GIS Applications for Water, Wastewater, and Stormwater Systems - Chapter 15 pptx

• Identifying valves to be closed for repairing or replacing broken water mains• System rehabilitation and repair • Case studies LIST OF CHAPTER ACRONYMS AM/FM/GIS Automated Mapping/Faci

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CHAPTER 15 Maintenance Applications

GIS can be used to prepare inspection or maintenance work orders simply by clicking on a sewer pipe or manhole This approach simply takes just a few minutes compared to the conventional method of locating and copying maps and typing the work order forms, which usually takes several hours

Displaying sewer CCTV inspection video in GIS The movie shows a sewer blocked by heavy root growth.

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• Identifying valves to be closed for repairing or replacing broken water mains

• System rehabilitation and repair

• Case studies

LIST OF CHAPTER ACRONYMS

AM/FM/GIS Automated Mapping/Facilities Management/Geographic Information System

AVI Audio Video Interleaved (digital movie format)

CCTV Closed-Circuit Television

CD Compact Disc

CMMS Computerized Maintenance Management System

DVD Digital Versatile Disc

GAAP Generally Accepted Accounting Principles

GASB Government Accounting Standards Board

HTML Hyper Text Markup Language (a file extension)

MPEG Moving Picture Experts Group (digital movievideo format)

O&M Operation and Maintenance

PDA Personal Digital Assistant (electronic handheld information device)

PDF Portable Document Format (Adobe Acrobat)

ROM Read Only Memory

VCR Video Cassette Recorder

VHS Video Home System (video cassette format) This book focuses on the four main applications of GIS, which are mapping, monitor- ing, modeling, and maintenance and are referred to as the “4M applications.” In this chapter

we will learn about the applications of the last M (maintenance).

To fully appreciate the benefits of GIS-based inspections, consider the followinghypothetical scenario On March 10, 2004, following a heavy storm event, a sewer

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customer calls the Clearwater Sewer Authority to report a minor basement floodingevent without any property damage An Authority operator immediately starts theGIS and enters the customer address The GIS zooms to the resident property andshows all the sewers and manholes in the area The operator queries the inspectiondata for a sewer segment adjacent to the customer property and finds that a minimovie of the closed-circuit television (CCTV) inspection dated July 10, 1998, isavailable The operator plays the movie and sees light root growth in the segment.

A query of the maintenance history for that segment shows that it has not beencleaned since April 5, 1997 This information indicates that the roots were nevercleaned and have probably grown to “heavy” status The operator highlights thesewer segment, launches the work-order module, and completes a work-order formfor CCTV inspection and root removal, if necessary The export button saves thework-order form and a map of the property and adjacent sewers in a PDF file Theoperator immediately sends the PDF file by e-mail to the Authority’s sewer cleaningcontractor The entire session from the time the customer called the Authority officetook about 30 min The operator does not forget to call the customer to tell him that

a work order has been issued to investigate the problem

BUNCOMBE COUNTY’S SEWER SYSTEM INSPECTION

AND MAINTENANCE

During the 1990s, the Metropolitan Sewerage District (MSD) of BuncombeCounty (North Carolina) spent more than $111 million rehabilitating the mostproblematic sewer lines in its system MSD’s aggressive sewer rehabilitationprogram has successfully implemented numerous rehabilitation technologies In

1999, MSD began assessing a method of comprehensive basinwide rehabilitation

In this approach, every pipe in a drainage basin was evaluated using CCTV footageand engineering analysis After evaluating this comprehensive basinwide rehabil-itation method for 4 years, MSD determined that it is overly time- and capital-intensive Seeking a more efficient and quicker method to fix the system, MSDdeveloped and implemented a new GIS-based rehabilitation method called “piperating.”

