Every local authority , other than a local authority in Wales, shall from time to time cause a review to be conducted of the quality for the time being, and the likely future quality within the relevant period, of air within the authority's area.
Every local authority in Wales must, in each calendar year, cause a review to be conducted of the quality for the time being, and the likely future quality within the relevant period, of air within the authority's area.
Where a local authority causes a review under subsection (1) or (1A) above to be conducted, it shall also cause an assessment to be made of whether air quality standards and objectives are being achieved, or are likely to be achieved within the relevant period, within the authority's area.
This subsection applies to a local authority where, on an assessment under subsection (2) above, it appears that any air quality standards or objectives are not being achieved, or are not likely within the relevant period to be achieved, within the local authority's area...
Where subsection (3) applies to a local authority, it must identify any parts of its area in which it appears that air quality standards or objectives are not likely to be achieved within the relevant period.
Where subsection (3) applies to a local authority in England, it must also—
For the purposes of subsection (5), a source is "relevant" if—