The study looked at pollution in storm runoff and sewage in urban areas of Wuhan City between 2003 and 2005. Researchers found that storm runoff in urban areas carried a lot of pollutants into the water, making the water quality worse. In some urban areas, storm runoff contributed to nearly 60% of suspended solids, about a quarter of chemical oxygen demand, and smaller amounts of total nitrogen and phosphorus in the water. The study suggests that controlling the pollution in storm runoff from urban areas is crucial for protecting water quality, especially by taking measures to reduce the amount of pollution in the first flush of runoff.