waterbycounty
EPA SDWIS

Jefferson County Water Quality

Jefferson County, Mississippi

Water Grade

C

Water Score

53.6

Violations

1

State Rank

#44

of 82 (1 = best)

EPA SDWIS Compliance

Drinking Water Quality

Water Quality Grade

C

Based on EPA compliance history and violation data

Water Score

53.6/100

Higher = better quality

Health Violations

1

Health-based violations

Violation Rate

11.7%

Systems with violations

Water Advisory: Jefferson County

Water Verdict

Jefferson County receives a below-average water quality assessment with a grade of C and a score of 53.6 out of 100. Residents should review their utility's Consumer Confidence Report and may want to consider additional water filtration for drinking.

Violation Context

Jefferson County has recorded 1 health-based violation, meaning the water system experienced at least one exceedance of federal contaminant limits or treatment requirements. At 11.7 violations per 1,000 residents, this rate is high and signals significant water quality management issues.

Consumer Guidance

Tap water in Jefferson County meets baseline standards, but residents who are immunocompromised or have young children may want to use an NSF-certified water filter as a precaution. With 1 recorded health violation, 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

Jefferson County has water quality close to the average county in Mississippi. Its water score is within 1.9 points of the state average, meaning its overall water system performance is broadly representative of Mississippi as a whole.

Past 5 years

Water Quality Monitoring

Monitoring Sites

6

Active in the past 5 years

Measurements Recorded

712

712 total readings

Most Measured

  • Physical
  • Nutrient
  • Organics, Other

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).

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Frequently Asked Questions

What is the water quality in Jefferson County, Mississippi?
Jefferson County, Mississippi has a drinking-water quality grade of C with a score of 53.6/100, based on EPA SDWIS compliance data. The county has 1 health-based drinking water violation over the past 5 years. Watershed health, monitoring records, and live streamflow are reported separately on this page.
Are there any water violations in Jefferson County?
Jefferson County has 1 health-based drinking water violation 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 Jefferson County?
EPA's Water Quality Portal records 712 measurements from 6 monitoring sites in Jefferson County over the past five years. The most frequently measured characteristic groups are Physical, Nutrient, Organics, Other. 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 Jefferson County water compare to the Mississippi average?
Jefferson County's SDWIS water quality score of 53.6/100 is higher than the Mississippi state average of 51.7. The average water quality grade across Mississippi is D, based on data from 82 counties with available SDWIS data.
Is tap water safe to drink in Jefferson County?
Based on EPA SDWIS data, Jefferson County has a water quality grade of C (53.6/100). 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 Jefferson County have clean drinking water?
Jefferson County has 1 health-based drinking water violation according to EPA records. With a water quality score of 53.6/100 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 Jefferson County rank for water quality in Mississippi?
Jefferson County ranks #44 out of 82 counties in Mississippi by SDWIS water quality score (1 = best). With a score of 53.6/100, 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.

Counties with Similar Water Quality

Lafayette County

Mississippi

C

53.2

Water score

Union County

Mississippi

C

54.1

Water score

Warren County

Mississippi

C

52.9

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.

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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