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Environmental Laboratory (NELAP) Accreditation

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

State of Texas Accreditation 

The Texas Commission on Environmental Quality (TCEQ) protects and improves the quality of the State's surface water and groundwater and ensures safe drinking water for its residents. This authority is granted in accordance with laws, policies, and rules established by the Texas Administrative Code, The NELAC Institute (TNI), and the U.S. Environmental Protection Agency. TCEQ laboratory accreditation program's rights and duties are defined by Title 30 of the Texas Administrative Code chapter 25.

Accreditation is voluntary; however, the commission may accept environmental testing laboratory data and analyses for use in commission decisions regarding any matter under the commission's jurisdiction relating to permits or other authorizations, compliance matters, enforcement actions, or corrective actions only if the data and analyses are prepared by an environmental testing laboratory accredited by TCEQ.

An environmental laboratory must be accredited if producing data for commission decisions for one of the following (after July 1, 2008): 

  • An environmental testing laboratory that provides analytical data relating to the Safe Drinking Water Act; 
  • The laboratory provides analytical data that is used for a commission decision or 
  • An in-house environmental testing laboratory is to be accredited if it allows for analytical data from a third party. 

Exceptions are listed in Title 30 of Texas Administrative Code chapter 25.6 (30 TAC 25.6). 

Application for Accreditation, Renewals, or Amendments 

Application for accreditation is for laboratories requiring accreditation by the State of Texas with TCEQ. Effective January 31, 2020, laboratories are assessed against the provisions of the 2016 TNI NELAP standard. This link has the summary of changes in the standards:  Changes to the various standards used in the National Environmental Laboratory Accreditation Program (NELAP)   

Laboratories will receive electronic copies of their certificates and scopes.  Hard copies will not be mailed.  

An application is used to renew a laboratory's accreditation or amend the laboratory's scope of accreditation. Please review the instructions on page 14 of the application before application completion. The application can be found at the link below: 

Submit all laboratory accreditation-related documents electronically.  There is no need to follow up with hard copies. 

The initial turnaround time for an application review is 45 days. Approval may take longer due to requests for additional information from the laboratory. Submission of requested documents promptly will ensure efficient application processing. Application progress can be checked here: 

Accreditation applications in progress 

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

The payment mailing address for USPS delivery is: 

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

The payment physical address for overnight/non-USPS (ex: FedEx) mail deliveries is: 

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

IMPORTANT NOTE: TCEQ will not process your application until all fees have been received. All fees associated with accreditation are nonrefundable if the laboratory chooses to withdraw or a denied application. Contact us to verify fee calculations before sending any monies. Our phone number is (512) 239–3754. You may also email us at 

State Rules for Fees and Accreditation 

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

General information about the fees relating to accreditation can be accessed in the Texas Administrative Code for environmental testing laboratory accreditation and certification. 

Suspending and Revoking Accreditation

The Program Manager or designee may initiate action to suspend a laboratory’s accreditation according to 30 TAC Chapter 80 , Contested Case Hearings. Reasons to deny accreditation application and revocation of accreditation, in whole or in part, are specified in 30 TAC 25.32 Reasons to suspend a laboratory’s accreditation, in whole or in part, are specified in 30 TAC 25.34 , Suspension of Accreditation. 

Laboratory Accreditation Procedure 6.0 Suspension and Revocation describes the requirements of concerning the suspension and revocation of laboratory accreditation, reinstatement of suspended accreditations, and appeals of suspensions and revocations.

Dropping Matrix, Method, and/or Analyte from Laboratory Field of Accreditation 

If the laboratory opts to drop a matrix, method, and/or analyte from the field of accreditation, the laboratory must submit a signed letter, which can be found here:   

If the laboratory has removed a matrix, method, and/or analyte that was previously accredited, it will have to go through the amendment process to add it back to the laboratory's field of accreditation. See the Application for Accreditation, Renewals, or Amendments process above. 

Application for Technical Manager 

Technical manager qualifications are based on one of the following general categories:  

  • education and experience;  
  • previous recognition or  
  • exceptions.  

To be recognized as a Technical Manager, an individual must meet the requirements from TNI V1M2 and the specific paragraphs within the standard for the different areas of recognition (e.g., chemistry, microbiology, etc.). A Technical Manager can also be recognized based on exceptions/previous recognition per TNI V1M2 

Technical Manager Qualification Form 

Fields of Accreditation 

Fields of accreditation (FoA) are the matrix, technology/method, and analyte combinations for which an environmental testing laboratory may be accredited. TCEQ's Laboratory Accreditation Program's FoAs can be found at the link below: 

Fields of Accreditation 

TNI LAMS is a central repository for information regarding the accreditation status of environmental laboratories.

