Agenda item

To consider a report by Councillor Barry Mellor, Lead Member for Environment and Transport (copy enclosed) regarding the project aiming to replace Pont Llanerch and risks associated with the construction of a bridge.

RESOLVED that Cabinet –

 

(a)      considered the report and detailed design stage report (attached at Appendix A to the report) and on the evidence of the risks presented, supported the conclusions of the Partnership Scrutiny Committee, and decided that the project aiming to replace Pont Llanerch be stopped, and

 

(b)      confirmed that it had read, understood and taken account of the Wellbeing Impact Assessment (Appendix B to the report).

Councillor Barry Mellor presented the report regarding the project aiming to replace Pont Llanerch and risks associated with the construction of a bridge.

 

The Corporate Director: Environment and Economy, Head of Highways and Environmental Services and Senior Engineer – Bridges and Construction attended.

 

Cabinet was guided though the report which included the extensive work carried out and complexities of the project to replace Pont Llanerch following its collapse in 2021.  The project had been split into three stages: Optioneering, Detailed Design and Construction.  The detailed design stage had been a complicated and lengthy process and raised some significant challenges, the main challenge being the foundation required for a new bridge.  Pont Llanerch was located above a freshwater aquifer within a layer of sandstone and Dwr Cymru/Welsh Water (DC/WW) had a freshwater extraction site next to the old bridge.  The foundation work for a new bridge would require drilling into the sandstone layers which had the potential to compromise water quality and a risk of supply loss to 85,000 DC/WW customers, and introduce a public health risk with wide reaching consequences.

 

Members were also guided through a technical presentation illustrating further details of the project’s optioneering and detailed design stages including reasoning behind the preferred option, foundations, ground investigations and outcome.  Cabinet was assured that every possible engineering solution for building a new bridge had been considered with the Council exhausting the optioneering and designing the most viable option for replacing the bridge.  However, it had not been possible to design a replacement bridge without creating an unknown level of risk to the water supply in the region with no known means of rectifying the problem.  The matter had been discussed at Partnerships Scrutiny Committee in April 2025 and their conclusions and recommendations had been set out in the report for Cabinet to consider.  Given the significant risks associated with construction of a replacement bridge it was recommended that Cabinet made a decision to stop the project.

 

Cabinet stated that all involved wanted Pont Llanerch to be rebuilt and that aim had been included as an ambition within the Corporate Plan with much work carried out in that regard with support from the Welsh Government and at significant cost.  However, having exhausted all options to design a replacement bridge it was clear from the expert engineering and risk management advice given that it would not be possible to construct a bridge without the risk of compromising the water supply to 85,000 homes with no known means of rectifying the problem and no insurance against that liability.  Main discussion points focused on the following –

 

·       given the complexities and technicalities of the project it was felt there was some public misconception and a general lack of understanding of the situation

·       a representative from DC/WW had been unable to attend the meeting to answer questions but a representative had attended the Partnerships Scrutiny Committee in April 2025 to help inform that debate and their stance remained the same in that proceeding with the project presented too high a risk to the water supply of homes and businesses across the majority of the north of Wales

·       the aquifer was a porous rock with water contained within it and filtered in the rock itself and extracted; it was approximately 22km long, 5km wide and 100m deep hence it would not be possible to move the bridge some distance up or down stream because it would still be located over the aquifer

·       the issue of a temporary bridge had been raised but it would still require the same foundations and so the risk remained, and it would not be feasible

·       Welsh Government had been fully supportive of the project and had supported the Council to invest almost £1.5m to consider and design the most viable option and would likely have funded the rebuild costs of a replacement bridge

·       there was reference in the Wellbeing Impact Assessment to improving alternative routes in the area and £900k had been secured from the Welsh Government’s Resilient Roads Fund to upgrade the diversion route around the bridge so they were better suited to commuter traffic; if a decision was taken not to build the bridge secondary options would be explored with local communities to maximise possible local business/commercial opportunities

·       as the Council was aware of the risk to the water supply it would not be insured against that risk if it was decided to build the bridge; it would not be possible to assess the level of impact beforehand and the resulting issues may not manifest during construction but years later and the Council would remain liable.

