waterbycounty
Compiled federal source snapshot

Mississippi Water Quality

Drinking water data for all 81 counties.

Avg SDWIS Compliance Index

51.2

Most Common Five-Year SDWIS Compliance Band

C

Counties with Data

81

of 81 total

County water atlas

Mississippi water signals by county

A state-level 2.5D view across drinking-water compliance, watershed impairment, monitoring density, and streamflow snapshot context. Pin any county, switch layers, then use the lens controls to compare index ranges, recorded violation rates, or impaired watersheds without leaving the page.

Counties

81

Avg SDWIS index

51.2

Watersheds

0

ATTAINS counties

Monitoring

81

40 fresh USGS snapshots

State atlas layers combine EPA SDWIS health-based violations, EPA ATTAINS 303(d) impairment assessments, EPA Water Quality Portal monitoring sites, and representative USGS NWIS streamflow gauges. Streamflow values appear only for fresh pipeline snapshots, not as a continuously updated stream. County pages include the observation time and year.

Prepared by ByCounty Editorial TeamPublished by WaterByCounty

Multi-source coverage in Mississippi

Beyond Drinking Water

EPA SDWIS

81/ 81

counties with drinking-water compliance data

402 health violations statewide (5yr)

EPA ATTAINS

—

No §303(d) assessments yet for Mississippi

EPA WQP

803

monitoring sites across 81 counties

325,567 total readings (5yr window)

USGS NWIS

40

counties with a fresh pipeline snapshot

0 above40 below

State atlas notes

What stands out in Mississippi

County water quality is not one number. The strongest read comes from comparing drinking-water compliance against watershed impairment, monitoring density, and streamflow context. Use these signals as a starting point, then open any county profile for source-level detail.

Compliance spread

Adams County has the highest value in the published state SDWIS Compliance Index table at 86.2/100, while Issaquena County has the lowest at 2.2/100. That is a 84.0 point gap inside one state.

Zero health violations

13

3+ health violations

40

Monitoring hubs

Harrison County120 sitesJackson County68 sitesHancock County38 sites

Lowest flow reads

Lee County1%Grenada County2%Harrison County2%

Highest fresh streamflow pipeline snapshots: Warren County (52%, observation 2026), Leflore County (37%, observation 2026), Perry County (36%, observation 2026). These are source-data observations, not household tap-water conclusions.

All Mississippi Counties

CountySDWIS Compliance Index
Adams County86.2
Alcorn County86.2
Attala County86.2
Carroll County86.2
Clarke County86.2
George County86.2
Neshoba County86.2
Simpson County86.2
Tishomingo County86.2
Walthall County86.2
Webster County86.2
Wilkinson County86.2
Winston County86.2
Lauderdale County68.2
Jones County67.8
Warren County66.3
Lee County65.1
Lincoln County63.1
Scott County62.9
Grenada County62.3
Leflore County62.3
Forrest County61.9
Clay County60.1
DeSoto County59.6
Lamar County59.1
Lowndes County59.1
Madison County59.1
Newton County58.9
Leake County58.3
Monroe County58.3
Chickasaw County58.0
Harrison County57.3
Pearl River County56.7
Jackson County55.9
Prentiss County55.2
Lafayette County54.1
Jefferson Davis County53.6
Tippah County53.5
Union County53.2
Kemper County52.2
Yazoo County52.2
Lawrence County51.4
Itawamba County51.2
Marshall County51.1
Amite County50.8
Oktibbeha County48.9
Choctaw County48.4
Pike County47.4
Jefferson County47.0
Marion County45.5
Hancock County45.2
Rankin County44.8
Washington County43.3
Calhoun County42.5
Pontotoc County42.4
Tunica County42.4
Hinds County41.5
Benton County41.1
Greene County39.9
Jasper County39.7
Stone County38.3
Yalobusha County37.8
Covington County37.6
Panola County37.1
Copiah County36.2
Claiborne County34.9
Perry County31.2
Humphreys County30.0
Wayne County29.9
Noxubee County28.6
Bolivar County28.5
Holmes County25.5
Montgomery County20.5
Sunflower County16.5
Franklin County16.2
Tate County15.6
Smith County15.0
Tallahatchie County13.1
Coahoma County8.8
Sharkey County4.2
Issaquena County2.2

Frequently Asked Questions

Which Mississippi county has the highest SDWIS Compliance Index?
Adams County has the highest SDWIS Compliance Index in the published Mississippi cohort at 86.2/100. This WaterByCounty relative comparison is not an EPA score and does not establish current conditions for a utility or address.
What does the Five-Year SDWIS Compliance Band mean?
The band is derived only from each county aggregation's recorded health-violation rate per 100,000 people served for the stated five-year source window. It is separate from the relative SDWIS Compliance Index and is not a current determination for a specific utility or address.
Which USGS streamflow records are shown across Mississippi?
WaterByCounty has 40 fresh USGS pipeline snapshots in the published Mississippi cohort. Each county page shows its observation timestamp and year. A pipeline snapshot is not a continuously updated reading or a tap-water safety measure.
Where can Mississippi residents find current official information?
Review the applicable utility's Consumer Confidence Report, active notices, and the state drinking-water agency. WaterByCounty's county-level historical aggregations do not establish the current status of a specific utility, address, private well, or household plumbing system.
What does Water Quality Portal monitoring volume show in Mississippi?
The published county records contain 325,567 results from 803 monitoring locations in the site's five-year aggregation. Monitoring volume does not by itself indicate better or worse water quality.

Data Sources

Drinking-water compliance data from the EPA Safe Drinking Water Information System (SDWIS) via the ECHO enforcement database. The WaterByCounty SDWIS Compliance Index reflects the recorded rate and is not an EPA score.

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.

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