System Resilience for Water & Waste Water Services in Scotland

Transcription

1 System for Water & Waste Water Services in Scotland Will Carroll Water Strategy Technical Lead 23 rd May 2018

2 System for Water & Waste Water Services in Scotland Water Supply Why is important Assessing our How can we improve Waste Water Applying our learning

3 System for Water & Waste Water Services in Scotland Water Supply Why is important Assessing our How can we improve Waste Water Applying our learning

4 Business Plan Water Supply Why is it important? Water supply identified as a high priority for customers. Dual supply capability estimated at 15%. Multiple near miss incidents identified. Long term strategy to increase connectivity between the main urban areas. Develop a risk assessment method and assess 48 systems serving populations over 15,000. Established and investment allowance to begin improvements agreed with stakeholders.

5 Without, what could happen Water Supply Why is it important? Direct Customer Impacts Increasing loss of service and customer Impact 140 litres per person per day litres per person per day Boil Water Do Not Drink Do Not Use No Water

6 Without, what could happen Wider Societal Impacts Water Supply Why is it important? School Closures Business Disruption Care Homes No Water Agriculture Hospital Disruption Fire Safety

7 What can customers cope with? Water Supply Why is it important? Duration of interruption (hr) When 50% of customers say they would not be able to cope 100, , , ,000 Number of customer affected by interruption

8 Scottish Water s response capability Water Supply Why is it important Duration of interruption (hr) Personal Bottle Water Delivery Customers Collect Bottle Water from Collection Points Static Tanks in Street Bottled Water Delivery to Vulnerable Customers Police In Control External Support Increasing numbers of customers Number of customer affected by interruption

9 Isn t this all just about service levels? Water Supply Why is it important? Service Service failures do occur to some customers every year Delivering what is promised for customers on a day to day basis These sorts of problems are real, but have a low probability of happening each year Being able to cope collectively when significant problems arise

10 System for Water & Waste Water Services in Scotland Water Supply Why is important Assessing our How can we improve Waste Water Applying our learning

11 Abstraction Estimating scale Water Supply Assessing our 1 Water Treatment Assess system components by service impact. Identify and confirm network back feeds. Assess storage time. Establish time until customers are impacted. 18hrs Storage 2 30 hrs 5 8hrs 4 Storage 3 12hrs Storage 48 hrs 6 Customers Customers Customers DMA 28 hrs

12 Assessing plausible threats Water Supply Assessing our We fit our approach to the type of asset under consideration: Relatively simple function Huge number of assets Standardised assessment Highly complex asset Only one per system Tailored assessment Weather & Climate Pollution Physical Damage Comms and Power Procurement & Staffing Societal Geological Miscellaneous Asset Failure Trunk Mains SRs & TWPs Treatment

13 Visualising system profile Impact on customer Water Supply Assessing our Assessed duration of interruption for customers All Customers Impacted Good drought reliability Significant risks in WTW / Pumping Station WTW, Water Resource & Pumping Station Risks Network Risks Increasing numbers of customers Poor network Number of customers affected

14 System for Water & Waste Water Services in Scotland Water Supply Why is important Assessing our How can we improve Waste Water Applying our learning

15 How close have we got? Water Supply Improving 196 Burncrooks 1997 Contamination 144 Tayside 2003 Drought Fife 2013 Drought 120 Kirbister 2006 Flooding Motherwell 2015 Contamination Bursts Bradan 1991 Burst Customers Affected Alnwickhill1997 Contamination Aberdeen 2015 Flood

16 Reliability DURATION Water Supply Threat Improving Coping thresholds supply Redundancy SCALE Resistance Recovery Response functional Redundancy

17 Resistance Cathodic protection repairs. Reliability Pipe bridge maintenance. Pipe inspection & follow on maintenance Functional Redundancy Increase system storage by 240ML. Duplicate hard to repair sections Water Supply Improving Milngavie & Balmore Supply Pumping Station Recovery Servitude Management - Tree clearance. Critical spares and equipment. Line & air valve maintenance. Network modelling & back feed planning. Temporary bypass options WTW WTW Pumping Station WTW WTW Response Multi-agency incident exercise Pumping Station Supply Redundancy Strategic link to Glasgow system & central belt network. SR Bradan Supply

18 System for Water & Waste Water Services in Scotland Water Supply Why is important Assessing our How can we improve Waste Water Applying our learning

19 Broad equivalency of the Safe & SuRe framework Waste Water Applying our learning Resistance Reliability Functional Redundancy MITIGATE Supply Redundancy ADAPT Recovery COPE Response

20 Strands of our Waste Water strategy to deliver effective and sustainable collection and treatment of waste water every minute of the day Waste Water Applying our learning SERVICE NETWORK TREATMENT NATURAL HAZARD SERVICE FAILURE RISK Risk to loss of drainage service in the event of extreme flooding Risk to loss of drainage service in the event of asset failure on the sewer network Risk of our treatment processes being unable to deliver compliant discharges Risk to our assets from natural hazards OUTCOME Customer Flooding Customer Flooding /Environmental Pollution Environmental Pollution Customer Flooding /Environmental Pollution GOAL Minimise service failure magnitude & duration, and recover when problems occurs

21 Use of the framework in treatment Waste Water Applying our learning Why is treatment important? Climate change toward more intense storm events and prolonged dry spells Tighter discharge permitting standards in future Treatment assets impacted by growth, age, and emerging pollutants. A framework to explore waste water treatment Prolonged dry weather THREAT BASED How can we reduce the peak loading? SYSTEM BASED What other treatment options are available? CONSEQUENCE BASED Can the environment cope with short periods of non-compliance? Environmental harm Increase in sewage influent ammonia concentration Non compliant discharge

22 System for Water & Waste Water Services in Scotland Water Supply Why is important Assessing our How can we improve Waste Water Applying our learning

23 System for Water & Waste Water Services in Scotland Will Carroll Water Strategy Technical Lead 23 rd May 2018