Glencorse WTW case study.pdf

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    Glencorse Water Treatment Works

    Scottish Water (2008b)

    Shane Bergin

    Edited by Pauline Thompson

    School of the Built Environment, Heriot-Watt University 2010

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    Contents

    Glossary of Terms ....................................................................................................... 31 Scottish Water ........................................................................................... 32

    Glencorse WTW ........................................................................................ 4

    3 Project Environmental Management ......................................................... 10

    Short Term Impacts .............................................................................. 10Long Term Impacts............................................................................... 11

    4 Land Use.................................................................................................... 11Short Term Impacts .............................................................................. 12Long Term Impacts............................................................................... 13

    5 Landscape Issues ....................................................................................... 13Short Term Impacts .............................................................................. 14Long Term Impacts............................................................................... 14

    6 Ecology and Biodiversity .......................................................................... 16Short Term Impacts .............................................................................. 16Long Term Impacts............................................................................... 177 Archaeology and Cultural Heritage ........................................................... 18Short Term Impacts .............................................................................. 19Long Term Impacts............................................................................... 19

    8 Water Issues .............................................................................................. 20Short Term Impacts .............................................................................. 21Long Term Impacts............................................................................... 21

    9 Renewable Green Energy .......................................................................... 25Carbon Footprint ................................................................................... 25

    10 Material Use .............................................................................................. 26Types of Materials Used ....................................................................... 27

    11 Waste Management ................................................................................... 29Waste Management Plan ...................................................................... 29

    12 Transport ................................................................................................... 30Short Term Impacts .............................................................................. 30Long Term Impacts............................................................................... 31

    13 Nuisance to Neighbours ............................................................................ 34Short Term Impacts .............................................................................. 34Long Term Impacts............................................................................... 35

    14 Community Relations and Joy in Use ....................................................... 35Construction Surgery ............................................................................ 36Education .............................................................................................. 36

    References ................................................................................................................... 37

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    Glossary of Terms

    CO2 Carbon Dioxide

    CoCoDAFF Counter Current Dissolved Air Flotation & Filtration

    EMP Environmental Management Plan

    ES Environmental Statement

    EU European Union

    GWTW Glencorse Water Treatment Works

    LCA Land Capability for Agriculture

    Ml Million Litres

    SEPA Scottish Environmental Protection Agency

    SS Suspended Solids

    SuDS Sustainable Drainage System

    UK United Kingdom

    USA United States of America

    WMP Waste Management Plan

    WRAP Waste & Resources Action Programme

    WTW Water Treatment Works

    The following information has been largely obtained from the 525 page Environmental

    Statement (Scottish Water, 2008a) provided by the Glencorse Scottish Water team and from

    the Scottish Water website. It was written at a stage when the project was only partially

    complete.

    1 Scottish Water

    Scottish Water is a publicly owned company in Scotland. It is the biggest company in

    Scotland to deal with drinking and waste water treatment and is answerable to the Scottish

    Parliament. Scottish Water provides water and waste water services for over 2.3 million

    households and businesses across Scotland. Over 2.3 billion litres of water is provided every

    day and nearly 1 billion litres of waste water is collected and treated in its numerous WaterTreatment Works (WTW) throughout Scotland before being returned to different

    watercourses throughout Scotland. (Scottish Water, 2008b)

    Scottish Water operates and maintains a wide range of property and infrastructure

    throughout Scotland. Glencorse WTW will be the largest single project in Scottish Waters

    programme (Scottish Water, 2008b)As Scottish Water is a public body it works with the

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    local communities and authorities to encourage the idea of sustainable development. Scottish

    Water integrates sustainable development into its day to day operations e.g. by using

    Sustainable Urban Drainage Systems such as green roofs and wetlands.

    2 Glencorse WTW

    Glencorse is a small village to the north of Penicuik, in Midlothian, Scotland. Glencorse is

    situated nine miles south of Edinburgh and is to the east of the Pentland Hills. It is a very

    picturesque location with a five star hotel, The Glencorse House, and the famous Glencorse

    golf course.

    The Glencorse WTW project will provide clean drinking water to over 500,000 customers

    across Edinburgh and the surrounding area. Glencorse WTW will meet the new EU quality

    standards set for drinking water. Scottish Water has set up Edinburgh Drinking Water Project

    and Glencorse WTW is the focal feature of this project. Edinburgh Drinking Water Project is

    a planned programme of capital investment to build a new WTW and replace ageing mains

    and storage tanks at Fairmilehead and Alnwickhill. Glencorse WTW will be the largest ever

    capital project constructed by Scottish Water. The project has a budget of 130 million and

    will have a maximum capacity of 175 million litres per day (Scottish Water, 2008a).

    The water treatment plant will be located to the east of the A702 road as can be seen in

    Figures 1 and 2. Figure 2 shows the site location of the Glencorse WTW, the pipeline and the

    location of Fairmilehead and Alnwickhill.

    The development at Glencorse will include a treatment building, a chemical building and a

    clear water tank to hold 90 million litres of treated water. The landscaping of the site will be

    done to make it as sustainable as possible. Finally a new access road will be created to

    connect Mauricewood Road to the site (Scottish Water, 2008b). Figures 3, 4 and 5 show the

    site layout.

