Nitrate in the Mississippi River and its tributaries, 1980 to 2008: Are we making progress?

Environmental Science & Technology
By: , and 

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Abstract

Changes in nitrate concentration and flux between 1980 and 2008 at eight sites in the Mississippi River basin were determined using a new statistical method that accommodates evolving nitrate behavior over time and produces flow-normalized estimates of nitrate concentration and flux that are independent of random variations in streamflow. The results show that little consistent progress has been made in reducing riverine nitrate since 1980, and that flow-normalized concentration and flux are increasing in some areas. Flow-normalized nitrate concentration and flux increased between 9 and 76% at four sites on the Mississippi River and a tributary site on the Missouri River, but changed very little at tributary sites on the Ohio, Iowa, and Illinois Rivers. Increases in flow-normalized concentration and flux at the Mississippi River at Clinton and Missouri River at Hermann were more than three times larger than at any other site. The increases at these two sites contributed much of the 9% increase in flow-normalized nitrate flux leaving the Mississippi River basin. At most sites, concentrations increased more at low and moderate streamflows than at high streamflows, suggesting that increasing groundwater concentrations are having an effect on river concentrations.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Nitrate in the Mississippi River and its tributaries, 1980 to 2008: Are we making progress?
Series title Environmental Science & Technology
Volume 45
Issue 17
Year Published 2011
Language English
Publisher ACS Publications
Publisher location Washington, D.C.
Contributing office(s) Colorado Water Science Center
Description 8 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Environmental Science and Technology
First page 7209
Last page 7216
Time Range Start 1980-01-01
Time Range End 2008-12-31
Country United States
Other Geospatial Mississippi River Basin