Yul Kwon:
We start off in southern China, where eight company executives have been detained for allowing the dumping of cadmium into a major waterway, endangering drinking water for millions of people. Cadmium is commonly used to manufacture batteries and paints. And exposure to the chemical raises the risk of kidney disease and cancer. CCTV has the story of one city in a race against the clock to contain the spill.

Reporter:
A tough battle is going on along the upstream of Liujiang River. These workers are the soldiers in controlling cadmium levels in the Longjiang River to prevent contamination downstream.

Nie Huiqun, Deputy Commander of Emergency Response Team:
We have worked along the Longjiang River for more than ten days, dumping polyaluminum chloride into the contaminated river. The chemical substance is harmful to the respiratory system and eyes. It's a tough battle, but we are determined to fight until the cadmium levels are back to normal.

Reporter:
Some of the team fell sick, but they chose to return to frontline after being discharged from hospital. This young man is one of them.

Peng Di, Firefighter:
I feel it is my obligation to stay and fight for the people of Liuzhou. I'm proud of what I am doing.

Reporter:
Personnel are working around the clock along the Longjiang River to stop the contamination and make sure the safety of water supply in the city of Liuzhou. Environmental crisis experts say the intense chemical measures are effective. And controlling the water volume of the Longjiang River by various hydroelectricity plants ensures that no large amount of contaminated water immediately gets into the Liujiang River.

Professor Zhang Xiaojian, Tsinghua University:
We do not think the contamination case will get worse. It's under control by a comprehensive method. We are confident that the level of cadmium will not exceed twice the national standard along the Liujiang River. Right now, the municipal water facility is well-prepared for cadmium. Even in the worst case scenario, the entire drinking water supply would be safe. But it will take some time to clear the contamination completely. So ensuring a normal life for the Liuzhou residents is a priority.

Yul Kwon:
According to one supermarket worker in Liuzhou, sales of bottled water have risen from an average of 100-200 bottles at this time of the year to over 2,000 bottles per day. And, as these Sina Weibo posts show, there's a growing fear that the water there is unsafe.

One post says:
"It was a wake-up call. Heavy metal polluting the water has been a direct threat to citizens' living environment."

Another post reads:
"People around me are mostly numb. I can't see it will serve as a wake-up call."

This one from the major city downstream from the spill:
"Living in Liuzhou, I have to use mineral water to wash vegetables and cook rice."

The authorities say that there are only trace amounts of cadmium in the river at Liuzhou, not enough to be hazardous, but one user reacted in disbelief:
"I'm speechless. Does it make a difference for us with a gap of only 0.0005?"

China aims to reduce industrial pollutants like cadmium and other heavy metals by 15 percent in the next three years. Environmental activists say that decades of rapid economic growth means authorities ignore industrial pollution and even collude with companies.