NGT frowns at rockblasting, asks MMRDA to think of alternatives

“The creation of a partial 1 to 1.5 m depth in limited portion will not yield major improvement in hydraulics. Blasting and activities associated with blasting can adversely impact water and sediment quality and biodiversity of the region,” the report stated.

MMRDA had been blasting the rocky outcrop on the Mithi river bed in an attempt to maintain a slope to prevent flooding of the river during the monsoon. On Friday, the tribunal asked NEERI to further study the impact of years of rock blasting undertaken in the river.

The tribunal was hearing a public interest litigation by NGOs Jal Biradari and Vanashakti, which have sought restoration of the river and challenged the rock blasting activities.

“Largely, rock blasting was being done in Mithi for the past two years. We had undertaken this activity only after the Central Water and Power Research Station, Pune, said it could help in increasing the slope of the river. We will now have to come up with an alternative solution and get additional approvals and environmental clearances, which could further delay the project,” said S B Tamsekar, chief engineer, MMRDA.

Meanwhile, the Maharashtra Pollution Control Board (MPCB), in its affidavit to the NGT on Friday, stated that the civic body has failed to identify sites for Sewage Treatment Plants (STP) along Mithi and Vakola nullah and also failed to submit a concrete proposal for construction of these STPs.

IIT-B had previously suggested STPs at 37 locations. However, the Brihanmumbai Municipal Corporation (BMC) has now submitted a proposal of just three STPs. The NGT had on March 18 ordered the MPCB to direct the BMC to submit a proposal on STPs that filter domestic sewage, which MPCB claims is the main source of pollution of the river.

According to the affidavit, BMC has proposed one STP on municipal land in Powai and two on Air Port Authority of India (AAI) land within their premises. Further, the BMC proposes to divert the discharge of the remaining pollution points into the existing municipal sewer network due to site constrains, and that alignment of proposed sewers is being finalised.

“It is not known whether the Air Port Authority has agreed to allot such land or given permission to construct 2 STPs on its own land. AAI already has two STPs of capacity 10 and 4 MLD at the international and domestic terminals and this is meant only for airport sewage,” said R R Vasave, sub regional officer, MPCB.

Moreover, the MPCB stated that BMC was directed to revoke licences granted to unauthorised units within the catchment area of the Mithi river within 30 days, but no information about revocation of licences had been received to date.
The next hearing is scheduled on April 28.

anjali.lukose@expressindia.com