Farmers asked to use slug pellets carefully to protect river water quality

We are calling on farmers on land near the rivers Derwent, Wiske and Ouse to manage the use of slug control pesticides carefully to reduce the impact they could have on tap water quality.

The pellets can occasionally leak into watercourses in Yorkshire’s farming heartlands around the rural outskirts of York, Northallerton, east of Pockington and Driffield.

An active ingredient in the pellets - metaldehyde - poses no danger to health or the environment, but its levels in the River Derwent, Wiske and Ouse have occasionally breached EU drinking water standards in the last year.

In response, ourselves and our partners including the National Farmers Union are encouraging farmers to adopt an Integrated Pest Management approach with less reliance on slug pellets.

Andrew Walker, Catchment Strategy Manager at Yorkshire Water, said: “We really appreciate the efforts farmers in Yorkshire are making to reduce the amount of metaldehyde getting into our rivers. These measures include switching to ferric based pellets; adhering to the new 10m buffer strips and implementing the new integrated pest management plans, and other cultivation techniques which can control slug populations without the need for chemicals.”

The Integrated Pest Management approach involves sowing seeds deeper into the soil to prevent slugs reaching them, rolling after seed drilling to consolidate the soil and make it harder for slugs to move about, use of traps to assess slug numbers, and using a more environmentally friendly alternative to metaldehyde called ferric phosphate.

Slug pellets are commonly used by farmers this time of the year to control slug infestations, which risk eating away at crops and damaging food production. For instance, it is estimated that around 22 per cent of land used for wheat growing is affected by slugs and necessitates the use of pellets, according to The Metaldehyde Steward Group (MSG).

NFU Vice President Guy Smith said: “Metaldehyde remains an important part of the management options available to farmers to control slugs and a crucial part of an integrated pest management plan. Using traps to assess slug pressures, ferric phosphate and cultivation are all useful alternatives to Metaldehyde as part of an integrated pest management plan and the NFU encourages all farmers to use a wide array of techniques to control slugs on farm”.

Trials in some parts of the UK have shown that 98.7% of metaldehyde contamination within rivers and streams comes via flowing field drains.

Our efforts to protect water quality are part of one of our key objectives to ensure customers are provided with water that is clean and safe to drink. Drinking water in Yorkshire remains excellent with 99.962% of hundreds of thousands of samples meeting tight regulatory standards in the last year.