COMPARATIVE IMPACT ASSESSMENT OF LAND AND MARINE SAND & GRAVEL

 

Contract Number: 059/2001

 

 

 

 

 

Final Report

 

 

May 2002

 

 

 

 

 

Thompson, A., Knapman, D. and Pethick, J.

 

Symonds Group Limited

 


Main Office:

Symonds House

Wood Street

East Grinstead

West Sussex

RH19 1UU

South Wales Office:

St Hilary Court

Culverhouse Cross

Cardiff

 
CF5 6ES



(This page is intentionally blank)


CONTENTS

 

1.    Executive Summary                                                                                        1

Scope and Method                                                                                                       1

Conclusions                                                                                                                2

Recommendations                                                                                                       3

2.    The Background to This Study                                                               6

The Key Issues                                                                                                           6

The Policy and Planning Background                                                                            7

Previous Technical Studies which led to this Report                                                        8

The Scope of this Study                                                                                               9

3.    The Main Reasons for Considering Alternatives                         12

Coastal Change                                                                                                         12

Sustainability                                                                                                             12

4.    The Methodology for This Study                                                        16

Introductory Comments                                                                                              16

Identifying Alternative Patterns of Supply                                                                     16

Selecting and Assessing Representative Sources and Sites                                          17

Comparing the Relative Sustainability of Alternative Patterns of Supply                          19

5.    The Current Pattern of Supply and Demand                                 20

Sand Dredged from the Bristol Channel                                                                        20

Aggregate Quarried within South East Wales                                                                23

Aggregate Imported from outside South East Wales                                                     24

Secondary and Recycled Materials                                                                              24

Demand for Aggregate in South East Wales                                                                 26

Summary of the Current Pattern of Supply and Demand                                                27

6.    Potential Alternative Patterns of Supply and Demand           32

Alternative Sources of Aggregate not Currently Exploited                                               32

Three Potential Alternative Patterns of Supply                                                              38

The Differences between the Current and Alternative Patterns of Supply                         46

7.    The Selection and Assessment of Representative Sites         48

Choosing a Set of Representative Sites                                                                       48

Assessing the Chosen Sites                                                                                       50

How the Case Studies Contribute to the Patterns of Supply                                           51

8.    The Comparative Sustainability of Alternative Patterns of Supply      54

Description of the Sustainability Assessment Process                                                  54

Pattern of Supply No. 2 Compared to the Current Pattern (No. 1)                                    54

Pattern of Supply No. 3 Compared to the Current Pattern (No. 1)                                    56

Pattern of Supply No. 4 Compared to the Current Pattern (No. 1)                                    58

Conclusions from the Sustainability Assessment Process                                             61

9.    Discussion, Conclusions and Recommendations                         64

Discussion                                                                                                                64

Conclusions                                                                                                              66

Recommendations                                                                                                     67

 

 

 

Appendix 1    Research Specification and Steering Group

Appendix 2    Supply Option Fact Sheets

Appendix 3    Site Assessment Check List

Appendix 4    Sustainability Assessment Model

Appendix 5    Coastal Change Issues

Appendix 6    Energy Issues

Appendix 7    Noise Issues

Appendix 8    Traffic Issues

Appendix 9    12 Case Studies

Appendix 10  Sustainability Assessment, Patterns of Supply No. 2 vs No. 1

Appendix 11  Sustainability Assessment, Patterns of Supply No. 3 vs No. 1

Appendix 12  Sustainability Assessment, Patterns of Supply No. 4 vs No. 1

 

 


1.                Executive Summary

Scope and Method

1.1               This report was commissioned in May 2001 by the National Assembly for Wales (the Assembly)[1]. The report is required as an aid to policy making, and in particular to assist in the difficult choice between continuing to dredge sand from the Bristol Channel or starting to quarry sand and gravel from potential land-based resources.

1.2               It addresses the uncertainties that surround dredging, and specifically the question of whether (and how) dredging sand from offshore sandbanks affects the beaches of South East Wales. Drawing on the findings of a more detailed, new interpretative report by Pethick and Thompson (2002), produced as part of this study, it concludes that, while no significant impacts on the coastline have yet been detected, some dredging, in particular from Nash Bank, may in future have effects on nearby beaches and the wider sediment environment. It therefore recommends that dredging from Nash Bank should be phased out over a period of 5 to 10 years.

1.3               Because of the high quality of the sand which is dredged from the Bristol Channel, replacing it from other sources will be neither easy nor cost-free. The report builds on earlier work undertaken by Symonds to identify potential land-based sand and gravel resources, and compares the overall sustainability (environmental, social and economic) impacts of switching part of the pattern of aggregate supply away from dredging to these and other alternative sources.

1.4               It does this by considering a range of policy scenarios, and the ways in which aggregates suppliers and users might be expected to respond to each one. All practical potential sources of primary, secondary and recycled aggregate are considered.

1.5               The option of stopping current dredging from near to the shore without licensing alternative sources of either dredged or quarried aggregate is assessed as part of this process, but that option is not preferred. The penalties are considered to outweigh the benefits. In particular, the impact of removing so much high quality sand from the market without making alternative provision is felt likely to generate clear and damaging social and economic impacts which do not adequately compensate for the environmental gains, particularly when compared with the alternative approaches. Utilisation of secondary materials (such as china clay sand and crushed rock sand) would be maximised, but at the cost of considerably greater energy consumption (and therefore increased emissions of greenhouse gases). The use of imported materials would also result in the export of some environmental impacts.

1.6               A less drastic approach, of withdrawing all nearshore dredging licences and replacing them with matching licences from further offshore, is also considered. This has the advantage that the disruption to the aggregate market would be reduced (especially if phased in over a period of time). The environmental gains would also be fewer (though not insignificant), and they would be won at the cost of some additional energy consumption.

1.7               An alternative approach, which would also require phasing-in over a period of 5 to 10 years, is also considered. This would involve shifting dredging further offshore, but reducing the overall tonnage that is taken. This would be accompanied by limited exploitation of land-based sand and gravel within South East Wales. It is the timescale for proving individual resources and gaining planning consent for their extraction that would require a considerable phase-in period.

1.8               These various approaches (which are intended to be instructive examples rather than recommended scenarios) are investigated by assessing a broad range of impacts on a balanced group of generally representative sites. Some of these sites are real (i.e. current activities at actual locations), while others are theoretical (e.g. locations where potential land-based resources might be exploited in future).

1.9               The selection of potential sources of supply, and the sites chosen to represent each option, were guided by a project Steering Group[2], whose help and guidance are gratefully acknowledged. Industry members of the Steering Group were actively involved in hosting many of the site visits which were central to the assessment procedure.

1.10            The report reaches the following conclusions:

Conclusions

(i)                   The policy prescriptions within 'Marine Aggregate Dredging Policy, South Wales' (MADP) are generally prudent, even though the evidence contained in this study points towards a slightly different interpretation of some of the facts compared to that which has obtained before.

(ii)                  There is evidence of sediment transport links between offshore sandbanks within some parts of the Bristol Channel and the beaches of South East Wales. The links are generally weak, however, and do not imply that dredging will inevitably have impacts on the beaches. The exception is Nash Bank where it is clear that dredging cannot continue indefinitely without eventually giving rise to localised impacts on the adjoining coast. No such impacts have yet been detected, and none are anticipated in the short to medium term, but it would be prudent to phase out the current operations here over the next 5 to 10 years.

(iii)                The cases of Nash and Helwick Banks are not directly comparable. Of the two, Nash Bank is far less resilient, because of its location in an area of very high rates of potential sediment transport, and relatively small rates of natural replenishment. Helwick Bank, by comparison, is located within an area of much greater sediment availability, where changes can be buffered by the input of sediment from Carmarthen Bay, without adverse effects on the beaches.

(iv)                 Over the last decade, Nash Bank has been losing volume at a rate that is higher than can be accounted for by dredging alone, and at current levels of shrinkage could be eliminated altogether within a period of 90 to 215 years. Long before that point it would cease to function as an effective breakwater, and impacts would then be felt on the adjacent shoreline. Alternatives to Nash, as an important source of high quality fine aggregate, therefore do need to be found.

(v)                  Most of the potential alternatives have very real practical and environmental costs attached to them. Secondary materials like china clay sand and crushed rock sand significantly increase the demand for water and cement in concrete (thereby increasing fossil fuel consumption and emissions of greenhouse gases), and recycled materials generally offer no effective substitute for sand (as opposed to coarse aggregate).

(vi)                 Good quality land-won sand and gravel deposits offer far greater potential in all of these respects, but also have inevitable impacts on landscape, ecology and the water environment (in particular). These, however, could largely be mitigated, through a combination of careful location and implementation of best working practices.

(vii)               Irrespective of environmental considerations, there is no real chance that all of the marine-dredged sand currently landed in South East Wales could be replaced, (even drawing on all realistic alternative sources of supply), without raising the cost and reducing the quality of construction. This would have definite adverse economic consequences for the region, and would not be justified on sustainability grounds. It would also result in environmental impacts being exported.

(viii)              Subject to detailed technical assessments of individual prospects being carried out to prove their quality, it should, however, be possible to replace a proportion of the marine-dredged sand by land-won alternatives. Providing that the associated environmental impacts were adequately mitigated, a partial substitution of marine sand with land-won alternatives would provide a more sustainable pattern of supply than that which exists as present.

(ix)                Overall, however, this study has indicated that the clearest increase in sustainability would be achieved by a gradual shift of dredging operations from inshore areas (particularly Nash Bank) to other areas further offshore and/or further west. This conclusion is subject to the findings of ongoing and future site-specific environmental assessments at the alternative dredging sites. It would be imprudent, therefore, to rule out the future need for land based sand and gravel resources.

(x)                 There is a strong economic case for avoiding precipitate change. Any of the alternative policy scenarios that have been considered could be phased in over a transition period, and clear policy statements of intent, tied to a clear timetable, will encourage more efficient and less disruptive market changes.

Recommendations

1.11            The recommendations that flow from the above conclusions are as follows.

(i)                   Consideration should be given to amending MADP to steer dredging further west along the Bristol Channel and, more specifically, to phase out dredging on Nash Bank over a period of 5 to 10 years. This could be achieved by giving notice that, within a minimum of 5 and a maximum of 10 years, sediment cell CBC1 (which includes Nash Bank) will be re-classified as a Policy 3 area; and that (more immediately) sediment cell IBC2 (which includes Culver Sands) will be re-classified as a Policy 2 area. Further independent research on the geomorphology and sediment dynamics of Culver Bank (not carried out in the present study) might demonstrate that the latter suggestion is unnecessary, but in the absence of such work, a precautionary approach is warranted.

(ii)                  Other things being equal, and subject to appropriate consideration of more detailed and ongoing technical studies, continued dredging on Helwick bank and new dredging proposals for the Nobel Banks area should be viewed favourably unless and until new evidence is found of adverse environmental impacts that can reasonably be linked to these operations.

(iii)                Until such time as it is modified in the light of unequivocal new evidence, the conceptual model developed for this study by Pethick & Thompson (2002) should be used by the Assembly as a context for the evaluation of future dredging applications and for establishing monitoring requirements to be attached to future licenses. These requirements should include full, three-dimensional analysis of bathymetric changes on both licensed areas and adjoining beaches / sand bodies.

(iv)                 As noted in 'Mineral Planning Policy Wales' (MPPW) and stated clearly in the draft 'Aggregates Technical Advice Note' (Aggregates TAN), Mineral Planning Authorities (MPAs) should, as a matter or urgency, safeguard significant areas of potential land-based sand and gravel resources (as identified in the earlier Symonds report) until such time as these are either exploited or proved by detailed investigations to be technically unsuitable.

(v)                  In anticipation of the need for at least some land-won sand and gravel in future years, the Aggregates TAN should provide mineral operators with a positive signal that well-founded applications for extraction within appropriate (generally unconstrained) locations will be given favourable consideration. This could take the form of ‘Provisional Preferred Areas’ as outlined in the earlier Symonds report on land-based extraction.

(vi)                 The Assembly and the South Wales Regional Aggregate Working Party should establish a mechanism for keeping future supply options under review. As well as monitoring the effects of marine dredging, it should monitor the progress of technical investigations of potential land-based and secondary aggregate resources, to determine the extent to which these can be relied upon, if and when required. Depending on the findings of such reviews, future policy options may need to be revised.

(vii)               To the extent that specific applications can be identified for the use of secondary aggregates such as crushed rock sand and china clay sand in place of primary aggregates, without giving rise to greater environmental impacts overall, the Assembly and Local Planning Authorities should look favourably on any proposals to develop facilities for the import of such materials into South East Wales by sea or rail.

(viii)              The South Wales Regional Aggregate Working Party and/or individual MPAs should carry out at least preliminary desk studies to seek to identify any significant stores of foundry sand in South East Wales in order to establish whether such a material offers a realistic alternative to primary aggregate.


(This page is intentionally blank)

 

2.                The Background to This Study

The Key Issues

2.1               Aggregates are crucial to society, contributing essential components to housing, commerce, industry, health and leisure facilities, the transport infrastructure and many other facets of modern life. This Study has been prompted by three main considerations central to the supply of aggregates to South East Wales, namely:

(i)                   the continuing uncertainty that surrounds the long-term effects of dredging for sand in the Bristol Channel, on which South East Wales is highly dependent;

(ii)                  a desire to achieve reasonable long-term security of supply as far as aggregate in South East Wales is concerned, even if that means considering the exploitation of land-based sources; and

(iii)                the importance which the Welsh Assembly Government (the Assembly) places on sustainability right across the spectrum of policy issues.

2.2               For several years South East Wales has relied heavily on the Bristol Channel for its sand, and more heavily on dredged sand than any other part of the UK. Many millions of tonnes of material have been removed, predominantly from sand banks relatively close to the shore. Over recent years local residents and interest groups have become increasingly concerned that changes which they have observed along the shoreline, affecting both beaches and cliffs, might be linked in some way to this dredging activity. This concern has created pressure on the Assembly to review its historic policy of supporting the granting of further licences to dredge. Most of the licences concerned are actually issued by the Crown Estate, which owns the sea bed below the low tide mark. Crown Estate decisions take into account of the Government View, which in this case is the view of the Assembly.

2.3               Set against this pressure to stop dredging is the fact that long-term reliance on marine sand has made it possible for each individual Mineral Planning Authority (MPA) in South East Wales to adopt what is essentially a presumption against land-based sand and gravel extraction. No active sand and gravel pits exist within the region and no policies are currently in place for the safeguarding of potential resources. From the standpoint of the individual MPA this could be justified, because:

(i)                   quarrying creates some adverse impacts on the surrounding population and environment, which are relatively well understood; and

(ii)                  the impacts associated with marine dredging had been adjudged (by others) to be acceptable.

2.4               A peremptory policy shift away from dredging and towards favouring land-based extraction would almost inevitably cause disruption in the market for sand over the short term, while applications to quarry sand and gravel went through the planning system. There are alternative sources of sand-like materials (notably crushed rock sand), but these are primarily suited to lower grade uses, and they are neither unlimited nor free of adverse impacts of their own.

2.5               The Assembly has a general objective of seeking sustainable solutions to policy dilemmas. It therefore seeks to promote a sustainable balance of supply sources for aggregate. It has to do this against a background of considerable uncertainty about what actually happens on the sea bed both with and without the influence of dredging, particularly as regards the long-term movement of sand and other sediments. This means that it is not self evident that accepting the known adverse impacts associated with land-based extraction in place of possible gains from stopping dredging constitutes a good bargain.

2.6               After all, the changes which are affecting the beaches and cliffs of South East Wales might simply be part of a very slow long-term process, or they might be due to rising sea levels and increased storm activity associated with global warming, or a combination of all of these.

2.7               In view of its complexity, and its importance, the issue of coastal change is introduced in Chapter 3 (and dealt with in depth in Appendix 5). Chapter 3 also provides a short overview of how this Study will deal with the complex question of sustainability.

2.8               Before that, a brief review of the policy background is provided, along with other essential background to understanding the methodology, which in turn is outlined in Chapter 4.

The Policy and Planning Background

2.9               The policy and planning background to this Study can be found in a range of documents of national, regional, local and site-specific relevance. These are briefly identified below.

2.10            At a national level, the Assembly issued 'Mineral Planning Policy Wales' (MPPW) in December 2000. This encourages each MPA in Wales to make provision for future land-based sand and gravel extraction within the areas for which they are responsible. Even if resources are not earmarked for development, MPPW encourages MPAs to safeguard known blocks of resources, so that future decisions to exploit them are not ruled out by the land having been 'sterilised' by built development.

2.11            In February 2002 the Assembly took matters a step further by issuing a Consultation Draft Minerals Technical Advice Note (Wales) covering aggregates (the Aggregates TAN). This document sets out detailed advice to MPAs and the aggregates industry on the delivery of the policies established in MPPW. When issued in its final form, the TAN will supersede Minerals Planning Guidance Note 6, which previously applied to both Wales and England.

2.12            At a regional level the Assembly initiated a consultation process by issuing a document entitled 'Marine Aggregate Dredging Policy, South Wales' in May 2001. The consultation period ended in July 2001, and responses are currently being considered. MADP, as the document is widely known, assigns one of four policy positions to all areas of the Bristol Channel in which the Assembly has an interest. This has been done to provide potential applicants for licences to dredge sand and gravel with prior guidance on the approach which the Assembly is likely to take.

2.13            These four policy positions are as follows:

(i)                   Policy 1: the Assembly will look favourably on dredging for marine aggregates in sediment environments where few constraints have been identified (i.e. a positive Government View is likely);

(ii)                  Policy 2: the Assembly will adopt a precautionary approach to policy until research and/or monitoring can reduce uncertainty of the actual or potential effects of marine dredging to acceptable levels (i.e. use dredging conditions to limit duration and tonnage of licence, and review at end of 5-year interim strategy period);

(iii)                Policy 3: the Assembly will not look favourably on dredging for marine aggregates in these sediment environments due to the significance of constraints identified (i.e. a negative Government View is likely);

(iv)                 Policy 4: the Assembly will safeguard marine aggregate resources in these sediment environments from sterilisation by seabed development and other activities at sea for dredging in the future.

2.14            There are 13 MPAs whose areas of responsibility lie wholly within the study area (which is referred to throughout this report as South East Wales). They are (in alphabetical order):

(i)                   Blaenau Gwent County Borough Council;

(ii)                  Brecon Beacons National Park;

(iii)                Bridgend County Borough Council;

(iv)                 Cardiff County Council;

(v)                  City & County of Swansea;

(vi)                 Merthyr Tydfil County Borough Council;

(vii)               Monmouthshire County Council;

(viii)              Neath Port Talbot County Borough Council;

(ix)                Newport County Borough Council;

(x)                 Rhondda-Cynon-Taff County Borough Council;

(xi)                Torfaen County Borough Council;

(xii)              Vale of Glamorgan.

2.15            At the western end of the Brecon Beacons National Park there is a small sliver of land which lies between the park's southern boundary and the northern boundary of Neath Port Talbot County Borough Council. This sliver of land includes small areas of Carmarthenshire and Powys, and is included within the study area for reasons of 'geographical common sense'. There are no quarries within this sliver of land. Figure 2.1 (at the end of this Chapter) shows the study area.

