The Air Quality Limit Values Regulations (Northern Ireland) 2002

Made: 8th March 2002

Coming into operation: 1st May 2002

The Department of the Environment, being a Department designated[^f00001] for the purposes of section 2(2) of the European Communities Act 1972[^f00002] in relation to measures relating to the control of pollution in ambient air, in exercise of the powers conferred on it by that section and of every other power enabling it in that behalf, hereby makes the following Regulations:

Citation and commencement

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Definitions and interpretation

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Duty to ensure that ambient air quality is improved

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Assessment of ambient air quality

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Classification of zones

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• (1) The Department shall classify each zone in relation to each of the relevant pollutants according to whether ambient air quality in that zone for that pollutant is required to be assessed by—

• (a) measurements;

• (b) a combination of measurements and modelling techniques; or

• (c) by the sole use of modelling or objective estimation techniques.

• (2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

• (3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

• (4) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

• (5) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

• (6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

• (7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Review of classifications

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• (1) The Department shall review the classification of each zone under regulation 5 at least once in every five years in accordance with Part II of Schedule 2.

• (2) The Department shall also review the classification of any zone under regulation 5 in the event of significant changes in activities affecting ambient concentrations in the zone of any of the relevant pollutants.

Method of assessment of ambient air quality

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• (1) The Department shall ensure that ambient air quality is assessed in each zone by following the specified method for each relevant pollutant in accordance with its current classification.

• (2) Where a zone is classified under regulation 5(1)(a) or (b) in relation to a relevant pollutant—

• (a) measurements of that pollutant must be taken at fixed sites either continuously or by random sampling; and

• (b) the number of measurements must be sufficiently large to enable the levels of that pollutant to be properly determined.

• (3) Schedule 3 shall have effect for the purposes of determining the location of sampling points for the relevant pollutants.

• (4) For each zone classified under regulation 5(1)(a) the Department shall ensure that, in respect of a relevant pollutant, the minimum number of sampling points for fixed measurement of concentrations determined in accordance with Schedule 4 is used for sampling the concentrations of that pollutant in that zone.

• (5) For each zone classified under regulation 5(1)(b) the Department shall ensure that, in respect of a relevant pollutant, the number of sampling points for fixed measurement of that pollutant in that zone, and the spatial resolution of other techniques, shall be sufficient for the concentrations of that pollutant to be established in accordance with Part I of Schedule 3 and Part I of Schedule 5.

• (6) Reference methods for—

• (a) the analysis of sulphur dioxide, nitrogen dioxide and oxides of nitrogen;

• (b) the sampling and analysis of lead; and

• (c) the sampling and measurement of PM₁₀

are set out in Schedule 6 and these methods must be used unless other methods are used which the Department considers can be demonstrated to give equivalent results or, in relation to the sampling and measurement of PM₁₀, which the Department considers can be demonstrated to display a consistent relationship to the reference method. .

• (7) The Department shall ensure that—

• (a) measuring stations to supply representative data on concentrations of PM2.5 are installed and operated using the method for the sampling and measurement of PM2.5 that it considers suitable; and

• (b) sampling points for PM2.5 are, where possible, co-located with sampling points for PM₁₀.

• (8) For zones which are classified under regulation 5(1)(b) or (c), the Department shall ensure that the information set out in Part II of Schedule 5 is compiled.

• (9) For sulphur dioxide, nitrogen dioxide and oxides of nitrogen the volume must be standardised at a temperature of 293°K and a pressure of 101,3 kPa.

Action plans

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Action to be taken where limit values are exceeded

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Zones where the levels are lower than the limit value

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Public information

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Revocation of Air Quality Standards Regulations (NI) 1990

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SCHEDULE 1 — Limit Values, Margins of Tolerance etc.

