Photo: sliplining in Longue Hougue lane
Phase one of Guernsey Water’s £2 million investment to improve drainage around St Sampson Harbour, is complete and should be operating by the end of April.
This is the first of four phases which will ensure effective drainage in the area and protect the environment from sewer flooding and pollution. It will also allow future development in the area.
The project is one of the biggest in the utility’s agreed 10-year Business Plan (launched in April 2016) and is due to be completed by the end of this year.
Phase one involved upgrading and extending the discharge rising main to enable the pumping station, located on the south side of St Sampson Harbour, to handle greater flows of wastewater. This reduces the need for the combined sewer outfalls (CSOs) to the north and south of the harbour entrance during high flows and heavy rainfall.
A storage tank has been installed in the car park along Bulwer Avenue which connects to the gravity sewer that flows down to Belle Greve Wastewater Centre (BGWwC).
Mark Walker, capital delivery manager at Guernsey Water said; “This work is complicated and has come with a few challenges along the way. As with a lot of engineering projects of this nature unforeseen issues arise which inevitably have a knock-on effect, however, we are optimistic that the project will be completed by the end of the year.
“As soon as the project is complete it should have an immediate effect on the characteristics of the CSOs at both the harbour’s north and south sides. The volumes spilled from the overflows and their frequency of use will be reduced providing an immediate benefit to the coastal waters. The frequency of incidents in areas prone to flooding from sewer overload will also be reduced.
“In this area the geography of the island dictates the need to pump foul water to our BGWwC. On occasional, particularly during heavy rainfall, the sewers become overloaded resulting in the need for the various CSOs to come into operation. This is by no means ideal. The investment we have made here reinforces the importance we place on our environment as well as our focus on longer term strategic improvements to the island’s wastewater infrastructure,” Mr Walker said.
Tenders will shortly be issued for phase two and three of the project which is to replace the Vale Road sewer, increasing its size and storage capacity and also a new gravity sewer around Summerfield Road and La Hure Mare roads. This latter work will take place during the summer months. The gravity sewer will divert flows from a very congested part of the network and will provide additional storage, reducing the levels and likelihood of spills from the CSOs. The work in Vale Road will be scheduled for the autumn/winter period.
The final tender (phase four) will be issued to upgrade the St Sampson Harbour pumping station itself.
For more background details see http://bit.ly/2nesFoc