{"text_format":"1","workbook":"xlsx","n_sheets":12,"sheets":["Cover","Notes","Introduction","1) a) Source","1) b) Pathway","1) c) Receptors","2) Site Hazard Rating","3) Likelihood","4) Site Risk and Classification","5) Standard Containment Designs","Sheet1","Risk Scoring"],"not_rendered":{"charts":0,"images":23,"macros":1,"external_links":1,"defined_names":56,"comments":4,"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","index":0,"n_rows":56,"n_cols":6,"rows_kept":56,"cut":false,"hidden":false,"merged":[]}
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[null,"JOB TITLE",null,null,null,"Blackburn IED Application"]
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[null,"JOB NUMBER",null,null,null,331002023]
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[null,"MADE BY",null,null,null,"Chloe Austin-Bangs and Elizabeth Wilson"]
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[null,"CHECKED BY"]
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[null,"DATE",null,null,null,"2022-10-10"]
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[null,"Description of spreadsheet",null,null,null,"This spreadsheet provides a secondary containment risk assessment for Blackburn Sludge Treatment Centre (STC) using the Anaerobic Digestion and Biogas Association (ADBA) secondary containment risk assessment tool. "]
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[null,"Sheet Number prefix",null,null,null,""]
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[null,"Member/Location",null,null,null,""]
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[null,"Drawing Reference",null,null,null,""]
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[null,"Filename",null,null,null,"Blackburn ADBA Draft_V1"]
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[null,"CONTENTS OF SPREADSHEET"]
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[null,"Sheet",null,"Description"]
[null,"Cover"]
[null,"Notes"]
[null,"Introduction",null,"Introduction to the ADBA Tool"]
[null,"1 a) Source",null,"The inventory of materials for Blackburn STC is provided in the worksheet 1a) Source "]
[null,"1 b) Pathway",null,"The Pathway information for Blackburn STC is provided in the worksheet 1) b) Pathway "]
[null,"1 c) Receptors",null,"The Receptor information for Blackburn STC is provided in the worksheet 1) c) Receptor."]
[null,"2) Site Hazard Rating",null,"The Site Hazard Rating is displayed in the worksheet 2) Site Hazard Rating"]
[null,"3) Likelihood",null,"The likelihood of loss of primary containment and the associated mitigation."]
[null,"4) Site Risk and Classification",null,"The Site Hazard Rating and Classification is in this worksheet"]
[null,"5) Standard Containment Design",null,"The Standard Containment Design is in this worksheet"]
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[null,"AUTHORISATION OF LATEST VERSION"]
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[null,"Type and method of check",null,null,null,"Review of method, inputs and assumptions"]
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[null,"Signatures & dates:",null,null,"Made by ","Chloe Austin-Bangs and Elizabeth Wilson"]
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[null,null,null,null,"Checked "]
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[null,null,null,null,"Reviewed"]
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[null,"REVISIONS",null,null,"Current Revision ","V1"]
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[null,"Rev.","Date","Made by","Checked"," Description"]
[null,"V1","2022-10-10","CA-B & EW","SH / PD / PW"]

{"sheet":"Notes","index":1,"n_rows":62,"n_cols":3,"rows_kept":62,"cut":false,"hidden":false,"merged":[[39,1,39,2],[46,1,46,2],[52,1,52,2],[61,1,61,2],[1,1,1,2],[3,1,5,2],[6,1,6,2],[7,1,9,2],[15,1,15,2],[19,1,19,2]]}
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[null,"(1) Purpose of spreadsheet"]
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[null,"This spreadsheet outlines the information and data utilised, as well as the assumptions applied to undertake a secondary containment risk assessment for Blackburn Sludge Treatment Centre (STC) based on the using the Anaerobic Digestion and Biogas Association (ADBA) secondary containment risk assessment tool and associated guidance. The ADBA risk assessment is based on CIRIA 736. Containment systems for the prevention of pollution: Secondary, tertiary and other measures for industrial and commercial premises. "]
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[null,"(2) Key Assumptions"]
[null,"Any assumptions are outlined in the spreadsheet."]
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[null,"(3) Basis of calculations"]
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[null,"ADBA Risk Assessment tool."]
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[null,"(4) References"]
[null,"All references are outlined in the spreadsheet."]
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[null,"(5) Special features"]
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[null,null,"Input Cell"]
[null,null,"Key Outputs"]
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[null,"(6) Holds or items that require Clarification"]
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[null,"(7) Summary"]
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[null,"Best Practice Guide"]

{"sheet":"Introduction","index":2,"n_rows":75,"n_cols":9,"rows_kept":75,"cut":false,"hidden":false,"merged":[]}
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[null,null,null,null,null,null,null,"Although this tool works as a standalone tool, we recommend you read this first:","ADBA CIRIA736 Bund Classification Assessment"]
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[null,"There are 5 steps to follow:"]
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[null,"1)","Identify the hazard posed to the environment by the inventory of materials held on the site and the location of the site"]
[null,null,"a. Categorise the source"]
[null,null,"b. Identify the pathways"]
[null,null,"c. Identify the receptor"]
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[null,"2)","The Site Hazard Rating is derived by this tool from the combination of the hazards assessed above"]
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[null,"3)","Calculate the likelihood of a loss of primary containment event occurring"]
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[null,"4)","The combination of the Site Hazard Rating and the likelihood of a loss of containment occuring gives the site risk rating and required secondary containment classification"]
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[null,"5)","From the class of containment needed, identify suitable designs from the 'Standard Containment Designs' sheet"]
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[null,"Additional Guidance"]
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[null,"The worksheets in this spreadsheet are protected to prevent inadvertant damage to the tool.  To remove the protection, the password is CIRIA736"]

{"sheet":"1) a) Source","index":3,"n_rows":39,"n_cols":15,"rows_kept":39,"cut":false,"hidden":false,"merged":[[3,12,3,14],[5,12,6,12],[25,1,25,3]]}
[]
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[]
[null,"Material","Material","Total Enclosed Quantity","units","Storage","Flammability","Corrosive","Ecotoxicity (based on LD and quantity)","Environmental hazard rating ","Justification",null,"Risk quantification"]
[null,"Feedstock",null,null,null,null,null,null,null,null,null,null,"Material","Volume (m3)","Environmental Hazard Rating"]
[null,null,null,null,null,null,null,null,null,null,null,null,"Wet Sludge","0-99","Low"]
[null,"Raw sludge ","Liquid",1800,"m3","Unthickened Sludge Storage Tank (above ground, glass fused to steel constructed tank) and associated pipework","Not flammable","No","Low","H","Permitted waste types (wet sludge) are non-hazardous, however include substances which exhibit a high source hazard and have an unfavourable influence on the oxygen balance (CIRIA Guidance, Appendix A2).  This would result in an Environmental Hazard rating of High. ",null,null,"100-999","Medium"]
[]
[null,null,null,null,null,null,null,null,"Feedstock Overall Rating","H","Any material with a \"High\" rating means the overall rating is High."]
[null,"Process"]
[null,"Dewatered / thickened sludge","Liquid",10000,"m3","Digesters x4 (partially buried, concrete unlined constructed tanks) and associated pipework","Not flammable","No","Low","H","Permitted waste types (wet sludge) are non-hazardous, however include substances which exhibit a high source hazard and have an unfavourable influence on the oxygen balance (CIRIA Guidance, Appendix A2).  This would result in an Environmental Hazard rating of High. "]
[null,"Post primary digested sludge","Liquid",1200,"m3","Post digestion tank no. 3 (above ground, glass fused to steel constructed tank) and associated pipework","Not flammable","No","Low","H","Permitted waste types (wet sludge) are non-hazardous, however include substances which exhibit a high source hazard and have an unfavourable influence on the oxygen balance (CIRIA Guidance, Appendix A2).  This would result in an Environmental Hazard rating of High. "]
[null,"Post primary digested sludge","Liquid",1800,"m3","Post digestion tank no. 1 & no. 2 (partially buried, concrete constructed tanks) and associated pipework","Not flammable","No","Low","H","Permitted waste types (wet sludge) are non-hazardous, however include substances which exhibit a high source hazard and have an unfavourable influence on the oxygen balance (CIRIA Guidance, Appendix A2).  This would result in an Environmental Hazard rating of High. "]
[null,"Dewatered / thickened sludge","Liquid",1400,"m3","EEH Feed Tank (above ground, glass fused to steel constructed tank) and associated pipework","Not flammable","No","Low","H","Permitted waste types (wet sludge) are non-hazardous, however include substances which exhibit a high source hazard and have an unfavourable influence on the oxygen balance (CIRIA Guidance, Appendix A2).  This would result in an Environmental Hazard rating of High. "]
[null,"Dewatered / thickened sludge","Liquid",1680,"m3","High Rate Enzymic Hydrolysis (EEH) No. 1-6 (above ground, glass fused to steel constructed tanks) and associated pipework","Not flammable","No","Low","H","Permitted waste types (wet sludge) are non-hazardous, however include substances which exhibit a high source hazard and have an unfavourable influence on the oxygen balance (CIRIA Guidance, Appendix A2).  This would result in an Environmental Hazard rating of High. "]
[null,"unthickened sludge","Liquid",800,"m3","Drum Thickener Feed Tank 1 & 2\n\n400m3 each.","Not flammable","No","Low","H","Permitted waste types (wet sludge) are non-hazardous, however include substances which exhibit a high source hazard and have an unfavourable influence on the oxygen balance (CIRIA Guidance, Appendix A2).  This would result in an Environmental Hazard rating of High. "]
[null,"Dewatered / thickened sludge","Liquid",1200,"m3","Centrate and filtrate tank","Not flammable","No","Low","H","Permitted waste types (wet sludge) are non-hazardous, however include substances which exhibit a high source hazard and have an unfavourable influence on the oxygen balance (CIRIA Guidance, Appendix A2).  This would result in an Environmental Hazard rating of High. "]
[null,"Dewatered / thickened sludge","Liquid",19,"m3","Lamella Plant","Not flammable","No","Low","H","Permitted waste types (wet sludge) are non-hazardous, however include substances which exhibit a high source hazard and have an unfavourable influence on the oxygen balance (CIRIA Guidance, Appendix A2).  This would result in an Environmental Hazard rating of High. "]
[null,null,null,null,null,null,null,null,"Process Overall Rating","H","Any material with a \"High\" rating means the overall rating is High."]
