Think for a few moments about each question. Try to answer them into your notes.  What is water quality?  Are all sources of water affected?  How do the pollutants get there?  What are some key pollutants?

 Physical, chemical, biological characteristics.  Concerns for drinking water, human safety, and ecosystem health.  Use scientific standards to test.  Water sources affected: ◦ Most often surface water ◦ Ground water is more difficult to detect

 Industrial pollution is a major cause  Runoff from agricultural areas (60%)  Urban storm water runoff  Discharge of untreated sewage (especially in developing countries where less money and governmental control prevents these accidents.)

◦ Measures acidity of water. Range of is neutral. (rainwater is typically from 6-6.7, with acid rain around )  Temperature ◦ Changes are not as frequent or dramatic as outside air temperature, water subject to ‘thermal pollution’ from factories and power plants. Impacts the wildlife that can live in the water.  TDS ◦ Total dissolved solids –amount of material suspended in the water (not just floating on top) –can be minerals, organic material (like decaying leaves or animal waste), or soil ◦ Measured in ppm (parts per million –amount of solids per million drops of water)

 Nitrogen ◦ Natural nutrient in soil, animal waste, or fertilizer applied to land – high levels indicate runoff from animal or croplands, or spill from sewage ◦ Measured in ppm  Phosphorus ◦ Natural nutrient in soil, animal waste, or fertilizer applied to land – high levels indicate runoff from animal or croplands, or spill from sewage ◦ Measured in ppm  Hardness ◦ Indicates presence of minerals in water –natural ◦ High levels indicate many minerals have recently been dissolved or eroded (or runoff) into water, can make water cloudy (murky) and difficult for plants/animals to live

 Comes from one specific location

Overflows of sanitary sewers Overflows of animal agriculture waste storage Illegal dumping Oil spills from barges in the ocean Smoke stacks from factories

 No specific dumping site  Runoff, leaky pipes (septic tanks), landfills, pollutants trapped in the water cycle are carried long distances.

 Excess nutrients in the water cause explosive plant growth  When many plants die, they produce a toxin (red algae)  Decaying plants also reduce the amount of oxygen in the water  Plant growth (like algae) can suffocate other life in a lake or pond.

 Gulf of Mexico

 Number one killer of children worldwide  About 80% of all diseases are water-related (WHO)  Often due to water infiltrated with sewage, spreading disease  Bacteria, virus, or protozoa are resposible – can’t be seen, smelled, or tasted and can be in “clean looking” water  Improvements in disposal and treatment have reduced number of illness in developed nations

This woman is drinking from a “Life Straw” –said to filter particles and bacteria from water. San Diego, CA 11/30/08