Stop Anaerobic Digester Pollution Of Our Rivers

The number of Anaerobic digester (AD) plants is increasing. In 2002, there were over 60 in operation in Wales, being built or in planning.

They are seen by many as a way of generating green energy and as a solution to the disposal and recycling of agricultural and other waste material.

But while ADs may help Wales achieve carbon targets, they are having some very negative effects on efforts to attain of biodiversity improvements. They are complex, industrial plants, many of which are damaging river environments.

In recent years, accidents at AD plants have caused catastrophic fish kills on rivers such as the Teifi and Wye. They are also a significant contributor to excessive nutrients in rivers when their end product (digestate) is spread on unsuitable land and finds its way into watercourses.

This is being allowed to happen through weak or non-existent regulation and a flawed planning system.

Given their growth in recent years and potential to damage the environment, it is surprising that specific regulations to the operation of anaerobic digesters do not exist.

How Anaerobic Digester Plants Can Harm Rivers

Poor Regulation

Poor Regulation

A lack of regulation of the AD industry and enforcement of permits by the authorities….



Spreading digestate to land can add extra nutrients to rivers that are already failing phosphorus targets….

The Black Hole Of Planning

The Black Hole Of Planning

Our planning system is failing to consider the effects of AD plants on the environment in its decision-making….

Our Aim

We are not against AD plants.

Along with our campaign partners Fish Legal, we believe that the operation of AD plants should never result in pollution of a Welsh river and the further loss of biodiversity. We need a planning and regulatory system that prevents this and protects the environment. Currently, it does not.

How Is This Achieved?

Welsh Government need to review our planning and regulatory system.

Specifically, we need:

  • Planning authorities to include the spreading of digestate from AD plants in their environmental considerations when deciding on new developments such as poultry units.
  • The introduction of licences to operate AD plants and a regulatory system that guarantees operators are fully qualified and capable of running them with minimal risk.
  • Authorities to ensure that all AD plants have the correct planning permissions to operate and that conditions are enforced – this is not happening in all cases at the moment.
  • For one of the conditions of operating is that records of digestate spreading areas are supplied to regulatory authorities and are therefore available to the public.
  • If digestate continues not to be considered a waste product and not regulated under waste laws, then new rules for agriculture apply to its spreading and that these are enforced effectively by NRW.
  • For all AD plants to be mandated to include technology to remove phosphorus from digestate.

Any finally,

  • For Welsh Government introduce incentive schemes to export digestate out of SAC catchments that are failing phosphorus targets. Digestate is a valuable fertiliser which is in high demand in certain areas of the UK. It needs to be spread there, not in insensitive SAC-designated river catchments that are suffering from high nutrient loads.

What you can do to help…..

  • Contact your local Member of Parliament, Senedd Member or a local Councilor to highlight this problem, put forward the concerns and what needs to change. Please refer them to this webpage if you wish. Fish Legal have produced a letter which you can send.
  • Join a citizen science group organised by your local rivers trust and help monitor water quality. You can find details of your local trust here.
  • Follow us on social media and help us raise awareness of this issue for the benefit of our precious rivers @AfonyddCymru

Thank you for your support.


Case Studies…..

Catastrophic Pollution, Afon Teifi

Chronic diffuse pollution case study – a Welsh SAC river