Question: What is an Odour Assessment?
Answer: An Odour Assessment is a specialist study that evaluates the potential for odour from a development or operation to affect nearby residents and other sensitive receptors. It considers the sources of odour, the effectiveness of any abatement, the local meteorology and the sensitivity of the surrounding area.
Odour assessments are commonly required for planning applications and environmental permits involving commercial kitchens, restaurants and takeaways, wastewater treatment works, anaerobic digestion and composting facilities, waste transfer stations, agricultural operations and industrial processes. They may also be needed where new housing is proposed close to an existing odour source.
Question: When is an Odour Assessment required for planning permission?
Answer: Local Planning Authorities typically request an odour assessment where a proposal could generate odour, or where new sensitive uses such as homes, schools or care homes would be introduced near an existing source. Common triggers include:
- New or extended commercial kitchens and hot food takeaways
- Residential development near sewage treatment works or waste facilities
- Waste, recycling, composting and anaerobic digestion facilities
- Intensive agricultural units
- Industrial processes with odorous emissions
- Discharge of planning conditions relating to kitchen extract systems
Environmental Health Officers will usually expect the assessment to follow the Institute of Air Quality Management (IAQM) Guidance on the Assessment of Odour for Planning.
Question: What methodology is used in an Odour Assessment?
Answer: The assessment approach is proportionate to the risk. Typical methods include:
- Qualitative risk assessment using the FIDOL factors (Frequency, Intensity, Duration, Offensiveness and Location)
- Odour source characterisation and review of abatement measures
- Sniff testing and odour diary surveys
- Olfactometry sampling to BS EN 13725
- Atmospheric dispersion modelling of odour concentrations
- Comparison against Environment Agency odour benchmark criteria
For kitchen extract systems, the assessment is normally undertaken with reference to the EMAQ+ Control of Odour and Noise from Commercial Kitchen Exhaust Systems guidance.
Question: What is odour dispersion modelling?
Answer: Odour dispersion modelling uses software such as ADMS or AERMOD to predict how odour emitted from a source travels and dilutes in the atmosphere. Results are expressed as odour units per cubic metre (ouE/m³) and compared with Environment Agency benchmarks, which range from 1.5 ouE/m³ for highly offensive odours to 6 ouE/m³ for less offensive odours, based on the 98th percentile of hourly means.
Modelling allows the assessment of different stack heights, abatement options and operating scenarios so that the design can be optimised before planning submission or permit application.
Question: What is a commercial kitchen extract odour assessment?
Answer: A commercial kitchen extract assessment is a risk-based assessment of a proposed restaurant, takeaway, café or food production facility. It considers the type and volume of cooking, the proximity and sensitivity of neighbours, the extract discharge location and the level of odour control proposed.
The assessment determines the appropriate level of abatement, such as grease filtration, carbon filtration, electrostatic precipitation or UV/ozone treatment, and the required discharge height and velocity. It is commonly used to support planning applications, change of use applications and the discharge of planning conditions.
Question: What mitigation measures can reduce odour impact?
Answer: Mitigation depends on the source but may include:
- Increased stack height and discharge velocity
- Carbon filtration, biofiltration or thermal oxidation
- Enclosure of odorous processes and negative pressure buildings
- Improved process management and housekeeping
- Restricting operating hours
- Buffer distances and site layout changes
- Odour management plans
Where mitigation is secured through planning conditions, the assessment provides the evidence that the measures are appropriate and achievable.
Question: What is an Odour Management Plan?
Answer: An Odour Management Plan (OMP) is a document that sets out how an operator will identify, control and monitor odour from a facility. It is commonly required by the Environment Agency as part of an environmental permit and by Local Planning Authorities as a planning condition.
An OMP typically includes a description of odour sources, control measures, monitoring procedures, complaint handling and contingency arrangements for abnormal operations.
Question: Why choose Syntegra Group for an Odour Assessment?
Answer: Syntegra Group prepares odour assessments for planning applications, permit applications and planning condition discharge across the UK. Our air quality consultants follow IAQM and Environment Agency guidance and have experience of both simple risk-based kitchen extract assessments and complex dispersion modelling for waste and industrial facilities.
Because we also provide mechanical design and acoustic consultancy, we can design extract and abatement systems that satisfy odour, noise and ventilation requirements together, avoiding conflicting advice and reducing the risk of objections from Environmental Health Officers.
