Minerals Local Plan.

4 Resource Considerations.

4.1 The proper management and conservation of resources is central to the County Council's aim of achieving sustainable development and protecting the environment.  In relation to the Minerals Local Plan this has implications in terms of ensuring a sufficient supply of minerals while at the same time avoiding the wasteful use of resources or the sterilisation of potentially valuable reserves. This will ensure that, even if all reserves allocated in this Plan are extracted, future generations will be able to meet their need for minerals.  The policies in relation to resource management are derived from the objectives set out in paragraphs 3.10 and 3.12.

The Extent of Resources.

4.2 The extent of resources in the County (excluding potential sources of recycled materials) is defined by its geology, and this has given rise to the range of mineral resources that are potentially available.  In terms of solid geology County Durham consists principally of a succession from west to east of Carboniferous and Permian rocks, with the Permian giving way to Triassic rocks in the south-east of the County; all the strata dip gently towards the east.  The Great Whin Sill, an igneous complex consisting of a number of sills and associated dykes, underlies much of the County but is best exposed in Upper Teesdale and to a lesser extent in Weardale. The Whin Sill has been extensively quarried for crushed road aggregate. The basic geology of the County is illustrated by Picture 4.1 ‘Geology of County Durham’

4.3 The rocks of Carboniferous age may be divided into three main lithological groups - the Carboniferous Limestone series, the Millstone Grit, and the Coal Measures.

4.4 The Carboniferous Limestone series is represented by alternations of sandstone, shale and relatively thin limestone bands, which crop out in the upper reaches of West Durham.  The Carboniferous sequence plays host to an ore field consisting of numerous mineral infilled fractures and although it is mainly developed in the Carboniferous limestone and Millstone Grit to the west of the County, in places it extends to the coal measures in the east. The orefield consists of two distinct zones, with an inner zone centred on Weardale dominated by fluorspar, and an outer zone in which barytes is the dominant mineral. Lead ore occurs and has been exploited throughout the ore field, but the richest deposits occur within the outer fringes of the fluorspar zone. This ore field is unique in that it carries economic deposits of the rare mineral witherite.

4.5 Although generally eroded away in the upper reaches of west Durham, the Millstone Grit increasingly forms the fells and ridges between the main Dales to the east of a line between Blanchland and Middleton in Teesdale.  The Millstone Grit series is represented by three groups of sandstone beds separated by shales, with a few thin coal seams.

4.6 The succession eastwards continues with the Millstone Grit being overlain by the Coal Measures, the division broadly corresponding with the easterly extent of the open moorland of west Durham.  The Coal Measures extend to the east of the Wear Valley, where they are overlain by Permian rocks.  Southwards the strata are thrown into strong undulations beyond the Butterknowle Fault and end in a sharp uprise beneath the Magnesian Limestone.  These boundaries to the east and south mark the extent of the 'exposed' part of the Durham coalfield; the concealed part of the field extends beneath the Permian strata eastwards across the County and continues beneath the North Sea.  The Coal Measures consist essentially of beds of sandstone and shales with numerous coal seams of varying thickness.  Ironstone and fireclay are sometimes found in conjunction with the coal seams.  Over the lowlands of the Wear valley and its tributaries the Coal Measures are covered by glacial drift deposits which gives rise, from time to time, to deposits of sand and gravel and brick clay.

4.7 The eastern edge of the Wear lowlands is marked by the outcrop of Permian rocks in the form of a bold escarpment running in a north - south direction between Pittington and Ferryhill and then turning south-westwards, with the outcrop gradually disappearing to the south of Shildon.  The base of the Permian is represented by the Basal Yellow Sands which outcrop north of Ferryhill.  Above the Basal Yellow Sands lies a thin bed of marl slate, followed by deposits of magnesian limestone which consists of a variable mixture of the minerals dolomite and calcite.  Where the mineral dolomite is the principal constituent and scarcely any free calcite is present, the deposit is referred to as a dolomite rock.  The occurrence of such deposits of dolomite is mainly confined to the lower beds of the Magnesian Limestone, the outcrop of which within the County is restricted to the lower slopes of the escarpment between Ferryhill and Pittington.  Throughout the remainder of the Magnesian Limestone series the rock ranges through varying degrees of dolomitised limestone to pure limestone.  Eastwards from the escarpment, the Magnesian Limestone is extensively covered by glacial drift deposits, which occasionally give rise to deposits of sand and gravel and brick clay.

4.8 Beds of rock salt and associated deposits of gypsum and anhydrite occur in the Permian strata between Hartlepool and Billingham.  Although the beds of rock salt thin rapidly to the west and are not thought likely to extend into the County, beds of gypsum have been proved south of Darlington.

Maintenance of Landbanks.

4.9 Controlling the supply of minerals is a necessary element in ensuring that resources are properly managed, that valuable reserves are not squandered, and that the cumulative impact of mineral working on the County is minimised. It is also important to ensure that the minerals industry has a sufficient supply of reserves to meet established needs and, where appropriate, to justify investment in new plant and equipment.

4.10 In general terms it is an aim of the Plan to provide for a sufficient stock of permitted reserves (a landbank) to ensure that the County's contribution to the supply of minerals is maintained. This is considered a reasonable method of ensuring continuity of supply and, although the existence of a landbank does not automatically preclude the granting of further planning permissions, landbanks are one criterion which  is used to assess the need for new working to be permitted.

4.11 For sand and gravel Minerals Planning Guidance Note 6 (MPG6) suggests a landbank equivalent to at least  seven years’ production, and this is reflected in the Structure Plan. MPG6 suggests a larger but unspecified landbank for crushed rock aggregate, and the Structure Plan proposes a landbank of at least 10 years. This is also considered appropriate for dimension (building) stone. MPG10 suggests that 15 years is the minimum landbank required for raw materials for the cement industry, and it is considered reasonable that this is extended to other minerals whose primary processing requires substantial investment in kiln equipment.

