With a population of about 320,000, St. Louis, Missouri, is the 60th largest city in the U.S. But due to an unusual arrangement, St. Louis, its metro area (population about 3 million), and surrounding St. Louis County (about 1 million) happens to be served by the fourth-largest sewer district in the U.S., just behind New York, Los Angeles and Chicago.“We’re odd,” says Jonathon Sprague, director of operations for the Metropolitan St. Louis Sewer District. “We cover the city and county of St. Louis, and about 90 small municipalities. So it’s an extreme-ly large system, and we have to be efficient
