2002 No. 94
ENVIRONMENTAL PROTECTION

The Air Quality Limit Values Regulations (Northern Ireland) 2002

Made
Coming into operation
The Department of the Environment, being a Department designated1 for the purposes of section 2(2) of the European Communities Act 19722 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 commencementF11.

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Definitions and interpretationF12.

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Duty to ensure that ambient air quality is improvedF13.

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Assessment of ambient air qualityF14.

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Classification of zones5.

(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.

F1(2)

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F1(3)

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F1(4)

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F1(5)

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F1(6)

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F1(7)

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Review of classifications6.

(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.

Annotations:
Commencement Information

I2Reg. 6 in operation at 1.5.2002, see reg. 1

Method of assessment of ambient air quality7.

(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 F2or, 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 plansF18.

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Action to be taken where limit values are exceededF19.

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Zones where the levels are lower than the limit valueF110.

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Public informationF111.

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Revocation of Air Quality Standards Regulations (NI) 1990F112.

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Sealed with the Official Seal of the Department of the Environment on 8th March 2002.

Dermot Nesbitt
Minister of the Environment

F1SCHEDULE 1Limit Values, Margins of Tolerance etc.

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SCHEDULE 2Upper and Lower Assessment Thresholds and Exceedances.

Regulations 5(5) and 6(1)

PART IUPPER 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 MATTER6

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

Margin of tolerance

Date by which limit value is to be met

1.

24-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

To be derived from data and to be equivalent to Stage 1 limit value.

1st January 2010

2.

Annual limit value for the protection of human health

Calendar year

20 mg/m3 PM10

50% on 1st January 2005 reducing every 12 months thereafter by equal annual percentages to reach 0% by 1st January 2010

1st January 2010

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

Regulation 7(3) and (5)

The following considerations will apply to fixed measurement.

PART IMACROSCALE SITING

(a)Protection of human health

Sampling points directed at the protection of human health should be sited:

(i)

to 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);

(ii)

to 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.

(b)Protection of ecosystems and vegetation

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

Regulation 7(4)

PART IMINIMUM 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

(a)Diffuse sources

Population of agglomeration or zone (thousands)

If concentrations exceed the upper assessment threshold

If maximum concentrations are between the upper and lower assessment thresholds

For SO2 and NO2 in agglomerations where maximum concentrations are below the lower assessment thresholds

0–250

1

1

not applicable

250–499

2

1

1

500–749

2

1

1

750–999

3

1

1

1 000–1 499

4

2

1

1 500–1 999

5

2

1

2 000–2 749

6

3

2

2 750–3 749

7

3

2

3 750–4 749

8

4

2

4 750–5 999

9

4

2

> 6 000

10

5

3

For NO2 and particulate matter: to include at least one urban-background station and one traffic-orientated station

(b)Point sources

For 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 IIMINIMUM 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

If maximum concentrations exceed the upper assessment threshold

If maximum concentrations are between the upper and lower assessment thresholds

1 station every 20 000 km2

1 station every 40 000 km2

In island zones the number of sampling points for fixed measurement should be calculated taking into account the likely distribution patterns of ambient air pollution and the potential exposure of ecosystems or vegetation.

SCHEDULE 5Data-quality Objectives and Compilation of Results of Air-quality Assessment.

Regulation 7(5) and (8)

PART IDATA-QUALITY OBJECTIVES

The following data-quality objectives for the required accuracy of assessment methods, of minimum time coverage and of data capture of measurement are laid down to guide quality-assurance programmes.

Sulphur dioxide, nitrogen dioxide and oxides of nitrogen

Particulate matter and lead

Continuous measurement

Accuracy

15%

25%

Minimum data capture

90%

90%

Indicative measurement

Accuracy

25%

50%

Minimum data capture

90%

90%

Minimum time coverage

14% (One measurement a week at random, evenly distributed over the year, or eight weeks evenly distributed over the year)

14% (One measurement a week at random, evenly distributed over the year, or eight weeks evenly distributed over the year)

Modelling Accuracy:

Hourly averages

50%–60%

Daily averages

50%

Annual averages

30%

50%

Objective estimation

Accuracy:

75%

100%

The accuracy of the measurement is defined as laid down in the “Guide to the Expression of Uncertainty of Measurements” (ISO 1993)7 or in ISO 5725-1 “Accuracy (trueness and precision) of measurement methods and results” (ISO 1994)8. The percentages in the table are given for individual measurements averaged, over the period considered, by the limit value, for a 95% confidence interval (bias + two times the standard deviation). The accuracy for continuous measurements should be interpreted as being applicable in the region of the appropriate limit value.

The accuracy for modelling and objective estimation is defined as the maximum deviation of the measured and calculated concentration levels, over the period considered by the limit value, without taking account of the timing of the events.

The requirements for minimum data capture and time coverage do not include losses of data due to the regular calibration or the normal maintenance of the instrumentation.

The Department may allow for random measurements to be made instead of continuous measurements for particulate matter and lead by methods for which accuracy within the 95% confidence interval with respect to continuous monitoring has been demonstrated to be within 10%. Random sampling must be spread evenly over the year.

PART IIRESULTS OF AIR QUALITY ASSESSMENT

The following information should be compiled for zones or agglomerations within which sources other than measurement are employed to supplement information from measurement or as the sole means of air quality assessment:

  • a description of assessment activities carried out;

  • the specific methods used, with references to descriptions of the method;

  • the sources of data and information;

  • a description of results, including accuracies and, in particular, the extent of any area or, if relevant, the length of road within the zone or agglomeration over which concentrations exceed limit value(s) or, as may be, limit value(s) plus applicable margin(s) of tolerance and of any area within which concentrations exceed the upper assessment threshold or the lower assessment threshold;

  • for limit values the object of which is the protection of human health, the population potentially exposed to concentrations in excess of the limit value.

