Water Resources Management Plan Options Appraisal Report

December 2013

Water Resources Supply-Demand Team

WRMP Options Appraisal Report

Contents 1 Introduction ...... 1 1.1 Objective ...... 1 1.2 Scope ...... 1 2 Options Appraisal Process ...... 1 3 Stage 1 – Unconstrained Options ...... 2 3.1 Unconstrained Options ...... 2 3.2 Water Resources Planning Studies ...... 3 3.3 MISER SI Modelling ...... 3 4 Stage 2 - Development of Feasible Options ...... 3 4.1 Screening Criteria ...... 4 4.2 Cost Estimates ...... 4 4.2.1 Asset Plus ...... 4 4.2.2 Cost confidence grades ...... 4 4.2.3 Capital cost estimate ...... 5 4.2.4 Operational cost estimate ...... 5 4.2.5 Carbon cost estimate ...... 6 4.2.6 Environmental and social cost estimate...... 7 4.3 Resource Sharing Options ...... 7 4.4 Third Party Options ...... 8 4.5 Leakage and Demand Management Options ...... 9 4.6 Willingness to Pay ...... 9 4.7 Climate Change ...... 12 4.8 Water Framework Directive no-deterioration ...... 12 5 Stage 2 - Economic Appraisal ...... 13 6 Stage 3 – Strategic Environmental Assessment & Habitats Regulations Assessment ...... 14 7 Water Resource Zone Options ...... 14 7.1 Fenland Resource Zone ...... 14 7.1.1 Unconstrained options ...... 14 7.1.2 Feasible options not progressed to Stage 2 ...... 15 7.1.3 Feasible Options ...... 15 7.1.4 Option F1 Kings Lynn and Wisbech Water Reuse ...... 16 7.1.5 Option F2 Kings Lynn Desalination ...... 18 7.1.6 Option F4 Ruthamford North RZ Transfer ...... 19 7.1.7 Option F5 Ruthamford North RZ Transfer ...... 19 7.1.8 Environmental considerations ...... 19 7.1.9 Costs ...... 20 7.1.10 Inter-dependencies, links and synergies ...... 21 7.2 Hunstanton Resource Zone...... 22 7.2.1 Unconstrained Options ...... 22 7.2.2 Feasible options not progressed to Stage 2 ...... 23 7.2.3 Feasible Options ...... 23 7.2.4 Option H1 Fenland RZ Transfer ...... 24 7.2.5 Option H2 Heacham Water Reuse...... 24 7.2.6 Option H3 Wash Desalination...... 25 7.2.7 Option H4 Hunstanton Groundwater Development ...... 26 7.2.8 Environmental considerations ...... 26 7.2.9 Costs ...... 27 WRMP Options Appraisal Report

7.2.10 Inter-dependencies, links and synergies ...... 28 7.3 Norwich & the Broads Resource Zone ...... 28 7.3.1 Unconstrained Options ...... 28 7.3.2 Feasible options not progressed to Stage 2 ...... 29 7.3.3 Feasible options discounted after draft WRMP ...... 30 7.3.4 Feasible Options ...... 30 7.3.5 Option NB1 Bacton Desalination ...... 31 7.3.6 Option NB5 Norwich Storage ...... 32 7.3.7 Option NB10 Norwich intake to existing bankside storage ...... 33 7.3.8 Option NB11 Norwich Water Reuse ...... 34 7.3.9 Option NB12 Bacton desalination (11 Ml/d) ...... 36 7.3.10 Environmental considerations ...... 36 7.3.11 Costs ...... 37 7.3.12 Inter-dependencies, links and synergies ...... 38 7.4 East Suffolk Resource Zone ...... 38 7.4.1 Unconstrained Options ...... 38 7.4.2 Feasible options not progressed to Stage 2 ...... 39 7.4.3 Feasible Options ...... 40 7.4.4 Option ES3 Ipswich Water Reuse ...... 41 7.4.5 Option ES4 Felixstowe Desalination ...... 42 7.4.6 Option ES6 East Suffolk RZ groundwater development ...... 43 7.4.7 Option ES10 South Essex RZ Transfer ...... 44 7.4.8 Environmental considerations ...... 44 7.4.9 Costs ...... 44 7.4.10 Inter-dependencies, links and synergies ...... 45 7.5 South Essex Resource Zone...... 45 7.5.1 Unconstrained Options ...... 45 7.5.2 Feasible options not progressed to Stage 2 ...... 47 7.5.3 Feasible Options ...... 47 7.5.4 Option SE1 Colchester Water Reuse ...... 48 7.5.5 Option SE2 East Suffolk RZ transfer (12 Ml/d) ...... 50 7.5.6 Option SE4 Amendment to Ardleigh Agreement ...... 50 7.5.7 Option SE6 South Essex RZ groundwater development ...... 50 7.5.8 Option SE7 Ardleigh reservoir extension ...... 51 7.5.9 Option SE8 East Suffolk RZ transfer (2Ml/d) ...... 51 7.5.10 Environmental considerations ...... 51 7.5.11 Costs ...... 52 7.5.12 Inter-dependencies, links and synergies ...... 53 7.6 Central Essex Resource Zone ...... 54 7.6.1 Unconstrained Options ...... 54 7.6.1 Additional options considered for Stage 2 economic modelling ...... 54 7.6.2 Feasible options not progressed to Stage 2 ...... 54 7.6.3 Feasible options ...... 55 7.6.4 Option CE1 South Essex RZ transfer ...... 55 7.6.5 Option CE2 West Suffolk RZ transfer ...... 55 7.6.6 Environmental considerations ...... 56 7.6.7 Costs ...... 56 7.6.8 Inter-dependencies, links and synergies ...... 57 7.7 Ely Resource Zone ...... 57 7.7.1 Unconstrained Options ...... 57 7.7.1 Additional options considered for Stage 2 economic modelling ...... 58 7.7.2 Feasible options not progressed to Stage 2 ...... 59 7.7.3 Feasible options ...... 59 7.7.4 Option E1 Fenland RZ transfer ...... 59 7.7.5 Option E2 Newmarket RZ transfer ...... 60 7.7.6 Environmental considerations ...... 60 WRMP Options Appraisal Report

7.7.7 Costs ...... 60 7.7.8 Inter-dependencies, links and synergies ...... 61 7.8 Newmarket Resource Zone ...... 62 7.8.1 Unconstrained options ...... 62 7.8.1 Additional options considered for Stage 2 economic modelling ...... 62 7.8.2 Feasible options ...... 62 7.8.3 Option NWM1 Ely RZ transfer ...... 63 7.8.4 Option NWM2 West Suffolk RZ transfer ...... 63 7.8.5 Environmental considerations ...... 63 7.8.6 Costs ...... 64 7.8.7 Inter-dependencies, links and synergies ...... 64 7.9 Cheveley Resource Zone ...... 65 7.9.1 Unconstrained options ...... 65 7.9.1 Additional options considered for Stage 2 economic modelling ...... 65 7.9.2 Feasible options ...... 65 7.9.3 Option CVY1 Newmarket RZ transfer ...... 66 7.9.4 Option CVY2 West Suffolk RZ transfer ...... 66 7.9.5 Environmental considerations ...... 66 7.9.6 Costs ...... 67 7.9.7 Inter-dependencies, links and synergies ...... 67 7.10 West Suffolk Resource Zone ...... 68 7.10.1 Unconstrained Options ...... 68 7.10.1 Additional options considered for Stage 2 economic modelling ...... 69 7.10.2 Feasible options not progressed to Stage 2 ...... 69 7.10.3 Feasible Options ...... 69 7.10.4 Option WS1 Newmarket Resource Zone Transfer ...... 70 7.10.5 Option WS2a East Suffolk RZ transfer (15 Ml/d) ...... 70 7.10.6 Option WS2b East Suffolk RZ transfer (resilience scheme) ...... 71 7.10.7 Option WS3 Bury St Edmunds Water Reuse ...... 71 7.10.8 Option WS4 Thetford water reuse ...... 72 7.10.9 Option WS5 River Lark flow augmentation ...... 73 7.10.10 Option WS6 South Essex RZ transfer ...... 74 7.10.11 Environmental considerations ...... 74 7.10.12 Costs ...... 75 7.10.13 Inter-dependencies, links and synergies ...... 76 7.11 Ruthamford North Resource Zone ...... 76 7.11.1 Unconstrained Options ...... 76 7.11.2 Additional options considered for Stage 2 economic modelling ...... 77 7.11.3 Feasible options not progressed to Stage 2 ...... 77 7.11.4 Feasible Options ...... 77 7.11.5 Option RHFA2 Peterborough Water Reuse ...... 78 7.11.6 Option RHFA3 Rutland dam raising ...... 79 7.11.7 Option RHFA5 Pitsford Dam Raising ...... 80 7.11.8 Option RHFA6 Canal transfer ...... 81 7.11.9 Option RHFA15 Reduce Ruthamford North RZ raw water export ...... 82 7.11.10 Environmental considerations ...... 82 7.11.11 Costs ...... 83 7.11.12 Inter-dependencies, links and synergies ...... 84 7.12 Ruthamford South Resource Zone ...... 84 7.12.1 Unconstrained Options ...... 84 7.12.2 Feasible options not progressed to Stage 2 ...... 85 7.12.3 Feasible options discounted after draft WRMP ...... 86 7.12.4 Feasible options ...... 86 7.12.5 Option RHA1 Ruthamford North RZ Transfer 1 ...... 87 7.12.6 Option RHFA7 Grafham Dam Raising ...... 87 7.12.7 Option RHFA8 Ruthamford South New Reservoir ...... 88 WRMP Options Appraisal Report

7.12.8 Option RHFA11 Recommission Ruthamford South RZ reservoir ...... 88 7.12.9 Option RHFA13 Ruthamford North RZ transfer 2 (39Ml/d) ...... 89 7.12.10 Option RHFA14 Huntington Water Reuse ...... 89 7.12.11 Environmental considerations ...... 90 7.12.12 Costs ...... 91 7.12.13 Inter-dependencies, links and synergies ...... 92 8 Stage 4 - Preferred Options ...... 93 9 Testing the Preferred plan ...... 93

Appendix A - Reports ...... A Appendix B – Unconstrained Options ...... B Appendix C – Water resources planning studies ...... C Appendix D – Carbon costs ...... D Appendix E – Benefits Assessment (BAG) Report ...... E Appendix F – Willingness to Pay Report ...... F Appendix G – Climate Change Assessment Report ...... G Appendix H – Water Framework Directive No Deterioration Report ...... H Appendix I – EBSD Optimisation Model Report ...... I Appendix J – Preferred plan options set ...... J Appendix K – Scenario Testing Results ...... K Appendix L – Metering Strategy ...... L

Author: Jo Ledger Date: December 2013 Reviewer: Steve Moncaster Date: December 2013 Reviewer: Mike Cook Date: December 2013

Version Date of Issue Reason for change 1 29 May 2013 Outline draft 2 30 May 2013 Issued with draft WRMP 3 12 December 2013 Issued with revised draft WRMP – NOT SEMD APPROVED 4 17 December 2013 Issued for SEMD approval 5 14 January 2014 SEMD Approved

File path \\Globalinfra.net\Teams\AW_TW_AM_IM\Private\13 - SUPPLY DEMAND\28b - PR14 Draft Revised\Option Appraisal Report\For SEMD approval\Option Appraisal Report -revised draft WRMP v5.doc

WRMP Options Appraisal Report

1 Introduction The Water Resources Management Plan (WRMP) requires water companies to complete a robust, transparent appraisal of options to ensure security of supply whilst protecting the environment at a cost acceptable to customers.

The options appraisal has been carried out in accordance with the Water Resources Planning Guideline – the technical methods and instructions1 (WRPG).

This report describes the options appraisal process undertaken by Anglian Water in support of the 2014 WRMP and details the options considered. This document refers to a number of other reports; these are listed in Appendix A.

1.1 Objective The object of this report is to provide a reference document which demonstrates compliance with the WRPG during preparation of the 2014 WRMP, showing that a clear and transparent process has been followed for developing and appraising options.

1.2 Scope This document includes:

1. Preamble (sections 2 to 6) • Describes the option appraisal process • Provides the assumptions and methods used. 2. Resource Zone Summaries (section 7) • Provides details of the unconstrained options and reasons for discounting options • Describes the feasible options • Includes a summary of environmental assessments (SEA, HRA, WFD no deterioration and climate change. • Provides capex, opex, carbon and environmental and social cost • Details any inter-dependencies, links and synergies 3. Appendices • Reports • Unconstrained Options • Water resources planning studies • Carbon costs • Benefits Assessment (BAG) Report • Willingness to Pay Report • Climate Change Assessment Report • Water Framework Directive No Deterioration Report • EBSD Optimisation Model Report • Preferred plan options set • Scenario Testing Results

This report also contains details of the preferred plan and how this has been tested to show that it performs robustly in a number of different scenarios.

2 Options Appraisal Process The WRPG describes a four-stage option appraisal process to determine a preferred solution. Figure 2.1 shows the approach set out in the WRPG.

1 Water resources planning guideline- the technical methods and instructions, October 2012, Environment Agency, Ofwat, Defra and the Welsh Government. 1

WRMP Options Appraisal Report

Figure 2.1: The stages of option appraisal process.

3 Stage 1 – Unconstrained Options

3.1 Unconstrained Options The WRPG describes the unconstrained options as a list of all possible options that must:

• Be technically feasible, and • Include resource sharing and 3rd party options.

To determine the unconstrained option set two workshops were held covering regional areas of Anglian Water:

• North and West – which covered Lincolnshire and the Ruthamford system • East – which covered Norfolk, Essex and Suffolk.

The workshops were attended by representatives from Anglian Water Operations Team, Water Resources Management Team, Asset Planning and the AMP5 capital delivery Alliance.

The workshops focused only on the resource scheme options; demand management options were identified and screened as a separate activity.

The unconstrained option workshops identified all technically feasible supply options for each RZ based on the AMP5 set of RZs. Unconstrained options were considered for all RZs, even those without a deficit.

An initial assessment of the supply demand balance provided an indication of the scale and location of deficits. This was used to inform the option appraisal process before the final demand forecast was completed.

WRMP Options Appraisal Report

A pro-forma was developed for each water resource zone (RZ) based on the generic options listed in Appendix 9 of the WRPG. The pro-forma included the following specific options set out in the WRPG:

• Resource sharing (including bulk supplies and transfers of water) • Options proposed by third parties.

The completed pro-forma with the complete list of unconstrained option can be found in Appendix B.

3.2 Water Resources Planning Studies To assess the feasibility of the unconstrained options a suite of studies were commissioned. These have been delivered by a combination of the Water Resources Management Team and the AMP5 capital delivery Alliance. Appendix C has a list of the studies.

The objective of the studies/tasks was to establish the high-level feasibility of each of the unconstrained options. The output from each task was confirmation of the feasible options, a schematic for each feasible option, estimates for capex, opex, and carbon and a report. Section 4.2 describes the cost estimation process in more detail.

As the supply demand forecast was developed, options within RZs with no deficits were not progressed any further. Any work done was recorded within the task reports but not followed through to development of scope and cost estimates.

3.3 MISER SI Modelling Anglian Water developed a bespoke, high-level strategic water resources model, using the MISER SI modelling software. The MISER model was developed primarily for assessment of RZ integrity, see ‘Review of Water Resource Zone Integrity, Final Report, Anglian Water, 19 February 2013’. However the model was also used to support development of options, in particular in the Ruthamford system where assessment of the complex network was required.

The MISER SI model is based on sub-RZ water balance data and represents the distribution and operation of key treatment and supply assets. The model is made up of water treatment works (WTWs), nodes for each planning zone (PZ) and interconnecting links. A report describing the technical specification of the MISER modelling software and its application provides more detail, see Appendix A.

4 Stage 2 - Development of Feasible Options The WRPG defines the feasible options set as options which have a reasonable chance of implementation. It should not include options with unalterable constraints or which have a high risk of failure. This definition is the basis of the unconstrained options assessment in the water resources planning studies, see section 3.2.

The output of each of the studies is a list of technically feasible options. These have been further investigated within the various environmental assessments including, • the Strategic Environmental Assessment (SEA) and Habitats Regulations Assessment (HRA), (see section 6) • the Water Framework Directive (WFD) no deterioration assessments • the sensitivity to climate change assessment

WRMP Options Appraisal Report

Using the findings from these studies the options have been screened against the criteria described below to determine the feasible options set taken forward to the economic assessment.

4.1 Screening Criteria The following screening criteria have been applied to screen the unconstrained options; these have been taken from the WRPG:

• The option does not address the problem • The option breaches unalterable planning constraints • Is not promotable • Has a high risk of failure.

Unit cost has not been used as a basis of screening any of the options.

Section 7 provides details of the options within each RZ and provides the reason for discounting options.

4.2 Cost Estimates

4.2.1 Asset Plus Asset Plus is an integrated system that incorporates service impact modelling, cost estimation, investment management and optimisation and is used as the basis for cost estimation within Anglian Water. Asset Plus uses cost models based on costs captured from the business and from specialist consultants. These models are used to estimate capex, opex and carbon quantities (embodied and operational). The estimates include all on-costs, project complexities and risks.

For the WRMP the optimisation function has not been used. Optimisation has been carried out using a specific model developed for water resource planning, see section 5.

The options developed for the WRMP have been based on plant group models which are defined as all scope items required to undertake a specific process function (e.g. nitrate removal or water booster pumping). The project complexities and risks have been developed individually for each option based on scheme specific information; this includes elements such as planning costs, land purchase and significant infrastructure crossings.

Asset Plus automatically profiles costs over a number of years to a defined set of business rules. These cost profiles have been used for the WRMP.

4.2.2 Cost confidence grades Cost confidence grades have been allocated to each of the feasible options as defined in Appendix 15 of the WRPG. Table 4.1 shows the grades allocated to the different types of feasible options, where 1 is the lowest and 5 the highest level of confidence.

WRMP Options Appraisal Report

Option Type Scope Score Cost Score

Transfer 4 5

Desalination 4 2

Water Reuse 4 4 Groundwater 5 5 Development Surface Water 5 5 Development New Reservoir 2 2

Dam raising 1 2

Leakage 5 5

Metering 5 5

Water efficiency 5 5 Table 4.1: Cost confidence grades allocated to different option types.

Anglian Water has assigned scope and cost scores below 3 for some options because the scope of works has been developed on limited information or there is a lack of relevant company experience. Where cost information from within the business is unavailable external data has been used.

4.2.3 Capital cost estimate The capital (capex) estimates are based on the scope of works identified in the various water resources planning study reports, see section 3. All costs taken from Asset Plus are based on September 2012 prices.

The capex estimate is based on the maximum capacity of the option. The maximum capacity has been determined by either the size of the deficit in the RZ to be supplied by the option or limited by the availability of the proposed resource. The initial capex associated with the planning, design and construction has been automatically profiled within Asset Plus, see section 4.2.1. This is the value used in the WRP3 tables for fixed capex.

Asset Plus has defined rules for costs and frequency of capital maintenance/replacement of assets (e.g. mechanical & electrical scope replaced every 15 yrs, civils every 50 years). This data has been used for variable capex in the WRP3 tables.

4.2.4 Operational cost estimate The operational (opex) estimate is based on the average capacity (ADSO) of the option. The average capacity has been determined by either the size of the deficit in the RZ to be supplied by the option or limited by the availability of the proposed resource. Opex estimates are based September 2012 prices.

The opex estimate has been split into fixed and variable opex. The fixed opex is based on the following Asset Plus categories:

• Labour • Replacement parts • Licences

WRMP Options Appraisal Report

• Infrastructure maintenance • Insurance • Corporate carbon reduction commitment • Scientific services • Rates.

For variable opex the following categories have been used:

• Power • Chemical • Miscellaneous & other.

The figures used for variable opex in the WRP3 tables are derived by dividing the annual opex cost by the average output from the option to provide a cost per Ml/d per year. This is then multiplied by either the capacity or utilisation depending on the table requirements.

4.2.5 Carbon cost estimate Asset Plus has been used to develop embodied and operational carbon quantity estimates for each feasible option in terms of tonnes of carbon dioxide equivalent (tCO2e).

Policy guidance2 was referred to for the latest traded price of embodied carbon. The costs in Table 3 of the Greenhouse gas emissions and energy appraisal: Toolkit supporting tables3 were used to calculate an average price per AMP period based on the central estimate. See Appendix D for more details.

The cost of operational carbon was taken from the Carbon Reduction Commitment paragraph in the HM Treasury annual Autumn Statement4. This states the forecast allowance price for 2014-15 as £16 per tCO2e.

The value used for embodied carbon is based on the traded price of carbon less the following,

• European Union emission trading scheme • Climate change levy • Carbon reduction commitment.

These are assumed to have been built into the price of materials and products purchased. The net result is the value of carbon for embodied emissions is zero until the year 2023.

2 Updated short-term traded carbon values used for UK public policy appraisal, Department of Energy & Climate Change, October 2012. https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/41794/6667-update-short-term- traded-carbon-values-for-uk-publ.pdf 3 Tables 1-20: supporting the toolkit and the guidance, Department of Energy & Climate Change, updated December 2012 https://www.gov.uk/government/policies/using-evidence-and-analysis-to-inform-energy-and-climate-change- policies/supporting-pages/policy-appraisal 4 HM Treasury Autumn Statement, 2013 6

WRMP Options Appraisal Report

4.2.6 Environmental and social cost estimate The 6-stage process set out in the Benefit Assessment Guidance5 (BAG) was followed to produce the fixed environmental and social costs. The more recent guidance on the costing of greenhouse gases, climate change and air quality impacts have also been applied. These costs were profiled in line with the capex profile taken from Asset Plus. Appendix E contains the BAG assessment of feasible options report with full assessment of the options.

4.3 Resource Sharing Options Details of the main trades and bulk transfers that are included in the plan are given below:

Company Company Trade Volume Volume Start (from) (to) (Ml/d) (Ml/d) Date (in Average Peak plan) Cambridge Anglian Barnham Cross 0.25 (-) 2015-16 Water Water Baseline Ardleigh Anglian Affinity East Agreement (70/30 5.4 7.2 2012-13 Water split) Amended Ardleigh Anglian Affinity East Agreement (80/20 2.6 3.6 2032-33 Water split) Anglian Affinity 2012-13 Grafham Export 91 109 Water Water Essex and Anglian Tiptree bulk 3.0 4.5 2012-13 Suffolk Water Water supply Anglian Severn Rutland Export 18 18 2012-13 Water Trent Water Table 4.2: Summary details of principal water trades between companies

The bulk supply from Cambridge Water will be available on delivery of our AMP5 Barnham Cross transfer scheme.

