PM 10 impacts: London & SE England Fuller & Green, 2004 YearNo of sites Fugitive Emissions: No of days exceeded 50 µg/m >
PM 10 impacts: London & SE England SitePeriod No of days exceeded 50 µg/m 3 Total measuredFugitive emissions Marylebone Road 14 July - 30 November (24) Kensington & Chelsea 2 15 June - 8 December Crystal Palace 16 March Croydon August Fuller & Green, 2004
Cardiff AURN Site 5m from re-development of site Reported in AQEG, 2005
BRE Research “Well controlled” demolition/construction site Monitored for 18 months from 2001 to 2003 Long term PM 10 increased by ~2 µg/m 3 close to site Impacts <150m Greatest impacts (>10 µg/m 3 increase over period) from: –Demolition/removal of material –Piling, soil removal + infilling –Foundation works –(and Easter break!)
Questions Raised Do construction sites have proportionally greater impact today? –Transport PM emissions declined (but TEOM/FDMS issue) –Construction PM emissions declined? GLA Best practice guidance 2006 –Has it reduced construction emissions? –What is the evidence? Monitoring undertaken - data not systematically analysed or readily available Little robust scientific evidence of the distance over which impacts may occur
Mineral Planning Statement 2 20 years old. Still relevant? High sensitivityMedium SensitivityLow Sensitivity Hospitals and clinicsSchoolsFarms Retirement homesResidential areasLight and heavy industry Hi-tech industriesFood retailersOutdoor storage Painting and finishingGlasshouses and nurseries Food ProcessingHorticultural land Offices Mineral Planning Statement 2 After Ireland, M, 1992 Hi-tech / food processing industries often filter the inlet air, so does this reduce its sensitivity?
Annoyance or Nuisance? Planning Policy Statement PSS23: –Statutory nuisance - is not intended to secure a high level of amenity but is a basic safeguarding standard intended to deal with excessive emissions. Nuisance does not equate to loss of amenity. –Significant loss of amenity will often occur at lower levels of emission than would constitute a statutory nuisance. It is therefore important for planning authorities to consider properly, loss of amenity from emissions in the planning process in its wider context and not just from the narrow perspective of statutory nuisance.
Mitigation Is there any need to assess the impacts when mitigation plays such a vital role in determining the effects? Does mitigation mean there are no residual effects? The guidance should determine the level of risk and the associated mitigation measures only? Or does it need to include the significance of the potential effects?
IAQM Guidance Consistency of approach Lack of robust evidence Every site is different Professional judgement required - cannot be too prescriptive Membership consultation – October Review comments – November Launch – November 17th Web site – December 2011 Examples on web site
Screening Criteria Step 1 – Screening Criteria An assessment will be normally be required where there are sensitive receptors within: – 350 m of the boundary of the site –100 m of the route(s) used by construction vehicles on the public highway, up to 500 m from the site entrance(s) Deliberately conservative
Defining the Risk of Dust Effects Step 2 – Risk of Dust Effects Define: –area surrounding the site For each activity define: –potential dust emission class and –risk category Assumes no mitigation
Four Sources Considered Demolition –Any activity involved with the removal of an existing structure (or structures). Earthworks –The processes of soil-stripping, ground-levelling, excavation and landscaping. Construction –Any activity involved with the provision of a new structure (or structures). Track-out –The transport of dust and dirt from the site onto the public road network, where it may be deposited and then re-suspended by vehicles using the network.
Risk Category Scale of works defines the potential dust emission class Potential dust emission class and distance of nearest receptor defines the risk category Ecological and human receptors Professional judgement (“qualified person”) Assessment may use other criteria, but must be justified
Potential Dust Emissions Class Example: Demolition Large –Total building volume >50,000m 3, potentially dusty construction material (e.g. concrete), demolition activities >20m above ground level Medium –Total building volume 20,000m 3 – 50,000m 3, potentially dusty construction material, demolition activities 10-20m above ground level Small –Total building volume <20,000m 3, construction material with low potential for dust release (e.g. metal cladding or timber), demolition activities <20m above ground, demolition during wetter months
Potential Dust Emissions Class Example: Construction Large –Total building volume >100,000m 3, piling, on site concrete batching; sandblasting Medium –Total building volume 25,000m 3 – 100,000m 3, piling, on site concrete batching Small –Total building volume <25,000m 3, construction material with low potential for dust release (e.g. metal cladding or timber)
Construction Risk Category 1 Based on distance from dust emitting activity or, if not known, from site boundary
Example: Summary Risk Effects Table - No Mitigation
Mitigation Step 3 – Mitigation Site specific, to take account of local conditions To be based on GLA mitigation –Large –Medium –Low Separate mitigation for the four sources
Effects & Significance Step 4 – Define Effects & Significant Depends on: –the potential risks set out within the risk category table –the duration for which the sources might be close to the sensitive receptors –the proximity and number of sensitive receptors –Presence of natural shelters, such as trees, to reduce the risk of wind-blown dust –the sensitivity of the receptor(s) –Background PM 10 concentrations
Example: Proximity & Number of Receptors Proximity bands –Less than 20m –20 to 40m/50m –40m/50 to 100m –More than 100m Number of human receptors (dwellings): –Less than 10 – – –More than 500
Significance Criteria for each Activity
Example: Summary Significance Table
Four step approach
Working Group Chair Claire Holman, ENVIRON Drafting sub group Carl Hawkings, ADM Ltd Claire Holman, ENVIRON Duncan Laxen, Air Quality Consultants Ltd Matt Stoaling, SLR Consulting Other Members Alaric Lester, TRL Amanda Gair, Gair Consulting Ltd. Anneliese Lithgow, Mott MacDonald Daniel Marsh, Kings College London, Deshni Nadar, London Borough of Tower Hamlets Edward Haythornthwaite, City of London Simon Cousins, Greater London Authority Stuart Upton, BRE Ad hoc member: Joanne Holbrook, Berrymans Lace Mawer
Thanks Fiona Prismall/Jon Pullen, RPS Katherine Hauser, Golders Associates UK Ltd Michelle Hackman, Aecom Graham Harker/Denise Welch, Peter Brett Associates John Lamb, SEPA Rachel Brooks, Dundee Council Kyri Eleftheriou-Vau, Royal Borough Kensington & Chelsea And Many Others
Version 2 Review guidance in 2013 Experience of using guidance will result in a Version 2 Feedback gratefully received