PART I — SULPHUR DIOXIDE

Limit values for sulphur dioxide

1.1

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Alert threshold for sulphur dioxide

1.2

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Minimum details to be made available to the public when the alert threshold for sulphur dioxide is exceeded

1.3

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PART II — NITROGEN DIOXIDE (NO2) AND OXIDES OF NITROGEN (NOx)

Limit values for nitrogen dioxide and oxides of nitrogen

2.1

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Alert threshold for nitrogen dioxide

2.2

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Minimum details to be made available to the public when the alert threshold for nitrogen dioxide is exceeded

2.3

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PART III — PARTICULATE MATTER (PM10)

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24-hour limit value for the protection of human health

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Annual limit value for the protection of human health

PART IV — LEAD

	Averaging Period	Limit Value	Margin of tolerance	Date by which limit value is to be met
Annual limit value for the protection of human health	Calendar year	0.5 μg/m³	0.4 μg/m³ on 19th July 2001, reducing on 1st January of each following year by equal annual amounts to reach 0 μg/m³ by 1st January 2005	1st January 2005

SCHEDULE 2 — Upper and Lower Assessment Thresholds and Exceedances.

PART I — UPPER AND LOWER ASSESSMENT THRESHOLDS

The following upper and lower assessment thresholds will apply:

• (a) SULPHUR DIOXIDE

	Health protection	Ecosystem protection
Upper assessment threshold	60% of 24-hour limit value (75 μg/m³) not to be exceeded more than 3 times in any calendar year	60% of winter limit value (12 μg/m³)
Lower assessment threshold	40% of 24-hour limit value (50 μg/m³) not to be exceeded more than 3 times in any calendar year	40% of winter limit value (8 μg/m³)

• (b) NITROGEN DIOXIDE AND OXIDES OF NITROGEN

	Hourly limit value for the protection of human health (NO₂)	Annual limit value for the protection of human health (NO₂)	Annual limit value for the protection of vegetation (NOx)
Upper assessment threshold	70% of limit value (140 μg/m³) not to be exceeded more than 18 times in any calendar year	80% of limit value (32 μg/m³)	80% of limit value (24 μg/m³)
Lower assessment threshold	50% of limit value (100 μg/m³) not to be exceeded more than 18 times in any calendar year	65% of limit value (26 μg/m³)	65% of limit value (19.5 μg/m³)

• (c) PARTICULATE MATTER[^f00006]

	24-hour average	Annual average
Upper assessment threshold	60% of limit value (30 μg/m³) not to be exceeded more than 7 times in any calendar year	70% of limit value (14 μg/m³)
Lower assessment threshold	40% of limit value (20 μg/m³) not to be exceeded more than 7 times in any calendar year	50% of limit value (10 μg/m³)
	Averaging Period	Limit Value
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124-hour limit value for the protection of human health	24 hours	50mg/m³ PM₁₀ not to be exceeded more than 7 times a calendar year
2Annual limit value for the protection of human health	Calendar year	20 mg/m³ PM₁₀

• (d) LEAD

	Annual average
Upper assessment threshold	70% of limit value (0.35 μg/m³)
Lower assessment threshold	50% of limit value (0.25 μg/m³)

PART II — DETERMINATION OF EXCEEDANCES OF UPPER AND LOWER AND LOWER ASSESSMENT THRESHOLDS

Exceedances of upper and lower assessment thresholds must be determined on the basis of concentrations during the previous five years where sufficient data are available. An assessment threshold will be deemed to have been exceeded if it has been exceeded during at least three separate years out of those previous five years.

Where fewer than five years' data are available, measurement campaigns of short duration during the period of the year and at locations likely to be typical of the highest pollution levels may be combined with results obtained from emission inventories and modelling to determine exceedances of the upper and lower assessment thresholds.

SCHEDULE 3 — Location of Sampling Points for the Measurement of Sulphur Dioxide, Nitrogen Dioxide and Oxides of Nitrogen, Particulate Matter and Lead in Ambient Air.

The following considerations will apply to fixed measurement.

PART I — MACROSCALE SITING

Protection of human healthaSampling points directed at the protection of human health should be sited:ito provide data on the areas within zones and agglomerations where the highest concentrations occur to which the population is likely to be directly or indirectly exposed for a period which is significant in relation to the averaging period of the limit value(s);iito provide data on levels in other areas within the zones and agglomerations which are representative of the exposure of the general population.Sampling points should in general be sited to avoid measuring very small micro-environments in their immediate vicinity. As a guideline, a sampling point should be sited to be representative of air quality in a surrounding area of no less than 200 m² at traffic-orientated sites and of several square kilometres at urban-background sites.Sampling points should also, where possible, be representative of similar locations not in their immediate vicinity.Account should be taken of the need to locate sampling points on islands, where that is necessary for the protection of human health.

