HS2 and air quality

Air quality

Emissions of air quality pollutants in the UK contribute to local, regional and international air pollution levels. High concentrations of air pollutants are known to be harmful to human health and the environment.
According to the National Atmospheric Emissions Inventory, Road Transport accounted for 11% of particulate matter emissions and was the highest contributor at 31% of oxides of nitrogen (NOx) emissions across the United Kingdom in 2018.

Improving the quality of the air we breathe is an important part of the Government’s 25 year Environment Plan. The plan sets out how to improve the environment within a generation and leave it in a better state than we found it.

By moving high speed trains on to a new, dedicated intercity line, HS2 will free up space on the existing rail network to run more local and regional commuter trains. With more reliable, local frequent stopping services available, people will be able to shift from road and air travel to rail which will improve the environment and the quality of the air we breathe.

On this page you will learn about what HS2 is doing to avoid and minimise our impacts on local air quality as we build the network.

In addition, there is also further information on quality assurance, and links to Environmental Statements and Information Papers.

HS2 in operation

Delivering HS2 will enable the shift from road and air to rail, improving the quality of the air we breathe and supporting the transition to a net-zero carbon economy by 2050.

HS2 will be powered by electricity from a rapidly decarbonising national grid. Unlike cars, lorries or planes, HS2 trains will not emit air quality pollutants during operation.

Minimising emissions while designing and constructing HS2

We are raising the bar on air quality standards and leaving a legacy for future infrastructure projects.

At HS2 we prioritise minimising emissions when designing and constructing the railway. We aim to be a good neighbour every single day, by respecting the people and communities we impact, being sensitive to their needs, and earning our social licence to operate.

We are setting high standards for the construction industry and will an important legacy through innovations in construction, and management of emissions and dust.

Designing out emissions

Through our design stage we aim to avoid and minimise emissions during construction and operation. Here are some examples of this approach.

Transporting excavated material by rail

We are cutting emissions by transporting excavated material by rail rather than lorries on highways, cutting emissions and improving air quality.

Case study: In partnership with London-based stakeholders, HS2 has provided an assurance that we will transport construction materials by rail, rather than road whenever possible. This means that we could have the potential to prevent approximately 55,000 lorry movements in the Camden area and reduce emissions by around 34%.

Limiting emissions from highway vehicles

Once pollutants have been emitted from a vehicle; it is very difficult to remove them from the atmosphere. HS2 has adopted a policy of setting vehicle emission standards for construction vehicles and Non-Road Mobile Machines. We have also introduced targets for the use of ultra-low emission vehicles, enabling us to reduce emissions at source.

Designing emissions out of HS2 stations and depots

HS2 buildings are designed to avoid emissions during operation, for example through heating and cooling of the building. We assess the full design life of the building and the future supply of energy and design out emissions wherever we can.

Preventing dust and emissions during demolition

We implement a best practice dust management mitigation protocol through demolitions, earthworks, construction and movement of spoil away from sites. All dust mitigation measures implemented across our sites are set out in the Code of Construction Practise (CoCP). Some of which include:

• Ensuring we strip the interior of the building before commencing demolitions. Buildings or structures to be demolished are sprayed with water and / or screened prior to and during demolition activities.
• Burning of materials / spoil is prohibited on site.
• Vehicles transporting materials within or outside of the construction site should not be overloaded. Deliveries entering or leaving the construction site should be covered to prevent material and dust spillages.
• We surface and maintain haul routes to control dust emissions. Haul roads are inspected regularly and methods to clean and suppress dust on haul routes (including watering) should be implemented.

Cutting emissions during construction

We aim to avoid emissions during construction, but where this is unavoidable, we have set stringent limits and do everything we can to minimise public and workforce exposure.
Air quality can be affected by construction in a number of ways, including:

• Exhaust fumes from vehicles and machinery;
• Exhaust fumes from changes to traffic flows due to road closures and diversions; and
• Dust from on-site activities.

We are taking action to minimise our impact on air quality through a range of measures (our mitigation measures).

Air quality emissions from vehicles and machinery and traffic flows

• We have set the lowest emission standards available for all contractors’ vehicle engines (e.g. lorries, vans, and cars), as well as set targets for contractors to go beyond this as technology improves. This currently includes Euro 6 requirements for all lorries across the route.
• We have set industry leading emissions standards for all machinery (e.g. excavators, dumpers, large cranes and piling machines).
• Contractors use designated lorry routes to minimise the use of local roads.
• We send our route plans to the local authority to review if there are going to be more than 24 vehicle movements per day.
•  We produce Local Traffic Management Plans with local and highway authorities and the emergency services before the start of work.
•  We train our lorry drivers on how to reduce their emissions.

