Have your say on options to reduce emissions from organic waste

This section outlines each of the current criteria that determine if NES-AQ regulations (as at 2026) apply to a landfill. It summarises feedback and evidence considered to date, and identifies potential changes to each of these criteria, on which we seek your feedback. 

Criterion 1: Facility has total capacity of no less than 1 million tonnes and criterion 2: Facility contains 200,000 tonnes of waste or more

These two criteria combined represent the size and capacity thresholds at which point landfill gas capture requirements come into effect. We believe that reducing these thresholds could be one way of supporting smaller facilities to operate as effectively as their larger counterparts. It would enable these facilities to continue to accept organic waste, which is important as in many parts of New Zealand smaller facilities are the only option for disposal.

Although gas generation rates vary between landfills for a range of reasons, including gaps in data, large landfills are generally likely to produce a higher volume of emissions. Equally, large landfills tend to achieve higher rates of gas capture, as they have a greater volume-to-surface-area ratio and are more likely to be able to invest in more sophisticated gas capture systems.⁶⁶ In a comparison of landfills operating under similar conditions, a landfill containing more tonnes of waste is likely to be producing more emissions because its environment is more anaerobic and a higher volume of organic waste is breaking down within it. The current regulations on landfill size and contents thresholds are based on this variability.

When the current regulations were under development, the volume of methane that could be collected at landfills below the thresholds was considered to be insufficient to justify investment in capture infrastructure. At that time too, gas collection systems were not normally installed until methane generation had begun.⁶⁷ Advances in technology and landfill engineering since then – from lining design to more effective gas-capture systems – suggest that reviewing the economic viability of these measures may be worthwhile. 

A long-term objective of the Ministry is for gas capture systems to cover organic waste that must be disposed of to landfill. New Zealand currently has 22 Class 1 facilities known to be without landfill gas capture, which are unlikely to be covered by the criteria of current regulations.⁶⁸ The Ministry’s objective could still be achieved by, for example, diverting organic materials from sites without landfill gas capture to those with capture, or increasing the number of sites equipped with landfill gas capture.

One option is to reduce the size thresholds at which the regulations apply. This would mean that additional smaller (and, in some cases, isolated) landfills would be required to manage their emissions through either installing landfill gas capture or changing the types of waste they accept. This could also affect consumers’ access to waste disposal options – particularly if isolated regional sites are forced to close due to higher compliance costs. Such sites play an important role in disaster waste management and support community resilience in response to severe weather events. 

It is also difficult to identify the appropriate threshold for the regulations, and therefore to administer them, as information on the size of individual landfills is largely held in consents that central government does not automatically receive. Central government receives tonnage information as part of annual requirements under the waste disposal levy, which it then uses to calculate levy obligations. 

^{66 Eunomia. 2025. Landfill Gas Management – Final report. Prepared for the Ministry for the Environment by Eunomia. Wellington: Ministry for the Environment.}

^{67 Ministry for the Environment. 2011. Users’ Guide to the Revised National Environmental Standards for Air Quality (PDF 1.7MB). Wellington: Ministry for the Environment.}

^{68 Of a total of 42 Class 1 facilities. It is difficult to establish why these sites do not have landfill gas capture equipped; limited data are available on total waste that built up through the lifetime of a landfill.}

Criterion 3: Facility is accepting or is likely to accept waste

Landfill gas capture requirements currently apply to open landfills only. Evidence indicates that management of emissions at closed landfills continues to be necessary for at least 30 years after they have stopped accepting waste. In early engagement, stakeholders have stated that this should be a focus area for emissions reductions. We are interested in understanding the barriers and operational implications that would be involved if regulations were changed to require landfill gas management at closed landfills as well. 

Currently, only open landfills are required to manage their landfill gas. A landfill is considered closed when it is no longer accepting waste for disposal.⁶⁹ However, a landfill continues to produce gases for at least 20 years,⁷⁰ and can do so for up to 50 years, following the last waste deposit.⁷¹ Closed landfills have no regulated management requirements for emissions and they are not covered by the ETS. Councils are directed to encourage effective and efficient waste management and minimisation through the Waste Minimisation Act 2008,⁷² including by ensuring disposal does not cause a nuisance. Councils may also impose consent conditions that require monitoring, but no national standards apply to managing emissions from closed landfills. 

