2

DeltaCivil Engineering Company Limited

ASHLEY RISING MAIN REPLACEMENT

FEASIBILITY STUDY FOR RIVER EXE CROSSING

CLIENT: DEVON COUNTY COUNCIL

SEPTEMBER 2008

Final Issue

NEWTOWN ROADHIGHBRIDGESOMERSETTA9 3PX

Telephone: 01278 764100Fax: 01278 764111

Email: [email protected]

Delta Civil Engineering Company Limited

J765 Feasibility Study for River Exe Crossing Rev A 30.09.08 Page 2 of 13

CONTENTS

1 Introduction Page 3

2 Options Page 4

3 Outline Method Statement Page 8

4 Specification Page 10

5 Environment Agency Page 11

6 Budget Estimate Page 12

7 Conclusion Page 13

Appendices

REVISION SUMMARY

Report Status/Issue No Date Issued Summary of ChangeFinal Issue 2 30.09.08 Text to pages 3-8 inclusive & 12, plus client Q&A

including sample MS as Appendix 3Draft Issue 1 10.09.08 -



1 Introduction

Devon County Council are to replace the existing leachate rising main which connects theirAshley Landfill site pumping chambers to their existing discharge tank within South WestWater’s Tiverton Sewage Treatment Works. Hydraulically, they require a 125mm IDdiameter HPPE pipe to be installed as a pumping main.

The preferred route is approximately 1.1 kms in length and travels from the landfill site alongthe A396 up to a field access gate. From here is it directed through a field, to the east of thehighway beneath the River Exe using HDD techniques and exits either within the STW,adjacent to the existing rising main or outside the STW in a field at the opposite end of thesite. From either of the proposed HDD exit locations the pipeline will continue in open cut tothe existing discharge tank.

Delta Civil Engineering has been asked to carry out a feasibility study to determine the mostcost effective and practical solution for crossing the River Exe using HDD techniques due tothe environmentally sensitive nature of the River Exe and its surrounding area. Currently weare able to table three HDD options (A, B and C) to minimise impact on the river and riverbanks during the drilling operations. The three routes are shown on sketch/drawingJ765/SK01 Rev 0 in the Appendices section of this report and each option is described indetail on the following pages.



2 Options

Option A

Launch location is situated in the field adjacent the A396 near the boundary hedge andtravels parallel to the existing outlet channel to an exit point located near the top of theembankment just past the circular concrete filter tank and before the outfall into the STWoutlet channel.

A predicted HDD profile (VSH drawing T783091-R-X-01) has been prepared for this originaloption and is included for your perusal. The drill length is 147.3 and is between 9.3m to11.4m below the river bed as it travels beneath the River Exe. This has been based on theground information provided and should mitigate the breakout of drilling fluids into the RiverExe during the drilling operation.

Advantages:

▪ Probably shortest route available.▪ Exits a short distance from existing tank approximately 70m.▪ Sufficient space for the welding and stringing out of pipeline within the STW, and safe

from flooding.▪ Reasonably flat drive with (53.67 L to 53.59 E).

Disadvantages:

▪ Launch location approximately 280 to 300m from field gate across very soft, wet field.▪ Security arrangements for welfare, materials and machinery.▪ Access and reinstatement costs would be high.▪ Complete field below flood plain levels supplied by the Environment Agency which

will involve the mitigation of risk to flooding, protection of machinery, materials andwelfare facilities. The Environment Agency advise that these items are not kept inthe field.

▪ Exit location close to existing mains.▪ Laying of open cut to existing tank will be laid within sloping bank, above existing

outfall into channel with access and working areas for machinery extremely tight.

Option B

The Launch location is within an existing hard standing inside the STW and travels beneaththe River Exe on a line towards the field access gate to an exit location approximately 70mfrom the river and a further 100m from access gate. The river is approximately 25m wide atthis crossing point.

The ground is approximately 2.5m higher than the exit level at Option A and would increasethe drive length to approximately 200m based on an exit drilling profile of 15 degrees.

The exit pit will be located approximately 100m from farm the gate with the welding andstringing out of the 160mm PE pipe taking place along the back of the field adjacent to A396,which can be tied to tree trunks or imported fence posts to secure in case of flooding prior toinstallation. This pipe stringing location is on the very edge of the flooding map supplied bythe Environment Agency (enclosed in Appendix 2).



Option B Continued

Advantages:

▪ Launch location above the flood plain levels.▪ Good security for welfare, materials and equipment.▪ No access road required or reinstatement costs, however drilling contractors will

need to look closely at access route to and through the STW to ensure thatmachinery can be transferred to the drill site location.

▪ Shorter access route (probably 100m) to exit location with minimal machineryrequired to excavate a small exit pit.

▪ Welding and stringing of pipeline will take place at top of field near hedge adjacent tothe A396 and will be secured in case of flooding although it is on the edge of theflood plain.

Disadvantages:

▪ No articulated vehicles can get to launch location.▪ Longer drive length.▪ May block off access route from field into STW for the farmer and may prohibit South

West Water’s site machinery.▪ Will have to offload and reload drilling machinery and recycling plants suitable for a

35t machine, possibly at beginning of access track near Tiverton. However, as a fall-back, if this was not considered cost effective or vehicles would struggle to accessthe launch location, the drive could commence on the other side of the river. Thiswould however increase the access costs, size of working area, but most importantlywill be located close to the river and in the flood plain and against EnvironmentAgency recommendations.

▪ Approximately 2.5m higher than exit location which will involve re engineering toprevent the drilled hole from emptying of drilling fluid during drilling operation (seeQ&A appendix 3 technical Q1).

▪ Open cut route from launch location to tank will interfere with South West Water’svehicular movements and will involve bends (not good practice for rising mains) andadditional manholes and thrustblocks.

Option C

This option has flexibility on its actual launch location. From our survey point, approximately33m from the STW exit gate post, it is approximately 85m to river bank, on a line to the fieldgate on opposite side of river. The ground falls quite rapidly for the first 20 to 30m and itwould help if we could launch as near to the river as possible along this route, to avoidexcessive level differences and keep the drilling fluid in the hole, without further engineering.

The actual drill length, based on a 2m difference in levels and on the same profile as OptionA, would increase the minimum drill length to approximately 155m, but the exit position willdetermined by the 11.4m cover to river bed, rising ground and similar drill profile of 15degrees.

The exit pit will be located approximately 100m from farm the gate with the welding andstringing out of the 160mm pipe taking place along the back of the field adjacent to A396,which can be tied to tree trunks or imported fence posts to secure in case of flooding. Thispipe stringing location is on the very edge of the flooding map supplied by the EnvironmentAgency (enclosed in Appendix 2).



Option C Continued

Advantages:

▪ Launch location mostly above the flood plain levels.▪ Good security for welfare, materials and equipment.▪ Short access and stoned working area to launch location, approximately 20 x 30m

required, with minimal reinstatement costs, however drilling contractors will need tolook closely at access route, to and through the STW, to ensure that machinery canbe transferred to the drill site location.

▪ Shorter access route (probably 100m) to exit location with minimal machineryrequired to excavate a small exit pit.