Discussions are currently being progressed with Severn Trent Water about a trade based on the Rutland Export. This would see Anglian Water paying Severn Trent a charge for retaining the bulk supply for use in the Ruthamford supply system.

To enable this trade to happen Severn Trent need to provide an alternative source of supply for their customers who currently receive the export. However, there is some uncertainty about the infrastructure required for this and so although the option is technically feasible, the cost and terms of the trade have yet to be agreed. For this reason the trade has not been included in our least- cost modelling. The significance of this is limited, since the modelling shows that no additional resources will be needed in the Ruthamford North RZ until AMP10.

The table does not include the minor cross-border connections that exist between adjacent water companies. These are referenced in Figure 4.1.

5 Benefit Assessment Guidance, Environment Agency, 2002 7

WRMP Options Appraisal Report

Figure 4.1: Transfers, existing trades and trades considered as part of the plan

4.4 Third Party Options Anglian Water were contacted during the preparation the draft WRMP by a major food processing company with a large discharge of waste water from their manufacturing process. This was estimated to approximately 4 Ml/d. It is currently being discharged to the River Wissey, in the Fenland RZ. The company expressed an interest to trade.

WRMP Options Appraisal Report

At the time of the discussion a surplus was forecast for Fenland RZ and so it was agreed that a trade would not be required. Since then, however, sources within Fenland RZ have been targeted for significant sustainability reductions. Given the sustainability reductions, a trade could become a feasible option and is being investigated further.

A similar trade with this company in the Norwich and the Broads RZ was discounted owing to concerns raised through the SEA and HRA process.

Another food processing company has also expressed an interest to trade within the Norwich and the Broads RZ. Investigations to determine if it will be feasible are being carried out.

4.5 Leakage and Demand Management Options Leakage options were developed from assessment of our distribution system. This is reported in the following document ‘Economics of Leakage Control for PR14’. The costs calculated in the report were adjusted to the retail price index (RPI) for the period September 2011-12 prior to inclusion in the optimisation model.

Our Least Cost Plan includes the leakage baseline forecast projection of 199 Ml/d. There are 5 leakage options per RZ. Each option includes social, environmental and carbon costs, however financial costs make up approximately 90% of total costs. It has been identified that the options are cost beneficial and have been included in the baseline forecast under the Preferred Plan. Therefore, the Preferred Plan includes the projected leakage baseline of 172 Ml/d, and is supported by our customers. An assessment of the cost benefit of our leakage programme can be found in the WRMP.

Demand management options were developed following the same approach as reported in the WRMP 2010. In the Anglian region, water efficiency and enhanced metering are proposed for areas that are either forecast to be in deficit, are vulnerable to loss of supply due to sustainability reductions, or have not previously been targeted for these activities. We are proposing to install 85,595 smart meters in the relevant areas which will mean 93% of our customers will have a meter fitted and 86.32% paying measured charges by the end of AMP6. The water efficiency audits are estimated to save 8-9Ml/d by the end of the forecast period. It has been identified that the demand management options are cost beneficial and therefore included in the baseline demand forecast under the Preferred Plan.

Anglian Water has not considered compulsory metering as an option as there currently is a high metering penetration and by the end of the forecast period optimal meter penetration will have been achieved. Cost benefit modelling shows that compulsory metering is less cost beneficial than the preferred strategy, see the WRMP for details. Also, our customers are not in favour of compulsory metering.

4.6 Willingness to Pay To determine customer attitudes to water resource issues, a series of stated preference surveys have been completed for the 2014 WRMP and are reported in the following documents:

• Anglian Water PR14 Willingness to Pay Survey: Final Report (eftec and ICS consulting, November 2012)

WRMP Options Appraisal Report

• Anglian Water PR14 Second Stage Water Resources: Final Report (eftec and ICS consulting, May 2013) • Anglian Water PR14 Customer Research: Completion Report (eftec and ICS consulting, May 2013)

All of the willingness to pay work was peer-reviewed for quality assurance and control. A summary of the main findings that relate to water resources is included in the Appendix F.

The November 2012 report examined customer attitudes to a wide range of water and wastewater service measures, including the frequency of hosepipe restrictions. From analysis of the survey results it was estimated that customers are willing to pay £644k per annum for a 1% change in hosepipe ban frequency. This “scaled” value takes account of the effect of all of the other investments that a water company could make and so is considered to be a conservative estimate. The equivalent unscaled value was £1,913k per annum.

In the second stage study, more detailed attitudes to water resource issues were examined. This included willingness to pay:

1. To avoid different types of restrictions, and 2. For different types of options for maintaining the supply-demand balance

The restrictions considered included hosepipe bans (temporary use bans); non- essential use bans and rota-cuts. For each, customer attitudes to different frequencies and durations were assessed.

The option types considered included:

• Leakage management • Metering • River abstraction • Reservoirs • Desalination • Water re-use • Water transfers from other regions

For both household and business customers, the results showed:

1. Rota-cuts were less desirable than non-essential use bans and non- essential use bans were less desirable than hosepipe bans 2. Higher frequency restrictions were less desirable than lower frequency restrictions 3. Leakage reduction is the preferred option for maintaining the supply- demand balance, followed by metering 4. Household customers did not differentiate between different supply-side options whereas business customers showed a preference for desalination and preferred reservoirs to abstraction and water re-use, and 5. For both household and business customers, the transfer of water from other regions was the least favoured option.

WRMP Options Appraisal Report

The household preference weightings for restriction type are given below:

Restriction Type Odds ratio

Hosepipe ban 0.0212

Non-essential Use Bans 0.0550

Rota Cuts 0.1001 Table 4.3: Household preference weightings for restriction type

The preference weights for each option type are summarised below:

Option Household Weighting Business Weighting

Abstraction 1.0 1.0 New reservoir 1.0 1.1 New desalination plant 1.0 1.3 Increase in metering 1.3 1.4 Water re-use 1.0 1.0 Leakage reduction 2.5 3.9 Transfers 0.9 0.9 Table 4.4: Preference weightings for water source options

Analysis showed that for a limited range of deficits (< 20 Ml/d) the £644k willingness to pay for a 1% change in the frequency of a hosepipe ban can be considered equivalent to £4.813m per annum per Ml/d of avoided deficit. From a combination of this and the preference weightings derived from the second stage survey, the following estimates of willingness to pay for different option types was estimated:

Option Value for loss or gain

Abstraction £4.813m New reservoir £4.813m New desalination plant £4.813m Increase in metering £6.404m Water re-use £4.813m Leakage reduction £12.471m Table 4.5: Willingness to pay for water option values (per Ml/d per annum)

The stated preference work also assessed the total amount that customers would be willing to pay for a well defined package of service enhancements. The result was that on average this was equivalent to £30 each per annum for household customers and 5% extra for business customers. The results of this work are reported in the following:

• Discover Discuss Decide: Summary of research into household and business customer and stakeholder views, Report to Anglian Water, October 2013, OPM.

WRMP Options Appraisal Report

For the WRMP, the willingness to pay data has been used to complete a cost benefit analysis for a number of demand management activities. The results show that these activities are cost beneficial and so the options have been included in the preferred plan. As a result, the baseline forecast for the preferred plan includes,

• A reduction in leakage from our Ofwat agreed 2014-15 SELL target of 211Ml/d to 172Ml/d • 180,000 water efficiency audits, with water savings of 48 l/property/day, and • The fitting of 85,000 household meters under our enhanced metering programme, with savings on switching from unmeasured to measured supplies of approximately 50 l/property/day

Details are given in the WRMP and the WRP tables.

Since we operate in an area of severe water stress, a cost benefit analysis was also completed for compulsory metering. This showed that compulsory metering would be more expensive than our preferred metering strategy, which is based on a combination of enhanced metering, meter options and a small number of selective (compulsory) meter installations, and would yield only marginal water savings.

4.7 Climate Change The WRPG require an assessment of the vulnerability of feasible options against the possible future impacts of climate change. A qualitative screening of the sensitivity of the feasible options to climate change has been undertaken. Research has shown that demand options are insensitive to climate change therefore only the supply side feasible options have been assessed.

A sensitivity score (1-3) has been assigned to each option, these are defined as,

• 1 - indicate low climate sensitivity • 2 - suggest limited sensitivity • 3 - denotes sources sensitive to the impacts of climate change.

Appendix G contains the full assessment of the sensitivity of supply options to climate change.

4.8 Water Framework Directive no-deterioration To meet the no deterioration requirement of the Water Framework Directive (WFD) the feasible options have been assessed in relation to the likely risk that a change in abstraction would result in deterioration of water body status.

The screening process was developed in conjunction with the Environment Agency. The screening methodology assigns an overall risk score for each abstraction point which has been used to identify licences where the residual risk is highest. Appendix H contains the WFD no deterioration assessment report.

WRMP Options Appraisal Report

5 Stage 2 - Economic Appraisal The economic appraisal was carried out using Anglian Water’s water resource planning optimisation model. The model follows the methodology set out in the Economics of Balancing Supply and Demand6 (EBSD) and the requirements of the WRPG.

The objective of the model is to find the least cost programme of options to maintain target level of headroom over the planning period by minimising discounted capex, opex, environmental and social and carbon costs. It considers the three demand scenarios – dry year annual average, dry year critical period and normal year annual average simultaneously to ensure deficits are satisfied. See the ‘Economics of Balancing Supply and Demand Optimisation Report, 2013’ in Appendix I for full details of the model.

The model uses the following data to complete the assessment of least cost solution:

• A discount rate of 4.5% has been used. • Variable opex is used to ensure assessment is based on utilisation costs rather than option capacity • Minimum option capacities are provided to ensure minimum operating costs are included in assessment • Capex and opex is included and discounted over an 80 year planning horizon • Utilisation is maintained at the 2040 value for subsequent years • The earliest potential option start date which is based on the implementation period for each option • Any interdependencies between option (e.g. mutual exclusivity and mutually dependency).

The model ensures that all options, including resource sharing options, leakage and demand management options, are assessed consistently. No aspects of the least cost solution have been determined outside of the optimisation modelling process.

The optimiser input tables are based on the WRMP tables, however some data manipulation is required. The following lists the assumptions used in the model and how this data has been inputted.

• All capex data is entered into Year 1 (i.e. there is no cost profile) • Capital maintenance has been annualised and added to the fixed opex so it is included in the assessment as an annual cost. This is because the model cannot consider costs profiled over the planning horizon • The value entered for variable opex is a unit cost (£ per Ml/d per year) rather than a total cost (£ per yr) in the WRMP tables.

The model run to determine the least cost solutions included the following data: • Capex – initial and maintenance • Opex – fixed and variable • Carbon - fixed and variable • Social and environmental costs – fixed and variable

6 Benefit Assessment Guidance, Environment Agency, 2002 13

WRMP Options Appraisal Report

6 Stage 3 – Strategic Environmental Assessment & Habitats Regulations Assessment A Strategic Environmental Assessment (SEA) and Habitats Regulations Assessment (HRA) have been completed for the draft WRMP. The following documents should be referred to for more detail:

• Strategic Environmental Assessment Scoping report, October 2012 • Strategic Environmental Assessment, Volume I: Main report, December 2013 • Strategic Environmental Assessment, Volume II: Appendices, December 2013 • Habitats Regulations Assessment, December 2013.

The SEA has been used to refine the feasible options set. The following feasible options have been discounted on the basis of the SEA:

• Cantley desalination plant • Lowestoft water reuse.

Options may have been discounted for reasons other than the SEA and these are listed in the individual water resource zone option descriptions, in section 7.

The HRA has identified the need for HRA appropriate assessments on the following options:

• Norwich water reuse (NB11) (Norwich and the Broads RZ) • Ruthamford North RZ transfer (RHFA1)

The option set has been developed iteratively in conjunction with work on the SEA and HRA process and the SEA and HRA do not alter the preferred plan, see section 8.

7 Water Resource Zone Options

For each RZ in deficit details of the unconstrained and feasible options are described in the following sub-sections.

7.1 Fenland Resource Zone

7.1.1 Unconstrained options The table below contains the list of unconstrained options considered for Fenland RZ. More details about the reason for discounting an unconstrained option or why an option type was not considered for Fenland RZ can be found in Appendix B in the Fenland RZ table.

Option Feasible Scheme Type Option Description Ref Option

Direct river abstraction River Wissey / Cut off Channel (WTW N extension) River Heach N River Ingol N North Norfolk Rivers N Gaywood River N

WRMP Options Appraisal Report

New reservoir storage Feltwell (Trent-Rutland-Ouse transfer) See table Pumped-storage reservoirs 7.2 North Norfolk Rivers (winter storage) N Wash Reservoirs N New reservoir storage Wash Barrage N Flood storage New Internal Drainage Board structure N SUDS - recharge lagoons N Groundwater sources Sandringham Sands N Nitrate removal/revised blending regime See table 7.2 Aquifer Storage and Sandringham Sands N Recharge Aquifer Recharge North Norfolk Rivers N Desalination F2 Kings Lynn Desalination Y Reclaimed domestic F1 Kings Lynn water reuse Y wastewater F1 Wisbech water reuse Y Reclaimed industrial and Industrial reclaimed water N commercial wastewater Bulk transfers By pipeline North Norfolk Coast RZ transfer N Wash Pipeline from Lincolnshire N F3 North West Norfolk transfer See table 7.2 F4, F5 Transfer from Ruthamford North RZ Y 3rd Party Options Trade 3rd party trade options N 3rd Party Options Shared Multi use reservoir (agriculture) N asset ownership Kings Lynn tankering (sea) N Tankering of water Icebergs N Improved/sophisticated Kings Lynn conjunctive use N conjunctive management Table 7.1: Unconstrained options for Fenland RZ

7.1.2 Feasible options not progressed to Stage 2 The table below describes feasible options identified at the unconstrained options workshop which after further work were discounted and not progressed to Stage 2 – economic modelling.

Option Option Name Reason for discounting Ref F3 North West Norfolk transfer Not adequate surplus to transfer from North Norfolk Coast RZ Feltwell reservoir (Trent- A feasible option but not taken through to Stage Rutland-Ouse transfer) 2 as would need to be developed as part of long term strategy. To be considered in the WREA. Nitrate removal/revised This option has been discounted as part of Task blending regime 4e). The study found that the sourceworks are constrained by other factors (e.g. licence) not the blending regime. Table 7.2 Fenland RZ Feasible options not progressed to Stage 2

7.1.3 Feasible Options Table 7.3 contains details of the feasible options considered for Fenland RZ in the economic modelling.

WRMP Options Appraisal Report

Opt Capacity (Ml/d) Implementation Asset Plus Option Name Ref Average Peak Min Period Solution ID Kings Lynn and F1 Wisbech water 12 16 8 3 years S9732269 reuse Kings Lynn F2 12 15 5 3 years S9732309 desalination Ruthamford North F4 RZ transfer (12 12 12 4 4 years S9734700 Ml/d) Ruthamford North F5 RZ transfer (25 25 25 8 4 years S9734908 Ml/d) Leakage Control FEN1 0.5 n/a n/a Package 1 Leakage Control FEN2 0.5 n/a n/a Package 2 Leakage Control Programme Not estimated FEN3 0.5 n/a n/a Package 3 delivered over AMP within Asset Leakage Control period Plus FEN4 0.5 n/a n/a Package 4

Leakage Control FEN5 0.2 n/a n/a Package 5 Water efficiency – FEN6 measured 0.3 n/a n/a Programme S10071045 household delivered over AMP

Water efficiency – period

FEN7 unmeasured 0.1 n/a n/a household Programme S10071112 FEN8 Enhanced Metering 0.7 n/a n/a delivered over AMP

period Table 7.3: Fenland RZ Feasible Options

7.1.4 Option F1 Kings Lynn and Wisbech Water Reuse Treated effluent from King’s Lynn Water Recycling Centre (WRC) is proposed to be combined with the effluent from Wisbech WRC and pumped into the river Wissey 2km upstream from the existing Water Treatment Works (WTW) abstraction point.

King’s Lynn WRC will require modification to incorporate a sidestream membrane bioreactor (MBR) and reverse osmosis (RO). The RO product water will be dosed with hydrogen peroxide or ozone and treated with ultraviolet (UV) radiation to provide additional virus inactivation and to breakdown any remaining organic species such as pesticides. The product water will be oxygenated and the pH will be increased prior to pumping water to the River Wissey.

The RO concentrate will be discharged at the existing King’s Lynn WRC into the tidal stretch of the River Great Ouse. The concentrate will have a salt concentration of significantly lower than ambient sea water.

At Wisbech WRC, the final effluent ammonia concentration is low therefore additional ammonia treatment is not required. RO will be required to reduce the salt concentration. The concentrate from the RO plant will be discharged with the current Wisbech discharge. An advanced oxidation process such as hydrogen peroxide and UV radiation will be required to achieve additional virus inactivation and destruction of oestrogen based chemicals. Figure 7.1 below shows the option schematic.

WRMP Options Appraisal Report

Identified Risks: • Cost Risk: There are a number of river crossings on the pipe route to the River Wissey which could impact on the design and construction programme. It would appear that there is insufficient space at the existing Wisbech WRC to build the new treatment works and additional land may be required. However there is sufficient space at the King’s Lynn WRC to build the new plant. Poor ground conditions may affect construction and due to the local topography around King’s Lynn and the Fenland area, the works may be at risk from flooding. Moreover, a Biological Aerated Flooded Filter (BAFF) may be required to remove the ammonia subject to modelling at a later design stage. • Programme Risk: Detailed consultations and engagements with key stakeholders such as the Environment Agency (EA) and the Drinking Water Inspectorate (DWI) could have an impact on the programme. • Environmental Risk: The discharge and re-abstraction of re-use water into the River Wissey would require approval from the Environment Agency and abstraction may be limited to the requirement to maintain the “hands-off” river flows.

The Wash

River Nene River Great Kings Lynn Ouse WRC

8.6 Ml/d 14 km

Wisbech WRC 7 Ml/d

11 km 11 km

15.6 Ml/d

WTW 14 km Into Supply

River Wissey

Key : (All proposed changes in red)

Existing Treatment Works Existing Pipe Intake Existing Sewer Treatment Works New Pipeline Outfall Existing WRC

Figure 7.1: Option schematic – F1, King’s Lynn and Wisbech water reuse

WRMP Options Appraisal Report

7.1.5 Option F2 Kings Lynn Desalination This option involves development of a desalination plant located south of King’s Lynn on the River Great Ouse. The river intake would be located on the river bank and the intake must be protected to prevent damage by ships. The salinity of the river water will vary with the tides and the RO feed pumps will be controlled by Variable Frequency Drives (VFDs) to optimise energy use. The brine will be discharged at the existing King’s Lynn WRC to minimise the increase in salinity during incoming tides when the brine will be drawn up the river towards the intake.

The proposed pre-treatment process comprises Dissolved Air Floatation (DAF) and Ultrafiltration (UF). The sludge from the DAF and chemical backwash waste from the UF will be discharged to the sewer network. The UF backwash waste will be discharged with the brine. The UF product will be collected and pumped to the desalination plant. A two-pass system with partial second pass is proposed subject to receipt of a full seawater analysis. The desalination plant has been designed and costed based on treating 100% seawater. However the salinity in the River Great Ouse will vary with the tide and the feed pressure to the RO will vary using a VFD on the feed pumps. Therefore, there could be a reduction in operating costs. Figure 7.2 below shows the schematic of the proposed option.

Identified Risks: • Cost Risk: The brine discharge would be at King’s Lynn WRC, therefore the brine discharge pipe would have to cross the River Great Ouse, thus leading to possible cost escalations. Moreover, the desalination plant will have large power requirements and a new electrical supply will be needed. • Quality Risk: the addition of large quantities of lime and carbon dioxide to achieve alkalinity concentrations prevalent in current water supply may result in higher levels of turbidity. Also, since the River Great Ouse is navigable, there is a possibility of oil spills which might result in permanent damage to the RO membranes. The pre-treatment methods of DAF and UF will reduce the risk but not eliminate it completely. • Programme Risk: Detailed consultations and engagements with key stakeholders such as the Environment Agency (EA) and the Drinking Water Inspectorate (DWI) could have an impact on the programme. • Public Relations Risk: There may be objections on environmental grounds due to the high power usage and brine discharge. • Technical Risk: Locating a desalination plant with an intake on a navigable river is problematic with significant construction risks and operation risks of damage due to collision with vessels. Furthermore, any oil discharges may result in irreversible RO membrane fouling and loss of output.

WRMP Options Appraisal Report

Key: (All proposed changes in red) Kings Lynn WRC Existing WRC

Treatment Works River Great Pumping Station 28.9 Ml/d Ouse (average) Existing Pipe

RO Concentrate Existing Sewer discharge New Pipeline

Intake

Outfall

Existing Service Water Reservoir

Kings Lynn 12 Ml/d Desalination (average) 14km Plant

Figure 7.2: Option schematic – F2, King’s Lynn Desalination Plant

7.1.6 Option F4 Ruthamford North RZ Transfer This option proposes to transfer water from the Ruthamford North RZ to Fenland RZ.

This option involves the construction of a 400mm diameter pumping main 36km long. There are a number of road and railway crossings along the route that are assumed to require directional drilling.

Identified Risks: • Cost Risks: Since there are a number of major road and railway crossings along the proposed pipeline route, directional drilling may lead to cost escalations. • Programme Risks: Close-coordination with the Highways Agency, Local Authorities and the Railway operators regarding the road and railway crossings is required to minimise project delays. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.1.7 Option F5 Ruthamford North RZ Transfer This option requires the same pipeline route as option F4, however it requires a 600mm pumping main. See section 7.1.6 for details.

7.1.8 Environmental considerations The conclusions of the environmental assessments described in sections 4.6, 4.7 and 6 are summarised below.

• No specific issues were identified as part of the BAG assessment other than those common to all options.

WRMP Options Appraisal Report

• The climate change vulnerability assessment concludes that both transfer options (F4, F5) are not sensitive to climate change but the donor RZs are vulnerable to climate change. The assessment scored both options as 2 – limited sensitivity. The desalination and reuse options (F1, F2) scored 1 – insensitive.

• The WFD no-deteriorations assessment concluded;

• F1 King’s Lynn and Wisbech water reuse Further investigation will be required to demonstrate that the diversion of effluent will not have an adverse effect on water quality and flow WFD status for the Wash SPA.

• F2 King’s Lynn desalination It cannot be concluded that this option will not lead to the deterioration of the Great Ouse waterbody WFD status. The desalinisation process involves the discharge of brine back to the waterbody. The location within a relatively small tidal estuary means that this presents risks to water quality which cannot be discounted without significant further investigation. The effects of any abstraction would also have to be assessed, both in terms of the reduction in flow in volumetric terms and the associated changes in tidal functioning and morphological processes.

