The study analyzed water pollution in China from 2008 to 2013 by looking at CODMn levels in various rivers. Over the years, the pollution decreased by 32.2%, with fewer heavily polluted sites. The Liaohe, Yellow, and Haihe Rivers showed significant improvements. Although COD discharge decreased overall, the Haihe River remained heavily polluted due to a lack of water resources. The number of heavily polluted sites reduced from 22 to 5, while rivers with good water quality remained fairly constant. This shows that efforts to reduce pollution have been successful in many areas, but challenges remain in heavily polluted rivers like the Haihe.