How To Design A Resource Recovery Facility

Transcription

1 GP PLANNING LTD ENVIRONMENTAL STATEMENT APPENDIX 12: Surface Water Drainage Design Summary S ES / AB Appendix July 2012

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3 SIDEGATE LANE LANDFILL, WELLINGBOROUGH, NORTHAMPTONSHIRE PROPOSED RESOURCE RECOVERY FACILITY SURFACE WATER DRAINAGE DESIGN SUMMARY Date: 13 th July 2012 Carried Out For: SITA (UK) LTD SITA House Grenfell Road Maidenhead SL6 1ES Telephone: Prepared By: TerraConsult Ltd Bold Business Centre Bold Lane Sutton St Helens WA9 4TX Tel: Facsimile:

4 Sidegate Lane Landfill, Wellingborough, Northamptonshire Proposed Resource Recovery Facility, Surface Water Drainage Design Summary DOCUMENT INFORMATION AND CONTROL SHEET Document Status and Approval Schedule Report No. 1601/R/02-1 Title Sidegate Lane Landfill, Wellingborough, Northamptonshire Proposed Resource Recovery Facility, Surface Water Drainage Design Summary Issue History Issue Status Date Signature Date 1 Draft for Client Approval Prepared By: A. Binns Checked By: C. S. Eccles Authorised By: C. S. Eccles 2 Final Prepared By: A. Binns BSc CEng FICE Checked & Authorised By: C. S. Eccles FGS CGeol CSci C Env UK Registered Ground Engineering Advisor Alan Binns C S Eccles C S Eccles Alan Binns C S Eccles DISCLAIMER TerraConsult Ltd completed this consultancy contract on the basis of a defined programme and scope of works and terms and conditions agreed with the client. This report was compiled with all reasonable skill, and care, bearing in mind the project objectives, the agreed scope of works, the prevailing site conditions, the budget, the degree of manpower and resources allocated to the project as agreed. TerraConsult Ltd cannot accept responsibility to any parties whatsoever, following the issue of this report, for any matters arising that may be considered outwith the agreed scope of works. This report is issued solely to the client and TerraConsult cannot accept any responsibility to any third parties to whom this report may be circulated, in part or in full, and any such parties rely on the contents at their own risk. July /02 Issue 2 i

5 Sidegate Lane Landfill, Wellingborough, Northamptonshire Proposed Resource Recovery Facility, Surface Water Drainage Design Summary SIDEGATE LANE LANDFILL, WELLINGBOROUGH, NORTHAMPTONSHIRE PROPOSED RESOURCE RECOVERY FACILITY SURFACE WATER DRAINAGE DESIGN SUMMARY CONTENTS INTRODUCTION... 1 SITE / PROPOSED DRAINAGE SYSTEM DESCRIPTION... 2 RESULTS... 4 CONCLUSIONS & DRAINAGE PROPOSAL... 5 APPENDICES Appendix A Results for the Critical Storms DRAWINGS 1601/2/001 Initially Proposed Drainage Details 1601/2/002 Revised Drainage Details July /02 Issue 2 ii

6 Sidegate Lane Landfill, Wellingborough, Northamptonshire Proposed Resource Recovery Facility, Surface Water Drainage Design Summary SIDEGATE LANE LANDFILL, WELLINGBOROUGH, NORTHAMPTONSHIRE PROPOSED RESOURCE RECOVERY FACILITY SURFACE WATER DRAINAGE DESIGN SUMMARY INTRODUCTION 1. TerraConsult were instructed by SITA UK Ltd (SITA) to carry out the preliminary design for the surface water drainage system of the proposed soil treatment and RDF Facility at the western side of their Sidegate Lane Landfill Site, Sidegate Lane, Wellingborough, Northamptonshire, NN8 1RN. 2. The proposed drainage design is required as part of the planning process prior to construction of a resource recovery facility to treat/blend soil, to produce Refuse Derived Fuel (RDF) and recycle road sweepings. 3. The surface water drainage system for this area of the site requires to link in to the proposed surface water management plan for the whole restored landfill site. The details of this have already been submitted to the Environment Agency for approval. Drawing No. 1601/2/001 provides the proposed design for the surface water management system for the whole site as previously issued to the Environment Agency. The area of the proposed new development plan has been added to the plan of the existing drainage proposal showing the main RDF facility and associated works. 4. The proposed development of the site is summarised below with the area shown on Drawing No. 1601/2/001: The demolition or removal of all existing temporary buildings; Earthworks in the southern part of the development area (Area B) in order to create a wider level area for the development; Construction of a new building approximately 90 m by 40 m in plan, which will house: i. RDF facility (produces bailed RDF, organic fines) with Waste Reception; ii. road sweepings treatment facility, so the majority of these can be recycled; Soil blending area to enable the recovery and reuse of soils which might otherwise go to landfill; Construction of new offices and welfare facilities for the site; New weighbridge facility for the site; Increased area of concrete hard standing in Area A and around the above facilities in Area B. July /02 Issue 2 Page 1 of 4

