Science Watersheds

• 1)Waste water leaves the house through a pipe

  2)It enters the septic tank. Here sludge sinks and scum floats on top.

  Bacteria live in the septic tank and breakdown the waste.

  3)Solids stay in the tank. Liquids move to the drainage field.

  4)Wastewater drips out of the pipes and is cleaned as it percolates.
• Sedimentation - sinking or settling to the bottom.
• Disinfect - UV light kills viruses and bacteria. We also add chlorine in this process.
• Coagulation/Flocculation -clumping together
• Chlorine - Kills bacteria
• Lime - Prevents Rust
• Alum - Makes small particles clump together.
• We also add fluoride to help with your teeth
• A watershed is an area of land where all the surface water drains into the same place because all the water in a watershed shares the same fate and flows to the same place. Watersheds are sensitive to pollution and land use.
• Coarse Screens - removes large solids
• Primary sedimentation - allows solids to sink to the bottom
• Scum - waste that floats
• Sludge - waste that sinks
• Activated sludge - has bacteria that helps keep break down waste.
• Aeration tanks

  • Air is added to help the bacteria grow and digest more waste
  • The bacteria dies off and sinks to the bottom of the final setting tank.
• The rise and fall of the water table and Saturated zone:

  -Flooding  up

  -Heavy Rain up

  -Drought down

  -Water export and Diversion (Bottled Water) down

  -Overuse of wells down

  -Farming and Industry down

  -Cities / Pavement down
• The order to get the water to you house is:

  Water from the lake - Intake - add chlorine, lime, and alum - sedimentation and coagulation / flocculation - Filtration - Disinfect - storage - DONE
• The order for the sewers and waste water is:

  your home to the coarse screens - primary sedimentation - aeration tanks - final setting tanks - disinfection - returned to the environment.
• The rock and soil in which all the open spaces are filled with water is called the saturated zone. The term Water Table refers to the upper level of the saturated zone.