▪ Open cut route from launch location to tank is quite straight forward and can beaccommodated by directing the pipeline underneath the boundary security fence on aline with the outside of the existing tank inlet (approximately 170m to 180m) mostlythrough natural ground and with very little interference to South West Water’s workstraffic.

▪ No additional manholes and thrustblocks.

Disadvantages:

▪ No articulated vehicles can get to launch location.▪ Will have to offload and reload drilling machinery and recycling plants suitable for a

35t machine, possibly at beginning of the STW access track near Tiverton. However,as a fall-back if this was not considered cost effective or vehicles would struggle toaccess the launch location, the drive could commence on the other side of the river.This would however increase the access costs, size of working area, but mostimportantly will be located close to the river and in the flood plain and againstEnvironment Agency recommendations.

▪ Approximate drive length between 155m to 180m.▪ The level difference between the drilling profile exit level on Option A is 1.2 to 1.7m

higher compared to possible launch Option C levels, but this can be dealt with by re-engineering to prevent the drilled hole from emptying of fluid during drilling operation.

Preferred Option

The preferred route is Option C. Although additional approximate survey information hasbeen obtained along the route from the launch location to the river, a full topographicalsurvey has not yet been carried out for this preferred alignment. Estimates have thereforebeen made of the ground levels along this route and the exit/entry points.

The soils investigation report by Frederick Sherrell Limited 2962.NS.JR, dated 3 August2007 has been taken into consideration to determine the optimum drilling profile and inparticular the necessary clearance beneath the river.

Initial assessment of the borehole data and laboratory test results in relation to the horizontaldirectional drilling method shows following relevant information:

▪ Presence of gravel layer of 1.6 to 2.2m thick: dense fine to coarse.▪ Mudstone/sandstone is fractured and thinly bedded with moderate permeability.

The rock strength indicated requires the use of rock tools: mud-motor with mill tooth tri-conebit for the pilot drilling and hole-opener/rock reamer for the reaming phase.

The minimum drilling radius selected for these tools is approximately 200m which results in aminimum drilling length of approximately 155m.



Preferred Option Continued

Due to the poor quality of the rock it is not possible to carry out accurate mud pressurecalculations. However, the cover to the river bed of 9.3m to 11.4m (as shown on HDDprofile drawing enclosed) is considered to be a safe cover for crossing the river in theanticipated soil conditions. The Environment Agency normally specifies minimum cover of5m for HDD crossings beneath sensitive rivers and have approved in principle our predicteddrill profile.

It is anticipated that a drilling length of between 155 and 180m (dependent upon agreedlaunch position) would enable us to achieve a similar clearance under the river bed asshown on the enclosed HDD profile drawing. This needs to be confirmed following a fulltopographical survey along the preferred option route C and sinking of an additionalborehole to 15m deep on the STW side of the river and on the opposite side of the drill toBH1.

Taking into account the depth of the crossing, the gravel and rock layers present and theenvironmental sensitivity of the crossing it is proposed to install a PE160mm PE100 SDR9(wall thickness 17.8m) with a nominal internal diameter of 124mm. Pressure rating requiredby Devon County Council to be confirmed.



3 Outline Method Statement

A working area will be established at the drilling site on land immediately south of the STW.Top soil will be removed and an area of hardstanding equal to about 600m² (20 x 30m) willbe provided on which the drilling and soil separation equipment will be established.

A temporary road/access route, 100 to 150m in length, will be constructed between the A396and the drill exit point in the low lying field to the east of the roads. A temporary compactedsoil platform/bund will be provided at the exit point to reduce the impact of the flooding fromthe river. The PE pipe will be welded into a single string at a suitable location in this field,probably on the higher ground nearer to the road. It is thought that no ground surfacepreparation will be needed for the welding operation.

The drilling equipment will be brought to the drilling site on several heavy vehicles travellingalong the narrow access road from Tiverton and through the STW. Careful selection ofvehicles and consideration should be given to double handing due to the constricted natureof the access route.

A drilling of this length and diameter would typically require an 18 ton drilling rig. However,based on potential hole stability problems in gravel and poor quality rock it is recommendedto utilise a 35t drilling rig as a minimum. This type of rig has generally speaking not onlymore pulling force and rotational torque, but also a larger pump and better mud mixingcapabilities. By using the larger rig the operation will be completed quicker and thereforereduce the risk of drilling fluid migrating into the river during more protracted operations.

The drilling rig will be set-up at the entry point with the correct entry angle as determined bythe designed drilling profile.

Drilling fluid (mud) will be prepared using a mixing plant assembled alongside the drilling rig.The main ingredient will be bentonite, an inert powdered clay, although additives may beused to adjust the physical characteristics of the mud. Chemicals which could beenvironmentally damaging will not be used. An ample water supply will be required for mudmixing and it is probable that the best source will be the river. An abstraction licence will beobtained from the Environment Agency. A mud cleaning facility to enable the drill cuttings tobe recovered will also be provided.

After equipment has been set-up, pilot drilling will commence utilising a mudmotor poweredby drilling fluid. The motor connected to the drill string will provide the rotation of the tri-conebit and necessary cutting action. The mixture of drilling fluids and cuttings will flow back tothe rig through the drilled hole. Fluid and cuttings will be separated on mud mixing/recyclingunit and fluid will be re-used. Cuttings (gravel and rock chippings) to be used on site or to bedisposed off to a licensed site.

The mudmotor/tri-cone bit will be steered along the trajectory/profile using either ourtensor/true track steering system or our Digitrac survey system. Accuracy of both systems istypically less than two metres.

Upon completion of the pilot, the hole will be reamed to approximately 250mm by connectinga rock reamer/hole-opener to the drill string at the exit point. During reaming the pilot holewill be enlarged by rotating the drilling string and reamer whilst pulling from the rig. Drillingfluid will flow initially to exit point and at some point switch to entry point. All fluid will betransported back to rig side for recycling using with vacuum tankers or mud return lineacross the river.



Outline Method Statement Continued

Upon completion of reaming operations, the product pipe string, laid out in line with thedrilled hole, will be pulled back using swivel and pulling head. The installed pipeline will bepressure tested to the client’s specification. After successful installation, all equipment willbe demobilised from the drilling site.



4 Specification

It is strongly recommended that a Horizontal Directional Drilling machine with a minimumpull-back capacity of 35 tonnes will be used with a high capacity mud pump and mudmixing/recycling unit.

The constituents of the drilling mud will be non-environmentally damaging.

The mud processing system will be designed and established on site in such a fashion as tomitigate the risk of mud escaping into the river or elsewhere.

The establishment and operation of the drilling equipment will be planned so as not tointerfere with South West Water’s operations in the STW or their access to the works.

The field in which the exit point is located is highly susceptible to flooding. All equipmenttaken into the field must be capable of being removed at a few hours notice. No equipmentmay be left unattended unless located on a temporary platform at least one metre high.(These arrangements are required by the Environment Agency.)

On completion of the works, drilling mud will be removed from the site to a licensed wastedisposal facility.

After removal of the drilling equipment the site will be cleaned-up and left tidy.