7 Sidegate Lane Landfill, Wellingborough, Northamptonshire Proposed Resource Recovery Facility, Surface Water Drainage Design Summary SITE / PROPOSED DRAINAGE SYSTEM DESCRIPTION 5. Sidegate Lane Landfill Site is located approximately 2 kilometres to the southwest of Finedon and 3.5 kilometres to the northeast of Wellingborough. The entrance to the site is from Sidegate Lane. The development site area is located approximately on the western side of the Sidegate Lane Landfill (Areas A and B shown on Drawing No. 1601/2/001). The approximate National Grid Reference for the development site is SP The site location is shown on Figure 1 below. SITE Figure 1: Site Location 6. The previously proposed surface water system for the site is shown on Drawing No. 1601/2/001 and comprises ditches which ring the site, (with intermediate pipes and an attenuation pond) leading to the discharge point on the north side of Sidegate Lane. This surface water management scheme has been designed in accordance with SuDS principals and would prevent the flooding within the boundary of the landfill site. July /02 Issue 2 Page 2 of 4

8 Sidegate Lane Landfill, Wellingborough, Northamptonshire Proposed Resource Recovery Facility, Surface Water Drainage Design Summary 7. For the purposes of this drainage assessment, the development site is divided into two areas of hard standing: a. Area A forms the northern part and the existing concrete slab will be extended to provide the soil treatment area. b. Area B forms the southern part and a new existing concrete slab will be constructed to provide the RDF, waste reception and road sweeping recycling area. 8. In addition to the above areas, part of the planning application area comprises soft landscaping and where these areas remain as soft landscaping there is no net change to the drainage so this part of the development does not affect the overall drainage assessment for the site so these areas will not be discussed further in this assessment. 9. The activity on Area A involves processing and blending soil so any incident rain has the potential to become contaminated. The drainage from this area requires bunding to prevent escape of potentially contaminated water and the water shall be collected so it can then be tankered off for treatment at a suitably licensed facility. It is currently proposed to install an underground drainage tank in order to collect the potentially contaminated surface water in this area but this underground tank may be change to an open lagoon similar to the lagoon currently on site. 10. The building on Area B will house activities that may generate a limited quantity of water from the wastes being treated and this could include potential contaminants. This building requires measures internally to prevent the escape of contaminated water by draining and water internally to a sump. This water can then be tankered off for treatment at a suitably licensed facility. The anticipated quantity of contaminated water within the building is anticipated to be limited. 11. The remainder of Area B including the roof of the building and all exterior hard standing and the roof of the new site offices can be drained off to the western edge of the area which is delineated by the ring ditch of the main landfill drainage system. DRAINAGE ANALYSIS Software 12. The Microdrainage WinDes (version 12.6) suite of computer programs was used which includes the full hydrograph method for analysing drainage networks for the determination of the required channel and pipe sizes, attenuation pond volumes, invert levels etc. July /02 Issue 2 Page 3 of 4