4.12 The maintenance of landbanks for the Plan period and beyond  will depend not only on the identification of environmentally acceptable sites which do not compromise interests of acknowledged importance,  but also on the availability of consistent, reliable and, where necessary, publicly available information of sufficient detail to enable the County Council to come to a considered judgement on the adequacy of the landbank. While the need for a degree of commercial confidentiality is recognised the industry has a clear responsibility to provide sufficient information to enable the accurate monitoring of landbanks.

Regional Aggregates Apportionment.

4.13 National estimates of the future need for aggregates are made in MPG6, broken down by region. These regional estimates are in turn used to define sub-regional County apportionments, setting out the share of the regional need for aggregates that the County should seek to meet. The sub-regional apportionments are agreed through the Regional Aggregates Working Party (RAWP) for the Northern region. The RAWP has agreed a Countywide apportionment of 51.3 million tonnes for magnesian limestone and 19.9 million tonnes for other crushed rock for the period 1992-2006 (Policy M 2).  Table 4.1 sets out the current position in relation to regional aggregates supply .

4.14 The sand and gravel apportionment for Durham includes an allowance for Cleveland, as only a limited amount of land-won material comes from that County. Current landbanks (1995) within  Durham provide overall for the extraction of 12.1 million tonnes sand and gravel, in excess of the total apportionment figure even after 3 years of the relevant apportionment period. The secession of Darlington from Durham may however require a future re-consideration of the landbank position between County Durham and the Tees Valley Authorities.

Source: RAWP

* based on RAWP apportionment. Using recent sales landbanks are 48.3 years (crushed rock) and 21.7 years (sand and grave
+ includes Tees Valley

Demands on Mineral Resources.

4.15 This section discusses the broad extent of workable deposits, the characteristics and uses of the minerals concerned, and identifies the need for more land for mineral extraction.

Coal

4.16 Within the County the Durham coalfield chiefly covers those areas east of the Pennine uplands, but including some of the Pennine fringe area.  The west of the coalfield, where the seams lie close to the surface or actually outcrop is known as the exposed coalfield.  Further east, the coal measures are overlain by a thick overburden of rock.  The quality of the coal also tends to decline in a west to east direction.  Historically, coalmining in the County has moved generally from west to east as the more accessible, better quality reserves in the west have been worked out.  As in other coalfield areas, the deep mined coal industry has been in decline for several decades.  The decline has been such that in 1993 the two remaining deep mines in County Durham, Easington and Seaham/Vane Tempest ceased production.

4.17 Within the exposed coalfield, which covers approximately 715km² (30% of the County), coal has also been worked by opencast methods.  Over the years, areas affected by opencast coalmining have spread to cover a significant proportion of the exposed coalfield with over 120km² having been worked or had approval for working. National policy states that it is not the role of the planning system to seek to set limits on or targets for opencast coal production.  The landbank approach is therefore not appropriate and a criteria based approach towards future opencast extraction is set out in Policy M 7.

4.18 Coal can also be extracted from the exposed coalfield by drift mines.  Such mines make a relatively small contribution to the supply of coal and the environmental implications are more localised than for opencast mines.  The main issues are the impact of surface development and the potential effects on drainage and of subsidence on nearby developments and on agricultural land.  Any proposals for new drift mines will need to be treated on their merits in the light of relevant policies.

Brickmaking material

4.19 There are essentially three types of material found in the County which can be used in brickmaking.  Shales are found within the coal measures and these are fairly widespread in occurrence.  Fireclay is also found within the coalfield particularly in association with certain seams such as the Brockwell.  Glacial deposits of clay found in the Team Valley are also used.  Deposits of glacial clay occur elsewhere in the County but these are spasmodic and unknown with any precision.  Due to the processes and machinery involved, glacial deposits and those found within the coal measures are not generally interchangeable and brickworks tend to use one or the other material.  Although there are no national guidelines the level of capital investment in brickmaking is such that a 15 year landbank for brickmaking material overall is proposed (Policy M 1).

Fireclay

4.20 Fireclay is produced in association with the extraction of certain coal seams in County Durham (e.g. Brockwell, Busty and Hutton seams) and the quality of these fireclays is recognised nationally by the brickmaking industry.  However, the industry also recognise the proportion of fireclays utilised remains relatively small compared with the considerable quantities liberated by opencast coal mining.  The mismatch between immediate demand and supply has led to wastage, failure to exploit and sterilisation of a valuable mineral resource.  Given the limited potential for further working within the exposed coalfield and in the interests of sustainable development, it is vitally important that operators exploit any fireclay produced and avoid wastage.

Brickclay

4.21 There are two brickworks in the County, at Todhills near Newfield, and at Eldon,  both of which are operated by Ambion Brick.  The Union Brickworks near Birtley lies in Gateshead Borough although the clay working which supplies it is within County Durham.  The supply of materials to the two brickworks comes mainly from “dedicated” sources (permitted reserves adjacent to the brickworks) and are supplemented by supplies from opencast coal sites.

4.22 A need for additional supplies has been identified at Todhills, as part of a co-ordinated programme of working and restoration around the brickworks (and for which a resolution to grant planning permission has now been passed, subject to a satisfactory legal agreement), and at Eldon, but it is unlikely that additional reserves will be needed at Union brickworks.

Magnesian Limestone

4.23 Limestone is a rock composed of the mineral calcite, whose principal chemical constituent is calcium carbonate.  Most limestones contain some magnesium carbonate, and where this becomes significant (between 5 and 15%) the rock is described as magnesian limestone.  Where the proportion is in excess of 15% the rock is commonly known as dolomite.

