DES MOINES -- The landscape of rural America has been radically altered in the last half century.

This time we're not talking about the rise of industrial agriculture with its vast livestock confinement facilities or genetically modified, fertilized crops. We're not talking about the encroachment of suburban sprawl. This isn't a story of wind turbines sprouting in the middle of cornfields or GPS-enabled tractors.

Today's worry is the disappearance of the lowly outhouse...