Real-time monitoring tracks nitrate pulse in Mississippi River Basin into the Gulf of Mexico
Cutting edge optical sensor technology is being used in the Mississippi River basin to more accurately track the nitrate pulse from small streams, large tributaries and ultimately to the Gulf of Mexico.
Excessive springtime nitrate runoff from agricultural land and other sources in the Mississippi drainage eventually flows into the Mississippi River. Downstream, this excess nitrate contributes to the Gulf of Mexico hypoxic zone, an area with low oxygen known commonly as the “dead zone.” NOAA-supported researchers reported that the summer 2013 dead zone covered about 5,840 square miles, an area the size of Connecticut.
These optical sensors measure and transmit nitrate data every 15 minutes to 3 hours and are located at the mouth of the Mississippi River near Baton Rouge, LA, and at several large tributaries to the Mississippi River—including the Missouri River at Hermann, MO; Ohio River at Olmsted, IL; Ohio, Illinois River at Florence, IL; and Iowa River at Wapello, IA – to track how nitrate concentrations from different areas of the watershed pulse in response to rainfall and seasons.
About 622 million pounds of nitrogen were transported in May and June of 2013 at the Mississippi River Baton Rouge station, said Brian Pellerin, USGS research hydrologist. “This is roughly equivalent to the amount of fertilizer nitrogen applied annually to about 4 million acres of corn…”
Real-time nitrate monitoring in Iowa is being used by drinking water utilities to determine when to switch on nitrate-removal systems or when to mix water with multiple sources that have lower concentrations. Both actions result in higher costs for drinking water. “Real-time nitrate concentrations in the Raccoon River at Van Meter, Iowa, peaked at 20.7 milligrams per liter in May 2013. This is more than double the U.S. Environmental Protection Agency’s maximum contaminant level for drinking water,” said Kevin Richards, Director of the USGS Iowa Water Science Center.
Most Americans don’t realize the role played, the responsibility of agribusiness in polluting our water table. All this crap polluting our waterways filters through local water tables on the way to tributaries, thence to major rivers on the way to contaminating larger bodies – like the Gulf of Mexico.
You might think farmers, from the local Farmer Giles to corporate behemoths might care about cost savings derived from spend/wasting less money on fertilizer destined to be surplus drained as runoff. Don’t worry. You and I get to subsidize it one way or another. Either directly priming the pump for corporate growers – or at the grocery checkout.