galway bay test site decommissioning plan march 2017 · 2017-03-14 · decommissioning...

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Galway Bay Test Site

Decommissioning Plan

March 2017

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CONTENTS 1. EXECUTIVE SUMMARY .......................................................................................................... 4

2. INTRODUCTION .................................................................................................................... 5

2.1. Marine Institute ...................................................................................................................... 5

2.2. SeaPower Limited ................................................................................................................... 5

3. BACKGROUND INFORMATION .............................................................................................. 5

3.1. Galway Bay Wave Energy Test Site ......................................................................................... 5

3.2. SeaPower Platform Device Location ....................................................................................... 5

3.3. Layout of facilities to be decommissioned ............................................................................. 6

3.4. Physical conditions relevant to decommissioning .................................................................. 7

3.4.1. Seabed Sediments ........................................................................................................... 7

3.4.2. Benthic communities ...................................................................................................... 7

3.4.3. Marine mammals ............................................................................................................ 8

3.4.4. Water quality .................................................................................................................. 8

3.5. Conservation areas relevant to decommissioning .................................................................. 8

3.6. Navigational activity in the area ............................................................................................. 8

4. DESCRIPTION OF ITEMS TO BE DECOMMISSIONED ................................................................ 9

4.1. Galway Bay Test Site ............................................................................................................... 9

4.1.1. SmartBay data buoy ........................................................................................................ 9

4.1.2. Waverider data buoy ...................................................................................................... 9

4.1.3. Dive boat moorings ......................................................................................................... 9

4.1.4. Cardinal marks ................................................................................................................ 9

4.2. SeaPower Platform ............................................................................................................... 10

5. DESCRIPTION OF PROPOSED DECOMMISSIONING MEASURES .............................................. 13

5.1. Introduction .......................................................................................................................... 13

5.2. Galway Bay Test Site ............................................................................................................. 13

5.2.1. Vessel specifications ..................................................................................................... 13

5.2.2. Dive boat mooring recovery ......................................................................................... 13

5.2.3. SmartBay data buoy ...................................................................................................... 13

5.2.4. Waverider data buoy .................................................................................................... 13

5.2.5. Cardinal marks .............................................................................................................. 14


5.3.1. Vessel specifications ..................................................................................................... 14

5.3.2. Device recovery ............................................................................................................. 14

5.3.3. Mooring recovery .......................................................................................................... 17

6. HEALTH AND SAFETY CONSIDERATIONS .............................................................................. 20

6.1. Galway Bay Test Site ............................................................................................................. 20


6.2.1. Safety ............................................................................................................................ 20

6.2.2. Contact List .................................................................................................................... 20

6.2.3. Permitting ..................................................................................................................... 20

6.2.4. Weather and sea-state criteria ..................................................................................... 21

6.2.5. Tides .............................................................................................................................. 21

6.2.6. Personnel responsible ................................................................................................... 21

7. ENVIRONMENTAL IMPACT ASSESSMENT ............................................................................. 22

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8. SCHEDULE .......................................................................................................................... 22


8.2. Galway Bay test site .............................................................................................................. 22

9. SEABED CLEARANCE............................................................................................................ 23

10. RESTORATION OF THE SITE ................................................................................................. 23

11. POST-DECOMMISSIONING MONITORING OF THE SITE ......................................................... 23

11.1. Cabled Subsea Observatory (licenced under 2014/02786) .............................................. 23

11.2. SmartBay data buoy .......................................................................................................... 24

11.3. Waverider Buoy ................................................................................................................ 24

Appendix I: Marine Notice. ......................................................................................................... 25

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1. EXECUTIVE SUMMARY

This document outlines a decommissioning plan for both the Galway Bay wave energy test site and

the Seapower Platform wave energy device. The Seapower Platform wave energy device has been

installed since October 2016 at the Marine Institute’s Galway Bay wave energy test site off the coast

of Spiddal, Co. Galway. The Galway Bay wave energy test site has been leased since March 2006.

The Galway Bay wave energy test site is located 1.5km off the coast of Spiddal in Galway Bay in

water depths ranging from 20m – 23m LAT (Lowest Astronomical Tide) and covers an area of 37

hectares measuring 670m East-West by 560m North-South. The Seapower Platform wave energy

device is located in the northwest quadrant of the Galway Bay wave energy test site. The wave

energy device is moored to the seabed using a system of 4 equal mooring legs, each made up of a

horizontal surface rope, a pendant buoy, a catenary chain cable and a drag-embedment anchor.

