Onsite sewage treatment is growing in diversity, and in regulatory control across Australia. This is occurring for both blackwater and greywater treatment, as the drought impact deepens and more of the community are exposed to options for ‘managing’ their own water. Regulators in each State are drafting and implementing Guidelines to cover a range of on-site system scenarios. In addition, more and more decentralised options are being tendered for sewage management in the commercial world. In this project we aim to use novel molecular tools, in combination with traditional physical/chemical/biological methods, to understand onsite treatment in a more detailed manner. The system tested is a new peat based biofilter which can be used for greywater or blackwater application, and can be retrofitted to current sewage systems. This project has been based on the AquaReuse greywater system for demonstration purposes, showing the strength of the information gained from the use of novel tools. The two systems investigated are installed at a caravan park in New South Wales (NSW) and a domestic residence in Tamborine, Queensland (QLD). A 20-week intensive sampling and analysis program was followed. The project monitored standard analytes such as biochemical oxygen demand (BOD5), suspended solids (SS) and thermotolerant coliforms (TC). Additionally, we studied the biological community using fluorescent in situ hybridisation (FISH) on a monthly basis and full-cycle ribosomal RNA analysis (rRNA) for one sample to assess the biological community inhabitants. rRNA analysis at the NSW facility demonstrated a highly diverse biological community, in keeping with its long established operating period. In contrast, FISH analysis at the QLD installation showed a less diverse and younger community. rRNA and FISH identified organisms that are mostly associated with nutrient removing functions.

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