[null,"Additives and site chemicals"]
[null,"Waste Oil","Liquid",null,"m3",null,"Flammable","No",null,"H","Oil has a high rating. Small amounts also held in small containers within the installation."]
[null,"Clean Oil","Liquid","10-100","m3","Oil (diesel) store (above ground, unlined metal)","Flammable","No",null,"H","Oil has a high rating. Small amounts also held in small containers within the installation."]
[null,"Liquid Polyelectrolyte - thickening","Liquid",null,"m3",null,"Not flammable","No",null,"M","Material stored externally on impermeable surfacing. Low ecotoxicity for the quantities stored."]
[]
[null,null,null,null,null,null,null,null,"Chemicals Overall Rating","M","The overall source assessment for additives and site chemicals is  considered to be Medium. "]
[null,"Fire fighting agents and cooling water spillages"]
[null,"Fire Fighting Agents harmful in their own right or contaminated by inventory","Liquid",null,null,null,"Not flammable","No","Low","L","Low in the example in the ADBA Tool."]
[null,"Fire fighting and cooling water contaminated by inventory",null,null,null,null,"Not flammable","No","Low","L","Low in the example in the ADBA Tool."]
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[null,null,null,null,null,null,null,null,"Spillages Overall Rating","L","All the hazards are \"Low\" therefore the overall rating is low"]
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[null,null,null,null,null,null,null,null,"Sources Overall Hazard Rating",{"$f":"IF(OR(J9=\"H\",J19=\"H\",J31=\"H\"),\"H\",IF(OR(,J25=\"M\"=\"M\"),\"M\",\"L\"))","v":"H"}]
[]
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["H"]
["M"]
["L"]

{"sheet":"1) b) Pathway","index":4,"n_rows":100,"n_cols":15,"rows_kept":100,"cut":false,"hidden":false,"merged":[]}
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[null,null,null,null,null,null,null,"Postcode","PR5 0XA"]
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[null,"Pathway - the route from primary containment to receptor",null,null,null,"Environmental hazard rating ","Notes","Source","Description","Link","Image","Source","Description","Source","Source"]
[null,"Site layout and drainage"]
[null,"If any of the site inventory has a runoff time of a few minutes…",null,null,null,null,"N/A  - Run-off time is an estimate of how long it would take to flow to the nearest receptor."]
[null,"If any of the site inventory has a runoff time of a few hours.…",null,null,null,"H","It is assumed the site inventory has a runoff time of a few hours due to the form of sludge and the distance to the receptors. 2D modelling has been completed for the site that identifies sludge would leave the site in the event of failure of the Digester No 4,  EEH Feed Tank, Enzymic Hydrolysis (EEH) No 6 Tank and Unthickened Sludge Storage Tank. Realistically, the physical property of sludge is slow flowing suspension and relatively immobile. Notwithstanding the limitations of the modelling software. "]
[null,"If any of the site inventory has a runoff time of a few days…",null,null,null,null,"N/A  - Run-off time is an estimate of how long it would take to flow to the nearest receptor."]
[null,"If any of the site inventory has a runoff time of a few weeks…",null,null,null,null,"N/A  - Run-off time is an estimate of how long it would take to flow to the nearest receptor."]
[]
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[null,"Topography, geology and hydrology"]
[]
[null,"Made ground (artificial deposit)",null,null,null,"M","A medium environmental hazard rating has been selected for geology due to made ground being encountered on site comprising of sandy gravelly clay at the surface. At BH202 a strong petroleum odour was noted in the made ground, this indicates that the high sand and gravel content of the made ground provides little barrier to surface infiltration. Clayey glacial till is present beneath the made ground in both locations.","ESI (2014) Hydrogeological Risk Assessment for Sludge Assets at Blackburn WWTW, Report Reference 60168ADR1","Both BH201 and BH202 encounter made ground comprising of sandy gravelly clay at the surface extending to 1.70 mbgl and 2.20 mbgl respectively. At BH202 a strong petroleum odour was noted in the made ground, this indicates that the high sand and gravel content of the made ground provides little barrier to surface infiltration. Clayey glacial till is present beneath the made ground in both locations."]
[null,"Superficial deposits - Unproductive Strata",null,null,null,"L","Superficial deposits on site include Glacial Till. This clayey till is sandy and contains sandstone and siltstone gravels. With depth the clay becomes stiffer and laminated but still remains slightly sandy and slightly gravelly. The Glacial Till superficial deposits are classified as Unproductive Strata with very limited permeability and groundwater flow potential therefore a Low Environmental Hazard Rating has been selected.","BGS geoviewer","Glacial Till","http://mapapps2.bgs.ac.uk/geoindex/home.html",null,"ESI (2014) Hydrogeological Risk Assessment for Sludge Assets at Blackburn WWTW, Report Reference 60168ADR1","Clayey glacial till is present beneath the made ground in both locations. At BH203, on the Site periphery shows a thin layer of topsoil beneath which superficial deposits consisting of clayey glacial till are present. None of the Site investigation boreholes encountered bedrock and all boreholes show clayey glacial till to the base. This clayey till is sandy and contains sandstone and siltstone gravels. With depth the clay becomes stiffer and laminated but still remains slightly sandy and slightly gravelly. "]
[null,"Bedrock - Secondary A Aquifer",null,null,null,"M","The site is underlaid by the Millstone Grit Group. Bedrock was not encountered in the site investigation boreholes and is likely to be up to 35 mbgl. The bedrock is designated as a Secondary A Aquifer however the permeability of the Millstone Grit is likely to be highly variable due to the range of lithologies present and the characteristic mudstone and siltstone layers.  A Medium Environmental Hazard Rating has therefore been selected.\n","BGS geoviewer","Millstone Grit Group","http://mapapps2.bgs.ac.uk/geoindex/home.html",null,"ESI (2014) Hydrogeological Risk Assessment for Sludge Assets at Blackburn WWTW, Report Reference 60168ADR1","None of the Site investigation boreholes encountered bedrock and all boreholes show clayey glacial till to the base. \n\nAnalysis of all available BGS logs from boreholes within 1 km of the Site indicates that the bedrock is likely to be as much as 35 mbgl (BGS, 2014) and covered by clay rich till material."]
[null,"Hole Brook",null,null,null,"H","Hole Brook is located to the east of the Site and at its closest point is approximately 50 m south-east of the Site. Hole Brook flows in an south-westerly direction. The confluence with the River Darwen is approximately 500 m downstream of the Site. \n\nHole Brook will transport any contaminants that enter the Brook through groundwater flow to other potential receptors downstream, i.e. River Darwen. \n\nA high risk has been selected as the 2D modelling for the site identifies sludge does leave the site.","Catchment Data Explorer (CDE)","Hole Brook is categorised as 'moderate' with regard to Ecological and Physio-chemical quality elements but fail for chemical elements.  \n\nDiffuse and point sources from a range of categories including Water Industry and Urban and transport, and physical modification are reasons for the waterbody failing to meet the  'good' ecological status.","Darwen - conf Roddlesworth to tidal | Catchment Data Explorer | Catchment Data Explorer",null,"ESI (2014) Hydrogeological Risk Assessment for Sludge Assets at Blackburn WWTW, Report Reference 60168ADR1","The Hole Brook, a tributary of the River Darwen flows north east to south west to the east of the Site (Figure 1.1). At its closest point it is approximately 50 m from the south east corner of the Site, it is here that discharge from the WwTW is pumped to surface water. The confluence with the River Darwen is approximately 500 m downstream of the Site. "]
[null,"Mitigation - do these apply?"]