As the decommissioning operations are not expected to greatly disturb the seabed, it is not

considered that specific site restoration measures will be necessary. It is considered that the

removal of the SeaPower platform device, site infrastructure, environmental monitoring platforms,

cardinal marks and associated moorings and anchors will disturb only a relatively small area of

seabed and will not impact any habitats of conservation importance.

In line with best practice the marine environmental monitoring platforms will remain deployed at

the test site for a period of 6 months after the decommissioning of the SeaPower Platform wave

energy device to verify that no adverse environmental impacts arise from the decommissioning

operations, and to record any changes in the test site environment subsequent to the cessation of

test site activity.

The different activities and schedule associated with the decommissioning operations for both the

Galway Bay wave energy test site and the Seapower Platform wave energy device are:

Seapower Platform:

• Device disconnection and tow to Galway Docks – 13th

March 2017

• Removal of first two moorings and anchors – 14th

March 2017

• Removal of final two moorings and anchors – 15th

March 2017

A Marine Notice will be issued by the Department of Transport, Tourism and Sport advising vessels

of the Seapower Platform decommissioning operation and the transport of the device, moorings and

anchors to Galway Docks.

Galway Bay wave energy test site

• Removal of dive boat moorings and anchors – week commencing 5th

June 2017

• Removal of waverider data buoy and moorings – week commencing 4th

September 2017

• Removal of SmartBay data buoy and moorings – week commencing 4th

September 2017

• Removal of cardinal marks and moorings – week commencing 11th

September 2017

Marine Notices will be issued by the Department of Transport, Tourism and Sport advising vessels of

the Galway Bay test site decommissioning operations in advance of operations.

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2. INTRODUCTION This document outlines a decommissioning plan for the Galway Bay wave energy test site and the

Seapower Platform wave energy device. The Seapower Platform wave energy device has been

installed since October 2016 at the Marine Institute’s Galway Bay wave energy test site off the coast

of Spiddal, Co. Galway. The Galway Bay wave energy test site has been leased since March 2006.

This document is submitted to the Marine Planning – Foreshore Section of the Department of

Housing, Planning, Community and Local Government. A copy of this document will be publically

available on the Marine Institute’s website.

2.1. Marine Institute The Marine Institute is the Government agency which operates and manages the Galway Bay wave

energy test site under foreshore lease 2016/01730.

2.2. SeaPower Limited SeaPower Limited (“Seapower”) is the company which owns and operates the SeaPower Platform

wave energy device, their ownership extending to the moorings and anchors for the device in the

Galway Bay test site.

3. BACKGROUND INFORMATION

3.1. Galway Bay Wave Energy Test Site The Galway Bay wave energy test site is located 1.5km off the coast of Spiddal in Galway Bay in

water depths ranging from 20m – 23m LAT (Lowest Astronomical Tide) and covers an area of 37

hectares measuring 670m East-West by 560m North-South (Figure 1). The site boundary is clearly

delineated by four cardinal marks at each corner of the site to indicate restrictions on vessel traffic

ensuring safety of vessels in the area and of equipment on site.

The Galway Bay wave energy test site has existing environmental monitoring platforms and

supporting infrastructure at the test site, both subsea and floating.

• Subsea cabled observatory licenced under 2014/02786

• SmartBay data buoy

• Waverider Buoy

• Cardinal marks at each corner of site

• Dive boat moorings for cabled observatory maintenance.

3.2. SeaPower Platform Device Location The Seapower Platform wave energy device is located in the northwest quadrant of the Galway Bay

wave energy test site. The water depth at the location of the device is 21m LAT (Lowest

Astronomical Tide). The wave energy device is moored to the seabed using a system of 4 equal

mooring legs, each made up of a horizontal surface rope, a pendant buoy, a catenary chain cable and

a drag-embedment anchor. The mooring area required for the Seapower Platform wave energy

device is approximately 500m x 500m.

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Figure 1: Location of Galway Bay wave energy test site off the coast of Spiddal.

