Green City: HIDCO plans to recycle waste water
West Bengal Housing and Infrastructure Development Corporation (WBHIDCO) is planning to go for reuse and recycle waste water as a part of its Green City Mission.
It has been decided that Sequential Batch Reactor (SBR) technology that consumes less area (about 50 per cent) less than the land required to set up a Sewage Treatment Plant (STP) will be set up in Action area III in New Town.
The technology clears water (5 BOD). This water will be supplied to Prakriti Tirtha known as Eco Park
and will be used to water eight children gardens, avenue plantation and cleaning of roads.
The decision was taken at a high-level meeting held between the engineers of WBHIDCO and Public Health Engineering department (PHE) on September 17.
Sewage water and black water that originates from domestic toilets and the liquid waste sources is treated in septic tanks and soak pits in rural and in semi-urban areas and in STPs in towns like New Town and Salt Lake.
Interestingly, in <g data-gr-id="54">Kolkata</g> there is no STP and waste water is purified and then offloaded to Vidyadhari drainage system by the Eastern Kolkata Wetland (EKW).
Waste water is off-loaded through Dry Weather Flow Channel (DWF) and Storm Weather Flow Channel (SWF).
It is recycled through a natural process and then taken to the Vidyadhari drainage system which was
set up by the British almost a century ago.
The STP technology has two major disadvantages. Firstly, huge space is required to set up the plant. Secondly, its level of purification which is 30 BOD is just fit for release in canals and rivers but unfit for use.
WBHIDCO has taken several steps under the Green City Mission in New Town. Installation of solar panel in offices has been encouraged along with construction of green buildings where additional FAR is given to the builder, the street lamps will be replaced by LED lamps in batches and rainwater harvesting is also encouraged.
Rainwater harvesting saves filtered water as cleaning, washing and flushing are done with the help of rain water.
The WBHIDCO is letting out area to nurseries to grow long trees and during Banomahatsov over
40,000 saplings have been planted to bring New Town under green cover.