{"text_format":"1","workbook":"xlsx","n_sheets":11,"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.","6.Pragmatic volume - Mitigation","7.Containment - Pragmatic","Template Settings","Settings"],"not_rendered":{"charts":0,"images":17,"macros":1,"external_links":3,"defined_names":164,"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-Howdon"]
[null,"Project Title:","NWG IED Permits "]
[]
[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:",100105164]
[null,"Project Manager:",null,null,"File Ref:",null,"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","Nicola Robinson/Nikos Triantafyllou",null,"Calc Nr:"]
[null,"Checker","Alastair Massey",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,"Infoworks ICM",null,null,null,null,"11.0.4"]
[]
[]
[]
[]
[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",{"$f":"Originator","v":"Nicola Robinson/Nikos Triantafyllou"},"NP","2022-07-25","Alastair Massey","AM","2022-08-03"]
[292575378,"2.Total vol. - Mitigation",{"$f":"Originator","v":"Nicola Robinson/Nikos Triantafyllou"},"NP","2022-07-25","Alastair Massey","AM","2022-08-03"]
[292576031,"3.Containment volume-Total vol.",{"$f":"Originator","v":"Nicola Robinson/Nikos Triantafyllou"},"NP","2022-07-25","Alastair Massey","AM","2022-08-03"]
[292576417,"4.Current asset evaluation",{"$f":"Originator","v":"Nicola Robinson/Nikos Triantafyllou"},"NP","2022-07-25","Alastair Massey","AM","2022-08-03"]
[292576606,"5.Containment type-Total vol.","Nikos Triantafyllou","NT","2023-02-21","Rachael Cross","RC","2023-02-21"]
[]
[null,"Approved by"]
[null,"Approver",null,"Signature",null,null,"Date"]
[null,"Anita Manns",null,"A. Manns",null,null,"2023-02-21"]
[]
[null,"Version History"]
[null,"Version","Description",null,null,"Originator","Checker","Date"]
[null,"P01","Initial Calculation",null,null,{"$f":"Originator","v":"Nicola Robinson/Nikos Triantafyllou"},{"$f":"Checker","v":"Alastair Massey"},"2022-07-25",null,"Latest Version","P03"]
[null,"P02","Updated with Client Comments",null,null,{"$f":"Originator","v":"Nicola Robinson/Nikos Triantafyllou"},{"$f":"Checker","v":"Alastair Massey"},"2022-07-25"]
[null,"P03","Updated for resubmission of permit application ",null,null,{"$f":"Originator","v":"Nicola Robinson/Nikos Triantafyllou"},"Alastair Massey and Rachael Crss","2023-02-21",null,"Last Checked","2023-02-21"]

{"sheet":"Introduction & Conclusion","index":1,"n_rows":22,"n_cols":3,"rows_kept":22,"cut":false,"hidden":false,"merged":[]}
[]
[]
[null,"Introduction"]
[null,"The application for a variation to the IED permit requires an assessment of the existing capacity available for accidental spills from the anaerobic digestion activity and biogas upgrading activity, and to identify potential high level tertiary containment mitigation that could be implemented in order for the sites to comply, as far as is reasonably practicable, with Best Available Technique (BAT), in terms of the requirement for the provision of tertiary containment","Please introduce what this spreadsheet is"]
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[null,"Purpose"]
[null,"The aim of the study is to support the application to vary the existing sewage sludge treatment activity (S0819 No 19) as authorised under the permit reference EPR/KP3394ZE to include the anaerobic digestion activity and biogas upgrading activity, and to consolidate the bespoke combustion activity under permit referenceEPR/YP3331HQ to the same Installation permit for the Howdon STW and STC (‘the Site’) onbehalf of Northumbrian Water Limited (‘Northumbrian Water’ or ‘the Operator’).","Please enter the purpose of the spreadsheet"]
[]
[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 during a 1 in 10 year rainfall event","Please define what the outputs of the spreadsheet should be"]
[]
[null,"Conclusions"]
[null,"A site containment option is proposed with 2.6m high walls and a flood gate protecting the River Tyne. Mobile pumps to be used to remove volume from bund from low point.  An improved maintenance and inspection regime is proposed to include daily operational inspection (See '2.Total vol. - Mitigation')","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":104,"n_cols":12,"rows_kept":104,"cut":false,"hidden":false,"merged":[[60,3,60,4],[55,8,56,8],[57,8,60,8],[56,1,56,2],[56,3,56,4],[57,1,57,2],[57,3,57,4],[100,1,100,2],[84,3,84,9],[61,1,61,2],[61,3,61,4],[62,1,62,2],[62,3,62,4],[63,3,63,4],[76,1,76,2],[79,3,79,9],[80,3,80,9],[81,3,81,9],[82,3,82,9],[83,3,83,9],[61,8,62,8],[61,9,62,9],[2,1,2,9],[85,3,85,9],[86,3,86,9],[87,3,87,9],[95,1,95,2],[54,1,54,2],[54,3,54,4],[55,1,55,2],[55,3,55,4],[58,1,58,2],[58,3,58,4],[55,9,56,9],[57,9,60,9],[59,1,59,2],[59,3,59,4],[60,1,60,2]]}
[]
[1.1000000000000001,"Source"]
[null,"Please note, this includes all sludge tanks on the Howden site. For all other processes under the IED permit (e.g. gas bag holders) please see 100105164_MSD_HOW\nAll wastewater treatment and biogas combustion treatment tanks have not been included in this assessment as these do not fall under the IED permit"]
[null,"Material","Physical properties","Maximum quantity, m3","units","Storage","Flammability","Corrosive","Ecotoxicity (based on LD and quantity)","Hazard rating "]
[null,"Thickened sludge day tanks","Sludge",2000,2,"Tank","Low","Low","Medium","L",null,{"$f":"D5*E5","v":4000}]
[null,"Strategic Sludge Storage Tanks","Sludge",10500,4,"Tank","Low","Low","Medium","L",null,{"$f":"D6*E6","v":42000}]
[null,"Screened Sludge Buffer Tank","Sludge",600,1,"Tank","Low","Low","Medium","L",null,600]
[null,"Advanced Anaerobic Digesters","Liquid with sludge, Gas (methane)",6000,3,"Tank","Medium","Low","High","M",null,18000]
[null,"Post Digestion Storage Tank","Sludge",4600,1,"Tank","Low","Low","Medium","L",null,4600]
[null,"THP Buffer Tanks (feed silos)","Liquid with sludge dry solids",320,2,"Silo","Medium","Low","Medium","L",null,640]
[null,"Cake Silo","Semi-Solid Cakes",500,1,"Silo","Medium","Low","Medium","L"]
[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 ",null,null,null,null,"Figure 1.2 Strategic Sludge Storing Tanks"]
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[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 concrete.\n\nThe superficial deposits underlying the site are classified as a combination of Unproductive Strata, Secondary Undifferentiated aquifers and unknown (lakes and landslip), indicating that they are not of significant value. The bedrock (PMCM) consists of siltstone, mudstones and sandstones of varying permeability. The PMCM formation is classed as a Secondary A superficial aquifer with low vulnerability.\n\nPermeable sub-soils/strata will thus act as a pathway. But the majority of the tank surroundings are impermeable.",null,"Direct contamination but over an extended period of time",null,"M",null,null,"The site is located on the northern banks of the River Tyne, approximately 75m inland. The remaining part of the historical Northumberland Dock lies approximately 50m to the east.\n\n\n[As per Site Condition Report 100105164_MSD_SCR_HOW, Hydrology, Page 3]","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,"L"]
