According to the reporter 's research, from the Shen Tau Bridge, where the two tributaries meet, it is a kilometer upstream along the Yueyang River to the spring. Clear water gushes from the spring, but it turns yellow soon after it flows into the river [1].

The reporter interviewed Mr. Wang, who was fishing at the river and caught a carp from the water. He said that the fact that fish can survive in the water proves that the water is not toxic, but the water here just appears yellow and sometimes smells bad [2]. But the fact that the fish can survive in the water does not mean that the river water is not polluted. Perhaps the pollution simply makes it more difficult for the fish to survive, reducing their survival rate, or affecting their bodies in unknown ways, such as the sex-changing effects [6].

Mr. Zhai, who sells fruit next to the river, said that three years ago the water used to be so clear that green water plants could be seen after the pollution treatment, but in the last two years the water has turned yellow again, becoming even more yellow after rain, and there is even oil floating on the surface and an unpleasant smell coming from it [2].

Professor Jiang Wenqiang of the School of Environmental Engineering at Qilu University of Technology said he had visited the Xiaofu River several times to take water samples for testing, and the report showed that the water contained a large amount of ferrous ions, which oxidized to trivalent iron ions after contact with the air, showing a deep yellow or even red color, followed by a process of precipitation, after which the water downstream became clear. Therefore, the odor that the public smelt at the river should be the smell of rust. The oily substance on the surface of the water is not a real oil stain, but a substance formed by the reaction between iron ions and calcium and aluminum ions in the water. Oil stains do not dissolve in water, but this film dissolves in the water when stirred. For example, when a cup of tea is left overnight, a layer of "tea scum" will form on the surface, which is the same thing, not "oil stains". In addition, Professor Jiang also said that in the environmental quality standards for surface water, the iron content is not an indicator of the quality of river water [2].

A car repairer next to the Xiaofu River said that he is over 60 years old and that this section of the river has had yellow water for as long as he can remember. There are coal mines in Boshan District, and there is definitely yellow water. These are groundwater, but not drinking water for residents. Many of the people interviewed thought that the yellowing of the river was related to the closure of the coal mines and the return of groundwater [2].

Zhang Lin of the water section of the Boshan District Ecological and Environmental Branch said that Boshan District is an old industrial area with very rich coal mining resources, but now it has all been closed. After these small coal mines were shut down, the groundwater level rose back up and formed an artesian flow [1]. Boshan District is located in a geological spring with rich resources, and when it enters the spring and summer season, the rainfall is abundant and the mine water rushes out from various springs, which is how the Yueyang River tributaries are formed [2]. Besides, the river is equipped with online water quality monitoring equipment so that the environmental protection department can monitor the data in real time. The water here is not drinking water for residents, and the river, which is about seven meters deep, has the primary function of flood control [1].

However, as the yellowing of the river has affected the cityscape as well as the well-being of residents, several river treatment options have been negotiated in the Boshan district, with plans to set up a mine water treatment plant at the upstream spring to allow the spring water to complete its oxidation reaction in advance and release clear water into the river [1]. This is also a common wish of the citizens of Boshan district [2].

According to the Zibo City Xiaofu River Basin Development Plan (2021-2035) issued by the Zibo Water Resources Bureau on September 2021, a mine water treatment project will be carried out at the confluence of the Xiaofu and Yueyang rivers, including river cleaning, river dredging and desilting, construction of ecological floating islands, planting of aquatic plants, upgrading of the river's green landscape, use of hinterland space to build artificial wetlands and small-scale sewage treatment facilities to address the problem of metal overloading in the Yueyang River [7].

In June 2022, the interview group of the event, Zibo Environmental Protection Century Walk visited Boshan District to learn about the green path of ecological and environmental management in the district. In the process, they learnt that the design scale of the Yueyang River mine water treatment facility was 4,000 cubic meters per day, covering an area of 1,700 square meters, with a total investment of more than 35 million Chinese Yuan. After treatment, the concentration of iron ions in the mine water was reduced to 0.05 ml/L, the river gradually regained its original color, the water quality was greatly improved and the urban landscape was enhanced [8].