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Site Reference Client Name Shotton Power Station for: GDF Suez Shotton Limited CRM.022.004.R.001A

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Page 1: GDF Suez Shotton Limited

Site Reference Client Name

Shotton Power Station for:

GDF Suez Shotton Limited


Page 2: GDF Suez Shotton Limited

Shotton Power Station – Restoration Scheme GDF Suez Shotton Ltd.

Contact Details:

Enzygo Ltd. The Granary Woodend Lane Cromhall Gloucestershire GL12 8AA

tel:01454 269237 fax:01454269760

email:[email protected]

Revised Restoration Scheme


Shotton Power Station


GDF Suez Shotton Limited




November 2013


Tom Bland, Principal Consultant

Reviewer: Kevin Parr, Director


This report has been produced by Enzygo Limited within the terms of the contract with the client 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.

Enzygo Limited Registered in England No. 6525159 Registered Office Stag House Chipping Wotton-Under-Edge Gloucestershire GL12 7AD

Page 3: GDF Suez Shotton Limited

CRM.022.004.R.001 Page 1 November 2013


1.0 INTRODUCTION ....................................................................................................... 2

2.0 BACKGROUND ......................................................................................................... 3

3.0 RESTORATION SCHEME........................................................................................... 4

4.0 SUMMARY ............................................................................................................... 9



Page 4: GDF Suez Shotton Limited

CRM.022.004.R.001 Page 2 November 2013


1.1. Introduction

1.1.1. Enzygo Limited (Enzygo) has been commissioned by GDF Suez Shotton Limited to prepare a Restoration Scheme for the land at Shotton Power Station, Deeside, Flintshire. The scheme is required by Condition 50 of the deemed planning permission for the facility.

1.2. The Site

1.2.1. The subject site comprises 5 hectares of land off Weighbridge Road, Deeside Industrial Estate, Deeside. The land is part of a former steelworks site which has subsequently been redeveloped.

1.2.2. The land is generally flat and currently contains the buildings, plant and infrastructure of the power station. In addition, the site contains internal roads and kerbs, car parking and a dedicated surface water management system. The site is fully enclosed with security fencing.

1.3. The Station

1.3.1. Shotton Power Station is a 210 megawatt (MW) gas-fired Combined Heat and Power (CHP) generating station.

1.3.2. The station was constructed in 2001 primarily to supply heat to the adjacent UPM Paper Mill. The station ceased generating power in June 2012.

1.3.3. The station operated under a deemed planning permission issued on 3 December 1998 by the Secretary of State for Trade and Industry in accordance with Section 36 of the Electricity Act 1989 and Section 90 of the Town and Country Planning Act 1990. A copy of the deemed planning permission is at Appendix 1 to this report.

1.4. Purpose of this Document

1.4.1. This document is intended to satisfy Condition 50 (Cessation of Works and Restoration of the Site) of the deemed planning permission for the site. Condition 50 states:

Within 18 months of the Site ceasing to be used for the purpose of electricity generation, the

Company shall restore the site to a condition satisfactory to the Council, unless by the expiry

of that period a planning permission or application for an alternative use for the Site has been

obtained or sought or otherwise approved in writing by the Council. Such restoration work

shall be undertaken in accordance with a detailed scheme submitted to, and approved in

writing by, and deposited with, the Council.

Reason: To ensure that the site is not allowed to become derelict after the cessation of

electricity generation.

1.4.2. By agreement with Flintshire County Council, the term ‘the Council’ in the above condition is interpreted as meaning the Local Planning Authority (LPA). Therefore the Restoration Scheme is to be submitted to and approved in writing by the LPA.

1.4.3. In accordance with the stated reason for Condition 50, the primary purpose of the Restoration Scheme proposed by this document is to ensure the site does not become derelict now that electricity generation at the site has ceased.

1.4.4. By agreement with the LPA (letter dated 10 October 2013 appended to this Statement) the site must be fully restored in accordance with an approved scheme no later than 30 June 2015.

Page 5: GDF Suez Shotton Limited

CRM.022.004.R.001 Page 3 November 2013


2.1. Introduction

2.1.1. The GDF Suez Shotton Limited CHP Site is one of 9 sites in the UK operated by GDF Suez

Energy International. The Site is located in Flintshire, North Wales on the Shotton Industrial Estate.

2.1.2. The Site comprises two gas turbines, each with a dedicated heat recovery steam generator which produces steam into a common pipework system capable of supplying a single steam turbine and process steam offsite. The plant has a dual fired capability. The primary fuel source is supplied natural gas with distillate available as an emergency backup fuel. The plant has a combined electrical capacity of 210MW power and is embedded into the 132kV grid system.