• F4/5 Ruthamford North RZ Transfer The proposed increase to abstraction has the potential to lead to a deterioration of the River Nene and River Welland waterbody status. The existing licence constraints mean that this risk is low, but further investigation is required. The operation of this scheme is unlikely to adversely affect Rutland Water SPA.

• The SEA and HRA concluded that options F1 and F2 could both have a likely significant effect, and would therefore require an Appropriate Assessment if taken forward. There are no significant negative effects associated with options F4/F5 following mitigation.

7.1.9 Costs WRMP table WRP3a contains the details of the capex, opex, environmental and social costs, these are summarised in the table below.

Environmental & Social Costs Average Opt. Capex Opex (Including carbon) Option Name capacity Ref (£k) (£k/yr) (Ml/d) Fixed Costs Variable (£k) (£k/yr) Kings Lynn and F1 Wisbech water 12 130,700 2,830 11 256 reuse Kings Lynn F2 12 54,000 3,970 5 307 desalination Ruthamford North F4 RZ transfer (12 12 22,100 220 3 16 Ml/d) Ruthamford North F5 RZ transfer (25 25 34,200 250 5 18 Ml/d) Table 7.4: Costs for Fenland RZ supply-side feasible options

WRMP Options Appraisal Report

The options have been ranked based on the Average Incremental Costs (AIC) and Average Incremental Social Cost (AISC) calculated in WRMP table WRP3a, these are shown in Table 7.5. The options have been raked in ascending AIC/AISC i.e. the option ranked 1 has the lowest AIC/AISC.

Opt Option Name AIC Ranking AISC Ranking Ref Kings Lynn and

F1 Wisbech water 12 12

reuse Kings Lynn F2 11 11 desalination Ruthamford North F4 5 5 RZ Transfer Ruthamford North F5 3 2 RZ Transfer Leakage Control FEN1 1 1 Package 1 Leakage Control FEN2 2 3 Package 2 Leakage Control FEN3 4 4 Package 3 Leakage Control FEN4 8 8 Package 4 Leakage Control FEN5 10 10 Package 5 Water efficiency – FEN6 measured 9 9 household Water efficiency – FEN7 unmeasured 7 7 household FEN8 Enhanced Metering 6 6 Table 7.5: Fenland RZ AISC and AIC ranking based on calculation within WRP3a

The ranking of AICs and AISCs varies from the options selected by the optimisation model. The model completes a more sophisticated analysis and takes into account the timing of option availability, utilisation capacity of option and ability for combinations of options to meet deficit.

7.1.10 Inter-dependencies, links and synergies The following inter-dependencies between options have been included in the optimisation model assessment,

• Options F4 and F5 are mutually exclusive • Leakage control packages were inter-dependent.

All the options would provide a degree of resilience if delivered earlier than required to meet growth requirements. However the benefit could only be realised up until the time the growth occurs and the resource is required to meet demand. The transfer options however could provide additional resilience if they were sized to provide capacity for a resilience deficit. This would increase the capex costs.

WRMP Options Appraisal Report

Anglian Water has committed to river restoration work on the River Nar in AMP6. This will involve establishing a working group in 2014/15. This will comprise Anglian Water, the Environment Agency, Natural England, the Norfolk Rivers Trust and the other members of the River Nar Partnership. This group will:

• Identify and assess the river morphological issues that need to be addressed through the restoration works • Develop a list of options for delivering the required changes • Complete a cost-benefit analysis on each option and identify the preferred option • Develop a programme of work for AMP6 that will deliver the preferred option.

The value of the proposed project is £300k which is planned to be delivered 2015/16 to 2017/18 at the start of AMP6. The project will target 3km downstream of the water treatment works and include assessment of the following options,

• The option to use the surface water and groundwater sources conjunctively, so that the impacts of operation of the treatment works on river flows can be minimised, and • The option to use abstraction from the existing groundwater sources to provide a net environmental benefit. This may be either a temporary or permanent arrangement.

7.2 Hunstanton Resource Zone

7.2.1 Unconstrained Options The table below contains the list of unconstrained options considered for Hunstanton RZ. The unconstrained options workshop was held before the assessment of RZ integrity spilt many of the original RZs. Therefore more details about the reason for discounting an unconstrained option or why an option type was not considered for Hunstanton RZ can be found in Appendix B in the Fenland RZ table.

Option Feasible Scheme Type Option Description Ref Option

River Heach N Direct river abstraction North Norfolk Rivers N New reservoir storage Feltwell (Trent-Rutland-Ouse transfer) See table Pumped-storage 7.7 reservoirs North Norfolk Rivers (winter storage) N Wash Reservoirs N New reservoir storage Wash Barrage N Flood storage New Internal Drainage Board (IDB) N structure SUDS - recharge lagoons N Groundwater sources H4 Hunstanton groundwater development Y Aquifer Recharge (AR) North Norfolk Rivers N Desalination H3 Wash Desalination Y Reclaimed domestic H2 Heacham water reuse Y wastewater

WRMP Options Appraisal Report

Reclaimed industrial and Industrial reclaimed water commercial wastewater (for domestic, N commercial and industrial users) Bulk transfers By pipeline H1 Fenland RZ transfer to Hunstanton Y North Norfolk Coast RZ (Wells/Docking) N Transfer Wash Pipeline from Lincolnshire N 3rd Party Options 3rd party trade options Trade 3rd Party Options Shared Multi use reservoir (agriculture) N asset ownership

Tankering of water H5 Hunstanton tankering (road) See table 7.7 Icebergs N Table 7.6: Unconstrained options for Hunstanton RZ

7.2.2 Feasible options not progressed to Stage 2 The table below describes feasible options identified at the unconstrained options workshop which after further work were discounted and not taken through to Stage 2 – economic modelling.

Option Option Name Reason for discounting Ref H5 Hunstanton tankering (road) Task 15 concluded that this option was unfeasible due to the high numbers of tanker deliveries per day down narrow country roads would be difficult to justify given the potential for disruption of local traffic. There are also high water quality risks. Therefore the option is considered not promotable with a high risk of failure before implementation. Feltwell reservoir (Trent- A feasible option but not taken through to Stage Rutland-Ouse transfer) 2 as would need to be developed as part of long term strategy. To be considered in the WREA. Table 7.7 Hunstanton RZ Feasible options not progressed to Stage 2

7.2.3 Feasible Options Table 7.8 contains details of the feasible options considered for Hunstanton RZ.

Opt Capacity (Ml/d) Implementation Asset Plus Option Name Ref Average Peak Min Period Solution ID Fenland RZ H1 1.0 1.0 0.3 3 years S9733174 transfer Heacham water H2 1.0 1.3 0.7 3 years S9732280 reuse

H3 Wash desalination 1.0 1.3 0.7 3 years S9732310

Hunstanton H4 groundwater 1.0 1.3 0.3 2 years S9740693 development Leakage Control HUN1 0.02 n/a n/a Package 1 Not estimated Leakage Control within Asset Plus HUN2 0.02 n/a n/a Package 2 HUN3 Leakage Control 0.02 n/a n/a Programme

WRMP Options Appraisal Report

Package 3 delivered over AMP Leakage Control period HUN4 0.02 n/a n/a Package 4

Leakage Control HUN5 0.01 n/a n/a Package 5

Programme S10071112 HUN8 Enhanced Metering 0.03 n/a n/a delivered over AMP

period Table 7.8 Hunstanton RZ Feasible Options

7.2.4 Option H1 Fenland RZ Transfer This option proposes to transfer water from Fenland RZ to Hunstanton RZ.

This option involves the construction of a 150mm diameter pumping main, approximately 6km long. Much of the pipeline route is across fields.

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Programme Risks: Detailed consultations with the Local Authorities and land owners could have an impact. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.2.5 Option H2 Heacham Water Reuse This option proposes that the effluent from the Heacham WRC will be treated and pumped and injected into the Sandringham Sands from where it will be abstracted and treated at an existing WTW.

The Heacham WRC will require a sidestream Membrane Bioreactor (MBR) and Reverse Osmosis (RO) to reduce the salt and soluble organics concentrations to drinking water standards. Depending on the requirements of the receiving aquifer, the product water will be oxygenated and the pH increased prior to injection. The RO concentrate would be discharged at the existing Heacham WRC into the North Sea. The concentrate will have a salt concentration significantly lower than ambient sea water.

The water will be injected into the upper layer of the aquifer which has a high nitrate concentration. As the total oxidised nitrogen (TON) of the treated effluent is less than 1mg/l (as N), then this should reduce the nitrate concentration of the abstracted water. An extension to the existing WTW will be required for the additional output. The water reuse plant capacity is based on 90% of the 2011 Dry Weather Flow (DWF). Any flow above this will be discharged in the current manner. A schematic of the proposed project is shown below in Figure 7.3.

Identified Risks: • Cost Risk: It would appear that there is sufficient space at the existing Heacham WRC to build a new treatment plant. However a larger site layout could lead to land acquisition costs. • Programme Risk: Detailed consultation with key stakeholders such as the Environment Agency and the Drinking Water Inspectorate could have an impact on the programme.

WRMP Options Appraisal Report

WTW (All proposed changes in red) WTW Extension Into 1.3 Ml/d Supply Existing Treatment Works

Treatment Works

Abstraction Existing WRC Sandringham Existing Pipe Sands Injection Existing Sewer North Sea New Pipeline Heacham Heacham Water Reuse Groundwater source WRC Works 1.3 Ml/d

8km Existing sewer

RO Concentrate River Heacham discharge

Figure 7.3: Option schematic – H2, Heacham water reuse.

7.2.6 Option H3 Wash Desalination This option is for a desalination plant close to Hunstanton. The seawater intake will be offshore beyond the surf zone to ensure reasonable quality of intake water. The brine may be discharged 500m away from the intake with the currents taking the brine away from the intake.

The proposed pre-treatment processes comprise of Dissolved Air Floatation (DAF) and Ultrafiltration (UF). The sludge from the DAF and chemical backwash waste from the UF will be discharged to the sewer. The UF backwash waste will be discharged with the brine. A two–pass system with partial second pass is proposed subject to receipt of a full sea water analysis. Figure 7.4 below shows the schematic of the proposed option.

Identified Risks: • Cost Risk: The intake and brine discharge pipes will have to be laid through the town, coastal roads and out to the sea. There could be delays in installing sub–sea pipelines in the event of bad weather. Moreover, the desalination plant will have large power requirements and will need a new electrical supply. As The Wash is a Special Protection Area (SPA) there may be restrictions in discharging the brine at Hunstanton meaning it may be necessary to discharge the brine further north. • Quality Risk: the addition of large quantities of lime and carbon dioxide to achieve alkalinity concentrations prevalent in current water supply may result in higher levels of turbidity. • Programme Risk: Detailed consultation with key stakeholders such as the Environment Agency and the Drinking Water Inspectorate could have an impact on the programme. • Public Relations Risk: There may be objections on environmental grounds due to high power usage and brine discharge.

WRMP Options Appraisal Report

Key: (All proposed changes in red) Existing Pipe Existing Treatment Works Existing Sewer Treatment Works New Pipeline RO Concentrate Pumping Station discharge Intake

Existing Water Reservoir North Outfall Sea 2.5 Ml/d (average)

500m minimum

3.8 Ml/d (average)

Wash 1 Ml/d 250-500m 5km Desalination (average) Plant

Figure 7.4: Option schematic – H3, Wash desalination

7.2.7 Option H4 Hunstanton Groundwater Development This option utilises two disused licensed groundwater sources. The option also requires construction of a further three groundwater sources, sites have been acquired by Anglian Water for these. New treatment is required to remove iron and manganese, including, • Aeration • GAC Adsorption • Chlorine Dosing • Contact Tanks.

Identified risks: • Anglian Water have engaged a consultant to run numerical groundwater model to confirm the sustainability of the resource.

7.2.8 Environmental considerations The conclusions of the environmental assessments described in sections 4.6, 4.7 and 6 are summarised below. • No specific issues were identified as part of the BAG assessment other than those common to all options. • The climate change vulnerability assessment concludes that the transfer option (H1) is not sensitive to climate change but the donor RZs are vulnerable to climate change. The assessment scored this option as 2 – limited sensitivity. The water reuse and desalination options (H2, H3) scored 1 – insensitive. The groundwater development option (H4) was rated as 2 – limited sensitivity. • The WFD no-deteriorations assessment, SEA and HRA concluded; • H1 Fenland RZ Transfer - The WFD no-deterioration assessment has considered the impact of a small increase across various groundwater sources within the Fenland RZ. The assessment has concluded no risk

WRMP Options Appraisal Report

of deterioration at two waterbodies and a medium risk for the Heacham Stream. The recommendation from the assessment is to review the outcome of the various investigations to determine the optimal balance between sources. • H2 Heacham water reuse - On the assumption that the water quality will be acceptable this option is considered to be having a benefit in terms of WFD waterbody status. The scheme would require an Appropriate Assessment if taken forward and the SEA identified a mitigation measure to re-route the pipeline. • H3 Wash desalination - There is a medium risk of WFD no- deterioration associated with this scheme that would require further investigation. An Appropriate Assessment would be required if taken forward. • H4 Hunstanton RZ groundwater development - Site specific information from the Environment Agency suggests that the upper reaches of the Heacham Stream may be at risk of deterioration as a consequence of the proposed option. Further hydro-ecological investigations are required to look at the sensitivity of the upper reaches to the implementation of this option.

7.2.9 Costs WRMP table WRP3a contains the details of the capex, opex, environmental and social costs, these are summarised in the table below.

Environmental & Social Costs Average Option Capex Opex (Including carbon) Opt. Ref capacity Name (£k) (£k/yr) (Ml/d) Fixed Costs Variable

(£k) (£k/yr) Fenland RZ H1 1.5 1,700 20 0 1 transfer Heacham H2 1 15,600 140 0 10 water reuse Wash H3 1 16,600 330 0 19 desalination Hunstanton RZ H4 1 3,900 60 0 4 groundwater development Table 7.9: Costs for Hunstanton RZ supply-side feasible options

The options have been ranked based on the Average Incremental Costs (AIC) and Average Incremental Social Cost (AISC) calculated in WRMP table WRP3a, these are shown in Table 7.10. The options have been raked in ascending AIC/AISC i.e. the option ranked 1 has the lowest AIC/AISC.

Opt Option Name AIC Ranking AISC Ranking Ref H1 Fenland RZ Transfer 3 3 H2 Heacham Water Reuse 9 9 H3 Wash Desalination 10 10 Hunstanton Groundwater H4 development 7 7 HUN1 Leakage Control Package 1 1 1

WRMP Options Appraisal Report

HUN2 Leakage Control Package 2 2 2 HUN3 Leakage Control Package 3 4 4 HUN4 Leakage Control Package 4 5 5

HUN5 Leakage Control Package 5 8 8 HUN6 Enhanced Metering 6 6 Table 7.10: Hunstanton RZ AISC and AIC ranking based on calculation within WRP3a

7.2.10 Inter-dependencies, links and synergies The only inter-dependencies between the Hunstanton options were for the Leakage packages. The Fenland RZ Transfer option is dependent on resources being available to transfer.

All the options would provide a degree of resilience if delivered earlier than required to meet growth requirements. However the benefit could only be realised up until the time the growth occurs and the resource is required to meet demand. The transfer option however could provide additional resilience if it was sized to provide capacity for a resilience deficit. This would increase the capex costs.

7.3 Norwich & the Broads Resource Zone

7.3.1 Unconstrained Options The table below contains the list of unconstrained options considered for Norwich and the Broads RZ. More details about the reason for discounting an unconstrained option or why an option type was not considered can be found in Appendix B in the Norwich and the Broads RZ table.

Scheme Sub- Option Option is Categories/Sub- Option Description Ref Feasible Components Direct river NB6, River Wensum Y abstraction NB7, NB10 River Yare N River Tas N New reservoir NB7 Existing storage Pits development (lining Y storage (On- pits) stream) Gravel Pit development N

New reservoir NB5 New Wensum Reservoir Y storage (Pumped- NB8 storage) Feltwell winter storage reservoir + See table transfer 7.12 New reservoir SUDS N storage (Flood storage) Groundwater NB9 Norwich groundwater development See table sources 7.12 Ringland perched ponds N Infiltration galleries Wensum gravels N

WRMP Options Appraisal Report

Aquifer Recharge Flood water management N (AR) Desalination NB1 Bacton Y NB3 Cantley Reuse (brackish river water or See table groundwater) 7.12 Reclaimed domestic NB2 Norwich water reuse Y wastewater NB4 Lowestoft/Great Yarmouth Reuse See table 7.12 Reclaimed industrial Review discharge consents N and commercial Sizewell N wastewater Bulk transfers (by Ouse - Wensum transfer (with Feltwell See table river) reservoir) 7.12 Bulk transfers (by Fenland RZ transfer N pipeline) Ruthamford North RZ Transfer N West Suffolk RZ Transfer N Essex and Suffolk Water transfer N Resource Sharing Essex and Suffolk Water transfer from N with other the Broads Water Companies Cambridge Water N (Trade) Resource Sharing Sizewell (with Essex and Suffolk water) N with other Water Companies (Shared asset ownership) 3rd Party Options 3rd party trade options N (Trade) 3rd Party Options Agricultural reservoirs N (Shared asset ownership) Table 7.11 Unconstrained options for Norwich and the Broads RZ

7.3.2 Feasible options not progressed to Stage 2 The table below describes feasible options identified at the unconstrained options workshop which after further work were discounted and not taken through to Stage 2 – economic modelling.

Option Option Name Reason for discounting Ref Feltwell reservoir (Trent- A feasible option but not taken through to Rutland-Ouse transfer) Stage 2 as would need to be developed as part

of long term strategy. To be considered in the WREA. NB3 Cantley Reuse (brackish river The SEA discounted this option due to potential water or groundwater) significant environmental effects of brine discharge and effects on designated sites. NB4 Lowestoft/Great Yarmouth Discounted as this option did not provide Reuse adequate resource to fully satisfy the sustainability reduction and SEA found that there would be potential environmental effects on designated site. NB9 Norwich groundwater Assumed to be delivered in AMP5 and included development in the baseline supply forecast. Therefore no longer an option. Table 7.12 Norwich and the Broads RZ feasible options not progressed to Stage 2

WRMP Options Appraisal Report

7.3.3 Feasible options discounted after draft WRMP A number of options proposed in the draft WRMP have been discounted. Table 7.13 describes the reason for this.

Option Option Name Reason for discounting Ref NB2 Norwich water reuse Scheme NB2 is a sustainability reduction scheme which provided an alternative raw water source to the Wensum. However this option did not provide adequate resource to fully satisfy the sustainability reduction so was discounted. A smaller Norwich water reuse option has been developed (NB11) which includes additional water treatment capacity and therefore provides additional DO. This option has been selected towards the end of the forecast to satisfy the deficit due to growth within the RZ. NB6 Norwich intake with Since the publication of the draft WRMP Anglian water has pre-treatment been working with the Environment Agency and Natural England to resolve concerns about the preferred option for delivering the Wensum sustainability reduction (NB10). As part of this work all the Norwich and the Boards RZ options have been revisited to ensure that a common approach is taken for all options. The preferred option (NB10) is to reinstate the downstream intake with a transfer back to existing storage pits. As the risks (water quality, low flow etc) can be managed and are considered acceptable for NB10 then the option to add additional upfront treatment process (NB6) is not required and therefore discounted. NB7 Norwich intake with As stated above all Norwich and the Boards RZ options lining existing bankside have been revisited. The preferred option (NB10) storage requires continued operation of storage pits without lining of the pits. The risks associated with not lining the pits are deemed acceptable therefore this option is not required and has been discounted. NB8 Norwich intake with This option to provide new bankside storage (NB8) was new bankside storage developed as an alternative to utilising the existing storage if the risks associated with continued operation of the pits were deemed unacceptable. Normal operation of the pits is acceptable and so this option has been discounted. Table 7.13: Norwich and the Broads RZ draft WRMP feasible options discounted

7.3.4 Feasible Options Table 7.14 contains details of the feasible options considered for Norwich and the Broads RZ.

Opt Option Name Capacity (Ml/d) Implementation Asset Plus Ref Average Peak Min Period Solution ID NB1 Bacton 46 57 11 3 years S9732305 desalination (46 Ml/d) NB5 Norwich storage 46 57 30 15 years S9735011

NB10 Norwich intake 46 57 30 4 years S9727487 to existing bankside storage NB11 Norwich water 11 13 5 3 years S10071274 reuse NB12 Bacton 11 13 7 4 years S10071273 desalination

WRMP Options Appraisal Report

(11 Ml/d) Leakage Control NTB1 0.4 n/a n/a Package 1 Programme Not estimated Leakage Control NTB2 0.4 n/a n/a delivered over AMP within Asset Package 2 period Plus Leakage Control NTB3 0.4 n/a n/a Package 3

Leakage Control NTB4 0.5 n/a n/a Package 4

Leakage Control NTB5 0.1 n/a n/a Package 5 Water efficiency – Programme delivered S10071045 NTB6 measured 0.5 n/a n/a over AMP period household Enhanced Programme delivered S10071112 NTB8 1.3 n/a n/a Metering over AMP period Table 7.14: Norwich and the Broads RZ Feasible Options

7.3.5 Option NB1 Bacton Desalination The proposed desalination site is located at Bacton, on the Norfolk coast. The sea water intake will be located offshore beyond the surf zone to ensure reasonable intake water quality. The brine may be discharged 500m from the intake location with the current taking the brine away from the intake.

The proposed pre-treatment comprises Dissolved Air Floatation (DAF) and Ultrafiltration (UF). The sludge from the DAF and chemical backwash waste from the UF will be discharged to the sewerage network for safe disposal. The UF backwash waste will be discharged with the brine. The output from the UF plant will be collected and pumped to the desalination plant. A two-pass system with a partial second pass is proposed subject to receipt of a full seawater analysis. A project schematic is shown below in Figure 7.5.

Identified Risks: • Cost Risk: The intake and brine discharge pipes will have to be laid through the town, coastal road and out to the sea. There could be delays installing sub-sea pipelines in the event of bad weather. The desalination plant will have high energy requirements and a new electrical supply will be needed. • Quality Risk: The addition of large quantities of lime and carbon dioxide to achieve a similar alkalinity concentration to the current water supply may result in higher levels of turbidity. Moreover, major oil spills at the intake location may result in plant shutdown. The pre-treatment process of DAF followed by UF should prevent oil being passed to the RO membranes which would cause irreversible reduction of the plant’s output.