    A new network of pipeline will be constructed to transport the treated water from the

    Glencorse site to Alnwickhill and Fairmilehead where the pipeline will connect into the

    existing network

    The GWTW project has been designed so that economic, operational, engineering, design

    and environmental factors were considered from the beginning, with the intention of finding

    the most sustainable option for the project.

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    The size of the project and the sensitivities of the surrounding area meant that impacts on

    the landscape was one of the major issues for the project and so had to be dealt with from the

    outset. The location and design of the built structures had to be achieved in a way that caused

    minimum disturbance to peoples views of the Pentland Hills from their properties. This was

    achieved by keeping landscape and visual impact to a minimum by sinking the structures into

    the ground. This will maintain the views from nearby properties of the Pentland Hills. The

    design also incorporated large landscaped areas and green roof technology for the aim of

    integrating the building into the natural landscape.

    All of the proposed sites for the new WTW were located within the Edinburgh Green Belt

    and so a new development plan was needed. The requirements and the location constraints of

    the new WTW it justified moving away from the Green Belt development plan. As realistic

    steps will been taken to maintain the existing landscape and countryside, minimise

    interference for the local community and to consider other important policy areas (for

    example the natural environment, tourism and traffic) that are in general agreement with

    Green Belt policy, the new development plan should not require significant change.

    Figure 1. Location of Glencorse WTW (Google Maps, 2010)

    Glencorse

    WTW Site

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    Figure 2. Ordnance Survey Map Showing Site and Pipeline. (Scottish Water, 2008a)

    The Glencorse water treatment works project has used sustainable development principles

    throughout its development, from its site location to the design process itself. Some examples

    of the use of sustainable development principles are the use of the existing water

    infrastructure, designing a gravity supplied system with energy recovery and the use of a pipe

    factory on site (a worldwide first) along with the high standards in design and choice of

    location to avoid unfavourable impacts on local residents. Natural and cultural heritage

    resources have all contributed to the reduction of environmental impacts of the Glencorse

    water treatment works.

    The Glencorse water treatment works proposal has been demonstrated as the most

    sustainable option when environment, cost, risk and engineering feasibility factors were

    Glencorse

    WTW Site

    Fairmilehead

    Alnwickhill

    Pipe Line

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    considered compared to the other locations that were available inside Edinburghs Green

    Belt.

    As can be seen from Figure 6 the construction timescale for the Glencorse WTW project is

    estimated to take thirty months to complete. This thirty month time scale includes a six month

    commissioning stage where the entire project will go through a series of checks and re-

    checks, and consideration of various scenarios to make sure it meets relevant standards for

    safety and quality. The pipeline is estimated to take twenty four months to complete. This

    timescale includes the pipe laying, reinstatement of the disturbed land and the testing of the

    pipeline

    Figure 3. Aerial View of Site, (Google Maps, 2010)

    PentlandHills

    GlencorseHouse

    GlencorseWTW Site

    BelwoodHouse

    GlencorseMains

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    Figure 4. Site layout. (Scottish Water, 2008a)

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    Figure 5. Site layout. (Scottish Water, 2008a)

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    Figure 6. Construction Timescale (Scottish Water, 2008a)

    3 Project Environmental Management

    Project environmental management is a way of controlling the potential impacts that can

    be caused from a construction project on the environment. These impacts can include water

    issues, land use issues, ecology and biodiversity issues, energy and material use issues, all of

    which will be managed through a construction Environmental Management Plan (EMP). This

    EMP will set out the minimum requirements for environmental protection for Scottish Water

    and its many sub contractors as they will be required to meet when constructing the WTW

    and pipeline. Impacts will be expected for a project of this scale and time length. Given these

    impacts of which are listed above are expected to happen in some degree, the aim of the EMP

    is to keep these impacts to a minimum without causing major delays to the construction

    timescale. The impacts of this WTW works from both a construction point of view and from

    a operating point of view will be discussed in the sections below.

    Short Term Impacts

    There will be a number of different short term impacts caused by construction and

    operation of the WTW. This will cause various impacts to areas in the surrounding

    community at different times over a period of thirty months assuming a construction period

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    of twenty four months and a commissioning period of six months. From the Environmental

    Statement (ES) we know that on average there will be one hundred and fifty people employed

    over the main construction period. Some impacts include noise from construction plant and

    traffic, increased traffic movement on surrounding roads, and the supply and removal of

    materials to the site. The EMP has strict instructions for each type of impact and they must be

    followed to minimise these short term impacts. For example, working is only allowed during

    normal working hours i.e. 0800 to 1900 Monday to Saturday, including deliveries to the site;

    this will reduce noise and traffic pollution impacts from out of hours working. The use of

    noise reducers on plant machinery to minimise noise pollution is another commitment in the

    EMP. The EMP should help reduce the interference to the local communities.

    Long Term Impacts

    The long term impacts of the WTW and pipeline will mainly be on visual amenity and thelandscape (see sections below for more information). The EMP also takes into account the

    operating of the WTW and pipeline and not just the construction stage. The EMP lists out

    requirements that have to be met on maintenance and running the WTW. This includes

    weekly maintenance of the landscape during the necessary months of the year, i.e. mowing of

    grass, upkeep of the grass roofs and the pruning of hedges and tress. This will reduce the long

    term visual impacts of the project. The long term impacts from the operation of the WTW

    will be reduced by the use of low noise emission equipment throughout the WTW i.e. pumps

    and fans.