The product pipe will be black PE160mm PE100 SDR9 with a nominated bore of 124mm(wall thickness 17.8mm). It will be welded in a single string before installation. Afterinstallation within the drilled hole it will be tested in accordance with client’s specification.

Attendances to be Provided by Main Contractor/Client

Preparation and fencing of works areas.

Licence to abstract water from the river for drilling purposes.

Final reinstatement of disturbed ground surfaces.

Liaison with land owners on both sides of the River Exe, including South West Water,Highways and farmers.

Provision of access to all launch and exit locations including through the STW and thepreferred open cut connection route.

Consent from the Environment Agency for carrying out the works (River Exe crossing).



5 Environment Agency

We have made contact with the Environment Agency regarding their requirements andobtained from them information, in respect of levels of flooding in the vicinity, which isincorporated into this document and should be seriously considered.

We have also had a recent telephone conversation with Tom Walling and he has confirmedthat our predicted HDD profile, based on Option A with cover levels to river bed of between7.3m and 9.4m, are acceptable to them and he needs no further information at this stage.However, he recommended that we provide them as soon as possible with a ConsentApplication Form for the works, which will have to include the Site Investigation andTopographical Survey information upon which the predicted HDD profile is based, and routealignment, so that approval can be obtained prior to tenders being sent out. Thesedocuments can then be incorporated into the tender package*. A minimum of eight weeks isrequired by the Environment Agency to formally approve any applications.

* It must be pointed out that whilst our recommended HDD profile can be included inthe contract documents, Delta Civil Engineering cannot accept any liability for thefeasibility information provided if the execution of the directional drilling works iscarried out by others. The profile is based on out own engineering and assumptionsand using our own equipment.



6 Budget Estimate

Because the exact route and distance has not yet been agreed, or the actual set uplocations for exit and entry pits which will determine quality and length/area of access routesto stoned working area it is not yet possible to provide you with a reliable cost for the works.However, an approximate budget band of £200K to £250K should be achievable (see Q&Apractical Q5 appendix 3).

This is dependent upon the information contained in the additional Site Investigation andTopographical Survey (still to be commissioned), plus the actual launch and exit locationsand quality of access routes and reinstatements etc, for the preferred route.


Appendix 1Drawing J765/SK01 Ashley Rising Main, Route OptionsDrawing T783091-R-X-01 Ashley Rising Main, Predicted HDD Profile for Crossing of River Exe


Appendix 2Email Dated 13 August 2008 from TomWallingham, Environment Agency

Environment Agency Flood Depth Data Map


Subject: RE: Preferrred Location of River Exe CrossingFrom: "Walling, Tom" <[email protected]>Date:Wed, 13 Aug 2008 11:48:46 +0100To: "Ian Forrest" <[email protected]>

Ian,

Many thanks for your email regarding the directional drill under the River Exe at Ashley, nearTiverton.

In line with the plan provided, the Agency's depth grid for the 100yr flood indicates a depth offlooding of approximately 2.0m (range from 1.8m to 2.2m) on the floodplain at point A.Unfortunately, I don't have any depth information for floods with a greater probability of occurrence.

>From an Environment Agency viewpoint, a compromise has to reached between the increase inflood risk with a temporary structure in the flood plain and the reduced risks of pollution and damageto the machinery through raising the height of the operating platform.

As a guide, I would say that it would be prudent to raise the working platform to approximately 1.0mabove existing ground levels. It would be your responsibility to ultimately decide a level and theAgency cannot be held liable for any suggested levels.

The Environment Agency would certainly stipulate that any material used to create the workingplatform would have to be removed from the floodplain on completion of works. In addition, theaerial extent of the raised working platform should be kept to a minimum so as to reduce the impactupon floodwater storage in the floodplain.

Regards,

Tom.


Appendix 3Client’s Queries and AnswersSample 35t Machine Method Statement


Dear Mike

Thank you for forwarding the draft feasibility study for the River Exe crossing and allowing us tocomment prior to full submission.

There are a couple of points that could do with developing and expanding and I have divided thesepoints into practical (ie the method statement needs expansion) and technical (to develop thespecification).

26 September 2008Please see answers to all questions below:

Answers:

Technical

Q1 Page 5 and 6 of your report. Can you confirm that it is possible to ensure the drilled holecan be kept full of fluid during the drilling operation and how this is done please?

A There are a number of methods that can be used to ensure the hole is always full of drillingmud. With this hole being relatively small in diameter and the small differential between rigand pipe side the risks involved, if the short section of hole nearest to the rig was to becomeempty, are very small.

Q2 Page 7 of your report (preferred option continued). Can you explain the significance andpossible implications of the lack of the mud pressure calculations? Will this add risk to thedrive?

A There is not a defined method of calculating mud pressure in rock formation. The purpose ofdoing these calculations in other types of sub-soil is to ensure the down hole pressure iscontrolled so as not to cause blow out situations. In rock the importance of designing a drillprofile that is in good stable formation.

Q3 Page 7 of your report: How the 10m figure has been arrived at and considered theacceptable depth?

A The 10m depth was approximate and based upon the information at hand; however this willbe re-visited when the third borehole information is available. (The actual depth below rivervaries from 9.3m to 11.4m and will be corrected in our final submission.)

Q4 Page 6 of your report: Can you provide backup information/specification to support theselection of the 200m radius due to the drill tools required (due to the rock strength)? Thiscauses the HDD to be below the original borehole information. This additional informationwill support the necessity to have the extra borehole.

A The 200m radius is dictated by the stiffness of the drill string and pipes which will have amud motor driving the drill bit.

Q5 Option A: ‘based on ground information and should mitigate the breakout of drilling fluids’.(7.3m to 9.4m below river bed level.) (This should have read 9.3m to 11.4m and will becorrected). How confident are you that the breakout would not occur? – what is the risk of itoccurring? How does this relate to the 10m depth below the river bed criterion as raised inpage 7 of your report?

A Please see answer to question 3 above.


Q6 Can you state how the drill would be tracked and the accuracy of the drill exiting the exitposition required?

A) We would use a down hole steering package which is hard wired to the surface where oursurveyor monitors the drill profile to maintain the design profile and exit location. In simpleterms, the likely accuracy will be well inside your requirements for connecting to the open cutsections at either end.

Practical

Q1 As I asked for in my letter (attached) of 22 May, I intend to submit the project specificmethod statement and specification to the EA prior to contract being let and incorporatingthis and a specification for the HDD into the spec for the tender documents, and hoping tobase it on your method statement. At the moment I don't have enough information.

A We are not prepared to provide a project specific method statement at this stage as this isusually submitted by the successful contractor after award. Also another tenderingcontractor may wish to undertake the drilling in a different way. However enclosed is asample method statement submitted to the EA for a similar scheme crossing under theR Severn in Shrewsbury, using a 35t machine which should suffice.

Q2 How much arisings (from mud mixing and drill cuttings) would be generated? Are they watersaturated to such an extent that they would be difficult to remove from site or/and wouldleave an unsightly mess if left on the farmers/SWW field? How are they normally dealt with?And what type of licensed site is required?

A We presently calculate approximately 80cu/m of arising/drilling mud. The arising will be ableto go to a normal waste reception site with the correct paper work. The drilling mud will betaken by road tanker by a licensed contractor to one of the EA designated sites. Nomaterials will be left on site.

