Wholebake Facility, Corwen

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1 December 2016 Waterco Ltd, Eden Court, Lon Parcwr Business Park, Ruthin, Denbighshire LL15 1NJ Tel: Web: w

2 DOCUMENT VERIFICATION RECORD CLIENT: SCHEME: INSTRUCTION: Wholebake Ltd Proposed industrial development at Ty n y Llidiart, Corwen Infiltration Test Report The instruction to carry out this report and associated infiltration testing was received from Justin Paul of J10 Planning Ltd acting on behalf of the client. DOCUMENT REVIEW & APPROVAL AUTHOR: CHECKER: APPROVER: Johanne Williams LLB (Hons) PgDip Aled Williams BSc (Hons) Victoria Griffin BSc (Hons), MSc, MIEnvSc, CEnv ISSUE HISTORY ISSUE DATE COMMENTS 13/12/2016 First issue w

3 Contents Introduction... 1 Methodology... 2 Test Results... 5 Conclusions... 7 Tables Table 1 Trial Pit Dimensions... 2 Table 2 Trial Pit 25% - 75% Effective Depth:... 5 Table 3 V p75 25 and a p50 Values... 5 Table 4 t p75 25 values... 6 Table 5 Infiltration rate... 6 Figures Figure 1 Infiltration Test Drainage Times... 6 Appendices Appendix A Location Plan & Aerial Image Appendix B Trial Pit Location Plan w

4 Introduction Waterco Consultants have been commissioned to undertake infiltration testing in pre-constructed trial pits to determine the viability of soakaways for a proposed commercial development at Ty n y Llidiart Industrial Estate, Corwen. A site location plan and aerial image are included in Appendix A. The construction of the infiltration trial pits was undertaken by others (Groundsolve Ltd), under the instruction of the Client s representative (J10 Planning Ltd). This report should be read in conjunction with the following reports; Groundsolve Ltd, Geo-environmental Report ( GEO-ENV REPORT ISSUE-mjs), dated November 2016 Waterco Ltd, FCA and Drainage Strategy, (not yet issued) The development is for the proposed erection of a food manufacturing factory with integrated warehousing and office facilities (Class B2 13,240 sqm), an ancillary employee wellbeing unit (Class D1 600 sqm); with 166 no. vehicle (including mobility spaces) and 30 no. cycle parking provision, means of vehicular access, servicing, bin storage, plant, electricity sub-station and associated landscaping provision. Ground Conditions Reference to the British Geological Survey online mapping (1:50,000 scale) indicates that the site is underlain by superficial Glacio-fluvial deposits generally comprising sand and gravel. The superficial deposits are identified as being underlain by the Elwy Formation which comprises of conglomerates, sandstone, siltstones and mudstones. Weather Conditions Waterco Consultants carried out infiltration tests on 21 st October The weather conditions on the day were overcast, having rained the previous night. w

The approximate trial pit locations are shown on the Infiltration Test Positions plan (provided by GroundSolve Ltd) in Appendix B.

5 Methodology The infiltration tests were carried out by Waterco Consultants in accordance with the BRE 365 specification. The infiltration tests were undertaken at four trial pits spread across the site. The approximate trial pit locations are shown on the Infiltration Test Positions plan (provided by GroundSolve Ltd) in Appendix B. The approximate trial pit dimensions are included in Table 1 below: Table 1 Trial Pit Dimensions Trial Pit Length (m) Width (m) Depth (m) Photographs of the trial pits are included below and overleaf; Photographs 1 and 2 Trial Pit 1 w

6 Photographs 3 and 4 Trial Pit 2 Photographs 5 and 6 Trial Pit 3 w

The trial pits were filled with stone, resulting in a 40% void ratio.

7 Photographs 7 and 8 Trial Pit 4 The excavated material is consistent with the superficial deposits identified by BGS mapping. A tanker, with an approximate capacity of 1600 gallons provided a source of water for the tests. The trial pits were filled with stone, resulting in a 40% void ratio. The test procedure was repeated three times in trial pits 2, 3 and 4 to replicate soil moisture conditions typical of the site when the soakaways become operative. However, trial pit 1 was abandoned after 6 hours as it had not emptied in that time. w

8 Test Results The infiltration rates have been calculated in accordance with the BRE 365 guidance; Soil infiltration rate, f = V p75 25 a p50 x t p75-25 whereby: V p75 25 = the effective storage volume of water in the trial pit between 75% and 25% effective depth; a p50 = the internal surface area of the trial pit up to 50% effective depth including the base area; t p75 25 = the time for the water level to fall from 75% to 25% effective depth. The effective depth of trial pits 2, 3 and 4 are provided in Table 2 below. The effective depth has been taken from the third test result, which represents the most conservative infiltration rate which will be used for design: Table 2 Trial Pit 25% - 75% Effective Depth: Trial Pit Water depth (m) 25% Effective Depth (m) 75% Effective Depth (m) Effective Depth (m) The V p75 25 and a p50 value for each trial pit, accounting for a 40% void ratio, has been calculated and provided in Table 3 below: Table 3 V p75 25 and a p50 Values Trial Pit V p75 25 (m³) a p50 (m²) Figure 1 overleaf shows the drain times at each trial pit. The drain times for the third test have been analysed as this represents the most conservative infiltration rate which will be used for design. w

