Most water is provided to the city by deep tubewells from underground water sources. Since the start of operations of the Sayedabad waste water treatment plant, in July 2002, the plant is providing 22.5 crore litres of water daily for the city which covers 18 per cent demand of the city.

This waste water treatment plant was established with Tk 586 crore, funded jointly by the Bangladesh and French governments and World Bank.

Sayedabad water treatment plant is using surface water from Sitalakhya, which is selected because of its easy access to the plant and quality of water as its chemical waste could be refined in this plant.

Dhaka Water and Sewerage Authority (WASA) says that they are supplying pure drinking water for the city people through underground tubewells and Sayedabad waste water treatment plant. The superintend engineer of Sayedabad plant said: "This water is 100 per cent pure as it goes under several steps of refineries and constant monitoring of its purity."

The river water drains through a lagoon built to carry raw water to the plant. Sediments and algae are left there. The raw water intake is mixed with chlorine to kill bacteria in the water. Aluminum sulfate is mixed for coagulation and flocculation of the wastes. The lime is mixed to improve the taste of the water. By this time the water of Sitalakhya becomes 80 per cent clean. After rapid sand filter treatment, 100 per cent clean water is ready to serve the city.

"One can drink this crystal clear pure water without doubt," said the superintend engineer.

But the fresh drinking water gets contaminated as it passes through the pipelines of WASA. WASA has a network of 2000 km pipelines around the city installed some 30 to 60 years back, of which 36 km is newly installed to supply the water of Sayedabad plant. Some pipelines are as old as 50 years. Due to leakage in the pipelines fresh water becomes infected with sewerage water.

Kazi Shish, the chief engineer of WASA said that according to the survey report 70 per cent of the water is contaminated in the private reservoirs and 30 per cent is contaminated through the pipelines. Pipeline leakage is done by illegal connection and also from the digging of sewerage, gas and other utility works.

WASA officials are aware of fresh water contamination. "The stink in the water is caused by leakage in the pipe lines," said Ajit Abu the superintend engineer of Sayedabad.

Engineer Shish also said, "We are aware of the situation and trying to repair the leakage in the pipes. We have also made public announcements in newspapers about how to clean the private reservoirs."