2.1.3. The existing layout of the site is shown on Figure 1 ‘Site Boundary’ in Section 5 of this report.

2.2. Access

2.2.1. Access to the Site is from A548 onto Weighbridge Road.

2.3. Station History

2.3.1. The Site was originally built by Eastern Electricity/TXU Europe and commenced commercial operation in 2001, operating as Shotton Combined Heat and Power Ltd. The plant is located near to the site of UPM's paper mill in Shotton and supplied process steam to the paper mill until June 2012.

2.3.2. In December 2002, TXU went into administration, and in January 2003, the administrators, PricewaterhouseCoopers successfully restarted the power plant. In October 2003, the plant was bought by Gaz de France (GDF). In 2008 Gaz de France merged with Suez (a major global utility company) to form GDF Suez.

2.3.3. In 2011 International Power and GDF Suez merged and Shotton CHP was integrated into International Power’s UK portfolio. Due to market conditions the station was no longer competitive in the UK market and International Power GDF Suez decided to close the station. International Power GDF Suez has rebranded and is now known as GDF Suez Energy International.

2.3.4. The CHP site is leased by GDF Suez Shotton Limited from Flintshire County Council, who are landowner and landlord.

2.3.5. The site was an operational power station until June 2012 and, having been built just over 10 years ago, is considered to be in good general condition.

Page 6: GDF Suez Shotton Limited

CRM.022.004.R.001 Page 4 November 2013


3.1. General

3.1.1. The general procedure envisaged for the restoration of the site in accordance with Condition 50 and in line with the landlord’s requirements will follow the steps outlined below:

Dismantling of all plant and equipment for re-use elsewhere;

Demolition and crushing of infrastructure not proposed for re-use (concrete pads, roads, kerbs, sumps etc.);

Removal of underground services;

Removal of all pile foundations to a depth of 2m below existing ground level;

Backfilling of the site with crushed demolition material from the site or other suitable material; and

Grading of the site to an approved level.

3.1.2. These proposed steps are detailed further in the sections below.

3.2. Dismantling plant and equipment

3.2.1. The CHP plant itself is to be dismantled for removal from site and reassembled overseas to continue operation as a generating station. The items to be removed from the site for this purpose include, but are not limited to:

Gas turbines including generators and transformers;

Steam turbine including generators and transformers;

Heat recovery steam generators (boilers) including chimney stack;

Water treatment plant;

Control and electrical switchgear;

Air cooled condenser; and

Fuel reception facilities and pumping equipment.

3.2.2. All plant to be dismantled for export will be removed from the site prior to the commencement of demolition, crushing and restoration of the land.

3.3. Demolition of concrete slabs, roads, kerbs and sumps

3.3.1. Following the removal of all plant and equipment in accordance with Section 3.2 above, all surface concrete slabs, sump bases, roads, kerbs, rubble and tarmac will be broken out and crushed on site. The only exceptions to this are entrance tarmac road and tarmac car park at the top of the entrance road. These will be retained.

3.3.2. All buildings will be removed and demolished.

3.3.3. The following is an indicative list of plant and equipment expected to be used in the crushing, grading and screening of demolition material and other demolition works on site:

2 x Hitachi 470 Excavators 1 x Hitachi 210 Excavator

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CRM.022.004.R.001 Page 5 November 2013

Machine Attachments

1 x magnet

2 x Shears

3 x buckets

2 x hydraulic breakers

CAT 226 Skid Steer

Extec Crusher

1 x Access Platform

4 sets Oxy/Propane cutting equipment.

1 x 40 cu yd skips 1 used for metals, 1 used for general waste.

3.3.4. The use of mobile crushing plant to process demolition material on site will be undertaken in accordance with the requirements of the Environmental Health Services department and will be controlled via a Part B permit (Section 3.5) issued under The Environmental Permitting Regulations (England and Wales) 2010. Suitable noise mitigation measures, in the form of a barrier or other equipment will be used to minimise the impact of the noise produced by the operation of the machine to acceptable limits at the site boundary.

3.3.5. During crushing operations, continuous spraying with water will be carried out to minimise dust emissions to surrounding site users and their neighbours. Dust emissions will be controlled in line with the operator’s environmental permit and current Best Available Techniques (BAT) (i.e. through application of Process Guidance Note 3/16(12) - Statutory guidance for mobile crushing and screening - September 2012).

3.3.6. All plant and machinery will be operated in accordance with the manufacturer’s specifications.

3.3.7. Crushed concrete and tarmac etc. will be used to restore the site to a level platform following demolition and removal of piles and foundations as detailed in Section 3.5 below.

