The Department of Health released for public comment a draft Government Sewerage Policy in December 2011 (Draft 2011 Policy). The consultation period ended on 1 April 2012 and we await formal adoption of the instrument in due course. Importantly, it is our recent experience that elements of the Draft 2011 Policy are being applied to development proposals currently being assessed.
The Draft 2011 Policy consolidates the two policies which previously guided the provision of sewerage, namely the:
Government Sewerage Policy – Perth Metropolitan Region; and
the Draft Country Sewerage Policy.
The new Draft 2011 Policy applies to both residential and non-residential development and subdivision across the State. It sets out criteria which if met, require development or subdivision to be connected to a reticulated sewerage system, this includes:
when any part of the development or subdivision is already connected to reticulated sewerage; or
where reticulated sewerage is located within 91 metres of the proposed development or subdivision and is capable, in the opinion of the local government, of being drained into such sewer; or
in a Public Drinking Water Source Area; or
when it has been identified within a local government planning scheme that the development or subdivision shall be connected to reticulated sewerage; or
when the absence of sewerage is likely to pose a risk of harm to public health; or
when the absence of sewerage is likely to pose an unacceptable impact on the environment or surface water supplies.
If the criteria listed above are not met, then the proposed subdivision or development may be exempt from the requirement to connect to a reticulated sewerage system. However in order for non-sewered development to be approved it must meet criteria for the safe provision of onsite sewerage disposal as set out in the policy, this includes:
Meeting minimum lot sizes based on soil category, extracted table 2 as follows:
|
Soil Category |
Soil Texture |
Minimum Lot Size |
|
1 |
Gravels and sands |
1000m² |
|
2 |
Sandy loams |
1000m² |
|
3 |
Loams |
1000m² |
|
4 |
Clay loams |
2000m² |
|
5 |
Light clays |
2000m² |
|
6 |
Medium to heavy clays |
2000m² |
The applicant demonstrating that the site is suitable for onsite sewerage disposal to the satisfaction of the Health Department. This demonstration should be by way of a report prepared by a person tertiary qualified in soil sciences, hydrology or engineering and who is appropriately qualified and experienced in soil site evaluations/assessments. The report must:
provide a "Site and Soil Evaluation" in accordance with wither AS/NZS 1547 On-site Domestic Wastewater Management and the Department of Health’s Code of Practice for On-Site Sewerage Management; or a geotechnical site investigation in accordance with AS 1726 Geotechnical Site Investigations; and
include in the "Site and Soil Evaluation" a soil profile to the minimum depth of 2.0m from ground level; and
be signed and guaranteed by the site assessor for a minimum period of ten years.
Lavan Legal comment
The new Draft 2011 Policy proposes to replace the existing system which requires the preparation of a site specific analysis to determine the capability of any given landholding to deal with effluent disposal safely.
The introduction of 1000m² minimum lot sizes specified for sites with gravels, sands, sandy loams or loamy soils may significantly improve the feasibility of many special residential/semi-rural developments which have previously been restricted by the existing policies.
The Draft 2011 Policy also provides greater guidance, setting out a clear framework for project development and assessment which will be a welcome relief for many landowners and developers who have been delayed by the uncertainty in the older policies.
Probably the most important implication of the new policy is the effect that it will have on those consultants who produce the "Site and Soil Evaluation" reports required under the new system. These reports must be signed and guaranteed by the author, with the policy stating that, by signing off on a report "…site evaluators/soil assessors shall accept professional liability for the site assessment and the resultant interpretations, conclusions drawn, and recommendations made."
It is therefore of paramount importance that site evaluators and soil assessors conduct their work in a transparent and accurate manner. In addition, however, it may necessitate the requirement for consultants to maintain up-to-date and sufficient professional liability insurance in order to avoid/indemnify potential liability into the future.
