The Air Quality Standards (Wales) Regulations 2007

Regulation 15(6)(b) Regulation 16(1)

SCHEDULE 7 Requirements for assessment methods other than fixed measurement

PART 1 Group A pollutants

1.  The following information must be compiled for zones within which sources other than fixed measurement are employed to supplement information from fixed measurement or as the sole means of air quality assessment—

(a) a description of assessment activities carried out;

(b) the specific methods used, with references to descriptions of the method;

(c) the sources of data and information;

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

(e) 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.

2.  Where possible, maps must be compiled showing concentration distributions within each zone.

PART 2 Group B pollutants

Requirements for air quality models

3.  Where an air quality model is used for assessment, references to descriptions of the model and information on the uncertainty must be compiled. The uncertainty for modelling is defined as the maximum deviation of the measured and calculated concentration levels, over a full year, without taking into account the timing of the events.

Requirements for objective estimation techniques

4.  Where objective estimation techniques are used, the uncertainty must not exceed 100%.

Standardisation

5.  For substances to be analysed in the PM₁₀ fraction, the sampling volume refers to ambient conditions.

PART 3 Ozone and ozone precursor substances

6.  The following information should be compiled for zones within which sources other than measurements are employed to supplement information from measurement—

(a) a description of the assessment activities carried out;

(b) specific methods used, with references to descriptions of the method;

(c) sources of data and information;

(d) a description of results, including uncertainties and, in particular, the extent of any area within the zone over which concentrations exceed long-term objectives or target values;

(e) for long-term objectives or target values whose object is the protection of human health, the population potentially exposed to concentrations in excess of the threshold.

7.  The National Assembly must ensure that maps are compiled showing concentration distributions within each zone.