Looking after our local drinking water source- Banwell Spring

The Banwell Bypass Construction Team will be holding a Zoom meeting on 16th December to discuss the Southern Link Road.   Building the southern Link road is problematic for several reasons, and it’s hoped that some light will be shed on the plans for this during the meeting, which parish Working Group participants will report back on.

One issue of concern is the groundwater source the Southern Link Road will impact, as the route goes through a groundwater source protection zone , an SPZ.  Banwell Spring is the fourth largest spring in the Mendips, with a catchment area of around 14 square kilometres, and discharges around 7 million cubic metres of water a year.  Bristol Water have a licence to abstract 4.85 Million cubic metres of water a year from Banwell Spring, and the rest of the water flows into the River Banwell.

Banwell Pumping Station- A hidden gem

Water from Banwell Spring is pumped via the Banwell Water Treatment Plant and pumping station,  which has a 30 megalitre per day capacity, and provides 120,000 people in Weston super Mare and the surrounding area with their drinking water. The pumping station in Banwell is unmanned, and you would  never guess its purpose from the building it is in, which looks very like the several other handsome old residential properties near the Old Bowling Green. The Banwell Plant has an automatic filtration system which also treats water from Winscombe bore hole and Blagdon reservoir.

Clean drinking water is a vital resource. We literally can’t live without it.  Building the bypass will involve cutting into land within the Banwell SPZ, and potentially interfering with the aquifer, the underground layer of water-bearing rock and other materials from which the water springs. Pollution and contamination from chemicals and other pollutants after a spills or accidents on the new road resulting in contaminated surface water are also a risk.

A detailed risk assessment and a hydrogeological risk assessment are part of the groundwater source protection process.

The Environment Agency must protect groundwater sources used to supply drinking water from pollution, like Banwell Spring, and there are detailed rules for its approach to protection. When it comes to transport developments for major new roads the Environment Agency usually requires a detailed risk assessment to show that groundwater pollution will not occur.

 Developers proposing schemes that present a hazard to groundwater resources, quality or abstractions must provide an acceptable hydrogeological risk assessment (HRA) to the Environment Agency and the planning authority. Any activities that can adversely affect groundwater must be considered, including physical disturbance of the aquifer. If the HRA identifies unacceptable risks then the developer must provide appropriate mitigation. If this is not done or is not possible the Environment Agency will recommend that the planning permission is conditioned, or it will object to the proposal. ( N6)

Physical disturbance of aquifers in SPZ1  : Within SPZ1, the Environment Agency will normally object in principle to any planning application for a development that may physically disturb an aquifer (N8.)  Obstruction of flow : The Environment Agency will only agree to proposals that could obstruct groundwater flow where mitigation measures can be agreed.  There must be not be an unacceptable change in groundwater levels or flow due to the proposal  ( N9)

( www.n-somerset.gov.uk/my-services/planning-building-control/planning-advice/supporting-documents/assessments/groundwater-protection-details )

Currently we have not been told if there is a detailed risk assessment or hydrogeological risk assessment carried out and referred to the Environment Agency. These will be of considerable interest given the importance of the Banwell SPZ1

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