./600/R-10/082
United States
Environmental Protection
Agency
pection
and Data Management for Effective Condition
Assessment of Collection Systems
Office of Research and Development
National Risk Management Research
ter Supply and Water Resources Division
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Innovative Internal Camera Inspection and Data Management for
Effective Condition Assessment of Collection Systems
by
Kathy Martel, P.E., and Mary Ellen Tuccillo, Ph.D.
The Cadmus Group, Inc.
Reggie Rowe
Independent Consultant
Christopher S. Feeney, Samantha Hogan and Gary DeBlois
The Louis Berger Group
Scott Thayer, Brian Bannon and Mark Ross
RedZone Robotics
Kevin Enfmger, P.E.
ADS Environmental Services, LLC
In Support of:
Contract No. EP-C-05-058
Task Order No. 59
Task Order Manager
Dr. Fu-hsiung (Dennis) Lai, P.E.
Water Supply and Water Resources Division
Urban Watershed Management Branch
2890 Woodbridge Avenue, Edison, NJ 08837
National Risk Management Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, OH 45268
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Disclaimer
The U.S. Environmental Protection Agency, through its Office of Research and Development, funded,
managed and collaborated in the research described herein. It has been subjected to the Agency's peer
and administrative review and has been approved for publication. Any opinions expressed in this report
are those of the author(s) and do not necessarily reflect the views of the Agency; therefore, no official
endorsement should be inferred. Any mention of trade names or commercial products does not constitute
endorsement or recommendation for use.
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Foreword
The U.S. Environmental Protection Agency (EPA) is charged by Congress with protecting the Nation's
land, air, and water resources. Under a mandate of national environmental laws, the Agency strives to
formulate and implement actions leading to a compatible balance between human activities and the ability
of natural systems to support and nurture life. To meet this mandate, EPA's research program is
providing data and technical support for solving environmental problems today and building a science
knowledge base necessary to manage our ecological resources wisely, understand how pollutants affect
our health, and prevent or reduce environmental risks in the future.
The National Risk Management Research Laboratory (NRMRL) is the Agency's center for investigation
of technological and management approaches for preventing and reducing risks from pollution that
threaten human health and the environment. The focus of the Laboratory's research program is on
methods and their cost-effectiveness for prevention and control of pollution to air, land, water, and
subsurface resources; protection of water quality in public water systems; remediation of contaminated
sites, sediments, and ground water; prevention and control of indoor air pollution; and restoration of
ecosystems. NRMRL collaborates with both public and private sector partners to foster technologies that
reduce the cost of compliance and to anticipate emerging problems. NRMRL's research provides
solutions to environmental problems by: developing and promoting technologies that protect and improve
the environment; advancing scientific and engineering information to support regulatory and policy
decisions; and providing the technical support and information transfer to ensure implementation of
environmental regulations and strategies at the national, state, and community levels.
This publication has been produced as part of the Laboratory's strategic long-term research plan. It is
published and made available by EPA's Office of Research and Development to assist the user
community and to link researchers with their clients.
Sally Gutierrez, Director
National Risk Management Research Laboratory
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Contents
Disclaimer ii
Contents iv
Figures vi
Tables vii
Acronyms viii
Acknowledgments viii
Executive Summary ix
Chapter 1. Introduction to Condition Assessment 1-1
1.1 Background 1-1
1.2 Steps to Developing a Condition Assessment Program 1-2
1.2.1 Step 1 - Identify Program Objectives 1-2
1.2.2 Step 2 - Evaluate Costs and Benefits of Condition Assessment 1-4
1.2.3 Step 3 - Develop Asset Inventory Database 1-5
Chapter 2. Overview of CCTV and Related Inspection Technologies 2-8
2.1 Introduction 2-8
2.2 Conventional CCTV Inspection 2-9
2.3 Zoom Camera Inspection 2-10
2.3.1 Zoom Camera Models 2-11
2.3.2 Examples of Utility Experience 2-12
2.4 Digital Scanning 2-14
2.4.1 Envirosight - DigiSewer 2-16
2.4.2 RapidView-IBAK, USA - PANORAMO 2-16
2.4.3 CleanFlow/Fly Eye System 2-17
2.4.4 Example of Utility Experience 2-17
2.5 Camera Deployment 2-18
2.5.1 Push Cams 2-19
2.5.2 Tractors/Crawlers 2-19
2.5.3 Segmented Robots 2-21
2.5.4 Emerging Technologies 2-21
2.6 Camera Selection Issues 2-22
Chapter 3. Overview of CCTV Inspection Data Analysis 3-24
3.1 Introduction 3-24
3.2 Methods for Inspection Prioritization 3-24
3.2.1 Selection of Assets for Inspection 3-24
3.2.2 Prioritization of Assets 3-25
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3.2.3 Asset Inspection 3-26
3.3 Defect Coding 3-27
3.3.1 Code Design and Format 3-27
3.3.2 Code Systems 3-28
3.4 Data Handling and Analysis 3-30
3.4.1 Spreadsheet Software 3-31
3.4.2 Condition Assessment/Asset Management Software 3-31
3.4.3 General Database Management Software 3-32
3.4.4 Pipe Rating and Scoring Methods 3-34
3.5 Role of CCTV Data in Asset Management Decision Making 3-35
3.5.1 CCTV Data Used in Condition-Based Prioritization Decisions 3-36
3.5.2 CCTV Used in Risk-Based Prioritization Decisions 3-37
References R-40
Appendix A. Utility Case Studies A-43
Case Study on Implementation of New Data Management System - City of Fort Worth Water
Dept, Fort Worth, Texas A-44
Case Study on Using a Risk Assessment Approach for a Sewer Pipe Inspection Program -
Seattle Public Utilities, Seattle, Wash A-50
Data Management Case Study - Huntsville, Ala A-55
Case Study on Comparison of In-House vs. Commercial Data Management System -
Metropolitan Government of Nashville and Davidson County - Metro Water Services A-58
Case Study on Use of Digital Scanning and Zoom Camera Technology - City of Hamilton,
Ontario, Canada A-66
Case Study on Application of Truck-Mounted Zoom Cameras - Hillsborough County Water
Resource Services, Florida A-71
Data Management Case Study - Northern Kentucky Sanitation District No. 1 A-78
Appendix B. Defect Code Systems B-87
PACP Defect Codes B-88
SCREAM™ Defect Codes B-93
Appendix C. Technology Vendors C-97
Appendix D. Example Inspection Report - Fort Worth, Texas D-102
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Figures
Figure 1-1. Condition assessment steps 1-3
Figure 1-2. Example of a GIS system 1-6
Figure 2-1. Illumi-Zoom camera 2-8
Figure 2-2. Example of infiltration 2-9
Figure 2-3. CCTV image of roots in lateral 2-9
Figure 2-4. Pole-mounted zoom camera 2-10
Figure 2-5. CUES-IMX truck-mounted zoom camera 2-11
Figure 2-6. PortaZoom camera 2-12
Figure 2-7. Aqua Zoom camera 2-12
Figure 2-8. Comparison of CCTV and zoom camera inspections 2-14
Figure 2-9. DigiSewer digital scanning camera deployed in pipe 2-15
Figure 2-10. Virtual pan & tilt and unfolded pipeline view from RapidView IBAK PANORAMO
system 2-15
Figure 2-11. DigiSewer digital scanning camera 2-16
Figure 2-12. RapidView IBAK PANORAMO system 2-17
Figure 2-13. Mobile robot inspection system 2-18
Figure 2-14. CUES camera float 2-18
Figure 2-15. Crystal Cam-push camera 2-19
Figure 2-16 (a) and (b). Examples of pipe inspection crawlers 2-20
Figure 2-17. PipeEye pipe inspection robot 2-22
Figure 3-1. Example CUES Granite XP pipe inspection map with camera image 3-32
Figure 3-2. The Northern Kentucky Sanitary District No. 1's example integration of general
database and condition assessment software 3-33
Figure 3-3. Typical steps from defect identification through prioritization of pipe rehabilitation
projects 3-34
Figure 3-4. Two optional condition-based decision approaches 3-36
Figure 3-5. Example risk-based prioritization decision framework for multiple internal condition
rating input sources 3-38
Figure 3-6. Example long-term risk-based prioritization decision framework 3-39
Figure A-l. Predictive failure curve for vitrified clay pipe A-52
Figure A-2. Comparison of failure curves for vitrified clay and concrete pipe A-54
Figure A-3. Sample inspection report for in-house data management system A-62
Figure A-4. Sample inspection report created using GraniteXP software A-63
Figure A-5. Comparison of CCTV and zoom camera inspections A-69
Figure A-6. Pipe defect location A-70
Figure A-7. Truck-mounted zoom camera A-73
Figure A-8. CUES-IMX optical zoom camera A-73
Figure A-9. Examples of pipe defects identified with zoom camera technology A-74
Figure A-10. Sanitation District No. 1's service area A-79
Figure A-l 1. Example District projection of the CCTV and zoom camera needs through 2017 A-81
Figure A-12. District 3's CSAP Data Flow Chart A-83
Figure A-13. Example SCREAM™ scoring displayed in gbaMS A-85
Figure B-l. Example of PACP coding methodology for 8 in. VCP, Huntsville, Ala B-91
Figure B-2. Example of SCREAM™ coding methodology for 8 in. VCP, Huntsville, Ala B-95
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Tables
Table 2-1. Inspection technology overview 2-8
Table 2-2. Zoom camera inspection summary 2-11
Table 2-3. Digital scanning inspection summary 2-16
Table 2-4. Push cam product comparison 2-19
Table 2-5. Lateral launcher product comparison 2-20
Table 2-6. Small-diameter tractor product comparison 2-20
Table 2-7. Long-range tractor product comparison 2-21
Table 3-1. Survey results of inspection frequency for conveyance systems 3-24
Table 3-2. Partial listing of defect codes for City of Fort Worth Water Department 3-27
Table 3-3. Example PACP structural defect codes and descriptions 3-28
Table 3-4. Advantages and disadvantages of the NASSCO PACP defect code system 3-29
Table 3-5. Advantages and disadvantages of the SCREAM™ defect code system 3-30
Table A-l. Summary of Fort Worth defect codes A-47
Table A-2. Summary of pipe inspections conducted 2004-2008 A-49
Table A-3. Factors that increase consequences and costs of pipe failure A-51
Table A-4. Asset life information for SPU sewer pipe A-52
Table A-5. Sewer system inventory A-58
Table A-6. PACP defect grades A-64
Table A-7. Comparison of traditional CCTV with zoom camera technology A-68
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Acronyms
AMWA Association of Metropolitan Water Agencies
CAMS Comprehensive Asset Management System
CCTV Closed-circuit television
CIP Capital Improvement Program
CIS Customer Information System
CMMS Computerized Maintenance Management System
CMOM Capacity, Management, Operation and Maintenance
CSAP Continuous Sewer Assessment Program
CUPSS Checkup Program for Small Systems
DMS Data Management System
DVD Digital Video Disk
FEMA Federal Emergency Management Agency
FIS Financial Information System
FWWD Fort Worth Water Department
GIS Geographic Information System
GPS Global Positioning System
HOPE High-density polyethylene
HID High-intensity discharge
I/I Infiltration and inflow
LCD liquid crystal display
LED Light-emitting diode
LSCCR Large Sewer Condition Coding and Rating
MACP Manhole Assessment Certification Program
MGNDC Metropolitan Government of Nashville and Davidson County
MWS Metro Water Services
NAAPI North American Association of Pipe Inspectors
NACWA National Association of Clean Water Agencies
NASSCO National Association of Sewer Service Companies
NRC-IRC National Research Council of Canada Institute for Research in Construction
O&M Operations and maintenance
PACP Pipeline Assessment and Certification Program
PTZ Pan-tilt-zoom
PVC Polyvinyl chloride
QA/QC Quality assurance/quality control
SCRAPS Sewer Cataloging, Retrieval and Prioritization System
SCREAM™ System Condition & Risk Enhanced Assessment Model
SPU Seattle Public Utilities
SQL Structured Query Language
SSET Sewer Scanning Evaluation Technology
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SSO Sanitary Sewer Overflows
USEPA U.S. Environmental Protection Agency
VCP Vitrified clay pipe
WEF Water Environment Federation
WERF Water Environment Research Foundation
WRc Water Research Centre
WRS Water Resources Services
WWTP Wastewater treatment plant
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Acknowledgments
The following individuals contributed their time and technical expertise to the development of utility case
studies that document specific innovative applications of CCTV technology and data management
practices:
Darrell Gadberry, City of Fort Worth, Texas
Terry Martin, Seattle Public Utilities, Seattle, Wash.
Mark Huber, City of Huntsville, Ala.
Kevin McCullough, Nashville and Davidson County, Nashville, Tenn.
Kevin Bainbridge, City of Hamilton, Ontario, Canada
Richard Kirby, Hillsborough County Water Resource Services, Tampa, Fla.
Brandon Vatter, Northern Kentucky Sanitation District No. 1, Fort Wright, Ky.
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Executive Summary
The primary objective of this guidance document is to identify and evaluate innovative closed-circuit
television (CCTV) and related technologies currently used by more advanced wastewater utilities to
conduct condition assessment programs. The document is intended to facilitate the transfer of these
innovative technologies to utilities at large. The steps in developing and implementing a condition
assessment program are presented along with related practical guidelines. Technology applications and
lessons learned from seven utility case studies are summarized and used to illustrate specific concepts.
Detailed case study reports are presented in Appendix A.
Chapter 1 provides an introduction to condition assessment, which is a major component of an asset
management program. Condition assessment provides the critical information needed to assess the
physical condition, remaining useful service life, and long-term performance of each asset. The
recommended approach for developing and implementing a condition assessment program is presented.
It consists of six steps:
• Step 1. Identify program objectives.
• Step 2. Evaluate costs and benefits of condition assessment.
• Step 3. Develop asset inventory database.
• Step 4. Inspect assets.
• Step 5. Analyze data.
• Step 6. Make decisions based on condition assessment data.
Steps 1 through 3 are discussed in Chapter 1, using examples from the utility case studies to illustrate key
points. Step 4 is discussed in Chapter 2, and Steps 5 and 6 in Chapter 3.
For Step 1, it is important to outline the utility-specific objectives as the initial step in program
development. Example objectives from the utility case studies include determining pipe condition,
planning maintenance strategies, addressing aging infrastructure, and addressing public scrutiny of rate
increases.
In Step 2, utilities may need to justify the costs and benefits of the condition assessment program to
obtain the approval of their governing board. Typical costs include direct costs of pipe inspection; labor
costs associated with program planning, data analysis and reporting; and cost of service disruptions due to
inspection work. Typical benefits of condition assessment include avoided costs for emergency repairs,
environmental damage, and premature replacement of pipe and improved customer service and service
reliability.
In Step 3, the utility develops an asset inventory database and compiles historical system data such as pipe
diameter, length, and installation dates; system map; and inspection and maintenance records for the
collection system. The utility should understand the content and form of existing data and should identify
data gaps and data quality issues. Some utilities have linked their asset inventory database with a
geographic information system. The City of Huntsville, Ala., has learned that it is important not only to
link CCTV data to a map, but also to integrate it with other inspection and repair data. When viewed
together, the various data help "tell the story" of an asset and its condition over time. The asset inventory
database is useful for other applications. For example, the Seattle Public Utilities uses the asset data as
input for a sewer pipe risk model.
Step 4 (inspect assets) is typically accomplished using conventional CCTV inspection. CCTV is a cost-
effective technology providing the broadest base level of data used in condition assessment. Since the
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late 1990s, many utilities have replaced analog video cameras with digital video cameras and have
identified a number of benefits. The emergence of other camera-based technologies such as zoom
cameras and digital scanning offers new options for inspection.
Zoom camera technology captures still images or recorded videos similar to traditional CCTV, but uses a
stationary camera mount. The camera is lowered into a manhole and the camera "zooms" down each pipe
entering or exiting the manhole. Utilities that have adopted zoom camera technology have realized
benefits in the speed and cost of inspections compared to inspection programs that use only conventional
CCTV. Disadvantages of zoom camera technology include the lack of pan and tilt viewing and the
inability to accurately measure and locate defects. Also, zoom cameras cannot see around horizontal
bends in pipes. Some utilities use zoom camera technology for system-wide screening to identify critical
pipes that need immediate maintenance or more detailed CCTV inspection.
Digital scanning provides a more consistent and complete assessment of pipe condition than CCTV, and
data can be assessed independent of the real-time sewer inspection. Digital scanning uses self-propelled
crawlers to transport digital cameras through sewer lines. Unlike conventional CCTV, digital scanning
uses high-resolution digital cameras equipped with wide-angle (fisheye) lenses, which allow the
generation of unfolded views of the sides of the pipes. This provides an excellent view of pipe conditions
and permits computer-aided measurement of defects and objects. Digital scanning has been used in
Europe and Asia for several years, but it has a limited history in North America. The City of Hamilton in
Ontario, Canada, is one North American utility that has begun to use digital scanning.
Innovations in CCTV camera deployment include extra-long-range tractors/floats, smaller tractors that
can be used for some laterals, tractors that are able to dispatch smaller lateral cameras from the main line
and segmented robots that can bend around odd angles in small-diameter pipes.
Some of the issues to consider in selecting a camera include the goals of the inspection program, the pipe
diameter and material, anticipated pipe conditions, the importance of the camera's production rate, the
level of detail required in the inspection data, and whether the utility plans to purchase equipment or use
vendors.
Step 5 (analyze data) involves the coding of pipe defects observed during inspection, the conversion of
defect codes to a pipe condition rating and the prioritization of pipes based on condition scores or risk-
based scores. Chapter 3 discusses the design and format of defect codes and industry standard code
systems such as those produced by the Water Research Centre (WrC), the National Association of Sewer
Water Agencies' (NASSCO's) Pipeline Assessment and Certification Program (PACP) and the System
Condition & Risk Enhanced Assessment Model (SCREAM™). Some utilities, such as Fort Worth,
Texas, have developed their own coding system to better serve their needs. The selection of a data
management system such as spreadsheets, condition assessment software and other database software is
discussed.
Step 6 (make decisions), the final step in the condition assessment process, uses CCTV data to prioritize
assets for various corrective actions including maintenance, further inspection and total pipe replacement.
Two primary approaches for decision making are condition-based and risk-based. Because systems
typically have more assets that need improvements than available resources, risk-based decision making
is generally a good approach. However, whenever the general condition of the asset or asset group is
problematic, then a condition-based decision is appropriate. The major difference between the two
approaches is the timing for performing corrective action.
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Chapter 1. Introduction to Condition Assessment
This report presents practical guidelines on internal camera inspection technology applications and data
management practices with a focus on identifying and promoting more innovative technologies and
practices. Technology applications and lessons learned from seven utility case studies are used as
practical examples in the main body of the report; detailed case study reports are provided in Appendix A.
Chapter 1 provides an introduction to condition assessment and presents a six-step approach for
developing and implementing a condition assessment program. This chapter also discusses the first three
program steps.
1.1 Background
Condition assessment is an important component of an asset management program, along with the
identification and location of assets. For more information on developing an asset management program,
see EPA's Checkup Program for Small Systems (CUPSS), which includes a free and easy-to-use tool for
developing a tailored asset management plan (http://www.epa.gov/cupss/).
Condition assessment is one of the core components of an asset management program. It provides the
critical information needed to assess the condition, remaining useful life and long-term performance of a
piping system. The U.S. Environmental Protection Agency (USEPA) defines "condition assessment" as
the collection of data and information through direct inspection, observation and investigation, indirect
monitoring and reporting, and the analysis of the data and information to make a determination of the
structural, operational and performance status of capital infrastructure assets (USEPA, 2007).
After the field inspection, pipe defects are classified using a standard coding system. Pipe condition is
assessed using a systematic method based in part on the defects discovered during the inspection in order
to produce consistent, useful information. Condition assessment information is used to evaluate/model
pipe deterioration and estimate the pipe's remaining useful life. It is also used to make decisions
regarding pipe rehabilitation, pipe replacement, or further inspections.
Condition assessment has gained considerable attention in recent years among municipalities and utility
districts as a major component of an asset management program. Condition assessment can be used to
prioritize infrastructure projects based on the likelihood of pipe failure, thereby easing the financial
burden on wastewater utilities and their customers. As Thomson et al. (2004) note, "An estimated $4.5
billion is expended every year on the rehabilitation and replacement of pipes for wastewater collection in
the U.S." Local and state governments are required to tabulate the value of their assets (i.e., buildings,
roads, utilities, etc.) to support the development of a unified cost accounting system, according to Bulletin
34 of the Governmental Accounting Standards Board. This program requires detailed financial
accounting of all assets; however, the level of detail to which it is implemented can vary from city to city.
Condition assessment can also assist utilities in implementing USEPA's proposed CMOM (Capacity,
Management, Operation and Maintenance) program for sanitary sewer collection systems (USEPA,
2005). The CMOM program requires a municipality that operates a sanitary sewer system to provide
adequate conveyance capacity for all parts of the system and to take all feasible steps to halt or mitigate
the impacts of sanitary sewer overflows (SSOs).
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1.2 Steps to Developing a Condition Assessment Program
Various approaches, ranging from simple to complex, have been developed for performing condition
assessment of piping systems. A typical approach follows these steps:
1. Identify program objectives.
2. Evaluate costs and benefits of condition assessment.
3. Develop asset inventory database.
4. Inspect assets.
5. Analyze data.
6. Make decisions based on condition assessment data.
Steps 1, 2 and 3 are discussed in this chapter. Step 4 is discussed in Chapter 2 and Step 5 and Step 6 in
Chapter 3.
Figure 1-1 presents an approach for condition assessment that recognizes its iterative nature. In this
example, the assets are first identified and an inventory database is established. Next, the impact
assessment is conducted to inspect assets and determine their physical conditions. The next step involves
setting priorities or rankings, from low to high priority, for different pipes in the system. This step helps
the utility determine how often each pipe should be inspected and maintained. As the utility completes
additional inspections and maintenance, the priority ranking changes and the utility focuses on the new
highest priority pipe. The ever-changing or iterative nature of the condition assessment process justifies
investments in asset inventory databases and data management software so that the highest quality
information is used to make decisions on asset management.
1.2.1 Step 1 - Identify Program Objectives
The utility may need to justify development of a condition assessment program to its governing board, its
customers, or its staff. Therefore, it is important to outline and communicate the drivers or reasons for
implementing the program. The program objectives may include the following:
• Comply with federal or state regulations.
• Collect pipe condition information needed for asset management program.
• Collect information on the pipes' service performance.
• Investigate and eliminate sources of infiltration and inflow (I/I) to increase available system
capacity.
• Extend asset life by conducting maintenance prior to asset failure.
• Improve performance of sanitary sewer systems.
• Improve operation and maintenance efficiency.
• Identify and improve management of high-risk pipes.
