What are reporting thresholds?
There are six categories of NPI reporting thresholds. Three categories relate to the use of substances, one category relates to emissions of nutrient to water, and two categories relate to fuel combustion or energy use. More details are in the NPI Guide and the NPI NEPM.
How can I tell if I need to report on the Category 1a threshold?
The Category 1a threshold relates only to Total Volatile Organic Compounds (Total VOCs), and is tripped when a facility uses 25 tonnes or more of VOCs within a reporting year.
To determine Category 1a emissions, 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's use of any single NPI substance that is a VOC may not trip the reporting threshold for that substance, the facility may have used more than 25 tonnes of 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. In this case, the Category 1a threshold is tripped and the facility will need to report emissions of Total VOCs.
A Safety Data Sheet (SDS) 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 SDS 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 cannot apply an emission factor or another emission estimation technique, your state or territory environment agency should be consulted.
How many significant figures are reported to the NPI?
Estimates of emissions and transfers must be reported to the highest level of precision that is justified by the data, in accordance with Australian Standard 2706-2003. However, the NPI website will only display the estimated data to two significant figures. For example:
- A reported value of 52,366,968 kg will be displayed as 52,000,000 kg
- A reported value of 0.000523 kg will be displayed as 0.00052 kg
How should zero emissions of an NPI substance be reported?
Please note that the reporting of a zero value for an emission or transfer will not be accepted.
A zero emission result for a process may be due to the application of a zero emission factor, or no emission factor being available for the relevant process. Two scenarios on how to deal with zero emissions are presented below:
- Scenario 1: The determination of emissions for a substance is required because the usage threshold (Category 1, 1a or 1b) has been tripped. However, the emission for the substance has been calculated to be zero, or it was not possible to calculate an emission value. In this case, the usage of the substance should be reported, but the emission field for the substance should be left blank.
- Scenario 2: The determination of emissions for a substance is required because the usage threshold for fuel or energy has been tripped. However, the emission for the substance has been calculated to be zero, or it was not possible to calculate an emission value. In this case, the substance should be deleted from the NPI reporting list in your report (see page 61 of the User Guide for Online Reporting System for assistance.
In both the above scenarios, an advisory message will need to be included in your report. For both the above Scenarios, an appropriate message might be "No EET or emission factor available". If reporting on a paper form, a clear reason for the missing emissions data should be provided.
How should emissions results obtained through analytical testing that are below the detection limit be reported?
Stating that the emission value of a listed substance is below the 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, the guidance above on reporting zero emissions should be followed. 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 to estimated emissions.
In all cases, the less than detection limit measurement should be based on the most accurate or appropriate methodology that is readily available for analysis of the listed substance.
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 that is determined through the use of an EET.
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 used by that industry and other sectors of the community.
Should spills from tailings dams be reported as 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 may settle within the buffer zone. A buffer zone can also allow a facility 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 combustion processes and from other on-site sources?
If combustion processes and/or sources trip a PM10 threshold, all the facility PM10 emissions from all sources must be reported. For example:
- A facility has tripped the PM10 threshold for processes and/or sources. The facility will need to determine and report emissions from the relevant processes/sources and must also include PM10 emissions generated from stockpiles.
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. Substances on the NPI substance list are not necessarily mutually exclusive. For example, pollutants such as PM10 and VOCs are aggregate substance groups that may comprise emissions from 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).
Do emissions from gas pipeline compressor stations and metering valves need to be calculated and reported to the NPI?
Emissions from these facilities should be calculated and reported to the NPI. The main substance expected to be reported is TVOCs. Some states and territories may require emissions from valve stations to also be reported. 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?
It can generally be assumed that there will be negligible 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.
Do I need to report NPI substances from dust suppression activities that use groundwater?
If non-processed water (water not affected by site operations) is used for dust suppression activities, the site is not required to determine emissions of NPI substances to land. If process water (water affected by site operations) is used for dust suppression activities, then the facility is required to determine emissions of NPI substances to land and report these.
Do I need to report emissions arising from abnormal events?
Emissions of NPI substances arising from abnormal operational events at a facility must be included in the facility's NPI report if one or more of the relevant thresholds for NPI substances have been tripped. Examples of abnormal operational events include:
- Spillages from pipelines and plant equipment
- Increased stack emissions as a result of the breakdown of pollution control equipment, e.g., malfunction of an electrostatic precipitator
- Purging of plant equipment during emergency shutdowns
If a facility trips a threshold for an NPI substance, all emissions of the relevant substance must be included when reporting to the NPI.
How should spent marc/pomace used as fertiliser on surrounding vineyards and/or paddocks be reported?
If the vineyards or paddocks are adjacent or contiguous to the winery and are subject to the same operational control, these areas are considered to be on-site for NPI reporting purposes. Any emissions of ethanol derived from marc/pomace weights should be reported as an emission to land.
If the vineyards or paddocks are not adjacent to the winery property and/or are not under the same operational control as the property, this can be reported voluntarily as a transfer (off-site reuse).
How should untreated winery wastewater used for irrigation on surrounding paddocks or woodlots be reported?
If the paddocks or woodlots are adjacent or contiguous to the winery and are subject to the same operational control, these areas are these areas are considered to be on-site for NPI reporting purposes. Any emissions of ethanol should be reported as an emission to land.
If the paddocks or woodlots are not adjacent to the winery property and/or are not under the same operational control as the property, this can be reported voluntarily as a transfer (off-site reuse).
How is intensive livestock defined?
Intensive livestock means the confinement of livestock to an area with watering and feeding facilities, where livestock are hand or mechanically fed for production purposes.
Examples of intensive livestock operations include piggeries, cattle feedlots or poultry farms.
How does the NPI define electricity for motive purposes?
Electricity for motive purposes means electricity that is used to make objects move, rather than electricity, e.g., for heating purposes. Electricity use for motive purposes covers electric conveyers, motors, mixers and lifts. It does not include electricity used to power kilns, ovens and furnaces and electricity use for these sources should be considered when determining emissions.