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Analytical Methods for Drinking Water

Learn about Drinking Water Analytical Methods

On this page:

What are Analytical Methods?

Analytical methods are procedures used to measure the amount of particular contaminants in water samples.

Analytical methods generally describe how to:

  • Collect, preserve, and store the sample
  • Gather, separate, identify, and measure contaminants in the sample
  • Meet quality control criteria
  • Report the results of the analysis

In general, an analytical method:

  • Applies to routine analyses of samples
  • Measures the drinking water contaminant(s) within a specific upper and lower limit
  • Provides data that are required to:
    • Demonstrate compliance, or
    • Meet monitoring objectives in a wide variety of drinking water conditions
  • Incorporates appropriate quality control criteria so that acceptable method performance is demonstrated during sample analysis

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Who Develops Methods?

EPA uses the Alternate Test Procedure Program to evaluate analytical methods from a variety of sources.

Methods are developed by:

  • EPA or other governmental organizations
  • Consensus method organizations such as Standard Methods and ASTM, International
  • Universities
  • Water laboratories
  • Commercial vendors

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How does EPA Approve Methods?

EPA approves methods:

  • When regulating new contaminants or through other rulemaking actions
  • Using the expedited approval process

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Who Uses the Methods?

Laboratories supporting public water systems must use EPA-approved analytical methods when analyzing samples to:

  • Meet federal monitoring requirements
  • Demonstrate compliance with drinking water regulations

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