Earthwork Construction Method Statement

_______________________________________________________________________________________________________ Slug of Auchrannie Construction Method Statement

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1.0 AMENDED CONSTRUCTION METHOD STATEMENT

1.1 Introduction

1.1.1 This Construction Method Statement has been amended following the completion of the

additional survey work contained in this Addendum including further detailed consideration of

matters arising from this survey work and revisions to the intake design.

1.1.2 It replaces in its entirety the Construction Method Statement contained in the Environmental

Statement at Appendix I.

1.1.3 In accordance with accepted best practice and relevant guidelines, this Code of Construction

Practice & Method Statement has been produced for the scheme, which presents site-specific

information on all aspects of project work that are expected to have an impact upon the

environment and describes the applicable preventative actions and mitigation aimed at limiting

any identified potential impacts.

1.1.4 The development of this document has informed the development process of the construction

method proposed for the scheme with a view to developing a Best Practicable Environmental

Option (BPEO) for the construction phase of the development.

1.1.5 As the current application is still in the planning phase and a contractor has yet to be appointed

to carry out the construction works for the scheme, some of the specific operational details and

method for the scheme have yet to be finalised. Different contractor companies have individual

construction codes of practice and practiced methodologies or conducting works in various

settings, but this Code of Construction Practice &Method Statement sets the overarching

conditions by which the appointed contractor will be obligated to operate, which will be subject

to modification following discussion and agreement between the respective environmental

specialists making up the EIA team and the appointed consulting engineer and on approval from

The Scottish Environment Protection Agency (SEPA).

1.1.6 The purpose of this Code of Construction Practice and Method Statement is to identify as many

potential risks to the environment from the range of specific construction activities to be carried

out at the development location.


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1.2 Methodology & Guidance

1.2.1 This Code of Construction Practice & Method Statement has been developed by iterative process

between the appointed hydroscheme design consultant and environment team for the project as

part of the requirements of the Environmental Impact Assessment Regulations1, the Habitats

Regulations Appropriate Assessment2and the Controlled Activities Regulations3.

1.2.2 A number of guidance documents relating to the construction of hydroelectric schemes on water

courses are available from a range of sources including the Scottish Environment Protection

Agency (SEPA). The guidance consulted in the preparation of this statement includes:

• Guide to hydropower construction best practice (SEPA, Natural Scotland);

• CAR practical guide (SEPA: http://www.sepa.org.uk/water/idoc.ashx?docid=f8e4798e-

2cab-4ceb-968b-f2a10d7fd8e7&version=-1);

• Salmon and Freshwater Fisheries Act (2005)

(www.opsi.gov.uk/legislation/scotland/ssi2005/20050174.htm);

• Control of Water Pollution from Construction Sites – Guide to Good Practice (SP156);

• Control of Water Pollution from Construction Sites – Guidance for Consultants and

Contractors (C532);

• Pollution Prevention Guideline (PPG) 5: Works and Maintenance In or Near Water

(www.sepa.org.uk/about_us/publications/guidance/ppgs.aspx);

• Pollution Prevention Guideline (PPG) 6: Working at Construction and Demolition Sites


• Pollution Prevention Guideline (PPG) 21: Pollution Incident Response Planning


• Position Statement: Sediment Management

(www.sepa.org.uk/water/water_regulation/guidance/engineering.aspx);

• Good Practice Guide: Bank Protection Rivers and Lochs


• Good Practice Guide: River Crossings


1 Town and Country Planning (Environmental Impact Assessment) (Scotland) Regulations 2011 2The Conservation (Natural Habitats, &c.) Regulations 1994 (as amended by the Conservation (Natural

Habitats,&c.) Amendment (Scotland) Regulations 2004) 3Water Environment (Controlled Activities) (Scotland) Regulations 2011


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• Good Practice Guide: Intakes and Outfalls


• Good Practice Guide: Construction Methods


• Hydroelectric schemes and the natural heritage: Scottish Natural Heritage 2010;

• The SUDS Manual (C697): Site Handbook for the Construction of SUDS;

• SNH Hydroelectric Schemes and the Natural Heritage

(www.snh.gov.uk/docs/C278964.pdf);

• Forests and Water Guidelines (4th Edition)

(www.forestry.gov.uk/pdf/FCGL002.pdf/$FILE/FCGL002.pdf)

1.2.3 This Code of Construction Practice & Method Statement is submitted to the Local Planning

Authority and Statutory Consultees (including SEPA) for consultation and a final version will be

issued for final sign-off by SEPA taking on board any further comments received.

1.3 Potential Impacts

1.3.1 Construction generally involves interaction with and change to the sub-surface environment

within the development site. Industrial land use (including electricity generation and distribution)

is also a recognised potential source of chemical contamination within the soil and water

environment.

1.3.2 Construction will result in the permanent creation of surface and underground features such as

machine chambers, pipelines, roadways, drains and utility ducts. The operations planned for the

site include the installation and maintenance of electrical generation equipment and associated

high voltage transformers, which utilise various lubricants and coolants of significant

contaminative potential within the site area, with the consequent risk of accidental release, spills

or leaks into the surrounding environment.

1.3.3 The development area is a largely natural, undisturbed site, with construction activity taking

place directly on bedrock, which will necessitate some vegetation and thin soil removal. The

requirement for the construction of underground structures in the form of the main turbine

building and the tailrace tunnel means that some rock and associated limited soil deposits will be

excavated and removed from site. Additional rock and soil will need excavation to form access


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roadways into the site from the nearest public roadway which is some distance from the top of

the gorge slope.

1.3.4 Construction will require the use of large plant and machinery within the gorge environment,

adjacent to the river and with regular transiting up and down the north bank slopes and across

the agricultural land to the north. Large quantities of construction materials and the permanent

operational equipment will also need to be transported and placed within the gorge environment.

5.3.5 The main items of plant to be used will include:

• 1 – 38 tonne tracked excavator, c/w rock breaker

• 1 – 8 tonne tracked excavator, c/w rock breaker

• 1 Volvo dump-truck

• 1 – 18 wheel lorry

• Caterpillar D4 bulldozer

• Tower cranes

• Drilling jumbo and road header equipment, sized for 4.7m wide by 4.7m high tunnel and

associated equipment

• 100/150mm diameter pumps

• Concrete vibrating pokers

• Various small tools

• Rock crushing machine

1.3.6 Temporary site offices, storage and operation and maintenance areas will require to be created

remotely from the gorge development area, increasing the overall amount of disturbance during

the construction phase.

1.3.7 Although the operation of the generation equipment is largely passive, the turbine and electrical

generation and distribution equipment will involve the long term storage and use of potentially

contaminating fluids (oils) within the development site.