Where possible maps shall be compiled showing concentration distributions within each zone and agglomeration.

SCHEDULE 6Reference Methods for Assessment of Concentrations of Sulphur Dioxide, Nitrogen Dioxide and Oxides of Nitrogen, Particulate Matter (PM10 and PM2·5) and Lead.

Regulation 7(6)

Annotations:
Commencement Information

I13Sch. 6 in operation at 1.5.2002, see reg. 1

PART IREFERENCE METHOD FOR THE ANALYSIS OF SULPHUR DIOXIDE

ISO/FDIS 10498 (Standard in draft) Ambient air—determination of sulphur dioxide—ultraviolet fluorescence method9.

PART IIREFERENCE METHOD FOR THE ANALYSIS OF NITROGEN DIOXIDE AND OXIDES OF NITROGEN

ISO 7996: 1985 Ambient air—determination of the mass concentrations of nitrogen oxides—chemiluminescence method10.

PART IIIAREFERENCE METHOD FOR THE SAMPLING OF LEAD

The reference method for the sampling of lead will be that described in the Annex to Directive 82/884/EEC11 until such time as the limit value in Schedule 1 to these Regulations is to be met, when the reference method will be that for PM10 specified in Part IV of this Schedule.

PART IIIBREFERENCE METHOD FOR THE ANALYSIS OF LEAD

ISO 9855: 1993 Ambient air—Determination of the particulate lead content of aerosols collected in filters. Atomic absorption spectroscopy method12.

PART IVREFERENCE METHOD FOR THE SAMPLING AND MEASUREMENT OF PM10

The reference method for the sampling and measurement of PM10 will be that described in EN 12341 “Air Quality—Field Test Procedure to Demonstrate Reference Equivalence of Sampling Methods for the PM10 fraction of particulate matter”13. The measurement principle is based on the collection on a filter of the PM10 fraction of ambient particulate matter and the gravimetric mass determination.

SCHEDULE 7Information to be included in the Plan or Programme for Improvement of Air Quality.

Regulation 9(4)

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(This note is not part of the Regulations.)

These regulations are made in the implementation in Northern Ireland of European Council Directive 96/62/EC on ambient air quality assessment and management, and European Council Directive 99/30/EC relating to limit values for sulphur dioxide, nitrogen dioxide and oxides of nitrogen, particulate matter and lead (“the relevant pollutants” in ambient air).

Regulation 3 places a duty upon any relevant government department to ensure that in each zone in Northern Ireland concentrations of relevant pollutants do not exceed the limit values. The limit values for each pollutant, and the date by which they are to be met, are set out in Schedule 1.

Regulation 4 requires the Department of the Environment (“the Department”) to assess ambient air quality in each zone in accordance with regulations 5 to 7.

Regulation 5 requires the Department to classify each zone in relation to each of the relevant pollutants in accordance with the method required to assess air quality in that zone. Regulation 5 together with Schedule 2 provide for the determination of upper and lower assessment thresholds for each relevant pollutant, and regulation 5 sets out the requirements for measurement or other assessment of air quality depending on pollution levels in relation to the thresholds.

Regulation 6 places a duty on the Department to review the classification of zones every five years or in the event of significant changes affecting levels of any of the relevant pollutants.

Regulation 7 requires the Department to ensure that specified methods are used for assessing air quality for each pollutant in each zone. Schedule 3 sets out how sampling points for the relevant pollutants are to be determined. Schedule 4 sets out criteria for the minimum number of sampling points for fixed measurements to assess compliance with limit values in zones where that is the only source of information, and with limit values for the protection of ecosystems or vegetation in certain other zones. Schedule 5 makes provision for data quality objectives for the required accuracy of assessment methods, and for compilation of the results of air quality assessment. Schedule 6 prescribes reference methods for the analysis, sampling or measurement of the relevant pollutants. Regulation 7 places a duty on the Department to ensure that measuring stations supply data on concentrations of PM2.5 particulate matter.

Regulation 8 requires the Department to draw up, after consultation with other relevant government departments, action plans indicating measures to be taken in the short term where there is a risk that limit values for any of the relevant pollutants, or alert thresholds for sulphur dioxide or nitrogen dioxide, will be exceeded. The alert thresholds for sulphur dioxide and nitrogen dioxide are set out in Schedule 1.

Regulation 9 requires the Department to draw up lists of zones where the levels of one or more of the relevant pollutants is above the limit value, or between the limit value and any margin of tolerance shown in Schedule 1. For such zones, the regulation places a duty on the Department to draw up, after consultation with other relevant government departments, a plan or programme, which must contain at least the information set out in Schedule 7 (including the location and origin of the pollution, the responsible authorities and the measures taken to deal with the pollution). Such relevant departments are obliged by the regulation to implement the plan or programme.

Regulation 10 requires the Department to list zones where levels of the relevant pollutants are below limit values. The regulation also places a duty on the Department and other relevant government departments to ensure that levels of these pollutants are maintained below the limit values, and to endeavour to preserve the best ambient air quality, compatible with sustainable development.

Regulation 11 requires the Department to ensure that up-to-date information on ambient concentrations of each of the relevant pollutants is routinely made available to the public. It prescribes the frequency and content of such information. Where alert thresholds for sulphur dioxide or nitrogen dioxide are exceeded, further information, set out Schedule 1 must be provided (this includes details of the place and time of the occurrence, forecasts, and precautions to be taken by sensitive populations).

Regulation 12 revokes for Northern Ireland and at different dates parts of the Air Quality Standards Regulations (NI) 1990 giving effect to limit values for the relevant pollutants in earlier directives.