2.16            At the local level, each MPA is responsible for considering local aggregate supply issues. The conclusions of this process should then be included within each Local Authority's Unitary Development Plan (UDP). One of the main policy drivers which led to this study being commissioned was the fact that none of the UDPs in South East Wales includes any provision for the land-based quarrying of sand and gravel, despite the growing pressure on marine dredging in the Bristol Channel. Some of this pressure has come from Local Authorities.

2.17            There are various environmental and planning designations which apply to areas of land and sea, and which constitute material considerations in any application to extract or process aggregate minerals. These designations include:

(i)                   landscape and countryside designations (such as National Parks, Areas of Outstanding Natural Beauty, Green Belt / Green Wedge, Heritage Coast, Recreation Areas, Areas of Special Landscape Value, and Common Land);

(ii)                  ecological and nature conservation designations (such as Special Protection Areas, Special Areas of Conservation (both actual and candidate areas), Ramsar Sites, Sites of Special Scientific Interest, National Nature Reserves, Marine Nature Reserves, Local Nature Reserves, Ancient Woodland, and Regionally Important Geological / Geomorphological Sites);

(iii)                historical designations (such as Scheduled Ancient Monuments; Listed Buildings Grades 1&2, Conservation Areas, Historical Parks Gardens and Landscapes, Archaeologically Sensitive Areas, and Sites of Archaeological Interest);

(iv)                 development planning and transport designations (such as proposed housing development areas, proposed commercial and employment areas, existing urban areas, and proposed transport improvement development areas);

(v)                  inland water-related designations (such as areas liable to flooding, areas within the fluvial floodplain, areas within the tidal floodplain, and areas above major groundwater aquifers).

Previous Technical Studies which led to this Report

2.18            Two technical reports in particular provide essential background to this study and this report. Both were commissioned by the Assembly, and both were completed in 2000. They are generally referred to as:

(i)                   'Bristol Channel Marine Aggregates Study', by ABP Research & Consultancy and Posford Duvivier Environment (referred to hereafter as ‘the BCMA Study’); and

(ii)                  'South Wales Sand & Gravel: Appraisal of Land-Based Extraction in South East Wales' by Symonds Group, (referred to hereafter as 'the Symonds report ').

2.19            The BCMA Study sought to establish the extent of resources of marine sand and (to a lesser extent) gravel in the Bristol Channel, and the impacts which its dredging may be having or might have in future. It divided the Bristol Channel into a series of 'sediment environments', of which 27 are wholly in Welsh waters, and six cross the boundary between England and Wales. These are the geographical units on which the proposals contained in MADP (see above) were based.

2.20            The Symonds report:

(i)                   identified a number of potential, but as yet unproven, resource blocks in South East Wales from which sand and gravel might be extracted in future;

(ii)                  reported on the extent to which these potential resource blocks coincided with environmental and planning designations in place at that time; and

(iii)                considered the general environmental and cost implications of exploiting alternative sources of sand and gravel, including out-of-area resources.

2.21            Other technical reports which are of significance include:

(i)                   Technical Report WF/00/3/C by the British Geological Survey (BGS), which sought to identify potentially suitable outcrops of hard rock for quarrying and crushing;

(ii)                  the Environmental Statement dated March 2000 prepared by EMU Environmental which accompanied the current application to continue dredging sand from Nash Bank;

(iii)                four reports on Nash Bank prepared by HR Wallingford (Study of impacts on the coastline, 1996; Review of survey data, 1999; Application for continued extraction, 1999; Review of survey data, 2000);

(iv)                 a report on Nash Bank by Resource Management Associates (Bathymetric and volume assessment 1997-2000 data, 2001);

(v)                  a report on Helwick Bank dated August 1997 by HR Wallingford;

(vi)                 a report by Coastal Geophysics entitled 'Southeast Swansea Bay: Geophysical survey, spring 1995;

(vii)               the South Wales Regional Aggregates Working Party Annual Report 2000;

(viii)              three reports by Collins et al from 1979, 1987 and 1995 reviewing sediment transport in the Bristol Channel.

2.22            The Environmental Statement and the Coastal Impact Study by HR Wallingford which will in due course accompany the current application to extend dredging sand from Helwick Bank had not been completed by the time this report was written, but will also constitute important documents once they are in the public domain.

The Scope of this Study

2.23            The technical component of the Research Specification issued by the Assembly is included as Appendix 1 to this report. It sets out the aims of the project, the background, the objectives, the general approach to be taken and the geographical scope of the study area.

2.24            The aims are:

(i)                   "to assess the relative environmental, amenity and economic impacts of utilising the various sand and gravel source options available in South East Wales"; and

(ii)                  "to provide robust data on the overall sustainability of various options, to support decision making on minerals policy".

2.25            The objectives are:

(i)                   "to take forward the issues identified in previous research into sand and gravel resources and constraints, regarding the need to formulate a strategy for aggregates provision in South East Wales";

(ii)                  "to thoroughly evaluate the relative environmental, amenity and socio-economic impacts of the various options for sand and gravel supply in South East Wales"; and

(iii)                "to study such options in the field and produce robust and meaningful conclusions which will allow some forecasting and aid in policy development".

2.26            The section on the general approach stresses the need for an approach "… that will involve a structured sample of a carefully selected range of sites, using strict and replicable data gathering and analytical protocols". It goes on to emphasise the importance of identifying "… the relative impacts of utilising potential resource options", and the fact that "… the research design must be aimed at acquiring data that is capable of demonstrating the comparative environmental and social costs or benefits of the resource options available".

2.27            Appendix 1 also lists the members of the Steering Group established by the Assembly to follow the progress of this study, and to provide feed-back on its approach and findings.
 (This page is intentionally blank)

 

3.                The Main Reasons for Considering Alternatives

Coastal Change

3.1               One of the most powerful driving forces for considering alternatives to marine-dredged aggregate is the concern that has been expressed that dredging sand from the seabed might have adverse impacts on the beaches and cliffs of South East Wales.

3.2               Historical topographic and bathymetric data reveal that there has been significant change along the coast of South East Wales: erosion of beaches and cliffs in some areas, and accretion in others. This has been ongoing since long before dredging began, however, and, despite considerable research effort, no specific trend in either the scale or pattern of changes has hitherto been identified that can be attributed, with any justification, to dredging activities.

3.3               Whilst this is true of the coast, it may not be the case for some of the licensed dredging areas themselves. At Nash Bank, for example, repeat bathymetric surveys have revealed significant changes to the overall size and shape of the westernmost part of the bank, as a direct result of dredging. These changes have been superimposed on, and have disrupted, a natural pattern of substantial, systematic morphological changes that has been taking place since long before dredging began.

3.4               The present study has, for the first time, investigated these changes in detail, from a geomorphological perspective, in order to determine their possible implications for future changes on the coastline.

3.5               The findings of the new research on coastal changes carried out in connection with this study are summarised in Appendix 5 and have fed into both the comparative sustainability assessment in Chapter 8, and the overall conclusions and recommendations set out in Chapter 9.

Sustainability

3.6               In recent years the issue of sustainability has also risen up the political and policy agenda. The general agreement on the importance of sustainability is often matched by a lack of agreement on what it means at a practical level. This section seeks to explain how sustainability is being dealt with in this study, starting with what it means.

3.7               To complement the definition of sustainability given in the 'Brundtland Report' (1987) (i.e. "meeting the needs of the present without compromising the ability of future generations to meet their own needs"), the following more recent definition of sustainable development (attributed to 'Forum for the Future', a UK-based sustainable development charity) is helpful.

"Sustainable development is a process which enables all people to realize their potential and improve their quality of life in ways that simultaneously protect and enhance the Earth's life-support systems"

3.8               Sustainable development clearly has a social and an economic component as well as an environmental one, and governments are inclined to give greater weight to the economic and social components than 'pure' environmentalists might. The British Government's vision of sustainable development (see, for example, 'A Strategy for Sustainable Development for the UK', May 1999) is based on balancing and achieving four broad objectives, which are expressed as follows:

(i)                   social progress which recognises the needs of everyone;

(ii)                  effective protection of the environment;

(iii)                prudent use of natural resources; and

(iv)                 maintenance of high and stable levels of economic growth and employment.

3.9               These objectives are described in greater detail in the same publication, and in Ministerial speeches, as follows:

(i)                   social progress encompasses sharing the benefits of prosperity, through a clean, safe environment, and improved health and education;

(ii)                  environmental protection involves ensuring that people's health does not suffer from poor air quality or other pollution, as well as protecting wildlife and the countryside;

(iii)                prudent resource use refers to using resources efficiently and minimising waste;

(iv)                 growth and employment are necessary so that everyone can share in high living standards and greater job opportunities, and to generate the income and wealth needed to pay for essential infrastructure and future investments.

3.10            The Web page http://www.wales.gov.uk/themessustainabledev/recent-e.htm tracks the Assembly's evolving policies and documents dealing with sustainable development, including 'Learning to Live Differently', which sets out the Assembly's general approach to sustainable development.

3.11            The related Web page at http://www.wales.gov.uk/themessustainabledev/index.htm provides an overview which endorses the approach outlined above, and confirms that "… the Assembly in its turn aims to add value to work done at the UK level on sustainability, building on the UK strategy, reflecting the needs of Wales as necessary". It also confirms that "… the theme of sustainable development, linked with that of social inclusion, runs through the Strategic Plan 'Better Wales' that the Assembly published in March 2000". ‘Better Wales’ has since been replaced by ‘Plan for Wales’, which can be accessed at www.planforwales.wales.gov.uk.

3.12            Sustainability is therefore all about balancing the demands of economic development and the needs of both individuals and society against the constraints created by natural systems and against each other. Above all it involves finding an appropriate utilisation rate for non-renewable resources, including energy, and avoiding actions which compromise the functionality of natural 'sinks' (e.g. the ability of natural systems to absorb and deal with pollution and waste of all kinds).

3.13            Whereas individual actions are important, true sustainability can only be achieved and measured taking into account the overall behaviour of a population and its impact on a region. It is not enough to live in a so-called sustainable house if the neighbourhood depends on unsustainable behaviour.

3.14            There are relatively simple conceptual models that link together:

(i)                   economic driving forces (including industry, households, the energy sector, transport services, agriculture and tourism); and

(ii)                  the stocks of natural resources on which they draw (including soil, minerals, water, air, flora and fauna); via

(iii)                the pressures that they create (in the form of emissions and waste).

3.15            However, the science that underpins such models is far from simple, and they cannot, as a general rule, be used for quantitative prediction.

3.16            Excessive (i.e. unsustainable) pressures lead to, and are eventually revealed by, severe impacts. Evidence of unsustainable pressures might include:

(i)                   climate change;

(ii)                  the progressive destruction of ecosystems (whether natural, modified or artificial), possibly leading to the extinction of certain species, or an inability to produce an essential benefit (such as food);

(iii)                the using up of a scarce mineral resource;

(iv)                 the fouling of drinking water supplies; or

(v)                  the destabilisation of natural systems (leading to, for example, increased flooding, even before taking into account the effects of climate change).

3.17            Comparable linkages exist between economic activity and social systems. Social systems can be thought of as 'human ecology', while the accumulated capital from earlier human activity is contained in (among other things) productive resources (such as factories and mines), archaeological remains, architectural heritage and the managed landscape which characterises much of the developed world (and an increasing share of the developing world).

3.18            An important test, which can be applied to any proposal or development, involves establishing whether it is likely to move the world closer to, or further from, the ideal of true sustainability. The specific mechanism by which this is achieved in the context of this study is described more fully in Chapter 7 and Appendix 4.

3.19            Briefly, the model which is used to view and assess the balance between the competing demands of the natural environment, the community and the need for economic development is based on the concept that the resources available to society can be treated as 'stocks of capital', from which a range of benefits can flow. These benefits include all of the things that are needed in order to maintain life and civilisation.

3.20            The stocks of resources can be broken down into environmental, social (mainly human) and economic capital. Figure 3.1 is a simplification (in that it combines the concepts of social and economic capital under a single heading).

 

Figure 3.1

12 items of environmental and social/economic capital involved in sustainability, and their relevance to aggregate production and use

No.

Six items of environmental capital

Notes/explanation

1

Fossil fuels.

Includes production and processing energy, plus transport/traffic from product delivery and workforce travel-to-work.

2

Soil resources and non-energy minerals.

Includes competition for land.

3

Fresh water resources.

Includes considerations of surface and groundwater.

4

The sea.

Includes water quality, currents and coastal processes.

5

The air and the climate.

Includes quarry and transport emissions of carbon dioxide, pollutants and dust.

6

Ecosystems.

Includes considerations of terrestrial and marine habitats, biodiversity and protected areas/species.

No.

Six items of social/economic capital

Notes/explanation

1

Human health.

Includes stress and health effects from noise, vibration, dust, general air quality, and from quality of life associated with surrounds (including landscape and visual quality). Potential future impacts would include those from landfills using void spaces.

2

Knowledge and learning.

Might include impacts associated with the quality of jobs and training, and potential impacts on archaeology and heritage.

3

Social inclusion.

Includes issues arising from employment (quantity and quality). Issues such as governance are not likely to arise.

4

Housing.

Includes availability and suitability of building materials, possible damage to housing, competition for space and possible flood impacts. Wider considerations include the relationship between housing and landscape, and countryside access.

5

The means of production

Might include impacts on factories, including availability of building materials.

6

Transport and energy infrastructure

Includes knock-on impacts from materials transport, plus contributions to infrastructure from relevant materials.

 


3.21            These are the 12 headings under which judgements on sustainability are taken in this study. The notes and explanations in Figure 3.1 are tailored to the specifics of this study and the issues raised by aggregate extraction and use.

 

4.                The Methodology for This Study

Introductory Comments

4.1               The choices involved in diversifying from the present heavy reliance on marine-dredged sand are not simple. Generally speaking land-based resources of sand occur in combination with gravel, though once sand and gravel have been dug, they are used either separately or in varying combinations, depending on the application. Within South East Wales, a large proportion of the marine-dredged (and gravel-free) sand is currently blended with crushed rock to achieve a suitable aggregate for making concrete.

4.2               Therefore replacing marine-dredged sand with quarried sand has knock-on implications for the gravel and crushed rock markets. In South East Wales, as in all other regions, the share of gravel and crushed rock in the aggregate market is significantly greater than the tonnage of sand.

4.3               It is also important to bear in mind that 'sand' is a varied material, and that different types of sand have different uses and limitations. Typically, marine sand is particularly 'soft', due to the rounded nature of its grains, whereas land-based sand is often more angular or 'sharp'. Sand produced by crushing rock from a quarry is considerably sharper still. These differences have practical implications, because the physical shape of grains, in combination with their size distribution, determines how easily worked the sand is when damp, and how much water, cement and other additives need to be used when mixing mortar or concrete.

4.4               This study seeks, above all, to compare alternatives to the present supply pattern. Although changes may be driven by changing the source(s) of sand, the knock-on impacts on gravel and crushed rock sources must also be considered. In other words, the comparison must be between balanced patterns of supply, and not between individual elements of the portfolio.

4.5               The methodology adopted in this study is first to characterise the current balance of sand and coarse aggregate supply to the South East Wales market, and then to consider the sustainability implications of reducing the supply of marine-dredged sand (by, for example, ceasing to dredge from one or more of the main areas that are currently licensed).

Identifying Alternative Patterns of Supply

4.6               The first step in the methodology is to describe the current supply pattern for sand and coarse aggregate, in order to establish the baseline against which alternatives need to be judged. This has been done by drawing on previous studies, other publicly available information and data provided by (among others) the members of the study Steering Group.

4.7               The outcome of this process is reported in Chapter 5, where it is confirmed that the large majority of sand used in South East Wales comes from three areas: Nash Bank (to the south of Porthcawl), Helwick Bank (to the south of the Gower peninsula) and Holm Sands (to the south of the Vale of Glamorgan). Most coarse aggregate comes from 17 limestone quarries spread throughout the region. There are currently no sand and gravel quarries in South East Wales.

4.8               The next step is to examine not just how changes in the current pattern of supply might be brought about, but also what these changes might be. This is done in Chapter 6, which sets out three alternative balanced patterns of supply responding to a range of possible future restrictions on marine dredging. In all three cases the intention is to predict, as far as is possible, the most likely market responses to the changed policy scenarios, and in particular the patterns of supply which might emerge. It must be stressed that these possible future patterns of supply are produced in order that they can be assessed, and so that conclusions can be drawn from that assessment. They are neither precise forecasts nor recommendations, simply assessment tools.

4.9               The three alternative scenarios are based on the following potential policy events, and accompanying assumptions:

(i)                   an end to the dredging of sand from Nash Bank, without any sand and gravel quarries being opened in South East Wales, and without any additional dredging licences being issued for dredging in the Bristol Channel;

(ii)                  an end to the dredging of sand from both Nash Bank and Helwick Bank, again without any new sand and gravel quarries being opened in South East Wales, but with two additional dredging licences being issued, permitting new dredging further offshore in the Bristol Channel;

(iii)                an end to the dredging of sand from both Nash Bank and Helwick Bank, but with sand and gravel and crushed rock quarries being permitted at various locations in South East Wales if required, and with two additional dredging licences being issued, permitting new dredging further offshore in the Bristol Channel.

4.10            The current position is referred to as either the baseline position or Pattern of Supply No. 1. The responses to the three alternative policy scenarios are referred to as Patterns of Supply Nos. 2, 3 and 4 respectively.

Selecting and Assessing Representative Sources and Sites

4.11            To compare the four patterns of supply at all convincingly, they need to be described in terms of their typical component elements. This is because the four patterns of supply involve drawing on changing combinations of materials from a range of different supply options (dredging, quarrying, recycling etc).

4.12            While some supply options are tied to a particular location, others may be carried out at a range of specified locations. A combination of supply option and location is referred to as a supply source. This relationships between a range of supply options and four different (and entirely notional) patterns of supply are illustrated schematically in Figure 4.1, while Figure 4.2 does the same thing for supply sources. However, it must be stressed that these are simplifications to illustrate a general point, not a summary of the actual patterns of supply to be considered in this study.

 

Figure 4.1

Schematic representation of the way in which individual supply options might be combined to create patterns of supply

Supply options

Notional patterns of supply

1

2

3

4

Dredging

25%

25%

35%

30%

Quarrying

75%

65%

40%

45%

Recycling

-

10%

25%

25%

Total

100%

100%

100%

100%

Note:

These figures are purely illustrative, and are not intended to represent either the current or the likely future position in South East Wales.

 

 

Figure 4.2

Schematic representation of the way in which individual supply sources might be combined to create patterns of supply

Supply sources

Notional patterns of supply

1

2

3

4

Dredging at A

25%

10%

5%

-

Dredging at B

-

15%

30%

30%

Quarrying at C

65%

50%

15%

20%

Quarrying at D

10%

15%

25%

25%

Recycling at E

-

10%

25%

25%

Total

100%

100%

100%

100%

Note:

These figures are purely illustrative, and are not intended to represent either the current or the likely future position in South East Wales.

 

4.13            In constructing viable patterns of supply, the first step is to ensure that all realistic supply options, including those employed at present, are considered. The general characteristics of these supply options then have to be set down on paper.

4.14            The principal supply options considered in this study are listed in Figure 4.3, and individual fact sheets detailing the characteristics of these material(s), their availability, the way(s) in which they are produced and the main impacts associated with their production, processing, transport and performance are given in Appendix 2. Figure 4.3 also shows whether the supply options concerned provide sand, coarse aggregate (gravel, crushed rock or fill material) or both.

