BHOPAL: Amid the shock, horror and public scrutiny around the water contamination deaths in Indore, the city, tagged until recently as one of the country’s cleanest on multiple parameters, has lurched into a fresh controversy around an alleged pollution cover-up. This, after the Madhya Pradesh Pollution Control Board (MPPCB) ordered the shutdown of all automated air-quality monitoring stations after finding them deliberately placed inside gardens and green zones to underplay real pollution levels. The state pollution watchdog also rejected the data thrown up by these air quality monitors till the ‘serious lapses’ are corrected.In a formal notice sent to the commissioner of the Indore Municipal Corporation, MPPCB enclosed a summary of its audit report stating that all Continuous Ambient Air Quality Monitoring Stations (CAAQMS) operating at Regional Park, Maguda Nagar, Bijasan Mata Temple Hill and Residency Park have been closed, and that no data generated by these stations will be accepted for regulatory or public display purposes unless the deficiencies are fully rectified. A copy of the letter is with TOI.The action follows a joint inspection by MPPCB headquarters and Indore teams on December 29 and 30, 2025. The inspection was carried out to verify the authenticity of Air Quality Index (AQI) data being displayed at the four locations. The board said it found “serious and similar deficiencies” in operation, maintenance and supervision across all stations, compromising the scientific reliability of the data.MPPCB’s most serious objection relates to the choice of locations. All four stations-Regional Park, Maguda Nagar, Bijasan Mata Temple Hill and Residency Park-were found to be located far inside gardens amid dense tree cover, away from main roads and activity zones. Such siting, the board noted, does not represent actual ambient air quality and violates prevailing technical guidelines, making accurate and comparative pollution assessment impossible.The alleged manipulation of pollution numbers comes just weeks after the National Green Tribunal (NGT) pulled up the state government over a petition claiming attempts undermine pollution levels by sprinkling water in areas where air quality monitoring stations are situated.The inspection team in Indore also flagged a lack of effective oversight by the municipal corporation. No authorised civic official was found to be regularly present at any of the stations, and there was no evidence of routine technical reviews, physical inspections or operational audits by the corporation.

Tree-shielded Monitors: MPPCB Rejects Data After AQI Monitors Found At Green Spaces

Serious irregularities were found in the functioning of the private agency appointed to operate the stations. According to the report, the vendor failed to provide valid calibration reports, did not maintain station logbooks, and used expired calibration gas cylinders, some of which showed signs of tampering with expiry dates. The vendor’s representative was also unable to perform on-site calibration for gaseous parameters such as sulphur dioxide (SO₂).Technical scrutiny revealed significant deviations in PM2.5 and PM10 calibration. Filter ribbons showed incomplete, cut and overlapping patches, pointing to improper sampling, while reuse of filter material-strictly prohibited under standard procedures-was also detected.Data analysis revealed PM2.5 levels exceeding PM10, a scenario MPPCB termed scientifically impossible, raising concerns over data handling, processing or manipulation.MPPCB has directed the civic body to realign the stations as per scientific norms, initiate action against the vendor under contractual provisions, and appoint a responsible officer for calibration, data validation and regular inspections. Until all deficiencies are corrected and verified, the board has made it clear that Indore’s air-quality data will remain off public and regulatory platforms.Copies of the notice have also been sent to the Central Pollution Control Board with instructions that Indore’s CAAQMS data should not be used on the SAMEER portal until further notice, while MPPCB’s Indore regional office has been asked to carry out regular inspections and report to headquarters.