Are our cities Bharat Stage-VI ready?

An Orientation Workshop in Mumbai

On advancing on-road emissions management for being BS-VI ready 

A joint initiative of the Department of Transport, Government of Maharashtra and Centre for Science and Environment (CSE), New Delhi 

Cities need a big shift in emissions monitoring of on-road vehicles after Bharat Stage VI (BS-VI) emissions standards get implemented from April 1, 2020 for massive emissions cut  

  • BS-VI emissions standards will reduce emissions from new vehicles by 80-90 per cent from the current BS-IV vehicles. But new generation emissions control systems will require more advanced on-road emissions inspection to keep vehicles low-emitting
  • Old vehicles – designed to emit three to eight times more pollution than the current BS-IV compliant vehicles -- also require scrutiny to keep emissions under check. Strengthen Pollution under Control Certificate Programme and phase in more advanced tests.
  • Mumbai experiencing 36 per cent increase in ambient particulate pollution. Has to fight vehicular pollution which isthe second highest contributor to particulates and nitrogen oxide concentration in the city.
  • Maharashtra and specifically the Mumbai Metropolitan Region are in the grip of rapid motorisation; hourly pollution concentration in Mumbai correlates strongly with traffic peaks. Pollution concentration of nitrogen dioxide during peak hours can increase by 65 to 78 per cent from the non-peak hours. Traffic exposure has enormous health risk.
  • Stringent on-road emissions management needed to reduce real world emissions in Mumbai and other cities of Maharashtra.  

Mumbai, February 3, 2020: On April 1, 2020, India – including Maharashtra and all other states-- will implementthe Bharat Stage VI (BS-VI) emissions standards to cut emissions from new vehicles by about 80-90 per cent from the current BS-IV fleet. India is the only vehicle-producing region in the world that will leapfrog directly from BS-IV to BS-VI emissions standards (by skipping the BS-V stage). 

But to sustain the emissions gains from the new fleet,cities need to be prepared with strong on-road emissions management to ensure these vehicles remain low emitting during their productive life on road and the real-world emissions from old and new vehicles do not deteriorate. BS-VI emissions control technologies will be significantly more advanced and sensitive to maintenance and will require a paradigm shift in the way we currently monitor tailpipe emissions. 

Tosensitise the implementing and regulatory agencies in Mumbai region about the new generation technology, management of advanced emissions control systems and consumer awareness aboutthe BS-VI regime,the Department of Transport, Maharashtra along withthe New Delhi-based think tank Centre for Science and Environment (CSE) convened a joint orientation workshop here today. 

The workshop brought together national and international expertsfromthe Automotive Research Association of India, the International Council on Clean Transportation (USA), Indian Oil Corporation and CSE to engage with the implementing agencies and regulators of the Mumbai regionincluding transport department, state pollution control board, Bombay Municipal Corporation, traffic police, bus transport corporation, petrol dealers associations, among others. It focused on the new genre of technology and emissions inspection approaches like remote sensing, real world emissions monitoring, integration of on-board diagnostic system, and infrastructure for dispensation of auto-grade urea and its quality control for NOxemissions control systems in diesel vehicles. 

Speaking at the workshop, Anumita Roychowdhury, executive director-research and advocacy, CSE, said: "This conversation has become necessary in view of the fact that transportation sector has emerged as an important source of air pollution in the region and the clean air action plan framed for Mumbai has asked for stringent control of tail pipe emissions and revamping of on-road emissions management.” 

What is at stake? 

Mumbai’s air quality is worsening: Annual average particulate pollution is rising in non-attainment cities of Maharashtra and particularly in the larger Mumbai region. According to the air quality data available under the National Ambient Air Quality programme, the three-year average of PM10 levels has increased by about 32 per cent between 2012-14 and 2016-18. Mumbai needs 59 per cent reduction in particulate concentration to meet the national ambient air quality standards. While this requires multi-sectoral action, the transport sector is a challenge-- according to a source assessment by Urban Emissions Info, transport is the second highest emitter of PM2.5 and NOx in Greater Mumbai. 

