Oxygen is not a water pollutant. In fact, oxygen is essential for the survival of life in water.

Some examples of water pollutants include: 

• Chemical pollutants: Pesticides, fertilizers, and waste from landfills and septic systems 
• Organic wastes, Microbial contaminants ,Nutrients ,Plastics ,Faecal waste ,Radioactive substances ,Phosphorus and nitrogen.