Good overview of the water quality situation in Iowa from Chris Jones, University of Iowa IIHR Research Engineer, on Iowa Public Radio. Take a listen to his interview, or, better yet, read the paper in PLOS One that the interview is based on. The work quantitates Iowa's contribution to the nitrate load which ends up in the Gulf of Mexico - and we're doing more than our share. It's worth your time.
Marty St. Clair is a chemistry and environmental studies professor at Coe College in Cedar Rapids, Iowa.