Interesting. I was not aware that the EPA and Corp were expanding the definition of "waters of the US" under 404 regulations. The original definition was broad. It would be a simple exercise to research it but based on memory it goes back to the 70s and probably the Jimmie Carter Era. I was working for Tesoro Coal Company. Tesoro submitted comments on the original definition as being broad and arbitrary. In practice, the definition never worked well. It made enforcement difficult.
I have not studied S.J. Res 22 but I would not doubt that a better definition would have some benefits to the regulated community. There are libraries of case law on 404 "Waters of the US". A portion of that is litigation on the definition.
PS: the 404 regulations were promulgated by the Corp not EPA. The massive Clean Water Act (for which EPA is the regulatory authority) used the 404 regulations to define the scope of the clean water act. There was a funny moment in Congress when a member of Congress criticized the two agencies for stretching the definition of "navigable waters". The navigable waters is a Corp term. When 404 permits were required for work in navigable streams, the Corp pushed the definition to extremes. To the point that one congressmen lamented that a navigable stream according to the Corp and EPA was any creek you could float a chicken down on a fence post.