3.3.8. The crushed material will be used to infill any voids as detailed in Section 3.6 below.

3.4. Removal of underground services

3.4.1. As part of the site restoration, all underground service drains, cables and piping within the red line boundary will be removed from the site.

3.4.2. The site drainage sump will be retained.

3.4.3. Following the removal of all underground services the ground will be levelled to leave a flat compacted graded surface as detailed in Section 3.6 below.

3.5. Treatment of pile foundations

3.5.1. The facility is constructed on pile foundations to a maximum depth of 17m. The depth of individual piles depends on the structure they support. The location of all piles in shown on the As Built drawing ‘SHT--00-M-A06T44-CX-001-H - Shotton Piling Layout of Piles’ at Section 5 of this report. These piles were surveyed at the time of construction.

3.5.2. All pile foundations within the fenced area identified on the red line site boundary drawing at Section 5 of this report will be treated in the following manner:

It is proposed to remove piles to a level of 2m below ground level.

The removal process is to be carried out with minimum disturbance to the surrounding ground material.

Page 8: GDF Suez Shotton Limited

CRM.022.004.R.001 Page 6 November 2013

After removal of the pile foundations in the above manner, the ground will be levelled to leave a flat compacted grade surface as detailed in Section 3.6 below.

An indicative cross-section of the proposed pile treatment is shown on Figure 3 in Section 5 of this report.

3.5.3. It has been established, via an independent engineer’s review undertaken by ABB Limited and through discussions with the Environment Agency during the Environmental Permit surrender process, that removal of piles on site to a depth of 2m below ground level will:

Cause minimal disruption to future development of the site;

Provide adequate depth for future construction of pad and raft foundations and adjacent drainage and services on site; and

Be a more appropriate course of action, from a sustainability point of view, than full pile removal.

3.5.4. To confirm the piles on site are located in accordance with the As Built drawing at Section 5, the location of all piles will be mapped at the time of the above works.

3.6. Backfilling

3.6.1. Following the demolition, removal of pile foundations and crushing as described in the sections above, all voids, trenches and the like arising from the demolition works will be backfilled with suitable crushed demolition materials.

3.6.2. Material used for backfilling will have a maximum size of 75mm and will be compacted in 200mm layers by vibrating roller to match the surrounding ground level.

3.6.3. Suitable inert material includes crushed and screened concrete, brickwork and hard blockwork provided it is entirely free from reinforcement, metals, wood, glass, plastic, soft blockwork, rubber, epoxy, vegetation and other impurities.

3.6.4. A quality protocol for crushed material that is to be used as backfill and grading will be put in place as part of the demolition contract to demonstrate the effective recycling of the suitable inert demolition material. The protocol will be based on advice from the Waste Resource Action Programme (WRAP).

3.6.5. It should be noted that the site is asbestos free. No asbestos will therefore be encountered during the dismantling, demolition and restoration of the site.

3.6.6. Any suspected contaminated materials will be segregated, sampled and tested (e.g. subject to Waste Acceptance Criteria (WAC) assessment). Where deemed necessary (i.e. for the protection of human health and protection of the environment) the materials will be removed from site for appropriate off-site treatment and disposal. All necessary waste transfer and/or consignment notes will be maintained.

3.6.7. It is important to remember that only the current site structures are to be processed, not the old steel works melt shop. There should not therefore be any contaminated material encountered. As such, a watching brief is expected to be sufficient to identify any previously unknown areas contamination (e.g. visible staining).

3.6.8. Prior to compaction of fill material, checks will be carried out to ensure that areas to be filled are free from loose rubbish and standing water.

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CRM.022.004.R.001 Page 7 November 2013

3.6.9. During fill operations all necessary precautions to ensure the stability of adjacent structures will be taken. Suitable fill material will be placed and compacted against structures in a sequence and manner to ensure stability and avoid damage where required.

3.6.10. It is envisaged that there will be a net zero balance of fill material and void space (i.e. no material will need to be imported to nor will suitable fill material need to be exported from the site).

3.6.11. Should material need to be imported to achieve agreed finished levels, only suitable clean engineering fill material shall be brought to site. Should there be a need to export clean fill material from the site, there are a number of potential receptors in the form of on-going construction projects in the local area that could receive the material.

3.7. Removal of unsuitable material

3.7.1. Any demolition material which contains impurities or is otherwise deemed unsuitable for use as fill material for the restoration of the site will be removed from the site and disposed of at a facility licensed to accept such material. Details of all material removed from site will be recorded.

3.7.2. If contaminated material is found it shall be clearly demarcated on the ground. Works in that area shall be suspended until agreement has been reached with the LPA regarding remedial actions.