4.24 The Lower Magnesian Limestone series, which only outcrops extensively along the escarpment between Pittington and Shildon, is the most important part of the Magnesian Limestone succession.

4.25 In October 1995 there were seven quarries working magnesian limestone from the escarpment. Most magnesian limestone is sold as aggregates for use in the roadbuilding and construction industries.  However, a significant proportion  is sold for non aggregate purposes.

4.26 In terms of the supply and demand situation for aggregates there are well established methods through the Regional Aggregates Working Party (RAWP) of assessing the adequacy of permitted reserves (Policy M 2). Current reserves are adequate to meet the  need for magnesian limestone, agreed by the RAWP, providing a landbank equivalent to over 30 years production. In County terms there would therefore appear to be no need to approve additional reserves for aggregate purposes during the Plan period.

4.27 Local circumstances have meant that, for the current round of RAWP apportionments, it has been decided to combine the magnesian limestone requirements from County Durham with that for Tyne and Wear. This combined figure of 59.1 million tonnes is similarly adequately provided for by landbanks in the short term. In the longer term as current landbanks are depleted, there may be a need to reconsider the position within the apportionment area as a whole, given important environmental and sustainability criteria.

4.28 Agricultural lime, which is used to correct the acidity of soil, is produced from quarries on the Magnesian Limestone escarpment.  The material is often the fines which remain after limestone and dolomite has been crushed and screened to meet specifications for aggregate or other markets.  Agricultural lime will continue to be produced from existing quarries and permissions on the Magnesian Limestone escarpment, and there is therefore  no need to permit additional working for this purpose.

4.29 Dolomite which has relatively low levels of impurities is considered to be 'high grade' and suitable for use in the production of magnesia, as a steel flux and as an iron sinter.  Evidence suggests that Thrislington Quarry and the area immediately to the east is the only area in Great Britain which contains dolomite of sufficient quality to be used both in the steel and magnesia industries.  Whitwell Quarry in Derbyshire also contains dolomite suitable for the steel industry.  A process of calcination (burning) is used to produce high grade products from the raw dolomite.  To maintain a landbank of permitted reserves of at least ten years throughout the Plan period additional reserves will need to be permitted at Thrislington Quarry (Policy M56).

4.30 Magnesian limestone of sufficient purity for glassmaking exists on the coast, at Hawthorn Quarry.  The quarry has extensive permitted reserves and is currently dormant, and there is therefore no need to provide for additional reserves in the Plan period.

Carboniferous limestone

4.31 The most commercially important of the limestone beds within the Carboniferous series is the Great Limestone.  It outcrops fairly continuously along the sides of Weardale above Frosterley.  In Teesdale, glacial drift deposits restrict its occurrence to localised pockets around Middleton in Teesdale and to the south of Barnard Castle around Boldron.

4.32 Although similar in some respects to magnesian limestone, Carboniferous limestone often differs in some of its physical qualities. In particular Carboniferous limestone tends to be harder than magnesian limestone, and therefore more suited to particular heavy duty uses, for example in sea defence works.

4.33 Carboniferous limestone aggregate is not dealt with explicitly through the RAWP, but is included as part of the general crushed rock apportionment. Current supplies are however sufficient to meet any particular need for Carboniferous limestone.

4.34 The only currently active quarry working carboniferous limestone for non aggregate purposes is Eastgate in Weardale.  This site is operated by Blue Circle and all of its production goes to cement manufacture at the adjacent works.  MPG10 "Production of raw material for the cement industry" states that mineral planning authorities should normally aim to maintain permitted reserves of at least 15 years.  Where significant new investment (such as a new kiln) is required, the guidance suggests that a landbank equivalent to at least 25 years production should be provided for.  Current reserves are not adequate to maintain a 15 year landbank and therefore additional supplies need to be identifed.

Igneous Rock (Whinstone)

4.35 Igneous rock is exceptionally hard and durable.  These qualities make it an important source of aggregate material for the top wearing course of roads which have to withstand heavy volumes of traffic.  It is also used as a concrete aggregate and in the construction of sea defences.  Igneous rocks are found as intrusions into the Carboniferous Limestone series in the west of the County.  The most important of these is the series of intrusions collectively known as the Whin Sill, from which the term Whinstone is derived.  This outcrops extensively in Upper Teesdale.  There is only one quarry currently producing igneous rock in the County, Force Garth in Teesdale.  Permitted reserves are extensive and there is no need to consider permitting additional reserves for the foreseeable future.

Sandstone

4.36 Sandstones occur within the Millstone Grit series and coal measures and outcrop in several parts of West Durham.  Traditionally, sandstone has been worked for use as building stone (also known as dimension stone) and this remains an important local industry in Teesdale.  More recently, sandstone has been worked increasingly as an aggregate.  Permitted reserves currently provide a landbank equivalent to approximately 86 years production and therefore there is no need to permit additional reserves.  In April 1995 there were nine active sandstone workings in the County.

Sand and Gravel

4.37 Three types of sand and gravel are produced in County Durham: concreting sand and gravel, Basal Permian sand and moulding sands (grits).  Although the RAWP has agreed a total apportionment of 11 million tonnes sand and gravel for the period 1992-2006 each type of material has its own particular characteristics and end uses and is therefore considered separately in terms of the adequacy of existing reserves.

