Bad smells from industry, farming and treatment processes can be a real nuisance, significantly affecting people’s lives and wellbeing.

Unpleasant, strong, long-lasting odours (smells) can become a problem if activities like industry, open landfills, wastewater treatment plants and rendering plants are not appropriately managed, particularly for people living nearby.

Complaints about odour emissions are one of the most frequent environmental pollution incidents reported to regulatory authorities. Approximately 11% of the complaints and incidents we received in the 2022-23 year were about odour.

Sources of odour in Otago could include:

• intensive indoor farming such as piggery and poultry farms
• stockpiles of organic waste on farmland
• agrichemical spray operations
• pulp and paper manufacturers
• commercial food processing and preparation
• meatworks and rendering plants
• commercial composting operations and landfills
• crematoriums
• wastewater treatment plants, pump stations and spray irrigation of effluent
• domestic sources, such as chimney smoke, outdoor burning, composting and house painting

Odours are caused by mixtures of chemicals that stimulate our sense of smell. Humans are very sensitive to a wide range of chemicals, and everyone reacts to odours differently. For example, someone who lives and works rurally may not be affected by silage smells while cityfolk may find them offensive. Some odours, like the smell of freshly mown grass, are pleasant while others are highly offensive.

An individual’s reaction can depend on the odour’s:

• frequency – how often it occurs
• duration and the time of exposure – for example, some odours may only occur during standard work hours, while others are more constant
• character and intensity
• location – for example, rural, industrial or public area

Sensitivity to odour can also vary depending on a person’s:

• age
• perception/view of the emitter
• mental state
• other compounding issues (such as stress at work or home)
• general state of health and wellbeing

Some odours are not culturally acceptable – for example, odours from a crematorium or wastewater treatment plant.

People can become de-sensitised to a smell over time and no longer find it offensive. For example, people who have grown up in a town where a particular industry is the main employer may generally accept those odour emissions as part of life.

The Regional Plan: Air for Otago (the Air Plan) helps us manage Otago’s air resource. It has policies and methods (which include rules) to address air quality issues in Otago.

If you’re concerned about an odour, we encourage you to talk with the organisation, business or homeowner who is responsible for it. Most people are reasonable and willing to discuss the problem, and we find that most situations can be resolved this way.

You can report nuisance odour to our 24/7 pollution hotline on 800 800 033, or email pollution@orc.govt.nz.  

It’s helpful if you can answer these questions:

• What does it smell like?
• How is it affecting you and making you feel? (coughing, feeling nauseous)
• What are the weather conditions? (calm, westerly wind, hot or cold)
• On a scale of 1-10, how intense is the odour?
• Is this still happening?
• How long did the odour last?
• Is the odour one-off, intermittent (coming and going) or continuous?

If you can’t agree on a solution with those causing the odour, our staff will assess the problem with a site investigation that involves a FIDOL survey to measure the odours:

• Frequency
• Intensity
• Duration
• Offensiveness/character
• Location

We also consider any previous, confirmed, odour complaints about the same site.

Our assessment is based on the Good Practice Guide for Assessing and Managing Odour, which you can find on the Ministry for the Environment's website.