waterbycounty
EPA SDWIS

Cass County Water Quality

Cass County, Michigan

Water Grade

F

Water Score

26.9

Violations

11

State Rank

#73

of 83 (1 = best)

EPA SDWIS Compliance

Drinking Water Quality

Water Quality Grade

F

Based on EPA compliance history and violation data

Water Score

26.9/100

Higher = better quality

Health Violations

11

Health-based violations

Violation Rate

80.5%

Systems with violations

Water Advisory: Cass County

Water Verdict

Cass County receives a poor water quality assessment with a grade of F and a score of 26.9 out of 100. The water supply has documented quality issues. Residents are strongly encouraged to use filtered or bottled water for drinking and to stay informed about utility improvement plans.

Violation Context

Cass County has recorded 11 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 80.5 violations per 1,000 residents, this rate is high and signals significant water quality management issues.

Consumer Guidance

Residents of Cass County are advised to use filtered or bottled water for drinking and cooking until water quality improves. A reverse-osmosis or activated-carbon filter certified to remove the contaminants listed in the utility's Consumer Confidence Report is recommended. With 11 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

Cass County has poorer water quality than the average county in Michigan. Its water score is 31.6 points lower than the state average, suggesting more challenges with contamination control or infrastructure than neighboring counties.

Past 5 years

Water Quality Monitoring

Monitoring Sites

41

Active in the past 5 years

Measurements Recorded

16K

16,476 total readings

Most Measured

  • Physical
  • Not Assigned
  • 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

335cfs

May 14, 6:45 PM UTC

vs Long-Term Average

109%

Near typical

Primary Streamgage

DOWAGIAC RIVER AT SUMNERVILLE, MI

USGS site
04101800
Drainage area
255 sq mi
Long-term mean
307 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 Cass County, Michigan?
Cass County, Michigan has a drinking-water quality grade of F with a score of 26.9/100, based on EPA SDWIS compliance data. The county has 11 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 Cass County?
Cass County has 11 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 much water-quality monitoring happens in Cass County?
EPA's Water Quality Portal records 16,476 measurements from 41 monitoring sites in Cass County over the past five years. The most frequently measured characteristic groups are Physical, Not Assigned, 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 Cass County right now?
Cass County's primary USGS streamgage on the DOWAGIAC RIVER is currently reading 335 cubic feet per second — 109% of the long-term mean of 307.34 cfs. Flow is within typical range for this gauge. For genuine real-time data, visit waterdata.usgs.gov.
How does Cass County water compare to the Michigan average?
Cass County's SDWIS water quality score of 26.9/100 is lower than the Michigan state average of 58.5. The average water quality grade across Michigan is D, based on data from 83 counties with available SDWIS data.
Is tap water safe to drink in Cass County?
Based on EPA SDWIS data, Cass County has a water quality grade of F (26.9/100). 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).
Why does Cass County have so many water violations?
Cass County has 11 health-based drinking water violations on record from the EPA SDWIS database. A higher violation count can result from aging infrastructure, underfunded water utilities, agricultural runoff contamination, or industrial pollution. Counties with more water systems may also see more violations simply due to scale. Residents concerned about water quality should consider independent water testing and home filtration systems.
How does Cass County rank for water quality in Michigan?
Cass County ranks #73 out of 83 counties in Michigan by SDWIS water quality score (1 = best). With a score of 26.9/100, 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

Menominee County

Michigan

F

27.2

Water score

Ogemaw County

Michigan

F

28.2

Water score

Lenawee County

Michigan

F

23.9

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.

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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