Across
- 3. group 1 metals
- 5. a range used to express the amount of hydrogen ions in a solution.
- 7. the amount of oxygen in the water.
- 8. pollution that does not have specific point of origin.
- 10. an organism that is sensitive to environmental conditions.
- 12. looking after something.
Down
- 1. drinkable.
- 2. a measure of how clear the water is.
- 4. excessive growth of nutrients in a body of water.
- 5. pollution that comes from a specific site.
- 6. waste that is washed down sinks, tubs and showers.
- 9. nitrogen compounds used for growth by plants and algae.
- 11. process of purifying water.