Across
- 4. the waste from burning coal and other FFs
- 6. the decomposition of wastewater
- 7. heavy metal
- 11. naturally occurring heavy metal
- 12. passed in 1972 and was originally the Federal Water Pollution Control Act of 1948
- 15. the water produced by human activities
- 18. human and animal waste enter bodies of water to create this
- 19. the amount of oxygen a quantity of water uses over a period of time at a specific temperature
- 20. a susbstance that can spread below and across the surface of the water and leave a thick covering that is difficult to remove
- 21. treated water then released to nearby rivers or streams
- 22. solid waste material settles out of wastewater
- 25. clear water layer in the middle of the septic tanks
Down
- 1. an organism that indicates whether or not disease-causing pathogens are likely to be present
- 2. oil that remains far below the ocean surface
- 3. a large container that receives wastewater from the house
- 5. human-made ponds lined with rubber to prevent the manure from leaking into the groundwater
- 8. the layer at the bottom of the septic tank, heavy waste
- 9. the combination of pipes and lawn
- 10. sounds emitted by ships and submarines that interfere with animal communication
- 13. an area with no life
- 14. a compound that occurs naturally in Earth's crust and can dissolve into groundwater
- 16. occurs when human activities cause a substantial change in the temperature of water
- 17. consists of discarded materials from households and industries that do not pose a toxic hazard to humans and other organisms
- 23. when a change in temperature kills many species
- 24. ship spilled 41 million liters of oil