9 Depth (m) Wholebake Facility, Corwen 0 Infiltration Test Drainage Times Trial Pit 2, Test 3 Trial Pit 3, Test 3 Trial Pit 4, Test Time (mins) Figure 1 Infiltration Test Drainage Times The t p75 25 values for trial pits 2, 3 and 4, taken from Figure 1 above, are shown in Table 4 below: Table 4 t p75 25 values Trial Pit t p75 25 values (mins) The calculated infiltration rates are shown in Table 5 below: Table 5 Infiltration rate Trial Pit Infiltration Rate m/s 1 Test abandoned x x x 10-4 w

10 Conclusions It can be concluded that soakaways would be a suitable method for surface water drainage in the location of trial pits 2, 3 and 4. The preferred location for a soakaway is beneath the proposed car park in the eastern extent of the site. As such the infiltration rate for trial pit 3 is most applicable to inform design. The development proposals may include an element of cut and fill earthworks and as such, final ground levels may vary when compared to existing ground levels. The infiltration rates should be verified at the detailed design stage, following confirmation of proposed site levels. w

11 Appendix A Location Plan & Aerial Image w

13 - Dimensions are in millimeters, unless stated otherwise. - Scaling of this drawing is not recommended. - It is the recipients responsibility to print this document to the correct scale.

12 13 - Dimensions are in millimeters, unless stated otherwise. - Scaling of this drawing is not recommended. - It is the recipients responsibility to print this document to the correct scale. - All relevant drawings and specifications should be read in conjunction with this drawing. N Sheep Dip Key 14 Application Boundary 12 Madryn Tyddyn Difyr El Sub Sta 6 to 11 Tk Path (um) 14 CWR Y GAER 1 7 LB 13b 13a Ty'n-y-llidiart Industrial Estate Path Track Sheep Dip Ty'n-y-llidiart El Sub Sta Ysgol Caer Drewyn d y Gaer ayground Trewyn-ba^ch Proposed Site (11.83 acres / 4.79 Hectares) Bryn Glas Heulfan Dismantled Railway Elwern Cemetery Bryn Hyfryd Ty Eira Chapel Cysgod y Gaer loches Caereuni Rhosnant 121 El Sub Sta 120 Playground Tydden Garreg GODRE'R GAER Delfryn Maestirion 163.2m FFORDD TY CERRIG ETL 164.5m 163.1m 163.1m 165.5m Path (um) Trem Arran Bryn MAESAFALLEN Hafod Garreg y Lwyd 1 Henfaes B 5437 Sandhurst Bryn Heulog Gwelafon LB TCB MAESAFALLEN Community Centre Path (um) Trim Trail DRAFT rev amendments by ckd date Wholebake Facility, Corwen Location Plan Path (um) 80 Car Park FB River Dee (Afon Dyfrdwy) Trewyn Fawr Leisure Centre SM Drain Path (um) Track Newark Beacon Innovation Centre, Cafferata Way, Newark, Nottinghamshire NG24 2TN o. +44 (0) f. +44 (0) e. info@umcarchitects.com Drawing Status: Drawn / Checked: Date: Scale: Planning DB / DSU 25/11/2016 A1 25m SCALE 1:1250 Drawing no: P001 - Revision:

13 ± NOTES: 1) ALL DIMENSIONS ARE IN METRES AND ALL LEVELS IN METRES ABOVE ORDNANCE DATUM UNLESS STATED OTHERWISE LEGEND Land Parcel A Land Parcel B Watercourse CLIENT: WHOLEBAKE LTD. Waterco Ltd Eden Court, Ruthin, LL15 1NJ SCHEME: AFON DYFRDWY / RIVER DEE TY'N Y LLIDIART INDUSTRIAL ESTATE, CORWEN PLOT TITLE: LOCATION PLAN PLOT STATUS: FINAL DATE: 08/11/2016 DRAWN: CHECKED: APPROVED: PLOT A3: m DH PLOT NAME: JW AW w10183-location_plan 1:4,000 (UNLESS STATED OTHERWISE) REV: - CONTAINS OS DATA CROWN COPYRIGHT (2016)

Ltd Eden Court, Ruthin, LL15 1NJ 01824 702220 www.waterco.

80 160 240 320 400 m DRAWN: DH PLOT NAME: CHECKED: JW APPROVED: AW w10183-aerial_image PLOT SCALE @ A3: 1:4,000 (UNLESS

14 ± NOTES: 1) ALL DIMENSIONS ARE IN METRES AND ALL LEVELS IN METRES ABOVE ORDNANCE DATUM UNLESS STATED OTHERWISE LEGEND Land Parcel A Land Parcel B CLIENT: WHOLEBAKE LTD. Waterco Ltd Eden Court, Ruthin, LL15 1NJ SCHEME: TY'N Y LLIDIART INDUSTRIAL ESTATE, CORWEN PLOT TITLE: AERIAL PLAN PLOT STATUS: FINAL DATE: 08/11/ m DRAWN: DH PLOT NAME: CHECKED: JW APPROVED: AW w10183-aerial_image PLOT A3: 1:4,000 (UNLESS STATED OTHERWISE) REV: - CONTAINS OS DATA CROWN COPYRIGHT (2016) BASEMAP: WORLD IMAGERY. SOURCES: ESRI, DIGITALGLOBE, GEOEYE, I-CUBED, EARTHSTAR GEOGRAPHICS, CNES/AIRBUS DS, USDA, USGS, AEX, GETMAPPING, AEROGRID, IGN, IGP, SWISSTOPO, GIS USER COMMUNITY

15 Appendix B Trial Pit Location Plan w

Final Environmental Assessment

Final Environmental Assessment For the National Foreign Affairs Training Center (NFATC) 2017 Master Plan Update Prepared by: The U.S. General Services Administration April 2017 65 NFATC 2017 Master Plan