4 The Proposed Air Quality Standards
4.1 Ambient air quality
4.1.1 Particles (PM10)
The proposed standard for fine particles (less than 10 microns in diameter - PM10) is 50 µg/m3 averaged over one day. The standard envisages that 'clean air' will be achieved if 50 µg/m3 is not exceeded more than five days in a year, or that no one-day exceedance is above a limit of 120 µg/m3.
These values are based on reviews of research into the health effects of PM10 and current concentrations in New Zealand (Ministry for the Environment, 2003b, 2003c, 2003d). It reflects a risk-based approach to setting a standard for health protection, given the absence of any threshold below which no adverse effects are observed, and may be referred to as an 'interim' standard. The concentration limit is consistent with several international standards, including the Australian national environmental protection measures (which New Zealand contributed to developing), United Kingdom objectives, and Californian standards. The maximum limit is based on the former World Health Organisation standard for PM10.
Where the standard is not met, regional councils must make that non-compliance public. In air sheds where the standard is not achieved, regional councils can only grant resource consents if they are confident that the net result of all activities in their air shed results in an improvement in air quality.
The proposed monitoring method is US 40 CFR Part 50, Appendix J, or an equivalent method. Where a tapered elemental oscillating microbalance (TEOM®) is used, it should be co-located with another sampling method, such as a high-volume sampler, to determine an appropriate conversion factor.
When inhaled into people's lungs, fine particles, especially those smaller than 10 microns in diameter (PM10), can cause premature death, respiratory diseases, and asthma attacks in asthmatics. These health effects, in turn, can increase hospital admissions, use of medication, days off school, and lost productive days (as people recover from symptoms). A recent report estimated that there are around 970 premature deaths each year in New Zealand from PM10 inhalation (Fisher et al, 2002). Such health impacts can also have impacts on local health services.
Response to submissions
In response to the submissions made, our advice to the Minister for the Environment will be to inform Cabinet that the emphasis of the proposed standard is improved regional air quality management. Regional councils will be required to decide whether to monitor for PM10, to publicly report any exceedances, and to use the standard as the basis for regional air shed planning. Regional councils will be required to comply with a 'proxy air plan' of no more than 1 exceedance of 50 ug/m3 by 2013. Councils can choose to implement an air quality plan that is stricter than the proxy air plan. The proposed upper limit of 120 ug/m3 will be removed, and the number of allowable exceedances will be reduced from 5 to 1.
No resource consent application will be granted where that consent is the primary source of exceedances. In a polluted airshed, an application may be granted if it will not adversely affect air quality improvement as accounted for in the regional air quality plan.
4.1.2 Nitrogen dioxide (NO2)
The proposed standard for NO2 is 200 µg/m3 averaged over one hour. The standard will be achieved if 200 µg/m3 is not exceeded more than nine hours per year (99.9 percentile of one year's monitoring data), and no one of these exceedances is above 300 µg/m3 averaged over one hour.
Regional councils will be required to make a decision whether to monitor for NO2 in their airshed. This decision will be based on whether they consider NO2 will be at levels of concern. Any non-compliance with the standard will be made public.
The concentration limit for NO2 is designed to protect the more vulnerable sub-groups in the population, including children, asthmatics of all ages (but especially child asthmatics), and compromised adults with chronic respiratory and cardiac disorders.
The concentration limit is consistent with the World Health Organisation (WHO) guideline value and the 2002 New Zealand guideline value, and is more stringent than the Australian national environmental protection measure (250 µg/m3, one-hour average). The maximum upper limit of 300 µg/m3 is consistent with the former WHO guideline value and the 1994 New Zealand guideline value.
Exceedances will be calculated on a fixed one-hour average basis and could potentially all occur on one day.
Response to submissions
In response to submissions, it will be emphasised that the standard is to be used as the basis for airshed planning. Regional councils will be required to decide whether NO2 is an issue, to monitor where relevant, and to publicly report any exceedances. No consent application will be granted where that application is the primary source of exceedances. Compliance with the standard will be used as the basis for any new resource consent conditions for activities that discharge significant amounts of NO2. The proposed upper limit of 300 ug/m3 will be removed.
