The first year of the UK’s largest ever metaldehyde-free farming trial has seen a 60 per cent drop in levels of the chemical detected in reservoir tributaries, it is claimed.
However, levels of metaldehyde continued to exceed limits set under European legislation in four out of the six reservoir catchments involved in the trial.
Farmers within the natural catchments of the reservoirs in Northamptonshire, Suffolk, Essex and Cambridgeshire have been working with Anglian Water’s team of advisors over the past year on the ‘Slug It Out’ campaign.
The area covers more than 7,000 hectares and as part of the campaign all farmers have agreed to use alternatives to metaldehyde to control slugs on their land.
The trial was launched to look at how levels of metaldehyde in rivers and reservoirs could be brought below the strict European standard of 0.1 micrograms per litre (or parts per billion) in treated water.
The first year of the trial saw 89 farmers signing up to take part – a 100 per cent uptake. The trial area covered 7,679 hectares and an estimated 1,613 kg of metaldehyde was removed from the farmed landscape.
Levels of metaldehyde detected in the Hollowell and Ravensthorpe Reservoirs in Northamptonshire were compliant with regulations and remained below the statutory limit during the trial’s first year. In Alton Water in Suffolk, Ardleigh Reservoir near Colchester, Pitsford Water in Northamptonshire and Grafham Water in Cambridgeshire there were still exceedances but overall levels were reduced significantly.
The average levels of metaldehyde in reservoir tributaries across all the catchments fell by 60 per cent, while the average peak levels detected within the reservoirs fell by 26 per cent.
Lucinda Gilfoyle, catchment strategy manager for Anglian Water, says: “What the first year of our trial has revealed is that by working together we can reduce metaldehyde levels in raw water sources – but that removing metaldehyde from the fields is not the silver bullet solution some may have hoped for.
“We know that a more detailed and longer term strategy is needed if we are to comply with pesticide regulations, and we will be building on these results as we move forward to help identify the package of measures needed.”