I mentioned before I was on the fringe of a lobbying effort. It related to a patent bill before Congress. The area is highly technical, and if left to actual people in Congress it could not possibly come out well. The same is true for their aids. A lot of these bills are very involved and very technical, not something a generalist can write or consider.
What Congress has done largely to date is basically say something like "Pollution is a problem, we're creating an Executive agency to fix it, with power to do stuff."
They have shifted power to the Executive branch in abdicating their authority, because they can't handle such issues. Then the "EPA" (in this case) hires bureaucrats and "experts" of whatever ilk and is empowered then to do stuff.