[null,"The site is located in an Environment Agency zone 1 flood risk area. However, the area approximately 50m to the east and 80m to the south of the site is located with a zone 3 flooding risk area due to the proximity of the River Tyne.",null,"The site is not at risk from coastal flooding (it is at risk of river flooding, Environment Agency flood risk High=5)",null,"L",null,null,"There are no boreholes used for drinking water supply within 1km of the site. However, there are two abstraction points one located approximately 400m south of the site used for mineral washing and the second approximately 1km west of the Installation which is used for industrial water used for dust suppression.\n[As per Site Condition Report 100105164_MSD_SCR_HOW, Hydrology, Page 3]","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,"There is impermeable road surfacing around the tanks. Ground naturally drains to this area\n\nIf inventory is lost or cascaded onto the road (saturated permeable ground), sludge will be transported through the drainage channel to the head of the wastewater treatment works",null,"Minutes - hours",null,"L"]
[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,"The bedrock (PMCM)consists of siltstone, mudstones and sandstones of varying permeability. ThePMCM formation is classed as a Secondary A superficial aquifer with low vulnerability.\n\n[As per Site Condition Report 100105164_MSD_SCR_HOW, Hydrogeology, Page3]","L"]
[null,"Site wastewater treatment capacity exceeded due to incoming flows –risks direct discharges to the watercourses if stormwater storage is exceeded. There is no history of surface flooding at the site.\n\n[As per Climate Change Risk Assessment, 100105164_ERA_CCRA_HOW, Page 8]",null,"Minutes - N/A (dependant on flooding extent)",null,"L"]
[null,null,null,"Overall",null,"M",null,null,"Overall","L"]
[]
[]
[null,"*Flooding in flood zone 3 only have a 1 in 100 year probability of happening in a year"]
[]
[]
[null,"Combination of Hazards",{"$f":"J12&F64&J64","v":"MML"}]
[]
[]
[null,"Overall risk rating for zone (Ciria 736) ","M"]
[]
[]
[]
[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","Strategic tanks are covered so it is not anticipated that overfilling/overflow of tanks will occur.",null,null,null,null,null,null,"1 in 100 to 1 in 1 Million","L"]
[null,"Structural failure - tank (catastrophic)","Catastrophic failure due to significant external damage\n\nPotential to lose total volume if pipework fails/break off of tank","Tanks are 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.\n\nIn the case of significant damage above ground, the total volume contained above ground could be lost. It is however very unlikely for the tanks to fail catastrophically structurally as the tanks are fit for purpose.\n\nTotal loss of containment could occur in case of pipe failure above the ground level - If total loss of containment occurs, sludge would flow freely. If pipework fails, jetting likely to occur. This sludge would be able to flow in all directions as there is no containment immediately around the tank. The sludge would predominantly flow to the south towards the Tyne river. There are bunds on the southern and eastern boundaries of the site which would limit the flow and inhibit any sludge from escaping the site and into the nearby watercourse. Yet these bunds do not contain the sludge completely as the estimated volume is exceeds 10.000 m3.",null,null,null,null,null,null,"< 1 in 1 Million","L"]
[null,"Structural failure - tank (partial)","Most likely through cracks formed in concrete \n\nMost critical cracks would be large cracks at low level along the side of the tank walls or tank base. \n\nCracks would need to be large >6mm to allow for sludge to pass through the crack freely. General screens at WwTW are 6-10mm, thus cracks would need to be in the same range to allow for sludge to pass freely.\n\nRoof failure","Tanks are primarily located above ground. Any significant loss of containment, would spill above ground. \n\nStructural failure of the tank would mainly be through cracks.  In the case of significant cracks forming above ground, the volume contained above ground would seep through the cracks . If the cracks are significant (>6mm), the tank could potentially lose the above ground volume over a long period of time (very unlikely).\n\nDue to operational presence on site, large drops in levels in the tanks and significant leaks above ground would be noticed. Significant cracks (>6mm) below/above ground would also be easily spotted if tank is inspected. \n\nProportion of volume could be lost, but from discussions with operations, no loss of containment was experienced.\n\nTotal loss of containment is unlikely (partial loss of containment would be more likely to occur)",null,null,null,null,null,null,"1 in 100 to 1 in 1 Million","M"]
[null,"Structural failure - pipework (catastrophic)","Loss of containment due to failure of above ground connecting pipework","In the unlikely event where the above ground pipework fails and breaks off, a significant volume could be lost if the necessary pump controls are not in place or the valves are not closed by operational staff to limit loss of containment.\n\nIf an incident occurred during manned hours, the pipes would be shut down immediately and valves closed by operational staff if the pipes were to fail. In the case where critical pipework fails and valves cannot mitigate the spillage, the digester could lose its full volume.\n\nTotal loss of containment could occur. - If total loss of containment occurs sludge will flow freely, it is able to flow in all directions as there is no containment immediately around the tank.he sludge would predominantly flow to the south towards the Tyne river. There are bunds on the southern and eastern boundaries of the site which would limit the flow and inhibit any sludge from escaping the site and into the nearby watercourse. Yet these bunds are quite insignificant in height and do not contain the sludge completely as the estimated volume is exceeds 10.000 m3.  The sludge will mainly flow to the south leading down to river Tyne located directly below the tank towards an outfall in the river, which has a penstock attached however it is not in full use so the outfall would allow sludge off site.",null,null,null,null,null,null,"< 1 in 1 Million","L"]
[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","It is assumed that the majority of pipework and connections are located above 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. If significant leaks, localised wet areas will be present above ground and jetting is likely to occur.\n\nIf loss of containment occurs above ground through leaks or damage to pipework, due to the permeable ground around tank, sludge will also percolate into the soil at a slow rate over a long period.\n\nDue to operational presence on site, significant leaks (above or below) ground would be noticed and loss of containment would be mitigated through operational measures (closing of valves). The site is manned and valves present on all pipework from all tanks would be able to be closed, minimising the risk of significant jetting.\n\nTotal loss of containment is unlikely (partial loss of containment would be more likely to occur)",null,null,null,null,null,null,"1 in 100 to 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 - some vehicle barriers/protection can be seen on site photos.\n\nVehicles could potentially impact and damage concrete digestion tank which is located above ground. Vehicular impact could cause some damage to the tank (cracking), if significant, proportion of above ground volume could be lost. Vehicle is however unlikely to damage underground sections of tanks or displace any liquid within them. \n\nTotal loss of containment could occur if the vehicle impact causes significant damage to the tank. High 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,"1 in 100 to 1 in 1 Million","M"]
