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Federal water data

County water report

Knox County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Knox County, Indiana.

Water grade

D

Water score

50.4

State rank

#53

of 92

Health violations

5

EPA SDWIS, 5-year lookback

Watershed impaired

44.1%

204 water bodies assessed

Monitoring sites

31

9,884 recent measurements

Live streamflow

123%

WABASH RIVER AT MEMORIAL BRIDGE AT VINCENNES, IN

Water at a glance

Key Water Indicators for Knox County

EPA SDWIS

Safety Grade

D

Score: 50.4 / 100

EPA SDWIS

Active Violations

5

5-year health-based lookback

EPA ATTAINS

Watershed Health

44% impaired

204 bodies assessed

USGS NWIS

Streamflow Snapshot

123% of mean

WABASH RIVER AT MEMORIAL BRIDGE AT VINCENNES, IN

EPA WQP

Monitoring Sites

31

9,884 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

D

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

50.4/100

Health violations

5

Health-based violations

Violations per 100K served

16.0

Population-normalized SDWIS rate

Editorial analysis

Understanding Knox County’s Water

Drinking Water Quality Overview

EPA SDWIS

Knox County's drinking water received a D grade, scoring 50.4 out of 100. Over the past five years, EPA SDWIS records 5 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 44.1% of assessed waterways are impaired (90 of 204 water bodies) across Knox County's watersheds. The leading impairment causes are escherichia coli (e. coli) and biological integrity. 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 WABASH RIVER at 17.6k cfs — flowing above its historical average at 123% of mean. 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. Knox County has moderate coverage with 31 active monitoring sites with 9,884 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 Knox County

Water Verdict

Knox County receives a below-average water quality assessment with a grade of D and a score of 50.4 out of 100. Residents should review their utility's Consumer Confidence Report and may want to consider additional water filtration for drinking.

Violation Context

Knox County has recorded 5 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 16.0 violations per 100,000 people served, this rate is high and signals significant water quality management issues.

Consumer Guidance

Knox County's drinking-water compliance is below average with a Grade D, indicating repeated or unresolved violations in the recent record. Knox County's drinking-water compliance score is 50.4 out of 100. The violation rate for Knox County is 16.0 per 100,000 people served. Residents are encouraged to use an NSF 53 or NSF 58-certified filter for drinking and cooking water until the underlying violations are resolved. Running tap water for 30 seconds before use and avoiding older lead-pipe connections can also reduce exposure risk. The current Consumer Confidence Report from your utility will specify the contaminants of concern. E. coli is the leading impairment cause in Knox County's watershed. With 31 active water-quality monitoring sites in Knox County, data coverage is strong. A pipeline streamflow snapshot from the WABASH RIVER gauge is also available on this page.

Regional Context

Knox County has water quality close to the average county in Indiana. Its water score is within 2.1 points of the state average, meaning its overall water system performance is broadly representative of Indiana 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 Knox County's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    E. coli (bacteria)

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

  • 2

    Biological Integrity

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

  • 3

    Pcbs in Fish Tissue

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

Source: EPA ATTAINS · Reporting cycle 2022

Official EPA Resources for Knox County

EPA How's My Waterway

Interactive watershed health data for Knox County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Knox County

Consumer Confidence Reports (IN)

Annual water quality reports from utilities in Indiana

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

44.1%

90 of 204 assessed

Moderate concern

Top Impairment Causes

  • 1

    ESCHERICHIA COLI (E. COLI)

  • 2

    BIOLOGICAL INTEGRITY

  • 3

    PCBS IN FISH TISSUE

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

31

Active in the past 5 years

Measurements Recorded

9.9K

9,884 total readings

Most Measured

  • Physical
  • Nutrient
  • Biological, Counts

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

17.6Kcfs

May 14, 6:45 PM UTC

vs Long-Term Average

123%

Above typical

Primary Streamgage

WABASH RIVER AT MEMORIAL BRIDGE AT VINCENNES, IN

USGS site
03343010
Drainage area
13,732 sq mi
Long-term mean
14.4K 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 Knox 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 Knox County, Indiana?
Knox County, Indiana has a drinking-water quality grade of D with a score of 50.4/100, based on EPA SDWIS compliance data. The county has 5 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 Knox County?
Knox County has 5 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 Knox County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 44.1% of Knox County's 204 assessed water bodies are classified as impaired (90 impaired). The top reported causes are ESCHERICHIA COLI (E. COLI), BIOLOGICAL INTEGRITY, PCBS IN FISH TISSUE. 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 Knox County?
EPA's Water Quality Portal records 9,884 measurements from 31 monitoring sites in Knox County over the past five years. The most frequently measured characteristic groups are Physical, Nutrient, Biological, Counts. 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 Knox County right now?
Knox County's primary USGS streamgage on the WABASH RIVER has a pipeline snapshot of 17,600 cubic feet per second — 123% of the long-term mean of 14,352.63 cfs. Flow is within typical range for this gauge. For the latest gauge feed, visit waterdata.usgs.gov.
How does Knox County water compare to the Indiana average?
Knox County's SDWIS water quality score of 50.4/100 is lower than the Indiana state average of 52.5. The average water quality grade across Indiana is D, based on data from 92 counties with available SDWIS data.
Is tap water safe to drink in Knox County?
Based on EPA SDWIS data, Knox County has a water quality grade of D (50.4/100). 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 Knox County have clean drinking water?
Knox County has 5 health-based drinking water violations according to EPA records. With a water quality score of 50.4/100 and grade D, 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 Knox County rank for water quality in Indiana?
Knox County ranks #53 out of 92 counties in Indiana by SDWIS water quality score (1 = best). With a score of 50.4/100, 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

Starke County

Indiana

D

50.4

Water score

Tipton County

Indiana

D

50.5

Water score

Wells County

Indiana

C

51.4

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.

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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