About 100 liters of a toxic mixture of oil and water and 60 kilograms of oil-contaminated soil have been collected as workers deal with the petroleum-laced liquid from Hanoi's water supply.

Since Tuesday, 30 clearance workers and three excavators have been cleaning the oil spill from sections of a creek that's upstream the Da River which is sourced by the Vinaconex Water Supply Joint Stock Company (Viwasupco) to process and supply clean water to 10 districts in the southwestern part of Hanoi.

Viwasupco sent the workers to the Tram mountain creek in Phu Minh Commune, Ky Son District of Hoa Binh Province, a northwestern neighbor of Hanoi.

A 2.5 ton tanker was seen dumping used oil into the creek on Tuesday last week.

Two out of five kilometers of the Tram creek have been contaminated with oil. As of Thursday morning, oil-stained vegetation had been cleared on either side of more than one kilometer of the creek.

A bird’s eye view of part of the Tram creek where an oil spill is being cleaned up,
October 17, 2019. Photo by VnExpress/Giang Huy.

During the cleanup, the water has turned even more blackish and pungent. Along the creek are many oil streaks that reek.

Some workers said the oil clearance will likely to go on until Sunday. When asked about the water's color remaining blackish, they said: "We have to wait for the rain which will cause water from upstream to flow down and clean the water here."

Apart from the collected oil-water mixture and dozens of kilograms of oil contaminated soil, the workers have also temporarily buried three to four oil seeped sand dunes.

Near the creek, roads, plants, and grass are also streaked with oil. The workers are spreading sand on the roads and uprooting oiled vegetation.

How the collected bags of oiled soil and plants will be disposed of has not been mentioned.

Viwasupco provides 300,000 cubic meters per day to 250,000 families in the entire southwestern part of Hanoi. One million people or an eighth of the capital city's residents depend on its supply.

On Thursday, the company restored its water supply after a one-day suspension for cleaning its pipes and reservoirs. 

But there has been no guarantee issued that the water is safe.

Police in Hoa Binh Province have opened a criminal probe and are looking for the truck and the driver that illegally dumped used oil into the environment, as well as the company or organization behind the incident.

They have also said Viwasupco must take responsibility for not suspending the water supply to residents immediately despite knowing about contamination at the source.