4.15            Some other types of secondary aggregate materials not listed in Figure 4.3 are also discussed in Chapters 5 and 6 (dealing with the current pattern of supply and future alternatives, respectively). However, as is explained there, none of these secondary materials offer direct alternatives to marine-dredged sand, which makes them of limited relevance to this study.

 

Figure 4.3

12 Supply Options considered in this study

 

Option

Description

Sand?

Coarse aggregate?

1

Marine-dredged sand from the Bristol Channel, close to the coast

Yes

No

2

Marine-dredged sand from the Bristol Channel, but further offshore than Option 1

Yes

No

3

Limestone aggregate from existing quarries in South East Wales

Yes

Yes

4

Land-won sand and gravel from future quarries in South East Wales

Yes

Yes

5

Crushed rock sand from existing Pennant Sandstone quarries in South East Wales

Yes

No(1)

6

Crushed rock sand from future hard rock quarries in South East Wales

Yes

No(2)

7

Crushed rock sand from the Glensanda coastal superquarry in Scotland

Yes

No(3)

8

China Clay sand from Cornwall and Devon

Yes

No

9

Land-won sand and gravel from quarries in England, delivered by rail and/or road

Yes

Yes(4)

10

Dredged materials from port maintenance in South East Wales

Yes(5)

Yes(6)

11

Foundry sand from the castings industry or old foundry landfills in South East Wales

Yes

No

12

Recycled aggregate produced from demolition waste in South East Wales

No

Yes

Notes

(1)

While the fines could be recovered as a substitute for sand, the coarse aggregate from Pennant Sandstone quarries would continue to be used as at present (i.e. primarily for road making, rather than for concrete).

 

(2)

The primary purpose of such a quarry would be to produce a sand substitute. Rock types suitable for this would probably be too weak for the production of useable coarse aggregate.

 

(3)

Glensanda is being considered primarily as a source of secondary sand. It is also a source of coarse aggregate for concrete, but would not be competitive with existing limestone quarries in South East Wales.

 

(4)

This material would probably be brought into South East Wales as mixed sand and gravel.

 

(5)

Material dredged from parts of the river Neath contains a high proportion of fine sand.

 

(6)

Although not coarse, some dredged material can displace aggregate as general fill material in some applications.

 

 

4.16            The Research Specification for this project confirms that the Assembly is looking for general guidance on the relative sustainability of different patterns of supply which can guide policy in the medium to long term. Although representative sites are to be considered, the conclusions drawn from them should not be tied to specific scales of activity and particular locations. In any event, while some of the supply options can be seen in action already, others are purely theoretical.

4.17            What is needed, therefore, is a set of broadly representative sites which are sufficiently specific to be credible, without giving rise to unfounded concerns regarding impending extraction or processing. Hence the representative supply sources identified and described in Chapter 7 are in some cases described along the lines of 'a recycling site on the outskirts of Cardiff' rather than 'a recycling site on XYZ Road, Cardiff'.

4.18            There is an inevitable trade-off between the number of sites that can be assessed and the cost and complexity of the study. Some supply options can be represented by a single general location, while others demand more examples at different (actual or potential) locations.

4.19            The selection of representative sites also has to take into account the degree of uncertainty associated with some impacts, and particularly those associated with marine dredging. Indeed dealing with uncertainty is one of the key aspects of the whole study, since the level of agreement even among experts on some topics is notably low.

Comparing the Relative Sustainability of Alternative Patterns of Supply

4.20            In Chapter 6, four patterns of supply are established (i.e. the current baseline position and three alternatives). In Chapter 7 these are linked to varying combinations of the individual site-specific case studies, as illustrated schematically in Figure 4.2. This enables the environmental and social/economic impacts of changing the pattern of aggregate supply to be assessed, because each pattern of supply will be made up of a group of individual case studies 'weighted' according to their relative contribution.

4.21            To compare relative sustainability, what matters is the difference between the current baseline and each alternative individual pattern of supply. Comparisons are therefore made (in Chapter 8) of three pairings:

(i)                   Pattern of Supply No. 2 compared to Pattern of Supply No. 1;

(ii)                  Pattern of Supply No. 3 compared to Pattern of Supply No. 1; and

(iii)                Pattern of Supply No. 4 compared to Pattern of Supply No. 1.

4.22            The broad issues involved in sustainability were set out in Chapter 3. A fuller discussion of the issues is included as Appendix 4 to this report, which also provides an overview of the specific process by which sustainability is assessed in practice.

4.23            Evaluating the impacts is achieved by asking a series of technical questions about the scenarios which are being compared. All of these questions are given in full in Appendix 4, and the results are reported in Chapter 8 and Appendices 7-9. As can be seen in Appendix 4, the questions seek to take a balanced approach to environmental concerns and to the social and economic consequences of a change to the present arrangements.

4.24            This highlights the difference between 'pure' environmental assessment and sustainability assessment, which is also concerned with issues such as the levels and quality of employment, and the state of a region's physical and social infrastructure.

5.                The Current Pattern of Supply and Demand

Sand Dredged from the Bristol Channel

5.1               There are four main dredging areas in Welsh waters in the Bristol Channel. Going from west to east, these are Helwick Bank, Nash Bank, Holm Sands and Bedwin Sands. Dredging at the first three of these sites (and some others) is licensed by the Crown Estate. Their website (see www.crownestate.co.uk/estates/ marine/area_maps2000/) shows 11 dredging licences in the Bristol Channel. These are listed in Figure 5.1, with the relevant block references and policies from MADP also given. One of these licences, which has now lapsed, was a relatively small one-off arrangement for the construction of the Cardiff Bay barrage. Another (Denny Shoal) primarily supplies Avonmouth on the English side of the Bristol Channel.

5.2               These dredging areas are also mapped on Figure 5.7 (which will be found at the end of this chapter), together with other land-based resource information.

 

Figure 5.1

Crown Estate dredging licences in the Bristol Channel, 2000

Area name

MADP block

MADP policy(1)

Crown Estate licence

Licensee

Helwick Bank

OBC11

2

373

Llanelli Sand Dredging Ltd(2)

Nash Bank

CBC1

2

376

Hanson Aggregates Marine Ltd

378

South Coast Shipping Ltd(3)

380

United Marine Dredging Ltd(4)

Holm Sands

IBC3

2

377

Hanson Aggregates Marine Ltd

379

South Coast Shipping Ltd(3)

381

United Marine Dredging Ltd(4)

Culver Sands

IBC2

1

389

Hanson Aggregates Marine Ltd

Middle Ground

SE4

2

385

South Coast Shipping Ltd(3)

Denny Shoal

SE4

2

391

Hanson Aggregates Marine Ltd

Bristol Deep

SE4

2

425 (lapsed)

Cardiff Bay Development Corporation

Notes

(1)

MADP Policy 1 implies a favourable view on dredging; Policy 2 implies a precautionary approach.

 

(2)

An associate company of Westminster Dredging Co Ltd, the UK operating division of the Royal Boskalis Westminster Group. Not a member of BMAPA.

 

(3)

Part of the RMC Group.

 

(4)

A joint venture between Hanson and Tarmac.

 

 

5.3               Most of the companies identified in Figure 5.1 are members of the British Marine Aggregate Producers Association (BMAPA, see www.bmapa.org for information). The assistance of BMAPA in helping to assemble and explain the information in this section of the report is gratefully acknowledged.

5.4               Helwick Bank, which lies within the Carmarthen Bay and Estuaries candidate Special Area of Conservation, is close to the edge of the study area. The licensee (Llanelli Sand Dredging, which is not a member of BMAPA) is based in Carmarthenshire, which is outside the study area. All of their sand is landed at Burry Port, to the west of Llanelli. This does not, of course, preclude sand from Helwick Bank from being supplied to customers in South East Wales.

5.5               The current licence for Helwick Bank, which expires in May 2003, is for up to 150,000 tonnes a year, which the licensee is seeking to raise in steps to 300,000 tonnes a year, and to extend at that rate (300,000 tonnes a year) for a further 15 years. Information provided in the Assembly in answer to a written question (WAQ 4313, March 2000) confirms that the average annual 'take' from Helwick Bank over the period 1995-1999 inclusive was 87,816 tonnes. Based on a short discussion with Llanelli Sand Dredging, it is estimated that around 30,000 tonnes a year of marine sand enters the South East Wales market from Helwick Bank/Burry Port, for sale in the Swansea area. Most of this (probably as much as 80%) is sold as builder's sand, with the balance used in concrete.

5.6               In addition to the applications outlined above, Llanelli Sand Dredging has submitted a separate application to dredge up to 300,000 tonnes a year from Nobel (North Outer Bristol Channel) Banks. Nobel Banks (which do not appear under this name on any charts) lie south west of Helwick Bank, and 90% of the application area of 98 km2 lies within MADP sediment area OBC10, which is subject to Policy 1 (explained in the footnotes to Figure 5.1). The remaining 10% is split between areas OBC11 and 19, both subject to Policy 2. The centre point of the application area lies 4-5 km south of the triple point between these three areas.

5.7               The primary contributor of marine-dredged sand in recent years, and particularly of builder's sand, has been Nash Bank. The annual limit on extraction is currently set at 900,000 tonnes. The licence was due to expire on 4 February 2001, but temporary extensions have been granted, first a 4-month extension to 4 June 2001, and then an 8-month extension to 4 February 2002 and most recently a 12-month extension to 4 February 2003. Information provided in the Assembly in answer to a written question (WAQ 4313, March 2000) confirms that the average annual 'take' from Nash Bank over the period 1995-1999 inclusive was just under 700,000 tonnes, compared to a figure of just over 1.25 million tonnes for the preceding 5-year period. The three companies which dredge Nash Bank (and Holm Sands, plus other areas individually) are members of BMAPA.

5.8               The largest licence, at least in terms of the upper tonnage limit, is the one which applies to Holm Sands. However, although the maximum annual 'take' from Holm Sands was set at 2,975,000 tonnes, the tonnage actually dredged has been well below the limit in recent years, at around 100,000-200,000 tonnes a year. This reflects relative difficulties in obtaining high quality materials competitively.

5.9               Sand from Nash Bank is landed at six ports and/or groups of river wharves in South East Wales (at Swansea, Briton Ferry, Port Talbot, Barry, Cardiff and Newport) plus Pembroke, which lies well to the west of the study area. Sand from Holm Sands is landed at five of the same six ports/wharves in South East Wales (as listed above, but excluding Port Talbot). There are concrete plants within the port areas at Swansea, Cardiff and Newport, and adjacent to one of the sand wharves at each of Briton Ferry and Newport.

5.10            Further south from Holm Sands lies Culver Sands. The current Culver Sands licence is small (around 18,000 tonnes a year). Although the licensed area spans the boundary between Welsh and English waters, the sand is all understood to be landed in South East Wales. A further licence application to dredge 1.5 million tonnes a year from Culver Sands was submitted in August 2000.

5.11            Middle Ground and Denny Shoal serve the markets of South East Wales (Barry, Cardiff and Newport) and Avon respectively. The upper licence limit for West Middle Ground is 250,000 tonnes a year, though significantly less than this (estimated at 40,000-60,000 tonnes a year) is dredged in a 'typical' year. There is also an application to dredge up to 1 million tonnes per year from North Bristol Deep by United Marine Dredging and Hanson Aggregates Marine.

5.12            A further operator (Severn Sands, not a member of BMAPA) dredges sand from non-Crown Estate land on Bedwin Sands. They hold a licence from Swangrove Estate and a planning permission from the former Gwent County Council which are both valid until 2015. Their licence is for up to 150,000 tonnes a year, of which roughly 40,000 tonnes of sand is landed at Chepstow and 110,000 tonnes within the port area at Newport, where Severn Sands operate a concrete plant. Severn Sands also submitted a further licence application relating to North Middle Ground in July 2000. That application is to dredge up to 400,000 tonnes a year for at least 10 years.

5.13            Figure 5.2 draws together the tonnages landed by the different companies at each of the ports in South East Wales.


5.14            Based primarily on information from BMAPA members, the split between concrete sand, coarse builder's sand (and similar), fine builder's sand (and similar) and low value uses (such as engineering fill, for which sand, and particularly soft sand, is not technically necessary) has been estimated, for the purposes of this study, to be 48:24:24:4. BMAPA's figures, supplemented by estimates covering the other two companies, show that the split between concrete sand and builder's sand was almost exactly 50:50. It is Symonds' own assumption that the 50% comprising builder's sand was divided 50:50 between coarse and fine sand, with a small amount (4% of the total) used as fill.

 

Figure 5.2

Where sand dredged in the Bristol Channel was landed in South East Wales in 2000 ('000 tonnes), and what it was used for (excluding fill)

Port - Company

'000 tonnes

Concrete sand

Building sand

Swansea - Llanelli Sand Dredging

30(2)

20%

80%

Swansea - BMAPA(1)

104

53%

47%

Briton Ferry - BMAPA(1)

203

53%

47%

Port Talbot- BMAPA(1)

6

10%

90%

Barry - BMAPA(1)

33

17%

83%

Cardiff - BMAPA(1)

301

41%

59%

Newport - BMAPA(1)

313

63%

37%

Newport - Severn Sand

110

63%(3)

37%(3)

Chepstow - Severn Sand

40

10%(3)

90%(3)

Total

1,140

50%(4)

50%(4)

Notes

(1)

Consolidated figures from Nash Bank, Holm Sands, Culver Sands and Middle Ground. Excludes 34,000 tonnes landed at Pembroke.

 

(2)

Actually landed at Burry Port, but supplied to the Swansea area.

 

(3)

Symonds' own estimates.

 

(4)

Calculated from the individual port tonnages.

 

 

5.15            The dredgers used in the Bristol Channel are of two types: trail dredgers and static dredgers. Both types screen and drain the sand before it enters the hold, and have the necessary equipment to discharge the sand direct to a quayside without the need for shore-based equipment. Once landed, the sand requires no further washing, cleaning or screening.

5.16            The three BMAPA members between them have the equivalent of 3.5 dredgers working in the Bristol Channel most of the time. Allowing for the two non-BMAPA members, for sand landed at Welsh ports outside the study area, for sand landed at English ports, and for dredgers which are moved to other parts of the UK for temporary periods, the dredging capacity serving the study area is approximately 4 full-time ships. Although the capacities of individual dredgers do vary, a 'typical' ship has the capacity to land 1,200 tonnes of sand per tide (i.e. 2,400 tonnes per day). Tidal factors mean that access to certain river wharves (particularly at Briton Ferry and Newport) is restricted for part of each month.

5.17            As can be seen from these figures, there is spare dredging capacity available in South East Wales. Four ships delivering sand at a rate of 2,400 tonnes per day could land the current estimated annual total (see Figure 5.2) of 1,140,000 tonnes in four months. Statistics from the Crown Estate (reported in the South Wales Regional Aggregates Working Party Annual Report, 2000) show that the tonnage of sand landed in South Wales from their licensed areas has fallen steadily from 1.64 million tonnes in 1996 to 1.31 million tonnes in 1998 and 1.06 million tonnes in 2000. These figures differ slightly from those reported above, but not by a significant amount. In any event, the downward trend is clear.

Aggregate Quarried within South East Wales

5.18            All of the aggregate quarried within the study area of South East Wales comprises crushed rock, and specifically:

(i)                   sandstone, of which the most important element is Pennant Sandstone, a premium quality coarse aggregate used primarily in road surfacing;

(ii)                  crushed Carboniferous Limestone, a traditional source of coarse aggregate for use in concrete, road construction (but not surfacing) and other applications.

5.19            There are five Pennant Sandstone quarries in South East Wales. In the mid-late 1990s these had an estimated combined output of around 1 million tonnes a year of saleable aggregate, though by 2000 output across the whole of South Wales had dropped appreciably (as reported in the South Wales Regional Aggregates Working Party Annual Report for 2000). The quarries are listed below in the second column of Figure 5.3.

 

Figure 5.3

Pennant Sandstone and Carboniferous Limestone quarries in South East Wales

Mineral Planning Authority

Pennant Sandstone quarries

Limestone quarries

Large

 (>500,000 tonnes/yr)

Medium

 (200-500,000 tonnes/yr)

Small

(<200,000  tonnes/yr)

Neath-Port Talbot

Cwm Nant Lleici (Agg. Industries), Gilfach (RMC)

 

 

 

Bridgend

 

Cornelly (1) (Camrian/ Tarmac)

Grove (Tarmac) (4)

Gaens (T S Rees)

Vale of Glamorgan

 

Wenvoe (RMC) (2)

Lithalun (Hanson)

Ewenny (Minimix), Longlands (Mason Bros), Pantyffynnon (Seth Hill)

Cardiff

 

Taffs Well (1) (RMC)

Creigiau (Tarmac)

Ton Mawr (T S Rees)

Newport

 

 

Penhow (Hanson)

 

Monmouthshire

 

(3)

Livox (Hanson)

 

Rhondda-Cynon-Taff

Craig-yr-Hesg (Hanson)

Forest Wood (Hanson)(2)

 

 

Merthyr Tydfil

Gelligaer (Hanson)

 

Vaynor(5) (Hanson)

 

Caerphilly

Hafod (Lafarge)

Machen (Hanson)

 

 

Blaenau Gwent

 

 

 

Trefil (Gryphonn)

Brecon Beacons National Park

 

 

Ammanford, Penderyn, Vaynor(5) (all Hanson)

 

Notes

(1)

Cornelly and Taffs Well are both major sources of non-aggregate limestone for industrial use.

 

(2)

Forest Wood is partly within Vale of Glamorgan and partly within Rhondda-Cynon-Taff.

 

(3)

Ifton (Hanson) is reported to be inactive, but is understood to be a candidate for re-opening.

 

(4)

Grove Quarry is currently inactive.

 

(5)

Vaynor is partly in Merthyr Tydfil and partly within the Brecon Beacons National Park.

5.20            A significant proportion of their output is exported beyond South East Wales, much of it to England and some as far as Scotland. Because of the nature of Pennant Sandstone and the uses to which it is put, it can be treated as a stand-alone product which is of relevance to the present study only because the large volume of fines generated in sandstone quarries (typically 35-45% of the total tonnage quarried) has some potential as a substitute for sand in concrete or bulk fill. Before sandstone fines can be used in concrete, however, they require some element of treatment to remove clay minerals and coal dust. This is discussed in more depth in Chapter 6.

5.21            The earlier Symonds report on land-based extraction reported that the non-cement limestone quarries in South East Wales had a combined output of around 7.5 million tonnes of aggregate between them. As with Pennant Sandstone, by 2000 output was reported to have fallen across all of South Wales, and the share ascribed to the study area in 2000 has been estimated at 5.5 million tonnes. Of this, around 600,000 tonnes is reported to be used in industry rather than as an aggregate. Most of the limestone quarries lie between the Pennant Sandstone quarries and the Bristol Channel.

5.22            All Pennant Sandstone and non-cement limestone quarries identified in the South Wales Regional Aggregates Working Party Annual Report for 2000 as being both active and within the study area are listed in Figure 5.3. They are arranged there by Local Authority area, working roughly from west to east along the coast, and then from south to north across the region. The non-Pennant sandstone quarries (which are not listed below) are Cefn Cribbwr in Bridgend, Fforch-y-Garan in Rhondda-Cynon-Taff, Bryn (Gelliargwelt Uchaf) in Caerphilly, and Pant in the Brecon Beacons National Park.

