LegalizeThe Air Quality Limit Values (Wales) Regulations 2002
| Benzene | Carbon monoxide | |
|---|---|---|
| Fixed measurements | Fixed measurements | Fixed measurements |
| Uncertainty | 25% | 15% |
| Minimum data capture | 90% | 90% |
| Minimum time coverage | 35% urban background and traffic sites (distributed over the year to be representative of various conditions for climate and traffic) 90% industrial sites | |
| Indicative measurements | Indicative measurements | Indicative measurements |
| Uncertainty | 30% | 25% |
| Minimum data capture | 90% | 90% |
| Minimum time coverage | 14% (one day’s measurement a week at random, evenly distributed over the year, or 8 weeks evenly distributed over the year) | 14% (one measurement a week at random, evenly distributed over the year, or 8 weeks evenly distributed over the year) |
| Modelling | Modelling | Modelling |
| Uncertainty: | ||
| Eight-hour averages | 50% | |
| Annual averages | 50% | |
| Objective estimation | Objective estimation | Objective estimation |
| Uncertainty | 100% | 75% |
The uncertainty (on a 95% confidence interval) of the assessment methods shall be evaluated in accordance with the “Guide to the Expression of Uncertainty of Measurements" (ISO 1993) or the methodology of ISO 5725:1994 . The percentages for uncertainty in the above table are given for individual measurements averaged over the period considered by the limit value, for a 95% confidence interval. The uncertainty for the fixed measurements should be interpreted as being applicable in the region of the appropriate limit value.
The uncertainty 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 into account 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 of the normal maintenance of the instrumentation.
The National Assembly may allow for random measurements to be made instead of continuous measurements for benzene if the uncertainty, including the uncertainty due to random sampling, meets the quality objective of 25%. Random sampling must be spread evenly across the year.
The following information should be compiled for zones and agglomerations within which sources other than measurement are employed to supplement information from measurement or as the sole means of air quality assessment:
- (0) a description of assessment activities carried out;
- (0) the specific methods used, with references to descriptions of the method;
- (0) the sources of data and information;
- (0) a description of results, including accuracies and, in particular, the extent of any area or, if relevant, the length of road within the zone 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;
- (0) 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.
ISO/FDIS 10498 (Standard in draft) Ambient air — determination of sulphur dioxide — ultraviolet fluorescence method .
ISO 7996: 1985 Ambient air — determination of the mass concentrations of nitrogen oxides — chemiluminescence method .
The reference method for the sampling of lead will be that described in the Annex to Directive 82/884/EEC 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.
ISO 9855: 1993 Ambient air — Determination of the particulate lead content of aerosols collected in filters. Atomic absorption spectroscopy method .
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". The measurement principle is based on the collection on a filter of the PM₁₀ fraction of ambient particulate matter and the gravimetric mass determination.
The reference method for the measurement of benzene will be pumped sampling on a sorbent cartridge followed by gas chromatographic determination.
The reference method for the measurement of carbon monoxide will be a method based on the non-dispersive infra-red spectrometric (NDIR) method.
Editorial notes
OJ No L296, 21.11.96, p. 55.
See regulation 10(8).
See regulation 10(10).
See regulation 10(11).
Regulation 9(3) of the Air Quality Limit Values (Wales) Regulations 2001 imposed a corresponding obligation to prepare a plan or programme for the attainment of the relevant limit values, in relation to these pollutants, by dates prior to the coming into force of these Regulations.
S.I. 2001/2683 (W.224).
S.I. 1989/317, amended by S.I. 1995/3146 and partially revoked, in relation to Wales, by S.I. 2001/2683 (W. 224).
OJ L229, 30.8.1980, p.30.
The figures for Margins of Tolerance for each of the relevant pollutants given in this Schedule are calculated from those given in Annex I of Directive 99/30/EC and Annexes I and II of Directive 2000/69/EC.
The upper and lower assessment thresholds for PM ₁₀ are based on the indicative limit values for 1 January 2010, which will be reviewed in the light of further information on health and environmental effects, technical feasibility and experience in the application of the existing “Stage 1" limit values.See Article 10 of Directive 99/30/EC.
Copies of this International Standards Organisation publication can be purchased from the British Standards Institution “BSI" sales department either by telephone on 020-8996-9001 or by post from the BSI, Standards House, 389 Chiswick High Road, London W4 4AL.
Copies of this International Standards Organisation publication can be purchased from the British Standards Institution “BSI" as for footnote (a) above.
Copies of this International Standards Organisation publication can be purchased from the British Standards Institution “BSI" sales department either by telephone on 020-8996-9001 or by post from the BSI, Standards House, 389 Chiswick High Road, London W4 4AL.
Copies of this International Standards Organisation publication can be purchased from the British Standards Institution “BSI" as for footnote (a) above.
Copies of this International Standards Organisation publication can be purchased from the British Standards Institution “BSI" sales department either by telephone on 020-8996-9001 or by post from the BSI, Standards House, 389 Chiswick High Road, London W4 4AL.
Copies of this International Standards Organisation publication can be purchased from the British Standards Institution “BSI" as for footnote (a) above.
OJ L378, 31.12.1982, p.15.
Copies of this International Standards Organisation publication can be purchased from the British Standards Institution “BSI" sales department either by telephone on 020-8996-9001 or by post from the BSI Standards House, 389 Chiswick High Road, London W4 4AL.
European Standards Institute “CEN" publication reference BSEN 12341, obtainable from the British Standards Institution “BSI" as for footnote (a) above.
Words in reg. 2 inserted (30.4.2005) by The Air Quality Limit Values (Wales) (Amendment) Regulations 2005 (S.I. 2005/1157), regs. 1(1), 3(1)
Words in reg. 8(6) inserted (30.4.2005) by The Air Quality Limit Values (Wales) (Amendment) Regulations 2005 (S.I. 2005/1157), regs. 1(1), 4
Reg. 10(12)-(14) inserted (30.4.2005) by The Air Quality Limit Values (Wales) (Amendment) Regulations 2005 (S.I. 2005/1157), regs. 1(1), 3(2)
Reg. 12(9) omitted (30.4.2005) by virtue of The Air Quality Limit Values (Wales) (Amendment) Regulations 2005 (S.I. 2005/1157), regs. 1(1), 3(3)
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