Solutions to floods, droughts and pollution that look upstream, downstream and everywhere in between save dollars and make sense.
The Madison Metropolitan Sewerage District in Wisconsin had a problem. Due to tightening state and federal regulations, it had to help decrease the amount of phosphorus in the 540-square-mile (1,400-square-kilometer) Yahara River watershed. It was already removing 95 percent of the phosphorus from its wastewater effluent; new phosphorus level limits would require the equivalent of 96 percent removal.
“Getting that 1 percent increment of phosphorus removal would have been a US$130 million addition to the treatment plant,” says Michael Mucha, chief engineer and director of the district, “and the public wouldn’t see that much improvement in the quality of water.”
But since the state and federal governments are regulating the final water quality — not one source’s discharge — the district decided to address the problem in another way.