Linking Receiving Water Impacts to Sources and to Water Quality Decisions: Using Nutrients as an Initial Case Study

Nitrogen and phosphorus loadings to waterbodies impact water quality by stimulating plant and algae growth, which may result in depletion of dissolved oxygen, degradation of habitat, harmful algal blooms, impairment of designated use, and impairment of drinking water sources. Effectively controlling nutrient loadings to receiving waters has become a major challenge for water resource managers. Recent requirements for numeric nutrient criteria in Florida have made this an urgent need. The Water Environment Research Foundation recently embarked upon a research challenge entitled “Linking Receiving Water Impacts to Sources and to Water Quality Management Decisions.” The subject work effort provides an initial case study related to this challenge and focuses on nitrogen as a source constituent and the primary linkage to Florida receiving water impacts. The purpose of this work effort was to provide an approach to:1) Establish the linkages between sources of nitrogen and the predicted and measured adverse impacts of nitrogen on receiving waters.2) Understand how the source-response linkage is influenced by source controls.3) Evaluate the effectiveness of nitrogen source control strategies.4) Evaluate the costs and benefits of available controls.5) Summarize available data and identify any gaps that would need to be filled to implement the recommended approach in Florida.