How effective are catchment approaches to reducing metaldehyde loss to water supplies? (HISCOCKU17SCI50)

The widespread use of pesticides in agriculture to control plant and insect pests which would otherwise reduce crop yields has been instrumental in enhancing global agricultural productivity since the mid-20th century (Popp et al., 2013). In East Anglia, an area of intensive arable agriculture, the use of metaldehyde to control slug populations creates the risk of diffuse pollution runoff that can then enter water supply sources (Cooper et al., 2016). There are significant economic costs associated with removing pesticides from drinking water. Although harmless to humans, water companies are required to maintain levels below 0.1 μg/L but the chemical nature of metaldehyde makes it difficult for water treatment works to remove it from drinking water and little is known about its persistence in the environment. As an alternative approach, changing catchment management practices to reduce the risk of nutrient and pesticide loss has received increased attention as a potential solution (Taylor et al., 2016).

This PhD project aims to understand the persistence of metaldehyde within soils and under what conditions metaldehyde runoff into drinking water might be mitigated. The research will be carried out in partnership with Anglian Water to assess metaldehyde use and runoff from land adjoining the Ardleigh Reservoir in Essex and the wider River Colne catchment. The project will employ GC-MS analytical techniques developed at UEA to assess the level of metaldehyde present at different points in sediment cores to determine how long metaldehyde may remain in different soil types.

The student will spend at least three months with Anglian Water as part of the Catchment and Coastal Management team gaining experience of working in a commercial environment and implementing the outcomes of their research. The student will gain field and laboratory experience of optimising methods for soil analysis and undertake further development of analytical techniques for detection of metaldehyde in soils. The successful student will become an associate of the EnvEast Doctoral Training Partnership.