Ecological concerns as city runs out of space to dispose drain silt, Pg3

Key Highlights:

• Delhi is facing a significant challenge in disposing of large quantities of silt extracted from its drains ahead of the monsoon season.
• Intensified de-silting operations have led to a substantial increase in silt removal, with the Irrigation and Flood Control (I&FC) Department removing 30.91 lakh MT this year.
• Conventional disposal methods, such as strengthening embankments, filling low-lying areas, and using landfill sites, have reached saturation.
• The extracted silt is often mixed with municipal waste, posing serious environmental risks and complicating disposal.
• The I&FC Department has invited Expressions of Interest (EOIs) from agencies specializing in legacy waste management, bio-mining, and bioremediation to find alternative solutions.

Delhi Silt.png

Detailed Insights:

• The problem is particularly acute because the dredged material is contaminated, making its handling, disposal, and reuse complex.
• Out of 77 drains under the I&FC Department, 22 discharge into the Yamuna river, highlighting the potential for river pollution.
• Approximately 25 mixed-flow drains, carrying both stormwater and sewage, contribute significantly to the contaminated silt.
• Traditional disposal practices are deemed neither environmentally sustainable nor viable for the long term due to saturated sites.
• The search for alternative methods includes assessing existing practices, characterizing dredged material, and developing treatment and reuse methods.
• Compliance with norms prescribed by the Central Pollution Control Board (CPCB), Delhi Pollution Control Committee (DPCC), and the National Green Tribunal (NGT) is a key requirement for new solutions.
• The de-silting drive aims to substantially improve drainage capacity, facilitate faster rainwater discharge, and strengthen flood prevention measures across the city.

Key Concepts Involved:

• De-silting: The process of removing accumulated silt and debris from drains and water bodies to improve their flow capacity.
• Bio-mining: A process of excavating old waste from landfills and separating it into different components for recycling, energy recovery, or safe disposal.
• Bioremediation: The use of living organisms, such as microbes, to remove pollutants, contaminants, and toxins from soil or water.
• Expressions of Interest (EOIs): A formal request by an organization for interested parties to submit proposals or demonstrate their capability for a project or service.