Automated Unidirectional Flushing Software Programs Proven Technology or Vaporware

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Automated Unidirectional Flushing Software
ProgramsProven Technology or Vaporware?
Presented by David Stangel, P.E. ds_at_msa-ep.com
Murray, Smith Associates, Inc.
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Engineer as a Designer of the Human Body

• Three engineering students were gathered together
  discussing the possible designers of the human
  body.
• One said, It was a mechanical engineer. Just
  look at all the joints.''
• Another said, No, it was an electrical
  engineer. The nervous systems has many thousands
  of electrical connections.''
• The last said, Actually it was a civil
  engineer. Who else would run a toxic waste
  pipeline through a recreational area?

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What is Unidirectional Flushing or UDF?

• The sequential closing of system valves and
  opening of hydrants to obtain adequate pipe
  velocities to flush debris, dirty/discolored
  water from the system

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How is it Different than Traditional Flushing
Methods?

• Additional planning is required
• Identification of flushing areas using hard copy
  maps
• Typically aided by a hydraulic model to identify
  valve/hydrant sequence and simulate velocities
  and discharge rates
• Targets velocities of 5 ft/s (min 3 ft/s)
• Traditional flushing doesnt guarantee adequate
  velocities
• Normally positive redundancy and looping works
  against flushing
• Traditional flushing may drop system pressure
  below 20 psi
• Traditional flushing may involve all hydrants
• UDF only flushes strategically placed hydrants

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UDF Compared with Traditional Flushing
Flushed Hydrant
Flushed Hydrant
Closed Valves
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Why Flush? (other than for obvious personal
reasons)

• Maintains distribution system water quality
• Restores disinfectant residual
• Reduces disinfectant demand
• Reduces bacterial growth
• Dislodges biofilms
• Removes sediments and deposits
• Restores flows and pressures
• Eliminates taste and odor problems

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Why Flush?

• Other reasons for UDF
• Increases general system understanding for staff
• Integrates new staff
• Identifies missing/broken valves/hydrants
• Leverages hydraulic model/GIS investment
• Uses less water than traditional techniques (up
  to 40)
• Corrosion control

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Keys to an Effective UDF Program

• Plan, plan, plan
• Quality maps with pertinent information for field
  crews
• Operations staff input
• Incorporate parts of existing flushing programs
  where possible
• Public notification
• Yearly or bi-yearly flushing schedule

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What Information is Required to Develop a UDF
Plan?

• Hydraulic model
• Requires a calibrated model
• Steady state or extended period mode
• Hydrant/valve GIS layers
• CAD information can be utilized if available
• Assumptions for locations can be made if layers
  dont exist
• Firm understanding of system operation

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UDF Software

• Recent releases by software vendors suggest that
  developing a UDF plan using their tools is an
  easy next step.Should we believe it?

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UDF Software cont.

• It is relatively straightforward with completely
  clean data in exactly the required format. We
  all know how often that is the case. ?

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Available Tools

• MWH Soft Bentley Systems
• MWH Soft
• UDF - separate module
• Requires InfoWater (ArcGIS) license
• Bentley
• Includes UDF with all platforms (stand alone,
  CAD, ArcGIS)

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Available Tools

• Pricing dependent on number of pipes
• Example List Prices for 5000 pipe model
• Bentley WaterGEMS 12k cost of AV
• MWH Soft - InfoWater 8k UDF 7k cost of AV
• MWH Soft
• Valves and hydrant laterals do not increase pipe
  count
• Pipes are not split
• Bentley
• Requires a split where hydrants intersect pipes
• Laterals must be entered
• No split for valves

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Approaches to UDF

• MWH Soft
• UDF focus
• Can automatically close all valves along pipe
  alignment
• Bentley
• Starts with conventional flushing
• Progresses to UDF
• Valves open as default
• User closes

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UDF Model Building Process

• Add valves/hydrants
• Was the model created from GIS?
• Valves/hydrants to be operated should be provided
• QA/QC
• Are hydrant and valve numbers populated and
  unique?
• Valves
• Does layer register with model?
• Hydrants
• Number of ports and size
• Elevations
• Hydrant laterals
• Length and diameter

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UDF Model Building Process

• Valves Hydrants are key for building the UDF
  database

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Hydrants

• Pertinent attributes associated with hydrant
• Requires preprocessing
• Pipe attributes not normally associated with
  hydrants
• Length, roughness, diameter
• Non-hydraulic information can be tracked

