In a major embarrassment for Indore, a city repeatedly hailed as one of India's cleanest, a shocking attempt to allegedly manipulate air pollution data has been uncovered. The Madhya Pradesh Pollution Control Board (MPPCB) has ordered the shutdown of all four automated air-quality monitoring stations in the city after discovering they were deliberately placed inside green zones to show lower pollution readings.
Stations Located in Gardens, Data Declared Invalid
The state's pollution watchdog took the drastic step following a joint inspection on December 29 and 30, 2025. The audit found "serious and similar deficiencies" in the operation and maintenance of the Continuous Ambient Air Quality Monitoring Stations (CAAQMS). In a formal notice to the Indore Municipal Corporation commissioner, the MPPCB stated that all stations operating at Regional Park, Maguda Nagar, Bijasan Mata Temple Hill, and Residency Park have been closed.
The board has outright rejected all data generated by these stations for regulatory or public display until the deficiencies are fully rectified. A copy of the letter is with the Times of India.
The most glaring irregularity was the choice of locations. All four stations were found installed far inside gardens, surrounded by dense tree cover, and situated away from main roads and human activity zones. The MPPCB noted that such siting violates technical guidelines and fails to represent the actual ambient air quality that citizens breathe, making any accurate pollution assessment impossible.
Technical Failures and Vendor Lapses Uncovered
The inspection revealed a cascade of failures in the system's management:
- The private agency appointed to operate the stations failed to provide valid calibration reports and did not maintain mandatory station logbooks.
- Expired calibration gas cylinders were found in use, with some showing signs of tampering with expiry dates.
- The vendor's representative was unable to perform on-site calibration for critical gaseous parameters like sulphur dioxide (SO₂).
- Technical scrutiny showed significant deviations in PM2.5 and PM10 calibration. Filter ribbons were found with incomplete, cut, and overlapping patches, indicating improper sampling.
- In a serious breach, the reuse of filter material, which is strictly prohibited, was detected.
Perhaps the most telling evidence of data manipulation was the finding that recorded PM2.5 levels were exceeding PM10 levels, a scenario the MPPCB termed "scientifically impossible." This anomaly directly raised concerns over data handling, processing, or outright manipulation.
Fallout and Directives for Indore Municipal Corporation
The controversy erupts just weeks after the National Green Tribunal (NGT) pulled up the state government over allegations of sprinkling water near monitoring stations to artificially lower pollution readings. The inspection team also flagged a complete lack of effective oversight by the Indore Municipal Corporation, with no authorized civic official regularly present at the stations and no evidence of routine technical reviews or audits.
The MPPCB has issued strict directives to the civic body:
- Realign the monitoring stations as per scientific norms to reflect true ambient air quality.
- Initiate action against the erring private vendor under contractual provisions.
- Appoint a responsible officer specifically for calibration, data validation, and regular inspections.
The board has made it clear that Indore's air-quality data will remain off public and regulatory platforms, including the Central Pollution Control Board's SAMEER portal, until all corrections are verified. The MPPCB's Indore regional office has been tasked with conducting regular inspections and reporting back to the headquarters. This episode casts a long shadow over the credibility of environmental data in a city that has built its reputation on cleanliness.
