Water Pollution

4. an area of the ocean that is depleted of oxygen, frequently due to pollution.
6. a water-tight container usually made of concrete, fiberglass, or polyethylene. Its job is to hold the wastewater long enough to allow solids to settle down to the bottom forming sludge, while the oil and grease floats to the top as scum.
7. Chemicals used to kill undesirable vegetation.
9. water that has been used in the home, in a business, or as part of an industrial process.
10. a for of nitrogen useful for plant growth.
11. a measure of acidity
12. An unusual, sudden or excessive abundance of algae. Algal blooms can adversely affect water quality.
14. That portion of precipitation or irrigation water that flows off a field or paved area and enters surface water.

1. The surrounding land area that drains into a lake, river or river system.
2. An essential nutrient containing phosphorus and oxygen.
3. When water is contaminated by pollutants
5. Rain with a higher than normal acid range.
8. the change in water quality that can harm organisms and make it unfit for human use change
11. the introduction of contaminants into the natural environment
13. Liquid flowing out of a system, such as a discharge of liquid waste from a factory or water leaving a sewage treatment plant.