Across
- 7. water below the Earth's surface in sediment and rock formations
- 8. fresh water on Earth's surface
- 9. an area of Earth's surface where water percolates down into an aquifer
- 12. chemical or biological agents that enter water and degrade the quality
- 13. the ability of rock or soil to allow water to flow through it
- 14. the buildup of pollutants at higher levels of the food chain
- 18. an underground formation that contains groundwater
- 19. a structure built across a river to control its flow
- 20. when a river is dammed an artificial lake forms behind it
Down
- 1. pollution discharged from a single source
- 2. process of removing salt from salt water
- 3. the area of land that is drained by a river
- 4. eutrophication caused by humans
- 5. water that is safe to drink
- 6. a flowing network of streams and rivers that move across the land
- 10. organisms that cause illness or disease
- 11. pollution that comes from many different sources
- 15. when the temperature of a body of water increases
- 16. percentage of the total volume of a rock that has spaces
- 17. water that contains waste from homes or industry