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EPA SDWIS

St. Joseph County Water Quality

St. Joseph County, Indiana

Water Grade

B

Water Score

68.6

Violations

3

State Rank

#19

of 92 (1 = best)

EPA SDWIS Compliance

Drinking Water Quality

Water Quality Grade

B

Based on EPA compliance history and violation data

Water Score

68.6/100

Higher = better quality

Health Violations

3

Health-based violations

Violation Rate

1.6%

Systems with violations

Water Advisory: St. Joseph County

Water Verdict

St. Joseph County receives a fair water quality assessment with a grade of B and a score of 68.6 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

St. Joseph County has recorded 3 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 1.6 violations per 1,000 residents, this rate is relatively low compared to many U.S. counties.

Consumer Guidance

Tap water in St. Joseph County is generally safe to drink based on available data. Residents should still review their utility's annual Consumer Confidence Report for transparency on detected contaminants. With 3 recorded health violations, staying informed about utility communications and boil-water notices is especially important. For long-term peace of mind, request your utility's latest Consumer Confidence Report and consider independent water testing if you have specific health concerns.

Regional Context

St. Joseph County has better water quality than the average county in Indiana. Its water score is 16.1 points higher than the state average, indicating stronger water system performance relative to neighboring counties.

Clean Water Act §303(d)

Watershed Health

Impaired Water Bodies

53.8%

99 of 184 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

93

Active in the past 5 years

Measurements Recorded

11K

11,363 total readings

Most Measured

  • Physical
  • Organics, Pesticide
  • 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).

Live USGS Streamgage

River & Stream Conditions

Current Discharge

4,400cfs

May 14, 6:15 PM UTC

vs Long-Term Average

121%

Above typical

Primary Streamgage

ST. JOSEPH RIVER AT SOUTH BEND, IN

USGS site
04101225
Drainage area
3,619 sq mi
Long-term mean
3,652 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; "% of typical" compares the latest reading against that average.

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Frequently Asked Questions

What is the water quality in St. Joseph County, Indiana?
St. Joseph County, Indiana has a drinking-water quality grade of B with a score of 68.6/100, 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 live streamflow are reported separately on this page.
Are there any water violations in St. Joseph County?
St. Joseph 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 St. Joseph County?
EPA ATTAINS assessments under Clean Water Act §303(d) indicate 53.8% of St. Joseph County's 184 assessed water bodies are classified as impaired (99 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 St. Joseph County?
EPA's Water Quality Portal records 11,363 measurements from 93 monitoring sites in St. Joseph County over the past five years. The most frequently measured characteristic groups are Physical, Organics, Pesticide, 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.
What's happening with rivers in St. Joseph County right now?
St. Joseph County's primary USGS streamgage on the ST. JOSEPH RIVER is currently reading 4,400 cubic feet per second — 121% of the long-term mean of 3,651.6 cfs. Flow is within typical range for this gauge. For genuine real-time data, visit waterdata.usgs.gov.
How does St. Joseph County water compare to the Indiana average?
St. Joseph County's SDWIS water quality score of 68.6/100 is higher 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 St. Joseph County?
Based on EPA SDWIS data, St. Joseph County has a water quality grade of B (68.6/100). This indicates good to excellent water quality with strong SDWIS compliance. 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 St. Joseph County have clean drinking water?
St. Joseph County has 3 health-based drinking water violations according to EPA records. With a water quality score of 68.6/100 and grade B, 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 St. Joseph County rank for water quality in Indiana?
St. Joseph County ranks #19 out of 92 counties in Indiana by SDWIS water quality score (1 = best). With a score of 68.6/100, 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

Lake County

Indiana

B

68.4

Water score

Harrison County

Indiana

B

67.1

Water score

Jackson County

Indiana

B

66.8

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, 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 Logan Johnson, Founder & Data EditorUpdated Reviewed by Logan Johnson, Founder & Data Editor

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