In a case appealed by Maui County, Hawaii, this week the Supreme Court heard arguments about whether the federal Clean Water Act permitting requirement, which normally extends only to point sources of pollution emitted into navigable waters, also extends to sources that originate from a point source but are conveyed to navigable waters by a non-point source — in this case, groundwater that moves polluted water from a state waste-water facility to the ocean (password required). Read more here and here.
