6th UF Water Institute Symposium Abstract

Submitter's Name	Victoria Hoge
Session Name	Poster Session - Water Quality - Water Management
Poster Number	47
Author(s)	Vickie Hoge,  St. Johns River Water Management District (Presenting Author)
	Lanie Meridth,  St. Johns River Water Management District
	Michelle Brown, St. Johns River Water Management District
	Tahmid Ibnat, St. Johns River Water Management District
	Developing a Biosolids Database for Watershed Modeling Efforts
	The St. Johns River Water Management District (SJRWMD) is currently in the process of completing a districtwide inventory of biosolids application for incorporation into watershed modeling efforts for evaluation of Total Maximum Daily Loads (TMDLs). Biosolids are the stabilized solids or slurries that are removed from municipal wastewater treatment processes or domestic septage and applied to pasture or other agricultural lands as a disposal method. Currently, there is no existing database of biosolids applications within the SJRWMD and there have been no extensive studies that evaluate biosolids as a potential source of excess nutrients. Thus, this work will help to improve our understanding of the effects of biosolids application on water quality within the St. John’s River and its tributaries. The Department of Environmental Protection (DEP) permits generating treatment facilities and residual application sites that receive and land apply biosolids. Biosolids land applied in Florida are generally Class B, or minimum quality for beneficial use through land application. Application rates of biosolids are determined by crop nitrogen demand, which can often result in an over application of phosphorus to the soil and increase the risk of nutrient runoff into nearby surface waters. The biosolids inventory includes yearly total nitrogen (TN) and total phosphorus (TP) biosolids application rates (lb/ac) for residual application sites districtwide between the years of 2000-2016. Within this period of record, the district has identified over 190 application sites and over 200 generating facilities that produce biosolids that are applied districtwide. Biosolids application data within the Upper St. Johns River basin (USJRB) was incorporated into the USJRB water quality model as a point source load. Currently, biosolids application data are being used to evaluate connections with water quality issues in surface water bodies proximal to application zones.