3.3. Layout of facilities to be decommissioned

The SeaPower Platform wave energy device, its mooring and anchors are located in the northwest

quadrant of the Galway Bay test site. The actual locations of the wave energy device and the four

anchors are detailed in Table 1.

Table 1: Coordinates of Seapower Platform wave energy device and anchors.

The location of the cardinal marks, dive boat moorings, the environmental monitoring platforms and

supporting infrastructure on site including the SeaPower Platform wave energy device, moorings and

anchors along with the separately licenced cabled subsea observatory is presented in Figure 2.

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Figure 2: Layout of Galway Bay test site

3.4. Physical conditions relevant to decommissioning

3.4.1. Seabed Sediments

The seabed of the test site is relatively flat and featureless. The shallow geology within the test site

consists of bedrock unconformably overlain by unconsolidated sediment. The unconsolidated

sediment layer is interpreted to consist of muddy fine sand to coarse sand and possibly shelly gravel.

The bedrock unit is interpreted to be granite or in deeper water a compacted unsorted sediment

unit. The removal of anchoring systems may give rise to some small-scale sediment displacement.

This is not anticipated to have any impact on the nature and distribution of marine sediments.

To ensure any impacts arising from the decommissioning of both the SeaPower wave energy device

and the test site will be negligible, in line with best practice it is recommended that post

decommissioning environmental monitoring be undertaken, including turbidity monitoring.

3.4.2. Benthic communities

All of the species present at the test site are typical of the area. No rare, sensitive or unusual species

have been recorded. Previous appraisals established baseline benthic fauna present at the test site

and found a high level of similarity between the sampled locations and the results of a benthic

faunal study carried out in 1981, suggesting that there has been no noticeable changes in benthic

fauna in this area since the establishment of the original test site in 2006. The disturbance to

sediment and the resultant increases in suspended sediments and turbidity and the subsequent

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deposition of sediments will be of such a scale that impacts on the benthos, fisheries, birds and

mammals will be negligible.


and the test site will be negligible, in line with best practice it is recommended that post

decommissioning environmental monitoring be undertaken.

3.4.3. Marine mammals

The presence of seals and cetaceans (whales, dolphins and harbour porpoises) has been assessed as

part of on-going research activity at the test site. Datasets from the test site are the longest

recorded in Ireland with c.900 days monitored across all studies. Monitoring was carried out during a

previous ocean energy device deployment at 2 control sites, one 1km east of the test site and the

second was 500m west of the test site. Results from this short-term deployment and monitoring

showed no significant difference in detections between sites, suggesting that the ocean energy

device did not influence harbour porpoise presence, either positively or negatively.


and the test site will continue to have no impact on marine mammals, in line with best practice it is

recommended that post decommissioning environmental monitoring be undertaken including

passive acoustic monitoring.

3.4.4. Water quality

Decommissioning of both the SeaPower wave energy device and the test site is not anticipated to

present any risks to water quality. In the marine environment, the main threat to water quality is oil

pollution arising from accidental leakage from the service vessels used in decommissioning. Vessels

engaged will be required to have appropriately trained staff to implement an oil pollution

emergency response plan and to have appropriate emergency response equipment in line with the

accredited HSEQ Management System. This will minimise the impact of any oil spill that might occur.

Overall, the decommissioning does not present any significant risks to water quality.

3.5. Conservation areas relevant to decommissioning There are no designated Special Areas of Conservation (SAC), proposed Natural Heritage Areas

(pNHA) or Special Protection Areas (SPA) at the location of the Galway wave energy test site.

3.6. Navigational activity in the area The Galway Bay wave energy test site has been classed as a low risk small scale development in an

area where the potential risks are low because the location of the test site is outside commercial

shipping routes, the site has been operating for eleven years, knowledge of the site location within

the local fishing community, the cardinal marking scheme demarcating safe passage routes around

the test site, and the inclusion of the test site on all Admiralty Charts for navigation purposes.

A Marine Notice will be issued by the Department of Transport, Tourism and Sport advising vessels

of the decommissioning operations at the test site and the transport of the SeaPower Platform wave

energy device, moorings and anchors to Galway Docks. Draft of the Marine Notice to be issued is

included in Appendix I.

