1. Chapter 14
Water Pollution

2. Water Pollution
Water pollution- the contamination of streams, rivers, lakes, oceans, or groundwater with substances produced through human activities and that negatively affect organisms.
Point sources- distinct locations that pump waste into a waterway.
Nonpoint sources- diffuse areas such as an entire farming region that pollutes a waterway.

3. LE 15-21 Non-point sources of water pollution Pollutant
Farms,
lawns, and
golf courses
Fertilizers,
herbicides, and
pesticides
Animal feedlots
(also non-point source)
Nutrients, waste,
and bacteria
Salt on winter roads;
oil, grease, and
chemicals
from urban runoff
Residential neighborhoods
and urban streets
Sewage treatment plants
Industrial waste
and toxic chemicals
Factories and
disposal sites
Construction
sites, and
deforested and
overgrazed
land
Eroded soil
Oil spills
Abandoned mines
(also point source)
Acid
drainage
Oil tankers

5. Human Wastewater
Water produced by human activities such as human sewage from toilets and gray water from bathing and washing clothes or dishes.

6. Three reasons scientists are concerned about human wastewater:
Oxygen-demanding wastes like bacteria that put a large demand for oxygen in the water
Nutrients that are released from wastewater decomposition can make the water more fertile causing eutrophication
Wastewater can carry a wide variety of disease- causing organisms.

7. Biochemical Oxygen Demand (BOD)
BOD- the amount of oxygen a quantity of water uses over a period of time at a specific temperature.
Lower BOD values indicate the water is less polluted and higher BOD values indicate it is more polluted by wastewater.

8. Eutrophication Effect on BOD & pH
Eutrophication is an abundance of fertility to a body of water.
Eutrophication is caused by an increase in nutrients, such as fertilizers.
Eutrophication can cause a rapid growth of algae which eventually dies, causing the microbes to increase the BOD.
Also the metabolic by products of photosynthesis increase pH levels in the water. CO2 is being taken in by plants.
When the decomposers metabolize the dead algae they release CO2 (H2CO3) into the water which creates carbonic acid which lowers the pH

9. Common Diseases from Human Wastewater
Cholera
Typhoid fever
Stomach flu
Diarrhea
Hepatitis

10. Treatments for Human and Animal Wastewater
Septic systems- a large container that receives wastewater from the house.

11. Treatments for Human and Animal Wastewater
Sewage Treatment Plants- centralized plants in areas with large populations that receive wastewater via a network of underground pipes.

12. Interactive animation http://www.gbra.org/septic.swf

13. SE 15-24 Wastewater treatment
Slide 1
Raw sewage enters treatment facility 1
Screens and
grit tank
Solid objects
and grit
removed
Oils and greases
float to the top
Solids disposed
at landfill 2
Primary
clarifier
Oils, greases,
and solids
removed
Solids sink to
the bottom
Gases chemically
treated to reduce
odor 3
Aeration
basin
Microbes
consume
organic matter
Some solids
returned
to seed
aeration
basin with
new microbes 4
Secondary
clarifier
Remaining
oils, greases,
and solids
removed
Sludge sent to
anaerobic digester 5
Filtering and
disinfection
Water filtered
with coal and
sand, and/or
disinfected
with chlorine
or UV light
Gas to generate
electricity
Biosolids for
cropland
Effluent discharged into waterways

14. Treatments for Human and Animal Wastewater
Manure lagoons- large, human-made ponds line with rubber to prevent the manure from leaking into the groundwater. After the manure is broken down by bacteria, it is spread onto fields as fertilizers.
Contamination of water with fecal coliform bacteria. Reside in intestines of humans and animals. Indicator species when testing water quality

15. Heavy Metals and Other Substances that can threaten human Health and the Environment
Lead
Arsenic
Mercury
Acids
Synthetic compounds (pesticides, pharmaceuticals, and hormones)

17. World Mercury Production - burning of coal,production of cement (limestone) Bioaccumulates in food chain & in humans

18. Acid Mining Drainage Runoff has a low pH Causes Iron to precipitate out from the sediment

19. Contaminants in U.S. Streams

20. Endocrine Disruption due to hormones Poison Water video

21. Oil Pollution Valdez spill video BP spill interactive

22. Ways to Remediate Oil Pollution
Containment using booms to keep the floating oil from spreading.
Chemicals that help break up the oil, making it disperse before it hits the shoreline-dispersants
Bacteria that are genetically engineered to consume oil- bioaugmentation
Industrial vacuums
Hose off with hot water on shoreline.
The Exxon Valdez oil is still present today on rocks, soil, sediment

23. OTHER WATER POLLUTANTS
Solid waste pollution (garbage)
Sediment pollution (sand, silt and clay) through removal of plant material
Thermal pollution-warm, filtered water from power plants
Noise pollution-disrupts sea animals sonar
Perchlorate-rocket fuel-causes thyroid gland issues
PCB’s polychlorinated biphenyls from manufacturing of plastics & insulating electrical wires. No longer made in U.S. Carcinogenic
G.E. dumping into Hudson River
PBDE Polybrominated diphenyl ethers –used as flame retardants children’s clothing, construction materials, furniture
Scientists have found in fish, aquatic birds, human breast milk. Can lead to brain damage, especially in children. Banned in Euorope, Washington state & California.

25. Water Laws
First major act 1948-Federal Water Pollution Control Act expaneded into
Clean Water Act- (1972) supports the “protection and propagation of fish, shellfish, and wildlife and recreation in and on the water”.
Issued water quality standards that defined acceptable limits of various pollutants in U.S. waterways. If necessary restore the chemical, physical and biological properties of natural water. It does not include groundwater.
Controlled by the EPA and state governments.

26. Water Laws
Safe Drinking Water Act- (1974, 1986, 1996) sets the national standards for safe drinking water.
EPA is responsible for establishing maximum contaminant levels (MCL) for 77 different elements or substances in both surface water and groundwater.
MCL considers the concentration of a compound to cause harm and the feasibility and cost to reduce the compound to such a concentration