Q3 Can you state the protection measures that could be taken to cover the exit hole from flood(ie bunds and/or capping off of opening).

A The excavation of a bund area using the existing material would need to be constructed.

Q4 I need to confirm that a 35 tonne machine can get through the STW. Can you provide thecontact details for the HDD firm with the 35t machine? I could then try to assess how theycould get through.

A I am happy for you to talk to them but they have assured me that if a 6 or 8 wheeler can getthrough the site then all their equipment is no wider than the trailer and therefore will getthrough. Others may have wider equipment but will have to visit site during the tenderperiod, as we will. The decision as the where we off load and transfer to trailers will be takenthen.

Q5 On the cost issue, can you confirm that the cost of £200K to £250K includes for excavation,haul roads? Can you base it on the preferred option C.

A The price band indicated should cover the HDD works and does include a small stonedaccess track (70 to 100m?) to exit location and access to launch location (30 to 50m whichwill be part of the 600 sq m stoned working area. No haul road(s) were included in ourbudgets. In our experience, if you are bit nervous, it may be prudent to add in a 5%contingency. Your choice!


Q6 I realise I didn't ask for this but could you give an indication of the length of time to carry outoption C? (I have allowed 12 weeks total inclusive of temporary haul roads and excavationsand clean up.)

A 5/6 weeks should be more than adequate for the HDD works only, including tidying up. Butthe open cut works will also require the use of the stoned access/working areas and shouldnot be reinstated until the connections at both ends have been completed and tested.


Sample 35t Machine Method Statement

Sheet 1 of 22

Central Networks / Balfour Beatty Utility Solutions

Horizontal Directional DrillingRiver Severn Crossing

132kV cable ducts

Method Statement

A1

stSeptember

2008Incorporating forward reaming S. Stone D. Lee S. Stone

0 8th

August 2008 Issued for approval D. Sharpe G. Snikkenburg J.S. Wattel

Rev.No

Date Description Prepared Checked Approved

ORIGINATOR COMPANY

DOCUMENT TITLE

Method StatementDirectional Drilling cable ducts

ORIGINATOR DOCUMENT NUMBER

CN- 087007-VSH-C1719-08.5 A

Rev.

DOC no. Method Statement

CN- 087007-VSH-C1719-08.5 Page of

2 22


!""#$ & '(!) *+,+- ./01 2)3Method Statement:Directional Drilling Cable Ducts

Rev. no. ARev.date:

08-08-08

The persons, who have signed this page, declare having read this Method Statement explainedto them by the person in charge of the works. By signing these persons also declare they willcomply with the company procedures and the regulation and procedures mentioned in thisMethod Statement.

The persons signing this page declare having the associated Risk Assessments explained anddiscussed with them by the person in charge of this works. By signing these persons declarethat they have understood it and comply with the Company Policy on Health & Safety &Environment.

Date Name Occupation Company Signature

J.S. Wattel General Manager VSH

D. Fish SHE Manager VSH

D. Lee Contract Manager VSH

S. Stone Project Manager VSH

G Lister Site Foreman VSH

R Travis Rig Hand VSH

M Steele Surveyor Slimdrill

M Hodgkin Mud Tech VSH

Ian Woodhouse Rig Hand VSH

Hans Vlasblom Driller VSH


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Rev. no. ARev.date:

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Contents

1. INTRODUCTION __________________________________________________________ 5

1.1 SITE RULES _______________________________________________________________ 5

1.2 WELFARE FACILITIES ________________________________________________________ 5

1.3 WORKING HOURS ___________________________________________________________ 6

1.4 RESPONSIBILITIES __________________________________________________________ 6

1.5 PERSONNEL ON SITE_________________________________________________________ 6

2. DESIGN & ENGINEERING __________________________________________________ 7

2.1 ACCESS TO THE SITE ________________________________________________________ 7

2.2 WATER SUPPLY ____________________________________________________________ 7

2.3 MUD RETURN LINE __________________________________________________________ 7

2.4 INTERFERENCE AND COOPERATION WITH OTHER CONTRACTORS________________________ 7

2.5 IMPACT ON SURROUNDINGS ___________________________________________________ 7

2.6 SOIL INVESTIGATION, ASSESSMENT AND EVALUATION_________________________________ 8

2.7 DRILLING PROFILE __________________________________________________________ 9

2.8 MUD PRESSURE CALCULATION ________________________________________________ 10

2.9 PULLING FORCE ___________________________________________________________ 10

2.10 DRILLING FLUID ___________________________________________________________ 10

2.11 CONTINGENCIES___________________________________________________________ 11

3. WORK METHOD _________________________________________________________ 12

3.1 INTRODUCTION ____________________________________________________________ 12

3.2 PRELIMINARIES____________________________________________________________ 12

3.3 TYPICAL SITE LAY-OUT / EQUIPMENT SET-UP ______________________________________ 13

3.4 RIG-UP__________________________________________________________________ 13

3.5 PILOT HOLE DRILLING _______________________________________________________ 14

3.6 REAMING AND PULLBACK ____________________________________________________ 15

3.7 REPOSITIONING ___________________________________________________________ 16

3.8 RIG DOWN _______________________________________________________________ 16

3.9 PROVING ________________________________________________________________ 16

3.10 CLEAR-UP _______________________________________________________________ 16

3.11 ABANDONING DRILLING ______________________________________________________ 16


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4. HEALTH, SAFETY AND ENVIRONMENTAL ___________________________________ 17

4.1 RISK ASSESSMENT _________________________________________________________ 17

4.2 TRAINING ________________________________________________________________ 17

4.3 PERSONAL PROTECTIVE EQUIPMENT____________________________________________ 17

4.4 EMERGENCY ARRANGEMENTS / FIRST AID________________________________________ 17

4.5 ENVIRONMENTAL ISSUES ____________________________________________________ 18

4.6 ARCAEOLOGICAL CONSIDERATIONS ____________________________________________ 19

4.7 COSHH_________________________________________________________________ 19

4.8 MATERIALS_______________________________________________________________ 19

4.9 DOCUMENTATION __________________________________________________________ 20

4.10 DRAWING T783086-R-X-01 REV 0 _____________________________________________ 21

4.11 PHOTO OF HDD LOCATION ___________________________________________________ 22


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1. INTRODUCTION

Central Networks via its framework contractor Balfour Beatty Utility Solutions intends to replacethe existing overhead lines across the River Severn in Shrewsbury by underground cable circuits.Three number horizontal directional drillings with a length of approx. 200m each are required toinstall the necessary ducts. Visser & Smit Hanab (UK) Ltd, an underground cable & pipelineinfrastructure solution provider with in-house horizontal directional drilling capabilities has beencontracted via Delta Civil Engineering to design and install these crossings.

This method statement describes the horizontal directional drilling process including design &engineering considerations. Separate detailed method statements will be issued on site foractivities like cranage, PE welding etc.

