Spotlight On: The Hampshire Water Transfer & Water Recycling Project
Water is one of the most precious resources on earth and without it, life as we know it would simply grind to a halt… but, despite this, resources are coming under increasing amounts of pressure from a variety of different angles, including climate change, population growth, urbanisation, pollution and water mismanagement.
It’s expected that the UK will see a water gap between supply and demand of around four billion litres of water per day by 2050, with river, reservoir and underground aquifer levels falling as demands for water increase.
In order to address this challenge, a twin-track approach will need to be adopted where new water supplies are delivered while water demand is simultaneously reduced through water efficiency improvements and leakage rate reduction.
Under the Environment Act 2021, the government has set out plans to reduce public water supply consumption in England by 20 per cent by 2037/2038.
Under the current revised draft resources plans, a 22 per cent reduction in per capita use would be reduced in this timeframe. Water companies are also expected to act quickly and install smart meters to deliver on their water efficiency commitments to reduce leakage.
Furthermore, a nine per cent reduction in non-household water consumption is also being sought by 2037/2038 to hit the water demand target. The current water management draft plans would achieve a reduction of 6.1 per cent.
But it’s not just about driving down demand… new water supplies will be necessary and decisions regarding these must be decided upon now – and there are various proposals for multiple schemes by 2050 contained within the revised draft water resource management plans, including desalination, water recycling, reservoirs and resource sharing between and within companies.
Hampshire water transfer scheme
The Hampshire Water Transfer and Water Recycling Project is one such scheme intended to help deliver new water supplies for homes and businesses so that less needs to be taken from chalk stream rivers throughout the county.
Hampshire itself is home to some of the best chalk streams in the UK – the River Test and the River Itchen. These are both delicate ecosystems supporting biodiversity and wildlife, and as such, new restrictions have been implemented on the amount of water that can be extracted from these sources for public supply.
This, coupled with the combined pressures of climate change and local population growth, means that the county needs to find new sources of water, with at least 166 million litres of water per day already required that aren’t sourced from rivers or aquifers… so it is now necessary to look to technology for potential solutions.
The project itself will involve the construction and operation of a water recycling plant in Havant, with one pipeline transferring treated wastewater to the plant and another transferring reject water from the plant to the Eastney Long Sea outfall.
Pipelines will also be constructed between this recycling plant and Bedhampton Springs, which would connect to others between the springs and Havant Thicket Reservoir.
This would enable the transfer of purified recycled water from the plant to the reservoir, as well as transferring source water from the reservoir to the pumping station at the water recycling plant site.
A backup system will also be set up, with underground pipelines built between the plant and the reservoir, one of which would transfer purified recycled water from the plant to the reservoir and the other to transfer source water back the other way to the pumping station.
What is water recycling?
Water recycling processes use advanced treatment techniques to turn wastewater into purified recycled water, which means that less needs to be extracted from the environment.
This particular project would see purified recycled water pumped to the Havant Thicket Reservoir, whereupon it would be pumped to the Otterbourne Water Supply works for further treatment to turn it into drinking water. During drought conditions, the pipeline could transfer up to around 90 million litres of water each day to the Otterbourne site for further treatment.
The treatment process uses special membranes, reverse osmosis and micro/ultra-filtration to remove salts and other such impurities. Because the process is so rigorous, other essential minerals like magnesium and calcium have to be added back in.
Planning permission
The Regulators’ Alliance for Progressing Infrastructure Development has just this week (February 24th) confirmed that the Hampshire project has now completed Gate Three of its Rapid gated process.
According to the New Civil Engineer, this means that solutions are now being prepared for development consent order or Town and Country Planning Act applications. Here, the focus will be on the breadth and comprehensiveness of activities that are being carried out ahead of the planning application submission.
Gate four is the final stage of the gated process, whereupon Ofwat’s major projects team will assume oversight of the solutions.