Onsite sewage management in the Richmond Valley Council area is governed by a number of guidelines and legislations mainly the Local Government (Approvals) Regulation 1993 and including the Local Government (Approvals) Amendment (Sewage Management) Regulation 1998. This regulation defines a ‘sewage management facility’ as:

• a human waste storage facility (such as a septic tank); and
• a waste treatment device intended to process sewage and includes a drain connected to such a facility or device.

Council regulate the installation and ongoing operation of on-site sewage management systems (OSMS) under Section 68 and 124 of the Local Government Act 1993 and are to ensure the performance standards for on-site sewage management, including protection of public health and prevention of environmental damage;

The On-site Sewage and Wastewater Management Strategy encompasses all single dwelling domestic on-site wastewater systems within the Richmond Valley Council area. The Strategy is divided into two (2) sections and eight (8) Appendices.

• Section 1 – Part A – Introduction to On-Site Sewage and Wastewater Management Strategy
• Section 2 – Part B – On-Site Sewage Management Systems Design, Installation Requirements, and Consultants Reports
• Appendix 1 – Types of Treatment Systems, Maintenance and Operational Requirements and Associated Components
• Appendix 2 – Land Application Areas
• Appendix 3 – Matrix for Use in Sizing Land Application Areas (Disposal Areas) for the Upgrade of Existing On-site Sewage Management Systems
• Appendix 4 – Blank Site and Soil Assessment Forms
• Appendix 5 – Daily Disposal Model
• Appendix 6 – (Local) Native plants suitable for Land Application Areas.
• Appendix 7 – Sub-surface Drip Irrigation Design Checklist
• Appendix 8 – Richmond Valley Council CID Checklist

Use of mounds in the construction of evapotranspiration beds

Since October 2009 no applications have been accepted by Richmond Valley Council that propose the use of mounds in the construction of disposal areas for evapotranspiration beds. This relates to the diagrams labelled ‘Typical Mounded System’ and ‘Cross Section of Typical Mounded System’.

The reasons for the removal of these diagrams from the strategy are:

• Fill often has highly variable properties, such as permeability.  Fill can be prone to subsidence and could contain material that might not be suitable for plant growth or for constructing disposal areas.
• Unpredictability of how the wastewater will be disposed of in the fill, possible creation of preferential flow paths leading to disposal area failure and concerns in regards to the even distribution of the wastewater at the interface of the fill and the existing natural ground level.
• Supply of fill – where did the fill come from?  Is it suitable for the disposal of wastewater?
• Inexperience with design and construction of mound systems.

Onsite sewage management daily effluent model

Richmond Valley Council has a computer model available to calculate daily household effluent demand, and minimum disposal area requirements for onsite sewage management. The model comprises an excel spreadsheet which, due to size restrictions the model is currently not available to download but please contact Council’s Environmental Health section on 02 6660 0300 to obtain a copy.