The study looked at water pollution in scattered water sources in southwest China's karst areas. They found that the pollution comes from both the water recharge and supply processes. The pollution includes bio-pollution (like visible and invisible organisms), physical pollution (such as high color and cloudiness), and chemical pollution (like high pH and unusual ion levels from waste). The pollution mainly happens during rainfall, runoff (surface and underground), and water storage and use. The researchers suggest ways to treat the water based on this pollution.