Cambridge Waste Water Treatment Plant Relocation Stage 2 - Coarse Screening Report 1 July 2020 Page intentionally blank for pagination when printed Mott MacDonald 22 Station Road Cambridge CB1 2JD United Kingdom T +44 (0)1223 463500 mottmac.com Anglian Water Services Ltd Lancaster House Ermine Business Park Cambridge Waste Water Lancaster Way Huntingdon Treatment Plant Relocation PE29 6XU Stage 2 - Coarse Screening Report 1 July 2020 Mott MacDonald Limited. Registered in England and Wales no. 1243967. Registered office: Mott MacDonald House, 8-10 Sydenham Road, Croydon CR0 2EE, United Kingdom Page intentionally blank for pagination when printed Mott MacDonald | Cambridge Waste Water Treatment Plant Relocation Stage 2 - Coarse Screening Report Document reference: 409071 | 03 | C.4 Information class: Standard This document is issued for the party which commissioned it and for specific purposes connected with the above- captioned project only. It should not be relied upon by any other party or used for any other purpose. We accept no responsibility for the consequences of this document being relied upon by any other party, or being used for any other purpose, or containing any error or omission which is due to an error or omission in data supplied to us by other parties. This document contains confidential information and proprietary intellectual property. It should not be shown to other parties without consent from us and from the party which commissioned it. This r epo rt h as b een pre par ed s olely fo r us e by the par ty which co mmissio ned i t (t he ‘Clien t’) in conn ectio n with t he c aptio ned pr oject. I t sho uld not b e us ed f or a ny o the r pu rpos e. No pe rson oth er t han the Clie nt o r a ny pa rty w ho h as ex pres sly ag ree d te rms of r elianc e with us (t he ‘Re cipien t(s)’ ) m ay r ely on the cont ent, i nfo rma tion or a ny views exp resse d in t he rep ort. W e acc ept no d uty o f ca re, resp onsibility or lia bility to any oth er recipie nt of this docu men t. T his r epo rt is c onfid ential and cont ains p rop riet ary in tellect ual p rop erty . 409071 | 03 | C.4 | | 1 July 2020 Mott MacDonald | Cambridge Waste Water Treatment Plant Relocation Stage 2 - Coarse Screening Report Contents Executive summary 1 1 Introduction 3 2 Stage 2 – Coarse Screening criteria 5 2.1 Red Amber Green (RAG) Assessment 5 2.2 Shape of Site Area 6 2.3 Ease of site access during construction and operation 7 2.4 Waste water transfer infrastructure 8 2.5 Contaminated land 11 2.6 Groundwater 12 2.7 Surface water 12 2.8 Nature conservation and biodiversity (including locally designated nature sites) 13 2.9 Historic environment 14 2.10 Landscape and visual amenity 15 2.11 Agricultural Land Classification 17 2.12 Development constraints 17 2.13 Impacts on local communities 19 3 Stage 2 – Coarse Screening results 21 3.1 RAG assessments 21 3.2 Discussion of results 23 4 Conclusion and Next Steps 29 4.1 Conclusions 29 4.2 Next Steps 29 5 References 30 Appendices 31 A. Drawings 32 B. RAG assessments 33 B.1 Shape of land parcel 33 B.2 Ease of site access during construction and operation 34 B.4 Waste water transfer infrastructure 35 B.5 Contaminated Land 36 B.6 Groundwater 37 409071 | 03 | C.4 | | 1 July 2020 Mott MacDonald | Cambridge Waste Water Treatment Plant Relocation Stage 2 - Coarse Screening Report B.8 Surface Water 38 B.9 Nature Conservation and Biodiversity 39 B.10 Historic Environment 49 B.11 Landscape and Visual Amenity 50 Agricultural Land Classification 52 B.12 Development constraints 53 B.13 Impacts on local communities 54 Tables Table 2.1: Assessment Criteria Adopted at Stage 2 6 Table 2.2: Definitions for establishing heritage value 14 Table 3.1: RAG assessment summary 22 Table 3.2: Rejection Register 26 Table 3.3: Shortlist of site areas 28 Figures Figure 1.1: Longlisted site areas 4 409071 | 03 | C.4 | | 1 July 2020 Mott MacDonald | Cambridge Waste Water Treatment Plant Relocation 1 Stage 2 - Coarse Screening Report Executive summary S.1. A site selection process, comprising a number of detailed appraisal steps was developed to identify sites that may be suitable for the relocation of the waste water treatment plant to replace the existing Cambridge WWTP. S.2. The first step was an Initial Options Appraisal, which examined the strategic issues to be considered in investigating relocation options, and also identified the most appropriate area in which to search for new WWTP sites (the Study Area). S.3. The Initial Options Appraisal concluded that the preferred solution for the relocation of the Cambridge WWTP would comprise a single new WWTP, within a Study Area covering the existing Cambridge and Waterbeach drainage catchment areas. S.4. The next step in the process was Stage 1 – Initial Site