"DSK" wrote
If you like analogies, here's one for you... The only water supply you
have is a pond. It has a certain amount of things already living in it.
It also has a group of people dumping their toilet into it. How large do
you want that pond to be? How much of it's shoreline should be wetlands
or marsh?

You could hypothesize an 8 foot tide if you like, but that will just
move the crap around within the pond.

OK, you've got the ecological balance to your liking, and you're happy
with your drinking water. Now have somebody come and dump their toilet
right over your water intake. Does that change things?

Unfortunately, that describes most the world. The Potomac starts above
Cumberland, Md and every town along the way dumps its sewage into it. Ditto
all the other rivers feeding the bay. By the time it reaches tidal Va the
once-sandy bottom is mud - except it isn't mud it's fecal material. The
Rappahannoc is better cuz Fredricksburg bought up the shore above town back
in the 1800s to preserve their drinking water so it don't become a sewer til
downstream.

We pass expensive laws that cut pollution but then in a few years the
population gets bigger and we're right back where we started.

The "enviro" that gets me is the one that wants to save the environment for
his four kids. I don't mind dumping near his intake - I gotta dump
somewhere - but I do use a lectrosan.