The environmental impact assessment for a controversial chemical project was made public on Tuesday in the latest move to dispel residents' fears by the plant owner and city authorities in Kunming.

Released on the website of the China National Petroleum Corp, the company behind the refinery project also known as CNPC, the report says the environmental risks are acceptable and all pollutants discharged can be recycled or filtered to be made harmless.

"We invested about 3.2 billion yuan ($521 million) in installing facilities to protect the environment - about 15 percent of the total costs," Hu Jingke, general manager of the company's Yunnan Petrochemical, told China Daily.