National Pollutant Inventory

Reporting emissions and transfers

Industry tips for NPI reporting

Reporting to the NPI

How is the NPI reporting year defined for reporters not using the standard NPI reporting year?

The standard NPI reporting year is 1 July–30 June. In some cases a state or territory environment agency may allow a facility to report outside the standard NPI reporting year. Regardless of reporting period dates, all facilities must submit their NPI report to their state or territory environment agency within three months of the end of their reporting period. Standard year reports must be submitted before the end of September, and calendar year reporter before the end of March.

Facility reports will be uploaded on the internet for the NPI reporting year in which their reporting period ends.

From when does the full list of 93 NPI substances need to be reported?

The National Environment Protection Measure (NEPM) for the NPI requires facilities to begin reporting against the full list of 93 NPI substances from 1 July 2009. This means that if a facility's reporting period ends after 1 July 2001, the full NPI list of 93 substances must be considered when reporting to their state or territory NPI Unit.

The new substances that were brought in by the NPI NEPM variation are:

More information on the NEPM variation.

Is there an emission estimation technique (EET) manual for my industry?

To determine if your industry sector has a manual, find out more about estimating emissions.

When a facility reports emissions for part of a year only, how will the state or territory environment agency present the facility data to the NPI?

In such circumstances, the data will be presented for the part year only. The state or territory environment agency will not extrapolate the facility data for the full year reporting period.

What is the NPI Online Reporting System (ORS)

The ORS is a web-based reporting tool which streamlines and simplifies NPI facility reporting for all participating stakeholders. The system replaces the old NRT software which was used in all jurisdictions except for NSW. Refer to Lodging NPI reports for more information

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Are facilities that have their ANZSIC code listed in a EET manual required to report to the NPI if their type of facility is not specifically covered in the manual?

Yes, once a manual is published covering an ANZSIC code, then all industry groups falling under that code are required to report to the NPI.

Can a national company, with a number of reporting facilities, provide one due diligence statement for all its facilities within a state or territory?

Yes.

Is a company complying with the NEPM and the relevant state or territory legislation if it reports on fewer substances than those for which it has triggered thresholds?

No. A facility must report emission estimates for all substances that trip the relevant thresholds.

Can facilities regard the physical boundary of their site or lease as the beginning point of an emission, and not report any emissions within that boundary?

No. Any release to the environment must be reported as it enters the environment. If on site emissions are not contained in purpose-built, approved receiving facilities, they are emissions to the environment and must be reported even if they are not detectable at the site boundary.

Determining thresholds and calculating emissions

What are reporting thresholds?

There are six categories of thresholds. Three thresholds relate to the use of substances, one to nutrient emissions to water, and two to fuel combustion or energy use. More details are in the NPI Guide and the NEPM for the NPI.

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How can I tell if I need to report on the Category 1a threshold?

Category 1a threshold relates only to Total Volatile Organic Compounds (Total VOCs) when a facility uses 25 tonnes or more of VOCs. That is bulk storage facility, uses 25 tonnes or more of VOCs and has a 25 kilotonne or greater design storage capacity for material containing VOCs.

To make a Category 1a determination, a facility must calculate and sum the tonnage of all VOCs used on site, both as individual substances and as constituents of other substances (such as fuel). While a facility may not have used enough of any single NPI substance that is a VOC to trip individual thresholds, they may have used enough VOCs in total to trip the Category 1a threshold for Total VOCs.

For example, a facility uses 400 tonnes of heating oil that consists of 12 weight percent VOCs and 88 weight percent of other substances; i.e. the facility has used 48 tonnes of VOCs. This clearly trips the category 1a threshold and, therefore, Total VOCs must be reported.

Note: a facility may also need to report on the individual NPI substances that are VOCs if their usage trips other reporting thresholds. (See also Calculating Thresholds, Definition of VOCs and double counting.)

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A Material Safety Data Sheet (MSDS) states a range, not a specific figure, for the amount of a substance in a mixture. What value should I use?

