“That’s Not Sand!” A Recycling Lesson from Mumbai’s Building Sites

Several years ago, a construction contractor in Mumbai ordered what he believed were truckloads of river sand for a new residential project. It arrived on time, looked sandy enough, and cost less than expected.

Soon after, masons started raising concerns. Concrete wasn’t setting correctly. Tiles kept popping. Walls developed cracks.

Upon inspection, the material turned out to be finely crushed Construction and Demolition (C&D) waste, sourced informally from a nearby demolition site.

The Irony

Had the material been processed correctly, it could have worked. Recycled C&D waste is usable in construction—if:

• It is processed at authorized facilities

• It undergoes proper screening and air classification

• It carries valid quality control certifications

In this case, the contractor received an untested, unauthorized mix—more like mystery chutney than building material.

Key Takeaways

Mumbai produces over 8,000 tonnes of C&D waste daily. Much of this waste ends up in informal supply chains or landfills. However, with proper systems, C&D waste can be:

• Reused as road base or backfill material

• Made into paver blocks and low-load concrete products

• Used to replace natural sand and aggregates in non-structural applications

  
  

The Punchline

The contractor now insists on certified recycled material. His reasoning?

“At least the bricks don’t crumble when I sneeze.”

Moral of the Story: 

Recycling works when it is standardized, scaled, and supervised. Let’s build smarter infrastructure, one that holds up to scrutiny, and maybe even a sneeze.