Introduction
The EPA Code of Practice 891.4 outlines specific setback distances for effluent dispersal to ensure the safe and effective management of wastewater, protecting both public health and the environment.
Setback distances vary based on the upslope or downslope location of treatment systems and effluent fields. For instance, the required distance where effluent treatment is up-slope from a boundary, primary septic systems require a 6m setback from the allotment boundary while secondary treatment will only require a 3m boundary where the field is up-slope. Buildings require a 6-meter setback for primary fields up-slope and only 3 meters for secondary effluent. Waterways necessitate a greater setback of 60 meters for primary effluent and secondary treated effluent requires a 30 meter setback for non-potable waterways as defined in the water Act 1989.
Understanding the differences between primary sewage, secondary sewage, and advanced secondary greywater systems is essential in wastewater management. Primary sewage treatment involves the removal of large solids and sediments through physical processes like sedimentation. This process does not significantly reduce pathogens or organic pollutants. Secondary sewage treatment, on the other hand, uses biological processes to degrade organic matter, significantly reducing pathogens and organic pollutants. Advanced secondary greywater systems go a step further by incorporating additional treatment stages such as filtration, disinfection, and nutrient removal. These systems treat greywater—wastewater from sources other than toilets, like showers and sinks—to a higher standard, making it suitable for non-potable uses such as irrigation. The stringent treatment levels in secondary and advanced secondary systems make them more effective in reducing environmental and health risks, thereby influencing the required setback distances. For more information regarding Land Capability Assessments for Septic speak to Chris or Request an obligation free quotation.