Limited Occurrence of Denitrification in Four Shallow Aquifers in Agricultural Areas of the United States.

The article presents a study on the ability of natural attenuation to mitigate agricultural nitrate contamination in recharging aquifers in four important agricultural settings in the U.S. The investigation utilized laboratory analyses, field measurements, and flow and transport modeling for monitoring well transects in the San Joaquin watershed, California, the Elkhorn watershed, Nebraska, the Yakima watershed, Washington, and the Chester watershed, Maryland. The spatial variations in nitrate distribution and denitrification is identified.