    4 Land Use

    The term Land Use covers brownfield, greenfield sites as well as areas of contaminated

    land. The land use efficiency of the Glencorse site will be assessed along with the risk of

    flooding. In crowed cities throughout the world land is a limited resource and Edinburgh is no

    exception. Developers, farmers and the local councils may all be looking to use the same

    piece of land.

    The Glencorse WTW site is located on grazing land not far from the Pentland Hills. It is

    bordered by the A702 road to the west, a tree plantation to the south, private detached houses

    to the east and woodland and a public right of way to the north. The site is located in the land

    lying between Glencorse Mains and Belwood House set back from the east side of the A702.

    The site is also bordered by Belwood Road which leads to the north edge of Penicuik. The

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    existing shelterbelts and mixed woodland stands of trees provide a feeling of intimacy and

    enclosure.

    The Glencorse site is a greenfield site with no areas of contaminated land. The design of

    the WTW has taken into account the limited size of the site. The layout of the site was

    designed cautiously, getting the best use out of the structures and buildings, and using space

    efficient processes whenever possible, this will help reduce the total amount of land required

    for the WTW project. The WTW project has used the existing land assets effectively by using

    the natural topography of the land to aid the flow of water in the pipes instead of using pumps

    to get the water to the city population. The design of the project took into account the amount

    of subsoil and topsoil that would need to be removed my incorporating this soil into the

    finished landscape design.

    The flood risk of this project has been taken into account with Sustainable urban DrainageSystems (SuDS) included in the design. This SuDS system will include the creation of a

    green roof, reinforced grass access tracks and a swale system, leading to a wetland area for

    the filtration of all run-off from grass and hard standing areas.

    Figure 7 shows a cross section view of the Glencorse WTW project. The structure has

    been built into the natural topography of the land

    Short Term Impacts

    The short term impacts on land use are mostly minor. The land that will be lost due to theconstruction of the site and the pipeline is of Land Capability for Agriculture (LCA) Class 3.1

    or lower. An area approximately two hectares in size of LCA Class 2 agriculture land will be

    temporarily used during the construction of the pipeline. This agricultural land will be of

    medium term loss as it will not be usable during the construction stage and will take several

    years before the land reaches its original potential of productiveness i.e. its ability to grow

    grass. This loss of productiveness is because once the topsoil is replaced and levelled it will

    have to be reseeded with native grass. This reseeding of grass can only be completed during

    certain time periods of the year to give the grass the best chance of growth i.e. late spring or

    early autumn. If this time period is missed reseeding of grass may have to be postponed until

    a later time. As well as the timing of seeding there is also the time it will take for the grass to

    mature to its original level, this can vary considerable depending on weather conditions and

    the soil properties.

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    Local trees species will be replanted to compensate for the trees that had to be removed

    during the construction stage. These trees will be replaced with native trees in greater

    numbers than had originally been there, however, some of these trees will be planted in

    different areas from their original location.

    Long Term Impacts

    The long term impacts on land use are very low. From the Environmental Statement (page

    21) we know that the most significant impact is the permanent loss of 4.32 hectares of LCA

    Class 3.2 agricultural land at the site of the WTW that is currently been used for grazing.

    Figure 7. Cross Section of WTW (Scottish Water, 2008a).

    5 Landscape Issues

    In order to address all the issues of visibility the design for the buildings and landscape

    have been developed as one to create a fully integrated design solution. To do this, two

    important things needed to be achieved. Firstly the buildings had to be embedded into the

    natural topography of the land and secondly to introduce green roofs across the development

    and timber cladding so that there would be less visual disruption when viewing from the

    Pentland Hills and surrounding areas. This was done so that the structure would resemble the

    nearby landscape.

    The design of the WTW minimises the visual impact of the proposed development by

    working with the existing site character of open green fields and boundary woodlands and it

    uses the landscape to conceal the building. Planting of native trees (Scots Pine, Beech, Oak,

    Ash, Rowan, Gean and Hawthorn) and hedgerows (Hawthorn and Beech) is confined to the

    site boundaries. This can be seen in Figure 8.

    Natural Topography

    WTW Structure

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    The green roofs will have a species rich grassland mix, which will include Sheeps Fescue,

    Wavy Hair Grass, Heath Bedstraw and Mat Grass along with associated flora such as Yarrow

    and Ladies Bedstraw.

    The landscaped planting design is set out to improve the existing site biodiversity by

    introducing more habitats and improving existing ones. The emphasis is on native species

    throughout. Figure 9 shows the different species been planted at the Glencorse WTW.

    Species rich grasslands, roadside hedges, woodland screen belts as well as swales and a

    wetland (as explained in a section below) are to be created to deal with the surface water

    drainage but also provide a new, aquatic habitat for flora and fauna.

