About 19% of Mumbai's population still has no access to the sewerage network

The target of providing 100 per cent sewerage coverage in Mumbai has still not been met. Nearly ten years after the Mumbai Sewerage Improvement Programme (MSIP) began, about 19 per cent of the city's population remains outside the sewerage network. To close the gap, the Mumbai municipal corporation has begun preparing a plan to expand and strengthen the sewerage system.

Consultants will be appointed for this, and the focus will be on removing the shortcomings in the city's sewerage system.

According to the corporation's figures, Mumbai currently has an operational sewerage network 2,080.279 km long. The network serves 85.74 per cent of the city's geographical area and 81.28 per cent of its population.

The gap is widest in slum areas. There are no underground sewer lines there, so many families have to depend on septic tanks. About 60 per cent of Mumbai's population lives in slum areas, which has made inadequate sanitation a serious problem. If septic tanks are not maintained properly, toxic gas can build up in them, leading to explosions and fatal accidents.

The lack of sewerage connections is also hampering efforts to provide toilets in homes under the Swachh Bharat Abhiyan. The shortage of space in densely populated settlements is a major difficulty.

In many parts of the city, untreated wastewater from slums and industrial units is discharged directly into rivers, drains and storm-water drains. This is increasing water pollution. In the next phase of the MSIP, the corporation plans to divert this wastewater into the sewerage network. A river rejuvenation plan has also been prepared to reduce pollution.

The proposed expansion will also cover areas under the authority of MHADA, the airport authority, the railways and the Mumbai Port Authority. To make infrastructure work easier at these locations, the corporation is also considering changes to rules.

Work on sewerage projects is facing hurdles because of Mumbai's geography, the uncertain make-up of the ground beneath the city, the shortage of space and delays in various legal clearances. Several approvals are needed, particularly to lay sewer lines through Coastal Regulation Zone (CRZ) areas, forest land and land belonging to different government departments.

To overcome these hurdles, the corporation has decided to hire consultants to prepare a detailed project report (DPR). A list of 12 consultancy firms has reportedly been shortlisted for this.

Mumbai's sewerage system is more than 130 years old. When the sewerage improvement programme began in 2016-17, the city had about 1,830 km of sewer lines. The length has now grown to 2,080.279 km. Even so, the target of 100 per cent sewerage coverage has not been met. The forthcoming DPR will identify gaps in the infrastructure and suggest ways to extend sewerage services to underserved areas. It is hoped this will reduce the discharge of untreated wastewater and improve sanitation and the environment in Mumbai.