• Reduce service disruptions due to pipe failure.
• Reduce environmental damage due to pipe failure.
• Reduce maintenance costs by reducing inspection frequency of low-risk pipes.
• Improve budget forecasting through expanded knowledge of pipe condition and maintenance
needs.
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Inventory database
Impact assessment
Priori tization
Frequency of
next inspection
Rehabilitation
Inspection
Condition
Assessmen
Decision- making
on rehabilitation
actions
Figure 1-1. Condition assessment steps. Source: McDonald and Zhao (2001).
In a survey of its membership, the Association of Metropolitan Sewerage Agencies (now called the
National Association of Clean Water Agencies, NACWA) found that most utilities (70 of 75 survey
respondents) conduct regular programs to physically inspect or evaluate their sewer systems using
techniques such as visual inspections, CCTV, and Sewer Scanning Evaluation Technology (SSET)
(AMSA, 2003). Also, 36 of 75 survey respondents primarily inspect the system to determine its
condition.
The City of Fort Worth, Texas has historically used CCTV inspections for a variety of purposes such as
evaluating the effectiveness of its cleaning program, documenting pipe condition following pipe
rehabilitation and new construction, and finding customer service lateral tap locations (see case study in
Appendix A).
The Seattle Public Utilities developed an asset management program in 2001 to address several concerns
including aging infrastructure, a lack of information on pipe condition, a trend of stricter environmental
regulations, and public scrutiny of recent rate increases. The immediate goal of the asset management
program for sewer assets was to minimize risk of infrastructure failure.
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7.22 Step 2 - Evaluate Costs and Benefits of Condition Assessment
To justify the development and implementation of a condition assessment program, the program's costs
must be documented and compared to the anticipated benefits. The costs are typically easier to quantify
and should include both the direct costs of inspection and the indirect costs to the utility and other parties
of carrying out the inspection and then collecting and analyzing the data. More specifically, the costs of
condition assessment include:
• Equipment and labor costs to conduct field inspections including excavation, traffic control, road
surface restoration, monitoring and data collection.
• Labor costs before and after fieldwork for planning, data analysis and reporting.
• Cost of service disruptions due to inspection work.
Aside from the costs associated with a specific technology, certain characteristics of a system or specific
pipe segments will influence inspection costs. Site location, site setup and the environment all affect
deployment costs. For example, difficult site access, high flows, large amounts of debris, and unusually
large or small pipes can lead to higher costs. Sewer cleaning alone can double or triple inspection costs.
Inspection costs will also vary depending on what specific work is completed as part of the inspection and
how the work is accomplished (contractors vs. the utility's equipment and manpower). When comparing
inspections costs for two different studies or systems, it is important to understand the work completed
and total costs for each case.
The benefits of a condition assessment program are more difficult to quantify and derive. The benefits
are mainly associated with the reduction in the risk of failure (likelihood and consequences of failure) and
the knowledge that allows maintenance, rehabilitation and replacement to be carried out on the most cost
effective schedule. Specific benefits of a condition assessment program may include:
• Reduced sources of I/I.
• Avoided emergency repair costs.
• Avoided costs of extended service disruptions due to a catastrophic failure.
• Avoided restoration costs due to environmental and property damage from a catastrophic failure.
• Avoided public health costs (i.e., injury, death, disease transmission) from catastrophic failure.
• Improved planning and prioritization of rehabilitation and replacement projects due to condition
assessment information and improved estimates of service life.
• Avoided costs of premature pipe replacement or rehabilitation.
• Improved customer satisfaction and fewer complaints.
• Improved service reliability.
Comparing the costs to benefits for inspection of gravity sewers and force mains, Thomson (2008) reports
that:
• The cost of inspection of gravity sewers is typically low with respect to the value of the asset
(e.g., the cost of inspection of a 12-in. diameter sewer at 13-ft depth is less than 1% of the asset
value) and the proportion decreases with increasing depth and diameter of the sewer.
• The benefits from inspection of gravity sewers are likely to exceed costs for all but small
diameter sewers at shallow depths.
• The cost of inspection offeree mains is high, with direct costs (temporary flow bypass, accessing
the line, etc.) often exceeding the costs of physical inspection.
• The monetary benefits of inspection may be less than the cost of inspection for smaller lines in
less populated areas (fail and fix approach may be chosen), although this ratio may change in
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environmentally sensitive areas. The benefits increase greatly for larger diameter force mains and
urban areas due to the increased risk of major consequences.
Contrary to Thomson's (2008) findings, some utilities have found that it is not cost-effective to inspect all
pipes, and a few have used a formal risk assessment procedure to identify and prioritize pipes that present
comparatively greater risks to public health and the environment. For example, Seattle Public Utilities
(SPU) determined that there was a critical need for risk assessment when a collection sewer pipe
collapsed and caused a sewage backup at a city hospital (refer to the detailed case study report in
Appendix A). At the time, all system pipes were scheduled for inspection on a 30-year cycle, and the lack
of current pipe condition information created a reactive mode of operation. A sewer pipe risk model,
originally developed by Hunter Water Australia (http://www.hwa.com.au/), was adapted and applied to
SPU's sewer network to calculate the cost of failure for individual pipe segments and the total annualized
cost to the utility over the period between CCTV inspections (Martin, 2004). To estimate the likelihood
of pipe failure, the model initially used predictive failure curves generated using a normalized Weibull-
type distribution and based on pipe age and material. SPU used the risk assessment and its benefit-cost
ratio to help select pipes for inspection and maintenance. Risk modeling conducted in 2004 showed that
the cost of conducting CCTV inspections of low-risk pipes exceeded the benefit gained by performing
condition assessment (Martin, 2004). Based on these findings, SPU decided to perform CCTV inspection
only on high-risk pipes (15% of total pipe length) using a 5-year inspection frequency. In 2007, SPU
improved the sewer pipe risk model by applying utility-specific condition information to improve the
model's initial estimates of the likelihood of failure (Martin, Johnson and Anschell, 2007). New pipe
condition curves were customized for SPU based on actual sewer pipe failure data and CCTV inspection
data. An on-going EPA-ORD project, Condition Assessment of Water Transmission and Distribution
Systems (Contract No. EP-C-05-057), is currently researching pipe condition curves
(http://www.epa.gov/awi/projects/). More information on Weibull distributions can be found at
http: //www. weibull .com/.
1.2.3 Step 3 - Develop Asset Inventory Database
When performing condition assessment, it is essential to compile an inventory of assets and existing
system data. For each pipe segment the following information should be included in the database:
• Unique identification number or code.
• Geographic information (e.g., elevation, latitude, longitude).
• Pipe material.
• Pipe geometry (i.e., diameter (if round), wall thickness).
• Depth.
• Slope.
• Year of installation.
• Soil type, bedding, backfill type.
• Failure history data.
• Maintenance history.
• Inspection records (e.g., smoke testing, dye tracer studies, camera inspections).
• Typical flow conditions.
System maps and geographic information system (GIS) databases (e.g., Figure 1-2) are good information
sources for the asset inventory database. Inspection and testing records may include I/I studies: flow data,
smoke testing, flow isolation studies, or dye tracer studies. Failure data from the system or research on
similar conditions (e.g., soil bedding type, material, age) in utility districts can be used to define the
likelihood of failure (Martin, 2004). The linking of the asset inventory database combined with
1-5
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maintenance records to a GIS system is a powerful planning tool. It provides a strong platform to present
the data geospatially.
The asset inventory database can be useful for many applications. The City of Fort Worth, TX has
developed an asset inventory database and demonstrated its value in reviewing multiple inspection
records for a single pipe segment over an extended period of time (refer to case study in Appendix A).
SPU uses its asset inventory database as input to a sewer pipe risk model. The model extracts GIS
attributes for each pipe (i.e., elevation, installation
date, material of construction, and proximity to
geologic or structural features) and uses this
information to calculate financial, social, and
environmental costs of pipe failure. For example, if
the sewer pipe is located underneath a building, a
multiplier is automatically applied to the cost formula
due to the added repair cost.
The utility should understand the content and form of
existing data in the asset inventory database, and
should identify data gaps and data quality issues.
When SPU used its GIS data as input to the sewer risk
pipe model, some incorrect data were found. For
example, pipe elevation data were suspect in about
20% of pipes. With Seattle's hilly terrain, pipe
Figure 1-2. Example of a GIS system. Source:
Black and Veatch Corp. (2004). Reprinted with
permission.
elevation and slope are critical parameters. Data corrections were made in the sewer pipe risk model.
Flow monitoring data should be included in the asset inventory database as the data are useful for
prioritizing which part of a system to inspect. Most systems conduct flow monitoring and store historical
flow monitoring data, but much of the information is not used. Flow monitoring data are traditionally
used to generate hydrographs, which provide information about flow conditions upstream of the meter.
Scattergraphs (displays of paired depth and velocity readings that look like a normal pipe curve under
normal flow conditions) are constructed to evaluate downstream flow conditions. The use of
scattergraphs can give more insight into the decision process and can be used to verify other inspection
data and to help calibrate models. Further background information on constructing and applying
scattergraphs is provided by ADS (2010).
The City of Huntsville, AL has taken an important step by incorporating CCTV inspection data and
digital video files into a GIS-based software application that allows managers and engineers to quickly
review CCTV inspections in context with other inspection and repair data (refer to case study in
Appendix A). Now, CCTV inspection data and video are easier to access, examine, and compare,
allowing managers and engineers to better understand the condition of a system and better plan and
manage operation and maintenance (O&M) and rehabilitation programs. The city has learned that it is
important not only to link CCTV data to a map, but also to integrate it with other inspection and repair
data. When viewed together, the various data help "tell the story" of an asset and its condition over time.
Huntsville found and resolved many discrepancies in existing GIS and condition assessment records. The
end result was a more accurate and accessible database of historical system conditions. Huntsville
recommends that, prior to implementing a similar program, utilities review the type of data needed for the
asset management program, including CCTV inspection data, to make sure that the historical asset
records are consistent with available GIS data.
Nashville, TN also learned that it is important to integrate GIS data with CCTV, asset, and maintenance
management data (refer to case study in Appendix A). The maintenance management system provides a
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wastewater network browser that stores information and allows it to link together items such as
maintenance records, complaints, work orders, and inspection reports. The data integration capability
permits users to view all related inspection records for a particular asset. A work order is generated and
required resources are selected (labor, equipment, materials). The GIS information is queried and the
inspection can proceed.
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Chapter 2. Overview of CCTV and Related Inspection Technologies
2.1 Introduction
The term "inspection technology" refers to the various methods used for detecting pipe defects, structural
and operational conditions and environmental conditions that could potentially affect pipe condition.
These technologies have varying abilities to detect and quantify specific types of pipe defects. A specific
inspection technology may have limited application depending on pipe material or pipe diameter. A
robust condition assessment method would likely include a variety of inspection technologies, based on
the specific characteristics of a utility's sewer network.
Camera-based inspection technologies (e.g., Figure 2-1) and their use in condition assessment for
wastewater collection systems are presented in this chapter. The chapter is organized into the following
sections:
• Conventional CCTV inspection.
• Zoom camera inspection.
• Digital scanning.
• Camera deployment.
• Camera selection issues.
Each technology is briefly described, and commercially available
and emerging products using the technology are discussed. Table 2-
1 provides a summary of typical applications for each technology.
Pushrod camera (also known as "push cam") technology, designed
for laterals and small diameter force main applications, is discussed
in Section 2.5.1.
Table 2-1. Inspection technology overview
Technology
A
01
1
Conventional CCTV
Digital scanning
Zoom camera
Sewer type
Gravity
•
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>8m.
6 in. -72 in.
>6 in.
Defects detected
— e
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•
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01
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2-8
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2.2 Conventional CCTV Inspection
CCTV inspection is a very effective method of evaluating and creating a permanent video record of
underground pipe conditions. The visual inspection of sanitary sewer lines enables a CCTV operator to
locate and identify specific defects that contribute to the infiltration of groundwater into the collection
system (Figure 2.2) and exfiltration of sewage into the
substrate. This is a well-established and common industry
method for pipeline assessment. In a recent survey report
(Thomson et al, 2004), 100% of survey respondents from
large wastewater utility districts relied on CCTV as their
primary method of collection system inspections; hence, it is
not surprising that the critical gaps identified in this survey
parallel the limitations of CCTV inspection. CCTV provides a
means to inspect a pipeline that is either too small or hazardous
for direct human entry inspection. The primary disadvantages
of the technology are that a CCTV inspection only provides a
view of the pipe surface above the waterline and does not
provide any structural data on pipe wall integrity or a view of
the soil envelope supporting the pipe.
Figure 2-2. Example of infiltration. Image
courtesy of RedZone Robotics, Inc.
The technology and level of ancillary equipment used for CCTV inspection of sewer systems vary
significantly based on the diameter of the line being inspected. In general, CCTV technology uses a
video camera with lighting to provide a visual record of the inside condition of a pipeline. The means to
convey the camera through the pipeline vary in complexity from simple pushrod cameras (push cams) to
complex remote-controlled robot crawlers. The level of optical control on the camera also varies in
complexity. The ability to pan, tilt, and zoom has become the industry standard for selecting sewer
inspection technology because it allows the operator to gain a full circumferential view of the pipe.
Data obtained from CCTV inspection include:
Evidence of sediment, debris, roots, etc.
Evidence of pipe sags and deflections.
Offset joints.
Pipe cracks.
Leaks.
Location and condition of service connections.
Figure 2-3 provides an example of a CCTV image that
documents root intrusion. As noted above, CCTV technology
has limitations because it can only provide a visual
representation of the inside surface of a pipe above the
waterline. Furthermore, the quality of defect identification and
pipe condition assessment using CCTV is highly dependent on
many factors including operator interpretation, picture quality, and flow level. In terms of benefits, it is a
cost-effective technology providing the broadest base level of data used in condition assessment.
Although other technologies can assess the structural condition of the pipe wall (e.g., electro-scanning,
acoustic monitoring systems), or the condition of the soil surrounding the pipe (e.g., infrared
thermography, ground-penetrating radar), these methods do not provide visual data on leaks, location of
service laterals or sediment/debris levels and location. Therefore, CCTV will remain an important
inspection tool in condition assessment programs.
Figure 2-3. CCTV image of roots in
lateral. Image courtesy of RedZone
Robotics, Inc.
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Sections 2.3 - 2.5 present innovative technologies related to CCTV and their use in condition assessment
for wastewater collection systems. The following technologies will be described, noting manufacturers or
providers and typical applications:
• Zoom camera inspection.
• Digital scanning.
• Camera deployment.
2.3 Zoom Camera Inspection
Historically, zoom cameras have been used to perform manhole
inspections and to inspect down the pipe in the vicinity of the
manhole using a camera mounted on the end of a telescopic pole.
Like traditional CCTV inspection, zoom camera inspection
involves the generation of still images or recorded video imagery
of a pipe of any material. The key difference is that the zoom
camera is stationary mounted on a truck, crane, pole (Figure 2-4)
or tripod positioned at a manhole and does not pass though the pipe
segment being inspected. The equipment is lowered into the
manhole to perform the inspection, and the camera "zooms" down
any pipe entering or exiting the manhole, capturing images of pipe
condition. Newer cameras can pan 360°.
Zoom cameras are not designed to replace conventional CCTV
systems, but rather to screen and prioritize pipes that need cleaning
or a more detailed inspection with the conventional CCTV camera.
Because the sewer pipe does not need to be cleaned before the
zoom camera inspection is conducted, the inspection crew can move quickly through a service area and
highlight pipe segments that require more detailed inspection. Further, the zoom camera inspection is not
subject to delays caused by obstructions in the pipe as often occurs with a crawler-mounted CCTV
camera. For these reasons, zoom camera inspection offers an increased production rate compared to
CCTV inspection.
Zoom camera performance is often measured in terms of the sight distance (i.e., how far down the pipe
the camera can capture an image), and the reader is urged to verify with field data the sight distance
claims by camera vendors. In general, sight distance varies with pipe diameter and lighting conditions
within the pipe and is limited by pipe conditions such as horizontal bends, deflections, blockages and
protruding services (where a building lateral extends into a main sewer line). Limitations on sight
distance also mean that defects in the middle of the pipe segment may not be detected; however, a large
percentage of defects are often found relatively close to the manholes. Possible reasons for this include
vibrations of the manhole due to surface traffic, development of soil voids around a pipeline due to
infiltration in and around a manhole, and vertical movement of manholes due to cold weather (Joseph and
DiTullio, 2003).
Although zoom camera inspection is a very efficient, cost-effective inspection method, there are some
drawbacks. Like all camera technologies, it is only useful for inspecting gravity sewers because force
mains and service laterals do not have manholes for access. Zoom camera inspection has the same
limitation as traditional CCTV pipe inspection in that the camera cannot see the pipe below the water
surface. Also, if the pipe deviates from a straight line due to sagging or deficient installation, the zoom
camera will not "see" the hidden defects. The zoom camera does not provide the same detailed visual
evaluation as conventional CCTV. Some zoom cameras lack pan and tilt viewing and cannot accurately
Figure 2-4. Pole-mounted zoom
camera. Image courtesy of
Envirosight. LLC.
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measure and locate defects. Limitations in image resolution, lighting and optical zoom also pose
challenges.
Several commercially available zoom camera models are described in the next section. The reader is
advised to contact the camera manufacturers directly for additional product information and new product
developments such as improved optical and digital zoom capabilities. Vendor contact information is
provided in Appendix C.
Table 2-2. Zoom camera inspection summary
SUMMARY
Sewer type
Material
Pipe size
Defects detected
Original application
Current application
Status
Advantages
Disadvantages
Gravity sewers only
Any
> 6-in.
Cracks, leaks, root intrusion, overall surface condition of pipe/manholes
Manhole inspection
Typically used to screen and prioritize pipes for more detailed CCT V
inspection and/or cleaning.
Commercially available
High production rate, effective/efficient at prioritizing segments requiring
more detailed inspection/maintenance
Inability to inspect manhole to manhole for average diameter lines, potential
to miss significant defects
2.3.1 Zoom Camera Models
The CUES-IMX truck-mounted zoom camera (Figure 2-5) has a total effective zoom ratio of 300:1
including a 25:1 optical zoom range. The camera is stabilized and remotely controlled by a telescopic
boom. It is equipped with high-intensity lights. The camera
mounting fork is designed to pan the camera head 360° continuously,
tilt mechanically 45° up or 90° down and tilt optically 166°. The
camera system can be mounted within an inspection van, all-terrain
vehicle or trailer. The camera housing is a damage-resistant,
waterproof enclosure 7 in. in diameter and 16 in. in length. The
CUES-IMX zoom camera system is equipped with data collection
software, GIS software and global positioning system (GPS)
equipment. The GIS software and GPS equipment are used to create
sewer maps in the field and to create an asset management database
for the system. Defects detected during the inspection can be stored
in a database along with photos and video clips. All data are geo-
referenced to the field-collected GPS coordinates. This is common
in the industry and the subject of further discussion in Chapter 3.
GE Technologies offers a truck-mounted pan-tilt-zoom (PTZ)
camera, the Everest Ca-Zoom 6.2 that has three interchangeable
camera heads. The PTZ 140 camera head has a 432:1 zoom
capability (36:1 optical zoom range) and is equipped with high-
powered halogen lighting. It can be deployed through 140-mm (5.5-
in.) openings. The PTZ100 and the PTZ270 have 40:1 zoom
capability (10:1 optical zoom range) and high-powered LED lighting. The PTZ100 fits through a 100-
mm (4-in.) opening; the PTZ270 fits through a 76-mm (3-in.) opening.
Figure 2-5. CUES-IMX truck-
mounted zoom camera. Source:
CUES, Inc. (2009). Reprinted
with permission.
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Figure 2-6. PortaZoom camera.
Source: CTZoom Technologies, Inc.
(2006). Reprinted with permission.
CTZoom Technologies manufactures and distributes the PortaZoom
camera (Figure 2-6). Key features of the PortaZoom camera
include its compact housing (6 in. in diameter), its 312:1 zoom
capability (26:1 optical zoom range) and its ability to pan 360°.
The camera has full-circumference integrated lighting including
peripheral lighting to reduce shadows. The PortaZoom camera can
be controlled by a commercially available joystick or by a standard
computer keyboard and compatible computer. It can be either
truck- or pole-mounted.
Aries Industries offers the HC3000 pole-mounted zoom camera, which has a 432:1 zoom ratio (36:1
optical zoom range). The camera has high-intensity detachable LED lights and can transmit images with
wireless technology. A small portable monitor is also available for viewing camera images during the
inspection.
AquaData Inc. manufactures the Aqua Zoom system (Figure 2-7).
Although not commercially available, it is used by company
professionals for consulting services. It is normally mounted on
either a truck or tripod, which is claimed to provide better stability
compared to pole-mounted devices. It uses a built-in control center
and video-recording equipment to perform pipe inspections.
Envirosight, LLC's smaller pole-mounted camera, QuickView, has a
total zoom capability of 432:1 (18:1 optical zoom range). The
manufacturer reports the camera has a sight distance of 50 to 250 ft
in pipe diameters of 6 in. to 60 in. The reader is advised to confirm
manufacturer's claims with actual field data.
2.3.2 Examples of Utility Experience
Figure t.-i. .
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inspection is less disruptive to traffic. Inspection rates reported in case studies are approximately 1 mile
per day. Hamilton reported 6,152 ft/day. An inspection of storm sewers in Fairfax County, Va., is
reported to have averaged 6,250 ft/day (Batman et al, 2008). Auburn reported that a 2-person crew can
inspect about 5,000 ft of pipe per day, including 25 manholes, or 10,000 ft without manholes. These rates
are roughly one-third to one-quarter of the time needed to inspect pipes using traditional in-line CCTV.
The cost of zoom camera inspection is reported to be one-half to two-thirds less than the cost of cleaning
and conventional CCTV inspection, based on case study reports. Auburn's program cost approximately
$1.00 per ft (with manhole inspection). Zoom camera inspection in Hamilton costs approximately $1.00
(Canadian) per ft, compared to $5.74 (Canadian) for CCTV. Hillsborough saved $11.4 million by using a
combined zoom camera and in-line CCTV program and recommended budgeting $1.00 - $2.00 per ft for
a system-wide zoom camera assessment. Fairfax County's costs averaged $3.30 per ft for its combined
zoom/CCTV program, and $4.90 per ft when only in-line CCTV was used.
Use of zoom camera technology has enabled utilities to limit and target the amount of pipe requiring more
detailed attention. By using a combined zoom and in-line CCTV approach, Fairfax County found that
only 66% of its pipe footage needed to be inspected by CCTV (including sections that could not be
accessed with a zoom camera). Of the pipe screened with zoom camera, only 36% required subsequent
in-line inspection. Auburn's zoom inspection program resulted in plans to clean and perform CCTV
inspections on 15,000 ft out of approximately 60,000 ft of pipe. Dallas, Texas, performed a pilot project
using AquaZoom and found that 70% of its pipes did not need cleaning, CCTV inspection, or other
attention (Renfro et al., 2005). Thus, unnecessary sewer cleaning was avoided, reducing overall program
costs.