4.1.3 Ozone (O3)
The proposed standard for O3 is 150 µg/m3 (one-hour average) with no allowable exceedances. Ambient O3 should be monitored using AS3580.6.1 - 1990.
Regional councils will be required to make a decision whether to monitor for O3 in their airshed. This decision will be based on whether they consider O3 will be at levels of concern. Any non-compliance with the standard will be made public.
Although there is no apparent health-effects threshold for O3, the proposed concentration limit standard aims to provide a reasonable level of protection for human health. As with particles, this represents a risk-based approach and may be referred to as an 'interim' standard. It aims to prevent effects on respiratory function in vulnerable sub-groups of the population, including those with asthma, those with chronic lung disease, healthy young adults undertaking active outdoor exercise over extended periods, and the elderly, especially those with cardiovascular disease.
The concentration limit is consistent with the 2002 New Zealand guideline value and is reasonably consistent with the European Directive value of 170µg/m3 (one-hour average).
Response to submissions
In response to submissions, it will be emphasised that the standard is to be used as the basis for airshed planning. Regional councils will be required to decide whether O3 is an issue, to monitor where relevant, and to publicly report any exceedances. No consent application will be granted where that application is the primary source of exceedances. Compliance with the standard will be used as the basis for any new resource consent conditions for activities that discharge significant amounts of O3.
4.1.4 Sulphur dioxide (SO2)
The proposed standard for SO2 is 350 µg/m3 averaged over one hour. The standard will be achieved if 350 µg/m3 is not exceeded more than nine hours per year (99.9 percentile of one year's monitoring data), and no one of these exceedances is above 570 µg/m3 (one-hour average).
Regional councils will be required to make a decision whether to monitor for SO2 in their airshed. This decision will be based on whether they consider SO2 will be at levels of concern. Any non-compliance with the standard shall be made public.
The proposed standard for SO2 is set to prevent adverse impacts on lung function and other respiratory symptoms of vulnerable sub-groups, including asthmatics and those with chronic obstructive lung disease. The value is consistent with the 2002 New Zealand guideline value. Further information on why it was chosen can be found in Recommended Amendments to the Ambient Air Quality Guidelines 1994 (Ministry for the Environment, 2000c).
The maximum nine allowable exceedances refers to nine hours on which the one-hour average can exceed 350 µg/m3, up to a maximum limit of 570 µg/m3 (one-hour average). This latter value is the same as the Australian national environmental protection measure for SO2 (NEPC, 1998).
Response to submissions
In response to submissions, it will be emphasised that the purpose of the SO2 standard will be to manage point source SO2 emissions. The proposed upper limit of 570 ug/m3 will remain. For new and renewed consent applications, consent conditions will limit emissions, to be calculated to meet ambient levels. Coercive action should follow breaches of consent conditions and ambient levels. Regional councils must consider cumulative SO2 sources.
4.1.5 Carbon monoxide (CO)
The proposed standard for CO is 10 mg/m3 averaged over an eight-hour period. The standard will be achieved if there are no more than nine exceedances per year. There is no upper maximum limit.
Regional councils will be required to make a decision whether to monitor for CO in their air shed. This decision will be based on whether they consider CO will be at levels of concern. Any non-compliance with the standard will be made public.
The proposed standard is designed to ensure that people are not exposed to concentrations of ambient CO that would result in a blood carboxyhaemoglobin level greater than 2.5% at any level of physical activity. It is set to protect the more susceptible sub-groups, including those with existing heart disease, children and developing foetuses. The standard value is based on reasonably comprehensive research indicating that CO has a threshold below which adverse health effects are very unlikely to occur.
The proposed standard concentration limit is consistent with the existing New Zealand 2002 guideline value. The proposed monitoring method is AS3580.7.1 - 1992.
Response to submissions
In response to submissions, it will be emphasised that the CO standard is to be used as the basis for airshed planning. Regional councils will be required to decide whether CO is an issue, to monitor where relevant, and to publicly report any exceedances. No consent application will be granted where that application is the primary source of exceedances. Compliance with the standard will be used as the basis for any new resource consent conditions for activities that discharge significant amounts of CO. The number of allowable exceedances per year will drop from 9 to 1, as the initial proposal contained a mathematical error.
