{"text_format":"1","workbook":"xlsx","n_sheets":9,"sheets":["Cover Sheet","Introduction & Conclusion","1.Risk assessment","2.Total vol. - Mitigation","3.Containment volume-Total vol.","4.Current asset evaluation","5.Containment type-Total vol.","Template Settings","Settings"],"not_rendered":{"charts":0,"images":18,"macros":1,"external_links":1,"defined_names":57,"comments":3,"pivot_tables":0},"unopened":[],"bounds":{"document_bytes":16777216,"sheet_cells":100000,"rows_first":2000,"rows_last":500,"rows_between":2000,"halvings":0,"cell_chars":16384,"cell_head_chars":4096},"cells_cut":0,"cells_raw":0,"read":"whole","date_system":"1900"}

{"sheet":"Cover Sheet","index":0,"n_rows":43,"n_cols":11,"rows_kept":43,"cut":false,"hidden":false,"merged":[[47,2,47,4],[48,2,48,4],[49,2,49,4],[42,2,42,4],[43,2,43,4],[44,2,44,4],[45,2,45,4],[46,2,46,4],[41,2,41,4],[26,1,27,1],[26,2,26,4],[26,5,26,7],[34,1,34,7],[35,1,35,2],[35,3,35,5],[35,6,35,7],[36,1,36,2],[36,3,36,5],[36,6,36,7],[38,1,38,7],[40,2,40,4],[25,2,25,7],[18,1,18,5],[18,6,18,7],[19,1,19,5],[19,6,19,7],[20,1,20,5],[20,6,20,7],[22,1,22,7],[23,1,23,3],[23,4,23,7],[24,1,24,3],[24,4,24,7],[15,1,15,5],[15,6,15,7],[16,1,16,5],[16,6,16,7],[17,1,17,5],[17,6,17,7],[13,3,13,7],[2,2,2,7],[3,2,3,7],[5,2,5,3],[5,5,5,7],[6,2,6,3],[6,5,6,7],[7,2,7,3],[7,5,7,7],[8,2,8,3],[8,5,8,7],[9,2,9,3]]}
[]
[null,"Project Information"]
[null,"Workbook Name:","IED Risk Register-Canterbury"]
[null,"Project Title:","SWS EMA - Lot 8 - EIA "]
[]
[null,"Section:","Industrial Emission Directive Permit",null,"Divn/Dept:",null,null,null,"Please select from the dropdown or for enter manually"]
[null,"Subject:","Risk Assessment",null,"Project Nr:",790101]
[null,"Project Manager:","Daniel Watson",null,"File Ref:","790101-MMD-IED-CAN-CA-C-001","790101-MMD-IED-CA-C-004","790101-MMD-IED-CA-C-004","Please use the format Project Number/PIMS Unique number (e.g. 123456/5) or project specific format"]
[null,"Originator","Hari Prasath/Nikos Triantafyllou",null,"Calc Nr:"]
[null,"Checker","Ashwin Powar/Rachael Cross/Daniel Watson/Tommaso Tosi",null,"Nr Sheets:",5,null,null,"This is updated automatically as sheets are added/removed"]
[null,"Template Version","E"]
[null,"Design Phase"]
[]
[]
[]
[null,"Computer Applications Used",null,null,null,null,"Version/Date",null,"Please enter any other programs used as part of the calculation"]
[null,"Microsoft Excel",null,null,null,null,2108]
[]
[]
[]
[]
[]
[null,"Scope of Checking"]
[null,"Manual calculations",null,null,"Computer generated calculations"]
[null,null,null,null,null,null,null,null,"Enter a description of the checks that are required/have been performed"]
[]
[null,"Sheets","Calculations by",null,null,"Checked by"]
[null,null,"Name","Signature","Date","Name","Signature","Date","Please keep an audit list of the authors and checkers of each calculation sheet"]
[292574555,"1.Risk assessment","Hari Prasath","HP","2022-09-09","Ashwin Powar","AP","2022-09-09"]
[292575378,"2.Total vol. - Mitigation","Hari Prasath","HP","2022-09-09","Ashwin Powar","AP","2022-09-09"]
[292576031,"3.Containment volume-Total vol.","Hari Prasath","HP","2022-06-28","Ashwin Powar","AP","2022-06-28"]
[292576417,"4.Current asset evaluation","Hari Prasath","HP","2022-06-28","Ashwin Powar","AP","2022-06-28"]
[292576606,"5.Containment type-Total vol.","Tom Reynolds","TR","2024-08-27","Anita Manns","AM","2024-08-27"]
[]
[null,"Approved by"]
[null,"Approver",null,"Signature",null,null,"Date"]
[null,"Robert Kennett",null,"RK",null,null,"2022-09-30"]
[]
[null,"Version History"]
[null,"Version","Description",null,null,"Originator","Checker","Date"]
[null,"P01","Initial Calculation",null,null,{"$f":"Originator","v":"Hari Prasath/Nikos Triantafyllou"},{"$f":"Checker","v":"Ashwin Powar/Rachael Cross/Daniel Watson/Tommaso Tosi"},"2022-08-30",null,"Latest Version",{"$f":"OFFSET(B40,COUNTA(B41:B51),)","v":"P03"}]
[null,"P02","Updated with SW comments",null,null,{"$f":"Originator","v":"Hari Prasath/Nikos Triantafyllou"},{"$f":"Checker","v":"Ashwin Powar/Rachael Cross/Daniel Watson/Tommaso Tosi"},"2022-09-09"]
[null,"P03","Updated to latest containment solution and to address EA RFI",null,null,"Tom Reynolds","Anita Manns","2024-08-27",null,"Last Checked","2022-09-09"]

{"sheet":"Introduction & Conclusion","index":1,"n_rows":22,"n_cols":3,"rows_kept":22,"cut":false,"hidden":false,"merged":[]}
[]
[]
[null,"Introduction"]
[null,"The IED permit application requires an assessment of \n1) the existing capacity available for accidental spills from the Sludge Treatment Centres (STC)\n2) identification of containment solution that could be implemented in order for the site to comply, as far as is reasonably practicable, with Best Available Technique (BAT), in terms of the requirement for the provision of secondary containment.\n\n","Please introduce what this spreadsheet is"]
[]
[null,"Purpose"]
[null,"The aim of the study is to support Southern Water’s permitting and sludge treatment strategy","Please enter the purpose of the spreadsheet"]
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[null,"Required Output"]
[null,"A high-level desktop-based risk assessment using the ABDA classification tool to calculate the sites overall risk rating based on a Source-Pathway-Receptor Analysis. Simulation of catastrophic failure of the largest above ground volume within a given bund","Please define what the outputs of the spreadsheet should be"]
[]
[null,"Conclusions"]
[null,"The preferred option is outlined on worksheet 5. This would provide containment for the required STC storage tanks to BAT and CIRIA C736 requirements.\n","If the spreadsheet/calculation has a conclusion please enter it here"]
[]
[null,"Assumptions"]
[null,"CIRIA 736 Proposal amended 201221, Clause 3.2 study, Points (7-18), Page 7.\n\n1.The failure risk is assessed for a Single tank\n2.Only the above ground volume is considered for failure","Please ensure all assumptions are stated\nPlease specify any assumptions that apply to the whole spreadsheet\nAssumptions on single sheets should be placed on the sheet\nAssumptions on a cell or range should be put next to the cell or in a comment on top of it"]
[]
[null,"Basic Design Information or Source and Reference"]
[null,"CIRIA report C736"]
[]
[]
[null,"Identify documents/technical records where output will be used"]

{"sheet":"1.Risk assessment","index":2,"n_rows":91,"n_cols":12,"rows_kept":91,"cut":false,"hidden":false,"merged":[[42,9,47,9],[43,1,43,2],[43,3,43,4],[44,1,44,2],[44,3,44,4],[41,1,41,2],[41,3,41,4],[42,1,42,2],[42,3,42,4],[42,8,47,8],[45,1,45,2],[45,3,45,4],[46,1,46,2],[46,3,46,4],[47,1,47,2],[47,3,47,4],[71,3,71,9],[48,1,48,2],[48,3,48,4],[49,1,49,2],[49,3,49,4],[50,3,50,4],[63,1,63,2],[66,3,66,9],[67,3,67,9],[68,3,68,9],[69,3,69,9],[70,3,70,9],[72,3,72,9],[73,3,73,9],[74,3,74,9],[82,1,82,2],[87,1,87,2]]}
