Despite the inconsistency of supply, 91% of those in urban areas have some access to safe drinking water, with sources including pumps, public taps, and wells and boreholes. Some households have tanks installed to alleviate the impact of service interruptions. Half of the city's water comes from a local aquifer, and there are four water treatment plants at the southern edges of the city. Water tariffs were put in place in 2004, but were removed in 2006 following the 2006 East Timorese crisis. Trials for water tariff re-introduction began in 2013. Increasing usage has led to the aquifer unable to match demand during the dry season, and development has limited recharge rates. Downstream areas also face saltwater intrusion.