4.1.6 International comparison
Table 5 provides an international comparison of the proposals discussed above.
Table 5: International comparison of air quality standards
| Pollutant |
New Zealand proposed |
Australia |
UK |
EU |
WHO |
|---|---|---|---|---|---|
| PM10 |
50 µg/m3 |
50 µg/m3 |
50 µg/m3 |
50 µg/m3 |
No safe level |
| NO2 |
200 µg/m3 |
256 µg/m3 |
200 µg/m3 |
200 µg/m3 |
200 µg/m3 |
| Ozone |
150 µg/m3 |
210 µg/m3 |
- |
170 µg/m3 |
- |
| SO2 |
350 µg/m3 |
570 µg/m3 |
350 µg/m3 |
350 µg/m3 |
- |
| CO |
10 mg/m3 |
- |
- |
- |
10 mg/m3 |
As can be seen from the above, the proposed national environmental standards for air quality are consistent with standards set internationally.
4.2 Dioxins and other toxic substances
4.2.1 Open burning of tyres
The burning of tyres in the open or in open containers is a prohibited activity
Burning tyres in the open emits significant quantities of hazardous air pollutants, including particles, dioxins, CO, polyaromatic hydrocarbons, and volatile organic compounds. Although a one-off tyre fire is temporary, the quantity of contaminants released and their concentrations can be significant. Some, such as dioxins, may bioaccumulate and cause contamination problems over time. The remaining ash residue also contains hazardous contaminants, potentially creating a contaminated site that requires remediation.
Smoke from tyre fires can be particularly dark and dense. It has the potential to cause short-term, acute health effects if inhaled (eye, nose and throat irritation, asthma attacks, respiratory difficulties) and significant odour nuisance. Smoke plumes can also reduce visibility on roads, leading to unsafe conditions. Its visual appearance may adversely effect people's perception of New Zealand's environment, which has a reputation for being clean and green.
In New Zealand, unwanted tyres are typically disposed of into landfills or shredded for reuse. Significant quantities are also stockpiled in the hope that an alternative disposal or reuse option will be found. In some parts of the country, farmers use tyres for holding down the plastic covers over silage, although this is decreasing with the increased use of silage wrap.
The burning of waste materials such as tyres in the open is typically a prohibited or non-complying activity within regional air quality plans. Consequently, it is unlikely to occur on a regular basis in New Zealand and may generally be the result of an illegal or accidental ignition of a tyre stockpile.
Under this national standard for dioxins and other toxic substances all burning of tyres in the open air or in open containers will be banned. The burning of tyres as a fuel source under appropriate conditions, such as in a cement kiln, would not be prevented by the standard. Councils would still be able to consider whether to grant consents for discharges to air from tyres burned in appropriately designed equipment with emission controls.
Response to submissions
In response to submissions, the standard will state that the ban does not apply to the burning of tyres as a fuel source at facilities with emission control equipment (e.g. cement kilns). The ban will be effective from 1 September 2004.
4.2.2 Road-seal burning
Road-seal burning is a prohibited activity
Road-seal burning is defined as the process of using flame and heat to burn excess bitumen off road surfaces. Road-seal burners are typically fuelled by diesel, which creates an open flame that comes into contact with the road surface, igniting the bitumen and burning it off (Pickett and Dravitzki, 1996).
Burning bitumen through this process emits large clouds of thick, dark smoke containing hazardous air contaminants, including dioxins, polyaromatic hydrocarbons, volatile organic compounds, particles, NO2, and CO. Although the discharge is relatively short term, significant quantities of contaminants are emitted in high concentrations. If inhaled by people in the surrounding local environment, these contaminants can cause acute health effects, such as lung, throat and eye irritation, asthma attacks, and coughing. The smoke plume can cause unacceptable environmental nuisance in terms of reducing visibility and producing noxious odours. Reduced visibility across roads may also cause safety concerns for motorists.
Transit and some local road-controlling authorities occasionally carry out road-seal burning to improve the road surface, usually in rural or remote areas away from major towns and cities. On the whole, agencies are moving away from seal burning to other options, such as high-pressure water blasting. During water blasting the debris and wastewater are collected and disposed of, usually to landfill.
