ナーン川
The current Jin River has eutrophication issues caused by different types of urban wastewater such as sewage discharge, road surface runoff, and effluent. Eutrophication is caused by excessive amounts of total dissolved phosphorus (TDP) and total dissolved nitrogen (TDN) in both the Fu River and the Nan River. Urbanization and wastewater in the City of Chengdu raises the TDP concentration in the Fu River. Compared to the Fu River, the Nan River has less TDP due to less wastewater input. Even though the concentration of TDN is considered low in both the Fu River and the Nan River, it is higher than the type 3 international standard requirements for water quality.