[null,"Vandalism","Vandalism of infrastructure - damage to pipes or tank causing loss of containment","No known vandalism to tanks or pipework - CCTV cameras on site. Site is enclosed by steel fencing all around.\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,"< 1 in 1 Million","L"]
[null,"Flooding","River flooding - Flood zone 1- \ndamage to pipes or tank causing loss of containment","The site is located in an Environment Agency zone 1 flood risk area. Areas withinzone 1 have 1 in a 1,000 chance of river or sea related flooding. However, the area approximately 50m to the east and 80m to the south of the site is located within a zone 3 flooding risk area due to the proximity of the River Tyne. Areas within flood zone 3 have been shown to be at a 1% or greater probability offlooding from rivers or 0.5% or greater probability of flooding from rivers/ the sea.\n[As per Site Condition Report 100105164_MSD_SCR_HOW, Flooding, Page 3]",null,null,null,null,null,null,"< 1 in 1 Million","M"]
[]
[null,"*Site is manned. Probability and frequency thus reduced"]
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[null,"Frequency of loss of containment (Ciria 736)","M"]
[]
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[1.4,"Overall zone hazard rating"]
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[null,"Overall zone hazard rating (Ciria 736)","HIGH"]
[]
[]
[1.5,"Containment required"]
[]
[]
[null,"Containment required","Class 3"]

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[]
[]
[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$81","v":"Strategic tanks are covered so it is not anticipated that overfilling/overflow of tanks will occur."},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!L81","v":"L"},"All tanks undergo a delegated inspection regime and the process parameters are monitored and understood by site operatives.\n\nDaily 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$82","v":"Tanks are primarily located above ground with a proportion below ground. For any loss of containment below ground, the sludge liquid will percolate into the permeable soil at a slow rate over a long period.\n\nIn the case of significant damage above ground, the total volume contained above ground could be lost. It is however very unlikely for the tanks to fail catastrophically structurally as the tanks are fit for purpose.\n\nTotal loss of containment could occur in case of pipe failure above the ground level - If total loss of containment occurs, sludge would flow freely. If pipework fails, jetting likely to occur. This sludge would be able to flow in all directions as there is no containment immediately around the tank. The sludge would predominantly flow to the south towards the Tyne river. There are bunds on the southern and eastern boundaries of the site which would limit the flow and inhibit any sludge from escaping the site and into the nearby watercourse. Yet these bunds do not contain the sludge completely as the estimated volume is exceeds 10.000 m3."},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!L82","v":"L"},"The above inspection and further mitigation proposals will be applicable to structural failure, also.\n\nBoth clean and contaminated surface water is directed to a pumping station which recirculates it back into the system. \nThe 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. \n\nRegular daily inspections of the site drainage systems and other equipment are to be undertaken, with any repairs and maintenance carried out if necessary. All complaints and other incidents are recorded in the site diary including actions taken.\n\nThe condensate is clean, uncontaminated water and is small in quantity.  Condensate traps are checked regularly and condensate is discharged to the head of the works.",null,null,null,null,null,null,null,null,null,"L"]
[null,null,"Structural failure - tank (partial)",{"$f":"'1.Risk assessment'!$D$83","v":"Tanks are primarily located above ground. Any significant loss of containment, would spill above ground. \n\nStructural failure of the tank would mainly be through cracks.  In the case of significant cracks forming above ground, the volume contained above ground would seep through the cracks . If the cracks are significant (>6mm), the tank could potentially lose the above ground volume over a long period of time (very unlikely).\n\nDue to operational presence on site, large drops in levels in the tanks and significant leaks above ground would be noticed. Significant cracks (>6mm) below/above ground would also be easily spotted if tank is inspected. \n\nProportion of volume could be lost, but from discussions with operations, no loss of containment was experienced.\n\nTotal loss of containment is unlikely (partial loss of containment would be more likely to occur)"},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!L83","v":"M"},"Original tank construction was reinforced concrete. \n\nIn the event that tank loses containment above or below ground through structural failure (cracks), sludge would weep through the cracks at a very slow rate. The volume would slowly flow down the side of the tank and gather around the tank. \n\nVery large cracks and the subsequent leaks (especially above ground) would be spotted by operations during their daily inspections and the tank would be isolated and drained down until repaired if the crack is significant. \n\nTo minimise loss of containment underground, it is advised that the tanks be structurally inspected on daily basis. Falling head tests should also be carried out to limit any potential leaks underground on weekly basis. Tank to be refurbished if necessary. Ultrasonic meters are suggested in Digestion tank which should alarm when pumps (feed pumps) are not in operation, but the level in the tank drops a certain distance to ensure any significant loss of containment underground is monitored.\n\nIn the unlikely event that tank loses significant containment above ground through structural failure (large cracks), based on topography, sludge will cascade towards the road to the north/west and eventually into the drainage system. Potential to infiltrate into the ground around tank (grass) or cascade into the drainage network (liquor return) is minimal.\n\nPermeable areas around the tanks (stone and grass) and low lying grassed area 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$84","v":"In the unlikely event where the above ground pipework fails and breaks off, a significant volume could be lost if the necessary pump controls are not in place or the valves are not closed by operational staff to limit loss of containment.\n\nIf an incident occurred during manned hours, the pipes would be shut down immediately and valves closed by operational staff if the pipes were to fail. In the case where critical pipework fails and valves cannot mitigate the spillage, the digester could lose its full volume.