How do groundwater flow systems affect the impact of on-farm mitigation measures on river receptor pollution?

How do groundwater flow systems effect the impact of on-farm mitigation measures on river receptor pollution? The challenge Agricultural diffuse pollution, particularly from nit…
Agricultural diffuse pollution, particularly from nitrate and phosphate, is a significant problem in the UK and is the focus of the national Demonstration Test Catchments (DTC) study — a UK Government initiative. https://www.wskep.net/index.php/waterr2b/sectors/farming-food/on_farm_mitigation/