Microbes transform nitrogen in tidal freshwater zones, usually causing denitrification, but recent research says areas of high nitrogen have been found.
Development and crop land use in the United States lead to elevated chloride levels in thousands of lakes.
Major snowmelt and runoff events in central Canada carry stormwater contamination to the South Saskatchewan River.
A recent renovation project is helping Omaha remodel aging sewers and improve water quality while offering more recreational opportunities to locals.