The concentration of phosphorus in the waters of Buffalo Creek ranges from about 0 milligrams per liter to over 0.2 milligrams per liter. In most of the upper part of the creek, the concentration is very low, under 0.05 milligrams per liter. However, it is over 0.2 milligrams per liter where Buffalo Flat Road passes over the creek. The concentration in Mifflinburg is 0.06 or 0.07 milligrams per liter. It steadily declines to about 0.03 milligrams per liter near the mouth.