When nature lover Wei Dongying describes the river that flows past her home, she conjures up the unappetizing image of a slick of evil-smelling soy sauce.

"Water in some parts of the river is dark black like soy sauce with white bubbles in it. One of the discharge pipes from the factories along the river is located just 10 meters from my home, and it stinks up my house all day long," 41-year-old Wei from Wuli Village in Hangzhou, Zhejiang Province, wrote in her diary.

Along with her husband Shao Guantong, Wei has kept a diary, taken thousands of photos and collected samples of polluted water to record the worsening pollution in the Qiantang River.

"I wrote to vent my anger and helplessness, and also because I want the government to set things right," she said.

Wei's family used to live a happy life fishing on the river. Things started to change in 1992 when chemical plants, pesticide and dye producers moved into industrial parks in the area. Around 30 chemical plants are now located in the small county, and most of them illegally pipe unprocessed toxic waste into the river.

Up until 2003, local fishermen could still earn an average of 30,000 yuan (US$3,870) a year from fishing, but their earnings dropped to 4,000 yuan last year, as pollution took its toll on the fish resources in the river.

Dozens of families in the village who used to fish the river have turned to other ways to make a living.

"The rivers have gone dark, the air smells and the fish are dead, this is what has become of our environment. I remember the day the water turned yellow and my 14-year-old son had to go to the neighbour's well to get clean well water for his bath," Wei said.

She said 60 of the 2,000 residents in her village have died since 1995. Deaths from cancer have more than quadrupled, and we are convinced that the pollution is the cause, she said. Wei reported the evidence she collected to the local environment bureau.

"But the bureau simply asked us what we thought they should do," Wei said.

According to the State Environmental Protection Administration, about 27 percent of China's waterways can no longer be used and 40 percent of major river drainage areas fail to meet standards.