Question to the Department for Environment, Food and Rural Affairs:

To ask the Secretary of State for Environment, Food and Rural Affairs, what assessment he has made of the potential impact of Southern Water's proposal to introduce recycled waste water in to the drinking water supply at the Havant Thicket Reservoir on the environment.

Southern Water have recently consulted on their proposal to turn treated wastewater, normally pumped out to sea, into purified recycled water. This water would then be pumped to Havant Thicket Reservoir, where it would be stored and mixed with spring water, before being pumped along a new pipeline and treated prior to going into supply.

The urgent need to protect the iconic chalk rivers of Hampshire means that action is needed now to ensure resilient and sustainable water supplies. Options such as water recycling mark a transition to water supplies that are not dependent upon the uncertainties of rainfall. These options are well established elsewhere around the world and are already operating elsewhere in the UK, to ensure resilient supplies in a changing climate.

All water recycling options including Southern Water’s must meet the environmental requirements for wastewater treatment discharges into the environment. Water re-abstracted from the environment for public water supply must also be treated to meet our high drinking water standards before use, in accordance with a robust risk assessment.

Recent research carried out for the Drinking Water Inspectorate indicated a high level of support (79% agreement) for the use of water recycling to supplement drinking water supplies.

An online survey and in-depth, online interviews were undertaken between July and September 2022. The online survey had 1,618 respondents with demographic representation broadly consistent with the UK adult population. Survey respondents were randomly allocated to groups so that the impact of two manipulated variables (relating to water recycling scheme design and to terminology) could be investigated. Overall, the survey showed that there was a relatively high Ref: DWI 70/2/348. Project Report ii level of support (79% agreement) for the utilisation of water recycling to supplement drinking water supplies. The survey results also showed that terminology has a stronger influence on levels of support for water recycling than scheme configuration (e.g. the presence of environmental buffers).