On a field scale, the study will focus on MCPA and its behaviour and fate post application for rush control treatment in a poorly draining impermeable grassland field. Once applied, monitoring will evaluate its movement via subsurface drains, shallow groundwater, overland flow and surface water streams. This will be achieved through the use of high-resolution monitoring as well as passive samplers, which are capable of providing overall average concentrations of MCPA lost via surface water streams. It is envisaged that the field experiment will start in Spring 2019