What are the primary sources of water pollution?

Agricultural runoff and municipal wastewater are recognized as primary sources of water pollution due to their significant contributions to contaminating water bodies. Agricultural runoff often contains fertilizers, pesticides, and herbicides, which, when it rains, can wash these chemicals into rivers, lakes, and groundwater. This process leads to nutrient loading and algal blooms, which can severely degrade water quality and harm aquatic ecosystems.

Municipal wastewater, on the other hand, is the water that is released from households, industries, and sewage treatment plants. This wastewater can contain pathogens, organic matter, nutrients, and various contaminants that pose risks to human health and the environment. If not properly treated, municipal wastewater can directly introduce harmful substances into water sources.

Together, these two sources account for a substantial portion of water pollution, affecting both aquatic habitats and human communities reliant on clean water supplies. Other options, while they may contribute to environmental degradation, do not have the same widespread or direct impact on water pollution as agricultural runoff and municipal wastewater.