CAQM Direction 85 Explained — Why Every NCR Construction Site Now Needs a Live AQI Sensor
CAQM Direction No. 85 (December 2024) made continuous AQI sensors mandatory at every NCR C&D site above 500 sqm. Here is exactly what builders must install, integrate and report in 2026.
In December 2024 the Commission for Air Quality Management (CAQM) issued Direction No. 85, a sweeping mandate that made continuous ambient air-quality monitors compulsory at every construction and demolition site above 500 square metres across the entire National Capital Region — Delhi, Gurugram, Faridabad, Noida, Ghaziabad and Greater Noida.
More than a year in, enforcement has tightened sharply. UPPCB, HSPCB and DPCC are jointly running surprise inspections under CAQM oversight, and the penalty for non-compliance has standardised at ₹50,000 environmental compensation plus a stop-work order. Here is the full operational playbook for 2026.
What Direction 85 actually mandates
Strip away the legalese and the direction requires four things at every covered site:
- A continuous ambient air-quality monitor measuring at minimum PM2.5 and PM10
- Sensor hardware from a CPCB-listed or equivalent calibrated OEM
- Live data push to the DPCC / CAQM central server via the official API
- A public-facing display board at the site gate showing the current AQI reading
Which sites are covered?
Direction 85 applies to every C&D site with plot area or built-up area exceeding 500 sqm anywhere in NCR. The size threshold is identical across Delhi, UP and Haryana — the CAQM direction overrides looser state-level rules. Even sites that were registered years ago under older norms must retrofit AQI sensors within 90 days of receiving a notice.
Approved sensor types and parameters
DPCC accepts continuous monitors that report at minimum PM2.5 and PM10. Multi-parameter sensors that also measure NO₂, SO₂, CO, ozone, temperature, humidity and wind speed score higher in inspections and are now the de-facto standard for sites above 2,000 sqm.
The sensor must be from a CPCB-listed OEM or carry an equivalent ISO 17025 calibration certificate not older than 12 months. Indigenous and imported sensors are both accepted — country of origin is not a criterion, only certification.
Installation specifications
Mount the sensor 3 to 4 metres above ground level, away from direct anti-smog gun spray, away from the site exit gate (so vehicle exhaust does not skew readings), and with clear airflow on at least three sides. Use a galvanised pole anchored in concrete, an anti-theft cage, weatherproof enclosure and surge protection on the power line.
Power can be grid, solar or hybrid. Solar with a 12-hour battery backup is preferred — it survives the load-shedding that plagues many Delhi NCR sites and removes a common reason for the sensor going offline during a surprise inspection.
DPCC API integration — the part most installers skip
A sensor that shows data only on its own dashboard is not compliant. The sensor must push readings to the DPCC / CAQM central server every 15 minutes using the official API. The integration involves obtaining an API key from DPCC, registering the device IMEI, configuring the push endpoint and verifying live readings appear on your DPCC dashboard.
Skip this step and your site is technically non-compliant the moment the inspector logs into the portal — even though the sensor is happily working on site.
Display board at the gate
The site gate must carry a live electronic display showing current AQI, PM2.5 and PM10 readings, refreshed at least every 15 minutes. A typical compliant board is a 32-inch outdoor LED screen fed from the same data stream as the DPCC API push.
Penalties for non-compliance
The standard penalty regime in 2026:
- First violation — ₹50,000 environmental compensation plus 30-day cure period
- Repeat violation — stop-work order plus enhanced compensation up to ₹5 lakh
- Third strike — project blacklisting and referral to NGT
What inspectors actually check
From the 60+ inspections our clients have hosted in the past year, the inspector follows a consistent pattern:
- Sensor physically present, powered and showing live data
- DPCC portal shows readings within the last 30 minutes
- Calibration certificate dated within the last 12 months
- Sensor location matches the GPS coordinates declared on the portal
- Gate display board powered and showing current AQI
Common excuses that do not work
Inspectors have heard them all: the SIM is being recharged, the sensor was sent for calibration yesterday, the electrician is on the way. None of these are accepted defences under Direction 85 — the equipment must be operational at the moment of inspection.
Recommended setup for 1,000–2,000 sqm sites
For typical Delhi NCR builder-floor and small commercial sites we recommend: one CPCB-listed multi-parameter sensor (PM2.5, PM10, NO₂, SO₂, CO, weather), solar with battery backup, 4G uplink with dual SIM failover, gate-mounted 32-inch LED display, AMC with quarterly calibration. End-to-end install plus DPCC integration completes in 2 working days.
Looking ahead — what's coming next
CAQM has signalled three upcoming tightenings: mandatory NO₂ measurement (currently optional), tighter PM2.5 daily-average thresholds aligned with WHO guidance, and integration with the C&D waste tracking portal. Sites that invest in multi-parameter, cloud-managed sensors today will avoid expensive retrofits in 2027.
Frequently asked questions
Does Direction 85 apply outside Delhi?
Yes. It applies across the entire NCR — Delhi, Gurugram, Faridabad, Noida, Ghaziabad, Greater Noida and surrounding districts notified by CAQM.
Can I use a basic PM2.5 sensor I bought online?
No. The sensor must be from a CPCB-listed OEM or carry an equivalent ISO 17025 calibration certificate, and must integrate with the DPCC API. Off-the-shelf consumer sensors do not qualify.
How often must the sensor be calibrated?
At minimum every 12 months. Most quality OEMs recommend 6-monthly calibration in NCR's dust-heavy environment to maintain accuracy.
What if the sensor goes offline during an inspection?
It is treated as non-compliance regardless of cause. Solar backup and dual-SIM 4G are the two cheapest insurance measures against this.
Need help with this on your site?
Talk to our compliance team for a free site visit anywhere in Delhi NCR.