Zoom camera accuracy compared to CCTV is an important criterion to consider. Utilities need to know
how much accuracy will be sacrificed by using zoom camera technology for its expected savings in time
and cost. The experience of one utility (Hamilton) provides a useful example. Hamilton compared the
results of pipe inspections using both CCTV and zoom camera, as illustrated in Figure 2-8 (Bainbridge
and Krinas, 2008). The graph compares how often the pipe condition ratings determined by CCTV and
zoom camera inspection are the same (shown as 0 on the x-axis) or different up to four condition ratings
(-4 and +4 on the x-axis). These results show that zoom camera and CCTV inspections resulted in the
same condition rating approximately 48% of the time. Further, the two technologies differed by one
condition rating about 31% of the time.
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CCTV VS Zoom Camera Ratings
T
1 I 2
1&99% 4,69%
Error Deviation
Figure 2-8. Comparison of CCTV and zoom camera inspections.
Source: Bainbridge and Krinas (2008). Reprinted with permission.
Utility experiences with camera sight distance were reported. It is important to note that sight distance or
estimates of pipe length that can be inspected vary depending on the camera model, pipe diameter, and
other pipe characteristics. Rinner and Pryputniewicz (undated) noted that zoom cameras can typically
inspect 40 ft to 60 ft in each direction in an 8-in. diameter pipe. Bainbridge and Krinas (2008) noted an
average zoom camera inspection distance of about 100 ft (30 m) based on inspection of 23,566 manholes
and associated piping in Hamilton, Ontario (camera model and pipe diameters unspecified). The
variability in these estimates may partially reflect the effects of pipe diameter and lighting on the ability
of the camera to see long distances into the pipe. In a larger pipe, for example, the sight distance may be
greater and more defects would be detected.
Bainbridge and Krinas (2008) used Hamilton's CCTV data to address questions about whether a zoom
camera's sight distance may cause a significant number of defects to be missed. Approximately 59% of
the defects identified by CCTV were located within 65 ft (20 m) of manholes, and 76% were within 100
ft (30 m) of manholes. Joseph and DiTullio (2003) estimated that "about 80% of defects ... are usually
located within the first 15 to 20 m [49 to 66 ft] from the manhole." Although the estimates in these two
studies differ, both suggest that a large percentage of defects will be detected by zoom camera because a
high concentration of defects is located within the commonly referenced zoom camera sight distances. In
the case of Hamilton, a zoom camera with an inspection distance of approximately 100 ft might be able to
detect 76% of the pipe's defects.
2.4 Digital Scanning
Digital scanning is a state-of-the-art camera inspection technology. Like conventional CCTV, digital
cameras are transported through sewer lines using self-propelled crawlers (Figure 2-9). Unlike
conventional CCTV systems, digital scanning uses high-resolution digital cameras equipped with wide-
angle lenses that allow the generation of two types of images: unfolded views of the sides of the pipes and
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circular views down the pipe (similar to CCTV) (Figure 2-10). The "unfolded" view of the inner pipe
surface provides an excellent view of pipe conditions. This permits computer-aided measurement of
defects and objects. Because digital scanning combines a large number of still digital images, it produces
a sharper image than video (Knight et al., 2009). Digital scanning provides a more consistent and
complete assessment of pipe condition than CCTV.
During the digital scanning process, data are transmitted to a
surface station for real-time viewing and recording for later
evaluation. With the defect coding occurring later in the office,
digital scanning can progress rapidly in the field. By comparison,
conventional CCTV relies on a camera operator in real-time to pan,
tilt and zoom the camera into critical areas to collect and store
images. If the operator does not see a defect, the camera is not
stopped for further investigation.
Digital scanning develops a full digital image of the pipe segment
independent of the camera operator. This allows the individual
reviewing the recording to control the direction of the PTZ features
and to stop the image at any point to capture video clips and
images. It provides a second level of quality control in the review
process and allows other individual(s)
involved in the process (e.g., designers,
rehabilitation contractors, and utility
owners) to gain insight into the pipe
condition. Digital scanning technology
is primarily used for gravity lines and
can be used with any pipe material. The
maximum pipe diameter that can be
inspected with digital scanning depends
on the specific equipment used, but one
manufacturer states that its product can
be used in pipes up to 72 in. in diameter.
Minimum pipe size is generally about 6
in. Its applicability for inspecting sewer
laterals is limited because laterals are
typically less than 6 in. in diameter and
Figure 2-9. DigiSewer digital
scanning camera deployed in pipe.
Image courtesy of Envirosight, LLC.
Figure 2-10. Virtual pan & tilt and unfolded pipeline view
from RapidView IBAK PANORAMO system. Source:
RapidView (2009b). Reprinted with permission.
access is generally through a small
diameter cleanout. Digital scanning has
limited application in force mains. Like
conventional CCTV technology, digital
scanning is only able to provide useful images above the waterline; force mains would have to be taken
out of service and drained before digital recording. Also, access to force mains typically restricts the use
of digital and CCTV technology because force mains are pressurized and do not have access manholes
required for the insertion of inspection equipment.
SSET was developed in Japan in 1994 and introduced through field trials in the United States in 1997.
The third-generation SSET was refined by Blackhawk-PAS for commercial marketing. SSET is no
longer manufactured or supported, although utilities and contractors that have invested in the equipment
continue to use it. SSET uses a fisheye lens that captures a hemispherical front view. The annular part of
the image gets digitally scanned and is used to produce the flattened side view of the pipe (Karasaki et al.,
2001). White LEDs provide cool, energy-efficient lighting. The unit also contains an inclinometer and
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gyroscope to provide information on location in the pipe. SSET can be used in pipes ranging from 8 in.
to 36 in. in diameter, operating at a rate of approximately 13 ft per minute.
Table 2-3. Digital scanning inspection summary
SUMMARY
Sewer type
Material
Pipe size
Defects detected
Original application
Status
Advantages
Disadvantages
Gravity sewers, limited applicability for force mains and service laterals.
Any.
6 to 72 in. (depending on model and conditions).
Cracks, leaks, root intrusion, overall condition of pipe.
Inspection of piping.
Commercially available; new applications under development.
Increased QA/QC control, additional project personnel able to review/control data
imagery; able to make digital measurements of defects; can compare data directly from
one inspection to the next.
More costly and lower production rate than CCTV; only works above water line.
Three digital scanning camera systems marketed in North America are designed for the investigation of
water, storm drain, and sewer pipelines. These products are described in the following sections; vendor
contact information is provided in Appendix C.
2.4.1 Envirosight - DigiSewer
The DigiSewer system is essentially a new-generation SSET system. It
was originally developed by DigiSewer and manufactured by IPEK
(provider of crawlers and cameras to Envirosight). DigiSewer was
designed to be used for borehole inspection and was first used in Europe in
2003. It was officially released to the North American market in 2007.
DigiSewer uses one high-resolution photo camera with a 180° wide-angle
fisheye lens integrated into the front of the rover crawler (Figure 2-11).
According to the vendor, DigiSewer can scan 6-in. to 32-in. diameter pipes
at a scan speed of 70 ft per minute and can scan pipes approximately 650 ft
in length.
2.4.2 RapidView- IRAK, USA - PANORAMO
The RapidView-IBAK, USA PANORAMO system was developed by IBAK Helmut Hunger GmbH &
Co. KG of Kiel Germany in partnership with RapidView, LLC. The application was first developed and
used in 2002. The first application in the United States was in 2007.
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The PANORAMO system (Figure 2-12) uses two high-resolution
digital photo cameras with 186° wide-angle lenses fit into the front
and rear sections of the housing. During pipe inspections, parallel
mounted xenon flashlights are triggered at the same position in the
pipe. The hemispherical pictures scanned are put together to form
360° spherical images. PANORAMO can scan pipes at a speed of
up to 70 ft per minute in forward or reverse. According to the
Figure 2-12. RapidView IBAK manufacturer, this camera system can be used for pipes ranging from
PANORAMO system. Source: 8 in. to 72 in. in diameter.
RapidView (2009b). Reprinted
with permission. During the PANORAMO scanning process, the data are transmitted
digitally to the inspection vehicle for later retrieval and analysis. The
scans can be viewed as live pictures for orientation purposes and for locating any obstructions. In
addition, the data are stored in the form of "PANORAMO films" on removable hard disks or DVDs.
2.4.3 CleanFlow/Fly Eye System
The CleanFlow system is a multi-sensor technology developed in New Zealand and distributed in the U.S.
by Cues, Inc. It includes laser, sonar and high-definition imaging. The sensors are typically mounted on
a float system; however, in low-flow conditions, the laser and high-definition camera are deployed using
a skid mount. The system is typically deployed in pipes with diameters of 24 in. to 66 in.
2.4.4 Example of Utility Experience
Digital scanning has been used in Europe and Asia for several years, but it has a limited history in North
America. The City of Hamilton is one example of a North American utility that has begun to use digital
scanning. In 2006, Hamilton conducted a pilot test using SSET for sewer pipes and was pleased with the
superior level of detail provided by this technology, which permits more defects to be coded than with
CCTV. Hamilton also benefited from a better understanding of the significance of a defect, as opposed to
CCTV results, which only document a defect's existence. The primary drawback with the SSET
equipment for Hamilton was the size of the pipe for which it was effective. It was found to work best in
smaller pipes (< 36 in. pipe diameter), but the extra expense of highly detailed inspections for the smaller
pipes was not justified. Smaller pipes carry lower risk due to the less severe consequences in the event of
failure. In larger, more critical pipes, a greater level of detail is needed, but the SSET was not as
effective.
Based on recent communication with Hamilton's contractor, pipes up to nearly 5 ft in diameter are now
being inspected with digital side scanning. Hamilton also noted that the overall cost for SSET inspection
was initially higher than for CCTV despite the greater speed of inspection; coding in the office increased
total labor costs. However, Hamilton's contractor has indicated that SSET inspection may now have a
cost comparable to CCTV. Hamilton's experience underscores the fluid nature of new technologies, both
with respect to technical capabilities and to cost.
As a relatively new technology, digital scanning can be expected to undergo continuing development to
increase its capabilities. Similar to most camera technologies, one of the limiting factors for digital
scanning performance is camera resolution. In general, resolution for digital scanning decreases with
larger pipe size. However, better lighting can help offset this limitation. SSET was originally designed
for pipes 8 in. to 12 in. in diameter, but the manufacturer worked to increase this range in response to
customer needs. With further development, optical and digital capabilities may continue to improve.
Current research is also focused on software enhancements for defect recognition and digital defect
measurements. Utilities may wish to keep abreast of developments in this technology as changes in
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performance and cost may make digital scanning a cost-effective option for pipes where a high level of
detail is needed.
2.5 Camera Deployment
Figure 2-13. Mobile robot inspection
system. Source: iPEK International
GmbH (2009). Reprinted with
permission.
In CCTV inspection, cameras are deployed into pipelines in
a variety of ways. Mobile robots called crawlers or tractors
(e.g., Figure 2-13) are available in a variety of sizes and
configurations, enabling their use in various pipes sizes.
These robots are typically introduced into the sewer via a
manhole. Cameras can also be mounted on float rigs (Figure
2-14) for inspecting large-diameter pipes that are partially
filled with water. Pushrod cameras are typically used in
smaller diameter pipes (6 in. and less) such as service laterals
and are typically introduced into the sewer through a
cleanout.
This section describes innovations to vehicles used to carry
CCTV cameras as well as technologies that can be added to
the conventional camera vehicles to further assist in CCTV inspection.
The combination and integration of two or more inspection technologies onto a robotic platform in order
to detect different types of defects and to address the disadvantages of a single inspection technology has
been proposed by several researchers. These multi-sensor inspection robots have been commercialized in
various forms in Europe, North America, Japan and Australia. The commercial versions include critical
sensors (e.g., CCTV, sonar and laser scanners); however, some of the more innovative sensors (e.g.,
infrared sensors, radioactive sensors and impact-echo hammers) have, for the most part, not been
deployed on commercial robots. The robotic platforms using the multi-sensor approach for the
assessment of wastewater collection systems include SAM (Sewer Assessment with Multi-Sensors) and
PIRAT (Pipeline Inspection Real-time Assessment Technique).
A variety of innovations have been applied to the tractors or crawlers that carry CCTV cameras. These
innovations include extra long-range tractors/floats, smaller than typical tractors that can be used for
laterals; tractors that are able to dispatch smaller lateral cameras from the main line; and segmented robots
that can bend around odd angles in small-diameter pipes.
Different camera tractor innovations are available from a
variety of vendors. Several commercial applications are
designed for the investigation of water, storm drain, and sewer
pipelines. Push cams are used almost exclusively in smaller
diameter sewers such as service laterals. Tractor innovations
have been broken down into four groups: small-diameter
tractors, long-range tractors, segmented tractors, and lateral
launchers (tractors that can launch lateral cameras off of the
main inspection vehicle).
Figure 2-14. CUES camera float. Source:
CUES, Inc. (2009). Reprinted with
permission.
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2.5.1 Push Cams
Pushrod camera, or push cam, technology involves the inspection
of pipelines with a small-diameter camera mounted to a pushrod
and reel setup that provides video of the pipeline (e.g., Figure 2-
15). This technology is primarily designed for laterals and small-
diameter force main applications. Conventional push cams use
straight view cameras capable of inspecting pipes 2-in. or more in
diameter. Advancements include push cams capable of inspecting
pipes smaller than 2-in. as well as steerable and pan/tilt push cams.
Push cams are typically used in environments that are too small for
crawlers/robotic camera vehicles in small-diameter water and
sewer pipes. Conventional push cam systems consist of a
camera/probe, cable/reel and computer/recorder/controller. The
probe used to advance the camera is usually a semi-rigid rod
constructed of fiberglass. The primary limitations are image
quality, lighting and the inability to move past obstructions. Table
2-4 summarizes a variety of commercially available push cams.
Table 2-4. Push cam product comparison
Figure 2-15. Crystal Cam - push
camera. Image courtesy of Inuktun
Services, Ltd.
Product
(Vendor)
Cry stalC am Push Camera
(Inuktun)
Flexiprobe
(Pearpoint)
Hydras
(Raprdvrew-IBAK, USA)
Orion
(Raprdvrew-IBAK, USA)
Orion L
(Raprdvrew-IBAK, USA)
Push Camera
(Insight Vision)
Pipe
Diameter
>2rn.
1 to 8 in.
>2rn.
>4 in.
>4rn.
1 to 12 in.
Inspection
Length
Not specified
500ft
Not specified
Not specified
Not specified
300ft
Notes
High-resolution low-light camera. Can be
tractor-mounted, can be used as a reverse
camera.
Interchangeable camera options with bright
white LED lighting.
Straight view camera only.
Pan and tilt functions.
Pan and tilt, includes "steer stick" allowing
device to be steered around bends or turns.
Uses Clearview line of camera heads; large
10.4-in. LCD monitor.
2.5.2 Tractors/Crawlers
Tractors and crawlers are mobile robots used to deploy CCTV through a pipeline (Figure 2-16). Most are
wheeled or tracked and tethered by a cable to a controller unit located near the point of entry to the sewer
system. Conventional CCTV inspection tractors are larger vehicles that cannot be deployed in smaller
pipes or laterals. Many of the tractors cannot be steered and can only inspect pipe runs of 300 to 500 ft.
Advancements in technology now include lateral launchers that are able to deploy smaller diameter push
cams into laterals, small-diameter tractors that can be deployed in pipes as small as 4 in. in diameter,
long-range tractors that can inspect pipes at great distances from the point of entry and segmented robots
that can bend around odd bends or angles in small diameter pipes. Tables 2.5, 2.6 and 2.7 summarize a
selection of commercially available innovative tractor and crawler technologies.
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IBAK LISY 150M
Figure 2-16(a). Source: RapidView
(2009a). Reprinted with permission.
CUES LAMP lateral inspection crawler
Figure 2-16(b). Source: CUES, Inc. (2009).
Reprinted with permission.
Figure 2-16 (a) and (b). Examples of pipe inspection crawlers.
Table 2-5. Lateral launcher product comparison
Product
(Vendor)
IBAKLISY150-M
(RapidView-IBAK, USA)
LAMP
(CUES)
LAMP II
(CUES)
Lateral Evaluation
Television System
(ARIES Industries)
Lateral Inspection System
(RS Technical Services)
Mainline
Pipe
Diameter
>6 in.
6 to 30 in.
6 to 15 in.
>8in.
8 to 24 in.
Inspection
Length
Not
specified
1,000ft
1,000ft
800ft
1,000ft
Lateral
Pipe
Diameter
N/A
2 to 6 in.
3 to 8 in.
3 to 6 in.
4 to 8 in.
Inspection
Length
N/A
<80ft
80ft
> 150 ft
<100 ft
Notes
Tungsten carbide wheel
for grip.
Optional sonde and
camera locating receiver.
Lateral camera has built-
in sonde for locating
laterals.
Lateral camera has built-
in sonde for locating
laterals.
Picture-in-picture format
allows simultaneous
viewing of main line and
lateral inspections.
Table 2-6. Small-diameter tractor product comparison
Product
(Vendor)
ELK T 100 Mini
(Pearpoint)
KRA65
(RapidView - IBAK, USA)
MightyMini Transporter
(RS Technical Services)
Pipe
Diameter
4 to 10 in.
>4 in.
4 to 12 in.
Inspection
Length
500ft
Not specified
500ft
Notes
Wheeled tractor
Steerable wheeled camera tractor with
electronic stabilizing function
4-wheel drive crawler with adjustable
cantilevered camera mount
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Product
(Vendor)
ROVVER 100
(Envirosight-IPEK)
Versatrax 100
(Inuktun)
Xpress Silver-Bullet
Crawler
(Insight Vision)
Pipe
Diameter
4 to 12 in.
4 to 24 in.
4 to 1 5 in.
Inspection
Length
660ft
600ft
600ft
Notes
Steerable, PVC wheel with titanium spikes for
traction
Tracked crawler
4-wheel drive crawler
Table 2-7. Long-range tractor product comparison
Product
(Vendor)
Versatrax 300 VLR
(Inuktun)
Responder
(RedZone)
Pipe
Diameter
>12 in.
>36 in.
Inspection
Length
6,000 ft
5,280 ft
Notes
Modular construction for onsite customization,
optional reverse camera can be mounted on crawler.
Skid steer enabled tractor, Kevlar reinforced
buoyant cable, submersible to 500 ft.
2.5.3 Segmented Robots
Electromechanica, Inc. designs custom inspection robotics and other applications. For example, a client
may have a specific type of small-diameter pipe system containing tees, wyes, or other angles that a
typical tractor or crawler cannot navigate. One such development is the Internal Pipe Inspection Robot.
This design uses a unique "inchworm" movement, which optimizes movement within the pipe. The robot
itself consists of three arm linkages that expand radially to force the different segments to grip the inside
of the pipe and move it along. It uses pneumatic cylinders to provide force to move itself through the
pipe. The robot can be outfitted with cameras, sensors or tools to accomplish many different types of
tasks in pipe inspection. As noted above, this is not a commercial product, but one that must be custom
ordered for a client's specialized needs.
2.5.4 Emerging Technologies
• Pushcams - The IPEK Agilios pushcam system was developed for small-diameter pipes and has
pan/tilt capability. It works in conjunction with the vision control unit and is battery powered.
• Autonomous Crawlers - An autonomous crawler does not require a real-time remote operator.
The crawler's behavior is programmed in advance of deployment. The vehicle is programmed to
cue off of particular environmental landmarks. For instance, RedZone Robotics has designed a
robot that constantly monitors the diameter of the pipe as the robot moves through the pipe.
Infrared sensors atop the vehicle sense when the distance to the roof of the pipe alters radically;
this is interpreted as a manhole. The vehicle may be programmed to stop at the first manhole it
encounters, or it may stop after encountering some specified number of manholes. Autonomous
crawlers are beginning to enter the marketplace.
• Autonomous Floaters - Automatika, Inc. is developing the prototype of an un-tethered pipe
inspection robot called PipeEye (Figure 2-17). The robot is a 12-in. sphere designed to float in
pipes greater than 24 in. in diameter. Cameras and lights will operate above the waterline, and
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ultrasonic transducers will operate below the waterline. The cam.™ «* LM*
PipeEye system is derived from an oil/gas pipeline
inspection module co-developed by Automatika and Shell
Oil. The system does not yet have a product status.
2.6 Camera Selection Issues
Although conventional CCTV will continue to be an important part
of a sewer assessment program, the emergence of other camera-
based technologies such as zoom cameras and digital scanning offers
new options for inspection strategies. Selection of camera-based
technologies will depend on a number of factors, and it may be Figure 2'17-
i , , 1 • r ,i ,i i • ,i inspection robot. Source: Schempf
advantageous to combine one of these newer methods with /™nm T, • * .1 -^ • •
,. . , . ,. „„„,,. (2000). Reprinted with permission.
traditional m-lme CCTV.
A utility investigating new camera technologies or implementing changes to its pipe inspection program
may benefit from performing a trial run or pilot project to ensure that proper test procedures are in place
and that inspection crews are properly trained. Hillsborough County, Fla., for example, benefited from a
pilot program, as described in a case study in Appendix A.
Some of the issues to consider in making camera selection decisions are described below.
• Reason for inspection. A utility needs to consider whether its goal is to conduct a system-wide
inventory and general inspection or to target known problem areas. For a comprehensive
inventory of a system, especially one in which it is anticipated that many pipes are in good
condition, a zoom camera may be a good choice. For pipe segments where problems are
anticipated, proceeding directly to CCTV or an advanced inspection method may be warranted.
• Time frame. If information is needed quickly or traffic control is a concern, the speed of
inspection may be an important consideration.
• Level of detail required. For critical pipes, a high level of detail may be needed, and utilities
may decide that a zoom camera will not be appropriate. In this case, a utility may select
traditional in-line CCTV or may opt for the greater detail provided by digital scanning, especially
if a goal is to track specific defects over time. For pipes of lower criticality (consequence of
failure), a zoom camera may be adequate and may be a less-expensive alternative.
• Anticipated pipe conditions. The pipe characteristics and condition may make certain
technologies more feasible than others. For example, extensive debris may hinder movement of
deployment devices such as push cams. A large number of bends in the pipe may limit the use of
a zoom camera. The size of manhole required for easy entry into pipes should also be considered.
Flow conditions are another important consideration. For example, low-flow conditions are
preferred when using technologies that inspect only the dry portions of a pipe.
• Types and sizes of pipes. The types of pipes will, to some degree, dictate the choice of camera.