4.38 Concreting sand and gravel is derived from three types of deposit.  River terrace deposits exist along the rivers Wear, Tees, Gaunless and Skerne and are usually the most predictable in terms of occurrence and quality.  Glacial deposits are variable in occurrence and their location is difficult to predict.  Their value as a concrete aggregate can be reduced by the presence of impurities such as coal.  Fluvio-glacial deposits are the material left by the melt waters of glaciers. They give rise to more uniform deposits of sand and gravel than glacial deposits, although the quality is generally not up to that of river terrace deposits, particularly those of the River Tees. In some circumstances concreting sand can also be produced from Basal Permian sands associated with the Magnesian Limestone escarpment, and this currently takes place at Crime Rigg Quarry.

4.39 Basal Permian sands outcrop at the foot of the Magnesian Limestone Escarpment and are often worked in conjunction with the magnesian limestone and dolomite.  These sands constitute a very clean and well graded deposit.  This softer and less angular sand is used for making plaster and mortar and is usually referred to as building sand.  Very fine deposits are used to make asphalt.  

4.40 Grits from the Millstone Grit series produce sand which contains a small proportion of clay which holds the grains in shape.  Such material is known as moulding sand or naturally bonded sand and is used in foundries or for other industrial purposes.  In April 1995 there was only one quarry producing moulding sand in the County, at Weather Hill in Wear Valley.  Output is very small and permitted reserves are likely to be adequate for the Plan period and well beyond. 

4.41 Table 4.2 sets out the position with regard to the adequacy of landbanks for sand and gravel extraction. A surplus of asphalt/building sand exists, but there is a shortfall of some 4 million tonnes of concreting sand and gravel. Although some of this will be provided from Tees Valley  (a relatively small amount at present), and some alternative supplies of coarse and fine aggregate are available from limestone quarries, it is nevertheless appropriate to provide additional areas for sand and gravel extraction over the Plan period (Policy M 6).

 Source: RAWP

Note: figures may not sum due to rounding

* building/asphalting sand

+concreting sand and gravel (also includes 'other sand and gravel' as defined for the purposes of regional aggregates monitoring)

Ganister

4.42 Ganister is a silica rock which is found within the Carboniferous Limestone and Millstone Grit series of west Durham outcropping on the fells above Weardale and within the lower coal measures in a belt running between Knitsley and Butsfield.  It is used in the manufacture of refractory bricks and cements.  For refractory use, the rock must have a minimum silica content of 97%.  In April 1995 there was only one active ganister quarry, at Harthope Head between upper Weardale and upper Teesdale.  Permitted reserves of ganister are such that there is no need to permit new working for the foreseeable future. 

Fluorspar

4.43 Fluorspar consists of fluorite together with variable amounts of associated minerals. Fluorite is composed almost entirely of calcium fluoride and is the only significant source of the element fluorine.  It is used as a flux in the iron and steel industry, in the chemical industry to manufacture hydrofluoric acid and in the aluminium industry to manufacture artificial cryolite, which is used as a flux in the production of primary aluminium.  Fluorspar is a vein mineral and is found within the central zone of the Northern Pennine orefield which is within the Carboniferous Limestone series and extends into the Millstone Grit and coal measures to the east.  The main fluorspar bearing veins are centred around upper Weardale and its tributary, the Rookhope Valley.

4.44 The last active fluorspar mine in the County, Frazers Grove mine in Weardale, closed in 1999.

Barytes

4.45 Barytes (Barium Sulphate) is a vein mineral which occurs on the margins of the North Pennine orefield.  It is used in a number of chemical applications, the nuclear industry, in coal working and in oil and gas well drillings.  The only currently active mine is at Close House, Lunedale, which is in the North Pennines AONB.  Permitted reserves at this mine are limited and additional allocations will be necessary if the mine is to continue working throughout the Plan period.

Oil and Gas

4.46 It is not currently known whether commercially exploitable reserves of oil and gas exist in County Durham.  The Government has, however, issued exploration licences within the County and the Plan will need to make general provision for possible commercial exploitation.

Peat

4.47 Areas of peat bogs exist in parts of the west of the County. These are all blanket bogs, which are commercially unattractive in respect of peat extraction when compared with the raised bogs found elsewhere in the country. It is therefore considered unlikely that there will be any proposals for commercial peat extraction within the County. Were any such proposals to arise however, they would be assessed against the  general policies of this Plan, in the light of Government Guidance contained in MPG13, which seeks to restrict  new extraction to areas "which have already been significantly damaged by recent human activity and are of limited or no current nature conservation or archaeological value."

Conclusions

4.48 There is a need to provide additional resources over the Plan period for extraction of the following minerals:

• concreting sand and gravel;
• high grade dolomite;
• limestone for cement manufacture at Eastgate;
• brickclay for Eldon and Todhills brickworks;
• barytes at Closehouse mine.

A criteria based approach is used to assess proposals for working opencast coal and fireclay (Policy M 7).

In addition the Plan will need to make allowance for the extraction of any oil and gas reserves which may be identified

Resource Conservation.

4.49 The principle of sustainability (see paragraph 3.3) suggests that permission to extract minerals should only be given where they are required to meet an established need. National policy is, however, equivocal on this point, Minerals Planning Guidance Note 1 recognising the need to conserve minerals as far as possible, but also stating that need should not be a requirement of planning proposals unless there are material planning objections which are not outweighed by other benefits. The potentially intrusive nature of mineral extraction is such that, in general, many proposals will raise material planning objections and will therefore require a consideration of need.

4.50 On this basis extraction in excess of established need will only be justified in special circumstances, where it has specific advantages in terms of:

1. the avoidance of significant sterilisation by other development;
2. the provision of aggregates in proximity to specific construction    projects;
3. reclaiming significant areas of derelict land;
4. improving existing planning permissions.

4.51 In order to retain existing employment and to avoid the unnecessary sterilisation of minerals, it may also be desirable to allow extensions to some existing workings even if there is no established need.  Where an existing site is operating satisfactorily an extension may also be less environmentally intrusive than a wholly new proposal.

