Ceylon Petroleum Corporation which has a monopoly of fuel supply at Sri Lanka's two international airports said the airport originally designed by China Harbhour Engineering Corporation (CHEC) did not incorporate a hydrant system.
CPC had negotiated with CHEC to build the hydrant system for 7.17 million US dollars.
The fuel terminal and a 1.2 kilometres of pipelines had been built by Amana Pipeline Construction LLC of UAE for 31.2 million US dollars after a competitive bidding, the CPC said.
It was time consuming to refuel large aircraft with refueling tankers of 30,000 litres.
The Airbus A380 had a capacity of 310,000 litres, Antonov 124 needed 348,000, a Boeing 747 needed 216,000 litres and an Airbus A340-600 had a capacity of 150,000 litres.
The terminal will have three storage tanks of one million litres each.
The hydrant system was faster and safer than using refueling tankers allowing for faster turnaround, CPC said.
The designs were verified and approved by Germanischer Lloyd Colombo (Pvt) Ltd, a third party inspector, the utility said.
The terminal will be supplied by 33,000 litre road tankers from the common user fuel terminal in Kolonnawa in Colombo, until a tank farm at Hambantota port is ready.
A corridor to build a 32 kilometre pipeline has also been earmarked from the port to Mattala.
It will be built when air traffic picks up.
Sri Lanka's President Mahinda Rajapaksa is due to open the terminal on June 22.