\n\nTotal loss of containment could occur. - If total loss of containment occurs sludge will flow freely, it is able to flow in all directions as there is no containment immediately around the tank.he sludge would predominantly flow to the south towards the Tyne river. There are bunds on the southern and eastern boundaries of the site which would limit the flow and inhibit any sludge from escaping the site and into the nearby watercourse. Yet these bunds are quite insignificant in height and do not contain the sludge completely as the estimated volume is exceeds 10.000 m3.  The sludge will mainly flow to the south leading down to river Tyne located directly below the tank towards an outfall in the river, which has a penstock attached however it is not in full use so the outfall would allow sludge off site."},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!L84","v":"L"},"If catastrophic failure of the above ground pipework occurs (i.e. rising main pipe failure), assuming the pumps have the necessary pressure controls (Low and high pressure switches to trip the pump), the volume contained in the pipe length should be contained within pipe and valve chamber.\n\nTo 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 inspected structurally on a daily basis for any leaks and necessary falling head tests conducted on weekly basis. Pipework and chambers to be refurbished or replaced, if necessary to BAT standards. \n\nIn the unlikely event that tank loses significant containment above ground through structural failure (large cracks), based on topography, sludge will cascade towards the road to the north/west and eventually into the drainage system. Potential to infiltrate into the ground around tank (grass) or cascade into the drainage network (liquor return) is minimal.\n\nPermeable areas around the tank (stone and grass) 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$85","v":"It is assumed that the majority of pipework and connections are located above ground. \n\nIf loss of containment occurs underground (through leaks, joints and seals), sludge will percolate into the soil at a slow rate over a long period. If significant leaks, localised wet areas will be present above ground and jetting is likely to occur.\n\nIf loss of containment occurs above ground through leaks or damage to pipework, due to the permeable ground around tank, sludge will also percolate into the soil at a slow rate over a long period.\n\nDue to operational presence on site, significant leaks (above or below) ground would be noticed and loss of containment would be mitigated through operational measures (closing of valves). The site is manned and valves present on all pipework from all tanks would be able to be closed, minimising the risk of significant jetting.\n\nTotal loss of containment is unlikely (partial loss of containment would be more likely to occur)"},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!L85","v":"M"},"No known visible leaks in the tank area.\n\nAs construction 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 the necessary leakage detection (falling head tests) should be done on weekly basis to check if any leakage is experienced.  All above ground pipework and chambers to be inspected structurally on daily basis for any leaks and necessary falling head tests conducted on weekly basis. Pipework and chambers to be refurbished or replaced, if necessary to BAT standards. \n\nIn the unlikely event that tank loses significant containment above ground through structural failure (large cracks), based on topography, sludge will cascade towards the road to the north/west and eventually into the drainage system. Potential to infiltrate into the ground around tank (grass) or cascade into the drainage network (liquor return) is minimal.\n\nPermeable areas around the tanks (stone and grass) 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$86","v":"No known vehicle impacts - some vehicle barriers/protection can be seen on site photos.\n\nVehicles could potentially impact and damage concrete digestion tank which is located above ground. Vehicular impact could cause some damage to the tank (cracking), if significant, proportion of above ground volume could be lost. Vehicle is however unlikely to damage underground sections of tanks or displace any liquid within them. \n\nTotal loss of containment could occur if the vehicle impact causes significant damage to the tank. High speed impact unlikely, but vehicle could damage pipework connected to tank (mixer pump) and cause a significant hole in the tank at low level. Could impact a potential weak point."},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!L86","v":"M"},"Vehicle barriers or bollards are proposed around front of the tanks along the road. Potential for the fence installed to be stronger and to be able to withstand some vehicular impact. The likelihood of such occurrence in low.\n\nThis is to mitigate any potential impacts from vehicles and potential damage which could lead to loss of containment. Since, The tank base is at road level there are chances of a vehicular collisions.\n\nPermeable areas around the tanks (stone and grass) 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,"Vandalism",{"$f":"'1.Risk assessment'!$D$87","v":"No known vandalism to tanks or pipework - CCTV cameras on site. Site is enclosed by steel fencing all around.\n\nIf vandalism damage were to occur, total loss of containment is unlikely, but could occur if significant damage or on theft of mixer pumps and pipework. Partial loss of containment would be more likely to occur if slight damage was done."},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!L87","v":"L"},"Access to Site and waste is restricted by a chain link security fence. The Site also benefits from a CCTV systems. Regular inspections of the boundary fencing and buildings are undertaken to ensure that these have not \nbeen compromised and continue to prevent easy access to Site.\n",null,null,null,null,null,null,null,null,null,"L"]
[null,null,"Flooding",{"$f":"'1.Risk assessment'!$D$88","v":"The site is located in an Environment Agency zone 1 flood risk area. Areas withinzone 1 have 1 in a 1,000 chance of river or sea related flooding. However, the area approximately 50m to the east and 80m to the south of the site is located within a zone 3 flooding risk area due to the proximity of the River Tyne. Areas within flood zone 3 have been shown to be at a 1% or greater probability offlooding from rivers or 0.5% or greater probability of flooding from rivers/ the sea.\n[As per Site Condition Report 100105164_MSD_SCR_HOW, Flooding, Page 3]"},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!L88","v":"M"},"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":65,"n_cols":9,"rows_kept":65,"cut":false,"hidden":true,"merged":[]}
[]
[]
[3.1,"Secondary containment volume requirement - Inventory volume (above ground)"]
[]
[null,"Strategic sludge storage tank 2",10500,"m3","(Inventory volume - above ground below overflow)"]
[]
[null,"Total volume",{"$f":"C5","v":10500},"m3"]
[]
[]
[null,"110% rule (CIRIA 736)"]
[]
[null,"*110% of largest tank",{"$f":"110%*C5","v":11550.000000000002},"m3"]
[]
[null,"Secondary storage to be provided",{"$f":"C12","v":11550.000000000002},"m3"]
