The Air Quality Standards (Wales) Regulations 2010

Assessment requirements

6.—(1) The Welsh Ministers must assess the level of sulphur dioxide, nitrogen dioxide and oxides of nitrogen, PM₁₀, PM_2·5, lead, benzene and carbon monoxide in ambient air in each zone in accordance with paragraphs (2) to (4) and the criteria set out in Annex III to Directive 2008/50/EC.

(2) In zones where the level of any pollutant mentioned in paragraph (1) exceeds the upper assessment threshold for that pollutant referred to in regulation 5, fixed measurements must be used in relation to that pollutant, but may be supplemented by indicative measurements or modelling or both in order to provide adequate information on the spatial distribution of the ambient air quality.

(3) In zones where the level of any pollutant mentioned in paragraph (1) is at or between the upper and lower assessment thresholds for that pollutant referred to in regulation 5, fixed measurements must be used in relation to that pollutant but may be combined with indicative measurements or modelling or both.

(4) In zones where the level of any pollutant mentioned in paragraph (1) is below the lower assessment threshold for that pollutant referred to in regulation 5, modelling or objective estimation techniques or both may be used instead of measurement in relation to that pollutant.

(5) Where fixed measurements are supplemented by modelling or indicative measurements then the Welsh Ministers must take account of the results of those supplementary methods in carrying out the assessment referred to in paragraph (1).

(6) In addition to the assessment referred to in paragraph (1), the Welsh Ministers must measure PM_2·5 at rural background locations away from significant sources of air pollution, in order to provide information on an annual average basis on the total mass concentration and chemical speciation concentrations of that pollutant.

(7) For the purposes of paragraph (6), measurement must be carried out in accordance with the criteria set out in Annex IV to Directive 2008/50/EC and must be coordinated with the monitoring strategy and measurement programme of the Cooperative Programme for Monitoring and Evaluation of the Long-range Transmission of Air Pollutants in Europe (EMEP), where appropriate.

(8) The data quality objectives and requirements set out in Sections A and C of Annex I to Directive 2008/50/EC must be applied in carrying out the assessment and measurement referred to in paragraphs (1) and (6).

(9) Save as provided for in paragraph (10), measurements under this regulation must be taken in accordance with the reference measurement methods specified in Section A and Section C of Annex VI to Directive 2008/50/EC.

(10) Alternative methods to those referred to in paragraph (9) may be used provided the conditions set out in Section B of Annex VI to Directive 2008/50/EC are complied with.

(11) In this regulation, “chemical speciation concentrations” (“crynodiadau ffurfiant rhywogaethau cemegol”) means the concentrations of different chemical components or species of PM_2·5.