It should be noted that this Method Statement should be read in conjunction with the followingdocuments:

• CN-087077-VSH-C1719-14.0: Health & Safety Plan construction phase

• CN-087077-VSH-C1719-14.3: Environmental Plan construction phase

None of the works described in this document are to commence unless signed copies of thesedocuments are on site. All Signed copies of these documents shall be kept on file, available forinspection.

1.1 Site rules

At their first visit to site all personnel will undertake the VSH Site Specific Introduction, at whichthe site organization, safety requirements and emergency arrangements will be explained. Alsothe Central Networks, Balfour Beatty & Delta specific project requirements will be introducedand adhered too.

A site register is to be completed at the start and end of each shift.

All visitors to site shall be subject to the same site rules as our employees.

1.2 Welfare Facilities

Welfare facilities in accordance with Construction (Design & Management) Regulations 2007shall be installed and maintained throughout the duration of the works.

The location of the welfare facilities will be at the rig side working location. The facilities shall beaccessible to all directly and indirectly involved personnel including representatives of CentralNetworks, Balfour Beatty and Delta.


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1.3 Working hours

V&SH tries to adhere to the European Working hour's directive with adequate rest breaks anddays off for our employees.Standard working hours are from 07:00 to 19:00 hours. However, in some cases the nature ofthe drilling process might cause us to work days in excess of 12 hours and Employers / MainContractors attendance could be required. However, this is not normal practice and if this ariseswill be communicated with parties involved.

1.4 Responsibilities

The Project Manager is responsible for safety on the site.The general duties of all employees are:

• To ensure that work is carried out so that accidents and ill health to themselves orothers are avoided.

• Too be responsible for there own actions.

• Co-operate with the Company to ensure that all work is carried out in accordance withcurrent Regulations.

• Report unsafe situations to their Supervisor without delay.

• Do not misuse anything provided for Health and Safety.

1.5 Personnel on site

Our site personnel will consist of, but not limited to, the following disciplines:

Occupation Total number onsite

Project Manager 1 personSite Supervisor 1 personDriller 35t rig 1 personDrilling crew 3 persons

PE welder 1 personPE welding operative 1 personExcavator operator 1 person


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2. DESIGN & ENGINEERING

2.1 Access to the Site

Access to the entry site will be from Sydney Avenue, North of the River Severn. It is foreseen totemporary remove part of the existing fence in order for the equipment to enter the field.Temporary road and hard standing for equipment will be created by steel plates or timber mats.Access to Sydney Avenue is via Newpark Road, care must be taken in Newpark Road as it isnot only a built up area a school is also situated along this road.

Access to the exit points and stringing area will be through the new Oswell Road development,south of the River Severn. It is foreseen to remove part of the hedge on the edge of the floodplain and create access across the kerb and services down to the flood plain by hardcorecovered by steel plates or timber mats. Access through Oswell Road is again through a built uparea and care must be taken with all transport movements.

2.2 Water Supply

Client / Main Contractor has obtained water abstraction license from the River Severn. TheAbstraction point is on the river bank just south of the rig site working area. A temporary watersupply line will be installed across the road and protected against passing traffic.

2.3 Mud Return line

Initially the pre-reaming operation will utilise the “forward” reaming method and initially avoid thetransportation of drilling fluid from the exit point back to the drilling rigs location on SydneyAvenue. However if drilling conditions dictate that conventional “backward” reaming is requiredthe drilling fluid will be transported around vacuum trucks will be used for the first crossing, forcrossings 2 and 3 it is foreseen to use one of the ducts installed in crossing no.1.

2.4 Interference and Cooperation with Other Contractors

No other activities are foreseen during the installation of the duct bundles. However, connectingduct work could be carried out at the same time. For safety reasons, no work by othercontractors should be carried out within fenced off working areas or within 10m of stringingarea. Cable installation cannot commence until all duct bundles have been installed andproved.

2.5 Impact on surroundings

Due to the closeness of Regents Drive, Bramley Close and New Park Road properties to the rigsite working area some noise nuisance could be expected. Whilst VSH drilling equipment issound proofed it is proposed to inform above properties at early stage to advise on plannedactivities and programme. An Environmental noise impact assessment will be carried out at theearly stages of the drilling process.


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Whilst no noise nuisance is foreseen to properties at Oswell Road and Arden Close near exitpoints and stringing area, access to these working areas is arranged through the new OswellRoad Development with a limited number of articulated lorries and other vehicles requiringaccess during the construction period. Nuisance cannot be completely avoided and residentsshould be informed timely on planned activities and programme. Contractors’ vehicles parkingwill be controlled and restricted by site supervision.

Selected entry & exit point locations as well as stringing area are on local council owned landcurrently used as recreational area by local residents. All personnel should be briefed on use ofthe land outside the working areas by general public of all ages and measures taken to limitendangerment and disturbance. Gates of sites should be kept close at all times and fencingshould be marked / signposted accordingly.

The project involves working on and near the floodplain of the River Severn. Whilst no floodingis expected during the construction period and / or has been witnessed during any of the sitevisits, rainfall would soon change this. Appropriate measures will be required to avoid run-offfrom sites into watercourse in case of unexpected flooding.

The exit point of HDD no. 1 is close to the 14m swing clearance of the existing overhead lines.Appropriate marking in accordance with applicable GS6 safety standard is required. Thestringing area crosses the overhead lines and special care should be taken during reaming &pull back operations where excavators are required, height restrictors will be fitted ifassessments demes this requirement. All personnel working on site are to be made aware andreminded of the dangers of working near overhead lines.

2.6 Soil Investigation, assessment and evaluation

In total 3 no. boreholes were taken including laboratory testing (see for full details reportPN071431 April 2007 and report PN081792 July 2008). Boreholes BH03 (near entry) and BH02(some distance from exit) have been used for the design of the crossings

The borehole data can be summarized as below:

BH03 (near entry point)- Gl to 1.3m Made ground- 1.3m to 5.6m Clay- 5.6m to 9.1m Gravel and gravelly coarse sand- 9.1m to 21,5m Weak mudstone with some thin sandstone layers (medium strong).

Horizontal section of drilling profile is situated in this layer-21,5 to 30m Medium strong sandstone with some weak mudstone layers.

BH02 (near exit point)- Gl to 0.4m Top soil- 0.4m to 9,5m Sandy / Gravelly clay- 9,5m to 23m Weak sandstone

Horizontal section of drilling profile is situated in this layer-23 to 32m Weak mudstone/sandstone/siltstone


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Assessment of the drilling logs and laboratory test results shows the requirement for utilizing amud motor with mill tooth bit for drilling the mudstone / sandstone and the use of low torquehole openers with mill tooth cutter sets for the reaming operations.

The use of the mud motor in combination with length and diameter of the drilling has resulted inselection of a 35t drilling to execute the works.

2.7 Drilling Profile

The following information was available for the design of the crossings:- Soil investigation as detailed above- Topographical survey of area including River Severn- EA Flood Defense Consent under WRA 1991 with site specific conditions- Oswell Road Development lay-out drawings with proposed drainage and electrical

infrastructure.

No other consent or stat (services) information has been provided.