    Short Term Impacts

    The short term landscape impacts from the construction of the WTW will come from

    activities due to top soil stripping, tree removal, earthworks, soil storage and the presence of

    construction fencing, accommodation and plant and vehicles. Adequate screening of the site

    was achieved by storage topsoil around the boundary of the site to a height of two metres

    where possible. The topsoil was limited to a height of two meters as any higher would

    damage the structure of the topsoil causing it to ineffective for use in areas where landscaping

    is to be carried out. This topsoil was also been seeded with grass to make it a more visible

    pleasant site to look at, it also helped stabilise the topsoil from wind erosion. The contractor

    compounds are stored in areas of low sensitivity; this is to reduce impacts on local residents.

    Long Term Impacts

    The long term impacts on landscape will result from the presence of new buildings, access

    roads, earthworks and planting of grass, trees and scrubs. The impacts of these building will

    be minimised by the use of green roofs and cladding made from timber veneers, this will

    maintain the green and natural appearance of the area when seen from the surrounding

    landscape.

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    Figure 8. Landscape View of WTW. (Scottish Water, 2008a).

    Figure 9. Species used on Glencorse WTW site. (Scottish Water, 2008a).

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    6 Ecology and Biodiversity

    There is a wide range of ecologies within the Glencorse WTW site and along the pipeline

    route and biodiversity plays a major part in these ecosystems. It was very important for

    Scottish Water that these different types of ecologies and the biodiversity were correctly

    surveyed before construction even began. This was because they needed to know exactly

    what was on the site and pipeline route so they could get a better understanding of the area

    and the problems they would have to overcome to build this WTW without destroying the

    local ecology and the biodiversity.

    Short Term Impacts

    The habitat that is to be lost for the short term due to construction of the pipeline is of low

    nature conservation value and is for the most part arable land or grassland. The impact in the

    short term is not considered significant as the land is either been replaced to the original

    standard or it has been improved. Fourteen hectares will be lost temporarily during the

    construction of the site but it will be restored after work has been completed. A further eight

    hectares of semi improved grassland will be temporarily lost during construction of the

    pipeline but this will also be restored on completion of the pipeline. One example of the

    methods used to help maintain the ecology during construction was to fence off of areas

    along the pipeline route to limit the movement of plant machinery.

    During the protected species survey it was found that there were signs of otters, bats and

    badgers located along the pipeline route. These animals will be monitored to make sure that

    the construction of the WTW does not have major effects to their lives or habitats. Indeed

    during construction a new badger sett was discovered that then required the pipeline to be

    rerouted.

    The impacts to fish life in the Glencorse Burn, Boghall Burn, Lothian Burn and the

    Swanston Burn in addition to three unnamed tributaries are also taken into account where the

    pipeline crosses. This impact will be reduced by controlling run-off going into the burn from

    the construction areas. The natural passage way for the fish will be altered during the

    construction of the pipeline under the watercourse by using a temporary piped diversion

    which is designed to allow fish to pass through. This will cause a temporary impact to the fish

    but not a significant one.

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    Long Term Impacts

    At the Glencorse site seventeen hectares of existing habitats will be lost due to the

    development of the Glencorse WTW project and its access roads. This is mainly made up of

    improved grassland which is of low nature conservation. Since mitigation measures are

    important for the site, six hectares of species poor grasslands will be replaced with greater

    species richness grassland. This improvement of grassland will cause an increase in the

    number of habitats on the site. Furthermore than this there will also be four hectares species

    rich grassland, one hectare of damp meadow and finally one hectare of woodland created.

    There will also be the habitats created from the nearly three hectares of green roofs which

    will also be species rich grassland.

    Most of the pipeline route goes through areas of land that are either improved grassland,

    semi improved grassland or arable land. The pipeline passes through Glencorse Valley,Logan Burn Wildlife Site and the Bush Estate Local Wildlife Site. The pipe line also passes

    through a number of tree belts which are designated under the Ancient Woodland Inventory,

    some of which are subject to tree protection orders. Careful routing of the pipeline has

    ensured that the number of trees affected will be minimised as much as possible. Over one

    hundred and twenty meters of linear tree belt will be lost along the length of the pipeline

    along twelve different tree belts. This is with a ten meter working area along the tree belt

    regions. There will not be replanting within this ten meter zone of the pipe because access

    needs to be available for maintenance and there is also the possibility of root damage to thepipeline. All of these tree belts are of low conservation significance i.e. they are either mature

    trees or a large number have been damaged. Other areas of the site will be planted with native

    woodland to mitigate the loss of these trees.

    SuDS are used to treat runoff water from the site before in enters the burns in order to

    protect the local ecologies.

    The long term impacts of the project on ecology are relatively low because the

    landscaping and planting of trees and hedgerows will have a positive effect on habitats. The

    trees and hedgerows that are to be lost will be replaced by a greater number of new trees thus

    creating even more habitats than was originally there.