For laterals, push cams are generally needed. For larger pipes (> 8 in.), CCTV may be used. For
gravity sewers of all sizes, CCTV, zoom cameras, and digital scanning may all be options. Large
diameter pipes can pose a challenge for camera-based inspection technologies. The maximum
diameter pipe for which a method is effective depends upon the capabilities of the specific model.
Lighting is an important consideration, as is the resolution of the camera. Strong lighting is
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needed to provide enough illumination for larger pipes. Utilities needing to inspect large
diameter pipes should consult with manufacturers and contractors to get further information.
• Purchasing vs. contracting. When considering a new technology, a utility will need to decide
whether to invest in the inspection equipment or to use a contractor. The utility should consider
whether the long-term need for the technology is sufficient to justify the expenditure to purchase
the equipment and software and to train staff. If several technologies are selected for a
comprehensive inspection and prioritization process, subcontracting at least some of the work
may be more economical.
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Chapter 3. Overview of CCTV Inspection Data Analysis
3.1 Introduction
Sewer condition assessment is performed to evaluate sewer performance status or to prioritize sewer
rehabilitation activities. CCTV is an important inspection technique in the condition assessment stage of
asset management. It is a traditional technique that relies on the operator's interpretation of visual images
to convert the defect image into data for use in corrective action decisions.
This chapter discusses CCTV inspection data for linear assets such as pipes with open channel flow and
how these data are analyzed and manipulated in the corrective action process. CCTV can also be used in
vertical assets such as manholes. Because all pipes were originally designed to perform at a specified
hydraulic performance level under specific conditions, CCTV inspections help reveal whether pipes are
performing as designed and, if not, to what extent the design performance is affected and what corrective
actions are appropriate.
3.2 Methods for Inspection Prioritization
One of the first decisions in the CCTV inspection process is to identify priority assets for inspection.
Ideally, an inspection would occur prior to a performance exception or problem (WEF, 2006).
3.2.1 Selection of Assets for Inspection
A well-developed inspection plan will consider how the data will be used in subsequent asset
management steps. The goal is to maximize the value of the inspection while minimizing inspection
costs. The plan should focus on program objectives, keeping in mind what data needs are driving the
inspections and subsequent decision making. In comparing the costs and benefits of inspection, utilities
should consider the value of data as an added benefit. Both the Fort Worth Water Department (FWWD)
and Northern Kentucky Sanitation District No. 1 stress the importance of weighing the benefits of the
data relative to the overall asset management objectives (see the detailed case studies, Appendix A).
In a survey of its membership, the Association of Metropolitan Sewerage Agencies (now called the
National Association of Clean Water Agencies, NACWA) gathered information on inspection frequency,
as detailed in Table 3-1 (AMSA, 2003). These survey results show that approximately half of survey
respondents inspect less than 10% of their systems each year, resulting in a 10-year or longer inspection
period for those systems.
Table 3-1. Survey results of inspection frequency for conveyance systems
Percent of Sewer Pipes Inspected
<1% per year
1% -<3% per year
3% - <5% per year
5%-<10%peryear
10%-<20% per year
20%-<50%peryear
% (Number) of Survey Respondents
3% (2 of 75)
8% (6 of 75)
15% (11 of 75)
25% (19 of 75)
27% (20 of 75)
4% (3 of 75)
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Percent of Sewer Pipes Inspected
>50% per year
No Answer
% (Number) of Survey Respondents
1%(1 of 75)
17% (13 of 75)
Source: AMSA (2003).
Use of an infrequent inspection rate requires prudence to identify critical assets that need more frequent
inspection. For example, the FWWD has a goal of inspecting its entire system within an eight-year
period. However, the more critical pipes are inspected at least every four years (see case study in
Appendix A). Northern Kentucky Sanitation District No. 1 uses the results of its CCTV scoring and trend
analysis to automatically schedule future CCTV inspections (see case study in Appendix A).
The condition assessment process does not rely solely on data from CCTV inspections because gathering
the data would take years. Therefore, condition assessment programs generally use a priority risk
approach based on probabilistic methods to select assets for inspection. Decisions about which assets to
inspect should be related to the utility's program objectives and the assets that pose the most threat in the
event of a performance problem. For example, if SSOs pose a significant threat, the utility may want to
focus on assets that present the greatest SSO risk.
3.2.2 Prioritization of Assets
Approaches for selecting which assets to inspect can vary from basic methods based on inspection history
or performance measures to more sophisticated methods that use predictive modeling and risk assessment.
The FWWD, for example, uses the following performance measures to help prioritize sewer inspections:
• SSOs per 100 miles.
• Stoppages/blockages per 100 miles.
• Customer complaints per 100 miles.
Software applications can be retrospective or predictive and rely on the integration of computerized
maintenance management systems (CMMS), GIS, customer information systems (CIS) or financial
information systems (FIS) (AMWA et al., 2007).
Three approaches described below can be used by almost any size utility to prioritize assets:
• The Canadian National Research Council's approach (McDonald and Zhao, 2001) uses an
"impact assessment" to prioritize assets for inspection. Impact assessment is a weighted average
of six impact factors: location, soil support, size, depth, sewer function and a seismic factor.
This method allows the uniform calculation of the impacts of failure or performance problems.
• The Sewer Cataloging, Retrieval, and Prioritization System (SCRAPS) is based on the general
approach of defining risk factors based on consequences and likelihood of failure using Bayesian
probability logic (Merrill et al., 2004). It is a tool that can be used when limited condition
information is available or retrievable. The term "Consequence of Failure" is defined as the
impact of a failure in terms of repair cost, disruption to the public and economy, impairment of
system operation, regulatory compliance, public health and safety, and damage to the
environment. The same terminology can be applied to the decision-making process used in
applying condition assessment to asset management. The impact of a failure must be understood
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and quantifiable. If the costs can be quantified, this impact can be compared to both the cost of
condition assessment and the cost of replacement or rehabilitation.
• NACWA, the Association of Metropolitan Water Agencies (AMWA), and the Water
Environment Federation (WEF) produced a publication titled "Implementing Asset Management:
A Practical Guide in 2007" (AMWA et al., 2007) that uses a top-down approach to prioritization.
The top-down approach uses risk factors similar to SCRAPS. However, this process is based on
assigning risk scores to an asset group or set of assets at a system or facility level through
spreadsheet matrices. Level of service values and weights are used to produce a numeric
consequence of failure score. The likelihood of failure matrix includes physical condition and
functional performance criteria that influence the remaining life of the asset. Institutional
knowledge and professional judgment are the primary sources of this information. The
consequence of failure score is multiplied by the likelihood of failure score, resulting in a risk
score used to prioritize the asset groups.
Section 3.5 further discusses risk-based prioritization but with more emphasis on its application to
selecting appropriate corrective actions such as pipe repairs, rehabilitation or replacement.
3.2.3 Asset Inspection
The type of inspection performed depends on the objective of the condition assessment program. The
climatologic and hydrologic differences across North America will influence the assessment objectives.
For example, in coastal areas with high annual rainfall, inspection may focus on pipe capacity. In dry and
seasonably warm regions, the assessment may focus on structural condition and service life. Program
objectives are discussed in more detail in Chapter 1.
The selected inspection technique needs to be appropriate for the type of asset, and it must provide the
data needed to make decisions. CCTV is the most commonly used method of inspecting sewers and
locating structural and maintenance defects. It is not a reliable method of locating I/I defects because of
difficulties in correlating ground water elevation and movement relative to the asset. The zoom camera is
a good, cost-effective method for screening pipes for more comprehensive CCTV inspection, as
illustrated in the Hillsborough County case study (see Appendix A).
A detailed work plan that integrates inspection procedures and data management protocols should be
established to produce consistent and reproducible inspection results. These documents ideally will
outline and address key assessment questions such as the following:
• Which assets are high priorities for inspection?
• How often are lower priority assets inspected?
• How will the CCTV data be used to make assessment decisions?
• What software tools are used for analyzing the CCTV data and planning maintenance work?
• What quality control checks will be performed and by whom?
• How are the CCTV data stored and managed?
• What resources are needed to support the data collection and analysis activities?
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3.3 Defect Coding
3.3.1 Code Design and Format
Defect codes classify defects by category, defect type and severity. This helps the utility owner determine
the overall physical condition of a pipe and its priority for further inspections and maintenance. Defect
codes serve multiple functions in the CCTV inspection and data analysis process:
• Codes serve as unique defect identifiers for operators to link an image from a pipe inspection to a
specific pipe defect.
• Standard codes provide a means to reduce operator subjectivity.
• Codes enable different industry coding systems to be "mapped" to each other.
Defect codes can be designed in various ways (e.g., one character or a string of characters). Their design
is largely influenced by the code system and CCTV software features. The most traditional design is an
acronym consisting of a string of letters or numbers that link to words describing the defect. For
example, the acronym BP might represent "broken pipe." The acronym BP3 would provide more
descriptive information if "3" represented major severity on a scale of 1 to 3. Similar examples are
illustrated in Tables 3-2 and 3-3. Table 3-2 shows some defect codes used by the City of Fort Worth, and
Table 3-3 lists some structural defect codes from the NASSCO Pipeline Assessment and Certification
Program (PACP) defect coding system. A complete list of defect codes used by Fort Worth is included in
its case study in Appendix A; PACP codes are provided in NASSCO (2001).
Table 3-2. Partial listing of defect codes for City of Fort Worth Water Department
Code
G
R
OB
DE
CC
CL
B
Code
Description
Grease
Roots
Obstruction
Debris
Crack,
Circumferential
Crack,
Longitudinal
Pipe Broken
Severity Ranking
12345
N/A
Less than
10% of pipe
diameter
Less than
10% of pipe
diameter
Less than
10% of pipe
diameter
Hairline
Hairline
Hairline
Less than
10% of pipe
diameter
10% to 20%
of pipe
diameter
10% to 20%
of pipe
diameter
10% to 20%
of pipe
diameter
Minor
Minor
Minor
10% to 20%
of pipe
diameter
20% to 30%
of pipe
diameter
20% to 30%
of pipe
diameter
20% to 30%
of pipe
diameter
Moderate
Moderate
Moderate
20% to 30%
of pipe
diameter
30% to 40%
of pipe
diameter
30% to 40%
of pipe
diameter
30% to 40%
of pipe
diameter
Major
Major
Major
More than
30% of pipe
diameter
More than
40% of pipe
diameter
More than
40% of pipe
diameter
More than
40% of pipe
diameter
Severe
Severe
Severe
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Table 3-3. Example PACP structural defect codes
and descriptions
PACP Code
B
BSV
BVV
CC
CL
CM
CS
D
FC
FL
FM
FS
H
HSV
HVV
XB
XP
Description
Broken
Broken soil visible
Broken void visible
Crack circumferential
Crack longitudinal
Crack multiple
Crack spiral
Deformed
Fracture circumferential
Fracture longitudinal
Fracture multiple
Fracture spiral
Hole
Hole soil visible
Hole void visible
Collapsed brick sewer
Collapsed pipe
Source: NASSCO (2001). Used with permission.
3.3.2 Code Systems
A number of code systems have been developed to classify pipe defects. These systems are described
below. In general, the code systems differ in their design and in the degree of detail with which the defect
is described. A desirable feature is a defect dictionary that fully describes the defect with a narrative and
example photos.
WRc and NASSCO Defect Code Systems
The Water Research Centre (WRc), a water, wastewater and environmental research-based consultancy
group in the United Kingdom, developed a set of codes to rank the severity of pipe defects. European
authorities adopted the WRc system as their benchmark pipe defect coding standard. The WRc defect
coding system is described in the Manual of Sewer Condition Classification - 4th Edition (WRc, 2004),
which can be purchased from NASSCO (http://www.nassco.org/).
In 2001, NASSCO developed a Pipeline Assessment and Certification Program (PACP) with associated
defect codes (http://www.nassco.org/training_edu/te_pacp.html) based on the WRc system (NASSCO,
2001). The PACP defect codes present several advantages and disadvantages, as listed in Table 3-4.
NASSCO has also developed the Manhole Assessment Certification Program (MACP), with associated
defect codes, and has initiated development of a similar code system for service laterals.
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Table 3-4. Advantages and disadvantages of the NASSCO PACP defect code system
Advantages
Disadvantages
Broad and well-established coding process
and training system across North America.
Readily available standardized coding and
data recording software.
Good defect code classification system.
Simple and intuitive defect grading scale for
operators.
Standardized codes limit the degree of code
customization and adaptations/improvements
to coding system as technology evolves.
Three separate rating processes provide
different condition interpretations for five
coding families (see details in Appendix B).
Simplistic grading hinders definitive analysis
cut-off points or sorting ranges when there
are a large number of assets.
Scoring process is not integrated with other
field inspection techniques.
No built-in or automated process that verifies
the correct code was entered. Verification
must be accomplished by a subsequent
quality control review.
An example utility application of the PACP coding system is provided by Metro Water Services (MWS)
in Nashville, Tenn. (see detailed case study in Appendix A). MWS replaced its in-house data
management and defect code system, and initially found that using the PACP coding system decreased
the department's productivity. As the staff adjusted to the new system, productivity and efficiency
increased. Inspection data are now quickly uploaded and available to all MWS employees within 24
hours of inspection. As a result, duplicative inspection efforts are avoided. Inspection results have been
much more consistent with the PACP coding system. The utility found that one disadvantage of PACP
coding is that it can be too detailed, making it difficult to get complete information when querying for
problems. For example, PACP coding has several observation codes for roots in the pipe. When
identifying a root problem, different personnel may use different codes. The use of different PACP codes
by operators may then cause difficulties when querying for root problems. If the user does not construct
the query using the same multiple observation codes that were used to code the defects, the user will not
find all instances of root problems.
SCREAM*™ Defect Code System
SCREAM™ was developed by CH2M HILL to provide an alternate approach for rating the overall
condition of a pipe. It has been integrated into vendor software such as CUES Granite XP software and
Wallingford Software's InfoNet program. The SCREAM™ code system is somewhat similar to PACP
but includes a more comprehensive list of codes. Manhole and lateral codes were also developed. The
SCREAM™ coding process presents several advantages and disadvantages, as summarized in Table 3-5.
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Table 3-5. Advantages and disadvantages of the SCREAM™ defect code system
Advantages
Disadvantages
Flexible code customization to match
historical or unique local nomenclature.
Defect codes have a base and maximum
score between which the defect is scaled
based on extent.
Code scores are specific to most popular pipe
materials.
Rating process produces one condition score
for each of four coding groups (see Appendix
B).
Code system integrates with other inspection
techniques.
Access limited through software vendors and
consultants; proprietary software.
Comprehensive code list mandates operator
training.
Training and certification materials need
more defect photo documentation.
No built-in or automated process to verify
that the correct code was entered.
Verification must be accomplished by a
subsequent quality control review.
System is not widely used.
Appendix B provides more detailed descriptions of the PACP and SCREAM™ code systems, as well as
examples to illustrate the coding process.
Alternative Defect Code Systems
The Large Sewer Condition Coding and Rating (LSCCR) system was developed by Canada's National
Research Council Institute for Research in Construction (NRC-IRC) based on condition assessment
procedures used by WRc and the cities of Edmonton and Phoenix. The LSCCR system is described in
Guidelines for Condition Assessment and Rehabilitation of Large Sewers (Zhao et al., 2001), which can
be downloaded at http://www.nrc-cnrc.gc.ca/obj/irc/doc/pubs/nrcc45130.pdf.
Another option for utilities is to develop their own defect code system. Using a so-called "homegrown"
defect code system allows the utility to standardize the condition assessment process at the utility level
while being tailored to meet system-specific needs. These defect code systems often mirror some features
of commercial software and typically offer a more basic coding method. Their simplicity may be
desirable for reducing operator errors and other reasons, but may limit the robustness of the data for use in
asset management decision making.
FWWD created its own defect code system (see partial listing in Table 3-2) based on feedback from
operators and technicians that the PACP system with 200 codes is too rigid, too complex and too
cumbersome. Operators tended to memorize a handful of defect codes and rarely used the others. In
some cases, the PACP codes were not specific enough for operator needs/requirements. FWWD's code
system is similar to the PACP system, but has fewer codes (75 vs. 200). Some utilities prefer this simpler
approach because there is less dependence on the operator's memory to recall an acronym when using
software drop-down lists and short-cut keyboard features in CCTV software interface screens.
3.4 Data Handling and Analysis
Data handling, including collection, storage, retrieval, analysis, and reporting, is an important yet often
overlooked component of a condition assessment program. Important questions to consider when
selecting a data management system include:
• Who needs access to what data?
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• What data do I need to review for short-term and long-term decision making?
• What reports will I generate from the data management system?
• How much training is needed to manipulate software or to view data?
• What is my budget for software and training?
• Are there licensing fees and other system maintenance costs?
• Do I want to integrate CCTV data with other historical data?
• Is my staff willing to change to a new, more complex system?
• Is my data transferable to another system if I decide to change vendors?
• Is my software open source or proprietary?
Since the late 1990s, many utilities have replaced analog CCTV cameras with digital models, and have
identified a number of benefits. For example, SPU has found that digital information has a long storage
life and requires little space. Data retrieval from analog videotapes is difficult, and the tapes degrade after
approximately 7 to 10 years (see case studies in Appendix A). Digital storage media (e.g., CDs and
DVDs) do have a finite storage life, so data may need to be transferred to other media as the technology
evolves. Furthermore, digital inspection data can be easily accessible to a greater number of utility
personnel via links from the GIS and computerized maintenance management system.
Utility owners have experienced some initial productivity loss and reluctance from the CCTV operators
when implementing the new data formats, and some have found a need for increased resources. The
FWWD, for example, found that more information technology support was needed to maintain its
software and additional training was required for CCTV operators (see Appendix A). Nashville MWS
and Northern Kentucky Sanitation District No. 1 also needed additional operator training and budgeting
support with the new CCTV software management system. The FWWD recommends that utilities select
CCTV inspection software that is non-proprietary, open architecture based and not developed by the
CCTV camera manufacturers.
There are three general approaches to data management software, with varying costs and degrees of
complexity:
1. Spreadsheet software.
2. Software specifically designed for condition assessment and asset management.
3. Database software that is not specifically designed for condition assessment.
3.4.1 Spreadsheet Software
Spreadsheet software offers the least costly option for data management and is the most familiar to utility
staff. Microsoft Excel and IBM's Lotus 1-2-3 are examples of popular spreadsheets. Most utilities are
likely to already have such software. A basic yet effective data management system can be designed;
however, as the database expands, the spreadsheets and data links can become overly cumbersome and
require a more advanced user to leverage the software. The Seattle Public Utilities used an Excel
spreadsheet to apply its pipe risk model (see Appendix A).
3.4.2 Condition Assessment/Asset Management Software
There are numerous commercially available data management programs for CCTV-generated data,
ranging in complexity and cost. Examples include Canalis (Aqua Data Inc.); CapPlan Sewer (MWH
Soft); Cass Works (RJN Group Inc.); CityWorks (Azteca Systems, Inc.); CTSpec (CTZoom Technologies
Inc.); gbaMS (GBA Master Series, Inc.); Granite XP (CUES); Hansen (INfOR); InfoNet (Wallingford
Software); Maximo® (IBM); and SEWERview (Cartegraph, Inc.). USEPA provides free asset
management software (Check Up Program for Small Systems, CUPSS) on its Web site
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VWi«;>* S
Figure 3-1. Example CUES Granite XP
pipe inspection map with camera image.
Source: CUES, Inc. (2009). Reprinted
with permission.
(http://www.epa.gov/cupss/). Figure 3-1 is an example of a
screen shot of a CUES Granite XP pipe inspection map and
camera image. The publication "Implementing Asset
Management: A Practical Guide" (AMWA et al., 2007)
discusses some of the currently available software
applications. Contact information for software vendors is
provided in Appendix C.
Commercially available software designed for condition
assessment offers various functions including:
• Document status of pipe being inspected.
• Provide access to text data, video and still photos.
• Code defects in different forms (i.e., acronym, bar
codes, touch screen images).
• Customize defect codes to capture local terminology,
match historical records and/or support specific local
policies/regulations.
• Store defect codes on pipe segments both spatially and temporally.
• Sort and categorize defects by location, type, severity, score, etc.
• Compile defect data into a searchable database.
• Incorporate cost accounting.
• Develop work orders for maintenance calls and ordering spare parts.
• Incorporate GIS functionality into the system.
The utility should identify software that can provide the desired functions. It should also confirm that the
software developer can provide training and technical support services as needed to ensure successful
implementation.
3.4.3 General Database Management Software
An alternative to commercially available software or a standard spreadsheet is a database designed
specifically for a utility's needs. This approach may offer advantages in data processing and analysis
time because the database is system-specific. However, it may involve additional up-front costs and
require additional technical expertise. Other costs include software licensing fees and staff training.
Database management software systems can be divided into two groups: desktop databases and server
databases. Commercially available desktop products include Microsoft Access, FileMaker Pro, Alpha
Five, Paradox and Lotus Approach. Desktop products provide the user with significant flexibility to
modify and customize analysis and reporting functions. Server databases, such as Microsoft SQL Server,
Oracle and IBM DB2, allow the efficient management of large amounts of data. Web-based applications
can be developed using either desktop products such as Microsoft Access or server databases.
Northern Kentucky Sanitation District No. 1 (developed its own database system and integrated it with
commercially available asset management software (see case study in Appendix A). District personnel
found that the process takes time to develop, but provides the flexibility to design engineering analysis
and generate reporting queries and work orders at substantial cost savings compared to the prior data
management practices. The district also uses condition assessment software discussed in Section 3.4.2
and integrates the software platforms, as illustrated in Figure 3-2.
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CSAP Tool
(SQL Database ancJ procedures)
Applies Logic
Figure 3-2. The Northern Kentucky Sanitary District No. 1's example integration of general database and
condition assessment software. Image courtesy of Northern Kentucky Sanitary District No. 1.
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3.4.4 Pipe Rating and Scoring Methods
CCTV data analysis is an important step in condition assessment of pipelines because the results
influence the overall pipe condition rating and risk scoring. The approach to CCTV data analysis depends
on several factors including:
• The type of asset inspected (e.g., pipe, manhole, service lateral).
• The camera technology used for pipe inspection (e.g., digital CCTV camera, zoom camera, digital
scanning).
• The method used to convert pipe defect codes to overall pipe rating and risk ranking.
Figure 3-3 shows the typical steps that occur from the first identification of a pipe defect to establishing
the pipe's priority ranking for pipe rehabilitation or replacement.
Defects
i
Defect Codes
Assign code based
on defect category,
type, and severity.
Defect Scores
Individual or
cumulative score
(numeric value) for
defects based on
adopted method.
Pipe Grade or
Score v
Cumulative
numeric score,
grade, or overall
alpha letter for all
defects in the pipe
segment.
Pipe Priority
Ordered scores
for all pipe
segments used
to establish
priority.
