We've noted, previously, that the Sanitary and Ship Canal is also the world's biggest open sewer. Dilute it enough, though, and St. Louis and Memphis might still draw water safely. Diluted or not, what remains eventually gets to the Gulf of Mexico. "While the agricultural runoff from farms — exempted under the Clean Water Act — is the main driver of the Gulf dead zone, Chicago’s sewage is the largest single source of phosphorus pollution."
Over the past few years, there have been summer dead zones elsewhere in the Lakes, including Green Bay and one notorious one that closed Toledo's water works for a few days. Yes, phosphorous fertilizers contribute to making crops more productive, and the feedstocks are relatively abundant.
Mightn't there, though, be ways of capturing the runoff for reuse?
That, however, is not what the article really wants people to Become Alarmed about. "Climate scientists say this issue is only expected to get worse in the future as a wetter climate in the Midwest — specifically one characterized by heavy rainfall in the winter and spring — creates more runoff." That "heavy rainfall in the winter and spring" is supposed to get readers worked up about global warming. You have to read on, though, to note that it wasn't heavy rainfall this year. "While the concentrations of nutrients in the Mississippi River basin weren’t particularly remarkable, the melting snow and spring rains poured into waterways, leading to record high river flows and delivering an overall larger nutrient load to the Gulf of Mexico." To add to our troubles, the wet grounds have meant corn and soybean planting is delayed, if not deferred for the crop insurance.