1.3.8 Decommissioning will most likely be an almost complete reversal of the construction activities,

with similar associated impacts, although it is unlikely that all of the concrete structures would be

entirely removed leading to a permanent change in the appearance and composition of some

exposed surfaces within the immediate vicinity of the river.


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1.3.9 The following sections introduce the broad categories of environmental impacts that are usually

associated with the construction of hydropower schemes.

1.4 Watercourse Impacts

1.4.1 Construction results in direct disturbance to surface rock and soil deposits and disturbance and

interaction with the sub-surface, including excavation and disposal of rock spoil. With rainfall,

open ground from construction activities near watercourses can act as a source of direct

contamination of the watercourse with sub-surface soils and debris. The subsequent settling of

dirt and silt can prevent sunlight from reaching aquatic plants, causing them to perish, and

sediments can clog fish gills and smother organisms inhabiting the river bed.

1.4.2 In addition, serious environmental harm can be attributed to pollution incidents from construction

sites through localised oil spills, concrete pouring and cement washout bays along with a number

of other potentially hazardous incidents.

1.4.3 Works in the river at both the intake works and tailrace outfall/plunge pool will not take place

during the spawning season as stated by the Tay District Salmon Fisheries Board of November to

March4. During the November to March period construction works to the tunnel will be

progressed, with the intake works and turbine house construction taking place from April to

October.

1.5 Geological Impacts

1.5.1 Excavation of in-situ bedrock from the main underground structures locations will require the use

of percussive breakers, but will be unlikely to result in significant changes in the overall exposure

of bedrock in the locality. Retained blocks of excavated rock would be of similar composition and

appearance to natural exposures / boulders that occur within the gorge, once exposed to

weathering for a few months or more. Excavation of upslope areas is likely to result in the

exposure of bedrock in places along the route of the rail system, with the future development of

soils mainly dependent on the suspended rail sections and undulating slope.

4http://www.tdsfb.org/salmon-spawning-times.htm


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1.5.2 Excess material will require off-site re-use or disposal at pre-designated sites in line with current

legislation. This excess spoil would be designated as suitable for general reuse or inert waste and

does not represent a major environmental hazard. Volumes will not be in excess of the local re-

use demand or capacity of local disposal facilities.

1.6 Hydrogeological Impacts

1.6.1 There is a small risk of localised areas of highly fractured / disaggregated rock being present in

close proximity to the river and this may result in river water being able to flow into any

excavations that are very close to the channel itself.

1.6.2 Physical separation of the development area from any small groundwater bodies in superficial

deposits beyond the crest of the gorge slopes will protect these bodies from any impacts.

1.6.3 Roadway drainage may intercept and modify some of the natural, small scale run-off channels

within the development area.

1.7 Soil Impacts

1.7.1 Local soils are sensitive to impact due to their thin and laterally inconsistent nature. However,

this sensitivity is reduced due to the inherent adaptability of the local soil environment to short

term changes in soil accumulation and erosion. Impacts on local soil receptors are similar to

those on geological receptors, with construction activity requiring a significant amount of

disturbance and removal of soil where it is present within the development footprint. The

increased level of disturbance during construction is also likely to result in a higher than normal

level of soil erosion in development areas, where this displaced soil could potentially enter

artificial drains or existing water run-off channels and ultimately the river Isla.

1.7.2 Modification of the local slopes around the development area will lead to changes in the extent

and rate of soil accumulation in both disturbed and undisturbed areas. Increasing the extent of

low slope gradients will increase soil accumulation and eventually soil coverage and vice versa.

Impacts are limited by the small areas of soil involved in relation to the wider gorge environment

and the fact that these impacts will be broadly similar to natural processes that already occur

across the site.


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1.8 Contaminated Land Impacts

1.8.1 Construction and operation of the site will involve potentially contaminating activities within the

currently uncontaminated development area. Construction machinery makes widespread use of

fuels, lubricants and hydraulic oils. Spills and leaks directly from machinery are a possibility

during on-site fuelling and maintenance, as are leaks from the temporary storage of these

materials within the development site. Similarly, the operational equipment to be installed at the

site includes lubrication and heat management fluids that have the potential to be a source of

contamination.

1.8.2 Unlike surface level construction activities, the placement of operational equipment in an

excavated chamber, below the level of surrounding groundwater means that the possible

outward migration of any spilled or leaked fluids in this area is strictly constrained to the

immediate vicinity and inside the structures and tunnels. The risk of any pollutant from the

turbine house will be minimal, as the floor of the structure will be reinforced concrete and all of

the perimeter walls, which will be up to 7m high, will be in reinforced concrete. Access doors into

the turbine house will be sealed watertight doors.

1.9 Species and Habitats Impacts

1.9.1 A number of potential minor adverse impacts have been predicted for species and habitats at the

proposal site and these have been addressed in detail in the Environmental Statement produced

for the proposal. Table 1 and Table 2 in Section 6 summarise all potential impacts with

associated mitigation measures for the construction and operational phases of the development

respectively.

1.10 Arboricultural Impacts

1.10.1 Most of the mature trees growing on this site are located at the top of the gorge and were

planted more than one hundred and fifty years ago. They were an intimate mix of oak and beech

that was typical of Victorian estate plantations. This mix tended to produce very high quality oak

logs, most of which have been harvested, leaving averagely formed beech.

1.10.2 The steep sides of the ravine contain much younger trees and are dominated by sycamore, with

some beech and ash. Most of these trees are less than thirty years old and seem to have grown


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from naturally dispersed seeds into the ground that is prone to slumping. Finally, there are a few

groups of more mature sycamore on the gentler slopes of the ravine.

1.10.3 The steepest slopes within the ravine are fairly unstable, with rock falls and land slips evident

throughout the site. Those trees growing on these steep slopes tend to have a very short life

expectancy before they succumb to a land slip and fall.

1.10.4 Even on the gentler slopes, there is evidence of unstable rooting, with lying oak and sycamore

evident on site.

1.10.5 It is only on the upper edges of the ravine that the trees are surviving for their normal life

expectancy. These create the impression of an old shelterbelt that is typical of the rural

landscape in this part of Scotland. These trees therefore have some significance in the local

landscape.

1.11 Construction Method and Potential Environmental Risks

1.11.1 The construction phase of the scheme will follow a number of phases, which are listed in the

following sections with predicted associated environmental impacts.

1.12 Phase 1.0: Site access to proposed intake works.

Proposed works

1.12.1 An access corridor for construction traffic has been identified from the public roadway. An

existing water bound surfaced lane runs for some 1.7 km to end at existing open pasture land.

This lane is approximately 3.0m wide and will be initially used to gain access to the proposed

intake works for construction traffic. The lane will be widened to a minimum of 4.5m, with

passing bays along its length and new water bound surfacing constructed to widened sections.

The existing water bound surfacing will be strengthened with excavated broken and crushed rock

from the proposed main construction works as this develops.

