| AAL |
| See Area of Attractive Landscape. |
| Abrasion |
| One of the two main grinding methods (definition: the process of scraping or wearing down by friction, usually between rigid surfaces moving in opposing directions). |
| Abstraction |
| This is the planned removal of water from a surface or underground water source (river, aquifer etc), usually under licence from the Environment Agency for a specific volume per unit time. |
| Acceleration |
| The rate of change of velocity measured in metres/second/second (m/s2) in metric. Acceleration can be measured using accelerometers which give an electrical charge proportional to the acceleration of the body. However, these are expensive and are subject to effects of wind and temperature etc. and so are not really suitable for frequent external monitoring in poor conditions. |
| Acceptable Levels |
| This is a contentious phrase, as what is acceptable to one person or community, may not be acceptable to another. It is usually taken to be the level of impact which lies below any limits defined in recognised guidelines or standards. |
| Acoustic Response |
| The noise which is generated by objects moving when being shaken, e.g. windows rattling and glasses knocking together. |
| ADAS |
| Established as the State Advisory Service in 1946 and subsequently becoming the National Agricultural Advisory Service, the ADAS name first appeared in 1971 and it became a private company in 1997. www.adas.co.uk |
| Aftercare |
| Planting, fertilising, watering, draining or otherwise treating the land for a specific end use. |
| Aggregate |
| Crushed rock, or sand and gravel, used in civil engineering work in a bound (as concrete) or unbound condition. They are classified into three categories; primary aggregate is extracted from naturally-occurring mineral deposits, secondary aggregate is a by-product from other quarrying operations (e.g. slate waste or colliery spoil) or industrial processes (e.g blast furnace slag) and recycled aggregate is derived from various sources (e.g. construction and demolition waste, road planings etc.) |
| Aggregate Levy |
| The Aggregate Levy was introduced in April 2002 at a rate of 1.60/tonne of primary aggregate produced. It is intended to address the environmental costs associated with quarrying operations and to encourage the use to recycled and secondary aggregates. |
| AGLV |
| See Area of Great Landscape Value. |
| Air classification |
| This is the process of approximate sizing of dry mixtures of particles using air currents. It complements the use of screens and sieves for coarser particles and usually applies to particles with grain size below 10 mesh (Tyler) size or 1.68mm. |
| Air classifiers |
| Machines for the approximate sizing of dry mixtures of particles using air currents. They complement the use of screens and sieves for coarser particles and usually applies to particles with grain size below 10 mesh (Tyler) size or 1.68mm. |
| Ambient Dust |
| The existing level of dust in the air in the surroundings. |
| Ambient Noise |
| The existing noise levels before an operation starts. Can be considered the background noise. |
| Ameliorate |
| To reorganise and improve. |
| Amenity |
| This is defined as the quality of being pleasant or agreeable and in this context usually refers to a facility which offers benefits to the local community. |
| ANFO |
| Bulk explosive comprising a mixture of Ammonium Nitrate prills and Fuel Oil. Can be mixed by hand or by bulk mixer. |
| Angle of nip |
| The angle formed between the fixed and moving crushing surface at which point the material will be pinched, typically applies to jaw, cone and roll crushers, this angle varies with machine size and material lump size. |
| Anthropogenic |
| Of or relating to the study of the origins and development of human beings
|
| Anvils |
| Replaceable metal impact plates or bars in an impact crusher, also known as breaker plates. |
| AONB |
| See Area of Outstanding Natural Beauty. |
| Appraisal |
| A rapid reconnaissance of a site and records to establish whether a mineral extraction or other development proposal has known or potential archaeological potential requiring further investigation. |
| Aquiclude |
| Rocks which have a very Iow permeability and are capable of acting as a barrier to groundwater flow.
|
| Aquifer |
| An aquifer is a water-saturated bed of rock, through which water can flow easily and which contains sufficient water to be used for water supply.
|
| Aquitards |
| Rocks and soils which have a Iow, but not insignificant, permeability.
|
| Archaeological Contractor |
| Archaeological organisation commissioned to carry out archaeological assessments, evaluations, excavations and other required mitigation works. |
| Archaeological Curator |
| A person or organisation with a statutory responsibility for the management and conservation of archaeological sites and archaeological evidence generally for a specific area. It includes County and District Archaeological Officers within a Sites and Monuments Record Office, National Parks Archaeologists and national bodies such as English Heritage, Cadw, Historic Scotland and the Department of Environment (Northern Ireland). |
| Area of Attractive Landscape (AAL) |
| These Areas of Attractive Landscape are of significant county-wide value and are large enough to warrant identification at the countywide scale. They have a special quality which is characteristic of the attractive landscape of the county. |
| Area of Great Landscape Value (AGLV) |
| Area of Great Landscape Value is the oldest scenic designation dating back to 1962, but the AGLV is only one of the many landscape or scenic designations identified by planning authorities in their development plans. |
| Area of Outstanding Natural Beauty (AONB) |
| Areas of Outstanding Natural Beauty are areas of precious landscape whose distinctive character and natural beauty are so outstanding that it is in the nationals interest to safeguard them. Their care has been entrusted to the local authorities, organisations, community groups and the individuals who live and work within them or who value them. The Countryside and Rights of Way Act, 2000 added further regulation and protection, ensuring the future of AONBs as important national resources.
National Association for Areas of Outstanding Natural Beauty |
| Areas of Search |
| Broader areas of land where mineral resources may be more uncertain, but permission could be granted to meet a shortfall. |
| Aspect |
| When relating to a slope, this refers to the direction the slope is facing. |
| Asphalt |
| A natural or artificial mixture of bitumen with aggregate for road surfacing and other applications. |
| Attenuation |
| Term used to describe the decrease in noise level. It is the opposite of amplification. |
| Attrition |
| One of the two main grinding methods (definition: the process of wearing down by friction, usually by particle-particle interaction). |
| Autogenous crushing |
| Crushing or milling which is achieved purely by the interaction between particles of the feed material. Semi-autogenous crushing is where comminution is partly achieved by autogenous crushing. |