Clean Water Act Analytical Methods

How to Get Methods Approved


The Clean Water Act requires EPA to establish testing procedures for analysis of pollutants through a formal notice and comment rulemaking process. These testing methods must be used for measuring pollutants for NPDES permit applications and any NPDES reporting requirements. The Office of Science and Technology (OST) within EPA’s Office of Water (OW) is responsible for developing, reviewing and promulgating these methods as well as developing alternatives to existing methods.

Methods Update Rules

Because promulgating methods through individual rulemakings would be very resource-intensive, OW periodically combines new methods and modifications to existing methods into a single package – a proposed “methods update rule” (MUR). Once EPA promulgates final rules, EPA codifies the approved methods at 40 CFR Part 136. These approved methods must be used for determining compliance with pollutant discharge limitations.

For its MURs, OST considers new or revised methods from two major sources. One is EPA’s Alternate Test Procedure (ATP) program. Under this program, method developers submit an application for a proposed new method or modification to an approved Part 136 method – an “alternative method” – directly to OST for evaluation for nationwide use. There are established, formal protocols for the ATP program that lay out specific requirements for submitting methods/modifications for consideration.

VCSB Methods

The second major source for new or revised methods is those methods that are adopted by a voluntary consensus standards body (VCSB) such as ASTM International and Standard Methods, or another government agency such as the United States Geological Survey. VCSBs may submit methods and modifications to OST under the provisions of the National Technology Transfer and Advancement Act (NTTAA). The NTTAA requires EPA to adopt methods approved by VCSBs, unless doing so would be inconsistent with applicable laws or is otherwise impractical. When VCSBs or other government agencies submit adopted methods for consideration, they must include the method in its final form, documentation that it has been approved/published by that VCSB or agency, the validation study plan, and the validation study report, including data and analysis that supported the method’s development and adoption. The VCSB or agency must comply with its own internal method testing criteria (e.g., ASTM D2777).