Alternate Test Procedures

The Clean Water Act Alternate Test Procedure (ATP) program is described at 40 CFR 136.4 and 40 CFR 136.5. This program allows a developer to ask for review (not approval) of a:

1. Method using a determinative technique (e.g., a pollutant detector) different from that in an existing Part 136 method, or
2. Modification to a Part 136 method that falls outside the scope of the modification flexibility described in the Part 136 method, or at 40 CFR 136.6.

A method developer may apply for review of a method modification or a new method through the ATP program.

Part 136.6 Flexibility to Modify Methods

If you use a modification to an approved 40 CFR Part 136 method and document the modification as described at 40 CFR Part 136.6, you will no longer receive or require a letter from EPA. The March 12, 2007 Methods Update Rule (MUR)  that promulgated 40 CFR 136.6 allows the regulated community more flexibility to modify approved methods without EPA review.

This regulation allows the analytical community greater flexibility to modify approved methods to lower the costs of measurements, overcome matrix interferences, or otherwise improve the analysis without EPA review. Laboratories that modify 40 CFR Part 136 methods may be private, public or commercial and may conduct analyses for one or more clients or facilities.