5.23            It is estimated that, of the 4.9 million tonnes of aggregate limestone (i.e. 5.5 million tonnes minus 600,000 tonnes) slightly under 300,000 tonnes of dust/fines is blended with marine-dredged sand and used in concrete as a 50:50 mix, with a further 1.6 million tonnes providing the coarse fraction of concrete. The remainder is used for other purposes.

Aggregate Imported from outside South East Wales

5.24            Some sand and gravel quarried outside the study area (e.g. from quarries in Carmarthenshire, Herefordshire or Gloucestershire) is used in South East Wales from time to time. The AM97 Collation of aggregate statistics stated that 114,000 tonnes were imported into South Wales. Since the majority of this would have been used in South East Wales, it has been assumed for the purposes of this study that an estimate of 100,000 tonnes a year should be included in the current baseline position. It is also assumed that this material is split 33:67 sand:gravel.

5.25            A modest amount of crushed rock sand from Glensanda is imported through Newport for use in concrete block manufacture. It is used in combination with marine-dredged sand.

Secondary and Recycled Materials

5.26            The earlier Symonds report on land-won aggregates identified a number of secondary and recycled aggregates currently used in the construction industry in South East Wales, as follows:

(i)                   fly ash (PFA) and furnace bottom ash from power stations;

(ii)                  various slags from steel works;

(iii)                minestone from collieries; and

(iv)                 recycled demolition waste.

5.27            The Research Brief also refers to maintenance dredging from harbours.

5.28            The only coal-fired power station operating in South East Wales is Aberthaw 'B', owned and operated by Innogy (formerly National Power). The amount of coal burned at Aberthaw, and therefore the amount of ash produced, varies from year to year. 'Typical' tonnages would be 50,000 tonnes of fly ash and 10,000 tonnes of furnace bottom ash.

5.29            Physically, fly ash is a much finer material than sand, and because it does not have the right grain size distribution it cannot be considered to be a substitute for sand either in concrete or in mortar. However, the physical and chemical characteristics of fly ash mean that it can be used as a cement substitute, which makes it more valuable than most general aggregate. Fly ash which is unsuited to use as a cement substitute (because, for example, it has too high a carbon content, or because it has become damp and gone lumpy while being stockpiled), can be used as a bulk fill material. During 2000 around 100,000 tonnes of fly ash from old ash lagoons at the Carmarthen Bay power station (just outside the study area) were used to create the Millennium Coastal Park at Llanelli. (Source: www.ukqaa.org.uk/casestudyllanelli).

5.30            Furnace bottom ash, or clinker, is almost all used in the manufacture of light-weight concrete blocks. Even if ground down to a smaller particle size it could only displace sand in the least demanding, lowest value applications, and even this is uncertain.

5.31            Power station ashes, therefore, can be used in some applications for which natural aggregates might otherwise be required. However, although they are used alongside natural sand and gravel, they are not direct substitutes for marine-dredged sand.

5.32            With the closure of parts of Llanwern, the only major remaining integrated steel works in South East Wales is at Port Talbot. For the period prior to the closure of Llanwern, Symonds' estimates for aggregate-type materials are: around 900,000 tonnes a year of air cooled blast furnace slag, around 750,000 tonnes a year of ground granulated blast furnace slag, around 1.15 million tonnes a year of basic oxygen furnace slag and 60,000 tonnes a year of electric arc furnace slag. A significant proportion of these materials were supplied to clients in England.

5.33            Ground granulated blast furnace slag is a very fine-grained, high quality, high value replacement for cement. As such it is further removed from natural sand than is power station fly ash. Air cooled blast furnace slag, basic oxygen furnace slag and electric arc furnace slag are quite different, with a much larger granule size. They are all mainly used as high performance roadstone materials, and none of them, therefore, has the potential to replace marine-dredged sand.

5.34            According to Chapter 9 of 'The reclaimed and recycled construction materials handbook' (CIRIA publication C513, 1999) "colliery spoil is the waste material produced in the process of extracting deep-mined coal and preparing it for sale. These solid wastes are disposed of on spoil heaps and are known as 'minestone' ". Although minestone can in theory be recovered from old spoil heaps, this can seldom be justified on either cost or environmental grounds.

5.35            Minestone is, by its very nature, a variable material with poor durability characteristics. The CIRIA report cited above acknowledges that a few unburnt spoils can be used to produce poor quality concrete, but points to road construction, landscaping, land reclamation and general fill as the most appropriate uses. Recently, significant volumes of minestone diverted direct from the mine (i.e. not tipped onto spoil heaps first) has been used in flood defence work in northern England.

5.36            In summary, minestone has extremely limited potential for use as a graded material, and certainly could not be used to replace marine-dredged sand. The last remaining deep mine in South East Wales is Tower Colliery, in Rhondda-Cynon-Taff, so the tonnage of available material is in any case low and declining.

5.37            The best available estimate for recycled aggregate (i.e. aggregate made from construction and demolition waste) is contained in another report by Symonds, for the Environment Agency and the DETR in association with the Assembly (published by the EA in 2001 as Technical Report P402 'Construction and Demolition Waste'). That report gave an estimate for all of Wales of just under 1.3 million tonnes of ‘hard’ construction and demolition waste, of which just under 150,000 tonnes was landfilled and just over 600,000 tonnes was used as aggregate in the open market. The balance was used in landfill engineering or restoration, or on registered exempt sites. These figures exclude materials which were wholly or mainly soil.

5.38            The most appropriate uses for recycled aggregates are similar to those for minestone, though the quality of the material is generally higher and more reliable. Most recycled aggregates are used as unbound materials in road and carpark construction and general engineering fill. The main 'problem' component of crushed and screened construction and demolition waste is the crusher fines, which can contain contaminants. They are sometimes used (in combination with compost and other materials) to make soil-type materials, but could (and should) not be used as a substitute for marine-dredged sand.

5.39            Based on the share of Wales' population in the South East region, 60% of the estimates given above for recycled aggregates have been included in the current baseline position.

5.40            'The reclaimed and recycled construction materials handbook' (CIRIA publication C513, 1999) also discusses the potential for using materials dredged from ports, estuaries and rivers (referred to here as 'maintenance dredging'). It deals with their use in landscaping, beach nourishment and river enhancement (see Chapter 12), and the use of silt in brick manufacture (see Chapter 7). It draws attention to the fact that sediment from ports may well be contaminated.

5.41            It lists all disposal licences applicable to maintenance dredging materials which were both active in 1998 and in excess of 500,000 tonnes. Of these around 9 million tonnes were in South East Wales, including one licence in Port Talbot (for 3.1 million tonnes), two licences in Cardiff (for 1.86 million tonnes and 999,999 tonnes), two licences in Swansea (for 1.3 million tonnes and 637,500 tonnes), and one licence in Newport (for 999,999 tonnes). The smaller of the two Cardiff licences was held by the Cardiff Bay Development Corporation; all others were held by Associated British Ports (ABP). ABP's website (see www.abports.co.uk) contains a section dedicated to dredging, and mainly to maintenance dredging. This confirms that most of the disposal that is carried out is at sea, or within the estuaries concerned. In other words, most of the 9 million tonnes is not landed.

5.42            There is, however, one location where much of the above does not apply. Dredged material from the mouth of the river Neath comprises predominantly sand, though this sand is finer than most commercially dredged sand, and apparently of limited commercial value as a consequence. The river Neath has for some years been dredged by/for BP, to facilitate access to their berth near the sand wharves. However, in March 2002 BP was due to vacate that berth, placing the onus for future dredging on the Neath Harbour Commissioners.

5.43            In 2000-2001 10,000 tonnes of fine sand from the river Neath was deposited on Sker beach in a trial involving BP, Shoreline Management Partnerships and Swansea Bay Coastal Engineering Group.

5.44            ABP's website also confirms that before a dredging disposal licence is issued, ABP must satisfy DEFRA (the licensing authority concerned) "… that it has taken reasonable steps to find alternative beneficial uses of dredged material. As most material from port areas is fine silt, such opportunities are rare unless it is suitable for an approved reclamation project. Where sand or gravel occur (more often associated with capital dredging) uses such as beach recharge or for sea defences may be possible. Increasingly, however, scientific study is showing that a possible beneficial use is to return dredged material to the estuary system at a convenient location in order to maintain the dynamics of the system and therefore conserve the morphological and ecological development".

5.45            The general presumption, therefore, is that these materials are generally of low (or no) value as a source of clean aggregate. For the purposes of this study, it is assumed that a nominal 50,000 tonnes a year of dredged material is used for functions (such as bulk fill) for which aggregate or soil would otherwise have to be dug or dredged, with the remainder replaced elsewhere at sea or in the estuaries from which it was dredged. Most maintenance dredging materials are not suitable as a substitute for marine sand, because they are completely different in terms of grain size and strength.

Demand for Aggregate in South East Wales

5.46            Figure 5.4 provides estimates for the distances travelled by marine sand, from the different ports at which it is landed to its point of first use. Because significant amounts of sand are used in concrete, and because several of the concrete plants are located at the ports where the sand is landed, this approach has an in-built tendency to understate the distance travelled to the point of final use. A significant part of this information was provided by the members of BMAPA, modified slightly to take account of the sand landed by the other operators, and then rounded.

5.47            The figures for Port Talbot and Chepstow are subject to greater uncertainty than the others, though they affect relatively small tonnages. Four of the ports (Swansea, Port Talbot, Barry and Chepstow) share a common transport pattern: 85% being supplied to users within 10 km of the port, 10% to users within 10-20 km, 4% to users within 20-30 km and 1% to users located further than 30 km away.

5.48            The figures for the three largest ports (Briton Ferry, Cardiff and Newport) are more reliable. The river wharves at Briton Ferry and Newport in particular tend to serve the more inland markets.

5.49            Merthyr Tydfil lies more than 30 km from each of Briton Ferry, Cardiff and Newport, and Abergavenny is approximately 30 km from Newport. Likewise, all of the towns along or close to the A465 between Merthyr Tydfil and Abegavenny (e.g. Tredegar, Ebbw Vale and Brynmawr) lie slightly over 30 km from Newport, as does Monmouth. All of the towns north of these, and almost all of the Brecon Beacons National Park, lie more than 30 km from any port.

 

Figure 5.4

Distance travelled by sand from port to point of first use ('000 tonnes and %)

Port

'000 tonnes landed

< 10 km

10-20 km

20-30 km

> 30 km

Swansea

134

113.9 (85%)

13.4 (10%)

5.4 (4%)

1.3 (1%)

Briton Ferry

203

132.0 (65%)

20.3 (10%)

20.3 (10%)

30.5 (15%)

Port Talbot

6

5.1 (85%)

0.6 (10%)

0.2 (4%)

0.1 (1%)

Barry

33

28.1 (85%)

3.3 (10%)

1.3 (4%)

0.3 (1%)

Cardiff

301

225.8 (75%)

45.2 (15%)

24.1 (8%)

6.0 (2%)

Newport

423

275.0 (65%)

63.5 (15%)

33.8 (8%)

50.8 (12%)

Chepstow

40

34.0 (85%)

4.0 (10%)

1.6 (4%)

0.4 (1%)

Total

1,140

813.7 (71%)

150.2 (13%)

86.7 (8%)

89.4 (8%)

 

 

5.50            Of the major towns closer to the coast, Bridgend lies furthest from any port, being over 20 km from Briton Ferry and Barry, and over 30 km from Cardiff.

5.51            When the tonnages are totalled and expressed as a percentage of all landings in South East Wales (see the bottom line of Figure 5.4), it can be seen that 71% of all sand travels less than 10 km from the port where it is landed to its point of use, with 13% travelling 10-20 km, 8% travelling 20-30 km, and 8% travelling more than 30 km.

5.52            As was noted above, this does not account for any transport then required to take ready mixed concrete or concrete blocks from the batching plant (and/or block making plant) to the point of final use.

Summary of the Current Pattern of Supply and Demand

5.53            Figures 5.5 and 5.6 pull together data from the preceding sections (and estimates based on them, and discussions at meetings of the Steering Group) to provide a summary of the current pattern of supply and demand for aggregate within South East Wales, omitting those materials which are not used as sand, aggregate or bulk fill, or as a substitute for them.

5.54            Figure 5.7 maps the various marine and land-based resource blocks and related facilities, together with major centres of aggregate demand.

5.55            The assumptions and approximations 'embedded' in Figures 5.5 and 5.6 are as follows:

(i)                   none of the marine sand landed in South East Wales is currently exported;

(ii)                  of the marine sand used in South East Wales 48% is used in concrete, 24% is used as coarse sand and 24% is used as fine sand, with the remaining 4% used in low value applications (such as fill) simply because it is the most appropriate material available at the relevant place and time;

(iii)                all imported sand and gravel is used in concrete, and is split 33:67 sand:gravel without requiring additional sand or gravel to be blended into the mix;

(iv)                 half of the marine sand destined for concrete is blended with crushed limestone dust/fines to achieve a roughly 50:50 mixture;

(v)                  every tonne of sand and limestone dust/fines used in concrete is matched by two tonnes of gravel/crushed rock;

(vi)                 most of the remaining crushed limestone is used as graded aggregate, with the balance used as bulk fill;

(vii)               three quarters of the Pennant Sandstone prepared as coated (or coatable) roadstone which is quarried in South East Wales is then exported to England or Scotland;

(viii)              for every tonne of Pennant Sandstone roadstone produced, 540 kg of fines are generated (i.e. 35% of the total volume quarried is fines, an estimate which is at the lower end of the generally accepted range), and most of this is used in 'blacktop' (some of it in England), in quarry restoration, or as fill material;

(ix)                50% of power station fly ash is used as bulk fill (the balance being used as a higher value cement substitute);

(x)                 55% of blast furnace steel slag is air cooled, most of which is then exported;

(xi)                50% of minestone is currently 'wasted' with the balance used as bulk fill;

(xii)              60% of Welsh construction and demolition waste occurs in South East Wales, and (in the absence of any evidence to the contrary) is processed and used in the same ways as in the rest of Wales;

(xiii)             50,000 tonnes of maintenance dredging waste is used as bulk fill on shore, with the balance disposed of offshore, even if some of this is used for beach recharge or similar.

 

Figure 5.5

Sources of aggregate in South East Wales (tonnes)

Material

Amount produced or landed in SE Wales

Imports (exports)

Wasted (or otherwise used)

Used as sand, coarse aggregate or fill in SE Wales

Marine-dredged sand

1,140,000(1)

0

0

1,140,000

Crushed limestone

5,500,000

0

(600,000)

4,900,000

Pennant Sandstone roadstone

800,000

(600,000)

0

200,000

Pennant Sandstone fines

432,000

(30,000)

(86,400)

315,600

Crushed rock sand from Glensanda

0

40,000

0

40,000

Imported sand and gravel

0

100,000

0

100,000

Power station fly ash

50,000

0

(25,000)

25,000

Air cooled blast furnace slag

907,500

(800,000)

0

107,500

Minestone

10,000

0

5,000

5,000

Recycled C&D waste

769,800

0

88,800 plus (364,200)

316,800

Maintenance dredging materials

50,000

0

0

50,000

Note

(1)

All but 18,000 tonnes from close to shore.

 

 

Figure 5.6

Uses of aggregate in South East Wales (tonnes)

Material

Used as sand, coarse aggregate or fill (see Fig 5.5)

Used in concrete

Sand (other than in concrete, incl. in blocks)

Graded aggregate

Ungraded aggregate or fill

Marine-dredged sand

1,140,000

547,200

273,600 (coarse) plus 273,600 (fine)

0

45,600

Limestone dust

373,600

273,600

60,000 (coarse) plus 40,000 (fine)

 

 

Other crushed limestone

4,526,400

1,647,912

 

2,158,866

719,622

Pennant Sandstone roadstone

200,000

0

0

200,000

0

Pennant Sandstone fines

315,600

3,156

28,404 (coarse)

0

284,040

Crushed rock sand from Glensanda

40,000

0

40,000 (fine)

0

0

Imported sand and gravel

100,000

100,000 (mixed sand and gravel)

0

0

0

Power station fly ash

25,000

0

0

0

25,000

Air cooled blast furnace slag

107,500

0

0

107,500

0

Minestone

5,000

0

0

0

5,000

Recycled C&D waste

316,800

0

0

79,200

237,600

Maintenance dredging materials

50,000

0

0

0

50,000

Total

7,199,900

2,571,868

715,604

2,545,566

1,366,862

 


(Figure 5.7 to be inserted here)

 


(This page is intentionally blank)

 

6.                Potential Alternative Patterns of Supply and Demand

Alternative Sources of Aggregate not Currently Exploited

Introductory comments

6.1               The earlier Symonds report on land-based extraction identified a number of potential sources of sand and gravel (or direct substitutes) which might be exploited at some future point. These were summarised (in Figure 4.3 of this report), together with the current sources of supply.

6.2               Figure 6.1 lists eight of those sources. They are either not currently exploited, or are only marginally exploited at present while having significant potential for expansion. The other four sources have been omitted from this chapter on the grounds that they have been discussed already in Chapter 5.

 

Figure 6.1

Eight currently unused or under-used Supply Options considered in this study

Option

Description

Sand?

Coarse aggregate?

2

Marine-dredged sand from the Bristol Channel, but further offshore than Option 1

Yes

No

4

Land-won sand and gravel from future quarries in South East Wales

Yes

Yes

5

Crushed rock sand from existing Pennant Sandstone quarries in South East Wales

Yes

No(1)

6

Crushed rock sand from future hard rock quarries in South East Wales

Yes

No(2)

7

Crushed rock sand from the Glensanda coastal superquarry in Scotland

Yes

No(3)

8

China Clay sand from Cornwall and Devon

Yes

No(4)

9

Land-won sand and gravel from quarries in England, delivered by rail and/or road

Yes

Yes(5)

11

Foundry sand from the castings industry or old foundry landfills in South East Wales

Yes

No

Notes

(1)

While the fines could be recovered as a substitute for sand, the coarse aggregate from Pennant Sandstone quarries would continue to be used as at present (i.e. primarily for road making, rather than for concrete).

 

(2)

The primary purpose of such a quarry would be to produce a sand substitute. Rock types suitable for this would probably be too weak for the production of useable coarse aggregate.

 

(3)

Glensanda is being considered primarily as a source of secondary sand. It is also a source of coarse aggregate for concrete, but would not be competitive with existing limestone quarries in South East Wales.

 

(4)

Coarse aggregate from china clay waste is also available, but is not being considered here.

 

(5)

This material would probably be brought into South East Wales as-dug, i.e. mixed sand and gravel.

 

 

6.3               Summary Fact Sheets for each of these can be found in Appendix 2. Nevertheless, some further comments are worth making.


Marine dredging

6.4               Various sources of marine-dredged sand are the subject of current applications, two of which (Culver Sands and Nobel Banks) fall wholly or largely inside sediment environments that are subject to MADP Policy 1 (i.e. the Assembly "… will look favourably on dredging …").

6.5               As reported in Chapter 5, the sediment environment known as Culver Sands (area IBC3) is already lightly exploited. It spans the Welsh-English border, which runs down the centre line of the Bristol Channel, and the part which is discussed here is the smaller portion in Welsh waters, some 10 km offshore, beyond Nash Bank. The application is for 1.5 million tonnes a year.

6.6               Nobel Banks is in a sediment environment that is not currently exploited, further offshore from Helwick Bank. It lies mainly (90%) within MADP area OBC10, with the balance split equally between areas OBC11 and OBC19. Area OBC10 is a MADP Policy 1 area, while the other two are Policy 2 areas. The application is for 300,000 tonnes a year.