WRMP Options Appraisal Report

Key: (All proposed changes in red)

Existing Treatment Works 104 Ml/d (average) Treatment Works RO Concentrate discharge Pumping Station Bacton Desalination Existing Pipe Plant 250-500m Existing Sewer

New Pipeline

158 Ml/d 500 m minimum (average) Intake

Outfall North 46 Ml/d Sea Existing Service Water (average) Reservoir 30 km

WTW

Figure 7.5: Option schematic – NB1, Desalination Plant at Bacton

7.3.6 Option NB5 Norwich Storage This option requires a large raw water storage reservoir to be constructed outside of Norwich. The reservoir would be filled from the existing intake at Norwich WTW and would require a twin pipeline between the WTW and the new reservoir.

This option has been developed to mitigate the scenario that a new “hands off flow” (HoF) licence condition is imposed at Norwich and additional storage would be required to allow for the periods when the river flows are below the HoF. It has been estimated that the storage requirements would be for approximately 38 days. A schematic of the proposed project is shown below in Figure 7.6.

Identified Risks: • Detailed modelling and assessment of resources available from the River Wensum may impact on the amount of storage required, having a significant impact on costs. • There is a risk that the HoF conditions imposed by the Environment Agency may be subject to change in the future to ensure Water Framework Directive compliance. • Detailed assessment may impact on the location and capacity of the reservoir. This could have significant impacts on costs. • Complications during the planning process such as a public inquiry may increase the implementation duration. • Quality Risk: The scope for this option does not include for additional treatment relating to water quality issues, in particular the removal of metaldehyde.

WRMP Options Appraisal Report

Figure 7.6: Option schematic – NB5, Norwich Storage

7.3.7 Option NB10 Norwich intake to existing bankside storage This option utilises the existing intake and storage pits by providing a new pipeline from the WTW to the pits. Water is then conveyed from the pits back to the WTW via the existing pipeline. A schematic of the proposed scheme is shown below in Figure 7.7.

Identified Risks • Cost Risk: Detailed design process alters pipeline route which could have significant impact on cost. • Quality Risk: The scope for this option does not include for additional treatment relating to water quality issues, in particular the removal of metaldehyde. • Programme Risk: Detailed consultations and engagements with key stakeholders such as the Environment Agency, Drinking Water Inspectorate and the local planning authority could have an impact on the programme. • Public Relations Risk: Increased volume of traffic during the construction period could lead to adverse reactions from the general public.

WRMP Options Appraisal Report

Existing storage pits

8 km

NORWICH Into Supply

WTW

Key : (All proposed changes in red)

Existing Treatment Works Existing Pipe Intake Existing Sewer Treatment Works New Pipeline Outfall Existing WRC New Pipeline (alternative) Bankside storage Asset not operated

Groundwater source

Figure 7.7: Option schematic – NB10, Norwich intake to existing Bankside Storage

7.3.8 Option NB11 Norwich Water Reuse This option proposes the treatment of Norwich WRC effluent and discharge into the existing storage pits. From there it would be transferred and treated via a new pipeline and additional water treatment capacity at Norwich WTW.

The effluent from the WRC would require ultrafiltration (UF) and a reverse osmosis (RO) stage will be included to achieve drinking water standards. The concentrate from the reverse osmosis plant will be discharged with the current discharge. The RO product will be treated with peroxide and UV.

A schematic of the proposed scheme is shown below in Figure 7.10

WRMP Options Appraisal Report

Identified Risks: • Cost Risk: It would appear that there is sufficient space at the existing WRC to build the new treatment works. However, site layouts should be prepared after verifying the space requirements and space availability at site. • Quality Risk: The water reuse plant should have the level of redundancy and design robustness as detailed in the Guidelines for Water Reuse (USEPA, 2012) in order to ensure that the water being pumped into storage pits meets the quality requirements. • Programme Risk: Detailed stakeholder engagement with key stakeholders such as the Environment Agency and the Drinking Water Inspectorate could have an impact on the programme. • Public Relations Risk: Whilst indirect potable water reuse has been widely practised in the South and East of England over many years, public perception issues will need to be carefully managed. • Environmental Risk: The discharge and re-abstraction would require approval from the Environment Agency.

Existing bankside storage

8 km NORWICH

Into WTW supply

16 km Existing sewer

Norwich WRC

Norwich Water Reuse Works

Key : (All proposed changes in red)

Existing Treatment Works Existing Pipe Intake Existing Sewer Treatment Works New Pipeline Outfall Existing WRC New Pipeline (alternative) Bankside storage Asset not operated

Groundwater source Figure 7.8: Option schematic – NB11, Norwich water reuse

WRMP Options Appraisal Report

7.3.9 Option NB12 Bacton desalination (11 Ml/d) This option is similar to option NB1 but with a smaller capacity. Option NB1 has been sized to match the sustainability reduction imposed on the Wensum. Option NB12 has been scoped to satisfy the increase in demand due to growth. See section 7.3.5 for details of NB1.

7.3.10 Environmental considerations The conclusions of the environmental assessments described in sections 4.6, 4.7 and 6 are summarised below. • No specific issues were identified as part of the BAG assessment other than those common to all options. • The climate change vulnerability assessment concludes that the desalination and water reuse options (NB1, NB11, NB12) are all insensitive to climate change and scored 1.The options utilising the intake at Norwich water treatment works (NB5, NB10) are sensitive in relation to water abstraction, available flow and environmental flow requirements. These options scored 3. • The WFD no-deteriorations assessment, SEA and HRA concluded; • NB1/12 – Bacton desalination - The moderate exposure and meso-tidal conditions mean that it can be reasonably concluded that this option would not lead to a deterioration in the WFD waterbody status. Further assessment is required to increase certainty in this conclusion, particularly for the larger option. The desalinisation process involves the discharge of saline rich water back to the coastal environment. Further investigation will be required to demonstrate that this release of water will not have an adverse effect on the aquatic environment. The HRA concluded a likely significant effect and the need for an Appropriate assessment should the option be taken forward. • NB5 – Norwich Storage - No specific WFD, HRA or SEA issues raised on the assumption that this uses existing intake with compliant licence conditions and that pipeline could be routed to avoid ancient woodlands and local nature reserves. • NB10 – Norwich intake to existing bankside storage - This scheme has been the focus of detailed discussions with the Environment Agency and Natural England and full details are provided in the Minimising the Environmental Impact of Abstractions section. The WFD assessment under normal operation concludes no risk of deterioration and the HRA has concluded no likely significant effect. We will continue to work with the Environment Agency to understand the risk of deterioration downstream during periods of low flow. • NB11 – Norwich reuse (growth scheme) - The risk of deterioration of WFD status associated with this scheme is considered to be low on the understanding that there will be no net loss of flow downstream. In addition the effluent will be treated to a higher standard than the prevailing water quality in the river. An Appropriate Assessment has been completed and confirmed that there would be no adverse effects on site integrity. The SEA has concluded potential climate change impacts due to increased CO2 output, but no other significant negative effects following mitigation.

WRMP Options Appraisal Report

7.3.11 Costs WRMP table WRP3a contains the details of the capex, opex, environmental and social costs, these are summarised in the table below.

Environmental & Social Costs Average Option Capex Opex (Including carbon) Opt. Ref capacity Name (£k) (£k/yr) (Ml/d) Fixed Costs Variable

(£k) (£k/yr) Bacton NB1 desalination 46 150,100 15,500 0 1,230 (46 Ml/d) Norwich NB5 46 67,200 510 142 42 storage Norwich intake to NB10 existing 46 21,700 290 0 25 bankside storage Norwich NB11 11 79,300 1,780 0 86 water reuse Bacton NB12 desalination 11 65,400 3,430 0 260 (11 Ml/d) Table 7.15: Costs for Norwich and the Broads RZ supply-side feasible options

The options have been ranked based on the Average Incremental Costs (AIC) and Average Incremental Social Cost (AISC) calculated in WRMP table WRP3a, these are shown in Table 7.16. The options have been raked in ascending AIC/AISC i.e. the option ranked 1 has the lowest AIC/AISC.

Opt Option Name AIC Ranking AISC Ranking Ref NB1 Bacton Desalination 10 10 NB5 Norwich storage 5 5

Norwich intake to existing 1 1 NB10 bankside storage

NB11 Norwich water reuse 11 11

NB12 Bacton desalination (11 Ml/d) 12 12

NTB1 Leakage Control Package 1 2 2

NTB2 Leakage Control Package 2 3 3

NTB3 Leakage Control Package 3 4 4

NTB4 Leakage Control Package 4 6 6

NTB5 Leakage Control Package 5 8 8 NTB6 Water efficiency 9 9 NTB8 Enhanced Metering 7 7 Table 7.16: Norwich and the Broads RZ AISC and AIC ranking based on calculation within WRP3a

WRMP Options Appraisal Report

7.3.12 Inter-dependencies, links and synergies The following inter-dependencies between options have been included in the optimisation model assessment,

• Options NB5 and NB10 are mutually exclusive as they all rely on the River Wensum • Leakage control packages were inter-dependent.

Only options NB1, NB11 and NB12 would provide a degree of resilience if delivered earlier than required to meet growth requirements. However the benefit could only be realised up until the time the growth occurs and the resource is required to meet demand.

Options NB1, NB5 and NB10 have been sized to match the sustainability reduction imposed on the Wensum. Options NB11 and NB12 have been scoped to satisfy the increase in demand due to growth.

7.4 East Suffolk Resource Zone

7.4.1 Unconstrained Options The table below contains the list of unconstrained options considered for east Suffolk RZ. The unconstrained options workshop was held before the assessment of RZ integrity spilt many of the original RZs. Therefore more details about the reason for discounting an unconstrained option or why an option type was not considered for East Suffolk RZ can be found in Appendix B in the East Suffolk and Essex RZ table.

Scheme Sub- Option Option is Categories/Sub- Option Description Ref Feasible Components

Direct river Existing intake pumps and licence maximisation N abstraction Mill River - licence maximisation N River Stour - trade with Essex and Suffolk Water N New reservoir Great Bradley See table storage (On- 7.19 stream) Reservoir dredging N

New reservoir Feltwell reservoir + transfers to Essex and See table storage (Pumped Suffolk WRZ 7.19 storage) New reservoir SUDS N storage (Flood storage) Reservoir raising Alton Water N Groundwater Gravel Pit exploitation N sources Baylham N North Ipswich groundwater N

ES6 Ipswich groundwater development Y

ES7 Belstead Brook chalk groundwater development See table 7.19 Infiltration galleries Ipswich N Woodbridge N Artificial Storage Mill River N

WRMP Options Appraisal Report

Aquifer Recharge SUDS N Desalination ES4 Felixstowe desalination Y Reclaimed ES2, Ipswich Water Reuse Y domestic ES3 See table wastewater 7.18 Reclaimed Sizewell N industrial and commercial wastewater Bulk transfers (by EOETs optimisation (+ trade with Essex and N river) Suffolk Water)

Bulk transfers (by ES10 South Essex RZ to East Suffolk RZ Y pipeline) ES1 Transfer from Ipswich PZ to Woodbridge PZ See table 7.18 ES5 Transfer WTW surplus to Semer PZ or Ipswich See table PZ 7.18 Resource Sharing Affinity Central N with other ES8, Essex and Suffolk Water See table Water Companies ES9 7.18 (Trade) Thames Water N Resource Sharing Sizewell N with other Water Companies (Shared asset EOETs extension N ownership) 3rd Party Options 3rd party trade options N (Trade) Tankering of water Tankering (Road) N Improved/sophistic Colchester Chalk (optimise use of surface water N ated conjunctive resources and back off Colchester Chalk) management

Table 7.17 Unconstrained options for East Suffolk RZ

7.4.2 Feasible options not progressed to Stage 2 The table below describes feasible options identified at the unconstrained options workshop which after further work were discounted and not taken through to Stage 2 – economic modelling.

Option Option Name Reason for discounting Ref Feltwell reservoir (Trent- A feasible option but not taken through to Rutland-Ouse transfer) Stage 2 as would need to be developed as part

of long term strategy. To be considered in the WREA. Great Bradley A feasible option but not taken through to Stage 2 as would need to be developed as part

of long term strategy and should be considered in the WREA. ES1 Transfer from Ipswich PZ to This option was developed before finalisation of Woodbridge PZ the RZ integrity assessment. Further evaluation found that adequate resources can be transferred via the existing infrastructure so this option was no longer required and discounted. ES2 Ipswich Water Reuse Originally two water reuse options were considered with different capacities. ES2 was

WRMP Options Appraisal Report

sized at 7 Ml/d but further evaluation as part of Task 3 found that the maximum capacity of the Ipswich water reuse scheme was only 11Ml/d. As these two options were so similar ES2 was discounted. ES5 Transfer WTW surplus to Semer Subject to on-going evaluation PZ or Ipswich PZ ES7 Belstead Brook Chalk Option discounted on further review of CAMS

ES8 Raw water import from Essex This option involved a raw water transfer from and Suffolk Water Essex and Suffolk Water which could be treated at a new water treatment works. This was proposed as an intermediate option as the new water treatment capacity could eventually be part of the water reuse scheme once Essex and Suffolk Water required the raw water themselves and were no longer able to trade. This option was discounted as Essex and Suffolk Water confirmed they did not have adequate resources to trade. ES9 Treated water import from This option was discounted as Essex and Essex and Suffolk Water Suffolk Water confirmed they did not have adequate resources to trade. Table 7.18 East Suffolk RZ feasible options not progressed to Stage 2

7.4.3 Feasible Options Table 7.19 contains details of the feasible options considered for East Suffolk RZ.

Opt Capacity (Ml/d) Implementation Asset Plus Option Name Ref Average Peak Min Period Solution ID Ipswich ES3 11 14 5 3 years S9734283 discharge reuse Felixstowe ES4 11 13 7 3 years S9734264 Desalination East Suffolk RZ ES6 groundwater 0.8 1 1 2 years S9734909 development South Essex ES10 6 6 2 4 years S9734910 WRZ transfer Leakage Control ESU1 0.3 n/a n/a Package 1

Leakage Control ESU2 0.3 n/a n/a Programme Not estimated Package 2 delivered over AMP within Asset Plus Leakage Control ESU3 0.2 n/a n/a period Package 3

Leakage Control ESU4 0.3 n/a n/a Package 4

Leakage Control ESU5 0.1 n/a n/a Package 5 Water efficiency ESU6 – measured 05 n/a n/a Programme

household delivered over AMP S10071045 Water efficiency period

ESU7 – unmeasured 0.1 n/a n/a household Table 7.19: East Suffolk RZ Feasible Options

WRMP Options Appraisal Report

7.4.4 Option ES3 Ipswich Water Reuse This option proposes additional treatment of the discharge from Ipswich WRC and discharged into the River Gipping, 2km upstream of the WTW intake.

Ipswich WRC would require a sidestream Membrane Bioreactor (MBR) and Reverse Osmosis (RO). The product water will be oxygenated and the pH increased prior to pumping to the River Gipping. RO generates two streams – the product water which will be pumped into the River Gipping and the concentrate which will be discharged at the existing Ipswich WRC into the tidal stretch of the River Gipping.

The existing WTW would require additional treatment capacity. A schematic of the proposed project is shown below in Figure 7.9.

Identified Risks: • Cost Risk: There is limited space available to construct additional treatment at the WRC. Site layouts should be prepared to establish whether additional land should be purchased. The abstraction point in the River Gipping is in an urban area and could result in considerable planning delays. • Quality Risk: The water reuse plant should have the level of redundancy and design robustness as detailed in the Guidelines for Water Reuse (USEPA, 2012) in order to ensure that the water being pumped into the River Gipping meets the quality requirements. • Programme Risk: Detailed consultation with key stakeholders such as the Environment Agency and the Drinking Water Inspectorate could have an impact on the programme. • Public Relations Risk: Whilst indirect potable water reuse has been widely practised in South East England for many years, this scheme would differ as it would deliberately reuse the effluent. Consequently public perception issues must be carefully managed to minimise objections. • Environmental Risk: The discharge and re-abstraction of re-used water into the River Gipping would require approval from the Environment Agency and abstraction may be limited to the requirement to maintain the “hands-off” river flows.

WRMP Options Appraisal Report

River Gipping

Ipswich Water Reuse Works

RO Concentrate discharge to existing outfall Ipswich WRC

10 km River Orwell 14.2 Ml/d 14.2 Ml/d

Key : (All proposed changes in red) 13 km

Existing Treatment Works

Treatment Works

Existing WRC

WTW Alton Water Existing Pipe Existing Sewer Into supply New Pipeline

Intake

Outfall

Figure 7.9: Option schematic – ES3, Ipswich water reuse

7.4.5 Option ES4 Felixstowe Desalination This option requires a desalination plant constructed near to the port of Felixstowe. The sea water intake would be located to the east of the site approximately 250 – 500m offshore beyond the surf zone to ensure reasonable quality of intake water. The brine will be discharged further offshore from the intake location and will be dispersed within 50 – 100m of the discharge points.

The proposed pre-treatment comprises Dissolved Air Flotation (DAF) and Ultrafiltration (UF). The sludge from the DAF and chemical backwash waste from the UF will be discharged to sewer. The UF backwash waste will be discharged with the brine. The UF product will be collected and pumped to the desalination plant. A two-pass system with partial second pass is proposed subject to receipt of a full seawater analysis.

The product water will be pumped into the treated water network. A schematic of the proposed project is shown below in Figure 7.10.

WRMP Options Appraisal Report

Identified Risks: • Cost Risk: The intake and brine discharge pipes will have to be laid through the town and out to the sea. There could be delays installing sub-sea pipelines in the event of bad weather. The intake and discharge pipes could be damaged by ships at anchor. The desalination plant will have large power requirements and a new electrical supply will be needed. • Quality Risk: the addition of large quantities of lime and carbon dioxide to achieve alkalinity concentrations prevalent in current water supply may result in higher levels of turbidity. The possibility of oil discharge at the port area is high and this may result in permanent damage to the reverse osmosis membranes. The pre – treatment of DAF and UF should reduce, but will not completely eliminate it. • Programme Risk: Detailed consultation with key stakeholders such as the Environment Agency (EA) and the Drinking Water Inspectorate (DWI) could have an impact on the programme. • Public Relations Risk: There may be objections on environmental grounds due to the high power usage and brine discharge.

12 km 25.6 Ml/d RO Concentrate (average) discharge 11 Ml/d Key: (All proposed changes in (average) red) 250-500m Existing Treatment Works 5 km

Felixstowe 38.9 Ml/d Treatment Works 500 m minimum Desalination (average) Plant Pumping Station

Existing Pipe

Existing Sewer North Sea New Pipeline

Intake

Outfall

Existing Service Water Reservoir

Figure 7.10: Option schematic – ES4, Felixstowe desalination

7.4.6 Option ES6 East Suffolk RZ groundwater development This option utilises a disused licensed groundwater source. New treatment is required to remove iron and manganese, including, • Aeration • GAC Adsorption • Chlorine Dosing • Contact Tanks.

WRMP Options Appraisal Report

Identified Risks: • Resource Availability Risks: Successful delivery of this option will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.4.7 Option ES10 South Essex RZ Transfer This option transfers water from South Essex RZ to East Suffolk RZ.

This option requires the construction of a 300mm diameter pumping main across a total distance of approximately 22 km. Much of the pipeline route is across fields. There are a number of road crossings and several river crossings along the route which are assumed to require directional drilling.

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Quality Risks: There are no identified risks associated with the quality of the water being pumped as the proposed pipeline is a closed conduit. • Programme Risks: Detailed consultation with the Highways Agency, Environment Agency and Local Authorities could have an impact on the project. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.4.8 Environmental considerations The conclusions of the environmental assessments described in sections 4.6, 4.7 and 6 are summarised below. • No specific issues were identified as part of the BAG assessment other than those common to all options. The climate change vulnerability assessment concludes that the reuse option (ES3) and the desalination option (ES4) are not sensitive to climate change and scored 1 –insensitive. The groundwater development (ES6) and transfer (ES10) scored 2 – limited sensitivity. • The WFD no-deterioration screening has identified a low risk associated with the abstraction sources in the donor RZ’s. • The SEA and HRA has not identified any significant negative effects following mitigation, with the exception of potential climate change impacts associated with the Ipswich water reuse scheme due to increased CO2 output.

7.4.9 Costs WRMP table WRP3a contains the details of the capex, opex, environmental and social costs, these are summarised in the table below.

Environmental & Social Costs Average Option Capex Opex (Including carbon) Opt. Ref capacity Name (£k) (£k/yr) (Ml/d) Fixed Costs Variable

(£k) (£k/yr) Ipswich ES3 11 64,900 1,700 115 138 water reuse ES4 Felixstowe 11 55,200 3,620 94 281

WRMP Options Appraisal Report

desalination

East Suffolk RZ ES6 0.8 4,500 80 10 3 groundwater development South Essex ES10 6 8,300 80 23 6 RZ transfer Table 7.20: Costs of East Suffolk RZ f supply-side easible options

The options have been ranked based on the Average Incremental Costs (AIC) and Average Incremental Social Cost (AISC) calculated in WRMP table WRP3a, these are shown in Table 7.21. The options have been raked in ascending AIC/AISC i.e. the option ranked 1 has the lowest AIC/AISC.

Opt AIC AISC Option Name Ref Ranking Ranking ES3 Ipswich discharge reuse 10 9 ES4 Felixstowe Desalination 11 11 ES6 East Suffolk RZ groundwater development 8 8 ES10 South Essex WRZ transfer 3 3 ESU1 Leakage Control Package 1 1 1 ESU2 Leakage Control Package 2 2 2 ESU3 Leakage Control Package 3 4 4 ESU4 Leakage Control Package 4 7 7 ESU5 Leakage Control Package 5 9 10 ESU6 Water efficiency – measured household 5 5 ESU7 Water efficiency – unmeasured household 6 6 Table 7.21: East Suffolk RZ AISC and AIC ranking based on calculation within WRP3a

7.4.10 Inter-dependencies, links and synergies The following inter-dependencies between options have been included in the optimisation model assessment,

• Leakage control packages were inter-dependent. • ES10 South Essex RZ to East Suffolk RZ is mutually exclusive to the two transfer options from East Suffolk RZ to South Essex RZ (SE2, SE8).

All the options would provide a degree of resilience if delivered earlier than required to meet growth requirements. However the benefit could only be realised up until the time the growth occurs and the resource is required to meet demand. The transfer option however could provide additional resilience if it was sized to provide capacity for a resilience deficit. This would increase the capex costs.

