Identification of the Susquehanna River as the primary contributor of nutrients to the upper Chesapeake Bay and recognition of the need to develop a nutrient management program for their mutual protection, prompted the Annapolis Field Office, EPA, to conduct a one-year comprehensive nutrient survey in the lower Susquehanna River Basin between Northumberland, PA., and Conowingo, MD. Three distinct hydrologic seasons were represented during the study period which provided the foundation for an in-depth evaluation of all water quality data obtained during this survey. Its principal objectives were: (1) Quantitative identification of average nitrogen and phosphorus loadings and determination of seasonal variations in nutrient loadings from every major sub-basin; (2) delineation of point source and non-point source nutrient contributions to establish effectiveness of controllability measure; (3) seasonal mass balance of nutrient loadings in the main stem; and (4) determination of the fate of nutrients in impounded areas.

Issued Oct. 1974.