Selection, which comprised mapping constraints within the Study Area to identify a longlist of potential site areas to be taken forward for further site selection. The initial site selection identified 14 potential areas that could be utilised for the relocation of Cambridge WWTP based on the baseline constraints. S.5. After the initial site selection stage, Stage 2 – Coarse Screening of the longlist of site areas is required to identify a shortlist of the best performing site areas, which would then be taken forward for further screening. This stage is the subject of this report. S.6. The objective of the Stage 2 coarse screening was to identify preferred site areas based on their cumulative performance against a range of criteria. Each site area was evaluated against 16 criteria using a red, amber and green (RAG) assessment which highlighted the potential significance of the different assessment criteria for each site area. The results for each site area were compared with one another on a qualitative basis to identify the best performing site areas to be included in the shortlist. S.7. The following conclusions have been drawn from this study. ● Although the results have been reviewed holistically, certain criteria were considered to be of greater importance in the context of the WWTP relocation. In order of importance these were: – Impacts on local communities – Shape of land parcel and construction complexity – Green Belt policy and site allocation – Carbon emissions ● Where, based on the RAG assessment and option comparison, site areas were clearly disadvantaged, compared with the other site areas, these were removed from further assessment. Site areas D, E, F, G, K, M and N were removed on this basis. ● The remaining seven site areas fell into two distinct groups: – Site areas A, B and C – Site areas that are outside of the Green Belt and have higher tunnelling impacts and risk (due to longer tunnels and greater impact on the Lower Greensand aquifer). – Site areas H, I, J and L – Site areas that are within the Green Belt and have lower tunnelling impacts and risk (due to shorter tunnels and reduced impact on the Lower Greensand and Grey Chalk aquifers). 409071 | 03 | C.4 | | 1 July 2020 Mott MacDonald | Cambridge Waste Water Treatment Plant Relocation 2 Stage 2 - Coarse Screening Report ● It was not considered possible to differentiate between the two groups, to remove one or the other from further assessment at this stage of the site selection process. It was also not possible to differentiate between the individual site areas within the groups at this stage. ● Development within Green Belt may be acceptable if certain ‘very special circumstances’ exist including, for example, there being no feasible alternatives. Therefore, further investigation is needed to confirm whether site areas outside of the Green Belt are feasible or not. S.8. The seven shortlisted site areas should be taken forward to Stage 3 – Fine Screening, in order to differentiate between the site areas and identify those that are considered to be more suitable. The fine screening stage would include the following assessments: ● Development of the waste water transfer infrastructure requirements for each of the shortlisted site areas ● Cost and carbon emissions estimates for development of a WWTP at each shortlisted site area including tunnelling, and ● Further assessment of the planning and environmental constraints at each of the site areas and whether they can be mitigated. 409071 | 03 | C.4 | | 1 July 2020 Mott MacDonald | Cambridge Waste Water Treatment Plant Relocation 3 Stage 2 - Coarse Screening Report 1 Introduction This section provides an introduction to Stage 2 – Coarse Screening (this report).Background 1.1.1 A site selection process, comprising a number of detailed appraisal steps was developed to identify sites that may be suitable for the relocation of the waste water treatment plant to replace the existing Cambridge WWTP. 1.1.2 The first step was an Initial Options Appraisal, which examined the strategic issues to be considered in investigating relocation options, and also identified the most appropriate area in which to search for new WWTP sites (the Study Area). 1.1.1 The Initial Options Appraisal concluded that the preferred solution for the relocation of the Cambridge WWTP would comprise a single new WWTP, within a Study Area covering the existing Cambridge and Waterbeach drainage catchment areas (Mott MacDonald Ltd, Cambridge Waste Water Treatment Plant Relocation - Initial Options Appraisal, 2020a). 1.1.2 The next step in the process was Stage 1 – Initial Site Selection, which comprised mapping constraints within the Study Area to identify a longlist of potential site areas to be taken forward for further site selection.