Dealing with water pollution is something that everyone (including governments and local councils) needs to get involved with. Here are a few things you can do to help. Learning about the issue (like you are doing) is the first and most important step. Here are a few more:

• You can help
  Never throw rubbish away anyhow. Always look for the correct waste bin. If there is none around, please take it home and put it in your trash can. That includes places like the beach, riverside, and water bodies.
• Use water wisely. Do not keep the tap running when not in use. Also, you can reduce the amount of water you use in washing and bathing. If we all do this, we can significantly prevent water shortages and reduce the amount of dirty water that needs treatment.
• Do not throw chemicals, oils, paints, and medicines down the sink drain or the toilet. In many cities, your local environment office can help with the disposal of medicines and chemicals. Check with your local authorities if there is a chemical disposal plan for residents.
• Buy more environmentally safe cleaning liquids for use at home and other public places. They are less dangerous to the environment.
• If you use chemicals and pesticides for your gardens and farms, be mindful not to overuse pesticides and fertilizers. That will reduce the runoff of the chemicals into nearby water sources. Start looking at options for composting and using organic manure instead.

  

• If you live close to a water body, try to plant lots of trees and flowers around your home so that when it rains, chemicals from your home do not drain into the water.

Governments, local councils, and laws
Many governments have strict laws that help minimize water pollution. These laws are usually directed at industries, hospitals, schools, and market areas on how to dispose of, treat, and manage sewage. Do you know the laws in your country? This is a good time to find out.
Local authorities must be vigilant and quick to deal with water issues in their community to prevent danger. Here is an example from Flint, Michigan, USA.

In many developed cities, waste or sewage treatment is very efficient and designed to minimize the pollution of water bodies. (The next page explains that process)

There are also lots of organizations and groups that help educate people about the dangers of water pollution. It is always great to join these groups because they regularly encourage other members of their communities to have a better attitude towards water.