Regional air quality plan rules vary with respect to road-seal burning. Several regional councils specify road-seal burning as a prohibited activity. Others ban it from the date from which the plan becomes operative, and one has a transitional period during which the activity is non-complying and then later is prohibited. This national standard for dioxins and other toxic substances will prevent any consents from being granted for road-seal burning. It will not be allowed anywhere in the country.
Response to submissions
There is no change from the original proposal, though it will be referred to as a ban on "bitumen burning". The ban will be effective from 1 September 2004.
4.2.3 Coated-wire burning
The burning of coated copper wire or any form of coated cable in the open or in an open container is a prohibited activity
Councils will not be able to grant discharge permits to those wishing to burn insulated wire or cable in the open air and it will be illegal without a permit. Councils would still be able to consider whether to grant consents for discharges to air from coated copper wire burnt in appropriately designed equipment with appropriate emission controls.
Depending on the amount and nature of wire being burned and the duration of the burn, the burning can create plumes of smoke containing significant emissions of hazardous air pollutants, including dioxins, particles and volatile organic compounds. If inhaled, these contaminants can cause similar acute health effects to those from road-seal burning and tyre burning, such as lung and eye irritation, asthma attacks and coughing.
Depending on the weather conditions, contaminants may also be deposited on the land near the site, potentially contaminating soils and waterways. The smoke plume can cause unacceptable environmental nuisance in terms of reducing visibility and producing noxious odours.
Most regional councils and unitary authorities specify this activity as a prohibited activity within their regional air quality plans. There are alternative, less-polluting methods of recovering metals from within used cables, such as mechanical stripping.
Response to submissions
There is no change from the original proposal. The ban will be effective from 1 September 2004.
4.2.4 Burning of oil in the open
The burning of any oil (e.g. used oil, re-refined oil, diesel oil, heavy fuel oil, light fuel oil) in the open is prohibited. 'In the open' means that the oil is not being burned in a properly designed appliance.
The burning of oil in an uncontrolled manner in the open can release significant quantities of contaminants into the air. The burning typically involves low burn temperatures and uncontrolled emissions, leading to smoke plumes containing potentially harmful pollutants such as fine particles, sulphur dioxide, polyaromatic hydrocarbons and volatile organics.
There is limited information available on the amount of oil that is burned in the open air in New Zealand and its potential health effects. However, emissions are considered to pose a significant potential health risk in terms of acute health effects from smoke inhalation, and nuisance to neighbouring residents.
Oil may also be burned in the open for fire training and film special effects. These temporary activities are usually undertaken away from populated areas with adequate controls. They will be exempt from this standard for dioxins and other toxic substances. However, they may still be subject to any regional or unitary authority plan requirements.
Response to submissions
In response to submissions, our advice to the Minister for the Environment will be to inform Cabinet that the ban does not apply to the burning of oil as a fuel source at facilities with emission control equipment (e.g. cement kilns). The ban will not apply to oil burned in the open for fire training and film special effects. The burning of oil for frost protection will be a discretionary activity. The ban will be effective from 1 September 2004.
4.2.5 Landfill fires
The known burning of material on a landfill is a prohibited activity
This proposed standard for dioxins and other toxic substances excludes the burning of gaseous waste through purpose-built equipment (landfill gas flaring) or the evaporation of landfill leachate through purpose-built equipment.
Landfill fires can release vast quantities and high concentrations of harmful contaminants into the air. The proposed Dioxin Action Plan (Ministry for the Environment, 2001a) estimated that 39% of dioxin discharges are from landfill fires. Fires typically release dense white smoke and products of incomplete combustion. At times, temperatures may get high enough to release contaminants such as arsenic from treated timbers, dioxins, polyaromatic hydrocarbons, particles and volatilised heavy metals. Landfill fires are one of the most significant sources of dioxins in New Zealand.
There is also a risk that landfill gases may be ignited by fires lit on or near a landfill site, so that fires can spread easily and are difficult to extinguish.
Contaminants from landfill fires can cause direct acute health effects (similar to those discussed already) if inhaled by people in the area, and can settle on the land around the site, potentially causing longer-term site contamination. Emissions may also cause longer-term health effects if significant amounts of harmful pollutants such as dioxins are inhaled. The resulting ash from the fire is also likely to contain toxic materials, making it difficult to dispose of.