[]
[1.1000000000000001,"Source"]
[]
[null,"Material","Physical properties","Maximum quantity","units","Storage","Flammability","Corrosive","Ecotoxicity (based on LD and quantity)","Hazard rating "]
[null,"Post digestion storage tank","Sludge with solids, Methane","1590 m3 (approximately) - total volume for tank\n\n[As per Main Supporting Document 790101_MSD_Main_CAN ,Page 2]","m3","Steel","Digestate isn't flammable","Low","Organic heavy - Nitrogen, \nPhosphorous, Ammonia, BOD, TSS, COD - Environmental hazard (algae blooms and death of organisms)\n\nPathogens - Human hazard (E.coli etc.)","M"]
[null,null,null,null,null,null,null,null,"Overall","M"]
[]
[1.2,"Pathway and Receptor"]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
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[null,"Figure 1.1 Site Layout with Source-Pathway-Receptor",null,null,null,null,null,null,"Figure 1.2 Site picture of Post digestion storage tank"]
[]
[]
[null,"Pathway - the route from primary containment to receptor (extent of loss of containment)",null,"Time of concentration/ duration of source outside containment",null,"Hazard - Transport potential ",null,null,"Receptor","Hazard - Damage potential"]
[null,"Tanks are surrounded by Gravel surrounding-permeable.\n\nPermeable sub-soils/strata will thus act as a pathway. ",null,"Direct contamination but over an extended period of time",null,"M",null,null,"The entire site is located within Flood zone 2 (between 1 in 100 and 1 in 1000 annual probability of flooding) 5 due to rivers or sea. The site is adjacent to a high risk\nand several medium risk areas to the east. The Great Stour River is located 15m to the north of the site area, flowing west to east.\n\n[As per 790101_MSD_CCRA_CAN, Page 10]","H"]
[null,"If the permeable area were to get saturated (high groundwater) or became blocked with sludge, areas will act as impermeable and transport sludge downstream.",null,"Direct contamination but over an extended period of time",null,"M"]
[null,"Fluctuating river water Level.\n\nThe entire site is located within low risk (zone 2) flood risk (between 0.1% - 1% change of flooding)\n\n[As per 790101_MSD_CCRA_CAN, Page 9]",null,"Duration depends on flooding extent",null,"L"]
[null,"Existing underground services - ductwork, tunnels etc. (locations not known)",null,"Direct contamination but over an extended period of time",null,"L"]
[null,"Existing underground sludge pipework",null,"Direct contamination but over an extended period of time",null,"M"]
[null,"If inventory is lost or cascaded onto the road, sludge will be transported through the drainage channel to the head of the wastewater treatment works",null,"Minutes - hours",null,"M"]
[null,"If the drainage channel were to get blocked,  it may overflow locally to the permeable surrounding area.",null,"Minutes - hours",null,"M",null,null,"One record of potentially infilled land (non-water) is recorded 178m northwest of the site, registered as unknown filled ground dated to 1989. \n\nThere is one record of potentially infilled land (water) recorded on site, recorded in the west of the site (unknown filled ground). There are nine further records of within 250m of the site area, all of which are recorded south of the site area,between 51 – 247m from the site area.\n\n[As per 790101_MSD_SCR_CAN, Page 5]","M"]
[null,"The site is not located within an area with the potential for surface flooding to occur. \nOn site, an outflow from ponds/wetland in the northwest of the site flows into the Great Stour River, 15m north of the site area. A second drain is marked to flow off site from the south east corner, flowing east along Sturry Road (A28) and joins the Great Stour 475m east of the site.\n\n[As per 790101_MSD_SCR_CAN, Page 4]",null,"Duration depends on flooding extent",null,"M",null,null,"There is one record of a Historic Landfill Site within 250m of the site area. The site is located 26m southeast of the site and is currently a public park. It is recorded as being operational between 1969 – 1989 and deposited waste included inert, commercial, household and special waste.\n\n[As per 790101_MSD_SCR_CAN, Page 5]","M"]
[null,null,null,"Overall",null,"M",null,null,"Overall","H"]
[]
[]
[null,"*Flooding in flood zone 3 only have a 1 in 100 year probability of happening in a year"]
[]
[]
[null,"Combination of Hazards",{"$f":"J6&F51&J51","v":"MMH"}]
[]
[]
[null,"Overall risk rating for zone (Ciria 736) ","H"]
[]
[]
[]
[1.3,"Frequency of loss of containment"]
[]
[]
[null,"Failure mode","Description","Existing consequence and mitigation measure",null,null,null,null,null,null,"Annual probability of loss of containment","Rating"]
[null,"Operational failure - tank (partial)","Overfilling/overflow of tank\n\nFoaming","Digested sludge is stored in 1 No. post digestion sludge storage tank before being dewatered by 2 No. centrifuges.In the event of overfilling/overflow or foaming conditions, the site is manned between 0700-2000 Monday-Friday and 0700-1700 on weekends and so any loss of containment can be dealt with immediately and with tankers being on site within 2hrs, as part of an emergency response KPI with local tanker operator MTSR. Spills out of hours can be attended to within 1 hr.\n\nBoth clean and contaminated surface water is directed to a pumping station which recirculates it back into the system. The stormwater drainage of potentially contaminated areas from within the Site boundary is routed into the head of the works with no discharge outside of the site boundary. This allows site operations some time to deal with the leaks from operational failures. Flows exceeding the drainage system capacity will require mitigation with an improved inspection regime to catch spills prior to becoming significant.\n\nAs per Main Supporting Document 790101_MSD_Main_CAN,Page 9]",null,null,null,null,null,null,"Between 1% (1 in 100 and 0.001% (1 in 1 million)","M"]
[null,"Structural failure - tank (catastrophic)","Catastrophic failure due to significant external damage\n\nPotential to lose total volume if mixer pipework fails/break off of tank - has been a failure mode for digesters in the past","The tank is primarily located above ground with a proportion below ground. For any loss of containment below ground, the sludge liquid will percolate into the permeable soil at a slow rate over a long period if not detected by the level or temperature alarms.\n\nIn the case of significant damage above ground, the total volume contained above ground could spill.\n\nIn the event of a catastrophic failure, sludge would flow in all directions as there is no containment immediately around the tank. The sludge would predominantly flow to the northern boundary. There is an existing natural ground slope along the road towards the northern boundary where the sludge will flow by gravity and reach the waterbody.",null,null,null,null,null,null,"Between 1% (1 in 100 and 0.001% (1 in 1 million)","M"]
