The northeast Songhua River benzene leak is disrupting China's downriver communities, as well as Russia's, where the Amur River awaits the pollution.
Chinese cities are combating the pollution and readying clean drinking water.
Meanwhile, China is urgently helping Russia plan for the onslaught of benzene coming its way from the November 13 China National Petroleum Corporation plant explosion.
Freezing temperatures have slowed the flow into Russia.
However, China is now trying to help Russia as much as possible, advising of the pollution advance and sending detection equipment.
China and Russia started jointly monitoring the pollution slick in the river last Friday, according to China's environmental agency, the State Environmental Protection Administration.
Both sides also will jointly monitor the pollution slick in Tongjiang, where the Songhua and Heilongjiang rivers intersect. The Heilongjiang River is called in Russia the Amur River, a major waterway.
Premier Wen Jiabao has written to his Russian counterpart Mikhail Fradkov, pledging to further enhance cooperation to reduce damage from pollution spills, Qin Gang, spokesman for the Chinese Foreign Ministry, told a news conference in Beijing yesterday.
In China, the Songhua pollution is advancing toward Jiamusi, the second-largest city on the river's lower reaches. The city has created a water supply source north of the river to ensure a safe supply.
The pollution passed Harbin, capital of Heilongjiang Province, which has declared its drinking water safe.
In Jiamusi, the new clean water source, known as the Jingbei water source, is designed to supply 200,000 tons of quality ground water daily.
Bracing for the pollution onslaught, Jiamusi completed the first phase of the project that went into operation on Monday, supplying 100,000 tons of water a day.
The city of more than 2 million people has closed the No. 7 waterworks, for fear of contamination.
The forward edge of the pollution slick was drawing near Dalai Town yesterday.
An earlier report said the city government is digging deeper wells citywide to ensure water safety.
Altogether, 192,000 people live in 159 villages along the 1-kilometer-long Songhua River banks in Jiamusi.
The 20,000 wells in the area were all shallow and susceptible to river water pollution.
The State Development Bank of China has approved a loan of 640 million yuan (US$79.2 million) to help Harbin deal with the pollution, Heilongjiang officials said yesterday.
Also yesterday, the State Council, China's Cabinet, set up an investigation team to probe the Jilin blast.
(Xinhua)