Report suggests Heathrow plan will not harm air quality compliance

Proposals for a third runway at Heathrow Airport will not harm progress towards EU NO2 goals if suitable mitigation measures are put in place, documents published by the government have suggested.

A report compiled by consultancy firm Parsons Brinckerhoff was published by the government on Tuesday (25 October) in the wake of its decision to back plans for the development of additional capacity at Heathrow Airport.

Heathrow Airport is to develop a third runway

The plan for a third runway at Heathrow was backed over plans for the enlargement of the existing runway, or a second runway at Gatwick airport in West Sussex.

The report was compiled to take into account the government’s Air Quality Plan, which was put forward in December 2015 to bring the UK into compliance with EU-proscribed limits in air pollutants.

In its report, Parsons Brinckerhoff claimed that an extended northern runway at Heathrow would likely lead to a high risk of exceeding the EU limit values for air pollutants in the Greater London area.

But, proposals for a new runway at Gatwick would not “cause or worsen” exceedances of EU limit values.

Third runway

Similarly, the report concluded the building of a third runway — the government’s preferred option — would not affect the zone compliance with EU air quality limits if mitigation measures are put in place to limit emissions at the A4 on Bath Road to the north of the airport.

The report said: “For Heathrow Northwest Runway the analysis showed that in 2030 or 2025, with the 2015 Air Quality Plan measures, the operation of the option neither causes nor worsens exceedances of EU limit values.”

It added: “There is a risk that the option results in worsened exceedances of limit values alongside some roads within London, but this would not affect the zone compliance since the maximum concentration within the zone is unaffected.”

The report notes that the majority of measures set out by Defra in its 2015 plan specific to London target non-compliant areas in the centre of the city, although some are aimed at reducing concentrations on links within the vicinity of Heathrow — including a 0.2μg/m3 reduction on Bath Road.

It concludes: “Scheme specific mitigation measures, as identified in the AC’s air quality local assessment, can reduce the impacts in the vicinity of the airport.

“In scenarios without the 2015 Plan measures, the option does not delay compliance within the Greater London Zone but increases the length of roads exceeding the limit. This conclusion is robust since all sensitivity tests show the same conclusion.”