[null,"Structural failure - tank (partial)","Most likely through defects formed in tank\n\nMost critical defects would be large defects at low level along the side of the tank walls or tank base. \n\nDefects would need to be large >6mm to allow for sludge to pass through the them freely. General screens at WwTW are 6-10mm, thus defects would need to be in the same range to allow for sludge to pass freely.\n\nRoof failure","Partial structural failure of the tank would be mainly through surface defects.In the case of significant defects forming above ground, the volume contained above ground would seep through the defects . If the defects are significant (>6mm), the tank could potentially lose the above ground volume over a long period of time if the level and temperature alarms are not functioning. However, this is unlikely. \n\nDue to operational presence on site and ability to get to site when not manned, large drops in levels in the tanks and significant leaks above ground would be noticed. Significant defects (>6mm) below/above ground would also be easily spotted during the daily visual inspections. ",null,null,null,null,null,null,"Between 1% (1 in 100 and 0.001% (1 in 1 million)","M"]
[null,"Structural failure - pipework (catastrophic)","Loss of containment due to failure of above ground connecting pipework and rising mains","In the unlikely event where the above ground rising mains to the post digested tank, heatamix pipework or de-gritting pipework fails and breaks off, a significant volume would spill out. Tank have level and temperature alarms so any required valve could be rapidly shut off by operational staff.\n\nThe consequence of a catastrophic containment failure is it's able to flow in all directions as there is no containment bunds immediately around the tank. \n\nTotal loss of containment is unlikely. A partial loss of containment would be more likely to occur.",null,null,null,null,null,null,"Between 1% (1 in 100 and 0.001% (1 in 1 million)","M"]
[null,"Structural failure - pipework (partial)","Loss of containment most likely to occur where there are weak points in the pipework - Most likely through failures where pipe connects with the structure, bolts/sealant at pipe flanges/valves or along any pipe pitting.\n\nWeak point could be created through either human damage (during maintenance/operation), erosion (high velocities and silt content within the pipe) or environmental (corrosion)\n\nValve failure/seizure","Majority of pipework and connections are located above ground. Some of the pipework is located below ground or within the chambers below ground. \n\nIf loss of containment occurs underground (through leaks, joints and seals), sludge will percolate into the soil at a slow rate over a long period and localised wet areas will be present above ground.\n\nIf loss of containment occurs above ground through leaks or damage to pipework, due to the permeable stone around tank, sludge will also percolate into the soil at a slow rate over a long period.\n\nTotal loss of containment is unlikely (partial loss of containment would be more likely to occur).",null,null,null,null,null,null,"Between 1% (1 in 100 and 0.001% (1 in 1 million)","M"]
[null,"Vehicular impact (partial to catastrophic)","Impact from vehicles - damage to pipes or tank causing loss of containment","No known vehicle impacts - Vehicular bollards exists around the tank\n\nHigh speed impact unlikely, but vehicle could damage pipework connected to tank (mixer pump) and cause a significant hole in the tank at low level. Could impact a potential weak point.",null,null,null,null,null,null,"< 0.001% (1 in 1 Million)","L"]
[null,"Vandalism","Vandalism of infrastructure - damage to pipes or tank causing loss of containment","No known vandalism to tanks or pipework.\n\nIf vandalism damage were to occur, total loss of containment is unlikely, but could occur if significant damage or on theft of mixer pumps and pipework. Partial loss of containment would be more likely to occur if slight damage was done.",null,null,null,null,null,null,"< 0.001% (1 in 1 Million)","L"]
[null,"Flooding","River flooding - Flood zone 2 and\nzone 3 - damage to pipes or tank causing loss of containment","The west of the Site is primarily considered at low risk of flooding from river and sea (long term), while the east of the Site is mostly at medium risk and a small area in the centre of the Site is at high risk of flooding from river and sea\n\n[As per 790101_MSD_Main_CAN, Page 14]",null,null,null,null,null,null,"Greater than 1% (1 in 100)","H"]
[]
[null,"*Site is manned. Probability and frequency thus reduced"]
[]
[]
[null,"Frequency of loss of containment (Ciria 736)","H"]
[]
[]
[1.4,"Overall zone hazard rating"]
[]
[null,"Overall zone hazard rating (Ciria 736)","High"]
[]
[]
[1.5,"Containment required"]
[]
[]
[null,"Containment required","Class 3"]

{"sheet":"2.Total vol. - Mitigation","index":3,"n_rows":16,"n_cols":22,"rows_kept":16,"cut":false,"hidden":false,"merged":[[4,3,4,9],[4,11,4,20],[5,1,12,1],[5,3,5,9],[5,11,5,20],[6,3,6,9],[6,11,6,20],[7,3,7,9],[7,11,7,20],[8,3,8,9],[12,3,12,9],[12,11,12,20],[15,1,17,9],[8,11,8,20],[9,3,9,9],[9,11,9,20],[10,3,10,9],[10,11,10,20],[11,3,11,9],[11,11,11,20]]}
[]
[]
[2.1,"Catastrophic failure - modes (loss of containment) "]
[]
[null,"Risk","Cause","Existing consequence and mitigation measure",null,null,null,null,null,null,"Existing zone risk rating","Proposed Mitigation",null,null,null,null,null,null,null,null,null,"Risk rating after mitigation"]
