Police in Jiangsu province have detained 19 suspects for allegedly dumping a massive volume of garbage on the banks of Taihu Lake in Suzhou.

Since mid-June, more than 12,000 metric tons of garbage were shipped from Shanghai to a dumping site near a drug rehabilitation clinic in the Suzhou Taihu National Tourism Vacation Zone.

Police said the plan was to dump more than 3 million tons of waste at a cost of 5.4 yuan ($0.80) per ton, over an 18-month period.

According to the local government, all the garbage has been removed and processed by authorized departments. Measures have been taken to restore the ecology of the site.

To avoid similar cases, the Suzhou government has recently created a regulation that prohibits the transportation of garbage to the city. Also, no companies or individuals are allowed to sign garbage delivery contracts.

Suzhou has appointed a deputy mayor to monitor the garbage-control system. Many government departments, such as police, transportation and urban management, will work to stop illegal garbage transportation.

Xu Hesheng, deputy secretary-general of the Shanghai Construction and Development Association, said that garbage can be transported between cities of the same province.

For megacities like Beijing, Shanghai, Tianjin and Chongqing that are not as big as the provinces, "sometimes they cannot treat garbage produced by others", Xu said.

However, Yang Xinhai, chief engineer at the Shanghai Academy of Environmental Sciences, said that people can earn a lot by shipping garbage out of Shanghai.

"Shanghai has the ability to treat all kinds of garbage it produces," said Yang. "There are mainly two methods to treat garbage in the city - to burn or to bury. It costs about 200 yuan to burn a ton of garbage, while the cost to bury a ton would be around 80 to 100 yuan."

"But transporting the garbage to other cities will cost far less than the other two methods."

He added that China's environmental protection departments encourage different areas to share garbage treatment facilities, but sharing facilities differs from dumping garbage in other areas.

"Private companies and individuals are often involved in dumping the garbage in other cities," Yang said. "The penalties imposed by the governments are not stringent, so they would rather take the risk to make money."

In mid-July, garbage shipped from Shanghai was also found in Nantong, Jiangsu province.

Guo Jun contributed to this story.