Mississippi State Department of Health
Mississippi drinking water lab certification, the MSDH Public Health Laboratory.
Which Mississippi agency certifies drinking water labs, how out-of-state labs qualify through reciprocity, what applies to wastewater data, and where your calibration requirements come from.
At a glance
How drinking water lab certification works in Mississippi.
Mississippi is not a NELAP state. The certification program the Mississippi State Department of Health describes covers drinking water labs, and out-of-state labs are recognized through reciprocity rather than certified directly.
Drinking water lab certification
- Drinking water program
- Water Supply Laboratory certification for chemistry and microbiology, operated by the Environmental Services Division of the Mississippi Public Health Laboratory, Mississippi State Department of Health
- Legal basis
- The Safe Drinking Water Act, for which MSDH is the state enforcement authority, and Rule 1.5.5 of the Mississippi Primary Drinking Water Regulation (Miss. Admin. Code 15-20-72), adopted under Miss. Code Ann. 41-26-6
- Who needs it
- Rule 1.5.5 requires each supplier of water to use a certified laboratory, or a party approved by the state where applicable, for the water quality analyses in the National Primary Drinking Water Regulations.
- In-state labs
- MSDH inspects and certifies laboratories located within Mississippi. Its participating lab list states that evaluation is ongoing and a lab’s status may change.
- Out-of-state labs
- MSDH does not directly certify out-of-state labs for EPA-regulated drinking water parameters. It honors reciprocal certification from the lab’s home state agency, and may recognize NELAP accreditation specific to drinking water.
- Wastewater
- MDEQ’s published wastewater pollution control regulations contain no laboratory certification chapter. Its NPDES permit rules reference 40 CFR Part 136 test procedures.
- NELAP status
- Not a NELAP accreditation body, as of October 2026. MSDH may recognize NELAP accreditation for drinking water reciprocity.
The accreditation cycle
Drinking water certification and reciprocity.
MSDH publishes its reciprocity requirements but not a full certification schedule. The steps below summarize the program page; contact the Laboratory Certification Officer and follow your certificate for the specifics that apply to your lab.
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Contact the program
In-state labs seeking certification and out-of-state labs seeking reciprocity start with the MSDH Laboratory Certification Officer.
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Certification document
Out-of-state labs have their certifying authority forward a document listing each analyte, method, status and expiration date, plus the most recent on-site evaluation and response.
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Proficiency testing
Out-of-state labs have their PT provider forward copies of current PT study results to MSDH.
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Status changes
Changes in certification status must reach MSDH within 30 days, and failure to report may end reciprocal certification.
Initial calibration
What auditors check in your initial calibrations.
Mississippi has no separate calibration rule. The calibration requirements come from the EPA-approved methods your lab is certified for, so auditors work from the methods under 40 CFR 141 for drinking water and 40 CFR 136 for permit data.
A range that brackets what you report
The lowest standard should sit at or below your reporting limit and the highest at or above the top concentration you report. Results outside the calibrated range need to be qualified.
Error at the low end, not r² alone
A correlation coefficient of 0.999 can still hide a low standard that back-calculates 30 percent off. Auditors look at relative error, especially at the lowest levels.
Records that rebuild the curve
Raw responses, the model and weighting used, any excluded points with the reason, and the verification that followed. An auditor should be able to reconstruct every initial calibration from the record.
Calibration set by the federal methods
Mississippi does not write its own calibration rule. Most drinking water compliance samples count only if analyzed by a laboratory certified by EPA or the State. For permit data, 40 CFR 136.7 lists calibration, initial and continuing, among the quality control elements to incorporate where an approved method lacks them, and MDEQ’s permit rules call for adequate laboratory controls and appropriate quality assurance procedures.
Source: 40 CFR 141.28; 40 CFR 136.7(c)(1)(vii); 11 Miss. Admin. Code Pt. 6, Ch. 1, Rule 1.1.4.A.18
For out-of-state labs, MSDH relies on the home program’s most recent on-site evaluation and response, so the assessment your primary certifying authority performed is what Mississippi reviews.
Self-check
Are your initial calibrations ready for a Mississippi assessment?
Tick what your lab could show an auditor today. Nothing you select is saved or sent anywhere.
6Checks to work through
Select each item your lab could show an auditor today.
A self-assessment to help you prepare, not a compliance determination.
Mississippi specifics
One certification program, built on reciprocity.