[null,"Some secondary and tertiary containment system is present (see Likelihood assessment)"]
[null,"Majority of spills will be contained within the hard surfaced and drained areas and returned to the WwTW for treatment. \n"]
[null,"2D modelling for the site identifies routes to river or watercourse (Hole Brook reaching River Darwen), mitigations have been applied and mitigation modelling confirms containment. \n"]
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[null,null,null,null,"Path & Mitigation Overall Rating","H","Justification: \n\n- Medium environmental hazard rating assessed for underlying bedrock Secondary A Aquifer and High rating for nearby Hole Brook.\n- Site investigation boreholes show that the Made Ground is underlain by a layer of clay. \n- Modelling identifies a catastrophic spill (failure of all tank installation areas) would leave the site via a potential route through overland flow in certain circumstances (see above). \n- Mitigation measures have been proposed in the modelling report to allow for effective containment of spills on site (see likelihood). "]
[null,"Climatic conditions"]
[null,"Annual rainfall > 1000 mm",null,1058.07,null,"M","The annual rainfall is greater than 1,000 mm","Met  Office","UK climate averages - Myerscough Climate Station","Myerscough (Lancashire) UK climate averages - Met Office"]
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[null,"Fire Fighting Water"]
[null,"Flammable materials normally present on site in large quantities",null,null,null,"L"," - There is limited flammable materials on the site that would combust over long periods and would require significant volumes of fire fighting water. \n - The key flammable material is in the digesters if an explosion on the headspace could communicate with the gas system, but in such scenario the main pollution is likely to be air.\n- Controls are in place in accordance with DSEAR.  A hazardous areas risk classification has been undertaken in accordance with DSEAR. Equipment is adequately rated in accordance with the zoning classification.\n - If firefighting was needed on the site, the drainage system returns surface water to treatment within the WwTW.\n - Firefighting water is therefore not considered to be a pathway risk. "]
[null,"Fire fighting and cooling water contaminated by inventory",null,null,null,"L"]
[null,"Location"]
[null,"Flooding",null,null,null,"L"," - A low environmental hazard rating has been selected as the site is classed as Flood Zone 1.","EA Flood Map for Planning","The site is classified as a Flood Zone 1 (low probability of flooding from rivers and the sea)","Flood risk information for this location - Flood map for planning - GOV.UK (flood-map-for-planning.service.gov.uk/)"]
[null,"Site is connected to a Wastewater Treatment Works",null,null,null,"L"," - The WwTW is designed with capacity to treat peaks in flow and loads including from surface water drainage input from the site.  \n - In the event of a catastrophic failure on site, the SCADA system would manage the Wastewater treatment process to contain any additional load within the system, where possible.  In addition high level and treatment alarms would alert site operators, who would start the emergency procedures in line with the site accident protocols in the site EMS and shut down/divert processes that risk the WwTW discharge consent. \n - The potential risk of releases via the WwTW is considered to be low. \n"]
[null,"The site slopes to the south.",null,null,null,"M","Topography at the WWTW slopes to the south towards Hole Brook by approximately 20m.","ESI (2014) Hydrogeological Risk Assessment for Sludge Assets at Blackburn WWTW, Report Reference 60168ADR1","The Site is situated on the north slope of the River Darwen valley and across the Site the land drops approximately 20 m from the north to south. A further 25 m drop in height is present between the Site boundary and the Hole Brook. "]
[null,null,null,null,"Site Considerations  Overall Rating","M"]
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[null,null,null,null,"Pathway Overall Hazard Rating",{"$f":"IF(OR(F23=\"H\",F36=\"H\"),\"H\",IF(OR(F23=\"M\",F36=\"M\"),\"M\",\"L\"))","v":"H"}]
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["H"]
["M"]
["L"]

{"sheet":"1) c) Receptors","index":5,"n_rows":94,"n_cols":20,"rows_kept":94,"cut":false,"hidden":false,"merged":[]}
[]
[null,null,null,null,null,null,null,null,null,null,null,"Postcode","PR5 0XA"]
[]
[null,"Receptors","Within","units",null,null,null,null,null,"Environmental hazard rating ","Notes","Source","Description","Link","Image","Source","Description","Source","Description","Source"]
[null,"Watercourses and bodies"]
[]
[null,"Hole Brook",50,"m",null,null,null,null,null,"H","Hole Brook is located to the east of the Site and at its closest point is approximately 50 m south-east of the Site. Hole Brook flows in an south-westerly direction. The confluence with the River Darwen is approximately 500 m downstream of the Site. \n\nHole Brook will transport any contaminants that enter the Brook through groundwater flow to other potential receptors downstream, i.e. River Darwen.  A High Environmental Hazard Rating has therefore been selected.",null,null,null,null,"ESI (2014) Hydrogeological Risk Assessment for Sludge Assets at Blackburn WWTW, Report Reference 60168ADR1","The Hole Brook is located approximately 50 m from the south east boundary of the Site. The change in elevation between the brook and the Site is approximately 25 m. Sludge leaking from the raw, digestion or liquor sources into the made ground and upper superficial deposits is expected to flow laterally towards the brook. The leaked contaminant would then form a seep upon reaching the slope edge and will flow down the slope to the brook as overland flow. "]
[null,"Bedrock - Secondary A Aquifer","Beneath site",null,null,null,null,null,null,"M","The site is underlaid by the Millstone Grit Group. Bedrock was not encountered in the site investigation boreholes and is likely to be up to 35 mbgl. The bedrock is designated as a Secondary A Aquifer however the permeability of the Millstone Grit is likely to be highly variable due to the range of lithologies present and the characteristic mudstone and siltstone layers.  A Medium Environmental Hazard Rating has therefore been selected.","BGS geoviewer","Millstone Grit Group","http://mapapps2.bgs.ac.uk/geoindex/home.html",null,"ESI (2014) Hydrogeological Risk Assessment for Sludge Assets at Blackburn WWTW, Report Reference 60168ADR1"]
[null,"Abstractions","Beneath site","m",null,null,null,null,null,"H","The site is located within a Zone 3 groundwater source protection zone, hence a High Environmental Hazard Rating has been selected. ","Magic map Source Protection Zones merged (England)","Magic map: SPZ3","Magic Map Application (defra.gov.uk)",null,"ESI (2014) Hydrogeological Risk Assessment for Sludge Assets at Blackburn WWTW, Report Reference 60168ADR1","A source protection zone (SPZ) zone 3 is present from the boundary of the sandstone to the west and from the River Darwen northwards within the sandstone aquifer. This SPZ zone 3 is located beneath the extreme north west corner of the site, but not beneath the sludge treatment facility. The abstraction associated with this source protection zone is approximately 2 km north west of the Site. "]
[null,"SSSI",2000,"m",null,null,null,null,null,"H","Darwen River Section Sites of Special Scientific Interest (SSSI) is located 455 m south-east of the site and Beeston Brook Pasture (SSSI) is located 1.8 km south-west of the Site. The status of each SSSI relates to geological interest and the biological environment respectively, therefore a High Environmental Hazard Rating has been selected.","Magic Map Statutory Designations",null,"Magic Map Application (defra.gov.uk)"]
[null,"WwTWs",50,"m",null,null,null,null,null,"L","The WwTWs activities encompass a significant number of assets over a large surface area.  Direct impact on site activities/operations are extremely unlikely as sludge would not accumulate to a depth where there was risk of disruption to electrical equipment (i.e. control cabinets) or other assets. "]
[null,null,null,null,null,null,null,null,"Water Overall Rating","H","Justification: Hole Brook has a High Environmental Hazard Rating which is located 50m south-east of the site and has the potential to carry contaminants from groundwater flow.  The Site is located within a SPZ 3 which is rated as a High Environmental Hazard. A SSSI (Darwen River Section) is located within 500 m of the Site which is rated as a High Environmental Hazard."]
[null,"Habitation"]
[null,"Commercial",200,"m",null,null,null,null,null,"L","Commercial properties are located to the north of the WwTW, the closest being located approximately 170 m to the north including a petrol station and hotel.\n","Google Earth (2022)"]
[null,"Highway - A59",200,"m",null,null,null,null,null,"L","A59 is located to the north of the WwTW, running east to west. Spring Lane and Cuerdale Lane are located immediately to the north-east and north-west respectively of the wider WwTW.","Google Earth (2022)"]
[null,"Residential dwellings",200,"m",null,null,null,null,null,"M","Individual residential properties are located within 200m of the site to the south and north-east.","Google Earth (2022)"]
[]
[null,null,null,null,null,null,null,null,"Habitation Overall Rating","M","Residences in close proximity to Site."]
