Prior to the installation or alteration of any OWMS, a permit must be obtained

• For systems that can treat up to 5,000 litres a day, you can apply through Council.
• For systems that can treat more than 5,000 litres a day, you need an operating licence and a development licence from the EPA. You don’t need further approval from Council.

When you submit an application to install or alter a septic system, ensure you have:

• Site plan of proposed effluent field (ensure features such as waterways, dams and buildings are included)
• Floorplan of all dwellings on site
• Certificate of Conformance of proposed system
• A Land Capability Assessment if requested during the planning process.

All OWMS works must comply with the permit issued by
- Colac Otway Shire,
- the Environment Protection Act 2017,
- the EPA Guidelines for onsite wastewater management,
- the EPA Guidelines for Effluent Dispersal and recycling systems
- the relevant Australian/New Zealand Standards.

If your OWMS application is approved, the licensed plumber detailed on the permit must contact the Health Protection Unit to arrange an inspection of the system prior to backfilling. Seven days’ notice is preferred, prior to the commencement of works.   

There are a number of different types of OWMS available. To choose a system that is right for you and your property, you should liaise with Council's Health Protection Unit, your Land Capability Assessment provider and a licensed plumber to ensure that the system conforms to relevant Australian and New Zealand Standards and Council's Domestic Wastewater Management Plan.

When planning where to locate the septic system, you should consider:

• Future use of the land – as it can’t be used in the future for other building etc.
• Minimum distances to boundaries, watercourses (including dams), other buildings, swimming pools, tennis courts and driveways. These distances can be found in the EPA guidelines. 
• Where livestock is kept – as they can’t be kept on an effluent disposal area.
• Distance to nearby trees and native vegetation.
• Suitable plants and vegetation for the Effluent Field (see link at the bottom of this page)

Whichever system you choose, you may be required to conduct a Land Capability Assessment (LCA). In unsewered areas, a LCA should be undertaken for each site that requires the installation of an OWMS, unless Council is satisfied the site is low risk or sufficient information (e.g. soil permeability rates, soil types, depths to water table, fractured rock and other limiting factors) has already been gathered about the site.

Some examples of when an LCA may be required to support an application include:

• Any allotment within a Special Water Supply Catchment Area
• Small lot size (under 4000m2)
• Soils with very low permeability
• Groundwater quality at risk
• Development use (i.e., high loading rate due to commercial/industrial activities)
• Susceptible ecological areas or water bodies nearby
• Lot characteristics such as slope, location of drains/easements/water courses etc

It may be one factor alone that triggers the need for an LCA or a combination of factors.

Individual landowners or developers (not EPA or Councils) are responsible for engaging a suitably qualified and experienced professional to undertake a LCA for unsewered developments or subdivisions. The Victorian Land Capability Assessment Framework, 2014 provides further guidance.

If you are unsure of whether an LCA is required, please contact Council’s Health Protection Unit on (03) 5232 9400 prior to submitting your application.

When you get a final inspection on your septic system, Council will also issue a certificate to use (CTU) an OWMS. There is no additional cost for this permit and you don’t need to apply again.

To obtain a CTU you will need:

• An inspection by Council's Health Protection Officer - the plumber should contact Council to organise this once the system has been installed.
• A Certificate of Compliance from the Victorian Building Authority (the plumber will organise this).
• A commission report (if applicable).
• An accurate, to scale, as-constructed site plan.
• An Electrical Certificate (if applicable)
• A copy of the maintenance service agreement if you’ve installed an Aerated Wastewater Treatment System.

To keep the system working well

✔   use biodegradable soaps and low-phosphorus, low sodium detergents
✔    arrange for regular servicing of treatment plants
✔    keep livestock and vehicles off the system
✔    divert stormwater runoff away from trenches or irrigation areas

x     don’t use powerful bleaches, whiteners, nappy soakers, spot removers and disinfectants
x     don’t put chemicals or paint down the drain
x     don’t put pads, tampons or nappies into the system
x     don’t build over the system (driveways, sheds, units etc.)

To reduce sludge building up in the tank

✔   scrape all dishes to remove fats, grease and food scraps before washing
✔    keep food waste out of the system
✔    pump out the tank at least once every 3 years

Avoid overloading the system

✔    space out water use as evenly as possible
✔    wash clothes only when there is a full load
✔    install water conservation fittings
✔    take showers instead of baths

x     avoid doing all the washing on one day
x     avoid using the washing machine and dishwasher at the same time

Responsibility for managing and maintaining an OWMS falls with the property owner. An owner of land on which an OWMS operates must provide the occupier with written information regarding the correct operation and maintenance of the system. Persons in control of an OWMS must take all reasonably practicable steps to ensure the system is maintained in good working order and does not pose a risk to human health or the environment.

These steps include:

• Regular desludging to remove the contents of the system, if applicable
• Ensuring the integrity of pipes, tanks and storage systems.
• Repairing and, when required, replacing all the components and fittings of the system.
• Maintaining the biological and chemical processes integral to the proper functioning of the system.
• Maintaining the integrity of the land used in connection with the system to ensure access to the system is not impeded.
• Complying with the system manufacturer's specifications and recommendations.
• Complying with any relevant council requirements.
• Monitoring the system for signs of fail.

Persons in control of an OWMS must keep and hold all records of maintenance activities carried out on the system, including any pump-out and service records, for five years after each activity. These records must be made available for inspection upon request by Council.  

It is essential to be vigilant about potential OWMS failures. This means paying attention to key warning signs and taking steps to address the issues, even if this might be contained to your property.

Warning signs of failure may include:

• the absorption field becoming wet with wastewater pooling on the surface
• wastewater runoff from the disposal area
• a smell of effluent near or from the system
• Shower, basin or toilets draining slowly

If you suspect your system may be failing, please contact a licensed plumber to inspect the system.

The Regulations also require landowners and occupiers to tell their council if their OWMS shows any signs of failure. You will need to explain to a council officer what has or is being done to fix the problem.

If others detect and report issues to council – such as offensive smells - and the owner or occupier has not reported it, a penalty may apply to the owner or occupier.

After you have connected to a reticular sewerage or upgraded your old septic or onsite wastewater management system (OWMS), the old septic tank or OWMS must be decommissioned.

The following steps are applicable:

• Have its contents pumped out by a licensed sewage sludge contractor and the inlet and outlet pipes sealed.
• Punch a hole in the bottom of the tank, the lids and any parts of the tank walls that sit above ground level so that they collapse into the tank.
• Fill the tank with clean earth or sand.
• Any chlorination pits on the sand filter outlets must follow the above process as these may have a direct connection to the stormwater drain.
• Notify Council of your decommissioning and provide a detailed and to scale site plan of the location.

Decommissioning Notification Form

EPA Permits and Domestic Onsite Wastewater Management Responsibilities

Council is meeting its statutory responsibilities in relation to the assessment, permit and approval process for domestic onsite waste water systems.

Since November 2015, Council has issued 484 permits. Systems installed post 1 July 2016 upon approval would be assessed as EPA compliant.

A calendar year break down of permits is as follow:

A focus of the domestic wastewater management plan activities, is also the auditing and inspections of onsite domestic wastewater systems within declared water supply catchments.

Systems have been assessed and education to property owners and occupiers has been provided.