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Llanelli Sand Dredging Ltd

Latest News / Non Technical Summary

Aggregate Production Licence Application,
Area 476 Nobel Banks:

Non Technical Summary

19 September 2002

Environmental Resources Management
Norloch House, 36 King's Stables Road,
Edinburgh EH1 2EU
Telephone 0131 478 6000
Facsimile 0131 478 3636
Email: post@ermuk.com
http://www.ermuk.com

This report has been prepared by Environmental Resources Management the trading name of Environmental Resources Management Limited, with all reasonable skill, care and diligence within the terms of the Contract with the client, incorporating our General Terms and Conditions of Business and taking account of the resources devoted to it by agreement with the client.

We disclaim any responsibility to the client and others in respect of any matters outside the scope of the above.

This report is confidential to the client and we accept no responsibility of whatsoever nature to third parties to whom this report, or any part thereof, is made known. Any such party relies on the report at their own risk.

ENVIRONMENTAL STATEMENT
Non Technical Summary

1 INTRODUCTION

1.1 AGGREGATE PRODUCTION LICENCE APPLICATION

Llanelli Sand Dredging Limited (LSDL) has applied for a production licence for 15 years from the Crown Estate for the extraction of marine aggregates from a site south west of the Gower Peninsula, South Wales.

The proposed licence area is shown in figure 1.

This Non Technical Summary (NTS) is part of an Environmental Statement (ES) that has been prepared by Environmental Resources Management (ERM). The ES reports on the results of an assessment of the environmental impacts of the proposals. The ES, together with a Coastal Impact Study (CIS), prepared by Hydraulics Research Wallingford Ltd, has been submitted with the production licence application as required under the consent procedure for marine aggregate dredging.

The NTS provides an overview of the proposals, and their potential effects upon the environment and the measures that would be taken to minimize these.

1.2 THE CONSENT PROCEDURE

Marine dredging licences are issued by the Crown Estate. As part of the consent procedure, applicants are required to submit a licence application, along with supporting documentation, to the Welsh Assembly Government (the Assembly) in order to obtain a Government View on whether a licence should be issued. The procedure requires that licence applications are advertised and interested parties, including Government departments, agencies and other bodies, are consulted on the proposals. Representations received from interested parties are considered by the applicant who seeks to resolve any concerns through discussion or correspondence. The applicant prepares a report summarising the consultees’ comments and discussions and arranges for a supplementary Environmental Statement to be prepared, outlining how the concerns of consultees were addressed and including a draft schedule of licence conditions. If a favourable Government View is issued, the Crown Estate, as owner of minerals on the seabed, is permitted to issue a production licence, which would include the agreed schedule of conditions.

1.3 OPPORTUNITY TO COMMENT

If you have received the NTS and would like to see the full ES, it is available for inspection during normal working hours at the following offices:

Carmarthenshire County Council
Environment and Economic Development Department
Council Offices
40 Spilman Street
Carmarthen
SA31 1LQ
Tel: 01267 224 655

City and County of Swansea
Planning Department
County Hall
Oystermouth Road
Swansea
SA1 3SN
Tel: 01792 635 735

Neath Port Talbot County Borough Council
Planning Department
Neath Civic Centre
Neath
SA11 3QZ
Tel: 01639 763333

Pembrokeshire Coast National Park
Winch Lane
Haverfordwest
Pembrokeshire
SA61 1PY
Tel: 01437 764636

Pembrokeshire County Council
Planning Department
County Hall
Haverfordwest
Pembrokeshire
SA61 1PY
Tel: 01437 764551

Copies of the ES are available on request from the addresses given below. A charge of £40 will be made as a contribution towards the costs of reproduction. Copies of the CIS are available from ERM at a cost of £40. The ES and CIS are also available on a CD at a cost of £10 plus VAT. Copies of the NTS are available free of charge from ERM or, may be downloaded from the LSDL website: http://www.llanellisand.co.uk.

ERM Norloch House
36 King’s Stables Road
Edinburgh
EH1 2EU
Tel - 0131 478 6000
Fax - 0131 478 3636
E-mail: wendy.fraser@erm.com
ERM contact – Wendy Fraser

If you wish to comment or make representations on the licence application, please write within 10 weeks of the date of publication of this document to ERM at the above address.

2 THE PROPOSALS

2.1 THE PRODUCTION LICENCE APPLICATION AREA

The proposed production licence area (Area 476) is located to the south west of the Gower Peninsula offshore of Carmarthen Bay. The production licence application site covers an area of 93 km2. The area has been named the Nobel Banks (North Outer Bristol Channel). The seabed in the Nobel Banks comprises numerous, approximately north to south orientated sand-waves, which merge in the north to become the southern margin of the relatively flat sandy plane of Carmarthen Bay.