The drilling routes and profiles of the 3 no. crossings have been designed within the followingconstraints:

- Minimum depth under firm river bed over the width of the river and 5m at each side ofthe channel of 3m as stipulated in EA consent

- Minimum combined bending radius imposed by mud motor in anticipated soils anddrilling rods of 35t rig

- Available fields for rig site working area and for stringing area- Avoiding trees both at entry & exit point and in drilling route wherever possible- Entry points close together and inline to minimize relocation of drilling rig spread

between individual drillings and which reduces safety risks (CDM)- Exit points as close as possible to edge of flood bank to minimize risk of disturbance by

flooding- Duct bundles required: 4no. PE160 or 3no. PE160 & 2 no. PE110- Maximise distance to overhead power lines crossing the river- Minimum depth required by down hole mud pressure calculation- Minimum risk of drilling fluid blow outs near entry & exit point

Drawing T783086-R-X-01 Rev0 show the proposed drilling profiles with the followingparticulars:

Drilling Entry Angle : 15 – 15 - 17 DegreesDrilling Exit Angle : 15 DegreesVertical Radius Entry : 200 – 250 - 300mVertical Radius Exit : 200 – 250 - 300mHorizontal Radius : 0 – 300 - 400mCombined Radius : 200 -212 -212mHorizontal Drilling Length : 215 – 209 - 204mDepth under river : 10 – 11.5 – 9.9m


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2.8 Mud Pressure Calculation

Typically VSH will carry out mud pressure modeling calculation in accordance with NEN3650:2003 (in the absence of applicable EN-BS standard). The calculation is carried out for thepilot hole drilling as the down-hole pressures in the annulus will be higher than during any otherphases of the horizontal drilling. Prior to start of each operational phase, a flow test will becarried out to enable calculation of the maximum allowable mud pressure for each drillingphase.

Due to the quality of the rock it is not possible to calculate the maximum allowable mudpressure in this case. Standard practice is to carry out flow test and monitor mud pressurecarefully during drilling for unexplained pressure increases.

2.9 Pulling Force

Pulling force check calculations of the cable duct bundles have been carried out in accordancewith the NEN 3650:2003.

2.10 Drilling Fluid

The drilling fluid has several functions which include the following:-

• Transportation of drilled solids and fluid out of the borehole

• Keeping the solids in suspension when circulation stops to prevent deposition ofsolids

• Stabilisation of borehole by static pressure against soil formation

• Creation of a filter cake to minimize the penetration and loss of drilling fluid into theformation and the flow of groundwater into the borehole.

• Lubrication of the product pipe / ducts during pull back, reducing the pull force on thepipe / ducts

• Cooling and lubrication of the drilling equipment, tools and drill pipe

Additional requirements:

• Minimum impact on surrounding soil formations

• No harmful impact on environment and groundwater

• No harmful impact on drilling equipment and product pipes / ducts

Our assessment of the soil investigation data has resulted in utilising a drilling fluid based onhigh quality OCMA bentonite mixed with fresh river water at a concentration of 80 kg/m3.

At this stage no additives are foreseen but small adjustments to the drilling fluid might need tobe made subject to locally encountered circumstances (See also section 5 Drilling FluidControl).

Drilling fluid breakouts that may occur will be dealt with by containing the flow within a smallbunded pit. The mud is then either pumped back to the holding pits / tanks, or collected by a


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vacuum tanker. Any residual mud can then normally be cleaned up. The normal practice tohave a supply of filled sandbags on site to contain any such breakouts will be followed.

In case of break out under the River Severn the EA will be contacted directly and specificmeasures to mitigate environmental impact and to avoid re-occurrence will be proposed

Drilling fluid and cuttings are tested during drilling for contamination and possible re-use ordisposal after the work has been completed. The drilling mud and cuttings will be transported toan appropriate licensed waste disposal site. Only licensed waste carriers will be used fortransportation of any drilling fluids.

2.11 Contingencies

The following major events can be identified:

1,Borehole instability and possible abandonment of down-hole equipment.2,Breakdown of major equipment components3,Product pipe stuck in borehole during pull-back4,Break-out and / or unidentified loss of drilling fluid

Mitigating measures:

In depth assessment of the soil information by in-house geologist, expert drilling fluidengineering, high class quality bentonite and polymers, dedicated drilling fluid engineer on siteat all times, constant monitoring of drilling and fluid characteristics and experienced drilling crewwill reduce chances of borehole instability considerable.

However, in case adverse soil conditions are encountered, the hole collapses and drilling toolsbecome stuck, it might be required to abandon the hole and tools and fill remaining annuluswith high density drilling fluid or grout. After careful analysis of the event, a new plan of actionwill be developed.

VSH owns and operate a large number of rigs and has a strict maintenance regime for all itsdrilling equipment including standard maintenance in our own workshops after every projectand periodic check of drilling tools by external party. All rigs are built to our own specificationtaking into account many years of experience in specialist field of directional drilling.

In the unlikely event of a major breakdown of a rig which cannot be repaired by our dedicatedon-site engineer within an acceptable timeframe, we will try to mobilize one of our other rigs tocomplete the drilling.

To successfully install the pipe a number of factors are of importance: clean hole, correctlyballasted pipe, profile design in line with pipe characteristics and expert drilling fluidengineering. Subject to drilling parameters experienced during the final reaming phase, it will bedecided whether a final wiper trip to clean the borehole is necessary and or required.

During the pull back, all above factors will be constantly monitored and action taken wererequired. In case pulling forces vary unacceptable from pre-calculated values as a result of a


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hole collapse or obstruction, it might be necessary to pull back the bundle to the stringing areaby winch or bulldozers.

In case of a major mud break out or loss of drilling fluid, all operations will cease until an actionplan has been developed.

3. WORK METHOD

3.1 Introduction

This project will be carried out with one of our 35tons midi drilling rigs. For the rig and ancillaryequipment an area of approx. 500 – 600 m2 is required, which is located on the entry side at thewest side of the River Severn and Sydney Avenue.

At the exit points on the east side of the River near the new Oswell Road housing developmentan area of approx. 100 m2 is required (not including the area necessary for making up andstorage of the pipeline).

In the following paragraphs the separate phases of the drilling operation will be described. Aproposed drilling profile drawing is submitted along with supporting calculations.

No drilling work will commence until Central Networks / Balfour Beatty / Delta has approvedmethod statements, drawings and risk assessments.

The Visser & Smit Hanab drilling operations comprise of the following major phases:

1. preliminaries

2. rig-up

3. pilot-hole drilling

4. pre-ream

5. pullback

6. rig-down

During the entire operation, activities will be reported daily in the driller’s logbook, includingdrilling/ pulling rates, mud properties, push/ pull force, torque etc.

3.2 Preliminaries

Prior to the rig mobilizing, the access arrangements and working areas will be prepared and thepipe strings welded. The exit, entry and mud storage pits shall be identified and, wherepossible, dug prior to the rig mobilizing.

Reference is made to section 2.1 & 2.2 for access arrangements. No top soil stripping isforeseen and working areas will be constructed from steel plates or timber mats offloading fromarticulated lorry by excavator or tele-handler and directly laid on the grass. The working areaswill be fenced off by Heras type fencing and appropriate signs will be installed.


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A separate method statement on PE welding and pipe stringing will be issued.