Figure 3-3. Typical steps from defect identification through prioritization of pipe rehabilitation projects.
Source: Kathula and Rowe (2004). Reprinted with permission.
Two pipe rating analysis methods are discussed below: PACP and SCREAM™. Details and examples
are provided in Appendix B.
PACP Rating Analysis System for Pipes
The PACP uses a numerical grading system to rate the severity of each pipe defect and calculate overall
pipe ratings based on grades for individual pipe segments. NASSCO (2001) describes the basis and
assumptions used in establishing this grading system:
"The PACP Condition Grading System only considers internal pipe conditions obtained
from TV inspection. While other factors such as pipe material, depth, soils, and surface
conditions also affect pipe survivability, those factors have not been included in this
version of the PACP Condition Grading System. The PACP Condition Grading System
should be used as a tool for screening pipe segments, allowing the User to quickly
determine which pipe segments have significant defects. It is expected that as the PACP
further develops the PACP Condition Grading System will expand to include other
factors."
The defect grading system uses a scale of 1 to 5, with 1 representing a minimal defect and 5 representing
the worst defect. Structural and O&M defects are graded separately based on the likelihood of further
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deterioration or failure. The PACP system uses several terms for expressing pipe condition (NASSCO,
2001):
• Segment Grade Scores: Each pipe segment (manhole-to-manhole pipe run) receives five
Segment Grade Scores, one for each of the five grades. The score equals the number of defects
multiplied by the grade number. For example, a pipe segment with six Grade 5 defects has a
Segment Grade 5 Score of 30 (6 defects multiplied by a grade of 5). If a pipe segment has no
defects for a particular grade, the Segment Grade Score for that grade is 0.
• Overall Pipe Rating: The sum of five Segment Grade Scores.
• Structural Pipe Rating: The sum of five Segment Grade Scores considering only structural
defects.
• Overall Pipe Rating Index: An expression of the average defect severity found in the pipe
segment. The index is calculated by dividing the Overall Pipe Rating by the number of defects.
• Structural Pipe Rating Index: The average severity of structural defects in the pipe segment. The
index is calculated by dividing the Structural Pipe Rating by the number of defects.
• O&M Pipe Rating Index: The average severity of O&M defects in the pipe segment. The index is
calculated by dividing the O&M Pipe Rating by the number of defects.
SCREAM™ Rating Analysis System for Pipes
The SCREAM™ rating analysis system includes coding individual defects, scoring the overall pipe
condition and scoring the structural, maintenance and I/I group defects. The coding of individual defects
includes calculation of a base score and a maximum score; the base score represents minor defects (e.g., a
point defect or a defect that affects 1 ft or less of pipe length) and the maximum score represents major
defects (e.g., a defect that affects the entire pipe segment). For both defect coding and pipe condition
scoring, a scoring scale of 1 to 100 is applied with 1 representing a very minor defect and 100
representing the most severe defect (e.g., a collapsed pipe).
The SCREAM™ methodology includes computation of an Overall Pipe Score for the aggregated defects
found in the pipe. It also computes a separate score for the structural, maintenance and I/I groups of
defects. These scores are calculated using a multiple attribute method that involves advanced root-
square-mean mathematical principles. One key principle is to identify and build upon the highest scored
defect value found in the inspection (Kathula, 2004).
3.5 Role of CCTV Data in Asset Management Decision Making
The purpose of this section is to highlight and summarize the role of CCTV data in asset prioritization
decisions, the final step in the condition assessment process. There are two ways of making decisions,
one based on pipe condition information and the second using a risk assessment approach. A risk-based
approach is the only way to prioritize for renewal assets that are in the same condition and display the
same deterioration rate. A strict condition-based approach is tenable only when resources are available to
renew all assets that are worse than a given threshold condition.
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3.5.1
CCTV Data Used in Condition-Based Prioritization Decisions
A utility may decide to proceed with work on a particular asset or group of assets because it has a historic
record of problematic performance or it meets certain performance measure criteria (see Section 3.2.2).
CCTV data are then used to help make a condition-based decision on what action should be used to
correct the asset and the priority given to this corrective action. There may be numerous locations and
assets that fall into this category and require a relatively short-term fix, for instance within a 1- to-5-year
period. However, even within this period, the asset corrective actions need to be prioritized.
The condition-based decision approach has two common decision sequences, which differ primarily on
when the cost of the corrective action is considered and what role it has in the prioritization. Figure 3-4
shows the two options.
In Option 1, CCTV inspection analysis leads to an internal condition rating, a prioritization decision, and
then a type of corrective action. In this option, the cost of the corrective action can be considered in the
selection of the corrective action or after the correction action is selected.
Option 2 is similar to Option 1 except that the corrective action decision is made immediately after the
internal condition rating. Generally, the cost of the corrective action is considered when the corrective
action decision is made and the cost influences the prioritization decision.
Option 1:
CCTV
•+*
Internal
Condition Rating
•+*
Prioritization
Decision
>>
uorrecnve
Action
Decision
or
CCTV
>>
Internal
Condition Rating
*
ItUIIBbLIVB
Action
Decision
>>
Prioritization
Decision
Option 2:
Figure 3-4. Two optional condition-based decision approaches.
Utilities typically use less costly inspection methods for initial evaluations, then progress to more
comprehensive and more costly techniques as warranted. For example, utilities may initially inspect
manholes and connecting pipes with zoom cameras if the manholes are readily accessible by field crews.
Zoom cameras enable utilities to screen the pipes and reduce the number of pipes that require CCTV
inspection to only those needing the more detailed investigation.
Utilities that use the PACP rating system need to decide which of the three PACP scoring methods is
preferred. A popular method is the Pipe Rating Index method previously discussed. Pipes rated as Grade
4 or 5, for instance, would be evaluated more closely or acted upon first compared to pipes with a of
Grade 1-3. The grading system screens the assets for further evaluation of replacement or rehabilitation
issues and development of a cost estimate for establishing a priority and schedule.
Utilities that use the SCREAM™ rating process prioritize corrective actions based on the single
numerical defect score. Usually the utility establishes a range of score values to determine the urgency of
a specific corrective action. For instance, Northern Kentucky Sanitation District No. 1 uses a structural
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score range of 81- 100 to trigger rehabilitation or replacement in its large inceptors, and a range of 61 -
80 triggers future inspections.
3.5.2 CCTV Used in Risk-Based Prioritization Decisions
Because of limited resources, most utilities must prioritize assets for inspection. Therefore, the condition
assessment process does not rely solely on CCTV data because it could take many years to complete a
system-wide inspection program (Rowe, 2009). The challenge is to understand the possible risks posed
by an asset failure and determine at what point to intervene to avoid a failed condition with an
unacceptable cost or consequence.
Risk is quantified by the combination of both the likelihood of failure and consequence of failure. CCTV
inspection provides data to improve the integrity of the likelihood of failure score. The mathematical
expression of risk is (AMWA et al., 2007):
Risk = [(Consequence of failure) x (Likelihood of failure)]
Various risk-based decision models have been developed for sewer assets. Because CCTV data are not
always available for every asset, predictive modeling is often used to determine the likelihood of pipe
failure until the asset can be directly inspected. For example, SPU uses a predictive model based on pipe
material decay curves to estimate the likelihood of failure (see the detailed case study in Appendix A).
Figure 3-5 presents an example of a risk-based approach to determine the priority assets for more
comprehensive inspections or other corrective actions. The "Likelihood of Failure" and "Consequence of
Failure" terms in the risk calculation are usually developed by constructing a matrix that lists the
important criteria or service level factors and the associated score (AMWA et al. 2007). The "Likelihood
of Failure" term considers both current internal condition information and time-based information (e.g.,
historical work order records). The "Consequence of Failure" term represents time-based information
since it considers future events related to pipe failures. Figure 3-5 shows how CCTV data can be
incorporated into the prioritization process. If the condition rating of an asset was initially determined by
a predictive approach and the asset is then inspected using CCTV, its risk rating should be recalculated
and its action reprioritized.
Figure 3-6 is another example of a risk-based prioritization decision framework where the internal
condition ratings are all based on CCTV data. Asset prioritization and corrective action Options 1 and 2
are the same as discussed above under Section 3.5.1, Condition-Based Prioritization Decisions.
In conclusions, the primary objective of this guidance document is to identify and evaluate innovative
CCTV and related technologies currently used by more advanced wastewater utilities to conduct
condition assessment programs. The document is intended to facilitate the transfer of these innovative
technologies to utilities at large. The steps in developing and implementing a condition assessment
program are presented along with related practical guidelines. Technology applications and lessons
learned from seven utility case studies are summarized and used to illustrate specific concepts. Detailed
case study reports are presented in Appendix A.
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Internal
Condition Rating
External
Condition Rating
Work Order
History
Flow Capacity
Option 1
Other Criteria
Environmental
Public Health
Asset Protection
Customer
Service
Other Criteria
Consequence of Failure
*Ł
«
S.
1 >
-+~
c
o _
lo
.S »
fi o
*fi
it
Corrective
•»• Action
Decision
or
Option 2
Figure 3-5. Example risk-based prioritization decision framework for multiple internal condition rating
input sources.
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CCTV
Internal
Condition Rating
External
Condition Rating
Work Order
History
Flow Capacity
Other Criteria
Environmental
Public Health
Asset Protection
Customer
Service
Other Criteria
I
1
LL
•5
O
O
Option 1
E
Option 2
Figure 3-6. Example long-term risk-based prioritization decision framework.
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References
ADS. (2010). Scattergraph Principles and Practice. Available on the internet at
http://www.adsenv.com/scattergraph. Accessed 2.22.10.
AMWA, NACWA and WEF. 2007. Implementing Asset Management: A Practical Guide. Alexandria,
VA: Association of Metropolitan Water Agencies, National Association of Clean Water
Agencies, Water Environment Foundation.
Association of Metropolitan Sewerage Agencies (AMSA) - currently National Association of Clean
Water Agencies). 2003. Wet Weather Survey-Final Report. Washington, D.C.
Bainbridge, K., and Krinas, H. 2008. Efficient condition management of sewer systems using both zoom
camera technology and "traditional CCTV." In Proc. Of the NASTT No-Dig Conference.
Batman, P.J., Ramamurthy, A., and Shelton, J. 2008. Blending Zoom Technology with Traditional CCTV
in a Condition Assessment Program. In Proc. Of the NASTT No-Dig Conference.
Black and Veatch Corporation. 2004. Sanitary Sewer Overflow Solutions: Guidance Manual. ASCE/EPA
Cooperative Agreement CP-828955-01-0. Washington, D.C.: USEPA Office of Wastewater
Management.
CTZoom Technologies, Inc. 2006. PortaZoom Camera. Quebec, Canada: CTZoom Technologies, Inc.
Available on the internet at http ://www. ctzoom.com/PortaZoom-camera. asp.
CUES, Inc. 2009. Products. Available on the internet at http: //www. cue sine. com/Products. html.
iPEK International GmbH. 2009. iPEK: ROWER. Available on the internet at
http://www.ipek.at/index. php?id=24&L=ypfawcmpsneig.
Joseph, S., and DiTullio, W., 2003. Evaluation of Collection Systems Using the Aqua Zoom Camera.
New Pipeline Technologies, Security, and Safety. In Proc. of International Conference on
Pipeline Engineering and Construction.
Karasaki, K., Shima, H., and Iseley, T. 2001. The coming of age of advanced digital optical scanning
technology for pipeline assessment. Available on the internet at
http://www.nastt.org/store/technical_papersPDF/85.pdf.
Kathula, V. S. and Rowe, R. 2004. Application of New Sewer Condition Assessment Methodology
Measures the Relative Conveyance Performance and Risk Impacts of FOG and Other Pipe
Defects. In Proc. of the Water Environment Federation Specialty Conference Collection Systems.
Milwaukee, Wisconsin.
Knight, M., Younis, R., Barrall, B., Russin, J., and Manners, C. 2009. Advances in Pipeline Asset
Management Using Digital Side Scanning Evaluation Technology. In Proc. Of the NASTT No-
Dig Conference.
Martin, T. 2004. Seattle Public Utilities Asset Management Sewer Pipe Risk Model. Presented at
Leading Edge Asset Management Conference, San Francisco, CA, July 27, 2004.
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Martin, T., Johnson, D., and S. Anschell. 2007. Using Historical Repair Data to Create Customized
Predictive Failure Curves for Sewer Pipe Risk Modeling. InProc.ofLESAM 2007 2nd Leading
Edge Conference on Strategic Asset Management. London, UK: IWA Publishing.
McDonald, S.E. and Zhao, J.Q. 2001. Condition Assessment and Rehabilitation of Large Sewers. Report
No. NRCC-44696. Institute for Research in Construction, National Research Council Canada,
Ottawa, Canada.
Merrill, M.S., Lukas, A., Palmer, R.N., and Hahn, M.A. 2004. Development of a Tool to Prioritize Sewer
Inspections. WERF, Alexandria, VA.
National Association of Sewer Service Companies (NASSCO). 2001. Pipeline Assessment and
Certification Program (PACP) Reference Manual. Available by contacting NASSCO at
http://www.nassco.org.
RapidView. 2009a. Inspection Tractors. Available on the internet at http://rapidview.com/tractors.htm.
RapidView. 2009b. Panoramo 3D Optical Scanner. Available on the internet at
http://rapidview.com/panoramo.htm.
Renfro, J.A., Kaakaty, C., DiTullio, W., and Renfro, M.A. 2005. Dallas project uses new inspection
technology. Texas H2O. Official Newsletter of the Texas Section AWWA, June/July 2005.
Rinner, J. and Pryputniewicz, S., N.d. To Zoom or Not to Zoom. 2009. Retrieved May 20, 2009 from
http://www.inframetrix.com/images/NEWEAPaper%209-08Westfordfmal.doc.
Rowe, R., Loechle, J., Kathula, V., Gray, J., Muller, J. 2009. Louisville MSD Integrates Sewer Pipe
Probability of Failure and Consequence of Failure to Guide Their Continuing Sewer System
Assessment Program. InProc.ofthe Water Environment Federation Collection System Specialty
Conference; Louisville, Kentucky.
Schempf, H. 2000. PipeEye. Automatika, Inc., QinetiQ North America. Available on the internet at
http://www.uvs-info.com/pdf/ugvspec/Automatika_USA_PipeEye.pdf.
Thomson, J.C. 2008. The Value of Inspection. Presented at: STREAMS Task Order 59 Condition
Assessment of Collection Systems Technology Forum. Sept. 11-12,2008. Edison, NJ.
Thomson, J.C., Hayward, P., Hazelden, G. Morrison, R.S., Sangster, T., Williams, D.S., and Kopchynski,
R.K. 2004. An Examination of Innovative Methods used in the Inspection ofWastewater Systems.
WERF: Alexandria, VA and IWA Publishing: London, United Kingdom.
USEPA. 2005. Guide for Evaluating Capacity, Management, Operation, and Maintenance (CMOM)
Programs at Sanitary Sewer Collection Systems. Report No. EPA-305-B-05-002, USEPA Office
of Enforcement and Compliance Assurance, Washington, D.C.
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Report No. EPA-ORD-NRMRL-CI-08-03-02, USEPA, Washington, D.C.
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Wastewater Systems. WEF, Alexandria, Virginia.
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Zhao, J.Q., McDonald, S.E., and Kleiner, Y. 2001. Guidelines for Condition Assessment and
Rehabilitation of Large Sewers. Available on the internet at http://www.nrc-
cnrc.gc.ca/obj/irc/doc/pubs/ nrcc45130.pdf.
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Appendix A. Utility Case Studies
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Case Study on Implementation of New Data Management System - City of Fort Worth Water
Dept, Fort Worth, Texas
This case study discusses the experience of the City of Fort Worth, Texas, in transitioning to a new
standardized coding system and data management software.
Lessons Learned
The City of Fort Worth Water Department (FWWD) has been very satisfied with the implementation of
its new standardized coding system adapted from PACP, digital video inspections and data management
software. Advantages of the new system include:
• 100% digital videos and photos and improved querying. Prior to the new system, staff had to
manually search for VHS tapes on a shelf and fast forward through the tape to find points of
interest. FWWD is now able to easily search for any inspection and quickly access all
information.
• Historic records. It is advantageous to have access to data from multiple inspections of a single
pipe segment and inspections performed over an extended period of time. These data can be used
to compare the results of past inspections to the results of current inspections as part of condition
assessment.
• Exporting of records. The new software has made it much easier to export inspection records
and recordings for review by developers and engineers.
• Standardized defect coding. The implementation of a standardized defect coding system has
greatly improved the consistency of inspection data. This has led to more efficient cleaning and
maintenance procedures.
One drawback is a need to routinely replace electronics in the inspection vehicles due to the harsh
conditions to which equipment is exposed. FWWD has also needed increased resources to provide more
information technology support to maintain the software and to provide additional training for CCTV
operators.
FWWD recommends that utilities select CCTV inspection software that is non-proprietary, open
architecture based and not developed by the CCTV camera manufacturers.
FWWD also recommends that if a small or medium-sized community plans to have more than one
inspection vehicle, it should plan to standardize the electrical components. CCTV vehicles are a harsh
environment for electronics, and FWWD has noticed hardware (motherboards, fans, video capture cards,
etc.) failures occurring more frequently than anticipated. The solution has been to purchase the
components, build the computers and replace the existing computers once every two years regardless of
their condition.
With respect to personnel training, FWWD realized that more IT support was needed within the
department to help with troubleshooting and maintenance of the software. The change in procedure also
necessitated training for CCTV operators in the use of the new computer-intensive techniques. Also, the
expense of purchasing licenses, maintaining a dedicated server, and training personnel is greater than the
cost of FWWD's previous system. Utilities will need to weigh the benefits of improved data management
against additional expenses.
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Background
FWWD provides drinking water and wastewater services for the community of Fort Worth, Texas, and 21
surrounding communities. The FWWD sewer collection system serves a population of approximately
660,000 people with approximately 208,000 service connections.
Initial construction of FWWD's collection system began in 1906 with multiple brick sewers. A large
expansion of the collection system took place in the 1940s with the installation of primarily vitrified clay
pipe. Throughout the following 60 years, pipelines were added to the collection system as the local
population grew. In 1962, FWWD constructed a 96-in. diameter sewer main, which is still the largest
pipe in the system. The current collection system spans a total of approximately 3,000 miles and has an
average age of 29 years. The collection system is a completely separate system with an average daily
flow of 120 million gallons per day (MOD). The collection system consists of eight major drainage
basins each of which is divided into 66 sub-basins averaging 237,000 linear ft of pipe. These sub-basins
are further divided into 325 sub-areas with an average 44,000 linear ft of pipe.
Historical CCTV Inspections and Defect Coding
FWWD initially instituted its CCTV program in the mid 1990s with the objective of inspecting the entire
system once every eight years. Historically, CCTV inspection was used for a variety of purposes such as
determining pipe condition, aiding in planning maintenance strategies, evaluating the effectiveness of its
cleaning program, performing post SSO evaluations, performing inspection of new construction and
finding customer service lateral tap locations.
FWWD personnel perform all inspections of pipes with diameters of less than 20in. For pipes with
diameters greater than 20 in., FWWD relies on contractors to perform CCTV, sonar and laser inspections.
Initially, FWWD made no allowances for CCTV software. When purchasing CCTV vehicles, the utility
did not specify any options so the vendors made equipment decisions. Inspection records were not saved,
and the analog VHS tapes were simply indexed and manually filed. To find a specific CCTV inspection,
office personnel would search for a tape and then fast forward and rewind through the footage. This
process resulted in shelves overfilled with inspection videos and no efficient method for retrieving
historical inspection records. At times, FWWD personnel found it easier to just re-inspect the pipe
segment.
Current CCTV and Defect Coding
In fall 2003, FWWD changed from analog video to digital video, implemented a new standardized coding
system and installed new data management software. An internal defect coding system was created based
on a 1 to 5 rating system for multiple pipe defects. Prior to this, the utility had not used a defect coding
system.
FWWD did not select a PACP-certified defect coding system because it was believed that the system is
too rigid, too complex and too cumbersome. There was concern that the PACP ratings would not be
consistently produced by their operators. Darrell Gadberry of FWWD said the following in an e-mail
message:
"I have talked to a lot of operators, technicians and managers regarding PACP. Managers
love it because they think they have a standardized CCTV program in place. Operators
hate it due to the extremely large amount of defect observation codes and rating
variables. Therefore they [operators] memorized a handful and rarely use the others. In
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some cases, the observation codes are not specific enough for their needs/requirements.
Since there is no consistency between each inspection and/or operator, there is very little
benefit for the technicians" (Gadberry, 2009).
For example, PACP coding has several different observation codes for roots in the pipe. When
identifying a root problem, different personnel may use different codes. The use of different PACP codes
by operators may then cause difficulties when querying for root problems. If the user does not construct
the query using the same multiple observation codes that were used to code the defects, the user will not
find all instances of root problems.
The internal defect coding system that FWWD created and implemented uses coding similar to PACP,
but the coding system is more streamlined and better tailored to FWWD's needs. For example, the
coding system uses 75 codes compared to 200 codes for the PACP coding system. The coding system
assigns ratings from 1 to 5 for each section of pipe inspected, with a rating of 1 representing the best
condition and a rating of 5 signifying the worst. The 1 to 5 rating can be given for each observation
within a pipe segment. Each observation is assigned a code, which is simply an abbreviation. The
observations are broken down into six categories: common text, operation and maintenance (O&M)
issues, pipe defects, tap connections, service lateral, and grade/alignment. Table A-l gives a list of
observation codes used by FWWD along with specific code descriptions and ratings (FWWD, 2007).
Even with this standardized coding system, FWWD management has noticed some inconsistencies among
operators. In an attempt to alleviate these inconsistencies, FWWD now employs two technicians who are
strictly dedicated to CCTV inspection review and assessment.
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Table A-l. Summary of Fort Worth defect codes
Code
G
R
OB
DE
CC
CL
B
H
X
I
J
SW
E
D
Code
Description
Grease
Roots
Obstruction
Debris
Crack,
Circumferential
Crack,
Longitudinal
Pipe Broken
Hole in Pipe
Collapse
Infiltration/
Inflow
Joint
Offset/Separated
Surface
Deterioration
Encrustation
Pipe Deformed
Severity Ranking
12345
N/A
Less than 10%
of pipe
diameter
Less than 10%
of pipe
diameter
Less than 10%
of pipe
diameter
Hairline
Hairline
Hairline
Less than 1A in.
