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Slug it Out is part of Anglian Water's way of working. The campaign is aimed at reducing the levels of the slug control pesticide Metaldehyde in our region’s waters before they reach our treatment works.

Although harmless to humans, Metaldehyde is very difficult to remove at water treatment works and meeting tough EU targets on it is a real challenge for the region.


As part of the campaign, we are carrying out a trial project around six key reservoirs to incentivise farmers to stop using metaldehyde and use an alternative chemical instead. The farmers will receive payments to cover their costs and for taking part.

The reservoirs involved are Alton Water in Suffolk; Ardleigh Reservoir near Colchester; Hollowell Reservoir, Ravensthorpe Reservoir and Pitsford Water in Northamptonshire and Grafham Water in Cambridgeshire.

Alongside this, Anglian Water’s team of catchment advisors will be talking to farmers and agronomists about how they can help reduce the amount of Metaldehyde in our rivers and reservoirs. Our aim is to help farmers do this in a way that fits into their business.

The regulatory level of Metaldehyde stipulated by the European Union’s Water Framework Directive is 0.1 micrograms per litre (or parts per billion) in treated water. This is the same as one drop in an Olympic sized swimming pool. Levels in reservoirs in our region regularly exceed this and removing it is not currently possible.

A failure to tackle Metaldehyde levels in our water now will inevitably result in additional regulation being forced on farmers further down the line, affecting individual farm businesses and the industry as a whole.

On top of this, Anglian Water spends large amounts of money removing pesticides from drinking water at our treatment works – this raises customers’ bills and wastes energy.

This Catchment Management approach is a proactive, responsible way of improving the water in our rivers and reservoirs while protecting our customers, our farming community and our environment.

Reservoir factsheets

Below you will find a factsheet on each reservoir in the trial project.