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Odour Complaints & your Odour Management Plan

Are you an operator with a site which produces emissions? If so, it’s likely that you have experienced odour complaints somewhere along the line. In fact, you’ve probably received even more than usual this year, thanks to most people having plenty of time to spend in their gardens. In this article we discuss why you get (and don’t get) odour complaints. Most importantly, we also look at how you can use them to your advantage and improve your odour management plan.



You guessed it, the answer is actually ‘false’. The chances are that you probably only get a few odour complaints here and there, which doesn’t seem so bad. But it’s easy to vastly under-estimate the scope of complaints. Here’s how.

A single complaint can indicate that there are another 25 people who have experienced the same issue but don’t complain. And despite not complaining through official channels, those people are likely to relay their experience to at least another 10 people. That means that for every complaint received, there could be more than 250 negative contact points. So a slightly bigger deal than it first appears then.

This is especially true in recent times, thanks to social media platforms such as facebook and twitter. It’s now much easier and faster than ever before to disseminate information to a far greater audience. And unfortunately, people are more likely to talk about a bad experience than a good one.


It’s very easy to think that if there are no (or very few) complaints, there’s no problem. But is that accurate? In our experience, there are many and varied reasons why somebody may choose not to complain.

There are many reasons people choose not to complain, including 'complaint fatigue'Perhaps most notable is that they may have a vested interest in the operator responsible for an odour. In small communities in particular, for example, the region’s main employer may be responsible. Understandable, then, to choose not to complain and risk your own livelihood.

Similarly, those working and living near odorous facilities can very easily develop a long-term tolerance to an odour. Which basically means they don’t smell it after a while. Think about when you go on holiday. The plane has a very particular smell to it when you board. But after a while, you get used to it and don’t smell it any more. Thank goodness.

People also get fed up with repeatedly complaining, especially if they don’t think it’s going to make a difference. It’s called ‘complaint fatigue’.

Or it could be that while an odour is annoying, it’s not that annoying. And if you know it won’t last long, why waste time and energy on it?

Suddenly that 250 negative contact points per complaint doesn’t seem too far-fetched.

However, if we go back to this year’s sudden increase in odour complaints, you’ll see these factors may be superseded. Suddenly there are far fewer options to keep us occupied, with many of us spending long periods at home and in our gardens. So, people have plenty of time on their hands and increased access to odour issues. A perfect storm for potential complaints.


Odour complaints are incredibly subjective, so of course there are factors to consider. A single report may be well meaning and accurate. However, the complainant could be mistaken about the date, time or source of an odour. On the other hand, a complaint could be malicious or part of an ongoing personal campaign. We tend to see this where a complainant has an ongoing issue with the operator.

To validate the extent of an odour issue, complainants may be asked to maintain odour logs. The Environment Agency has developed an Odour Complaint Report Form (which you can find in their H4 Odour Guidance Document). It’s designed to capture a range of factors which help qualify the accuracy of a complaint. This helps to identify incident patterns, process behaviour and daily patterns. The Environment Agency Officer will use it to build a picture of what’s actually going on at a site. They should also conduct site visits, or field monitoring.

Of course this requires a good awareness of the way odour disperses, as a single ‘sniff’ may give a vastly skewed picture of an odour emission. Often, analytical techniques and modelling such as dispersion modelling are more effective to get a full picture.


Data from odour sampling surveys is extremely useful when developing your odour management plan

Sniff surveys are a useful tool

You may also find it worthwhile to conduct your own odour measurement and impact analysis activities. This could include a sniff survey or an odour sampling survey. The data output of these kinds of analysis can be critical. Firstly, for improving your odour management plan. And secondly in court cases, to demonstrate an effective response to odour complaints.


There’s no immediate need to panic if you receive a few odour complaints. They do not substantiate a permit breach. Importantly though, they do provide evidence of patterns of odour emissions. The regulator can use this to support their investigation which may achieve substantiation of a permit breach. Complaints can also corroborate evidence of known failures and demonstrate the extent of impact on the local community, when an operator fails to control its process. Patterns of failure and response can be very influential in court cases involving odour complaints.

Having said that, it’s also true that odour complaints can be very powerful for operators. How? They give you an opportunity to demonstrate your commitment to responding to (and addressing) odour management problems. The best way to do this is with a robust and effective odour management plan.


An odour management plan is a detailed document which outlines how you manage odours on your site(s). It should form the basis of daily best practises for your employees and be consulted regularly. The plan will give instructions about how to effectively assess, mitigate and manage odour emissions. It should also include a complaints management procedure, outlining what to do when you receive a complaint.

Examples of potential odour sources, which should be considered as part of an odour management plan

These are some examples of potential odour sources, which should be considered as part of an odour management plan

When you put together your odour management plan, you should think about who or what ‘receptors’ are near to your site (for example schools, business, homes) and how your emissions may impact them. You should also look at each of your processes and take action to minimise their odour output. Your plan should also include a robust system for ongoing monitoring. This allows you to check the performance of your processes and address any issues before they become problematic.


First of all, don’t worry! It’s not unusual for an odour management plan to need a bit of tweaking (or creating). The good news is that if your working life is currently a bit quieter due to Covid-19 restrictions, now’s a great time to tackle it. There are lots of resources available to help you. To get you started, here’s what’s available from the Environment Agency and the IAQM.

What’s more, our team at Silsoe Odours have plenty of experience and would be happy to talk through your odour queries. Please do feel free to give us a call on 01525 860222.


Environment Agency
Additional guidance for H4 Odour Management – how to comply with your environmental permit

Institute of Air Quality Management (IAQM)
Guidance on the assessment of odour for planning

Odour Study Day
Would you like to know more about odour complaints, and the implications for your odour management plan? Join us at the CPD-certified Odour Study Day training course.
Book early to avoid disappointment, as places fill up fast.

Updated 28th July 2020
Ref: Professor Phil Longhurst, Cranfield University

5 Responses

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  3. […] to grow faster and smells to travel further. Many of our customers experience higher levels of odour complaints, despite no change in odour sources. Not only that, but odours also get more attention over the […]

  4. […] could potentially have an odour impact on the local community. Ultimately this is likely to lead to odour complaints for the operator, as well as possible contravention of their operating […]

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