Under continuous check

The continuous emission monitoring system to curb air and water pollution can herald a new era in India's environmental regime


                    A biomedical waste incinerator in Bengaluru. The government has ordered that all common pollution treatment facilities must install CEMS (Photo: Sanjeev K Kanchan)
A biomedical waste incinerator in Bengaluru. The government has ordered that all common pollution treatment facilities must install CEMS (Photo: Sanjeev K Kanchan)

India's environmental governance is on the verge of a big overhaul. Between January and May this year, closure notices were issued to around 500 industries that failed to install continuous emission monitoring system, or CEMS.

CEMS is a real-time air and water pollution monitoring system introduced by the Central Pollution Control Board (CPCB) in February 2014 in 17 categories of most polluting industries and common pollution treatment facilities of the country. The board also ordered the 11 state pollution control boards (SPCBs) in the Ganga basin to direct industries within their jurisdictions to install CEMS for wastewater. Till March 2016, more than 80 per cent of the 2,764 industrial units that were supposed to install CEMS have either done so or started the process. Some SPCBs have also initiated CEMS installation in the polluting industries listed under CPCB’s ‘‘Red’’ category.

S M R Prasad, associate vice-president, JSW Steel, says CEMS will strengthen regulation over industries, make the system more transparent and industries more vigilant, and provide evidence to regulators to take actions on defaulters. Industrial pollution monitoring in India is done by SPCBs, mostly on quarterly basis. Except on the day when they are being inspected, most industries rarely follow emission norms. Though SPCBs are required to undertake regular checks, shortage of workforce, huge workload and inadequate infrastructure/technology hinder effective monitoring. Most industries falsely show compliance to emission norms by under-reporting their pollution levels. They get away with it because the existing mechanism to monitor, control and report pollution is severely inadequate. This is likely to change with CEMS.

How it works

CEMS comprises a pollution sampling and conditioning system, and a set of analysers or sensors integrated with hardware and software systems to collect, handle and transfer data (see ‘Smoke tracker’).

Smoke tracker
 
Continuous emission monitoring system or CEMS offers a close, accurate and transparent assessment of gaseous and particulate matter emissions from stacks
 

 
Key stages of CEMS

1
Equipment selection: Industry selects the correct type of sampler and analyser. There are various types of analysers depending on the techniques they work on. For instance, photometric (based on light penetration), chemical reactions, electrical, magnetic or thermal characteristics of pollutants or a combination of these.

2
Installation and analysis: The sampler is installed in the stack for gaseous air pollution monitoring. For monitoring particulate matter, no sampler is required. The sensor is directly installed in the stack. The sampler collects samples from the pollution source and sends them to the analyser, which is either installed close to the sampler (in-situ CEMS) or at a distance (extractive CEMS).

3
Data acquisition and handling: After measurement, the analyser sends information in the form of low-voltage signals to a system of hardware and software which translates them into readable data and passes it to regulators through the Internet.


Selection of the correct type of analysers is very crucial and is generally done on the basis of parameters such as pollution characteristics, plant operations and regulations. As a best practice, a certified analyser or sensor is selected by an industry and installed. This mechanism is prevalent in Europe. Alternatively, the regulator can check the performance of analysers during installation, which is the practice in the US. Analysers should be checked periodically for accuracy, which may get affected due to factors like high temperature, pressure and moisture in the pollution source. The entire CEMS process is automatic, which would be of great use for countries like India where resources are meagre and infrastructure weak.

Journey so far

The first push for CEMS in India came in 2011 when CPCB started trading in particulate matter (PM) emission in three states—Gujarat, Maharashtra and Tamil Nadu—for a selected group of industries as a pilot. This required CEMS-based PM emission monitoring. The project is still struggling because CEMS is yet to be properly implemented.