 

The Leader stated that the Council would be negligent if it was to proceed with the construction of the bridge given the risk to the water supply for which the Council would be held liable with no known means of rectifying the problem.

 

The Leader invited local members Councillors James Elson (Trefnant) and Chris Evans (Tremeirchion) to speak on the matter.

 

Councillor Elson stated that the options and design phases had resulted in a dream bridge, but the communities just needed a bridge, and the Council must deliver on that promise.  He believed there had to be a practical solution to deliver a bridge within the existing constraints such as a single-track or temporary prefabricated bridge set on benches without affecting the aquifer and referred to a quote from a local construction company for that work.  He also felt that officers had no appetite for building a replacement bridge and stressed the need to find a solution.

 

Councillor Evans echoed those comments and felt there had been little engagement from the Council which had been detrimental to the project.  He felt the time taken and amount spent on the project to be a matter for the Governance and Audit Committee.  Councillor Evans felt consideration should be given to a temporary bridge advising that a local building contractor had confirmed a bridge was possible.  He highlighted the detrimental effect on residents, businesses and the local school and stressed the need for a crossing.  Finally, he asked Cabinet to defer the decision pending a motion to full Council to review/consider other options.

 

The Leader referred to the evidence heard that any replacement bridge would come with a risk and he questioned the value for money of a temporary bridge.  The Council and the Welsh Government had been determined to build a replacement bridge and had worked extremely hard towards that aim, but the risk presented was too great and the Council had a corporate responsibility and duty of care in that regard.  It would not be appropriate for the Council to put itself in a position of liability and risk contaminating the water supply to thousands of residents.  The matter had been debated at length by Cabinet and Partnerships Scrutiny Committee and a number of public meetings had been attended by officers.  Officers added that they had been criticised both for spending too much time and money to deliver the project and for not doing enough, emphasising that they had worked hard to deliver the project and had explored every option to deliver a bridge to the required safety standards in an area subjected to flooding.  However, given the high risk to the water supply with no means of rectifying the problem the project had come to an end.  Discussions around a temporary or other type of bridge would be a different project and required a separate discussion. 

 

The Leader thanked Councillors Elson and Evans for diligently representing their communities and shared their frustration that the project could not proceed.

 

In response to further questions from members officers advised that –

 

·       the probability of the risk to the aquifer was difficult to ascertain but the consequences would be severe

·       drilling would create a vibration which presented a risk of fissures appearing in the aquifer: irrespective of the type of bridge it would need the same foundations

·       the design aimed to spread the load and weight of the bridge over a wider area

·       any bridge in that location required the same level of foundations to maintain its safety, irrespective of whether it was temporary, a footbridge or cycle bridge

·       the issue with the bridge was not the weight bearing down on it by vehicles etc., it was the water pressure coming from the side of the bridge that undermined the foundations which needed to be suitable to deal with that pressure of water and the undermining that took place

·       explained the blending process used by DC/WW with two other water sources to supply 85,000 properties and the purity of the water from the Pont Llanerch site meant the water treatment was far lower than normal – if the water supply was affected it would take years to address and the Council would be liable.

 

Councillor Barry Mellor highlighted the experience and expertise of the company commissioned by the Council in this matter whose advice should be accepted.

 

RESOLVED that Cabinet –

 

(a)      considered the report and detailed design stage report (attached at Appendix A to the report) and on the evidence of the risks presented, supported the conclusions of the Partnership Scrutiny Committee, and decided that the project aiming to replace Pont Llanerch be stopped, and

 

(b)      confirmed that it had read, understood and taken account of the Wellbeing Impact Assessment (Appendix B to the report).