[]
[]
[null,"*Note that 10% includes for rainfall and is the minimum allowable storage that can be provided"]
[]
[3.2,"Loss of containment - Time to empty fully"]
[]
[null,"Quick estimation of rate of loss of containment. Modelling will, however, simulate an instantaneous failure of the full volume"]
[]
[null,"Rate of flow from tank:"]
[]
[null,"Tank volume",null,null,{"$f":"C5","v":10500},"m3"]
[]
[]
[null,"Diameter of pipe (d)",null,null,0.3,"m"]
[null,"Area",null,null,{"$f":"PI()*(E28/2)^2","v":7.0685834705770348E-2},"m2"]
[null,"Discharge coefficient (Cd)",null,null,0.61]
[null,"Gravitational acceleration (g)",null,null,9.81,"m/s2"]
[]
[]
[null,"Height within tank (H),m","Flow rate (Q)\nm3/s","Diameter of Tank(m)","Volume in tank (m3) - above ground","% volume lost","Time to drop in level (min)","Time to empty (cumulative) - min"]
[null,14.85,{"$f":"$E$30*$E$29*(SQRT(2*$E$31*B35))","v":0.73599515287384487},30,{"$f":"PI()*((D35/2)^2)*B35","v":10496.846453806897},{"$f":"($E$25-E35)/$E$25","v":3.003377326765206E-4},null,{"$f":"G35","v":0}]
[null,14.5,{"$f":"$E$30*$E$29*(SQRT(2*$E$31*B36))","v":0.72727009248714725},30,{"$f":"PI()*((D36/2)^2)*B36","v":10249.4460323367},{"$f":"($E$25-E36)/$E$25","v":2.3862282634599979E-2},{"$f":"(E35-E36)/(MAX(C35:C36))/60","v":5.6024015127493332},{"$f":"H35+G36","v":5.6024015127493332}]
[null,14,{"$f":"$E$30*$E$29*(SQRT(2*$E$31*B37))","v":0.71462095204466269},30,{"$f":"PI()*((D37/2)^2)*B37","v":9896.0168588078486},{"$f":"($E$25-E37)/$E$25","v":5.7522203923062037E-2},{"$f":"(E36-E37)/(MAX(C36:C37))/60","v":8.099447902960426},{"$f":"H36+G37","v":13.701849415709759}]
[null,13.5,0.70174384413130164,30,9542.587685278997,9.1182125211524093E-2,8.2428120930782818,{"$f":"H37+G38","v":21.944661508788041}]
[null,13,0.68862598008725528,30,9189.1585117501454,0.12484204649998615,8.3940689679619123,30.338730476749951]
[null,12.5,0.67525332885228295,30,8835.7293382212938,0.15850196778844822,8.5539703639041917,38.892700840654143]
[null,12,0.66161044112154532,30,8482.3001646924422,0.19216188907691026,8.7233723608483693,47.616073201502516]
[null,11.5,0.64768024014632586,30,8128.8709911635897,0.22582181036537241,8.9032546334901728,56.519327834992687]
[null,11,0.6334437711043962,30,7775.4418176347381,0.25948173165383448,9.0947443821198934,65.614072217112579]
[null,10.5,0.61887989854729897,30,7422.0126441058865,0.29314165294229655,9.299146181848025,74.913218398960609]
[null,10,0.6039649381386899,30,7068.5834705770339,0.32680157423075867,9.5179795616365208,84.431197960597132]
[null,9.5,0.58867220435130785,30,6715.1542970481823,0.36046149551922074,9.7530267959498893,94.184224756547025]
[null,9,0.57297144942028688,30,6361.7251235193307,0.39412141680768281,10.006394359951019,104.19061911649804]
[null,8.5,0.55682815978158007,30,6008.2959499904791,0.42778133809614483,10.280592918618641,114.47121203511668]
[null,8,0.54020266308182641,30,5654.8667764616275,0.46144125938460689,10.578642839815153,125.04985487493184]
[null,7.5,0.52304897942320239,30,5301.4376029327759,0.49510118067306896,10.904215451060461,135.95407032599229]
[null,7,0.50531332116876759,30,4948.0084294039243,0.52876110196153103,11.261825292110606,147.21589561810291]
[null,6.5,0.4869321002209307,30,4594.5792558750727,0.5624210232499931,11.657096654124263,158.87299227222718]
[null,6,0.46782922942086774,30,4241.1500823462211,0.59608094453845517,12.097140900770826,170.970133172998]
[null,5.5,0.44791238604829781,30,3887.720908817369,0.62974086582691724,12.591103451942883,183.56123662494088]
[null,5,0.42706770335678129,30,3534.291735288517,0.66340078711537931,13.150978648859477,196.71221527380035]
[null,4.5,0.40515199731136975,30,{"$f":"PI()*((D56/2)^2)*B56","v":3180.8625617596654},0.69706070840384138,{"$f":"(E55-E56)/(MAX(C55:C56))/60","v":13.792862769020548},{"$f":"H55+G56","v":210.50507804282091}]
[null,4,0.38198096628019124,30,2827.4333882308138,0.73072062969230345,14.538953934747285,225.04403197756821]
[null,3.5,0.35731047602233135,30,2474.0042147019622,0.76438055098076552,15.420889377927962,240.46492135549616]
[null,3,0.33080522056077266,30,2120.5750411731105,0.7980404722692277,16.485624186156564,256.95054554165273]
[null,2.5,0.30198246906934495,30,1767.1458676442585,0.83170039355768977,17.806509266980321,274.75705480863303]
[null,2,0.2701013315409132,30,1413.7166941154069,0.86536031484615172,19.506053591899779,294.26310840053281]
[null,1.5,0.23391461471043387,30,1060.2875205865553,0.89902023613461379,21.808430902120922,316.07153930265372]
[null,1,0.19099048314009562,30,706.85834705770344,0.93268015742307586,25.182206903885753,341.25374620653946]
[null,0.5,0.1350506657704566,30,353.42917352885172,0.96634007871153793,30.841778755855934,372.09552496239542]
[null,0,0,30,0,1,43.616861804241857,415.71238676663728,"Minutes to empty to ground level"]

{"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","Strategic Sludge Storage Tank 2"]
[null,"Description","Sludge from the primary and secondary settlement tanks is treated by drum thickening before transfer to the THP buffer tanks, where it is combined with imported sludge from other sewage works. The combined sludge is then transferred to four strategic sludge storage tanks (each with volumetric capacities of 10,000m3)."]
[null,"Number of tanks","1 (Risk assessed for one tank only)"]
[null,"Volume of tank","10500 m3 (approximately) - total volume for tank\n\nAssumed full volume above ground due to lack of available drawings."]
[null,"Material of tank","Concrete"]
[null,"Above/below ground?","Above ground"]
[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 Eastern direction\n\n[As per drawing 100105164_MSD_DrainagePlan_HOW]"]
[null,"Year of construction","-"]
[null,"Surrounding area","Immediate surrounding external area is permeable ground, then hard standing."]
[]
[null,"Pump rate - to Strategic Sludge Storage Tank 2","-"]
[null,"Pump rate - from  Strategic Sludge Storage Tank 2","-"]
[]
[]
[null,"Is asset fit for purpose?","The tanks were originally designed and constructed to hold 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 visible in photos"]
[null,"Condition of pipework\n\nPipe leaks, corrosion?","No visible issues/leaks reported by operational staff"]
[null,"Protection of assets ","No vehicle impact protection - Vehicle barriers or bollards are proposed around front of the tanks along the road. Potential for the fence installed to be stronger and to be able to withstand some vehicular impact."]
[null,"Control/monitoring/alarming measures in place?","It is assumed that 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":174,"n_cols":23,"rows_kept":174,"cut":false,"hidden":false,"merged":[[26,1,26,4],[26,5,26,11],[27,1,27,4],[4,1,4,13],[32,1,32,20],[20,1,22,9],[29,1,29,4],[27,5,27,11],[28,1,28,4],[28,5,28,11],[29,5,29,11],[39,12,39,14],[40,12,40,15],[141,2,146,10],[39,11,40,11],[131,12,132,12],[136,12,137,12],[77,1,78,10],[141,14,145,22],[173,1,179,10],[101,1,106,10],[135,1,139,11],[70,1,75,10],[67,13,75,23],[111,18,112,18],[111,19,111,21],[112,19,112,22],[84,17,102,21]]}
[]
[]
[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"]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[5.2,"Catastrophic failure"]
[]
[null,"Catastrophic failure assumes the tank loses all its above ground volume and that the total volume would need to be contained."]