3.3 Typical site lay-out / equipment set-up

The sketch below shows a typical lay out of rig side working area for 35t drilling spread.

Please note that the above plan is for a typical HDD site, and that at the proposed locations onthis project changes might be made to suit the specific site, create safe working area, minimizesimpact on environment and cause the minimal of disturbance to the general public, otherworkers and traffic.

3.4 Rig-up

Prior to starting any activities the VSH Project Manager will hold a project induction and toolboxmeeting with all personnel on site outlining planned activities, specific risks and any otherissues concerning Health, Safety & Environment.

Drilling rig and ancillary equipment will arrive on site by using Sydney Avenue. Trailers will beunloaded at the drilling location by mobile crane or Hiab lorry. Crane documentation and liftingplan will be in place prior to any lifting activities taking place.

The entry and exit points will be confirmed prior to rigging up.

Upon completion of the HDD checklist, the drilling rig will be aligned along the project centerlineand elevated to the requisite designed vertical entry angle of approx.15 degrees.

The recycling unit, mud tanks, pumps and generators will be set-up and connected to thedrilling rig, concurrent with the rig-up and the setting of the down-hole survey instruments which


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are employed for monitoring the pilot hole. These need to be calibrated at the drilling locationbefore the drilling bottom hole assembly will be made up.

Each instrument unit shall be separately aligned along the drilling route centerline at a locationfree of magnetic interference. During the calibration, the instrument shall be physicallypositioned relative to the pre-surveyed control points and the instrument bearing shall bemeasured and stored in the "up-hole computer unit". On completion of the alignments, therecorded bearings (as stored in the computer) will be correlated with the survey bearings of thecontrol points.

An additional component of the directional measuring system is known as the Tru-Tracker. Thissystem creates its own magnetic field which largely reduces the influence of the earth magneticand gravitational fields and is used to verify the steering instruments readings, thereby assuringaccuracy at the exit location. The Tru-Tracker utilizes a wire grid located on the ground surfaceat both entry and exit points. Whilst drilling in areas not covered by the Tru-Tracker grid,steering will be carried out via natural magnetic bearings.

Concurrent to the survey head the Eclipse sonde will be calibrated as an alternative survey unit.

3.5 Pilot hole drilling

After rig-up is completed, VSH will commence drilling a ± 6-1/2” pilot hole along the designprofile. Drilling mud, consisting of a mixture of fresh water and the drilling compound will bepumped down the drill string to the mud motor creating a rotary cutting action and drilling fluidwith cuttings will flow back to the entry pit through the drilled hole.

In order to minimize the risk of mud blow outs whilst carrying out the drilling operations, careshall be taken to keep the mud pressures between the minimum and maximum calculatedpressures.

It is envisaged that the required quantity of water for mixing drilling fluid will be delivered to siteutilizing a 6” pump located on the bank of the River Severn and 6” hose will deliver the water tothe working area.

Directional control is accomplished by rotating the drill string to orientate a bent housing on thedown-hole assembly, thereby creating a steering bias in the direction and plane of the benthousing. If a change in direction is required, the drill string is rotated, thereby changing the benthousing to the desired orientation.

The trajectory of the pilot hole is determined by taking periodic surface readings of theinclination and azimuth of the bottom-hole assembly. These readings in conjunction withmeasurements of the distance drilled since the last survey are used to calculate the horizontaland vertical co-ordinates of the bottom-hole assembly relative to the entry point at the surface.

Surface readings are taken by a survey, which is placed in a non-magnetic drill collar connectedto the down-hole assembly. Inclination and azimuth are obtained by sensing the anglesbetween the reference frame in the down-hole survey package and the earth's magnetic and


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gravitational fields. This information is transmitted as a signal to the surface computation unitwhere it is reduced to the X, Y and Z coordinates of the down-hole sensors; i.e. the bottom-holeassembly. Directional surveys are taken every six meters when a joint of drill string is added, ormore often if required. Survey coordinates are plotted along the design plan and profiledrawings to monitor the course of the drill bit. If unacceptable deviations occur, the drill string iswithdrawn sufficiently to re-drill the pilot hole within acceptable limits. Deflections of the bore-hole path will be held to a tolerance equivalent to the minimum radius of curvature, allowable.During the crossing of the River Severn no Tru-tracker readings can be taken.

After the bottom-hole assembly exits in the stringing area at an exit angle of approx. 15degrees, the down-hole assembly is removed at the exit point and the location will be surveyedand recorded for the as-built drawing.

During pilot hole, drilling and during the other phases of the horizontal drilling operation thedrilling fluid will flow out of the drilled hole at the entry point or during reaming at entry and exitpoint. The mud will be directly pumped from where the fluids reach the surface into temporarymud-storage and recycled.

To further enhance the progress of the drilling, any drilling fluid break out’s that may occur willbe dealt with by containing the flow within a bunded pit. It may also be possible to increase theviscosity of the drilling compound to help stem any flow. The normal practice to have a supplyof filled sand bags on site to contain any drilling fluid breakouts will be followed.The mud is then either pumped back to the holding pits/tanks, or collected by a vacuum tanker.Any residual mud will be cleaned up.

3.6 Reaming and Pullback

Once the pilot hole has been completed, a series of reaming sessions will follow. These will bedetermined based on the experiences gained from the pilot hole. The hole will be enlarged byattaching gradually bigger hole-openers to enlarge the hole to the required size. The followingreaming diameters are foreseen: 14”and 22”. Initally forward reaming will be utalised to avoidadditional traffic though the built up areas. However if drilling conditions dictate that backwardreaming should be required vacuum tankers will be utalised as described in section 2.3

Once the hole is at the required diameter, a wiper trip to clear the hole of any cuttings might becarried out if required in preparation for the pull back operation.The cable duct installation pass known, as the "pullback" will follow. Prior to pullbackpreparations, the borehole contains a continuous string of drill pipe from the pipe side to the rig.

The pull back assembly, to be determined on site, based on conditions during the pilot drill andreaming operations, will be attached to the drill pipes. A swivel connects the down-holeassembly to the duct to prevent torsional stress from being transmitted to the cable ducts.The actual pulling force will be measured during the pullback operation on the rig. The pullbackduct configurations will be as follows, HDD crossing No1 = 3 x 160mm and 2 x 110mm. HDDcrossing No2 = 4 x 160mm. HDD crossing No 3 = 3 x 160mm and 2 x 110mm.


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3.7 Repositioning

Upon successful completion of the first bore, the rig is repositioned and the process asdescribed in paragraphs 3.3 to 3.5 will be repeated for the second bore and third boring.

3.8 Rig down

Upon completion of the pullback operation of the third bore, the down-hole assembly isremoved from the pipeline and the rig and ancillary equipment will be disassembled. Afterdisassembly of the equipment, it will be loaded on to trucks and demobilised from the workareas in accordance with the program.

3.9 Proving

On completion of the duct installation, the ducts will be proved by pulling a mandrel and foampig through, with a draw cord that will be later left in each duct ready for the cable installation.Ducts ends will be temporary capped and left above ground for tie-in to connecting duct work.