6.7               North Middle Ground is also the subject of a new application to dredge, but it lies entirely within a MADP Policy 2 area (SE4).

Quarrying

6.8               The availability of sand and gravel resources within South East Wales was central to the earlier Symonds report on land-based extraction. That report identified an estimated 111.6 million tonnes of minerals unaffected by known environmental and planning constraints. The large majority of this (98.3 million tonnes, or 88%) is in three areas, as follows:

(i)                   an estimated 39.0 million tonnes near Pontarddulais, to the north of Swansea;

(ii)                  an estimated 34.0 million tonnes near Pyle, spanning the boundary between Neath Port Talbot and Bridgend; and

(iii)                an estimated 25.3 million tonnes in the Pontyclun-Cowbridge area, spanning the boundary between Rhondda-Cynon-Taff and Vale of Glamorgan.

6.9               These estimated tonnages are divided into several blocks in each case, meaning that they would have to be exploited (if that option were pursued) as several small-medium quarries.

6.10            Figure 6.2 is taken from the earlier Symonds report (where it was Table 5.1) to show the estimated amounts in all areas, and the proportions constrained and unconstrained by existing environmental and planning constraints. The only changes made from the source table involve re-ordering the blocks to run west to east and south to north (as with the quarries discussed in Chapter 5), and to omit those areas where no potential resources were identified. These resource blocks are also plotted on Figure 6.3.

6.11            Whereas it may well be reasonable to look first at unconstrained areas when seeking the most suitable sites for future quarries, it must be borne in mind that some of the environmental and planning constraints could well be overcome. For example, much of the Usk Valley falls within the Brecon Beacons National Park. That does not in itself preclude the development of quarries, but it does place an obligation on the proponent of any future quarry to explain how quarrying would be compatible with its surrounds. The Upper and Middle Usk Valley is also a considerable distance from the main markets for aggregate, which lie relatively close to the coast, between Swansea and Newport.

6.12            While this present study was in progress, Symonds was informed that one of the larger prospects in the Usk Valley (for which only limited borehole data had been available in 1999) has been further investigated by a quarry operator. Auger holes were drilled, samples were taken, and the samples were subject to grading, physical and chemical analysis. A geophysical survey was also undertaken. The gravel fraction was found to be from a mixture of rock types, and the sand fraction was found to be generally somewhat fine. The recoverable reserve was estimated to be only around one third of that indicated in the earlier Symonds report, and the quality was felt unlikely to be competitive with those materials which are currently available in the market, particularly for the manufacture of concrete.

6.13            Whilst the results of this evaluation should not be regarded as representative of the Usk Valley as a whole, they do serve to emphasise the uncertainty surrounding the estimates contained in Figure 6.2.


 

Figure 6.2

Summary of constraints on potential sand and gravel resources identified in Symonds' previous report to the Assembly

Area

Total quantity unaffected by known environmental or planning constraints

Total quantity affected by known environmental or planning constraints

Total estimated quantity within potential resource blocks

Pontarddulais

39.0 million tonnes

31.3 million tonnes

70.3 million tonnes

Vale of Neath

3.3 million tonnes

0.0 million tonnes

3.3 million tonnes

Pyle

34.0 million tonnes

1.9 million tonnes

35.9 million tonnes

Bridgend

3.7 million tonnes

8.0 million tonnes

11.7 million tonnes

Cowbridge-Pontyclun

25.3 million tonnes

29.6 million tonnes

54.9 million tonnes

Upper Rhymney Valley

2.6 million tonnes

1.4 million tonnes

4.0 million tonnes

Lower Rhymney Valley

1.3 million tonnes

12.3 million tonnes

13.6 million tonnes

Lower Usk Valley

0.5 million tonnes

40.8 million tonnes

41.3 million tonnes

Middle Usk Valley

1.9 million tonnes

132.8 million tonnes

134.7 million tonnes

Upper Usk Valley

0.0 million tonnes

23.3 million tonnes

23.3 million tonnes

Total

111.6 million tonnes

281.4 million tonnes

393.0 million tonnes

 

 

Secondary materials from South East Wales

6.14            It is estimated (see, for example, BGS Technical Report WF/00/3/C page 4) that 35-45% of the material dug in Pennant Sandstone quarries and 25% of the material from limestone quarries comprises fines. Most limestone fines are currently used in concrete and in applications such as Macadams (roadbase and base course material, in combination with marine sand), but not all Pennant Sandstone fines find a beneficial use, and some are stockpiled. Figure 5.7 shows the locations of the five existing Pennant Sandstone quarries.

6.15            This study concentrates on the Pennant Sandstone fines (rather than limestone fines, which are already very heavily used), since they represent the more readily accessible source of 'new' material. For the purposes of this study the lower end of the fines range (i.e. 35%) has been used for estimating how much material is produced which might be more fully utilised.

6.16            BGS Technical Report WF/00/3/C notes that Pennant Sandstone crusher fines are "… not considered a waste material but are treated as a residue of the crushing and screening process, which can be sold into certain markets. The restrictions are specifications and costs … some may be used locally on site in the construction of landscaping features or in site restoration". One of the market segments into which Pennant Sandstone fines are sold is asphalt making, reflecting their polish resistant properties.

6.17            In principle, as recognised both in the BGS report and in the earlier Symonds report on land-based extraction, it might be possible to screen more of this material to yield a concreting sand. However, screening alone would not be enough to render the sand-like material suitable. This is because:

(i)                   crushed rock sands typically have a different size distribution than natural sand, with more fines and more large grains, and a deficiency in the middle size range (from 0.15-2.00 mm);

(ii)                  Pennant Sandstone fines in particular contain mainly very fine grains with even fewer grains in the middle and upper size ranges than other crushed rock samples;

(iii)                Pennant Sandstone fines also contain small amounts of coal and clay minerals, predominantly in the smallest fines fraction (<0.075 mm), which could be deleterious for use in concrete, and would need to be removed.


(Figure 6.3 to be inserted here)

 


6.18            The BGS report notes that "… if the finer grain sizes are removed by washing, the material is then too coarse for most applications, due to the lack of 'medium grained' material. The coarse fractions cause workability problems and crushed rock sand is hence not used for building sand (it is too 'harsh')".

6.19            A separation process based on washing/flotation would bring its own problems related to the 'sogginess' of the washed material. Air separation might overcome these problems if the necessary machinery could be developed, but there is no prospect of this in the forseeable future. Most industry sources remain to be convinced about the practicalities of producing any significant amounts of sand substitute from Pennant Sandstone fines without investing in very expensive processing machinery, but screening the as-dug rock prior to feeding the primary crusher shows some evidence of raising the quality and useability of the crusher fines which are an unavoidable by-product of the roadstone production process.

6.20            It should also be recognised that washing out the coal and clay fractions would also inevitably involve significant volumes of water. Even with maximum recycling and recovery, there would be a need for fresh water, and a need to discharge some of the water at the end of the process.

6.21            Whereas using fines from Pennant Sandstone quarries involves using an under-utilised material, another alternative would be to quarry other, weaker rock types for the specific purpose of grinding it up to a sand-like size distribution. Although considerable energy would be required to grind the rock, provided the source rock had been correctly chosen in the first place it might not require further processing to remove impurities such as coal and clay minerals.

6.22            The BGS investigated a range of potential locations for hard rock quarries for this specific purpose in 2000. This is the primary focus of Technical Report WF/00/3/C. As well as using geological mapping to draw general conclusions about the distribution and availability of resources, they collected samples from a range of accessible outcrops, which they submitted for laboratory testing.

6.23            They concluded (see the Executive Summary) that "… the Devonian strata produced crushed rock sands which are likely to be too fine grained for use in concrete and related applications, although a few samples from both the Senni Formation and the Brownstones gave more acceptable results. However, the crushed rock sands produced from the samples of Carboniferous sandstones - the Basal Grit, the Farewell Rock and the unnamed sandstones of the Lower and Middle Coal Measures - gave gradings which are mostly within the required limits for concreting sands. These sandstones are therefore likely to be the best targets for manufacturing sand from hard-rock resources in South East Wales".

6.24            A significant proportion of the BGS' sampling and investigations related to locations in Carmarthenshire, and which therefore lie outside the scope of this study. However, their general conclusion holds good for the rocks which are found in a relatively narrow band along the outer edge of the coalfield. This band runs in a massive arc from north of Bridgend, past Caerphilly, to the west of Cwmbran and northwards to Blaenavon. From there it turns westwards, running along the heads of the valleys, close to the southern border of the Brecon Beacons National Park.

6.25            Within the study area, some of the technically best samples tested by BGS came from the area around Blaenavon. Relatively few samples from the Lower Rhymney valley were tested, and none from the area to the west of Cwmbran. A further potential area lies to the east of Newport and north of Chepstow. No samples from this area were tested, because there are few if any surface outcrops of carboniferous rock that enable samples to be collected relatively easily.

6.26            Other minor secondary aggregate materials available (and used) within South East Wales include ground glass and rubber crumb (from tyres). Such materials have limited application as substitutes for primary aggregate in some specialist applications (such as road construction or general fill), but not as a substitute for marine-dredged sand. Ground glass, for example, can be used as 6 to 14 mm chippings within road surfacing materials, but is generally not produced as a sand grade material. These sources are therefore not considered further in this study.


Out-of-area materials

6.27            An alternative, which lies midway between using Pennant Sandstone fines and specially quarried crushed rock, would be to make greater use of the fines from an existing hard rock quarry elsewhere, such as Foster Yeoman's coastal quarry at Glensanda (in Scotland), or Tarmac's Bantry Bay coastal quarry (in Ireland). This would involve using material from the fraction which currently goes to low value applications (or is stockpiled, effectively as waste), but it would involve long-distance transport.

6.28            Material from the Bantry Bay gritstone quarry, like Pennant Sandstone, contains impurities which would need to be removed before the crushed rock sand could be used in concrete. Glensanda therefore represents the more straightforward option.

6.29            Glensanda currently exports crushed rock to continental Europe and crushed rock sand to the South East of England in large boats. Limited tonnages are also supplied in small boats to South East Wales for use in block manufacture, so Foster Yeoman has access to the necessary logistical support to arrange for additional deliveries of material in whatever boat sizes might be required. A reasonable working hypothesis would be for limited additional shipments to be made in boats of the same size as existing ones, rather than in larger boats.

6.30            None of the crushed rock options would produce a substitute for sand for use in mortar or plaster. Using crushed rock in concrete also reduces the workability of the mixture, and increases the demand for both water and cement.

6.31            The only very large-scale resource of waste sand in the UK is in Cornwall and west Devon, at the china clay quarries to be found there. Every tonne of 'good' china clay generates roughly 900 kg of micaceous residue (very fine sand and mica), 3.7 tonnes of coarse china clay sand (quartz silicate), and 2 tonnes each of waste rock and overburden. Although the ratio between 'good' material and micaceous residue is reasonably constant, the amounts of coarser wastes can vary considerably from pit to pit. Typically, the deeper the pit, the more waste is generated.

6.32            Some of the coarse china clay sand is already used, mainly in Cornwall, as a fine aggregate, in concrete and in block manufacture. The economics of re-use or recovery are almost entirely dominated by the distance between the quarry and the main markets for aggregates, because the materials which can be produced are of a relatively low value. However, there are also very substantial waste tips, some of which are constraining the development of new china clay areas. These tips are physically distinct from the tailings ponds into which the very fine micaceous residue is pumped in order to separate the solids from the liquid by natural gravity.

6.33            The factor which has traditionally stopped china clay sand being shipped to areas of the UK in deficit for sand has been the transport cost. The railway link over the Tamar cannot take large freight trains, and road transport is both excessively costly and environmentally damaging.

6.34            In 2000, following investments in new infrastructure, china clay was shipped by sea to the South East of England on a trial basis by Atlantic Aggregates Ltd of St Austell. They already view South East Wales as a target market for future development.

6.35            The material would arrive by sea. The size of each shipment would be limited to a maximum of 3,000 tonnes by the dimensions of the harbour at Par. Material is available at a price of £5 per tonne free on board (fob) Par. It is currently being used as building sand (in conformity with BS 1200 - Building sands from natural sources) as well as for the manufacture of concrete and concrete blocks, as a filler in black top, as chippings and as hardcore. According to 'The reclaimed and recycled construction materials handbook' (CIRIA publication C513, 1999), china clay sand used in concrete "… has a high water demand, which reduces the concrete strength. This is compensated by adding cement, which, in turn, increases the cost of the mix". Cement manufacture is an energy intensive process, so the environmental consequences of higher cement use have to be considered. Energy issues are considered further in Appendix 6, and the main sustainability assessment is reported in Chapter 8.

6.36            One further option involves importing significantly larger volumes of mixed sand and gravel from quarries in England, either by road, or by rail. Material imported by rail would either be blended at the rail head, or transferred to trucks for final distribution by road. It is unlikely that imports would be on a sufficient scale to justify rail transport.


6.37            If imports were on the sort of scale necessary to provide building sand as well as concrete aggregate (which is unlikely), some of the sand would need to be screened for separate use. The remaining gravel fraction could conceivably be mixed with crushed rock sand for use in concrete.

6.38            A final option, which remains speculative, concerns the recovery of foundry sand from old foundry landfills. It is known that the castings industry in South East Wales is small, but it was probably more extensive from the 1940s to the 1970s. Evidence from England shows that some engineering works simply dumped spent foundry sand in on-site dedicated landfills, not realising its aggregate potential. Where such landfills exist, recovering the material is relatively easy provided access is reasonable. This assumes that the landfill has not been built on, and has not been revegetated in a manner that makes it ecologically valuable.

6.39            Some development work using foundry sand in applications such as concrete block manufacture and 'blacktop' has been carried out, as reported in 'The reclaimed and recycled construction materials handbook' (CIRIA publication C513, 1999). However, concrete companies report some limitations on its use in concrete, mainly due to the presence of heavy metals and clay.

6.40            Because of the uncertainties surrounding the availability of foundry sand it has not been built into the alternative patterns of supply. However, it is recommended that MPAs be encouraged to identify any such resources in their planning areas for potential future recovery.

6.41            Other secondary aggregate materials, such as slate waste, are not really relevant here, because they cannot be used as a substitute for marine sand. If the transport constraints can be overcome, slate waste is most likely to be used in relatively low grade applications such as bulk fill. With processing, some slate waste can be used as a light-weight aggregate. A report on the potential for re-using slate waste has been published by the Assembly under the title 'North Wales Slate Tips - A Sustainable Source of Secondary Aggregates' (Arup, 2001).

Three Potential Alternative Patterns of Supply

Introductory comments

6.42            As explained in Chapter 4, the three alternative scenarios are based on the following policy events and assumptions:

(i)                   an end to the dredging of sand from Nash Bank, without any sand and gravel quarries being opened in South East Wales, and without any additional dredging licences being issued for dredging in the Bristol Channel;

(ii)                  an end to the dredging of sand from both Nash Bank and Helwick Bank, again without any new sand and gravel quarries being opened in South East Wales, but with two additional dredging licences being issued, permitting new dredging further offshore in the Bristol Channel;

(iii)                an end to the dredging of sand from both Nash Bank and Helwick Bank, but with sand and gravel and crushed rock quarries being permitted at various locations in South East Wales if required, and with two additional dredging licences being issued, permitting new dredging further offshore in the Bristol Channel.

6.43            The baseline position was set out at the end of Chapter 5, and has been summarised for ease of reference in Figure 6.4.


 

Figure 6.4

Pattern of Supply No. 1 (tonnes)

Material

Used in concrete

Coarse sand

Fine sand

Graded aggregate

Ungraded aggregate or fill

Marine-dredged sand

547,200

273,600

273,600

0

45,600

Limestone dust

273,600

60,000

40,000

0

0

Other crushed limestone

1,647,912

0

0

2,158,866

719,622

Pennant Sandstone roadstone

0

0

0

200,000

0

Pennant Sandstone fines

3,156

28,404

0

0

284,040

Sand and gravel from local quarries

0

0

0

0

0

Crushed rock sand from local quarries

0

0

0

0

0

China clay sand

0

0

0

0

0

Crushed rock sand from Glensanda

0

0

40,000

0

0

Imported sand and gravel

100,000

0

0

0

0

Power station fly ash

0

0

0

0

25,000

Air cooled blast furnace slag

0

0

0

107,500

0

Minestone

0

0

0

0

5,000

Recycled C&D waste

0

0

0

79,200

237,600

Maintenance dredging materials

0

0

0

0

50,000

Total

2,571,868

362,004

353,600

2,545,566

1,366,862

 

 

6.44            Pattern of Supply No. 2 involves the replacement of some (but not all) of the sand currently dredged from Nash Bank. This is because economic theory is clear regarding what happens when a step-change event occurs which restricts supplies of a commodity: the price rises and the quantity traded falls. Since this is an important point, and one that is easily forgotten, the theory behind it is explained here.

6.45            Most people are familiar with the very basic principles of supply and demand. At any point in time producers of a commodity respond to higher prices by supplying more, while consumers respond by demanding less. There is only one stable price (the 'market clearing price') at which supply and demand are in balance (see Figure 6.5, where P0 is the market clearing price, and Q0 is the amount which consumers want to buy and suppliers to sell at P0). Any temporary departure from P0  or Q0 causes disruption, but eventually the market settles back to the same balance between supply and demand.


 

Figure 6.5

'Classic' supply and demand equilibrium

Supply 'curve'

 
Price

 

 

 

 

 

 

 

Demand 'curve'

 
P0

 

 

 

 

 

Q0

Quantity

 

 

6.46            A step-change event is different. A step-change event involves a significant change either in consumers' desire to buy the product, or in producers' ability to supply the previous volume at the previous market clearing price. Examples of step-change events are:

(i)                   the introduction of significant new technology (making it possible for producers to make the product more cheaply, thereby enabling them to cut their prices, stimulating greater demand from consumers);

(ii)                  the arrival of a new competing product (this changes the amount that consumers want to buy, because if the new product is attractive, they use money that previously would have purchased the 'old' commodity: for example the arrival of oranges permanently changed the demand for apples);

(iii)                the granting of a subsidy to consumers by government (which raises the amount which they want to buy, without changing producers' preferences at all).

6.47            These step-changes are all expressed as a shift in one or other of the curves in the basic supply and demand model. New technology would shift the supply curve to the right (i.e. producers are happy to make more than before at the same price). A new competitor for consumers' cash would shift the demand curve to the left (i.e. consumers want less than before at the same price). A consumer subsidy would shift the demand curve to the right (i.e. consumers want more at the old shelf price, because someone else is paying part of the cost).

6.48            Taking some or all of the marine-dredged sand away from the aggregate equation of South East Wales amounts to shifting the supply curve upwards and to the left (see Figure 6.6). It does not affect consumers' preferences (their demand curve stays still), but the market clearing price rises from P0 to P1. As a consequence, the volume of material that consumers want to buy falls from Q0 to Q1.

6.49            This is a long-winded way of explaining that in the absence of a directly comparable source of supply, restricting or removing marine-dredged sand from the supply side of the equation in an otherwise free market will raise prices for sand in South East Wales and reduce its consumption. Some consumers may adopt different construction systems; others will build less. The market will not, however, simply bring in as much sand as before from elsewhere at a higher price, except in the short term to meet unavoidable contractual obligations.


