Police in Suzhou, Jiangsu province, intercepted eight vessels from Shanghai that were about to dump garbage on the banks of picturesque Taihu Lake in the Suzhou Taihu National Tourism Vacation Zone.

A total of 4,000 metric tons of garbage on the vessels was covered by tarpaulins. It consisted of construction waste and house hold materials.

According to Suzhou Release, the official WeChat account of Suzhou city, more than 10 vessels fled the scene when local maritime authorities arrived.

Since March, vessels from Shanghai have scattered more than 20,000 tons of garbage across 2,400 square meters along banks before being reported by local residents. The company that hired the vessels planned to get rid of 4 million tons of waste over an 18-month period at a cost of 5.4 yuan ($0.80) per ton.

Gu Liming, deputy chief of Suzhou's Jinting township, which has jurisdiction over the vacation zone, said the vessels came from Jiading in suburban Shanghai.

"The local environmental protection bureau conducted tests and confirmed that the water around the dump site has not been polluted," said Gu. "The bureau will strictly monitor the water quality and garbage treatment."

The dump site is 2 kilometers from the water intake for Jinting township and lies near the water intake for Suzhou's heavily populated Wuzhong and industrial park districts.

"My vessel carries 400 tons of garbage a time, and we can earn about 1,000 to 2,000 yuan from that," a vessel owner, surnamed Liu, was quoted by Suzhou Release as saying. He said the waste would be used by a construction firm to pave roads.

Yang Xinhai, chief engineer at Shanghai Academy of Environmental Sciences, said only part of the construction waste could theoretically be used to pave roads, but only after it is treated.

"The garbage dumped in Suzhou consists of construction waste and household and decoration materials," Yang said. "It cannot be used in construction projects."

According to Yang, it costs about 70 to 80 yuan to treat a ton of household waste in Shanghai.

Ma Jun, director of Institute of Public and Environmental Affairs, said rising costs and increasingly strict regulations on garbage treatment stimulate some people to take the risk of dumping trash in other cities.

"Both the construction and household waste pose great danger to Taihu Lake, whose water quality needs to be improved even without new pollution," Ma said, adding that environmental protection authorities must monitor not only garbage from large construction sites but also from other sources, such as interior decoration.

The Suzhou government has ordered the removal of all garbage dumped on the banks of the lake. Some people suspected of arranging and dumping the garbage have been detained as local police investigate the case.

Guo Jun contributed to this story.