Full details of all our mitigation measures are in our Code of Construction Practice.

Dust Control

• We require all our contractors to control and limit their dust, air pollution, odour and exhaust emissions during works.
• Our contractors use a range of dust management methods including damping down using mobile water sprayers, handheld hoses and water cannons. Damping is when water traps pollutants stopping them from escaping into the air. Some machinery used in demolitions is specifically fitted with water sprayers to allow for damping down at source.
• We monitor the particulate matter (PM) levels at key sites along the route to make sure our mitigation measures are appropriate for the level of pollutants at a specific site. We cater each control to each specific activity.

How do we monitor air quality?

We continuously monitor real-time dust concentrations and nitrogen oxide at key sites along the route, as determined by the Institute of Air Quality Management’s best practice guidance.

In line with this best practice guidance our on-site dust monitors trigger alerts, which provide real-time feedback to contractors, allowing us to respond quickly to emissions wherever and whenever they occur.

We undertake NO2 diffusion tube monitoring at key locations, identified in the Environmental Statement, where significant impacts from our works may occur.

Our air quality monitoring surveys add to existing national and local monitoring activities by Defra, local authorities, communities and academic institutions.
We produce monthly monitoring reports per Local Authority area. We also produce an Annual Air Quality Report which highlights compliance against our emission requirements as well as details the monitoring undertaken in a year.

Driving industry-wide innovation on air quality

We are working with industry leaders and academia to encourage innovation and set new standards in the industry to improve air quality on construction sites.

We’ve set ambitious targets for our supply chain to minimise emissions, and to develop best practice solutions that can drive down emissions across the whole construction industry.

We are:

• Changing industry Best Practice – The Institute of Air Quality Management Guidance on Monitoring in the vicinity of Demolition and Construction Sites (October 2018) was updated following the our study with Kings College London to evaluate construction site monitoring strategies. This study has resulted in an adjustment of the trigger alert level for PM10 as well as a set of quality assurance measures that should be implemented across construction sites.
•  Developing Non-Road Mobile Machinery (NRMM) low emission technology to reduce our environmental impact. The NRMM retrofit could, once the research is completed, add technology to existing exhaust and engine systems to reduce emissions and recertify them as a newer engine class.
•  Trialling the replacement of diesel power equipment with ultra-low emission engines on our sites. The project is funded by Innovate UK. The system offers hybrid and heat recovery technology along with real time measurements compared to equivalent diesel engines.
• Leading the way with clean air measures by adopting a new plant emissions scheme, working with the Construction Equipment Association. HS2 has supported the development and adoption of the Non-Road Mobile Machinery (NRMM) Emission Compliance Verification Scheme as part of a bid to create greener construction sites.

Assurance and further information

Quality assurance

HS2 Ltd has been recognised for its plans to minimise the project’s environmental impact. We were awarded an ISO 14001 certificate from Lloyd’s Register of Quality Assurance for our work in areas such as carbon emissions, air and water quality, biodiversity and waste.

Air Quality Strategy

This document sets out the strategy by which High Speed Two (HS2) will meets its sustainability policy with respect to air quality. The document is a guide to the relevant air quality policy and legislation, and the potential impacts of the scheme.

It sets out our approach to avoid, reduce and mitigate emissions, and how ‘best practicable means’ can be determined. This includes measures to control dust during construction, and how emissions associated with construction vehicles and machinery will be managed.

Environmental statements & Information Papers

HS2 Phase One environmental statement volume 3: route-wide effects

Chapter 4 of the Phase One Environmental Statement (2013) presents the assessment of the Air Quality of the Proposed Scheme during construction and operation.

Phase One Air Quality Information Paper

This paper outlines the carbon footprint and greenhouse gas assessment for HS2 Phase One.

Environmental Minimum Requirements  The Code of Construction Practice also has information on carbon and climate change adaptation and resilience.

HS2 Phase 2a environmental statement volume 3: route-wide effects

Chapter 3 of the Phase 2a Environmental Statement (2017) presents the assessment of the Air Quality of the Proposed Scheme during construction and operation.

Phase 2a Air Quality Information Paper

This paper outlines the carbon footprint and greenhouse gas assessment for HS2 Phase 2a.