The Delhi Development Authority (DDA) has begun a process to retrieve the land allotted to the now-defunct Millennium Bus Depot and a section of the Rajghat thermal power plant used to dump fly ash as part of its floodplain restoration project.
The proposal, which is still to be finalised, will see the area developed as an ‘ecotourism’ space. However, the DDA is yet to decide how to deal with the fly ash remnants.
The development authority had allotted 13.35 hectares of the proposed 30-hectare floodplain project to the Delhi Electric Supply Undertaking (now Indraprastha Power Generation Company) in 1985-86. Around seven hectares from this was further allotted to the Delhi Transport Corporation for the Millennium Bus Depot, set up prior to the Commonwealth Games in 2010. The depot was later shut as it was functioning on the floodplains. However, structures built on the site continue to stand.
The Indraprastha Power Generation Company land is being considered to be permanently allotted to the DDA, an official told The Indian Express.
The official added that since the area was used as a dump yard for fly ash, a lot of leaching had taken place. One option being considered is to treat the fly ash so that it becomes inert.
A team from Jamia Millia Islamia is studying the area and recommending how to handle the remaining fly ash.
Department of Civil Engineering Professor Gauhar Mehmood said heavy metals, such as cadmium, aluminium, and lead, were present in the area, which had a high pH value of around 9.4.
The fly ash has been consolidated as it has been there for some time, Professor Mehmood told The Indian Express, adding that remedial measures would have to be undertaken if any activity was done in the area.
The varsity team is still researching some areas, while a report was submitted to the DDA about a year ago, he added.
Possible neutralisation methods for the toxic elements, according to Professor Mehmood, include phytoremediation and the introduction of geomembranes.
He told The Indian Express that if water bodies were created and geomembranes introduced, the configuration of these should be done in such a manner that the toxic elements were neutralised. This would result in the river not being affected. Diluting the toxic elements ensures that it will not contaminate the river and the groundwater, he said.
Phytoremediation uses plants to remove pollutants, while geomembranes are used to control leachate flow.
The development authority plans to set up an ‘oceanarium’ and ‘river museum’ at the site, providing details on the river and its restoration. Revenue generated from this site could then be used to maintain the other floodplain areas.
The project cost has been estimated around Rs 86.73 crore.
The DDA official said the proposal was not final, but might be used to meet requirements the national capital might have for eco-friendly structures to bring people and introduce them to the project.