BEIJING (Reuters) - As many as 60,000 metric tons of heavy crude oil could have been spilled into China's northeast coastal waters as a result of an explosion that rocked the port of Dalian on July 16, Greenpeace said on Friday.
A pipeline blast at Dalian's Xingang port caused fires that spread to a nearby oil storage facility, disabling many of the port's control systems and disrupting cargoes for almost two weeks until full operations resumed on Thursday.
The government said only 1,500 metric tons had been spilled as a result of the accident, and that the clean-up operations had basically been completed on Tuesday this week, but the environmental group, which has conducted ten days of fieldwork in Dalian, cast doubt on both claims.
"It is habitual for governments and oil companies to understate the size of an oil spill, and to understate the environmental impact of an oil or chemical spill, and to overstate the impact of their response," said Richard Steiner, an oil spill expert with the University of Alaska invited by Greenpeace to help conduct investigations in the area.
"The severity of the discrepancy is unusual -- this is a very large oil spill and I cannot help believe that the government understands that."
Yang Ailun, Greenpeace's climate campaign manager, said the valves on the oil storage facilities at Dalian's Xingang port were not sealed until July 22.
She said Greepeace was also informed that local workers were compelled to release large quantities of oil into the sea in order to avoid the bigger threat that the blaze would engulf a nearby tank of dimethylbenzene.
Officials with PetroChina, which operates the oil storage facilities at the port, were unable to confirm or deny the claims when contacted by Reuters on Friday.
Steiner said an explosion of dimethylbenzene would have caused a toxic cloud and required an evacuation of everyone living within at least two miles of the facility.
"It is our understanding from firefighters that they made the decision to drain the additional tanks there in order to keep the fire from getting larger and in order to protect the dimethylbenzene tank that was nearby," he said.
"This indicates a very serious design flaw in the facility that needs to be fixed," he added.
As many as 4,000 fishing boats were recruited in a "low-tech" 10-day clean-up mission off Dalian's coast, using buckets to scoop the oil out of the water.
But the residual oil in Dalian's coastal waters could still cause untold damage to nearby fisheries and shrimp farms as it disperses, and the full impact on local marine life could last more than a decade, Steiner said.
"There is still quite a bit of oil in the water. There are many kilometers of beaches that are heavily oiled and this cleanup has to continue certainly throughout August and possibly through the autumn, and there will be oil on some of these beach sediments for many years into the future."
Reporting by David Stanway, Editing by Sanjeev Miglani