Across
- 2. relating to, involving, or requiring free oxygen
- 5. avoiding the depletion of natural resources in order to maintain an ecological balance
- 6. scattered pieces of rubbish or remains
- 7. the tendency of a body to float or to rise when submerged in a fluid
- 10. the process of cleaning something, especially with a chemical, in order to destroy bacteria
- 11. liquid waste or sewage discharged into a river or the sea
Down
- 1. allow (a liquid, gas, or other substance) to flow out from where it has been confined
- 3. water that is safe to drink or to use for food
- 4. in short supply; shortage
- 8. the disposal of waste material by burying it, especially as a method of filling in and reclaiming excavated pits
- 9. whirls in the ocean