Around 210,000 liters of gasoline has leaked on to the beach in the south-central province of Phu Yen since last month and very little of it has been cleared so far.
Gasoline from the Vung Ro storage facility belonging to the Phu Yen Commodity Joint Stock Company has spread along an area of more than 500 square meters of the Mu U beach in Dong Hoa District.
Investigators found a leak in an underground pipe connecting the store with another one along the coast.
The company has reported that it has retrieved one third of the gas, using shovels, dippers and buckets. It has also dug a ditch 25 meters long and 0.8 meters deep next to the sea to prevent the gas from flowing into the sea. Pumps have been used to collect the gasoline from the ditch.
But the solution has not worked well after the petrol has seeped deep into the sand. "There's no other way but to wait for the sun to make the gasoline evaporate," said Vung Ro deputy head Nguyen Xuan Dung.
Nguyen Kim Phuc, director of Phu Yen Department of Natural Resources and Environment, also said the province has not figured out how to fix the problem.
While local residents are worried the gasoline will penetrate into the sea or local water sources and damage their shrimp farms, Phuc said the worry was unfounded because "the gas will be retained in the sand."
Residents in several communes of Dong Hoa District are already unable to use water in their area as it has oil scum left over by US soldiers spilling gasoline when transporting it through the area.
The provincial environmental police on Saturday collected sand samples from the area to evaluate the effect of the leaked gasoline on the environment.
Petroleum businesses in Vietnam are required to set up plans to deal with oil leaks and spills and submit them for approval before they begin operations. The Phu Yen Commodity Company has been asked to do so several times by officials of the Ministry of Natural Resources and Environment.
The province People's Committee on Saturday imposed a fine of VND65 million (US$3,400) on the company for violating the environment protection law.