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Reducing Non-Point Source Loss of Nitrate Within the Santa Fe Basin
Goals and Objectives
The Santa Fe River in north central Florida has been identified as impaired due to elevated levels of nitrate. A survey of several tributaries in the Santa Fe River Watershed identified one significant source of nitrates to be a container nursery in the middle section of the watershed. Runoff from this area first infiltrates vertically through a surface layer of well drained sands then moves laterally on top of a clay aquitard eventually discharging to surface water through seeps. Nitrate leached through potted plants in the nursery during irrigation and rainfall events results in increased nitrate levels in the surficial aquifer and tributaries and eventually results in increased nitrates loads to the Santa Fe River. Extension activities included an evaluation and demonstration of container nursery Best Management Practices (BMPs) and a novel “denitrification wall” technology to decrease nitrate loads from the nursery and demonstrate how these practices can reduce nitrogen loads, while maintaining an economically viable nursery operation. Results indicated that enhanced cyclical irrigation techniques and reduced fertilizer application reduced nitrate sources by 78% and nitrate levels in the watershed downstream from the denitrification wall had nitrogen levels reduced by 65%. Amortization of treatment cost over a 15-year conservative life expectancy of the denitrification wall suggested that cost of nitrogen removal using this technique are around $0.79 per kilogram of nitrogen removed making it one of the lowest cost technologies to remove nitrate from surficial groundwater.
Available Outputs

Title: Evaluation of a Denitrification Wall to Reduce Surface Water Nitrogen Loads. J. Environ. Qual. 41:724–731 (2012) doi:10.2134/jeq2011.0331
Authors: Schmidt, C.A., M.W. Clark

Title: Final Report: Reducing Nonpoint Source Loss of Nitrate within the Santa Fe Basin: Efficacy of Container Nursery BMPs and Denitrification Wall
Authors: Clark, Mark, Casey Schmidt, Thomas Yeager

Title: Presentation: Nutrient Criteria, Natural Buffers and Practices to Reduce Nitrate Loads at the Source. Presented at the Santa Fe Springs Working Group meeting, Feb 16, 2011.
Authors: Clark, M.W.
Project Lead
Clark, Mark W
Project Participants
Clark, Mark W
Additional Participants
Casey Schmidt
Thomas Yeager
Level 2: WI Assisted Project
Water, Land Use and Ecosystems
Grant Award Dates
4/3/2007 to 10/1/2011