Water has the chemical formula H2O, making it an inorganic substance. It is the primary chemical component of the Earth's hydrosphere and the fluids of all known living things (in which it serves as a solvent[1]). It is transparent, flavorless, odorless, and almost colorless. In spite of not providing food, energy, or organic micronutrients, it is essential for all known forms of life. Its molecules are made up of two hydrogen atoms joined by covalent bonds and have the chemical formula H2O.

1. WATER POLLUTION –Part 4

2. OCEAN POLLUTION
• Harmful algal blooms (HAB) are caused by
explosive growth of harmful algae from
sewage and agricultural runoff.
Figure 21-11

3. Ocean Pollution

4. Ocean Garbage Patches
• Form in ocean gyres
• Have high concentration
of plastic pelagic garbage
in upper water columns
• The plastics break down
to molecular sizes and
get into the food chain
• For more information:
Photo courtesy of AP / Scripps Institution of Oceanography /
Mario Aguilera
en:Image:Oceanic gyres.png.
Marine Debris Program - Marine
Debris Info

5. Oxygen Depletion in the Northern
Gulf of Mexico
• A large zone of
oxygen-depleted
water forms for
half of the year in
the Gulf of
Mexico as a
result of HAB.
This is called the
“Dead Zone.”
Figure 21-A

6. Has anything been done?
• 50 countries with at least 80% of the world’s
merchant fleet have agreed not to dump sewage
and garbage at sea, but this agreement is difficult
to enforce and is often violated
• London Dumping Convention of 1972- 100
countries agreed not to dump highly toxic
pollutants and high-level radioactive wastes in
the open sea beyond the boundaries of their
national jurisdictions.

7. OCEAN OIL POLLUTION
• Most ocean oil pollution comes from human
activities on land.
– Studies have shown it takes about 3 years for many
forms of marine life to recover from large amounts
of crude oil (oil directly from ground).
– Recovery from exposure to refined oil (fuel oil,
gasoline, etc…) can take 10-20 years for marine life
to recover.

8. OCEAN OIL POLLUTION
• Tanker accidents
and blowouts at
offshore drilling
rigs can be
extremely
devastating to
marine life
(especially diving
birds, left).
Figure 21-13

9. Oil and the Ocean cont.
• The effects of oil on ocean ecosystems depend
on a number of factors: type of oil, amount
released, distance of release from shore, time
of year, weather conditions, average water
temperature, and ocean currents.
• Spills can result in the death of numerous
aquatic organisms.

10. Cleaning Up Oil Spills
• Mechanical Methods:
– Floating booms to contain the oil spills or keep it
from reaching sensitive areas
– Skimmer boats to vacuum up some of the oil into
collection barges
– Absorbent pads or large feather-filled pillows to
soak up oil on beaches or in shallow water.

11. Cleaning Up Oil Spills cont.
• Chemical Methods:
– Coagulating agents to cause floating oil to
clump together for easier pickup or sink to
the bottom where it will do less harm
– Dispersing agents to break up oil slicks

12. Cleaning Up Oil Spills cont.
• Fire can burn off floating oil, but this method
causes more harm than good (air pollution).
• Natural Action:
– Wind and waves will mix oil with water
– Bacteria will biodegrade some of the oil

13. Gulf Oil Spill
Deepwater Horizon rig in flames,
last April.
Burning off surface oil
Seabird caught in the oil slick
on a beach on Louisiana's
East Grand Terre Island

14. http://nanopatentsandinnovations.blogspot.com/2010/06/gulf-oil-spill-transcript-national.html
Graphic shows efforts to reduce effects of oil spill

15. Oil Pollution Act
• It has strengthened the government’s ability to prevent and
respond to catastrophic oil spills.
• It provides the money and resources necessary to respond to
oil spills. A trust fund financed by a tax on oil is available to
clean up spills when the responsible party is incapable or
unwilling to do so (the largest source of income for the fund
is from the 5-cents-per-barrel tax on imported and domestic
oil).
• Requires oil storage facilities and vessels to submit to the
federal government plans detailing how they will respond to
large discharges.
• The OPA also requires the development of Area Contingency
Plans to prepare and plan for oil spill response on a regional
scale.
• The Oil Pollution Act caused a major restructuring of the oil
industry

16. Fig. 21-14, p. 509
Reduce input of toxic pollutants
Solutions
Coastal Water Pollution
Prevention Cleanup
Use wetlands, solar-aquatic,
or other methods to treat sewage
Require at least secondary
treatment of coastal sewage
Sprinkle nanoparticles over an
oil or sewage spill to dissolve
the oil or sewage without
creating harmful by-products
(still under development)
Improve oil-spill cleanup
capabilities
Recycle used oil
Regulate coastal development
Protect sensitive areas from
development, oil drilling, and
oil shipping
Ban ocean dumping of sludge and
hazardous dredged material
Ban dumping of wastes and
sewage by maritime and cruise
ships in coastal waters
Separate sewage and storm lines
Require double hulls for oil tankers

17. PREVENTING AND REDUCING
SURFACE WATER POLLUTION: The
Clean Water Act
• Reduces direct pollutant discharges into
waterways
• Finances municipal wastewater treatment
facilities
• Manages polluted runoff
– Goal is to restore and maintain the chemical, physical, and
biological integrity of the nation's waters
• Originally focused on regulating discharges from
point source facilities and not non-point sources

18. PREVENTING AND REDUCING
SURFACE WATER POLLUTION:
The Clean Water Act
• Starting in the late 1980s, efforts to address polluted
runoff have increased significantly.
• Evolution of CWA programs has also included shift from
a program-by-program, source-by-source, pollutant-by-
pollutant approach to more holistic watershed-based
strategies.
• Emphasis now on protecting healthy waters and
restoring impaired ones.
http://www.epa.gov/owow/watershed/wacademy/acad2000/cwa/

19. PREVENTING AND REDUCING
SURFACE WATER POLLUTION
• The key to reducing nonpoint pollution – most
of it from agriculture – is to prevent it from
reaching bodies of water.
– Farmers can reduce runoff by planting buffers and
locating feedlots away from steeply sloped land,
flood zones, and surface water.

20. The Nitrogen Cycle:
Bacteria in Action
Figure 3-29
http://www.epa.gov/maia/html/nitrogen.ht
ml