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Environmental Laboratory (NELAP) Accreditation

This page offers information on the Agency's National Environmental Laboratory Accreditation Program (NELAP)

Effective January 31, 2020, laboratories are assessed against the provisions of the 2016 TNI NELAP standard.

Please see link for summary of changes below.

Changes to the various standards used in the National Environmental Laboratory Accreditation Program (NELAP)Exit the TCEQ(PDF)


COVID 19 Response procedures

UPDATE 1.1 (replaces Update 1):

The Texas Capital Metro area has issued a stay-at-home order for all residents.  As a result, laboratory accreditation staff may not have immediate access to mail deliveries until the order is rescinded.  In an effort to ensure submitted documents are available to laboratory accreditation staff for processing as expeditiously as possible, we are requesting laboratories adhere to the following until the situation has returned to full normality.

1.  Submit all laboratory accreditation payments to the TCEQ revenue section at the following address.  Do not submit them directly to the TCEQ Laboratory Accreditation Program.

Texas Commission on Environmental Quality
Cashier's Cage
P.O. Box 13088, MC-214
Austin, TX 78711-3088

Their physical address for overnight/non US mail deliveries is:

Texas Commission on Environmental Quality
Cashier's Cage
12100 Park 35 Circle
Austin, TX 78757

2.  Submit all laboratory accreditation-related documents electronically. 

3.  If you do not know the e-mail address of the individual recipient, please use the mailbox, which is being monitored in real time during regular office hours. 

If you have any questions about these directives, please contact the TCEQ Laboratory Accreditation Program at

COVID 19 notification:

In response to the COVID 19/Coronavirus, TCEQ Laboratory Accreditation Program (LAP) personnel are working remotely.  The LAP will continue to operate during this time with the following exceptions:

  1. TCEQ is now doing limited assessments after consultation with the laboratory.  Laboratories with scheduled assessments by third-party assessors may contact the assessors directly to discuss the viability of the onsite assessment at the scheduled time.  Any rescheduling of the onsite assessment will not affect the laboratory’s accreditation renewal.
  2. LAP personnel will not have immediate access to their phones.  They will be checking their messages periodically; however, there may be a delay in a response.  If possible, send an email message in conjunction with the voice message as LAP personnel have immediate access to their emails.  In addition, the LAP will be monitoring and responding to email messages sent to
  3. Laboratories will receive electronic copies of their certificates and scopes.  Hard copies will not be mailed.

The TCEQ LAP encourages laboratories to ensure the safety of their employees, and understands there may be some disruptions to normal operations.  Any laboratories that are closing due to COVID19 need to notify the TCEQ LAP as soon as possible.  In addition, the TCEQ will evaluate situations where a laboratory is unable to fulfill any requirements in the standard as a result of disruptions from COVID 19 on a case-by-case basis.

The TCEQ will be providing updates on our web page and through our laboratory email notification system as the situation changes.

Additions to the TCEQ's Fields of Accreditation (FoAs) - MUR and Drinking Wate

On April 12, 2019, the TCEQ Laboratory Accreditation Program issued a revision to its Fields of Accreditation (FoAs) to include the following analytical methods:

EPA 608.3, EPA 624.1, and EPA 625.1 in Non-Potable Water; and

SM 4500-Cl¯ B, and ASTM D516-11 in Drinking Water.

The fields were revised to incorporate revised methods from the most recent Method Update Rule (MUR) and add methods requested by the TCEQ Drinking Water Program. The additional methods and analytes are shown in Appendix A.

