In the first of two posts, we look at two of the other effluent recycling plants that Southern Water has in its plans for the future, based on information published in the current WRMP consultation documents. This post highlights Sandown, on the Isle of Wight; the next one covers Littlehampton, further along the coast in West Sussex.
Southern Water’s has increased the capacity of its proposed Sandown effluent recycling plant, now planned to provide up to 8.5Ml/day with a later delivery date between 2030 and 2031. The slippage in dates results from the slippage of schedule for other effluent recycling plants at Littlehampton and Budds Farm at Havant, as well as continued controversy surrounding the company’s proposed change of use for Portsmouth Water’s Havant Thicket Reservoir.
The proposed Sandown plant would discharge recycled effluent into the Eastern Yar, probably some distance upstream from the plant, for dilution with fresh river water and re-abstraction further downstream.
The location for the recycling plant is described in the Technical Report as being ‘on a combination of landfill site and a flood plain’, with a ‘contractor … engaged to support development and delivery’ with a ‘current forecast date for start of operations of March 2030’.
The former landfill site, which can be seen to the east of the Sandown wastewater and sludge treatment plant in the image below, may raise similar concerns to those raised for Budds Farm site at Havant.
The current dates represent a slippage from earlier published plans, due to a number of different factors. These include delays and complexities obtaining planning approval for the water recycling plant. A full Environmental Impact Assessment is now required as the construction will be on a combination of a landfill site and a flood plain. Extensive ground investigations are required to inform construction methodology, mirroring similar issues with the Havant Budds Farm project. There are complexities associated with building on a former landfill site that require environmental and ecological investigations.
Southern Water needs a River Yar discharge permit for the recycled effluent and modifications are required to the existing Sandown water treatment works permit to account for the water discharged from the recycling plant. Southern Water will need to carry out extensive sampling to support the discharge permit application. The company has also yet to establish requirements for Biological Net Gain (BNG) across the development site.
[Update – 10-2025] -The reject stream of warm brine from the recycling plant along with debris from routine maintenance of the reverse osmosis membrane filters is expected to be pumped out through the Sandown No. 1 long sea outfall, shown at the bottom right in this map extract from Southern Water’s ‘Clean Rivers and Seas’ service.
An interesting fact from the consultation documentation is that the pipeline between the Isle of Wight and the mainland has only one direction of flow. Water cannot currently be moved from the island to the mainland, so while Southern Water’s plans for utilisation of both the Newchurch groundwater option and the Sandown effluent recycling option creates additional supply availability on the IOW, it does not reduce the island’s reliance on the Hampshire drought options.
Havant Matters 