Virginia DCLS and VELAP
Virginia environmental lab accreditation, VELAP and the DCLS rules.
Which Virginia rule applies to your lab, how commercial, non-commercial and drinking water labs are assessed, how out-of-state labs qualify, and the calibration rules written into the code.
At a glance
How environmental lab accreditation works in Virginia.
Virginia’s Department of General Services is a NELAP accreditation body as of October 2026. Its Division of Consolidated Laboratory Services (DCLS) applies three separate rules depending on whether a lab is commercial, non-commercial or drinking water only.
NELAP accreditation body
- Program
- Virginia Environmental Laboratory Accreditation Program (VELAP), run by the Division of Consolidated Laboratory Services, Department of General Services
- Commercial labs
- Commercial labs testing for compliance with the Virginia Air Pollution Control Law, the Virginia Waste Management Act or the State Water Control Law must hold accreditation under 1VAC30-46, which applies the 2016 TNI Standards from October 1, 2022 under the April 1, 2022 amendments (1VAC30-46-15).
- Non-commercial labs
- Typically municipal or industrial labs providing analytical data for their owner. They are certified under 1VAC30-45, which sets its own quality system standards.
- Drinking water
- Labs testing drinking water for microbiological or chemistry parameters may be certified under 1VAC30-41 and the EPA drinking water certification manual. Commercial labs may instead include drinking water in their 1VAC30-46 accreditation.
- Outside these rules
- Labs owned by citizen monitoring groups meet DEQ quality assurance requirements instead of 1VAC30-45 or 1VAC30-46, and Virginia higher education labs doing research for DEQ are exempt unless DEQ requires otherwise (1VAC30-45-30).
- Out-of-state labs
- DCLS does not provide primary TNI accreditation to labs in other states that offer it. Labs accredited by another NELAP-recognized body may apply for secondary accreditation (1VAC30-46-140). Drinking water reciprocity is under 1VAC30-41-90.
- NELAP status
- The Department of General Services is a NELAP accreditation body accrediting to the 2016 TNI Environmental Laboratory Sector Standard.
The accreditation cycle
From application to renewal.
The steps below summarize 1VAC30-46 for commercial labs, with the non-commercial and drinking water differences noted. Your certificate and DCLS correspondence govern the specifics for your lab.
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Apply by field
Primary applicants under 1VAC30-46 submit two successful unique TNI-compliant PT studies for each field of accreditation.
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One-year accreditation
Accreditation and certification expire one year after they are granted. DCLS renews annually when the lab maintains compliance, signs the compliance certificate and reports acceptable PT results.
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Proficiency testing
Commercial PT requirements follow Volume 1, Module 1 of the 2016 TNI Standard. Non-commercial labs keep at least one acceptable PT study each calendar year, completed by September 30. Drinking water labs complete at least one WS PT study per calendar year.
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On-site assessment
Commercial labs are assessed initially and every two years. Non-commercial and drinking water labs are assessed at least once every three years, and DCLS may assess non-commercial labs every two years after certain non-compliances.
Initial calibration
What auditors check in your initial calibrations.
Commercial labs are assessed against the 2016 TNI Standards that 1VAC30-46 incorporates by reference. Non-commercial labs are assessed against 1VAC30-45, which writes its calibration requirements into the code itself.
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 rules written into 1VAC30-45
1VAC30-45-740 requires every initial calibration to be verified with a standard from a second manufacturer or lot, sets 0.995 or greater for the calibration coefficient unless the method specifies otherwise, requires the lowest standard to be above the detection limit, and sets a minimum of two standards when the method is silent.
Source: 1VAC30-45-740
1VAC30-45-740 also requires raw data sufficient to reconstruct each initial calibration, and an SOP for choosing the number of calibration points. Commercial labs meet the equivalent TNI requirements under 1VAC30-46.
Self-check
Are your initial calibrations ready for a Virginia 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.
Virginia specifics
One agency, three rules.
Which rule applies depends on who the lab works for. A commercial lab is accredited to the TNI standard under 1VAC30-46. A municipal or industrial lab reporting its own data is certified under 1VAC30-45. A lab that only tests drinking water continues under 1VAC30-41, while a commercial lab may fold drinking water into its 1VAC30-46 accreditation.
The difference matters for calibration. 1VAC30-46 points to the 2016 TNI Standards, but 1VAC30-45 states its own requirements: second-source verification, a 0.995 calibration coefficient unless the method says otherwise, a lowest standard above the detection limit, and records that permit reconstruction of the curve. An assessor reviewing a non-commercial lab works from that section.
As of October 2026 the rules are stable. Periodic reviews of both 1VAC30-45 and 1VAC30-46 concluded in July 2026 with the decision to retain each regulation with no changes. The drinking water rule, 1VAC30-41, was last amended effective August 14, 2024.
How WLTR helps
Calibration evidence ready for a Virginia assessment.
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 DCLS assessor.
See how your own ICAL data looks when every analyte and model is laid out for review.
Questions
Virginia accreditation FAQs
Is Virginia a NELAP state?
Yes. TNI lists the Virginia Department of General Services as a NELAP accreditation body accrediting to the 2016 TNI Environmental Laboratory Sector Standard. DCLS runs the program as VELAP.
Who needs accreditation under 1VAC30-46?
Commercial labs testing for compliance with the Virginia Air Pollution Control Law, the Virginia Waste Management Act or the State Water Control Law. Non-commercial labs, typically municipal or industrial, are certified under 1VAC30-45 instead.
Can an out-of-state lab be accredited in Virginia?
DCLS does not provide primary TNI accreditation to labs in other states that offer TNI accreditation. A lab accredited by another NELAP-recognized body may apply for secondary accreditation under 1VAC30-46-140. For drinking water, reciprocal certification is available under 1VAC30-41-90, and out-of-state labs holding NELAP drinking water accreditation apply under 1VAC30-46.
How long does Virginia accreditation last?
One year. Both 1VAC30-46 and 1VAC30-45 state that accreditation or certification expires one year after it is granted, and 1VAC30-41 certifies drinking water labs for one year. DCLS renews annually.
Does Virginia have its own initial calibration rule?
For non-commercial labs, yes. 1VAC30-45-740 requires second-source verification, a 0.995 or greater calibration coefficient unless the method specifies otherwise, a lowest standard above the detection limit and at least two standards when the method is silent. Commercial labs follow the 2016 TNI Standards under 1VAC30-46.
Sources
Primary sources for this page.
- TNI, NELAP accreditation bodies (opens in a new tab)
- DCLS, commercial environmental laboratories (VELAP) (opens in a new tab)
- DCLS, non-commercial environmental laboratories (opens in a new tab)
- DCLS, drinking water laboratories (opens in a new tab)
- 1VAC30-46, commercial environmental laboratories (opens in a new tab)
- 1VAC30-45, non-commercial environmental laboratories (opens in a new tab)
- 1VAC30-45-740, measurement traceability and calibration (opens in a new tab)
- 1VAC30-41, drinking water laboratories (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 Virginia Department of General Services. Spot something out of date? Tell us at admin@wltr.tech.
Before your next assessment
See your Virginia ICALs the way an assessor 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.