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Hydrants

• Auto-associated to model pipes in InfoWater UDF
• Auto-calcs mainline distance
• Hydrants can be associated mid-pipe
• Must be built into Bentleys network
• Includes splits at hydrant laterals

Generated by InfoWater UDF
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Valves

• Ensure correct valve/pipe association
• Auto-associated
• InfoWater UDF
• Bentley
• Non-hydraulic information can be tracked

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Valve Registration

• Making our life interesting

• What we want to see

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Registration Issues

• Valve registration can be critical
• If the user wants to use valve ids for closing in
  the field

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Model Tools

• Many InfoWater QA/QC and data building tools are
  unavailable in UDF
• Unique valve/hydrant identifiers
• Hydrant elevation interpolation
• Association of lateral attributes to hydrants
• Lateral length and diameter
• Visual check for valve associations
• General editing of valve/hydrant databases
• Cannot fully leverage Domain Manager in UDF

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Model Tools cont.

• In general the Bentley flushing tools are
  integrated into the modeling platform
• Biggest limitation is the requirement for
  building hydrants and laterals into the model
  database
• Adds pipes to model increasing price
• Adds unneeded complexity for most modeling
  procedures

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UDF Model Building

• Dont underestimate the effort
• Can be significant depending on input data
  quality
• Particularly if the model has not been created
  from GIS
• When old data is put to a new use, previously
  unknown issues arise
• Plan for it ?

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UDF Analysis Criteria

• Typical flushing velocity
• Min 3 ft/s
• Target 5 ft/s
• Shear stress criteria can be used in InfoWater
• Min system pressure typically 20 psi

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Analysis Process

• Using large format system map
• Mark up flush zones
• Typically pressure zones or smaller
• Each zone associated with a primary source
• Each zone includes a number of flush sequences
• Work from source to system periphery

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Analysis Process

• In the model
• Identify initial flush pipeline(s)
• Identify what hydrant(s) will be opened
• Identify valves to be closed
• Take care not to isolate portions of the system
  from water
• Minimize valve closures
• Labor intensive for field crews

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Example InfoWater UDF Flushing Sequence
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Tabular InfoWater UDF Output
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What Does the Field Crew Use?

• They need to know
• What system sources should be operating
• What valves should be closed and when they should
  be reopened
• Identify valve number and/or street intersection
• What hydrants should be opened
• Identify hydrant number
• Identify flow to target
• Identify how long to run hydrant
• They need a series of maps clearly showing the
  sequences and associated information

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What is Currently Availablefor Field Maps?
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Field Maps

• Bentley does not offer field map template
• Utilities are turning to in house or consulted
  ArcGIS programming to develop field maps
• Some utilities want maps in the same format as
  their standard field books

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So What Should You Do?

• Software vendors focus on first to release
  rather than the products polish
• Positive
• Vendors willing to work with users to enhance
  products
• Negative
• Enhancement turnaround time can be slow due to
  large number of software packages supported
• What level of usability and beta testing should
  users expect?
• Price dependant

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Who Should Purchase these Tools?

• Developing a flushing program
• Not like modeling tools that are used regularly
• Takes an initial focused effort
• No need to redo on a weekly/monthly basis
• unless growing rapidly
• If utilities use Bentley then they already own it
• Otherwise
• Utilities No
• Consultants Yes

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Additional Development

• Primary areas for further development
• InfoWater UDF
• Model building and QA/QC
• Field map customization capability
• Bentley
• Associate hydrants without permanent pipe splits
• A field map generator

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Future Enhancements

• MWH Soft
• Committed to more than 20 enhancements
• More incentive
• UDF module sold separately
• Bentley
• Open to suggestions for enhancements
• Less incentive
• Included in modeling suite

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Summary

• UDF
• Ensures adequate flushing velocities are being
  achieved
• Can reduce the number of hydrants operated
• Can reduce the amount of flushed water used
• Can reduce the frequency of required flushing
• Does a more effective job of removing debris,
  biofilm and dirty water
• Provides a target flow rate for flushing
• Should minimize unnecessary low pressures

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Summary cont.

• AWWA and industry supports UDF plan development
  beyond traditional flushing
• Software tools will be more valuable/usable once
  additional enhancements have been made
• If a utility has
• Invested in a hydraulic model
• Accurate valve/hydrant information
• they can develop a UDF plan with reasonable
  effort

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So Flush Away!

• Special Thanks to
• Sammamish Plateau Water and Sewer District
• City of Redmond, Oregon
• Matt Caldwell, Bentley Systems
• Erick Heath, MWH Soft
• Questions?
• ds_at_msa-ep.com