According to The 2002 Landfill Review and Audit (Ministry for the Environment, 2003f), the number of landfill fires, both intentional and accidental, has decreased significantly over the past eight years, so that in 2002 only 17% of landfill sites had experienced a fire, and these were at either small rural sites (where burning was not part of the formal management at the site) or minor incidents on larger landfills. Formally banning deliberate fires on landfills on a national basis will ensure that this figure is further reduced and that harmful emissions of dioxins and effects are prevented.
Accidental fires around landfills can be reduced through improved landfill management. Accidental fires have been caused by sparks from the exhaust systems of site plant or vehicles, smoking on the landfill by staff or users, and uncontrolled dumping of waste materials such as ashes or hazardous substances that can ignite when mixed. Good management procedures are specified in resource consent conditions, and further guidance is available in the Guide to Landfill Consent Conditions (Ministry for the Environment, 2001b).
Response to submissions
No change is proposed to the standard as a result of submissions. The standard will make clear that all reasonable actions are taken to extinguish any landfill fire. The ban will be effective from 1 September 2004.
4.2.6 Waste incineration in schools and hospitals
The proposed standard is to prohibit:
-
all new waste incinerators in schools and hospitals that do not have a resource consent
-
by 2008, all existing waste incinerators in schools and hospitals that do not have a resource consent
School and hospital incinerators can emit significant quantities and concentrations of contaminants into the air, including dioxins, particles, and volatile organic compounds. The quantity, concentration and toxicity of the contaminants released depends on the amount and type of waste being burnt, the temperatures reached in the firebox, and whether there is sufficient oxygen available for combustion. Chlorinated plastics have the potential to create harmful dioxin emissions.
The potential health effects caused by emissions from low-temperature incineration depend on the amount and nature of the waste being burnt, the likelihood of local residents and children inhaling the contaminants, the dispersion of smoke from the incinerator, and the frequency with which the incinerator is used.
Children and sick people are particularly sensitive to air pollutants. Hospitals and their environs can also be considered to be sensitive receiving environments.
Table 6: Number of North Island schools with incinerators
View number of North Island schools with incinerators (large table)
This standard for dioxins and other toxic substances will prohibit any new school and hospital incinerators unless they secure a resource consent through a publicly notified process. Existing school and hospital incinerators will be banned from 2008 unless they secure a resource consent through a publicly notified process.
We are hopeful that the approach proposed in this standard will be effective earlier than 2008. The Ministry of Health accepts this proposed standard provided that hospital incinerators are able to continue if they obtain a resource consent by 2006.
Response to submissions
In response to submissions, our advice to the Minister for the Environment will be to inform Cabinet that all new and existing school and hospital incinerators will be banned, unless they obtain resource consent by 1 September 2005.
4.2.7 High-temperature hazardous waste incineration
New high-temperature hazardous waste incinerators are a prohibited activity
This dioxin standard applies to any new high-temperature incinerators burning wastes that are considered to be hazardous as defined in the Ministry for the Environment's proposed draft definition of hazardous waste (Ministry for the Environment, 2002b). The draft New Zealand hazardous waste definition is similar to that used by Environment Australia to enforce the Basel Convention. [See Section 3 of Information Paper No. 2, Distinguishing Wastes from Non-Wastes under Australia's Hazardous Waste Act, www.deh.gov.au/industry/chemicals/hwa/index.html.] 'High temperature' is considered to include incinerators typically operating above 850 degrees Celsius.
Hazardous waste incinerators discharge potentially harmful contaminants into the air. The amount and type of contaminants released depend on the nature and amount of waste burnt, the combustion conditions (such as temperature and residence times), and the effectiveness of emissions control equipment. The health and environmental impacts of these contaminants depend on the sensitivity of the receiving environment (e.g. whether there are places nearby where people gather or live), the frequency of incinerator use, and the dispersion of the pollutants away from the stack.
There is a significant history of public concern associated with emissions from hazardous waste incinerators, mainly centred on emissions of dioxins. Research indicates that there is no safe level of exposure to dioxins and that meeting even extremely low atmospheric standards does not guarantee protection.