The target resources typically comprise medium grained sands. The commercially marketable sand resources of the Nobel Banks are located primarily on the sand-waves, and on parts of the coastal shelf to the north, towards Carmarthen Bay. The troughs between the sand-waves constitute a substantial proportion of the application area, the deeper parts of which contain unsuitable materials and are beyond the operating capability of the dredging plant likely to be available. For the foreseeable future, dredging would be limited to a maximum depth of approximately 32m Below Chart Datum (BCD).

A voluntary exclusion zone 500m either side of a SOLAS cable which runs through the licence application area has been proposed. The licence application area also excludes the adjacent Carmarthen Bay and Estuaries candidate Special Area of Conservation (cSAC), which lies to the north east.

The resource is suitable for a wide range of end uses including the manufacture of concrete, general building and construction, beach nourishment, coastal defences and as fill for reclamation projects. The production licence application is for a maximum of 4.5 million tonnes over a 15 year licence term, based on the extraction of 300,000 tonnes per year.

2.2 EXTRACTION METHODS

Aggregate extraction would be carried out using a trailer-suction-hopperdredger. This type of dredger trails a suction pipe along the seabed while moving forward at speeds of 1 to 3 knots. The draghead creates shallow furrows 1-2m in width on the seabed. In sandy sediments the draghead removes approximately 0.2 to 0.3m of material each time it passes over the seabed.

The sediment would be pumped directly from the seabed into a hopper on the dredger where it would be stored before being transported to shore. For construction aggregate, the material would be stockpiled onshore before sale. The high quality of the resource is such that no onshore treatment, washing or grading before sale would be required.

2.3 EXTRACTION PROGRAMME

Recovery of 300,000 tonnes each year would typically equate to a total of approximately 400 hours of dredging (less than 5% of the year) within areas defined by the proposed licence. Using LSDL’s dredger the Sospan Dau, the dredging would be confined to approximately two 2-hour dredging periods each day. If a larger dredger was to be used, the dredging time on the application area would be less. In order to optimise vessel occupation, it would be likely that dredging on the Nobel Banks would be undertaken with possibly 2 to 3 campaigns each year, each of 4 to 6 weeks duration. Three active dredging zones would be operated at any one time, covering a total of no more than 15km2 (5.79 square miles), to provide the required range of material sizes.

2.4 NEED FOR THE PROPOSALS

Marine aggregates are expected to remain an important resource within the United Kingdom, and are likely to continue to provide a significant proportion of the aggregates used in South Wales. There is a lack of existing sustainable alternative sources of fine aggregates to supply the South Wales market and there would be substantial difficulties in developing new landbased fine aggregate resources. The Nobel Banks have been identified in an independent report commissioned by the Assembly as strategically important to the South Wales aggregates market.

The Nobel Banks fall mainly within the Outer Bristol Channel Area 10 as identified in the Assembly’s South Wales Marine Aggregate Dredging Policy Consultation Document. This is a Policy 1 area, favoured for marine aggregate exploitation, providing there are no overriding environmental constraints.

2.5 AGREED KEY MITIGATION MEASURES

• LSDL would implement the following key mitigation measures to reduce the impact of the proposals. The environmental assessment takes these measures into account.
• exclusion of dredging within 500m either side of the SOLAS telecommunications cable route;
• exclusion of the area of the Carmarthen Bay and Estuaries cSAC;
• restriction of the active dredging area to 15km2 at any one time, comprising three designated zones which would be defined following the development of LSDL’s Resource Management Plan (RMP);
• 6 months notice (to the Assembly, DEFRA and Crown Estates) to change the active dredge zones;
• the dredging vessels to be used would be fitted with Differential Global Positioning System that would allow accurate positioning of the vessel within 1m. This would allow the resource to be targeted accurately and avoid interference with other seabed users and structures;
• any dredging vessel would also be fitted with an Electronic Management System (EMS) to ensure that dredging operations are kept within the agreed extraction zones. The EMS, which would be monitored by the Crown Estate, would record the vessel’s position every 30 seconds during dredging operations and whilst in transit to and from the licence area;
• the dredging vessel would be equipped with the appropriate navigation and warning equipment (lights, fog warnings, radar and VHF radio) and would comply with the requirements of the International Regulations for Preventing Collisions at Sea (1972);
• access by other vessels to the zone being dredged would be restricted during periods of dredging activity. At all other times, there would be no restriction to activities throughout the whole of the proposed licence area;
• a programme of environmental monitoring would be carried out by LSDL. The scope of the monitoring would be agreed with the Assembly and DEFRA and would be specified in the licence conditions. It would be likely to include bathymetric surveys, to ensure that extraction levels are within those specified in the licence conditions and to safeguard the integrity of other seabed structures such as cables; and
• adherence to the Joint Nautical Archaeology Policy Committee (JNAPC) code of practice regarding potential archaeological interest (see Annex B).

