Dust
Dust created through the process of aggregate recycling can have a significant impact on the environment.
Environmental Protection Act 1990
Dust, smoke, fumes, odours and deposits constitute statutory nuisance under Section 79 of the Environmental Protection Act 1990. Part I of the Act prescribes certain substances and processes for control and authorisation for continued operation by the Environment Agency or local authority – the latter being the enforcing authority for operations involving minerals and waste.
Operators have to demonstrate the use of best available techniques not entailing excessive cost (BATNEEC) before an authorisation to operate is granted. Part III of the Act deals with the statutory nuisances from dust etc. from premises. If it is satisfied that a statutory nuisance does exist, it is section 79 and 80 of the Act that deal with the duties of the local authority and the mechanism for serving an abatement notice. However, the local authority cannot go ahead with nuisance proceedings without the consent of the Secretary of State, if an authorisation for the operation has been granted under Part I of the Act.
Planning Conditions
Appropriate planning conditions can ensure the prevention of dust at source using the principles of entrainment, enclosure, water suppression and good house-keeping. Quantitative dust limits are rarely set as planning conditions. Waste Management licences will normally provide conditions requiring the sheeting of loaded vehicles where applicable, but are constrained in what can be required outside the licensed area.
Guidance on the interaction between control of dust imposed by planning conditions and by statutory nuisance legislation is given in the Minerals Policy Statement 2: Controlling and mitigating the environmental effects of mineral extraction in England (March 2005).
For more information, please consult the Planning Module and the Waste Management Regulations Module.
PM10 are the very small particles of dust that can reach deep into the lungs. The Quality of Urban Air Review Group (QUARG) in their 3rd report (1996) found the following levels of PM10 in the environment attributed to certain activities:
- 2% construction
- 11% mining and quarrying
- 26% road transport
- Not a significant source - plant use in processing recycled and secondary aggregates.
Dust Source Types
Dust sources associated with mineral, waste and construction type activities fall into two types:
- Stationary - Material crushing, screening and segregation plant and conveyor transfer of material, large stockpiles/spoil heaps with no containment where the surface is vulnerable to wind erosion.
- Mobile - Vehicles travelling over unmade surfaces, particularly at high speeds, cause particles to be elevated with the finer particles capable of being carried long distances beyond site boundaries. Transportation and handling of material using loaders, excavators, and lorries can produce dust through spillage and wind erosion.
The following help eliminate wind entrainment of dust and therefore stop the dust becoming airborne at source.
- Buildings - Crushers and screeners operating inside would need specialist dust collection and filtration equipment for the working environment and to reduce dust escaping, through material access and exit from the building.
- Temporary enclosures - Constructed using sheet material such as plywood on scaffolding.
- Localised enclosures - Can be fabricated to fit around specific dust sources on site.
- Bays or bunkers - Help to contain granular material.
- Water suppression - Fine water spray heads directed into a dust cloud help mitigate dust concentrations and the effectiveness of this can be further improved by adding a chemical wetting agent to the water.
- Minimise drop height of material - Free falling fine material can be taken by the wind and larger material can fragment on compaction, therefore discharge of the material from chutes should be as close as possible to the stockpile.
