Odour Impact Assessment
Expert odour impact assessments for planning applications and environmental permits across the UK. Industrial, waste, agricultural and food processing operations — assessed to IAQM and Environment Agency standards.
Specialist Odour Assessment for Complex Operations
Odour is one of the most emotive and legally significant environmental issues facing industrial operators, waste companies, food processors and farmers. A poorly managed or inadequately assessed odour impact can result in planning refusals, permit conditions, enforcement action or community opposition that brings an operation to a standstill. Conversely, a well-prepared odour impact assessment — one that honestly characterises the source, rigorously assesses the impact and identifies proportionate mitigation — can unlock planning consent, secure a permit variation, or demonstrate compliance to a sceptical regulator.
At Air Dust Odour, we prepare odour impact assessments for a wide range of industrial, waste, agricultural and food processing operations. Our approach is rigorous, transparent and aligned with the IAQM and Environment Agency guidance frameworks. We combine desktop analysis, site characterisation, sniff testing and, where necessary, advanced dispersion modelling to produce assessments that are technically credible and proportionate to the risk.
We are equally at home preparing a planning odour assessment for a new anaerobic digestion plant or an environmental permit odour assessment for an existing waste transfer station under EA scrutiny. Whatever your regulatory context, we have the expertise to prepare an assessment that addresses the right questions in the right framework.
Our Odour Impact Assessment Services
From planning applications to environmental permits and complaints investigations, we provide the full range of odour impact assessment services.
Planning Odour Assessment
Odour impact assessments prepared in accordance with the IAQM Guidance on the Assessment of Odour for Planning for inclusion in planning applications and Environmental Statements. We assess odour significance using a structured source-pathway-receptor framework, characterise the sensitivity of surrounding receptors, and identify proportionate mitigation measures — all presented in a clear, LPA-ready report.
Environmental Permit Odour Assessment
Odour assessments for new environmental permit applications, permit variations and compliance demonstrations, prepared in accordance with Environment Agency H4 horizontal guidance. We characterise odour sources, assess off-site impacts, prepare Odour Management Plans (OMPs), and assist operators with EA pre-application discussions and information requests.
Odour Dispersion Modelling
Advanced atmospheric dispersion modelling using ADMS to predict odour concentrations at sensitive receptors from point, area and volume sources. We present results as contour plots and exceedance statistics, comparing predicted concentrations against relevant odour benchmarks (ouE/m³ at defined percentiles) to support both planning and permit applications with quantitative evidence.
Odour Survey & Sniff Testing
Olfactory surveys (sniff testing) carried out by trained assessors to characterise the frequency, intensity, duration, offensiveness and hedonic tone of odour at receptor locations. Surveys are conducted across multiple site visits on different days and weather conditions, providing qualitative evidence to complement modelling or to support complaints investigations and enforcement responses.
Operations Requiring Odour Assessment
We have prepared odour impact assessments for a wide range of industrial, waste and food processing operations across the UK. The common thread is that all involve significant odour-generating processes and require a credible, independently prepared assessment to satisfy the planning authority or environmental regulator.
If your operation generates odour and you need to demonstrate that it is properly managed and assessed — whether for a new application, a permit renewal, a complaint investigation or an enforcement response — we have the expertise to help.
- Waste transfer stations
- Composting facilities
- Anaerobic digestion
- Food manufacturing
- Rendering plants
- Sewage treatment works
- Intensive livestock farming
- Landfill gas operations
- Industrial processes
- Commercial kitchens
- Fish processing
- Malting & brewing
Standards & Guidance We Follow
Our odour impact assessments are grounded in the current regulatory and technical frameworks, ensuring they are accepted by both planning authorities and the Environment Agency.
Frequently Asked Questions
When do I need an odour impact assessment?
An odour impact assessment is required in three main situations: when applying for planning permission for a development that generates significant odour emissions; when applying for or varying an environmental permit where odour is a key emission; or when investigating an existing odour problem in response to complaints or regulatory enforcement. The assessment demonstrates whether odour from the operation is likely to cause an unacceptable impact at nearby sensitive receptors and identifies appropriate mitigation measures.
What is the difference between an IAQM and Environment Agency odour assessment?
The IAQM Guidance on the Assessment of Odour for Planning is the primary framework for odour assessments submitted as part of a planning application — focusing on significance to nearby receptors. The Environment Agency's H4 guidance is used for permit applications and compliance assessments at regulated facilities, covering source characterisation, Odour Management Plans and monitoring. Both frameworks can be relevant to a single site — for example, a new composting facility will need a planning assessment at application stage and will be regulated by H4 operationally.
What does an odour dispersion model involve?
Odour dispersion modelling uses specialist software — typically ADMS — to simulate the atmospheric dispersion of odour from a source and predict concentrations at surrounding receptors. The model accounts for meteorological data, terrain, and source characteristics such as emission rate, height, temperature and velocity. Outputs are odour concentration contour plots and exceedance statistics compared against relevant benchmarks, providing the quantitative evidence needed by the Environment Agency or planning authority.
How is odour measured and characterised?
Odour can be measured in several ways. Dynamic olfactometry (EN 13725) uses a trained human panel to determine odour concentration in European Odour Units per cubic metre. Field olfactometry uses a portable dilution device at the site boundary. Sniff testing involves trained assessors making multiple visits to characterise the frequency, intensity, duration, offensiveness and character of odour at receptor locations. Chemical analysis can identify specific odorous compounds. The appropriate method depends on the purpose of the assessment and the regulatory framework.
How much does an odour impact assessment cost?
The cost depends on the complexity of the source, the number and sensitivity of receptors, and the methodology required. Desktop assessments for lower-risk planning applications start from around £1,000 to £1,500. Assessments involving dispersion modelling typically start from £2,500 to £4,000. Sniff testing programmes, olfactometry and combined planning and permit assessments are priced on a project-specific basis. We provide a clear, fixed-fee proposal after a brief conversation about your project.