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4. DESCRIPTION OF ITEMS TO BE DECOMMISSIONED

4.1. Galway Bay Test Site Decommissioning of the Galway Bay wave energy test site will commence on 20

th March 2017 with

the cessation of deployments and WEC testing at the test site.

Existing test site infrastructure consisting of the two dive boat moorings and anchors will be

removed from the test site within three months of the 20th

March 2017.

The marine environmental monitoring platforms (SmartBay data buoy and waverider data buoy) and

cardinal marks at the test site will remain in position for a period of six months after the

decommissioning of the test site and the SeaPower Platform wave energy device to verify that no

adverse environmental impacts arise from the decommissioning operations, and to record any

changes in the test site environment subsequent to the cessation of activity.

The four cardinal marks will be maintained in their current positions to mitigate any navigational

risks and to protect the environmental monitoring equipment, including the licenced cabled

observatory on the seabed.

The cardinal marks, environmental monitoring equipment and associated moorings will be removed

upon completion of the post-decommissioning environmental monitoring, at a date no later than six

months from the 19th

March 2017.

There will be no deployments or WEC testing during the decommissioning and monitoring period.

4.1.1. SmartBay data buoy

The SmartBay data buoy provides for environmental monitoring of the marine environment at and

above the water’s surface. The SmartBay data buoy is 2.5m in diameter and is 5m high above the

water line. It is located in the southeast corner of the test site. It floats on the sea surface and is

moored to the seabed using two chain moorings affixed to two 2-tonne weights.

4.1.2. Waverider data buoy The waverider buoy records the wave climate at the test site. The waverider buoy is 0.9m in

diameter and located at the eastern edge of the test site. It floats on the surface and is moored to

the seabed using a single point rope mooring affixed to a 0.5 tonne weight.

4.1.3. Dive boat moorings

The dive boat moorings are surface floats are located on the sea surface 15m west of the cabled

subsea observatory and are moored to the seabed using two rope moorings affixed to two 1-tonne

weights. The floats are 0.5m in diameter.

4.1.4. Cardinal marks

The cardinal marks delimit the extent of the test site and are used to ensure safety of navigation

around the site, and serve as protection for devices and instrumentation within the test site. The

cardinal marks are 4m high above the water surface and sit on a 2m diameter buoy. The cardinal

marks are located at the northeast, northwest, southeast and south west corners of the test site.

The cardinal marks float on the surface and are moored to the seabed using a single point chain

mooring affixed to 2 tonne weight.

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4.2. SeaPower Platform The SeaPower Platform wave energy device is made up of two, low draught, floating bodies hinged

together as shown in Figure 4 and Figure 5. The device is 16.79m long, 4.5m wide and weighs

approximately 26 tonnes. Standard, off-the-shelf shackle and joining components are used

throughout. The four point moorings to be recovered during the decommissioning are detailed in

Table 2. The mooring arrangement, and component parts are shown in Figure 6

Figure 4: SeaPower Platform wave energy device.

Figure 5: Plan view of SeaPower Platform wave energy device.

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Table 2: Mooring and anchors to be recovered during decommissioning

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Figure 6: Mooring arrangement and components.

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5. DESCRIPTION OF PROPOSED DECOMMISSIONING MEASURES

5.1. Introduction The Marine Institute are committed to its decommissioning obligations under the existing foreshore

lease for the test site (2016/01730) and SeaPower Ltd., are committed to its decommissioning

obligations under the “Agreement for the Utilisation of the SmartBay test site and the Provision of

Operational, Technical and Other Supports” with the Marine Institute.

5.2. Galway Bay Test Site The decommissioning procedure for the dive boat moorings, environmental monitoring equipment,

cardinal marks and associated moorings for the Galway Bay wave energy test site is described below.

5.2.1. Vessel specifications

For the decommissioning works the Marine Institute will be obliged to procure vessels through the

Marine Institute’s Vessel Framework Agreement, a competitive tendering mini-competition process.

Thus the exact vessel specifications can only be determined on appointment of the vessel. A specific

risk assessment will be undertaken for each activity, tailored to the specific tasks determined by the

appointed vessel.

5.2.2. Dive boat mooring recovery

• Attach lifting equipment from vessel crane to buoy lifting eyes and lift on to deck.

• Secure mooring on deck and break link in mooring from buoy.