The certification program MSDH describes is for drinking water. Its Public Health Laboratory runs Water Supply Laboratory certification for chemistry and microbiology, inspecting and certifying labs located in Mississippi. The same program page also covers certification of labs that test milk and dairy samples.
Out-of-state labs are not certified directly for EPA-regulated drinking water parameters. MSDH honors certification from the lab’s home state agency, may recognize NELAP accreditation specific to drinking water, and expects the certifying authority to forward the certificate, the most recent on-site evaluation and any change in status. Reciprocal labs must also phone in Maximum Contaminant Level exceedances immediately, with a written report within two weeks, and report positive total coliform or E. coli compliance samples within two hours of detection.
For wastewater, MDEQ’s list of wastewater pollution control regulations includes no laboratory certification chapter. Its NPDES permit rules reference test procedures in 40 CFR Part 136 and require adequate laboratory controls and appropriate quality assurance procedures as part of proper operation and maintenance. We found no 2025 or 2026 change to these laboratory provisions.
How WLTR helps
Calibration evidence ready for a Mississippi inspection.
WLTR independently reviews the calibration your instrument software produced. Your analyst still makes the final call. What changes is that the evidence is complete, consistent across analysts, and ready before the auditor asks for it.
- Each analyte reviewed one at a time in the instrument software.
- The model and weighting are whatever the batch was processed with.
- r² is the number most people look at, even though it does not measure error at the low end.
- QA signs off without an independent check on the curve.
- Every analyte and every candidate model side by side in the Calibration Intelligence dashboard.
- Diagnostics run automatically and the best fit curve is identified, with the reasons recorded.
- Relative error at every level, including the lowest standard, shown on one screen.
- A traceable record your QA manager can review, sign and hand to a state auditor.
See how your own ICAL data looks when every analyte and model is laid out for review.
Questions
Mississippi accreditation FAQs
Is Mississippi a NELAP state?
No. As of October 2026, no Mississippi agency is on TNI’s list of NELAP accreditation bodies. MSDH may recognize certification through a NELAP accrediting authority for drinking water reciprocity.
Who certifies drinking water labs in Mississippi?
The Environmental Services Division of the Mississippi Public Health Laboratory, Mississippi State Department of Health, which operates the Water Supply Laboratory certification program for chemistry and microbiology.
Can an out-of-state lab report drinking water data in Mississippi?
Yes, through reciprocity. MSDH does not directly certify out-of-state labs for EPA-regulated drinking water parameters, but it honors home state certification, and may recognize NELAP accreditation for drinking water, when the certifying authority forwards the certificate and on-site evaluation and the PT provider forwards current PT results.
Does Mississippi certify wastewater labs?
We found no wastewater laboratory certification program. MDEQ’s published wastewater pollution control regulations contain no laboratory certification chapter, and its NPDES permit rules reference 40 CFR Part 136 test procedures.
Does Mississippi have its own initial calibration rule?
No separate rule. Calibration requirements come from the EPA-approved methods for drinking water and, for permit data, from 40 CFR Part 136, where 136.7 lists initial and continuing calibration among its quality control elements.
Sources
Primary sources for this page.
- MSDH, Environmental Laboratory Certification Program (opens in a new tab)
- MSDH, Water Supply Certification in-state participating labs (opens in a new tab)
- Miss. Admin. Code 15-20-72, Rule 1.5.5, laboratory certification (Justia copy) (opens in a new tab)
- MDEQ, wastewater pollution control regulations (opens in a new tab)
- 11 Miss. Admin. Code Pt. 6, Ch. 1, NPDES and state permit regulations (opens in a new tab)
- TNI, NELAP accreditation bodies (opens in a new tab)
- 40 CFR 136.7, quality assurance and quality control (eCFR) (opens in a new tab)
- 40 CFR 141.28, certified laboratories (Cornell LII copy) (opens in a new tab)
This page summarizes public program information to help labs prepare. Requirements change, and the agency’s current rules and guidance always take precedence. WLTR is not affiliated with or endorsed by the Mississippi State Department of Health. Spot something out of date? Tell us at admin@wltr.tech.
Before your next assessment
See your Mississippi ICALs the way an auditor will.
Bring a recent initial calibration. We will walk you through every analyte and candidate model in the Calibration Intelligence dashboard, the best fit, and the record your QA manager would sign.
Request a demoHow the methodology works
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