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Functionally Equivalent BMPs

Stormwater technologies and BMPs can be approved for use in Washington State either through TAPE or by being deemed “functionally equivalent”. Functionally equivalent technologies are manufactured products that can do the work of existing BMPs found in the Stormwater Management Manual for Western Washington or the Stormwater Management Manual for Eastern Washington. These products do not need to go through the TAPE program.

Companies interested in receiving a Functionally Equivalent approval must identify the BMP in the manual for which they are seeking equivalency. They then must submit to Ecology their specifications, calculations, operation manuals and other information demonstrating they are equivalent to the BMP they’ve identified.

The Functionally Equivalent Stormwater BMP application document provides more information on the process and information required for approval. Products and companies that have gone through the review process and received Functional Equivalent approval can be found on Ecology’s webpage.