In April 2015, the Ministry of Forest and Climate Change (MoEFCC) issued a draft notification to make installation of CEMS legally binding. However, since the basic infrastructure required for implementing CEMS was not in place, concerns were raised by industry and the notification was put on hold. Currently, CPCB is only targeting installation and adoption of CEMS and not checking whether the data being collected complies with the emission norms. But as stakeholders gain experience, a compliance mechanism must be developed.

A CEMS analyser installed on a stack

Teething troubles

The CEMS technology is new to India, and industry, SPCBs, device manufacturers and technology providers are facing several difficulties. To understand the challenges, Delhi-based non-profit Centre for Science and Environment (CSE) carried a survey in early 2016. The survey revealed several interesting facts. It was found that a number of CEMS technologies are available in the market but industries have no skills to choose the one most suited to their needs. Moreover, many indigenous manufacturers are offering cheap CEMS equipment but there is no system for certification or quality assurance. And internationally certified, imported equipment are not enough to meet the market demand.

The survey also found that there is a need to frame guidelines and protocols for installation, performance check, calibration and verification of CEMS equipment. Empanelled laboratories should perform these checks and verifications, but India has no such system. A uniform system for data acquisition, handling and reporting with desired level of security and reliability is also missing. Lack of coordination with CPCB has made several SPCBs in the country disinclined in implementing CEMS. Prasad says that availability of skilled workforce and suppliers of CEMS are some of the other major difficulties, but this is a learning period and industry will get used to it with time.

Despite the teething troubles, the CEMS initiative has brought many positive changes, the most important one being the change in approach of industries towards pollution monitoring and reporting.

R Dhanasekaran, chief scientific officer at the Tamil Nadu Pollution Control Board, says that since the industries know they are being watched, the violations have decreased. With CEMS installation, a decrease in local pollution levels has been noted in the state. In the US, nitrogen oxides (NOX) and sulphur dioxide (SO2) emission from the power sector substantially declined during last decade with the help of CEMS, says Jeremy Schreifels, branch chief of US Environmental Protection Agency (see ‘CEMS should be based...’).

'CEMS should be based on a strong legal foundation'
 
Jeremy Schreifels, branch chief of US Environmental Protection Agency (USEPA), says that CEMS is very effective in curbing emissions. Excerpts from the interview

How did CEMS take form in the US?

In the 1960s and 1970s, when many parts of the US were facing severe air pollution, USEPA asked industries to install CEMS to measure excess emissions. In 1980, CEMS for SO2 and NOX was mandated for the power sector. With the Clean Air Act Amendments in 1990, CEMS for CO2, NOX and SO2 gases was mandated for coal-fired power sector under the Acid Rain Program (ARP).

Which institutions are involved in the CEMS framework?

Industries operate CEMS and report the data electronically to USEPA for validation. USEPA and state agencies also conduct audits of CEMS implementation and provide guidelines and other support for implementation.

What initial challenges did the US face in implementing CEMS?

USEPA works with state agencies, equipment vendors, service providers, industries and the public to assess the problems and identify solutions. All through the course of implementation of CEMS, USEPA has been continuously enhancing its programmes to improve data completeness and accuracy.

What improvement has CEMS brought to the environmental regime in the US?

CEMS has helped USEPA in implementing many federal emission reduction programmes like ARP, NOx SIP Call, Clean Air Interstate Rule, Cross-State Air Pollution Rule and the northeastern states' Regional Greenhouse Gas Initiative. The NOX and SO2 emissions from the power sector have declined by 62 and 78 per cent respectively during last decade.

What should the government keep in mind while implementing CEMS in India?

The CEMS programme should be based on a strong legal foundation that provides performance-based approach for data accuracy and reliability. Incentives for proper CEMS implementation, quality assurance, standardised electronic reporting, provisions for missing data substitution, centralised administration with assistance from local and regional governments and flexibility for low-emitting sources are also necessary.



Learning curve

Though CEMS is new to India, it has been in use in the US and Europe for the past 40 years. The system did not work smoothly from the time it was launched. William Averdieck, founder and managing director of the UK-based firm PCME Limited, a leading supplier of continuous particulate monitors in Europe, and chairperson of EN14181 task group of Source Testing Association, a non-profit involved in development and implementation of emission norms in the European Union, says that in the beginning the industries were in the dark on what quality of monitoring was expected to comply with legislation (see ‘Regulation, incentives for industries a must).