N/A
N/A
N/A
N/A
N/A
N/A
Less than 10%
of pipe
diameter
10% to 20% of
pipe diameter
10% to 20% of
pipe diameter
10% to 20% of
pipe diameter
Minor
Minor
Minor
1A in. to 1 in.
diameter
N/A
N/A
N/A
N/A
Minor
Minor bumps,
folds and
wrinkles on the
pipe walls
10% to 20% of
pipe diameter
20% to 30% of
pipe diameter
20% to 30% of
pipe diameter
20% to 30% of
pipe diameter
Moderate
Moderate
Moderate
1 in. to 2 in.
diameter
N/A
Dripping
Minor
N/A
Moderate
Moderate
bumps, folds
and wrinkles on
the pipe walls
20% to 30% of
pipe diameter
30% to 40% of
pipe diameter
30% to 40% of
pipe diameter
30% to 40% of
pipe diameter
Major
Major
Major
2 in. to 3 in.
diameter
N/A
Running/steady
stream
Moderate
Heavy
deterioration,
major aggregate
projection.
Major
Major bumps,
folds and
wrinkles on the
pipe walls
More than 30%
of pipe diameter
More than 40%
of pipe diameter
More than 40%
of pipe diameter
More than 40%
of pipe diameter
Severe
Severe
Severe
More than 3 in.
diameter
Complete failure
imminent
Gushing/pouring
Severe
Heavy
deterioration,
major aggregate
projection is
beyond repair
Severe
Major bumps,
folds and
wrinkles on the
pipe, could be
damaged during
cleaning
Source: FWWD, 2007
Note: Other codes include break-in tap connection (TB), factory tap connection (TF), service lateral defective (SLD), pipe
material change (MC), diameter change (DC), camera underwater (CU), camera emerged (CE), upward change in gradient
(LU), downward change in gradient (LD), line bends left (LL), and line bends right (LR).
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Data Management and Inspection Strategy
FFWD selected its data management software (Inspect IT by Infrastructure Technologies) for several
reasons:
• The ability of Structured Query Language (SQL) to manage, standardize, and query data; manage
reports; and link to CMMS or GIS.
• The ability to store multiple inspections of the same pipe segment over an extended period of
time.
• The ability to use the software in lieu of CMMS.
• The ability to coordinate the software with ESRI GIS software.
• The ability to have all data maintained on a single dedicated server.
CCTV, sonar, and laser inspections are captured digitally and stored on a dedicated SQL server. FWWD
maintains an extensive archive of over 19,000 digital videos and 27,000 digital photos on its server. In
total, its digital library holds approximately 3.4 terabytes of data.
FWWD also uses ESRI's ArcView software and IBM's Maximo asset management software for its GIS
and CMMS, respectively. FWWD is able to link inspection records to ArcView to create asset-based
datasets for all pipe segments within the collection system. The GIS datasets also include record
drawings and construction information. This has allowed FWWD to monitor pipe age and type when
conducting and scheduling inspections. The Maximo software is used to coordinate sewer inspections
and maintenance with other City of Fort Worth departments.
FWWD now prioritizes inspections to focus budgeted resources according to need. FWWD calculates the
following performance indicators for each sub-area of the collection system on an annual basis:
• SSOs per 100 miles.
• Stoppages/blockages per 100 miles.
• Customer complaints per 100 miles.
Using this process each year, FWWD selects approximately 285 miles of sanitary sewer for cleaning,
television inspection and condition assessment. Each sub-area is identified in the FWWD GIS dataset,
which is used to create work orders in FWWD's CMMS. Each cleaning and inspection work order is
specific to one sewer segment.
Inspection frequency is based on the known sewer condition. A 4-year frequency is used for sub-areas in
the worst condition; a 4-to 6-year frequency is used for average condition; and an 8-year frequency is
used for the best condition. This method also minimizes the possibility of unnecessary inspections
damaging old clay pipes, especially those of small diameter. Table A-2 summarizes inspections
conducted from 2004 to 2008.
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Table A-2. Summary of pipe inspections conducted 2004-2008
Pipe Material
Cast Iron
Concrete
Cured in Place, Lined, high-density
Ductile Iron
Polyvinyl Chloride
Vitrified Clay
polyethylene (HOPE), etc.
Pipe Size (in.)
6 to 18
6 to 72
6 to 42
6 to 42
6 to 36
6 to 27
Inspection
Length (miles)
6.27
369.15
14.66
38.16
395.41
167.38
All inspection records associated with the project are exported and linked to the original GIS dataset. A
visual observation of all O&M, structural and capacity recommendations is performed to determine the
project's effectiveness.
At the completion of the project, a standardized two-page summary is prepared along with associated
tables and maps documenting all system deficiencies and recommendations. All O&M recommendations
are addressed by FWWD. The structural and capacity recommendations are included in the FWWD's
Capital Improvement Program (CIP). An example of a sub-area summary report can be found in
Appendix D.
References
Gadberry, Darrell. (2009). E-mail Interview.
Fort Worth, Texas Water Department (FWWD). (2007). City of Fort Worth Water Department CCTV
Inspection and Defect Coding Program.
Contact: Darrell Gadberry, Water Systems Superintendent
1608 11th Avenue
Fort Worth, TX 76102-4397
Phone: 817-999-7907
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Case Study on Using a Risk Assessment Approach for a Sewer Pipe Inspection Program -
Seattle Public Utilities, Seattle, Wash.
This case study discusses development and implementation of a sewer pipe risk model to analyze costs
and benefits of CCTV inspection.
Lessons Learned
Seattle Public Utilities (SPU) has found the application of a sewer pipe risk model to be a worthy
investment. SPU determined that there was a critical need for risk assessment when a collection sewer
pipe collapsed and caused a sewage backup at a city hospital. At the time, all system pipes were
scheduled for inspection on a 30-year cycle, and the lack of current pipe condition information created a
reactive mode of operation.
The main benefits of the risk model are the information gained from risk assessment and the automation
of the decision process. Some utilities have found that it is not cost-effective to inspect all pipes. Risk
assessment can be used to identify and prioritize pipes that present comparatively greater risks to public
health and the environment. The automation of this risk assessment process is necessary for any system
with a complex network of pipes.
Application of SPU's risk model has resulted in unforeseen benefits. Modeling results helped SPU
realize that some model input data were incorrect. For example, GIS attributes including pipe elevation
data were suspect in about 20% of pipes. With Seattle's hilly terrain, pipe elevation and slope are critical
parameters. Since GIS data are also used for SPU's hydraulic model, data corrections made as a result of
the sewer pipe risk modeling project also helped to improve the accuracy of hydraulic model output.
Background
SPU is a municipal utility owned by the City of Seattle. It provides retail water, wastewater and drainage
and solid waste services to approximately 700,000 Seattle residents. Approximately 112 to 115 MGD of
wastewater is collected from the SPU system and treated at King County's West Point treatment facility.
SPU has more than 2,000 miles of pipe with an average age of almost 75 years. Approximately one-third
of the system has combined sewers and two-thirds consist of separate sanitary sewers. Wastewater
collection pipe ranges in diameter from 6 in. to 12 ft. Prior to 1950, sewers were primarily constructed
with vitrified clay, whereas concrete has been the predominant material of construction since 1950. The
sewer pipe infrastructure has a net worth of approximately $2.5 billion (2007 dollars).
SPU started performing CCTV inspection of sewer pipes in the late 1960s. Today, inspections are
conducted using in-line digital cameras, other equipment, and trucks—all owned by the utility. SPU also
owns one zoom camera and uses its inspection results (e.g., presence of tree roots inside pipe) to adjust
pipe maintenance schedules as warranted. It has not developed a unit cost comparison of the different
camera technologies the utility has used. SPU can store information from the digital CCTV cameras
much longer and in a much smaller space than it could information from the older, analog cameras, and
the analog videotapes degraded after 7 to 10 years. The digital inspection data are easily accessed by more
utility staff members via links from the GIS and computerized maintenance management system. SPU
uses a PACP-certified method for coding pipe defects with Granite XP asset inspection and decision
support software (http: //www. cue sine. com/).
Since the inception of the CCTV inspection program, all sewer pipes have been inspected on a 30-year
cycle regardless of age, condition, material of construction, location or diameter. This approach to
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assessing pipe condition has two major flaws (Martin, 2004). First, the infrequent CCTV inspections
seldom identify potential pipe failures, and second, inadequate resources are allocated to high-risk pipes
(pipes that have the potential for high financial, environmental and social failure costs to the utility and
the greater community).
In 2001, SPU developed an asset management program to address several concerns including aging
infrastructure, a lack of information on pipe condition, stricter environmental regulations and public
scrutiny of recent rate increases. For sewer assets, the immediate goal of the asset management program
was to minimize risk of infrastructure failure. The initial steps in implementing this program included
establishing an inventory of pipe infrastructure and developing a modeling tool to support a risk-based
pipe replacement and rehabilitation program.
Sewer Pipe Risk Model
In 2003, a sewer pipe risk model originally developed by Hunter Water Australia
(http://www.hwa.com.au) was adapted and applied to SPU's sewer network in order to calculate the risk
cost of failure for individual pipe segments and to calculate the total annualized cost to the utility over the
period between CCTV inspections. The risk cost of failure is determined by multiplying the estimated
consequences of failure by the estimated likelihood of failure. SPU uses the risk assessment and its
benefit-cost ratio to help select pipes for inspection and maintenance.
To estimate the consequences of pipe failure, the model extracts GIS attributes for each pipe (i.e.,
elevation, installation date, material of construction and proximity to geologic or structural features) and
uses this information to calculate the financial, social and environmental costs such as the factors listed in
Table A-3. For example, if the sewer pipe is located underneath a building, a multiplier is automatically
applied to the cost formula due to the added repair cost.
Table A-3. Factors that increase consequences and costs of pipe failure
Baseline Generic
Financial Costs for
Repairing Sewer
Failure
Labor
Equipment
Material
Shoring
Dewatering
Bypass pumping
Administration
Location-Specific Factors That
Increase the Cost of a Sewer Failure
Financial Factors
Under a body of water
Under railroad tracks
Under a building
Within a known slide area
Within a wetland area
On a steep slope
High-capacity sewage pipe
In dense urban area
Environmental
Factors
Property damage
Regulatory non-
compliance
Environmental damage
Social Factors
Unfavorable publicity
Social disruption
Damage to public health
Regulatory non-compliance
Source: Martin, 2004
To estimate the likelihood of pipe failure, the model uses predictive failure curves that are specific to each
pipe based on age and material. This method assumes that pipe failure is due to material deterioration and
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does not occur before the pipe is 20 years old. Model inputs are summarized in Table A-4. An example
predictive failure curve for vitrified clay pipe is shown in Figure A-l. These failure curves are generated
using a normalized Weibull-type distribution. More information on Weibull distributions and curves can
be found at http://www.weibull.com/. SPU received "off-the-shelf sewer pipe curves from Hunter Water
Australia.
Table A-4. Asset life information for SPU sewer pipe
Material of Construction
Vitrified clay
Concrete
Pipe relining
Polyvinyl chloride
Asphaltic concrete
Brick
Ductile iron
Cast iron
Corrugated metal pipe
First Failure1
(Years)
20
20
20
20
20
20
20
20
20
Remaining Life
(Years)
100
60
30
80
60
60
60
60
40
Total Life
(Years)
120
80
50
100
80
80
80
80
60
Assumes that pipe failure is due to material deterioration and does not occur before the pipe is 20 years old.
Source: Martin, 2004
5.0% •
^ •> ac\°L.
"5 i^ -» cox. .
LL u_
Ł ti 2 5% •
o o 9nv
•= N 1 5% .
=3 S 1'5A-
,
s I
^ 1
^ 1
^^ I
^^ I
^*^ I
— -"^ I
T— '
0 10 20 30 40 50 60 70 80 90 100 110 120
Pipe Age (Years)
Figure A-l. Predictive failure curve for vitrified clay pipe. Source: Martin et al. (2007). Reprinted with
permission.
The risk model, developed using a Microsoft Excel spreadsheet, is based on system-specific attributes and
causative factors. What causes pipe failure in one system may not be a critical factor in other systems.
For example, steep slopes are a major factor in Seattle, while a city on the Great Plains may have other,
more critical factors. Therefore, it is important that the model developer is familiar with the system
design and operating parameters.
Risk modeling conducted in 2004 showed that the cost of conducting CCTV inspection on low-risk pipes
exceeded the benefit gained by performing condition assessment, preventing a point failure (Martin,
2004). Therefore, SPU decided to perform CCTV inspection only on high-risk pipe (15% of total pipe)
using a 5-year inspection frequency. Low-risk pipe was allowed to run to failure without CCTV
inspection and repaired reactively. It is important to note that SPU's decision to run pipes to failure is not
a universal recommendation but a utility-specific decision. Utilities that are operating under a consent
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order are not allowed to run pipe to failure. The following example illustrates the 2004 modeling results
(Martin, 2004).
Example of Risk Modeling by SPU (Martin, 2004)
87-year-old pipe at 12-ft depth.
Point repair costs predicted by model: $36,000.
Probability of failure in the next 5 years: 5.9%.
Risk cost of repair in the next 5 years: $36,000 x 5.9% = $2,100.
Estimated life cycle cost of CCTV inspection assuming a 5-year frequency: $600.
Risk cost > CCTV inspection cost (by a factor of 3.5).
SPU's conclusion: Based on cost-benefit analysis, this pipe is high risk and should
be inspected.
In 2007, SPU conducted an analysis to verify the accuracy of the existing predictive failure curves using
actual sewer pipe failure and repair records (Martin et al., 2007). Based on anecdotal field reporting,
CCTV inspection data and the number of scheduled and emergency repairs, the existing curves were
suspected of over-predicting failure of most pipes and of poorly characterizing the failure modes of
different pipe materials. The 2007 analysis included a review of 15 years of point repair data (1989 -
2004) for vitrified clay and concrete pipes, which represent more than 90% of SPU's sewer pipes. Study
results indicate that vitrified clay pipes and concrete pipes incurred point failures at much lower rates than
predicted by the existing failure curves. In the early 2000s, pipe failures due to material deterioration
triggered about 150 annual repairs, compared to 800 annual repairs estimated by the predictive failure
curves to be needed.
The 2007 analysis also found a statistically significant correlation between certain local conditions (steep
slopes, clay soils and fill soils) and increased potential for pipe failure (Martin et al., 2007). For example,
86 actual pipe failures have been identified via inspection in 164,308 ft of clay pipe that is located on
steep slopes. Based on pipe age, the existing predictive failure curves estimated that 50 failures would
occur in these pipes. The observed failures exceeded the 95% confidence level of the prediction,
therefore the model was judged inadequate.
As a result of this analysis, SPU identified the following action steps (Martin et al., 2007):
• Pipes on steep slopes, in clay or in fill should be assigned higher likelihood of failure multipliers
in the risk model, resulting in higher risk scores and more frequent inspections in the future.
• Concrete pipes should be assigned a conservatively high predicted failure rate in the model in
order to accelerate the inspection frequency because the predominant failure mode is expected to
shift to structural failure in the near future.
• SPU will continue to conduct strength testing of existing sewer pipe segments to provide
information on structural degradation trends of the sewer pipe network.
New failure curves were customized for SPU based on actual sewer pipe failure data and CCTV
inspection data (Martin et al., 2007). Inspected pipes were first categorized according to their failure
history. For Type 1 failures (pipes that failed prior to their first inspection date), the pipe's service life is
not known exactly but can be estimated based on known dates for pipe installation and inspection. For
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Type 2 failures (pipes that failed during the period between the first and second inspections), the pipe's
service life can be estimated based on known dates for the two inspections, a narrower window than Type
1 failures. Pipes were then analyzed using a statistical parameter estimation method known as Maximum
Likelihood Estimation to generate the new curves. This method finds the most likely failure curve for a
dataset. The new failure curves are shown in Figure A-2 as a comparison to the existing curves.
2.0%
0.0%
100 120
Pioe Age (Years)
140
160
180
200
Figure A-2. Comparison of failure curves for vitrified clay and concrete pipe. Source: Martin et al. (2007).
Reprinted with permission.
Recently, EPA conducted a system audit and determined that SPU should conduct CCTV inspections of
all collection system piping within the next 6 to 7 years. To meet EPA requirements, SPU will conduct
these system-wide CCTV inspections using the risk model to establish a risk-based inspection schedule.
SPU will continue to improve the inspection program, balancing the need to maximize ratepayer value
while meeting EPA requirements.
References
Martin, T. (2004). Seattle Public Utilities Asset Management Sewer Pipe Risk Model. Presented at
Leading Edge Asset Management Conference, San Francisco, and CA. July 27, 2004.
Martin, T., Johnson, D., and S. Anschell. (2007). Using Historical Repair Data to Create Customized
Predictive Failure Curves for Sewer Pipe Risk Modeling. In Proceedings of LESAM 2007 2nd
Leading Edge Conference on Strategic Asset Management. London, UK: IWA Publishing.
Contact: Terry Martin, Acting Director of Asset Management and Economic Services
Phone: (206) 615-1744
E-mail: terry.martin@seattle.gov
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Data Management Case Study - Huntsville, Ala.
Lessons Learned
Prior to applying an advanced asset management software tool, the City of Huntsville had no direct link
between CCTV data and GIS data, which made locating and evaluating inspection data a difficult task.
Huntsville has learned that it is important not only to link CCTV data to a map, but to also to integrate
CCTV data with other inspection and repair data. When viewed together, the various data help "tell the
story" of an asset and its condition over time.
While implementing this software tool, the city found many discrepancies in existing GIS and condition
assessment records. These discrepancies were readily identified when GIS records and condition
assessment records were compared. At first, this comparison created additional work to resolve
discrepancies in existing records. However, the end result was a more accurate and accessible database of
historical system conditions. Prior to implementing a similar program, other utilities should review the
type of data needed for their asset management programs, including CCTV inspection data, and make
sure that the asset numbers used are consistent with available GIS data.
Although the city has not yet achieved reductions in the cost of CCTV inspections or improved
performance of CCTV crews as a result of implementing the new data management software, the city
expects to realize cost reductions in the future as staff members become more proficient at data analysis
and decision making related to prioritizing sewer lines for inspection. The new software has improved
the accessibility to and dissemination of inspection data among city staff.
The city has also found that data management objectives change and expectations increase as staff
members become familiar with the new software product and as initial objectives and expectations are
met. The key is finding a solution flexible enough to change direction with the city's evolving needs.
Background
The City of Huntsville provides sewer service to a total population of 170,000 within the city limits. It
also serves the City of Triana and a small portion of the City of Madison. The average daily flow is about
22.7 MGD and is distributed to five wastewater treatment plants.
The first significant parts of the collection system were built in the late 1950s and early 1960s. Currently,
the collection system includes over 1,250 miles of sanitary sewers, with an average age of 28 years. The
system does not include any combined sewers. Sewers are constructed of a variety of materials, including
vitrified clay, poly vinyl chloride (PVC), ductile iron, cast iron and concrete. Sewers range in diameter
from 6 to 60 in.
Huntsville conducts CCTV inspections using two in-house crews. The inspections cost $0.95 per foot of
pipe. A local contractor has also been retained for on-call work, and other contractors are used
periodically as needed. The city does not use outside contractors frequently enough to establish typical
unit costs. The city has conducted CCTV inspections for many years and continues these activities as an
integral part of its asset management program. The average inspection frequency for sanitary sewers is
about seven years.
CCTV inspections are conducted for a variety reasons, including acceptance of new sewers, O&M, and
condition assessment. New sewers are inspected prior to acceptance and prior to the expiration of their
warranty period. Existing sewers are inspected to investigate blockages and overflows, identify sources
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of I/I and facilitate repairs within the system. Sewers are also inspected in conjunction with other public
works activities, such as road resurfacing projects.
CCTV inspections are conducted using analog-type cameras. Video images are recorded in a digital
format on the CCTV trucks. The city has no digital or zoom cameras; however, it has taken an important
step by incorporating CCTV inspection data and digital video files into a GIS-based application which
allows managers and engineers to quickly review CCTV inspections in context with other inspection and
repair data. Now, CCTV inspection data and video are easier to access, examine and compare with
related data. This allows managers and engineers to better understand the condition of the system and
plan and manage O&M and rehabilitation programs.
Summary of Data Management System
Pipe defects are coded in accordance with the PACP-certified inspection protocol. This provides data
reliability. A second level of data reliability is the ability to validate that the CCTV data matches GIS
data. CCTV inspection data are imported into a commercially available GIS-based asset management
software application named InfoNet, developed by Wallingford Software
(http://www.wallingfordsoftware.com/products/infonet/). Data are imported into InfoNet by city
personnel via a PACP-compliant database. The import process uses several data queries to assess data
quality and identify inconsistencies with existing GIS data. InfoNet is also used to import GIS data from
the city's GIS Department and other inspection data and repair records from internal and external sources.
The city began using InfoNet in 2006, and it was first used to maintain and evaluate manhole inspection
and smoke testing data from an outside contractor. Supporting CCTV inspection data from in-house
crews were then added to develop a more complete condition assessment of the inspected areas. Since
then, the use of InfoNet continues to expand.
Software/Hardware Requirements
Windows 2000 or XP is required to run InfoNet. Ten gigabytes of local free disk space are recommended
for optimal use. The InfoNet master database is often maintained on a server and accessed by multiple
users. Huntsville has not encountered any data storage limitations to date.
Software training is recommended for all new users, and further training is recommended for more
advanced users. Annual software support includes software updates, as well as telephone and Web-based
support provided by technical services representatives based in Fort Worth, Texas.
Costs
InfoNet user and viewer licenses are available, and the unit cost varies with the number of licenses that
are purchased. Huntsville currently owns one user license and four viewer licenses. The user license was
purchased in 2006 for about $15,000, and the annual support fee is about $2,500. The viewer licenses
were purchased for about $6,000 each, and the annual support fee is about $900 per viewer license.
Advantages:
• "Off-the-shelf software application.
• View CCTV inspection data in GIS-based environment.
• View CCTV inspection data in context with data from other sources.
• Powerful structured query language functionality to analyze data.
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Disadvantages:
• Requires more proactive attention to maintain integrity of GIS data.
• May require minor modifications to existing data gathering procedures.
• May overwhelm new users until training is completed.
The InfoNet software application is now used by the Huntsville to maintain all CCTV inspection data and
actively manage its in-house pipe cleaning program. With the addition of inputting sewer pipe cleaning
records into InfoNet, the utility expects that this information will soon begin to drive CCTV inspection
work. The application also serves as a repository for other inspection and repair data, including:
• Manhole inspection.
• Smoke testing.
• Sewer cleaning.
• Root control.
• Repair/rehabilitation.
• Customer complaints.
• SSOs.
CCTV data are used to help direct grease management and root control efforts, as well as on-going I/I
reduction programs. CCTV data are also used to plan pipe replacement, pipe bursting and cured-in-place
lining projects.
Contact: Mark Huber, Collection System Manager
City of Huntsville
Phone: (256) 883-3767
E-mail: Mark.huber@hsvcitv.com
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Case Study on Comparison of In-House vs. Commercial Data Management System -
Metropolitan Government of Nashville and Davidson County- Metro Water Services
This case study discusses the experience of Metro Water Services (MWS) (Nashville, Tenn.) in changing
from an in-house data management and defect coding system to a PACP-certified commercial software
product.
