Call us free on 0808 168 9540
Call us free on 0808 168 9540
As expert odour impact assessment consultants, Phlorum is experienced in providing the full range of odour consultancy services across Sussex, London, Surrey, and Kent.
This includes conducting odour surveys and OMPs and providing expert witness services at Public Inquiries in the UK.
An odour impact assessment survey measures and evaluates the character, concentration, and contextual effects of an odour or mixture of odours. Air quality assessments of the potential for an odour to be considered offensive are necessary for various reasons related to air quality assessments for development planning and the operation of some industrial processes.
Improvements to the environmental permitting process mean that the requirement for smelly industries to prevent their odours from spreading off-site has allowed land close to them to be opened up for odour-sensitive types of development, such as residential housing.
Odour is a human sense, like touch or taste. As such, it only exists in our brains, getting there from the interpretation of external stimuli by special nerve cells. Odours could therefore be described as emotional responses to mixtures of pungent airborne chemicals.
This means that the human nose is still the best measuring device we have to assess the strength and character of odours. There are some specific odorous chemicals produced by some processes (such as hydrogen sulphide from sewers) that can be measured directly by scientific instruments, but many nuisance odours are complex mixtures of many different compounds that are hard to measure with anything other than a human nose.
Monitoring of odours with the human nose can include simple scoring systems used by trained assessors to assess the odours by simply smelling them using approved ‘sniff-test’ methodologies. A step further than this is to take samples of odorous air and quickly transport them to a laboratory before the compounds naturally break down.
In the laboratory, a device called an olfactometer can then be used to numerically measure the concentration of the odorous cocktail, with notes on the character of the odour helping to determine is offensiveness using odours wheels and other types of descriptor tools.
Difficulties in monitoring odours are that people’s sensitivities and perceptions of different odours vary widely. Most odours are complex mixtures of different compounds.
Additionally, the concentrations at which some odours are detected are very low and the periods over which they can be experienced as offensive can occur intermittently over just a few seconds, making collecting and analysing samples difficult.
The human nose is often the best monitoring equipment for determining an odour’s strength, character, and offensiveness. This can be done via an individual assessor in the field, a panel of “calibrated” assessors, or a laboratory environment with a field sample using an olfactometer.
For the same reasons that monitoring odours can be difficult, accurately predicting odour concentrations from a proposed source, such as a new restaurant or sewage treatment plant, can also be very difficult. However, computer dispersion models and other assessment techniques are recognised by regulators to provide useful information for determining planning applications and the granting of environmental permits.
There can be various reasons why an odour assessment might be needed.
In regulatory terms, many industrial processes require their environmental permit to consider and potentially mitigate odorous emissions. As such, it can be a requirement for any odour complaints to be investigated to determine whether or not any enforcement action might be necessary. This could then lead to an improvement notice to prevent the emissions from causing further nuisance complaints in the future.
Action to prevent odours from occurring can also be directed against restaurants and other odorous commercial uses such as nail painting bars. These are particularly an issue in dense urban areas where people live in close proximity to such businesses.
Another common reason for needing an odour assessment is to determine the extent of odour that might emanate from a smelly process and how close to it sensitive development might be allowed. This is particularly relevant to the siting of new residential developments on land close to sewage treatment works.
Environmental permitting and planning requirements usually clarify whether an odour survey and assessment are necessary. An odour impact assessment can be required for many situations where offensive odours might cause a nuisance.
If a Statutory Nuisance is caused, then a notice can be served on the offender to stop activities causing the nuisance and/or for improvement works to be undertaken to prevent further nuisance occurring in the future.
Phlorum is routinely appointed to provide odour monitoring and impact assessment reports for proposed facilities and to determine or refute nuisance complaints from existing processes.
Generally, these processes do not produce significant odours. However, some processes can be highly offensive, such as tankering of stored blood and handling some wastes (scorched hair, black gut contents, and lairage mucking out).
Certain activities associated with animal waste can be particularly odorous. Uncovered slurry tanks from dairy farms and muck spreading on fields can be sources particularly prone to nuisance complaints. Pig farming and most intensive husbandry processes require careful planning and mitigation as they can generate very high levels of offensive odours.
Many types of food processing result in odours that, in the right context, could be considered quite pleasant. However, if they are intense and persistent, the odours could quickly become a nuisance to local residents. Some processes emit odours that many consider unpleasant, such as beer brewing and seafood handling.
Similar to food processing, commercial kitchen odours can be quite pleasant, but they can become invasive and irritating if they are a constant annoyance. In urban centres, where residential and commercial kitchen uses are often located on top of one another, nuisance odours from restaurants can be a common problem.
The treatment of sewage and other waste waters is a vital infrastructure service. With demands for development on suitable land and improving technology to treat such waste, proposals to build property closer to treatment works require a more thorough and accurate assessment of odours as part of the planning process.
Many processes use a wide range of highly odorous chemicals, such as organic volatile compounds, which can be detected at very low concentrations and can result in elevated nuisance complaints.
The following is a list of odour survey and assessment services offered by Phlorum:
If you are unsure which odour assessment services you require, please don’t hesitate to contact one of our expert air quality consultants, who will gladly offer advice based on your specific needs and circumstances.
