The NPI NEPM defines an emission as the release or discharge of a substance to the environment, in any physical state. A transfer is the movement, on-site or off-site, of a substance to a mandatory or voluntary reporting transfer destination. Transfers were added to the NPI by the 2007 variation of the NEPM.
Key points
- Emission: a release to air, land or water
- Transfer: a substance moved in waste to a reporting destination
- Groundwater releases are reported as emissions to land
- Mandatory destinations are containment, destruction, sewer or linked treatment
- Do not add emissions and transfers together
Emissions by medium
- Air: point sources such as stacks and vents, and fugitive sources such as equipment leaks, materials handling, open vessels and vehicle exhaust.
- Land: releases on site, including spills, leaks and surface impoundments. Releases to groundwater are reported as emissions to land.
- Water: discharges to surface waters such as rivers, lakes, estuaries, the sea and stormwater. Groundwater is excluded.
The NPI meaning of fugitive emissions is broad. Under NGER the same term is narrower, covering only greenhouse gases released in extracting, processing, storing or delivering fossil fuel.
Transfer destinations
- Mandatory destinations are places of final disposal: containment such as landfill, tailings storage and underground injection, off-site destruction, an off-site sewerage system, or off-site treatment that leads only to one of these.
- Voluntary destinations are where the substance is reused, recycled, reprocessed, purified, immobilised, remediated or used for energy recovery.
Reading the data
DCCEEW cautions that a transfer is not a discharge to the environment and that adding emissions and transfers together is misleading. Releases that occur during a transfer, or from the transfer destination, are emissions.
Emissions to land or transfers
Substances placed in a purpose-built, approved containment facility, such as a landfill or tailings storage facility, are transfers. Substances spilt or leaked onto land outside such a facility are emissions to land, even if the release stays within the site.
Overburden, waste rock, uncontaminated soil and similar materials are excluded from transfers under the NEPM definition and the NPI Guide. A facility’s emissions and transfers are published side by side but in separate files in the data.gov.au download.
Why it matters
Classifying a waste stream as an emission or a transfer changes where it appears in the public data and whether it must be reported at all, because transfer reporting is triggered only by Category 1, 1b and 3 thresholds.
References & sources
Primary regulatory documents and authoritative references underpinning this answer.
- DCCEEW: Transfers of NPI substances in waste, frequently asked questionsdcceew.gov.au
- DCCEEW: National Pollutant Inventory datadcceew.gov.au
- National Environment Protection (National Pollutant Inventory) Measure 1998legislation.gov.au
- DCCEEW: National Pollutant Inventory Guide (Version 6.1)dcceew.gov.au
- National Greenhouse and Energy Reporting (Measurement) Determination 2008legislation.gov.au