[null,"Other"]
[null,null,null,null,null,null,null,null,null,null,null," "]
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[]
[null,null,null,null,null,null,null,null,"Receptors Overall Hazard Rating",{"$f":"IF(OR(J12=\"H\",J18=\"H\"),\"H\",IF(OR(J12=\"M\",J18=\"M\"),\"M\",\"L\"))","v":"H"},null,"  "," "]
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[]
[]
[]
["H"]
["M"]
["L"]

{"sheet":"2) Site Hazard Rating","index":6,"n_rows":106,"n_cols":5,"rows_kept":106,"cut":false,"hidden":false,"merged":[[12,1,12,3],[3,1,3,4]]}
[]
[]
[]
[null,"Calculated hazard ratings:"]
[null,"Source","Pathway","Receptor","Site Hazard Rating"]
[null,{"$f":"'1) a) Source'!J34","v":"H"},{"$f":"'1) b) Pathway'!F39","v":"H"},{"$f":"'1) c) Receptors'!J23","v":"H"},{"$f":"IF(E106<6,\"Low\",IF(E106<10,\"Medium\",\"High\"))","v":"High"}]
[]
[]
[]
[]
[]
[]
[null,"Possible Combination",null,null,"Site Hazard Rating"]
[null,"L","L","L","Low"]
[null,"M","M","L","Low"]
[null,"H","L","L","Low"]
[null,"M","M","M","Medium"]
[null,"H","M","L","Medium"]
[null,"H","H","L","Medium"]
[null,"H","M","M","High"]
[null,"H","H","M","High"]
[null,"H","H","H","High"]
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[null,"Rating lookup table"]
[null,"L",1]
[null,"M",2]
[null,"H",3]
[]
[null,"This assessment score"]
[null,{"$f":"VLOOKUP(B6,B101:C103,2,FALSE)","v":3},{"$f":"VLOOKUP(C6,B101:C103,2,FALSE)","v":3},{"$f":"VLOOKUP(D6,B101:C103,2,FALSE)","v":3},{"$f":"B106*C106*D106","v":27}]

{"sheet":"3) Likelihood","index":7,"n_rows":173,"n_cols":9,"rows_kept":173,"cut":false,"hidden":false,"merged":[[74,1,86,1],[74,3,86,3],[74,4,86,4],[74,5,86,5],[100,1,112,1],[100,3,112,3],[100,4,112,4],[100,5,112,5],[87,1,99,1],[87,3,99,3],[87,4,99,4],[87,5,99,5],[20,6,20,7],[22,1,34,1],[22,3,34,3],[22,4,34,4],[22,5,34,5],[113,1,125,1],[113,3,125,3],[113,4,125,4],[113,5,125,5],[35,1,47,1],[35,3,47,3],[35,4,47,4],[35,5,47,5],[48,1,60,1],[48,3,60,3],[48,4,60,4],[48,5,60,5],[61,1,73,1],[61,3,73,3],[61,4,73,4],[61,5,73,5]]}
[]
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[null,"Rational for the assessment of likelihood "]
[null,"Identification of risks is based on the individual sources of potentially polluting material (sludge tanks, etc.) and on the general site risk identified in the CIRIA guidance"]
[null,"Assessment of the unmitigated risk of emissions from each source is based on the potential for failure of any containment measures provided. "]
[null,"This considers the primary, secondary and tertiary containment associate with each source and the potential breach of these containment measures."]
[null,"The likelihood of failure is quantified, based on the guidelines provided in CIRIA 736 and United Utilities experience of containment failures on their sites. "]
[null,"Basing the quantification of containment failure on United Utilities experience on their own sites therefore accounts for the United Utilities design specification, making the assessment relevant to the designs. ",null,"The identification of the likelihood of the loss of containment ad subsequent release of contaminants "]
[null,"The mitigation applied to the risks considers the operational and maintenance procedures, including regular inspecting and testing of containment measures.  "]
[null,"Based on the regular inspecting and testing of containment measures it is considered that the potential for catastrophic failures would be identified prior to failure and either decommissioned and replaced (for example tanks) or repairs (e.g. pipelines)"]
[]
[]
[]
[]
[]
[null,"Risk ","Description of Risk","UNMITIGATED LIKELIHOOD \n","Mitigation applied","MITIGATED LIKELIHOOD",null,"Low","Site Overall Likelihood"]
[null,"Digester x4 (2,500 m3 each, 10,000 m3 total)\n\nSpillage of non hazardous sludge: \n - catastrophic failure of tank;\n - tank overflow; or\n - tank leaks.","Containment:\n- Concrete unlined tank construction, tank is self-contained / has lid\n- Partially buried concrete tank. Sit on concrete bases surrounded by a gravel surface","M"," - Tanks are surrounded by impermeable hardstanding which drains to the head of works which would return spills for treatment. Roads and turning areas should also be impermeable concrete.\n - TCM checks are conducted regularly. \n - Blackburn STC is either manned, or when not, monitored by the Integrated Control Centre (ICC) on a 24/7 basis using SCADA and critical process alarms. A significant spill would be identified quickly, and the spill management procedure initiated, ensuring a rapid clean up.  SCADA controls would also, via a number of surrogate metrics, such as level monitoring, transfer, pump and valve status, provide rapid process control indications of certain loss of containment scenarios. \n - United Utilities has a fleet of sludge tankers across their region which form part of the operational response to sludge spills to be utilised rapidly in the event of a spill at Blackburn STC.\n - Existing site drainage pipes and manholes are regularly inspected and maintained. Site inspection tours of the impermeable surface, storage tanks and above ground drainage system are carried out daily by site-based staff and monthly by the site’s Environmental Regulatory Adviser (ERA). These tours include visual inspection of the site drains to ensure they are working as expected.\n - Dependant on the age of the asset non-destructive testing (NDT) is carried out every 10, 5, 2 years and yearly on all tanks and associated ancillary assets. The risk of catastrophic failure will therefore be identified before failure occurs. \n - The EMS contains procedures for visual inspections and actions to be taken in the event of tank failures.\n - In the event of overflow of contaminants it is possible that sludge could flow directly into groundwater. In this event UU will react with an emergency spill response and clean up the area that has been contaminated. \n - Additional mitigation measures to reduce the impact from loss of containment events e.g. kerbing, containment walls, sacrificial areas, are detailed in Blackburn Sludge Treatment Centre Secondary Containment Modelling Assessment.","L"]
[null,null,"Failure risks and Mitigation Measures:"]
[null,null," - Catastrophic tank failure -  The tanks are constructed from concrete; tanks are maintained to UU specifications.  Tanks are surrounded by impermeable surfacing. The risk is therefore considered medium."]
[null,null," - Tank overflow or leaks - Due to level monitors and the interlock on feed pumps, the risk of overflow is considered to be low. The high-level overflow also drains into the site drainage system and is then returned to the head of the works. "]
[null,null," - Potential for minor leakage Where above ground, pipework is visually inspected on a regular basis for leaks.  Emission due to leaks is therefore considered medium."]
[null,null,"-Shortcomings or failure in operational control system: the site is maintained inline with a proactive maintenance schedule and the EMS to ensure ongoing operation of all plant items. Operators are trained in the running of plant items. Likelihood of emissions due to operational failure is considered to be low"]
[null,null,"- Abuse -all site staff and tanker Operators are trained to operate the plant items. No risk of overflow, due to level monitors and the interlock on feed pumps. Likelihood of emissions due to abuse is low"]
[null,null,"- Impact - Tanks are away from access roads and is protected by kerbs. Likelihood of emissions due to impacts low."]
[null,null,"- Vandalism, etc. - the STC and WwTW are within a fenced and gated site, with access to the site controlled and CCTV system operational.  Likelihood of emissions due to vandalism is considered to be low"]
[null,null,"- Fire, explosion - the tank is vented so flammable gasses would not build up in the tank.  Likelihood of emissions due to fire or explosion is considered to be low"]
[null,null,"- Geological factors - There has been no evidence of wider geotechnical issues during the time the WwTW has been operational on the site.  The tank was designed after geotechnical input parameters.  Likelihood of emissions due to geological issues is low"]
[null,null,"- Ageing - Ageing / deterioration were considered at the point of design. Visual inspections and maintenance regime are in place to identify any potential defects caused by ageing.  Likelihood of emissions due to age is considered to be low"]
[null,null,"- Lightning strike - the tanks are similar height relative to other structures within the area therefore unlikely to be struck by lightning.  Likelihood of emissions due to lightning is low"]
[null,"Post digestion tank no. 3 (1,200 m3) \n\nSpillage of non hazardous sludge: \n - catastrophic failure of tank;\n - tank overflow; or\n - tank leaks.","Containment:\n- Glass fused to steel tank construction, tank is self-contained / has lid\n- Above ground, glass fused to steel constructed tank. Sit on concrete bases surrounded by a gravel surface","M"," - Tanks are surrounded by impermeable hardstanding which drains to the head of works which would return spills for treatment. Roads and turning areas should also be impermeable concrete.\n - TCM checks are conducted regularly. \n - Blackburn STC is either manned, or when not, monitored by the Integrated Control Centre (ICC) on a 24/7 basis using SCADA and critical process alarms. A significant spill would be identified quickly, and the spill management procedure initiated, ensuring a rapid clean up.  SCADA controls would also, via a number of surrogate metrics, such as level monitoring, transfer, pump and valve status, provide rapid process control indications of certain loss of containment scenarios. \n - United Utilities has a fleet of sludge tankers across their region which form part of the operational response to sludge spills to be utilised rapidly in the event of a spill at Blackburn STC.\n - Existing site drainage pipes and manholes are regularly inspected and maintained. Site inspection tours of the impermeable surface, storage tanks and above ground drainage system are carried out daily by site-based staff and monthly by the site’s Environmental Regulatory Adviser (ERA). These tours include visual inspection of the site drains to ensure they are working as expected.\n - Dependant on the age of the asset non-destructive testing (NDT) is carried out every 10, 5, 2 years and yearly on all tanks and associated ancillary assets. The risk of catastrophic failure will therefore be identified before failure occurs. \n - The EMS contains procedures for visual inspections and actions to be taken in the event of tank failures.\n - In the event of overflow of contaminants it is possible that sludge could flow directly into groundwater. In this event UU will react with an emergency spill response and clean up the area that has been contaminated. \n - Additional mitigation measures to reduce the impact from loss of containment events e.g. kerbing, containment walls, sacrificial areas, are detailed in Blackburn Sludge Treatment Centre Secondary Containment Modelling Assessment.","L"]
[null,null,"Failure risks and Mitigation Measures:"]
[null,null," - Catastrophic tank failure -  The tank is constructed from glass fused to steel; the tank is maintained to UU specifications.  Tank is surrounded by impermeable surfacing. Based on the CIRIA risk criteria for steel tanks, the risk is therefore considered medium."]
