AP Environmental Science

Water pollution, watersheds, and wetlands - chap 21

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I. Definition of a watershed

II. Importance of watershed emphasis

A. drinking water
B. recreation
C. wildlife habitat
D. fisheries

III. Stream habitats

        A. Stream habitat consists of riffles and runs
        B. The River Continuum Concept helps explain the changing conditions that follow rivers downstream, and the associated ecological changes
 
        C. The importance of streamside vegetation and the effect of development on stream flow
 

IV. Estuaries and other wetlands

A. Definition of an estuary

1. "semi-enclosed coastal embayments where freshwater rivers meet the sea"

  • What's an Estuary??
  • more links
  • Estuary.gov
  • EPA National Estuary Program

    • 2. brackish and salt water; conditions change with the tide
    3. types of estuaries

    a. coastal plain (some have deltas)
    b. bar-built estuaries
    (form behind sandbars, such as Florida Bay)

    c. fjords (such as in Norway and Alaska)

    d. tectonic

    B. Various habitats within an estuary

    1. salt marshes - on edges; affected by tides
    2. mud flats - mud exposed by tides
    3. channels - always water present

    C. Importance of estuaries and other wetlands

    1. economic - many commercially important fin and shell fish live in estuaries
    2. "nurseries" for larval stages of many creatures
    3. high biodiversity - this is always true for an "edge" community, where two habitats meet

    4. natural water filtration/purification

    5. flood water/runoff absorption

    D. Other types of wetlands - definitions and significance.

    1. freshwater marsh
    2. swamp
    3. bogs and fens
    4. woodland and prairie ponds

    Where are the wetlands?  Check out the National Wetlands Wetlands Inventory (click on wetlands mapper)

            E. Threats specific to wetlands: development - covering and filling in of wetlands
     
        1. development - covering and filling in of wetlands
     
     

    2. wetland mitigation laws

    IV. Pollution and water quality (overview of pollutants table 21-1 p. 495)

    A. Point sources

    B. The following pollutants come primarily from Non-point sources (more information) (note -- the pollutants listed below can also come from point sources, especially CSOs and sewage treatment plants)

    Use the acronym TONS to help you remember the major types:

    1. Toxic compounds (PCB's etc) (more info) (some are endocrine disrupters or carcinogens)

                    2. Oxygen-demanding materials (water treatment plants, animal manure, etc) (see fig. 21-4 and 21-3)

                    3. Nutrients - nitrate and phosphate (note statistics - what happens to 100 pounds of nitrogen)

                    4. Sediment

    C. other water pollutants - also usually from non-point sources

    1. heat (thermal pollution)

    2. infectious agents (table 22-2)

                3. Environmental estrogens

                4. Salt: view short video on the effects of salts | read case study focused on New York City area

    D. Air sources and acid rain

    E. Possible link between pollution and Pfiesteria (more about Harmful Algal Blooms)
    F. Status of streams 
    G. Status of lakes
    1.overview of Great Lakes pollution issues
     
    H. Status of groundwater
    1. sources of contamination – fig. 21-7 and 21-8
    I. Status of oceans and coastal waters - fig. 21-10

    VI. Cleaning up pollution

    A. clean water act - passed 1972, revised 1990 and 2000
    B. TMDL's - if bodies of water do not meet these standards, they are placed on a "dirty waters" list.  The EPA requires that a plan be created, indicating the Total Maximum Daily Load of pollutants allowed in the water - and strategies to achieve the necessary reductions.
    C. State laws
    C. Handling waste water
    1. Sewage treatment plants – fig. 21-16 and 21-17

    2. septic systems – fig. 21-15

    3. reducing storm water: natural treatment in gardens or wetlands
     
    * Bioretention systems can help with parking lot and road waste
    * Rainscapes - info about rain gardens and related stuff | more on rain gardens | how to create a rain garden (March 2007 Bay Journal)
    * more info - Riversides program
    * storm water reduction strategies in Montgomery and PG county
    * using "living shorelines" to reduce erosion
    D. Drinking water quality – p. 514-516
    E. Chesapeake Bay program

     

    F. Other programs aimed at cleaning up estuaries/wetlands/rivers:

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