Download Environmental Science - Manistique Area Schools

Environmental Science
Chapter 5
Notes #2
Water - Review
Renewable resource
constantly circulated by the water cycle
70% of Earth’s surface is water
Earth + Atm = 336 million cubic miles of water
97% = salt water, 3% = Fresh
-
-
-
77% of fresh = polar ice caps
Very small fraction of water is available for our use
Water- Review
 Surface
Water
 Fresh water found above ground
 Dams/Rivers
 Groundwater
 Water that seeps underground
• Aquifer –Water percolates down,
millions yrs.
 Recharge zone – area of land from
where water makes its way to an aquifer
Water- Review
 Solutions

1. Desalinization/Desalination

2. Towing Water

3. Water Conservation
Freshwater Pollution
 Water

2


Pollution
Introduction of chemical, physical, and/or
biological agents that degrades the water
quality and affects the organisms that depend
on it
underlying causes
Industrialization
Human population growth/explosion
Freshwater Pollution
 Types

of Pollution
Point Pollution
• Pollution discharged from a single source that is
easy to identify and trace –
• therefore is easily regulated

Nonpoint Pollution
• Pollution from many sources
• Difficult to regulate/control
• EPA study = 96% of polluted water is a result on
nonpoint pollution
Freshwater Pollution
 Examples

of Pollution Sources
Pathogens
• Disease causing organisms such as bacteria,
virus, parasites, worms etc…

Heavy Metals
• (ex. Mercury and lead)
Chemicals (organic/inorganic)
 Physical agents (heat, soil, etc)
 Radioactive waste

 All
can affect photosynthesis
Freshwater Pollution

Wastewater Treatment Plants
 (they purify and clean wastewater)
 Wastewater – water that goes down a drain
 Other product = “sludge” Hazardous
• If treated it can be used as fertilizer


Sometimes use aerobic bacteria (use oxygen)
to decompose sewage
Perform fecal coliform tests to check for sewage
• Looking for poo/ Escherichia coli

Remove materials high in P and N
• (ex. Phosphates)
Freshwater Pollution
 Affects



on Ecosystem
Biological Magnification
The toxin that gets passes on to each “eater”
increase up the food chain
• Spill over algae
• each little herbivores each eat two algae
• little fish each eat 10 herbivores
• A big fish eats 10 little fish
Immediate damage
• Ex. Oil spill
Freshwater Pollution
 Affects

on Ecosystem
Artificial Eutrophication
• Eutrophic – abundance of nutrients
 Occurs naturally over long periods of time
• Caused by humans – EX. P and N
 Sewage/Fertilizer run-off, causes
excessive growth of algae.
 Algae blooms form, increase in bacteria
 Algae dies, uses lots of Oxygen to
decompose, bacteria use oxygen
 Less Oxygen for fish
 Fish die
Freshwater Pollution

Affects on Ecosystem

Thermal Pollution
• Too much heat added to water
• Comes from industry
 Use water for cooling that gets release
back into bodies of water
• Creates unnaturally warm areas
• Reduces Oxygen dissolved in water
• Plants and animals die
• Commonly = point pollution

Traced back to power plants
Freshwater Pollution
 CWA of

1972 (Clean Water Act)
To keep the nation’s surface waters clean
enough to swim and fish in
 Groundwater
pollution will be a problem
for 100’s of years

Takes a LONG time to recharge
 Bottled


Water
Filtered and treated tap water
Not tested as often as the public water supply