Manage C&D waste better to fight air pollution: CSE

New Delhi: With India’s construction industry booming, the country’s cities are all set to see a marked increase in the generation of construction and demolition (C&D) waste. This expected growth in the C&D waste stream is all the more alarming as it will add to the problem of air pollution that Indian cities have been struggling with.

“The existing operational C&D waste sector is projected to more than double in the coming years. If not fully recovered and recycled, construction waste can turn into a major polluter choking our cities. Though progressive steps are underway to set up C&D processing plants in cities, these have been marred by complaints of underutilisation and unviability due to inefficient waste management and market linkages,” says a new study by Centre for Science and Environment (CSE) that was released here today. Debris Dilemma: Promoting self-sufficiency – as the study is titled – presents a detailed review of 16 C&D waste recycling plants spread across India.

Releasing the report in a national stakeholder conference held in New Delhi, Anumita Roychowdhury, executive director, CSE, said: “C&D waste management and construction dust mitigation are integral to all clean air action plans of the 131 non-attainment cities (NACs) under the National Clean Air Programme of the Union Ministry of Environment, Forest and Climate Change. Cities are mandated to set up recycling plants to process waste to produce value-added products such as recycled aggregates, paver blocks etc, that can be brought back as a resource to the construction industry itself.”

Roychowdhury added: “Recycling of C&D waste enables full recovery of resources and adds economic value to the waste, creates livelihood and jobs. But their utilisation and economic viability are compromised due to weak waste management system in cities and poor market uptake of the recycled products by the construction agencies.”

The CSE study

Of the more than 35 new C&D waste recycling plants that are being set up in India, CSE has investigated and assessed the performance of 16 plants to understand the current gaps and the requisite policy pathways to make them scalable and effective.

The field investigation has evaluated the multifaceted processes and technologies that are applied in a C&D recycling plant, the product range produced from waste, effectiveness of waste management in sustaining waste feed to the plants, market uptake of the recycled products, and the overall economic viability of these plants. Says Rajneesh Sareen, director of CSE’s sustainable buildings and habitat programme: “What we have found is that despite making huge investments, most recycling plants are struggling economically. These plants continue to rely heavily on support from municipalities. Without a viable financial model and market integration, expanding such facilities will face difficulties and this can further weaken the overall waste management ecosystem.C&D waste is not just an environmental hazard; it's an efficiency hurdle for cities.”

UjjwalMitra, ADG (training and research), National CPWD Academy, said: “Reconstruction is a new reality. C&D waste generation from reconstruction is expected to rise from 7 percent to 15-16 percent of the construction portfolio. This will have huge land and energy implications if not handled well.” India's building space is projected to more than double in the next 20 years. There is enormous demand for sand and gravel,which increasesthe environmental footprints of mining. This rising demand has led to a six-fold increase in sand trade over the past 20 years, and to environmental issues like erosion, biodiversity loss and water salination. As a result, imports of sand have gone up.

Says Sareen: “Recycling of C&D waste can help substitute and reduce the demand for virgin material as approximately 80-90 per cent of C&D waste can be repurposed for various applications such as landscaping, earthworks and civil engineering projects. Using recycled aggregates causes 40 per cent lesser CO₂ emissions compared to using virgin materials – this is because it helps reduce embodied energy and lowers carbon footprints.”

Areas of concern

Municipalities do not have an adequate revenue stream to pay for illegally dumped waste in a city – they are unable to recover the costs from informal and anonymous waste generators. This has often resulted in municipalities under-capitalising the C&D recycling plants to avoid paying for the tipping fees. Plant operators often do not get sufficient C&D waste as feed for the recycling plants owing to inefficient waste collection and leakages in the system – they lose out on the potential revenue that can be generated from the sale of recycled products.

This increases their dependency on the tipping fee paid by the municipality for sustenance. This model is unsustainable, and discourages more C&D recycling plants from being set up.

The way forward

The CSE assessment study lists a few do’s:

A more aligned effort by construction companies, municipalities and recycling plants to create a robust ecosystem for efficient waste collection, segregation and transportation to the recycling plants to sustain the feedstock.

Municipality needs to support and create a well-structured ecosystem and a smart concessionaire agreement. This will allow the municipality to reduce its own involvement and associated expenses in C&D waste recycling.

Policy mandates for uptake of recycled products by construction agencies and plant operators’ own innovative marketing strategy for recycled products needed for ensuring economic viability of the plants.

Municipalities often face staffing limitations that make it challenging to fully address illegal dumping. Smarter concessionaire agreements that incorporate third-party enforcement can help to bridge this gap.

High disposal fees burdens the small waste generators, leading to illegal dumping. Rationalised fees for small waste generators, with cross-subsidies from bulk waste generators (like the Delhi model), can help them improve the formal disposal methods. A user-friendly system for waste pick-up, accessible collection points and awareness can drive the improvement.

Integration of the informal sector for primary waste collection can leverage the widespread network and capabilities of informal waste collection systems and enhance the efficiency of waste collection and transportation.

C&D recycling plants can have a successful business model if sales and market uptake of recycled products is efficient. This can also foster competition and encourage more recycling plants in cities.

With advancements in recycling technologies recycled aggregates can effectively replace natural material. This, however, requires more updated codes and standards for quality control.

Quality concerns limit the market uptake of C&D recycled products in the construction sector. Incorporating material testing labs in new recycling plants can ensure high standards and increase the use of recycled materials.