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  1. Home
  2. Certification of Laboratories for Drinking Water

Learn About Laboratory Certification for Drinking Water

On this page:
  • Laboratory role
  • Proficiency testing studies
  • Laboratory integrity
  • Certification officer training

Laboratory role

Certified laboratories use approved methods to analyze drinking water compliance samples from public water systems (PWSs). This provide the PWSs with reliable information on the quality of their water. The laboratory results are used to monitor PWS compliance with health-based and aesthetic standards.

Laboratories must:

  • Be certified by EPA or the state to analyze drinking water samples for compliance monitoring
  • Successfully analyze proficiency testing (PT) samples at least annually for each method and analyte for which they desire certification
  • Use approved methods
  • Pass periodic on-site audits

Proficiency testing studies

Many states use PT providers accredited by the American Association for Laboratory Accreditation (A2LA) or the American National Standards Institute (ANSI)-American Society for Quality (ASQ) National Accreditation Board/ACLASS.

State certification programs may:

  • Require laboratories to participate in a specific PT program or permit participation in any accredited PT study
  • Elect to serve as PT study providers themselves
  • Require PWSs to have their PT results sent directly to the state by the PT study provider
  • Increase the frequency of PT studies

Laboratory integrity

EPA recommends that state laboratory certification programs and certified labs develop standard operating procedures for consistently producing drinking water analytical results that are reliable.

Developing standard operating procedures:

  • Deters fraud
  • Helps ensure appropriate practices
  • Helps maintain the integrity of drinking water analytical results

If you suspect fraudulent or inappropriate activity related to drinking water analysis, contact your state, your EPA region, or EPA’s Office of Enforcement and Compliance Assurance.

If the suspected fraud involves laboratories that do business with EPA, contact EPA’s Office of Inspector General.


Certification officer training

EPA conducts chemistry and microbiology certification officer training courses, typically annually. In general, training attendees:

  • Are experienced professionals nominated by their regional laboratory certification program manager to attend the training
  • Have at least a bachelor's degree or equivalent education, experience or both in the discipline they will certify
  • Have recent laboratory experience in the discipline they will audit

Certification of Laboratories for Drinking Water

  • Learn About Laboratory Certification
  • Laboratory Certification Manual
  • Contact Information for Certification Programs and Certified Laboratories
Contact Us About Certification of Laboratories for Drinking Water
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on July 30, 2024
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