• Attach vessel winch wire to mooring and winch rope on board until 0.5 tonne sinker weight is at

surface.

• Attach lifting strap to sinker and lift onboard.

5.2.3. SmartBay data buoy

• Attach lifting equipment from vessel crane to buoy lifting eyes and lift buoy on to deck.

• Secure both sides of 2 point mooring on deck, and break the link on one side of mooring from

buoy.

• Attach vessel winch wire to detached mooring and winch chain onboard until sinker weight is at

surface.


• Break the remaining side of mooring, attach winch wire to mooring and winch chain onboard

until sinker weight is at surface.


5.2.4. Waverider data buoy


• Secure bungee section of mooring on deck and break link in mooring from buoy.

• Pull rubber bungee section in by hand until bottom rope is reached.

• Attach vessel winch wire to bottom rope mooring and winch onboard until clump weight is at

the surface.

• Attach lifting strap to clump weight and lift onboard.

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5.2.5. Cardinal marks


• Secure mooring on deck and break link in mooring from buoy.

• Attach vessel winch wire to mooring and winch chain onboard until sinker weight is at surface.


5.3. SeaPower Platform The decommissioning procedure for the SeaPower Platform wave energy device will essentially be a

reversal of the installation process. The process is described below.

5.3.1. Vessel specifications

For the decommissioning works, SeaPower Ltd., with their subcontractor Atlantic Towage Ltd., plan

to use the Atlantic Towage’s vessel “MV Ocean Bank” to remove the device from the site and for the

tow to Galway Docks and to remove the moorings and anchors and transport to Galway Docks.

Specifications for the vessels is included.

The above arrangements are subject to charter agreement. In the event that Atlantic Towage and

their vessels are not contracted then alternate vessels of similar specification and certified to

undertake the scope of work will be procured.

5.3.2. Device recovery

The SeaPower Platform wave energy device will be released from its four point mooring according to

the following method statement. Disconnection is contingent on the north facing surface ropes

being in good condition. It is assumed that weather conditions are suitable for mobilizing personnel

onto the SeaPower Platform wave energy device for disconnection operations.

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NB: If neither of the Permanent Surface Ropes are deemed fit for use as tow ropes then the

following steps will apply.

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5.3.3. Mooring recovery

The SeaPower Platform wave energy device will be released from its four point mooring according to

the following method statement. While the method statement refers to the Northerly mooring, the

method statement is applicable to the removal of all four moorings. Disconnection is contingent on

the north facing surface ropes being in good condition. It is assumed that weather conditions are

suitable for mobilizing personnel onto the SeaPower Platform wave energy device for disconnection

operations.

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At this point in time it is envisaged that one or two moorings will be recovered from site at a time

and delivered onto the quay at Galway Docks. The method described above can be used to recover

all four moorings.

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6. HEALTH AND SAFETY CONSIDERATIONS

6.1. Galway Bay Test Site

The decommissioning of the Galway Bay test site will be undertaken according to the test site’s ISO

accredited Health, Safety, Environmental and Quality (HSEQ) plan. Full copy of the HSEQ system can

be provided upon request. Extracts from the HSEQ system are referenced in the specific Health and

Safety considerations for the SeaPower Platform decommissioning below.

6.2. SeaPower Platform

6.2.1. Safety

The scope of work will be discussed with all parties in a “Toolbox Talk” prior to any work

commencing.

The Senior Onsite Engineer acting on behalf of the SeaPower Ltd., will be designated prior to the

commencement of operations. Any incidents are to be reported to the SP Senior Onsite Engineer,

who in turn will report them to SP HSE advisor and test site duty manager. Any onsite emergencies

will be managed as outlined in the appropriate Emergency Response Bridging Document.

All personnel are to be issued with high visibility warm and waterproof clothing, safety boots, gloves

and 275n life jackets fitted with flashing lights and hard hats.

6.2.2. Contact List

6.2.3. Permitting

The work scope will require a Permit To Access (PTA) issued by test site operators prior to

mobilisation to site. The PTA is to detail:

• Any restrictions imposed on the work scope

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• The extent of any simultaneous operations being performed by other operators on site

• The up to date coordinates of all assets on the site

• The permit is to be closed out with the test site operators on completion of the works.