Appendix A (PDF)

The TCEQ Water Quality Division (WQD) will accept analytical data from accredited and in-house laboratories based on the previous Method Update Rule (2012) up to but not beyond August 28, 2019. The WQD will accept analytical data from non-accredited and in-house laboratories using the new laboratory methods in the current Methods Update Rule (2017) within six months after the FOA effective date or if the laboratory has accreditation for the pollutant and new method in a state other than Texas. For questions regarding what data will be accepted, please contact the TCEQ WQD at 512-239-4539 or For questions regarding the two new Drinking Water methods, please contact the Quality Assurance Officer for the Water Supply Division at 512-239-4691 or

In order to add any of these additional parameters to an existing scope of accreditation, a laboratory must submit:


  • An amended application
  • Applicable FoA sheets
  • A $250.00 administrative fee
  • Associated documentation including:
    • Standard Operating Procedures
    • Demonstrations of Capability and Method Detection Limit Studies
    • Applicable PT results for all parameters being added (that are also Fields of Proficiency Testing (FoPTs) )


  • An amended application
  • Applicable FoA sheets
  • A $250.00 administrative fee

Note: The laboratory will not have to pay the $250 administrative fee to change their scope of accreditation if it is done as part of the laboratory’s annual renewal. Any applicable category fees will still apply. If a laboratory has submitted PT results for EPA Methods 608, 624, and 625, they are not required to submit PT results for EPA Methods 608.3, 624.1 and 625.1.

TCEQ will review applications in the order they are received. Laboratories submitting incomplete or inaccurate applications will be notified of the deficiencies and will need to submit a corrected application. The corrected applications will be placed in the queue based on the date TCEQ receives the corrected application. Due to the time required to review the applications, any initial or corrected application received after May 28, 2019, may not be reviewed by August 28, 2019.

Link to the EPA Methods Update Rule - 2017 web pageExit the TCEQ

Subscribe to Laboratory Accreditation Program e-mail updates

Go to this link: Get e-mail updates on your choice of topics.Exit the TCEQ

After entering your e-mail address and personal preferences, mark the Laboratory Accreditation / Environmental Laboratory (NELAC) Accreditation box.

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Application, Fields of Accreditation, Checklists, and Procedures

Application (PDF) (Revision 10 - February 2020)

Fields of Accreditation (FoAs) (PDF) (Revision 18 - April 2019)

Technical Manager Qualification Form (PDF) (Revision 0 - February 2020)

History of changes to the Fields of Accreditation (PDF)

The current list of accredited laboratories, with links to their scope of accreditation, can be accessed here:

List of Accredited Laboratories (PDF)

The accreditation team uses the 2016 TNI Quality Systems checklist Exit the TCEQ to determine each laboratory's conformance to the elements of this Standard. A copy of the TNI checklist is now available directly from their web page.

Be advised that you must have a copy of the TNI Standard ELV1, Management and Technical Requirements for Laboratories Performing Environmental Analyses (2016) before you may download this checklist.

TCEQ (Internal) Accreditation Procedures (PDF)

Accreditation applications in progress (PDF)

For administrative information, please contact our records specialist at 512/239-3754 or e-mail us at

For additional information, including suitable ways to obtain traceability of measurements, or to make a complaint, please contact the program manager at 512/239-1990 or e-mail us at

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Laboratory Resources

FAQ guides. This is a document addressing frequently asked questions regarding the Texas laboratory accreditation program:

FAQ guides (PDF)

Corrective Action Response (CAR) form.

CAR form (Word)

Corrective Action Response Guidelines For TCEQ Accredited Laboratories (Presentation from 2017 Trade Fair) (Powerpoint)

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External Links

The NELAC Institute (TNI) Exit the TCEQ

National Environmental Laboratory Accreditation Program (NELAP) designated proficiency testing providers Exit the TCEQ

NELAP Fields of Proficiency Testing Exit the TCEQ

Link to the EPA Methods Update Rule - 2017 web pageExit the TCEQ

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Our mailing address is:

Texas Laboratory Accreditation Program
Texas Commission on Environmental Quality
P.O. Box 13087, MC-165
Austin, TX 78711-3087

Our physical address for overnight mail delivery is:

Texas Laboratory Accreditation Program
Texas Commission on Environmental Quality
12100 Park 35 Circle, Bldg B, MC-165
Austin, TX 78753

Rules (Including Fees) and Accreditation Standards

Title 30, Texas Administrative Code, Chapter 25Exit the TCEQ , Subchapters A and B (for a schedule of fees refer to §25.30)

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