4.52 However there  may be cases where extensions will not be appropriate.  The scale and extent of quarrying on the Magnesian Limestone Escarpment, together with the large potential reserves allocated in the Plan, make it unnecessary and undesirable to allow further extensions, other than that  allocated in the Plan, in this area (Policy M 54). Extensions to opencast coal or fireclay  sites will be considered under Policy M 7 and Policy M 8.

The Use of Waste and Recycled Materials

4.53 Increased use of recycled materials and material previously consigned to waste as a mineral working deposit will help to reduce the demand on green field sites and conserve resources for the future.  The re-use of material occurs mainly in relation to aggregates and bulk fill.  Recycled construction materials can be used in place of newly won aggregates as fill material and road planings can be recycled.  Extracting material from a mineral working deposit such as a colliery spoil heap can have the added advantage of removing eyesores from the local environment.

4.54 MPG6 sets national objectives for reducing the proportion of aggregates supply from primary land won sources in England, from 83% in 1992 to 68% by 2006. Such objectives are  implicit in the derivation of regional and sub-regional apportionments for aggregates (Policy M 2). It would not therefore be appropriate to define further targets for increased use of secondary or recycled minerals, although the potential for use of such material will be a material consideration in determining the need for new land won mineral extraction (Policy M 6, Policy M 10, Policy M 12, Policy M 22 and Policy M 23).

4.55 In general terms, changes in market prices and specifications in favour of the use of recycled and waste materials will be necessary before any major impact on the demand for newly won minerals, particularly aggregates, can be achieved.  However, it is considered appropriate that the County Council, as both minerals planning authority and a major specifier of construction aggregates, encourages greater use of recycled and waste materials.

4.56 Although not strictly secondary materials there may also be scope for the better use of minerals which are currently discarded as waste or sold for lower grade uses. Examples of this include the potential use of limestone fines, either directly or when blended with fine sand, as a concreting sand and the increased utilisation of high grade limestone resources for high grade end uses through improved processing.

Construction and demolition waste recycling facilities

4.57 The recycling of construction and demolition waste material involves the use of heavy machinery such as crushers and conveyors. The potential impacts are likely to relate to noise and dust emissions and the transport of materials to and from the site. As well as suitable industrial locations opportunities may also exist to locate recycling facilities at active quarries where similar environmental impacts tend already to have been taken into account. In order to reclaim suitable material from the waste stream there is also scope for this type of facility in conjunction with landfilling operations. The need for sites and facilities for all forms of recycling, and the locational criteria to apply, will be considered fully in the Waste Local Plan.

Areas for Extraction.

4.58 One of the main functions of the Plan is to identify potential areas in which mineral extraction may be acceptable.  The different characteristics of different materials, in terms of their need and occurrence, however requires that a number of approaches are taken to the identification of such areas.  The Minerals Local Plan uses the following  approaches:

• for sand and gravel, where there is an overall need for further reserves, broadly based areas of search are defined;
• for major extensions relating to existing sites, a site specific or 'preferred areas' approach is adopted;
• for coal, and associated fireclay extraction, a criteria based approach.

Areas of Search for sand and gravel.

4.59 The method used to define the draft areas of search used the extent of mineral resources as a starting point, these being established through a study of published sources and in consultation with industry.  Areas were then excluded where mineral extraction would cause harm to interests of acknowledged importance.  Land excluded from areas of search through this process include:

• high quality landscapes, as defined nationally and in Structure and local plans;
• the undeveloped coast;
• Sites of Special Scientific Interest (SSSIs);
• Local Nature Reserves;
• sites with potentially adverse access and traffic problems;
• best and most versatile agricultural land;
• historic parks and gardens;
• scheduled ancient monuments;
• ancient semi natural woodland;
• appropriate stand off distances from residential areas.

4.60 Given the broad designation of areas of search it is not appropriate to include detailed environmental considerations in the criteria used to define them.  Assessment of local environmental factors is therefore the subject of separate policies to be applied to specific proposals for mineral working.

4.61 The areas of search will not represent areas where proposals for mineral extraction will automatically be approved.  All proposals will need to be considered in terms of their specific impacts and will need to conform with policies aimed at protecting the environment and quality of life for local people, as well as any area specific advice contained in Section 6.1. Proposals will also be required to meet an established need, except as allowed for in paragraphs 4.49-4.52.

4.62 It is acknowledged that, in the interests of resource conservation, it may in certain circumstances be desirable to allow limited working of land beyond the boundary of an area of search as part of a scheme for the extraction of deposits largely within it.  Where this is the case extraction outside the area of search would only be acceptable where an intending operator could demonstrate in advance that they are able satisfactorily to overcome all the factors that led to the original exclusion of such land.  Proposals with more than 50% of their area outside an area of search should be treated as lying wholly outside for the purposes of the Minerals Local Plan.

4.63 Areas of search for sand and gravel have been defined at 5 locations throughout the County.  They have been defined with the aim of minimising the impact on local communities and the environment whilst providing a reasonable choice of areas to meet needs throughout the Plan period. A more detailed explanation of the background to the definition of the areas of search is contained in the technical working paper.

Opencast Coal and Fireclay.

Opencast coal

4.64 The exposed coalfield within County Durham has seen extensive opencast coal mining activity over the past 50 years. A major issue of concern is the fact that communities and the local environment in some parts of the coalfield have suffered from the cumulative impacts of a succession of sites over many years. Such impacts have been compounded by the unpredictable, transient nature of opencast coal mining and the re-working of previously restored sites. The extent of past working, when combined with other planning constraints across the exposed coalfield, mean  that there is now only limited potential for further acceptable sites to be found.

