On World Water Day, special correspondent Steve Sapienza reports on innovative techniques to assist slum dwellers in Bangladesh in getting access to clean water. This report is the most recent in a series on global population issues in collaboration with National Geographic magazine and the Pulitzer Center on Crisis Reporting.

The capital of Bangladesh, Dhaka, is one of the world's fastest-growing cities but also one of the poorest with a population estimated at 15 million is expected to increase to 20 million by 2025. Over 2,000 new people come to the city every day from rural areas hoping for a better life in the city. Unfortunately, due to lack of infrastructure, the majority of these newcomers end up in poverty-ridden slums.

There are almost 5,000 slums in and around Dhaka City. Access to clean water and safe sanitation are difficult to come by. Local clinics are overwhelmed with patients suffering from water-borne diseases such as cholera, diarrhea and E.coli.

Dhaka Water and Sewage Authority, DWASA, is responsible for supplying the city's population with safe water. Residents need city approval before they can extract water or connect to city water pipes. But approval to use city water is only given to residents who can provide proof of land ownership. This leaves four million slum dwellers without legal access to city water.

To address this urgent issue, non-government organizations have developed a system where DWASA provided clean water to communities who forms a water committee that pays to install the pump and for the costs of operation and maintenance. These committees also collect and pay the water bills. The success of earlier NGO-backed water points now enables community groups in slums to negotiate directly with the city for legal water access without NGO help. Today, there are over 1,000 water connections in 100 slums.

"Almost 5,000 slums are in and around Dhaka City. And almost one-third of the population are living in -- at the low-income communities and slum areas. Most of them don't have ownership over those pieces of land that they're residing. But the main challenge is provisioning essential services for this huge number of population, mainly water and sanitation." Khairul Islam, Country Director, WaterAid

"We are now having about 400 patients every day. But in August, September, sometimes we go up to 1,200 a day. Then I can tell you, the average of a year is 120,000 patients every -- in a year. So, this hospital is a quite busy one, most of them having E. coli diarrhea and cholera diarrhea." Dr. S.K. Roy, International Center for Diarrheal Disease Research

1. Where is Bangladesh?
2. What is a 'developing country'?
3. Name two water-borne diseases.

1. How do you get access to clean water? Where does your water source come from?
2. Why do you think it is so difficult for people living in developing countries to access safe, clean water?
3. If you were the president of Dhaka Water and Sewage Authority, how would you ensure clean and affordable water to the city's poorest citizens?