Iran has one of the highest percentages of population in the Middle East with access to safe drinking water, with an estimated 92% of its people enjoying such access (nearly 100% in urban areas and about 80% in rural areas as of 2007). There is a considerable shortfall in sewage treatment; for example, in Tehran the majority of the population has no wastewater treatment, with raw sewage being injected directly into the groundwater. As the water crisis deepens with an expanding population, this pollution of groundwater causes increasing health risks.