A hydraulic engineer of the Brihanmumbai Municipal Corporation (BMC), Ashok Tawadia has stated that the locals in Mumbai, Maharashtra, will now be able to drink water directly from the taps.
According to the continued research, the average 0.7 per cent of water samples collected daily across Mumbai between April 2018 and March 2019 tested positive for Coliform bacteria, a group of microorganisms present in water bodies that indicate water may or may not be fit for drinking. The average of which in Mumbai tap water is far better than the WHO norm of 5% limit.
However, there is a word of caution attached to this advantage. In order to receive potable water, the locals need to ensure the cleanliness of underground and overhead water storage tanks. “Our water is potable and if residents can ensure their tank are regularly cleaned, they can drink water straight from the taps”, claimed Ashok Tawadia.
In the past, international agencies have noted that the water available with the BMC’S master Balance Reservoir at Bhandup was considered to be one of the purest all across the world. However, the water that reached the locals was inferior in quality due to the distribution system.
This has been worked on and since December 2018 ‘pure’ water has been flowing across the city’s 7,000 km water distribution system. Tawadia stated that according to the samples collected since December, the content of E coli is less than 1 per cent. The number dropped further in March as the content fell down to 0.7 per cent. According to international standards, less than 5 per cent of water samples can contain coliform bacteria.
The transformation in the city’s water quality started in 2012-13 after a severe outbreak of waterborne diseases in the C ward (Marine Lines, Kalbadevi, Pydhonie, etc).
Firstly, the steel water pipelines used for surface distribution were converted into underground concrete water tunnels. Mumbai today has 14 such underground tunnels. Secondly, in slums, the numerous bunches of water pipelines laid close to sewage lines were removed and replaced with a single six- or nine-inch pipeline and connections were provided close to tenements.
To assist the project, the additional municipal commissioner Rajiv Jalota joined hands with the National Environmental Engineering Research Institute (NEERI). The water testing laboratories were upgraded and the BMC adopted the membrane filter technique. The testing of the samples is now done by the health department instead of the water supply department.
Around 358 water sampling points were identified by the water supply department in 257 water zones of Mumbai. Each point provides water to 10,000 people. The samples were collected from 36 outlets of the 37 reservoirs of the city. In all, 125 water samples are collected every day.
The BMC collects around 36,000 samples through the year and the percentage is calculated once annually. From 17 per cent, it is now remarkably down to 0.7 per cent.