"South Shropshire is such a special place to live. Our rivers and streams sustain a rich variety of wildlife. I want to see them protected for future generations.
Residents have recently contacted me with their concerns about plans announced by Severn Trent to divert wastewater from Bishop’s Castle sewage treatment works at the River Kemp into the River Onny.
This prompted me to contact Severn Trent for a more detailed update..."
Severn Trent have told me that the proposals are aimed at improving the River Clun as a Special Area of Conservation (SAC) by reducing phosphate released into the area. It combines with upgrades already programmed at the sewage treatment works, to further reduce the amount of phosphate released.
They have stated that the project would transfer fully treated final effluent only, as there is no storm overflow at Bishop’s Castle. That said, I know this has been raised as a concern by local residents who feel it will negatively impact the River Onny.
Importantly, Severn Trent added that the scheme will not be funded unless the Environment Agency formally approve it after they have made their own assessment of the project. I will be following this and looking to see what assessment they make of the proposals. There will also be further investigations to ensure there is “no deterioration” to the River Onny.
On 31st January 2025. the Environment Agency told me:
The Clun Special Area of Conservation (SAC) was designated for its population of endangered freshwater pearl mussels. The Clun population is one of only a few lowland populations remaining in the UK. The complex life cycle of the mussels is dependent on good water quality, suitable substrate and healthy populations of salmon or trout. SACs have the highest level of protection of any ecologically designated sites in the UK. Natural England have assessed the condition of the SAC as ‘Unfavourable Declining’, due in part to the impact of excess nutrients entering the river.
The Bishops Castle Sewage works currently discharge into the Snakescroft Brook, a tributary of the River Clun. Treatment works within the River Clun Catchment have seen upgrades, however, to further reduce the environmental impact of their operations on the Clun SAC, Severn Trent proposed a Water Industry National Environment Programme (WINEP) action to transfer treated effluent from Bishops Castle to the River Onny.
We are working with Natural England, and we have advised Severn Trent Water that they will need to undertake an environmental assessment to understand the potential impacts of any transfer. The outcomes of this work would need to be agreed with the regulators before any scheme could proceed. We have been informing the scope of the assessment which will consider the impact of the proposal on the hydrology, ecology (fish) and water quality of both the River Onny and water bodies in the Clun catchment. We would expect Severn Trent to have completed their assessment by April 2027.
If, after the investigation is completed, Severn Trent wish to proceed with the proposal, they will need to apply to our National Permitting Service who will undertake a permit determination. The determination will be objective, evidence-based, and consider comments received through a formal consultation process. If a permit is issued, our “no deterioration” principle will apply. This ensures that discharges do not cause a decline in the biological, chemical, or ecological status of the receiving waters, and do not prevent a water body from achieving good Water Framework Directive status in the future. More information on this policy can be found at Water companies: environmental permits for storm overflows and emergency overflows - GOV.UK
Nutrient neutrality is a policy aimed at preventing new developments from increasing nutrient pollution in protected sites. If the transfer from Bishops Castle Sewage Treatment Works proceeds, new housing developments that connect to the mains drainage system at these works would not contribute additional wastewater nutrients to the River Clun SAC and would not need to meet nutrient neutrality requirements.
No determination will be made on the proposed pipeline transfer until Severn Trent undertakes the environmental assessment and applies to our National Permitting Service. Public comment will be invited through our formal consultation process. Further information on the WINEP is available at Water Industry National Environment Programme (WINEP) | Engage Environment Agency.
Next Steps:
Rest assured; I will be closely monitoring this situation for developments. I know many fellow residents care a great deal about protecting our natural environment, as do I. I am also interested in hearing from those this might impact. So, please contact me to let me know your thoughts and take part in my poll below:
