Aerated waste water treatment systems use bacteria to treat waste in one or two tanks before pumping the treated water out for local disposal. The treated water can be used to irrigate gardens through underground systems, but must not be used in sprinklers or micro-sprays because there is a risk of contamination.

An aerated waste water treatment system must have electricity to pump air into the treatment tanks and pump out the effluent. This type of waste water system requires regular doses of chlorine and three-monthly maintenance by a specialist or a trained local operator. Before specifying an aerated waste water treatment system or any other package treatment system, confirm that these essential criteria can be met. Also confirm that the system will work with the water quality and average household population.

Ensure

• B3.4.1.

  the system components, tank and below ground irrigation lines, are big enough to deal with peak population loads

• B3.4.2.

  the soil is suitable for below ground effluent disposal

• B3.4.3.

  reliable electricity is available

• B3.4.4.

  maintenance staff are available and affordable for the chlorine dosing and three-monthly service

• B3.4.5.

  irrigation lines are below ground

• B3.4.6.

  the tanks and irrigation lines are protected from vehicles

• B3.4.7.

  that an overflow system has been incorporated to ensure that the waste water does not flow into the house yard if the system fails

• B3.4.8.

  the tanks and irrigation lines can be accessed for maintenance.

• B3.4.9.

  the system is installed in accordance with AS/NZS 1546.3 2001 On-site domestic wastewater treatment units - Aerated waste water treatment systems.

Consider

• irrigating a sunny area of the yard to improve evaporation rates
• locating the tanks down wind of the house to minimise odours entering the house.

• that building contracts include a requirement that all in-ground drainage works be inspected and tested before they are backfilled
  

  When: COMPLETED DESIGN & SPECIFICATION
  DURING CONSTRUCTION
  AT HANDOVER

• organise for these in-ground drainage work inspections to be undertaken by an inspector with qualifications to certify the works.
  

  When: COMPLETED DESIGN & SPECIFICATION
  DURING CONSTRUCTION
  AT HANDOVER
  FINAL COMPLETION
  TRADE TEST

• the manufacturer has certified the design of the system to suit the water quality, household population and climate and that the design has been approved by local or state/territory authorities for use in this area
  

  When: COMPLETED DESIGN & SPECIFICATION
  DURING CONSTRUCTION

• layout plans for all services are provided before construction commences
  

  When: COMPLETED DESIGN & SPECIFICATION

• openings are covered and barriers are erected to prevent people falling into the tanks or excavations during construction
  

  When: DURING CONSTRUCTION

• construction of the system is supervised, ideally by three inspectors: i) state or territory health department or local council ii) building supervisor iii) community environmental health worker or other health worker
  

  When: COMPLETED DESIGN & SPECIFICATION
  DURING CONSTRUCTION
  AT HANDOVER

• vehicle barriers are erected around the aerated wastwater system works during and immediately after construction to prevent access by builders' and residents' vehicles.
  

  When: COMPLETED DESIGN & SPECIFICATION
  AT HANDOVER
  FINAL COMPLETION
  TRADE TEST

• electricity is connected to the aerated wastwater system and all moving parts are working
  

  When: AT HANDOVER
  FINAL COMPLETION
  TRADE TEST

• 'as-built' drawings are provided on completion of the wastewater works
  

  When: FINAL COMPLETION
  TRADE TEST

• the plumber provides the certificate of plumbing and aerated system installation required by local, state or territory regulations
  

  When: DURING CONSTRUCTION
  AT HANDOVER
  FINAL COMPLETION
  TRADE TEST

• total length of effluent irrigation lines is suited to local regulations, population and climate
  

  When: COMPLETED DESIGN & SPECIFICATION
  DURING CONSTRUCTION
  AT HANDOVER
  FINAL COMPLETION

• the aerated wastwater system tanks and irrigation lines are accessible for maintenance
  

  When: COMPLETED DESIGN & SPECIFICATION
  DURING CONSTRUCTION
  AT HANDOVER
  FINAL COMPLETION

• the yard is graded to direct stormwater away from the aerated wastwater system system and to ensure that waste water will drain away from the living area if the waste water system fails.
  

  When: COMPLETED DESIGN & SPECIFICATION
  AT HANDOVER
  FINAL COMPLETION

As part of cyclical maintenance:

• refill the chlorine required by the system, as recommended by the manufacturer
  

  Who : Plumber

  When : 6 Months

• ensure the entire system is serviced by a licensed contractor every three months or as required by the manufacturer.
  

  Who : Plumber

  When : 3 Months

AS 1546.3:2017 On-site domestic wastewater treatment units - Secondary treatment systems

Guidance Notes for Wastewater Management, NT Department of Health – Public Health Directorate, 2020 https://nt.gov.au/__data/assets/pdf_file/0007/947788/guidance-notes-for-wastewater-management.pdf

Code of Practice for Wastewater Management, NT Department of Health – Public Health Directorate, 2020 - https://nt.gov.au/__data/assets/pdf_file/0011/947783/code-of-practice-for-wastewater-management.pdf

Downs, S 1997, Aerobic Waste Water Treatment Systems in Aboriginal Communities (draft report), Centre for Appropriate Technology Inc., Alice Springs.

Khalife, M 2001, Waste water workshop, sponsored by the Aboriginal Housing Authority of South Australia and Nganampa Health Council Inc.

Marshall, G 2000, ‘Sewage’ in G. Harris (ed.) Environmental Health Handbook: A Practical Guide for Remote Communities, Menzies School of Health Research, Casuarina, Northern Territory, pp. 107−20.

Marshall, G 1998, Sewerage Systems in Remote Indigenous Communities, cat. no. 98/8ex, Centre for Appropriate Technology Inc., Alice Springs.

Van Dok, W 2000, ‘The Water-efficient Garden: A Guide to Sustainable Landscaping in Australia’, Water-efficient Gardenscapes, Glen Waverley, Victoria.