An alarm over massive environmental damage along the Yangtze River and its Three Gorges reservoir has been raised by officials as authorities plan to spend billions of yuan treating sewage and planting forests in a major clean-up campaign.

"Generally speaking, the ecological state (of the river) is still far from what the people are demanding," said Jia Zhibang, director of the State Forestry Administration at a press conference organized by the State Council Information Office on Tuesday.

"For numerous reasons, the forests on both sides of the river have been seriously degraded, as is reflected in barren mountains and hills that have led to repeated natural disasters."

The environment of the Yangtze River, China's longest waterway which flows through 19 provinces, autonomous regions and municipalities, is crucial to the safety and wellbeing of more than 400 million people living in the river basin which covers 18.75 percent of the country's total land area, Jia said.

An increase in forest coverage along the 600-kilometer-long water area behind the Three Gorges Dam to 65 percent from the current 22 percent is a crucial part of the plan, Chongqing mayor Huang Qifan said at the same news briefing.

The forestry campaign is predicted to cost more than 10 billion yuan ($1.5 billion) over the next three to five years.

But plans to clean the river also target urban pollution. Chongqing, a mega-city of more than 30 million people upriver from the reservoir, is set to invest heavily in wastewater treatment, Huang said.

While about 75 percent of the city's sewage is treated before disposal in the river and about 80 percent of garbage is buried or treated, this is still not enough for a healthy river, Huang said.

To combat river pollution, Chongqing, which has invested 50 billion yuan on sewage treatment facilities in recent years, will invest another 28 billion yuan over the next three years, Huang said.

A weekly report released by the Environmental Monitoring of China agency on Aug 17 revealed that just two of the 18 monitoring stations along the Yangtze River graded the water quality as good.

The total volume of sewage discharged into the river reached nearly 30 billion tons, including at least 9 billion tons of domestic sewage in 2005, according to an annual report by the Yangtze River Water Resources Commission.

The river is facing serious pollution with tons of sewage discharged into it every second, Ma Yi, deputy chief of the regional bureau of East China Sea fishery management, which is affiliated to the Ministry of Agriculture, told the Shanghai-based Oriental Morning Post in July.

Launched by the Ministry of Environmental Protection, a two-month national crackdown on potentially polluting chemical factories situated near rivers and lakes starts in September, the 21st Century Business Herald reported.

About 400,000 chemical factories are estimated to be inspected in the campaign, said Zou Shoumin, director of the ministry's environmental supervisory bureau.

In a related development, environmental group Greenpeace China has released a report on its website claiming that two kinds of Yangtze River fish, catfish and carp, were found to be tainted with chemicals from industrial waste, namely, alkylphenols and perfluorinated compounds.

Greenpeace took 32 samples near four cities situated along the river, and tested them with an independent organization. The tests showed that synthetic chemicals were found in all the sampled fish.

The fish, part of the diet of many people, could carry "hormones, such as natural estrogens, or upset the normal functioning of the endocrine (glands) system in other ways," warned Wu Yixiu, a campaigner for Greenpeace China.

However, Zhai Yuxiu, deputy director with the Yellow Sea Fisheries Research Institute at the Chinese Academy of Fishery Sciences, expressed doubt over the report's credibility.

"It's undeniable that some fish in the Yangtze River are polluted by industrial chemicals, but still, such a small sample hardly reflects overall fish quality and it is unclear whether the fish could damage people's health," Zhai told China Daily on Tuesday.