A stretch of the Sunter River that passes community unit (RW) 03 in Cipinang Muara, Duren Sawit subdistrict, East Jakarta, turned blue on Thursday, allegedly because of industrial waste.

Mahfud, a worker of the East Jakarta water body management unit, claimed he was the first person who noticed the polluted river.

The 50-year-old filed a report with his supervisors. 

“The waste started flowing into the Sunter River from a community drainage system yesterday at around 11 a.m.,” he told tempo.co on Friday.

There was a significant amount of blue liquid waste, Mahfud said, adding that he noticed the pollution began to go away at 1:40 a.m. on Friday.

“[Another worker] said the pollution was disappearing early in the morning,” Mahfud said, referring to a worker who was on duty securing an excavator.

He suspected that the waste came from a house adjacent to the river. 

“Despite the waste, I didn’t see any dead fish in the river,” he said.

Tempo.co reported that the river turned red on Friday morning at 11 a.m. (das)