Mississippi Private Well Water Quality 2026

PFAS Contamination Across Mississippi

Mississippi sits in one of the most PFAS-affected regions of the country yet remains one of the least protected states. A 2023 Consumer Reports investigation conducted in partnership with Mississippi Spotlight — a collaboration between Mississippi Today, the Clarion Ledger, and Mississippi Public Broadcasting — tested 149 municipal and private well water samples across all 82 counties. PFAS was detected in 146 of those 149 samples. Nearly a third of all samples exceeded the EPA’s health advisory for PFOA, and almost half exceeded the advisory for PFOS. Around 23% of counties had total PFAS levels above the 10 ppt maximum recommended by Consumer Reports and used as the limit by the International Bottled Water Association.

The counties with the highest total PFAS levels in the study were: Alcorn (93 ppt), Carroll (52 ppt), Lamar (47 ppt), Harrison (46 ppt), Forrest (44 ppt), and Holmes (43 ppt). The MSDH confirmed to investigators that it does not test for PFAS — citing past results that did not indicate its presence, despite those earlier tests having used detection thresholds at least five times higher than the EPA’s current limits of 4 ppt for PFOA and PFOS.

Mississippi has no state-level PFAS MCLs. It is not among the 14 states that have enacted their own enforceable PFAS limits. The state relies entirely on the federal EPA standard, which applies to public water systems only, with a compliance deadline of 2031. Private well owners sit entirely outside this framework — with no testing requirements, no notification rights, and no remediation obligations on any responsible party.

An EWG analysis of Department of Defense data identified nine sites in Mississippi where the military used PFAS-containing firefighting foam (AFFF). Key sites include Columbus Air Force Base — where PFAS concentrations in local groundwater have been reported far exceeding EPA advisory levels — and Gulfport Regional Airport and Camp McCain, both listed as sites with known or suspected PFAS contamination. PFAS from AFFF is highly mobile in groundwater and can migrate into private wells far beyond the boundaries of any installation.

Arsenic and Lead: Found in Every Sample Tested

The Consumer Reports investigation found measurable arsenic in every single one of the 149 samples tested across Mississippi. Two counties recorded arsenic above the 3 ppb level that Consumer Reports and health experts recommend as a ceiling: Greene County at 3.7 ppb and Pike County at 3.6 ppb. The current EPA legal limit stands at 10 ppb, though the EPA previously considered lowering it to 3 ppb. Arsenic enters groundwater both naturally and through industrial and agricultural activity. It is colourless, odourless, and tasteless — undetectable without laboratory testing.

All 149 samples also contained measurable lead. The only sample to exceed the EPA’s action level came from a private well in Carroll County, which was 22% above the EPA threshold. Carroll County also recorded 52 ppt total PFAS — the second-highest in the state. Because the sample came from a private well, no regulatory action was triggered and no corrective measures were required.

Nitrate and Agricultural Contamination in the Delta

The Mississippi Delta — one of the most intensively farmed regions in the United States — poses a particular nitrate risk for private well owners. Shallow alluvial wells in the Delta are vulnerable to agricultural runoff from the cotton, corn, and soybean farming that dominates the region. USGS groundwater investigations have sampled wells in Delta counties including Bolivar and Washington, finding evidence of agricultural chemical infiltration in shallow groundwater.

Nitrate above the EPA MCL of 10 mg/L is dangerous for infants under six months, interfering with the blood’s ability to carry oxygen — a condition known as methemoglobinemia or “blue baby syndrome.” It is colourless, odourless, and tasteless. Risk is highest in shallow wells near agricultural land and wherever septic systems sit close to well casings.

The alluvial aquifer underlying the Delta also tends to carry elevated iron and manganese, along with hydrogen sulfide — responsible for the “rotten egg” smell sometimes reported in well water across central Mississippi. While largely aesthetic at typical levels, elevated manganese has a health advisory level of 0.3 mg/L that warrants attention.

Bacteria, Coastal Risks, and Regional Variation

Coliform bacteria — including E. coli — are among the most frequently detected contaminants in Mississippi private wells. Bacterial contamination enters through poorly sealed wellheads, flooding events (common in the state’s low-lying areas), deteriorating well casings, or septic systems located too close to a well. The MSDH recommends a minimum 50-foot separation between a well and any potential contamination source, and 100 feet from treated sewage discharge. Many older wells across the state pre-date these standards.

Along Mississippi’s Gulf Coast, saltwater intrusion into shallow freshwater aquifers is an increasing concern as groundwater extraction grows and sea levels rise. Well owners in Hancock, Harrison, and Jackson counties may experience elevated chloride levels and deteriorating water taste as intrusion boundaries advance. Coastal plain counties also tend to produce iron-rich water from wells, which can stain fixtures and laundry even at levels below any health threshold.

In north-central Mississippi, limestone geology produces naturally hard water. Some central and northern counties also show low levels of naturally occurring radon in groundwater. While radon in water is a much smaller concern than radon in indoor air, well owners with any concern can arrange a combined air and water test.

Regulatory Situation for Mississippi Well Owners

Private residential wells in Mississippi are not regulated under the Mississippi Safe Drinking Water Act or its federal equivalent. The MSDH offers a bacteriological testing service for private well owners for approximately $10 per sample — but this covers bacterial contamination only. For nitrate, heavy metals, PFAS, or any other chemical contaminant, well owners must arrange and fund their own testing through a certified private laboratory. The MSDH publishes a list of certified private laboratories through its Drinking Water Lab Certification Program.

Mississippi has set no state-level PFAS MCLs. The MSDH confirmed in 2023 that it does not test for PFAS at all — the state’s position being that past results did not indicate PFAS presence, despite those earlier tests using thresholds far above what the EPA now considers safe. Private well owners with PFAS contamination have no legal recourse, no right to notification, and no requirement for any remediation.

Check our Mississippi municipal water quality page for city-by-city tap water data, our Jackson water quality page for the state capital’s specific history, or use our live boil water notice tracker for active advisories across Mississippi.

Known High-Risk Areas in Mississippi

If you live near any of the following locations, well water testing is urgent — not precautionary.

How to Test Your Mississippi Well Water — and What to Do Next

Given Mississippi’s contamination profile — PFAS detected across all 82 counties, measurable arsenic in every sample tested, bacterial risk statewide, and agricultural nitrate concentrated in the Delta — every private well owner in the state should test annually for bacteria and nitrate as a minimum. PFAS and arsenic testing should be a priority for all well owners at least once, and treated as urgent for anyone living near a military installation, airport, or industrial facility.

The MSDH offers bacteriological testing for approximately $10 through healthyms.com or by calling 1-855-220-0192. For chemical testing — PFAS, arsenic, nitrate, metals, and other contaminants — contact a MSDH-certified private laboratory: Bonner Analytical in Hattiesburg (601-264-2854), Micro-Methods in Ocean Springs (228-875-6420), or the City of Meridian Lab (601-484-6836). The MSU Extension Well Owner Network also holds periodic free testing clinics across the state — contact them on 662-325-1788 to find one near you.

For filter options, our well water filter guide covers reverse osmosis systems for PFAS, arsenic, and nitrate; UV disinfection for bacteria; and whole-house well systems for comprehensive treatment. Browse our full water filter solutions page or check your ZIP code for local water quality context.

For nearby Southeast well water risks, see our pages on North Carolina wells, Florida wells, and Georgia wells. Return to the private well water directory to find your state.