In the summer of 1969, the Cuyahoga River in Cleveland contained so much chemical waste that it caught on fire.

This really got people’s attention. Water pollution in the U.S.was very severe. It led to clean-up campaigns and new laws toprevent pollution.

By definition, water pollution is the addition of any substancethat will have a negative effect.

Even before there were factories, water supplies were polluted.

Substances that cause pollution are called pollutants.

So how does water get polluted?

The major sources of water pollution are:

1. Industrial waste

2. Animal waste

3. Agricultural chemicals

4. Runoff from roads

A point source of pollution is from a specific place.

For example, you can see the waste emptying from these pipes.

A nonpoint source cannot be tied to one specific point.

The pollutants may travel a long way.

Is this picturing showing a point source or nonpoint source of pollution?

Types of Pollutants:

1. Industrial waste -

A. chemicals may be dumped into rivers

B. smoke and exhaust may enter the air

Once chemical smoke enters the atmosphere, it will return to Earthin the form of acid rain.

Acid rain can kill fish in lakes and even cause statues and buildings to deteriorate.

2. Animal waste - may enter water as farm runoff or sewage

Sewage treatment plants help to prevent this from happening today.

3. Agricultural Chemicals - includes fertilizers and pesticides

4. Runoff - oily substances washed off of roads

If a body of water has become polluted, can it be cleaned up?

Let’s look at an example.

In the 1920’s, the Bronx River was clean and beautiful.

By 1990, it was severely polluted.

However, through clean-up efforts like this one, the BronxRiver is on its way to recovery.

What can you do to help clean-up or prevent water pollution?

Most importantly, be aware. Knowing the causes and effects of water pollution is the first step in being able to prevent it.

Be sure to dispose of chemicals properly.

Participate in a clean-up day!

Is this steam polluted?