A wnaiff y Gweinidog gadarnhau'r amserlen ar gyfer cydymffurfio â thargedau nitrogen deuocsid yn y tymor hir mewn perthynas ag allyriadau trafnidiaeth ar ffyrdd?
Current air quality legislation makes provision for 'limit values', rather than targets, for NO2. Ministers must ensure levels do not exceed the limits set out in Schedule 1 of the Air Quality Standards (Wales) Regulations 2010 in any zone. Where levels are in exceedance, Ministers must draw up and implement an air quality plan to achieve limits in that zone. Such a plan must ‘include measures intended to ensure compliance with any relevant limit value within the shortest time possible’.
Our monitoring has revealed that annual mean concentrations last year continued to remain below the limit of 40 micrograms per cubic metre of air at A494 Deeside and A483 Wrexham in the North Wales air quality zone. No further exceedances in the zone since 2020 have been identified, however we continue to monitor air quality at these sites to ensure long-term compliance.
We have also seen improvement in the South Wales air quality zone, although a number of uncertainties remain as to how sustained compliance can be achieved. We continue to work with consultants to develop our understanding of the issues and further potential mitigations.
We will shortly be publishing our Welsh Government update to our supplemental plan for tackling roadside nitrogen dioxide concentrations 2017, describing the progress that has been made. Alongside this we will consult on Welsh Transport Appraisal Guidance Stage 2 appraisals of shortlisted measures to tackle more recently identified exceedances on the M4 between Llandarcy and Lon-las, and on the A470 between Coryton and Nantgarw.