1.12.2 The access corridor will extend across open pastureland from the end of the existing lane for

some 0.8 km. Over 500m of this is a travelled track used by farm machinery, the surface not

being water bound. The proposed access corridor /roadway will then extend across a section of

poor marsh pastureland for some 300m. Along these sections, topsoil strip and excavation will


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take place and excavated broken and crushed rock used for roadway construction. The width will

be a minimum of 4.5m with passing bays.

1.12.3 A secure fenced materials storage compound will be established at the entrance to the off-site

access route in a convenient location, but sufficiently well back from the public road to allow

delivery vehicles to safely gain access without causing impediment to traffic on the public road

system. Site entrance signage will be displayed at the site road entrance with compliant sight line

splays in place. This will allow main items of materials, pipes, formwork, etc. to be quickly off-

loaded for collection and incorporation/usage in the works as and when needed. This will more

easily control traffic movement along the access corridor during construction.

1.12.4 At the end of the access corridor roadway, some 150m away from the top of the embankment

leading down to the proposed intake works, a secure fenced site compound will be constructed.

This will include space for offices, welfare facilities for the workforce, storage containers and

plant and equipment storage.

1.12.5 A hand railing and maintenance rail systems to the proposed intake works and tunnel head (and

turbine house) will be created down the sloping embankment. These will be suspended above

the ground in places due to the undulating slope. Selective areas of treescape vegetation will

require removal to achieve this but areas of vegetation beneath the suspended stairway and rail

tracks will be left or restored.

1.13 Potential Environmental Risks

• Increased traffic movement and traffic pollution on public roadways and farmland;

• Disturbance of natural drainage pathways through open farmland;

• Disturbance of nesting areas in treescape which requires removal;

• Disturbance of habitat in hedges and pastureland;

• Disturbance of side slope and embankment habitat;

• Soil erosion or loss from workings on side slope into river; and

• Waste pollution from sanitary welfare facilities in the site compound.


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1.14 Phase 2.0: Access tunnel

Proposed works

1.14.1 Excavation to create the tunnel head will take place, this area to later form part of the outlet

chamber of the intake structure. The excavation will be around 6-7m deep, through rock, the

upper levels of sandstone and lower levels of volcanic conglomerate. Rock-breakers mounted on

tracked excavators will be used and the broken rock transported up the embankment to the

farmland plateau for storage for re-use.

1.14.2 A working platform will be created at the low level for construction equipment access to form the

access tunnel, which will be around 4.5m wide and 4.5m high. Percussion machine mounted drills

will be used to form the tunnel to the proposed turbine house, some 210m downstream of the

proposed intake.

1.14.3 Excavated rock will be brought back to the tunnel heading on bogeys on a winched rail system

and tipped for removal and loading onto dumpers to haul up to the storage area. When sufficient

broken rock is accumulated at the storage area, a remotely sited rock crushing machine will

reduce the rock down to suitable size for access roadway construction. A dust mitigation strategy

will put forward in the method statement by the contractor which will be reviewed and amended

as appropriate by the Ecological Clerk of Works to ensure compliance with the project’s

environmental protection obligations. It is expected that this strategy will include the use of

plastic strip doors for access, filtered ventilation for workers, screening, etc.

1.14.4 This will happen in several phases as tunnel excavation proceeds. The end of the tunnel will

broken-out at the proposed turbine house location and a working platform constructed. Local

widening of the area will take place to enable construction of the turbine house structure to take

place. Excavation for the turbine tailrace and downdraft will be made from the working platform.

This will be taken down to a level below the lower mini-Slug river bed level.

1.14.5 A smaller lower working platform will be created at this level, to allow for access for local

deepening of the river channel to create a “plunge pool” which will enable submergence of the

turbine tailrace outlet structure. All excavated rock will be taken back through the access tunnel

for removal to the storage area and activity re-use.


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• Disturbance of side slope/embankment habitat;

• Soil erosion/loss from workings on side slope into river;

• Spillage of excavated rock fines from excavation and haulage activities into the river,

causing sedimentation in the river channel;

• Spillage/leakage of hydro-carbon fuels/oils from plant equipment from the tunnel during

construction finding a way into the river.

1.16 Phase 2.1: Tailrace Outlet and Plunge Pool

Proposed works

1.16.1 Excavation to create the plunge pool will be required, working in the river to shape the pool to

allow full submergence of the tailrace outlet. The plunge pool will require a gradual graded

excavation downstream slope to meet the river bed again. The bedrock will be shaped relatively

flat to mirror other shallow pools on the river bed.

1.16.2 In retreating from the plunge pool basin, excavation of the lower working platform and tailrace

and downdraft will be completed and a reinforced outlet headwall constructed with a fish screen

installed on guides and rear guides on the structure for stop-logging measures to be used when

removing the fish screen for cleaning and regular maintenance.

1.16.3 The tailrace flumed outlet will then be installed up to turbine hall level and the excavated working

area around this concreted back to the exposed rock surfaces. A concrete platform will be

installed at a suitable level above the outlet headwall to allow access for fish screen removal and

maintenance.

1.16.4 A concrete mix with a high Ground Granular Blast Slag (GGBS) content will be used for the in-

river concrete structures to mitigate any short term increased alkalinity in the water course once

the coffer dams have been removed. Where practical, pre-cast pre-weathered concrete units will

be used to form sections of the intake structure in order to further reduce the possibility of

concrete spillages.


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1.16.5 Works in the river at the tailrace outfall/plunge pool will not take place during the spawning

season as stated by the Tay District Salmon Fisheries Board of November to March5. Instead

during the November to March period construction works to the tunnel will be progressed, with

the tailrace outfall/plunge pool construction taking place from April to October.


• Disturbance of side slope and or embankment habitat;

• Loss of excavated rock fines from excavation into the river, causing sedimentation in the

river channel;

• Basin bed and side wall erosion leading to accumulation of sediments in the basin;

• Spillage of concrete and associated construction materials into the river; and



1.18 Phase 2.2: Turbine House

Proposed works

1.18.1 Any remaining excavation for foundations of the turbine house will be completed and again

excavated rock removed up the tunnel to the tunnel head for onward removal.

1.18.2 The foundations and main superstructure of the turbine house will then be carried out, with

equipment and materials brought through the access tunnel.

1.18.3 The tunnel wall to the river side meeting the turbine house and the superstructure walls of the

turbine house will be constructed to a level that will flood-proof the tunnel and turbine house

from river flooding up to a 1 in 200 year event, including an allowance of 20% for climate

change. All landside working spaces around the turbine house superstructure will be backfilled

and finishes to exposed concrete completed sympathetically with the surroundings.



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river channel;




1.20 Phase 3.0: Intake Works

Proposed works

1.20.1 The excavation works for the intake structure will commence during the excavation works to the

access tunnel, but programming of the construction activity of the structure will be linked into the

completion of the access tunnel.