Lessons Learned
The change from an in-house data management and coding system to a commercial system and
standardized coding has yielded several benefits. Under the new system, inspection data are now quickly
uploaded and available to all MWS employees within 24 hours of inspection and hence duplicative
inspection efforts are avoided. The Granite XP software allows MWS schedulers to know daily exactly
which sewer lines have been inspected, and it eliminates the need to request hard copies of inspection data
and manually update paper maps. Inspection results have been much more consistent with the addition of
PACP coding. Initially, use of the PACP coding system decreased the department's productivity due to
the staffs lack of familiarity with the system. As the staff has adjusted to the new system, productivity
and efficiency have increased. The one disadvantage noted is that the PACP coding can be too detailed,
making it difficult to get complete information when querying for problems.
Introduction and Background
Sewer construction in Nashville began in 1823 with the installation of brick and clay pipes to convey both
storm water and sanitary sewerage to the Cumberland River. In 1884, a cholera epidemic precipitated the
mass construction of sewers in Nashville. As Nashville and Davidson County's population grew, so did
the sanitary sewer system. By 1950, the system had grown to nearly 400 miles of sanitary sewer serving
a population in excess of 300,000. During the 1980s, Davidson County began an aggressive sewer
expansion program to provide sanitary sewer service for the more densely populated areas of the county.
MWS is a department of the Metropolitan Government of Nashville and Davidson County (MGNDC),
which provides drinking water, wastewater and storm water services. Today, MWS's sewer system
serves an area of approximately 739 square miles. The system has approximately 2,740 miles of gravity
sewer lines and 150 miles offeree main. The gravity sewer lines range between 6 in. and 16 ft in
diameter, with the majority of pipes having a diameter of 36 in. or less. The force mains range from 6 in.
to 36 in. in diameter. A summary of pipe size and corresponding mileage is shown in Table A-5
(MGNDC, 2006).
Table A-5. Sewer system inventory
Type of Pipeline
Gravity Sewer
Force Main
Pipeline Length (miles)
<8in.
2,150
60
10 in. to 24 in.
450
60
> 24 in.
140
30
Total
2,740
150
MWS's collection system uses many types of pipe including vitrified clay, brick, PVC, concrete, cast iron
and ductile iron. The system serves approximately 172,000 residential, commercial and industrial
customer connections and a total population of 660,000. Approximately 92% of service connections are
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residential. The remaining 8% are commercial and industrial. There are also approximately 22,000
customer accounts in satellite municipalities or utility districts (MGNDC, 2006). Counties, municipalities
and entities served by MWS include Davidson, Madison, Goodlettsville, Nolensville/College Grove and
Lakewood.
MWS maintains and operates three wastewater treatment plants (WWTPs): Central WWTP, Dry Creek
WWTP, and Whites Creek WWTP. The average daily flow of wastewater transmitted to the three
wastewater treatment plants from August 2005 to July 2006 was 120.7 MGD (MGNDC, 2006).
Estimated average daily flow for 2009 was 129.3 MGD. A large majority (93%) of MWS's sewer system
is solely dedicated to sanitary sewerage, with a small amount (7%) of combined sewers located in
downtown Nashville.
History ofCCTV Use by MWS
MWS began using CCTV in the late 1960s to inspect gravity sewers. The utility first used a trailer-
mounted CCTV unit that employed a manually operated winch to move the camera between manholes.
MWS uses CCTV inspection for many reasons, including:
• Locate defects contributing to leaks during wet weather.
• Identify rehabilitation needs.
• Inspect after clearing line blockage.
• Identify restrictions and other causes of SSOs.
• Identify service locations.
• Investigate customer complaints.
• Conduct routine maintenance.
Currently, Nashville has six cameras with pan and tilt features and two zoom cameras. The city is in the
process of replacing one camera that is 10 to 15 years old. MWS currently has a fleet of six CCTV truck
units, which is maintained and operated by in-house staff. All inspection personnel have received full
PACP Condition Grading System certification in order to ensure that standards are maintained. MWS
uses outside contractors to inspect collection sewers larger than 60 in. in diameter.
Data Management
Inspection data were formerly documented using a labor-intensive process employing VHS tapes and
handwritten inspection forms. The information was then coded in a separate step, which subjected the
data to potential transcription errors. There was no ability to query historic VHS tapes to compare
historic inspections of pipe segments or possibly compare inspections of similar pipe materials.
The department's first CMMS consisted of a Microsoft Access database, which allowed users to input,
view, organize and code inspection data. MWS incorporated an internal (non-standardized) defect coding
system with the database. The internal coding consisted of a 1 to 5 ranking system, with the number 1
meaning "like new condition" and the number 5 signifying "emergency repair needed." In addition,
MWS scanned hand-written CCTV reports for inclusion in the database. Other information tracked in the
CMMS includes date, time and location of routine cleaning activities; specific lines cleaned; equipment
used; identity of cleaning crew; presence of roots, grease or debris; any specific problems; size, material
and length of pipe; and manhole status.
The data management and coding system was designed in-house in the 1990s, based on industry
standards at the time. The system served MWS well, but did not optimize the possibilities available with
the current state of the technology. MWS recognized the need to expand its database management to aid
A-59
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in condition assessment. In 2006, MWS completed a CMOM report, allowing MWS to evaluate its
internal processes and programs. MWS recognized that its current system had several problems:
• The internal defect coding lacked consistency; a segment of pipe inspected by several employees
could be given different ratings by each person.
• Data could not be easily viewed by all personnel; most MWS personnel had to file a request to
obtain any information from the database.
• MWS was not able to use digital video technology that was available; instead, it was limited to
scanned still photographs.
The CMOM report included the following recommendations regarding CCTV inspections, data
management and defect coding:
• Develop and implement standard line condition codes (1 to 5) for use when televising sewer lines.
These codes will be manually recorded on TV Inspection Reports.
• Evaluate the software available for entering standard defect codes from guidelines into CMMS.
• Develop a written standard method of prioritization of all assessment practices.
• Evaluate ways to prioritize the frequency of CCTV inspection for various sewer categories. For
example, new PVC sewers may be inspected less often than old clay and brick sewers.
• Purchase software for TV units that will allow priorities to be entered into the CMMS.
MWS has made major changes to its sewer inspection program in the past three years. MWS replaced its
in-house data management software and inspection coding system with the commercial Granite XP
software (from CUES) and a Hansen-based CMMS, using PACP criteria that provide a standardized
method for defect coding. The new platform provides MWS with the ability to conduct queries such as
comparing multiple inspection results of a particular pipe within the past five years. Query results are
available very quickly and can help MWS determine the root cause of a pipe defect (e.g., pipe material,
pipe age, installation conditions).
Granite XP is a flexible and customizable data collection and management software platform that
integrates CCTV data with MWS's asset and maintenance management data (Hansen software) and GIS
data (ESRI's ArcGIS software). Hansen provides a wastewater network browser, which stores
information and allows it to link items such as maintenance records, complaints, work orders and
inspection reports. The combination of Granite XP and Hansen software permits users to navigate
particular assets and view all inspections. A work order is generated in Hanson and required resources
are selected (labor, equipment, materials). The GIS information is queried and the inspection can
proceed. The data are saved and coded directly into the system. This automates the entry information
and provides the utility with the information needed for decision making. Granite XP has a business
licensing agreement with Hanson and ESRI to work directly with both software platforms.
GraniteXP has many features that MWS considered substantial improvements over its previous system,
including the ability to:
• Import ESRI asset data into Granite XP from a master GIS database.
• Create custom reports that can be saved in PDF, HTML or ASCII file format.
• Search using keyword and filtering capabilities by projects, assets, inspections and observations.
• View video and still images simultaneously.
• Select an observation on a pipe graph and instantly access that point in a video.
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Granite XP has four editions available to meet the needs of the individual users. A brief description of
each edition is given below (further information can be found on the Internet at
http://www.cuesinc.com/Granite-XP.html):
• The Inspection Edition is designed for field use and is often integrated with camera systems to
capture, assess and store inspection data. MWS has five Inspection Edition licenses, allowing the
CCTV crews to upload and submit each day's inspection data on a flash drive.
• The Enterprise Edition allows users to manage inspection information and create customized
reports, videos, still pictures and database files. It can be useful for preparing data for
applications such as GIS and PACP coding. MWS has one Enterprise Edition license, allowing a
staff member to maintain, update and manage the system.
• The Engineering Edition allows users to modify and review data, synchronize inspections,
capture images from playback and generate reports. MWS's three Engineering Edition licenses
allow selected personnel to input daily CCTV data obtained by the inspection crews.
• The Viewer Edition allows users to review and share field data and generate reports. MWS has
licensing for over 50 Viewer Editions.
MWS has found its licensing to be sufficient to meet the department's needs. Every MWS employee has
instant access to view anything within Granite XP. Although Granite XP allows for internet transmission
of data through a wireless server, MWS has chosen to use flash drives instead.
Figures A-3 and A-4 are examples of reports prepared using the in-house system and Granite XP,
respectively. Compared with the older handwritten version, the Granite XP report presents inspection
data in a concise, consistent, easy-to-read format. The report can be quickly viewed by the reader for the
most crucial information, improving efficiency.
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MWS.
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CUES, Inc.
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Phone: 407-849-0190
Fax: 407-425-1569
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The PACP, developed by NASSCO, provides a mechanism for creating reliable descriptions of pipe
conditions. The goal of PACP is to provide the ability to quantitatively measure the difference in pipe
condition between one inspection and subsequent inspections, and to prioritize among different pipe
segments. PACP uses a basic coding method based on a grade of 1 to 5. A grade of 1 is assigned to pipes
with only minor defects, and a grade of 5 is assigned to pipelines with defects needing immediate
attention. Table A-6 gives the grades and corresponding descriptions within the PACP system.
Table A-6. PACP defect grades
5
4
3
2
1
Immediate Attention
Poor
Fair
Good
Excellent
Defects requiring immediate attention.
Severe defects that will become grade 5 defects within the
foreseeable future.
Moderate defects that will continue to deteriorate.
Defects that have not begun to deteriorate.
Minor defects.
MWS is currently on schedule to inspect all of their sewers within an 8-year period. Due to the recent
deployment of Granite XP software and implementation of PACP coding, MWS has not finished the first
full round of inspections.
MWS has historically used a comparison of identified defects with the cost/difficulty of the anticipated
rehabilitation. For example, when a single pipeline defect is identified, MWS will call for a point repair
to physically correct the defect. Utility staff will typically do two point repairs on a line segment, but
once three or more defects are noted, MWS moves towards rehabilitation of the entire line. Entire
pipeline rehabilitation is typically done with cured in-place liners, although other methods have been used
in the past. The service line from the mainline sewer to the property or easement line is rehabilitated at
the same time. MWS has occasionally rehabilitated a line with only one or two defects if the line is under
a busy roadway where the dig and repair methodology is costly and has a high impact on the public. The
new software and coding system has not changed MWS's approach to rehabilitation, but it has facilitated
the process. The Granite XP software has made it easier to search for pipes that are in need of repair.
The use of a standardized defect coding system such as PACP coding allows MWS staff, consultants and
other external data users to easily compare MWS with other systems data without need to learn their
particular defect coding system.
Since the conversion to Granite XP and PACP coding, MWS has noticed a substantial increase in
consistency and efficiency. Listed below are several reasons for the noted increase.
• Improved turnaround time on data: Inspection crews bring in their flash drives at the end of
each business day and upload data to the system. This allows all videos, still photographs and
condition reports to be available to all MWS personnel within 24 hours of an inspection.
• More efficient inspection scheduling: The Granite XP software allows MWS schedulers to
know exactly which sewer lines have been inspected on a day-to-day basis. Inspection crews no
longer double up on inspections because of the time delay of inputting data and using it for daily
operations. Under the previous system, a paper map was used to track completed inspections.
Sewer lines not marked on the map were considered available for inspection. In some instances,
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maps were not kept current with inspections, resulting in the re-inspection of sewer lines that had
been recently inspected.
• Instant access of database: All MWS personnel now have instant access to all information
within the database from their computer. In the past, MWS personnel had to request database
information and wait for it to be printed and distributed.
• Standardized coding: The PACP coding and the corresponding personnel certification have
greatly improved the consistency of the CCTV inspection reports.
As part of its Corrosion and Odor Control Program, MWS uses its CCTV inspection program to monitor
pipe corrosion from industrial entities. MWS compares CCTV data from previous inspections to locate
areas experiencing unusual levels of corrosion. In addition, MWS is attempting to track the origin of
corrosive damage within the sewer collection system and is working on a program that will ensure the
accountability and responsibility of industrial entities that may be damaging the system.
Considerations for New Users
MWS cautions potential new users to expect a significant drop in productivity when first implementing a
new CMMS and defect coding system. Although MWS staff is highly experienced, the change of both a
new software package and a new coding system initially caused confusion. Employees would need to
reference software and PACP manuals in order to complete tasks that had previously been completed in
moments. MWS noted that productivity increased relative to the old system once its personnel adjusted.
MWS would also advise any utility interested in implementing a new data management system to provide
software training to multiple employees. MWS initially assigned one staff member to be solely
responsible for managing the entire database. MWS has since realized that this was a mistake and has
begun training several other staff members.
The only disadvantage to the new system of data management noted by MWS is that the system can be
too detailed. Within the PACP system are multiple levels of coding for defects such as roots, cracks, and
breaks. This has created complications in querying for problems. For example, if the user performs a
search for "roots," only a small portion of the actual root problems within the collection system may be
identified. The others defects may be categorized as "root balls," "root clusters," or another detailed
name that describes the same problem. MWS is currently working to adjust its queries accordingly.
References
Metropolitan Government of Nashville and Davidson County, Tennessee (MGNDC). (2006). EPA
CMOM Self-Assessment Report.
Contact: Kevin McCullough
1616 3rd Avenue North
Nashville, TN 37208
Phone: (615) 862-4840
Email : Kevin.Mccullough@nashville.gov
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Case Study on Use of Digital Scanning and Zoom Camera Technology - City of Hamilton,
Ontario, Canada
This case study discusses the experience of the City of Hamilton in using digital scanning and zoom
camera in its sewer condition assessments.
Lessons Learned
The City of Hamilton makes strategic use of a variety of sewer inspection methods to provide information
for making decisions on infrastructure management. Zoom cameras are used for system-wide inspections
and are useful for selecting pipes that need more detailed inspection. Although a zoom camera provides
less detail than CCTV, it is an acceptable tradeoff for its lower cost and faster inspection time. For pipes
requiring additional inspection, an array of methods is available, including digital scanning. The level of
detail acquired by scanning is superior to CCTV. However, Hamilton has only used digital scanning to a
limited degree because of the cost and pipe size limitations. Hamilton recently received indications that
its contractors may now be able to scan larger pipes, and may also be able to offer costs comparable to
CCTV. This may increase the role that digital scanning plays in Hamilton's inspection strategy.
Hamilton's experience shows the value of selecting methods with different costs and different levels of
detail according to need. The city's ongoing experience also illustrates that newer technologies such as
digital scanning will continue to evolve, and the costs of such technologies may become competitive with
traditional CCTV.
Background
The City of Hamilton's Water and Wastewater division provides drinking water and wastewater services
to a population of 520,000 in Hamilton, Ontario. The system handles, on average, 111 MOD, with a
maximum peak flow of about 159 MGD. The system has a total of 2,700 km (1,678 miles) of sanitary,
combined and storm sewers. The 21% of the system (580 km or 360 miles) is combined; 41% (1,100 km
or 684 miles) is sanitary sewer and 38% (1,020 km or 634 miles) is storm sewer. The system also has 45
km (28 miles) offeree mains. The system dates back to 1850; its average pipe age is approximately 59
years. The system has many deep, critical sewers of large diameter. Pipe materials include clay,
concrete, reinforced concrete and brick. Pipe diameters range from 200 mm (8 in.) to 2,500 mm (100 in.).
Overall Inspection Strategy
Zoom camera technology is used to scan the entire system, and inspection results are then used along with
Hamilton's risk-based decision management strategy to prioritize pipes for further inspection. The
selection of additional inspection technologies depends on the level of accuracy and detail needed for the
particular pipe under consideration. A number of additional technologies are used after the completion of
baseline zoom camera inspections: CCTV, sonar, laser and digital scanning (limited application). New
technologies applicable to wastewater applications are actively investigated and their limitations
considered. Several inspection methods may be needed in order to achieve the desired level of accuracy
for assessing the condition of critical pipes. The use of advanced technologies such as sonar and laser can
be expensive ($15 - $30 per meter or $4.57 - $9.14 per foot, in Canadian currency).
Experience with Digital Scanning
In 2006, Hamilton participated in a pilot test of digital scanning using the SSET system manufactured by
Blackhawk-PAS. This product is no longer available commercially, and technical support is no longer
available. At the time of the pilot test, SSET was the only available digital scanning system. New
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products have since emerged in North America (PANORAMO, Digisewer). Since performing the pilot
test, Hamilton has used digital scanning twice on critical pipes (15 in. (375 mm) clay pipe and 24 in. (600
mm) concrete pipe) and has been very satisfied with the results. The digital scanning inspection was
performed by a contractor. Pipe defects observed during the inspection are coded using the WRc third
edition defect coding standard. Data are stored and maintained in a CMMS. Staff training is the same as
for CCTV; inspectors must be NAAPI (North American Association of Pipeline Inspectors) certified,
which entails training in defect coding in much the same way as PACP.
SSET uses a fisheye lens mounted on the front of a crawler or tractor unit. The annular segment around
the edges is scanned and used to produce an unfolded view of the pipe. The unit travels through pipe at a
constant speed of about 13 ft per minute (additional information can be found on the Internet at
http://www.hydromaxusa.com/sset.html). White LEDs are used for a light source, providing a bright
light that is close to natural light (Karasaki et al, 2001). The unit also includes an inclinometer and a
gyroscope, which permit recording of vertical and horizontal movements, helping to accurately locate the
unit within the pipe (Knight et al., 2009). This facilitates tracking of defects through time. Digital
scanning produces a high level of imaging, picking up more detail than CCTV. It permits the reviewer to
code defects that might not be visible with CCTV. This greater detail also allows a better understanding
of the significance of a defect, rather than only documenting its existence.
The primary drawback with the SSET equipment has been that its effectiveness is limited to small pipes.
Hamilton has only successfully inspected pipes up to 600 mm (24 in.) in diameter. Although the SSET
system has been most effective in small pipes, highly detailed inspections are not needed for the smaller
pipes because their cost of failure is lower than that of larger diameter pipe. The additional cost of
performing digital scanning has not been justifiable. In larger, more critical pipes, a greater level of detail
is needed, but SSET is not effective in these larger pipes due to problems with focal length. Based on
communications with Hamilton's contractor, digital scanning is now being used for pipes up to 5 ft in
diameter. One issue remains: SSET has problems with pipes that are not circular, and many of
Hamilton's larger, critical pipes are oval in shape.
Cost has driven Hamilton's decisions regarding the use of digital scanning rather than CCTV. In its
experience, the field costs are not greatly different than for CCTV because the digital scanner moves
more quickly through the pipe. However, the net cost was greater due to the data processing conducted in
the office. With CCTV, defects are observed and coded in the field. With digital scanning, images are
reviewed and coded in the office, increasing the overall time and labor cost associated with this
technology. Utilities considering digital scanning are encouraged to compare the costs of digital scanning
versus CCTV and make sure that any potential added costs can be rationalized. The cost of inspection
should be weighed against the cost of pipe failure. If net costs are as low as for CCTV, then digital
scanning would be the method of choice due to its superior level of detail. Hamilton's contractor recently
indicated that digital scanning may now have a cost comparable to CCTV. The improved cost, along with
an improved ability to inspect larger pipes, may enable Hamilton to use digital scanning in more of its
system. Hamilton will be exploring this possibility.
Experience with Zoom Camera Technology and Comparison to CCTV
Based on 10 years of experience, Hamilton has found zoom cameras to be a very effective and
economical inspection method and uses the results to decide where to employ CCTV and other advanced
inspection methods. As of May 2008, zoom camera inspections had been completed on 1,441 km (about
895 miles) of main pipelines (about 55% of the network) (Bainbridge and Krinas, 2008). Although zoom
camera technology provides a lower level of detail than CCTV, Hamilton has found that it identifies
enough pipe defects to provide a basis for focusing CCTV and other inspection work.
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Unlike CCTV, a zoom camera does not move through the sewer system. It is lowered into a manhole
chamber, where it remains stationary, rotating 360° along its vertical axis. It is used to inspect all the
sewers that enter the manhole chamber. Each pipe segment gets viewed twice, once from the manhole at
each end, resulting in two ratings for each pipe segment. As with CCTV, Hamilton's zoom camera defect
coding is completed using the WRc third edition.
The viewing distance depends on such factors as pipe deflection, debris, and other obstructions. Based on
zoom camera inspection of 23,566 manholes and associated piping in Hamilton, Bainbridge and Krinas
(2008) found the average inspection distance was 30 m (98 ft); the associated range of pipe sizes was not
provided. The zoom camera cannot see around horizontal deflections (i.e., bends) in pipes; therefore, if
there are a significant number of bends without access points, the utility of the zoom camera may be
limited. Sewers do not need to be cleaned in advance of a zoom camera inspection.
Table A-7 compares the average price and other parameters for CCTV vs. zoom cameras. The zoom
camera technology is several times cheaper than CCTV, and it can inspect pipes much faster. Using a
zoom camera, Hamilton's system can be surveyed in less than half the time that would be required for
traditional CCTV.
Table A-7. Comparison of traditional CCTV with zoom camera technology
Technology
Traditional
CCTV
Zoom
Camera
Adjusted
Inventory,
m (miles)
2,566,000
(1,594 miles)
2,566,000
(1,594 miles)
Average
Price/m
(Canadian
dollars)
$5.74
$0.977
Funding
Requirements
(Canadian
dollars)
$14,728,840
$2,506,982
Average
Production Rate
(Meters/day/crew)
700 m (2,297 ft)
1,875m (6, 152 ft)
Time Required
to Inspect 100%
of Sanitary
Sewers (years)3
10.0
3.8
Source: adapted from Bainbridge and Krinas, 2008, and used with permission
a Based on 365 work days per year.
Hamilton has been able to compare the results of inspections in pipes that have undergone both CCTV
and zoom camera inspection. This analysis provides some understanding of how the two methods differ.
Figure A-5 shows the results of a statistical analysis of condition ratings from CCTV and zoom camera
inspections. It was found that zoom camera and CCTV inspections resulted in the same ratings (zero on
the X axis in Figure A-5) approximately 48% of the time. The assessments differed by a condition rating
of 1 about 31% of the time.