7.5 South Essex Resource Zone

7.5.1 Unconstrained Options The table below contains the list of unconstrained options considered for South Essex RZ. The unconstrained options workshop was held before the assessment of RZ integrity spilt many of the original RZs. Therefore more details about the reason for discounting an unconstrained option or why an option type was not

WRMP Options Appraisal Report

considered for South Essex RZ can be found in Appendix B in the East Suffolk and Essex RZ table.

Scheme Sub- Option Option is Categories/Sub- Option Description Ref Feasible Components

River Stour N Direct river River Colne N abstraction River Fynn/River Deben N River Blackwater N New reservoir Great Bradley See table storage (On- 7.23 stream) New reservoir Feltwell reservoir + transfers to South Essex RZ See table storage (Pumped- 7.23 storage) SE7 Ardleigh extension (see resource sharing below) Y

New reservoir SUDS N storage (Flood storage) Reservoir raising Ardleigh Reservoir N Bartlow/Bures N Groundwater SE6 South Essex RZ groundwater development Y sources Treat high fluoride groundwater sources See table 7.23 Braintree N Infiltration galleries Halstead N SE3 South Essex RZ aquifer recharge See table Artificial Storage 7.23 Aquifer Recharge SUDS N (AR) Reclaimed SE1 Colchester Water Reuse Y domestic Tilbury/Chelmsford (trades) N wastewater Reclaimed Colchester/Ipswich industrial study (discharge N industrial and consents) commercial wastewater Sizewell N Bulk transfers (by EOETs optimisation (+ trade with Essex and N river) Suffolk Water)

Bulk transfers (by SE2 East Suffolk RZ to South Essex transfer Y pipeline) Resource Sharing SE4 Affinity East (Ardleigh agreement) Y with other Water Companies Affinity Central N (Trade) Essex and Suffolk Water N Thames Water N Resource Sharing Sizewell N with other Water Companies EOETs extension N (Shared asset ownership) SE7 Ardleigh upgrade - gravel pit extension Y 3rd Party Options 3rd party trade options N (Trade) Trade high fluoride water See table 7.23

WRMP Options Appraisal Report

Tankering of water Tankering (Road) N Icebergs N Improved/sophisti Colchester Chalk (optimise use of surface water N cated conjunctive resources and back off Colchester Chalk) management

Other SE5 Refurbish Colchester WTW to maximise DO See table 7.23 Table 7.22: Unconstrained options for South Essex RZ

7.5.2 Feasible options not progressed to Stage 2 The table below describes feasible options identified at the unconstrained options workshop which after further work were discounted and not taken through to Stage 2 – economic modelling.

Option Option Name Reason for discounting Ref SE3 South Essex RZ aquifer Option does not provide additional DO and has recharge and storage therefore been discounted as part of WRMP. SE5 Refurbish Colchester WTW to Included in the baseline forecast, capital maximise DO maintenance scheme Feltwell reservoir + transfers to A feasible option but not taken through to South Essex RZ Stage 2 as would need to be developed as part of long term strategy and should be considered in the WREA. Treat high fluoride groundwater This option has been discounted as part of sources Task 4e). The study found that the sourceworks are constrained by other factors (e.g. licence) not the blending regime. Great Bradley A feasible option but not taken through to Stage 2 as would need to be developed as part of long term strategy and should be considered in the WREA. Table 7.23 South Essex RZ feasible options not progressed to Stage 2

7.5.3 Feasible Options Table 7.24 contains details of the feasible options considered for South Essex RZ.

Opt Capacity (Ml/d) Implementation Asset Plus Option Name Ref Average Peak Min Period Solution ID Colchester SE1 16 21 5.3 3 years S9734274 discharge reuse East Suffolk RZ SE2 12 12 3.6 3 years S9734684 transfer (12 Ml/d) Amendment to SE4 Ardleigh 2.6 3.6 0 within 1 year S9738901 Agreement South Essex RZ SE6 groundwater 1 1.4 1 2 years S9735321 development Ardleigh reservoir 3 years SE7 2 3 0.5 S10071041 extension (see note below) East Suffolk RZ SE8 2 2 0.6 4 years S10071261 transfer (2Ml/d) Leakage Control SEX1 0.2 n/a n/a Package 1 Not estimated Leakage Control Programme within Asset Plus SEX2 0.2 n/a n/a Package 2 delivered over SEX3 Leakage Control 0.2 n/a n/a AMP

WRMP Options Appraisal Report

Package 3 Leakage Control SEX4 0.2 n/a n/a Package 4 Leakage Control SEX5 0.1 n/a n/a Package 5 Water efficiency SEX6 – measured 0.4 n/a n/a Programme household S10071045 delivered over Water efficiency AMP SEX7 – unmeasured 0.1 n/a n/a household Table 7.24: South Essex RZ Feasible Options

Table note: construction period for Ardeligh extension would be 3 years but the date water available is dependent on when gravel pit site is available to develop into reservoir.

7.5.4 Option SE1 Colchester Water Reuse This option proposes to treat the discharge from the Colchester WRC and transfer it to the River Colne, 2km upstream of the WTW intake.

Colchester WRC will require a sidestream Membrane Bioreactor (MBR) and Reverse Osmosis (RO). The product water will be oxygenated and the pH increased prior to pumping to the River Colne. The RO concentrate would be discharged at the existing Colchester WRC into the tidal stretch of the River Colne. The concentrate will have a salt concentration significantly lower than ambient sea water. The water reuse plant capacity is based on 90% of the 2011 DWF and any flow above this will be discharged in the current manner. The sidestream MBR should be designed as a Biological Nutrient Removal (BNR) plant to maximise biological phosphorous removal thereby reducing the ferric sulphate dosing requirements. Ferric sulphate will be dosed in to the aeration tanks as a trim to reduce the phosphate concentration feeding the RO plant to minimise calcium phosphate scale formation in the RO membranes. Phosphate will be rejected by the RO plant and consequently the phosphate concentration in the water to be discharged to the River Colne will be very low.

The permeate from the RO process will be dosed with carbon dioxide and then with lime to achieve the desired alkalinity and pH values. Dosing with hydrogen peroxide, hypochlorite and ultraviolet (UV) radiation will be required to achieve the desired virus/pathogen removal. The water will then pass through a carbon dioxide stripper where water cascades down a forced draft packed tower which will then reduce the concentration of carbon dioxide and subsequently reduce the required dose of sodium hydroxide to achieve a final pH. The additional benefit of the use of carbon dioxide stripper is that the water will be aerated prior to discharge.

The WTW would require additional treatment capacity. A schematic of the proposed project is shown below in Figure 7.11.

Identified Risks: • Cost Risk: There is limited space available to construct additional treatment at Colchester WRC. Site layouts should be prepared to establish whether additional land should be purchased. The abstraction point in the River Colne is in the city centre and could result in considerable planning delays. • Quality Risk: The water reuse plant should have the level of redundancy and design robustness as detailed in the Guidelines for Water Reuse (USEPA, 2012) in order to ensure that the water being pumped into the River Colne meets the quality requirements.

WRMP Options Appraisal Report

• Programme Risk: Detailed consultation with key stakeholders such as the Environment Agency and the Drinking Water Inspectorate could have an impact on the programme. • Public Relations Risk: Whilst indirect potable water reuse has been widely practised in South East England over many years, this scheme would differ as it would deliberately reuse the effluent. Consequently public perception issues must be carefully managed to minimise objections. • Environmental Risk: The discharge and re-abstraction of re-used water into the River Colne would require approval from the Environment Agency and abstraction may be limited to the requirement to maintain the “hands-off” river flows.

WTW

21 Ml/d Into supply

River Colne

River Colne 21 Ml/d RO Concentrate Colchester discharge to Water Reuse existing sewer Works

Colchester WRC

Key : (All proposed changes in red)

Existing Treatment Works Existing Pipe Intake Existing Sewer Treatment Works New Pipeline Outfall Existing WRC Bankside storage

Figure 7.11: Option schematic – SE1, Colchester water reuse

WRMP Options Appraisal Report

7.5.5 Option SE2 East Suffolk RZ transfer (12 Ml/d) This option involves transfer of water from East Suffolk RZ to South Essex RZ.

This option involves the construction of a 400mm diameter pumping main across a total distance of approximately 22 km.

Much of the pipeline route is across fields. There are number of road crossings and several river crossings along the route which are assumed to require directional drilling.

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Programme Risks: Detailed consultation with the Highways Agency, Environment Agency and Local Authorities could have an impact on the project. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.5.6 Option SE4 Amendment to Ardleigh Agreement This option involves Anglian Water increasing its proportion of the Colchester WTW output. The current arrangement with Affinity Water proportions the output from the WTW as 70:30 to Anglian Water. This option increases Anglian Water’s proportion to 80:20.

The scheme assumes that the WTW output is restored to its maximum capacity as part of the capital maintenance programme. There are no capex costs associated with this option; it requires an increase in opex only.

Identified Risks: • The current agreement expires at the end of AMP5. Affinity Water has confirmed that they do not intend to change the current position of 70:30 and could consider an 80:20 spilt. However there is a risk that this option will not be available for the full 25 year planning horizon.

7.5.7 Option SE6 South Essex RZ groundwater development This option utilises a disused licence groundwater source. The scheme would require a new groundwater source pump and treatment via additional aeration, rapid gravity filters and disinfection capacity. There is adequate space within the existing WTW to accommodate the additional treatment facilities.

Identified Risks: • Quality risk: The groundwater may contain sodium, potassium and ammonium concentrations which are in excess of those permitted in Water Supply (Water Quality) Regulations 2000. • Resource Availability Risks: Successful delivery of this option will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

WRMP Options Appraisal Report

7.5.8 Option SE7 Ardleigh reservoir extension This option utilises the gravel pits adjacent to Ardeligh reservoir to provide additional storage. The pits are being created as part of mineral extraction however once this work has been completed these pits would be available to adapt into a reservoir. The reservoir would be filled from the existing abstraction on the River Colne within the existing licence. Additional treatment capacity would be required to treat the additional yield from the new storage volume.

The scheme would provide an additional 2 Ml/d deployable output at average.

Identified Risks: • Cost risks: there are number of options for the scope of works carried out by the mineral extraction company in relation to the reservoir ancillary structures prior to hand over to Anglian Water (i.e. inclusion of draw-off works etc in their scope). A change in scope may have an impact on the capex and opex for this option. • Programme risks: The scheme is dependent on when the mineral extraction is complete and the gravel pits are available to be converted to a reservoir. • Resource Availability Risks: Successful delivery of this option will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

Existing Abstraction from River Colne

Draw-off Reservoir conduit extension Existing WTW Existing Into reservoir supply 630mm dia New pipeline PS New 3Ml/d WTW

Figure 7.12: Option schematic – SE7 Ardleigh reservoir extension

7.5.9 Option SE8 East Suffolk RZ transfer (2Ml/d) This option requires the same pipeline route as option SE2, however it requires a 200mm diameter pumping main.

7.5.10 Environmental considerations The conclusions of the environmental assessments described in sections 4.6, 4.7 and 6 are summarised below. • No specific issues were identified as part of the BAG assessment other than those common to all options. • The climate change vulnerability assessment concludes that both transfer options (SE2, SE8) are not sensitive to climate change but the donor RZs are vulnerable to climate change. The assessment scored both options as 2 – limited sensitivity. The groundwater development (SE6) also scored 2 – limited sensitivity. The reuse option (SE1) and amendment to Ardleigh agreement (SE4) scored 1 – insensitive to impacts of climate change. The Ardleigh extension (SE7) scores 3 – sensitive in relation to water abstraction, available flow and environmental flow requirements.

WRMP Options Appraisal Report

• The WFD no-deteriorations assessment, SEA and HRA concluded the following for the South Essex RZ options, • SE1 Colchester water reuse - The HRA screening has concluded potential for likely significant effect on the Colne Estuary SPA and requirement for an Appropriate Assessment if taken forward. The SEA concluded that pipeline re-routing would be required to avoid local nature reserves and ancient woodland. Further investigation into water quality issues required by no WFD issues expected. • SE2 East Suffolk RZ transfer (12 Ml/d) - No significant negative effects identified in SEA, assuming that pipeline can be re-routed to avoid ancient woodland. • SE4 Amendment to Ardleigh agreement - The WFD no-deterioration screening has identified a low risk associated with increased abstraction from the River Colne that will require further investigation. No other significant negative effects have been identified in the SEA. • SE6 South Essex RZ groundwater development - The WFD no- deterioration assessment has identified a low risk of deterioration associated with increased abstraction from the Chalk that will require further investigation. No other significant negative effects have been identified in the SEA. • SE7 Ardleigh reservoir extension - The WFD no-deterioration screening has identified a low risk associated with increased abstraction from the River Colne that will require further investigation. The HRA screening has concluded potential for likely significant effect on the Colne Estuary SPA and requirement for an Appropriate Assessment if taken forward. • SE8 East Suffolk RZ transfer (2Ml/d) - No significant negative effects identified in SEA, assuming that pipeline can be re-routed to avoid ancient woodland.

7.5.11 Costs WRMP table WRP3a contains the details of the capex, opex, environmental and social costs, these are summarised in the table below.

Environmental & Social Costs Average Option Capex Opex (Including carbon) Opt. Ref capacity Name (£k) (£k/yr) Fixed (Ml/d) Variable Costs (£k) (£k/yr) Colchester SE1 16 74,400 1,540 0 146 water reuse East Suffolk SE2 RZ transfer 12 11,300 140 0 10 (12 Ml/d) Amendment SE4 to Ardleigh 2.6 0 240 0 4 agreement South Essex RZ SE6 1 3,100 60 0 1 groundwater development Ardleigh SE7 reservoir 2 10,700 190 0 11 extension

WRMP Options Appraisal Report

East Suffolk SE8 RZ Transfer 2 6,000 40 0 2 (2Ml/d) Table 7.25: Costs of South Essex RZ supply-side feasible options

The options have been ranked based on the Average Incremental Costs (AIC) and Average Incremental Social Cost (AISC) calculated in WRMP table WRP3a, these are shown in Table 7.26. The options have been raked in ascending AIC/AISC i.e. the option ranked 1 has the lowest AIC/AISC.

Opt Option Name AIC Ranking AISC Ranking Ref SE1 Colchester discharge reuse 12 12 SE2 East Suffolk WRZ transfer 3 3 Amendment to Ardleigh 5 5 SE4 Agreement South Essex RZ groundwater 11 11 SE6 development SE7 Ardleigh reservoir extension 13 13 East Suffolk RZ Transfer 10 10 SE8 (2Ml/d) SEX1 Leakage Control Package 1 1 1 SEX2 Leakage Control Package 2 2 2 SEX3 Leakage Control Package 3 4 4 SEX4 Leakage Control Package 4 6 6 SEX5 Leakage Control Package 5 9 9 Water efficiency – measured 7 7 SEX6 household Water efficiency – unmeasured 8 8 SEX7 household Table 7.26: South Essex RZ AISC and AIC ranking based on calculation within WRP3a

7.5.12 Inter-dependencies, links and synergies The following inter-dependencies between options have been included in the optimisation model assessment,

• Leakage control packages were inter-dependent • ES10 South Essex RZ to East Suffolk RZ is mutually exclusive to the two transfer options from East Suffolk RZ to South Essex RZ (SE2, SE8).

All the options would provide a degree of resilience if delivered earlier than required to meet growth requirements. However the benefit could only be realised up until the time the growth occurs and the resource is required to meet demand. The transfer option however could provide additional resilience if it was sized to provide capacity for a resilience deficit. This would increase the capex costs.

WRMP Options Appraisal Report

7.6 Central Essex Resource Zone

7.6.1 Unconstrained Options The unconstrained options workshop was held before the assessment of RZ integrity which spilt the original East Suffolk and Essex RZs and created the Central Essex RZ. The table below contains the list of unconstrained options specific to Central Essex RZ. Transfer options into the RZ were developed once the Central Essex RZ had been created.

More details about the reason for discounting an unconstrained option or why an option type was not considered for Central Essex RZ can be found in Appendix B in the East Suffolk and Essex RZ table.

Scheme Sub- Option Option is Categories/Sub- Option Description Ref Feasible Components

Groundwater Bartlow/Bures N sources Infiltration galleries Halstead N Tankering CE3 Tankering (road) N Table 7.27: Unconstrained options for Central Essex RZ

7.6.1 Additional options considered for Stage 2 economic modelling The table below contains details of additional options considered for the economic modelling for the revised draft WRMP.

Option Reason for including in Stage 2 economic Option Name Ref modelling CE1 South Essex RZ Transfer Central Essex RZ was not in deficit for the draft WRMP therefore this option was not developed previously. CE2 West Suffolk RZ Transfer Central Essex RZ was not in deficit for the draft WRMP therefore this option was not developed previously. Table7.28: Additional options considered for Stage 2 economic modelling

7.6.2 Feasible options not progressed to Stage 2 The table below describes feasible options identified at the unconstrained options workshop which after further work were discounted and not taken through to Stage 2 – economic modelling.

Option Option Name Reason for discounting Ref CE3 Tankering (road) Due to the high numbers of tanker deliveries per day down narrow country roads will be difficult to justify given the potential for disruption of local traffic. High WQ risks. Therefore the option is considered not promotable with a high risk of failure before implementation. Table 7.29 Central Essex RZ feasible options not progressed to Stage 2

WRMP Options Appraisal Report

7.6.3 Feasible options Table 7.30 contains details of the feasible options considered for Central Essex RZ.

Opt Capacity (Ml/d) Implementation Asset Plus Option Name Ref Average Peak Min Period Solution ID South Essex RZ CE1 1.5 1.5 0.5 3 years S10071097 Transfer West Suffolk RZ CE2 1.5 1.5 0.5 4 years S10071293 Transfer Leakage Control CEX1 0.1 n/a n/a Package 1 Leakage Control CEX2 0.1 n/a n/a Package 2

Programme CEX3 Leakage Control Not estimated 0.1 n/a n/a delivered over AMP Package 3 within Asset Plus period

Leakage Control CEX4 0.1 n/a n/a Package 4 Leakage Control CEX5 0.1 n/a n/a Package 5 Water efficiency CEX6 – measured 0.1 n/a n/a Programme S10071045 household delivered over AMP

Water efficiency period

CEX7 – unmeasured 0.02 n/a n/a household Table 7.30: Central Essex RZ feasible options

7.6.4 Option CE1 South Essex RZ transfer This option transfer water from South Essex RZ to Central Essex RZ.

The option requires the construction of a 150mm diameter pumping main a total distance of approximately 12km. Much of the pipeline route is across fields. There are a number of crossings which are assumed to require directional drilling.

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Programme Risks: Detailed consultation with the Highways Agency, Environment Agency and Local Authorities could have an impact on the project. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.6.5 Option CE2 West Suffolk RZ transfer This option transfers water from West Suffolk RZ into the north of Central Essex RZ. The transfer is over 3 sections.

The total length of the transfer is approximately 34km via a 150mm diameter main. It also requires 3 new pumping stations.

WRMP Options Appraisal Report

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Programme Risks: Detailed consultation with the Highways Agency, Environment Agency and Local Authorities could have an impact on the project. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.6.6 Environmental considerations The conclusions of the environmental assessments described in sections 4.6, 4.7 and 6 are summarised below.

• No specific issues were identified as part of the BAG assessment other than those common to all options. • The climate change vulnerability assessment concludes that both transfer options are not sensitive to climate change but the donor RZs are vulnerable to climate change. The assessment scored both options as 2 – limited sensitivity. • No WFD no-deterioration issues were identified • No HRA issues were identified • No significant negative effects have been predicted through the SEA

7.6.7 Costs WRMP table WRP3a contains the details of the capex, opex, environmental and social costs, these are summarised in the table below.

Environmental & Social Costs Average Opt. Option Capex Opex (Including carbon) capacity Ref Name (£k) (£k/yr) (Ml/d) Fixed Costs Variable (£k) (£k/yr) South CE1 Essex RZ 1.5 3,700 30 0 1 transfer West CE2 Suffolk RZ 1.5 8,500 80 0 4 Transfer Table 7.31: Costs of Central Essex RZ supply-side feasible options

The options have been ranked based on the Average Incremental Costs (AIC) and Average Incremental Social Cost (AISC) calculated in WRMP table WRP3a, these are shown in Table 7.32. The options have been raked in ascending AIC/AISC i.e. the option ranked 1 has the lowest AIC/AISC.

WRMP Options Appraisal Report

Opt Option Name AIC Ranking AISC Ranking Ref CE1 South Essex RZ Transfer 5 5 CE2 West Suffolk RZ Transfer 9 7 CEX1 Leakage Control Package 1 1 4 CEX2 Leakage Control Package 2 2 1 CEX3 Leakage Control Package 3 6 6 CEX4 Leakage Control Package 4 7 8 CEX5 Leakage Control Package 5 8 9 Water efficiency – measured CEX6 4 3 household Water efficiency – unmeasured CEX7 3 2 household Table 7.32: Central Essex RZ AISC and AIC ranking based on calculation within WRP3a

7.6.8 Inter-dependencies, links and synergies The following inter-dependencies between options have been included in the optimisation model assessment,

• Leakage control packages were inter-dependent.

Both the transfer options would provide a degree of resilience if delivered earlier than required to meet growth requirements. However the benefit could only be realised up until the time the growth occurs and the resource is required to meet demand. The transfer option however could provide additional resilience if it was sized to provide capacity for a resilience deficit. This would increase the capex costs.

7.7 Ely Resource Zone

7.7.1 Unconstrained Options The unconstrained options workshop was held before the assessment of RZ integrity which spilt the original Cambridgeshire and West Suffolk RZ and created the Ely RZ. The table below contains the list of unconstrained options specific to Ely RZ. Transfer options into the RZ were developed once the Ely RZ had been created.

More details about the reason for discounting an unconstrained option or why an option type was not considered for Ely RZ can be found in Appendix B in the Cambridgeshire and west Suffolk RZ table. The option references for the feasible options in the table below are specific to Ely RZ. The Cambridgeshire and West Suffolk table in Appendix B has been updated to reflect these new option references where applicable. Where an option is not feasible the original option reference (denoted CWS) has been used.