The pipe rating method has five main elements: (1) CCTV information, (2) adefect scoring system, (3) GIS database software, (4) sanitary sewer overflow (SSO)history, and (5) engineering analysis These components are combined to generatespecific projects for problem lines Each structural defect noted in the video inspection

is given a defect score, in accordance with MSD’s standardized scoring system Forexample, a circumferential crack is given a score of 20, and a collapsed pipe isassigned a score of 100 Defects are then embedded within the GIS database, withappropriate scores attached Upon quantifying all structural defects within a pipesegment, three defect ratings are generated in the GIS: (1) peak defect rating, (2)mean defect rating, and (3) mean pipeline rating These ratings allow users to visualizethe severity of pipe defects using GIS Figure 15.1 shows an ArcGIS screenshot ofmean pipeline ratings Such maps are used in prioritizing pipe segments for repairwork They are also used to determine when several point repairs should be made to

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a line as apposed to excavating the entire line (Bradford et al., 2004) Additionalinformation about this application is provided in Chapter 17 (Applications Sampler)

ASSET MANAGEMENT

As discussed in Chapter 14 (AM/FM/GIS Applications), at present our water andwastewater infrastructure, especially in the older cities, is in critical stages of deteri-oration and has started to crumble Nationally and internationally, aging water andwastewater infrastructure is imposing enormous costs on local communities (Boothand Rogers, 2001) In the U.S., cities and utilities are demanding billions of dollars

of government grants and funds for renovating their water infrastructure Due to an

“out-of-sight, out-of-mind” philosophy and the lack of funds to follow a preventivemaintenance practice, the replacement is mostly performed on a react-to-crisis basis

A crisis maintenance program only corrects infrastructure problems after they havehappened Notwithstanding the conventional wisdom, this reactive approach may not

be the best strategy as substantial expenditure and inconvenience can be avoided byreplacing a deteriorated pipeline before it actually breaks A preventive maintenanceprogram is proactive because it strives to correct a problem before it occurs.For water and wastewater systems, asset management can be defined as managinginfrastructure capital assets to minimize the total cost of owning and operating themwhile delivering the service levels customers desire (Booth and Rogers, 2001) Atypical asset management system has five components (Doyle and Rose, 2001):

Figure 15.1 ArcGIS screenshot of mean pipeline ratings for the Metropolitan Sewerage District

(MSD) of Buncombe County, North Carolina.

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1 Facilities inventory: Describes each system element in an asset group GIS can

be very useful in completing this task.

2 Condition assessment: Classifies each asset according to its capability to perform the intended function.

3 Valuation: Assigns a financial value to inventoried assets consistent with Generally Accepted Accounting Principles (GAAP).

4 Operations, maintenance, repair, and replacement management: Arguably the heart

of a management system, this component tracks and records data about work orders and customer complaints, issues and tracks preventive and predictive maintenance schedules, and generates crew assignments and work-site maps GIS has extensive capabilities to fulfill this part.

5 Analysis and evaluation: Considered as the brains of an asset management system, this component prioritizes work effort, analyzes cost-effectiveness, and optimizes asset performance.

An asset management system helps predict the future condition of assets andmajor rehabilitation costs for planning purposes An effective asset managementsystem can reduce the cost of system operation and maintenance (O&M) Everysuccessful maintenance program should begin with an accurate system map because

it is difficult to maintain a system if the users do not know where the water or sewerlines are A well-constructed GIS should be used to create the system map Historicalmaintenance data should also be linked with the GIS because it is difficult to schedulemaintenance when you do not know the last time it was done (Gaines, 2001) AGIS-based asset management system can be used as a decision support system forcapital improvement planning (CIP) For example, CH2M HILL (Atlanta, Georgia)used ESRI’s MapObjects GIS software to develop an infrastructure capital assetmanagement (ICAM) toolkit that can be used in a Web-based browser/server orstand-alone computing environment (Booth and Rogers, 2001)

