Excess nutrient such as nitrogen and phosphorus can cause toxic harmful algal blooms. These harmful algal blooms cause significant economic loss and public health risks across the nation. New methods to reduce nutrient pollution include using algae in wastewater treatment plants to reduce nitrogen and phosphorus before it is released to the environment. The goal of this research is to understand the types of nutrients that make algae more toxic in the environment. This goal will be achieved through experiments that grow algae on wastewater and examine different wastewater nutrient sources that cause environmental pollution. This work will be performed in collaboration with wastewater utilities as well as community groups that monitor and report harmful algal blooms. This research can be used to improve our wastewater treatment and reduce nitrogen and phosphorus pollution. These results can further inform public policy on the types of nutrients that are most important in causing toxic algal blooms. Eutrophication and nutrient management for point and non-point source pollution remain a critical challenge. While efforts to reduce eutrophication most often focus on limiting phosphorus discharges to the environment, nitrogen is an important driver in algal bloom growth and toxicity. The overall goal of this research is to improve the total nutrient recovery from algal wastewater treatment processes and to understand the role of organic and inorganic nitrogen in harmful algal