9 Sidegate Lane Landfill, Wellingborough, Northamptonshire Proposed Resource Recovery Facility, Surface Water Drainage Design Summary Analysis Parameters 13. On-site attenuation and storage was designed so that the maximum discharges to the outfall do not exceed the rural (green field) run-off with a minimal amount of off-site flooding for the 1 in 100 year storm plus 30%. 14. The proposed drainage systems were tested by applying storm events with durations of between 15 minutes and 1 week, and magnitudes with probable return periods of 1, 30 and 100 years (the rainfall intensity being increased by 30% to allow for climate change). 15. Pipe and channel roughness coefficients were taken as the typical values suggested by the Microdrainage program suite from established hydraulic texts. 16. Surface water runoff into the drainage system is governed by surface soil type (permeable/impermeable), surface textures (woodland, rough grazing etc) and topography (slope steepness). The software uses the following general equation to calculate the runoff: Q = CIA Where: Q = runoff flow into ditch/pipe C = runoff coefficient I = average intensity of rainfall during the time of concentration A = Area of the site contributing runoff into the particular pipe or ditch RESULTS 17. The detailed results of the analyses are given in Appendix A2 and are summarised below: a. The critical storms are those with a 100 Year Return Period (with additional 30% added to rainfall intensity to account for climate change). b. The discharge rate at the site outfall is unaltered from the original full site discharge rate by the development. It stays at 530 l/s which is just below the rural runoff rate of l/s for a 100 yr return period storm. c. The relatively small amount (690 m 3 ) of off-site flooding (with relatively minor effects) determined for the original full site system, increases slightly to 885 m 3 (i.e. an increase of 195 m 3 ). This is considered to be minor because the flood water will be contained in a low depression in a field and will not spread. d. The size of the attenuation pond located at MH 128 remains unaltered. July /02 Issue 2 Page 4 of 4

10 Sidegate Lane Landfill, Wellingborough, Northamptonshire Proposed Resource Recovery Facility, Surface Water Drainage Design Summary CONCLUSIONS & DRAINAGE PROPOSAL 18. The results of the drainage analysis indicates that there is minimal additional off site flooding based on the incorporation of the proposed development into the previously proposed drainage scheme as presented on Drawing No 1601/2/ The originally proposed drainage system for the site has stormwater attenuation in three areas: attenuation pond; open ditches/swales; over sized pipes. 20. The previously proposed attenuation pond is located on the western side of the landfill in an area which has been landscaped with a wide range of established trees and vegetation. The proposal for this attenuation pond would involve removal of a significant portion of this vegetation and existing habitats. Therefore in order that the drainage proposal does not have a detrimental effect on the ecology and alternative location for the attenuation pond was sought in areas of lower ecological value. It is now proposed that two attenuation ponds will be formed in areas of lower ecological value as indicated in Drawing No 1601/2/002: North westerly attenuation pond this is located in an area which is currently grassed; Southerly lagoon in an area where landfill restoration has not yet been completed. 21. Preliminary calculations have shown that: a. The critical storms are those with a 100 Year Return Period (with additional 30% added to rainfall intensity to account for climate change). b. The discharge rate at the site outfall is unaltered from the original full site discharge rate by the development. It stays at 530 l/s which is just below the rural runoff rate of l/s for a 100 yr return period storm. c. During/after the 100 year critical storm there will be a relatively small amount (750 m 3 ) of off-site flooding (with relatively minor effects) from the whole landfill site which will be an increase of only 60 m 3 compared to the originally proposed 690 m 3 without the resource recovery facility. This is considered to be minor because the flood water will be contained in a low depression in a field and will not spread. July /02 Issue 2 Page 5 of 4

11 Sidegate Lane Landfill, Wellingborough, Northamptonshire Proposed Resource Recovery Facility, Surface Water Drainage Design Summary DRAWINGS July /02 Issue 2

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14 Sidegate Lane Landfill, Wellingborough, Northamptonshire Proposed Resource Recovery Facility, Surface Water Drainage Design Summary APPENDIX A SUMMARY RESULTS OF WINDES DRAINAGE ANALYSES FOR THE CRITICAL STORMS July /02 Issue 2

15 TerraConsult Ltd Page 1 Bold Business Centre Job 1601: Sidegate Lane Sutton Soil treament/rdf area St Helens WA9 4TX Surface Drainage Date Designed by A Binns File mdx Checked by Micro Drainage Network W.12.6 Summary of Critical Results by Maximum Level (Rank 1) for SGL-Perm Margin for Flood Risk Warning (mm) 75.0 DVD Status ON Analysis Timestep Fine Inertia Status ON DTS Status ON Profile(s) Summer and Winter Duration(s) (mins) 15, 30, 60, 120, 180, 240, 360, 480, 600, 720, 960, 1440, 2160, 2880, 4320, 5760, 7200, 8640, Return Period(s) (years) 1, 30, 100 Climate Change (%) 30, 30, 30 PN Storm Return Period Climate Change First X Surcharge First Y Flood First Z Overflow O/F Act. Lvl Exc Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Micro Drainage Ltd

