China's high-profile central environmental inspection has criticized two centrally administered State-owned enterprises for their subsidiaries' environmental violations, urging them to adhere to a path of green development.

The criticisms of the China National Gold Group and China Nonferrous Metal Mining (Group) were made public amid an ongoing monthlong inspection that is also covering five provincial-level regions, including the provinces of Jilin, Shandong and Hubei.

All seven inspection teams had started their work at the end of last month.

The team that covers China National Gold found environmental violations in nine of its 13 mining companies in Yunnan and Guizhou provinces and the Guangxi Zhuang autonomous region, the Ministry of Ecology and Environment said in a news release issued Sept 6. The inspection office is based at the ministry.

The inspection teams, launched in 2016, are staffed by current ministry officials and led by minister-level retirees. The inspectors report to a central leading group headed by Vice-Premier Han Zheng.

The branch of Yunnan Gold and Mining Group in Zhenyuan county was found to have mined an area more than 27 hectares bigger than the area it had approval to mine, causing damage to the local environment, and it had also illegally constructed four sites covering a total area of 16 hectares to accommodate waste rock.

The company should have completed a land rehabilitation task last year, but inspectors found that the project remained unfinished, the news release said.

For an extended period of time, a subsidiary of China National Gold in Guigang, Guangxi, neglected its duty in rolling out pollution control measures, leaving surface water around its mining area contaminated, the ministry said.

The company had yet to finish construction of a drainage ditch for a waste rock site that should have been built before 2013.

Due to lax pollution control measures, a pond downstream of the mining area had become a reddish-brown water body. The concentration of arsenic in the pond exceeded the upper limit for water quality of Grade III, the third-highest in China's five-tier water quality system.

Exposure to high levels of arsenic can be fatal.

"Failing to adhere to the philosophy of green development and putting the environment first", China National Gold and its subsidiaries attached inadequate importance to addressing their branches' inefficient use of natural resources and poor performance in environmental restoration, the news release said.

The inspection of Daye Nonferrous Metals Group Holdings, a subsidiary of China Nonferrous Metal Mining in Hubei province, found environmental pollution and hazards, a separate news release said.

Inspectors also found environmental violations at Daye's Fengshan copper mine.

Local authorities had summoned or sent notifications to Daye seven times since 2017, urging the company to rectify its outstanding environmental problems.

"But the company resorted to a muddle-through approach every time," it said.

Daye was asked to rectify environmental violations at its smelting plant in a previous inspection in 2016, but some of the violations had yet to be rectified.

Environmental violations were also found in all five of the provincial-level regions the inspectors visited.