The amount of solid waste generated in Buenos Aires has increased by 30 per cent in the last 10 years. This was found during the first-ever study on the city's solid waste. In 1991, the average daily production of waste in the city was 3,353 tonnes, which has now increased to 5,050 tonnes. The study further states that three per cent of the city's population has no access to the sewage and sanitation systems. An analysis of the waste generating capacity of different localities revealed that the areas most active are the ones inhabited by upper and middle-income groups.