[null,null,"Operational failure - tank (partial)",{"$f":"'1.Risk assessment'!$D$68","v":"Digested sludge is stored in 1 No. post digestion sludge storage tank before being dewatered by 2 No. centrifuges.In the event of overfilling/overflow or foaming conditions, the site is manned between 0700-2000 Monday-Friday and 0700-1700 on weekends and so any loss of containment can be dealt with immediately and with tankers being on site within 2hrs, as part of an emergency response KPI with local tanker operator MTSR. Spills out of hours can be attended to within 1 hr.\n\nBoth clean and contaminated surface water is directed to a pumping station which recirculates it back into the system. The stormwater drainage of potentially contaminated areas from within the Site boundary is routed into the head of the works with no discharge outside of the site boundary. This allows site operations some time to deal with the leaks from operational failures. Flows exceeding the drainage system capacity will require mitigation with an improved inspection regime to catch spills prior to becoming significant.\n\nAs per Main Supporting Document 790101_MSD_Main_CAN,Page 9]"},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!L68","v":"M"},"All tanks undergo a delegated inspection regime and the process parameters are monitored and understood by site operatives.\n\nSite operators are on site between 0700-2000 Monday-Friday and 0700-1700 on weekends. Daily site inspection regime will consist of the a site walkover. Any defects located will be escalated to site manager for a repair resolution to be determined. If there is not an immediate risk posed by the defective asset and large scale repair is required then, the asset planning team will be informed in order to plan the necessary repairs. Any reactive works required will be undertaken by Site Operations team. \n\nInspection/Frequency\n>Walk round the site, identify and clear up any waste materials: Daily\n>Note signs of any deterioration of tanks or surroundings: Daily\n>Note any small leaks or spills, fix them and clean them up immediately: Daily\n>Integrity/Condition assessment all key sludge assets - Drain tank and inspect condition: 10 yearly\n\nFurther mitigation\n >A proactive planned preventative maintenance (PPM) and replacement programme linked to asset lifespan. Site Manager ensures the PPM is implemented effectively to minimise the probability of equipment malfunction. \n >A robust leak detection and repair plan will be set out and enacted\n >The site will be monitored using a telemetry to monitor tank levels and process flows. Trigger levels will be assigned to risk rating and proportional response will be taken. Alarms that protect against a loss of containment will have a response time the same as for other emergencies (Approx. 1 hr).\n>Penstock valves will be placed at strategic SW chambers to reduce the risk of sludge flows getting in to the SW drainage system. An automated solution for closing them and also any need for regrading of surfaces to reduce risk will be looked into at detailed design.\n\nControl of substances hazardous to health (COSHH) assessment undertaken for all raw materials.",null,null,null,null,null,null,null,null,null,"L"]
[null,null,"Structural failure - tank (catastrophic)",{"$f":"'1.Risk assessment'!$D$69","v":"The tank is primarily located above ground with a proportion below ground. For any loss of containment below ground, the sludge liquid will percolate into the permeable soil at a slow rate over a long period if not detected by the level or temperature alarms.\n\nIn the case of significant damage above ground, the total volume contained above ground could spill.\n\nIn the event of a catastrophic failure, sludge would flow in all directions as there is no containment immediately around the tank. The sludge would predominantly flow to the northern boundary. There is an existing natural ground slope along the road towards the northern boundary where the sludge will flow by gravity and reach the waterbody."},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!L69","v":"M"},"The above inspection and further mitigation proposals will be applicable to structural failure, also.\n\nAs part of proposed mitigation, regular daily inspections of the site drainage systems and other equipment are to be undertaken, with any repairs and maintenance carried out if necessary.",null,null,null,null,null,null,null,null,null,"L"]
[null,null,"Structural failure - tank (partial)",{"$f":"'1.Risk assessment'!$D$70","v":"Partial structural failure of the tank would be mainly through surface defects.In the case of significant defects forming above ground, the volume contained above ground would seep through the defects . If the defects are significant (>6mm), the tank could potentially lose the above ground volume over a long period of time if the level and temperature alarms are not functioning. However, this is unlikely. \n\nDue to operational presence on site and ability to get to site when not manned, large drops in levels in the tanks and significant leaks above ground would be noticed. Significant defects (>6mm) below/above ground would also be easily spotted during the daily visual inspections. "},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!L70","v":"M"},"The inspection and further mitigation proposals outlined as mitigation for Operational failure will be applicable to structural tank failure, also.\n\nTo minimise loss of containment underground, it is advised that the tanks be visually inspected on daily basis and structurally inspected with increased regularity. Falling head tests should also be regularly carried out to limit any potential leaks underground. Tank to be refurbished if necessary.\n\nPermeable areas around the tanks and low lying grassed areas are also to be replaced with impermeable hardstanding to remove the pathway to the ground. Soakaways to be filled in (concrete) and all connected drainage to connect to liquor return.",null,null,null,null,null,null,null,null,null,"L"]
[null,null,"Structural failure - pipework (catastrophic)",{"$f":"'1.Risk assessment'!$D$71","v":"In the unlikely event where the above ground rising mains to the post digested tank, heatamix pipework or de-gritting pipework fails and breaks off, a significant volume would spill out. Tank have level and temperature alarms so any required valve could be rapidly shut off by operational staff.\n\nThe consequence of a catastrophic containment failure is it's able to flow in all directions as there is no containment bunds immediately around the tank. \n\nTotal loss of containment is unlikely. A partial loss of containment would be more likely to occur."},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!L71","v":"M"},"To mitigate the very unlikely occurrence where the above ground pipework could fail/collapse, the necessary pump controls (Low and high pressure switches to trip the pump) need to be put in place, if not already, if there is a sudden loss of pressure in the rising mains (feed, mixing, hot water pumps rising mains), the pumps should stop. \n\nAll above ground pipework and chambers to be visually inspected daily. Structural inspections and falling head testing should be undertaken with increased regularity to test for any leaks. Pipework and chambers to be refurbished or replaced, if necessary to BAT standards. \n\nPermeable areas around the tank and low lying grassed areas is also to be replaced with impermeable hardstanding to remove the pathway to the ground. Soakaways to be filled in (concrete) and all connected drainage to connect to liquor return.",null,null,null,null,null,null,null,null,null,"L"]
