Nutrient transport and interactions of groundwater and surface water in a Great Lakes clay basin

Session: Nutrient Sources, Transport, and Internal Cycling (3)

Ceilidh Mackie, University of Guelph, [email protected]
Jana Levison , University of Guelph, [email protected]
Andrew Binns, University of Guelph, [email protected]
Scott Gardner, University of Guelph, [email protected]
Elisha Persaud, University of Guelph, [email protected]

Abstract

Nutrient export from agricultural land to surface waters presents a significant environmental concern within the Great Lakes Basin. This research investigates spatial and temporal variations of phosphorus and nitrate and groundwater-surface water interactions in an agriculturally dominated clay plain system within the Great Lakes Basin. Data collection via continuous sensor deployment and discrete sampling of stream water, groundwater, hyporheic zone, and tile drainage water is being conducted in the Upper Parkhill Watershed in southwestern Ontario. Samples are analyzed for fundamental nutrient species (total, total dissolved, soluble reactive, and particulate phosphorus, and nitrate-N) to examine the transport of agriculturally-derived nutrients through the groundwater-surface water interface in a Great Lakes tributary. Total phosphorus (TP) concentrations in the surface water ranged from 0.007 to 0.324 mg/L and <0.003 to 0.150 mg/L in groundwater from June to December 2018. Tile drainage TP concentrations ranged from 0.027 to 0.066 mg/L and 0.051 to 0.203 mg/L in the hyporheic zone. The quantification of nutrient concentrations across various hydrological pathways will aid in identifying nutrient contamination hotspots and allow for the creation of a conceptual model to elucidate the hydrogeological processes affecting nutrient transport in clay-dominated subsurface settings.