Water Pollution

5. Environmentalist who calls for redesigning the sewage treatment system
8. Processed petroleum products
10. This process is used to kill disease-carrying bacteria and some viruses
11. City that is known for its water purity
13. Percent of waste entering the Chesapeake Bay and then flushed into the Atlantic Ocean
14. Tanker that released a huge amount of oil and contaminated 1,500 kilometers offshore
15. Sewage treatment that uses screens and grit tanks to remove large floating objects
17. RElease waterborne and airborne toxins that damage fisheries, kill birds, reduce tourism, and poison seafood
19. This outbreak infected more than 300,000 people and caused at least 3,500 deaths

1. By itself, primary treatment removes this percent of suspended solids
2. Oil as it comes out of the ground
3. More than 150 cities in the U.S. use natural or artificially created these to treat sewage as a lower-cost alternative to expensive waste treatment plants
4. Bacteria used in secondary sewage treatment to remove dissolved oxygen-demanding organic wastes
5. 85% of the sewage from large cities along this sea is discharged into the sea untreated
6. According to them, improvements to U.S. households regarding drinking water would cost each household an average of $30 a year
7. River's watershed that contains more than half of all U.S. croplands
9. Percentage that scientists estimate of oil that can ever be cleaned up from a major spill
12. "It is a hard truth to swallow, but nature does not care if we live or die. We cannot survive without oceans, for example, but they can do just fine without us."
16. Reducing this is the key to protecting oceans
18. Here, households receive a strip of cloth for filtering out cholera-producing bacteria from drinking water
19. Bear the brunt of the inputs of pollutants and wastes into the ocean