A team of experts has been set up to test drinking water believed to have killed 700 chickens.

The intense publicity surrounding the "red water" has led to the resignation of the head of environmental protection and the company responsible for the pollution issuing a public apology.

"Experts have taken samples from ditches and underground water, including the water pumped from 50 and 100 meters deep," Tian Hongxia, a spokeswoman for Cangxian county, Hebei province, said on Sunday. "They need time to test all the samples."

They have been conducting tests on red water since it was exposed on March 29, yet no results had been released as of Sunday.

Before the results were released, the government suggested residents and livestock not use shallow groundwater.

The water running through ditches or pumped from deep underground in Xiaozhuzhuang village was found to be red and with an unpleasant odor.

At least 700 chickens died after drinking the water since November, according to media reports.

The serious water pollution has attracted much public attention.

Yuan Wenchao, 35, who lives in the neighboring village about 10 km away, said his family has started to check the color of the water before drinking.

"I think without effective measures for control, we will suffer the same fate as the chickens," he said.

Yet the county's former head of environmental protection, Deng Lianjun, denied any risk. "The color does not mean the water is polluted. You know, after boiling with red beans the water has that color, too."

His response to the pollution drew more criticism, forcing him to resign. The county government announced on Friday that they dismissed Deng as Party secretary of the bureau and suggested the Standing Committee of People's Congress remove him as head of the bureau.

The company responsible for discharging pollutants in rivers for a number of years, Hebei Jianxin Chemicals, has issued a public apology. The company's branch in Cangxian was closed after a sulfur trioxide leak in 2011.

The company said the remaining materials caused the pollution, and they will take full responsibility.

"We will remove the remaining manufacturing shop and equipment as soon as possible and follow the professional suggestions on environment modification," the announcement from the company said on Friday, yet no detailed measures have been released.

Liu Xiaoduan, a researcher with the Chinese Academy of Geological Sciences, said: "Based on the strange color of the drinking water, we can say that the water has been polluted.

"We have the technology and skills to restore the water quality as long as we find the pollutants and ways of pollution," she said, adding that the priority is to keep the source of pollution under control.

Ma Jun, director of the Institute of Public and Environmental Affairs, said the company should take measures to improve the situation, but said the government is lacking in supervision.

"Cangxian is not the only place where rivers were polluted by large chemical or steel companies for years," he said. "They can cause the pollution over a long time without punishment all because they are the major contributor of government revenue."

The most important solution to reduce the chance of pollution is to improve the law and make individuals and groups pay a higher price for pollution, he added.

Pei Pei in Shijiazhuang contributed to this story.

zhengjinran@chinadaily.com.cn