Work to replace the existing system – which is now over 60 years old – began in 2017 and, since then, more than 150,000 tonnes of rock have been excavated from Bellozanne Valley to create 5,400sq/m of extra space.
Household recycling facilities, the scrapyard and the clinical waste incinerator were relocated to La Collette to accommodate the development.
According to engineers, the new system will be capable of providing waste-water treatment for a population of around 118,000 people and its capacity could be expanded by up to 20% at a later date if necessary.
Specialist UK contractors are now working to install equipment, including £4.1 million odour-control covers, which sit on top of the sewage settlement tanks. The application to build the plant was initially refused but then granted on appeal with the condition that the odour-control covers were installed.
A government spokesperson said: ‘The new sewage treatment works is due to be completed by the end of 2022, as planned, despite a delay of approximately 12 weeks due to weather and the impact of the coronavirus pandemic.
‘nmcn PLC, were awarded the design and build contract in September 2018, and have been working with local and off-Island subcontractors and suppliers to meet the staged project deadlines. Construction on all the main civil infrastructure and installation of mechanical and electrical equipment are ongoing but still subject to Covid-19 restrictions.’
The spokesperson added that the construction of the inlet works, where raw sewage arrives at the plant, along with the primary settlement tanks – where untreated effluent is first held – are now complete. The tanker import facility – where road tankers can drop off waste – has also been finished.
Contractors are now working to install electrical and mechanical infrastructure and odour-control covers.
The spokesperson added: ‘Works are expected to be commissioned in stages with the first stage being fully completed by mid-2021.
‘Construction activities have been impacted by Covid-19 travel restrictions and off-Island supply chain issues. However, work will continue to target the overall programme irrespective of any challenges.’