Nine sections of pipe, totalling more than two and a half miles in length, will shortly be making their voyage from Norway, as part of the final phase of Guernsey Water’s upgrade of the island’s wastewater facilities.
Production will be completed imminently on the purpose-built, high density polyethylene pipes which are being manufactured by Pipelife Norway AS. The pipes are being produced in Stathelle (a town in Norway) and stored directly from the factory on the fjords in preparation for their seven-day journey to the island.
“The pipes will arrive in Guernsey at the end of April/early May and will, subject to formal agreement, be temporarily moored at Soldiers’ Bay, where they will be fitted with concrete collars in preparation for being placed on the seabed via a controlled sinking operation,” said Mark Walker, Capital Delivery Manager at Guernsey Water.
“This work is the final phase of a long-term project Guernsey Water is undertaking to provide the most effective wastewater disposal solution for the island.”
Guernsey’s current long sea outfall, which extends more than a mile from Belle Greve into the Little Russel, is more than 45 years old; the short sea outfall, which extends about 400m to just beyond the low water tide mark, is more than a century old. A survey conducted in 2011 showed that both pipes were in a state of significant disrepair. A further study, conducted by global marine experts Intertek Metoc, provided a detailed model for the pipes’ replacement that would ensure optimum results and protect the island’s bathing waters.
“The new outfalls will discharge wastewater in optimum dispersion zones. A combination of the Little Russel’s unique tidal range and the preliminary sewage treatment undertaken at the Belle Greve Wastewater Centre, built during an earlier phase of the project, make this the most appropriate and most sustainable solution. We have also built a four million litre storm storage tank, which will minimise the volume and frequency of excess flow through the short sea outfall during heavy rainfall,” said Mr Walker.
The project will include onshore work to install the new pipes from Belle Greve Wastewater Centre across Les Banques coast road, where a new chamber will be built adjacent to the slipway.
“The project is set to be completed by the end of October and while we hope that residents and islanders understand the inevitable disruption the works will involve, we also hope they recognise the efforts we have gone to in order to minimise the impact. Replacement of the outfalls is absolutely vital for the island and, along with the other phases of our liquid waste strategy, will ensure that Guernsey meets the requirements of water quality legislation now and in the future,” said Mr Walker.