The Liangtan River in the Three Gorges Reservoir area is facing nitrate pollution in both its surface water and groundwater. The pollution is mainly caused by human activities. The study found that the surface water in the middle-upper reaches of the river basin is polluted, with the lower reaches being even more severely affected. Groundwater is also heavily polluted, with nitrate and nitrogen levels exceeding safe limits. The pollution in groundwater increases as you move from the upper reaches to the middle reaches of the river. In some areas, the nitrate concentration in groundwater surpasses the safe limit of 10 mg/L.