[null,null,"Structural failure - pipework (partial)",{"$f":"'1.Risk assessment'!$D$72","v":"Majority of pipework and connections are located above ground. Some of the pipework is located below ground or within the chambers below ground. \n\nIf loss of containment occurs underground (through leaks, joints and seals), sludge will percolate into the soil at a slow rate over a long period and localised wet areas will be present above ground.\n\nIf loss of containment occurs above ground through leaks or damage to pipework, due to the permeable stone around tank, sludge will also percolate into the soil at a slow rate over a long period.\n\nTotal loss of containment is unlikely (partial loss of containment would be more likely to occur)."},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!L72","v":"M"},"As tank was fit for purpose at the time of construction, secondary containment provision is not considered for the underground pipework.\n\nTo assess the condition of underground pipework and chambers, CCTV and leakage detection (falling head tests) should be done on a regular basis to check if any leakage is experienced.  All above ground pipework and chambers to be visually inspected on daily basis for any leaks. Pipework and chambers to be refurbished or replaced, if necessary to BAT standards.\n\nPermeable areas around the tanks and low lying grassed areas is also to be replaced with impermeable hardstanding to remove the pathway to the ground. Soakaways to be filled in (concrete) and all connected drainage to connect to liquor return.",null,null,null,null,null,null,null,null,null,"L"]
[null,null,"Vehicular impact (partial to catastrophic)",{"$f":"'1.Risk assessment'!$D$73","v":"No known vehicle impacts - Vehicular bollards exists around the tank\n\nHigh speed impact unlikely, but vehicle could damage pipework connected to tank (mixer pump) and cause a significant hole in the tank at low level. Could impact a potential weak point."},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!L73","v":"L"},"If the existing vehicle bollards lacks the structural integirty, they are to be replaced with new Vehicle barriers or bollards.Potential for the fence installed to be stronger and to be able to withstand some vehicular impact. The likelihood of such occurrence is low.\n\nThis is to mitigate any potential impacts from vehicles and potential damage which could lead to loss of containment. ",null,null,null,null,null,null,null,null,null,"L"]
[null,null,"Vandalism",{"$f":"'1.Risk assessment'!$D$74","v":"No known vandalism to tanks or pipework.\n\nIf vandalism damage were to occur, total loss of containment is unlikely, but could occur if significant damage or on theft of mixer pumps and pipework. Partial loss of containment would be more likely to occur if slight damage was done."},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!L74","v":"L"},"Site is restricted by 2m high chain link security fencing with barbed wire top in the east of Site to the north of the aeration lane and in the south of Site, and palisade fencing in the west of the Site. The river which borders the north and eastern parts of the Site also acts as a natural barrier. 2m high dual swing manual metal entry gates secure the main access and are closed at all times when not in use and locked out of hours. The Site is staffed 0700-2000 Monday-Friday and 0700-1700 on weekends. The Site also benefits from a CCTV system (normal and thermal), with cameras positioned in key locations around the Site, including one Automatic Number Plate Recognition (ANPR) camera on the main gate. Regular inspections of the boundary fencing and buildings are undertaken to ensure that these have not been compromised and continue to prevent easy access to Site.\n\n[As per Main Supporting Document 790101_MSD_Main_CAN, Site Security, Page 25]",null,null,null,null,null,null,null,null,null,"L"]
[null,null,"Flooding",{"$f":"'1.Risk assessment'!$D$75","v":"The west of the Site is primarily considered at low risk of flooding from river and sea (long term), while the east of the Site is mostly at medium risk and a small area in the centre of the Site is at high risk of flooding from river and sea\n\n[As per 790101_MSD_Main_CAN, Page 14]"},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!L75","v":"H"},"Ensure flood plan for site follows EA guidance.\n\nInclude provision of sump pump to keep site clear of floodwater.\n\nEnsure diesel generators are at sufficient height to ensure they are not at risk of flooding (coastal or otherwise)",null,null,null,null,null,null,null,null,null,"L"]
[]
[]
[null,"Implementing the above measures will significantly reduce the probability and risk of failure from the concrete tanks and significantly reduce the amount of secondary containment. As per CIRIA 736, the above will need to be implemented in conjunction with a good maintenance strategy as mentioned in Box 5.2,Page 60."]

{"sheet":"3.Containment volume-Total vol.","index":4,"n_rows":20,"n_cols":5,"rows_kept":20,"cut":false,"hidden":false,"merged":[[11,3,12,13]]}
[]
[]
[3.1,"Secondary containment volume requirement - Inventory volume (above ground)"]
[]
[]
[null,"Tanks","Volume (m³)",null,"Single bund solution (see worksheet 5)"]
[null,"Digestor 1",1450]
[null,"Digestor 2",1450]
[null,"Post Digestion Storage Tank",1590]
[null,"Thickened Sludge Storage tank",1200]
[null,"Sludge reception tank",100]
[null,"Post Screened Storage Tank 1",300,"PSSTs are within the bund but tanks are substantially buried. Full volume listed for calcs in relation to the 25% rule as a conservative approach. Practical spill scenario volume would be lower (above ground proportion only). Known to not be the largest tank so does not impact 110% rule"]
[null,"Post Screened Storage Tank 2",300]
[null,"Total",{"$f":"SUBTOTAL(109,Table1[Volume (m³)])","v":6390}]
[null,0.25,{"$f":"0.25*Table1[[#Totals],[Volume (m³)]]","v":1597.5}]
[null,1.1000000000000001,{"$f":"MAX(C7:C13)*1.1","v":1749.0000000000002}]
[]
[null,"Applicable rule (largest of the two)",1.1000000000000001]
[]
[null,"Secondary containment capacity required",{"$f":"C16","v":1749.0000000000002},"m3"]

{"sheet":"4.Current asset evaluation","index":5,"n_rows":24,"n_cols":3,"rows_kept":24,"cut":false,"hidden":false,"merged":[]}
[]
[]
[4.0999999999999996,"Current Asset Evaluation","Post digestion storage tank"]
[null,"Description","Digested sludge is stored in 1 No. post digestion sludge storage tank before being dewatered by 2 No. centrifuges."]