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    7 Archaeology and Cultural Heritage

    This section will assess the likely effects that the proposed WTW and associated

    infrastructure will have on archaeology and cultural heritage. The main objectives of the

    archaeology and cultural heritage study are to:

    1. Identify the cultural heritage that is relevant to the proposals,

    2. Judge the proposed development in terms of its archaeological potential,

    3. Assess the possible effects of the construction and operation of the WTW on the

    archaeology and cultural heritage resource, and finally

    4. To identify any measures, where possible, to mitigate any significant impacts.

    To get a better understanding of the archaeological and cultural heritage a baseline survey

    of the proposed development areas was undertaken. The location of all known archaeological

    and cultural heritage sites was obtained from a wide range of sources including Historic

    Scotland, the National Monuments Record of Scotland, Midlothian Councils Sites and

    Monuments Record. Ordnance Survey maps and other maps held by the Map Library of the

    National Library of Scotland were also examined to gain a better knowledge of the site and

    any significant historic landscape changes. Local plans and reconnaissance field surveys and

    archaeological field surveys were also used when a better understanding of the area was

    achieved.

    After the desk study was completed a reconnaissance field survey was carried out at the

    Glencorse site and on the pipeline route. At the WTW site at Glencorse the survey extended

    fifty meters beyond the actual site boundary, and for the pipeline route a one hundred metre

    wide corridor was taken. The aims of this reconnaissance field survey were to:

    1. Locate all visible cultural heritage features and identify what state they were in

    2. Identify any areas where there could be buried archaeological remains

    3. Measure any possible effect the WTW would have on the archaeology and

    cultural heritage

    From the information received from the desk study and reconnaissance field study it

    showed that there was evidence of archaeological remains on the site (Figure 10). An

    Archaeological Field Evaluation was therefore carried out at the Glencorse site which found

    evidence of a Roman military fortlet. From the Environmental Statement (page 246) we know

    that in total eighty eight trenches were excavated to look for archaeological findings, this

    amounting to five per cent of the total WTW site. Eleven of the trenches were aimed at the

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    Roman remains that were believed to be on the site. All of the spoil removed from the

    trenches over the Roman fortlet was metal detected to make sure nothing was missed.

    Short Term Impacts

    The short term impacts from the construction of the WTW on archaeological and cultural

    heritage are low. This is because the chosen option for mitigation of the archaeological and

    cultural heritage is to preserve the important remains in situ wherever possible and by

    recording where it is not possible. It is evident from the Environmental Statement (page 243)

    that recording of certain archaeological remains were carried out. This involved assessing the

    findings by excavation and publishing any findings. Known sites of archaeological

    importance will be avoided where possible. The orientation and siting of the WTW has been

    changed to avoid the Roman military installation for any construction excavation or building

    works being undertaken at the site. This area will however be used as a temporary storagearea during the construction stage of the project but is deemed not to cause damage to the

    Roman remains. An archaeologist was then employed by the developer to observe the

    excavation of earth for the different purposes, including foundations, service trenches and

    landscaping activities. The archaeologist will investigate and record any findings he/she may

    find. A watching brief will be conducted as a general method at specific locations during

    topsoiling operations within other development locations where archaeological remains could

    be located.

    Long Term Impacts

    The long term impacts of the WTW on archaeological and cultural heritage are much more

    significant. The remains of a Roman military installation near Glencorse Mains will be

    affected by the construction of the WTW. Although the Roman military remains will not be

    directly impacted on by the construction of the WTW because of the design layout, there is

    the topographic situation of the site which will be altered considerably through the

    construction of the new building adjacent to it. A series of field boundaries within the WTW

    site will be lost during the construction stage and some will be lost forever as structures and

    infrastructure for the WTW will be constructed on them. Wherever possible these boundaries

    will be reinstated with stone walls, timber fencing or hedgerows.

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    Figure 10. Trenches for Roman Remains. (Scottish Water, 2008a).

    8 Water Issues

    Scottish Water are using an innovative Counter Current Dissolved Air Flotation &

    Filtration (CoCoDAFF) system to treat the water (Figure 11). With the use of a CoCoDAFF

    system it has considerably reduced the size and impact of the treatment works. Without this

    new technology it would mean using a traditional separate process unit of Dissolved Air

    Flotation and Rapid Gravity Filters.

    Glencorse WTW site lies within the catchment of the River Esk. The site has two drainage

    ditches on it, one lies to the north of the site and the other lies to the east of the site. Both

    drainage ditches feed into the Glencorse Burn as can be seen in Figure 12.

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    The pipeline will cross three burns (Glencorse Burn, Boghall Burn and the Swanston

    Burn) where a technique of cut and cover will be used. The pipeline will also have to be

    tunnelled under the Lothian Burn at two different points as can be seen in Figure 12. The

    water quality of these Burns is shown in Table 1.

    The water quality of the four burns before construction of the WTW is as follows; the

    Glencorse Burn is of good quality, the Boghall Burn is of moderate quality, with good water

    chemistry but only limited biology due to a lack of fauna life, the Lothian Burn is in good

    quality, with good biology and aesthetics, and finally the Swanston Burn is of poor quality

    due to its poor fauna life.

    The risk of flooding in the nearby watercourses is increased because of the effluent going

    into the burns from the wetland at the Glencorse site. As can be seen from Figure 13 the

    Glencorse Burn is the only burn near to the site that is at risk of flooding. This is a generalmap which shows the flooding of the local burns. Flooding could be caused during an

    extensive period of rainfall.

