Some tariff packages may be offered only to particular groups, such as those in receipt of social security benefits (OECD, 1999). In Australia, for example, Sydney Water provides a range of residential safety nets. In the United States, there are examples of low-income and disabled households receiving rebates based on income, percentage discounts on water bills, waivers of fixed charges and fixed allowances (credits) on bills (OECD, 1999).