The main pollution slick in the Songhua River has left the section of Harbin, a northeast Chinese city of 3.8 million people where water supply has been suspended for four days, local environmental authorities announced Sunday.

The latest inspection result shows that by 6 a.m. on Sunday no benzene was found in the water at Sifangtai, the water source site in the upper reach of Harbin section, while the nitrobenzene level has met the national standard with a concentration of 0.0050 milligrams/liter, according to Lin Qiang, spokesman for the Heilongjiang Provincial Environmental Protection Bureau.

Harbin, depending on the Songhua for water, shut down its water supply system in the wee hours on Wednesday because of a highly polluted water stretch in the river. The pollution resulted from a blast at a petrochemical plant on Nov. 13 in neighboring Jilin Province.

The city is scheduled to resume water supply at 11 p.m. on Sunday.

Soruce: Xinhua