Draft Guidelines for the Reuse of Greywater in Western Australia

APPENDIX 4 – SECONDARY TREATMENT SYSTEMS
One option for a secondary treatment system that collects, treats and disinfects greywater
to a standard of 20 mg/L BOD5, 30 mg/L SS and 10 cfu thermotolerant coliforms / 100mL
prior to irrigation via drip and/or surface irrigation methods is detailed below.
Conversion of Aerobic Treatment Units (ATU) systems to greywater systems
The conversion of disused ATU’s to greywater systems is permitted subject to the
following:
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The ATU is to be installed, operated and maintained in accordance with the “Code of
Practice for the Design, Manufacture, Installation and Operation of Aerobic Treatment
Units Serving Single Dwellings” November 2001.
The effluent quality prescribed for ATU’s must continue to be maintained.
Desludging of ATU’s to allow conversion is not necessary.
DRAFT
Draft Guidelines for the Reuse of Greywater in Western Australia
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