On grey water duming

Environmentalists are often amusing in the contradictory positions they're willing to take. The latest example is the ban on cruise ships dumping grey water within 3 miles of shore.

At first, that sounds like something that you'd sort of expect to be a bad thing. But then how do you reconcile that with cities being incentivised to use grey water for irrigating parks and other public places? If it's illegal to dump it in Monterey Bay, how ought it to be a good idea to spray it on the lawn at the local public park?

Just to be clear, grey water is not sewage (that is, toilet output). Grey water is water that has been used, but other than for septic reasons. Think water from showers. So if shower water shouldn't be dumped in the bay, then should people be allowed to swim in it?

And is making the cruise ship wait until it's 3 miles offshore significant? If it's dumping while the tide is going in, the tide will carry it right into shore.

Norman, coordinate.