CHATTOGRAM: The huge quantity of diesel spilled from the two derailed tank waggons at Chittagong Goods Port Yard (CGPY) of the Bangladesh Railway, posing a threat to the environment.
It is also concerning that the floating oil is flowing on the canals leading to the Karnaphuli River, which is flowing into the Bay of Bengal.
Environmentalists worry that if the oil spill is not properly cleaned up, it will have a negative effect on the local environment, croplands, and aquatic life.
Sources said that the accident occurred when the three waggons derailed at the CGPY, located in the city’s Halishahar area, at around 7:00 pm on Wednesday.
The oil was loaded at a government oil depot and transported by train to Dhaka. Each of the waggons was carrying some 30,000 litres of diesel.
Oil spilled from two waggons while another remained intact. However, the quantity of the spilled oil couldn’t be ascertained immediately.
The oil spilled into a drain beside the yard, which was draining into the nearby canal "Moheshkhal" via a branch.
However, the sluice gate of the canal remained closed since Wednesday, and it saved the area from devastation at an early stage, said the environmentalists.
The railway authority salvaged two of the derailed waggons until the afternoon, while work was going on for the rest.
Some 30 people were seen collecting the floating oil using foam, bottles, and buckets from the canal. They stored them in drums and sold them to shops that sell loose oil.
The oil collector said they rushed to the spot immediately after the accident and have been collecting oil since then.
They could collect eight to 10 litres of oil each until Thursday afternoon.
According to Railway (East) Divisional Manager Abidur Rahman, oil spilled from two of the three wagons, but no oil was spilled.
Though each of the waggons contained some 30,000 litre oil, the actual quantity of the spilled oil could not be known immediately.
Some of the oil also went to the canal through the drain and its branches, he said.
Abidur said a three-member committee headed by the Divisional Transportation Officer was formed to unearth the cause of the accident.
On the other hand, officials of the Department of Environment (DoE) inspected the area and collected samples from different spots.
The DoE Metro Inspector Md Monir said the sluice gate at the mouth of the canal remained closed on Wednesday.
They collected samples of the water from both inside and outside of the sluicegate, he said.
 "A good quantity of oil was found in the canal water. We also collected a sample of river water. A little quantity of oil was noticed in the river water," he said.
Professor Dr Muhammad Edrise Ali, an environmentalist,  said the oil will definitely reach the river and then the sea from the canal during the low and high tides.   
 "The closed sluicegate will help to some extent in this regard. Steps should be taken to remove the oil from the canal water properly to save the environment in the area," he said.
The marine creatures of the canal and river, the croplands, and the environment in the area will face long-term degradation due to the accident, said the professor.