Ambient Air Quality Monitoring

What we monitor

Ambient air quality monitoring is carried out against the National Ambient Air Quality Standards (NAAQS, 2009), which set limits for twelve parameters. In practice most industrial consents call for a subset:

• Particulate matter - PM₁₀ and PM_2.5
• Sulphur dioxide (SO₂) and oxides of nitrogen (NO_x)
• Carbon monoxide, ozone and ammonia
• Volatile organic compounds and benzene, where the process warrants it
• Heavy metals - lead, arsenic, nickel - on the particulate fraction

Why the sampling plan matters more than the lab

A perfectly analysed sample from the wrong location proves nothing. Station siting has to account for the predominant wind direction, distance from the source, nearby receptors and obstructions - and for EIA work, upwind and downwind stations are required so the baseline can be separated from the plant's own contribution.

This is the part that gets challenged at appraisal, and the part that cannot be corrected retrospectively.

Monitoring for environmental clearance

An environmental clearance application needs one full season of baseline data, excluding the monsoon, at multiple stations. That is three months of fieldwork that cannot be shortened, and it is the single most common reason EC timelines slip. If clearance is on your roadmap, baseline monitoring should start before the rest of the application does.

Reports you can file

Results are issued on NABL accredited formats with method references, detection limits and the analyst's signature - the form MPCB, GPCB and appraisal committees accept. Standard turnaround is seven to ten working days from sampling.