1.20.2 It will be necessary to ensure that no flooding risk of the tunnel can take place as a result of on-

going works to the intake structure.

1.20.3 To facilitate the construction of the wash over intake structure, a temporary cofferdam will be

constructed upstream of the proposed intake works structure using sandbags in polypropylene

sacks of approximately 1 tonne weight.

1.20.4 Ductile iron pipes, minimum 900mm diameter, will be shaped through the bottom of the

cofferdam wall and temporarily secured to facilitate continuous river flow and create a “dry”

working area to construct the intake structure.

1.20.5 Any pumping necessary to control seepage through the sandbagged cofferdam or during times of

rain will be carried out using electric sump pumps (which will be available at all times), these

being run by a small generator which shall be located in a position clear of the river and in a

bunded area. Strict control of fuelling and operation will be employed to mitigate fuel

leakage/spillage. The pumped water will then be transferred to a point outside the river

environment for processing in the suds/sediment storage system.


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1.20.6 In order to minimise destruction of River Jelly lichen within the “dry” working area it is proposed

that the RJL can be kept damp at times using bog mats and pumped water which would help to

maximise its chances of survival during construction of the intake works and penstock.

1.20.7 After clearing the foundation area for the structure, to create a level working surface,

reinforcement bars shall be dowelled into the rock at river bed level and at end wall locations, in

order to secure the structure. The intake structure will be keyed into the river bedrock and the

existing rock wall and rock sloping embankment.

1.20.8 The structure will be poured or placed and grouted in sections, starting from the North side of

the river. At the appropriate stage, the 900mm diameter pipes will be removed and taking

account of local RJL populations the cofferdam shape modified.

1.20.9 The Contractor will be required to ensure that no accidental spillage of concrete, concrete

grouting materials and any other materials that would lead to environmental pollution of the

River and its environs takes place.

1.20.10 A concrete mix with a high Ground Granular Blast Slag (GGBS) content will be used for the in-

river concrete structures to mitigate any short term increased alkalinity in the water course once

the coffer dams have been removed. Where practical, pre-cast pre-weathered concrete units will

be used to form sections of the intake structure in order to avoid excessive spillage.

1.20.11 Construction of the intake works will take place outside the salmon spawning season as stated by

the Tay District Salmon Fisheries Board of November to March6.


1.21.1 The main identified potential environmental risks associated with the construction of the wash-

over intake design are as follows:



river channel;




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• Spillage/leakage of hydro-carbon fuels/oils from plant equipment during construction

finding a way into the river.

1.22 Phase 4.0: Access Tunnel Lining

Proposed works

1.22.1 Concrete lining to the walls and floor of the access tunnel will commence after the intake works

are constructed. This will include ducting, drainage, a maintenance rail system at floor level and

support saddles for the penstock. The watertight bulkhead cross-walls and door-ways at each

end of the tunnel will not be completed until the turbine equipment has been taken to the turbine

hall for installation.





1.24 Phase 1.0: Penstock Installation

Proposed works

1.24.1 After completion of the tunnel lining and associated works, the penstock pipes will be brought to

the tunnel head/access chamber and installed in the access tunnel. Formed openings through the

bulkhead walls will then be grouted up at each end of the tunnel.





1.26 Phase 6.0: Access steps and maintenance rail system

Proposed works


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1.26.1 All access stairways in the intake works outlet chamber and roof flooring will be installed and

steps, hand railing and maintenance rail systems installed on the sloping embankments to gain

pedestrian access to the intake works (and turbine house) from the farmland plateau area at the

top of the embankments.





1.28 Phase 7.0: Commissioning and Demobilisation

Proposed works

1.28.1 The electrical supply cabling from the Turbine Generator will, after exiting from the access

tunnel, be laid in a trench up the embankment and from the top of the embankment taken up a

line pole and go overhead to connect to the grid system. The works will be commissioned and

site reinstatement and full demobilisation take place.


• Disturbance of side slope/embankment habitat; and

• Soil erosion/loss from workings on side slope into river.

1.30 Environmental Mitigation Measures

1.30.1 In accordance with SEPA guidance, ‘Engineering in the Water Environment Good Practice Guide:

Temporary Construction Methods’, a number of measures shall be adopted for the construction

phase of the scheme aimed at minimising the risk of contamination of the watercourse and

habitat.

1.30.2 The broad range of categories defining the mitigation strategy include:

1. Planning and Site Set-up;

2. Site Clearance, Management and Reinstatement;

3. Pollution Prevention Management;


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4. Measures to avoid spillages of construction materials into watercourses and rivers;

5. Measures to avoid sedimentation of the watercourse;

6. De-watering of isolated area;

7. Treatment and/or disposal of contaminated water;

8. Temporary river crossing;

9. Re-instatement of bed and banks; and

10. Pollution Incident Contingency Plan.

Each of the following sub-sections presents the broad mitigation measures for each of the

categories.

1.31 Planning and Site Set-up

Access and Material Disposal and/or Re-Use

1.31.1 Appropriate measures shall be employed (track edge drainage, side ditches and pipes etc.) to

remove surface water emanating from access tracks. Cut-off drains shall be installed on the haul

route to prevent erosion and direct polluted surface water to diversion drains or treatment areas.

1.31.2 Appropriate SUDS shall be incorporated to reduce run-off rate and improve water quality where

appropriate and to treat contaminated water.

1.31.3 All excavated topsoil and subsoil will be stored and bunded on-site for reuse/replacement and/or

filling of selective areas of land. All stored topsoil and subsoil will be securely located and

stabilised to prevent contamination of the watercourses. No excavated soils will be taken off-site.

1.32 Site Clearance, Management & Reinstatement

Pre-earthworks Drainage

1.32.1 Cut-off and diversion ditches shall be installed ahead of the main earthworks activities to

minimise the effects of collected water on stripped or exposed soils once earthworks commence.

The drainage ditches shall intercept any surface run-off and direct it to the existing low points in

the ground for collection, allowing clean water flows to be transferred through the works without

mixing with the “construction” drainage.


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1.32.2 Cut-off and diversion ditches shall be installed on the “high-side” boundary of the areas that will

be affected by the earthworks operations and will generally follow the natural flow of the ground

with a shallow longitudinal gradient.

1.32.3 Where there is a significant build up of water in the construction area, pumping may be required

to avoid further build up, or to allow works to progress in that area. The disposal of the pumped

water shall comply with General Binding Rules 10 and 11 of the requisite CAR licence and shall be

incorporated within the SUDS design.

1.33 Storage areas and waste

1.33.1 Both the main storage compound and site compound will be fenced off and all offices, huts and

containers securely locked each night. Waste disposal material from bins will be collected at the

end of each day and taken to a secure central storage area. Robust secure sanitary and

associative waste facilities will be used and regular collections of the waste taken off-site for

appropriate disposal.

