IWNL is appointed by Ofwat, on a site-by-site basis, to provide water and/or wastewater services; this is known as a New Appointment and Variation (NAV). IWNL own and operate the water and wastewater network in these areas, providing services to customers including supply of water, wastewater services, metering, and billing. IWNL has all the same duties and responsibilities as the previous statutory water company.