Yichang, a central Chinese city on the bank of the Yangtze River, will close or relocate all its chemical enterprises within 1 kilometer of the river and its key tributaries by the end of next year.

Vice-Mayor Yuan Weidong also promised to remove those in areas that may damage drinking water resources by the end of 2019 and relocate hazardous-chemical plants located in highly populated areas by the end of this year.

He said that 25 of the city's 134 chemical plants had been shut down by the end of 2017, in answer to the nation's call for green manufacturing and protecting the 6,300-km-long Yangtze, China's longest river.

China has made environmental protection and green manufacturing a top priority for development of the Yangtze River Economic Belt, a region encompassing 11 provinces and municipalities, including Hubei province, where Yichang is located, and considered to be a future growth engine for the country's economy.

According to the National Development and Reform Commission, the country's economic regulator, China will shut down petrochemical enterprises in environmentally sensitive areas alongside Yangtze by June this year.

"The decision helps to protect the ecosystem as it is effective in preventing wastewater disposal to the Yangtze," said Li Guocai, a former senior engineer at Shandong Academy of Agricultural Machinery Sciences.

Even legally operating enterprises within the 1 kilometer will be encouraged to close or relocate by 2020, according to the NDRC.

For instance, Tiantian Chemicals Co Ltd, located some 100 meters from the Yangtze, was officially closed in 2016. The company mainly produced coals, fertilizers, and other chemical products.

It was environmentally friendly and had guaranteed safe production, said Li Xianrong, Tiantian's manager.

The board of directors, however, decided to close it in consideration of the long-term development for Yichang in answer to the national plan.

"Before it was shut down, the firm has achieved annual revenue of 320 million yuan ($49 million) and 50 million yuan in tax and profit," said Li Xianrong.

"The company had good profit with high growth," Li said. "However, the traditional way of processing coals and other chemical products hinders it from transforming to green and sustainable manufacturing."

Li said the government's compensation totaling 26 million yuan has helped the company's staff to hunt for jobs.