1.34 Storage Compound

1.34.1 The storage compound for pipes, etc and wash-down of concrete lorries will be sited at a suitable

location on the approach laneway to the site. The wash-down area shall be contained within a

dedicated SUDS area, with an impermeable blanket at base level and free draining granular

make-up to create a hard standing area. A small outlet from the blanket will be taken to a silt

interceptor and the clean filtered outlet from here taken to the nearest watercourse. The

footprint area will be around 30m x 40m.

1.35 Site Compound

1.31.1 The site compound will be located at the end of the access route to the proposed intake works ,

some 150m north of the top of the top of the gorge. The footprint area will be around 30m x

40m and the compound will house site huts, welfare facilities, containers and a fuel storage area.

The plant will be kept here overnight.

1.31.2 A metered water supply will be brought to the site compound for use in kitchens, washing and

toilet facilities. The toilets will be Portaloo toilets with a small Biodisc Treatment plant and


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effluent storage tank. There will be regular removal of effluent and sludge by tanker to an off-site

Waste Water Treatment Plant.

1.31.3 A SUDS system will be installed at the site compound, similar to the storage compound, with

both a silt and oil interceptor underground tank. An underground tank will collect and store water

from these, which will then be removed for disposed of off-site.

1.31.4 The stored water at both compounds will be tested for contaminants before removal. If found to

be unsuitable, this will be taken off-site by a registered Waste Contractor to an appropriate

licensed waste disposal facility. The footprint area will be around 30m x 40m.

1.36 Rock Storage Compound

1.36.1 The footprint area of this will be around 30m x 30m and this will be located behind the site

compound area, and suitably bunded, with excavated soil and silt fences and/or straw bales.

1.36.2 Both the storage compound and site compound will have secure fencing and the rock storage will

have a sheep-wire fence. All fenced areas will only be accessible through lockable gates.

1.37 Pollution Prevention

1.37.1 The Contractor shall appoint a Spillclean Contractor, who will provide a Pollution Spill Plan, this to

be agreed with and approved by SEPA. This document will be issued to the entire workforce and

a copy kept in site offices, site huts and all plant and site vehicles.

1.37.2 All waste for disposal off site shall be taken away by a registered Waste Contractor to an

appropriate licensed waste disposal facility.

1.38 Sedimentation Control

1.38.1 A combination of silt fences, silt traps and straw bales will be used to prevent silts entering the

river Isla and associated water courses. These will be inspected regularly to remove silt and

where required reinstate the fences or replace the straw bales to ensure their continuing

effectiveness.

1.38.2 The silt removed shall be disposed of to bunded settlement lagoon area on-site which will be

filled in and soiled over at the end of the construction period.


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1.38.3 Sediments arising in areas of excavation in the river for intake works and tailrace outfall and

plunge pool shall be captured within the cofferdam areas and collected in polypropylene bags,

then sealed before removal from the cofferdam to the settlement lagoon area.

1.39 Access to Intake Structure and tunnel head area

1.39.1 To minimise the extent of treescape removal, a staircase and maintenance rail track system less

than 2.5m wide from the top of the embankment slope will be made to the tunnel head and

intake works. Part of the staircase and rail tack system will be constructed to suspend above the

ground which will allow the protection or restoration of vegetation beneath it. Excavators will

travel down this corridor with a cable winch attachment used to control both descent and ascent,

similarly for dumpers removing excavated materials. Anchorage points at the top of the slope will

be used for secured the cable winch equipment.

1.40 Protection of Trees

1.40.1 A protective barrier, 2.3m high and comprising a vertical and horizontal framework of scaffolding,

well braced to resist impacts and securely supporting weldmesh panels, shall be erected to

protect all trees adjacent to construction traffic. No construction traffic, materials or debris will be

permitted within this zone of protection.

1.40.2 Where temporary access is to be established within the 'zone of protection' surrounding trees,

ground surfaces will be protected by a layer of sharp sand, approx. 50 mm thick, overlaid with a

geotextile membrane on which a temporary surface of no fines granular material, at least 150

mm thick, is laid. Where traffic is turning on these surface, stout planks will be laid over the

geotextile membrane and below the granular material. The trunks of adjacent trees will be

suitably protected.

1.40.3 The de-construction procedure for temporary access protective measures will essentially be the

reverse of the construction phase with all temporary materials being safely removed for

alternative use or safe disposal off-site. Any required reinstatement of temporarily access areas

will be carried out in accordance with best practice directed by the project ECoW together with

input from SNH.


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1.40.4 Where permanent surfaces are to be constructed close to retained trees, within the zone of

protection as defined by BS5837: Trees in Relation to Construction, accumulated organic material

and loose soil will be carefully removed to leave existing topsoil in situ. The tree root zone will be

protected with a layer of sharp sand, on which a firm sub-base of no-fines granular material

supported on a geotextile membrane and a 100mm three dimensional cell product (e.g. Terram’s

Cellular System). The permanent surface will be constructed on this sub-base using established

design guidelines.

1.41 Recreation and Access

1.41.1 All access routes will be sign-posted with alternative paths being incorporated where necessary.

1.41.2 Site phasing will ensure that exemption from access rights due to building and engineering works

is kept to a minimum area, and only where works are active.

1.42 Reinstatement

1.42.1 Reinstatement of the construction area shall be carefully planned prior to any works taking place.

1.42.2 The reinstatement shall include a degree of landscaping followed by replacement of the topsoil

over the area. All reinstatement shall be carried out in accordance with the relevant conditions of

the associated planning consent.

1.42.3 Suitable material for reinstatement shall be appropriately stored and managed, near to the site

compound but away from watercourses and other sensitive receptors with suitable buffers in

place.

1.43 Plant testing

1.43.1 Where possible all equipment and plant on site will use biodegradable hydraulic oils and

lubricants.

1.43.2 All equipment using hydrocarbon fuels, lubricants or other pollutants, shall be tested for potential

leakages at the Contractor’s yard, prior to coming to the site. This shall be witnessed and logged.


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1.43.3 The plant shall be placed, suitably supported, on a clear polythene sheet and the engine allowed

to run at tick-over speed for 30 minutes.

1.43.4 The plant shall then be used to lift or excavate or carry out other such functions for a 15 minute

period, which will replicate the intended use on site.

1.43.5 The sheet shall then be examined for potential leakages. Should any leakage be found, the

equipment shall either be repaired and the test repeated, or an alternative piece of complient

equipment sourced and used instead.

1.43.6 The details of all plant so tested and found to be acceptable shall be logged as equipment to be

used on the site. This test shall be carried out within 24 hours of plant being delivered to the site.

No plant shall be sent to the site without firstly going through this test. This test shall be

repeated on site after the plant arrives and immediately before use in the vicinity of the intake

works or any other site activity.