In such circumstances, the occupier should take the mid-point of the range advised on the MSDS as the relevant figure for threshold calculations.

How should I report emissions if no emission factors or other emission estimation techniques are available?

If your facility has exceeded a NPI substance threshold and you can't apply an emission factor or other emission estimation technique, your state or territory environment agency should be consulted.

How many significant figures are reported to the NPI?

Data is displayed on the NPI database to two significant figures. This means that facilities are required to report emissions to air, land and water to a precision of two significant figures. If the third significant figure is a 5, the second figure is rounded to the closest even number (for example 12.5 is rounded to 12 and 13.5 is rounded to 14) as outlined in Australian Standard 2706 - 1984.

How should zero emissions of an NPI substance be reported?

If the NPI substance emission is required to be reported because a threshold is exceeded and emission is estimated to be zero, then you should report the figure '0' to the NPI.

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How should emissions based on below detection limit in analytical tests be reported?

An indication that a listed substance is below detection limit is not the same as stating that the substance is not present. If the best available information indicates no presence of a substance in the waste-stream, a facility may report zero. The facility should document that it considered available data in making this determination.

If, based on best available information, there is reason to believe that the listed substance is likely to be present in the waste-stream, a concentration equivalent to half of the detection limit should be used in the estimated emission calculation.

In all cases, the less than detection limit measurement should be based on the most accurate or appropriate methodology readily available for analysis of the listed substance. Acceptable use of zero in these situations is always at the discretion of the relevant state or territory environment agency.

Can a facility report on a range of emission amounts for substances, rather than giving a specific emission amount?

No. The NPI requires the reporting of estimated emissions — that is, emissions from a facility that are calculated using an accepted EET. Facilities should always report a specific emission amount arrived at through the use of an EET.

If a company develops an electronic emission calculation tool that is based on an approved EET, would this be regarded as an alternative EET that would require approval?

If the electronic tool is based on the EET in an NPI EET Manual and is transparent in its estimation method, it will be classified as an approved EET. If the estimation method is not transparent, then the tool needs to be submitted to the relevant state or territory environment agency for approval.

Are explosives used in mines and quarries classed as fuel?

Explosives are classed as fuel for the purposes of NPI reporting threshold calculations. The total mass of the explosive is to be included in the calculation (e.g. total mass of ammonium nitrate/fuel oil mixture, not just the fuel oil component).

Are the NPI substances contained in ore or waste rock moved around facilities such as mines relevant to the NPI?

Category 1 substances contained in mined ore or waste (including overburden) should be included in NPI reporting threshold calculations. For example, Category 1 substances in material moved to a waste dump landfill are to be taken into account when determining a facility's use of a NPI substance. See the NPI Guide for more information.

The placing of a substance on the waste dump landfill is not regarded as an emission of the substance to the environment. Any loss of an NPI substance from the waste dump landfill is regarded as an emission (e.g. escaping in leachate or as wind-blown particulate matter) and if the NPI substance reporting threshold is tripped, it must be reported.

What are tailings?

Tailings are sludge, mineral residue and wastewater (apart from final effluent) resulting from ore extraction or processing. In some cases this may be the slag from pyrometallurgical processes. Tailings vary widely in properties and constituents depending on the mineral being processed and the extraction process used. This means that the environmental impact and human health effects of tailings also vary widely.

In some industries the term tailings is being replaced by other terms to more accurately reflect the nature of the material. Any future change in terminology the NPI uses will reflect the terminology that industry and other sectors of the community use.

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Are spills from tailings dams reportable emissions?

Yes. Any spills or leakages that lead to an emission to the environment to air, land or water must be reported if a reporting threshold is tripped.

How does industry use buffer zones in relation to emissions?

Many industries use buffer zones to decrease their impact on neighbouring communities.

Buffer zones do not decrease the emissions of a substance, but they do allow additional substance dispersion prior to crossing the facility boundary. In some cases, particulate material settling may occur within the buffer zone. A buffer zone can also provide a facility with the opportunity to monitor, or take action to control emissions before release beyond the facility boundary.