    Short Term Impacts

    The short term effects of the Glencorse WTW project have been dealt with by having the

    surface water run-off channelled during the construction stage to the two burns located on

    site, either to the south east burn or to the north-east burn. Drainage water from the top-soil

    and sub-soil storage areas at the north of the site will be channelled to the wetland where after

    some retention time an adequate amount of suspended solids will have been settled out of the

    water thus leaving it safe to enter the Glencorse Burn. There will only be minor impact to the

    surface water during the construction stage. During the pipeline construction phase of the

    project four burns will have to be crossed as explained above, this will cause minor short

    term impacts to these burns but will have no impacts on the groundwater or to flooding.

    Long Term Impacts

    The long term effects of the Glencorse WTW on water issues have been reduced by the

    installation of grass roofs and a Sustainable urban Drainage System to reduce and manage

    water run-off rates from the site. Clearly there will be some impact from the construction of

    the WTW and the pipeline. However the inclusion of SuDS systems should greatly improve

    the water issues around Glencorse. These SuDS include swales and a wetland as were

    explained in more detail in a previous section. These systems will provide some treatment to

    the water run-off before it is discharged into the drainage ditch located on site. The

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    impermeable road surfaces will be laid to allow falls of surface water to be collected in

    swales around the perimeter. These will be connected into the southern perimeter swale

    which links to the low level wetland area. All of the wastewater generated from the water

    treatment process including the drainage from inside the plant and from the wash down areas

    will be released into the sewer where it will be treated at the waste water treatment plant.

    Special underground tanks will be constructed in areas where spills and leaks of diesel,

    chemicals and any other hazardous materials are stored, so they can be safely collected and

    disposed of offsite without causing any contamination to the sites water.

    Figure 11. Counter Current Dissolved Air Flotation System (Scottish Water Sustainability, 2008)

    Table 1. Water quality of Local Burns. (SEPA Scottish Environmental Protection Agency (2007))

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    Figure 12. Map of Rivers and Burns. (Scottish Water, 2008a).

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    Figure 13. Areas Prone to Flooding. (Scottish Water, 2008a).

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    9 Renewable Green Energy

    As this is a new project and sustainability is of the upmost importance to Scottish Water,

    they have incorporated renewable energy or green energy techniques into the design of the

    project. A new project is a good opportunity to include a system to generate renewable green

    energy in a time of high energy demand. It also shows Scottish Waters commitment to the

    environment and national energy demands.

    Renewable green energy will be generated by using a system of hydro electric turbines

    within the pipeline system at the Glencorse WTW. It is possible to generate this renewable

    green energy because the water within the pipes is at high pressure. The pressure is high due

    to the height difference between the low altitude sites for Glencorse WTW and Alnwickhill

    and the high altitude water source at Megget and Glencorse reservoirs. Glencorse WTW and

    Alnwickhill are both being used as a location for the turbines. The new pipe route under

    construction will connect up to the existing network of pipes at Alnwickhill. It is necessary to

    reduce the water pressure as it approaches Glencorse and Alnwickhill for safety reasons, thus

    it is an ideal place to generate electricity as this will help reduce the water pressure.

    The energy from the water pressure will be converted into electricity by installing a

    turbine (e.g. Figure 14) in buildings above ground at Glencorse and Alnwickhill. The

    electricity generated from Alnwickhill will feed renewable power into the national grid and

    the energy generated at Glencorse will help meet the energy demand of the WTW. From the

    Environmental Statement (page 10) it is estimated that 65% of the energy requirements of the

    WTW could be generated by these turbines.

    Carbon Footprint

    The Glencorse water treatment project took its carbon footprint levels into account when

    designing and planning the project. It was extremely important that carbon footprint was kept

    as minimum as possible. This was achieved by designing the building in a manner that means

    water will not be pumped throughout the WTW but instead it will be moved using a gravity

    feed system. This will reduce the energy demands and CO2 emissions of the works

    substantially. The latest techniques and technology will be used during construction and

    operation stages to minimise energy use. Scottish Water hopes this project will be an example

    for other large engineering projects with respect to the reuse and recycling of construction

    materials.

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    Figure 14. Hydro Electric Turbines. (My Wind Power Systems, 2006).

    10 Material Use

    As Scottish Water is aiming for a high standard of sustainability for this WTW, material

    use plays an extremely important role in achieving this. Scottish Water has set a minimum

    target of 10% for the use of recycled materials within the project (Scottish Water

    Sustainability, 2008) All materials selected by the various contractors for use in the project

    will have to be checked by Scottish Water as part of the EMP to see if a more sustainable

    recycled material could be used. This should lead to the 10% target being exceeded

    considerably. It is also important that locally sourced materials are used throughout the

    construction stage e.g. concrete and asphalt to minimise the distance vehicles would have to

    travel. This will be discussed more in the transport section.

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    Types of Materials Used

    For a project of this size it is common that there would be a wide range of materials used

    throughout the construction period and for the operation period. The following is just a few

    examples of the different materials used during the construction of the WTW.

    The excavation required to construct all the structures at the WTW will create a large

    volume of material. This material mainly made up of topsoil and subsoil is estimated from the

    Environmental Statement (page 72) to be over 430,000 m3. There is such a large volume

    because the design of the WTW means the structures making up the WTW have been built

    into the topography of the land. The majority of the volume i.e. 250,000 m3of material will

    be used on site for backfilling, creating development platforms and for landscaping. The

    remaining 180,000 m3 of material will be disposed of offsite to alternative sites or to landfills.

