State-run Indian Oil Corp (IOC) aims to invest $600m in upgrading its newest Paradip refinery in the eastern state of Odisha to start producing road vehicle fuels compliant with Euro VI emission standards by April 2020, four years earlier than initially planned, Reuters reported. The decision is to help India combat rising pollution as the country has 13 of the world’s 20 most polluted cities, with New Delhi being the worst, according to the World Health Organization’s report from 2014.

The Paradip refinery, designed to produce Euro IV and Euro V compliant fuels, has a production capacity of 300,00b/d. The production of Euro VI requires installation of some new units such as isomerisation, diesel hydrotreater and hydrogen units.

In addition to supplying markets in east and south of India, the refinery’s output is expected to compete with supplies from plants in the Middle East and China, according to Energy Business Review.

The $5.2b refinery is IOC’s most advanced plant processing the heaviest and dirtiest crude oil available at a cheaper rate. Commissioned in 2015, the refinery is estimated to operate at full capacity from the fiscal year 2017/18. Initially, it was scheduled to begin operations in 2012, but the project was delayed due to problems in supplies from contractors, environmental concerns, and natural calamities, The Economic Times informed.