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Alternate Test Procedures to Perform Clean Water Act Monitoring in EPA's Pacific Southwest (Region 9)

When performing Clean Water Act (CWA) monitoring for National Pollutant Discharge Elimination System (NPDES) compliance, only approved analytical methods identified in 40 CFR Part 136 may be used to analyze for regulated constituents.

Parties interested in modifying one of these approved methods, or seeking to use a new method not in Part 136, must apply to use an alternate test procedure (ATP) in the Region in which the discharging facility is located. Applications are submitted to the Region upon concurrence by the State representative responsible for assisting in NPDES permitting. Contact the following individuals if interested in applying for an alternate test procedure:

Once received by the Region, applications are reviewed in accordance with procedures set forth in 40 CFR Part 136.5.

CWA Analysis and Sampling Procedures, Final Methods Update Rule (MUR) effective September 27, 2017 modifies the testing procedures approved for analysis and sampling under the Clean Water Act. The changes adopted in this final rule fall into the following categories:

  1. New and revised EPA methods (including new and/or revised methods published by voluntary consensus standard bodies (VCSB), such as ASTM International and the Standard Methods Committee);
  2. Updated versions of currently approved methods; methods reviewed under the alternate test procedures (ATP) program;
  3. Clarifications to the procedures for EPA approval of nationwide and limited use ATPs; and
  4. Amendments to the procedure for determination of the method detection limit to address laboratory contamination and to better account for intra-laboratory variability.

EPA Region 9 highlights that 40 CFR Part 136.3(e), Table II, Required Containers, Preservation Techniques, and Holding Times take precedence over those specified in the method.

EPA’s proposed update for 2019 is available at: Methods Update Rule-2019. Additional information on the ATP application process may be found on EPA's Clean Water Act Analytical Methods website, including instructions on how to apply for ATPs.