WRMP Options Appraisal Report

Scheme Sub- Option Option is Categories/Sub- Option Description Ref Feasible Components

Direct river Little Ouse N abstraction New reservoir Great Bradley see storage (On- Table7.35 stream) New reservoir Feltwell see storage (Pumped- Table7.35 storage) New reservoir SUDS N storage (Flood EA flood protection scheme (artificial recharge) N storage ) Groundwater Great Yeldham re-commission N sources Great Bartlow N Infiltration galleries Little Ouse N Aquifer Recharge SUDS N Reclaimed Review discharge consents N industrial and commercial wastewater Bulk transfers (by E1 Fenland RZ Transfer Y pipeline) South Essex RZ Transfer N Central Essex RZ Transfer N Resource Sharing Affinity water (East and Central) N with other Water Essex and Suffolk - Abberton Trilogy N Companies (Trade) CWS9 Cambridge Water see Table7.35 3rd Party Options 3rd party trade options N (Trade) Trade high fluoride water N 3rd Party Options gravel pit development N (Shared asset Sizewell N ownership) Improved/sophistic ESW Abberton Trilogy N ated conjunctive management Table 7.33: Unconstrained options for Ely RZ

7.7.1 Additional options considered for Stage 2 economic modelling The table below contains details of additional options considered for the economic modelling for the revised draft WRMP.

Option Reason for including in Stage 2 economic Option Name Ref modelling E2 Newmarket RZ Transfer Newmarket RZ was created after the unconstrained options workshop and this transfer became a feasible option Table7.34: Additional options considered for Stage 2 economic modelling

WRMP Options Appraisal Report

7.7.2 Feasible options not progressed to Stage 2 The table below describes feasible options identified at the unconstrained options workshop which after further work were discounted and not taken through to Stage 2 – economic modelling.

Option Option Name Reason for discounting Ref CWS9 Trade with Cambridge water Re-evaluation of need for AMP5 as water quality scheme. Feltwell reservoir + transfers to A feasible option but not taken through to South Essex RZ Stage 2 as would need to be developed as part of long term strategy and should be considered in the WREA. Great Bradley A feasible option but not taken through to Stage 2 as would need to be developed as part of long term strategy and should be considered in the WREA. Table7.35 Ely RZ feasible options not progressed to Stage 2

7.7.3 Feasible options Table 7.36 contains details of the feasible options considered for Ely RZ.

Opt Capacity (Ml/d) Implementation Asset Plus Option Name Ref Average Peak Min Period Solution ID Fenland RZ E1 15 15 5 4 years S10071264 Transfer Newmarket RZ E2 5 5 2 3 years S10071265 Transfer Leakage Control Programme ELY3 0.1 n/a n/a Not estimated Package 3 delivered over AMP within Asset Plus Leakage Control period ELY5 0.1 n/a n/a Package 5

Programme Enhanced S10071112 ELY6 0.3 n/a n/a delivered over AMP Metering period

Water efficiency ELY7 – measured 0.1 n/a n/a Programme household delivered over AMP S10071045 Water efficiency period ELY8 – unmeasured 0.02 n/a n/a household Table 7.36: Ely RZ feasible options

7.7.4 Option E1 Fenland RZ transfer This option transfers water from Fenland RZ to Ely RZ.

The option requires the construction of a 500mm diameter pumping main a total distance of approximately 32 km. Much of the pipeline route is across fields. There are a number of crossings which are assumed to require directional drilling.

WRMP Options Appraisal Report

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Programme Risks: Detailed consultation with the Highways Agency, Environment Agency and Local Authorities could have an impact on the project. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.7.5 Option E2 Newmarket RZ transfer This option transfers water from Newmarket RZ to Ely RZ. Newmarket RZ only has a marginal surplus at the end of the forecast and a new transfer into the donor RZ would be required to support Ely RZ, see section 7.7.8.

The option requires construction of 300mm diameter gravity main approximately 10 km long. Much of the pipeline route is across fields. There are a number of crossings which are assumed to require directional drilling.

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Programme Risks: Detailed consultation with the Highways Agency, Environment Agency and Local Authorities could have an impact on the project. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.7.6 Environmental considerations The conclusions of the environmental assessments described in sections 4.6, 4.7 and 6 are summarised below.

• No specific issues were identified as part of the BAG assessment other than those common to all options. • The climate change vulnerability assessment concludes that both transfer options are not sensitive to climate change but the donor RZs are vulnerable to climate change. The assessment scored both options as 2 – limited sensitivity. • WFD no-deterioration screening has identified a low risk associated with sources in donor RZ’s. • The SEA has concluded that there will be no significant negative effects following mitigation.

7.7.7 Costs WRMP table WRP3a contains the details of the capex, opex, environmental and social costs, these are summarised in the table below.

WRMP Options Appraisal Report

Environmental & Social Costs Average Opt Capex Opex (Including carbon) Option Name capacity Ref (£k) (£k/yr) (Ml/d) Fixed Costs Variable (£k) (£k/yr) Fenland RZ E1 15 23,400 160 4 12 transfer Newmarket E2 5 3,900 0 0.5 0 RZ transfer Table 7.37: Costs of Ely RZ feasible supply-side options

The options have been ranked based on the Average Incremental Costs (AIC) and Average Incremental Social Cost (AISC) calculated in WRMP table WRP3a, these are shown in Table 7.38. The options have been raked in ascending AIC/AISC i.e. the option ranked 1 has the lowest AIC/AISC.

Opt Option Name AIC Ranking AISC Ranking Ref E1 Fenland RZ Transfer 2 2 E2 Newmarket RZ Transfer 1 1 ELY3 Leakage Control Package 3 6 6 ELY5 Leakage Control Package 5 7 7 ELY6 Enhanced Metering 5 5 ELY7 Water efficiency – measured 3 3 household ELY8 Water efficiency – unmeasured 4 4 household Table 7.38: Ely RZ AISC and AIC ranking based on calculation within WRP3a

7.7.8 Inter-dependencies, links and synergies The following inter-dependencies between options have been included in the optimisation model assessment,

• Leakage control packages were inter-dependent • Option E2 Newmarket transfer is mutually exclusive to option NWM1 Ely transfer. As the transfer between RZs would only operate in one direction.

Both transfer options are supplied by RZs in deficit or with a marginal surplus at the end of the forecast which could trigger a new resource or transfer into the donor RZ. Therefore either option could form part of a larger strategic transfer depending on the upstream options selected to support the transfer. The capacity of the transfer modelled reflects this;

• The Fenland RZ transfer (E1) has been sized for 15 Ml/d which is adequate size to satisfy the Ely RZ deficit and downstream RZs such as Cheveley RZ and West Suffolk RZ. This option would be supported by new resources and transfers out of Ruthamford North RZ. • The Newmarket RZ transfer (E2) has been sized for the Ely deficit and the Cheveley RZ. This option would be supported by new resources and transfers out of West Suffolk RZ and East Suffolk RZ.

WRMP Options Appraisal Report

All the options would provide a degree of resilience if delivered earlier than required to meet growth requirements. However the benefit could only be realised up until the time the growth occurs and the resource is required to meet demand. The transfer option however could provide additional resilience if it was sized to provide capacity for a resilience deficit. This would increase the capex costs.

7.8 Newmarket Resource Zone

7.8.1 Unconstrained options The unconstrained options workshop was held before the assessment of RZ integrity which spilt the original Cambridgeshire and West Suffolk RZ and created the Newmarket RZ. At the end of the forecast Newmarket RZ has a marginal surplus therefore specific options have not been developed for Newmarket RZ. The options presented would form part of a larger transfer supporting either Ely RZ or Cheveley RZ.

Both Newmarket RZ options are supplied by RZs in deficit at the end of the forecast therefore a new resource or transfer into the donor RZ would be required. For details of the unconstrained options considered for supporting the Newmarket RZ options see the Cambridgeshire and West Suffolk table in Appendix B.

7.8.1 Additional options considered for Stage 2 economic modelling The table below contains details of additional options considered for the economic modelling for the revised draft WRMP.

Option Reason for including in Stage 2 economic Option Name Ref modelling NWM1 Ely RZ Transfer Ely RZ was created after the unconstrained options workshop and this transfer became a feasible option NWM2 West Suffolk RZ transfer West Suffolk RZ was created after the unconstrained options workshop and this transfer became a feasible option Table7.39: Additional options considered for Stage 2 economic modelling

7.8.2 Feasible options Table 7.40 contains details of the feasible options considered for Newmarket RZ.

Opt Capacity (Ml/d) Implementation Asset Plus Option Name Ref Average Peak Min Period Solution ID NWM1 Ely RZ transfer 9 9 3 3 years S10071268 West Suffolk RZ NWM2 6 6 2 4 years S10071262 transfer

Programme Leakage Control Not estimated NWM5 0.01 n/a n/a delivered over Package 5 within Asset Plus AMP period

Water efficiency Programme NWM6 – measured 0.1 n/a n/a delivered over household S10071045/1 AMP period Water efficiency

NWM7 – unmeasured 0.02 n/a n/a

household Table 7.40: Newmarket RZ feasible options

WRMP Options Appraisal Report

7.8.3 Option NWM1 Ely RZ transfer This option transfers water from Ely RZ to Newmarket RZ.

The option requires construction of 300mm diameter pumped main approximately 10 km long. Much of the pipeline route is across fields. There are a number of crossings which are assumed to require directional drilling.

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Programme Risks: Detailed consultation with the Highways Agency, Environment Agency and Local Authorities could have an impact on the project. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.8.4 Option NWM2 West Suffolk RZ transfer This option transfer water from West Suffolk RZ in Newmarket RZ.

The option requires approximately 22km of new 400mm diameter pumped main. The majority of the pipeline is across fields and there are a number of crossings which are assumed to require directional drilling.

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Programme Risks: Detailed consultation with the Highways Agency, Environment Agency and Local Authorities could have an impact on the project. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.8.5 Environmental considerations The conclusions of the environmental assessments described in sections 4.6, 4.7 and 6 are summarised below.

WRMP Options Appraisal Report

• No other significant negative effects have been identified through the SEA or HRA.

7.8.6 Costs WRMP table WRP3a contains the details of the capex, opex, environmental and social costs, these are summarised in the table below.

Environmental & Social Costs Average Opt Capex Opex (Including carbon) Option Name capacity Ref (£k) (£k/yr) (Ml/d) Fixed Costs Variable (£k) (£k/yr) Ely RZ NWM1 9 4,700 130 11 10 transfer West Suffolk NWM2 6 11,400 100 34 7 RZ transfer Table 7.41: Costs of Newmarket RZ supply-side feasible options

The options have been ranked based on the Average Incremental Costs (AIC) and Average Incremental Social Cost (AISC) calculated in WRMP table WRP3a, these are shown in Table 7.42. The options have been raked in ascending AIC/AISC i.e. the option ranked 1 has the lowest AIC/AISC.

Opt Option Name AIC Ranking AISC Ranking Ref NWM1 Ely RZ transfer 1 1 NWM2 West Suffolk RZ transfer 2 2 NWM5 Leakage Control Package 5 5 5 Water efficiency – measured NMW6 4 4 household Water efficiency – unmeasured NWM7 3 3 household Table 7.42: Newmarket RZ AISC and AIC ranking based on calculation within WRP3a

7.8.7 Inter-dependencies, links and synergies The following inter-dependencies between options have been included in the optimisation model assessment,

• Option NWM1 Ely transfer is mutually exclusive to option E2 Newmarket transfer. As the transfer between RZs would only operate in one direction.

The Newmarket options would form part of a larger transfer scheme supporting either/both Ely RZ and Cheveley RZ. Both transfer options are supplied by RZs in deficit at the end of the forecast which could trigger a new resource or transfer into the donor RZ. Therefore either option could form part of a larger strategic transfer depending on the upstream options selected to support the transfer. The capacity of the transfer modelled reflects this;

• The Ely RZ transfer (NWM1) has been sized for 9 Ml/d which is adequate size to satisfy deficits in downstream RZs such as Cheveley RZ and West Suffolk RZ. This option would be supported by new resources and transfers out of Ruthamford North RZ.

WRMP Options Appraisal Report

• The West Suffolk RZ transfer (NWM2) has been sized for the Ely deficit and the Cheveley RZ. This option would be supported by new resources and transfers out of West Suffolk RZ and East Suffolk RZ.

All the options would provide a degree of resilience if delivered earlier than required to meet growth requirements. However the benefit could only be realised up until the time the growth occurs and the resource is required to meet demand. The transfer option however could provide additional resilience if it was sized to provide capacity for a resilience deficit. This would increase the capex costs.

7.9 Cheveley Resource Zone

7.9.1 Unconstrained options The unconstrained options workshop was held prior to the assessment of RZ integrity which spilt the original Cambridgeshire and West Suffolk RZ and created the Cheveley RZ. No specific unconstrained options were identified for Cheveley RZ and subsequently two transfer options have been proposed to support Cheveley RZ.

Both of these options are supplied by RZs in deficit at the end of the forecast or with a marginal surplus. Therefore a new resource or transfer into the donor RZ would be required. For details of the unconstrained options considered for supporting the Cheveley RZ options see the Cambridgeshire and West Suffolk table in Appendix B.

7.9.1 Additional options considered for Stage 2 economic modelling The table below contains details of additional options considered for the economic modelling for the revised draft WRMP.

Option Reason for including in Stage 2 economic Option Name Ref modelling CVY1 Newmarket RZ transfer Newmarket RZ was created after the unconstrained options workshop and this transfer became a feasible option CVY2 West Suffolk RZ transfer West Suffolk RZ was created after the unconstrained options workshop and this transfer became a feasible option Table 7.43: Additional options considered for Stage 2 economic modelling

7.9.2 Feasible options Table 7.44 contains details of the feasible options considered for Cheveley RZ.

Opt Capacity (Ml/d) Implementation Asset Plus Option Name Ref Average Peak Min Period Solution ID Newmarket RZ CVY1 1 1 0.2 3 years S10071346 transfer West Suffolk RZ CVY2 1 1 0.2 3 years S10071347 transfer Water efficiency CVY3 – measured 0.01 n/a n/a Programme household delivered over S10071045 Water efficiency AMP period CVY4 – unmeasured 0.002 n/a n/a household Table 7.44: Cheveley RZ feasible options

WRMP Options Appraisal Report

7.9.3 Option CVY1 Newmarket RZ transfer This option transfers water from Newmarket RZ to Cheveley RZ.

The option requires approximately 3km of new 150mm diameter pumped main. The majority of the pipeline is across fields and there are a number of crossings which are assumed to require directional drilling.

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Programme Risks: Detailed consultation with the Highways Agency, Environment Agency and Local Authorities could have an impact on the project. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.9.4 Option CVY2 West Suffolk RZ transfer This option transfers water from West Suffolk RZ to Cheveley RZ.

The option requires approximately 12km of new 200mm diameter pumped main. The majority of the pipeline is across fields and there are a number of crossings which are assumed to require directional drilling.

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Programme Risks: Detailed consultation with the Highways Agency, Environment Agency and Local Authorities could have an impact on the project. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.9.5 Environmental considerations The conclusions of the environmental assessments described in sections 4.6, 4.7 and 6 are summarised below. • No specific issues were identified as part of the BAG assessment other than those common to all options. • The climate change vulnerability assessment concludes that both transfer options are not sensitive to climate change but the donor RZs are vulnerable to climate change. The assessment scored both options as 2 – limited sensitivity. • WFD no-deterioration screening has identified a low risk associated with sources in donor RZ’s. • The SEA has concluded that there will be no significant negative effects following mitigation.

WRMP Options Appraisal Report

7.9.6 Costs WRMP table WRP3a contains the details of the capex, opex, environmental and social costs, these are summarised in the table below.

Environmental & Social Costs Average Opt Capex Opex (Including carbon) Option Name capacity Ref (£k) (£k/yr) (Ml/d) Fixed Costs Variable (£k) (£k/yr) Newmarket CVY1 1 1,100 20 0.1 1 RZ Transfer West Suffolk CVY2 1 3,100 30 0.4 1 RZ Transfer Table 7.45: Costs of Cheveley RZ supply-side feasible options

The options have been ranked based on the Average Incremental Costs (AIC) and Average Incremental Social Cost (AISC) calculated in WRMP table WRP3a, these are shown in Table 7.46. The options have been raked in ascending AIC/AISC i.e. the option ranked 1 has the lowest AIC/AISC.

Opt Option Name AIC Ranking AISC Ranking Ref CVY1 Newmarket RZ transfer 1 1 CVY2 West Suffolk RZ transfer 4 4 Water efficiency – measured CVY3 3 3 household Water efficiency – unmeasured CVY4 2 2 household Table 7.46: Cheveley RZ AISC and AIC ranking based on calculation within WRP3a

7.9.7 Inter-dependencies, links and synergies The following inter-dependencies between options have been included in the optimisation model assessment,

• Option CVY1 and CVY 2 have been modelled mutually exclusive. As only one transfer into the RZ would be implemented.

Option CVY1 is supplied by Newmarket RZ which has a marginal surplus by the end of the forecast which is not adequate to fully satisfy the Cheveley deficit. Therefore a new transfer into Newmarket would also be required to support this option. The West Suffolk RZ transfer CVY2 would also require a new resource or transfer into West Suffolk.

WRMP Options Appraisal Report

7.10 West Suffolk Resource Zone

7.10.1 Unconstrained Options The unconstrained options workshop was held before the assessment of RZ integrity which spilt the original Cambridgeshire and West Suffolk RZ and created the West Suffolk RZ. The table below contains the list of unconstrained options specific to West Suffolk RZ.

More details about the reason for discounting an unconstrained option or why an option type was not considered for West Suffolk RZ can be found in Appendix B in West Suffolk RZ table. The option references for the feasible options in the table below are specific to West Suffolk RZ. The West Suffolk table in Appendix B has been updated to reflect these new option references where applicable. Where an option is not feasible the original option reference (denoted CWS) has been used.

Scheme Sub- Option Option is Categories/Sub- Option Description Ref Feasible Components

Direct river River Colne with a trade with Essex & Suffolk N abstraction Water via Newmarket Ouse Essex Transfer Scheme (EOETS) Little Ouse N New reservoir Great Bradley See Table storage (On- 7.49 stream) New reservoir Feltwell See Table storage (Pumped- 7.49 storage) New reservoir SUDS N storage (Flood EA flood protection scheme (artificial recharge) N storage ) Groundwater Great Yeldham re-commission N sources Great Bartlow N Ixworth unused groundwater source N Infiltration galleries Little Ouse N Artificial Storage CWS8 Bury St Edmunds Scheme Y and Recovery Aquifer Recharge SUDS N Reclaimed WS3 Bury St Edmunds WRC reuse Y domestic CWS6 Haverhill WRC reuse See Table wastewater 7.49 WS4 Thetford WRC reuse Y Reclaimed Review discharge consents N industrial and commercial wastewater Bulk transfers (by Central Essex RZ Transfer N pipeline) Resource Sharing Affinity (East and Central) N with other Water Essex and Suffolk - Abberton Trilogy N Companies (Trade) 3rd Party Options 3rd party trade options N (Trade) Trade high fluoride water N 3rd Party Options Sizewell N (Shared asset

WRMP Options Appraisal Report

ownership) Improved/sophistic ESW Abberton Trilogy N ated conjunctive management Other WS5 River Lark flow augmentation Y Table 7.47: Unconstrained options for West Suffolk RZ

7.10.1 Additional options considered for Stage 2 economic modelling The table below contains details of additional options considered for the economic modelling for the revised draft WRMP.

Option Reason for including in Stage 2 economic Option Name Ref modelling WS1 Newmarket RZ transfer Newmarket RZ was created after the unconstrained options workshop and this transfer became a feasible option WS2 (a&b) East Suffolk RZ transfer East Suffolk RZ was created after the unconstrained options workshop and this transfer became a feasible option WS6 South Essex RZ Transfer South Essex RZ was created after the unconstrained options workshop and this transfer became a feasible option Table7.48: Additional options considered for Stage 2 economic modelling

7.10.2 Feasible options not progressed to Stage 2 The table below describes feasible options identified at the unconstrained options workshop which after further work were discounted and not taken through to Stage 2 – economic modelling.

Option Option Name Reason for discounting Ref CWS6 Haverhill water reuse Following further review of RZ integrity Cambridgeshire and West Suffolk RZ has been split into a number of new RZs for the revised draft WRMP. This option is no longer applicable to the new configuration of RZs. Feltwell reservoir + transfers to A feasible option but not taken through to South Essex RZ Stage 2 as would need to be developed as part of long term strategy and should be considered in the WREA. Great Bradley A feasible option but not taken through to Stage 2 as would need to be developed as part of long term strategy and should be considered in the WREA. Table 7.49 West Suffolk RZ feasible options not progressed to Stage 2

7.10.3 Feasible Options Table 7.50 contains details of the feasible options considered for West Suffolk RZ.

Opt Capacity (Ml/d) Implementation Asset Plus Option Name Ref Average Peak Min Period Solution ID Newmarket RZ WS1 8.5 8.5 3 4 years S10071271 transfer East Suffolk RZ WS2a 15 15 5 4 years S9734695 transfer (15 Ml/d) East Suffolk WRZ Not in Asset WS2b Transfer (resilience 4.7 4.7 0 4 years Plus scheme) WS3 Bury St Edmunds 5.0 6.2 3 3 years S9732287

WRMP Options Appraisal Report

water reuse Thetford water WS4 2.9 3.6 2 3 years S9732286 reuse River Lark flow WS5 4.5 4.5 4.5 3 years S10053563 augmentation South Essex RZ WS6 15 15 4.5 4 years S9734697 Transfer Leakage Control WSU1 1.3 n/a n/a Package 1 Leakage Control WSU2 1.3 n/a n/a Package 2 Leakage Control WSU3 1.3 n/a n/a Package 3 Programme Not estimated Leakage Control delivered over AMP within Asset WSU4 1.4 n/a n/a Package 4 Plus

Leakage Control WSU5 0.4 n/a n/a Package 5

Water Efficiency Programme S10071045 WSU6 Audits (measured 0.3 n/a n/a delivered over AMP households Table 7.50: West Suffolk RZ Feasible Options

7.10.4 Option WS1 Newmarket Resource Zone Transfer This option involves the transfer of water from Newmarket RZ to West Suffolk RZ.

The option requires the construction of a 400mm diameter pumping main across a total distance of 22 km.

Much of the pipeline route is across fields. There are a number of road crossings and several river crossings along the route which are assumed to require directional drilling.

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Programme Risks: Detailed consultations with the Highways Agency, Environment Agency and Local Authorities could have an impact on the project. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.10.5 Option WS2a East Suffolk RZ transfer (15 Ml/d) This options involves transfer of water from East Suffolk RZ to West Suffolk RZ.

This requires the construction of a 600mm diameter pumping main from over a total distance of 36 km. Two new pumping stations are also required.

Much of the pipeline route is across fields. However, there are some major and minor road crossings and several river crossings along the route which are assumed to require directional drilling.

