Online Continuous Emission Monitoring Systems (OCEMS)

Context:

In a bid to enforce stricter emission monitoring norms, the Central Pollution Control Board (CPCB) has directed State Pollution Control Boards (SPCB) to close down industrial units that haven’t installed Online Continuous Emission Monitoring Systems (OCEMS).

Background

Industries, particularly so-called Grossly Polluting Industries, are mandated to report their emissions to pollution control boards.
The CPCB has been insisting that industries install OCEMS that relay data to the CPCB as well as the SPCB offices.
The CPCB has since 2015 made it mandatory for industries to install OCEMS.
While the government claims a compliance of nearly 80%, updated figures this year on recalcitrant industries are not available.

Guidelines

The CPCB has finalised guidelines this month that specify the kind of sensors and monitoring equipment that can be deployed for the purpose.
It will also now become mandatory for a new industrial unit to install an OCEM to commence operations.
The CPCB directs SPCB/PCC (pollution control committee) to issue closure directions under the Water and Air pollution control Acts to industries falling under 17 categories of industries if found operating without OCEMS.
The industries that require OCEMS include distilleries (including fermentation industry), sugar, fertiliser, pulp & paper (paper manufacturing with or without pulping), pharmaceuticals, dyes and dye-intermediates, pesticides, tanneries, thermal power plants, iron and steel, zinc, copper and aluminium smelters.

OCEMS

In recent years Online Emission Monitoring Technology has received attention and interest in context of providing accurate and continuous information on particulate matter/ gaseous emission from stacks.
There are already commercially available systems for monitoring parameters such as PM, HCl, HF, NH3, SO2, CO, O2, CO2, NOx, VOC, etc.
The Continuous Emission Monitoring (CEM) System comprises of the total equipment necessary to determine the concentration of gaseous emission and/or particulate matter concentration and/or emission rate using analytical measurements and a computer program to provide results in units of the applicable emission limits or standards.
Whenever, say ammonia discharge levels are breached by an industry, an sms alert is sent out to officials who can then trigger action.

Advantages

CEMS provide continuous measurement of data for long periods of time, at the monitoring site of interest, without skilled staff being required to perform the analysis.
All the major steps in traditional analysis like sample collection, transportation, conditioning, calibration and analysis procedures including QC are usually automated in on-line analysers.
In case of sudden disturbance in the system, the on-line analysers provide timely information for taking immediate corrective/preventive steps compared to conventional methods.

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