1.44 Leakage Avoidance

1.44.1 Leachability testing of rock and artificial materials used for water bound surfacing and hard

standing areas at compounds will be carried out, also Taste or Flavour and Odour testing in

accordance with BS 6920. At suitable locations, silt traps will be installed and regularly inspected

and maintained.

1.44.2 Any on-site generator to run pumps, concrete vibrators, rock breaking equipment, etc. shall be

located in such a position that zero risk of fuel leakage takes place. A spill dish, equivalent to

150% of the fuel tank capacity shall be located under the generator, which itself will be placed in

a bunded structure.

1.44.3 Any fuel supply tanks for excavators, generators, etc. shall be sited in a secure compound at a

suitable location, to be agreed on site, where zero risk of fuel leakage takes place.

1.44.4 The tanks shall be bunded with the bund capacity being in excess of 25% of stored fuel or 110%

of the largest container capacity.

1.44.5 Good practice shall be used in accordance with the Water Environment (Oil Storage) (Scotland)

Regulations 2006.


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1.44.6 Any tank storage area in an “at risk” location will be removed off-site at the end of each day and

stored at a “no risk” secure area. Tanks in an “At risk” location include those which are located

immediately adjacent to the slope or a watercourse/non bunded area. Plant requiring refuelling

will be required to be transported to and from the fuel supply tank area.

1.44.7 No fuel or lubricating oil containers shall be brought to the activity site. Machines needing

lubricants shall be transported to and from the fuel supply tank area.

1.44.8 The method of fuelling of machines and the use of lubricants shall be such that no risk of

pollutants to the environment takes place. All containers used shall be safely disposed of off-site.

Jerry cans shall have long nozzles which can be manually locked. Drip trays containing oil

absorbent mats will be used during all refuelling operations. All used mats will be taken off-site

and disposed off to a licensed disposal facility.

1.44.9 All plant shall be removed off-site to a suitable safe compound, where no inherent risk of

pollution can occur in the event of vandalism of machines in the compound.

1.44.10 The per annum grease usage for the turbine equipment will be less than 1 kg. The hydraulic tank

in the turbine house will contain 80 litres of biodegradable hydraulic oils located within a 100 litre

spillage bund.

1.44.11 Replacement grease and hydraulic oils for the turbine house will be brought down the access

tunnel in sealed lockable containers and only opened when in the turbine house. Disused grease

and hydraulic oils will be removed from the turbine house in sealed, lockable containers for

removal off-site.

1.45 Measures to avoid spillages of construction materials into watercourses and rivers

1.41.1 The Contractor will be required to list all materials to be used in the works and a risk register

made on these materials.

1.41.2 Under General Binding Rule (GBR) 10 of the Controlled Activities Regulations, discharges of run-

off water from construction sites are required to be treated by a Sustainable Urban Drainage

System (SUDS) or equivalent.

1.41.3 A SUDS Plan will be developed for the scheme to slow flows, allow adequate settlement and

biological action to take place before water is discharged to the watercourse. An appropriate


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SUDs discharge point and regime will be agreed with SNH. In addition, a management plan will

be agreed on and drawn up to demonstrate that all reasonable steps are taken to mitigate

against accidental spillages into watercourses or rivers. These will include:

• All concrete for construction in or adjacent to watercourses or rivers shall be pumped to

mitigate against accidental spillage from excavator buckets or concrete skips. Chutes to

deliver concrete into formwork shall be used.

• Spillage kits shall be located adjacent to concreting activities.

• Wash-down of concrete trucks shall not be permitted at or near any watercourse or river.

The concrete trucks shall be washed down at a suitable location within the main storage

compound.

• Vegetable based shutter oil shall be used for all formwork.

• All polypropylene bags will be tested prior to and after filling and prior to placement in

the river to create the temporary cofferdams.

1.46 Measures to avoid sedimentation of the watercourse

1.46.1 Where watercourses are crossed or access roads run parallel and adjacent to them, silt traps will

be installed at suitable locations and regularly inspected and maintained.

1.46.2 Excavation works in the river areas will take place and suitable sedimentation traps shall be

located adjacent to the workings. These will be regularly taken out and sediments removed and

disposed of at appropriate locations and traps replaced.

1.46.3 Excavation works in rivers shall take place at periods of low flow to assist in better management

of sediment removal.

1.46.4 Diversion shall be implemented on the upstream perimeter of the site or immediately upstream of

areas of exposed soil on the site (e.g. excavations, embankments and stockpiles) to divert

uncontaminated water away from soils etc. Drains will be lined with a non-erodible material such

as turf or geotextiles.

1.46.5 Buffer strips will be located at the top and bottom of embankment slopes and bails or sediment

traps located here to trap sediments. Regular inspection of and removal of soils and sediments

from these will be carried out to maintain effectiveness.


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1.46.6 A buffer strip will also be required and sediment trap installation at the platform on the slope at

the tunnel heading, where excavated rock materials are removed from the tunnel. Regular

inspection of and removal of rock fines will also be carried out.

1.47 De-watering of isolated area

1.47.1 A cofferdam shall be constructed to facilitate construction of the intake structure and penstock

tunnel. To ensure that any adverse impacts to the RJL are minimised, it is proposed that an RJL

specialist will liaise closely with the ecological clerk of works to specifically oversee and monitor

this phase of works.

4.47.2 The area of the riverbed temporarily utilised by the cofferdam is defined as 7.5m across the full

width of the riverbed. However in order to avoid covering (and potentially destroying) particularly

dense RJL populations it may be necessary to micro-site the cofferdam. This will involve the

contractor liaising with the ecological clerk of works and RJL expert to determine the correct

position and location for the cofferdam to minimise impacts to local RJL populations.

4.47.3 The following measures shall be employed to avoid pollution of the watercourse and surrounding

environment:

• The sands and gravels used for temporary access to the intake works and for the

temporary cofferdam shall be sourced from the immediate area.

• The sandbags used for the cofferdam shall be of strong polypropylene to minimise the

risk of wash-out of the sand particles.

• The access across the river for construction of the intake works will be formed using

gravel or sand filled polypropylene bags, placed carefully over the existing river channel

to form a suitable width of path to facilitate removal of and delivery of materials and

equipment to the construction area. Steel plating or other suitable material should be laid

on the polypropylene sandbags to take the construction traffic.

• Construction of the formwork for the concrete walls of the intake shall use suitable foam

sheeting or other means to prevent grout loss. A vegetable based shutter oil will be used

for formwork. Concrete spillage is to be avoided and any concrete accidentally spilled in

the working area of the intake will be immediately contained and cleaned off. This will be

made possible via the use of spill trays around the working area of the cofferdam. If any


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concrete is accidentally spilled then the material from the spill tray will be bagged up and

removed from the site and disposed of Concrete will be pumped into forms to

minimise and reduce the risk of spillage.

