Describe the purpose of the discharge. Refer to sub-regulations 28(e) and 29(1) of the Environment Protection Regulations 2021 and describe it accordingly. This should include:

• a justification or reasons why you need to discharge waste to an aquifer. Refer to the waste hierarchy. Explain why other ways to dispose are not possible.
• a high-level description of the source, amount and quality of waste and any treatment before discharge
• a high-level description of the area that would be the discharge zone, including the proposed delivery techniques, for example, single point bores, bore fields/arrays, infiltration galleries or seepage pits.
• a high-level description of the likely effect on any environmental values identified in the Environment Reference Standard (ERS) as it relates to regulation 28(e).

What the Environment Protection Regulations 2021 say about regulations 28 and 29:

• Sub-regulation 28(e) – prescribed matters the Authority (this means EPA) must take into account when determining to issue a permit for an activity A18 includes whether granting the permit may adversely affect any environmental values identified in any relevant environment reference standard.
• Sub-regulation 29(1) – circumstances in which an application for a permit must be refused for an activity A18 includes the discharge or deposit of waste to an aquifer is not for at least one of the following purposes – a) aquifer recharge b) irrigation drainage c) stormwater disposal d) backfilling or underground mine workings with tailings e) mine rehabilitation f) in-situ desalination g) groundwater tracers h) greenhouse gas sequestration operations i) remediation of groundwater in an aquifer by injection of water or remediation chemicals.

Describe the quality and chemical composition of the waste discharge. Include a description of any treatment done before discharge, for example, any sampling and analysis of the waste and waste stream. Include:

• the total volume or rate (volume/time) of waste to be discharged
• the time frame the discharge will happen
• how the discharge will happen, for example, continuous, pulsed, periodic
• the intervals or time between discharge events (where relevant)
• the time over which the whole project will happen. This means the whole time from start to finish, including pilot trial and full scale.

Provide a description of:

• the location and properties of the aquifer, for example:
• flow direction
• depth
• aquifer geology
• aquifer permeability/transmissivity

• applicable environmental values of groundwater identified in the ERS. Base this on the available information collected from site or regional studies
• existing/background quality of groundwater, for example, the extent of existing background levels of any contamination
• existing groundwater extractive uses within 2 km of a proposed discharge location. Indicate the use, the distance from the site and whether they are up gradient, down gradient, or cross gradient
• existing surface water receptors, including groundwater dependent ecosystems (GDEs) within 2 km of a proposed discharge location . List the approximate distance and direction from the site.

Undertaking a Hydrological Assessment (with reference to Hydrogeological assessment (groundwater quality) guidelines Publication 668) will provide a robust structure for describing the aquifer characteristics.

The Environment Protection Regulations 2021 have more information.

Describe extent of impacts to the environmental values of the aquifer, for example, potential extents of migration. This means how far into the environment the waste might travel. Include the results of fate and transport modelling (or justification why modelling was not performed).

Provide details of any environmental and health risk assessments (or justification why risk assessment was not performed).

Describe the physical effects to the aquifer. This should include:

• displacement/mounding effects
• changes in groundwater flow direction
• changes to groundwater discharge locations, including GDEs

Where modelling is available, include:

• a description of the model and reasons for choosing that model
• sensitivity analysis conducted and any error margins
• assumptions underpinning the model and reasons for those assumptions

Undertaking a Hydrological Assessment (with reference to Hydrogeological assessment (groundwater quality) guidelines (Publication 668) will provide a robust structure for describing the aquifer characteristics and associated risks from the activity.

Find more information

• Assessing and controlling risk: A guide for business (publication 1695)
• Reasonably practicable (publication 1856)
• Hydrogeological assessment (groundwater quality) guidelines (publication 668) 
• Barnett et al, 2012, Australian groundwater modelling guidelines, Waterlines report, National Water Commission, Canberra
• National Environment Protection (Assessment of Site Contamination) Measure, 1999, Volume 3, Schedule B2, Section 4 – Conceptual Site Models
• National Environment Protection (Assessment of Site Contamination) Measure, 1999, Volume 3, Schedule B2, Section 10 – Contaminant fate and transport modelling
• National Environment Protection (Assessment of Site Contamination) Measure, 1999, Volume 6, Schedule B5a, Ecological Risk Assessment

Provide a description of:

• the proposed environmental quality objectives for monitoring and management
• the proposed groundwater quality monitoring plan including locations, frequency, chemical analysis suites and monitoring period (pre, during and post-discharge)
• the proposed triggers and plans should unexpected adverse outcomes happen
• any community/stakeholder consultation undertaken.