16 TerraConsult Ltd Page 2 Bold Business Centre Job 1601: Sidegate Lane Sutton Soil treament/rdf area St Helens WA9 4TX Surface Drainage Date Designed by A Binns File mdx Checked by Micro Drainage Network W.12.6 Summary of Critical Results by Maximum Level (Rank 1) for SGL-Perm PN Storm Return Period Climate Change First X Surcharge First Y Flood First Z Overflow O/F Act. Lvl Exc Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % 100/15 Summer Micro Drainage Ltd

17 TerraConsult Ltd Page 3 Bold Business Centre Job 1601: Sidegate Lane Sutton Soil treament/rdf area St Helens WA9 4TX Surface Drainage Date Designed by A Binns File mdx Checked by Micro Drainage Network W.12.6 Summary of Critical Results by Maximum Level (Rank 1) for SGL-Perm PN Storm Return Period Climate Change First X Surcharge First Y Flood First Z Overflow O/F Act. Lvl Exc Winter % 30/15 Winter Summer % 30/15 Summer Winter % 30/15 Summer Winter % 30/15 Summer Winter % 100/15 Summer Winter % 100/15 Summer Winter % 30/15 Summer Winter % 30/15 Summer Winter % 30/15 Summer Winter % 30/15 Winter Winter % 30/15 Summer Winter % 30/15 Summer Winter % 30/15 Summer Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % Winter % 30/60 Summer Micro Drainage Ltd

18 TerraConsult Ltd Page 4 Bold Business Centre Job 1601: Sidegate Lane Sutton Soil treament/rdf area St Helens WA9 4TX Surface Drainage Date Designed by A Binns File mdx Checked by Micro Drainage Network W.12.6 Summary of Critical Results by Maximum Level (Rank 1) for SGL-Perm PN Storm Return Period Climate Change First X Surcharge First Y Flood First Z Overflow O/F Act. Lvl Exc Winter % Winter % Winter % Winter % PN US/MH Name Water Level (m) Surch'ed Depth (m) Flooded Volume (m³) Flow / Cap. O'flow (l/s) Micro Drainage Ltd Pipe Flow (l/s) Status MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK* MH OK* MH OK* MH OK MH OK MH OK MH OK MH OK MH OK* MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK

19 TerraConsult Ltd Page 5 Bold Business Centre Job 1601: Sidegate Lane Sutton Soil treament/rdf area St Helens WA9 4TX Surface Drainage Date Designed by A Binns File mdx Checked by Micro Drainage Network W.12.6 Summary of Critical Results by Maximum Level (Rank 1) for SGL-Perm PN US/MH Name Water Level (m) Surch'ed Depth (m) Flooded Volume (m³) Flow / Cap. O'flow (l/s) Pipe Flow (l/s) Status MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH SURCHARGED* MH FLOOD RISK* MH FLOOD RISK* MH FLOOD RISK* Micro Drainage Ltd

20 TerraConsult Ltd Page 6 Bold Business Centre Job 1601: Sidegate Lane Sutton Soil treament/rdf area St Helens WA9 4TX Surface Drainage Date Designed by A Binns File mdx Checked by Micro Drainage Network W.12.6 Summary of Critical Results by Maximum Level (Rank 1) for SGL-Perm PN US/MH Name Water Level (m) Surch'ed Depth (m) Flooded Volume (m³) Flow / Cap. O'flow (l/s) Pipe Flow (l/s) Status MH FLOOD RISK* MH FLOOD RISK* MH FLOOD RISK* MH FLOOD RISK* MH FLOOD RISK* MH FLOOD RISK* MH FLOOD RISK* MH FLOOD RISK* MH FLOOD RISK* MH SURCHARGED* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK* MH OK MH OK MH OK MH OK MH OK MH OK MH SURCHARGED* MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH OK MH FLOOD MH OK MH OK Micro Drainage Ltd

21 TerraConsult Ltd Page 7 Bold Business Centre Job 1601: Sidegate Lane Sutton Soil treament/rdf area St Helens WA9 4TX Surface Drainage Date Designed by A Binns File mdx Checked by Micro Drainage Network W.12.6 Summary of Critical Results by Maximum Level (Rank 1) for SGL-Perm PN US/MH Name Water Level (m) Surch'ed Depth (m) Flooded Volume (m³) Flow / Cap. O'flow (l/s) Pipe Flow (l/s) Status MH OK MH OK Micro Drainage Ltd

22 Leaders in waste management environmental & ground engineering consultancy TerraConsult Limited Bold Business Centre Bold Lane, Sutton St. Helens WA9 4TX Telephone: +44 (0) Fax: +44 (0) Website: FS EMS