Odour, dust and air pollution

Types of air pollution

Common pollutants that cause complaints

• Agricultural: Cattle farm, Manure Heap, Muck spreading, Grassy
• Roads and vehicle: Tarmac laying, Car fumes, Lorry Fumes
• Chemical: Paint Fumes, Thinners, Disinfectant, Bleach, Ammonium, Adhesives/Glue, Strong soap
• Waste: Mouldy, Musky, Sewage Works, Blocked Drain
• Smoking
• Combustion: Smokey Bonfire, Burning Rubber, Burning Plastics
• Food: Smell of rancid, rotten and stale foods, spicy foods, Off fat, Frying smells, Burnt fat / Oil, Fish oil, Sickly sweet, Fruity

What is air pollution with regards to statutory nuisance

What constitutes a statutory nuisance – how is it decided?

Air pollution as a statutory nuisance is generally defined as material interference with use and enjoyment of premises.  For example, the word "enjoyment" may mean exercising your rights over your land. 

The requirements for consideration of statutory nuisance is that it must be an unreasonable or intolerable intrusion, it must be exceptional, it must be incongruous or out of character.  It normally affects comfort and convenience.  It is normally an on-going set of circumstances and not a transient and/or trivial occurrence.

If the local authority considers the odour or other air pollution to be a statutory nuisance then an abatement notice can be issued to the person responsible.

MAS provide assistance on statutory nuisance to local authorities, residents and producers of emissions.  For more information see our page Investigating a statutory nuisance

Does this include impact on use and enjoyment of commercial premises

Personal comfort is just one element of nuisance.  If the local authority is satisfied that the impact from the air pollution affects trading, for example if customers complain, or if the impact is causing staff difficulties, for example complaints from staff, threat of leaving or difficultly in recruiting new staff, then there can be considered a material impact on the owner.

If the effects are real and there is clear impact with evidence of it then it could be a considered a nuisance and action can be taken by the local authority.  The test for nuisance is not the same as for residential premises in terms of the actual impact but commercial to commercial is not excluded from the regulations over air pollution. 

Meteorological effects on air pollution

After sunset and before sunrise stable atmospheric and inversion conditions are common, occurring up to about 40% of the night time.  Stratification of the atmospheric boundary layer occurs under these conditions trapping emissions close to the ground increasing concentrations and the risks of adverse impact.  If there are night time operations this risk can be substantial.

Masking odour as a form of mitigation

Our olfactory ability (sense of smell) can separate the odour of putrescent food, mould and a range of other volatile chemicals emitted from waste.  Any masking agent is merely an added odour which combines to give what in sound we would describe as a cacophony of noise. 

One problem is that perception of an odour may change from pleasant to unpleasant with increasing concentration, intensity, time, frequency and previous experience with the specific odour.  The extent of masking odorant necessary to ensure some masking occurs can equally lead to serious adverse impact from the artificially induced masking compound which becomes unpleasant due to its frequency, intensity and artificial nature.  The masking agent is usually instantly recognised as an atypical / artificial smell as it is not something normally experienced from place to place. 

The consequence is that masking odorants can commonly exacerbate the effects rather than reduce them not least by reminding the sufferer of what is normally associated with the masking compound; periods of bad odour. 

Odour masking systems are very much a last resort mechanism where the problem is unavoidable, for example in a case of excavation of a landfill site or in the case of contaminated land where short term site remediation is needed.  This is at best a method which can sometimes reduce serious cases of pungent malodour on an ad-hoc basis depending on the meteorological conditions.  It is incapable of addressing the malodour likely from this site, especially on the scale required.  There is a serious risk that the concentration of masking chemicals needed would itself lead to complaints.  

In any event a major problem in this case is the manner in which the volatile chemicals and dust related odorous compounds, such as moulds, disperse.  The inability to match this with the masking compounds or treat the same pockets of air is a major problem.  In summary it is likely this approach will have varying effects, sometimes coinciding with the malodour and producing the "cacophony" effect, sometimes creating its own problem and sometimes leading to intermittent bouts of malodour and artificial scent in succession.  This gives an appearance of action but is either valueless or counter-productive. 

Local topography and its effects of air pollution

One serious problem for sites which emit malodorous air is the effect of the local micro-climate which leads to the trapping of affected air near the ground.  In this case the nearby body of water and open ground to the south of the site leads to an area of localised cooler air and higher humidity.  This is known to exacerbate problems and is likely to create a micro-climate with malodour laden air brought back to ground level.  This requires thorough investigation. 

Odour management proposal example

An example of a site with common odour problems is a waste recycling facility. Adverse effects are widely recognised to occur when operated without well designed odour control plant for this type of facility. 

For a waste recycling centre situated inside a building next to odour sensitive dwellings, it would be necessary to ensure well sealed building envelopes to prevent fugitive odour emissions and apply a negative pressure environment through extraction.  The extracted air then needs either treating or high-level dispersal.  Even where a building has low air leakage a substantial rate of extraction is required.  Where doors are opened for entry by vehicles, greater air extract rates are required to ensure fugitive emissions are minimised.