sentences:  Additional evidence of high phosphate levels is that the pH of Royce Brook consistently tested as basic, and fertilizers tend to be basic.Also, water flowing over large stones in Royce Brook usually results in large bubbles on the surface of the water, which is usually regarded as a result of high phosphate levels.An earlier research project was conducted in the late summer of 2004, at the same location of where the 2006 testing occurred.