In many cases, through more effective planning and management of ture improvements and system operations, organizations can realize annual savings

infrastruc-of 20 to 40% (Stern and Kendall, 2001) Boston Water and Sewer Commission(BWSC) has approximately 27,500 catch basins In 2000, BWSC started enhancingits asset management program for locating, inspecting, and maintaining its catchbasins BWSC improved the productivity and efficiency of its catch basin preventivemaintenance program by integrating it with GIS and a computerized maintenancemanagement system (CMMS) In lieu of using global positioning system (GPS), thecrews determined the precise location of catch basins by using a measuring wheel

to measure distance from known points to the basin’s center BWSC utilized held touch-screen computers in the field to collect geographic location informationand more than 25 attributes GIS data in Shapefile format and a GIS interfaceprovided the backbone of this application The traditional paper-based data collectionmethods typically averaged 24 catch basin inspections per day, but the GIS-basedmethod boosted this rate to approximately 42 per day

hand-Boston Water and Sewer Commission’s GIS-based field-data-collection approach increased the catch basin mapping productivity by more than 40% compared with traditional, paper-based data collection methods (Lopes et al., 2002).

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In the U.S., two key drivers are motivating improved asset management practices

in water and wastewater utilities: (1) GASB 34 requirements, and (2) wet-weatheroverflow requirements

GASB 34 APPLICATIONS

In 1999, the Government Accounting Standards Board (GASB) issued Rule 34(known as GASB34) to govern financial reporting requirements of approximately85,000 state and local governments in the U.S Considered the most significantchange in the history of government financing reporting in the U.S., GASB 34requires the cities to adequately account for and report their capital asset inventory

in a complete, accurate, and detailed manner (Booth and Rogers, 2001) The capitalassets include infrastructure networks such as roads, bridges, and water, wastewater,and stormwater systems

The literature indicates that a GIS-based approach saves time spent in locating,organizing, and confirming the accuracy of field inspection information (Criss,2000) Industry experts believe that utilities can cut their maintenance costs in half

by implementing GIS-based preventive maintenance programs Thus, integration ofGIS and maintenance management software is a natural progression for GIS appli-cations in the water and wastewater industry For instance, the Wastewater CollectionDivision of Fairfax County, Virginia, linked the county’s sewer maps with thesanitary sewer maintenance management system database, making it easier to accessmaps during field activities (Fillmore et al., 2001) The City of Denver, Colorado,linked the city’s sewer system GIS to an information management system to effi-ciently track and manage maintenance operations (Gaines, 2001)

WET WEATHER OVERFLOW MANAGEMENT APPLICATIONS

Management of wet weather overflows is a fertile field for GIS technology Byusing geographic information in mapping, facilities management, and work ordermanagement, a wastewater system manager can develop a detailed capital improve-ment program or operations and maintenance plan for the collection system.Broken and damaged sewers, laterals, and manholes usually contribute signifi-cant amounts of wet weather inflow and infiltration (I/I) to a wastewater collectionsystem This contribution often results in combined sewer overflows (CSO) fromcombined sewer systems and sanitary sewer overflows (SSO) from sanitary sewersystems

In the U.S., CSO discharges are regulated by U.S EPA’s National CSO Policy.The policy requires a System Inventory and Physical Characterization report Majorportions of this report can be completed using GIS The CSO policy’s Nine MinimumControls (NMC) mandate proper operation and regular maintenance programs forthe sewer system and CSO outfalls that can also benefit from inspection and main-tenance applications of GIS SSO discharges are being regulated by U.S EPA’s SSOrule that requires implementation of a Capacity, Management, Operations, and

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Maintenance (CMOM) program CMOM requires the system owners/operators toidentify and prioritize structural deficiencies and rehabilitation actions for eachdeficiency CMOM requirements offer a dynamic system management frameworkthat encourages evaluating and prioritizing efforts to identify and correct perfor-mance-limiting situations in a wastewater collection system CMOM is a combina-tion of planning tools and physical activities that help communities optimize theperformance of their sewer systems CMOM requirements mandate that the systemowner/operator properly manage, operate, and maintain, at all times, all parts of thecollection system The owner/operator must provide adequate capacity to conveybase flows and peak flows for all parts of the collection system CMOM requirementsinclude “maintaining a map” (Davis and Prelewicz, 2001), which is the simplestapplication of GIS as described in Chapter 9 (Mapping Applications).