It can be difficult to identify who is liable for managing environmental impacts when the land use or ownership has already changed – for example, where development has since occurred on a closed landfill. It can also be difficult to retrofit landfill gas capture systems. Changes to regulations could recognise these issues by requiring only landfills currently in operation to install landfill gas capture infrastructure that will persist after the landfill has closed. In early engagement, disposal facility operators and councils have identified a need for further direction on responsibilities for emissions management during and after closure of landfills. 

We are proposing that closed landfills become subject to landfill gas capture requirements. Other options are available to support better emissions management at closed landfills. The Ministry prepared guidance around closing and closed landfills in 2001,⁷³ which could be reviewed now to ensure it remains best practice. Landfills in New Zealand have made significant technological advances in the 25 years since that guidance was developed and operative rules in place at the time have evolved. Despite this, the Ministry’s guide remains the core guidance available for the sector, and industry guidelines are designed to be read alongside it.⁷⁴

^{69 WasteMINZ. 2023. Technical Guidelines for Disposal to Land – Revision 3.1 (PDF 3.1MB). Auckland: WasteMINZ.}

^{70 Ministry for the Environment. 2001. A Guide for the Management of Closing and Closed Landfills in New Zealand (PDF 692KB). Wellington: Ministry for the Environment.}

^{71 South Australia Environment Protection Authority. 2019. Landfill gas – methane (Waste information sheet) (PDF 281KB). Adelaide: South Australia Environment Protection Authority.}

^{72 Waste Minimisation Act 2008, Part 4.}

^{73 Ministry for the Environment. 2001. A Guide for the Management of Closing and Closed Landfills in New Zealand (PDF 692KB). Wellington: Ministry for the Environment.}

^{74 WasteMINZ. 2023. Technical Guidelines for Disposal to Land – Revision 3.1 (PDF 3.1MB). Auckland: WasteMINZ.}

Criterion 4: The waste that is in or to be included in the landfill is likely to consist of 5 percent or more (by weight) of matter that is putrescible or biodegradable

Although multiple classes of landfill can accept organic waste, not all sites doing so are equipped with landfill gas capture infrastructure. In line with the intent for any organic waste to be disposed of at landfills with gas capture in place, we propose removing the 5 percent threshold for incidental inclusion. Under this approach, any site that accepts organic waste for disposal would be required to manage its emissions. 

All organic waste produces emissions as it decomposes in anaerobic environments in landfill. Class 3, 4 and 5 landfills are not permitted to accept any putrescible or degradable elements; they may only accept inert or virgin excavated natural materials. Class 1 and 2 landfills and industrial monofills can accept organic materials, but we are not aware of sites outside of Class 1 complying with the landfill gas capture requirements under the current NES-AQ. 

We are interested in finding out about sector views on removing the 5 percent threshold so that all sites accepting any putrescible and biodegradable materials must manage their methane emissions or stop accepting putrescible waste. Requiring sites that accept putrescible materials to manage their emitted methane is the approach that is most likely to avoid leakage across landfill classes and to send most of the organic waste disposed of to sites that can manage the emissions effectively. Industry guidelines state that landfill gas should already be monitored at all Class 1 and 2 landfill sites, so monitoring systems are likely to be in place already at many impacted facilities.

A lack of monitoring requirements for waste composition makes it difficult to determine the level of compliance with the 5 percent threshold in regulation – which is designed to allow for incidentally including organic materials in otherwise inert waste loads. Removing this composition-based criterion would simplify regulation for facilities, as they would not need to actively monitor the composition of the waste at their sites to calculate whether they are breaching the 5 percent threshold. 

