What happens to water when we're done with it?

Out of sight, out of mind. (At my age, alas, I no longer live within the confines of that dictum. I can forget, misplace and overlook things that are smack in front of my face. But I digress.)

What many folks can’t see they can indeed overlook. And all too many Americans have never seen what happens to the water that flows down the kitchen sink and out of the house. But with each load of laundry or flush of the toilet, we create wastewater that gets mingled together and heads toward treatment plants.

The average American makes 100 gallons of wastewater per day. While it’s natural to think that...