[null,null," - Tank overflow or leaks - Due to level monitors and the interlock on feed pumps, the risk of overflow is considered to be low. The high-level overflow also drains into the site drainage system and is then returned to the head of the works. "]
[null,null," - Potential for minor leakage Where above ground, pipework is visually inspected on a regular basis for leaks.  Emission due to leaks is therefore considered medium."]
[null,null,"-Shortcomings or failure in operational control system: the site is maintained inline with a proactive maintenance schedule and the EMS to ensure ongoing operation of all plant items. Operators are trained in the running of plant items. Likelihood of emissions due to operational failure is considered to be low"]
[null,null,"- Abuse -all site staff and tanker Operators are trained to operate the plant items. No risk of overflow, due to level monitors and the interlock on feed pumps. Likelihood of emissions due to abuse is low"]
[null,null,"- Impact - Tanks are away from access roads and is protected by kerbs. Likelihood of emissions due to impacts low."]
[null,null,"- Vandalism, etc. -the STC and WwTW are within a fenced and gated site, with access to the site controlled and CCTV system operational.  Likelihood of emissions due to vandalism is considered to be low"]
[null,null,"- Fire, explosion - the tank is vented so flammable gasses would not build up in the tank.  Likelihood of emissions due to fire or explosion is considered to be low"]
[null,null,"- Geological factors - There has been no evidence of wider geotechnical issues during the time the WwTW has been operational on the site.  The tank was designed after geotechnical input parameters.  Likelihood of emissions due to geological issues is low"]
[null,null,"- Ageing - Ageing / deterioration were considered at the point of design. Visual inspections and maintenance regime in place to identify any potential defects caused by ageing.  Likelihood of emissions due to age is considered to be low"]
[null,null,"- Lightning strike - the tank is similar height relative to other structures within the area therefore unlikely to be struck by lightning.  Likelihood of emissions due to lightning is low"]
[null,"Post digestion tank no. 1 and no. 2 (900 m3 each, 1,800 m3 total) \n\nSpillage of non hazardous sludge: \n - catastrophic failure of tank;\n - tank overflow; or\n - tank leaks.","Containment:\n- Concrete tank construction, tanks are self-contained / have lid\n- Partially buried, concrete constructed tanks. Sit on concrete bases surrounded by a gravel surface","M"," - Tanks are surrounded by impermeable hardstanding which drains to the head of works which would return spills for treatment. Roads and turning areas should also be impermeable concrete.\n - TCM checks are conducted regularly. \n - Blackburn STC is either manned, or when not, monitored by the Integrated Control Centre (ICC) on a 24/7 basis using SCADA and critical process alarms. A significant spill would be identified quickly, and the spill management procedure initiated, ensuring a rapid clean up.  SCADA controls would also, via a number of surrogate metrics, such as level monitoring, transfer, pump and valve status, provide rapid process control indications of certain loss of containment scenarios. \n - United Utilities has a fleet of sludge tankers across their region which form part of the operational response to sludge spills to be utilised rapidly in the event of a spill at Blackburn STC.\n - Existing site drainage pipes and manholes are regularly inspected and maintained. Site inspection tours of the impermeable surface, storage tanks and above ground drainage system are carried out daily by site-based staff and monthly by the site’s Environmental Regulatory Adviser (ERA). These tours include visual inspection of the site drains to ensure they are working as expected.\n - Dependant on the age of the asset non-destructive testing (NDT) is carried out every 10, 5, 2 years and yearly on all tanks and associated ancillary assets. The risk of catastrophic failure will therefore be identified before failure occurs. \n - The EMS contains procedures for visual inspections and actions to be taken in the event of tank failures.\n - In the event of overflow of contaminants it is possible that sludge could flow directly into groundwater. In this event UU will react with an emergency spill response and clean up the area that has been contaminated. \n - Additional mitigation measures to reduce the impact from loss of containment events e.g. kerbing, containment walls, sacrificial areas, are detailed in Blackburn Sludge Treatment Centre Secondary Containment Modelling Assessment.","L"]
[null,null,"Failure risks and Mitigation Measures:"]
[null,null," - Catastrophic tank failure -  The tanks are constructed from concrete; tanks are maintained to UU specifications.  Tank is surrounded by impermeable surfacing.The risk is therefore considered medium."]
[null,null," - Tank overflow or leaks - Due to level monitors and the interlock on feed pumps, the risk of overflow is considered to be low. The high-level overflow also drains into the site drainage system and is then returned to the head of the works. "]
[null,null," - Potential for minor leakage Where above ground, pipework is visually inspected on a regular basis for leaks.  Emission due to leaks is therefore considered medium."]
[null,null,"-Shortcomings or failure in operational control system: the site is maintained inline with a proactive maintenance schedule and the EMS to ensure ongoing operation of all plant items. Operators are trained in the running of plant items. Likelihood of emissions due to operational failure is considered to be low"]
[null,null,"- Abuse -all site staff and tanker Operators are trained to operate the plant items. No risk of overflow, due to level monitors and the interlock on feed pumps. Likelihood of emissions due to abuse is low"]
[null,null,"- Impact - Tanks are away from access roads and is protected by kerbs. Likelihood of emissions due to impacts low."]
[null,null,"- Vandalism, etc. -the STC and WwTW are within a fenced and gated site, with access to the site controlled and CCTV system operational.  Likelihood of emissions due to vandalism is considered to be low"]
[null,null,"- Fire, explosion - the tank is vented so flammable gasses would not build up in the tank.  Likelihood of emissions due to fire or explosion is considered to be low"]
[null,null,"- Geological factors - There has been no evidence of wider geotechnical issues during the time the WwTW has been operational on the site.  The tank was designed after geotechnical input parameters.  Likelihood of emissions due to geological issues is low"]
[null,null,"- Ageing - Ageing / deterioration were considered at the point of design. Visual inspections and maintenance regime in place to identify any potential defects caused by ageing.  Likelihood of emissions due to age is considered to be low"]
[null,null,"- Lightning strike - the tanks are low relative to other structures within the area therefore unlikely to be struck by lightning.  Likelihood of emissions due to lightning is low"]
[null,"EEH Feed Tank (1,400 m3)\n\nSpillage of non hazardous sludge: \n - catastrophic failure of tank;\n - tank overflow; or\n - tank leaks.","Containment:\n- Metal tank construction, tank is self-contained / has lid\n- Above ground, glass fused to steel tank. Sit on concrete bases surrounded by a gravel surface","M"," - Tanks are surrounded by impermeable hardstanding which drains to the head of works which would return spills for treatment. Roads and turning areas should also be impermeable concrete.\n - TCM checks are conducted regularly. \n - Blackburn STC is either manned, or when not, monitored by the Integrated Control Centre (ICC) on a 24/7 basis using SCADA and critical process alarms. A significant spill would be identified quickly, and the spill management procedure initiated, ensuring a rapid clean up.  SCADA controls would also, via a number of surrogate metrics, such as level monitoring, transfer, pump and valve status, provide rapid process control indications of certain loss of containment scenarios. \n - United Utilities has a fleet of sludge tankers across their region which form part of the operational response to sludge spills to be utilised rapidly in the event of a spill at Blackburn STC.\n - Existing site drainage pipes and manholes are regularly inspected and maintained. Site inspection tours of the impermeable surface, storage tanks and above ground drainage system are carried out daily by site-based staff and monthly by the site’s Environmental Regulatory Adviser (ERA). These tours include visual inspection of the site drains to ensure they are working as expected.\n - Dependant on the age of the asset non-destructive testing (NDT) is carried out every 10, 5, 2 years and yearly on all tanks and associated ancillary assets. The risk of catastrophic failure will therefore be identified before failure occurs. \n - The EMS contains procedures for visual inspections and actions to be taken in the event of tank failures.\n - In the event of overflow of contaminants it is possible that sludge could flow directly into groundwater. In this event UU will react with an emergency spill response and clean up the area that has been contaminated. \n - Additional mitigation measures to reduce the impact from loss of containment events e.g. kerbing, containment walls, sacrificial areas, are detailed in Blackburn Sludge Treatment Centre Secondary Containment Modelling Assessment.","L"]
[null,null,"Failure risks and Mitigation Measures:"]
[null,null," - Catastrophic tank failure -  The tank is constructed from glass fused to steel; tanks are maintained to UU specifications.  Tank is surrounded by impermeable surfacing. Based on the CIRIA risk criteria for steel tanks, the risk is therefore considered medium."]
[null,null," - Tank overflow or leaks - Due to level monitors and the interlock on feed pumps, the risk of overflow is considered to be low. The high-level overflow also drains into the site drainage system and is then returned to the head of the works. "]
[null,null," - Potential for minor leakage Where above ground, pipework is visually inspected on a regular basis for leaks.  Emission due to leaks is therefore considered medium."]
