The company hopes this will prevent the pesticide metaldehye from entering the watercourse and breaching levels set out in the European Union’s Water Framework Directive.
Yorkshire Water, along with Natural England, is calling on farmers to avoid applying the pesticide within six metres of a watercourse, to carry out precision pelleting so it is only used where needed, and to apply the minimum amount needed to avoid drainage and run-off losses.
The pesticide, which is harmless to humans, cannot be removed from the water at water treatment works, so any metaldehyde that enters the water is likely to breach the EU’s 0.1 microgram per litre standard for drinking water.
Yorkshire Water catchment strategy manager Andrew Walker said: “We are not saying to farmers to stop using slug pellets, but instead to ensure they are applied correctly and to consider alternative measures that have a lower environmental and water impact.
“This way, crops will continue to be protected from nuisance slugs without adversely affecting raw water supplies.”
The River Hull is one of the region’s metaldehyde hotspots, with concentration levels of the chemical occasionally breaching regulatory limits. It is particularly noticeable in watercourses around Driffield and Beeford.
The call from Yorkshire Water follows a trial project launched by Anglian Water, which sees the company pay farmers to take part in the trial project, and to use other chemicals that are easier to remove from the water supply.
The Slug It Out campaign has seen 100 per cent of the farmers targeted by Anglian Water sign up to the trial.