waterbycounty
Federal water data

County water report

Union County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Union County, Tennessee.

Water grade

D

Water score

50.5

State rank

#77

of 95

Health violations

3

EPA SDWIS, 5-year lookback

Watershed impaired

33.3%

27 water bodies assessed

Monitoring sites

15

2,510 recent measurements

Live streamflow

No gauge

Primary USGS station not mapped

Water at a glance

Key Water Indicators for Union County

EPA SDWIS

Safety Grade

D

Score: 50.5 / 100

EPA SDWIS

Active Violations

3

5-year health-based lookback

EPA ATTAINS

Watershed Health

33% impaired

27 bodies assessed

USGS NWIS

Streamflow Snapshot

No gauge

Primary USGS gauge not mapped

EPA WQP

Monitoring Sites

15

2,510 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.

50.5/100

Health violations

3

Health-based violations

Violations per 100K served

15.8

Population-normalized SDWIS rate

Editorial analysis

Understanding Union County’s Water

Drinking Water Quality Overview

EPA SDWIS

Union County's drinking water received a D grade, scoring 50.5 out of 100. Over the past five years, EPA SDWIS records 3 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 33.3% of assessed waterways are impaired (9 of 27 water bodies) across Union County's watersheds. The leading impairment causes are escherichia coli (e. coli) and mercury. 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. Union County has moderate coverage with 15 active monitoring sites with 2,510 recent measurements on record. Predominant monitoring categories include biological, counts and physical. 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 Union County

Water Verdict

Union County receives a below-average water quality assessment with a grade of D and a score of 50.5 out of 100. Residents should review their utility's Consumer Confidence Report and may want to consider additional water filtration for drinking.

Violation Context

Union County has recorded 3 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 15.8 violations per 100,000 people served, this rate is high and signals significant water quality management issues.

Consumer Guidance

Union County's drinking-water compliance is below average with a Grade D, indicating repeated or unresolved violations in the recent record. Union County's drinking-water compliance score is 50.5 out of 100. The violation rate for Union County is 15.8 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 Union County's watershed. With 15 active water-quality monitoring sites in Union County, data coverage is strong.

Regional Context

Union County has poorer water quality than the average county in Tennessee. Its water score is 20.8 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 Union County's water environment

Watershed Impairment Causes (EPA ATTAINS)

  • 1

    E. coli (bacteria)

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

  • 2

    Mercury

    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 Union County

EPA How's My Waterway

Interactive watershed health data for Union County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Union County

Consumer Confidence Reports (TN)

Annual water quality reports from utilities in Tennessee

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

33.3%

9 of 27 assessed

Moderate concern

Top Impairment Causes

  • 1

    ESCHERICHIA COLI (E. COLI)

  • 2

    MERCURY

  • 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

15

Active in the past 5 years

Measurements Recorded

2.5K

2,510 total readings

Most Measured

  • Biological, Counts
  • Physical
  • 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).

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 Union 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 Union County, Tennessee?
Union County, Tennessee has a drinking-water quality grade of D with a score of 50.5/100, based on EPA SDWIS compliance data. The county has 3 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 Union County?
Union County has 3 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 Union County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 33.3% of Union County's 27 assessed water bodies are classified as impaired (9 impaired). The top reported causes are ESCHERICHIA COLI (E. COLI), MERCURY, 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 Union County?
EPA's Water Quality Portal records 2,510 measurements from 15 monitoring sites in Union County over the past five years. The most frequently measured characteristic groups are Biological, Counts, Physical, 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 Union County water compare to the Tennessee average?
Union County's SDWIS water quality score of 50.5/100 is lower than the Tennessee state average of 71.3. The average water quality grade across Tennessee is C, based on data from 95 counties with available SDWIS data.
Is tap water safe to drink in Union County?
Based on EPA SDWIS data, Union County has a water quality grade of D (50.5/100). 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).
Does Union County have clean drinking water?
Union County has 3 health-based drinking water violations according to EPA records. With a water quality score of 50.5/100 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 Union County rank for water quality in Tennessee?
Union County ranks #77 out of 95 counties in Tennessee by SDWIS water quality score (1 = best). With a score of 50.5/100, 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

Monroe County

Tennessee

D

49.4

Water score

Robertson County

Tennessee

C

53.4

Water score

Roane County

Tennessee

D

46.5

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

Explore more data for Union County

Property TaxCost of LivingCrime RateIncomeHealthSchoolsDisaster RiskWeatherCounty Score