    The design of the WTW was to integrate the structures into the topography of the

    landscape in a way that the structures are mostly obscured at ground level when viewed from

    sensitive viewpoints. However, as the structures are not fully sub-surface, the design strategy

    is to incorporate elements of finishes that would be sympathetic to the surrounding landscape.

    These include green roofs which were discussed in more detail above. The green roofs have

    edge canopies of zinc which form the gutters. Larch timber veneer cladding systems will be

    used on south east gable elevations. The faades of these buildings will be finished with

    untreated sustainably sourced local timber. A Kalwall translucent walling system allows

    natural light into the building thus reducing the amount of artificial light required, thereby

    reducing the energy demands of the building.

    Table 2 below is taken from the Environmental Statement (page 71) and provides a list of

    the different buildings and their external finishes.

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    Figure 15. Material storage during construction. ( Heriot-Watt University)

    Table 2. Building and Finishes. (Scottish Water, 2008a).

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    11 Waste Management

    The Scottish Government has set a minimum target of using 10% recycled materials for all

    construction projects over 1 million in valuation. Scottish Water (2008b) This 10% will befor all public bodies organisations in Scotland including the local authorities. The Scottish

    Water team for the Glencorse WTW will aim to exceed this 10% target by carefully

    considering the source of their materials and by employing a productive waste management

    plan. With the help of WRAP (Waste & Resources Action Programme) the Glencorse Project

    team hope WRAP experience and management will increase the recycling levels of the

    project far beyond the 10% target.

    Waste Management Plan

    The Waste Management Plan (WMP) is a very important part of any construction project

    especially when you take into account the large percentage of construction and demolition

    waste that has to be disposed of in the UK each year. To make construction projects more

    sustainable, waste minimisation has to be improved. The WMP for the Glencorse WTW

    looked at the possibility of recycling waste produced on site. This reuse of materials will

    reduce the chance of pollution caused by the waste and will preserve resources of virgin

    materials for further uses and generations.

    The main element of the WMP was to make sure as much as possible of the topsoil and

    subsoil was reused on site and not disposed of in landfills. As explained in the previous

    section, 430,000 m3of topsoil and subsoil was excavated from the Glencorse WTW site with

    250,000 m3 reused on site for backfilling, creating areas for further construction and for

    landscaping. This has a reuse entitlement of over 58% which is a major achievement for a

    construction project the size of Glencorse WTW.

    The WMP was also incorporated during the design of the WTW. One element of the

    WMP that was included the design of the WTW was to build a sewer pipe which runs

    between the WTW at Glencorse and the existing sewer near the City of Edinburgh Bypass.

    This sewer will take the wastewater from the water treatment process i.e. the sludge, internal

    drainage, drainage from wash-down areas and the domestic waste from the workforce.

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    Finally, on a smaller scale, the WMP includes, e.g., methods to contain any outbreaks of

    contamination of the site. If any spills and leaks from diesel, chemicals and any other

    hazardous materials were to occur in storage areas they would be collected in special

    underground tanks and taken off-site by licensed contractors. Licensed carriers will collect

    and dispose of all waste generated on the Glencorse site and will be taken to licensed

    facilities. The clearance and disposal of the existing vegetation growing on the site was

    disposed of with the most environmentally beneficial methods.

    12 Transport

    As can be seen from Figure 16, there are a number of different roads within the vicinity of

    the Glencorse site. Traffic activity over the construction period will impact upon a number of

    different users, these include other road users (e.g. drivers, cyclists and pedestrians), people

    living and working close to the roads and the construction site, and walkers and other leisure

    users of the area.

    An additional innovation for this project is the mobile pipe production technology which is

    a worlds first. It meant the site based pipe factory will manufacture 15km of pipe (Scottish

    Water, 2008a). This allowed extra long pipe sections to be made. The benefits of this are

    huge reductions in vehicle movements, carbon footprint as well as time and cost savings

    (Figures 17, 18 and 19).

    Short Term Impacts

    It should be noted that construction is a temporary activity and that construction

    movements will change greatly over the construction timeline of the project, depending on

    which phase of work is been carried out at that time. The majority of access to the Glencorse

    site will come from the A702 (T) road as shown in Figure 16.

    From the Environmental Statement we know that the peak traffic movement should be

    during September to November 2009 (months 13 15) of the construction stage. This is

    because it is a period where a number of construction activities overlap i.e. soil removal,

    concrete works, building works and installation works. This will result in an increase in the

    number of heavy good vehicles, light good vehicles and cars using the surrounding roads

    with most interference coming between the peak time periods of 0700 and 0800 and 1700 and

    1900 when people are coming and leaving the site. The short term impacts are considered to

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    be of moderate significance. This A road is large enough for heavy good vehicles to travel

    on without causing major delays or obstructions. Any impacts that have been raised during

    the construction stage through the monthly meetings with the local residents have been dealt

    with. These included providing on site road weepers and wheel washing facilities to keep

    mud and dust on the roads to a minimum.