[]
[]
[null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,"Typical reinforced concrete wall section view"]
[null,"Material type of containment to be provided"]
[]
[null,"Type",null,null,null,"Applicability"]
[null,"Reinforced concrete/masonry flooring and bund",null,null,null,"Due to relatively large volume from loss of containment, use of a masonry/concrete bund is generally not appropriate for local containment. Because local containment necessitates a deeper bund or a long concrete wall, difficulties arise. The containment's high wall height poses a health and safety danger of a potential fall and being trapped if the tank breaks while someone is within the enclosure. Furthermore, because concrete is vulnerable to heat shrinkage and expansion, which can cause cracks, concrete/masonry bunds require constant inspection and maintenance to ensure their impermeability. Sheet pile walls are preferred to achieve complete impermeability of the containment, if space for bunded areas is not available."]
[null,"Earth banked basins, bunds and flooring",null,null,null,"Soil within site is of permeable nature - Clay or impermeable soil type not plentiful\n\nPotential for stabilised soil (lime and cement used to make it impermeable) for bund construction.\n\nArea of which bunding can be provided is however limited - assuming for example a bund height of 300mm, crest width of 100m, side slopes of 1:3 - a base width of the bund of at least 2,000mm is required.\n\nDependant on area required and nature of surrounding area, might be applicable\n\nNot applicable within the import sludge tank area."]
[null,"Containment tank",null,null,null,"There is a disused tank with a volume of approximately 660m3 to the east of the digestors. Flow could be channelled towards these disused tanks (which are in a state of disrepair). "]
[]
[]
[5.3,"Catastrophic failure in existing situation (Do Nothing) - Visualisation"]
[]
[]
[]
[]
[]
[null,null,null,null,null,null,null,null,null,null,null,null,"Visualisation as a video file"]
[null,null,null,null,null,null,null,null,null,null,null,"File Name","Base.mp4  (No Rainfall)"]
[null,null,null,null,null,null,null,null,null,null,null,null,"Base Rainfall.mp4 (Rainfall included )"]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[5.4,"Type of containment to be provided"]
[]
[null,null,null,null,null,null,null,null,null,null,null,null,null,"At this outline stage of design, the options have mainly considered 'Local' systems with passive containment assets including walls or bunds, depending on available space. Some options have included flood gates, where unavoidable, due to: the large volume of containment required; the topography of the site; or other local constraints such as proximity to sensitive receptors. In these cases, it is proposed the flood gate be locally or remotely automated. The need for flood gates can be reassessed at the next stage of design by design optimisation and a pragmatic estimation of the spill risk/volume. Similarly, penstock valves are proposed as part of the options but these can be either automated or manually operated following a pragmatic appraisal of the risk of sludge getting out of the site through the surface water drainage network. "]
[null,"Option 1: Site Containment"]
[]
[null,"Volume is proposed to be contained within the site. Where currently permeable (stone and grass), to be made impermeable with either converting this to a concrete surface or via lining.  Mobile pumps to be used to remove volume from bund from the low point.  Daily operational inspection to ensure any rainfall runoff within the bund is removed.\n\nVolume is proposed to be contained within the site and will be constructed within the treatment works site boundary.Sheet piled walls to be constructed ranging up to 2.6 m. This would limit flow throughout the entire site and contain it to the site boundary. The area to the north of the sheet piled wall and the road running through the middle of the site would be proposed to store the sludge. The approximate area of this area for storage is 27,860m2, which with a wall 2.4m high at its lowest point gives a storage volume of 66,864m3. \n\nPlease note that the Howden site is already lined due to contaminent risk and therefore additional lining is not required as part of this option.\n\nThis option protects the entire site from failure into the nearby watercourses from all the tanks listed in the permit. This sheet piled wall will be reviewed and the height refined as part of the detailed design process."]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
[]
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[]
[null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,"Advantages\nContains sludge within the site.\nPossible failure in another tank will be contained likely to be contained with the proposed solution.\nDisadvantages\nWalls are high and a gate is required limiting access"]
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[null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,"Visualisation as a video file"]
[null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,"File Name","Option.mp4  (No Rainfall)"]
[null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,"Option Rainfall.mp4 (Rainfall included )"]
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[null,null,null,null,null,null,null,null,null,null,null,null,null,null,"Flood Gate location"]
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[null,null,"As part of the assessment, sensitivity testing has been carried out to ensure that the proposed option contains the flows within the site not just for the tank being assessed but also the other tanks under the permit within the site. As a result of this, the wall was extended on the eastern side of the site.",null,null,null,null,null,null,null,null,null,null,null,"(left) Potential gate location accessed by a ring road around site. If the gate is a permanent point of access to the site the current gate structure will ned replaced with an impervious flood gate. \n"]
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[5.4,"Preferred Option"]
[]
[null,"The proposed option is the sludge to be contained within the site itself. It is the only applicable solution due to the fact that an enormous volume of sludge is to be contained over 10.000 m3.\n\nThe volume is proposed to be contained within the site boundaries with additional penstocks to block the flow. Mobile pumps to be used to remove volume from bund from low point.  Daily operational inspection to ensure any rainfall runoff within the bund is removed and that the penstocks are operational. \n\nThis option will be constructed by competent personnel and will be reviewed and refined in the detailed design stage. This is anticipated to be constructed by the end of 2024, as per the regulation date and funding."]

