Harbin, China ? Running water returned to this northeast city of 3.8 million people Sunday, ending a five-day shutdown blamed on a chemical spill that embarrassed the government and highlighted China’s mounting environmental problems.

However, officials warned that what was coming out the tap in frigid Harbin still was too dirty to drink.

Water service started returning to this provincial capital shortly after the government said toxins spewed into the Songhua River by a chemical plant explosion had returned to safe levels. Residents said service did not resume in some areas for several more hours.

“When that running water came back on, it was a completely wonderful feeling. It’s been four days since I had a shower,” said Cao Sijun, 46.

Local television showed the governor of Heilongjiang province, where Harbin is located, drinking a glass drawn from the tap in a Harbin family’s home after service resumed.

But the government warned the public that supplies lying in pipes for five days were too dirty to drink, although safe enough for housecleaning and laundry. It said it would announce on radio and television when the water was safe enough first to bathe in and later to drink.

“We still have to wait a little longer,” sighed Wang Yixin, a 34-year-old entrepreneur.

The deadly Nov. 13 chemical plant explosion in Jilin, a city upstream, was a political disaster for President Hu Jintao’s government and cast a harsh light on the environmental costs of China’s breakneck development.

Hu’s government issued embarrassing apologies to China’s public and to Russia, where a border city downstream is bracing for the arrival of the benzene slick that was 50 miles long.

The pollutants were expected to reach Russian territory within days and Khabarovsk, a city of 580,000, within weeks. A top Russian environmental official told the Ekho Moskvy radio Sunday that the nation would airlift 50 tons of activated carbon to treatment plants along the Amur River to absorb the toxins.

Environmentalists criticized China’s response to the spill and questioned the decision to allow a facility handling such materials near a key water source.