 

New supply 'curve'

 
Figure 6.6

Establishment of a new supply and demand equilibrium after a step change in supply

Old supply 'curve'

 
Price

 

 

 

P1

 

 

 

Demand 'curve'

 
P0

 

 

 

 

Q1

Q0

Quantity

 

 

6.50            Examples of likely adaptation behaviour which would help to reduce the volume of sand demanded would include:

(i)                   greater use of steel in place of concrete in both buildings and civil engineering structures;

(ii)                  greater use of wood and metal cladding in place of brick facing in buildings;

(iii)                greater use of wood and gravel in the garden DIY market (e.g. by building fences and decking and installing gravel paths in preference to garden walls and paved patios/paths).

6.51            Reflecting this piece of theory, Pattern of Supply No. 2 does not involve as much sand as the baseline position.

6.52            In constructing the proposals for Patterns of Supply Nos. 2-4 due note has been taken of the findings of the earlier Symonds report on land-based extraction. Reflecting the economic modelling and analysis which was undertaken at that time, Table 6.13 in that report ranked the potential supply options on the basis of their probable ability to compete. The findings from Table 6.13 can be summarised as follows:

(i)                   the existing scenario of marine-dredged sand and crushed limestone was adjudged to offer the best combination of price and technical suitability;

(ii)                  crushed rock fines from existing Pennant Sandstone quarries were ranked No. 2, though the report warned that "… processing difficulties mean that this source could substitute for only a small proportion of the existing supply of marine-dredged sand";

(iii)                sand and gravel from potential new quarries in South East Wales was ranked No. 3, on the assumption that "… several sources would need to be worked simultaneously throughout the study area to substitute effectively for the existing combination (of materials)", and "… this would have economic impacts on the existing limestone producers";

(iv)                 crushed rock from potential hard rock sources in South East Wales was ranked No. 4;

(v)                  imported china clay sand from Cornwall was ranked No. 5, and adjudged to be "… a marginally viable prospect";

(vi)                 imported crushed rock fines from Glensanda was ranked No. 6, though it was noted that it would "… contribute to an increase in the cost of construction materials";

(vii)               imported sand and gravel from land-based sources in adjoining parts of England and Wales was ranked No. 7, mainly on the basis of "… very high transport costs" which might be partially overcome by taking advantage of "… opportunities for back haulage in Pennant Sandstone lorries returning to South Wales".

6.53            The alternative scenarios underlying Patterns of Supply Nos. 2 and 3 include the assumption that no new sand and gravel quarries (including crushed sand quarries) would be opened in South East Wales. This therefore rules out the third and fourth ranked options from the foregoing list. Guidance from the Steering Group has also encouraged a more positive view to be taken towards the final option (importing sand and gravel by road), provided the scale is not excessive. This reflects the fact that imports already occur, and could be expanded to a modest degree relatively easily.

Pattern of Supply No. 2

6.54            An end to dredging of sand from Nash Bank would involve the loss of around 700,000 tonnes a year of marine-dredged sand currently landed at Swansea, Briton Ferry, Port Talbot (a very small amount), Barry, Cardiff and Newport. The biggest impacts would be felt in the area between Swansea/Neath in the west and Cardiff in the east, since these markets are almost entirely dependent for their supplies of sand on Nash Bank.

6.55            Dredging from Helwick Bank has been at a rate of roughly 90,000 tonnes a year, which is comfortably below the permitted level of 150,000 tonnes a year. It is assumed that, in the absence of sand from Nash Bank, the overall 'take' from Helwick Bank would be raised to more like 140,000 tonnes a year. This would permit the 34,000 tonnes of sand currently supplied to Pembroke from Nash Bank to be replaced by sand from Helwick Bank, and the supply to the Swansea area market from Helwick to be raised from 30,000 to, say, 45,000 tonnes a year.

6.56            Similarly, there is scope for the 'take' from Holm Sands to be raised within the existing licence constraints, from around 150,000 tonnes a year to, say, 200,000 tonnes a year. In theory the 'take' could be raised considerably further, but there are reported to be real technical constraints to raising it significantly.

6.57            Finally, the 'take' from Middle Ground might be expected to rise from around 90,000 tonnes a year to, say, 125,000 tonnes a year.

6.58            The net effect of these changes would be to reduce landings of sand within the study area by around 600,000 tonnes a year (a reduction of 700,000 tonnes from Nash Bank, partially offset by increases from the other areas totalling around 100,000 tonnes a year).

6.59            The employment and environmental effects of these changes are considered in Chapter 8.

6.60            Based on market 'feel' (as opposed to complex modelling), it has been assumed that this step change in the supply pattern (namely a loss of over half of current supplies of marine-dredged sand before any resultant adjustments involving other materials) would lead to a noticeable price rise for sand, and a reduction in the volume bought by users. The volume reduction has been assumed to be 7.5%.

6.61            Including the adjustments described above, it is assumed that the overall response of the companies operating in the market would be broadly as follows:

(i)                   an extra 100,000 tonnes of sand a year would be supplied to the study area from Helwick Bank, Holm Sands and Middle Grounds, leaving a shortfall of 600,000 tonnes of marine-dredged sand compared to the baseline position;

(ii)                  no sand at all would be used as fill;

(iii)                more limestone would be crushed to dust/fines, with a small (roughly 2.5%) increase in the overall demand for limestone;

(iv)                 all (as opposed to much) concrete made with marine-dredged sand would also include the maximum contribution from limestone dust/fines;

(v)                  greater use would be made of limestone dust/fines in other applications currently supplied by marine-dredged sand;

(vi)                 a modest contribution would be made by Pennant Sandstone fines in applications such as concrete, 'blacktop' and block making, without increasing the total amount of sandstone quarried. Most would still be used for bulk fill or quarry restoration;

(vii)               imports of Cornish china clay sand for use in concrete and as a coarse building sand would start (at a rate of one small boat a week, say 130,000 tonnes a year, delivered to several or all of the ports);

(viii)              imports of mixed sand and gravel would rise by 50% (to 150,000 tonnes a year, all being delivered by road), with all of this material used in concrete (as at present);

(ix)                in addition to material supplied for block making, a small share of the demand for concrete sand and fine building sand would be met from crushed rock sand imported from Glensanda, delivered in small boats to a range of ports;

(x)                 10,000 tonnes of fine sand which is already dredged from the river Neath would be landed at Briton Ferry and utilised in construction.

6.62            Figure 6.7 contains a set of specific numbers which are consistent with the above principles. Those numbers which differ from Pattern of Supply No. 1 are shown in bold.

 

Figure 6.7

Pattern of Supply No. 2 (tonnes)

Material

Used in concrete

Coarse sand

Fine sand

Graded aggregate

Ungraded aggregate or fill

Marine-dredged sand

339,460

53,160

147,380

0

0

Limestone dust

339,460

160,000

90,000

0

0

Other crushed limestone

1,460,834

0

0

2,158,866

809,362

Pennant Sandstone roadstone

0

0

0

200,000

0

Pennant Sandstone fines

10,000

20,000

35,700

0

249,900

Sand and gravel from local quarries

0

0

0

0

0

Crushed rock sand from local quarries

0

0

0

0

0

China clay sand

21,497

108,324

0

0

0

Crushed rock sand from Glensanda

20,000

0

60,000

0

0

Imported sand and gravel

150,000

0

0

0

0

Power station fly ash

0

0

0

0

25,000

Air cooled blast furnace slag

0

0

0

107,500

0

Minestone

0

0

0

0

5,000

Recycled C&D waste

0

0

0

79,200

237,600

Maintenance dredging materials

0

0

10,000

0

40,000

Total

2,341,251

341,484

210,900

2,545,566

1,366,862

 

 


Pattern of Supply No. 3

6.63            An end to dredging of sand from both Nash Bank and Helwick Bank would involve the loss of around 730,000 tonnes a year of marine-dredged sand from the South East Wales market. The adjacent South West Wales market would also lose around 70,000 tonnes from Helwick Bank and 34,000 tonnes from Nash Bank.

6.64            Where Pattern of Supply No. 3 differs significantly from No. 2, however, is that in No. 3 it is assumed that the applications to dredge from both Nobel Banks and Culver Sands would be approved, though not necessarily with the upper annual tonnage limits as proposed. Both applications refer wholly or largely to sediment areas where the Assembly is inclined to take a broadly favourable view on applications to dredge (Policy 1).

6.65            The application to dredge from Nobel Banks is for 300,000 tonnes a year, and the application for Culver Sands is for 1.5 million tonnes a year. As a working hypothesis, this Pattern of Supply assumes that the maximum annual 'takes' are set at the same levels as those which apply to Helwick Bank and Nash Bank respectively (i.e. 150,000 tonnes a year for Nobel Banks, and 900,000 tonnes a year for Culver Sands), enabling the resources to last significantly longer as a consequence.

6.66            It is known that the resources on Holm Sands are becoming increasingly difficult to recover. Whereas Pattern of Supply No. 2 assumes that they would have to be dredged in order to make up for the loss of Nash Bank, in Pattern of Supply No. 3 it is assumed that the rate of 'take' from Holm Sands would continue to decline.

6.67            So long as dredging from Middle Ground and Bedwin Sands continues at roughly the current rate, Nobel Banks and Culver Sands would be able to make up the full shortfall from ceasing to dredge Helwick and Nash Banks, and from reducing the 'take' from Holm Sands. Pattern of Supply No. 3 assumes that the combined 'take' from Holm Sands and Middle Ground would be 200,000 tonnes a year. Combined with 150,000 tonnes a year from Bedwin Sands, this would mean that 350,000 tonnes a year would be from close to shore, with the balance (790,000 tonnes a year) from further offshore.

6.68            Therefore, the only difference between Pattern of Supply No. 3 and the base case would be the move from near-shore to offshore dredging, and the consequent changes in impacts on the marine environment and the use of energy resulting from the greater travel distances involved.

Pattern of Supply No. 4

6.69            As for Pattern of Supply No. 3, an end to dredging of sand from both Nash Bank and Helwick Bank would involve the loss of around 730,000 tonnes a year of marine-dredged sand from the South East Wales market, and the loss of around 104,000 tonnes a year from the adjacent South West Wales market.

6.70            Pattern of Supply No. 4 assumes that new licences are issued for dredging further offshore, and that new sources of land-based supply are approved. However, with the availability of land-based sand and gravel, it is assumed that the maximum annual 'takes' from Nobel Banks and Culver Sands are set at 75% of the levels included in Pattern of Supply No. 3, (i.e. 112,500 tonnes a year for Nobel Banks, and 675,000 tonnes a year for Culver Sands), enabling the resources to last significantly longer as a consequence.

6.71            Since the tonnage dredged is seldom if ever equal to the upper limit set in the licence, it is assumed that the actual tonnage supplied to the study area from Nobel Banks would be unchanged from the base case (30,000 tonnes), and that the actual tonnage supplied from Culver Sands would be 520,000 tonnes a year (excluding 34,000 tonnes a year supplied to Pembroke, as at present).

6.72            The assumptions regarding Holm Sands, Middle Ground and Bedwin Sands are the same as they were in Pattern of Supply No. 3 (i.e. that they would provide no more than 350,000 tonnes a year between them).

6.73            The net effect would be 350,000 tonnes a year from close to shore, and 550,000 tonnes a year from further offshore: a total of 900,000 tonnes a year of marine-dredged sand, or a reduction of 240,000 tonnes a year compared to the base case.

6.74            Including the adjustments described above, it is assumed that the overall response of the companies operating in the market would be broadly as follows:

(i)                   900,000 tonnes of sand a year would be dredged, 350,000 tonnes from close to shore and 550,000 from further offshore, leaving a shortfall of 240,000 tonnes of marine-dredged sand compared to the baseline position;

(ii)                  no sand at all would be used as fill;

(iii)                imports of mixed sand and gravel from England would cease, and be replaced by just under 350,000 tonnes a year of sand and gravel from three newly-developed quarries in South East Wales (one to the north of Swansea, one between Port Talbot and Pyle, and the third in the Pontyclun-Cowbridge area), with all of this material used in concrete;

(iv)                 all (as opposed to much) concrete made with marine-dredged sand would also include the maximum contribution from limestone dust/fines, though the total demand for crushed limestone would fall slightly;

(v)                  the contribution made by Pennant Sandstone fines and crushed rock sand from Glensanda in applications such as concrete, 'blacktop' and block making would remain unchanged.

6.75            Figure 6.8 contains a set of specific numbers which are consistent with the above principles. Those numbers which differ from Pattern of Supply No. 1 are shown in bold.

 

Figure 6.8

Pattern of Supply No. 4 (tonnes)

Material

Used in concrete

Soft sand

Sharp sand

Graded aggregate

Ungraded aggregate or fill

Marine-dredged sand

352,800

273,600

273,600

0

0

Limestone dust

352,800

60,000

40,000

0

0

Other crushed limestone

1,417,512

0

0

2,158,866

765,222

Pennant Sandstone roadstone

0

0

0

200,000

0

Pennant Sandstone fines

3,156

28,404

0

0

284,040

Sand and gravel from local quarries

349,090

0

0

0

0

Crushed rock sand from local quarries

0

0

0

0

0

China clay sand

0

0

0

0

0

Crushed rock sand from Glensanda

0

0

40,000

0

0

Imported sand and gravel

0

0

0

0

0

Power station fly ash

0

0

0

0

25,000

Air cooled blast furnace slag

0

0

0

107,500

0

Minestone

0

0

0

0

5,000

Recycled C&D waste

0

0

0

79,200

237,600

Maintenance dredging materials

0

0

0

0

50,000

Total

2,475,358

362,004

353,600

2,545,566

1,366,862

 


The Differences between the Current and Alternative Patterns of Supply

6.76            Some supply options and sources remain constant across all four patterns of supply. These elements are as follows:

(i)                   Pennant Sandstone used as high quality roadstone aggregate;

(ii)                  crushed hard rock sand from local sources (zero in all cases);

(iii)                power station ash;

(iv)                 steel slag;

(v)                  minestone;

(vi)                 recycled aggregate.

6.77            The supply sources that vary are the following:

(i)                   marine-dredged sand (from close to shore);

(ii)                  marine-dredged sand (from mid-Channel);

(iii)                limestone dust;

(iv)                 other crushed limestone;

(v)                  Pennant Sandstone fines used as a sand substitute;

(vi)                 locally quarried sand and gravel;

(vii)               china clay sand from Cornwall;

(viii)              crushed hard rock sand from Glensanda;

(ix)                imported sand and gravel from England delivered by road;

(x)                 maintenance dredging materials.

6.78            Figure 6.9 shows the differences between the four patterns of supply for these specific combinations of supply options and source locations. In practice the use of both crushed limestone and Pennant Sandstone fines is very similar in all four cases.

6.79            It has to be stressed that these are not intended to be fully detailed predictions of what would happen under each of the alternative policy scenarios, and the assumptions which are described here are not intended in any way to reflect on the merits or otherwise of the various applications to dredge marine sand from the Bristol Channel which are currently being considered by the Assembly. They are intended to be credible approximations to what might happen following a period of adjustment, with enough variation to bring out differences in the four patterns of supply when they are compared.

 

Figure 6.9

Relationship between individual supply options and four proposed patterns of supply (tonnes)

Supply options

Patterns of supply

1

2

3

4

Marine-dredged sand (from close to shore)

1,122,000

522,000

350,000

350,000

Marine-dredged sand (from mid-Channel)

18,000

18,000

790,000

550,000

Limestone dust from local quarries

373,600

589,460

373,600

452,800

Other crushed limestone (local)

4,526,400

4,429,062

4,526,400

4,341,600

Locally quarried Pennant Sandstone fines

315,600 (284,040 as fill)

315,600 (249,900 as fill)

315,600 (284,040 as fill)

315,600 (284,040 as fill)

Locally quarried sand and gravel

0

0

0

349,090

China clay sand from Cornwall

0

129,821

0

0

Crushed rock sand from Glensanda

40,000

80,000

40,000

40,000

Imported English sand and gravel

100,000

150,000

100,000

0

Maintenance dredging materials

50,000 (all as fill)

50,000 (40,000 as fill)

50,000 (all as fill)

50,000 (all as fill)

 

 

7.                The Selection and Assessment of Representative Sites

Choosing a Set of Representative Sites

Introductory comments

7.1               In order to compare the four patterns of supply using a sample of representative sites, it was necessary to select sites which represent all significant elements of the baseline Pattern of Supply No. 1, plus sites which represent all significant additions proposed in all of the alternatives. It was also necessary to achieve a reasonable balance between urban and rural settings, and between different parts of the study area.

7.2               Furthermore, it was agreed that some of the supply options which have not been actively pursued in the patterns of supply should also be treated on a similar basis, so that if they needed to be considered in future, the necessary information is available.

7.3               Taking all of these considerations into account, the sites which were chosen are described below and listed in Figure 7.1.

Marine-dredged sand and sea-borne imports

7.4               Although site visits could not be made to the offshore dredging locations, Nash Bank was viewed from the adjacent cliffs, and visits were made to some of the beaches which have generated particular concern as part of the review of coastal processes.

7.5               Visits were made to the sand wharves at Newport and Briton Ferry. These visits were organized primarily to cover the land-based impacts arising from the handling and dispatch of dredged sand, and to allow additional discussions with the dredging companies about operational impacts unrelated to coastal processes.

7.6               The local land-based impacts of potential imports of crushed rock from Glensanda and china clay sand from Cornwall were covered in part through discussions with ABP at Swansea, in part by speaking to the producing companies, and in general terms by the visits to the sand wharves (see above).

Quarries

7.7               Existing limestone quarries were represented by two sites: one large and the other medium-sized, one close to an urban area and the other in a more rural setting. Both quarries have processing facilities to enable them to ship a range of aggregate products.

7.8               Visits were also made to two Pennant Sandstone quarries, both to look at their existing operations, and to look at the potential for expanding the processing of fines.

7.9               Even though at the point that visits were being arranged it was thought unlikely that a hard rock quarry in South East Wales would finally be included within any of the Patterns of Supply, one potential quarry location was visited.

7.10            Six sites identified in the previous Symonds study as possible locations for future sand and gravel quarries in South East Wales were visited, and operational information was gathered from comparable quarrying operations in England. The six sites are geographically widely spread, and occupy a range of settings (urban and rural, constrained by planning and environmental designations and unconstrained). Four are in valley bottoms, and two are more typical of glacial deposits.

Other materials

7.11            Although no changes were expected in the use of recycled demolition waste materials, one representative site was visited. No site visits related to maintenance dredging were organized, but some discussions were held with interested parties.

7.12            Discussions were held with Corus about the possibility of visiting the unused portion of the Llanwern steel works in order to see if it might offer some potential for a major aggregate handling centre for primary, secondary and recycled aggregate. This was not pursued when it became clear that this might well have adverse operational impacts on the remaining steel processes, and on Corus' own proposals for the redevelopment of the remainder of the site.

 

Figure 7.1

Representative sites assessed through site visits

No.

Site

Justification

1

Nash Bank (off Vale of Glamorgan) and nearby beaches

Largest source of marine-dredged sand, clearly visible from cliff tops at Nash Point (as a complement to extensive data review).

2

Sand wharves at Newport

Important urban port for landing marine-dredged sand towards the east of the study area.

3

Sand wharves at Briton Ferry (Neath-Port Talbot)

Important but relatively rural river wharves for landing marine-dredged sand in the west of the study area.

