Ways Water is Polluted

Industry
There are three main ways that industries contribute to water pollution. They pollute by disposing of waste directly into waterways, emitting toxic gases that cause acid rain and changing the temperature of water with their disposals into waterways.
Direct disposal of waste into natural waterways causes waste to build up within the water. A pungent odor is the result. Additionally, this waste decreases the amount of oxygen in water, causing the death of aquatic animals or other organisms.
The emission of toxic fumes into the air causes acid rain. When the acid rain falls, it contaminates local natural waterways including streams, rivers and lakes. This causes the death of many aquatic animals. Other animals drinking the water may become ill and die, too.
Thermal pollution occurs when water used to cool hot machinery is released into waterways and the temperature of the water is drastically increased. This temperature change may cause aquatic life to die and numbers to be reduced. Additionally, such a temperature increase decreases the amount of oxygen in water, causing more of a chance of death to organisms.

Agriculture
It's common for farmers to use fertilizers and other chemicals on their crops to help them grow. However, these chemicals and nutrients added to the soil can soak into the underground water supplies. Additionally, when it rains, these chemicals join the run-off water and flow into streams, rivers and lakes, thus polluting them. Even just the sediments of dirt, without any chemicals, are pollutants in the fact that they cause the waterways to become cloudy and muddy.

Homes
Households are a leading cause of water pollution by the trash they create. Even if taken to landfills, often this trash finds its way to natural waterways. Human waste, disposed of typically by sewers, pollute water. Any time a septic system is not installed properly or bursts beneath the ground, the underground water supply may be polluted. Oils and anti-freeze leaked from vehicles pollute water