[null,"Number of tanks","1 (Risk assessed for one tank only)"]
[null,"Volume of tank","1590 m3 (approximately) - total volume for tank"]
[null,"Material of tank","Steel"]
[null,"Above/below ground?","Above ground tank "]
[null,"Pipe material","All connecting pipework is thick-walled – some above ground and some below ground."]
[null,"Drainage for zone","The drainage is directed towards the Northern direction\n\n[As per Canterbury WTW Drainage, 720116/M104/2401]"]
[null,"Year of construction","-"]
[null,"Surrounding area","Gravel surrounding tank - permeable"]
[]
[null,"Pump rate - to Post digestion storage tank","-"]
[null,"Pump rate - from  Post digestion storage tank","-"]
[]
[]
[null,"Is asset fit for purpose?","The tanks were originally designed and constructed to hold digestion sludge and has been operating with no notable concerns.  \n\nTank has not undergone a change of use"]
[null,"Condition of the tank\n\nAny tank failures - cracks, flaking, corrosion, overflows, overfilling?","no structural concern"]
[null,"Condition of pipework\n\nPipe leaks, corrosion?","No visible issues/leaks reported by operational staff"]
[null,"Protection of assets ","The existing vehicular bollards needs to be tested for integrity. If found defective, new vehicular protection/bollards needs to be provided"]
[null,"Control/monitoring/alarming measures in place?","All tanks undergo a delegated inspection regime and the process parameters are monitored and understood by site operatives"]
[null,"Secondary containment provided?","None"]
[null,"Secondary containment condition?","N/A"]

{"sheet":"5.Containment type-Total vol.","index":6,"n_rows":164,"n_cols":14,"rows_kept":164,"cut":false,"hidden":false,"merged":[[140,1,140,10],[142,1,142,10],[148,1,148,10],[120,1,120,10],[121,1,121,10],[122,1,122,10],[123,1,123,10],[124,1,124,10],[149,1,149,10],[150,1,150,10],[151,1,151,10],[152,1,152,10],[153,1,153,10],[163,1,163,10],[154,1,154,10],[155,1,155,10],[156,1,156,10],[157,1,157,10],[158,1,158,10],[159,1,159,10],[160,1,160,10],[161,1,161,10],[162,1,162,10],[115,1,115,10],[116,1,116,10],[117,1,117,10],[118,1,118,10],[119,1,119,10],[111,1,111,10],[112,1,112,10],[113,1,113,10],[114,1,114,10],[106,1,106,10],[107,1,107,10],[108,1,108,10],[109,1,109,10],[110,1,110,10],[99,1,99,10],[100,1,100,10],[103,1,103,10],[104,1,104,10],[105,1,105,10],[98,1,98,10],[4,1,4,13],[59,1,59,20],[62,1,62,4],[95,1,95,10],[97,1,97,10],[96,1,96,10]]}
[]
[]
[5.0999999999999996,"Containment to be provided"]
[]
[null,"Based on a High site risk rating for the zone, Class 3 containment is required. Bunds, as shown below, or concrete walls will be used"]
[]
[null,null,null,null,null,null,null,null,null,null,null,null,null,"Typical Bund section view"]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[null,null,null,null,null,null,null,null,null,null,null,null,null,"Typical reinforced concrete wall section view"]
[]
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[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[5.2,"Location of largest tank"]
[null,"Post Digestion Storage Tank 1590m3, largest tank per sheet 3 is shown below"]
[]
[]
[]
[]
[]
[]
[5.3,"Catastrophic failure in existing situation (Do Nothing) - Visualisation"]
[]
[]
[null,"Figure 5.3.1 Visualisation of Do Nothing Option"]
[]
[]
[null,null,null,null,null,null,null,null,null,null,null,null,"Do nothing scenario is provided for information only."]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[5.4,"Containment Solution Proposal"]
[]
[null,"Proposal Summary"]
[null,"The solution is for a site-wide containment bund combining the use of new and existing surfaces and kerbs, speed humps and low walls."]
[null,"The containment volume required is based on the larger of the 110% of the largest tank or 25% of the total volume of the tanks (see worksheet 3 for calculation). In this solution the 110% rule applies."]
[null,"Extensive existing hard surfaces will be remediated to be used and new impermeable areas will be installed as required to provide an appropriate containment bund floor surface for the full extent of the bund area. An estimate of the area required of each is provided below.\nDetailed survey outcomes regarding the remediation and reuse of existing surfaces in line with the below comments will determine the need for additional new impermeable surfaces."]
[null,"The containment solution provides the required means of containment for a potential event of spillage from the sludge storage tanks by way of providing a contained and impermeable area with no hydraulic links to outside the bund. A spill from any of the tanks within the bund would be contained within the bund. As such any spilled sludge is appropriately contained in line with the referenced guidance.\nThe solution accomodates operational access needs and the existing topography."]
[null,"Localised bunds were found to have significantly high walls and a significant impact on access routes (including emergency), as such this option was not progressed."]
[null,"The site drainage will be modified to ensure a compliant solution, new sumps and pumps with associated pipework may be required. Given the site-wide solution a lartge proportion of the existing drainage will become the bund drainage solution. This will be inspected and remediated (or replaced) to ensure it meets containment standard requirements. A means of isolating the drainage from other site areas and the discharge to the WtW will be provided to provide a means for the discharge to be tested and if acceptable, discharged to the WtW. Existing site dranage will be modified to create a separate drainage solution to the bunded areas and will similarly be tested and returned to the WtW. Should a spill / fail be identified separate procedures will be utilised to facilitate recovery (as below)."]
[]
[null,"Containment Solution Scope"]
[null,"New containment will be built to contain 110% of the total tank inventory volume, the final local height of the walls remains subject to final confirmation from further design but illustrative heights are shown on the image to the right (note that some taller kerbs will realistically be short walls)."]
[null,"The current anticipated solutions are a combination (as most suited to a given area):\nSpeed humps (or where taller is required, road tables) where access routes are required to be retained.\nKerbs (including remediation or existing) where the height required is within standard kerb heights.\nShort reinforced concrete walls of various heights based on local need.\nEarth banks lined with concrete canvas may be utilised where space permits to reduce cost and embodied carbon.\nNo additional wall types are considered appropriate for this solution."]
