Stop Anaerobic Digester Pollution of Rivers

Anaerobic digesters are suspected of contributing to high phosphorus levels in Welsh rivers through the spreading of digestate, the industry’s nutrient-rich liquid end-product.

Tuesday 14th March, 2023

Afonydd Cymru and Fish Legal have called on Welsh Government to stop pollution of rivers in Wales from anaerobic digester plants.

In a letter to the Climate Change and Rural Affairs ministers last week, both organisations expressed concerns about the industry, calling for an urgent review of Wales’s planning and regulatory controls over it.

In addition to biogas generation, anaerobic digestion plants are widely regarded as a solution to the disposal of agricultural and other waste material, such as poultry manure.

The industry, however, has caused catastrophic pollution events in Welsh rivers and is also suspected of contributing to high phosphorus levels through the spreading of digestate, its nutrient-rich liquid end-product.

Fish Legal and Afonydd Cymru have now called for a complete review by Welsh Government. In the letter they point to failures in planning by local authorities and in permitting and enforcement by Natural Resources Wales that have created the loopholes which enable the anaerobic digester industry to pollute.

They have also called for an “Appropriate Assessment” of the cumulative impacts of digestate spreading on entire catchments of Special Area of Conservation (SAC)-designated rivers, regardless of local authority or national boundaries.

 Gail Davies-Walsh, CEO of Afonydd Cymru, said:

Afonydd Cymru first made an appeal to Welsh Government to better regulate this industry back in 2017. Since then, we have not seen any progress while the number of anaerobic digester plants is on the up. We are not against anaerobic digestion but the industry must stop damaging Welsh rivers already in crisis. Natural Resources Wales’s own monitoring data shows a strong correlation between the spreading of digestate and diffuse pollution, especially when it comes to high phosphorus levels in rivers.

We are particularly concerned that Natural Resources Wales are not carrying out the required checks to ensure manures and digestate is being spread without causing pollution. One potential solution would be for Welsh Government to devise schemes to export manures out of Wales to other parts of the UK, where fertiliser is desperately needed. Providing the right scheme is put in place, there is considerable opportunity for agriculture here.

Penelope Gane, Head of Practice at Fish Legal said:

The Welsh Government needs to get a handle on the anaerobic digestion industry because, between them, the planning authorities and Natural Resources Wales are leaving Welsh rivers dangerously exposed to pollution.

She added: “It is an industry that has so far evaded scrutiny. Yet with phosphorus contributions in rivers being looked at for other sectors, it is high time the Welsh Government turned its attention to the impacts of anaerobic digesters and spreading.

Posted: March 27, 2023