NPI data

The NPI is an internet-based database that provides free information to the community, government and industry on the emissions and transfers of substances to our environment. The NPI is unique as it shows on a geographical basis, where substances are being emitted, and in what amount.

NPI data sources

The NPI database contains data from three main sources: facility emissions, facility transfers and diffuse emissions.

Facility data

Australian industrial facilities that meet the reporting criteria are required by law to report annually to the NPI. The criteria are based on how much fuel, electricity and the amount of NPI substances they have used.

If any NPI thresholds are exceeded, the facility must calculate the emissions and transfers of substances in waste from their site, and provide the results to the environmental agency in their state or territory. These agencies review all NPI reports for accuracy. When the data is correct, it is published on the NPI website in March each year.

Industry sectors

Industries as diverse as sugar milling, soft drink making, mining, hospitals and brick manufacturing report to the NPI . Facilities are grouped into industry sectors using the 2006 Australian and New Zealand Standard Industrial Classification (ANZSIC) codes. This enables each facility to compare its results against other facilities in the same ANZSIC code, and for the community and decision makers to track emissions from different industry sectors.

Industry guidance materials are available to assist facilities in reporting to the NPI. These materials provide the information to assist with calculating the emissions: mass balance, engineering calculations, direct measurement (monitoring) and emission factors.

Are any facilities excluded from reporting?

The NPI National Environment Protection Measure (NEPM) specifically excludes the following types of facilities from reporting to the NPI :

  • mobile emission sources (for example, an aircraft in flight or a ship at sea) operating outside the boundaries of a fixed facility
  • petrol stations
  • dry cleaners that employ less than 20 people
  • scrap metal handling facilities that do not reprocess batteries or engage in metal smelting and
  • agricultural production facilities, including the growing of trees, aquaculture, horticulture or livestock raising unless it involves intensive livestock production (for example, a piggery, poultry farm or a cattle feedlot) or processing agricultural produce.


Emissions from a facility may be to air (i.e. from a chimney), to land (i.e. a spill) and water (i.e. a licensed discharge from a facility into a river) and must be reported if a reporting criteria is triggered.


In addition to emissions data, the variation of the NPI NEPM introduced the reporting of transfers.

If waste is transported to a destination for containment or destruction, reporting is mandatory. Containment destinations include landfill, tailings storage facilities, underground injection or other long term purpose built waste storage structure. It also includes the transport or movement of substances contained in waste to a sewerage system.

Reporting may be voluntary if transfers are to a destination for reuse, recycling, reprocessing, purification, partial purification, immobilisation, remediation or energy recovery.

Diffuse emission data

Diffuse data are emissions within airshed and water catchment study areas. The data includes emissions from smaller industries, and mobile and non-industrial sources. They are included to provide a more comprehensive picture of emissions to the environment.

Smaller industries are those that have not triggered thresholds for reporting to the NPI such as commercial printers or small bakeries. Mobile sources are transport-related, and include motor vehicles, aircraft and ships. Non-industrial sources cover both household activities, such as lawn mowing, cigarette smoking, barbeques and domestic wood heating, and area-based sources such as bushfires and urban emissions to watercourses.

Emissions from diffuse sources are estimated by state and territory environment protection agencies.

Most of the 93 NPI substances are emitted to air and are considered in airshed studies. However in most water catchments, only total nitrogen and total phosphorus are considered when estimating diffuse emissions. Diffuse data are not collected for emissions to land.

The boundaries of NPI airsheds are selected by government agencies. More than 30 studies have been completed covering all capital cities and many urban regions in Australia.

The boundaries of water catchments are determined by the drainage of interconnected river systems, which sometimes cross state or territory borders. More than 30 catchment studies have been completed for the main urban and rural areas in Australia.

What is an airshed?

An airshed is a body of air, bounded by meteorology and topography, in which substance emissions are contained.

What is a water catchment?

A water catchment is the land area drained by a creek or river system.

Diffuse data studies are not updated annually. State and territory agencies use the best available methods to calculate the diffuse emissions as they become available. Ongoing work is being undertaken to improve the accuracy of diffuse emissions data. Diffuse emissions estimation technique manuals are available to assist in identifying the best way of determining the emissions.