6.2.4. Weather and sea-state criteria

The working weather criteria is at the discretion of the SeaPower Senior Onsite Engineer and the

Vessel Master, however it has been assessed as being nominally:

• Wave height to be less than 1.5m Hs, with an average period of more than 8 seconds

• Average wind speeds to be less than 15 knots.

Due consideration must also be given to the effects of; wind and wave direction, tide, combinations

of sea and swell and bimodal sea-states.

Appropriate sources of data for weather forecasting are:

• SmartBay data buoy

• Met Eireann – VHF Ch16

As per DNV recommendations the required weather window to perform any operation up to a

suitable abandonment point will be the estimated time taken to perform the operation plus vessel

demobilisation time, multiplied by a factor of safety of 2.0.

Under no circumstance shall the weather working limits be exceeded without detailed assessment

with the client, the Vessel Master and, where applicable the MWS. Mooring recovery activities may

be restricted by wave forces encountered locally at the test site which are lower than those specified

above.

6.2.5. Tides

The tides in Galway Bay flood from a westerly direction. The tidal range varies between 3 to 5m

maximum. Local currents on site run East to West at approximately 1 knot and more on Springs.

Galway Docks are tidal and the Dock gates will be opened ONLY two hours before high water and

closed at high water. Please refer to Galway Docks Tide Times.

6.2.6. Personnel responsible

All personnel involved in the scope of wok have the responsibility and the authority to halt the

operations if they are in anyway unhappy with any safety aspect of the work.

Vessel Master: Ultimately responsible for the safety of all onboard and the safe operation of the

vessel and vessel equipment and therefore holds primacy.

• Responsible for the management of vessel crew

• Responsible for emergency response aboard the vessel

• Responsible for the interface with shipping agents and/or maritime authorities

SeaPower Senior Onsite Engineer:

• Responsible for the safe execution of the work in accordance with the approved procedures

and for initiating change control procedures, where necessary. Additionally, required to

ensure that the correct revision of the procedures and drawings are onboard and have been

issued to all involved.

• Is the “Person in Charge” of the offshore worksite and had ultimate authority during the

scope of work, with the exception of vessel safety or emergency response situations. Has

authority to halt work for safety technical or quality assurance reasons.

• Implements onsite risk assessment and toolbox talks

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• Responsible for the day to day organisation of the deck activities in liaison with the vessel

deck crew.

• Responsible for the mobilisation of all supplied equipment required for the scope of work.

• Responsible for the mobilisation and management of any required contractors.

• Responsible for interfacing with Test Site operators, including all permitting issues.

SeaPower Onsite Engineer:

• Assisting the Senor Onsite Engineer in the execution of the work and the recording of as-

recovered data.

• Assisting in the mobilisation of all supplied equipment required for the scope of work.

• Assisting in the mobilisation and management of any required contractors.

Vessel Deck Crew:

• Responsible for the operation of vessel equipment (including cranes and winches)

• Responsible for rigging operations

• Responsible for the day to day organisation of the deck activities in liaison with the

SeaPower Senior Onsite Engineer.

7. ENVIRONMENTAL IMPACT ASSESSMENT An assessment of the environmental impacts has been conducted previously which included

decommissioning of devices and the test site.

To ensure any impacts arising from the decommissioning of both the SeaPower Platform wave

energy device and the test site will have no impact on the environment, in line with best practice it is

recommended that post decommissioning environmental monitoring be undertaken, to include

passive acoustic monitoring, turbidity monitoring, tidal currents, wave climate and meteorological

conditions.

8. SCHEDULE

8.1. SeaPower Platform The table below summarises the SeaPower decommissioning programme at the Galway Bay wave

energy test site. The decommissioning of the SeaPower Platform wave energy device, moorings and

anchors is expected to take place between 13th

March 2017 and 19th

March 2017.

The different activities associated with the decommissioning operations are summarised below.

• Device disconnection and tow to Galway Docks – 13th

March 2017

• Removal of first two moorings and anchors – 14th

March 2017

• Removal of final two moorings and anchors – 15th

March 2017

The exact date and duration on site will depend on the weather and tidal conditions.

8.2. Galway Bay test site The table below summarises the decommissioning programme for the Galway Bay wave energy test

site. The decommissioning of the Galway Bay wave energy test site will take place between 20th

March 2017 and 19th

September 2017.

