The big dig to help make Mersey cleanest for years

Oct 5 2007 Liam Murphy, Liverpool Daily Post

TWO £7.5m holes being dug in Wirral will help keep the Mersey clean and free from sewage. The “holes” are actually storage tanks being built by United Utilities to help take the water when the sewers overflow during storms.

The largest hole at New Brighton has proven to be almost a tourist attraction in itself, and is 23m deep and 20m wide.

A second storage tank is being built at Hoylake, and although it is much smaller – 11m deep and 7.5m across – the two can hold more than 7m litres of water, or enough to fill more than three Olympic-sized swimming pools.

According to United Utilities, they will mean the Mersey estuary at New Brighton and watercourses in Hoylake will be the cleanest they have been for decades.

David Schofield, United Utilities project manager, said: “This is great news for the environment and the whole community in New Brighton and Hoylake.

“Once it is completed, the water will be the cleanest it has been for years.”

At times of heavy rainfall, water running off the streets and rooftops drains into the sewer network.

If the sewer cannot cope with the amount of water, the overflows act like safety valves, discharging the excess into the watercourse and estuary.

However, the new storage tank will hold this excess water and then send it safely back down the sewer network following the storm.

Mr Schofield said: “This is typical of the type of improvements United Utilities is carrying out across the region, helping to transform coastlines, rivers and streams. It is a great example of the type of investment our customers’ water bills help to fund.

“Our aim is to carry out this important work as quickly as possible.”

The two projects are part of United Utilities’ plans to spend £2.9bn over the next five years on improving water quality.

At New Brighton, the tanks are being built on the seafront and to minimise the impact of the building work, rather than digging up the front, a tunnel has been burrowed out beneath the surface to connect the pumps to the storage tank.

Work on both facilities is due to be completed early in the New Year and when completed, it is planned that the land above will be reinstated.