4.65 The difficulties in finding acceptable sites reflects the particular situation found in County Durham. The general settlement  pattern in the coalfield consists of small, scattered communities that developed around individual collieries. The absence of major areas of open countryside remote from such communities has intensified the difficulties of identifying sites which would not adversely affect them. The pattern of opencasting in Durham, with large numbers of relatively small sites, and re-working of areas has added further to the cumulative impacts on these communities.

4.66 Opencast coal mining on the scale experienced has led to a widespread loss of traditional landscape features and associated wildlife. This has had a significant impact on the area, with the loss of subtle landscapes developed over centuries, which not even sympathetic restoration schemes can recreate adequately. Areas of High Landscape Value (AHLVs) are particularly sensitive to the intrusiveness of opencast working, and the loss of traditional landscape features. Although a few small areas within AHLVs have been worked previously for opencast coal the greater part of them remains undisturbed by such mineral working. The sensitivity of the AHLVs is such that many of them, for example the Derwent Valley, have previously enjoyed protection from all working. The AHLVs therefore represent the main areas of landscape within the exposed coalfield remaining free from the impacts of opencast working. As a result proposals for working within AHLVs will need to pay particular attention to impacts, including piecemeal and cumulative effects, on their special character and quality in accordance with Policy M 23.

4.67 The eastern part of the exposed coalfield contains some areas of high environmental quality, particularly around the City of Durham and along the valley of the River Wear. As a result much of this area is designated as an AHLV. Although opencast coal mining has not been as widespread as in the west of the exposed coal field, large scale quarrying activity on the Magnesian Limestone Escarpment has had significant impacts. The importance of this environment, not only to the immediate surrounding area but as a gateway to the County, further limits the scope for  opencast coal mining in this area.

4.68 About 20% of the exposed coalfield in the County is now within the general extent of the North Durham Green Belt whose main purpose is to keep land permanently open.  Whilst national policy does not exclude mineral extraction in Green Belts, mineral extraction would be subject to compliance with a number of tests.  The general extent of the Green Belt and the test are explained in paragraph 5.4.  The revised MPG 3 “Coal Mining and Colliery Spoil Disposal” strengthens the general guidance in PPG 2 and states that applications to extract coal in the Green Belt should be tested against the highest environmental standards.  It is important that the period of mineral extraction is kept to a minimum to maintain the openness of the Green Belt.  Associated operations, such as the stockpiling of  overburden and minerals, should be subject to similar constraints as these activities can be visually detrimental to the openness of the Green Belt due to their siting, material or design.  Where planning permission is granted to extract coal, stringent conditions should be attached to ensure the site is well operated and restored to the highest standards.

4.69 It is therefore becoming increasingly difficult to find sites in County Durham that can be worked without damaging the environment to an extent that local communities and society in general find unacceptable. However, there may be scope for a continuing modest level of opencast coal extraction within the County. There may be some areas where it is possible to develop proposals which, when considered against the environmental policies of this Plan (including cumulative impact), do not raise significant environmental concerns. Elsewhere there may be instances where the benefits to local communities of a proposal clearly outweigh the adverse impacts that will result from mineral working.

4.70 The nature of modern opencast working involving the movement of large amounts of material makes it a particularly suitable method of addressing contaminated and/or derelict land. Although only limited amounts of derelict land remain within the coalfield, there may be scope to allow opencast extraction as a means of reclaiming such land without the public expense that would otherwise arise. It is also possible that new areas of dereliction may arise during the Plan period which require reclamation. In assessing any such applications it will be important to ensure that the area proposed for opencasting fairly and reasonably relates to the extent and nature of dereliction.

4.71 Similar benefits may arise in allowing opencasting where it would enable the reclamation of contaminated land. The amount of contaminated land within the exposed coalfield area is not currently known. However, since 1997 several opencast schemes have successfully addressed areas of contamination. When assessing whether land is derelict or contaminated close attention will be paid to the formal definitions of such land, as set out in Appendix 3. As with derelict land it will be important to ensure that any area proposed for opencasting fairly and reasonably relates to the extent and nature of contamination.

4.72 The avoidance of unnecessary sterilisation of minerals, wherever possible, will help to reduce pressure on other sources of supply, and will help to ensure that mineral reserves are not, in effect, wasted. Such benefits from prior extraction of coal should be realised, wherever they can be accommodated in an environmentally acceptable manner, provided that the ensuing development is not prejudiced or delayed significantly. Ideally, in order to avoid potential problems of delay, any potential opencasting should be included in an overall programme for the development.

4.73 Extensions to opencast workings, or a series of proposals in the vicinity of particular communities, add to the impacts from sites, and prolong the uncertainty and disruption for those affected. These problems are compounded by the difficulties of achieving the most appropriate restoration for an area in overall terms from a series of fragmented proposals. Given their short life, relative to other kinds of mineral extraction, piecemeal workings of this kind should be avoided, and an outline of any proposed future workings in an area should be included in the original application. In some circumstances, and in consultation with local communities, it may be possible to agree in advance a programme of working sites in an area to achieve their exploitation in an acceptable manner. Where previously unforeseen circumstances, for example unexpected geological faulting, lead to an application for an extension, any such proposal will be considered under Policy M 7.

Fireclay

4.74 Opencast coal seams generally occur in conjunction with other minerals, notably fireclay and brickclay.  In the interests of sustainable development, the efficient use of mineral resources is desirable and it is important that the opportunity to work these other minerals commercially is fully explored and exploited.  The co-ordinated working of mineral deposits can reduce the need to extract minerals elsewhere and prevent the unnecessary sterilisation of valuable mineral resources.