[null,"New impermeable surfaces meeting the required 10^-9m/s impermeability will be installed in line with CIRIA C736. \nThis is planned to be a combination of reinforced concrete and concrete canvas but some localised applications may be more suited to alternative solutions from table 8.2 of CIRIA C736.\nNew impermeable areas will provide a continuous surface over the area identified as within the bunded area, this includes existing gravel areas between tanks, existing surfaces and equipment. Details for tie in to existing structures to ensure an appropriate containment solution will either be to manufacturers details or developed on specifically for the application.\nExtensive existing surfaces will be utilised, the extent remains subject to detailed survey and identification of appropriate remediation to ensure it meets the required standard."]
[null,"The footprint of any permananent assets (including other tanks) that are within bund areas are excluded from use for containment volume calculations."]
[null,"The site operator will have a daily (or with cause) action to empty the bund of rainwater. \nThe scope may include new sumps and electrical pumps but will include new sample points and the required pipework to return the rainwater to the works inlet. A means of isolation for the bund will be provided. \nThe pump would be manual start and require a check by the operator for evidence of any spills prior to starting the pump. The pump will have an anti-syphon arrangement and auto-shutoff at low-level. The location of sumps and pipework routes will be identified in detailed design. "]
[null,"CIRIA C736 requires rainfall allowance in capacity calculations for 10% AEP rainfall for; 24 hours [prior to the incident], the duration of the incident, eight days [after the incident] (or other period appropriate to the particular site circumstances).\nThe final wall heights will include for appropriate freeboard and rainwater containment volumes based on the completion of design and calulations.\nA rainwater allowance of up to 136mm in line with a worst-case region 3 rainfall for 24 hours plus 8 days may be applied to the final wall height subject to final design. \nThe solutions shall remain 'as drawn' but the wall height will vary to accomodate the final calculation.\n"]
[null,"Additionally a firefighting foam allowance of >100mm is required if the contents are combustable. These products are not combustable so this alowance does not need to be applied.\nSurge allowance of 250/750mm is recommended in line with CIRIA C736 table 6.3. \nFor this solution surge scenario is partcularly of consideration given the distance between the tanks and containment walls and the realistic surge height in relation to this. Allowing dynamic modelling outcome to be utilised/considered over a blanket allowance would provide a more appropriate containment solution.\nThe final confirmed height of walls including freeboard allowance remains subject to detailed design and final calculations.\nNo bunds are covered so rainfall is relevant.\nAn operator action for starting the bund drain pumps daily as required aligns to the 24 hours pre-incident requirement.\nThe duration of the event depends on the severity (partial failure/catestropic) but it is considered feasible to utilise road tankers (for holding) to empty bunds at any given point. These are used widely by the company. The CIRIA C736 allowance for 8 days post incident rainwater capacity is considered in relation to the ability to manage water levels post-incident. In this scenario it is considered feasible to manage water levels within the bund by using tankers in the event of significant rain."]
[null,"The allowance for post incident rainwater is anticipated to be related to particular site circumstances as CIRIA C736 allows.\nThis requires completion of the design and [it is anticipated] this will be part of further sdiscussion with local EA officers to gain agreement.\nFurther design and operational planning will determine the detail of a recovery scenario (ie. calculations for tanker attendance time, pump rate for removal vs rainfall accumulation), the outcome of this will inform the final allowance for freeboard for rain and the findings will be reflected in the final wall heights.\nThe suggested freeboard allowance for surge does not align to the peak heights from the spill modelling (allowed by CIRIA C736 as alt. to standard allowance).\nAs such the overall freeboard remains subject to confirmation to ensure a given solution is able to contain a practical spill scenario."]
[null,"In the event of a spill the contained sludge and any rainwater can not be returned to the works inlet. Road tankers may be utilised to empty the bund with suction hoses, intially for holding capacity but also allows for appropriate testing and subsequent disposal. This will form part of revised spill procedure based on the final design and further assessment and planning."]
[null,"No allowance for firefighting foam capacity has been made as the substances under consideration are not flammable.  As such, fire is not a scenario that is considered practically feasible and is considered to align to CIRIA C736 figure 4.3 for non-combustible contents\nThis remains subject to acceptance by the Environment Agency in design development and acceptance of improvement condition plans. Should it be deemed required an allowance can be made on wall heights to accommodate this."]
[null,"Overfilling tanks has not been modelled as the operational control processes (level gauges, SCADA etc) are thought to be sufficiently robust to demonstrate this spill scenario requires less containment than a catastrophic tank failure scenario. Additionally the tank modelled is the largest tank within a bund and tank transfers are only completed from single tank to single tank. Surveys in relation to level gauges etc to address BAT 19 and subsequent analysis of findings will determine if this correct."]
[null,"The use of flood gates has been excluded from the solution on the basis their operation is not guaranteed to be timed correctly, presents a single point of failure and may adversely impede any response scenario."]
[null,"The distance of tanks from walls means jetting to outside of the bunded area is thought unlikely, this remains subject to further evaluation and calculation in the next stage of design including consideration of tank types and the orientation (e.g. concrete tanks, insulation, other buildings/existing fences etc). Should a jetting risk be determined appropriate mitigating measures will be implemented as part of the overall solution to ensure any liquids remain within the bunded area."]
[null,"The bunded areas may be re-profiled locally to achieve the required falls to accommodate new sumps and pumps. Existing surfaces have appropriate falls already so are not anticipated to be reprofiled. "]
[null,"The drainage solution for the area will be reviewed and further intrusive surveys completed to ensure any existing drainage that may be utilised is of good condition and retains water in line with the bunding requirements. It is anticipated that drainage modifications will be required to ensure all bunded areas are captured and surface water dealt with in line with BAT. This requires additional survey and design work to determine the most appropriate solution.\nAny existing soak aways (or areas providing a similar effect) within a bunded area will be removed and appropriate BAT compliant drainage solutions provided.\nRoof areas where BAT permits for uncontaminated rainwater to be directed to the ground (outside the bund) will be considered to reduce the amount of water flowing in drains or (subject to testing etc) returned to the WtW."]
[null,"Existing pits, chambers and other existing assets in the bunded area will be reviewed on a case by case basis to determine the most appropriate solution to provide the required level of containment.\nThis is anticipated to require the replacement of pit covers with water tight/sealed versions to ensure containment. This is not reflected in CIRIA C736 but is considered appropriate and the wholesale removal of pit and ducts, underground chambers and pipework is cost-prohibitive."]
