Lanark air quality management area consultation

Detailed assessment to the revocation of Lanark air quality management area, South Lanarkshire: Executive Summary

Ricardo Energy & Environment have been commissioned by South Lanarkshire Council to undertake a detailed assessment of air quality at Lanark, South Lanarkshire.

An air quality management area encompassing the whole town of Lanark was declared in June 2016 due to likely breaches of the nitrogen dioxide hourly mean and annual mean air quality objectives.

Measured nitrogen dioxide concentrations have declined over recent years; on this basis, South Lanarkshire Council are currently considering revocation of the Lanark air quality management area. This detailed assessment aims to provide evidence that will aid the council in deciding if revocation is appropriate, or if an air quality management area is still required in Lanark or may be required in the future.

The assessment includes the following main elements:

• A review of measured nitrogen dioxide concentrations within the air quality management area over recent years.
• Detailed dispersion modelling of nitrogen dioxide concentrations for the most recent year of 2019
• A sensitivity analysis of potential fluctuations in annual mean pollutant concentrations attributable to meteorological conditions.
• Detailed dispersion modelling of nitrogen dioxide concentrations in a future year (with estimates of road traffic emissions attributable to future housing allocations in/around the air quality management area included).
• A review and detailed dispersion model of particulate matter (PM2.5) in 2019 and future years. Although Lanark does not have an air quality management area declaration for exceedance of particulate matter (PM2.5), the pollutant was included in this assessment to avoid the possibility of re-declaring an air quality management area for particulate matter (PM2.5) at a future date.

The review of pollutant measurements over the last ten years has concluded:

• An annual mean in excess of the nitrogen dioxide 40 µg.m-3 objective was measured at the Bloomgate diffusion tube in 2013. Since then, measured concentrations have in general declined at all measurement sites. In 2019, all measured concentrations were significantly less than the 40µg.m-3 objective.
• For particulate matter (PM2.5), annual mean concentrations have been consistently below the Scottish objective of 10 μg.m-3 since monitoring began in 2015.
• The dispersion modelling study of current and future road traffic nitrogen dioxide and particulate matter (PM2.5) emissions indicated that:
• In 2019, the nitrogen dioxide and particulate matter (PM2.5) annual mean objectives were not exceeded at any locations where relevant human exposure is present within the study area.
• The sensitivity analysis conducted using a meteorological dataset from 2009 through to 2019 indicates that is unlikely that exceedances of the nitrogen dioxide or particulate matter (PM2.5) annual mean objective will occur at these receptor locations due to inter-annual variability in weather conditions.
• In 2025, when likely traffic growth and inter-annual variability in weather conditions are considered, the nitrogen dioxide and particulate matter (PM2.5) annual mean are not predicted to exceed the Scottish objectives at any locations where relevant human exposure is present within the study area.
• In 2025 with future developments, the nitrogen dioxide and particulate matter (PM2.5) annual means are not predicted to exceed the Scottish objectives at any locations where relevant human exposure is present within the study area

In light of the conclusions of this detailed assessment of air quality, South Lanarkshire Council may wish to consider revocation of the Lanark air quality management area at this time.