COMMITMENT & INTEGRITY DRIVE RESULTS

Union Sanitary District’s Collection System Hydraulic Model and Pipe Condition Assessment Program

– the ongoing evolution of a powerful planning tool

Rollie Arbolante – Union Sanitary DistrictJennifer Chang & Gisa Ju – Woodard & Curran

PUG 2018 Sharing Technologies SeminarThursday, February 22, 2018

Union Sanitary District800+ miles of sewer22 mgd ADWF (current)57 mgd PWWF (current)73 mgd PWWF (future)

Early Planning Efforts1989 Sewer Master Plan

➢ Collection system-wide➢ Flow projections and hydraulic model➢ Recommended capacity projects and 6-year cycle

of CCTV inspection1993 District-wide Master Plan

➢ Transport & Treatment Systems➢ Refined design flow projections

These studies set the stage for an on-going master planning process

Master Planning Process

Capacity Deficiencies

Design Conditions

Flow Meter Data

Land Use Data

Rehabilitation Needs

Cost Data

Inspection Data

O&M Data

Condition AssessmentCapacity Assessment

Recommended CIP

Hydraulic Model

Database ProgramAlternative

Analysis & Prioritization

Capacity Assessment Methodology

Build Network• Asset data• Operation data• Land Use data

Calibrate Model• Flow meter data• Rain gauge data• SCADA data

Assess Capacity• Future conditions• Design storm• Deficiency criteria

Develop Projects• Capacity improvement• Capital costs• Priorities

Hydraulic Model Simulates System Performance

USD Hydraulic Model Evolution – Model SoftwareSNAP Model (Static) HydroWorks™

(Fully Dynamic)InfoWorks™

(GIS interface) InfoWorks ICM™

1989 201820171999 2004

•Static•Non-graphical•No hydraulic gradeline•No user interface

•Fully dynamic•Powerful GIS interface•Vast capabilities

USD Hydraulic Model Evolution – Model NetworkMost

10-inch sewersGradual

refinementsRedefine

“subareas” All Pipe Network

1989 201820172000

USD Hydraulic Model Evolution – Land Use DataDigitized AutoCad map +

aerial photo overlays + ArcGIS Mapping + Customer Billing Databases

1995 201820042000

Customer Billing Database• Address and APN• Land Use Type (CIXZ)• Residence Type• Vacant or Not Served• Volume Per Year Usage

USD Hydraulic Model Evolution – Design FlowsPeaking factors, conservative I/I

rates Less conservative RDI/I assumptions

Design storm update, calibrated

RDI/IRDI/I sensitivity

studied“Calibrated” vs. “Design” BWF

Design storm update

1989 201820152000 2008 20121997

Hydraulic Model Planned Future EnhancementsAll-pipe model

▪ Increases detail and accuracy of flow routing

▪ Facilitates development reviews

▪ Confirms capacity needs for rehabilitation projects

Condition Assessment Methdology

Condition Rating Based on CCTV Data▪ Values defined by District staff

▪ Structural, maintenance, and total ratings

▪ Minimum “default” rating for sewers on 3 to 36-mo. maintenance frequency

Critical Rating Establishes Priorities

Critical Rating = Condition Ratingx Total IF

Impact factors reflect consequence of failure

Critical Rating reflects total risk

(Value from 1 to 2)

Structural Rehabilitation Methods Considered ▪ Full-segment replacement

▪ Full-segment lining

▪ Spot repair of severe defects

▪ Spot repair of moderate and severe defects

“Best” Method Based on Lowest Annual Cost of OwnershipCost of ownership also considers maintenance cost over remaining life of pipe

➢ Replacement – 100-year life @ 72-mo. maintenance frequency➢ Lining – 75-year life @ 72-mo. maintenance frequency➢ Spot Repair – remaining life based on current pipe age and number

of unrepaired defects @ current maintenance frequency

Pipe Condition Assessment Program EvolutionPCAP

Developed

Changes to CCTV codes, Hansen updates, new manhole numbering

system, GIS, localized liner spot repair

“Annual cost of ownership”

concept

NASSCO PACP

InfoMaster™1995 20182012

Powerful Planning Tools Facilitate Great Results

Address capacity deficiencies

1995 – Multiple deficiencies2017 – No capacity projects

Optimize rehabilitation

Lifecycle cost methodInfoMaster™ benefits

Increase confidence

Reduce assumptionsImprove resolutionApply elsewhere

In Conclusion▪ Through cyclic Master Plan updates, the District’s hydraulic model and

condition assessment methodology have continually improved in detail and usefulness

▪ Master Plans ensure timely identification of capital needs

▪ USD serves as an excellent example of leveraging effective planning tools in a systematic approach to quality public stewardship

Acknowledging 20+ Years of EffortDISTRICT STAFF

Andy Morrison (retired)Bernie Graef (retired)

Chris ElliotCurtis Bosick

Dan Tolvtvar (retired)Dwight Dorsey (retired)

James SchofieldJeff Roletto (retired)Jesse Gill (retired)

Manuel Terra (retired)Matt Faria (retired)

Mohammad GhouryPaulette Roberson

Raymond ChauRich Czapkay

Richard Currie (retired)Richard ScobeeRollie Arbolante

Russell Wogerman (deceased)Sami GhossainShawn Nesgis

Susan Whitelock (retired)Todd Jacob

Consultants and Subconsultants: Woodard & Curran (RMC), MWH, Talavera & Richardson, E2, V&A, ADS, and Total Flow

COMMITMENT & INTEGRITY DRIVE RESULTS

QUESTIONS?

Contact informationRollie Arbolante (USD)

rolliea@unionsanitary.ca.gov510.477.7500

Gisa Ju (Woodard & Curran)gju@woodardcurran.com925.627.4100

Jennifer Chang (Woodard & Curran)jchang@woodardcurran.com415.321.3400