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[]
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[6.1,"Catastrophic failure - modes (loss of containment) - pragmatic solution"]
[]
[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$81","v":"Strategic tanks are covered so it is not anticipated that overfilling/overflow of tanks will occur."},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!$L$81","v":"L"},{"$f":"'2.Total vol. - Mitigation'!$L$6","v":"All tanks undergo a delegated inspection regime and the process parameters are monitored and understood by site operatives.\n\nDaily site inspection regime will consist of the a site walkover. Any defects located will be escalated to site manager for a repair resolution to be determined. If there is not an immediate risk posed by the defective asset and large scale repair is required then, the asset planning team will be informed in order to plan the necessary repairs. Any reactive works required will be undertaken by Site Operations team. \n\nInspection/Frequency\n>Walk round the site, identify and clear up any waste materials: Daily\n>Note signs of any deterioration of tanks or surroundings: Daily\n>Note any small leaks or spills, fix them and clean them up immediately: Daily\n>Integrity/Condition assessment all key sludge assets - Drain tank and inspect condition: 10 yearly\n\nFurther mitigation\n >A proactive planned preventative maintenance (PPM) and replacement programme linked to asset lifespan. Site Manager ensures the PPM is implemented effectively to minimise the probability of equipment malfunction. \n >A robust leak detection and repair plan will be set out and enacted\n >The site will be monitored using a telemetry to monitor tank levels and process flows. Trigger levels will be assigned to risk rating and proportional response will be taken. Alarms that protect against a loss of containment will have a response time the same as for other emergencies (Approx. 1 hr).\n>Penstock valves will be placed at strategic SW chambers to reduce the risk of sludge flows getting in to the SW drainage system. An automated solution for closing them and also any need for regrading of surfaces to reduce risk will be looked into at detailed design.\n\nControl of substances hazardous to health (COSHH) assessment undertaken for all raw materials."},null,null,null,null,null,null,null,null,null,"L"]
[null,null,"Structural failure - tank (catastrophic)",{"$f":"'1.Risk assessment'!$D$82","v":"Tanks are primarily located above ground with a proportion below ground. For any loss of containment below ground, the sludge liquid will percolate into the permeable soil at a slow rate over a long period.\n\nIn the case of significant damage above ground, the total volume contained above ground could be lost. It is however very unlikely for the tanks to fail catastrophically structurally as the tanks are fit for purpose.\n\nTotal loss of containment could occur in case of pipe failure above the ground level - If total loss of containment occurs, sludge would flow freely. If pipework fails, jetting likely to occur. This sludge would be able to flow in all directions as there is no containment immediately around the tank. The sludge would predominantly flow to the south towards the Tyne river. There are bunds on the southern and eastern boundaries of the site which would limit the flow and inhibit any sludge from escaping the site and into the nearby watercourse. Yet these bunds do not contain the sludge completely as the estimated volume is exceeds 10.000 m3."},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!$L$82","v":"L"},{"$f":"'2.Total vol. - Mitigation'!$L$7","v":"The above inspection and further mitigation proposals will be applicable to structural failure, also.\n\nBoth clean and contaminated surface water is directed to a pumping station which recirculates it back into the system. \nThe stormwater drainage of potentially contaminated areas from within the Site boundary is routed into the head of the works with no discharge outside of the site boundary. \n\nRegular daily inspections of the site drainage systems and other equipment are to be undertaken, with any repairs and maintenance carried out if necessary. All complaints and other incidents are recorded in the site diary including actions taken.\n\nThe condensate is clean, uncontaminated water and is small in quantity.  Condensate traps are checked regularly and condensate is discharged to the head of the works."},null,null,null,null,null,null,null,null,null,"L"]
[null,null,"Structural failure - tank (partial)",{"$f":"'1.Risk assessment'!$D$83","v":"Tanks are primarily located above ground. Any significant loss of containment, would spill above ground. \n\nStructural failure of the tank would mainly be through cracks.  In the case of significant cracks forming above ground, the volume contained above ground would seep through the cracks . If the cracks are significant (>6mm), the tank could potentially lose the above ground volume over a long period of time (very unlikely).\n\nDue to operational presence on site, large drops in levels in the tanks and significant leaks above ground would be noticed. Significant cracks (>6mm) below/above ground would also be easily spotted if tank is inspected. \n\nProportion of volume could be lost, but from discussions with operations, no loss of containment was experienced.\n\nTotal loss of containment is unlikely (partial loss of containment would be more likely to occur)"},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!$L$83","v":"M"},{"$f":"'2.Total vol. - Mitigation'!$L$8","v":"Original tank construction was reinforced concrete. \n\nIn the event that tank loses containment above or below ground through structural failure (cracks), sludge would weep through the cracks at a very slow rate. The volume would slowly flow down the side of the tank and gather around the tank. \n\nVery large cracks and the subsequent leaks (especially above ground) would be spotted by operations during their daily inspections and the tank would be isolated and drained down until repaired if the crack is significant. \n\nTo minimise loss of containment underground, it is advised that the tanks be structurally inspected on daily basis. Falling head tests should also be carried out to limit any potential leaks underground on weekly basis. Tank to be refurbished if necessary. Ultrasonic meters are suggested in Digestion tank which should alarm when pumps (feed pumps) are not in operation, but the level in the tank drops a certain distance to ensure any significant loss of containment underground is monitored.\n\nIn the unlikely event that tank loses significant containment above ground through structural failure (large cracks), based on topography, sludge will cascade towards the road to the north/west and eventually into the drainage system. Potential to infiltrate into the ground around tank (grass) or cascade into the drainage network (liquor return) is minimal.\n\nPermeable areas around the tanks (stone and grass) and low lying grassed area are also to be replaced with impermeable hardstanding to remove the pathway to the ground. Soakaways to be filled in (concrete) and all connected drainage to connect to liquor return."},null,null,null,null,null,null,null,null,null,"L"]
[null,null,"Structural failure - pipework (catastrophic)",{"$f":"'1.Risk assessment'!$D$84","v":"In the unlikely event where the above ground pipework fails and breaks off, a significant volume could be lost if the necessary pump controls are not in place or the valves are not closed by operational staff to limit loss of containment.\n\nIf an incident occurred during manned hours, the pipes would be shut down immediately and valves closed by operational staff if the pipes were to fail. In the case where critical pipework fails and valves cannot mitigate the spillage, the digester could lose its full volume.\n\nTotal loss of containment could occur. - If total loss of containment occurs sludge will flow freely, it is able to flow in all directions as there is no containment immediately around the tank.he sludge would predominantly flow to the south towards the Tyne river. There are bunds on the southern and eastern boundaries of the site which would limit the flow and inhibit any sludge from escaping the site and into the nearby watercourse. Yet these bunds are quite insignificant in height and do not contain the sludge completely as the estimated volume is exceeds 10.000 m3.  The sludge will mainly flow to the south leading down to river Tyne located directly below the tank towards an outfall in the river, which has a penstock attached however it is not in full use so the outfall would allow sludge off site."},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!$L$84","v":"L"},{"$f":"'2.Total vol. - Mitigation'!$L$9","v":"If catastrophic failure of the above ground pipework occurs (i.e. rising main pipe failure), assuming the pumps have the necessary pressure controls (Low and high pressure switches to trip the pump), the volume contained in the pipe length should be contained within pipe and valve chamber.