Wastewater Collection Systems Flashcards
Sewage (Wastewater)
Is the Liquid containing contaminants that is generated by toilets, showers, sinks and industrial processes.
Sewerage
Is the whole system of sewers and pump stations which convey sewage to a treatment plant.
Sewer
Is the pipeline which conveys sewage normally by gravity flow.
Pressure main
Is a pipeline conveying pumped flow
Sewage Treatment Plant (STP) or Wastewater Treatment Plant (WWTP)
Is where sewage is treated to the standard required for discharge to land or receiving waters
Effluent
Refers to the partially or fully treated sewage from septic tanks or a Sewage Treatment Plant.
Influent
Refers to the sewage entering a Sewage Treatment Plant or partially treated sewage entering subsequent treatment process
Conventional Gravity Sewerage
Advantages
- Low operations and maintenance cost
- No equipment at house
- All sewage removed from site
Disadvantage
- Higher capital cost
- Greater disruption during construction
Common Effluent Disposal
Advantages
- Smaller pipes, flatter grades
- Reduced organic load at WWTP
- Reduced peaking factors
Disadvantages
- Septic tanks must be maintained
- Requires septage facility
Variable Grade Sewers
Advantages
- Smaller, shallower pipes
- Reduced organic load at WWTP
- Reduced peaking factors
Disadvantages
- May need higher maintenance
- Pump and check valves required at low properties
- Septic tanks must be maintained
- Requires septage facility
Septic Tank Effluent Pumping
Advantages
- Smaller shallower pipes
- Reduced organic load at WWTP
- Reduced peaking factors
- Reduce infiltration
Disadvantages
- Septic tanks must be maintained
- Requires septage facility
- Large number of pumps to run and maintain
- Potential odour and corrosion issues
Grinder Pumps (and pressure mains)
Advantages
- Smaller shallower pipes
- Reduced infiltration
- All sewage removed from site
Disadvantages
- Large number of pumps to run and maintain
- Septic effluent
- Potential odour and corrosion issues
Vacuum System
Advantages
- Smaller shallower pipes
- Reduced infiltration
- All sewage removed from site
Disadvantages
- Unfamiliar technology
- Vacuum pump discharge odour
- Potential odour problem due to seasonal loading