The different activities associated with the decommissioning are summarised below.

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• Removal of dive boat moorings and anchors – week commencing 5th

June 2017

• Removal of waverider data buoy and moorings – week commencing 4th

September 2017

• Removal of SmartBay data buoy and moorings – week commencing 4th

September 2017

• Removal of cardinal marks and moorings – week commencing 11th

September 2017

9. SEABED CLEARANCE The decommissioning process will leave no seabed debris, as the Seapower Platform device, dive

boat moorings, environmental monitoring equipment and cardinal marks including the moorings and

anchors, will be removed completely.

10. RESTORATION OF THE SITE As the decommissioning operation is not expected to greatly disturb the seabed, it is not considered

that specific site restoration measures will be necessary. It is considered that the removal of the

device, dive boat moorings, environmental monitoring equipment and cardinal marks including the

moorings and anchors will disturb only a relatively small area of seabed and will not impact any

habitats of conservation importance.

11. POST-DECOMMISSIONING MONITORING OF THE SITE Given that the seabed will be completely cleared as a result of the decommissioning process, it is not

considered that any post-decommissioning seabed surveys will be required to identify debris.

Post-decommissioning monitoring of the marine environment within the test site will be required for

a period of six months, until the 19th

September 2017 to ensure no adverse impacts arise from the

decommissioning of the SeaPower Platform wave energy devices, or from cessation of activities at

the test site. Decommissioning monitoring of the site can be accomplished with the existing

monitoring platforms at the site:

• Cabled Subsea observatory licenced under 2014/02786

• SmartBay surface data buoy

• Waverider Buoy

The results of the monitoring programme will be updated on a quarterly basis and a final report on

the decommissioning and monitoring results, with conclusions, will be submitted to the Marine

Planning – Foreshore Section of the Department of Housing, Planning, Community and Local

Government on or before 31 December 2017

11.1. Cabled Subsea Observatory (licenced under 2014/02786) Provides for environmental monitoring of the marine environment below the water surface. It is

located in the southwest corner of test site at the end of the Galway Bay Cable. It sits on the seabed

and is anchored under its own weight. The instruments on the cable end equipment consist of:

• a conductivity, temperature and pressure sensor,

• a dissolved oxygen sensor,

• a turbidity and fluorescence (chlorophyll) sensor,

• a hydrophone to measure underwater sound,

• an ADCP (Acoustic Doppler Current Profiler) to measure water current speeds,

• an acoustic fish tag receiver to monitor fish migration patterns and,

• a high definition television camera to record underwater video footage

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11.2. SmartBay data buoy Provides for environmental monitoring of the marine environment at, and above, the water surface

at the test site. The instruments on the buoy consist of:

• a carbon dissolved organic matter sensor

• a meteorological sensor measuring

� wind speed and direction,

� atmospheric pressure,

� air temperature and,

� humidity.

11.3. Waverider Buoy The waverider buoy records the wave climate at the test site.

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Appendix I: Marine Notice.

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Marine Notice: Decommissioning of wave energy device and moorings at Galway Bay

ocean energy test site.

SeaPower Ltd and Atlantic Towage & Marine Ltd are due to remove a wave energy device

and associated moorings at the Marine Institute’s ocean energy test site in Galway Bay,

located within the following co-ordinates:

Latitude Longitude

53°13.90’N 009°15.55’W

53°13.90’N 009°16.15’W

53°13.60’N 009°15.55’W

53°13.60’N 009°16.15’W

The “MV Ocean Bank” (Callsign EIHO7) is scheduled to arrive on site on the 13th

March 2017

to commence the disconnection of the wave energy device from the four point moorings.

The “MV Ocean Bank” will tow the wave energy device from the test site to Galway Docks

on the 13th

March 2017.

The “MV Ocean Bank” will commence recovery of the four moorings and anchors from the

test site on 14th

March 2017 and transport to Galway Docks.

The location is shown on the map below, and the duration of the operation will be

approximately 5 days depending upon weather or other operational conditions.

The vessel will display appropriate lights and markers. The vessels will be

broadcasting/listening on VHF Channel 16 during the project.

galway bay test site decommissioning plan march 2017 · 2017-03-14 · decommissioning...

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