National Aquatic Resource Survey data
Surface water monitoring data from national aquatic surveys (lakes, streams, rivers). 

This dataset is associated with the following publication:
Stoddard , J., J. Van Sickle, A. Herlihy, J. Brahney, S. Paulsen , D. Peck , R. Mitchell , and A. Pollard. Continental-scale increase in stream and lake phosphorus: Are …