PACP Based Asset Management

Transcription

1 PACP Based Asset Management Objectives of Asset Management Maintain function or level of service as cost effectively as possible Maintain individual components (assets) at lowest life cycle cost possible Asset Management in Wastewater Systems Key asset management questions: What pipes, manholes, and laterals do we own? Where are these assets located? What are their materials, dimensions, depth, and ground cover? What is the condition of each asset? What other community assets would be affected by failure of a particular asset? Which assets are critical to sustained performance? What are my best O&M and CIP investment strategies? What will be the rehabilitation cost? What effect will this have upon the utility budget? How should all of this be communicated to stake holders? 1

2 PACP in Asset Management PACP can assist in developing an asset management plan by collecting asset information such as: Pipe segment length Relative location details Pipe size Pipe shape Pipe material Upstream manhole data Pipe segment lateral data Consequence of failure Defect codes (Structural and O&M) Condition grades Risk in Asset Management Risk = Calculation that takes into account Physical condition The impact of failure to System performance Stakeholders Risk in Asset Management Risk Likelihood of something bad happening and Severity of consequence(s) of failure 2

3 Risk in Asset Management Risk = LoF x CoF Likelihood of Failure (LoF) -Probability of failure of an asset Consequence of Failure (CoF) -Direct and indirect impacts that would result from an asset failure Likelihood Of Failure (LoF) PACP condition grades can determine segment scores Segment scores can be used to calculate Likelihood of Failure for pipelines The Modified PACP Quick Rating based upon highest grade defect observed within a particular pipe segment Appendix C PACP Condition Grading System PACP Grading System for Pipelines, Manholes and Laterals 5 Most significant defect grade 4 Significant defect grade 3 Moderate defect grade 2 Minor to moderate defect grade 1 Minor defect grade 3

4 Pipe Rating System PACP Quick Rating 10 to 14 =A 15 to 19 = B 20 to 24 = C Etc. 10 to 14 =A 15 to 19 = B 20 to 24 = C Etc. Likelihood of Failure Rules An asset s Likelihood of Failure is determined based on the following scenarios: No condition assessment data is available Condition assessment data is available and there are no defects There are no more than 9 occurrences of the highest condition grade The second character is a letter (indicating more than 9 occurrences) In all cases we divide the first two digits of the quick rating by 10 Calculate LoF 4

5 Calculate LoF Consequence of Failure (CoF) Direct and indirect impacts on the vicinity and community due to a potential asset failure Expressed as Triple Bottom Line (TBL) o Economic Impacts o Social Impacts o Environmental Impacts Consequence of Failure (CoF) Social costs Sustainability Environmental costs Economical costs 5

6 Economical Impacts Impact of Direct and Indirect economic losses o Direct costs Asset Repairs Legal Fees Fines o Indirect costs Property Values Increased Insurance Rates Utility's Credibility Typically expressed in dollars and include property damage, repair cost, and production loss, etc. Social Impacts Impact on Society due to asset failure Factors include o Number of properties/clients affected o Types of affected properties (hospitals, schools, businesses, parks, critical services, etc.) o Duration of Failure o Utility s Credibility o Public Health and Safety In addition, there must be consideration for safety issues (i.e. public exposure to health-threatening problems, injuries, or even fatalities) Environmental Impacts Impact to ecological conditions occurring as a result of asset failure Environmentally cost considerations based on o Proximity to wetlands and waterways o Federal Emergency Management Agency (FEMA) flood zones o Possible contamination of potable water sources o Sensitivity of nearby soils 6

7 Rating Methodology 56 inch combined trunk sewer 100 feet downstream of a Combined Sewer Overflow (CSO) that crosses a body of water Higher CoF Vs. Lower CoF 8 inch sanitary sewer at the upstream end of the system that only serves one resident Rating Methodology Considers locational and demographical information o Network Position o Location of Pipe o Proximity to Environmentally Sensitive Features o Service to customer of significant importance o Accessibility for maintenance and inspection A good GIS map helps to determine these considerations CoF assigned on a scale from 1 to 6 Assets with no CoF assigned are given a value of 0 (Zero) CoF Examples CoF Descriptions and Associated Factors Examples include o Pipe Depth o Relative Network Position of the Pipe o Pipe Diameter o Location of Pipe o Distance between Pipe and Waterway o Customers of High Importance o Accessibility The system owner must decide upon CoF factors and weighting 7

8 Pipe Depth Typically an economicconsideration since deeper pipe is generally more expensive to repair/replace * Assets with no CoF assigned shall be given a value of 0 (Zero) Relative Network Position of Pipe Pipe Diameter o Economic Costs more to repair, replace, and rehabilitate o Social Impacts more customers o Environmental impacts to sensitive geographical area Relative Network Position Sum of relative position of all pipes discharging to an upstream structure Pipe Diameter Affects Economic, Environmental and Social costs Larger diameter pipes generally Serve more customers Cost more to rehabilitate * Assets with no CoF assigned shall be given a value of 0 (Zero) 8

9 Relative Network Position of Pipe Relative Network Position of Pipe Location of Pipe GIS based maps with layers including street network, buildings, waterways and other datasets can be utilized to assign Consequence of Failure based on surface location Location of Pipe Disruption to the community and the cost of managing emergency repairs of a pipe Accessibility for repair, rehabilitation or replacement in case of emergency Pipe failure on a major road causes more disruption to traffic compared to failure of a pipe on a local road * Assets with no CoF assigned shall be given a value of 0 (Zero) 9

10 Proximity to Environmentally Sensitive Features Consequence of Failure factor is set based on the distance between a pipe and an environmentally sensitive feature Factor affected by the nature of the sensitive environment GIS can be set-up to assign CoF based on distance to environmentally sensitive features Service to Customer of Significant Importance Hospitals, schools, manufacturing facilities, emergency services, etc., as determined by utility Providing uninterrupted service to these facilities may be a priority for the utility 10

11 Accessibility for Maintenance/Inspection Response time for a service crew may be significantly higher if access is difficult Failure may cause significant damage to the environment as well as private properties due to delays in response 11

12 Sample Calculation of Overall CoF 4.03 Enter Consequence of Failure value in Field 22 of the PACP Inspection Form Header Section Managing Asset Risk Risk matrix provides a basis for a maintenance and rehabilitation program Overall risk a function of LoF and CoF 12

13 Appendix D PACP Based Risk Management Considers PACP Role Regarding Risk Management in Asset Management Managing Asset Risk CoF and LoF have a range between 0 and 6 A score of 0 (LoFor CoF) represents a data gap Information should be promptly collected Do not use/graph 0 scores! On the graph o The green area represents assets with lower risk o The red area represents assets with higher risk; resources should be focused on rehabilitating assets that fall in the red area Non-zero risk scores can be used to prioritize projects Collect asset condition information Sample Asset Management Plan Graph this data to help set priorities 13

14 Managing Asset Risk (Examples) 2.4, , , , , , 2.1 Managing Asset Risk (Examples) $40,000 available for rehab $25,000 available for rehab $20,000 available for rehab 2.4, , , , , , 2.1 Successful Asset Management Results Shift from emergency response to strategic riskbased management of critical assets Reduce the number of asset failures Minimize the negative impacts of failures when they occur Improve performance & reliability of the system Manage O&M costs more accurately 14

15 Questions? More Information? Ted DeBoda, PE Jane Bayer NASSCO, Inc. (410)