Contamination of China's Huaihe River remained at a medium level last year, showing no improvement or further degradation, a government report said on Monday.

The report released by the Ministry of Environmental Protection, which was upgraded from State Administration of Environmental Protection (SEPA) in March, said overall water quality of the Huaihe River last year was almost the same as that of 2006.

Water quality in China falls into five categories, with grade one regarded as safe to drink with only minor processing, and five as the worst with a warning against human contact.

Medium level contamination means that 20 to 40 percent of the water is graded level five in quality.

Located in central and east China, the Huaihe river catchment area covers 270,000 square kilometers, and is the supplier of water to one sixth of the country's 1.3 billion people.

The river, China's third longest, has suffered in from excessive discharges of industrial and daily waste, most of the pollutants being ammonia and nitrogen, from riverside provinces including Jiangsu, Anhui, Shandong, and Henan.

The SEPA had ordered local governments to adjust industrial structure, arrange agricultural and industrial production based on the river's capacity and push forward emissions licensing systems.

In 2004, it also ordered the four provinces to lower chemical oxygen demand (COD), a measure of water pollution, in 2007 by at least 20 percent compared with that of 2000.

Research conducted by environmental officials in late February in the four provinces showed all four fulfilled the goal last year, according to the report.

"Pollution of China's Huaihe River remains at medium level in 2007, but the problem has not been significantly improved," said the report. The ministry urged local governments to accelerate the construction of waste processing plants, and cut discharges of nitrogen and ammonia.

(Xinhua News Agency April 22, 2008)