An £11 million project to upgrade screening provisions at Belle Greve Wastewater Works is nearing completion.
Located on the east coast of Guernsey, Belle Greve houses the Island’s only wastewater collection and treatment plant. As part of the upgrade works a new plant comprising screens and grit removal equipment will be installed inside the building in order to provide full odour control at the facility.
In addition, new storm-water storage tanks will be installed at Belle Greve to increase the capacity of wastewater during peak flows. The storage tanks will also prevent the need to discharge untreated overflow into the sea.
Work began on site in March 2012 under the management of Guernsey Water and their appointed consultants, Atkins Ltd. Construction and engineering specialist Trant (Guernsey) Ltd is the main contractor on the project.
At present a number of works have been carried out at the site, including the laying and re-routing of high-voltage cables, clean water and foul water pipes; the excavation of the storm tank area and the construction of the penstock chamber. Piling works for inlets and the installation of blinding layer and ground anchors to the storm tank have also taken place.
The state-of-the-art mechanical screens will remove grit and non-biodegradable material larger than 6mm in diameter. Washed and compacted screenings and grit will then be transported to local landfill sites for disposal. Once the non-biodegradable content has been removed from the flows, the remaining biodegradable elements will be broken down through a natural process without detriment to the environment.
Chris Sheppard, Guernsey Water, said:
“The existing plant is over 40 years old and as spare parts are becoming increasingly difficult to obtain it was decided that upgrade works were a necessity at the facility. There have also been issues with odour nuisance to neighbours and unscreened discharges being released to the sea.
“Following the results of a scientific study by global experts Intertek Metoc, the States of Guernsey agreed that the Island’s wastewater could continue to be discharged into the Little Russel, provided that all non-biodegradable material was removed.
“The Metoc study provided firm evidence that the Guideline Bathing Water quality compliance standard could be achieved but it was acknowledged that the liquid flows discharged to sea needed to be of a higher quality.”
Before work began on the project, Guernsey Water, Atkins and Trant held two public drop-in sessions for local residents and businesses. The sessions allowed members of the public to learn more about the project and air any of their concerns.
Throughout the project site staff have maintained a close relationship with the public to make sure that any issues can be identified and rectified quickly. In addition, all efforts have been made to assess the impact the improvement project will have on the environment.
Chris Sheppard added:
“As with all of its operations, Guernsey Water carefully considers the environmental impacts that a project might have, and the Belle Greve project is no exception.
“As part of the preliminary project work, a land swap was organised with the Environment Department in order to protect a recognised reed bed. The new storm tank structure will also be built fully below ground so as not to impinge on the views of the Chateau des Marais – a historic castle in St. Peter Port.”
Belle Greve Wastewater Works is due for completion in July 2013.