The 2017 Report to the Arkansas-Oklahoma Arkansas River Compact Commission, September 28, 2017
The 2017 report shows that phosphorus is trending downward in the Illinois River watershed. Data shows that Oklahoma's instream, numeric phosphorus limit of 0.037 mg/L total phosphorus is exceeded by 91-percent at the Oklahoma and Arkansas border near Watts, Oklahoma and by 78-percent at Tahlequah. Oklahoma's average annual total phosphorus loading is more than 37,000 kilograms per year at the Oklahoma border with Arkansas near Watts and 37,698 kilograms per year at Tahlequah.
See select data from 2017 report (pdf file).