To ask the Secretary of State for International Development what assessment she has made of the applicability in development work of nanofiltration techniques developed by Strathclyde Water Services in co-operation with Thames Water. [20250]

Department for International Development (DFID) supports research into a range of water filtration techniques suitable for application in development work, and in this context has considered nanofiltration. The process is sensitive to the quality of the raw water and the technology places significant demands on operators, DRID therefore favours more robust and simple processes such as slow sand filtration to meet the needs of poor communications. Our research programmes will review the potential of the process for DFID as UK water industry research and practical experience evolves.