4.75 The brickworks operating in County Durham have particular requirements for fireclay resources which are best provided by local supplies.  Where fireclay is extracted, it is important that priority is given to local brickworks to utilise the resource so that current production and employment levels are maintained.  It is recognised that the local brickworks may not be able to use the fireclay produced (at any given time) for various reasons and it is imperative that fireclay supplies are not wasted.  When this occurs, the resource should be utilised by other brickworks throughout the region and country. 

4.76 In the event that no brickworks can utilise the fireclay resource, every effort should be made to avoid the unnecessary sterilisation of the mineral by the stockpiling or storage of the mineral for future use.  This would accord with the principles of sustainable development.  It is recognised that there is the potential to store or stockpile fireclay both on and off-site, above and below ground, but that each of these options have particular problems. Extensive testing of the characteristics and firing qualities of the fireclay will need to be investigated by the operator prior to any decision on its subsequent storage or stockpile.  This is a matter which will need to be assessed on an individual site basis and would be subject to planning conditions and/or obligations attached to any planning permission.  This balanced strategy should provide fireclay to assist in meeting local, regional and national demand for this mineral.

Drift Mines

4.77 The above approach applies only to coal extracted by opencast methods.  The limited surface impact associated with drift mines means that they should be judged solely in terms of the relevant general policies.  Particular attention will need to be paid when considering proposals for drift mines to the possibility of subsidence, and to the minimisation of waste and the impacts of its disposal (Policy M 36). 

Preferred areas for dolomite, limestone, brickclay and barytes.

4.78 The assessment of resources (paragraphs 4.15-4.48) identified specific needs in relation to a number of existing workings and site specific preferred areas are defined for dolomite, limestone for cement manufacture, brickclay and barytes.

4.79 The submission of a proposal within a preferred area does not guarantee its acceptability. All proposals will need to be considered in terms of their specific impacts and will need to conform with policies aimed at protecting the environment and quality of life for local people as well as the site specific policies and advice contained in Section 6.  Particular attention will be paid to the need for high grade minerals (Policy M 18), especially if the demand from specialist end uses does not meet expectations.

Todhills brickworks.

4.80 In accordance with Policy M 1, the Mineral Planning Authority (MPA) will aim to provide a landbank of 15 years for the brickworks.  Existing reserves of material will allow extraction up to 2014.  Therefore, additional material will be needed beyond 2014 to maintain a 15 year landbank.  If significant new investment (such as a new kiln) is agreed with the MPA, the brickworks should be provided with a landbank of at least 25 years.

4.81 Given that insufficient information exists to identify either a site specific or preferred area for the extraction of brick making materials, an area of search for clay extraction is allocated to the immediate south east of the brickworks, as identified on proposals map Inset 8.  Any working of this area of search will be required to progress in a southerly direction, commencing to the immediate south of the brickworks.

4.82 The area of search does not represent an area where proposals for mineral extraction will automatically be approved.  However, the continued availability of clay and shale over the longer term is desirable in order to encourage continued investment which would assist in securing the long term future of the brickworks.  Proposals for working in the area of search will be considered in terms of their specific impacts and will need to conform with policies dealing with the protection of the environment and the quality of life of local people, as well as any specific advice contained in Section 6.3(b).

4.83 The strategy for Todhills brickworks should set out the approach to working deposits in the area of search and contain objectives and proposals for the mitigation of landscape and visual impacts.  The area of search rises progressively to the southeast and consequently it would become increasingly difficult to screen operations in views from the north. Any proposal for future working must ensure that impacts on the character of the landscape and on surrounding communities are minimised, and this is likely to be best achieved through a co-ordinated programme of screening (including substantial advanced planting), phased working and restoration. The design of screening measures will need to be agreed with the MPA and planned well in advance of any mineral extraction (10 to 20 years) to ensure that advanced planting achieves the necessary scale and visual density to screen operations effectively.

Proposals outside identified areas.

4.84 Paragraphs 4.15-4.48 examine the position in relation to different minerals in County Durham and in many cases conclude that current reserves are adequate to maintain an identified landbank. Where a shortfall has been identified however, the Plan has identified areas of search and preferred areas as potential areas where mineral extraction may be acceptable. In order to give a degree of certainty to residents, and protect sensitive areas, new proposals outside these areas will not be allowed unless they are justified by special circumstances.  These circumstances are set out in Policy M12, and are aimed at permitting extraction only where it is needed and cannot take place within an area of search or preferred area, or where it has specific advantages in terms of the issues outlined in paragraphs 4.49-4.51. The Minerals Local Plan’s approach to need is outlined in paragraphs 4.49-4.50. A specific approach towards opencast coal is set out in Policy M 7, and to quarrying in the Magnesian Limestone Escarpment area in section 6.5.

4.85 Parts of the County have been identified as areas of particular landscape importance (the North Pennines Area of Outstanding Natural Beauty and Areas of High Landscape Value).  Such designated landscape areas will be particularly sensitive to the impact of mineral extraction and therefore require additional protection from mineral working.  If there is a need for working outside preferred areas or areas of search this should, wherever possible, take place outside such designated areas, and this principle is outlined in Policy M 22 and Policy M 23.

Borrow Pits.

4.86 "Borrow Pit" is a term used to describe temporary quarries on, or in the vicinity of, major civil engineering construction sites which are used solely to supply material for this construction project, and which are sometimes used for the disposal of surplus materials.  Their main advantage is in reducing the need to transport minerals, thereby limiting costs and reducing the disturbance on the local road system.

4.87 To be set against their apparent advantages there are, however, a number of other considerations.  The most important of these is the difficulty in obtaining satisfactory working and restoration of small scale, temporary projects often worked by firms with little experience of restoring mineral sites to the high standard now required.  In addition, because borrow pits are tied to one project they are vulnerable to problems relating to technical quality.  Where only low grade material is required, allowing a borrow pit may preclude consideration of the use of suitable waste or recycled materials.  Any advantage gained from reduced traffic on local roads will also be negated where there is a need to import fill in order to restore the site.

