Khabarovsk, Russia ? Residents of this Far East city stocked up on water Tuesday in the hours before the arrival of a toxic slick of chemicals that could force authorities to shut off water and central heating in subzero temperatures.

With the chemicals that spilled last month from a factory explosion upriver in China expected to reach Khabarovsk by today, the regional governor said hot water supplies might have to be suspended for as long as seven days and cold water for three days.

“We hope we can deal with the situation but we have to prepare ourselves for a cutoff of water supplies,” Gov. Viktor Ishaev was quoted as saying by the ITAR-Tass news agency.

Sergei Vlasov, a spokesman for the Emergency Situations Ministry, told The Associated Press late Tuesday that the spill was still about 44 miles up the Amur River from city limits, and it was unclear when the slick would arrive.

Yekaterina Vityuk uses stored drinking water in her home in the village of Nizhnespasskoye, 43 miles southwest of Khabarovsk, Russia. Residents of Khabarovsk on Tuesday braced for a possible cutoff of water and central heating as a toxic river slick approached.

The Nov. 13 chemical plant explosion dumped 100 tons of toxins into northeastern China’s Songhua River, disrupting water supplies to millions of Chinese and straining relations with neighboring Russia.

Apartment blocks in this city of 580,000, where daytime temperatures hovered around 4 below zero, are warmed by water heated at central facilities. Authorities said they may have to shut down that central heating to stop the chemicals from entering municipal pipes.

Dmitry Kotenev, a 60-year-old retired serviceman, bought two 1.3-gallon bottles of water, plastic cutlery and plates, and pounds of frozen fish. He said his apartment was full of water stored in canisters, washing bowls and cooking pots.

“This is a Khabarovsk resident’s New Year reserves,” he said.

Others, like Galina Osipova, opted to leave the city. The 30-year-old waited in line to buy a plane ticket to Moscow, 3,800 miles away.

“I don’t have any faith in the authorities and I have decided to wait out the effects of this spill with my relatives in Moscow,” she said.

Since news of the spill, Russia has tried to minimize the effect on Khabarovsk by using tons of charcoal to filter the water and building temporary dams.

Upriver, Chinese workers were also rushing to finish a temporary dam, a Chinese official said Tuesday. Work began Friday to dam a waterway along the Heilong River, which merges with another river to become the Amur.