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Odour Assessment & Survey Consultants

Essentially being a complex human sense, odour is a difficult thing to measure and assess. However, a lot of work has gone into developing suitable monitoring equipment and assessment tools that have gone some way to allowing odour impacts to be characterised and quantified.

As expert odour assessment consultants, Phlorum is experienced in providing the full range of odour consultancy services, including the presentation of expert evidence at Public Inquiries. At Phlorum we ensure that all staff engaged in odour work regularly have their olfactory senses tested and calibrated.

What Is An Odour Assessment Survey?

An odour assessment survey is a means by which the character, concentration and contextual effects of an odour is, or mixture of odours are, measured and evaluated.

Odour is a function of the human response to the sense, or perception, of smell. As such, odour assessment can be quite a subjective and difficult thing. The character and strength of different odours are the key parameters that cause some of them to be considered offensive. In different contexts, some odours might cause a nuisance, whilst in others, they can be acceptable, or even pleasant. For example, the smell of perfume can be offensive if it is particularly strong and pervasive, particularly when experienced in an area where it is not wanted – e.g. while eating in a restaurant – whilst other odours are particularly offensive and undesirable in any context – e.g. sewage or rotting flesh.

Assessment of the potential for an odour to be considered offensive is necessary for a variety of reasons related to 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 spreading offsite has allowed land close to them to be opened up for odour sensitive types of development, such as residential housing.

What Are The Difficulties In Monitoring Odour?

Further difficulties in monitoring odours are that there are wide variations in the sensitivities and perception of people to different odours, and most odours are made up of a complex mixture 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 being offensive can occur intermittently over just a few seconds, which can make collecting samples and analysing them very difficult.

Often the best monitoring equipment for determining the strength, character and offensiveness of an odour is the human nose. This can be via an individual assessor in the field, a panel of “calibrated” assessors, or in a laboratory environment with a field sample using an item of equipment called 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.

Why Undertake An Odour Assessment Survey?

Olfactometer odour assessment

There can be a variety of 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 in order to determine how close to it sensitive development might be allowable. This is particularly relevant to the siting of new residential developments on land close to sewage treatment works.

Who Needs An Odour Assessment Survey?

Environmental permitting and planning requirements are usually clear on whether survey and assessment of odours might be necessary. Where some sources are not covered by these provisions, Statutory Nuisance law can usually be applied. However, under this law, what might reasonably represent a statutory nuisance can be quite widely interpreted. Therefore, odour assessment can be required for a multitude of 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.

Abattoir waste odour monitoring

Phlorum is routinely appointed to provide odour monitoring and assessments for proposed facilities and for determining or refuting nuisance complaints from existing processes. Examples of projects we have worked on include odour assessments for the following types of processes, industries and uses:

  • Abattoirs Odours

    Generally, these processes do not produce significant odours. However, some processes such as tankering off stored blood, handling some wastes (scorched hair and black gut contents and lairage mucking out) can be highly offensive.

  • Agriculture and Animal Husbandry Odour

    Certain activities associated with animal waste can be particularly odorous. Uncovered slurry tanks from dairy farms and muckspreading on fields can be sources that are particularly prone to causing nuisance complaints. Pig farming and most intensive husbandry processes require carefully planning and mitigation as they can cause very high levels of offensive odours.

  • Food Processing Odour

    Many types of food processing result in odours that in the right context could be considered quite pleasant. However, if they are strong and persistent then the odours could quickly become a nuisance to local residents. Some processes emit particular odours that many would consider unpleasant, such as beer brewing and seafood handling.

  • Restaurant Odour

    Similar to food processing, commercial kitchen odours can be quite pleasant, but these can become quite 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.

  • Wastewater (Sewage Treatment Works) Odour

    The treatment of sewage and other waste waters is a vital infrastructure service. With demands for development on suitable land am d with the improvement in technology to treat such waste, proposals to build property closer to treatment works is requiring more and better assessment of odours as part of the planning process.

  • Industrial Processes Odour

    A huge variety of processes use a wide range of highly odours chemicals such as organic volatile compounds, which can be detected at very low concentrations and which can result in elevated nuisance complaints.

Our Odour Assessment Services

The following is a list of odour survey and assessment services offered by Phlorum:

  • Odour Expert Witnesses;
  • Odour Impact Assessments in support of planning and Environmental Permitting;
  • Odour Dispersion Modelling;
  • Odour Sampling and Analysis (laboratory olfactometry undertaken by a subcontractor);
  • Odour Surveys;
  • Odour Management Plans;
  • Odour complaint and nuisance investigation;
  • Odour mitigation planning and advice on mitigation measures; and
  • Odour abatement plant options appraisal.

If you are unsure which odour assessment services you require, please don’t hesitate to contact one of our expert consultants, who will be happy to offer advice based on your specific needs and circumstances.