Exam 3 Flashcards
Point Source
pipes, ditches, and sewage outfalls
Nonpoint sources
runoff from agricultural fields, lawns, forestry, and parking lots
Atmospheric deposition and gaseous pollutants that dissolve in water
HARDEST TO CONTROL
Living Organisms as a Pollutant
- pathogens and fecal coliform
- contributes to 26 mil deaths/yr
- highest in urban areas from untreated human sewage, animal waste in fields, and meat packing factories sending waste into water
Types of toxins and how they’re pollutants
heavy metals - remain in ecosystems for long periods of time and are from industry and fossil fuels
Inorganic acids - acids in streams are a byproduct of industrial processes and mining, acid rain is from combustion of ffs
Salt - sources are from road salt, toxic in high doses, and can change salinity in ecosystems
toxics organics - pesticides, herbicides, cleaning agents
Bioaccumulation
ingested and metabolize, stored in fatty tissues
Biomagnification
more concentrated in successive tropic levels of food web
Sediment as a pollutant
80% of water degradation comes from erosion
Erosion…
- smothers bottom dwellers
- decreases water clarity
- may have nutrients/toxins attached
Thermal pollution
decreases DO, loss of riparian vegetation, harmful to cold-blooded organisms
Plastic pollution
microplastics are found in humans and fish, plastic fragments can absorb toxic chemicals and harbor dangerous microbes
What does the oxygen sag curve tell us?
Tells the direction of the flow of dissolved oxygen. Right after the DO hits the decomposition zone, it decreases. Gets higher when there is more flow in the recovery zone. (8 ppm for fish and 2 ppm for microorganisms)
Biological Oxygen Demand
the amount of oxygen consumed in five days by microorganisms in the water
How have humans altered the N cycle? Gulf of Mexico?
we’ve added more nitrogen, so algal blooms are caused more frequently in coastal ecosystems
Clean Water Act
restore and maintain chemical, physical, and biological integrity of the nation’s water
all water should be swimmable and fishable
set limits on discharge by industries and municipalities
Groundwater
water that lies beneath the ground surface, filling the pore space between soil particles, sedimentary rock layers, and cracks/crevices
Vadose zone
all material between the earth’s surface and zone of saturation
Water table
upper boundary of the zone of saturation
Capillary fringe
layer of variable thickness that directly overlies the water table (takes up water through capillary action)