Operators of landfills currently accepting putrescible and biodegradable materials could choose whether to invest in landfill gas capture or to no longer accept these materials. The impact of this change on landfill revenue will vary depending on the definitions of ‘putrescible’ and ‘biodegradable’ used, and whether these materials include timber. Changing the acceptance criteria based on landfill gas capture status may also encourage greater uptake of resource recovery facilities where these are available. Where disposal continues, it is preferable to dispose of organic waste at sites equipped for landfill gas capture.

We are interested in views on whether passive gas management systems would be an acceptable alternative where the landfill gas produced is insufficient to warrant or enable flaring or use of gas collected. These systems are considerably cheaper for operators to install.

Criterion 5: Facility has a landfill gas collection system designed and operated to ensure any surface discharge of gas does not exceed 5,000 parts of methane per million parts of air 

Regulations in some other countries, including in places with landfill and environmental conditions similar to New Zealand’s, require a more restrictive maximum surface discharge of methane. Early engagement with some stakeholders has highlighted that landfills are in many cases already achieving the lower threshold of 500 parts of methane per million parts of air (ppm). We propose that the Ministry reviews whether it is feasible to accordingly reduce this limit from the current 5,000 ppm.

When compared with regulations and guidance from other jurisdictions (table 4), New Zealand’s limit of 5,000 ppm represents a relatively high level of surface emissions.

Table 4: An international comparison of regulations and guidance for maximum limits of methane surface emissions concentration

An external review of the NES-AQ⁷⁵  recommends reducing the threshold in New Zealand to 500 ppm. Early stakeholder engagement identified support for this change, and some landfill operators reported that they are already meeting this lower threshold. Publicly available results from research or measurement of direct surface emissions at landfills in New Zealand are limited. Operators are not required to report these emissions to central government, although many are likely to be monitoring their surface emissions to assess their level of compliance with regulations. While one-off studies have identified a variety of sites that have methane concentrations below the lower threshold of 500 ppm, their measurement methodologies vary. ^76, 77   

Tools that reduce surface emissions are the same as those used to target other measures discussed in this document – mostly through landfill gas capture. Proposals to increase the efficiency of landfill gas capture would therefore be complementary to this change and would support operators in achieving the lower 500 ppm threshold. 

^{75 Emissions Impossible. Unpublished. Review of Activity Standards in National Environmental Standards for Air Quality.}

^{76 O’Sullivan-Moffat HTC. 2022. Urban Methane Emissions in Auckland, New Zealand (PDF 4.5MB) (Thesis – Master of Science in Geology). Wellington: Victoria University of Wellington.} 

^{77 Pattle Delamore Partners Ltd. Unpublished. Class 2 Landfill Gas Capture Feasibility Study. Prepared for the Ministry for the Environment.}

Criterion 6: Facility has a landfill gas collection system in which the gas is flared, or used as fuel or for generating electricity 

We do not propose any changes to criterion 6 at this stage. This criterion could be reviewed in future, once implementation of broader biogas and landfill gas capture work has begun and the economic opportunities of landfill gas capture for a variety of sites become clearer.

Most landfills with landfill gas capture systems flare the gas captured. This process destroys the gas and prevents direct methane release by converting it into a combination of carbon dioxide and water. Some landfills also use this flared gas, or otherwise processed landfill gas, to create an energy source. Regulation 27 of the current NES-AQ contains additional rules for how to operate a flare.⁷⁸ 

We consider that regulation 27 remains fit for purpose. However, we are interested in feedback about possible changes to this criterion or to regulation 27 that would further improve the management of emissions, and the economic opportunities arising from reusing energy from organic waste. Please also see option 3: Enabling organic processing solutions, including biogas. 

^{78 Resource Management (National Environmental Standards for Air Quality) Regulations 2004, reg 27.}

Many of the Class 1 landfills that receive the highest volumes of waste are already capturing at least 60 percent of their emissions. Using models, some operators have reported and evidenced higher efficiencies up to 100 percent and, where they have not yet achieved 100 percent, the ETS incentivises them to continue improving their performance. 

