Southern Water is planning a pilot aquifer storage and recovery project in Worthing to help secure future water resources.

The company is looking into the possibility of using aquifer storage and recovery (ASR) to store drinking water in a natural underground reservoir.

ASR involves taking water from rivers – in this case the River Rother - during wet, winter months, treating it, then transferring it into an aquifer where it can be stored underground until it is needed during hot, dry periods. It is then pumped back to the surface, retreated and put into supply.

ASR is one of a number of long-term options Southern Water is exploring as part of its 25-year Water Resources Management Plan. Research with 1,000 customers highlighted it as the most popular option for providing water, ahead of surface reservoirs and desalination.

Southern Water’s pilot scheme would take place on the former Charmandean Quarry, near Lyons Farm retail park. It would involve drilling a new borehole on a working site of around 20m x 30m and laying a temporary water main and sewer.

The borehole would take about four months to build, depending on the agreed drilling programme. Once the borehole has been built there would be an initial phase of test pumping lasting up to four weeks. The results of this testing would be analysed before a decision is made on whether further testing is appropriate. Any further testing would last up to six months. The testing twould be used to establish how much water a permanent scheme could supply, how sustainable it would be and the cost of building and running it.

Southern Water aims to submit a planning application to Worthing Borough Council and the South Downs National Park Authority this autumn. Subject to planning permission being granted, it would then aim to start work on the pilot scheme in 2015.

Commenting on the proposals, Southern Water’s Water Strategy Manager Meyrick Gough said:

“An ASR scheme would work as an underground reservoir where we could safely store water until it is needed. Customers have told us this is a scheme they would like us to progress. The pilot would help us establish how much water the scheme could supply, how sustainable it would be and the cost of building and running it."

He added that the company has already carried out initial environmental surveys of the area and is now talking to customers about the pilot project, before submitting a planning application. The water firm is holding a public exhibition in Worthing on 13th November to explain its plans for the project.

If the pilot is successful Southern Water would then look to develop a permanent scheme following consultation with customers and apply for the appropriate planning permission and licences,.

Southern Water anticipates that a permanent ASR scheme would then become fully operational between 2020 and 2025 in AMP7. The water from a permanent scheme would predominantly be supplied to the Brighton and Worthing areas but could also be pumped into north Sussex if required.

ASR is already widely used in the USA and there are also operational ASR schemes in countries including Canada, Australia and South Africa. There are a currently a number of other ASR trials in the UK (carried out by companies including Thames Water and Yorkshire Water) that have been completed or are underway.