Nevada NDEP
Nevada environmental lab certification, NDEP and NAC 445A.
Which Nevada program certifies your lab, which standards the code adopts, how out-of-state labs qualify, and what auditors look for in your initial calibrations.
At a glance
How environmental lab certification works in Nevada.
Nevada is not on TNI’s list of NELAP accreditation bodies. One NDEP program certifies labs for drinking water and for the state’s other environmental programs, under two parts of NAC Chapter 445A that adopt the NELAC Standards by reference.
State program (non-NELAP)
- Program
- Nevada Laboratory Certification Program, Nevada Division of Environmental Protection (NDEP). Program contacts are listed under NDEP’s Bureau of Safe Drinking Water.
- Rules
- NAC 445A.0552 to 445A.067, certification of laboratories to analyze substances in water, and NAC 445A.542 to 445A.54296, certification of laboratories to analyze drinking water
- Who needs it
- NDEP lists Safe Drinking Water, Water Pollution Control (Wastewater), Corrective Actions (Environmental Cleanup), Waste Management, and Mining Regulation and Reclamation as programs that rely on Nevada certified labs. NDEP states that not all analyses are regulated by the program.
- Standards adopted
- The NELAC Constitution, Bylaws and Standards, EPA 600/R-98/151 (NAC 445A.0608), and for drinking water the 2003 NELAC Standard, EPA/600/R-04/003 (NAC 445A.54252), each in the form most recently published by EPA
- Categories
- Analytes are certified by category under NAC 445A.0624, including trace metals, volatile organic chemistry, extractable organics, nutrients, microbiology, radiochemistry, toxicity and PCBs
- Out-of-state labs
- Must be certified by their primary accrediting body for every parameter requested, and that body must send NDEP their certificate, scope and last onsite assessment report with corrective actions. For drinking water, NAC 445A.54274 sets further conditions, including an evaluation within the prior 2 years.
- NELAP status
- Not a NELAP accreditation body as of October 2026. NAC 445A.0628 still lets a lab apply for certification by the Division or pursuant to NELAP.
The accreditation cycle
From application to renewal.
The steps below summarize NAC Chapter 445A and NDEP’s program pages. Your certificate, scope and program correspondence govern the specifics for your lab.
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Apply by category and analyte
Request an application from the program and certify each category, method and analyte you report. Out-of-state labs have their primary accrediting body send their certificate, scope and last onsite assessment report directly to NDEP.
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Proficiency testing
A certified lab must analyze a PT sample not less than once every 6 months (NAC 445A.0634 and 445A.54276). NDEP requires passing two of the last three PTs in the past 18 months, and a missed study counts as a failure.
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Inspections
NDEP inspects certified labs not less than once every 2 years (NAC 445A.0638 and 445A.5428). Inspections are announced, though the rule allows unannounced inspections.
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Annual renewal
Certificates expire July 31 of each year. Renewal requires satisfactory PT results and a statement of compliance (NAC 445A.0646).
Initial calibration
What auditors check in your initial calibrations.
Calibration expectations in Nevada come from the NELAC Standards that NAC Chapter 445A adopts by reference, from the approved methods you are certified for, and from the quality manual the rule requires you to keep.
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.
A quality manual that states your accuracy
NAC 445A.0636 requires a quality manual, adopted under section 5.5 of the NELAC Standards, that sets out the lab’s requirements for sensitivity, precision and accuracy for each method or analyte. Where a provision can be read more than one way, the more restrictive interpretation applies.
Source: NAC 445A.0608, 445A.0618 and 445A.0636
Nevada’s code adopts the NELAC Standards rather than the current TNI standard, so read your methods and quality manual against the edition the code names.
Self-check
Are your initial calibrations ready for a Nevada 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.
Nevada specifics
One program, two sets of rules.
Nevada certifies environmental labs through one NDEP program, but the code splits the work in two. NAC 445A.0552 to 445A.067 covers labs analyzing substances in water for the state’s environmental programs, and NAC 445A.542 to 445A.54296 covers drinking water. Both parts set the same July 31 expiration and the same minimum of one inspection every 2 years.
The standards are older than many labs expect. The water rule adopts the NELAC Standards published as EPA 600/R-98/151, and the drinking water rule adopts the 2003 NELAC Standard, EPA/600/R-04/003. The code still describes a NELAP certification path, but Nevada does not appear on TNI’s current list of NELAP accreditation bodies.
The drinking water part was amended by R130-22A, effective January 5, 2024, including its NELAC adoption section. In 2026, under Governor Lombardo’s Executive Order 2026-003, NDEP is reviewing all of its regulations, with a public workshop scheduled for October 26, 2026. Check for changes to Chapter 445A as of October 2026.
How WLTR helps
Calibration evidence ready for a Nevada 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 an NDEP auditor.
See how your own ICAL data looks when every analyte and model is laid out for review.
Questions
Nevada accreditation FAQs
Is Nevada a NELAP state?
No. Nevada does not appear on TNI’s list of NELAP accreditation bodies as of October 2026. NDEP certifies labs under NAC Chapter 445A, which adopts the NELAC Standards by reference.
Who certifies drinking water and wastewater labs in Nevada?
The Nevada Laboratory Certification Program at NDEP. Drinking water labs are certified under NAC 445A.542 to 445A.54296, and labs for wastewater and other programs under NAC 445A.0552 to 445A.067.
How long does Nevada certification last?
Certificates expire July 31 of each year. NDEP emails renewal applications in May, and renewal requires satisfactory PT results and a statement of compliance under NAC 445A.0646.
Can an out-of-state lab be certified in Nevada?
Yes. NDEP asks out-of-state labs to be certified by their primary accrediting body for every parameter requested, and that body must send NDEP the last onsite assessment report. For drinking water, NAC 445A.54274 also requires state or EPA certification, an equivalent state program, and an evaluation within the prior 2 years.
What are Nevada’s proficiency testing rules?
NAC 445A.0634 and 445A.54276 require a certified lab to analyze a PT sample not less than once every 6 months. NDEP requires labs to pass two of the last three PTs in the past 18 months, counts a missed study as a failure, and wants results sent directly from the PT vendor.
Sources
Primary sources for this page.
- TNI, NELAP recognized accreditation bodies (opens in a new tab)
- NDEP, Laboratory Certification (opens in a new tab)
- NDEP, applying to the program (opens in a new tab)
- NDEP, proficiency testing information (opens in a new tab)
- NAC 445A.0628, certification by Division or pursuant to NELAP (Justia copy) (opens in a new tab)
- NAC 445A.0646, renewal of certification (Justia copy) (opens in a new tab)
- NAC 445A.54252, drinking water NELAC adoption (Justia copy) (opens in a new tab)
- NAC 445A.54274, out-of-state drinking water labs (Justia copy) (opens in a new tab)
- NDEP, use of certified laboratories (Environmental Cleanup) (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 Nevada Laboratory Certification Program at NDEP. Spot something out of date? Tell us at admin@wltr.tech.
Before your next assessment
See your Nevada 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
Running environmental methods? See how WLTR works for environmental testing labs and water and wastewater utility labs.