LAQM Technical Guidance TG(08) Consultation

This page contains the new and recently revised tools and reports that have been prepared to accompany the Consultation Document for the revised Technical Guidance Note LAQM.TG(08). Part of this site is still under construction, as it has not been possible to provide all of the tools and reports at this stage. Some of the tools are reliant on the new vehicle emissions factors currently being prepared by DfT. Other tools are currently under development and test.

All of the tools and reports will be available by the publication of the final TG(08) document in December 2008, but this site will continue to be populated throughout the course of the consultation period, and users are advised to check frequently for updates. Where possible, indicative timescales are provided in the following sections.

Please read the LAQM.TG(08) Consultation Document first, and then test the tools in the context in which they are presented. Then follow the instructions to provide your comments - your feedback will be much appreciated.

Web-based Reporting

Defra and the Devolved Administrations will be moving to web-based reporting for Progress Reports and USAs from 2009. This will provide a uniform on-line template which will enable both the production and appraisal of these reports to be carried out in a much simpler manner.

The web based templates are currently being completed, and will be tested by a number of local authorities. The web based templates will be available in December 2008.

Background Maps for NO_x, NO₂ and PM₁₀

Revised maps of background concentrations of NOx, NO₂ and PM₁₀ for all years from 2006 to 2020 will be made available. The contribution to concentrations of NO_x and PM₁₀ from individual emission sectors will also be provided to enable contributions to be subtracted if detailed local modelling of a sector has been carried out. This should avoid double counting issues. The maps can also be used to adjust background monitoring data values to a different year. The revised background maps will be available in December 2008

NO_x to NO₂ Model

A new spreadsheet model to estimate roadside NO₂ concentrations from concentrations of NO_x. This model incorporates the impact of expected changes in the fraction of NO_x emitted as NO₂ (f-NO₂) and changes in regional concentrations of NO_x, NO₂ and O₃. The tool,allows default assumptions for f-NO₂ and regional oxidant values to be assigned according to local authority boundaries if required. This spreadsheet model can also be used to estimate NO_x from roadside NO₂ diffusion tube measurements if required. It is planned that this model will be available in August 2008.

This report provides an updated analysis of the relationship between the annual mean and the number of exceedences of the 1-hour objective for nitrogen dioxide. It is intended to confirm whether the existing relationship still holds. Such a relationship is useful for Local Authorities who are monitoring annual mean NO₂ concentrations using diffusion tubes, or who wish to estimate the likelihood of the 1-hour objective being exceeded from modelling studies. Monitoring data have been analysed from a multiple network base of around 200 monitoring sites across the UK. This report is supplementary to the LAQM Technical Guidance (08).

This spreadsheet has been designed to assist Diffusion Tube users in calculating the Precision and Accuracy (Bias) of their co-location studies. It also helps in adjusting diffusion tube results using the bias adjustment calculated. This includes 95% confidence intervals in the Bias Adjustment calculations.

TEOM VCM Correction

King's College ERG have developed a new model to correct TEOM concentrations to "gravimetric equivalent" values, based on the purge concentrations measured by FDMS analysers. To assist local authorities with the Volatile Correction Model, ERG has developed a web portal that will allow the correction algorithms to be automatically applied.

This calculator allows local authorties to predict the annual mean NO₂ concentration for a location ("receptor") that is close to a monitoring site, but nearer or further from the kerb than the monitor.

Nitrogen Dioxide Fall off with Distance Report

This report supports the NO₂ with Distance from Roads Calculator which is provided above. It brings together the results of measurements of concentrations of nitrogen dioxide made at different distances from busy roads to explore the consistency of the pattern of decline. It then examines the ability of commonly used models to reproduce the observed pattern of decline.

Since the publication of LAQM.TG(03), additional information related to the air quality impacts of airport operations has become available, and it is now appropriate to review these threshold criteria in light of this new information. This analysis has helped to formulate the updated guidance to be published in LAQM.TG(08).

This report provides background information on methods of assessing the impact of biomass combustion appliances on air quality proposed for inclusion in the new Technical Guidance.