    Long Term Impacts

    The long term impacts from transport issues are not considered significant when the WTW

    is in operation. This is because during the WTW operation stage there will be only minimum

    vehicular movement coming to and from the site. It is estimated from the Environmental

    Statement that it will require six people to run the WTW daily. There will also be addition

    maintenance staff coming and going from the site in works vehicles. There will be an average

    seven heavy good vehicles making chemical delivers every week. There should be nomovement of vehicles outside the standard working hours of the WTW. This is to reduce any

    potential impacts to the surrounding community.

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    Figure 16. Map of Road Network (Scottish Water, 2008a).

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    Figure 17.Pipe Production Facility (Scottish Water Progress, 2009)

    Figure 18. Finished Pipe Section (Scottish Water Progress, 2009)

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    Figure 19. Excavated Trench and Pipeline during a site visit by Heriot-Watt University civil engineeringstudents. ( Heriot-Watt University)

    13 Nuisance to NeighboursNuisance to neighbours is a very wide description unlike some of the other sections

    described above. When dealing with the topic of nuisance to neighbours it typically does not

    have a major effect on the environment. However during their time of incidence it can cause

    stress and difficulties for the neighbouring communities thus it can be a major problem for

    Scottish Water.

    The nuisances in question are mainly noise, vibrations, air quality, dust and lighting. These

    can be very hard to control in large construction projects like Glencorse WTW.

    Short Term Impacts

    The short term noise impacts from the construction of the WTW should not be significant

    at any of the noise sensitive properties adjacent to the WTW provided noise control standards

    are meet during construction works. There will however be an increase in local traffic noise

    especially during September to November 2009 when earthwork machinery will be in

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    operation on Mauricewood Road. Impacts from vibrations will occur adjacent to some

    properties where road breaking is required. Road breaking uses pneumatic drills and jack

    hammers to remove asphalt and pavements. Road breaking is required to lay new access

    roads and incorporate the SuDS systems, i.e. the swales into the design. This will only be for

    a very short time period and is the only cause of vibrations. Dust impacts will only occur

    when there are extreme prolonged dry conditions and, if that was to occur, wheel washing

    facilities at the main exit to the site along with road sweepers would be introduced to control

    dust. Contractors should inform local residents of certain operations where the potential for

    impacts would be at their highest. A traffic code of conduct for vehicles entering the site

    would be implemented, which basically means certain minor roads were to be avoided to

    minimise noise to local residents. The contractor should also provide contact information to

    deal with any complaints.

    Long Term Impacts

    The long term impacts of the construction of the WTW on neighbours are very minimal.

    Noise levels coming from the operation will be kept within the noise regulations. This is

    achieved through the design of the WTW. Mitigation measures will be used, such as

    enclosing noisy equipment and the use of specialised external finishing of the structures so

    that they absorb noises. There should not be any long term impacts associated with vibrations

    coming from the operation of the WTW to any of the nearest residential receptors. There will

    be no significant long term impacts coming from dust and lighting.

    14 Community Relations and Joy in Use

    Throughout the life of the Glencorse WTW project Scottish Water have involved and

    informed the communities affected by the project. When choosing the site location for the

    new WTW for Edinburgh, there was an extensive discussion carried out with the local

    community, authorities and agencies. These discussions will continue with the people from

    the Glencorse community throughout the construction stage of the WTW and should help

    community gain a better understanding of what is planned, designed and built throughout the

    time line of the project. It is very important to have close community involvement when

    constructing such a large project to avoid complaints and possible delays to the construction

    and increased expense.

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    The Communications Plan is one of the most important aspects of a successful project

    Figure 20 shows the Glencorse WTW Project Communication and Stakeholder Map:

    Scottish Water undertook it's largest ever consultation exercise in order to gain the buy-in

    of the local community. Through this consultation process the public were reassured that

    Scottish Water would minimise disruption during construction and that in the long term

    views from Pentland Hills etc would be unaffected. There were very few objections during

    the planning stage. Scottish Water also considered redeveloping the existing WTW at

    Fairmilehead and Alnwickhill. This was ruled out as it would have been too expensive and

    the supply of drinking water to Edinburgh and the surrounding area would have been greatly

    interrupted during the construction stage.

    Construction Surgery

    Through Scottish Waters experience from other large construction projects throughout

    Scotland they have come to the conclusion that a regular community meeting is required to

    keep local communities happy before and during the construction phase of any project. From

    these productive community meetings the relationships between local community members

    and members of Scottish Water have grown to such an extent that these meetings have been

    changed to construction surgeries. By construction surgeries it means people from the

    community will be able to meet and discuss any problems or simply to ask a question to

    members from the Scottish Water Glencorse WTW team in a more casual one to one way.

    Construction surgeries will be held at regular time intervals during which members from the

    Scottish Water Glencorse team will be available in the afternoons and early evenings to

    answer any queries about the WTW project.

    Education

    Large civil engineering projects of the scale of Glencorse WTW do not come around often

    especially in rural areas like Glencorse. Projects of this scale bring great opportunities to the

    local community i.e. schools, colleges and universities (Figure 19), it gives them direct

    experience of how a multimillion pound development like Glencorse WTW is planned,

    designed and constructed. Education is seen as a key way of introducing community relations

    and joy in use to the community. During the course of the construction stage of the project

    Scottish Water has provided a number of open days and will continue providing open days

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