WRMP Options Appraisal Report

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Programme Risks: Detailed consultations with the Highways Agency, Environment Agency and Local Authorities could have an impact on the project. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.10.6 Option WS2b East Suffolk RZ transfer (resilience scheme) This option assumes that the resilience scheme proposed for delivery in AMP6 can be utilised to supply Bury St Edmunds in West Suffolk RZ.

The resilience scheme has been designed to provide an alternative source to Bury St Edmunds. The scope consists of 4 new pumping stations and a 400mm new pipeline from East Suffolk RZ to Bury St Edmunds. The pipeline covers a total distance of 45km.

The resilience scheme has a total capacity of 8 Ml/d but would be operated at 3.3Ml/d in standby mode. The standby flows have been accounted for in the baseline supply demand forecast. The costs for WS2b are based on the additional operational costs to transfer flow above 3.3Ml/d i.e. up to an additional 4.7Ml/d.

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Programme Risks: Detailed consultation with the Highways Agency, Environment Agency and Local Authorities could have an impact on the project. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.10.7 Option WS3 Bury St Edmunds Water Reuse This option proposes to treat 90% of the Dry Weather Flow (DWF) from Bury St Edmunds WRC, through an advanced treatment process and to inject the treated water into the chalk aquifer as part of a Managed Aquifer Recharge Scheme (MAR).

The advanced treatment process will comprise ultrafiltration (UF) and Reverse Osmosis (RO). The final effluent ammonia consent is low with a 95 percentile value of 2 mg/l. Consequently, there is no requirement to treat the effluent to remove ammonia through modification of the existing process. The RO process generates two streams – the product water which will be pumped to the injection groundwater source and the concentrate which will be discharged at the existing Bury St Edmunds WRC into the River Lark. The concentrate will have a salt concentration of 3000-5000 mg/l and will be diluted with the final effluent from the WRC.

Ferric Sulphate will be dosed before the UF process to improve membrane performance and to precipitate iron phosphate which, in turn result in reduced calcium phosphate scaling risk in the RO membranes. Phosphate will be rejected

WRMP Options Appraisal Report

by the RO process and consequently, the phosphate concentration in the water to be injected into the aquifer will be very low.

The additional water could be abstracted from the aquifer and treated at the the existing WTW. The water reuse plant capacity is based on 90% of the 2011 DWF and any flow above this will be discharged in the current manner.

Figure 7.13 below shows a schematic of the proposed option.

Identified Risks: • Cost Risk: There is limited space available to construct additional treatment at the WRC. Site layouts should be prepared to establish whether additional land should be purchased. Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Environmental Risk: The discharge and re-abstraction of re-used water into the aquifer would require approval from the Environment Agency. • Technical Risk: A pilot study would be required to confirm the feasibility of this option.

Bury St Bury St (All proposed changes in red) Edmunds River Lark Edmunds Water Reuse WRC Works Existing Treatment Works

Existing sewer Treatment Works 6.21 Ml/d Existing WRC 8km RO Concentrate Existing Pipe discharge Existing Sewer

Injection New Pipeline

Groundwater source 6.21 Ml/d Abstraction Into Supply

WTW WTW Extension Figure 7.13: Option schematic – WS3 Bury St Edmunds water reuse

7.10.8 Option WS4 Thetford water reuse This option proposes that the effluent from the Thetford WRC be treated and pumped to the chalk aquifer as part of a Managed Aquifer Recharge Scheme (MAR).

For this purpose, the Thetford WRC will require a sidestream Microbiological Reactor (MBR) and Reverse Osmosis (RO). Depending on the requirements of the receiving aquifer, the product water will be oxygenated and the pH increased prior to pumping the water to the injection well. The RO process generates two streams – the product water which will be pumped to the injection groundwater source and the concentrate which will be discharged at the existing Thetford WRC into the River Little Ouse. The concentrate will have a salt concentration of 3000- 5000 mg/l and will be diluted with the final effluent from the Thetford WRC.

The sidestream MBR should be designed as a Biological Nutrient Removal (BNR) plant to maximise biological phosphorous removal thereby reducing the ferric sulphate dosing requirements. Ferric sulphate will be dosed in to the aeration tanks as a trim to reduce the phosphate concentration feeding the RO plant to minimise calcium phosphate scale formation in the RO membranes. A carbon dioxide stripper has been included to remove CO2 in the RO permeate thereby

WRMP Options Appraisal Report

reducing the sodium hydroxide dose required to achieve a neutral pH. However, the stripper will also oxygenate the water which may not be desirable in the aquifer. Consequently, the stripper could be removed and the sodium hydroxide dose increased to get the desired water quality standards for aquifer injection.

Water could be abstracted and treated at the exisitng WTW. A schematic of the proposed scheme is shown below in Figure 7.14.

Identified Risks: • Cost Risk: There is limited space available to construct additional treatment at Thetford WRC. Site layouts should be prepared to establish whether additional land should be purchased. Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Environmental Risk: The discharge and re-abstraction of re-used water into the aquifer would require approval from the Environment Agency • Technical Risk: A pilot study would be required to confirm the feasibility of this option.

3.58 Ml/d Abstraction Into Supply

WTW WTW Key: (All proposed changes in red) Extension Injection Existing Treatment Works

Treatment Works 3km 3.58 Ml/d Existing WRC River Little Ouse Thetford Existing Pipe WRC Thetford Existing Sewer Existing Water Reuse sewer Works New Pipeline

Groundwater source RO Concentrate discharge

Figure 7.14: Option schematic – WS4, Thetford water reuse

7.10.9 Option WS5 River Lark flow augmentation This option seeks to mitigate the effects of water abstractions on the flow of the River Lark. The proposal focuses on the 8 km stretch of the River Lark through Bury St Edmunds.

The proposed scheme involves abstraction of water from the River Lark downstream of Bury St Edmunds WRC for transfer and discharge to the river upstream of the town.

This option requires a new river offtake downstream of the WRC and a 7 km long new pipeline to discharge the water back to the river upstream of Bury St Edmunds, thus increasing the flows through the town. Implementation of this option should lead to improved flows through Bury St Edmunds with related benefits for ecology and visual amenity.

Identified Risks: • Cost Risks: The pipeline route needs detailed route survey. There may be significant cost escalations due to unforeseen ground conditions during pipeline constructions.

WRMP Options Appraisal Report

• Environmental Risks: Construction impacts and significant disruption along the proposed pipeline route may lead to adverse environmental impacts. • Programme Risks: Detailed consultation with the Environment Agency and Local Authorities could have an impact on the project.

7.10.10 Option WS6 South Essex RZ transfer This proposal involves transfer of water from South Essex RZ to West Suffolk RZ.

This option involves the construction of a 500mm diameter pumping main across a total distance of approximately 35 km. A new pumping station is also required.

Much of the pipeline route is across fields. There are a number of road crossings and several river crossings along the route which are assumed to require directional drilling.

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Programme Risks: Detailed consultations with the Highways Agency, Environment Agency and Local Authorities could have an impact on the project. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.10.11 Environmental considerations The conclusions of the environmental assessments described in sections 4.6, 4.7 and 6 are summarised below.

• No specific issues were identified as part of the BAG assessment other than those common to all options. • The climate change vulnerability assessment concludes that the transfer options (WS1, WS2a, WS2b, WS6) are not sensitive to climate change but the donor RZs are vulnerable to climate change. The assessment scored these options as 2 – limited sensitivity. The reuse options (WS3, WS4) scored 1 – insensitive. For the River Lark augmentation scheme (WS5) the assessment assumed the source is secure, so rated it as 1 - insensitive. • The WFD no-deteriorations assessment, SEA and HRA concluded; • WS1 Newmarket RZ transfer - The SEA has not identified any significant negative effects following mitigation measures to re-route the pipeline around an ancient woodland. • WS2a/2b East Suffolk RZ transfer -The SEA has not identified any significant negative effects following mitigation measures unless the pipeline cannot be routed around an ancient woodland. • WS3 Bury St Edmunds water reuse -The WFD assessment concludes a likely positive effect as a result of increased flows, although some further assessment has been recommended. The SEA recommended that the pipeline should be re-routed to avoid SSSI, local nature reserves and ancient landfill sites. • WS4 Thetford water reuse -The WFD assessment has identified a potential concern with deteriorating water quality which would need to be

WRMP Options Appraisal Report

investigated further. The HRA screening concluded potential for likely significant effect on the Breckland SPA and Breckland SAC. An Appropriate Assessment would be required if the scheme is taken forward. The SEA also concluded that further investigation is required into feasibility of re-routing pipeline. • WS5 River Lark flow augmentation -The WFD assessment concluded a likely positive impact subject to some further investigation regarding water quality. The SEA has not identified any significant negative impacts. • WS6 South Essex RZ transfer -The SEA has identified a need for the pipeline to avoid an ancient woodland area and a local nature reserve. No other significant negative effects.

7.10.12 Costs WRMP table WRP3a contains the details of the capex, opex, environmental and social costs, these are summarised in the table below.

Environmental & Social Costs Average Opt Capex Opex (Including carbon) Option Name capacity Ref (£k) (£k/yr) (Ml/d) Fixed Costs Variable (£k) (£k/yr) Newmarket WS1 8.5 11,000 70 2 4 RZ transfer East Suffolk WS2a RZ transfer 15 28,000 180 5 13 (15Ml/d) East Suffolk RZ transfer WS2b 4.7 0 50 0 4 (resilience scheme) Bury St WS3 Edmunds 5 33,600 360 2 34 water reuse Thetford water WS4 2.9 21,200 710 2 17 reuse River Lark WS5 flow 4.5 3,000 10 1 1 augmentation South Essex WS6 15 23,400 140 4 10 RZ transfer Table 7.51: Costs of West Suffolk RZ supply-side feasible options

The options have been ranked based on the Average Incremental Costs (AIC) and Average Incremental Social Cost (AISC) calculated in WRMP table WRP3a, these are shown in the table below. The options have been raked in ascending AIC/AISC i.e. the option ranked 1 has the lowest AIC/AISC.

Opt Option Name AIC Ranking AISC Ranking Ref WS1 Newmarket RZ transfer 5 4 East Suffolk RZ transfer (15 WS2a 8 7 Ml/d) East Suffolk WRZ Transfer WS2b 1 1 (resilience scheme) WS3 Bury St Edmunds water reuse 11 11 WS4 Thetford water reuse 13 12 River Lark Recirculation WS5 2 2 Scheme WS6 South Essex RZ Transfer 6 6

WRMP Options Appraisal Report

WSU1 Leakage Control Package 1 3 3 WSU2 Leakage Control Package 2 4 5 WSU3 Leakage Control Package 3 7 8 WSU4 Leakage Control Package 4 10 10 WSU5 Leakage Control Package 5 12 13 Water Efficiency Audits WSU6 9 9 (measured households Table 7.52: West Suffolk RZ AISC and AIC ranking based on calculation within WRP3a

7.10.13 Inter-dependencies, links and synergies The following inter-dependencies between options will be included in the optimisation model assessment,

• Options WS3 and WS5 are mutually exclusive as they both rly on the discharge from Bury St Edmunds Water Recycling Centre. • Options WS2a and WS2b are mutually exclusive as you would not construct both transfers. • Leakage control packages were inter-dependent.

The transfer options (WS2a, WS2b and WS6) are supplied by RZs in deficit by the end of the forecast therefore a new resource will be required in the donor RZs. WS1 is supplied by Newmarket RZ which only has a marginal surplus by the end of the forecast and a new transfer would be required into the donor RZ.

7.11 Ruthamford North Resource Zone

7.11.1 Unconstrained Options The table below contains the list of unconstrained options considered for Ruthamford North RZ. The unconstrained options workshop was held before the assessment of RZ integrity spilt many of the original RZs. Therefore more details about the reason for discounting an unconstrained option or why an option type was not considered for Ruthamford North RZ can be found in Appendix B in the Ruthamford RZ table.

Scheme Sub- Option Option is Categories/Sub- Option Description Ref Feasible Components Direct river Lower Welland Nene (Brackish) N abstraction New reservoir Manton Reservoir N storage (On-stream) Eyebrook/Cransley/Sywell reservoirs N New reservoir South Lincolnshire Reservoir See Table storage (Pumped- 7.55 storage) Reservoir intake - maximise refill N opportunities

WRMP Options Appraisal Report

New reservoir SUDS N storage (Flood storage) RHFA3 Rutland Water Y RHFA5 Pitsford reservoir Y Reservoir raising Eyebrook Reservoir N Ravensthorpe & Hollowell Reservoir N Infiltration galleries Upper Nene gravels N River Gravels - Brampton N Reclaimed domestic RHFA2 Peterborough water reuse Y wastewater Reclaimed industrial Industrial reclaimed water N and commercial wastewater Bulk transfers (by RHFA6 Grand Union (Pitsford/Grafham) Y canal) Resource Sharing RHFA4 Severn Trent system to Northampton N with other Thames Water N Water Companies (Trade) 3rd Party Options 3rd party trade options N (Trade) Improved/sophisticat Ruthamford conjunctive use N ed conjunctive management Table 7.53: Unconstrained options for Ruthamford North RZ

7.11.2 Additional options considered for Stage 2 economic modelling The table below contains details of an additional option considered for the economic modelling for the revised draft WRMP.

Option Reason for including in Stage 2 economic Option Name Ref modelling RHFA15 Reduce Ruthamford North RZ The revised draft supply demand balance raw water export confirmed that there is adequate surplus in Central Lincolnshire RZ so that the raw water export from Ruthamford North RZ could be reduced. Table 7.54: Additional options considered for Stage 2 economic modelling

7.11.3 Feasible options not progressed to Stage 2 The table below describes feasible options identified at the unconstrained options workshop which after further work were discounted and not taken through to Stage 2 – economic modelling.

7.11.4 Feasible Options Table 7.56 contains details of the feasible options considered for Ruthamford North RZ.

WRMP Options Appraisal Report

Capacity (Ml/d) Implementation Asset Plus Opt Ref Option Name Average Peak Min Period Solution ID Peterborough RHFA2 25 34 8 3 years S9732278 Reuse Rutland Dam RHFA3 16 20 5 15 years S9734660 Raising Pitsford Dam RHFA5 11 14 5 15 years S9734666 Raising RHFA6 Canal Transfer 40 50 10 4 years S9749022 Reduce Ruthamford Not estimated RHFA15 8 8 8 within 1 year North RZ raw in Asset plus water export Leakage Control RTN1 0.9 n/a n/a Package 1 Leakage Control RTN2 0.9 n/a n/a Package 2 Leakage Control Programme Not estimated RTN3 0.9 n/a n/a Package 3 delivered over within Asset Leakage Control AMP6 Plus RTN4 0.8 n/a n/a Package 4

Leakage Control RTN5 0.4 n/a n/a Package 5 Programme Enhanced RTN6 0.07 n/a n/a delivered over S10071112 Metering AMP6 Water Efficiency Audits - RTN7 1.45 n/a n/a measured household S10071045 Water Efficiency Audits Programme RTN8 0.26 n/a n/a unmeasured delivered over AMP household Water Efficiency Audits Extra- Not estimated RTN9 1.92 n/a n/a measured within Asset+ household Table 7.56: Ruthamford North RZ Feasible Options

7.11.5 Option RHFA2 Peterborough Water Reuse This option involves additional treatment at Peterborough WRC and transfer to the River Nene 2km upstream of the intake to the reservoir.

Peterborough WRC would require a sidestream Membrane Bioreactor (MBR) and RO (Reverse Osmosis). The product water will be oxygenated and the pH increased prior to pumping the water to River Nene. RO generates two streams - the product water which will be pumped to the River Nene and the concentrate which will be discharged at the existing WRC. The concentrate will have a salt concentration of 3000-5000 mg/l which will be diluted by the final effluent from the existing WRC.

The water will then pass through a Carbon Dioxide stripper where the water cascades down a forced draft packed tower which will reduce the concentration of Carbon Dioxide and subsequently reduce the required dose of sodium hydroxide to achieve a final pH. The additional benefit of the use of Carbon Dioxide stripper is that the water will be aerated prior to discharge.

WRMP Options Appraisal Report

The treated effluent will be pumped to the River Nene, upstream of the intake. The WTW will have to be expanded to treat the additional water. A schematic of the proposed project is shown below in Figure 7.15.

Identified Risks: • Cost Risk: There is limited space available to construct additional treatment at the WRC. Site layouts should be prepared to establish whether additional land should be purchased. Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Environmental Risk: The discharge and re-abstraction of re-used water into the River Nene would require approval from the Environment Agency.

Rutland Water

Peterborough WRC RO Concentrate discharge to the existing sewer

WTW Peterborough Water Reuse Works

Into supply River Nene

Key : (All proposed changes in red)

Existing Treatment Works Existing Pipe Intake Existing Sewer Treatment Works New Pipeline Outfall Existing WRC Bankside storage

Figure 7.15: Option schematic – RHFA2, Peterborough water reuse

7.11.6 Option RHFA3 Rutland dam raising This option involves a 10% increase in volume at Rutland Water by raising the dam, resulting in a 20 Ml/d rise in hydrological yield. Initial assessment shows that 10% increase in volume would require the dam to be raised by about 1m.

The option requires significant ancillary works including relocation of amenity facilities, buildings, footpaths and additional embankments to protect roads. The treatment works would also need to be expanded.

WRMP Options Appraisal Report

may result in storage below target curves for a prolonged period, putting the supply demand balance at risk in Ruthamford. • Modifications to existing structures more than anticipated such as the offtake system, bellmouth overflow and draw off tower which could increase costs. • The recently constructed lagoons at the upstream end of the reservoir may have to be modified, which could add significant costs. • There is a risk that licensing conditions changing either prior to or post raising of the dam mean that the full capacity of any increase in the volume of the reservoir cannot be utilised. • Planning permission costs and timescales are likely to be a significant risk and cost to any proposed raising. • Environmental permissions and mitigation costs and timescales are also likely to be a significant risk and cost. • Significant leisure facilities located around Rutland Water would be affected by the raising of the dam, adding to costs and the risk of stakeholder objections.

7.11.7 Option RHFA5 Pitsford Dam Raising This option involves increasing Pitsford Reservoir capacity by 50%, giving a 13.8 Ml/d rise in yield.

Costs have been based on increasing the capacity of Pitsford Reservoir by an asymmetric raising on the downstream side with an inclined extension to the core. A 3m rise in top water level would provide at least a 50% increase in storage capacity.

Identified risks • Design/construction risks which could have a significant impact on costs include damage to the existing dam during construction, additional loading leads to ground failure. • Lowering the water level during construction works to allow for the safe raising of the dam, could impact the operating regime of the reservoir. This would result in storage well below target curves for a prolonged period, putting the supply demand balance at risk in Ruthamford. • Modifications to existing structures more than anticipated such as the offtake system, overflow and draw off tower. • There is a risk that licensing conditions changing either prior to or post raising of the dam mean that the full capacity of any increase in the volume of the reservoir cannot be utilised. • Planning permission costs and timescales are likely to be a significant risk and cost to any proposed raising. • Environmental permissions and mitigation costs and timescales are also likely to be a significant risk and cost. • Significant leisure facilities located around Pitsford reservoir would be affected by the raising of the dam, adding to costs and the risk of stakeholder objections.

WRMP Options Appraisal Report

7.11.8 Option RHFA6 Canal transfer As part of the drought planning work an option was developed to transfer 50 Ml/d via the canal network to support Pitsford reservoir and WTW.

Anglian Water carried out a separate study ‘British Waterways Transfer to Pitsford Reservoir, Water Resources Assessment, AW Water Resources Team, July 2012’ looked at the possibility of the resource as a supply demand option. The report assesses the potential benefit of the transfer on the storage and yield of Pitsford reservoir. The report concludes that a 50Ml/d transfer would be used approximately 60 days a year when winter flows in the Nene, historically have dropped low enough for the transfer to be required. This would provide an increase in reservoir yield of 17.5Ml/d.

The option involves a transfer of 50 Ml/d direct from Severn Trent Water’s wastewater treatment works (WwTW) via the Coventry/Oxford and Grand Union canals to the reservoir intake. This is then transferred via existing infrastructure to Pitsford reservoir. Additional treatment capacity is required to treat the additional yield from the reservoir. Treatment to remove Metaldehyde (UV and peroxide dosing) will be required at both the existing works and the new treatment expansion. A 400mm diameter, 6km transfer into the treated water network is also required.

The canal transfer requires a number of pumping stations, adjustable weirs and siphons to overcome level differences along the canal system. Associated with a total of 8.5km of 600mm diameter new pipework is required.

Figure 7.16 below shows the schematic of the proposed option.

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Programme Risks: Detailed consultations with the Highways Agency, Environment Agency, Canal and River Trust and Local Authorities could have an impact on the project. • Water quality: There are potential high water quality risks with this scheme. These are planned to be evaluated as part of the WREA. River Trent

New PS

WwTW

Canal Existing WTW Into supply

reservoir New WTW To existing service intake reservoir

New River Nene PS

Figure 7.16: Option schematic – RHFA6, Canal Transfer

WRMP Options Appraisal Report

7.11.9 Option RHFA15 Reduce Ruthamford North RZ raw water export The existing raw water transfer to Central Lincolnshire RZ could be reduced and utilised within Ruthamford North RZ.

The existing 15Ml/d raw water transfer from Rutland Water to Grantham. This would be reduced to 7 Ml/d leaving and an additional 8Ml/d at Rutland which could be treated at the existing WTW.

The 8 Ml/d reduction at Grantham would be off set by the output from the new Lincoln WTW. The treated water from Lincoln WTW will be transferred towards the Grantham area by a transfer scheme being implemented as part of the drought mitigation work. Both the transfer and the Lincoln WTW will be completed and operational by the end of AMP5.

There are only operational costs associated with this scheme. For the purpose of modelling the additional operational costs with treating an extra 8Ml/d at the existing WTWs have been included.

