force mains: not to be forgotten assets

8/8/2019 Force Mains: Not To Be Forgotten Assets

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WEFTEC10

New Orleans, LouisianaOctober 26, 2010

FORCE MAINS:

NOT TO BE FORGOTTENASSETS

Bryon Livingston, P.E. Black & Veatch

Alireza Parhami, P.E. Black & Veatch

Stacy Gallick Johnson County Wastewater


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WEFTEC10 New Orleans, Louisiana

Force Mains: Not-to-be-forgotten assets

Introduction

Force Mains in a Collection System

Overview of Johnson Countys System

Coordination With Asset Management Plan

System for Evaluating Force Mains

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Force Mains in the Collection System

Not Like the Other Pipelines

No Access like Manholes in the Gravity System

No Periods of Low Flow to Inspect or Maintain

No Excess Capacity or Redundant Pipeline to Take

Out of Service Failure Can Create Dramatic Consequences

Sink Holes Not Just Overflows

Pressurized System



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Catastrophic Events



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External Loads

Soil

TrafficOverburden

Bedding Condition and Material

Internal Corrosion

External Corrosion

Design and Construction Practices

Leakage

SoilCharacteristics

Contraction

Loads

Temperature

Many Factors Impact Service Life of a Pipe

Movement

Water Characteristics



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Johnson County Wastewater Asset management plan

2008 Developed Asset Management Plan

Completed A Basic Level 1 Review Of MostFacilities

Process Identified The Need For AdditionalInformation On Force Mains

Force Mains Not The Typical Asset In TheCollection System



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Background information

Johnson County Wastewater (JCW) Serves

Communities In Northeast Johnson County Kansas System Contains 40 Miles Of Force Mains

Sizes Vary From 4 To 42 Materials Primarily Ductile And Cast Iron With Some

PVC, HDPE And PCCP





Service area

Serves 500,000

Customers Multiple Sewer

Districts

32 Lift Stations

2,100 Miles OfCollection System

60 mgd TreatmentCapacity





JCWs asset management plan

Established Process For Management Of Assets

Treatment Plants, Lift Stations, CollectionSystem

Established Rating And Terminology

Identified Force Mains Required Unique Process

When Establishing an Asset Management Plan Remember

to Allow For Modifications Based on Better Data





Asset management - method tomanage force mains

Recognized Lack Of Data On Force Mains

Actual Location Of Pipe In The Alignment

Condition Of The Pipe

Required Procedure To Prioritize And EstablishMethods For Collecting Data For ConditionAssessment

Consistent With Existing Process

Recognized Force Mains Require A Unique

Procedure





Force main procedure

Inspection Prioritization Based On Risk Analysis

Provide Procedure For Collection Of DataRoutinely And By Inspection

Compatible With Asset Management PlanMethodology

Develop A Priortization Matrix That Is Flexible AndEasy To Use





Prioritization matrix

Based Upon Risk Analysis Process

Probability Of Failure (POF)

Consequence Of Failure (COF)

POF X COF = RISK Modified To Include Redundancy

POF X COF X REDUNDANCY = Business RiskExposure





Factors for probability of failure

Pipe Length

Pipe Material

Pipe Age

Pipe Break Data

Multiple Material In Pipeline





Probability of failure factors


Each

Parameter isWeighted

RatingsEstablished For

EachParameter




Factors for consequence of failure

Pipe Diameter

Pipe Alignment

Pipe Physical Location

No Manholes To Locate Pipeline

Estimated Duration Of Service Interruption

Land Use Adjacent To Pipeline





Consequence of failure factors


Each

Parameter isWeighted

RatingsEstablished For

EachParameter




Priority ranking results


POF x COF x

Redundancy =Business Risk

Ranking




Force main inspection priorities

Provide A Numerical Ranking Based On Business

Risk Exposure Method Allows Adjusting Of Weighting On Factors

To Meet Specific Concerns

Revised in the Future Based on Data Collected





Inspection and condition assessment

procedure

Develop A Standard Approach For Inspection Procedures

Inspection Plan Evaluate Leak Detection

Conduct Testing And Inspection

Evaluate Data To Complete Condition Assessment

Identify Inspection Technologies For Various Pipe Materials

Ductile And Cast Iron

PVC And HDPE

Pre-stressed Concrete Cylinder Pipe (PCCP)





Relationship to asset management plan

Builds Upon Level 1 Assessment Data

Establishes Priorities For Force Mains Inspections

Results Of Condition Assessment Compatible With

Existing Plan Provides The Condition Of The Pipe For Managing

As An Asset In Future Planning





Capital planning with results





Implementation of procedure

Determine Priority Inspection From Matrix

Evaluation Collect Data And Conduct Inspection Of Pipeline

Complete Condition Assessment Based On FieldData

Prioritize Pipeline For Rehabilitation Or

Replacement





Collection of data

Implement Data Collection In Operation Work

Orders Following Form Developed From Review Of Several

Utilities

Simple Is Better

Complete Inspections Of Priority Pipelines

Update Gis Information From Gathering Efforts





Work order datacollection





Conclusions

Force Mains Require Unique Procedure In The

Asset Management Plan Condition Assessment Is A Difficult Task

Prioritization of Pipelines Results in BetterManagement of Assets



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WEFTEC10

New Orleans, LouisianaOctober 26, 2010

Questions?

Bryon Livingston, P.E.Email: [email protected]

Stacy GalickEmail: [email protected]

Alireza Parhami, P.E.Email: [email protected]
mailto:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]:[email protected]

force mains: not to be forgotten assets

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