waterbycounty
EPA SDWIS

Harrison County Water Quality

Harrison County, Mississippi

Water Grade

C

Water Score

57.9

Violations

15

State Rank

#34

of 82 (1 = best)

EPA SDWIS Compliance

Drinking Water Quality

Water Quality Grade

C

Based on EPA compliance history and violation data

Water Score

57.9/100

Higher = better quality

Health Violations

15

Health-based violations

Violation Rate

8.1%

Systems with violations

Water Advisory: Harrison County

Water Verdict

Harrison County receives a fair water quality assessment with a grade of C and a score of 57.9 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

Harrison County has recorded 15 health-based violations, indicating multiple instances where federal contaminant limits or treatment requirements were not met. At 8.1 violations per 1,000 residents, this rate is high and signals significant water quality management issues.

Consumer Guidance

Tap water in Harrison 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 15 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

Harrison County has better water quality than the average county in Mississippi. Its water score is 6.2 points higher than the state average, indicating stronger water system performance relative to neighboring counties.

Past 5 years

Water Quality Monitoring

Monitoring Sites

121

Active in the past 5 years

Measurements Recorded

69K

69,349 total readings

Most Measured

  • Physical
  • Nutrient
  • Microbiological

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

1,280cfs

May 14, 6:15 PM UTC

vs Long-Term Average

212%

Well above typical

Primary Streamgage

WOLF RIVER NR LANDON, MS

USGS site
02481510
Drainage area
308 sq mi
Long-term mean
605 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 Harrison County, Mississippi?
Harrison County, Mississippi has a drinking-water quality grade of C with a score of 57.9/100, based on EPA SDWIS compliance data. The county has 15 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 Harrison County?
Harrison County has 15 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 Harrison County?
EPA's Water Quality Portal records 69,349 measurements from 121 monitoring sites in Harrison County over the past five years. The most frequently measured characteristic groups are Physical, Nutrient, Microbiological. 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 Harrison County right now?
Harrison County's primary USGS streamgage on the WOLF RIVER is currently reading 1,280 cubic feet per second — 212% of the long-term mean of 604.82 cfs. This is well above typical — often a signal of recent precipitation or storm runoff. For genuine real-time data, visit waterdata.usgs.gov.
How does Harrison County water compare to the Mississippi average?
Harrison County's SDWIS water quality score of 57.9/100 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 Harrison County?
Based on EPA SDWIS data, Harrison County has a water quality grade of C (57.9/100). 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).
Why does Harrison County have so many water violations?
Harrison County has 15 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 Harrison County rank for water quality in Mississippi?
Harrison County ranks #34 out of 82 counties in Mississippi by SDWIS water quality score (1 = best). With a score of 57.9/100, 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

Kemper County

Mississippi

C

57.9

Water score

DeSoto County

Mississippi

C

58.1

Water score

Lawrence County

Mississippi

C

57.5

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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