Nine people were sentenced to up to six and a half years in prison in Changshu, Jiangsu province, on Friday for dumping more than 40,000 metric tons of trash into the Yangtze River and the cities it runs through.

Three principal criminals, surnamed Ni, Zhou and Zhang, were sentenced by Changshu People's Court to six and a half years, five years, and four years and three months for the serious water pollution and major economic losses caused by their illegal acts.

They were also fined from 1 million ($145,000) to 400,000 yuan. Six accessory criminals were sentenced one and a half years to two years behind bars.

According to the court, from August to December 2016, the three principal criminals dumped more than 20,000 tons of garbage into the Nantong and Taicang sections of the Yangtze and buried nearly 23,000 tons of garbage in Huzhou, Zhejiang province and Dangtu, Anhui province.

Prosecutor Han Lijia said that the amount of the garbage was shocking and had caused very serious water pollution.

"The Yangtze River is an extremely important river with heavy shipping and provides drinking water to many cities," he said. "The pollution not only affected the safety of navigation channels, but greatly influenced the lives of surrounding residents."

In December 2016, the government of Taicang had to shut down two water intake sites for more than two days after the garbage polluted a drinking water reserve.

The garbage, according to the court, contained toxic substances including medical and household waste and stretched more than 10 kilometers on the Yangtze. In one batch, the amount of volatile toxic substances was more than 80 times the allowable standard, with some even exceeding standards 32,200 times.

Han said that the government had spent greatly to salvage the garbage and control the water and soil pollution.

"The local governments of cities along the river, such as Taicang, Changshu and Shanghai, have spent more than 10 million yuan to restore the polluted environment," said Han. "The ecological losses caused by dumping the garbage reached more than 20 million yuan."

The court found that Tianshun Garbage Clearance Service Co in Haiyan county, Zhejiang province, signed a contract with the local sanitation management center to transport trash to incineration plants in April 2016.

But it subcontracted the disposal to unqualified parties, which later dumped or buried the garbage directly, at extremely low prices, from August to December.

Cases of illegally dumping or burying garbage have been reported by Chinese media from time to time. According to Xinhua News Agency, more than 100,000 tons of garbage were dumped or used as landfill in the Yangtze River estuary and surrounding areas in 2016.