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UCDOIM 143 Revision 2 24/03/2021
Foreword
The Ultra Clear single tank domestic aerated wastewater treatment systems, Models ST10 and ST8, have been
designed to meet NSW Health Guidelines and Australian Standard AS1546.3:2017. The systems have been tested at
the Jimboomba, QLD AWTS test site.
The Ultra Clear single tank systems have been designed by Darryl Rebbeck. The design allows ease of maintenance
and servicing, allowing easy and full access to all chambers, to ensure the efficient functioning of your system.
This handbook will provide information on the function of your ULTRA CLEAR AWTS. Your authorised service
technician will be able to help further if you have any queries.
March 2021
Description & Function
Primary Treatment
Sewage from the dwelling flows into the primary treatment tank. Wastewater and solids are treated through
sedimentation and anaerobic digestion, with the lighter materials of oils and fats floating to the surface to form a crust.
Anerobic bacteria digest and reduce the organic load or Biochemical Oxygen Demand (BOD
5
).
Aerobic Treatment
Settled wastewater from the primary chambers flows into the first aeration chamber overflowing into the second aeration
chamber, with media pack fixed below water level. Oxygen is supplied to the liquid through four air diffusers and
microbes attach to two media packs, producing an aerobic state which reduces the organic load and nitrifies ammonia.
Sludge Return
The settling sludge in the sedimentation chamber is returned to the primary inlet of septic chamber.
Clarifier/Settling Chamber
After aeration the wastewater overflows into the clarifier/settling chamber. Suspended solids are allowed to settle under
quiescent conditions. Settled particles referred to as sludge, return automatically to primary chamber inlet by sludge
return. This method aids with de-nitrification and provides a constant flow of food supply, which supports the treatment
process during limited usage.
Disinfection
Water flows through a regulated chlorination device to the disinfection chamber, removing final pathogens before flowing
into the pump chamber. Chlorinated water flows into the disinfection chamber, providing a minimum of 300 litres contact
time prior to pump cycle. Any remaining solids settle in base of settling chamber to be removed during regular
maintenance by venturi device
Effluent Disposal
Treated effluent is automatically pumped to disposal area using a minimum 10 metre head pump, with a pump out cycle
of greater than 120 litres.
The maintenance of filters and irrigation sprinklers is the responsibility of the owner or tenant of property.
Air Supply
Air is supplied to the aeration chamber by a Nitto LA80B or equivalent air blower. This produces a nominal 80
litres/minute air flow at 1320mm water depth, providing air to the manifold which is regulated using taps to the four air
diffusers and venturi air lift devices.
