The largest cost components of the bill are the sewage and wastewater levies. This includes a water pollution levy and is the approximate average for the category "residents” or “households”. The OECD survey referred to above suggests that the Netherlands compares well with countries that recover costs from revenues through w'ater bills (e.g. Belgium-Wallonia and Flanders, England and Wales, France, Sweden, Switzerland). This figure initially increased from 109 litres in 1970 to a peak of 149 litres in 1990, but subsequently declined (CBS, 2013).