Lakes, rivers and the air in many places in China are still polluted, some seriously, in spite of continuous efforts to control pollution, a Chinese environmental official said Tuesday.

Zhang Lijun, Deputy Minister of Environmental Protection, said environmental protection departments across the country should press enterprises harder on pollution control.

"The general situation of environmental pollution does not allow us to be optimistic," Zhang told a national meeting on pollution control in Shanghai.

"The fundamental way to overcome this is to continue to press enterprises to reduce pollution emission through technology and management," he said.

China classifies water quality in major rivers and lakes into six levels, ranging from level I, which is good enough to be used as a source of drinking water, to level VI, which is too polluted to be used even for farm irrigation.

The quality of the water sampled in almost a quarter of the monitoring stations set up along major rivers such as the Yangtze and the Yellow rivers averaged at level VI, according to a document circulated at the meeting.

For monitoring particulate matter and sulfur dioxide as major air pollutants, the China Environmental Monitoring Center classifies air quality in urban areas into five levels, ranging from level I or excellent, level III or slightly polluted, to level V or hazardous.

A national report on China's environment, issued by the Ministry of Environmental Protection (MEP) in November last year, said the air quality of 39.5 percent of 320 cities of prefecture level and above averaged level III or worse.

Pollution in 28 major lakes remained serious, with the quality of almost 40 percent of the water at level VI.

Water in urban regions also faced serious pollution, with 90 percent of river water and about half of underground water polluted.

Zhang Lijun said China had invested 51 billion yuan (US$7.46 billion) by September last year into 2,712 water treatment projects, 881 of which were operational.

These projects, scattered along five rivers, two lakes, and in reservoir areas of the Three Gorges Dam on the Yangtze River, should reduce pollution as measured by chemical oxygen demand (COD).

COD is a measure of the amount of oxygen in water consumed during the decomposition of organic matter and the oxidation of inorganic chemicals such as ammonia and nitrite, often contained in wastes discharged in natural waters.

The meeting was convened less than one week after a chemical factory illegally dumped disinfectant phenol into a river in east China's Jiangsu Province, causing the suspension of tap water supplies to at least 200,000 residents in Yancheng City for three days.

While two people allegedly responsible for the accident have been detained and would face prosecution pending further investigations, Zhang Lijun said polluting enterprises would find their operations more difficult if proposed regulations were adopted.

The MEP was considering a policy to deprive polluting enterprises from enjoying favorable treatment in subsidies and taxation, usually given by investment-seeking local governments.

The ministry, responsible for evaluating the environmental impacts of proposed projects, also demanded a ban on firms exporting products if they fail to meet pollution control standards, Zhang said.

Last year, 156 projects with a total investment of 473.7 billion yuan (US$69.28 billion) failed environmental evaluations due to potentially high energy consumption and pollution emissions, including many chemical and coal-burning plants.

In 579 projects that passed the evaluation, with a total investment of 2.4 trillion yuan, clean production technology and facilities had been used to ensure the reduction of pollutants, such as sulfur dioxide, Zhang said.

(Xinhua News Agency February 24, 2009)