Eight people have been detained for illegally dumping carcinogenic waste on hills in southwestern Yunnan Province's Qujing City, local government officials said yesterday.

The waste directly caused the deaths of 77 cattle and polluted 40,000 cubic meter of water in a reservoir and another 3,000 cubic meters in a nearby river, local offcials?said.?[hrzb.cn]

The waste directly caused the deaths of 77 cattle and polluted 40,000 cubic meter of water in a reservoir and another 3,000 cubic meters in a nearby river, they said.

However, there was no danger to public water sources or to the area's vegetable supplies, Qujing's Vice Mayor Chen Jun told a press conference.

On May 28 this year, two workers delivering industrial waste from a chemical plant to a fuel company tried to cut transport costs by illegally dumping 5,212 tons of chromium-contaminated waste in the hills near Qujing's Sanbao and Yuezhou towns, the vice mayor said.

As the dumping point was far from the source where residents collect water for daily use, the incident didn't compromise the safety of drinking water but did cause direct economic losses estimated at 95,000 yuan (US$14,898), Chen said.

The government later carried out inspections on vegetables in farmlands near the dumping point but found no trace of contamination.

The eight people who have been detained for severely damaging the environment include the two workers who dumped the waste, the deputy manager and a worker with the chemical plant, Luliang Chemical Industry Co, and workers with the fuel company who were in charge of waste transportation.

The chemical company was fined 300,000 yuan for damaging the environment and production there has been halted, Chen said.

"The accident shows that the supervision of industrial companies is lacking in the area, while unsound emergency plans failed to inform residents of the current environment condition," Chen said.

He promised that by the end of this year the government would have completed treatment to render the carcinogenic waste produced by the chemical company harmless.

Another 149,400 tons of waste containing chromium, which is piled near the Nanpan River, will also be treated by the end of next year to ensure the substance does not pose a threat to the water source, Chen said.

Qujing government officials said high walls using special materials had been built around the chromium-contained waste to prevent it leaking, while they are trying to relocate the chemical company as soon as possible.

The officials also said they would be developing new technologies to refine chromium material from the waste and have it recycled.