4

Port of Swansea

Potential landing point for alternative materials, in the west of the study area. Under the same management as Port Talbot.

5

Wenvoe (Vale of Glamorgan)

Major existing limestone quarry close to an urban centre.

6

Penhow (Newport)

Medium existing limestone quarry in a more rural setting.

7

Hafod (Caerphilly)

Pennant Sandstone quarry towards the east of the study area.

8

Cwm Nant Lleici (Neath-Port Talbot)

Pennant Sandstone quarry to the west of the study area.

9

Site south of Blaenavon (Torfaen)

Potential hard rock quarry for producing crushed rock sand.

10

Site west of Aberystwyth (Brecon Beacons NP)

Potential sand and gravel quarry in the Usk valley to the north of the study area, in a rural setting, with multiple planning designations, including the Brecon Beacons National Park.

11

Site south of Usk (Monmouthshire)

Potential sand and gravel quarry in the Usk valley to the east of the study area, in a rural setting, constrained by planning designations and possible flooding.

12

Site near Lower Machen (Newport)

Potential sand and gravel quarry in the Rhymney valley to the east of the study area, in a rural setting, constrained by a major aquifer and possible flooding.

13

Site north of Cowbridge (Vale of Glamorgan)

Potential sand and gravel quarry in the Thaw valley near the centre of the study area, in a rural setting, unconstrained by planning designations.

14

Site east of Pontarddulais (Swansea)

Potential sand and gravel quarry exploiting glacial deposits to the west of the study area, in a rural setting, unconstrained by planning designations.

15

Site west of Pyle (Neath-Port Talbot)

Potential sand and gravel quarry exploiting glacial deposits in the west/centre of the study area, close to an urban area, unconstrained by planning designations.

16

Site south east of Cardiff

Recycling centre for construction and demolition waste on the urban fringe.

 


Assessing the Chosen Sites

7.13            With the exception of the visit to Nash Point, all site visits took place during the week 15-19 October 2001. The non-Nash site visits involved a full team of specialists from Symonds in:

(i)                   environmental geology and impacts on the water environment (Dr Alan Thompson);

(ii)                  noise, vibration and air quality (David Leversedge);

(iii)                landscape, visual and amenity impacts and ecology (Roger Cooper);

(iv)                 land use planning and transportation (Peter Hine);

(v)                  economics, environmental management and sustainability (David Knapman).

7.14            The site visits divided roughly equally between 'real' activities on 'actual' sites and 'potential' activities on 'theoretical' sites. This second group required some assumptions to be made. In this respect the approach that was taken had much in common with a screening process for selecting a preferred site for a development project. All of the sites were assessed using the prompt list set out in Appendix 3, ignoring those questions which did not apply to the specific case under consideration.

7.15            Given that some of the sites related to just one part of a supply chain, and that more than one example of certain important elements of the supply system were included in the selection of sites visited, the relationship between the site visits and the supply option Case Studies which arose from them was not a simple 1:1. The supply option Case Studies are listed in Figure 7.2, together with the linkages between the site visits and the Case Studies. The supply option Case Studies themselves can all be found in Appendix 9.

 

Figure 7.2

Supply option Case Studies

No.

Title

Site visits contributing to the Case Study

Other sources contributing to the Case Study

1

Sand dredged from Marine Aggregate Dredging Policy 2 Areas, and landed at wharves in South East Wales

1, 2, 3

Documents supplied by dredging companies and others

2

Sand dredged from Marine Aggregate Dredging Policy 1 Areas, and landed at wharves in South East Wales

2, 3

Documents supplied by dredging companies and others

3

Aggregate from carboniferous limestone quarries in South East Wales

5, 6

 

4

Aggregate from Pennant Sandstone quarries

7, 8

 

5

Sand and gravel from potential new quarries in river valley deposits in South East Wales

10-13

Earlier Symonds report

6

Sand and gravel from potential new quarries in glacial deposits in South East Wales

14, 15

Earlier Symonds report

7

Sand and gravel imported by road from existing quarries in England

-

Information supplied by quarrying company

8

Crushed rock sand from a potential new, dedicated quarry in South East Wales

9

BGS report

9

Crushed hard rock sand from Glensanda

4

Information supplied by Foster Yeoman (company that owns Glensanda)

10

China clay sand from Cornwall

4

Information supplied by Imerys and Atlantic Aggregates

11

Maintenance dredging material from the river Neath

2

Information supplied by Neath Harbour Commissioners

12

Secondary and recycled aggregate

16

 

 

 

How the Case Studies Contribute to the Patterns of Supply

7.16            The four patterns of supply (to be compared and assessed for their contributions to sustainability in Chapter 8) were set out in Chapter 6. The comparisons and assessments to be made are:

(i)                   Pattern of Supply No.2 compared to Pattern of Supply No.1;

(ii)                  Pattern of Supply No.3 compared to Pattern of Supply No.1; and

(iii)                Pattern of Supply No.4 compared to Pattern of Supply No.1.

7.17            Figure 6.9 (at the very end of Chapter 6) sets out the differences between all four patterns of supply. However, the comparisons between each pair of patterns of supply only needs to take account of those elements which differ between the two, so some of the comparisons are less complex than others.

7.18            The key differences between each pair of patterns of supply are set out in Figure 7.3, together with references to the directly relevant Case Studies.

 

Figure 7.3

Differences between the three pairs of Patterns of Supply

Nos.

Differences (compared to Pattern of Supply No. 1)

Case Studies of greatest relevance, and direction of change

2 vs 1

Sharply reduced dredging of sand close to shore (522,000 tonnes vs 1,122,000 tonnes).

Less of No. 1

Marginal (2.5%) increase in crushed limestone production.

More of No. 3

Same level of Pennant Sandstone fine production, but more diverted from fill to higher value uses (66,000 tonnes vs 32,000 tonnes).

No change, No. 4

Large volume of coarse china clay sand imported from Cornwall (130,000 tonnes vs nil).

More of No. 10

Twice as much crushed rock sand imported from Glensanda (80,000 tonnes vs 40,000 tonnes).

More of No. 9

50% more mixed sand and gravel imported from England (150,000 tonnes vs 100,000 tonnes).

More of No. 7

Same level of maintenance dredging, but some of it used as fine building sand rather than fill (10,000 tonnes vs nil).

More of No. 11

Overall reduction (9%) in the tonnage of aggregate going into concrete (2,340,000 tonnes vs 2,570,000 tonnes).

n/a

3 vs 1

Very sharply reduced dredging of sand close to shore (350,000 tonnes vs 1,122,000 tonnes).

Less of No. 1

Very sharply increased dredging of sand from mid-Channel (790,000 tonnes vs 18,000 tonnes).

More of No. 2

4 vs 1

Very sharply reduced dredging of sand close to shore (350,000 tonnes vs 1,122,000 tonnes).

Less of No. 1

Very sharply increased dredging of sand from mid-Channel (550,000 tonnes vs 18,000 tonnes).

More of No. 2

Marginal (2%) reduction in crushed limestone production.

Less of No. 3

Large volume of mixed sand and gravel quarried locally (350,000 tonnes vs nil).

More of No. 5 and/or No. 6

Complete cessation of imports of mixed sand and gravel from England (nil vs 100,000 tonnes).

No more No. 7

 

 

7.19            These comparisons are worked through in Chapter 8, using the Symonds model for assessing progress towards sustainability, which is more fully described in Appendix 4.


(This page is intentionally blank)

 

8.                The Comparative Sustainability of Alternative Patterns of Supply

Description of the Sustainability Assessment Process

8.1               The Symonds model for assessing progress towards sustainability is described in Appendix 4. In essence, it works by asking 37 specific questions designed to show whether (and how) one course of action would be expected to generate a greater or lesser impact than an alternative. It does this for a series of environmental, social and economic receptors and issues.

8.2               The answers to the 37 specific questions which are posed for each 'comparison pair' are then used to evaluate whether the change under consideration is likely to:

(i)                   increase or decrease the stock of capital of a series of environmental, social and economic resources; and

(ii)                  increase or decrease the flow of these same resources.

8.3               By looking at both stocks and flows, the model seeks to distinguish between a large depletion in stocks which has no impact on the rate at which resources are being drawn down, and an equally large depletion which reduces the rate at which resources are used in future. By way of illustration, energy expended to raise the thermal efficiency of a process or structure is inherently less damaging, and more sustainable, than the same amount of energy expended to build a 'business as usual' process or structure, let alone a process or structure which is more wasteful than the outgoing original.

Pattern of Supply No. 2 Compared to the Current Pattern (No. 1)

8.4               Pattern of Supply No. 2 is the pattern which might be expected to emerge if the dredging licence for Nash Bank was withdrawn, without any sand and gravel quarries being opened in South East Wales, and without any additional dredging licences being issued for dredging in the Bristol Channel.

8.5               The main differences between the two Patterns of Supply, as previously summarised in Figure 7.3, are:

(i)                   a sharp reduction in dredging of sand from close to shore (522,000 tonnes vs 1,122,000 tonnes);

(ii)                  a marginal (2.5%) increase in crushed limestone production;

(iii)                the same level of Pennant Sandstone fine production, but with more fines being diverted away from use as fill, and into higher value uses as a sand substitute (66,000 tonnes vs 32,000 tonnes);

(iv)                 a large volume of coarse china clay sand imported from Cornwall (130,000 tonnes vs nil);

(v)                  twice as much crushed rock sand imported from Glensanda (80,000 tonnes vs 40,000 tonnes);

(vi)                 50% more mixed sand and gravel imported from England (150,000 tonnes vs 100,000 tonnes);

(vii)               the same level of maintenance dredging, but with some of the material used as fine building sand rather than fill (10,000 tonnes vs nil);

(viii)              an overall reduction (9%) in the tonnage of aggregate going into concrete (2,340,000 tonnes vs 2,570,000 tonnes).

8.6               The full sustainability assessment of Pattern of Supply No. 2 compared to Pattern of Supply No. 1 (the current pattern) can be found in Appendix 10. The main elements of this comparison, and the conclusions which arise from it are illustrated in Figure 8.1 and summarised in Figure 8.2


 

Figure 8.1:

'Sustainability Scorecard' for Pattern of Supply No. 2 compared to Pattern of Supply No. 1 (the current pattern)

 

 

Clear

Increase in stock (short term)

 

 

Most

Sustainable

 

(2-1) (2-5) (2-10)

­

­­

(2-12)

­

(2-7)

­

Minor

 

(2-2) (2-4)

­­

No

Clear                           Minor

Increase in rate of use (long term)

change

Minor                       Clear

Decrease in rate of use (long term)

 

(2-9)

­

 

 

Minor

Decrease in stock (short term)

 

 

 

 

 

 

 

Least

Sustainable

 

Clear

 

 

 

 

NB:

Only those items of capital where Pattern of Supply No. 2 differs from the current pattern are shown.

Key:

(2-N)

Pattern of Supply No. 2, item of capital number N (see below).

 

N

Item of capital

 

1

2

3

4

5

6

7

8

9

10

11

12

Fossil fuels

Soils and non-energy minerals

Fresh water

Seas and oceans

Clean air and healthy climate

Healthy ecosystems

Human health

Knowledge

Social inclusion

Housing

Means of production

Transport and energy infrastructure

 


8.7               The sustainability gains from Pattern of Supply No. 2 are a reduction in the rate of use (and therefore depletion) of one group of non-renewable resources (marine sand), and a reduction in the potential damage that might otherwise be done to the marine and coastal environment by continued dredging from Nash Bank.

8.8               These gains are at the cost of an increase in the rate of use of another group of non-renewable resources (fossil fuels), and the environmental and social damage done by increased energy consumption and lower levels of economic activity.

8.9               This is illustrated in Figure 8.1 opposite, which provides a 'sustainability scorecard' for Pattern of Supply No. 2 compared to the current pattern of supply. The same information is summarised in Figure 8.2 below, which provides the 'headline findings' from the full sustainability assessment in Appendix 10.

 

Figure 8.2

Predicted differences in the rates of depletion of items of environmental and human/social capital as a result of switching from Pattern of Supply No. 1 to Pattern of Supply No. 2

Gains

èèè

Clear reduction in the rate of depletion

2 - Soils and non-energy minerals

4 - Seas and oceans

Neutral

 

No (or very little) change in the rate of depletion

3 - Fresh water

6 - Healthy ecosystems

8 - Knowledge

11 - Means of production

Losses

ççç

Probably a small increase in the rate of depletion

7 - Human health

Small increase in the rate of depletion

12 - Transport and energy infrastructure

Clear but small increase in the rate of depletion

1 - Fossil fuels

5 - Clean air and healthy climate

9(1) - Social inclusion

10 - Housing

Note:

(1)

Together with a minor decrease in the stock of capital as a result of increased unemployment.

 

 

8.10            Pattern of Supply No. 2 is therefore not inherently more (or less) sustainable than the current pattern, but it does allow certain gains to be traded off against other losses.

Pattern of Supply No. 3 Compared to the Current Pattern (No. 1)

8.11            Pattern of Supply No. 3 is the pattern which might be expected to emerge if the dredging licences for both Nash Bank and Helwick Bank were withdrawn, again without any new sand and gravel quarries being opened in South East Wales, but with two additional dredging licences being issued, permitting new dredging further offshore in the Bristol Channel.

8.12            The only differences between the two Patterns of Supply, as previously summarised in Figure 7.3, are:

(i)                   a very sharp reduction in dredging of sand from close to shore (350,000 tonnes vs 1,122,000 tonnes);

(ii)                  a very sharp increase in dredging of sand from mid-Channel (790,000 tonnes vs 18,000 tonnes).


 

Figure 8.3:

'Sustainability Scorecard' for Pattern of Supply No. 3 compared to Pattern of Supply No. 1 (the current pattern)

 

 

Clear

Increase in stock (short term)

 

 

Most

Sustainable

 

(3-1) (3-5)

xx

Minor

(3-6)

x

 

 

(3-4) x

No

Clear                           Minor

Increase in rate of use (long term)

change

Minor                       Clear

Decrease in rate of use (long term)

 

 

Minor

Decrease in stock (short term)

 

 

 

 

 

 

 

Least

Sustainable

 

Clear

 

 

 

NB:

Only those items of capital where Pattern of Supply No. 3 differs from the current pattern are shown.

Key:

(3-N)

Pattern of Supply No. 3, item of capital number N (see below).

 

N

Item of capital

 

1

2

3

4

5

6

7

8

9

10

11

12

Fossil fuels

Soils and non-energy minerals

Fresh water

Seas and oceans

Clean air and healthy climate

Healthy ecosystems

Human health

Knowledge

Social inclusion

Housing

Means of production

Transport and energy infrastructure

 

 


8.13            The full sustainability assessment of Pattern of Supply No. 3 compared to Pattern of Supply No. 1 (the current pattern) can be found in Appendix 11. The main elements of this comparison, and the conclusions which arise from it are as follows.

8.14            As with Pattern of Supply No. 2, the only sustainability gains from Pattern of Supply No. 3 are in the marine environment. They involve a possible reduction in damage to marine ecosystems (a small and uncertain gain), and a much clearer and important gain in terms of reduced impact on beaches as a result of shifting dredging further offshore (and, specifically, away from Nash Bank). These gains are at the cost of a small increase in the rate of use of fossil fuels, and the environmental damage done as a result of this.

8.15            This is illustrated in Figure 8.3 opposite, which provides a 'sustainability scorecard' for Pattern of Supply No. 3 compared to the current pattern of supply. The same information is summarised in Figure 8.4 below, which provides the 'headline findings' from the full sustainability assessment in Appendix 11.

 

Figure 8.4

Predicted differences in the rates of depletion of items of environmental and human/social capital as a result of switching from Pattern of Supply No. 1 to Pattern of Supply No. 3

Gains

èèè

Clear reduction in the rate of depletion

4 - Seas and oceans

small reduction in the rate of depletion

6 - Healthy ecosystems

Neutral

 

No change in the rate of depletion

2 - Soils and non-energy minerals

3 - Fresh water

7 - Human health

8 - Knowledge

9 - Social inclusion

10 - Housing

11 - Means of production

12 - Transport and energy infrastructure

Losses

ççç

Clear but very small increase in the rate of depletion

1 - Fossil fuels

5 - Clean air and healthy climate

 

8.16            On balance, Pattern of Supply No. 3 is inherently more sustainable than the current pattern, offering a major environmental gain at the expense of relatively small losses.

Pattern of Supply No. 4 Compared to the Current Pattern (No. 1)

8.17            Pattern of Supply No. 4 is the pattern which might be expected to emerge if there was an end to the dredging of sand from both Nash Bank and Helwick Bank, accompanied by a more permissive attitude towards new sand and gravel (and crushed rock) quarries in certain parts of South East Wales, and with two additional dredging licences being issued, permitting new dredging further offshore in the Bristol Channel.

8.18            The main differences between the two Patterns of Supply, as previously summarised in Figure 7.3, are:

(i)                   a very sharp reduction in dredging of sand from close to shore (350,000 tonnes vs 1,122,000 tonnes);

(ii)                  a sharp increase in dredging of sand from mid-Channel (550,000 tonnes vs 18,000 tonnes).

(iii)                a marginal (2%) reduction in crushed limestone production;


 

Figure 8.5:

'Sustainability Scorecard' for Pattern of Supply No. 4 compared to Pattern of Supply No. 1 (the current pattern)

 

 

Clear

Increase in stock (short term)

 

 

Most

Sustainable

(4-6)

¥

(4-3)

¥

 

(4-7)

¥

Minor

 

 

(4-1) (4-2)

¥¥

 

 

(4-4) (4-5)

¥¥

No

Clear                           Minor

Increase in rate of use (long term)

change

Minor                       Clear

Decrease in rate of use (long term)

 

(4-9)

¥

 

 

Minor

Decrease in stock (short term)

 

 

 

 

 

 

 

Least

Sustainable

 

Clear

 

 

 

 

NB:

Only those items of capital where Pattern of Supply No. 4 differs from the current pattern are shown.

Key:

(4-N)

Pattern of Supply No. 4, item of capital number N (see below).

 

N

Item of capital

 

1

2

3

4

5

6

7

8

9

10

11

12

Fossil fuels

Soils and non-energy minerals

Fresh water

Seas and oceans

Clean air and healthy climate

Healthy ecosystems

Human health

Knowledge

Social inclusion

Housing

Means of production

Transport and energy infrastructure

 

 


(iv)                 a large volume of mixed sand and gravel quarried locally (350,000 tonnes vs nil);

(v)                  a complete cessation of imports of mixed sand and gravel from England (nil vs 100,000 tonnes).

8.19            The full sustainability assessment of Pattern of Supply No. 4 compared to Pattern of Supply No. 1 (the current pattern) can be found in Appendix 12. The main elements of this comparison, and the conclusions which arise from it are as follows.

8.20            Pattern of Supply No. 4 offers several sustainability gains: in the marine environment by moving dredging further offshore and by reducing the overall 'take' of dredged aggregate, and by reducing overall energy use and the associated emissions of greenhouse gases and other pollutants. These gains are, of course, not free: they come at the cost of a small reduction in direct employment, and some damage to terrestrial ecosystems and the water environment as a consequence of land-based quarrying.

8.21            This is illustrated in Figure 8.5 opposite, which provides a 'sustainability scorecard' for Pattern of Supply No. 4 compared to the current pattern of supply. The same information is summarised in Figure 8.6 below, which provides the 'headline findings' from the full sustainability assessment in Appendix 12.

