Surface irrigation uses a network of spray points to apply effluent just above the ground's surface. For older systems that were approved for surface irrigation more than 10-15 years ago, most local councils allowed movable surface sprays, so the irrigation line could be moved around the yard. These days any surface spray irrigation requires to be in fixed locations, with all irrigation lines buried more than 100mm underground with either pop-up sprays or fixed spray heads on risers, to distribute the treated effluent.
This spray application system can only be used with effluent treated to a secondary or tertiary standard (such as aerated wastewater treatment systems). A Wastewater disposal area plan, will be submitted with your application to install a wastewater treatment system (Section 68) to council for approval, once approved, the proposed disposal area can not change without council approval.
Chlorination, the most common type of effluent disinfection, does not kill all bacteria and viruses, so surface irrigation poses a public health risk unless systems are well designed and maintained. Advanced secondary aerated wastewater treatment systems, are safer for surface irrigation, but in most cases not the best option, preferred by local governing authorities, in these modern times.
Common problems with surface irrigation are:
- surface saturation and effluent runoff into stormwater drains, creeks or neighbouring properties
- poor ground/soil quality, to allow moisture & nutrient uptake.
- unreliable aeration or disinfection systems can cause irrigation with contaminated effluent
- system not designed or approved for its location
- no service agreement with a qualified service provider for regular maintenance and inspections.
- poorly maintained irrigation disposal areas, (long grass), will cause wet areas, minimising airflow.
Movable wastewater surface sprays
Fixed wastewater Irrigation