The Nagapattnam Refinery also known as Cauvery Basin Refinery^[1] was the second oil refinery constructed by Chennai Petroleum Corporation Limited. It is situated at Kaveri Basin at Nagapattinam.^[2] The initial unit was set up in Nagapattinam with a capacity of 0.5 million metric tonnes per annum in 1993 but later on in 2002 this was boosted to 1 million metric tonnes per annum. LPG is separated out in a gas treating unit built in 1996.^{[3][unreliable source]}