3 IMPACTS OF THE PROPOSALS

The effects of the proposals on the environment, including the physical, natural and human environment (ie people using the area for various activities) are summarised below.

3.1 PHYSICAL PROCESSES

Nobel Banks is one of a number of sand-wave fields extending from south of the Gower Peninsula almost as far as Lundy Island. The seabed of the Nobel Banks area has a series of 2 to 5km long north-south orientated sandy ridges, 500 to 2000m apart and ranging from 8 to 16m in height and 25 to 44m in depth BCD. The bulk of the sand within each wave is relatively immobile but that there is a layer of mobile sand at the surface. This may be the result of the sand-waves either being relict features formed thousands of years ago, or being active but changing so slowly that movement cannot be detected over a time scale of decades.

In the Bristol Channel in general, tidal currents move seabed sediment towards the west, whereas storm waves move seabed sediment in an easterly direction. There is no proven link between the sediments within the proposed Nobel Banks dredging area and areas closer inshore, eg Helwick Bank and the Gower Peninsula. The Nobel Banks may act as a buffer to changes in sediment transport between adjacent areas.

The assessment of the potential impacts that might result from the proposed dredging operations on the physical environment of the Nobel Banks has shown:

• the Nobel Banks are not acting as a barrier to storm waves under current conditions because they are too deep. Further deepening would not affect the height of waves that approach the coast, and no impacts on the coast are predicted from the changes in height of the sand-waves;
• tidal currents would be slightly altered in the immediate area of the depression created by the dredging due to the changes in bathymetry, but modelling predicts there would be no appreciable difference in currents outside the dredging area;
• long-term impacts on the morphology of the seabed would occur with a potential reduction in crest height of some sand-waves by up to 2 to 3m. The form of the sand-waves would however remain, albeit at a greater depth. The results of the CIS indicate that the Nobel Banks are stable or are changing only very slowly. It is predicted that the changes in tidal and wave induced currents that would occur as a result of the dredging would be negligible and would not cause impacts on sand-waves or banks beyond the dredging zone. The impacts would be restricted to the immediate area of the dredging and would be limited in extent; and
• no effects on the general sediment transport regime in the Bristol Channel, and particularly on coastal sediment transport, are anticipated, due to the comparatively small amount of sand that would be removed. Specifically, no beach draw-down is predicted as a result of the proposed operations. Monitoring of the Nobel Banks would identify offshore morphological changes at an early stage and appropriate measures, such as alteration of the dredging programme, would be taken as necessary to prevent any adverse effects.

3.2 WATER QUALITY

Sand would be temporarily released into the water during dredging activities, resulting in a temporary and slight increase in localised suspended sediments and turbidity. The coarser material (above 0.125mm) would settle out rapidly affecting only a small area around the dredger path, but fine sediments (<0.063mm) would take longer to settle and would form a plume extending along the direction of the prevailing tidal current.

There is only a small proportion of fine sediment in the seabed material of the Nobel Banks and the dredging strategy has been designed to target areas of clean sand (ie areas with high sand and low mud, fines or coarse material content). Also, there are no known areas of contaminated sediment within the Nobel Banks area. Suspended solids from dredging would be likely to add to background levels for a short period of time and distance from the dredge site prior to decreasing as a result of the sediment settling out of suspension and mixing with un-impacted waters. Impacts on water quality would therefore be limited in degree, extent and duration.

The results of the CIS indicated that there would be no significant impacts to coastal areas and therefore there would be no impacts on coastal sites designated for their geological or nature conservation interest. The proposed licence area is considered not to be an important feeding area for birds and no impacts on birds or on sites designated for their bird interests are expected.

Disturbance to seabirds, sea mammals and fish due to the presence of the dredging vessel would be of short duration and magnitude taking into account the scale and duration of the dredging operations and the existing levels of shipping traffic in the area.

The dredging operations would have a direct impact on seabed habitats and the associated animal communities. The seabed habitats and the types and numbers of animals identified during a field survey carried out in 2000 showed that the dredging areas are generally similar to the surrounding area and other sand banks in the coastal waters of the British Isles. A few species found were considered to be rare and have been recorded infrequently. However, the seabed communities and species are adapted to sediment disturbance, which would occur naturally on the Nobel Banks during storms.

