Delhi’s waste-to-energy plants more polluting than coal units: Study

A new analysis has found that four major waste-to-energy incineration plants in Delhi have a cumulative Pollution Index score of 100, meaning they are more polluting than coal-fired thermal power plants and petrochemical industries. The Pollution Index (PI) for any industrial sector is a number from 0 to 100, and an increasing PI value denotes a higher degree of pollution load from the industrial sector.

The findings challenge the Central Pollution Control Board’s (CPCB) 2025 reclassification of waste-to-energy (WTE) facilities from the ‘red’ category to the newly created ‘blue’ category, which grants critical regulatory exemptions, according to the analysis published by the Centre for Financial Accountability (CFA).

Industrial sectors with a PI score of 80 and above come under the red category, and are subject to stringent monitoring, frequent inspections, and continuous emission monitoring. In January 2025, the CPCB created a new tier in its industry classification framework -- the blue category, which was not assigned based on a PI score range.

Instead, it was reserved for facilities designated as ‘essential environmental services’ (EES) for managing waste from domestic and household activities, according to the analysis. Subsequently, WTE facilities, which were in the red category, were moved to the blue category.

“Blue category plants, in contrast to those put in red and orange categories, are required to ‘self-assess’ their PI scores, introducing a structural conflict of interest into the very mechanism designed to protect the public from pollution,” the analysis said.

The move was made despite CPCB’s own reports showing that WTE facilities across India generate thousands of tons of hazardous waste per annum. For instance, CFA’s study looked at Delhi’s WTE plants in Okhla, Ghazipur, Narela-Bawana and Tehkhand using pollution data drawn from CPCB’s technical documents and regulatory submissions before the National Green Tribunal and the Supreme Court.

The analysis found that municipal waste incineration inherently generates three categories of pollution. One, toxic air pollutants (including dioxins and heavy metals); two, multiple streams of industrial wastewater (leachate, ash quenching effluent, scrubber water); three, large volumes of hazardous ash requiring secured disposal.

Moreover, the analysis revealed that the cumulative PI for these WTE plants is 100 out of 100, unlike CPCB’s cumulative PI score of 97.6 out of 100 for the facilities.

“By documenting the score as 97.6 instead of 100, the CPCB avoids admitting that WTE plants have reached the absolute maximum ‘ceiling’ of pollution potential,” the study said. It added that WTE facilities are not only generating tonnes of hazardous waste but also emitting 68 per cent more greenhouse gases per unit of energy than coal plants.

“By ‘bluewashing’ these facilities, the state effectively sanctions the most ‘toxic industry’ to continue its operation by dismantling existing environmental and health safeguards,” the study said.