L&T adopts sustainable solid waste management measures at MTHL project site
Installs bio-toilets and a sewage treatment plant
The Mumbai Trans Harbor Link (MTHL) project is one of the most awaited infrastructure projects in Mumbai city partly because it has been a long-delayed one but, more importantly, because it will ease traffic congestion towards New Mumbai and beyond.
At its peak time, the project is estimated to have a 4,500+ work force and with the site located in an environmentally sensitive coastal regulatory zone area of Sewri, Mumbai, the project team were tasked to plan to mitigate any conceivable environmental risks.
Since the project site is located next to the sea, the issue of sewage and waste management was a challenge especially as some of the normal solutions were untenable. “We were faced with several challenges when we started to plan for sewage disposal and waste management,” informs the L&T Construction spokesperson. “Firstly, the area did not come under the purview of the Municipal Commission of Greater Mumbai; then there were no existing sewage network drains in the vicinity and the groundwater table is too shallow to construct a soak pit. We evaluated several other options too including a conventional 150 KLD sewage treatment plant.”
Finally, in consultation with MMRDA, L&T adopted a low-cost solution of installing DRDO-Patented Bio Digester Tanks to treat the sewage with culture specially developed for use in areas that experience wide temperature fluctuations. The advantages of this system are manifold: zero operation and maintenance cost; no need of manpower for operations and no chemical required for treatment. Other benefits are that there is no sludge generation and the treated water can be discharged directly into drains and meets the Maharashtra Pollution Control Board Discharge Standards.
Totally 36 such Bio Digester Tanks of 400 litres capacity each have been installed underground near each of the infrastructure buildings at the site and have been so designed to last the duration of total execution time of around four and a half years. An added advantage is that once the project is completed, these bio tanks can be emptied by MCGM mobile suction tanker services and the empty tanks can be installed at any other location of L&T Construction where temporary sewage treatment is required.