When setting up and operating any stormwater harvesting and reuse project, including a managed aquifer recharge (MAR) scheme, you must abide by the regulations. For example, there are rules about the quantity and quality of water that you can recharge into the aquifer for later extraction. The regulations are in place to protect the state’s environmental assets, including rivers, groundwater systems and other water resources and other users of the resources.
MAR schemes in South Australia are regulated as follows:
- The Natural Resources Management Act 2004 has specific provisions that primarily deal with water quantity issues, including prescription, control of use, development of catchment and water allocation plans and environmental flows. The Department for Environment and Water (DEW), under the objectives and principles within the NRM Act 2004, regional NRM Plans, and Water Management Plans, regulates water affecting activities, such as construction or modification of wells, infrastructure works in watercourse or on flood plains or drainage or injection of water into aquifers where the EPA is not the relevant authority. This includes injection of water such as roof runoff through a closed system from a catchment area less than 1 ha in the Greater Adelaide Metropolitan area, groundwater or mains water anywhere across the state and stormwater or watercourse water in areas outside of the Greater Adelaide Metropolitan Boundary. The DEW and the Natural Resources Management boards are responsible for managing the quantity of water (the injection and extraction volumes) in relation to ensuring minimal negative impacts on natural water resources. This includes providing the scientific knowledge and technical assessment to ensure regulator decision making assists MAR schemes cause minimal or negligible impacts.
- The Environment Protection Authority SA is the main regulator of the quality of water drained or discharged into an aquifer. The Environment Protection Act 1993 requires that you obtain a works or development approval before you build a MAR scheme. It also requires that you gain an environmental authorisation before carrying out activities of ‘environmental significance’, including the ‘discharge’ of waters to aquifers. All MAR schemes, regardless of their size or geographical location, are required to adhere to the requirements of this Act and to the Environment Protection (Water Quality) Policy 2015 and other relevant policies.
- The Public Health Act 2011 contains provisions for the protection of public health, including sanitation and water supply. Under this Act, the Public Health (Wastewater) Regulations 2013 provide details about the management of wastewater systems, including the reuse of the recycled water. SA Health manages the human health aspects of the use of recycled water, such as stormwater and treated wastewater after the water is extracted. Under the Public Health Act 2011 and the Public Health (Wastewater) Regulations 2013 approval is required for all uses of recycled water. Although no formal approval is required for use of recycled water, the EPA will refer an EPA licence application to SA Health for them to undertake an assessment. SA Health will assess applications and provide written confirmation if satisfied that the use of recycled water poses no significant risk to public health and will provide the EPA with conditions that are required to be applied to an EPA licence. The EPA then notifies SA Health if the application has been successful and an EPA licence has been issued. For further information see the South Australian Recycled Water Guidelines.
- The Development Act 1993 provides for the consideration of any scheme that is deemed to be a ‘development’. If your MAR scheme proposal is deemed to be a development, you may need to submit a development application form to the relevant planning authority. Contact your local council in the first instance for advice.
How do MAR schemes help meet water security goals?
A number of key targets within our state’s long term Water for Good plan directly relate to stormwater harvesting and reuse schemes, such as ‘supply 60 gigalitres of stormwater per year by 2050’ for Greater Adelaide.
What are the benefits to the environment?
Stormwater and wastewater contain substances such as sediments, metals, pesticides, herbicides, nutrients and organic compounds which can pose adverse risks to human health and the environment.
However, with good-quality treatment systems, stormwater harvesting and reuse schemes can benefit groundwater resources (through replenishment of declining aquifer groundwater levels and alternative irrigation water supply) and other environments such as urban streams and the Gulf St Vincent.
If the recycled water is not treated to an appropriate level, recharge of this water into an aquifer can cause a risk to human health and the environment, including rendering an aquifer unsuitable for certain beneficial uses (e.g. potable or irrigation).
Drainage or discharge and subsequent extraction of water can also cause hydrogeological impacts, such as movement of existing contaminated or saline groundwater plumes into areas of better water quality, and excessive pressurisation. This is why MAR schemes in South Australia are regulated to provide confidence that they are viable and sustainable.