Most regional plans specify hazardous waste incineration as a discretionary or non-complying activity, although in some regions it is a prohibited activity. A national environmental standard prohibiting high-temperature hazardous waste incineration would supersede these regional requirements.
The Ministry for the Environment originally proposed an emission limit standard for high-temperature incineration of 0.1 ng/m3 (Ministry for the Environment, 2001a). However, even this low standard is not a guarantee of protection. The remaining ash residue is also highly toxic and difficult to dispose of. Incineration is an obsolete technology for disposing of hazardous wastes and more environmentally friendly technologies are available. The Ministry considers that a more direct and efficient method of reducing emissions of dioxins is to control the activities that cause them, which is why we have put forward this proposal to ban new high-temperature incineration of hazardous waste.
There are currently only three high-temperature hazardous waste incinerators operating in New Zealand: at Auckland airport, in New Plymouth and near Christchurch airport. The airport facilities burn medical waste, quarantine waste and police-sourced wastes.
This dioxin standard does not apply to metal plants, cement kilns and other industries that burn waste (e.g. tyres, used oil and pot liners from aluminium smelters) at high temperatures as a fuel source.
Response to submissions
In response to submissions, our advice to the Minister for the Environment will be to inform Cabinet that the ban will not apply to the three existing hazardous waste incinerators. These existing sites are at Auckland and Christchurch airports, and the Dow facility in New Plymouth. The ban will be effective from 1 September 2004.
4.3 Design standard for wood burners
Any new wood-burning appliance installed into a house in an 'urban area' must be identical (in terms of the features that are likely to affect its emissions) to a unit that has been tested in accordance with AS/NZS 4013:1999 ('Domestic solid-fuel-burning appliances - Method for determination of flue gas emission') or an equivalent
The wood-burning appliance must also meet an emission limit of 1.5 g of particulate matter per kilogram of fuel burned, averaged over high, low and medium burn rates
The costs and benefits of the wood-burner design standard are examined (in summary) in Appendix 1 of this report. This standard aims to improve the consistency and certainty with which new wood-burning appliances are used in New Zealand and, over time, to reduce potential increases in emissions and improve air quality, especially where new lower-emitting burners replace older units.
The emission limit requirement in the proposed standard supersedes the emission limit of 4 g/kg specified in the joint Australian - New Zealand standard. This more stringent limit reflects the serious PM10 pollution issues associated with emissions from domestic fires in many New Zealand towns and cities, and the need to bring about significant improvements to reduce adverse health effects.
There are over 50 wood-burner models on the market that meet the proposed emission limit of 1.5 g/kg. A full list of the complying models is available on the Environment Canterbury website. There are currently no coal-fired solid-fuel-burning appliances that would meet the proposed emission limit of 1.5 g/kg.
If appropriate testing shows that any other domestic heating appliance (with or without emissions control equipment) can meet an average emission limit of 1.5 g/kg tested on a range of burn rates, this would also be deemed to meet the standard and manufacturers can market it as such.
The proposed standard will apply to space-heating appliances, including those with water-heating devices. Excluded appliances are listed in the AS/NZ standard. They include open fireplaces, central-heating appliances, cooking appliances, and appliances used solely for water heating. Where appropriate, councils can determine specific regional requirements for these other appliances in regional air quality plans (see section 15(2) of the RMA).
The standard will apply to any new solid-fuel-burning appliance with a maximum heat output of 40 kW used in a dwelling house in an urban area in New Zealand. The definition of 'urban area' has yet to be confirmed, but is likely to be based on district plan zonings or population densities.
This is one part of this package of standards where it is clear that some local areas may require more demanding requirements. New appliances in Christchurch are one example where the councils may impose a stricter requirement. Councils can also implement other programmes, such as public education on how to use burners and incentives schemes to encourage people to convert to cleaner forms of heating.
Response to submissions
After considering submissions, our advice to the Minister for the Environment will be to inform Cabinet that the limit of 1.5 g/kg will apply to all wood burners in New Zealand. We will also advise that an efficiency standard of 65% will apply. The standards will be effective from 1 September 2005. We will clarify that the standard applies only to wood burners, and does not include coal burners.
