Aquatic and Terrestrial Pollution
What you must know
Identify point-source vs. nonpoint-source pollution. Know major water pollutants: sediment, nutrients (nitrogen and phosphorus causing eutrophication and dead zones), pathogens, heavy metals, PCBs, oil, and thermal pollution. Understand wastewater treatment (primary, secondary, tertiary) and septic systems. Study solid and hazardous waste - landfills, leachate, incineration, brownfields, and the waste hierarchy (reduce, reuse, recycle). Know bioremediation and phytoremediation. Understand pesticide persistence and bioaccumulation/biomagnification up food chains. Know noise and light pollution and brownfield redevelopment.
Traps
- Reversing bioaccumulation (organism takes up) and biomagnification (concentration rises up the chain).
- Calling agriculture nonpoint - it usually is, unlike a factory pipe.
- Forgetting sediment is a major water pollutant by volume.
- Assuming recycling is the top of the hierarchy - reduction and reuse come first.
Worked example / rule of thumb
A lake receiving fertilizer runoff from many farms is nonpoint-source nutrient pollution → algal bloom → oxygen depletion → dead zone. Rule: nutrients in, algae up, oxygen down.