One is to adjust tariff structures to account for household size, so as to avoid penalising large families. This solution is being adopted in an increasing number of OECD countries, including the Brussels and Flanders region in Belgium, Luxembourg, and some municipalities in Greece, Portugal and Spain. An example is the system adopted in the Wallonia region of Belgium, where water prices have included a charge destined for the Social Water Fund, to be distributed to low-income households.