Every country that adopted CEMS faced initial challenges. China and South Africa being the other cases in point. These developing countries adopted CEMS in the past decade and faced similar troubles. They are still trying to fine-tune the system.

'Regulation, incentives for industries a must'
 
William Averdieck is the founder and managing director of the UK-based firm PCME Limited, a leading supplier of continuous particulate monitors in Europe. He is also the chairperson of EN14181 Task Group of Source Testing Association (STA), a non-profit involved in development and implementation of emission norms in the European Union. He has over 25 years of experience in environment regulations

How did continuous emission monitoring system (CEMS) start in the UK?

CEMS started for the power sector and major industrial sources in the 1970s. The Environmental Protection Act, 1990, led CEMS installation across a broader set of industries. In 2000, CEMS was made mandatory under Large Combustion Plant Directives and Waste Incineration Directives.

What difference do you see between CEMS frameworks in the UK and the US?

In the UK, CEMS equipment is first evaluated under certain predefined conditions, as per the Environment Agency of England and Wales Monitoring Certification Scheme (MCERTS), and then used in relevant industries. In the US, the equipment validation is made when the analyser is being installed and tested for performance in an industry. This process is expensive but ensures data quality. Most importantly, CEMS results have legal implications in the US.

Who are the stakeholders of CEMS framework in the EU and what are their roles?

The European Environment Agency publishes the norms, standards, guidelines and regulates implementation while CSA group, a non-profit certification body, administers MCERTS. STA, a trade association for regulators, process operators, test houses and suppliers, helps in regulatory and technical issues associated with emissions. Testing, certification and validation of equipment is done by TUV, a German organisation. The European Committee for Standardization (CEN), is an association that brings together the national standardisation bodies of 33 European countries. CEN Technical Committee 264 develops standards for air quality in Europe.

What challenges were faced in launching CEMS in the UK?

CEMS equipment approval schemes were missing in the beginning and industries were in the dark on what quality of monitoring was expected to comply with legislation. Adoption of MCERTS helped sort out quality issues.

What factors should India consider while implementing CEMS?

Quality and suitability of CEMS should be kept in mind. Poor data is of no use to industry or the regulator. There is a need to have regulation and incentives for industries to properly operate CEMS.


For India, it is crucial to have a time-bound strategy to resolve the issues. The foremost need is to develop a guideline for selection of suitable equipment for monitoring various types of pollution. This should be supported by a certification system or a system to check the performance of equipment at the time of installation. Regular health and accuracy check of CEMS equipment is also a must. Empanelment of pollution monitoring laboratories is another area where the government needs to work. Industries have been outsourcing the manual pollution monitoring job to external labs recognised by MoEFCC or the National Accreditation Board for Testing and Calibration Laboratories. But these labs have not been evaluated for their ability to handle CEMS equipment. Therefore, a system for identification and empanelment of labs is required.

India also requires a tamper-proof data transfer, storage and publishing mechanism. With CEMS, regulators can keep a closer vigil but there is a chance of tampering with the data before it is sent to the regulator. Therefore, a uniform and tamper-proof system, such as a secure software, data encryption, parallel data transfer to regulator directly, must be used. MoEFCC and CPCB have made a promising start but there is a long way to go.

This story was published in the August 1-15, 2016 issue of Down To Earth magazine.

Move from news to views and get in-depth reports on issues that matter to you, every fortnight.
Subscribe now »

We are a voice to you; you have been a support to us. Together we build journalism that is independent, credible and fearless. You can further help us by making a donation. This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together.

Comments are moderated and will be published only after the site moderator’s approval. Please use a genuine email ID and provide your name. Selected comments may also be used in the ‘Letters’ section of the Down To Earth print edition.

Scroll To Top