\n\nTo mitigate the very unlikely occurrence where the above ground pipework could fail/collapse, the necessary pump controls (Low and high pressure switches to trip the pump) need to be put in place, if not already, if there is a sudden loss of pressure in the rising mains (feed, mixing, hot water pumps rising mains), the pumps should stop. \n\nAll above ground pipework and chambers to be inspected structurally on a daily basis for any leaks and necessary falling head tests conducted on weekly basis. Pipework and chambers to be refurbished or replaced, if necessary to BAT standards. \n\nIn the unlikely event that tank loses significant containment above ground through structural failure (large cracks), based on topography, sludge will cascade towards the road to the north/west and eventually into the drainage system. Potential to infiltrate into the ground around tank (grass) or cascade into the drainage network (liquor return) is minimal.\n\nPermeable areas around the tank (stone and grass) and low lying grassed areas is also to be replaced with impermeable hardstanding to remove the pathway to the ground. Soakaways to be filled in (concrete) and all connected drainage to connect to liquor return."},null,null,null,null,null,null,null,null,null,"L"]
[null,null,"Structural failure - pipework (partial)",{"$f":"'1.Risk assessment'!$D$85","v":"It is assumed that the majority of pipework and connections are located above ground. \n\nIf loss of containment occurs underground (through leaks, joints and seals), sludge will percolate into the soil at a slow rate over a long period. If significant leaks, localised wet areas will be present above ground and jetting is likely to occur.\n\nIf loss of containment occurs above ground through leaks or damage to pipework, due to the permeable ground around tank, sludge will also percolate into the soil at a slow rate over a long period.\n\nDue to operational presence on site, significant leaks (above or below) ground would be noticed and loss of containment would be mitigated through operational measures (closing of valves). The site is manned and valves present on all pipework from all tanks would be able to be closed, minimising the risk of significant jetting.\n\nTotal loss of containment is unlikely (partial loss of containment would be more likely to occur)"},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!$L$85","v":"M"},{"$f":"'2.Total vol. - Mitigation'!$L$10","v":"No known visible leaks in the tank area.\n\nAs construction was fit for purpose at the time of construction, secondary containment provision is not considered for the underground pipework.\n\nTo assess the condition of underground pipework and chambers, CCTV and the necessary leakage detection (falling head tests) should be done on weekly basis to check if any leakage is experienced.  All above ground pipework and chambers to be inspected structurally on daily basis for any leaks and necessary falling head tests conducted on weekly basis. Pipework and chambers to be refurbished or replaced, if necessary to BAT standards. \n\nIn the unlikely event that tank loses significant containment above ground through structural failure (large cracks), based on topography, sludge will cascade towards the road to the north/west and eventually into the drainage system. Potential to infiltrate into the ground around tank (grass) or cascade into the drainage network (liquor return) is minimal.\n\nPermeable areas around the tanks (stone and grass) and low lying grassed areas is also to be replaced with impermeable hardstanding to remove the pathway to the ground. Soakaways to be filled in (concrete) and all connected drainage to connect to liquor return."},null,null,null,null,null,null,null,null,null,"L"]
[null,null,"Vehicular impact (partial to catastrophic)",{"$f":"'1.Risk assessment'!$D$86","v":"No known vehicle impacts - some vehicle barriers/protection can be seen on site photos.\n\nVehicles could potentially impact and damage concrete digestion tank which is located above ground. Vehicular impact could cause some damage to the tank (cracking), if significant, proportion of above ground volume could be lost. Vehicle is however unlikely to damage underground sections of tanks or displace any liquid within them. \n\nTotal loss of containment could occur if the vehicle impact causes significant damage to the tank. High speed impact unlikely, but vehicle could damage pipework connected to tank (mixer pump) and cause a significant hole in the tank at low level. Could impact a potential weak point."},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!$L$86","v":"M"},{"$f":"'2.Total vol. - Mitigation'!$L$11","v":"Vehicle barriers or bollards are proposed around front of the tanks along the road. Potential for the fence installed to be stronger and to be able to withstand some vehicular impact. The likelihood of such occurrence in low.\n\nThis is to mitigate any potential impacts from vehicles and potential damage which could lead to loss of containment. Since, The tank base is at road level there are chances of a vehicular collisions.\n\nPermeable areas around the tanks (stone and grass) and low lying grassed areas is also to be replaced with impermeable hardstanding to remove the pathway to the ground. Soakaways to be filled in (concrete) and all connected drainage to connect to liquor return."},null,null,null,null,null,null,null,null,null,"L"]
[null,null,"Vandalism",{"$f":"'1.Risk assessment'!$D$87","v":"No known vandalism to tanks or pipework - CCTV cameras on site. Site is enclosed by steel fencing all around.\n\nIf vandalism damage were to occur, total loss of containment is unlikely, but could occur if significant damage or on theft of mixer pumps and pipework. Partial loss of containment would be more likely to occur if slight damage was done."},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!$L$87","v":"L"},{"$f":"'2.Total vol. - Mitigation'!$L$12","v":"Access to Site and waste is restricted by a chain link security fence. The Site also benefits from a CCTV systems. Regular inspections of the boundary fencing and buildings are undertaken to ensure that these have not \nbeen compromised and continue to prevent easy access to Site.\n"},null,null,null,null,null,null,null,null,null,"L"]
[null,null,"Flooding",{"$f":"'1.Risk assessment'!$D$88","v":"The site is located in an Environment Agency zone 1 flood risk area. Areas withinzone 1 have 1 in a 1,000 chance of river or sea related flooding. However, the area approximately 50m to the east and 80m to the south of the site is located within a zone 3 flooding risk area due to the proximity of the River Tyne. Areas within flood zone 3 have been shown to be at a 1% or greater probability offlooding from rivers or 0.5% or greater probability of flooding from rivers/ the sea.\n[As per Site Condition Report 100105164_MSD_SCR_HOW, Flooding, Page 3]"},null,null,null,null,null,null,{"$f":"'1.Risk assessment'!$L$88","v":"M"},{"$f":"'2.Total vol. - Mitigation'!$L$13","v":"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"]
[]
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[null,"Implimenting 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 implimented in conjunction with a good maintenance strategy"]

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[7.1,"Secondary containment volume requirement - Inventory volume (above ground)"]
[]
[null,"The most probable failure of the tank, based on experience, is assumed to be through leakage or discharge from pipe connections into the tank (mixer pump pipework) and cracks in the tank, causing it to lose a proportion of its total volume and in worst case scenario all its above ground volume. \n\nDue to the very unlikely event of catastrophic failure of the tank, causing total loss of containment, the secondary containment volume was based on the worst case between the foaming volume (most likely) and the loss from the digester through significant leaks and cracks (1500mm of digester height)."]
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[7.2,"Above ground volume - containment to be provided"]
[]
[null,"Catastrophic failure",{"$f":"'3.Containment volume-Total vol.'!C7","v":10500},"m3"]
[]
[null,"Foaming volume",{"$f":"1.1*105","v":115.50000000000001},"m3"]
[null,"1000mm height loss of tank",{"$f":"1*(PI()*(15/2)^2)","v":176.71458676442586},"m3"]
[null,"1500mm height loss of tank",{"$f":"1.5*(PI()*(15/2)^2)","v":265.07188014663882},"m3"]
[null,"15% of digester",{"$f":"1420*0.15","v":213},"m3"]
[]
[null,"Pragmatic volume",{"$f":"MAX(C17:C20)","v":265.07188014663882},"m3"]
[]
[7.3,"Estimate of area required - local containment (proportion of volume)"]
[]
[]
[null,"Volume loss","Height of containment (mm)","Area based on flat ground (m2)"]
[null,{"$f":"$C$22*1.1","v":291.5790681613027},100,{"$f":"B28/(C28/1000)","v":2915.7906816130267}]
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