We consider that it may be necessary to complement the ETS with a regulatory regime that aims to uplift the performance of those sites that are still reporting lower efficiencies. Due to advancing technology, we can now expect higher performance where landfill gas capture is installed than we could when regulations were drafted in 2004. Higher capture efficiencies provide a financial benefit for landfill operators subject to the ETS, and stronger regulation can help them achieve this.

International efficiency rates vary greatly: reported average efficiencies range from 30 percent in Iceland, to more than 60 percent in the United States, United Kingdom and Finland. Site-specific efficiency rates can also vary widely. For example, rates in operational sites in the United Kingdom were found to range between 26 and 91 percent in 2014.⁷⁹ The approximate average gas capture efficiency in New Zealand, weighted by methane generation per facility, is 47 percent. Ministry surveys between 2023 and 2025 indicate that estimated landfill gas capture efficiencies currently range from 40 to 80 percent, although the data are self-reported and therefore highly uncertain.

Due to the broad range of efficiencies reported locally and internationally, officials are testing a 60 percent minimum capture efficiency requirement. This would mean that all sites subject to landfill gas capture (under the criteria outlined in section 5.1) would need to ensure that their systems are capturing at least 60 percent of the landfill gas that they produce. This could be achieved through improvements to infrastructure and practice, both for gas capture and broader landfill conditions, such as lining, capping and waste placement.

^{79 Eunomia. 2025. Landfill Gas Management – Final report. Prepared for the Ministry for the Environment by Eunomia. Auckland: Eunomia.}

Under the Resource Management Act 1991 (the authorising legislation for the NES-AQ), regional councils, unitary authorities and territorial authorities have responsibilities for compliance monitoring and enforcement related to landfill gas management. Responsibility for adopting and executing a local compliance monitoring and enforcement regime sits with each individual council, while national legislation establishes a broad framework. This tiered system is based on the principle that decision-making is best carried out at the level closest to the resources affected.⁸⁰As a result, regions have taken varied approaches, influenced by factors specific to their location (including GDP, land area, population, and population growth rates).⁸¹

Central government can support local government in this role through providing fit-for-purpose environmental and planning standards at a national level, and national policy direction, along with meaningful guidance, where useful. National guidance that is already available to the sector is the Ministry’s Guide to Landfill Consent Conditions (PDF 1MB).

Created in 2001, it reflects the experience of consent authorities in implementing the Resource Management Act 1991 and aims to provide guidance on the methods councils can use to enforce consent conditions.⁸² This guidance could be updated to align with ongoing resource management system reforms.

We are not proposing any specific changes to compliance monitoring and enforcement responsibilities. However, through feedback we would like to better understand what is –and what is not – working for those currently involved in monitoring landfills. 

^{80 Environment Foundation. 2025. Environment Guide: RMA. Retrieved 15 May 2026.}

^{81 Sprout. 2025. Analysis of the 2024/2025 Compliance Monitoring and Enforcement Metrics (PDF 4MB). Prepared for Te Uru Kahika Regional and Unitary Councils Aotearoa by Sprout.}

^{82 Ministry for the Environment. 2001. Guide to Landfill Consent Conditions. Wellington: Ministry for the Environment.}

The Government has indicated that it will consider introducing national environmental standards after enacting the new planning system legislation this year.⁸³ That includes considering air quality standards in this new context. No decisions on progressing new national instruments have been made at this stage.

Under the Resource Management Act 1991, the standards in the NES-AQ set a guaranteed minimum level of health protection for people living in New Zealand. Many of the standards have co-benefits for the operations of waste systems. Several regulations in the NES AQ may be of interest to the waste sector, including:

• regulation 6: Prohibition on the lighting of fires and burning of waste at landfill
• regulations 7–10: Prohibitions on the burning of tyres, bitumen, coated wire, and oil
• regulation 11: Incinerators at schools and healthcare institutions
• regulation 12: High-temperature hazardous waste incinerators.

^{83 Ministry for the Environment. 2025. The New Planning System: Fact sheet (PDF 281KB). Wellington: Ministry for the Environment.}