2nd UF Water Institute Symposium Abstract

Submitter's Name	Mike Jerauld
Session Name	Poster Session: Hydrologic, Biogeochemical and Ecological Processes 1
Category	Hydrologic, biogeochemical and ecological processes
Poster Number	217
Author(s)	Mike Jerauld,  Soil and Water Science Department, University of Florida
	James Jawtiz,  Soil and Water Science Department, University of Florida
	Michael Korvela, South Florida Water Management District
	Factors controlling long-term phosphorus removal in six large constructed treatment wetlands in the Everglades basin, Florida
	Over the past 15 years, the South Florida Water Management District has constructed 6 treatment marshes, called Stormwater Treatment Areas (STAs), to capture the phosphorus (P) from agricultural runoff before it enters the Everglades, an oligotrophic wetland susceptible to anthropogenic eutrophication. Because of the massive investment to construct these 18,000 ha wetlands, it is important to evaluate their long-term sustainability and to identify the STA components, processes and parameters that regulate P retention. Period-of-record hydrologic and water quality data are analyzed here to evaluate the impacts of various factors on treatment performance. Outflow P concentration was jointly controlled by areal P loading rate and inflow P concentration. Phosphorus mass removal effectiveness (PMRE) was not correlated with estimated wetted area*time, depth distribution or hydraulic residence time. Water column P forms were removed differentially in the STAs, but the composition of the influent TP pool did not predict PMRE. Removal of P was well correlated with the removal of calcium (Ca) but not correlated with Ca loading. Of the wetland components currently manageable by the District, only the areal P loading rate was found to affect outflow concentrations. The highly stochastic nature of the currently available datasets is a limiting factor in the illumination of process-level P dynamics that may be necessary to explain the apparent variability.