The following link details the changes to TCEQ's FoAs: 

History of Changes to the Fields of Accreditation 

List of Accredited Laboratories 

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

List of Accredited Laboratories 

For accessibility purposes, the list will open as a Word document with the list of laboratories accredited by TCEQ's Laboratory Accreditation Program under the standards adopted by the National Environmental Accreditation Program (NELAP). To access the interested laboratory's list of accredited analytes and methods, click the link under the Field of Accreditation column. An Excel document will open.  

TNI Checklists  

The accreditation team verifies laboratory compliance with The NELAP Institute's (TNI)  2016 Quality Systems standard using the checklist below. The Quality Systems checklist contains copyright-protected language from ISO/IEC 17025:2005. 

 A copy of the TNI checklist is available directly from TNI's web page: 

2016 TNI Quality Systems checklist  

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. If you have a copy, please ensure your copy is the 2016 version. 

TCEQ Laboratory Accreditation Procedures 

TCEQ's Laboratory Accreditation Team utilizes the procedures to ensure compliance with TNI's 2016 version of Volume 2 (EL-V2-2016-Rev 2.0) for accrediting bodies. The link below has been updated as revisions have been issued. 


TCEQ Laboratory Accreditation Assessors 

Laboratory accreditation staff have switched to a hybrid work schedule, with the bulk of the time spent working remotely.  

Laboratory accreditation staff will not have immediate access to their phones.  They will check their messages periodically; however, a response may be delayed.  If possible, send an email message in conjunction with the voice message, as staff can access their emails immediately. 

TCEQ Operating Budget

TCEQ laboratory accreditation program is a part of the environmental agency for the state. The operating budget can be found here: About Us - Texas Commission on Environmental Quality -

Subscribe to Laboratory Accreditation Program email updates. 

Go to this link: Get email or text updates on your choice of topics. 

After entering your email address or phone number, select "Environmental Laboratory Accreditation" from the list. You can unsubscribe at any time. 

Laboratory Actions

Appeals for Nonconformities

If the laboratory does not agree with a nonconformity, then the laboratory may reach out to the lead assessor who will forward the appeal to the Program Manager. The Program Manager will decide outcome of the appeal and notify the laboratory.

Corrective Actions and TCEQ's Corrective Action Response (CAR) Form 

A corrective action (CA) is an action taken to address the effect(s) of a nonconformity, defect, or other undesirable situation (e.g., repair, rework); eliminate the causes of the nonconformity, defect, or other undesirable situation; and prevent recurrence. Some corrective actions must address critical nonconformities that significantly affect data quality or defensibility, including any repeat deficiencies from a previous assessment. 

This form must be used by a laboratory to respond to a nonconformity identified during their TCEQ assessment.  

CAR form 

The following link supplies instructions and guidance for completing the CAR form and addressing C.A.s effectively: 

CAR form instructions 

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

Method Update Rule (MUR) for Laboratories 

These are revisions to laboratory methods for non-potable water and drinking water, adding to FoAs for proficiency testing, and how these apply to your lab's accreditation. 

MUR information 

Frequently Asked Questions  

These questions are addressed in the FAQ guide (PDF) about questions regarding TCEQ's environmental laboratory accreditation program: 

 FAQ guides 



To make a complaint, please get in touch with the program manager at 

Contact Us 

Our email address: 

This email is being monitored in real-time during regular office hours. 

If you are sending administrative information, please include "Attention: Records Specialist" in the subject line of your email. 

If you require additional information, including suitable ways to obtain measurement traceability, please include "Attention: Program Manager" in your email's subject line. 

Our mailing address for USPS delivery 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/non-USPS delivery (ex: FedEx) is: 

Texas Laboratory Accreditation Program 

Texas Commission on Environmental Quality 

12100 Park 35 Circle, Bldg. B, MC-165 

Austin, TX 78753 


Helpful Internal resources 

TCEQ Method Update Rule (MUR) for Laboratories 

TCEQ Air Quality 

TCEQ Public Drinking Water  

TCEQ Surface Water Quality Monitoring  

TCEQ Unregulated Contaminated Monitoring Rule 


Helpful External Links 

Note some of these sites may require a subscription 


The NELAC Institute links: 

The NELAC Institute (TNI)   

National Environmental Laboratory Accreditation Program (NELAP) designated proficiency testing providers.   

NELAP Fields of Proficiency Testing   


EPA links: 

EPA-Approved CWA Chemical Test Methods  

EPA-Approved CWA Microbiological Test Methods  

EPA Definition and Procedure of the Method Detection Limit (MDL)  

EPA Solid Waste Manual 846 (SW-846)  

EPA Methods Update Rules (MUR) 


Other links: 

Federal Register  

Code of Federal Regulations (CFR)  

40 CFR 136 : Guidelines Establishing Test Procedures for the Analysis of Pollutants 

40 CFR 141: National Primary Drinking Water Regulations  

Standard Methods