Some wet weather overflow management experts believe that use of GIS is a must for CMOM compliance.

AutoCAD Map GIS Application for CMOM

The Stege Sanitary District (SSD) located near San Francisco Bay serves apopulation of approximately 40,000 in a 5.5 mi2 area The goal of a CMOM program

is the ultimate elimination of any type of overflow from the sanitary sewer system.SSD was challenged with the goal of “no overflows” in 1996 To meet this goal, anew maintenance model was implemented for sanitary sewers that used AutoCADMap GIS and Microsoft Access database software to identify system conditionscausing overflows, and prompted immediate action to correct problems via repair

or replacement Those lines showing the greatest damage and whose repair orreplacement were within the budget constraints established by the District, would

be immediately set right The ability to make effective and economic decisionsregarding the capital replacement needs of the system based on the actual degradation

of the system provided a degree of asset management that had not been readilyavailable to the management The SSD experience indicated that proactive mainte-nance provides the most cost-effective means of managing the system to achievethe goal of “no overflows.”

During 1992 to 1994, SSD created the sewer and manhole layers in AutoCADformat and linked the capacity model output to these layers to identify line segmentsthat were overloaded Complete GIS capability was added later with the use ofAutoCAD Map, an extension of the common AutoCAD drafting program that addsthe feature of linking information from external databases During 1994 to 2001,information was collected in a database on the physical system characteristics,system hydraulic performance under selected flow conditions, system overflows,routine maintenance activities, CCTV inspections, and repairs and replacements Alldatabase information was linked to the mapped line segments, thereby allowing aneasy evaluation of problem distribution throughout the system with a textual andgraphical response from the database query The relational database program used

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was Microsoft Access, which is compatible with AutoCAD Map All of the workwas completed on a desktop PC (Rugaard, 2001).

CCTV INSPECTION OF SEWERS

Traditionally, municipalities have relied on analog video for internal inspection

of sewers In this technique, remote-controlled and self-propelled cameras movethrough sewer lines to record the pipe’s internal conditions on a video tape In aparallel operation, technicians create paper logs identifying the location, size, andother key information about the pipe Referred to as CCTV inspection, this methodhas been considered to be the most effective and economical method of pinpointingthe sources of I/I contribution For instance, by the late 1990s the City of Boston,Massachusetts, had conducted 12 million ft of CCTV inspection on video tapes.Using an inspection cost of one dollar per foot, the cost of collecting this informationcould be at least $12 million CCTV inspection videotapes contain a wealth of usefulinformation about the state of a collection system, yet they have been often treated

as single-use items A lot of money is spent on video inspections, yet inspectiondata are frequently underutilized mainly because accessing the information from theconventional video tapes and paper inspection log sheets has been difficult and timeconsuming (Criss, 2000)

GIS can be used as a document management system for CCTV inspection data.For example, users can click on a rehabilitated sewer pipe to see the “before” and

“after” movies on their computer screen This application, however, requires verting VHS video tapes to computer files (digital movies) Once converted andstored on computers, the valuable information once hidden in videotapes can beretrieved with the click of a mouse, eliminating the need for other equipment (TV,VCR, and cables) and office space to house the equipment CDs take up 70% lessshelf space than VHS tapes As a side benefit, digital movies can be used to createmultimedia presentations for utility management when requesting maintenance andrehabilitation funds After all, a video is worth a thousand pictures Most video tapeshave a short shelf life of approximately 10 years and their video quality and perfor-mance are inferior to digital media Unlike VHS tapes, digital videos do not losepicture quality when copied Digital technology also allows high-resolution snap-shots of defective pipe segments takenfrom the video Dynamic segmentation andimage integration features allow storage and display of these images with footagereading and a description of the pipe defect For benefits like these, experts predictthat by 2008, approximately 90% of wastewater utilities will be using digital videotechnology (Bufe, 2003)

con-As stated in the preceding text, integrating CCTV videos with GIS requiresmigrating from video tapes to digital movies Four migration methods are possible:

1 Convert existing video tapes to digital files

2 Digitize existing video tapes

3 Retrofit tape systems with digital systems

4 Record directly in digital format

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Convert Existing Video Tapes to Digital Files

In this method (which is the simplest), the existing video tapes are converted tomultimedia computer files in the AVI or MPEG format The hardware required forthis method includes TV, VCR, multimedia computer, CD or DVD burner, and avideo capture card Video capture cards allow display of TV or VCR output on acomputer screen Some multimedia computers have built-in (internal) video capturecards If an internal card is not installed, an external card that typically costs a fewhundred dollars should be used A video capture and editing software, which typi-cally comes with the card, is also required Figure 15.2 shows a screenshot of DigitalVideo Producer, a video capture software from Asymetrix Corporation

The TV is connected to the VCR, and the VCR is connected to the video capturecard (if external) or the computer (if internal) using AV cables When a tape is played

in the VCR, the user sees the video on the TV and on the computer screen Thevideo capture software has a VCR-like console with play, stop, and record buttons.When the user clicks on the software’s record button, usually at the beginning of asewer defect (e.g., collapsed pipe, root growth, break-in lateral, etc.), the computerstarts to record the video in a computer file, usually in AVI or MPEG format The

Figure 15.2 Screenshot of Digital Video Producer’s video capture capability.

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file recording stops when the STOP button is clicked, usually at the end of the sewerdefect Instead of converting the entire video tape, generally 5 to 30 sec mini moviesshowing problem areas are captured because the resulting files can be very large.For example, a 5 to 15 sec video segment recorded in color with sound can be 30

to 60 MB in size Sound can be turned off to reduce the file size Finally, in order

to free up the computer hard disk space, the recorded digital movies are copied todigital media (e.g., CD-ROM or DVD-ROM) Raw video files can be compressed

to optimize disk space A CD cannot store more than 15 to 30 min of uncompresseddata However, in compressed format such as MPEG-1 or MPEG-2, 1 to 1.5 h ofvideo can be stored on a CD and 6 to 12 h on a DVD Figure 15.3 shows a samplemini movie in AVI format showing a collapsed pipe

Digitize Existing VHS Tapes

This is basically a more efficient and automatic implementation of the previousmethod Special video software is used for compressing and indexing video tapes todigital media For example, the Tape-to-CD module of flexidata pipe survey reportingsoftware from Pearpoint, Inc (Thousand Palms, California), uses advanced optical char-acter recognition (OCR) technology to read the footage count displayed on the monitor

Figure 15.3 Sample mini movie in AVI format showing collapsed sewer pipe.

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screen This product was designed using skills and expertise gained in the development

of automatic recognition of vehicle license plates It allows the Pearpoint system toprovide indexing of sewer records against the footage shown on the original videotape.The resulting CD will not only contain the original real time video but also a report

WinCan

WinCan from WinCan America, Inc (Durango, Colorado), is another example

of video software that allows the user to capture either videos or pictures Picturesmay be captured in several different formats such as JPG or BMP Mini movie filescan also be created in increments of 5 to 35 sec Videos may be captured in severaldifferent formats, including the most common, MPEG and AVI WinCan can inte-grate stored pictures, live video from the camera or VCR, and stored movies in thepipe inspection database Figure 15.4 shows a screenshot of the WinCan interface.The left window lists the inspected pipes in the WinCan project database The rightwindows shows the mini movies for the selected pipes The bottom window displaysthe observed defects for the selected pipe WinCan also allows personal digitalassistant (PDA)-based manhole reporting The PDA (e.g., an iPAQ or PalmPilot) isused in the field to gather data with the user standing above the structure A cus-tomized WinCan software is added to the user’s PDA Pull-down menus and easyfill-in fields make gathering the data as easy as using the full WinCan software.Back in the office, the user HotSyncs the PDA with the computer and the information

is simply added to WinCan (WinCan, 2001)

