fertilizer

It has become a rite of summer. Every year, a "dead zone" appears in the Gulf of Mexico. It's an area where water doesn't have enough oxygen for fish to survive. And every year, the National Oceanic and Atmospheric Administration commissions scientists to venture out into the Gulf to measure it.

The U.S. may be on the verge of a boom in new fertilizer plants, which could be good news for farmers, but not the environment.