3.10 Clear-up

Upon successful proving of the ducts, the working areas will be cleared and debris removed.Final reinstatement will be carried out by Main Contractor upon completion of tie-in / cableinstallation. Prior to final demobilization from site, the working areas shall be inspected by arepresentative of the Client / Main Contractor and any outstanding works will be rectified.

3.11 Abandoning drilling

Owing to the fact that drilling shall always occur in parts of which the underground is largelyunknown, there is always a slight change that the drilling can not be completed.

However, in the unlikely event that the drilling can not be completed as anticipated for whateverreason there are in principle two scenarios to be followed:

• Mobilize a different rig (larger) and re-design drilling

• Abandon drilling; recover the equipment, backfill the drilled section, find alternativecrossing option.

Depending on the cause of the abandonment, the most suitable solution shall have to beselected. The technical decision shall be made in close relation with the designers and theProject Management team.

Before works are to recommence approval shall be sought from all the stakeholders. Under nocircumstances shall the Drilling Operator deviate from the approved plan without prior writtenconsent from the stakeholders.


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4. HEALTH, SAFETY AND ENVIRONMENTAL

The following paragraphs contain issues relating to health safety and environment.

4.1 Risk Assessment

RISK ASSESMENTSVSH1 Abrasive Wheels VSH15 Power ToolsVSH2 Excavations VSH16 Mobile CranesVSH3 Underground Services VSH17 Work on or Near WaterVSH4 Hot Work Fire VSH18 Working at HeightVSH6 Use of Compressed Air Equipment VSH19 HousekeepingVSH7 Site Fencing Operations VSH22 Hand ToolsVSH8 Highly Flammable Liquids VSH23 Reversing VehiclesVSH9 Control of Diesel VSH25 ElectricityVSH11 Mobile Plant VSH27 Drilling PlantVSH12 Roadwork VSH38 Mud PitsVSH14 Overhead Electrical Cables VSH39 Lone Worker Site

See CN-087077-VSH-C1719-14.0: Health & Safety Plan construction phase for copies of theabove Risk Assessments

4.2 Training

All personnel are fully trained to a minimum of Safety Awareness and individuals on requestcan produce certification. A site induction meeting is carried out on a job by job basis and VSHwill operate an ongoing site induction course for all visitors.

Be advised that all Main Contractor's and Clients staff will be required to be inducted by a VSHrepresentative before they are allowed access to the working rig site.

4.3 Personal Protective Equipment

Minimum PPE requirement of hardhat, safety footwear and high visibility clothing are to be wornat all times on site. Additional PPE, such as eye protection, ear defenders and gloves areavailable on site and will be worn as directed.

4.4 Emergency Arrangements / First Aid

At their first visit to site all personnel will also undertake the VSH Site Specific Induction, atwhich the site organization, safety requirements and emergency arrangements will beexplained. First Aid kits and trained First Aider’s are available on site and will be clearlyidentified.


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Copies of the emergency information sheet will be displayed at locations on site: welfarefacilities / canteen.

4.5 Environmental issues

Comply at all times with current environmental legislation and the requirements of Client’s siteEnvironmental Plans, Environmental Impact Assessment, Pollution Prevention Control Plan andCentral Networks Environmental policy

V&SH’s drilling equipment is very frequently used in environmentally sensitive areas like naturereserves etc., as well as in very densely populated areas like housing estates. Both areas callfor equipment and crew to adapt to and consider the world outside of the site. All equipment istherefore insulated for noise, equipped with fully enclosed motor compartments to ensure no oilleakage takes place and using, wherever possible, environmentally friendly oils and lubricants.

The Foreman will be responsible for checking the integrity of all fencing twice a day and reportany breaches to the principal contractor. A heras type fence complying with HSG151 will beerected around all drilling operations.

Waste Management

Identify none hazardous waste and hazardous waste. For none hazardous waste, ensure thatwaste transfer note is completed; ensure, under the duty of care, consignment notes arecompleted giving full details of waste and that persons receiving waste are holders of wastemanagement license or a registered carrier of waste. All operations are undertaken to conformwith the List of Waste Regulations 2005 and Waste Consignment Note Requirements Sept2005

Environment Agency informed prior to consignment/transfer to registered waste carrier or wastemanagement license holder.

Environmental Protection

Care will be taken that existing watercourses and ponds are not polluted, dirtied or obstructedduring the construction period. A ditch watch will be maintained with an Emergency Responsecrew available during all working times.Burning of rubbish on site will not be allowed.All existing footpaths and rights of way are to be kept clear at all times.Diesel and fuel storage tanks will be double skinned or bunded.Static plant will be placed on drip trays the capacity of which will be 110% of the combined oiland fuel capacity of the plant item.All VSH drilling & auxiliary equipment is silent packed to limit noise levels.Undertake weekly environmental site inspection and continuous monitoring.


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4.6 Arcaeological Considerations

In the absence of archeological information no allowance has been made in our method foradditional activities.

4.7 COSHH

COSHHCA.08 Gas OilCA.13 Marker paintCA.14 Tool joint compoundCA.16 BentoniteCA.17 WD-40 AerosolCA.20 Copper anti seize greaseCA.23 Fuel oilCA.24 Propane GasCA.25 Acetylene (dissolved)CA.26 OxygenCA.29 Butane Gas

See CN-087077-VSH-C1719-14.0: Health & Safety Plan construction phase for copies of theCOSHH Assessment relating to the above index.

4.8 Materials

All materials delivered to site will be delivered by dedicated vehicles and offloaded bycompetent, certified slinger to a designated lay down area ready for use.

Drilling CompoundThis material will be delivered to site in 25kg bags or in one tonne bags complete with liftingstraps and will be removed from the 40' articulated unit by an excavator or telescopic handlerwith a minimum SWL of 2 tonnes. The material itself is an inert substance and data sheets areattached to COSHH assessment.

Residual drilling compound is to be transported from each location by approved licensedtransporters

WaterThe necessary water shall be supplied from River Severn. A copy of the EA abstraction license(including specific requirements) organized by Client / Main Contract will need to be availableon site.


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ElectricalAll electrical equipment to be utilized on site will be labeled and certified and all currentcalibration certificates are to be on site for inspection.All major electrical rig connections will be made via a junction box into a fuse box arrangementand through to earth by a qualified electrician.

4.9 Documentation

All relevant documentation relating to drilling parameters and forces are recorded on sitecontinually and are available for inspection on contact of the Project Manager or Supervisor


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4.10 Drawing T783086-R-X-01 Rev 0


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4.11 Photo of HDD location


Appendix 4Photographs Options A, B and C Exit and Launch Locations, Plus Open Cut Routes


Access to and Launch Location – Route A




Exit Location – Route A(and Open Cut Extension to Tank)


OPENCUT


Launch Location – Route B



Launch Location – Route C


??


Proposed Vehicular Access Route toLaunch Locations B & C



Exit Location – Route B & C


EXIT

OPENCUT

HDD LINETO GATE


Open Cut Route from Launch Location C toSettlement Tank


OPENCUT ROUTE

OPENCUT


OPENCUT

OPENCUT


Example of River LevelsJune & August 2008


11 June 2008

12 August 2008

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