Good air quality is important for our health and quality of life.
Our is designed to provide the public with information relating to local air quality in Uttlesford, to fulfil Uttlesford District Council's statutory duty to review and assess air quality within its area, and to determine whether or not the air quality objectives are likely to be achieved.
In 2021, Uttlesford District Council measured no exceedances of the Air Quality Objectives.
Air quality in Uttlesford is determined by many factors, including traffic exhaust, emissions from local industry, and domestic sources.
The Environmental Health service monitors air quality under the framework for local air quality management set out in the Environment Act 1995, to assess whether national air quality objectives contained in the government's National Air Quality Strategy are being met. Air Quality standards are set for the following pollutants which are known to cause harm:
- Sulphur dioxide
- Nitrogen dioxide
- Particulate matter
- Carbon monoxide
National Air Quality Objectives
The National Air Quality Objectives are set out in the Air Quality Standards Regulations 2010 on legislation.gov.uk for the purpose of local air quality management.
For the protection of human health
Maximum daily running 8-hour mean
200 µg/m3 not to be exceeded more than 18 times a year
Particles (PM10) (gravimetric)
50 µg/m3, not to be exceeded more than 35 times a year
350 µg/m3, not to be exceeded more than 24 times a year
125 µg/m3, not to be exceeded more than 3 times a year
Particles (PM2.5 )
25 µg/m3 to be achieved by 2020
100 µg/m3 : not more than 10 annual exceedances
Daily 8hr mean
For the protection of vegetation and ecosystems
Note: µg/m3 = microgram per cubic metre
Where national targets are not being, or are unlikely to be achieved, the local authority must declare an Air Quality Management Area (AQMA) and implement an Action Plan. Most AQMAs are declared as a result of nitrogen dioxide from road vehicle emissions.
Uttlesford declared an AQMA in May 2012 to include major road junctions in Saffron Walden, based on the annual mean for nitrogen dioxide not being met at the Debden Road/London Road junction and the Thaxted Road/East Street junction. The area is centred on Elm Grove off Hill Street and a map of the area is shown below:
The AQMA enables the Council to take air quality into account as a material consideration when determining planning applications or appeals for larger developments inside or close to the AQMA. An application must be accompanied by an Air Quality Assessment if one or both of the following apply:
- .The development could lead to a measurable deterioration in air quality as a direct result
- The development would introduce or increase human exposure in areas where existing air quality does not meet the air quality standard.
The assessment must consider the:
- existing air quality in the vicinity of the proposed development
- likely impact on local air quality as a result of the proposed development including additional traffic and/or introduction of new emissions sources, such as combustion plant
- proposed measures for mitigating the impact on air quality including design measures to limit public exposure
- level of increased exposure by the public to pollutants taking account of any mitigation measures
If an application is approved, the Council can seek financial contributions towards mitigating the impacts.
Information on current air quality including the five main pollutants that can cause material health effects is provided using an index produced by the Department for Environment Food & Rural Affairs (Defra) called the Daily Air Quality Index, which can be viewed on the Air Information Resource page on the Defra website.
Local air quality monitoring data
Air quality monitoring is undertaken at two automatic monitoring stations located in Saffron Walden, and currently at 39 other sites throughout the district using diffusion tubes. In addition the council has deployed one Osiris particle monitor and two Aeroqual AQY sensors.
You can see the current real time air quality at our two automatic monitoring stations at:
All times shown are GMT.
All combustion processes in air produce oxides of nitrogen, including nitrogen dioxide (NO2) and Nitric Oxide (NO). Road transport is the main source, followed by the electricity supply industry and other industrial and commercial sectors. NO2 is associated with adverse effects on human health. At high levels NO2 causes inflammation of the airways, and long term exposure may affect lung function and respiratory symptoms. NO2 also enhances the response to allergens in sensitive individuals.
Nitrogen dioxide Automatic Monitoring Data
Over the past 11 years the data for Uttlesford shows no exceedances of the annual mean NO2 objective at the automatic monitoring sites.
In the years when the hourly mean was exceeded, the number recorded was well within the number acceptable to meet the 1 hour standard (200µg/m3 not to be exceeded more than 18 times/year).
Diffusion tube monitoring data
During 2021 nitrogen dioxide was monitored at 39 sites using diffusion tubes. No exceedances of the Annual Mean objective were found for the fifth year running.
Central Saffron Walden continues to be designated as an Air Quality Management Area (AQMA) although having no exceedances of the Annual Mean objective for five years running gives the Council grounds to examine whether the AQMA can be revoked.
It should also be noted that a number of the diffusion monitoring tubes, including those where the exceedances have occurred in the past, are located on street furniture for practical reasons, situated immediately alongside the carriageway. As a result they are exposed to higher levels of emissions than the neighbouring houses.
Results of NO2 diffusion tubes
Particulate Matter (PM) is categorised on the basis of the size of the particles.
