Reducing surface runoff is the most general way to reduce water pollution because surface runoff is a primary pathway through which pollutants are transported from land to water bodies, causing widespread contamination. When rainwater or melted snow flows over the ground surface, it picks up and carries various pollutants such as petroleum substances, herbicides, fertilizers, pesticides, sediments, and other contaminants into rivers, lakes, and oceans. This results in water pollution that affects drinking water quality, aquatic ecosystems, and soil health. Key reasons include:
- Surface runoff transports pollutants like pesticides and fertilizers into surface waters, leading to water contamination and harmful effects on aquatic life, including genetic alterations and death of species.
- Runoff can cause eutrophication in lakes due to excessive nutrients like nitrogen and phosphorus, disrupting ecosystems.
- Pollutants carried by runoff can contaminate groundwater used for drinking.
- Runoff not only removes contaminants from soil but can also deposit pollutants onto cleaner soils, spreading pollution further.
- Reducing runoff limits the movement and concentration of these pollutants, directly reducing water pollution at its source.
Thus, controlling or reducing surface runoff addresses the fundamental process that carries diverse pollutants to water bodies, making it an effective and broad solution for mitigating water pollution.
