Wastewater system setback distances

Septic tanks and Wastewater systems need to be installed according to the requirements set out by the Environment Protection Authority's Code of Practice - Onsite Wastewater Management. Even when onsite wastewater management systems are properly designed, installed and maintained, potential environmental and public health risks exist.

The consequences of failing systems are diverse and depend on the type of treatment system, the characteristics of the site and the wastewater, the sensitivity of the surrounding environment and proximity of neighbouring households and land use.

To minimise the potential risks, onsite wastewater management systems must be installed with a ‘buffer’ or ‘setback distance’ to the property structures and the surrounding environment.  Setback distances from primary and secondary sewerage and greywater systems are listed below.


 Landscape feature or structure  Setback distances (m)
 Primary sewage and greywater systems  Secondary sewage and greywater system  Advanced secondary greywater systems
 Up-slope of Surface Waters
 Dam, lake or reservoir (potable water supply)
 300m  300m*  150m
 Waterways (potable water supply)  100m  100m*  50m
 Waterways, wetlands (continuous or ephemeral, non-potable); estuaries, ocean  beach at high-tide mark; dams, reservoirs or lakes (stock and domestic, non-potable)  60m  30m  30m
 Wastewater field up-slope of building  6m  3m  3m
 Wastewater field down-slope of building  3m  1.5m  1.5m
 Wastewater up-slope of cutting/escarpment
 15m  15m  15m
 Allotment boundary
 Wastewater field up-slope of adjacent lot  6m  3m  1m
 Wastewater field down-slope of adjacent lot  3m  1.5m  0.5m
 Water supply pipe  3m  1.5m  1.5m
 Wastewater up-slope of potable supply channel  300m  150m  150m
 Wastewater field down-slope of potable supply channel  20m  10m  10m
 Gas supply pipe  3m  1.5m 1.5m
 In-ground water tank  15m  7.5m  3m 
 Stormwater drain  6m  3m  2m
 Recreational areas
 Children’s grassed playground  6m  3m   2m
 In-ground swimming pool  6m  3m  2m 
 Groundwater bores
 Category 1 and 2a soils  NA  50m  20m
 Category 2b to 6 soils  20m  20m  20m
 Vertical depth from base of trench to the highest seasonal water table  1.5m  1.5m   1.5m 
 Vertical depth from irrigation pipes to the highest seasonal water table  NA  1.5m  1.5m 


* Setback requirement can be reduced by 50% if specific conditions are met - refer to Table 5 in EPA Code of practice  - onsite wastewater management(PDF, 2MB) (page 41).