State looks at recycling to fix water woes ……Devraj Dasgupta I TNN
Mumbai: The state government will soon come out with a policy on recycling waste water in a bid to tackle the growing shortage of water in cities and towns across Maharashtra. The state wants all civic bodies, including Mumbai, to reuse at least ten percent of it’s waste water for nonpotable purposes.
Sources in the government said construction sites, manufacturing industries and power plants in the state need huge amount of water as they are expanding fast to cater to consumer demand. Moreover, the rising consumption of potable water in homes, hotels and offices across cities and towns is also adding to the demand for fresh water.
Against this backdrop, government authorities feel there would be a crisis situation unless there is better management of water. The state has formed an expert committee headed by A K Jain, principal secretary (water resources), to explore ways of recycling water going down the drains, literally.
Says Jain, “Almost 70 percent water supplied to homes and commercial establishments turns into waste water. Due to leakages, often waste water makes it’s way to a river, breeds bacteria in residential areas or pollutes ground water table”. The attempt is to not only recycle water for non-potable use but also check pollution of water sources.
At present, all municipal corporations and councils in the state collect waste water through drainage pipelines at the Sewage Treatment Plant (STP). However, waste water receives only primary treatment at STP, leaving impurities.
“We are looking at giving secondary and tertiary level treatment to waste water after it’s primary cleaning at the STP,” said Jain. The tertiary treatment plant (TTP) would be in close proximity to the basic STP, he added.
Authorities have identified at least three modern techniques used worldwide—rapid sand filters, reverse osmosis and ultra filtration—for tertiary treatment of waste water.
“We are talking to experts on implementing the most cost-effective tertiary treatment technology,” said Jain. The committee is also talking to various industry bodies, power plants, real estate developers on use of recycled waste water.
“Look at the advantages of recycling waste water in a city like Mumbai,” said Anil Diggikar, additional commissioner in BMC.
“The city needs 3,400 million litres per day (MLD) of fresh water. The construction industry alone needs close to 200 million litres of water per day. They can surely use recycled water,” he said.
However, he was quick to mention that tertiary treatment of waste water and its transportation back to users premises/sites would have a high cost. “Suppose BMC recycles waster water next to its STP at Malad. The civic body can make it mandatory for all construction sites and gardens in 20-km radius of Malad plant to use this recycled water, but who would bear the transportation cost is the big issue yet to be resolved,” he said.