Rapid motorisation making air more toxic and harmful: It took 30 years for Maharashtra to get its first five million vehicles – thereafter, it has progressively added another five million withinmuch shorter timespans of seven years, five years, three years and now two years. In Greater Mumbai particularly, the vehicle stock is doubling every decade. This also means that future growth will happen based on BS-VI emissions standards. 

Traffic hotspots more polluted: CSE has analysed daily PM2.5 and NO2 levels for 10 monitoring stations in Greater Mumbai from November 1, 2019 to January 25, 2020 – and has found several hotspots that have levels higher than the city mean. Seven out of 10 stations have higher average than the city’s mean for PM2.5. These include Colaba, Kurla, Sion, Worli, Ville Parle, Vasai West etc. Five out of 10 stations have higher average than the city’s mean for NO2. All these stations are close to major traffic junctions. 

Problem ofolder vehicles: There is also the inflated stock of older vehicles. As much as 40 per cent of the existing vehicle stock belongs to the pre-2010 age group. Pre-BS-I to BS-III compliant vehicles in Mumbai are 34 per cent of the total stock. BS-III was introduced way back in 2005. Pre-BS-III vehicles are 13 per cent of the stock. BS-I and BS-III heavy-duty vehicles emit eight times and four times higher respectively than the BS-IV fleet; BS-I and BS-III light duty vehicles emit thrice and 1.4 times higher respectively than BS-IV vehicles. In fact, pre-BS-I vehicles can be eight to 16 times more polluting. Improving the on-road emissions management for older vehicles stock to address gross pollution is important. Even though Maharashtra has implemented a green tax to disincentivise older vehicles, strategies will have to be made more holistic.  

Exposure to vehicular fume can be significantly high: CSE’s granular analysis of hourly change in concentration of PM2.5 and NO2for selected days during the three consecutive months of November and December 2019 and January 2020 shows higher pollution during peak traffic time. Additionally, a day has been tracked for traffic speed on the eastern and western expressways (based on Google speed data). This also shows strong correlation between slow traffic speed and hourly build-up of pollution during morning and evening peaks. During morning and evening peaks, the average traffic speed varies between 20-25 km/hour that can even dip below 15 km/hour. During those peak hours the hourly pollution concentration increases. In fact, the NO2 levels – that are more strongly related to traffic – increase by 78 per cent during evening peak hours in November (compared to the non-peak hours under study), 26 per cent in December, and 65 per cent in January. 

Clean air action plan for Mumbai has asked for improved on-road emissions management – need firm roadmap for implementation: The newly approved clean air action plans have asked for a range of improvements. This includes regular checking of vehicular emissions and issuing pollution under control (PuC) certificate; remote sensing; retrofitting particulate filters in diesel vehicles (with BS-VI fuels); checking fuel adulteration; scrappage policy for old vehicles; I/M for older buses; restricting commercial vehicles entering the city; promoting battery-operated vehicles (buses); tax exemptionfor CNG, hybrid and electric buses; weigh-in motion bridges at the border to prevent overloading; freight traffic management; green buffers along traffic corridors; construction of expressways and bypass roads to decongest etc. All of these will have to be implemented in a time-bound manner. 

What will change substantially with BS-VI: The big change is awaited with the introduction of BS-VI vehicles in 2020. The gap between emission limits for petrol and diesel cars will narrow down substantially. Particulate limits for different segments of diesel cars will be 82 to 93 per cent lower than the BS-IV level. Nitrogen oxide emissions limit will be 68 per cent lower. Similarly, particulate limits for heavy duty vehicles will be 50-67 per cent lower than the BS-IV level. For the first time, India will introduce particle number count in exhaust emissions to ensure vehicle manufacturers use the most effective diesel particulate filter that can have over 95 per cent efficiency in controlling particulate matter with 10 ppm sulfur fuel. Also, for the fist time, India will monitor real world emissions from vehicles. 