When a facility triggers the PM10 reporting threshold, does it need to report on emissions from both its combustion processes and from other possible sources on site?

If combustion processes and/or sources trip a PM10 threshold, all the facility PM10 emissions from all sources must be reported. For example, in addition to combustion sources, PM10 emissions generated from stockpiles need to be included.

If I report emissions of substances contained in PM10 (e.g. lead and compounds) and must also report PM10 to the NPI, can I subtract the estimate of the substances contained in the PM10 emissions from the estimate of PM10?

No. This is because the substances on the NPI substance list are not always mutually exclusive. For example, pollutants such as PM10 and VOCs are aggregate substance groups that may comprise the emissions of other substances reported to the NPI.

Do I report substances which are VOCs if I report the NPI substance Total VOCs?

If emissions of individual Volatile Organic Compounds (VOCs), such as benzene, exceed their reporting thresholds, you will need to report them separately as well as reporting 'Total Volatile Organic Compounds' if the threshold for TVOCs is exceeded (See definition of Total VOCs).

Should gas pipeline compressor stations and metering valves report to the NPI?

These facilities should report to the NPI. The main substance expected to be reported is TVOCS. Some states and territories may require valve stations reports from by the facility. Contact the state or territory to determine if reporting is required.

Can fluoride compound emissions from natural gas and liquefied petroleum gas combustion be estimated?

Generally you can estimate zero emissions of fluoride compounds from natural gas and LPG combustion. An exception may be where a facility operator knows that fluoride compounds or fluorine are in the natural gas or LPG they use, or if the methods of using these fuels are likely to result in emissions e.g. in a cement kiln. Check with your supplier and refer to your NPI industry sector manual for more details.

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Substance definitions

What is the definition of PAHs (polycyclic aromatic hydrocarbons)?

For NPI reporting, PAHs are an aggregate substance group made up of the 16 US EPA Priority Pollutant PAHs (or the subset of those for which data is available) and reported as total PAHs. This list of PAHs and their Chemical Abstract Services Registry (CASR) numbers is provided below.

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Should Total PAHs be reported, or specific PAHs?

Emissions of total PAHs as equvalents of Benzo(a)pyrene should be reported to the NPI.

What is the definition of a Total Volatile Organic Compound (TVOC) for NPI reporting purposes?

For the purpose of NPI reporting, Total VOC are defined as any chemical compound based on carbon chains or rings with a vapour pressure greater than 0.01 kPa at 293.15 K (i.e. 20ºC), that participate in atmospheric photochemical reactions.
Specifically excluded are:

The intent of the inclusion of Total VOCs is in recognition of the combined effect of compounds that contribute to smog formation that may not otherwise have been captured due to individual substances not meeting a usage threshold in their own right. The most common sources of Total VOCs emissions are from the storage and use of liquid and gaseous fuels, the storage and use of solvents and the combustion of fuels.

Download the definition

If you cannot access the definition, please contact the Department of the Environment, Water, Heritage and the Arts — npi@environment.gov.au — to organise a suitable alternative format.

Should a facility report separately on nitrogen, nitrates and nitrites?

The NEPM for the NPI states that total nitrogen refers only to those amounts of nitrogen that give rise to nitrate/nitrite ions. Since this may be possible for a range of nitrogen compounds in a range of environmental conditions, the following pragmatic definition can be applied:

Total Nitrogen is the sum of nitrate (NO3), nitrite (NO2), organic nitrogen and ammonia (all expressed as N).

Note: for laboratory analysis purposes Total Kjeldahl Nitrogen (TKN) is a test performed that determines both organic nitrogen and ammonia.

Are polychlorinated dioxins and furans reported as total emissions?

For the NPI, polychorinated dioxins and furans should be reported based on the toxic equivalence (TEQ), which is a means of scaling the emissions of each species of dioxin and furans according to their relative toxicity.

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Mt Stromlo Water Treatment Plant. Credit: Steve Wray.