Sources of water contamination

Factories often discharge harmful chemicals like acids and dyes into rivers. What is this type of waste called?

• Plastic bags
• Factory waste
• Tree leaves
• Rainwater

Untreated sewage contains bacteria, organic waste, and nitrogen compounds. What household waste is this?

• Drinking water
• Sewage
• Cooking gas
• Vegetables

Rainwater can carry urea, ammonia, and pesticides from farms into rivers. This process is known as:

• Boiling
• Filtration
• Runoff
• Evaporation

Fecal matter in sewage introduces bacteria like E. coli into water. This is an example of:

• Fertilizer pollution
• Biological contamination
• Oil spill
• Mineral leaching

During construction, materials like cement and dust can enter water, changing its pH. This is:

• Sand
• Bricks
• Mud and debris
• Grass

Crude oil spilled from ships floats on water and reduces oxygen levels. Which activity causes this?

• Fishing
• Swimming
• Shipping and drilling
• Rainfall

Garbage near rivers releases toxic leachate, which can dissolve into water. What does this lead to?

• Clean water
• Soil enrichment
• Water contamination
• Water purification

Old metal pipes can release lead ions (Pb²⁺) into water. Which metal is responsible?

• Iron
• Lead
• Calcium
• Zinc

Which of the following is not likely to add harmful chemicals or microbes to water?

• Industrial waste
• Sewage
• Rainwater (from clouds)
• Agricultural runoff