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Method Update Rule (MUR) for Laboratories

Revisions to lab methods for non-potable water and drinking water, adding to fields of accreditation (FoAs) for proficiency testing, and how these apply to your lab’s accreditation.

In 2019, the TCEQ Laboratory Accreditation Program revised its fields of accreditation (FoAs) to include the following analytical methods:

  • Non-Potable Water: EPA 608.3, EPA 624.1, and EPA 625.1
  • Drinking Water: SM 4500-Cl¯ B, and ASTM D516-11

This revision incorporates methods from the most recent Method Update Rule (MUR) and adds methods that the TCEQ Drinking Water Program requested. Find the additional methods and analytes in Appendix A: Analytes and Methods for Water Quality Testing Adobe Acrobat PDF Document.

Applying to Add to Your Labs’ Accreditation

To add any of the additional parameters listed in Appendix A (above) to an existing scope of accreditation for your lab, submit the following, depending on whether your lab is accredited as a Primary Lab or Secondary:

Primary Labs

  • 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 proficiency testing (PTs) results for all parameters being added [that are also fields of proficiency testing (FoPTs)]

Secondary Labs

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

Note: Your laboratory will not have to pay the $250 administrative fee to change the scope of accreditation if it is done as part of the laboratory’s annual renewal. Any applicable category fees will still apply. If your laboratory has submitted PT results for EPA Methods 608, 624, and 625, you 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. Corrected applications will be placed in the queue based on the date received.

For application forms and where to send them, see our NELAP Accreditation webpage.

Need More Information?

For questions about what data will be accepted, contact the TCEQ Water Quality Division at 512-239-4539 or

For questions about the two new Drinking Water methods, contact the quality assurance officer for the Water Supply Division at 512-239-4691 or

For more information about the EPA methods see the EPA Methods Update Rules