Protection of ecosystems and vegetationbSampling points targeted at the protection of ecosystems or vegetation should be sited more than 20 km from agglomerations or more than 5 km from other built-up areas, industrial installations or motorways. As a guideline, a sampling point should be sited to be representative of air quality in a surrounding area of at least 1,000 km². A sampling point may be sited at a lesser distance or to be representative of air quality in a less extended area, taking account of geographical conditions.Account should be taken of the need to assess air quality on islands.

PART II — MICROSCALE SITING

The following guidelines should be met as far as practicable:

• the flow around the inlet sampling probe should be unrestricted without any obstructions affecting the airflow in the vicinity of the sampler (normally some metres away from buildings, balconies, trees, and other obstacles and at least 0.5 m from the nearest building in the case of sampling points representing air quality at the building line);

• in general, the inlet sampling point should be between 1.5 m (the breathing zone) and 4 m above the ground. Higher positions (up to 8 m) may be necessary in some circumstances. Higher siting may also be appropriate if the station is representative of a large area;

• the inlet probe should not be positioned in the immediate vicinity of sources in order to avoid the direct intake of emissions unmixed with ambient air;

• the sampler’s exhaust outlet should be positioned so that recirculation of exhaust air to the sampler inlet is avoided;location of traffic-oriented samplers:for all pollutants, such sampling points should be at least 25 m from the edge of major junctions and at least 4 m from the centre of the nearest traffic lane,for nitrogen dioxide, inlets should be no more than 5 m from the kerbside,for particulate matter and lead, inlets should be sited so as to be representative of air quality near to the building line.

The following factors may also be taken into account:

• interfering sources;

• security;

• access;

• availability of electrical power and telephone communications;

• visibility of the site in relation to its surroundings;

• safety of public and operators;

• the desirability of co-locating sampling points for different pollutants;

• planning requirements.

PART III — DOCUMENTATION AND REVIEW OF SITE SELECTION

The site-selection procedures should be fully documented at the classification stage by such means as compass-point photographs of the surrounding area and a detailed map. Sites should be reviewed at regular intervals with repeated documentation to ensure that selection criteria remain valid over time.

SCHEDULE 4 — Criteria for Determining Minimum Numbers of Sampling Points for Fixed Measurement of Concentrations of Relevant Pollutants in Ambient Air.

PART I — MINIMUM NUMBER OF SAMPLING POINTS FOR FIXED MEASUREMENT TO ASSESS COMPLIANCE WITH LIMIT VALUES FOR THE PROTECTION OF HUMAN HEALTH AND ALERT THRESHOLDS IN ZONES AND AGGLOMERATIONS WHERE FIXED MEASUREMENT IS THE SOLE SOURCE OF INFORMATION

Diffuse sourcesaPopulation of agglomeration or zone (thousands)If concentrations exceed the upper assessment thresholdIf maximum concentrations are between the upper and lower assessment thresholdsFor SO₂ and NO₂ in agglomerations where maximum concentrations are below the lower assessment thresholds0–25011not applicable250–499211500–749211750–9993111 000–1 4994211 500–1 9995212 000–2 7496322 750–3 7497323 750–4 7498424 750–5 999942> 6 0001053For NO₂ and particulate matter: to include at least one urban-background station and one traffic-orientated station

Point sourcesbFor the assessment of pollution in the vicinity of point sources, the number of sampling points for fixed measurement should be calculated taking into account emission densities, the likely distribution patterns of ambient-air pollution and the potential exposure of the population.

PART II — MINIMUM NUMBER OF SAMPLING POINTS FOR FIXED MEASUREMENTS TO ASSESS COMPLIANCE WITH LIMIT VALUES FOR THE PROTECTION OF ECOSYSTEMS OR VEGETATION IN ZONES OTHER THAN AGGLOMERATIONS