More advanced emissions control system will require more improved emissions monitoring than PuC: To make these technologies work during the useful life of the vehicle on the road and to prevent emissions frauds like the Volkswagen scandal and dieselgate in Europe, India has also adopted real world driving emissions testing using portable emissions measurement systems (PEMS) for vehicle certification at the national level. But its actual application for certification has been delayed for both light duty and heavy duty vehicles until 2023. Until then, only data will be collected and assessed. One of the reasons why heavy duty vehicles in Europe could avoid the dieselgate debacle is because of early adoption of both real world PEMS testing and in-service conformity requirement (testing of emissions in real world when vehicles are in use). Specifications for on-board diagnostic systems that record details of vehicle performance for monitoring are more stringent. The durability requirement of emissions control systems has been specified for a minimum distance range of 160,000 km which is substantially higher than the current requirement. 

PuC will not be adequate to detect anomalies in emissions and emissions control systems in vehicles efficiently. More advanced systems of remote sensing and integration of OBD would be needed with regular inspection programmes. 

Maintain fuel quality: From April 1, 2020 sulphur content of petrol and diesel will reduce drastically 10ppm to allow efficient performance of advanced emissions control systems in new vehicles. BS-VI vehicles must not be misfuelled with sulphur-rich fuels or adulterated fuels. Their systems, once affected, can recover to some extent if the use of near-zero sulfur fuels is restored, but recovery takestime due to sulfate storage on the catalyst. To ensure steady and expanded uptake of BS-VI fuel and prevent misfuelling,fuel quality surveillance is needed. A new assessment of fuel quality in Mumbai, Thane, and Nagpur carried out by the International Council on Clean Transportation (ICCT) has shown good compliance with various paramaters for both BS-IV petrol and diesel. Diesel sulfur levels varied between 17 and 32 ppm, whereas petrol sulfur levels varied between 10 and 28ppm. These data suggest that we are unlikely to face any major fuel quality challenge in implementing BS-VI standards in April 2020. Clean fuel is also needed to reduce excessive engine wear, deposits and corrosion. More importantly, clean fuel opens up the opportunity for retrofitting of on-road vehicles with advanced emissions control systems. 

New generation emissions control systems require stringent surveillance: People are still not aware that new diesel vehicles will come equipped with selective catalytic reducing mechanism (SCR) system to reduce NOx emissions. This will require periodic refill of the urea tank placed close to the exhaust to neutralise NOx emissions. Cities will need to be ready with a dispensation system for auto grade urea. The extra cost of refill may also lead to disabling of the SCR system causing uncontrolled emissions. Similarly, it is important to ensure that advanced particulate traps are not clogged and functioning properly through a self-cleansing process. This will require physical checking as well as integration of the on-board diagnostic system with the PuC regime. Remote sensing measurements may also be needed to check emissions while vehicles are being driven on the road. 

The steps forward

To leverage the BS-VI transition,it will be important to ensure the followingin Mumbai and other regions of Maharashtra: 

  • Strengthen the PuC system and its enforcement for the legacy vehicles: Adapt the system to new PuC norms and upgrade systems and instruments for authentic and credible tests. Carry out PuC audit to identify gaps for proper enforcement. Improve level of compliance so that everyone turns up for tests.
  • Phase in more advanced on-road emissions inspection to ensure the advanced emissions control systems are performing optimally: PuC programme will not be adequate for this. Introduce remote sensing monitoring that can measure a range of parameters even as the vehicles are moving on the road to identify and fix the gross polluters for maximum impact. Integrate on-board diagnostic systems already installed in new vehicles to automatically record and alert anomalies to the vehicle users while vehicles are moving on the road.
  • Need strong surveillance of fuel quality to stop adulteration and misuse of high sulphur fuels: New ICCT data on fuel quality surveillance in Mumbai shows there is still not much deviation from the legal specs for fuels. This is encouraging and must be strengthened further.
  • Adopt measures of physical and other checks to prevent emissions frauds and emissions cheating by using defeat devices or by disabling advanced emissions monitoring systems.
  • Build consumer awareness related to this new technology to reduce risks.  


For more on this, please contact Sukanya Nair of The CSE Media Resource Centre, sukanya, nair@cseindia.org
/ 88168 18864.