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On-site Wastewater

on-site wastewater assessments, effluent disposal, land capability assessment, wastewater treatment

On-site Wastewater Management

There are a number of different types of on-site wastewater assessments required by local councils in relation to development applications.  The most common is when an existing dwelling is being extended or a secondary dwelling is proposed for the allotment. In this scenario the assessment will comprise the following:

  • review of the ‘capability of the site' to assess if it can accept an increase in hydraulic and/or nutrient loading

  • assessment of suitability of the existing wastewater treatment system  (e.g. septic tank/reed beds/aerated wastewater treatment system (AWTS)/ETA beds/irrigation)

  • recommendations on the type of upgrade that may be required to the existing wastewater treatment system and/or what type of system needs to be installed to service the newly proposed dwelling

On-site Wastewater System Options

LFA takes a site specific approach to each assessment and will liaise directly with the landowner, builder or architect to discuss their on-site wastewater system preferences. When required, LFA will also consult on-site wastewater system manufacturers to discuss specifications and site specific application. On complex sites LFA may seek input or design review from third party designers to allow on-site wastewater system design to be tailored to a specific site.

LFA always recommends the use of passive gravity-fed on-site wastewater treatment systems where it is practical to do so, as their use minimises maintenance and running costs.

Note to Landholders

Constraints posed by on-site wastewater treatment systems can often restrict the type/size of development proposed for a site.  Early consideration of the constraints posed by the management of on-site wastewater can lead to more efficient project outcomes.  Site constraints are explained in detail in council On-site Wastewater Strategy documents. One of the primary constraints that needs to be considered is the buffer distance required to drainage lines from effluent Land Application Areas (LAAs):

  • 40m to ephemeral (i.e. periodically dry) drainage lines

  • 100m to permanent water (not including farm dams)

Often in rural settings land application areas for treated wastewater can be located within buffer areas, however this is site specific, and usually requires an increase in the level of treatment of the wastewater.

COuncil On-site Wastewater Strategy

Each local council in the Northern Rivers has its own On-site Wastewater Strategy that needs to be considered when undertaking wastewater assessments within their particular Local Government Area (LGA).  LFA liaises on a regular basis with relevant council staff to ensure that assessments are completed in a timely and cost-effective way.

Further detail can be found in the various council strategy's on the links below:

Installation of low pressure effluent dosing system - On-site Wastewater System Design

On-site wastewater system installation_Lismore



LFA have undertaken a wide variety of assessments for various clients:

  • Newton Denny Chapelle

  • CivilTech Consulting Engineers

  • A. Fletcher & Associates Pty Ltd

  • Virginia Kerridge Architect

On-site wastewater assessment_buffer distances

On-site wastewater system_constraints to effluent land application area