Sandown Water Recycling Project

We’re planning to introduce a water recycling plant in Sandown. This will provide a new source of water for our customers on the Isle of Wight and reduce the reliance on the mainland.

Why does the Isle of Wight need water recycling?

Currently, around one-third of the Isle of Wight’s water supply comes from the River Test in Hampshire and is pumped across to the Island via the Cross-Solent Main. However, we need to find new sustainable sources of water to help keep taps and rivers flowing, following reductions in the amount of water we can take from the River Test and its associated aquifer. The pressures of a growing population and changing climate are also adding to this need.

You can use the infographic below to find more information about our proposed plans.

An infographic illustrating the proposed location of a water recycling plant in the Sandown area

An aerial view of Goddards Green Wastewater Treatment Works

Our Water Recycling Plant

We’re proposing to recycle wastewater at our Sandown Wastewater Treatment Works. We plan to use advanced wastewater treatment processes at a new facility to clean the water before it's transferred to our proposed new water recycling plant. At the water recycling plant, the treated wastewater would be purified further using tried and tested advanced water recycling techniques. After purification, the treated recycled water would be used to supplement the Eastern River Yar levels for further abstraction downstream. We would then pump the water to the existing Sandown Water Supply Works. Here, it would be treated to drinking water standards and supplied to our customers on the Isle of Wight.

A Southern Water engineer inspects a control valve at a wastewater treatment works

The new pipeline

We’re also proposing to build new water transfer pipelines and pumping stations to connect our proposed new water recycling plant to our existing Sandown Water Supply Works. Throughout 2023, we’ll be undertaking ground surveys to work out the best route for the new water pipeline. We’ll have a proposed route later in 2024, which will be shared at a public consultation, expected in late 2024. The consultation will be open to everyone, who will be invited to give their views on the developing proposals to help shape them.

Our Water Recycling Plant

The new pipeline

The timeline

Here's a timeline of what we've already done and how we'll carry out the Sandown Water Recycling Project over the coming years.

2019

In 2019 we published our Water Resources Management Plan (WRMP). This plan sets out what we can do to ensure a reliable water supply in the years ahead.

2024

We'll then hold a public consultation in 2024. This is so we can share our plans for the project and hear your views.

2024

After consultations, we anticipate that we'll submit our consent application in 2024.

2024

Following our application, we'll then receive a decision on our consent application.

2025

We then plan to begin construction on the project in 2025.

2027

By 2027, we plan to have the new Sandown water recycling plant in operation.

Frequently asked questions

Will this affect the taste and smell of my water?

Just like water across the country has its own distinct taste influenced by the geology of the local area, the water taken from the reservoir may taste different from existing supplies due to the change in source. The reservoir, while open to the environment (soil, plants, wildlife), may also influence a change in taste from existing supplies. This water will, of course, continue to meet strict drinking water quality standards and be wholesome to drink. We’re working with a range of international experts, our regulators and environmental organisations to develop our plans.

These proposals are separate from the current approved plans for Havant Thicket Reservoir. If they are to go ahead, they'll be subject to further engagement, consultation and planning consent. This is just one of the strategic solutions we're exploring to address water shortages in Hampshire.

Will water recycling be used just in a drought or more regularly?

The Hampshire Water Transfer and Water Recycling Project is being developed for use primarily during periods of drought. To ensure the continued availability and cleanliness of the water recycling plant and associated pipelines, a continuous ‘sweetening flow’ of water would be pumped into Havant Thicket Reservoir and then onward to Southern Water’s Otterbourne Water Supply Works for further treatment.

Are you considering the potential environmental impacts of water recycling on the reservoir?

A range of studies and investigations are ongoing as part of the consenting process for the Hampshire Water Transfer and Water Recycling Project. We'll prepare a Preliminary Environmental Information Report which will form part of our next stage of public consultation in 2024. This document will report the preliminary findings on any likely significant environmental impacts of the project based on the information available at the time and is designed to inform consultees’ responses to the next consultation. We'll continue to undertake environmental assessments and the main Environmental Impact Assessment will be documented in an Environmental Statement that will be submitted as part of the Development Consent Order application.

Environmental commitments made in respect of the reservoir, particularly around the wetland, will be maintained.

Would putting recycled water into the reservoir impact the reservoir design or operation?

The Hampshire Water Transfer and Water Recycling Project is not expected to require any changes to the size or layout of the reservoir as per the planning approval.

Would Southern Water’s proposals impact the potential for community/leisure facilities at Havant Thicket Reservoir?

All the environmental and community commitments approved in the original planning application for Havant Thicket Reservoir will be maintained if these additional proposals are progressed.

Why not look at storing winter rainfall in aquifers?

Aquifer storage and recovery is where treated water is pumped into an aquifer when surplus water is available. This would then be subsequently abstracted during a drought. It needs the aquifer to be “confined” – where it’s one separate underground body of water where the water would remain.

We’ve investigated this option in Hampshire and do have plans for one such scheme in the Lower Test (where the chalk is confined by London Clay) but it can only provide about 5.5 million litres a day. This is much less than the water transfer and water recycling option we’re pursuing. This project is currently forecast for 2040–41. The issue elsewhere in Hampshire is that the aquifer is unconfined – e.g., the water would simply flow away and could not be guaranteed to remain where it’s put.

Reject stream

Impurities removed from the recycled water will be released back into the Solent via the existing long sea outfall at Budds Farm (5.7km out to sea). This is called the reject stream and will mix with the remaining treated wastewater from Budds Farm. As the source water for water recycling is treated wastewater, there won't be any increase in impurities in the reject stream (as these impurities would have already been in the treated wastewater) but they will be more highly concentrated. We're modelling the reject stream quality and exploring with the Environment Agency whether this increase in concentration requires any application to amend our current permit for the long sea outfall.