exam 3, water pollution

Question 1

What is eutrophication and what causes it?

Answer 1

Eutrophication: abundance of N and P paired with a lack of O that causes algae to grow in excess and create dead zones in bodies of water
- Caused when waterways are polluted by N and P (fertilizers)

Question 2

What’s the difference between point and nonpoint source pollution?

Answer 2

Point sources
- Discrete and confined sources
- Pipes from industrial or municipal facilities
- Usually treated on-site and regulated by permit
Non-point sources
- Intermittent and diffuse sources
- Runoff pollution
- Difficult to control; a variety of pollutants
- Urban courses → street runoff
- Rural sources → agriculture and mining

Question 3

What is acid mine drainage, what causes it, and what impacts does it have?

Answer 3

• Discharge of acidic water with elevated concentrations of dissolved metals that drain from mines
• Caused by sulfide minerals’ interaction with O-rich water near the surface in mines
• Introduces toxins to aquatic plants & animals, mobilizes other toxic chemicals, worsens water pollution

Question 4

What are wetlands and what are their key characteristics?

Answer 4

• Areas inundated by water or saturated to depth for some days out of the year
• Characterized by hydric soil, hydrophytic plants, services they provide to the ecosystem
• Buffers, filters, sponges, recharge areas

Question 5

Why did the Cuyahoga River catch on fire?

Answer 5

• The rise in industrialization in the late 19th century led to pollutants making their way into the river
• 1969 - water was oil-soaked & train spark caused the river to catch fire

Question 6

Why are nitrogen and phosphorus important for water quality?

Answer 6

An overabundance of these two elements can cause eutrophication & algal bloom and can release toxins that kill wildlife

Question 7

What is saltwater intrusion and what causes it?

Answer 7

• Displacement of fresh groundwater by saltwater
• Caused by groundwater wells being pumped too close to coastal areas, groundwater is overpumped and saltwater finds its way to the pump

Question 8

How do wastewater treatment plants work?

Answer 8

• Wastewater treatment plans follow a 2-part system
• Primary treatment removes 30-40% of pollutants
• Secondary treatment removes 90% of organic materials

Question 9

Why are wetlands important in controlling water pollution?

Answer 9

• Wetlands combat water pollution by absorbing and filtering toxins
• More wetlands = more filtration