[null,"No retrofitted leak detection under existing tanks is proposed, alternative solutions to manage the risk will be developed. \nThis will include tank inspections, tank periodic hydrotesting and (subject to contamination hydrogeologist review of the application) boreholes to monitor for leakage where tanks are underground.\nThe basis for this is that retrofitting may cause settlement issues or create voids under tanks which would counter the objective of the leak detection. Additionally most tanks have either a concrete tank base, or a concrete foundation under the tank base, thus providing an appropriate impermeable surface in line with CIRIA C736."]
[null,"The majority of the pipework will be within the bund and thus provided with appropriate containment. Existing underground pipework would not be replaced wholesale but will be tested/inspected and appropriate solutions developed based on the findings.\nOver time the underground pipework would be replaced with above-ground pipework as and when other projects require changes to the site layout/operation. Where pipework is not within the bunded area a case by case review will determine an appropriate means of leak detection and secondary containment (based on factors like insulation, condition, routing, pumped/gravity system)."]
[null,"Existing process areas are provided with hardstanding and drainage which is thought to be of acceptable quality (remains subject to detailed survey). a failure of equipment within the process area would be appropriately contained within the bunded area. Any remedial action identified from survey to meet the required standard will be undertaken."]
[null,"Spill modelling has not been completed for all tanks as CIRIA C736 does not require this, nor is it thought required as part of normal good practice. The containment of all tanks and the suitability of the design for this scenario has been assured through consideration of existing topo and consideration of the flows in a given area relative to the volume of the tanks in consideration."]
[null,"Provisional DSEAR guidance suggests any methane present would disperse rapidly and not present a potentially explosive atmosphere. Further evaluation of this will be undertaken in design and may determine the need for design changes which would be incorporated to the solution outlined."]
[]
[]
[]
[null,"Modelling notes."]
[null,"The model was built in Infoworks ICM 2021.9 and provides a 2D output of a 3D scenario"]
[null,"The model utilised a combination of LiDAR / Digital Terrain Model data with topographical survey data as an additional reference"]
[null,"A mesh was created by the modeller to represent the topography of the existing site"]
[null,"Drainage was excluded on the basis that modification of drainage systems will be required to ensure no links to outside the bund."]
[null,"Building areas were excluded from containment volume areas - assumes no flooding of internal areas of the building"]
[null,"The whole area is treated as impermeable surface reflecting the required final state for the bund floor"]
[null,"Levels and wall heights represent 'settled' levels"]
[]
[]
[]
[null,"Solution Development Notes with respect to the wider context within which IED will be delivered"]
[]
[null,"The design for the containment continues to progress and remains subject to further development."]
[null,"The design will require sign off by a competent civil or structural engineer."]
[null,"CIRIA C736 compliance is the objective (and BAT is the referenced requirement). \nA few elements regarding CIRIA C736 details in the context of this application will be reviewed by a qualified engineer for suitability and as outlined in CIRIA C736 we will look to discuss this with the EA as our regulator. \nSome queries are in line with additional guidance offered by the Agency in other forums (TaF, Defra meetings et. al.).\nThis may include:\n\n\n\n\n\n\n"]
[null,"Accounting for rainfall accumulation in bunds will be reviewed in further detail to determine final wall heights - this will look to consider:"]
[null,null,"Operational process in no-spill scenario for daily removal of rainwater and return to head of works (inc. determining the presence of spilled sludge)"]
[null,null,"Emergency response in spill scenario for removal of sludge (likely using road tankers and suction)"]
[null,null,"Allowance for climate change in rainfall calculations"]
[null,null,"Duration of AEL rainfall required to be accommodated with respect to CIRIA C736 and the final operational basis for normal and spill scenarios"]
[null,"Steel plating over joints as the origin of this (within CIRIA C736) was in related to a fire scenario for hydrocarbon storage and may not be required for STC/sludge facility/storage."]
[null,"The relationship between the risk assessment 'CIRIA classification' and the details for the solutions proposed, particularly differentiating between Class two and class three requirements."]
[null,"The use of Concrete Canvas (as it is not listed in CIRIA C736 table 8.2 but can be demonstrated to meet the 10^-9m/s impermeability requirement)"]
[null,"The need for sub-surface 1m impermeable soil based on type of stored material (re. CIRIA C736 figure 8.4) and the requirement for under-bund lead detection (class 3). An alternative solution with lower carbon impact may be proposed for the sub-surface and based on SMR in-situ remediation solution. "]
[null,"Where existing surfaces are proposed to be utilised the details in CIRIA C736 may not be fully achieved as retrofitting of water bars is not considered feasible. A suitably qualified person will be required to approve any proposed solutions."]
[null,"The use of sealed covers for existing pits as not clearly defined in CIRIA C736 but considered to be an effective and realistic solution"]
[null,"The context in which IED will be delivered at this site will look to reflect the wider guidance provided around IED implementation."]
[null,"The following points are considered relevant factors in provision of the final solution implemented at the site:"]
[null,"Wording of improvement conditions and agreement for acceptable solutions with Local Agency Installation Officers only being possible upon receipt of permit/draft permit"]
[null,"Appropriate accommodation of the SW Bioresources Strategy regarding future site use and remaining asset life requirements"]
[null,"Specifically the plan to stop AD at this site at the end of AMP8 (March 2030) and thus the retirement of the digestor related assets."]
[null,"This leads to investment focussed on the assets that are retained longer term and a risk-evaluated investment basis for the digestor related assets."]
[null,"This may (subject to assessment) be supported by additional measures such as enhanced tank inspections and boreholes for leak identification"]
[null,"To include Director commitment to site closure"]
[null,"This element is reflected in an Uncertainty mechanism with respect to Ofwat submissions"]
[null,"Demonstration of appropriate risk-management for the time period required, including consideration of the tank condition, material and inspection report for remaining life"]

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[null,"MM Logos"]
[null,"Name","Picture Name","Logo"]
[null,"MM","LogoMM",null,"Logo should be of width <=3cm, height <=1.4cm \nRename the logo picture with the name in the Picture Name column (no spaces)"]
[null,"MMB","LogoMMB",null,"Logos can be added to the sheets using the 'Other Settings' button in the ribbon"]
[null,"GBM","LogoGBM"]

{"sheet":"Settings","index":8,"n_rows":6,"n_cols":2,"rows_kept":6,"cut":false,"hidden":true,"merged":[]}
[]
[null,"Please use this page for any settings including lists used in dropdown (validation) cells"]
[]
[null,"Lists"]
[]
[null,"List1"]