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County water report

Shelby County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Shelby County, Ohio.

Water grade

C

Water score

59.3

State rank

#49

of 88

Health violations

2

EPA SDWIS, 5-year lookback

Watershed impaired

0.0%

4 water bodies assessed

Monitoring sites

10

1,028 recent measurements

Live streamflow

57%

Great Miami River at Sidney OH

Water at a glance

Key Water Indicators for Shelby County

EPA SDWIS

Safety Grade

C

Score: 59.3 / 100

EPA SDWIS

Active Violations

2

5-year health-based lookback

EPA ATTAINS

Watershed Health

0% impaired

4 bodies assessed

USGS NWIS

Streamflow Snapshot

57% of mean

Great Miami River at Sidney OH

EPA WQP

Monitoring Sites

10

1,028 recent readings

Source: EPA SDWIS · Safe Drinking Water Information System

Drinking Water Compliance

Compliance grade

C

Based on EPA SDWIS compliance history.

Water score

Higher scores indicate cleaner recent compliance records.

59.3/100

Health violations

2

Health-based violations

Violations per 100K served

6.9

Population-normalized SDWIS rate

Editorial analysis

Understanding Shelby County’s Water

Drinking Water Quality Overview

EPA SDWIS

Shelby County's drinking water earned a C grade, scoring 59.3 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). None of the assessed waterways are listed as impaired (0 of 4 water bodies) across Shelby County's watersheds. 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 2026-05-14T14:30:00.000-04:00) puts Great Miami River at 300.0 cfs — well below its long-term average at 57% of mean — low-flow conditions worth noting for water-dependent ecosystems. 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. Shelby County has moderate coverage with 10 active monitoring sites with 1,028 recent measurements on record. Predominant monitoring categories include physical and inorganics, minor, metals. 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 Shelby County

Water Verdict

Shelby County receives a fair water quality assessment with a grade of C and a score of 59.3 out of 100. The water supply meets baseline federal standards, but there may be periods of elevated contaminant levels or infrastructure concerns worth monitoring.

Violation Context

Shelby County has recorded 2 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 6.9 violations per 100,000 people served, this rate is moderate and suggests recurring water quality challenges.

Consumer Guidance

Tap water in Shelby County meets baseline standards but the compliance record shows room for improvement, with a Grade C rating. Shelby County's drinking-water compliance score is 59.3 out of 100. The violation rate for Shelby County is 6.9 per 100,000 people served. Residents who are immunocompromised, pregnant, or have young children may benefit from using an NSF 53-certified filter. Contacting your local utility for the current Consumer Confidence Report will confirm which specific violations were recorded and whether they have been resolved. There are 10 active water-quality monitoring sites in Shelby County. A pipeline streamflow snapshot from the Great Miami River gauge is also available on this page.

Regional Context

Shelby County has water quality close to the average county in Ohio. Its water score is within 3.1 points of the state average, meaning its overall water system performance is broadly representative of Ohio 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.

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

0.0%

0 of 4 assessed

Mostly healthy

Top Impairment Causes

No specific impairment causes reported for the assessed water bodies in this county.

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

10

Active in the past 5 years

Measurements Recorded

1.0K

1,028 total readings

Most Measured

  • Physical
  • Inorganics, Minor, Metals
  • Organics, Pesticide

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

300cfs

May 14, 6:30 PM UTC

vs Long-Term Average

57%

Well below typical

Primary Streamgage

Great Miami River at Sidney OH

USGS site
03261500
Drainage area
541 sq mi
Long-term mean
528 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.

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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 Shelby County:CModerate

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 Shelby County, Ohio?
Shelby County, Ohio has a drinking-water quality grade of C with a score of 59.3/100, 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 Shelby County?
Shelby 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 Shelby County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 0.0% of Shelby County's 4 assessed water bodies are classified as impaired (0 impaired). 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 Shelby County?
EPA's Water Quality Portal records 1,028 measurements from 10 monitoring sites in Shelby County over the past five years. The most frequently measured characteristic groups are Physical, Inorganics, Minor, Metals, Organics, Pesticide. 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 Shelby County right now?
Shelby County's primary USGS streamgage on the Great Miami River has a pipeline snapshot of 300 cubic feet per second — 57% of the long-term mean of 527.53 cfs. This is well below typical — often a signal of drought stress on source water. For the latest gauge feed, visit waterdata.usgs.gov.
How does Shelby County water compare to the Ohio average?
Shelby County's SDWIS water quality score of 59.3/100 is higher than the Ohio state average of 56.2. The average water quality grade across Ohio is D, based on data from 88 counties with available SDWIS data.
Is tap water safe to drink in Shelby County?
Based on EPA SDWIS data, Shelby County has a water quality grade of C (59.3/100). This indicates moderate compliance. Some violations have been recorded but overall standards are maintained. 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 Shelby County have clean drinking water?
Shelby County has 2 health-based drinking water violations according to EPA records. With a water quality score of 59.3/100 and grade C, 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 Shelby County rank for water quality in Ohio?
Shelby County ranks #49 out of 88 counties in Ohio by SDWIS water quality score (1 = best). With a score of 59.3/100, 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.

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