• No paints will be used in any of the permanent works in the intake works.

• Any chemical storage shall take place at a suitable distance from watercourses or the

river to eliminate any pollution risk.

• The Contractor shall have suitable equipment and materials on site, as agreed with SEPA,

to deal with any pollution incident that could arise as a result of accident, negligence or

vandalism. The Contractor’s personnel shall be briefed so that they have a working

knowledge of spillage equipment and its use in dealing with potential pollution incidents.

• Any and all incidents, however trivial, shall be reported, logged and immediate advice

sought and dealt with to the satisfaction of SEPA.

1.47.2 The Contractor shall compile an Emergency Action Plan containing contact names and out of hour

contact details for key project personnel for distribution to key stakeholders, statutory bodies and

any potentially impacted parties.

1.48 Treatment and/or disposal of contaminated water

1.48.1 All surface water from construction sites will be treated through sustainable urban drainage

systems (SUDS). The appropriate CIRIA manuals (The SUDS Manual, Control of Water Pollution

from Construction Sites shall be consulted and the local SEPA office shall be contacted for advice

in developing an appropriate SUDS strategy for the scheme.

1.49 Temporary river crossing

1.49.1 The access across the river for construction of the intake works will require to be formed using

gravel or sand filled polypropylene bags, placed carefully over the existing river channel to form a

suitable width of path to facilitate removal of and delivery of materials and equipment to the

construction area. Steel plating or other suitable material should be laid on the polypropylene

sandbags to take the construction traffic.

1.50 Re-instatement of bed and banks


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1.50.1 The North bank of the River Isla at the proposed intake works and tailrace positions is primarily a

bedrock bluff with little or no vegetation on it. Limited excavation will take place here in a

controlled manner to key the intake structure into the rock.

1.50.2 As the banks of the River Isla at the development site mainly consist of bedrock and rock

fragments of various grades, any areas of the bank impacted during the project construction

phases shall be reinstated to mirror their original form.

1.50.3 Both the North and South embankments at the development site have primarily bedrock faces

with little or no vegetation on the surface. Excavation will be required in the river channel to

construct a plunge pool basin for a submerged tailrace headwall outlet structure. The tailrace

outlet headwall will be orientated in the direction of flow.

1.50.4 The excavation here will be through hard volcanic bedrock and the erosion risk to both the basin

bed and opposite embankment will be minimal. The headwall structure will be built into the rock

face, so scouring of and around the structure will again be minimal.

1.50.5 The outlet cross-sectional area of the tailrace will be sized to reduce outlet velocities to velocities

of less than or equivalent to the river flow prior to the turbine installation.

1.51 Pollution Incident Contingency Plan.

1.51.1 The appointed contractor will be required to submit a Pollution Incident Contingency Plan (PICP)

for review and agreement with the Planning Supervisor, the Consulting Engineer, the Client and

SEPA prior to contract start. The PICP will form an integral part of the Contractor’s Health and

Safety Plan and as such will be rigorously enforced.

1.51.2 The PICP will include, but not be limited to, the following scope of work:

• All vehicles shall carry temporary hole repair kits to stop leaks immediately on noticing.

• Any spillage shall be contained with the use of spillage kits and the area temporarily

bunded (with soil if expedient).

• The affected spillage area shall be excavated with due haste to avoid seepage and any

contaminated material removed off-site to a licensed disposal facility.


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• All vehicles/plant shall carry spillage kits, which will also be placed at strategic locations

on the site.

• Floating booms will be readily available in the event of any major spills to the river.

1.52 Maintenance

1.52.1 The Contractor shall ensure that all drainage requirements are designed and installed prior to

construction commencement and appropriate monitoring and maintenance will be applied with

the following measures implemented:

• Plan and map silt mitigation for the site and number all the different treatment areas on

the site e.g. silt pond 1 (SP1), drainage ditch 2 (DD2) etc. This will prove useful when

inspecting, recording and informing staff of problem areas;

• Record details of the weather, inspections and maintenance carried out etc.

• Monitor and maintain all ditches, ponds, pipes, silt fences etc. on a regular basis.

Monitoring should be carried out in accordance with the weather conditions – for

example, more frequent inspections should be carried out during and after periods of

heavy rainfall;

• Regularly check the watercourse(s) downstream of the construction area for signs of

discolouration, sediment build up etc;

• Any permanent settlement lagoons should be checked for leakage and, following periods

of heavy rainfall, if there has been sufficient settling of sediments, water levels should be

lowered to allow increased containment capacity to be available within the lagoon for the

next rainfall period; and

• Any ditches should be checked for blockages, and kept clear and in good order. Any

growing vegetation in ditches should be left as this will aid in the filtering of some of the

sediments.

1.53 Requirements of Wildlife and Riparian Vegetation Management

1.53.1 Table 1 and Table 2 summarise all potential impacts with associated mitigation measures for the

construction and operational phases of the development respectively.


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1.53.2 Table 1: Construction Phase Mitigation Measures

Valuedignificant Impact Mitigation Propose

Valued Ecological

Receptor

Likely Significant impact Mitigation Proposed

River Tay Special

Area of

Conservation

(SAC)

Deterioration and/or pollution of

habitat and food sources within the

designated boundary and within

supporting (nondesignated)

semi-natural areas arising from

release of pollution and/or high

volumes of sediments within the site

and onwards transmission via

uncontrolled site drainage. Potentially

impacting upon salmonid, lamprey

and otter ecology.

.

Construction of tailrace may reduce

spawning habitat availability for

salmonids and suitable lamprey

ammocoete substrates.

Construction and pollution

prevention methodology as detailed in

the Construction Method Statement

(CMS).

Tail race plunge pool and screening

design as detailed in Design Statement.

Use of coffer dam and piped access to

maintain river flows during the in-river

construction works phase.

Construction subject to timing

restraints in respect of Atlantic

Salmon spawning periods.

Bats (All Species)

Direct, Temporary (Short-Term)

adverse impacts at a localised (site)

level are indicated as a result of

lighting of the site for security

purposes during twilight and

darkness hours. This can impact on

the utility of boundary vegetation for

Construction subject to timing

restraints in respect of nocturnal works.


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commuting and foraging bats

generally, although the species

identified are less susceptible.

Otter

Lutralutra




supporting (nondesignated) semi-

natural areas arising from release of

pollution and/or high volumes of

sediments within the site and

onwards transmission via



and otter ecology.

Construction and pollution prevention

methodology as detailed in the CMS.



Construction subject to timing restraints

in respect of Atlantic Salmon spawning

periods.


in respect of nocturnal works.

Nationally Important

Nationally

Important VERs

Den of Airlie SSSI

Den of Airlie

National

Nature Reserve

(NNR)











and otter ecology.


methodology as detailed in the CMS.





periods.

