Environmental Science

Fertilizer Runoff Study on the Ouachita River

Click HERE for the final paper and results
*This is a large file!

A pilot pollution study on a portion of the Ouachita River is now under way.  The purpose of the study is to chart sources of fertilizer pollutants in the river as they are being washed into the Ouachita following field preparation and rainfall.  The study will utilize past data along with current data and correlate it with runoff caused by rain.  The primary sites will be Sterlington, Monroe, andColumbia. 

Round 1

The first round of testing (2/12/05) has already indicated an elevated level of nitrogen based compounds at Columbia but not at Monroe or Sterlington.  Thus, a source must be located between Monroe and Columbia.  More samples will be gathered between Monroe and Columbia in order to localize the source or sources.  Another observation is the increase in sulfate levels as one progresses southward down the river from 5 ppm in Sterlington to 8 ppm in Monroe to 13 ppm in Columbia.

Round 2

The second round of testing (3/13/05) was primarily aimed at targeting the increased levels of nitrogen compounds found at Columbia during the first round of testing.  However March testing indicated the levels were near those of the other locations.  It fell from 135 ppm to 0.204 ppm - a more normal reading.  The explanation of this anomaly remains elusive.  Two more sites, Logtown and Columbia Lock and Dam, were added in an attempt to isolate the source.  The source has, for now, disappeared.  Certainly with only two samples, no pattern can be discerned. 

A point of note plowing had begun on one field near Sterlington along U.S. 165.  No other fields showed signs of cultivation.  All other fields should have been plowed and fertilized prior to the April sampling.  Rainfall will be needed to move any fertilizers toward the river.

Also, a preliminary compilation of data from previous years does show an annual pattern in fertilizer pollutants.  The data base is extensive and will take a while to process the information.

Delta students will assist Professor Wheeler in this test.  Professor Buddy Barnett, who teaches chemistry at Delta, is also assisting with testing.  A special thanks to Professor Barnett.  Also a thanks to Professor Brien Dunn who assists with photography.

Historical Data

Long term data has been compiled and graphed.  A significant increase in nitrogen compounds is noted at all three sites in April/May of each year.  This increase would definitely correspond with the fertilizing of fields.  Cultivation and fertilization of area fields begins at the end of March and continues through early April.  Thus an increase in nitrogen compounds can be expected.  Correlation with rainfall data will be performed over Easter break (last week of March) as soon as the data arrives from Baton Rouge.

Phosphate increases were a bit more difficult to detect.  Sterlington and Columbia showed a slight increase in May thus creating a slight increase in the overall average of the span of river between Sterlington and Columbia.  A possible reason for the slight increase is the actual amount of phosphates used on crops.  Fertilizers tend to be more nitrogen based; therefore one should expect a more significant increase in nitrogen compounds as opposed to phosphates. 

Based on the historical data, an increase in nitrogen based compounds, usually showing up in either April or May, may or may not be detected in the ongoing testing procedure prior to the end of the semester.  However, studies will continue into the summer with a more extensive study in the fall of 2005. 

Data and graphs can be found on each sites page by clicking the links below.