[null,null,"-Shortcomings or failure in operational control system: the site is maintained inline with a proactive maintenance schedule and the EMS to ensure ongoing operation of all plant items. Operators are trained in the running of plant items. Likelihood of emissions due to operational failure is considered to be low"]
[null,null,"- Abuse -all site staff and tanker Operators are trained to operate the plant items. No risk of overflow, due to level monitors and the interlock on feed pumps. Likelihood of emissions due to abuse is low"]
[null,null,"- Impact - Tanks are away from access roads and is protected by kerbs. Likelihood of emissions due to impacts low."]
[null,null,"- Vandalism, etc. -the STC and WwTW are within a fenced and gated site, with access to the site controlled and CCTV system operational.  Likelihood of emissions due to vandalism is considered to be low"]
[null,null,"- Fire, explosion - the tank is vented so flammable gasses would not build up in the tank.  Likelihood of emissions due to fire or explosion is considered to be low"]
[null,null,"- Geological factors - There has been no evidence of wider geotechnical issues during the time the WwTW has been operational on the site.  The tank was designed with geotechnical input parameters.  Likelihood of emissions due to geological issues is low"]
[null,null,"- Ageing - Ageing / deterioration were considered at the point of design. Visual inspections and maintenance regime in place to identify any potential defects caused by ageing.  Likelihood of emissions due to age is considered to be low"]
[null,null,"- Lightning strike - the tank is similar height to other structures within the area therefore unlikely to be struck by lightning.  Likelihood of emissions due to lightning is low"]
[null,"Enzymic Hydrolysis (EEH) x6 (280 m3 each, 1,680 m3 total)\n\nSpillage of non hazardous sludge: \n - catastrophic failure of tank\n - tank overflow or\n - tank leaks.","Containment:\n- Glass fused to steel tank construction, tanks are self-contained / has lid\n- Above ground, glass fused to steel constructed tanks. Sit on concrete bases surrounded by a gravel surface","M"," - Tanks are surrounded by impermeable hardstanding which drains to the head of works which would return spills for treatment. Roads and turning areas should also be impermeable concrete.\n - TCM checks are conducted regularly. \n - Blackburn STC is either manned, or when not, monitored by the Integrated Control Centre (ICC) on a 24/7 basis using SCADA and critical process alarms. A significant spill would be identified quickly, and the spill management procedure initiated, ensuring a rapid clean up.  SCADA controls would also, via a number of surrogate metrics, such as level monitoring, transfer, pump and valve status, provide rapid process control indications of certain loss of containment scenarios. \n - United Utilities has a fleet of sludge tankers across their region which form part of the operational response to sludge spills to be utilised rapidly in the event of a spill at Blackburn STC.\n - Existing site drainage pipes and manholes are regularly inspected and maintained. Site inspection tours of the impermeable surface, storage tanks and above ground drainage system are carried out daily by site-based staff and monthly by the site’s Environmental Regulatory Adviser (ERA). These tours include visual inspection of the site drains to ensure they are working as expected.\n - Dependant on the age of the asset non-destructive testing (NDT) is carried out every 10, 5, 2 years and yearly on all tanks and associated ancillary assets. The risk of catastrophic failure will therefore be identified before failure occurs. \n - The EMS contains procedures for visual inspections and actions to be taken in the event of tank failures.\n - In the event of overflow of contaminants it is possible that sludge could flow directly into groundwater. In this event UU will react with an emergency spill response and clean up the area that has been contaminated. \n - Additional mitigation measures to reduce the impact from loss of containment events e.g. kerbing, containment walls, sacrificial areas, are detailed in Blackburn Sludge Treatment Centre Secondary Containment Modelling Assessment.","L"]
[null,null,"Failure risks and Mitigation Measures:"]
[null,null," - Catastrophic tank failure -  The tanks are constructed from glass fused to steel; tanks are maintained to UU specifications.  Tanks are surrounded by impermeable surfacing. Based on the CIRIA risk criteria for steel tanks, the risk is therefore considered medium."]
[null,null," - Tank overflow or leaks - Due to level monitors and the interlock on feed pumps, the risk of overflow is considered to be low. The high-level overflow also drains into the site drainage system and is then returned to the head of the works. "]
[null,null," - Potential for minor leakage Where above ground, pipework is visually inspected on a regular basis for leaks.  Emission due to leaks is therefore considered medium."]
[null,null,"-Shortcomings or failure in operational control system: the site is maintained inline with a proactive maintenance schedule and the EMS to ensure ongoing operation of all plant items. Operators are trained in the running of plant items. Likelihood of emissions due to operational failure is considered to be low"]
[null,null,"- Abuse -all site staff and tanker Operators are trained to operate the plant items. No risk of overflow, due to level monitors and the interlock on feed pumps. Likelihood of emissions due to abuse is low"]
[null,null,"- Impact - Tanks are away from access roads and is protected by kerbs. Likelihood of emissions due to impacts low."]
[null,null,"- Vandalism, etc. -the STC and WwTW are within a fenced and gated site, with access to the site controlled and CCTV system operational.  Likelihood of emissions due to vandalism is considered to be low"]
[null,null,"- Fire, explosion - the tank is vented so flammable gasses would not build up in the tank.  Likelihood of emissions due to fire or explosion is considered to be low"]
[null,null,"- Geological factors - There has been no evidence of wider geotechnical issues during the time the WwTW has been operational on the site.  The tank was designed with geotechnical input parameters.  Likelihood of emissions due to geological issues is low"]
[null,null,"- Ageing - Ageing / deterioration were considered at the point of design. Visual inspections and maintenance regime in place to identify any potential defects caused by ageing.  Likelihood of emissions due to age is considered to be low"]
[null,null,"- Lightning strike - the tank is similar height relative to other structures within the area therefore unlikely to be struck by lightning.  Likelihood of emissions due to lightning is low"]
[null,"Unthickened Sludge Storage Tank (1,800 m3)\n\nSpillage of non hazardous sludge: \n - catastrophic failure of tank\n - tank overflow or\n - tank leaks.","Containment:\n- Glass fused to steel tank construction, tank is self-contained / has lid\n- Above ground, glass fused to steel tank. Sit on concrete bases surrounded by a gravel surface","M"," - Tanks are surrounded by impermeable hardstanding which drains to the head of works which would return spills for treatment. Roads and turning areas should also be impermeable concrete.\n - TCM checks are conducted regularly. \n - Blackburn STC is either manned, or when not, monitored by the Integrated Control Centre (ICC) on a 24/7 basis using SCADA and critical process alarms. A significant spill would be identified quickly, and the spill management procedure initiated, ensuring a rapid clean up.  SCADA controls would also, via a number of surrogate metrics, such as level monitoring, transfer, pump and valve status, provide rapid process control indications of certain loss of containment scenarios. \n - United Utilities has a fleet of sludge tankers across their region which form part of the operational response to sludge spills to be utilised rapidly in the event of a spill at Blackburn STC.\n - Existing site drainage pipes and manholes are regularly inspected and maintained. Site inspection tours of the impermeable surface, storage tanks and above ground drainage system are carried out daily by site-based staff and monthly by the site’s Environmental Regulatory Adviser (ERA). These tours include visual inspection of the site drains to ensure they are working as expected.\n - Dependant on the age of the asset non-destructive testing (NDT) is carried out every 10, 5, 2 years and yearly on all tanks and associated ancillary assets. The risk of catastrophic failure will therefore be identified before failure occurs. \n - The EMS contains procedures for visual inspections and actions to be taken in the event of tank failures.\n - In the event of overflow of contaminants it is possible that sludge could flow directly into groundwater. In this event UU will react with an emergency spill response and clean up the area that has been contaminated. \n - Additional mitigation measures to reduce the impact from loss of containment events e.g. kerbing, containment walls, sacrificial areas, are detailed in Blackburn Sludge Treatment Centre Secondary Containment Modelling Assessment.","L"]
[null,null,"Failure risks and Mitigation Measures:"]
[null,null," - Catastrophic tank failure -  The tank is constructed from glass fused to steel; tank is maintained to UU specifications.  Tank is surrounded by impermeable surfacing. Based on the CIRIA risk criteria for steel tanks, the risk is therefore considered medium."]
[null,null," - Tank overflow or leaks - Due to level monitors and the interlock on feed pumps, the risk of overflow is considered to be low. The high-level overflow also drains into the site drainage system and is then returned to the head of the works. "]
[null,null," - Potential for minor leakage Where above ground, pipework is visually inspected on a regular basis for leaks.  Emission due to leaks is therefore considered medium."]
[null,null,"-Shortcomings or failure in operational control system: the site is maintained inline with a proactive maintenance schedule and the EMS to ensure ongoing operation of all plant items. Operators are trained in the running of plant items. Likelihood of emissions due to operational failure is low"]
[null,null,"- Abuse -all site staff and tanker Operators are trained to operate the plant items. No risk of overflow, due to level monitors and the interlock on feed pumps. Likelihood of emissions due to abuse is low"]
[null,null,"- Impact - Tanks are away from access roads and is protected by kerbs. Likelihood of emissions due to impacts low."]