Use of coffer dam and piped access to

maintain river flows during the in-river


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construction works phase.



periods.

River Isla (open

water)










impacting upon salmonid, lamprey,

bat and otter ecology.





As above

River Jelly Lichen

and other lichen

species

Potential disturbance of River Jelly

Lichen on the cliff face at NO 27898

52898 and at intake and upstream

(NO 276 529).

Potential disturbance of other Lichen

species in close proximity to the

construction site such as


methodology as described in the CMS.

Relocate and mark other lichen species


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Gyalectaulmi and

Opegraphaparaxanthodes.

Bryophyte

assemblage

Direct loss of bryophyte assemblages

to construction area.


water quality arising from release of

pollution and/or high volumes of




impacting upon, bryophyte

communities.

As for River Isla

Upland Mixed Ash

Woodland

Slight loss of this habitat type due to

construction activities

Habitat Management Plan agreed with

SNH, the Upland Mixed Ash

Woodland components of which are

embedded within Scottish Woodland’s

10 year long term management plan for

the Den of Airlie SSSI.

The agreed HMP extends outwith the

formal boundary of the development

site.

Calcareous

scree/Rocky slopes

(includes inland

cliff, rocky outcrops,

chasmophytic

vegetation)

Slight loss of this habitat type due to

construction activities

Habitat Management agreed with SNH.

The agreed HMP extends outwith the

formal boundary of the development

site.

Eurasian Badger Potential disturbance to badger sett. Badger sett to be protected with semi-


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Melesmeles

permanent exclusion fencing prior to

construction.

Breeding & Nesting

Assemblage

Potential destruction and/or

disturbance of nest sites.

All site clearance works to be conducted

outwith bird breeding season

Locally Important

VERS

[no mitigation

required or

proposed]


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1.53.3 Table 2: Operational Phase Mitigation Measures

Valued Ecological Receptor Likely Significant Impact Mitigation Proposed

River Tay Special

Area of Conservation (SAC)


habitat and food sources within

the designated boundary and

within supporting (non-

designated) seminatural areas

arising from release of

pollution during maintenance

activities and/or sediments from

site drainage and maintenance

activities within the site and


uncontrolled site drainage.

Potentially impacting upon

salmonid, lamprey and otter

ecology.

Operation of tailrace may reduce




Maintenance schedules and

pollution prevention methodology

as detailed in CMS.

Tail race plunge pool and

screening design as detailed in

Design Statement.

Maintenance subject to timing

restraints in respect of nocturnal

works.

Otter

Lutralutra





designated) seminatural areas

arising from release of

pollution during maintenance

activities and/or sediments from



as detailed in CMS.



Design Statement.


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site drainage and maintenance

activities within the site and





ecology.







works.



works.

Den of Airlie SSSI

Den of Airlie National Nature

Reserve (NNR)



the


supporting (non-designated)

seminatural areas arising from


volumes of sediments within the

site and onwards transmission

via uncontrolled site drainage.



ecology.


spawning habitat availability

forsalmonids and suitable

lamprey ammocoete substrates.



as detailed in CEMP.



Design Statement.



works.


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River Isla (open water)





designated) semi-natural areas

arising from release of pollution

and/or high volumes of






ecology.







as detailed above.



Design Statement.

Flushing operations subject

to timing restraints in respect of

Atlantic Salmon spawning

periods.



works.

River Jelly Lichen and other

rare lichen species

Potential disturbance of other

Lichen species in close proximity

to the construction site such as

Gyalectaulmi and

Opegraphaparaxanthodes.

Use of GGBS concrete mix and

pre-cast pre-weathered concrete

units for in-river structures.

Clearly indicate and relocate

other lichen species as

appropriate under guidance from

SNH.

Screening and other mitigation as

per CMS RJL specific detail.


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Bryophyte

assemblage

As for River Isla

Upland Mixed Ash Woodland

Slight loss of this habitat type

due to operational maintenance

activities

Habitat Management Plan agreed

with SNH, the Upland Mixed Ash

Woodland components of which

are embedded within Scottish

Woodland’s 10 year long term

management plan for the Den of

Airlie SSSI.

The agreed HMP extends outwith

the formal boundary of the

development site.

Calcareous scree/Rocky slopes

(includes inland cliff,

rocky outcrops,

chasmophyticvegetation)

No specific mitigation proposed

in respect of this habitat type.

ignificant Impact Mitigation Proposed


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1.54 Environmental Clerk of Works

Introduction

1.54.1 The appointed contractor will be required to ensure that the design, execution and completion of

all works comply with the standards and requirements of the Environmental Assessment

documents prepared for the Slug Hydro Electric power scheme. To ensure compliance an

Environmental Clerk of Works (ECoW) will be appointed to oversee all stages of work.

The Environmental Clerk of Work’s role is described below.

1.55 Overall Responsibilities

1.51.1 The ECoW will be an integral part of the construction team. The role of the ECoW will be to

conduct regular site inspections to monitor both the works and the environmental control and

protection measures being implemented. Certain responsibilities set out in the Employer’s

Requirements will be performed by the permanent on-site Clerk of Works who is able to more

closely monitor works on a daily basis. This will involve identifying and ensuring the protection of

sensitive areas on or around the site during construction. In conjunction with regular site visits

the ECoW will remain on site at all times during sensitive construction activities.

1.56 Site Attendance and Inspection

1.56.1 The ECoW will liaise with the Contractor’s Site Management team (via the nominated

environmental contact) in terms of the works programme and the nature of activities to be

undertaken. This will inform the extent and location of each particular inspection. The ECoW will

generally undertake all site inspections; however, specialists (such as River Jelly Lichen and

Arboreal specialists) will attend site where the need arises to monitor specific activities or works

at certain locations. The need for input from such specialists will be determined by the ECoW in

discussion with the Contractor’s nominated environmental contact.

1.56.2 During the first two months of site works the ECoW will attend site on a weekly basis to inspect

activities being undertaken and to ensure that proper environmental control and protection

measures are implemented, in accordance with relevant measures set out in the Environmental

Statement.


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1.56.3 Once evidence is shown that measures are being implemented effectively, site attendance will be

reduced to regular monthly visits, with additional visits as the need arises (i.e. depending on the

works programme and nature/location of activities on site).

1.57 Reporting

1.57.1 The ECoW is responsible for preparing site inspections reports following each site visit recording

what activities/measures have been inspected. A summary of the findings of the particular

inspection will be recorded and recommendations for mitigation identified where required. These

recommendations will be inspected during the next visit to check that they have been properly

implemented.

1.57.2 Site inspection reports will be provided to Contractor’s Site Management team who will notify all

relevant site staff of their obligations.

Earthwork Construction Method Statement

Documents

Transcript of Earthwork Construction Method Statement