Sewage Treatment Plant - BIOROCK - How does it Work

How the BIOROCK Sewage Treatment System Works

• The BIOROCK system consists of a separate settlement tank, which can be an existing traditional brick or concrete septic tank, followed by the BIOROCK sewage treatment plant.

• The raw sewage first enters a settlement tank which separates the solids from the liquid part of the effluent.  This tank is ordered seperately at the time of order.  This settlement tank is fitted with an effluent filter which prevents solids exiting the tank.  New settlement tanks are made for us by Conder and these digest most of the solids anaerobically and only require emptying every 3 to 4 years.  (Existing traditional 2 stage septic tanks can also be used as this settlement tank and in these cases you would only order the BIOROCK sewage treatment plant.) 

• The Primary Effluent then enters the BIOROCK sewage treatment plant which uses alternate layers of air passages and natural fibre material contained in nets.  This stone fibre is in constant contact with the air to treat the effluent in exactly the same way as Nature treats effluent in the soil or on the margins of a pond.

• Bacteria grow in the stone fibre and digest the organic material as it is trapped in the matrix and the cleaned water trickles through.

• The Stone Fibre is self cleaning and so far, in the 13 years since the current design has been in operation, has not required replacement.  The photo on the right shows the stone fibre under a microscope,  The top photo is new stone fibre and the bottom photo is the top layer of the stone fibre after 18 months in the BIOROCK.  Note the completely open filter matrix with just the newly trapped solids being digested by the bacteria in the fibres.

• Instead of using electricity-guzzling compressors to provide the air, the BIOROCK biofilter sewage treatment plant utilises the wind and natural 'chimney-draft' to pull the air through the plant with no electricity required.  The low end of the chimney has its inlet within 5 metres of the BIOROCK tank and the high end of the chimney usually exits underground and discharges within 10 metres up the side of the house or shed wall, tree, telegraph pole. etc. as a soil vent pipe.

• The Conder settlement tank is included when you order the BIOROCK sewage treatment system package.  This is also vented to a soil vent pipe and therefore no smell is emitted from the tank.

 The final effluent can be discharged either to a soakaway or a watercourse

Septic tank emptying by WTE