The main impacts would be in the areas directly affected by the dredger’s suction device (the draghead), with a lesser impact extending to other areas in the vicinity of the dredging due to the deposition of suspended sediments. The affected areas would recover as they become re-colonised by animals from the surrounding areas. Re-colonisation by animals that are suited to living in disturbed sediments would likely be rapid, but it could take some time for seabed animal communities to become fully re-established.

The removal of seabed animals in the dredged areas would result in a reduction in the available food resources. It is considered, however, that this reduction would be small in relation to the potentially available food resources from similar habitats in the area.

Important species such as salmon and sea trout are able to move away from unfavourable conditions, and impacts on potential migration routes are not expected, given the scale and duration of the dredging operations.

It is considered that the dredging activities would not have a significant cumulative impact on the natural environment when combined with other activities ongoing in the area.

3.4 COMMERCIAL FISHING

The exclusion of fishermen from the active dredging zones would have a direct impact on fishermen who fish regularly within the licence application area. No fishermen work exclusively in the area and since dredging operations would only take place in a limited number of zones and periods each year, it is considered that the exclusion of fishermen from the area being dredged would not affect the commercial viability of any fishing activities.

The main impact to fisheries would be the loss of and damage to habitats and benthic (bottom dwelling) communities which are important for commercial species. A small area of seabed would be affected and the impacts caused would be small and short lived. Significant secondary impacts on commercial fish species are not anticipated.

The ongoing fishing activities within the proposed licence area already have an impact on fish, shellfish and the habitats. The proposals would result in some further impacts but no significant cumulative impacts on the viability of fisheries are anticipated.

There is little reported recreational fishing activity in the area and therefore no impacts are predicted.

3.5 DREDGING AND DUMPING ACTIVITIES

There would be no impacts to ongoing aggregate extraction and dredge spoil disposal operations as these are all some distance from the Nobel Banks. The dumping operation at Swansea Bay is sufficiently distant not to cause any impact on the quality of dredged material from Nobel Banks.

3.6 SHIPPING AND NAVIGATION

Area 476 is close to a shipping lane and the approach channel for Swansea Dock. Vessels passing through this area mainly comprise cargo vessels travelling to and from the north west and Milford Haven. Other vessels include the Roll-on Roll-off (ro-ro) ferry from Swansea to Cork, which operates 6 days per week in summer and 4 days per week in winter.

Normal maritime navigation procedures would be observed and it is predicted that no routine impacts would occur on shipping and navigation in the area.

3.7 INDUSTRIAL AND SUBMARINE MANMADE INSTALLATIONS

The only submarine structure within the boundary of Area 476 is the SOLAS Telecommunications cable which runs from Port-Eynon Bay to Kilmore Bay in Ireland. This cable is laid in a south west direction and intersects the eastern and western boundary of the proposed licence area. A 500m exclusion zone either side of the cable is proposed.

Effects from sediment transport would not be anticipated from the dredging activities except in their immediate vicinity, and these would not affect the cable route.

3.8 MARITIME ARCHAEOLOGY AND CULTURAL HERITAGE

No records of any wrecks or non-wreck sites (sunken archaeology formerly on dry land) of archaeological importance have been identified within the vicinity of the licence application area.

No adverse impact on coastal archaeology or historic sites is anticipated from the proposed dredging operations. Impacts on any unknown sites that might be of archaeological and historical importance would be reduced by adoption of the JNAPC Code of Practice in the event of discovery of items or sites.

3.9 MILITARY INTERESTS

There are no sites of military interest within or surrounding the proposed licence area and no impacts from the proposals are predicted.

3.10 LEISURE, RECREATION AND AMENITY

Tourism is recognised as one of the most important sectors in the local area.

The Nobel Banks are approximately 10km from the nearest coast. The proposed licence area is considered not to be particularly important for small leisure craft and other users such as divers, kayakers and wind surfers. For larger pleasure craft on passage through the area, the presence of a dredging vessel is considered not to present a significant hazard as the vessel would comply with the requirements of the International Regulations for Preventing Collisions at Sea and would be present for relatively short operational dredging periods.

Localised and short-lived elevated levels of suspended sediment would be expected when the dredger is working, as a result of the dredging plume and overspill discharge. Given the distance of the operations from coastal areas, no impacts on bathing water quality are predicted.

The intermittent presence of a dredging vessel at a minimum distance of 10km from the coast would have no noise or visual impact on people on the coast.

Dredging on the Nobel Banks would not alter the patterns of sediment transport and deposition in the coastal areas of the Gower Peninsula and there would be no impact from the dredging proposals on any beaches.