3.8. Fencing

3.8.1. The boundary security fencing and site access gates will be retained in their current positions on site.

3.9. Levels

3.9.1. Site levels will be restored to an approximately level platform, as is currently the case across the site. Existing levels are shown on the existing site layout drawing at Section 5 of this report.

3.9.2. At present, there is some variation in levels across the site depending on the overlying use (e.g. road, building platform). As such, levels are proposed to be retained to ensure a flat, building platform suitable for future development is left at the site. The proposed post-restoration levels are shown on Figure 2 in Section 5 of this report.

3.9.3. At the edges of the site, ground levels contour up or down to tie in with the adjoining land. The pre-existing ground level surrounding the site slopes down gently from north to south. As such, to obtain a level site platform, the site was cut into the ground at the northern end of the site and raised at the southern end. This has resulted in some berms around the site that will be retained following restoration. At the site edges, ground levels will be matched to surrounding ground levels by battering the ground at an angle no greater than 30o.

3.9.4. At the western end of the site the land slopes down to meet the industrial estate access road, Weighbridge Road. Within the site this slope has been planted with a number of semi-mature trees. This slope continues along the alignment of Weighbridge Road outside the boundaries of the site and will be retained following restoration of the site.

3.10. Noise and Dust Mitigation

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CRM.022.004.R.001 Page 8 November 2013

3.10.1. Measures will be taken to ensure works on site do not generate unacceptable levels of noise or dust during the restoration of the site. These works will include:

Damping of exposed surfaces during prolonged spells of dry weather;

Sheeting of all loads which export demolition material from the site on to the public highway (in accordance with Condition 10 of the deemed planning permission for the facility);

No vehicle will be allowed on the public highway unless its wheels are clean; and

All plant and equipment used in the restoration works will be operated in accordance with the manufacturer’s specification and will be fitted with any necessary silencing equipment.

3.11. Timeframes

3.11.1. It is currently envisaged that the dismantling, demolition and restoration of the site will follow the timetable below.

Item Timeframe

Dismantling and removal of CHP plant for export (during which time no material would leave site)

3 months

Off-site removal of assets and shipping to final destination 2 months

Demolition of remaining structures 3 months

Total project timeframe 8 months

3.11.2. It is proposed that the start date, and consequent end date, for the project will be advised to the LPA within 3 months of the date of this report. In any case, the full restoration of the site, as required by Condition 50 of the deemed planning permission, will be completed by the agreed date of 30 June 2015.

3.12. Vehicle Movements

3.12.1. The dismantling and export of the site infrastructure is estimated to generate approximately 220 loads leaving the site. It is envisaged that this will include approximately 94 abnormal indivisible loads moving from the site. All relevant authorities will be notified of this operation as required.

Page 11: GDF Suez Shotton Limited

CRM.022.004.R.001 Page 9 November 2013


4.1. This Restoration Scheme is intended to discharge the requirements of Condition 50 of the deemed planning permission for the Shotton CHP Facility, owned and operated by GDF Suez Shotton Limited.

4.2. The purpose of the scheme is to ensure the site does not become derelict following cessation of generating activity. The facility ceased generating in June 2012.

4.3. The main aspects of this Restoration Scheme are:

The removal of all plant and equipment from the site;

Demolition of concrete pads, roads, kerbs and sumps on site;

Crushing and screening of demolition material;

Removal of pile foundations to a depth of 2 metres below existing ground level; and

Use of suitable crushed material from on site for the backfilling of the site to existing ground levels.

4.4. The works required by the Restoration Scheme will take approximately 5 months to complete.

4.5. The restoration of the site as proposed by this Restoration Scheme is considered to be the most appropriate approach to ensure that the restoration works are completed to a satisfactory standard whilst minimising any potential environmental harm as a result of the works. The restoration will also result in a developable building platform for future use of the site.

4.6. The restoration of the site is also subject to the Permit Surrender requirements of Environmental Permitting (England and Wales) Regulations 2010 administered by the Environment Agency.

Page 12: GDF Suez Shotton Limited

CRM.022.004.R.001A November 2013


Figure 1 – Site Boundary

Figure 2 - Proposed Site Layout

Figure 3 – Indicative Cross Section of Pile Removal

SHT--00-M-A06T44-CX-001-H - Shotton Piling Layout of Piles

Page 13: GDF Suez Shotton Limited

CRM.022.004.R.001A November 2013


Department of Trade and Industry Deemed Planning Permission dated 3

December 1998

Letter from the Environment Agency regarding Environmental Permit

surrender dated 29 January 2013

Extension of time letter from Flintshire County Council dated 10 October


Page 14: GDF Suez Shotton Limited