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Federal water data

County water report

Mifflin County Water Report

Drinking-water compliance, watershed health, monitoring records, and river conditions for Mifflin County, Pennsylvania.

Water grade

C

Water score

51.5

State rank

#17

of 67

Health violations

4

EPA SDWIS, 5-year lookback

Watershed impaired

0.0%

16,815 water bodies assessed

Monitoring sites

56

12,460 recent measurements

Live streamflow

61%

Juniata River at Lewistown, PA

Water at a glance

Key Water Indicators for Mifflin County

EPA SDWIS

Safety Grade

C

Score: 51.5 / 100

EPA SDWIS

Active Violations

4

5-year health-based lookback

EPA ATTAINS

Watershed Health

0% impaired

16,815 bodies assessed

USGS NWIS

Streamflow Snapshot

61% of mean

Juniata River at Lewistown, PA

EPA WQP

Monitoring Sites

56

12,460 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.

51.5/100

Health violations

4

Health-based violations

Violations per 100K served

14.2

Population-normalized SDWIS rate

Editorial analysis

Understanding Mifflin County’s Water

Drinking Water Quality Overview

EPA SDWIS

Mifflin County's drinking water earned a C grade, scoring 51.5 out of 100. Over the past five years, EPA SDWIS records 4 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). None of the assessed waterways are listed as impaired (0 of 16,815 water bodies) across Mifflin 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 Juniata River at 2.1k cfs — running somewhat below its historical average at 61% 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. Mifflin County has extensive coverage with 56 active monitoring sites with 12,460 recent measurements on record. Predominant monitoring categories include inorganics, minor, metals 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 Mifflin County

Water Verdict

Mifflin County receives a below-average water quality assessment with a grade of C and a score of 51.5 out of 100. Residents should review their utility's Consumer Confidence Report and may want to consider additional water filtration for drinking.

Violation Context

Mifflin County has recorded 4 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 14.2 violations per 100,000 people served, this rate is high and signals significant water quality management issues.

Consumer Guidance

Tap water in Mifflin County meets baseline standards but the compliance record shows room for improvement, with a Grade C rating. Mifflin County's drinking-water compliance score is 51.5 out of 100. The violation rate for Mifflin County is 14.2 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. With 56 active water-quality monitoring sites in Mifflin County, data coverage is strong. A pipeline streamflow snapshot from the Juniata River gauge is also available on this page.

Regional Context

Mifflin County has better water quality than the average county in Pennsylvania. Its water score is 12.6 points higher than the state average, indicating stronger water system performance relative to 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 Mifflin County's water environment

Official EPA Resources for Mifflin County

EPA How's My Waterway

Interactive watershed health data for Mifflin County

EPA ECHO: Drinking Water Systems

Search water utilities and violation records for Mifflin County

Consumer Confidence Reports (PA)

Annual water quality reports from utilities in Pennsylvania

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

0.0%

0 of 16,815 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

56

Active in the past 5 years

Measurements Recorded

12K

12,460 total readings

Most Measured

  • Inorganics, Minor, Metals
  • Physical
  • 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).

Live USGS Streamgage

River & Stream Conditions

Current Discharge

2,110cfs

May 14, 6:30 PM UTC

vs Long-Term Average

61%

Below typical

Primary Streamgage

Juniata River at Lewistown, PA

USGS site
01564895
Drainage area
2,519 sq mi
Long-term mean
3,473 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 Mifflin 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 Mifflin County, Pennsylvania?
Mifflin County, Pennsylvania has a drinking-water quality grade of C with a score of 51.5/100, based on EPA SDWIS compliance data. The county has 4 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 Mifflin County?
Mifflin County has 4 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 Mifflin County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 0.0% of Mifflin County's 16,815 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 Mifflin County?
EPA's Water Quality Portal records 12,460 measurements from 56 monitoring sites in Mifflin County over the past five years. The most frequently measured characteristic groups are Inorganics, Minor, Metals, Physical, 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.
What's happening with rivers in Mifflin County right now?
Mifflin County's primary USGS streamgage on the Juniata River has a pipeline snapshot of 2,110 cubic feet per second — 61% of the long-term mean of 3,472.67 cfs. Flow is within typical range for this gauge. For the latest gauge feed, visit waterdata.usgs.gov.
How does Mifflin County water compare to the Pennsylvania average?
Mifflin County's SDWIS water quality score of 51.5/100 is higher than the Pennsylvania state average of 38.9. The average water quality grade across Pennsylvania is F, based on data from 67 counties with available SDWIS data.
Is tap water safe to drink in Mifflin County?
Based on EPA SDWIS data, Mifflin County has a water quality grade of C (51.5/100). 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 Mifflin County have clean drinking water?
Mifflin County has 4 health-based drinking water violations according to EPA records. With a water quality score of 51.5/100 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 Mifflin County rank for water quality in Pennsylvania?
Mifflin County ranks #17 out of 67 counties in Pennsylvania by SDWIS water quality score (1 = best). With a score of 51.5/100, it falls in the top 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

Butler County

Pennsylvania

C

51.2

Water score

Northampton County

Pennsylvania

C

51.8

Water score

Berks County

Pennsylvania

C

52.0

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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