MAR schemes vary significantly in scale.
The source and amount of water to be recharged to the aquifer and the type of aquifer, impacts on the complexity of the scheme. The scale of the scheme will also influence the amount of work that needs to be undertaken to design, develop and operate the scheme.
Three categories of MAR schemes have been established to provide a guide to the amount of detail of different schemes. Note: this is a general guide only and depending on different circumstances, schemes may be more complex than initially indicated and require far more detail.
A domestic MAR scheme is where rainwater is collected from domestic dwellings, such as a house and sheds, through a closed system fitted with a first flush diverter, and drained directly to a suitable aquifer.
This type of scheme is seen as low risk to the aquifer system, as volumes are generally less than 500 kilolitres, water is drained under gravity pressure and subsequent extraction is unlikely. However, a strict set of criteria must be met and a department drainage or discharge permit will be required.
If extraction of water post injection is proposed and the property is within a prescribed area, a department water licence and a recharge allocation is also required.
Domestic schemes have the same obligations as commercial schemes to comply with the Environment Protection (Water Quality) Policy 2015. These include the obligations to protect the environmental values of the receiving aquifer. Non-compliance could lead to action by the Environment Protection Authority (EPA).
Small scale MAR
A small scale MAR scheme is where less than 20 megalitres per year of source water, such as stormwater or watercourse water, is to be drained to an aquifer.
The stage one assessment process
may indicate that this type of scheme is considered low risk without preventative measures needing to be put in place. This is not to say that these schemes will not need scrutiny in the future.
The scheme must also comply with the Environment Protection (Water Quality) Policy 2015
Large scale MAR
All other MAR schemes are classed as potentially high risk and will be required to undertake the full four stage assessment process described in the Australian Guidelines for Managed Aquifer Recharge.
These schemes will require collaboration between the Environment Protection Authority and the Department for Environment and Water (DEW), and will need preventative measures to be put in place and managed during the life of the scheme.
The viability and sustainability of a MAR scheme needs to be tested at a number of points during the process to avoid disappointment and unnecessary expense if it does not meet expectations.
Licence and permit requirements
MAR schemes that require approval via an authorisation through the Environment Protection Authority to discharge water to an underground aquifer are those:
- with a surface water capture area greater than one hectare within the Adelaide metropolitan area
- with a surface water capture area greater than one hectare within specified areas of the City of Mount Gambier
- injection of water containing antibiotic or chemical water treatment with a discharge volume greater than 50 kL per day anywhere in the state. Typically, treated wastewater contains water treatment chemicals.
MAR schemes within metropolitan Adelaide that have a surface water capture area less than one hectare or surface water schemes outside of the Adelaide metropolitan area require a permit to drain or discharge.
All schemes that propose to extract the water in a prescribed area will require a licence to extract and a recharge allocation.
When developing a MAR scheme that will require an authorisation from the Environment Protection Authority, proponents must obtain a works approval or a development approval prior to the construction of the scheme, followed by an EPA licence to operate the scheme. Where a development approval is required the proponent will need to lodge a development application with the appropriate planning authority, typically the local council. Where no development approval is required, proponents are to submit two applications to the Environment Protection Authority:
- one for the EPA works approval
- one for the EPA licence.
The requirements for each submission and application forms are available from the Environment Protection Authority SA.