Page Last Updated: 14/04/2021

The FAQ pages are currently undergoing consolidation into new documents. From time to time this page will be updated to indicate where relevant information contained within the FAQs has been moved to.

Bookmarked links to individual FAQ pages should be updated to follow the new guidance locations.

FAQSort by TitleKeywordsPublished Date (sort)
139How do I process short-term NO2 diffusion tube monitoring survey results to obtain an annual mean NO2 concentration estimate?diffusion tube short-term annual mean NO214/04/2021
8 Where can I find information about Air Quality Monitoring Equipment Suppliers?Monitoring supplier equipment mcerts 19/01/2021
140Can I use a ‘Low Cost’ Sensor System for LAQM Reporting?Monitoring Low-Cost Equipment Sensors19/01/2021
105Impacts of Vegetation on Urban Air PollutionAQAP Planning Modelling Road Mitigation Tree Vegetation 02/12/2020
41How effective are physical barriers alongside busy roads in reducing pollutant concentration at adjacent areas?Planning AQAP Road mitigation trees reducing barrier 01/12/2020
138How do I bias adjust my diffusion tube data if I change supplier and/or preparation method during the course of a year?Bias diffusion tubes preparation method change supplier15/10/2019
103What will happen if a local authority fails to achieve the prescribed objectives in its area?AQMA AQAP Exceedence exceeding exceedance objective AQMA fails 16/10/2017
15 None of the screening tools available for stacks (e.g. the HMIP D1 method or the LAQM Emissions Screening Tools) are applicable to my installation due to a low exit velocity, or buildings taller than the stack. How do I assess its air quality impact?Modelling Industrial exit velocity stack building taller D1Height screen 13/10/2017
93 Where there are multiple boilers/furnaces which are individually below the Clean Air Act threshold of 366.4 kilowatts and are served by several chimneys, how should we check whether or not exceedences of the NO2 objective are likely?Industrial Pollutant Boiler Clean Air Act Multiple NO2 NOX Nitrogen 13/10/2017
99 How do I calculate chimney height for fan-diluted emissions below roof level?How do I calculate chimney height for fan-diluted emissions below roof level?13/10/2017
137What Defra funding sources can Local Authorities access to support their air quality work?AQAP Funding Grant Fund06/10/2016
127What are the steps and timescales involved in the appraisal process for Review and Assessment reports, Air Quality Action Plans and Action Plan Progress Reports? How may a local authority track their reports through the appraisal process?Reporting AQAP appraised appraisal assessment Progress report submission 01/02/2011
5 Measured nitrogen oxides (NOx) and/or nitrogen dioxide (NO2) concentrations in my local authority area do not appear to be declining in line with national forecasts. Should I take this into account in my Review and Assessment work?Pollutant Diffusion Nitrogen NOx NO2 trends 01/09/2010
16 How do I calculate an appropriate chimney height to ensure emissions of NO2 from small gas boilers controlled by the Clean Air Act do not lead to an exceedence of the Air Quality Strategy's objective for nitrogen dioxide (NO2) prescribed in the Air Quality Regulations 2000, SI No 928?Modelling Industrial chimney D1 clean air act Stack Height CHM 01/03/2010
18 Can I use the Chimney Heights Memorandum to determine the stack height for room-sealed boiler flue systems?Modelling Industrial chimney height memorandum room-sealed boiler 01/03/2010
42 How effective is photocatalytic paint in reducing ambient nitrogen oxides?AQAP Planning paint photocatalytic mitigation effective 01/03/2010
46 How should emissions from gas boilers, not subject to LAPC/PPC controls, be considered for the purposes of LAQM reviews and assessments?Industrial Modelling boiler gas small chimney height approvalfurnace 01/03/2010
89 The Process Guidance Note states that a stack height calculation is required following the HMIP D1 Method. Where can I find this?Industrial Modelling D1 Stack Chimney Height clean air act 01/03/2010
100How do I calculate an appropriate chimney height for furnaces/boilers not subject to controls under the Clean Air Act?Modelling Industrial chimney height stack boiler gas CHMlow Nox burner Memorandum condensing 01/03/2010
101How do I calculate chimney height for multiple gas boilers/furnaces which are individually below the Clean Air Act threshold of 366.4 kilowatts and are not served by one single chimney but several separate ones?Modelling Industrial chimney multiple clean air act Stack Height 01/03/2010
110What should I do if the targets set for 2010 continue to exceed the air quality objective/EU limit value?AQMA AQAP Exceedence exceeding exceedance 01/03/2010
111What is the Supplementary Assistance: Chimney Height Calculation Spreadsheet?Modelling Industrial Pollutant SO2 Stack Chimney Height 01/03/2010
129What level of detail in respect of cost effectiveness of measures is required in the action plan?AQAP Cost Measure 01/03/2010
130Where do I find good practice LTP2 examples?AQAP LTP good practice example report shared priority 01/03/2010

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