Tennessee TDEC
Tennessee drinking water lab certification, TDEC and the EPA manual.
Who certifies drinking water labs in Tennessee, which rule and manual apply, how out-of-state labs qualify, and what auditors look for in your initial calibrations.
At a glance
How drinking water lab certification works in Tennessee.
Tennessee is not a NELAP accreditation body. The Laboratory Certification Program in TDEC’s Division of Water Resources certifies drinking water labs under the public water system rules, which tie certified labs to the EPA drinking water certification manual.
Drinking water lab certification
- Program
- Laboratory Certification Program (LCP), Division of Water Resources, Tennessee Department of Environment and Conservation
- Legal basis
- Tenn. Comp. R. & Regs. 0400-45-01-.14, Laboratory Certification, within Chapter 0400-45-01, Public Water Systems
- Who needs it
- Under 0400-45-01-.14(1)(a), drinking water sample analyses may be considered only if they were analyzed by a laboratory certified by the Department. Certified labs are designated state-certified laboratories.
- Scope
- The LCP certifies labs for chemistry, microbiology and radiochemistry parameters and Cryptosporidium. The TDEC program pages cited here describe drinking water certification and do not describe a program for wastewater or other environmental labs.
- Quality standard
- Certified labs must comply with the latest edition of the EPA Manual for the Certification of Laboratories Analyzing Drinking Water, except where it differs from the chapter (0400-45-01-.14(1)(h)). TDEC guidance cites the 5th edition, January 2005.
- Out-of-state labs
- TDEC states that labs outside Tennessee may be certified by reciprocity, and the rule lets the Department authorize acceptance of analyses from labs certified by other states or by EPA (0400-45-01-.14(8)).
- NELAP status
- Not a NELAP accreditation body as of October 2026. TDEC certifies drinking water labs under its own rule.
The accreditation cycle
From application to on-site audit.
The steps below summarize Rule 0400-45-01-.14 and TDEC’s Laboratory Certification Program guidance. Your certificate and LCP correspondence govern the specifics for your lab.
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Apply with records
Submit the application with proof that the lab successfully completed proficiency testing or performance evaluation samples. TDEC’s microbiological requirements also call for the lab’s Quality Assurance Plan and an on-site evaluation by a certification officer.
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Certification rating
A lab that meets all criteria and has completed PT is rated Certified. A lab that has failed a PT, reported compliance data late, or fallen short of the required quality may be rated Provisionally Certified.
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Annual PE samples
To hold full certification for an analyte, labs must analyze performance evaluation samples (if available) acceptable to the Department at least once a year (0400-45-01-.14(9)(a)1).
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Three-year on-site audit
Certified labs must have an on-site audit by the certification officer every three years (0400-45-01-.14(1)(d)).
Initial calibration
What auditors check in your initial calibrations.
Tennessee’s certification rule points to the EPA drinking water certification manual rather than a TNI module, so a certification officer reviews your calibrations against that manual and the chapter’s own requirements.
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.
The EPA manual, adopted by rule
Rule 0400-45-01-.14(1)(h) requires certified labs to comply with all requirements in the latest edition of the EPA Manual for the Certification of Laboratories Analyzing Drinking Water, except where they differ from the chapter. Your calibration and quality control records are reviewed against that manual.
Source: Tenn. Comp. R. & Regs. 0400-45-01-.14(1)(h)
TDEC’s guidance names the 5th edition of the EPA manual, dated January 2005, and EPA still lists the Fifth Edition with its supplements. Confirm with the Laboratory Certification Program which supplements your audit will apply.
Self-check
Are your initial calibrations ready for a Tennessee 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.
Tennessee specifics
In Tennessee, the EPA manual is the yardstick.
Tennessee does not certify to the TNI standard. Rule 0400-45-01-.14 requires certified labs to follow the latest edition of the EPA Manual for the Certification of Laboratories Analyzing Drinking Water, except where the chapter sets something different, and TDEC’s guidance cites the 5th edition of January 2005. TDEC’s microbiological requirements ask for the lab’s Quality Assurance Plan with the application, and certification depends on PT results and an on-site evaluation.
Out-of-state labs have a route in. TDEC states that labs outside Tennessee may be certified by reciprocity, supported by documentation of an audit by the lab’s home or parent state, and the rule lets the Department authorize acceptance of analyses from labs certified by other states. TDEC’s list of laboratories certified for drinking water analyses, dated August 19, 2025, includes a section for out-of-state laboratories.
Keeping certification is a recurring obligation. The rule calls for performance evaluation samples at least once a year and an on-site audit every three years, and a provisional status may last up to one year plus any extension. The program pages cited here cover drinking water; they do not describe a TDEC certification program for wastewater labs.
How WLTR helps
Calibration evidence ready for a Tennessee audit.
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 TDEC certification officer.
See how your own ICAL data looks when every analyte and model is laid out for review.
Questions
Tennessee accreditation FAQs
Is Tennessee a NELAP state?
No. TDEC is not on TNI’s list of NELAP accreditation bodies as of October 2026. It certifies drinking water labs under its own rule, 0400-45-01-.14.
Who certifies drinking water labs in Tennessee?
The Laboratory Certification Program in the Division of Water Resources, Tennessee Department of Environment and Conservation, for chemistry, microbiology and radiochemistry parameters and Cryptosporidium.
Can an out-of-state lab be certified in Tennessee?
Yes. TDEC states that labs outside Tennessee may be certified by reciprocity, with documentation of an audit by the home or parent state, and Rule 0400-45-01-.14(8) lets the Department authorize acceptance of analyses from labs certified by other states.
How often are PT samples and audits required?
Rule 0400-45-01-.14 requires performance evaluation samples (if available) acceptable to the Department at least once a year and an on-site audit by the certification officer every three years.
Does Tennessee have its own calibration rule?
The rule ties certified labs to the latest edition of the EPA Manual for the Certification of Laboratories Analyzing Drinking Water, except where the chapter differs, so a certification officer reviews calibration and quality control records against that manual.
Sources
Primary sources for this page.
- TDEC, Laboratory Certification Program (opens in a new tab)
- TDEC, microbiological laboratory certification requirements (opens in a new tab)
- TDEC, laboratories certified for drinking water analyses (opens in a new tab)
- Tenn. Comp. R. & Regs. 0400-45-01-.14 (Justia copy) (opens in a new tab)
- Chapter 0400-45-01, Public Water Systems (Cornell LII copy) (opens in a new tab)
- TNI, NELAP accreditation bodies (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 Tennessee Department of Environment and Conservation. Spot something out of date? Tell us at admin@wltr.tech.
Before your next assessment
See your Tennessee ICALs the way a certification officer 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
Running environmental methods? See how WLTR works for environmental testing labs and water and wastewater utility labs.