Across
- 5. acid that is deposited on earth
- 7. an area in water with extremely low oxygen levels
- 10. a massive change in water temperature that kills organisms
- 13. increase in fertility in a body of water
- 15. underground septic systems made of pipes laid out
- 17. the middle layer in a septic tank
- 19. how much oxygen an area of water uses over time
- 21. when water becomes rich in nutrients
- 22. non chemical water pollution that occurs when the temperature of the water changes
- 23. the legislation that protects fish and wildlife recreation
- 24. the heavy stuff from wastewater
- 25. industrial compounds that manufacture plastic
Down
- 1. The standard of drinking water
- 2. pond lined with rubber that handles manure
- 3. harmless microorganisms in human intestines that are associated with sewage
- 4. streams, ricers, lakes and the ocean that is contaminated with substances
- 6. a small sewage treatment system
- 8. a big area that pollution comes from
- 9. legislation of national standards for safe drinking water
- 11. a large container that wastewater goes into
- 12. a single point that pollution is from
- 14. a liquid that humans drink
- 16. a species that indicates if a disease is likely to be present
- 18. water from livestock and human activities
- 20. chemicals used for rocket fuel