Wastewater Flashcards
Sewage (or wastewater):
the liquid containing contaminants that is generated by toilets, showers, sinks and industrial processes
Sewerage:
the whole system of sewers and pump stations, which convey sewage to a treatment plant
Sewer:
the pipeline which conveys sewage normally by gravity flow
Pressure main (or rising main)
a pipeline conveying pumped flow
Sewage Treatment Plant (STP):
or Wastewater Treatment Plant (WWTP)
where sewage is treated to the standard required for discharge to land or receiving waters
Effluent
the partially or fully treated sewage from septic tanks or a STP
Influent
the sewage entering a STP or partially treated sewage entering subsequent treatment processes.
Advantages of Conventional Gravity Sewerage (CGS):
- low operations and maintenance cost
- no equipment at house
- all sewage removed from site
Disadvantages of of Conventional Gravity Sewerage (CGS):
- higher capital cost
- greater disruption during construction
Advantages of Common Effluent Disposal (CED)
- smaller pipes, flatter grades
- reduced organic load at WWTP
- reduced peaking factors
Disadvantages of Common Effluent Disposal (CED)
- septic tanks must be maintained
- requires septage facility
Advantages of Variable Grade Sewers (VGS)
- smaller, shallower pipes
- reduced organic load at WWTP
- reduced peaking factors
Disadvantages of Variable Grade Sewers (VGS)
- may need higher maintenance
- pump and check valves required at low properties
- septic tanks must be maintained
- requires septage facility
Advantages of Septic Tank Effluent Pumping (STEP)
- smaller, shallower pipes
- reduced organic load at WWTP
- reduced peaking factors
- reduced infiltration
Disadvantages of Septic Tank Effluent Pumping (STEP)
- septic tanks must be maintained
- requires septage facility
- large number of pumps to run and maintain
- potential odour and corrosion issues