 

Figure 8.6

Predicted differences in the rates of depletion of items of environmental and human/social capital as a result of switching from Pattern of Supply No. 1 to Pattern of Supply No. 4

Gains

èèè

Clear reduction in the rate of depletion

4 - Seas and oceans

5 - Clean air and healthy climate

Clear but small reduction in the rate of depletion

1 - Fossil fuels

2 - Soils and non-energy minerals

Neutral

 

No (or very little) change in the rate of depletion

8 - Knowledge

10 - Housing

11 - Means of production

12 - Transport and energy infrastructure

Losses

ççç

Very small increase in the rate of depletion

7 - Human health

Clear but small increase in the rate of depletion

3 - Fresh water

9(1) - Social inclusion

Clear increase in the rate of depletion

6 - Healthy ecosystems(2)

Note:

(1)

(2)

Together with a minor decrease in the stock of capital as a result of increased unemployment.

Reducing with time if sites are restored to enhance biodiversity.

 


8.22            Whilst Pattern of Supply No. 4 offers more gains, compared with the current situation, than do either of the other alternatives, it does so at the expense of some important losses. Whilst some of these are capable of mitigation, the overall sustainability balance is less positive than that offered by Pattern of Supply No. 3.

Conclusions from the Sustainability Assessment Process

8.23            This section draws together the results of the three 'comparison pairs' set out above (and in more detail in Appendices 10-12) in an effort to draw whatever conclusions can reasonably be drawn about the sustainability implications of the three possible policy changes.

8.24            All three 'comparison pairs' yield conclusions about the expected impacts on stocks and flows of 12 items of environmental and human/social capital. Because the changes under consideration are policy changes rather than physical developments, the changes in capital are very limited, certainly when compared to the likely changes in rates of future use of resources.

8.25            Figure 8.7 sets out the comparisons, including the baseline case (Pattern of Supply No. 1), which clearly involves no change from the present position. Figures 8.1, 8.3 and 8.5 present the same information, but in a more visual way, to facilitate comparisons between the four patterns of supply.

8.26            The main points to be noted from Figure 8.7 and from a comparison between Figures 8.1, 8.3 and 8.5 are as follows:

(i)                   all gains (i.e. items to the right of the 'no change' point on the 'sustainability scorecards') are environmental;

(ii)                  in Patterns of Supply Nos. 2 to 4 there are trade-offs between some environmental gains and a mixture of environmental and human/social losses;

(iii)                Pattern of Supply No. 2 offers two clear gains but many more minor losses;

(iv)                 Pattern of Supply No. 3 offers one major and one minor gain at the expense of fewer (and smaller) losses;

(v)                  Pattern of Supply No. 4 offers more gains than the other two, but also some clear losses, most notably affecting terrestrial ecosystems.

8.27            The human/social losses (which affect Patterns of Supply Nos. 2 and 4) are all almost certainly capable of mitigation. If such mitigation is assumed, then Pattern of Supply No. 2 may present a slight improvement in overall sustainability, compared with the current situation, and No. 4 becomes an even starker choice (between savings of natural resources and a reduction in global warming on the credit side, and potential damage to terrestrial ecology on the other). Overall, Pattern of Supply No. 3 appears to offer the prospect of a more sustainable outcome than the others, but the differences are relatively slight and are influenced by the weighting attached to individual issues.

 

Figure 8.7

Predicted differences in the rates of depletion of items of environmental and human/social capital between four pattern of aggregate supply

Items of capital

Baseline (Pattern of Supply No. 1)

No. 2 vs No. 1

No. 3 vs No. 1

No. 4 vs No. 1

1. Fossil fuels

No change

Small increase

Very small increase

Small reduction

2. Soils and non-energy minerals

No change

Clear reduction

No change

Small reduction

3. Fresh water

No change

Very little change

No change

Small increase

4. Seas and oceans

No change

Clear reduction

Clear reduction

Clear reduction

5. Clean air and healthy climate

No change

Small increase

Very small increase

Clear reduction

6. Healthy ecosystems

No change

Very little change

Very small (and uncertain) reduction

Clear increase(2)

7. Human health

No change

Probably a small increase

No change

Very small increase

8. Knowledge

No change

Very little change

No change

Very little change

9. Social inclusion

No change

Small increase(1)

No change

Small increase(1)

10. Housing

No change

Small increase

No change

No change

11. Means of production

No change

Very little change

No change

No change

12. Transport and energy infrastructure

No change

Small increase

No change

No change

Note:        (1)           Together with a minor decrease in the stock of capital due to increased unemployment.

                (2)           Reducing with time if sites are restored to enhance biodiversity.

 


(This page is intentionally blank)

 

9.                Discussion, Conclusions and Recommendations

Discussion

9.1               Chapter 2 establishes that aggregates are crucial to society, and describes three main considerations which were central to the decision to commission this study, namely:

(i)                   the continuing uncertainty that surrounds the long-term effects of dredging for sand in the Bristol Channel, on which South East Wales has traditionally been highly dependent;

(ii)                  a desire to achieve reasonable long-term security of supply as far as aggregate in South East Wales is concerned, even if that means considering the exploitation of land-based sources; and

(iii)                the importance which the Assembly places on sustainability right across the spectrum of policy issues.

9.2               Chapter 3 explains in more detail why coastal processes are perceived as such an important issue, and describes what is meant by sustainability.

9.3               The work which has been done for this study on coastal processes, and which is summarised in Appendix 5, has gone some way to resolving the long-standing differences of opinion and interpretation which had for many years divided the researchers who have studied the Bristol Channel, and who have attempted to predict the consequences of dredging for sand.

9.4               This has fed into the sustainability assessment, which is based on a comparison of the likely consequences of three policy scenarios which might be put forward as alternatives to the present position. These three policy scenarios, as set out in Chapter 4, are as follows:

(i)                   an end to the dredging of sand from Nash Bank, without any sand and gravel quarries being opened in South East Wales, and without any additional dredging licences being issued for dredging in the Bristol Channel;

(ii)                  an end to the dredging of sand from both Nash Bank and Helwick Bank, again without any new sand and gravel quarries being opened in South East Wales, but with two additional dredging licences being issued, permitting new dredging further offshore in the Bristol Channel;

(iii)                an end to the dredging of sand from both Nash Bank and Helwick Bank, but with sand and gravel and crushed rock quarries being permitted at various locations in South East Wales if required, and with two additional dredging licences being issued, permitting new dredging further offshore in the Bristol Channel.

9.5               As is made clear there, these are not policy prescriptions, but theoretical options designed to highlight the real choices to be made. The selection of these options does not imply any judgement on the merits (or otherwise) of the various applications to dredge sand from the Bristol Channel that are currently being considered by the Assembly.

9.6               Chapters 5-7 provide an analysis of these three policy scenarios, and an assessment of what they might mean in practice. It is a fundamental plank of this study that any comparison between policies (or between aggregate supply options) must be between complete portfolios of supply, not between pairs of individual elements (such as marine dredging and quarrying). This is because aggregates vary in their quality and potential uses, such that varying one element in the equation generally has knock-on impacts on all (or most) of the other elements. Most obviously, replacing marine-dredged sand with quarried sand inevitably has knock-on effects on the pattern of demand for crushed rock, because quarried sand almost always comes mixed with gravel, which will therefore displace some of the crushed rock that was formerly blended with marine sand for use in concrete.

9.7               One of the crucial findings from the analysis reported in Chapters 5-7 and the accompanying Appendices, is that marine dredged sand is a very high quality material, which makes high quality concrete with a relatively low input of cement and water. The manufacture of cement requires very considerable amounts of energy, with the result that replacing marine sand with alternative materials which have a higher need for cement, generates a noticeable increase in the emission of greenhouse gases (mainly carbon dioxide from fuel combustion).

9.8               These considerations, and many others, fed into the conclusions on the overall sustainability of the different policy options (and their accompanying patterns of aggregate supply) which are reported in Chapter 8. These results were obtained using Symonds' sustainability model (described in Appendix 4). Like all models, this is intended to be an aid to decision making, not a rigid mould into which every situation should be forced. It also generates an 'audit trail', in the sense that any user or interested party can work through the specific questions answered in response to each proposed change, to see how each individual answer affects the broader questions about sustainability. This is important since, as noted in Chapter 8, the differences in overall sustainability are relatively slight, and are likely to be influenced by the weighting attached to each issue by different people.

9.9               In particular, the conclusions from Chapter 8 need to be considered in the light of the findings on coastal change reported in Appendix 5. The latter are included in the sustainability assessment itself, but they also merit particular attention, given that concerns about coastal change were substantially responsible for prompting the Assembly to commission this piece of research in the first place).

9.10            Therefore, the wider question is: when both coastal processes and wider sustainability are considered on a roughly equal basis, how (if at all) does this change the conclusions about policy choices?

9.11            The evidence on coastal change (in Appendix 5) suggests that there are indeed links between dredging activity and coastal processes, and that these are likely, in some cases and particularly around Nash Bank, to be reflected in future changes to adjacent beaches if dredging continues. The timescale for these delayed effects is likely to be measured in decades rather than years, suggesting that the prudent response would be to seek alternative arrangements to the dredging of sand from some of these areas.

9.12            What emerged from the wider review of data from the Bristol Channel was that the cases of Nash and Helwick Banks are not directly comparable. The evidence from Helwick Bank suggests that losses from current dredging are replaced from external sources, and that those sources are not the beaches of the Gower peninsula. The most likely sources of sediment involved here are extensive sand deposits within Carmarthen Bay and the sand wave field that includes the Nobel Banks prospecting area.

9.13            As reported in paragraph 9.4 above, the sustainability assessment looked at three main alternatives to continued dredging, which in the specific context of Nash Bank can be summarised as:

(i)                   an end to all dredging from Nash with no replacement licences issued;

(ii)                  an end to dredging from Nash, but with the current tonnage of sand replaced by permitting dredging from further offshore (including Culver Sands); and

(iii)                an end to dredging from Nash, but with some dredging from further offshore (including Culver Sands) allowed, together with some land-based quarrying of sand and gravel.

9.14            The conclusion from Appendix 5 is that, rather than simply shifting dredging further offshore (from Nash to Culver and Helwick to Nobel), it may also be preferable to shift at least some of the dredging towards the west as well as further offshore. This would favour amended versions of Patterns of Supply Nos. 3 and 4, with some of the dredged sand being taken from the Nobel Banks area rather than all from Culver Sands, an end to dredging from Nash Bank phased in over 5 to 10 years, and continued dredging (subject to a precautionary approach) at Helwick Bank.

9.15            However, as the description of current arrangements in Chapter 5 showed, one of the big merits of the current pattern of supply is that most of the marine-dredged sand used in South East Wales is landed very close to its point of first use, keeping road transport to a minimum. Any move to replace sand dredged from Nash/Culver with equivalent volumes from Helwick/Nobel would either require the dredgers to sail further in order to discharge their sand at the same ports and wharves as are currently used, or it would require additional road haulage from Burry Port (and/or Swansea and/or Briton Ferry) to major markets such as Cardiff and Newport.

9.16            Chapter 6 establishes that, with the exception of quarried sand and gravel, most of the potential alternatives to marine-dredged sand have very real practical and environmental costs attached to them. Secondary materials like china clay sand and crushed rock sand significantly increase the demand for water and cement in concrete, and recycled materials offer no effective substitute for sand (as opposed to coarse aggregate).

9.17            The economic case, also set out in Chapter 6, argues for gradual rather than sudden change, and there is nothing in the data on coastal processes to suggest that a managed change cannot be accommodated, over a period of 5 to 10 years. This is similar to the time period that would be required to investigate and progress licences to quarry sand and gravel within South East Wales.

9.18            In general, patterns of supply that rely on a balance of sources are inherently more stable than those that rely on a small number of sources. This is particularly true when one of those sources (i.e. marine dredging) attracts strong hostility from certain segments of the general public, whatever the basis for that hostility.

9.19            Thus, whilst the sustainability analysis favours a shift in the location of dredging (Pattern of Supply No. 3) slightly more than the increased use of alternative (primary and secondary) land-based materials (Pattern of Supply No. 4), it would be prudent to investigate and safeguard these alternative materials for future use and, subject to adequate mitigation of environmental impacts, to develop some of them now.

9.20            In the case of land-based sand & gravel, detailed investigations need to be carried out by mineral operators to assess the technical suitability of potential resources, especially in areas where ecological and landscape impacts can be minimised. To encourage this, mineral operators need to be given a clear signal that technically sound proposals for mineral development in such areas are likely to be met with a favourable response.

9.21            In the case of secondary materials (such as china clay sand, crushed rock sand and foundry sand), the conclusions from this study are that, although they cannot replace marine-dredged sand without significant adverse implications for sustainability, they can displace some of it from certain market segments (not including concrete). They can certainly be used instead of primary aggregates in many low grade applications (such as bulk fill) and positive steps should be taken to achieve this.

Conclusions

9.22            The key conclusions from this study are as follows.

(i)                   The policy prescriptions within MADP are generally prudent, even though the evidence contained in this study points towards a slightly different interpretation of some of the facts compared to that which has obtained before.

(ii)                  There is evidence of sediment transport links between offshore sandbanks within some parts of the Bristol Channel and the beaches of South East Wales. The links are generally weak, however, and do not imply that dredging will inevitably have impacts on the beaches. The exception is Nash Bank where it is clear that dredging cannot continue indefinitely without eventually giving rise to localised impacts on the adjoining coast. No such impacts have yet been detected, and none are anticipated in the short to medium term, but it would be prudent to phase out the current operations here over the next 5 to 10 years.

(iii)                The cases of Nash and Helwick Banks are not directly comparable. Of the two, Nash Bank is far less resilient, because of its location in an area of very high rates of potential sediment transport, and relatively small rates of natural replenishment. Helwick Bank, by comparison, is located within an area of much greater sediment availability, where changes can be buffered by the input of sediment from Carmarthen Bay, without adverse effects on the beaches.

(iv)                 Over the last decade, Nash Bank has been losing volume at a rate that is higher than can be accounted for by dredging alone, and at current levels of shrinkage could be eliminated altogether within a period of 90 to 215 years. Long before that point it would cease to function as an effective breakwater, and impacts would then be felt on the adjacent shoreline. Alternatives to Nash, as an important source of high quality fine aggregate, therefore do need to be found.

(v)                  Most of the potential alternatives have very real practical and environmental costs attached to them. Secondary materials like china clay sand and crushed rock sand significantly increase the demand for water and cement in concrete (thereby increasing fossil fuel consumption and emissions of greenhouse gases), and recycled materials generally offer no effective substitute for sand (as opposed to coarse aggregate).

(vi)                 Good quality land-won sand and gravel deposits offer far greater potential in all of these respects, but also have inevitable impacts on landscape, ecology and the water environment (in particular). These, however, could largely be mitigated, through a combination of careful location and implementation of best working practices.

(vii)               Irrespective of environmental considerations, there is no real chance that all of the marine-dredged sand currently landed in South East Wales could be replaced, (even drawing on all realistic alternative sources of supply), without raising the cost and reducing the quality of construction. This would have definite adverse economic consequences for the region, and would not be justified on sustainability grounds. It would also result in environmental impacts being exported.

(viii)              Subject to detailed technical assessments of individual prospects being carried out to prove their quality, it should, however, be possible to replace a proportion of the marine-dredged sand by land-won alternatives. Providing that the associated environmental impacts were adequately mitigated, a partial substitution of marine sand with land-won alternatives would provide a more sustainable pattern of supply than that which exists as present.

(ix)                Overall, however, this study has indicated that the clearest increase in sustainability would be achieved by a gradual shift of dredging operations from inshore areas (particularly Nash Bank) to other areas further offshore and/or further west. This conclusion is subject to the findings of ongoing and future site-specific environmental assessments at the alternative dredging sites. It would be imprudent, therefore, to rule out the future need for land based sand and gravel resources.

(x)                 There is a strong economic case for avoiding precipitate change. Any of the alternative policy scenarios that have been considered could be phased in over a transition period, and clear policy statements of intent, tied to a clear timetable, will encourage more efficient and less disruptive market changes.

Recommendations

9.23            The recommendations that flow from the above conclusions are as follows.

(i)                   Consideration should be given to amending MADP to steer dredging further west along the Bristol Channel and, more specifically, to phase out dredging on Nash Bank over a period of 5 to 10 years. This could be achieved by giving notice that, within a minimum of 5 and a maximum of 10 years, sediment cell CBC1 (which includes Nash Bank) will be re-classified as a Policy 3 area; and that (more immediately) sediment cell IBC2 (which includes Culver Sands) will be re-classified as a Policy 2 area. Further independent research on the geomorphology and sediment dynamics of Culver Bank (not carried out in the present study) might demonstrate that the latter suggestion is unnecessary, but in the absence of such work, a precautionary approach is warranted.

(ii)                  Other things being equal, and subject to appropriate consideration of more detailed and ongoing technical studies, continued dredging on Helwick bank and new dredging proposals for the Nobel Banks area should be viewed favourably unless and until new evidence is found of adverse environmental impacts that can reasonably be linked to these operations.

(iii)                Until such time as it is modified in the light of unequivocal new evidence, the conceptual model developed for this study by Pethick & Thompson (2002) should be used by the Assembly as a context for the evaluation of future dredging applications and for establishing monitoring requirements to be attached to future licenses. These requirements should include full, three-dimensional analysis of bathymetric changes on both licensed areas and adjoining beaches / sand bodies.

(iv)                 As noted in MPPW and stated clearly in the draft Aggregates Technical Advice Note (Aggregates TAN), MPAs should, as a matter or urgency, safeguard significant areas of potential land-based sand and gravel resources (as identified in the earlier Symonds report) until such time as these are either exploited or proved by detailed investigations to be technically unsuitable.

(v)                  In anticipation of the need for at least some land-won sand and gravel in future years, the Aggregates TAN should provide mineral operators with a positive signal that well-founded applications for extraction within appropriate (generally unconstrained) locations will be given favourable consideration. This could take the form of ‘Provisional Preferred Areas’ as outlined in the earlier Symonds report on land-based extraction.

(vi)                 The Assembly and the South Wales Regional Aggregate Working Party should establish a mechanism for keeping future supply options under review. As well as monitoring the effects of marine dredging, it should monitor the progress of technical investigations of potential land-based and secondary aggregate resources, to determine the extent to which these can be relied upon, if and when required. Depending on the findings of such reviews, future policy options may need to be revised.

(vii)               To the extent that specific applications can be identified for the use of secondary aggregates such as crushed rock sand and china clay sand in place of primary aggregates, without giving rise to greater environmental impacts overall, the Assembly and Local Planning Authorities should look favourably on any proposals to develop facilities for the import of such materials into South East Wales by sea or rail.

(viii)              The South Wales Regional Aggregate Working Party and/or individual MPAs should carry out at least preliminary desk studies to seek to identify any significant stores of foundry sand in South East Wales in order to establish whether such a material offers a realistic alternative to primary aggregate.


(This page is intentionally blank)

 



[1] The term ‘Welsh Assembly Government’ was adopted during 2001 with respect to the policies and decisions of the Assembly by or on behalf of Ministers and the Cabinet, but the National Assembly for Wales remains the legal name for the corporate body. Throughout this report, the term ‘the Assembly’ has been used to refer to both the National Assembly and the Assembly Government.

[2] Membership of the project Steering Group is detailed in Annex 1 at the end of this report.