[null,null,"- Vandalism, etc. -the STC and WwTW are within a fenced and gated site, with access to the site controlled and CCTV system operational.  Likelihood of emissions due to vandalism is considered to be low"]
[null,null,"- Fire, explosion - the tank is vented so flammable gasses would not build up in the tank.  Likelihood of emissions due to fire or explosion is considered to be low"]
[null,null,"- Geological factors - There has been no evidence of wider geotechnical issues during the time the WwTW has been operational on the site.  The tank was designed with geotechnical input parameters.  Likelihood of emissions due to geological issues is low"]
[null,null,"- Ageing - Ageing / deterioration were considered at the point of design. Visual inspections and maintenance regime in place to identify any potential defects caused by ageing.  Likelihood of emissions due to age is considered to be low"]
[null,null,"- Lightning strike - the tank is similar height relative to other structures within the area therefore unlikely to be struck by lightning.  Likelihood of emissions due to lightning is low"]
[null,"Drum Thickener Feed Tank 1 & 2 (800m3 - 400m3 each)\n\nSpillage of non hazardous sludge: \n - catastrophic failure of tank\n - tank overflow or\n - tank leaks.","Containment:\n- Glass fused to steel tank construction, tank is self-contained / has lid\n- Above ground, glass fused to steel tank. Sit on concrete bases surrounded by a gravel surface","M"," - Tanks are surrounded by impermeable hardstanding which drains to the head of works which would return spills for treatment. Roads and turning areas should also be impermeable concrete.\n - TCM checks are conducted regularly. \n - Blackburn STC is either manned, or when not, monitored by the Integrated Control Centre (ICC) on a 24/7 basis using SCADA and critical process alarms. A significant spill would be identified quickly, and the spill management procedure initiated, ensuring a rapid clean up.  SCADA controls would also, via a number of surrogate metrics, such as level monitoring, transfer, pump and valve status, provide rapid process control indications of certain loss of containment scenarios. \n - United Utilities has a fleet of sludge tankers across their region which form part of the operational response to sludge spills to be utilised rapidly in the event of a spill at Blackburn STC.\n - Existing site drainage pipes and manholes are regularly inspected and maintained. Site inspection tours of the impermeable surface, storage tanks and above ground drainage system are carried out daily by site-based staff and monthly by the site’s Environmental Regulatory Adviser (ERA). These tours include visual inspection of the site drains to ensure they are working as expected.\n - Dependant on the age of the asset non-destructive testing (NDT) is carried out every 10, 5, 2 years and yearly on all tanks and associated ancillary assets. The risk of catastrophic failure will therefore be identified before failure occurs. \n - The EMS contains procedures for visual inspections and actions to be taken in the event of tank failures.\n - In the event of overflow of contaminants it is possible that sludge could flow directly into groundwater. In this event UU will react with an emergency spill response and clean up the area that has been contaminated. \n - Additional mitigation measures to reduce the impact from loss of containment events e.g. kerbing, containment walls, sacrificial areas, are detailed in Blackburn Sludge Treatment Centre Secondary Containment Modelling Assessment.","L"]
[null,null,"Failure risks and Mitigation Measures:"]
[null,null," - Catastrophic tank failure -  The tank is constructed from glass fused to steel; tank is maintained to UU specifications.  Tank is surrounded by impermeable surfacing. Based on the CIRIA risk criteria for steel tanks, the risk is therefore considered medium."]
[null,null," - Tank overflow or leaks - Due to level monitors and the interlock on feed pumps, the risk of overflow is considered to be low. The high-level overflow also drains into the site drainage system and is then returned to the head of the works. "]
[null,null," - Potential for minor leakage Where above ground, pipework is visually inspected on a regular basis for leaks.  Emission due to leaks is therefore considered medium."]
[null,null,"-Shortcomings or failure in operational control system: the site is maintained inline with a proactive maintenance schedule and the EMS to ensure ongoing operation of all plant items. Operators are trained in the running of plant items. Likelihood of emissions due to operational failure is low"]
[null,null,"- Abuse -all site staff and tanker Operators are trained to operate the plant items. No risk of overflow, due to level monitors and the interlock on feed pumps. Likelihood of emissions due to abuse is low"]
[null,null,"- Impact - Tanks are away from access roads and is protected by kerbs. Likelihood of emissions due to impacts low."]
[null,null,"- Vandalism, etc. -the STC and WwTW are within a fenced and gated site, with access to the site controlled and CCTV system operational.  Likelihood of emissions due to vandalism is considered to be low"]
[null,null,"- Fire, explosion - the tank is vented so flammable gasses would not build up in the tank.  Likelihood of emissions due to fire or explosion is considered to be low"]
[null,null,"- Geological factors - There has been no evidence of wider geotechnical issues during the time the WwTW has been operational on the site.  The tank was designed with geotechnical input parameters.  Likelihood of emissions due to geological issues is low"]
[null,null,"- Ageing - Ageing / deterioration were considered at the point of design. Visual inspections and maintenance regime in place to identify any potential defects caused by ageing.  Likelihood of emissions due to age is considered to be low"]
[null,null,"- Lightning strike - the tank is similar height relative to other structures within the area therefore unlikely to be struck by lightning.  Likelihood of emissions due to lightning is low"]
[null,"Centrate and filtrate tank (1,200 m3 540m3 above ground)\n\nSpillage of non hazardous sludge: \n - catastrophic failure of tank\n - tank overflow or\n - tank leaks.","Containment:\n- Concrete tank construction, tanks are self-contained.\n- Partially buried, concrete constructed tanks. Surrounded by a permeable surface","M"," - Tanks are surrounded by permeable surface.\n - TCM checks are conducted regularly. \n - Blackburn STC is either manned, or when not, monitored by the Integrated Control Centre (ICC) on a 24/7 basis using SCADA and critical process alarms. A significant spill would be identified quickly, and the spill management procedure initiated, ensuring a rapid clean up.  SCADA controls would also, via a number of surrogate metrics, such as level monitoring, transfer, pump and valve status, provide rapid process control indications of certain loss of containment scenarios. \n - United Utilities has a fleet of sludge tankers across their region which form part of the operational response to sludge spills to be utilised rapidly in the event of a spill at Blackburn STC.\n - Existing site drainage pipes and manholes are regularly inspected and maintained. Site inspection tours of the impermeable surface, storage tanks and above ground drainage system are carried out daily by site-based staff and monthly by the site’s Environmental Regulatory Adviser (ERA). These tours include visual inspection of the site drains to ensure they are working as expected.\n - Dependant on the age of the asset non-destructive testing (NDT) is carried out every 10, 5, 2 years and yearly on all tanks and associated ancillary assets. The risk of catastrophic failure will therefore be identified before failure occurs. \n - The EMS contains procedures for visual inspections and actions to be taken in the event of tank failures.\n - In the event of overflow of contaminants it is possible that sludge could flow directly into groundwater. In this event UU will react with an emergency spill response and clean up the area that has been contaminated. \n - Additional mitigation measures to reduce the impact from loss of containment events e.g. kerbing, containment walls, sacrificial areas, are detailed in Blackburn Sludge Treatment Centre Secondary Containment Modelling Assessment.","L"]
[null,null,"Failure risks and Mitigation Measures:"]
[null,null," - Catastrophic tank failure -  The tanks are constructed from concrete; tanks are maintained to UU specifications.  Tank is surrounded by permeable surfacing.The risk is therefore considered medium."]
[null,null," - Tank overflow or leaks - Due to level monitors and the interlock on feed pumps, the risk of overflow is considered to be low. The high-level overflow also drains into the site drainage system and is then returned to the head of the works. "]
[null,null," - Potential for minor leakage Where above ground, pipework is visually inspected on a regular basis for leaks.  Emission due to leaks is therefore considered medium."]
[null,null,"-Shortcomings or failure in operational control system: the site is maintained inline with a proactive maintenance schedule and the EMS to ensure ongoing operation of all plant items. Operators are trained in the running of plant items. Likelihood of emissions due to operational failure is considered to be low"]
[null,null,"- Abuse -all site staff and tanker Operators are trained to operate the plant items. No risk of overflow, due to level monitors and the interlock on feed pumps. Likelihood of emissions due to abuse is low"]
[null,null,"- Impact - Tanks are away from access roads and is protected by kerbs. Likelihood of emissions due to impacts low."]