7.11.10 Environmental considerations The conclusions of the environmental assessments described in sections 4.6, 4.7 and 6 are summarised below. • No specific issues were identified as part of the BAG assessment other than those common to all options. • The climate change vulnerability assessment concludes that the canal transfer (RHFA6) and water reuse (RHFA2) options are not sensitive to climate change. The assessment scored both options as 1 – insensitive. The reservoir options (RHFA3, RHFA5) are scored 3 – sensitive in relation to water abstraction, available flow and environmental flow requirements. The reduction in raw water export (RHFA15) is rated 2 –limited sensitivity but the donor RZ is vulnerable to climate change. • The WFD no-deteriorations assessment, SEA and HRA concluded; • RHFA2 Peterborough water reuse -The preliminary environmental investigations have not flagged up any significant issues with flow or quality to the River Nene or the Counter Drain associated with this reuse scheme. The HRA screening identified the potential need for an Appropriate Assessment and requirement to re-route the pipeline. • RHFA3 Rutland dam raising -Further WFD investigation will be required to demonstrate that an increase to abstraction will not affect water quality in the River Nene and River Welland. Further investigation will be required to demonstrate that the increase in water levels at Rutland Water will not affect the biological elements or water quality in the waterbody. The HRA screening has identified the need for an Appropriate Assessment if taken forward due to potential likely significant effect on Rutland Water SPA. The SEAS has also identified the need to investigate potential impacts on the Scheduled Monument on site. • RHFA5 Pitsford dam raising -Further WFD investigation will be required to demonstrate that an increase to abstraction will not affect water quality in the River Nene. Further investigation will be required to demonstrate that the increase in water levels at Pitsford reservoir will not affect the biological elements or water quality in the waterbody. The SEA has not highlighted any other concerns. • RHFA6 Canal transfer -The HRA screening and SEA has identified the need to re-route the pipeline to avoid SSSI’s and local nature reserves. No

WRMP Options Appraisal Report

other significant negative effects have been identified. A WFD assessment would need to be completed to review any potential impacts at source. • RHFA15 Reduce Ruthamford North RZ raw water export -No environmental concerns identified with this option.

7.11.11 Costs WRMP table WRP3a contains the details of the capex, opex, environmental and social costs, these are summarised in the table below.

Environmental & Social Costs Average Opt Capex Opex (Including carbon) Option Name capacity Ref (£k) (£k/yr) Fixed Costs Variable (Ml/d) (£k) (£k/yr) Peterborough RHFA2 20 103,500 4,400 9 350 water reuse Rutland Dam RHFA3 16 107,800 400 499 27 Raising Pitsford Dam RHFA5 11 58,900 430 186 27 Raising RHFA6 Canal Transfer 13 73,100 1,470 6 103 Reduce RHFA1 Ruthamford 8 0 160 0 12 5 North RZ raw water export Table 7.57: Costs of Ruthamford North RZ supply-side feasible options

The options have been ranked based on the Average Incremental Costs (AIC) and Average Incremental Social Cost (AISC) calculated in WRMP table WRP3a, these are shown in Table 7.58. The options have been raked in ascending AIC/AISC i.e. the option ranked 1 has the lowest AIC/AISC.

Opt Option Name AIC Ranking AISC Ranking Ref RHFA2 Peterborough Reuse 12 12 RHFA3 Rutland Dam Raising 9 9 RHFA5 Pitsford Dam Raising 11 11 RHFA6 Canal Transfer 10 10 Reduce Ruthamford North RZ RHFA15 1 1 raw water export RTN1 Leakage Control Package 1 2 2 RTN2 Leakage Control Package 2 6 6 RTN3 Leakage Control Package 3 7 7 RTN4 Leakage Control Package 4 8 8 RTN5 Leakage Control Package 5 13 13 RTN6 Enhanced Metering 3 3 Water Efficiency Audits – RTN7 5 5 measured households Water Efficiency Audits – RTN8 14 14 unmeasured households Water efficiency extra – RTN9 4 4 measured household Table 7.58: Ruthamford North RZ AISC and AIC ranking based on calculation within WRP3a

WRMP Options Appraisal Report

7.11.12 Inter-dependencies, links and synergies The following inter-dependencies between options have been included in the optimisation model assessment,

• Leakage control packages were inter-dependent.

The canal transfer option is dependent on resources being available at Severn Trent Water’s wastewater treatment works to transfer.

7.12 Ruthamford South Resource Zone

7.12.1 Unconstrained Options The table below contains the list of unconstrained options considered for Ruthamford South RZ. The unconstrained options workshop was held before the assessment of RZ integrity spilt many of the original RZs. Therefore more details about the reason for discounting an unconstrained option or why an option type was not considered for Ruthamford South RZ can be found in Appendix B in the Ruthamford RZ table.

Scheme Sub- Option Option is Categories/Sub- Option Description Ref Feasible Components Direct river RHFP4 River Ouse direct intake (peak only) Y abstraction New reservoir RHFA8 Additional Grafham site Y storage (On-stream) New reservoir South Lincolnshire Reservoir See Table storage (Pumped- 7.60 storage) Foxcote reservoir extension N RHFA9 Maximise refill opportunity for all other See Table reservoirs 7.60 New reservoir SUDS N storage (Flood storage) Reservoir raising RHFA7 Grafham Water Y Foxcote Reservoir N Groundwater RHFA10 Pulloxhill See Table sources 7.60 Maximising licences (Oolite/Woburn N sands) Clapham groundwater sources N Infiltration galleries Upper Nene gravels N Houghton N Clapham infiltration system N River Gravels - Brampton N Artificial Storage Greensand ASR N and Recovery Aquifer Recharge MAR/SUDS - Greensand - Leighton N Buzzard MAR/SUDS - Greensand - Ampthill/Flitwick N

WRMP Options Appraisal Report

MAR/SUDS - Greensand - Shefford N MAR/SUDS - Greensand - Biggleswade N Reclaimed domestic RHFA14 Huntingdon WRC Y wastewater Reclaimed industrial Industrial reclaimed water N and commercial wastewater RHFA1, Mains reinforcements that improve LoS Y RHFA13, RHFP1, Bulk transfers (by RHFP2, pipeline) RHFP3, RHFP6, RHFP8 Resource Sharing RHFA12 Affinity (trading Great Ouse Water Act) N with other Cambridge Water- to St Ives/Huntingdon N Water Companies Thames Water N (Trade) 3rd Party Options 3rd party trade options N (Trade) Improved/sophistica ASR N ted conjunctive Ruthamford conjunctive use N management Great Ouse Water Act (GOWA) operating N rules - review

Other RHFA11 Recommission Ruthamford South RZ Y reservoir Table 7.59: Unconstrained options for Ruthamford South RZ

7.12.2 Feasible options not progressed to Stage 2 The table below describes feasible options identified at the unconstrained options workshop which after further work were discounted and not taken through to Stage 2 – economic modelling.

Option Option Name Reason for discounting Ref South Lincolnshire Reservoir A feasible option but not taken through to Stage 2 as would need to be developed as part of long term strategy and should be considered in the WREA. RHFA9 Maximise refill opportunity for This option was not presented in the draft all other reservoirs WRMP. It was discounted before the publication of the draft as it was assumed that the work required to restore the intake will be carried out as asset maintenance. Therefore the baseline DO was calculated assuming the intake had been refurbished and the option discounted. RHFA10 Pulloxhill Assumed to be delivered in AMP5 and included in the baseline supply forecast. Therefore no longer an option. Table 7.60 Ruthamford South RZ feasible options not progressed to Stage 2

WRMP Options Appraisal Report

7.12.3 Feasible options discounted after draft WRMP A number of options proposed in the draft WRMP have been discounted. Table 7.61 describes the reason for this.

Option Option Name Reason for discounting Ref RHFP1 RHF North Transfer 3 The original option set for Ruthamford was developed using an early version of the supply demand balance which showed a peak deficit greater than the average deficit. Therefore a set of peak specific options were developed (denoted RHFP1, P2 etc). However the final supply demand balance used for the draft WRMP and the revised draft WRMP shows a smaller peak deficit than at average. Therefore the option set developed for average are adequate to satisfy the peak deficits and the peak specific options have been discounted. RHFP2 RHF North Transfer 4 See above.

RHFP3 RHF North Transfer 5 See above.

RHFP4 River Ouse direct intake See above. (peak only) RHFP5 Ruthamford North RZ See above. transfer Table 7.61: Ruthamford South RZ draft WRMP feasible options discounted

7.12.4 Feasible options Table 7.62 contains details of the feasible options considered for Ruthamford South RZ.

Opt Capacity (Ml/d) Implementation Asset Plus Option Name Ref Average Peak Min Period Solution ID Ruthamford North RZ RHFA1 24 24 7.2 4 years S9734561 transfer 1 (24Ml/d) Grafham Dam RHFA7 40 50 10 15 years S9734661 Raising New Ruthamford RHFA8 26 33 7 15 years S9734672 South RZ reservoir Recommission Ruthamford RHFA11 9 12.5 5 3 years S10071359 South RZ reservoir Ruthamford North RZ RHFA13 39 39 12 4 years S9734562 transfer 2 (39Ml/d) Huntingdon RHFA14 5.4 5.4 3 3 years S9732302 water reuse Leakage Control Programme RTS1 1.8 n/a n/a Package 1 delivered over AMP Not estimated Leakage Control within Asset RTS2 1.8 n/a n/a Package 2 Plus Leakage Control RTS3 1.8 n/a n/a Package 3

WRMP Options Appraisal Report

Leakage Control RTS4 1.8 n/a n/a Package 4 Leakage Control RTS5 0.5 n/a n/a Package 5 Enhanced Programme S10071112 RTS6 1.17 n/a n/a Metering delivered over AMP RTS7 Water efficiency 1.32 n/a n/a Programme S10071045 – measured delivered over AMP household RTS8 Water efficiency 0.21 n/a n/a – unmeasured household Water efficiency extra – Not estimated RTS9 1.92 n/a n/a measured within Asset+ household Table 7.62 Ruthamford South RZ Feasible Options

7.12.5 Option RHA1 Ruthamford North RZ Transfer 1 This option involves utilising the surplus in Ruthamford North RZ available at average.

This option involves the construction of a 900mm diameter pumping main approximately 21 km. Most of the pipeline route is across fields. There are a number of road crossings and river crossings along the route which are assumed to require directional drilling.

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme. • Programme Risks: Detailed consultation with the Highways Agency, Environment Agency and Local Authorities could have an impact on the project. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.12.6 Option RHFA7 Grafham Dam Raising This option involves increasing the reservoir volume at Grafham Water by 50% which would result in a yield increase of 50 Ml/d. The increase of the reservoir volume remains within the licence for refill and for abstraction.

The dam would need to be raised by 3m or more and to achieve the 50 % increase. The option proposed is an asymmetrical raising of the dam with both the upstream slope of the dam extended and the downstream slope of the dam steepened with the impermeable core of the dam also being raised.

The treatment works would also need to be expanded.

WRMP Options Appraisal Report

may result in storage well below target curves for a prolonged period, putting the supply demand balance at risk in Ruthamford. This would also impact on Affinity Water’s entitlement under the Great Ouse Water Act. • Modifications to existing structures more than anticipated such as the offtake system, overflow and draw off tower. • There is a risk that licensing conditions changing either prior to or post raising of the dam mean that the full capacity of any increase in the volume of the reservoir cannot be utilised. • Planning permission costs and timescales are likely to be a significant risk and cost to any proposed raising. • Environmental permissions and mitigation costs and timescales are also likely to be a significant risk and cost. • Significant leisure facilities located around Grafham Water would be affected by the raising of the dam, adding to costs and the risk of stakeholder objections.

7.12.7 Option RHFA8 Ruthamford South New Reservoir This option proposes the construction of a new reservoir close to Grafham water.

A study was undertaken to identify potential new reservoir sites which can be supplied from the existing intake or which can be supplied from Grafham Water. The area of search has concentrated on sites within 10 km of the intake or Grafham Water.

High level assessment of topography and geology have both been considered in determining suitable sites. Although the topography of the area is not particularly favourable (inevitably the best site is occupied by Grafham Water) the geology appears reasonable.

The option would require an expansion of Grafham WTW.

Identified Risks • Substantial delay through the planning and consent process, and possibly refusal of permission. • Unforeseen geological conditions, increasing construction costs. • Changes to the abstraction licence from the River Great Ouse. • Substantial increase in energy costs. • Objections to flooding / demolition of properties, particularly where there is heritage interest. • The Catchment Abstraction Management Strategy (CAMS) process does not identify adequate resource availability.

7.12.8 Option RHFA11 Recommission Ruthamford South RZ reservoir This option requires a new water treatment works to be constructed to treat the yield from the existing licenced Foxcote reservoir. The original water treatment works was decommissioned in the 1990s. The scope of works to recommission the treatment works includes,

• Micro strainers • Coagulation • ultra filtration membranes • UV/peroxide dosing for removal of Metaldehyde • GAC • UV disinfection • Washwater treatment

WRMP Options Appraisal Report

A recent study has investigated the potential environmental impacts of operating the reservoir and fluctuating levels. This concluded that mitigation measures would be required to protect habitat within the reservoir. These measures have been included in the capex estimate.

Identified risks: • Cost risks: The construction of the new water treatments works is on the site of the old works. There are risks of additional demolition required, contaminated ground discovered and condition of existing assets to be reused worse than anticipated. All of these could impact on the capex, opex and the programme. • Programme risk: Programme Risks: Detailed consultation with the Environment Agency and Natural England could have an impact on the project.

7.12.9 Option RHFA13 Ruthamford North RZ transfer 2 (39Ml/d) This option is similar to option RHFA1 but provides a larger capacity transfer and requires an additional 21 km of pipeline to boost supplies in the Milton Keynes area. If it were selected by the optimiser model it may also select a new resource in Ruthamford North RZ to support this transfer.

The transfer involves the construction of a 1200mm diameter pumping main with a total distance of approximately 21 km and 10km of 600mm diameter pumping main.

Much of the pipeline route is across fields. There are a number of road crossings and river crossings along the route which are assumed to require directional drilling.

Identified Risks: • Cost Risks: Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme • Programme Risks: Detailed consultations with the Highways Agency, Environment Agency and Local Authorities could have an impact on the project. • Resource Availability Risks: Successful delivery of transfer schemes will be conditional of approval from the Environment Agency and Natural England in respect to the Water Framework Directive (WFD) no-deterioration assessment, see Environmental considerations section below.

7.12.10 Option RHFA14 Huntington Water Reuse This option proposes additional treatment at Huntingdon WRC and transfer of effluent to feed the existing WTW.

At Huntingdon WRC a sidestream Membrane Bioreactor (MBR) and Reverse Osmosis (RO) would be required. The product water will be oxygenated and the pH increased prior to pumping to WTW, which would have to be expanded to treat the additional water.

The RO process will generate two streams – the product water which will be pumped to the reservoir and the concentrate which will be discharged from Huntingdon WRC into the River Great Ouse.

A schematic of the proposed project is shown below in Figure 7.41.

WRMP Options Appraisal Report

Identified Risks: • Cost Risk: It would appear that there is insufficient space at the existing Huntingdon WRC to build the new treatment works. Site layouts should be prepared after verifying the space requirements and it should be established whether additional land should be purchased. Any modifications to the pipeline route could have an impact on both capex and opex costs and the programme • Public Relations Risk: Whilst indirect potable water reuse has been widely practised in South East England over many years, this scheme would differ as it would deliberately reuse the effluent. Consequently public perception issues must be carefully managed to minimise objections.

River Great Ouse (All proposed changes in red)

Existing Treatment Works Existing RO Concentrate sewer discharge Treatment Works

Existing Water Recycling Centre Existing Pipe 15km Huntingdon Huntingdon Existing Sewer Water Reuse WRC Works New Pipeline Asset not operated

WTW Intake Extension

Into Supply WTW Figure 7.41 Option schematic – RHFA14, Huntingdon water reuse

7.12.11 Environmental considerations The conclusions of the environmental assessments described in sections 4.6, 4.7 and 6 are summarised below. • No specific issues were identified as part of the BAG assessment other than those common to all options. • The climate change vulnerability assessment concludes that both transfer options (RHFA1, RHFA13) are not sensitive to climate change but the donor RZs are vulnerable to climate change. The assessment scored both options as 2 – limited sensitivity. The reservoir options (RHFA7, RHFA8, RHFA11) are scored 3 – sensitive in relation to water abstraction, available flow and environmental flow requirements. The reuse scheme (RHFA14) is rated 1 or 2 (insensitive or limited sensitivity). • The WFD no-deteriorations assessment, SEA and HRA concluded; • RHFA1 Ruthamford North RZ transfer 1 (24 Ml/d) -The HRA screening concluded no adverse effect on site integrity for the Upper Nene Valley Gravel Pits SPA with appropriate mitigation. The SEA concluded no significant negative effects apart from potential climate change impacts due to increase CO2 output. The existing wildlife lagoons were created as mitigation to enable the abstraction licence at Rutland Water to be maximised.

WRMP Options Appraisal Report

• RHFA7 Grafham dam raising -Further WFD investigation will be required to demonstrate that an increase to abstraction will not affect water quality in the River Great Ouse. Further investigation will be required to demonstrate that the increase in water levels at Grafham Water will not affect the biological elements or water quality in the waterbody. Significant negative effects associated with CO2 output have been identified, but the SEA has not highlighted any other concerns. • RHFA8 New Ruthamford South RZ reservoir - The SEA and HRA screening has highlighted the need to re-route the pipeline to avoid a SSSI but no other significant issues. The WFD screening identified a low risk of deterioration which would need to be investigated further if the scheme were taken forward. • RHFA11 Recommission Ruthamford South RZ reservoir -A detailed WFD no deterioration assessment has been completed for this option to recommission the Foxcote reservoir. No specific issues were identified for the River Ouse, but there are water quality risks for the reservoir which will require mitigation measures. No other significant negative effects predicted in the SEA. • RHFA13 Ruthamford North RZ transfer 2 (39 Ml/d) -In addition to the issues highlighted with RHFA1, the SEA has identified a requirement to re-route the pipeline to avoid a scheduled monument. • RHFA14 Huntingdon water reuse -The HRA screening and SEA has concluded that, if taken forward, this option would require an Appropriate Assessment due to a likely significant effect at Portholme SAC. The pipeline would need to be re-routed to avoid a SSSI. It is assumed that relevant discharge consents and treatment would have a benefit in term so of water quality. No WFD deterioration issue shave been identified.

7.12.12 Costs WRMP table WRP3a contains the details of the capex, opex, environmental and social costs, these are summarised in the table below.

Environmental & Social Costs Average Opt. Option Capex Opex (Including carbon) capacity Ref Name (£k) (£k/yr) Fixed (Ml/d) Variable Costs (£k) (£k/yr) Ruthamford North RZ RHFA1 24 30,400 320 5 27 Transfer 1 (24Ml/d) Grafham dam RHFA7 40 92,900 680 759 51 raising New Ruthamford RHFA8 26 274,500 930 684 495 South Reservoir Recommission Ruthamford RHFA11 9 19,800 520 2 32 South RZ reservoir Ruthamford RHFA13 North RZ 39 75,300 640 11 53 Transfer 2

WRMP Options Appraisal Report

(39Ml/d)

Huntingdon RHFA14 5.4 41,000 670 3 57 water reuse Table 7.63: Costs of Ruthamford South RZ supply-side feasible options

The options have been ranked based on the Average Incremental Costs (AIC) and Average Incremental Social Cost (AISC) calculated in WRMP table WRP3a, these are shown in Table 7.64. The options have been raked in ascending AIC/AISC i.e. the option ranked 1 has the lowest AIC/AISC.

Opt Ref Option Name AIC Ranking AISC Ranking Ruthamford North RZ transfer RHFA1 3 2 1 (24Ml/d) RHFA7 Grafham Dam Raising 10 10 New Ruthamford South RZ RHFA8 15 14 reservoir Recommission Ruthamford RHFA11 11 11 South RZ reservoir Ruthamford North RZ transfer RHFA13 5 5 2 (39Ml/d) RHFA14 Huntingdon water reuse 14 13 RTS1 Leakage Control Package 1 1 1 RTS2 Leakage Control Package 2 2 3 RTS3 Leakage Control Package 3 4 4 RTS4 Leakage Control Package 4 9 9 RTS5 Leakage Control Package 5 13 15 RTS6 Enhanced Metering 7 7 Water efficiency – measured RTS7 8 8 household Water efficiency – RTS8 12 12 unmeasured household Water efficiency extra – RTS9 6 6 measured household Table 7.64: Ruthamford South RZ AISC and AIC ranking based on calculation within WRP3a

7.12.13 Inter-dependencies, links and synergies The following inter-dependencies between options have been included in the optimisation model assessment,

• Reservoir options RHFA7 and RHFA8 are mutually exclusive • Transfer options RHFA1 and RHFA13 are mutually exclusive • Leakage control packages were inter-dependent.

WRMP Options Appraisal Report

8 Stage 4 - Preferred Options The optimiser model has been run to determine the least cost solution, see section 5.

To develop the preferred plan a number of ‘do the right thing’ options have been included. Cost benefit modelling, supported by customer willingness to pay (see section 4.5) led to leakage options and demand management options being included in the baseline supply forecast and the model run to determine the preferred plan.

The option set has been developed iteratively in conjunction with work on the SEA and HRA process, see section 6 and therefore the SEA and HRA do not alter the preferred plan.

Appendix J contains the preferred option set, including the output from the optimiser model. This shows when options are required to start.

The WRPG requires an assessment of the feasible options to deliver better value water than that provided by the existing assets in order to minimise total costs (i.e. do any of the schemes proposed provide opex savings when compared to the existing assets). Table 8.1 shows the preferred option types and describes the impact on overall opex when compared with costs associated with operating existing asset.

Comparison of opex with existing Option Type assets. The opex considered for the transfer schemes in the optimisation is just for the Transfer transfer itself, based on utilisation. Water will be treated by existing works; therefore there will be no overall savings. Water reuse requires more expensive treatment when compared to existing traditional treatment works. Also requires Water Reuse long transfers. Therefore no opex saving of operating water reuse scheme in preference to existing assets. Table 8.1: Comparison of preferred options opex with existing assets.

The other option selected is the trading option – Ardleigh Agreement. This requires the transfer of operational costs from Affinity Water to Anglian Water. There is no opportunity to operate other existing sources in preference as these would be operating at their maximum deployable output. Therefore there will be no overall opex saving.

9 Testing the Preferred plan To ensure that the preferred plan is a robust, adaptable plan for maintaining the security of supply, the feasible option set have been tested in a number of different scenarios. These included:

• Plan B – removal of the preferred options. This tests whether the plan is flexible to adapt to failure to deliver one or more of the preferred options • Worst case climate change impacts on water available for use

WRMP Options Appraisal Report

• Worst case sustainability reduction scenario includes all of the NEP Phase III unknown sustainability changes and reductions • Worst case high population growth scenario based on projections provided by Edge Analytics which in particular look at worst case high migration • Recent actuals scenario in which the deployable output is capped at recent actual levels of abstraction.

Each of these scenarios test whether a combination of the preferred options and the other feasible options can mitigate supply-demand risk of the 25-years to 2040. The plan was also tested against a worst case combination of the climate change, sustainability reduction, population growth and recent actual abstraction scenarios. Appendix K contains details of the options selected under each scenario for each water resource zone.