The Pollution Control Department (PCD) will evaluate environmental damage caused by last week's oil spill off the coast of Rayong province.
The department's chief said they will calculate how much compensation Star Petroleum Refining Plc is required to pay for clean-up after oil leaked from one of its pipelines in the Gulf of Thailand.
"The PCD doesn't know at present what the cost of the rehabilitation efforts will be, so we need time to get more information, but according to the law, the company must pay to clean up the environment," the chief said.
On Jan 25, the company's undersea pipeline broke. Initially, 400,000 litres of crude oil were reported to be have been spilt but the company later adjusted the figure to 160,000 litres.
The Department of Marine, the Department of Marine and Coastal Resources, the navy and the company have since applied measures to limit the impact of the oil spill by using buoys and dispersants.
The company has apologised for the accident and expressed a willingness to cover the costs of the cleanup.
Meanwhile, the governor ordered a disaster zone in the area, together with warning people not to swim in the sea. He has also suspended seafood consumption.