[null,null,"- Vandalism, etc. -the STC and WwTW are within a fenced and gated site, with access to the site controlled and CCTV system operational.  Likelihood of emissions due to vandalism is considered to be low"]
[null,null,"- Fire, explosion - the tank is vented so flammable gasses would not build up in the tank.  Likelihood of emissions due to fire or explosion is considered to be low"]
[null,null,"- Geological factors - There has been no evidence of wider geotechnical issues during the time the WwTW has been operational on the site.  The tank was designed after geotechnical input parameters.  Likelihood of emissions due to geological issues is low"]
[null,null,"- Ageing - Ageing / deterioration were considered at the point of design. Visual inspections and maintenance regime in place to identify any potential defects caused by ageing.  Likelihood of emissions due to age is considered to be low"]
[null,null,"- Lightning strike - the tanks are low relative to other structures within the area therefore unlikely to be struck by lightning.  Likelihood of emissions due to lightning is low"]
[]
[]
[]
[null,"Risk","Examples of mitigation options","Reduction in likelihood","Detail of measures"]
[null,1,"Operational Failures"]
[null,null,"The team will carry out periodic design reviews and a comprehensive HAZOP involving all the designers (process, civil, drainage, electrical) to ensure primary containment failure risk is very low. In addition operator training will be strengthened with detailed standard operating procedures.",-2,"(Taken from consultant's HAZOP report, for example)"]
[null,null,"Maintenance programme in place",-1]
[null,null,"Audit process in place",-1]
[]
[null,2,"Shortfalls in design"]
[null,null,"Plant control will be assessed at the HAZOP stage",-2]
[null,null,"No outlets below normal liquid level",-1]
[]
[null,3,"Structural failure – materials, components, detailing, corrosion or when exposed to heat and flame"]
[null,null,"Pre-cast concrete tank",-2]
[null,null,"Tank design has no history of failure",-1]
[null,null,"Tank failure risk assessment completed?",-1]
[null,null,"Steel valves",-1]
[null,null,"Structures will be built to British Standards with contractors that work under ISO9000",-1]
[]
[null,4,"Abuse – inappropriate change of use or other misuse"]
[null,null,"Change control procedure in place with sign off from competent personnel in applicable disciplines",-2]
[]
[null,5,"Vehicle impact"]
[null,null,"Armco crash barriers around tank",-2]
[null,null,"Tanks in bund not accessible by vehicles",-2]
[null,null,"Restricted vehicular access to site",-1]
[]
[null,6,"Vandalism, terrorism, force majeure etc"]
[null,null,"lockable valves on outlets (that are locked when not in use by procedure)",-1]
[null,null,"automatic and manual shut off valves",-1]
[null,null,"The site will include fencing where access is open to public",-1]
[null,null,"Passive CCTV system",-1]
[null,null,"Monitored CCTV with motion detection and warning signs",-2]
[]
[null,7,"Fire or explosion"]
[null,null,"DSEAR assessment completed",-2]
[null,null,"Control of ignition sources on site",-1]
[]
[null,8,"Geological factors -subsidence etc"]
[null,null,"Site investigations will be provided to the civil contractor for the design of the foundations",-1]
[]
[null,9,"Ageing or deteriorating assets/sub-components."]
[null,null,"Ageing/deterioration factored into plant design",-1]
[]
[null,10,"Lightning strike"]
[null,null,"Catenary or multiple lightning conductors supplied by specialists",-1]

{"sheet":"4) Site Risk and Classification","index":8,"n_rows":23,"n_cols":11,"rows_kept":23,"cut":false,"hidden":false,"merged":[]}
[]
[]
[]
[]
["Activity","Site Hazard Rating","Likelihood","Overall Site Risk Rating","Indicated Class of Secondary Containment Required"]
["Site - overall summary score",{"$f":"'2) Site Hazard Rating'!E6","v":"High"},{"$f":"'3) Likelihood'!H22","v":"Low"},{"$f":"IF(D23<3,\"Low\",IF(D23<5,\"Medium\",\"High\"))","v":"Medium"},{"$f":"IF(D6=\"Low\",\"Class 1\",IF(D6=\"Medium\", \"Class 2\",\"Class 3\"))","v":"Class 2"}]
["Digester x4","High","Low","Medium",{"$f":"IF(D7=\"Low\",\"Class 1\",IF(D7=\"Medium\", \"Class 2\",\"Class 3\"))","v":"Class 2"}]
["Post Digestion Tank no. 3","High","Low","Medium","Class 2"]
["Post Digestion Tanks no. 1 and no. 2","High","Low","Medium","Class 2"]
["Sludge Import Tank","High","Low","Medium","Class 2",null,null,null,null,null," "]
["Thickened Sludge Holding Tank","High","Low","Medium","Class 2"]
["EEH Reactor x6","High","Low","Medium","Class 2"]
["Liquor Balancing Tank x2","High","Low","Medium","Class 2"]
["Unscreened Sludge Buffer Tank","High","Low","Medium","Class 2"]
[]
[]
[]
["Rating lookup table"]
["Low",1]
["Medium",2]
["High",3]
[]
[{"$f":"VLOOKUP(B6,A19:B21,2,FALSE)","v":3},{"$f":"VLOOKUP(C6,A19:B21,2,FALSE)","v":1},null,{"$f":"A23*B23","v":3}]

{"sheet":"5) Standard Containment Designs","index":9,"n_rows":129,"n_cols":6,"rows_kept":129,"cut":false,"hidden":false,"merged":[]}
[]
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[]
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[]
[]
[]
[]
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[]
[]
[]
[]
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[]
[]
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[]
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[]
[]
[]
[]
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[]
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[]
[]
[]
[null,"# ","Material ","When used ","How ","Why "]
[]
[]
[null,"A ","Clay ","If plentiful on site ","1m thick, sheepsfoot roller etc. ","Low cost & effective. "]
[]
[]
[null,"B ","Stabilised soil ","If soil tested and is suitable ","Sample and test to determine amount of lime, cement and depth. ","Low cost & effective when no clay on site. "]
[]
[]
[null,"C ","Bentonite matting ","If A or B not suitable ","Prepare sub, roll out and cover. ","Moderate cost. Quick & easy to lay. Tolerant of damage. "]
[]
[]
[null,"D ","Landfill liner type foil ","If A, B or C not suitable ","Prepare sub, roll out, weld and cover. "]
[]
[]
[null,"E ","Concrete ","Small areas only ","Shutter, place mesh and pour fibre reinforced.","Only if A, B, C or D not suitable. "]

{"sheet":"Sheet1","index":10,"n_rows":46,"n_cols":13,"rows_kept":46,"cut":false,"hidden":true,"merged":[]}
[]
[]
[null,null,1,null,2,null,3,null,4,null,5,null,6]
[null,null,"Ag Man",null,"Ag Man & PGC",null,"Ag Man & FW",null,"PGC & FW",null,"FW",null,"Indus & commercial inc green waste"]
[null,"Approx size typical plant +/- 50 %","150 kW",null,"500 kW",null,"1 MW",null,"1 MW",null,"1.5 MW",null,"> 2MW"]
[1,"Source"]
[null,"Farm yard manure","L"]
[null,"Slurry","L"]
[null,"Energy Crops","L"]
[null,"Energy Crop silage","M"]
[null,"Energy crop silage effluent","H"]
[null,"Food waste","-"]
[null,"Green waste","-"]
[]
[null,"Digestate","L",null,"L",null,"M",null,"M",null,"H"]
[null,"Based on vol and aquatic pollutant results"]
[]
[null,"Separated digestate solids","L"]
[null,"Separated digestate liquid","L"]
[]
[null,"Rainwater or surface water runoff contaminated by inventory","L"]
[]
[null,"Fire Fighting Agents harmful in their own right or contaminated by inventory","N/A"]
[]
[null,"Fire fighting and cooling water contaminated by inventory","N/A"]
[]
[2,"Pathway"]
[null,"Site layout and drainage"]
[]
[null,"Topography, geology and hydrology"]
[]
[null,"Climatic conditions"]
[]
[3,"Receptors"]
[null,"Groundwater","See groundwater sheet (similar to amaya's inventory sheet)"]
[]
[null,"Surface water"]
[]
[null,"Local Water Quality"]
[]
[null,"Protected areas"]
[]
[null,"Overall site hazard rating"]
[]
[]
[4,"Liklihood"]

{"sheet":"Risk Scoring","index":11,"n_rows":17,"n_cols":20,"rows_kept":17,"cut":false,"hidden":true,"merged":[[1,17,4,17],[7,11,7,14]]}
[null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,null,"Risk Rating"]
[null,"Rating",null,"Likelihood",null,null,"Consequence","incident level",null,null,null,{"$f":"L6*$P$2","v":4},{"$f":"M6*$P$2","v":8},{"$f":"N6*$P$2","v":12},{"$f":"O6*$P$2","v":16},4,"H","Consequence",null,"High"]
[null,"Very low",null,1,"up to 10%",null,1,"Category 4",null,null,null,{"$f":"L6*$P$3","v":3},{"$f":"M6*$P$3","v":6},{"$f":"N6*$P$3","v":9},{"$f":"O6*$P$3","v":12},3,"M",null,null,"Medium High"]
[null,"Low",null,2,"up to 20%",null,2,"Category 3",null,null,null,{"$f":"L6*$P$4","v":2},{"$f":"M6*$P$4","v":4},{"$f":"N6*$P$4","v":6},{"$f":"O6*$P$4","v":8},2,"L",null,null,"Medium Low"]
[null,"Medium",null,3,"up to 50%",null,3,"Category 2",null,null,null,{"$f":"L6*$P$5","v":1},{"$f":"M6*$P$5","v":2},{"$f":"N6*$P$5","v":3},{"$f":"O6*$P$5","v":4},1,"VL",null,null,"Low"]
[null,"High",null,4,"up to 70%",null,4,"Category 1",null,null,null,1,2,3,4]
[null,null,null,null,null,null,null,null,null,null,null,"VL","L","M","H"]
[null,null,null,null,null,null,null,null,null,null,null,"Likelihood"]
[]
[]
[null,"Category 1 – major, serious, persistent and/or extensive impact or effect"]
[null,"on the environment, people and/or property "]
[null,"Category 2 – significant impact or effect on the environment, people"]
[null,"and/or property "]
[null,"Category 3 – minor or minimal impact or effect on the environment, people"]
[null,"and/or property "]
[null,"Category 4 – substantiated incident with no impact."]