Controversial sewage works hit by delays

Ted Peskett, local democracy reporter

Controversial work to build a sewage development at a popular city park has been hit by delays.

Plans for the sewage pumping station at Hailey Park in Llandaff North were approved in September 2022, which prompted residents and campaigners to raise thousands of pounds and open a legal challenge against Cardiff Council’s decision.

Campaigners, who argued Welsh Water’s plans should have faced more scrutiny, lost their legal challenge which was heard at Cardiff Civil Justice Centre in July 2023.

The development went ahead and Welsh Water said tunnelling work for the pumping station would take place up until 2024 before construction started.

Tunnelling

In a timeline published on Welsh Water’s website, it states work on the pumping station was expected to take place from October 2024 to April 2025.

However, Welsh Water now expects tunnelling to commence around February 2025 and the removal of the site compound to take place in October 2025, with the restoration of the field and landscaping anticipated to extend into 2026.

The not-for-profit water company is currently doing work to reduce the ground permeability around the pumping station shaft after it came across higher than expected groundwater flow rates.

It expects this work to be completed by this October.

A Welsh Water spokesperson said: “A significant amount of testing, sampling, and surveying was done before work started on the new pumping station in Hailey Park, Cardiff, however, this is not 100% conclusive given that the geology is assessed based on specific borehole locations.

“There is always the possibility that despite the preparatory work, conditions can differ when looking across a wider area.

“The grouting works mentioned are required to allow the construction of the pumping station shaft, where ground water levels need to be managed to facilitate the construction of the shaft to protect against movement of the ground during construction activity and to ensure the safety of individuals involved.”

Sewage

The purpose of the station at Hailey Park will be to pump sewage that’s travelled from the Plasdwr housing development, across the River Taff, up to the level of an existing sewage system. From there it can then be transported to Cardiff Wastewater Treatment Works.

Welsh Water said the sewage needs to be transported there because Cog Moors Wastewater Treatment Works does not have the capacity to take on all of the sewage from Plasdwr.

Llandaff North residents and campaigners said they were worried about the impact the pumping station would have on biodiversity and access to green space.

Welsh Water’s plans for the pumping station are accompanied by a landscaping scheme which is designed to mitigate the project’s visual and environmental impacts.

On current issues at Hailey Park, a Welsh Water spokesperson added: “The permeability of the ground will not create any risk to the functionality of the pumping station in the longer term, as above the mitigation is required to construct the pumping station shaft.

“We understand the impact these unforeseen delays have on the local community and are working diligently to minimise disruptions and get the work done as quickly and safely as possible.”

Welsh Water said its timeline for works at Hailey Park remains dependant on weather conditions and other factors that could impact excavation and tunnelling works.