4.88 In general terms the Mineral Planning Authority considers the problems relating to borrow pits outweigh their advantages.  Their exploitation therefore needs to be strictly controlled, in line with the following policy.

Safeguarding mineral deposits.

4.89 The finite nature of mineral resources makes it important to safeguard deposits of potential economic significance against sterilisation by other types of development.  The sterilisation of deposits reduces the extent of workable reserves, thereby limiting the range of options for future extraction and possibly leading to increased pressure on sensitive areas.

4.90 The Minerals Local Plan seeks the protection of important mineral deposits through policies aimed at:

1. preventing the sterilisation of significant quantities of mineral deposits which are or may become of economic importance;
2. allowing mineral extraction in advance of other development.

Preventing the sterilisation of mineral deposits.

4.91 As existing resources are used up it becomes increasingly important that the remaining deposits are kept available to meet future needs.  The County Council has defined those areas considered to contain mineral deposits of existing or potential economic importance (other than coal and vein minerals which are protected by arrangements involving the Coal Authority) as Mineral Consultation Areas, together with appropriate safeguarding zones, on the proposals map.  Within these areas district councils are required to consult the County Council on planning applications which could have the effect of sterilising mineral deposits. Where significant quantities of minerals are affected by proposals in a Mineral Consultation Area development may be opposed, although certain kinds of development, such as infill development may be acceptable (see Appendix. B ‘Development in Mineral Consultation Areas.’).

4.92 The situation may arise where a proposed development within a Mineral Consultation Area is acceptable in respect of all other relevant considerations.  In any such instance the main issues to be considered will be:

1. the availability of suitable alternative sites for the development; and
2. the particular importance of the mineral reserves that would be sterilised by development.

4.93 The designation of a Mineral Consultation Area does not give any indication that mineral working will be acceptable.  Their definition is intended solely as a means of protecting finite resources to meet long term needs.  All applications for extraction will be considered against the relevant policies contained elsewhere in this Plan.

Extraction in Advance of Other Approved Development

4.94 Where another type of development is approved on a site containing minerals, opportunities may exist to avoid sterilisation by their prior extraction.  Care will, however, be needed to ensure that any additional disturbance caused by extraction is kept to an acceptable level.

Information about mineral resources.

4.95 Although the basic geology of the County is established, mineral exploration will be necessary in order to refine knowledge about the extent of deposits, and in proving potential reserves.  Most exploration is of relatively short duration and has a limited environmental impact, and some of it is permitted development.  Where planning permission is required applications will be considered on the effects of the exploration activity itself, rather than on the possible merits of any future proposal to exploit the mineral.  Similar considerations will be taken into account by the County Council when responding to consultations on proposals where planning permission may be granted under the terms of the General Development Order.

4.96 Mineral exploration may also have an adverse impact on the agricultural management of the land concerned. Suitable conditions may therefore need to be imposed on any planning consent to ensure that the works are carried out in a manner which protects the agricultural quality of the land and associated features.

4.97 In the interests of resource protection and minimising the effect on local communities it is important that, where this does not have an unacceptable environmental impact, reserves are worked comprehensively.  In order to achieve this information on the extent of mineral deposits beyond the site of any individual proposal will be required in order to ensure that piecemeal working of deposits does not take place.

The efficient use of minerals.

4.98 Mineral resources are finite and it is important to make the best use of them so that current needs can be met without jeopardising the ability of future generations to meet theirs.  This involves not only reducing the need for newly won minerals (Policy M 4 - Policy M 5) but also ensuring that mineral working takes place as efficiently as possible and that scarce resources are not used when alternatives exist.

The Conservation of High Grade Mineral Resources

4.99 Some industrial processes require high grade minerals in terms of their quality or purity such as dolomite from the magnesian limestone escarpment, some of which is suitable for use in the chemical, metallurgical and glass industries (see also section 6.5). Although mineral deposits will usually comprise material of varying qualities, it is important that these scarce resources are not used for more general purposes, such as construction aggregates, when lower grade alternatives are readily available. The Mineral Planning Authority, through the use of conditions and/or agreements shall seek to ensure that these resources are  worked in the most efficient manner possible so that proper use can be made of their special qualities and that they remain available for the future. Although this approach primarily relates to dolomite at present, industrial specifications may change and other minerals may be considered as high grade during the Plan period.

The Concurrent Working of Minerals

4.100 When two or more minerals are found together in the same site it is often beneficial in economic and environmental terms for the minerals to be worked together.  Examples in Durham are brickmaking materials which are often found in conjunction with coal suitable for opencasting and permian sand which can often be extracted from magnesian limestone quarries.  Where minerals are worked together, the need for the potentially damaging working of green field sites can be reduced and wasteful restoration and the sterilisation of reserves can be avoided.

Oil and gas.

4.101 Were commercially exploitable supplies of oil and gas to be found in County Durham then the nature of their occurrence and extraction mean that the areas of search or preferred area approach will not be appropriate.  Separate policies are therefore required to deal with the possible development of any reserves of oil or gas.

4.102 There are three stages involved in the exploitation of oil and gas deposits.  The exploration stage to locate deposits, the appraisal stage to determine the extent of deposits and the production stage.  Each stage requires a separate licence issued by the Government in addition to any necessary planning permission.  Exploration licences covering parts of Durham have been issued but as yet no production has been proposed.

4.103 Any proposed exploration for oil and gas will be considered under the general policy on mineral exploration.  In the case of appraisal and production it is important to prevent the piecemeal development of deposits in order to avoid the unnecessary proliferation of the industrial structures associated with such activity.

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