| Topic: | Re:Re:Re:Re:Re:Re:Re:Re:Re:Re:Public Meeting "Out of breath?" - Air quality in Wandsworth, the facts & what's being done about it | |
| Posted by: | Tim Henderson | |
| Date/Time: | 06/03/12 10:25:00 |
| TfL issued a report yesterday on the Air Quality impact of the changes they are making to implement the Olympic Route Network for the Games in the summer. It included some interesting info on the mitigation measures they intend to make - including some work on buses to reduce NO2. Apparently they have only sorted out how to deal with single decker buses currently, but they are proposing to change the route 170 to the modified buses in the near future (as well as others outside the Putney area). This route doesn't go over the bridge and along the High Street, unlike some of the other single decker alternatives, but at least it is something. ---------------------------------------------------------- http://www.tfl.gov.uk/assets/downloads/corporate/tfl-orn-air-quality-report-march-2012.pdf 3.19 As highlighted, mitigation in relation to NO2 is difficult. Retrofitting buses on routes which pass through or intersect with NO2 exceedence areas that potentially experience increased concentrations as a result of the ORN, with Selective Catalytic Reduction technology, would deliver benefits. Trials of SCR retrofit equipment for buses in London are ongoing. To date, the technology has been fully developed and tested for single-decker vehicles and we plan to roll-out this technology on appropriate buses and routes to reduce local NOx emissions. 3.20 On this basis, five Euro 3 single-decker routes have been identified as candidates for retrofit in relation to the Games. The map below shows these routes – the 100, 112, 170, 178 and 322. The grey lines show the wider bus network and the orange lines other single-decker routes (so possible candidates for retrofit) – but those selected are considered the most relevant on the basis of the analysis undertaken. The timescales for this are tight, but for routes 100, 170, 178 and 322 it should be possible to deliver retrofitted buses on street ahead of the start of the Olympics. For route 112, the timescales may be just after the Games period itself. In the context of yearly limit values, this would still help to mitigate some impacts seen during the Games but also deliver ongoing air quality legacy benefits. Meanwhile, new buses (Euro V) are also being introduced on Route 46 ahead of the Olympics. 3.21 SCR reduces NOx emissions from these buses by a minimum of 70 per cent and depending on the bus model potentially more. This would provide some benefits during the Games time by reducing NOx emissions and helping offset some of the potential increases – although this is not a ‘direct mitigation’ as in the case of dust suppressants, given that buses are only a proportion of the emissions in these areas. But, significantly, it would provide ongoing and legacy benefits. The retrofitting of the five routes covering 54 buses should save around 25 tonnes of NOx per year. 3.22 Since we are limited to single-decker buses and so a relatively small number of routes where we can take action this would not address all the areas identified as potentially impacted. TfL is also therefore exploring the potential for re-deploying existing cleaner buses – the scope for this is limited given contractual issues and the concern about impacting adversely on areas from which the buses are redeployed, but there may be some opportunities for the limited period of the Games in a small number of areas. 3.23 While these measures will not directly mitigate the impacts in the locations which could experience an increase in concentrations, we consider that they represent a practicable means of reducing NOx emissions in key areas and in a way that provides ongoing benefits. 3.24 Owing to highly transient, low temperature duty cycles and vehicle packaging complications, SCR technology has to be carefully designed to meet specific bus requirements and be extensively tested to ensure its effectiveness and durability. While this work has been completed for single-decker buses it is still ongoing for double decker buses. TfL is currently working on this and it is expected to be able to include double-decker buses soon as part of the TfL and DfT bus retrofit programme. This will not be in time for the Games itself, but the wider roll-out on specified double-decker routes should start shortly after. The programme for the further routes to be targeted (covering up to 1,000 buses) is currently being finalised and the retrofitting will take place through 2012/13 and 2013/14. This will deliver ongoing reductions in NOx emissions of around 400 tonnes per year. |