A recent newspaper report on the hidden pollution perils around the five drinking water sources in Nanjing, capital of east China's Jiangsu Province, has aroused widespread attention.

Qian Feng, director of the Nanjing Environmental Protection Bureau, said surveys have been carried out to determine how serious the reported potential threat really is.

"Not only is regular research done, but there are also conferences every season to discuss pollution problems. We are working hard with other government departments to remove any hidden perils," he said.

The Nanjing Morning Post reported that household waste, ships and different kinds of factories are polluting the city's water sources along the Yangtze River.

The newspaper found hidden pollution perils in every water source protection zone.

For example, there were three plants, a shipyard, a meat-packing plant and a pharmaceudical plant within 2,000 meters of the upper reach of the spot where Shangyuanmen Water Works gets its water. Every one of those facilities discharges waste water every day.

A worker at a meat-packing plant, who asked to remain anonymous, said the waste water disposed met national sewage discharge standards.

However, according to the newspaper report, half of the sewage disposal pools at the plant were unused.

Another example can be found near the spot where Pukou Water Works gets its water, where a dock can be found. Sanitary sewage and oil leaking from the ships there are polluting the water quality.

About 500 meters from the Beihekou Water Works' water intake area, there is a pumping station that discharges the sewage of nearby residents every two or three days and only 270 meters away, there was a huge dust heap, as long as 100 meters, along the river bank that is full of plastic bags and lunch boxes.

A 500-metre-long pigpen with about 1,000 pigs is located 700 meters away from the water source and all of its sewage water goes into the river.

Qian, however, said the newspaper's conclusions were not scientific.

"The result of these investigations may not be very accurate."

He used the pigpen as an example, saying it is not 700 meters, but 1,650 meters away from the water source.

"Anyway, we cannot exclude the possibility that there are some hidden perils of pollution, and the report is both a reference and a warning to us," he said.

According to him, the area within 100 meters of the upper and lower reaches of the water sources is the first-class protection zone, 100 to 1,000 meters is the second-class protection zone, and 1,000 to 2,000 meters is the quasi-protection zone.

"There are no pollution sources in the first-class protection zone of all the five water sources in the city," Qian said.

"But there may be some pollution sources in the second-class and quasi-protection zones, our work is to remove these hidden perils. New factories that might cause pollution cannot be built, and the old ones will be moved to other places step by step."

(China Daily July 26, 2004)