health-based violations

Violations per 100K served

49.4

Population-normalized SDWIS rate

Editorial analysis

Understanding Hardin County’s Water

Drinking Water Quality Overview

EPA SDWIS

Hardin County's water systems carry a failing grade, scoring 34.2 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 32.6% of assessed waterways are impaired (44 of 135 water bodies) across Hardin County's watersheds. The leading impairment causes are mercury and polychlorinated biphenyls (pcbs). 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. Hardin County has limited coverage with 3 active monitoring sites with 994 recent measurements on record. Predominant monitoring categories include organics, pesticide and organics, other. 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 Hardin County

Water Verdict

Hardin County, Illinois receives a poor water quality assessment with a grade of F and a score of 34.2 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 135 water bodies in the county's watershed, with 32.6% 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 Hardin County, Illinois show 2 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 49.4 violations per 100,000 people served, this rate is high and signals significant water quality management issues. Independent monitoring is comparatively sparse here — 994 water-quality results logged in the EPA Water Quality Portal over the past five years — so the utility's own reporting carries extra weight.

Consumer Guidance

Drinking-water compliance in Hardin County is rated Grade F, reflecting significant health-based violations in the recent reporting period. Hardin County's drinking-water compliance score is 34.2 out of 100. The violation rate for Hardin County is 49.4 per 100,000 people served. An NSF 53 or NSF 58-certified filter is recommended for drinking and cooking water. Check the Consumer Confidence Report from your utility to identify the specific contaminants and required corrective actions — utilities are legally required to notify customers of violations. Mercury is the leading impairment cause in Hardin County's watershed. There are 3 active water-quality monitoring sites in Hardin County.

Regional Context

Hardin County has poorer water quality than the average county in Illinois. Its water score is 13.6 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 Hardin County's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    Mercury

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

  • 2

    Polychlorinated Biphenyls (Pcbs)

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

  • 3

    Cause Unknown

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

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for Hardin County

EPA How's My Waterway

Interactive watershed health data for Hardin County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Hardin County

Consumer Confidence Reports (IL)

Annual water quality reports from utilities in Illinois

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

32.6%

44 of 135 assessed

Moderate concern

Top Impairment Causes

  • 1

    MERCURY

  • 2

    POLYCHLORINATED BIPHENYLS (PCBS)

  • 3

    CAUSE UNKNOWN

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

3

Active in the past 5 years

Measurements Recorded

994

994 total readings

Most Measured

  • Organics, Pesticide
  • Organics, Other
  • Physical

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 Hardin 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 Hardin County, Illinois?
Hardin County, Illinois has a drinking-water quality grade of F with a score of 34.2/100, 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 Hardin County?
Hardin 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 Hardin County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 32.6% of Hardin County's 135 assessed water bodies are classified as impaired (44 impaired). The top reported causes are MERCURY, POLYCHLORINATED BIPHENYLS (PCBS), CAUSE UNKNOWN. 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 Hardin County?
EPA's Water Quality Portal records 994 measurements from 3 monitoring sites in Hardin County over the past five years. The most frequently measured characteristic groups are Organics, Pesticide, Organics, Other, Physical. 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 Hardin County water compare to the Illinois average?
Hardin County's SDWIS water quality score of 34.2/100 is lower than the Illinois state average of 47.8. The average water quality grade across Illinois is D, based on data from 102 counties with available SDWIS data.
Is tap water safe to drink in Hardin County?
Based on EPA SDWIS data, Hardin County has a water quality grade of F (34.2/100). 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).
Does Hardin County have clean drinking water?
Hardin County has 2 health-based drinking water violations according to EPA records. With a water quality score of 34.2/100 and grade F, 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 Hardin County rank for water quality in Illinois?
Hardin County ranks #68 out of 102 counties in Illinois by SDWIS water quality score (1 = best). With a score of 34.2/100, 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

Livingston County

Illinois

F

34.4

Water score

Piatt County

Illinois

F

33.4

Water score

Greene County

Illinois

F

35.3

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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