Mississippi: Certified labs by state

Mississippi residents with private wells are mainly directed to the Mississippi State Department of Health for bacteriological sampling and to Mississippi State University Extension for private-well guidance. The state also maintains an official list of Mississippi drinking-water laboratories participating in MSDH’s certification program, which is the practical starting point for chemical or mineral testing. ([msdh.ms.gov](https://www.msdh.ms.gov/MSDHSITE/_STATIC/30%2C0%2C76%2C762.html?utm_source=openai))

Checked against official sources on October 4, 2026. Rules and links change; confirm with the office listed before you act.

Official resources in Mississippi

Mississippi State Department of Health — Private Well Water Testing

Official state page for private-well sampling; explains MSDH tests private wells for bacteriological contamination only and links to the online application. ([msdh.ms.gov](https://www.msdh.ms.gov/MSDHSITE/_STATIC/30%2C0%2C76%2C762.html?utm_source=openai))

Mississippi State Department of Health — Water Supply Certification: In-State Participating Labs

Official list of in-state laboratories participating in MSDH’s drinking-water lab certification program for chemistry and/or microbiology. ([msdh.ms.gov](https://msdh.ms.gov/msdhsite/_static/14%2C1112%2C188.html?utm_source=openai))

Mississippi State University Extension — Mississippi Well Owner Network

Free Extension education program for household well owners; the page says participants may have their water screened for E. coli at program events. ([extension.msstate.edu](https://extension.msstate.edu/natural-resources/water/mississippi-well-owner-network?utm_source=openai))

Key facts for Mississippi

MSDH says its private-well service tests for bacteriological contamination only; mineral, chemical, or other contaminant testing should go through a private laboratory. ([msdh.ms.gov](https://www.msdh.ms.gov/MSDHSITE/_STATIC/30%2C0%2C76%2C762.html?utm_source=openai))
MSU Extension recommends private wells be tested at least annually; at minimum, test for nitrates and bacteria each year. ([extension.msstate.edu](https://www.extension.msstate.edu/publications/protecting-your-private-well?utm_source=openai))
MSU Extension says broader chemistry testing can be done initially and every 3 years, and arsenic or uranium can be checked at least once with yearly follow-up if contamination is suspected. ([extension.msstate.edu](https://extension.msstate.edu/publications/assessing-and-protecting-water-quality-the-home-and-community?utm_source=openai))
MSDH’s radon page says most of Mississippi is EPA Zone 3, but radon in water from a private well could still be unacceptably high. ([msdh.ms.gov](https://www.msdh.ms.gov/MSDHSITE/_STATIC/44%2C0%2C100.html?utm_source=openai))
MDEQ’s 2025 AgChem report says none of its samples exceeded EPA drinking-water MCLs; among inorganic constituents, manganese, iron, barium, and arsenic were most frequently detected. ([mdeq.ms.gov](https://www.mdeq.ms.gov/wp-content/uploads/2025/09/2025-AgChem-Report-Annual-Final.pdf?utm_source=openai))
The Mississippi Well Owner Network is a free educational program, and its page says private well owners may have water screened for E. coli bacteria at each program. ([extension.msstate.edu](https://extension.msstate.edu/natural-resources/water/mississippi-well-owner-network?utm_source=openai))

What to do next

Start with MSDH’s private-well page if you want a state-collected bacteria sample, but use the MSDH participating-labs list for chemicals or minerals like arsenic, uranium, or nitrate. ([msdh.ms.gov](https://www.msdh.ms.gov/MSDHSITE/_STATIC/30%2C0%2C76%2C762.html?utm_source=openai))
Ask the lab for sampling instructions before collecting water; MSU Extension says proper containers, handling, and prompt return are important for valid results. ([extension.msstate.edu](https://www.extension.msstate.edu/publications/protecting-your-private-well?utm_source=openai))
Check the Mississippi Well Owner Network calendar for nearby events if you want free training and possible E. coli screening tied to a workshop. ([extension.msstate.edu](https://extension.msstate.edu/natural-resources/water/mississippi-well-owner-network?utm_source=openai))

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