WinCan interacts with GIS packages in two ways: (1) interfaces with the GISdatabase and (2) updates the GIS database In the first method, the WinCan databaseinterfaces with the GIS database by using a metadatabase This metadatabase con-tains information from WinCan projects, such as unique manhole identifiers, linesection numbers, street names, and pipe sizes When a GIS user attempts to access

a particular feature (e.g., a manhole or line segment), the software searches themetadatabase to determine if the feature is available If an associated WinCan report

is available, the software opens the report and highlights the specific item The usercan then display associated pictures, videos, or inspection data This method requirestoggling between WinCan and the GIS software In the second method, an externalutility appends the WinCan data to the GIS database GIS users can then select thelocations in their maps and view WinCan database and associated graphics withoutstarting the WinCan program (Criss, 2000)

Retrofit Tape Systems with Digital Systems

The typical cameras on board the CCTV inspection vehicles are adequate foruse in digital applications Most simply need the addition of a compression unit toconvert their analog signals to a digital format In this method, digital video pro-cessing hardware and software are installed in the CCTV inspection vehicle andlinked to an existing tape system

Pearpoint equipment users can interface the Pearpoint hardware directly withWinCan This eliminates the need for a separate overlay system with encoder

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Figure 15.4 WinCan software screenshot.

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According to Pearpoint, the installation is much easier with no hardware integrationand wiring/soldering necessary Camera inclination and other Pearpoint featuresfunction instantly with appropriate setup.

Another example of this approach is the PipeTech™ Software Suite from sular Technologies, Inc (Ada, Michigan) PipeTech is an innovative solution forsimplifying sewer inspection projects It allows collection, editing, analysis, andarchiving of all inspection data digitally, eliminating the need for VHS tapes andthe stacks of paper attachments that normally accompany an inspection project.PipeTech’s Scan product is an on-site solution for video recording and incidentreporting Scan captures and compresses video in real time and facilitates the record-ing of incident locations Incidents are entered on an electronic log sheet and areautomatically cross-referenced with their occurrences in the video Scan eliminatesthe need for a TV, VCR, and VHS tapes in the video vehicle Videos captured usingScan are clearer than those captured through a VCR (PipeTech, 2000)

Penin-Video software such as WinCan and PipeTech also provide an on-screen pipeline

or a video viewer for retrieval of stored images and movies Consisting of a linesegment graphic, these utilities allow the user to scroll along a line segment and displayobservations, photos, or movies by clicking on any desired location An example isshown in Figure 14.3 for Hansen’s Infrastructure Management System This is possiblebecause the defect location is cross-referenced with the video In addition to the typicalstop, play, and pause controls, video step and loop controls help the user to directvideo progression Seeking to any instant of video is also possible

Record Directly in Digital Format

In this method, no VHS tapes are involved at all The sewer inspection video isrecorded directly in onboard computers as digital movies, using digital cameras.This method requires installation of appropriate digital recording hardware in theCCTV vehicle For example, Pearpoint manufactures several video pipeline inspec-tion systems with digital color video cameras

This system offers complete integration of data and video It enables a technician

to watch the video as it is recorded and flag the video for defects in real time Userscan then jump to the flagged video frames without searching through the entire video(Bufe, 2003)

Linking Digital Movies to GIS

The digital movies created by using one of the preceding methods should belinked to the sewers layer in the GIS database This will enable users to click on asewer line in the GIS map to display the digital movie of the sewer defect Thefollowing steps should be performed to accomplish the linkage in ArcView 3.x:

1 Add a new field to the sewer layer table to store the movie filename Figure 15.5a

shows an ArcView 3.2 database table for sanitary sewers containing a field named

“Movie” for holding the movie filenames.

2 Enter the video filename for each sewer segment for which a movie is available 2097_C015.fm Page 319 Thursday, December 9, 2004 12:36 PM

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