PM10 consists of particles less than 10 micrometres in diameter, and PM2.5 consists of particles with a diameter of less than 2.5micrometres in diameter. Exposure to Particulate Matter (PM) is associated with respiratory and cardiovascular illness and mortality. The finer the particle, the greater the risk of inhalation deep into the respiratory system with associated ill health effects.
PM is made up of a wide range of materials and arise from a variety of sources. Concentrations of PM comprise primary particles emitted directly into the atmosphere from combustion sources and secondary particles formed by chemical reactions in the air. PM derives from both human-made and natural sources (such as sea spray and Saharan dust). In the UK the biggest human-made sources are stationary fuel combustion and transport. Road transport gives rise to primary particles from engine emissions, tyre and brake wear and other non-exhaust emissions. Other primary sources include quarrying, construction and non-road mobile sources.
Uttlesford District Council monitors PM2.5 concentrations at four locations across the district using one BAM 1020 reference monitor, one Osiris particle monitor and two Aeroqual AQY sensors. No exceedances of the Annual Mean objective have been found.
PM 10 continues to be monitored at the automatic station located at London Road, Saffron Walden. No exceedances of the Annual Mean objective have been found. Exceedances of the 24-hour mean have been recorded but are well below the AQS maximum number permitted of 35 per year.
Generally air quality in Saffron Walden remains good with a low likelihood of any serious impacts on health. However the Council is not complacent and regards air quality as an important aspect affecting the quality of life within the town and district. It is keen to ensure that air quality does not deteriorate in the future nor that it should be adversely affected as a result of new developments.
The AQMA covering the town centre requires any proposal for development which may affect air quality within the AQMA to be supported by an Air Quality Impact Assessment and provide for mitigation measures where necessary, to ensure there is no worsening of the air quality.
In addition to junction improvements and other proposed mitigation measures, the introduction of revised EU wide emission controls for vehicles produced from 2013 onwards is expected to contribute to improved air quality within the town to reduce the likelihood of further exceedances of the AQSs.
Having declared the centre of Saffron Walden as an Air Quality Management Area, the Council is obliged to develop and carry out remedial action aimed at meeting the air quality objectives within the AQMA and to reduce the likelihood of future exceedances over for the 5 year life of the plan.
An Action Plan has been developed, and following a period of statutory consultation, was adopted by Cabinet in October 2017.
A key measure is traffic management and other physical intervention like cycle routes, and development of the plan has been dependent upon input from Essex County Council Highways officers. Other measures focus on behavioural change and modal shift towards sustainable forms of transport, and ensuring a consistent and integrated approach towards development control, through policies and technical guidance to developers.
An annual review of the plan will be undertaken to assess progress of implementing the measures and to ensure the proposed actions remain appropriate. Progress each year will be reported in the Air Quality Annual Status Report as part of our statutory duties set by Defra.
The plan has the co-benefit of reducing exposure to fine particulates, a duty which Defra has placed with local authorities due to the known health impacts.
Apart from the Action Plan measures, Uttlesford continues to enforce legislative controls to reduce emissions throughout the district, and to provide public information and guidance on air quality issues.
1. Industrial Emissions. The Pollution Prevention and Control Act 1999 requires that operators of certain industrial processes apply to either the Environment Agency or a local authority, depending on the nature of the process, for a permit to control air and other emissions. UDC permits 26 processes which are inspected at least annually to ensure compliance with the conditions of their permit. Processes permitted by local authorities are divided into two categories - those that have the potential to impact on air, land, water and the noise environment, called part A2 processes, of which there are two in Uttlesford. These permits also control other matters including waste management and energy efficiency. The remainder, called part B processes, are considered to impact only on the air, and include facilities such as larger petrol stations, users of solvents, concrete crushers and cement batching. Operators are required to comply with conditions which are deemed to meet best practical techniques available for controlling emissions. Failure to do so can result in legal action being taken.
Further information on the processes can be obtained by contacting the Environmental Health Section.
2. Statutory Nuisance. The Environmental Protection Act 1990 defines a number of Statutory Nuisances including bonfires, dust , fumes and gases emitted from premises. Where a local authority is satisfied that a statutory nuisance exists, is likely to exist or recur, it must serve a Notice on the person responsible to require abatement of the nuisance. Failure to comply with the terms of the Notice may result in prosecution. We have put together some information on bonfires.
3. Dark Smoke. The Clean Air Act 1993 regulates emissions of dark smoke from chimneys and from industrial or trade premises
4. Chimney Heights. The Clean Air Act 1993 requires local authorities to approve the height of chimneys from certain processes to ensure satisfactory dispersal of emissions into the atmosphere.
People in good health usually encounter no serious short term side effects from moderate levels of air pollution. However elevated levels and/or long term exposure to pollution can affect human health, ecosystems and buildings. People with lung or heart conditions are at greater risk, and asthmatics may find poor air quality triggers attacks or leads to increased use of inhalers.
Further information can be found on our Air Pollution - information on prevention and control page.
► Further information about air quality in the county is available from Essex Air