Nitrate concentrations and loads in the Illinois River from 1983 to 2014 were correlated with agricultural nitrogen use efficiency and nitrate discharged from Chicago's treated wastewater, say researchers. The amount of nitrate that flowed down the river each year from 2010 to 2014 was 10 percent less than the average amount during a baseline period of 1980 to 1996. This reduction is a positive step toward the ultimate goal to reduce nitrate concentrations by 45 percent.

Source: Illinois River water quality improvement linked to more efficient corn production