The water supply has returned to normal in three residential areas of the densely populated Sichuan Province in southwest China after a month-long battle to dilute chemicals that leaked into the Tuojiang River.

The river is the sole water source in those areas.

More than 1 million people were left without potable water after a combination of synthetic ammonia and nitrogen from the No 2 Chemical Fertilizer Plant under the Sichuan General Chemical Group leaked into the river, said the provincial Environmental Protection Bureau.

The density of ammonia and nitrogen in the affected section was 152 times higher than the national standard when the serious leakage was reported late last month.

The Tuojiang River feeds into China's main shipping artery, the Yangtze River.

The State-owned plant, a major taxpayer, was shut down on March 2.

On the same day, local authorities shut down water supplies.

The tap water had turned to a yellowish-black color, smelled badly and caused skin irritation.

"Look at my skin, there are so many swellings on my arms and legs. They are all caused by the polluted water," a local newspaper quoted Li Xusheng, a nurse with the People's Hospital in Jianyang city, as saying.

During the past few weeks, more than 1 million people in the afflicted counties and cities - Jianyang, Zizhong and Neijiang - had to wait in line for several hours to get clean water pumped from wells.

Local and provincial governments also mobilized hundreds of water tanks to fetch drinking water from other regions day and night.

The serious pollution killed about 500,000 kilograms of fish and the direct economic loss is estimated to have surpassed 100 million yuan (US$12 million), said the local environmental protection bureau.

"I have never seen or even dreamed that so large amount of fish could jump out of the river and die," said Zhou Changchun, a villager in the Xingguang Village near Jianyang.

Zhou said it is common to see dead fish floating on the surface of the Tuojiang River every winter when pollution becomes serious and in early spring when water levels in the river drop.

"But the pollution is the worst this time," said Zhou.

After a preliminary investigation, officials found that an equipment breakdown at the chemical plant led to the spill, according to a survey report from the bureau.

The plant upgraded its equipment late last year, but a trial operation in January proved that the new equipment, treating the chemical wastes with a high concentration of synthetic ammonia and nitrogen, was not functioning properly.

However, the machine was still put into operation on February 11 without any repair work.

According to the report, that led to the chemical waste being directly dumped into the Tuojiang River.

Liu Xiaofeng, vice-governor of the province, said factory employees and officials involved will receive heavy punishments according to laws and regulations.

There are also ongoing discussions about compensation levels for the afflicted areas, said Liu during a provincial environmental protection conference held on Sunday.

Provincial water resource authorities have opened six reservoirs stationed at the river to allow fresh water to flow since March 9 in order to clean up and dilute the water.

To date, the density of ammonia and nitrogen has been lowered considerably while the diluted chemicals have drifted more than 100 kilometers.

Now the three counties and cities at the pollution site can again draw water from the river and the chemicals down at the lower reaches do not pose a serious threat to residents living there, said the bureau.

In the wake of the serious pollution of the Tuojiang River, the province has launched a thorough inspection along the river, and in another two rivers - the Minjiang River and Jialing River - that are also the tributaries to the Yangtze River.

Operation will be suspended in all the factories along the rivers that do not meet environmental standards by April 15, said the vice-governor.

Sichuan Province is one the provinces that introduced a new pilot project last year to rank the performance of local officials by linking it with their efforts to protect the environment.

(China Daily April 1, 2004)