1.1

• • Water Quality - measure of the amount of substances in a water sample; description of how pure a water sample is
• All water contains many naturally occurring substances (even if it is distilled)
• how substances reach water supply

  1. surrounding vegetation and wildlife
  2. precipitation and runoff from adjacent land
  3. biological, physical and chemical processes in the water
  4. human activites
• • Salinity - The amount of dissolved salts in water
• • Fresh water can be found on Earth’s surface and underground
  • As it flows, it dissolves minerals from the soil and rocks it passes through
  • Different regions will have different dissolved materials
• • Hard water -contains a high concentration of calcium and magnesium
  • It leaves mineral deposits, called scale
  • Sinks, Tubs, Dishwashers, Coffee Pots, etc.
• • Water from a well is usually safer than surface water because it is from a source deep underground that is often protected from most natural and human-made pollutants
• • Most cities and towns get their water from surface sources (lakes & rivers) and this water is at a greater risk of having pollutants within it
• water testing criteria

  • Taste & Odor
  • Turbidity (cloudiness) & Color
  • Toxic substances & other pollutants
  • Bacteria
  • Hardness or mineral content
  • pH (acid/base)
  • Dissolved oxygen
  • Solids, including floating materials
  • Dissolved solids
• Distillation: technique for separating solutions that involves boiling and condensing the water
• • Reverse Osmosis: movement of water through a membrane from an area of lower water concentration to an area of higher water concentration; used to purify the water
• • Osmosis: movement of water particles through a membrane from an area of high water concentration to an area of low water concentration