With an increasing number of applications to develop rural residential developments featuring onsite effluent treatment systems, local councils are more frequently requiring land capability assessments (LCA) to be undertaken to assess the impact of onsite effluent treatment systems prior to approval being granted. For developments with lot sizes of less than 1ha, the use of on-site

The two most significant impacts associated with onsite effluent treatment systems are considered to be excess nutrients and biological hazards. With the strict environmental conditions and guidelines that are in place today it is appropriate that these issues are addressed accordingly.

Excess nutrients can have significant effects on sensitive receptors such as local waterways, including lakes, dams or rivers and creeks.

Biological hazards can have a significant impact on the health of local residents who may utilise soils or water contaminated by pathogens commonly associated with human waste products.

LCAs undertaken by 360 Environmental utilise the latest information available to assess the capability of soils to absorb and purify overflow from onsite effluent treatment systems.

LCAs can be undertaken in the form of simple desktop studies or more detailed assessments which include site visits, soil sampling and profiling with an onsite drilling rig.

The inclusion of onsite sampling is considered to be beneficial as the information provided allows a more detailed assessment based on limiting factors within the soil profile which are not generally available through regional soil mapping.

Environmental opportunities and constraints (EOCs) can be incorporated into the LCA if required by the client.

These EOCs will include information in the report such as:

• A detailed site inspection of the project area by an Environmental Scientist;  A review of historical and current land uses using title information, historical aerial photography and interviews with persons knowledgeable of past and current landuse activities;
    
• Review of previous environmental approvals and current zonings using town planning information and interviews with people knowledgeable with respect to these aspects;
   
• Review of the available information on topography, geology and soil profiles, surface hydrology, groundwater, contaminated sites, acid sulfate soils, flora and fauna, and Aboriginal and European heritage sites. Databases and digital mapping information will be used to provide an understanding of the features of the site and potential actions or requirements relating to the features identified.
   
• Review of the environmental policies relevant to the subject site and the provision of advice regarding potential opportunities or constraints to be managed as part of the planning process.
   
• Liaison with Town Planners regarding any environmental requirements relevant to the site.
   
• Develop a preliminary environmental assessment of the site including assessment of existing vegetation and flora information such as declared rare flora and threatened ecological communities, conservation status of fauna, drainage and nutrient management, potential soil and groundwater contamination from prior land use, acid sulphate soils and provision of potential management options.
   
• Provision of advice and development of a checklist for the environmental approval processes required to facilitate the development on the subject site.

The inclusion of EOCs provides a more detailed assessment that allows more accurate assumptions and recommendations for the site to be made.

By including the EOCs in the LCA clients will gain a greater understanding of the environmental process of the site with respect to onsite effluent treatment and often find that regulatory authorities more readily respond to the results of the LCA.