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CCTVVS Zoom Camera Ratings
&ror Deviation
Source: Bainbridge and Krinas (2008). Reprinted with permission.
Figure A-5. Comparison of CCTV and zoom camera inspections.
As another means to assess the accuracy of zoom camera technology, CCTV data were used as a basis to
determine how many defects were located within the zoom camera's functional range. Figure A-6
(Bainbridge and Krinas, 2008) shows the percentages of defects located within 20 m (66 ft) (purple bars)
and 30 m (98 ft) (green lines) of manholes. The x-axis indicates the defect type. About 59% of defects
were found within 20 m (66 ft) of manholes and 76% were within 30 m (98 ft). This analysis provides
some indication of the percentage of defects that are likely to be detected because of their proximity to the
camera.
Bainbridge and Krinas' (2008) analysis suggests that zoom camera technology may not be as accurate as
CCTV. However, Hamilton has found the level of accuracy sufficient for its sewer management strategy.
Hamilton's zoom camera inspection program has resulted in more than 5,000 work orders and beneficial
economic and social impacts.
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RATE OF STRUCTURAL DEFECT CODES WITHIN 20m (30m) OF
•3
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Source: Bainbridge and Krinas (2008). Reprinted with permission.
Figure A-6. Pipe defect location.
References
Bainbridge, K., and Krinas, H. (2008). Efficient condition management of sewer systems using both
zoom camera technology and "traditional CCTV". North American Society for Trenchless
Technology 2008 No-Dig Conference and Exhibition, Dallas, Texas, April 27-May 2, 2008.
Karasaki, K., Shima, H., and Iseley, T. (2001). The coming of age of advanced digital optical scanning
technology for pipeline assessment. Available on the Internet at
http://www.nastt.org/store/technical_papersPDF/85.pdf.
Knight, M., Younis, R., Barrall, B., Russin, J., and Manners, C. (2009). Advances in Pipeline Asset
Management Using Digital Side Scanning Evaluation Technology. North American Society
(NASTT) and the International Society for Trenchless Technology (ISTT) International No-Dig
Show 2009. Toronto, Ontario Canada March 29-April 3, 2009.
Contact: Kevin Bainbridge, Senior Project Manager, Subsurface Infrastructure
77 James St. North, Suite 320
Hamilton, Ontario, Canada
Phone: 905-546-2424, Ext. 5677
E-mail: Kevin.bainbridge@hamilton.ca
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Case Study on Application of Truck-Mounted Zoom Cameras - Hillsborough County Water
Resource Services, Florida
This case study focuses on the experience of Hillsborough County Water Resources Services (WRS) in
using a truck-mounted zoom camera along with in-line CCTV as part of a two-year comprehensive
manhole and gravity sewer inventory and condition assessment project.
Lessons Learned
WRS has gained valuable experience from its successful condition assessment project. Lessons learned
include the following:
• If a large-scale project assessment is proposed, a pilot project demonstration of the field and
office procedures should be conducted to ensure that proper procedures and appropriate quality
assurance and quality control data protocols are in place.
• Using zoom camera technology as the first step in field review has proven to be effective, both
for acquiring technical data in a timely manner and for maximizing cost benefits.
• Regular communication with customers is critical for large-scale field-intensive projects. It is
important to clearly define the authority the contractors have in the field in dealing with
customers.
Utility Background
WRS provides water, wastewater, and reclaimed water services to approximately 483,000 customers in
unincorporated Hillsborough County, Fla., with minor overlap areas with the cities of Tampa and Temple
Terrace. Located northeast of Tampa Bay on the central Gulf Coast of Florida, WRS was formed in the
1970s by purchasing and centralizing many small franchise utilities. In the early 1980s, WRS undertook
a major construction program to regionalize the system into two service areas, eliminating many
franchises. At the time the project was initiated, the county was growing at an annual rate of 3 to 4 %.
WRS currently manages infrastructure worth more than $1.2 billion.
The county's wastewater systems consist of one secondary wastewater treatment plant and six advanced
wastewater treatment plants with more than 692 pumping or lift stations. The annual average daily flow
is 36.4 MGD. The collection system includes 655 miles offeree mains and approximately 1,268 miles of
gravity sewer pipelines ranging from 4 to 42 in. in diameter. The sanitary system is 100% separate from
the storm water system. Although parts of the system are very old, the average age of the entire system is
close to 25 years, with a remaining useful life of 15 to 20 years. Eighty percent of the gravity sewers are
constructed of PVC and 20% are vitrified clay pipe (VCP). The system also includes approximately
31,045 manholes constructed of pre-cast concrete (88.3%) and brick (10.2%) (Kirby et al., 2008). The
PVC pipe has an average age of approximately 20 years and an estimated remaining useful life of 40 to
50 years. The average age of the VCP pipe is approximately 40 years.
In 1998, WRS decided to change from a reactive run-to-failure management approach to a proactive
approach. A 20-year capital improvement program was established through rate increases and
refinancing plans in order to rehabilitate, repair or replace assets known to be at imminent risk of failure.
In 2003, WRS began development of a Comprehensive Asset Management System (CAMS) program to
address its aging infrastructure, to develop a proactive maintenance program and to address the problem
of having a wide assortment of software systems that did not communicate with each other. A CMMS
was selected as the backbone of the CAMS. In order to populate the CMMS with accurate and
comprehensive data, inventory and assessments of all WRS assets were undertaken. The evaluation was
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broken down into two parts: above-ground assets at plant or pump station sites, and linear assets of the
collection and distribution system. The assets were further broken down into manholes and gravity pipes;
hydrants, valves and large meters; plant and pump station equipment; and pressure pipes.
Project Objectives
In May 2006, the utility began a two-year comprehensive manhole and gravity sewer inventory and
condition assessment project. The principal objectives of the project were to:
• Locate all manholes (on road, off road, and in easements) and cleanouts with survey-grade GPS
coordinates.
• Inspect all manholes and pipelines.
• Find the immediate maintenance and structural needs.
• Clean and obtain detailed information about structural defects in manholes and pipelines
requiring attention in the short term.
• Establish the maintenance and structural condition of each asset.
• Provide GIS and CAMS attributes in a format easily integrated into the existing software
databases.
Project Approach and Planning Steps
Knowing that the collection system was relatively new and constructed mostly of PVC pipe, WRS
anticipated that its gravity sewer system was generally in good condition. Based on CCTV inspections
conducted from 1973 to 1998 using analog cameras, WRS estimated that only about 20% of the gravity
sewer system would require maintenance or structural improvement.
An investigation of new inspection technologies was conducted to see if costs and time could be saved by
employing new technologies or condition assessment processes. WRS chose to use a combination of
zoom camera and in-line CCTV inspection technology and to use a third-party inspection company,
InfraMetrix LLC of Tampa, to locate immediate maintenance and structural defects and to document with
video the maintenance needs and structural condition of manholes and pipelines. According to
InfraMetrix, inspection with zoom camera technology was four times faster than conventional in-line
CCTV and was less expensive. Conventional in-line CCTV was used to inspect only pipelines that had
failed or where failure was imminent and to provide important condition information for future
maintenance and capital planning.
Prior to initiating fieldwork, InfraMetrix developed an implementation plan that included descriptions of
the project procedures and protocols. The plan was submitted for county approval. The implementation
plan was tested on a pilot scale to demonstrate the efficacy of the field and office procedures and to allow
the WRS to modify the plan before a significant amount of data were collected. The pilot program began
in September 2006 and involved inspections of 1,000 manholes and connecting pipelines.
One of the greatest challenges of the project was to develop and implement an efficient and effective
strategy for data management. During the pilot project, daily procedures and software applications were
developed to manage collected survey, inspection and condition assessment data. To ensure compliance
with existing county systems, InfraMetrix conducted a number of data source reviews and process design
sessions with WRS and its program manager. Using input from these sessions, procedures were
developed to manage data for the duration of the project (Kirby et al., 2007). Quality assurance/quality
control (QA/QC) protocols were applied to the survey-grade GPS coordinates, and in-house QA/QC
procedures were performed to check the quality of physical characteristic, inventory, and condition of the
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data. Based on the results of the pilot project, minor refinements were made to customize the field and
office procedures to best fit the county's needs (Kirby et al., 2007).
Inspection Program
The assessment portion of the project included inspection of gravity sewers with zoom camera and
standard in-line CCTV inspection technology, where warranted, to collect physical attribute and condition
data. The initial inspections were conducted using zoom camera technology from street level. Manholes
and pipelines located within the right-of-way and within 400 ft of the right-of-way were inspected using
truck-mounted zoom camera inspection equipment (see Figure A-7). Manholes and pipelines located
more than 400 ft beyond the right-of-way were inspected using a tripod mounting for the zoom camera
instead of the truck-mounted boom and mast.
Source: CUES, Inc. (2009). Source: CUES, Inc. (2009). Reprinted with
Reprinted with permission. permission.
Figure A-7. Truck-mounted zoom Figure A-8. CUES-IMX optical zoom camera.
camera.
The CUES-IMX camera (Figure A-8) has a 25:1 optical zoom lens that is stabilized and remotely
controlled by a telescopic boom. The camera mounting fork is designed to pan the camera head 360°
continuously, tilt mechanically 45° up or 90° down and tilt optically 166°. The CUES-IMX system
includes the camera, high-intensity discharge (HID) lighting heads, mast system and controller.
According to vendor literature, the CUES-IMX camera can view up to 75 ft of 6-in. diameter pipe
segments; however, the reader is advised to verify such claims with field data. More information on the
technology can be found on the Internet at http: //www. inframetrix. com and http: //www. cue sine. com.
Figure A-9 shows how the zoom camera is inserted in the manhole and the types of pipe defects that can
be identified.
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Source: InfraMetrix LLC (2008). Reprinted with permission.
Figure A-9. Examples of pipe defects identified with zoom camera technology.
The software and GPS equipment in the zoom camera truck are used to create sewer maps in the field,
locate defects, and capture video and photographic documentation of the condition of the sewer system.
Inspection data are geo-referenced to GPS coordinates collected in the field. Video records of manholes
or other vertical structures and pipelines are provided on graphically indexed CD-ROMs, DVDs, or hard
drives linked to the GIS maps.
According to the vendor, the cost to inspect manholes or other buried structures starts at $45 per structure.
Prices vary based on location, depth, and required deliverables. Because zoom camera inspections do not
require confined space entry or pipe cleaning prior to inspection, more pipe footage can be inspected for
less money than by using other inspection methods. The vendor claims that pipeline inspection with
zoom camera technology can be performed for about one-third of the cost of in-line CCTV. A utility
should budget $1.00 to $2.00 per linear ft for a system-wide gravity sewer assessment. This cost will
cover collecting GPS coordinates for manholes, mapping, inspection of manholes and pipelines by zoom
camera, data management (creating/updating GIS and work order management databases to include
physical characteristic data and condition data), cleaning and performing in-line CCTV inspection of
pipelines that require immediate attention and prioritizing future inspection, maintenance, and
repair/rehabilitation activities.
Following completion of the pilot-scale program, the countywide program was initiated in January 2007,
beginning in the northern- and southern-most extremities of the county and moving toward the center.
Five work crews inspecting an average of 30 manholes and connecting pipelines per day per crew were
needed to complete the project in the two-year timeframe. According to InfraMetrix, a two-man crew can
inspect approximately one mile of pipe per day with manholes and about two miles of pipe per day
without manholes. A typical manhole and pipeline inspection can be performed in 15 to 20 minutes,
according to the company.
To determine the internal condition grade for each pipeline, a team of PACP-certified viewers reviewed
the manhole and pipeline videos produced from both zoom and in-line CCTV cameras. The viewers
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considered safety issues, structural defects, evidence of previous I/I, active infiltration sources, and debris
accumulation recorded by the video cameras to determine an internal condition grade for the manholes
and pipelines. This assessment was done in accordance with the defect codes for a modified MACP for
manholes and PACP for pipelines developed by NASSCO. Each manhole and pipeline was given an
internal structural condition grade and an O&M and construction condition grade. Data were stored using
SPL Enterprise Asset Management Software.
An external condition grade was assigned to each manhole and pipeline considering soil conditions,
evidence of surcharging, depth to water table, evidence of previous failure, pipe slope and depth, evidence
of subsidence, evidence of corrosion, location (e.g., grass, pavement, near wetlands), evidence of surface
depression, and difficulty to access.
All pipelines determined to have a PACP condition grade of 3 or higher were recommended for cleaning
and further inspection with conventional inline CCTV equipment. These recommendations were
submitted monthly to the county's program manager for review and approval of the work. These
pipelines were cleaned and inspected during the project, resulting in no pipelines with an O&M grade
equal to or greater than 3 at the completion of the project. Approximately 1,500 manholes were
scheduled for rehabilitation.
The sewer system was found to be in better condition than expected. This resulted in significant savings,
which allowed InfraMetrix to provide additional support including:
• Developing a standardized manual that includes procedures for data collection, cleaning and
CCTV, and emergency responses.
• Providing recommendations for job codes for generating work orders from the MACP and PACP
defects.
• Developing a methodology for prioritizing future maintenance and capital improvements.
• Determining useful life and remaining life for the manholes and pipelines.
• Providing manhole and pipeline improvement recommendations.
• Presenting the findings and conclusions in a report on maintenance and capital planning.
The project was completed approximately $1 million under budget. These funds were set aside to pay for
the rehabilitation of manholes and pipelines assigned a structural condition grade of 4 or 5. WRS
estimated that it saved approximately $11.4 million and 3,200 crew days with the inspection approach
combining zoom camera technology and in-line CCTV.
The video information and physical characteristics captured in the inspection data were used to develop
proactive O&M and capital improvement programs for pipe renewal and replacement and to improve the
accuracy of hydraulic models. As an added bonus, the video inspection files provide an accurate visual
condition assessment that can be used in case a hurricane leads to debris accumulation or structural
damage in the sewer system. The information can be used when applying for Federal Emergency
Management Agency (FEMA) disaster reimbursement.
The schedule and inspection frequency of future manhole and pipeline inspections are based on the risk of
failure. This risk evaluation is based in part on a risk score, calculated by multiplying the condition grade
by a criticality factor. The criticality factor ranges from 1 to 9 and indicates the severity of the
consequence of failure. It takes into account a variety of factors such as depth of the pipe, the overlying
street and traffic conditions and the type of service (e.g., hospital, school). The system also has a built-in
"fudge factor" in case there is a compelling reason to change the criticality that is not already included in
the criticality factor. Once the risk score is calculated, it is used along with other information such as pipe
age and material to prioritize and schedule inspections as well as O&M and capital needs for the future.
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Problems Encountered and Resolved
During this two-year comprehensive manhole and gravity sewer inventory and condition assessment
project, several problems occurred in gaining access to private property and locating buried manholes.
County staffers were brought in to assist in gaining access; multiple attempts to contact residents were
needed in some cases. Specific problems encountered and recommended actions are listed below.
• Cleaning operations may result in customer claims - must be responsive to customer concerns.
• High flows may limit inspection - must anticipate working at night when flows are low.
• Private pumping stations connected to public sewers produce unexpected flows at unexpected
times - must be patient and plan ahead.
• Manholes may be located under sheds, fences and pool decks within backyard easements and
buried under pavement - allow enough time to locate and uncover manholes.
WRS also found grease to be an ongoing problem. Pipelines that had to be cleaned due to grease build up
were likely to need cleaning in a relatively short time to prevent blockage. Some areas were more prone
to this buildup than others.
Considerations for New Users
WRS recommends that utilities define project objectives as early as possible. Establishing a thorough
scope and standards in the planning stages will minimize changes through the life of the project. WRS
did make some relatively minor changes to the scope of contractor duties after the start of the project.
These included taking still photos of defects to assist line maintenance staff in repairs; defining effort and
time for difficult to locate assets needing extraordinary effort; developing a method to add newly
completed assets to the scope during the process; and making minor improvements to customer
notification. These minor scope changes could have been included in the original project scope.
With dollars being limited for most utilities, a utility might choose to survey representative areas for
analysis and develop predictive methodologies based on information gathered. However, in the long
term, it is recommended that all assets be inspected. When the county initiated this program, minimal
data were available from similar projects. As more utilities pursue this type of system analysis, more
information is becoming available to help in the planning.
Conclusion
According to WRS staff, the main project objectives were met. WRS developed an inventory of system
assets including their location and physical condition. The county now has good asset data that can be
used to prioritize current capital and operational needs and to plan for future maintenance and capital
needs.
References
InfraMetrix LLC. (2008). Gravity Sewer Assessment Using Zoom Camera Technology. InfraMetrix
LLC, Tampa, Fla..
Kirby, Richard, Richard Cummings, and William DiTullio. (2007). Asset Management in Practice:
Lessons Learned from Hillsborough County. Underground Infrastructure Management,
S eptember/October.
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Kirby, Richard, William DiTullio, and Ron Thompson. (2008). Hillsborough County Fla. 's Sewer Asset
Management Program Pays Immediate Dividends. Underground Infrastructure Management,
November/December.
Contact: Richard Kirby, Chief, Utility Technical Design Team
Hillsborough County Water Resource Service
Tampa, Fla.
Phone: (813) 272-5977 Ext. 43332
E-mail: kirbyr@hillsboroughcountv.org
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Data Management Case Study - Northern Kentucky Sanitation District No. 1
This case study describes the enhancements to the District's data management system and the
improvements implemented in data flow from field collection through analysis.
Lessons Learned
Northern Kentucky Sanitation District No. 1 (District) was eager to show progress in making collection
system improvements to support their CMOM program. In 2006, the District accelerated the pace of field
evaluations and system improvements. At the same time, planning was initiated and improvements were
made to the data management system (DMS). The District realized that large amounts of valuable data
were being collected, but data analysis and identification of correction actions were not being performed
in an efficient manner. The District also realized that field tasks were being duplicated in the office,
which was both frustrating and costly.
The lesson that became evident was the value the DMS provided in the execution of fundamental work.
DMS improvements were given a higher priority and specific data flow logic was carefully reviewed in
order to:
• Ensure that the correct data were being captured in the field.
• Understand what short-term and long-term decisions the data would support.
• Ensure that data were properly stored so that future retrieval would be easy and convenient.
Background
The District's sewer system covers approximately 200 square miles over 33 communities in three
counties (Boone, Kenton and Campbell), and serves approximately 98,000 customer accounts and
245,000 customers. The collection and treatment system service area (Figure A-10) is composed of
approximately:
• 49,586 manholes.
• 3,769 catch basins in the combined sewer system.
• 1,665 miles of sewer lines (10% combined and 90% separate sewers).
• 141 pump stations.
• 15 flood pump stations.
• Two regional wastewater treatment plants (WWTPs) and eight small WWTPs with a total
average daily flow of 36 MGD and a maximum flow exceeding 55 MGD.
The majority of the collection system is 50 to 100 years old, with diameters ranging from 8 in. to 120 in.
The common pipe materials are concrete and clay for smaller sewers, and brick and rock for sewers over
48 in. Since the 1970s, PVC has been used for new sewers 4 to 18 in. in diameter. PVC constitutes
approximately 25% of the current system.
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Combined sewer area
Separate sewer area
WWTPs
Storm water service area
Figure A-10. Sanitation District No. 1's service area.
Data Management for an Asset Management-Based Approach to Corrective Action Prioritization
Sewer System Assessment Program: During its CMOM development, the District decided to develop a
more proactive collection system inspection, cleaning, and rehabilitation/replacement program. The
District also established a coordinated approach to address both the Nine Minimum Control requirements
for the combined sewer system and the CMOM requirements for the sanitary sewer system. In concert
with the CMOM self-assessment and the Nine Minimum Control activities, the District began a holistic
Continuous Sewer Assessment Program (CSAP) in 2007. This formalized CSAP guides the District's
assessment and rehabilitation/replacement work, and many collection system data management activities.
An objective of the CSAP is to take a proactive and coordinated asset management-based approach to
assess the infrastructure's condition and manage corrective actions. Through the CSAP, the District can
more effectively prioritize and implement system inspection, cleaning, and rehabilitation/replacement.
This will enable the identification of wet weather I/I sources, ensure sufficient capacity in both dry and
wet weather, and reduce SSOs.
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The CSAP is a high-level program consisting of several specific CMOM activities supporting the
collection system. Six O&M programs are incorporated into the larger scale CSAP:
• Trouble call.
• Preventative O&M.
• Sonar.
• Sanitary sewer evaluation survey.
• Large diameter sewer assessment.
• Manhole inspection.
Assessment Prioritization Approach: A key component of the CSAP is the prioritization of assets for
assessment and subsequent rehabilitation or replacement. Typically, the basin areas where problems are
known to exist or where there is a high likelihood of problems should receive the most immediate
attention and inspection. Other factors, such as consequence of failure (criticality), also play a key role in
prioritization. The CSAP data management system enables basin prioritization to be completed using a
comprehensive and easily retrievable dataset. This is preferable to the more traditional pipe age and
material projection methods used when data are limited or are not supported by a sophisticated data
management system.
The following data categories were selected for each basin to produce a basin score and corresponding
basin rank:
• Service performance priority (measures risks of blockages).
• Structural performance priority (measures risks of collapse).
• Work order history priority (used to estimate frequency of problem occurring).
Although these criteria will dictate most of the sewer and manhole inspections, there are certain assets or
groups of assets which require priority inspection, regardless of basin priority:
• All major sewer interceptors and large combined sewers inspected with zoom camera and sonar
techniques.
• All sewers within 50 ft of major creeks.
• All sewers downstream of SSOs.
• All sewers in basins that have I/I percentages greater than 10%.
The District is allocating resources in the most cost-effective manner by performing earlier initial
inspections and more frequent re-inspection of high priority areas. It is estimated that the entire collection
system (approximately 7.9 million ft) will be inspected via CCTV within 10 years, with re-inspection of
critical assets occurring throughout the 10-year cycle.
The lower priority sewers and newer sewers are inspected after year five of the program. The CSAP
provides the data needed to focus cleaning, rehabilitation and replacement on the sewers with the greatest
need. The re-inspection process informs cleaning or rehabilitation decisions, resulting in a more cost-
effective program. This approach reduces the risk of service-related overflows compared to a linear
inspection and cleaning approach (start at the top of the system and progress downward). An example
projection of CCTV and zoom camera needs through the year 2017 is shown in Figure A-l 1 (2008
CMOM self-assessment report).
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Projected Annual Inspection Footage Including
Zoom Camera
2,000,COO -
1,800.003 -
1,600,300 -
1,400.000 -
1,200.030 -
1,000.000 -
800.000 -
600,000 -
400,000 -
200,000 -
2010
2011
2012 2013
Year
Source: Image courtesy of Northern Kentucky Sanitation District No. 1.
Figure A-ll. Example District projection of the CCTV and zoom camera needs through 2017.
Basin inspections are divided into three phases based on their priority scores:
• Phase 1 comprises all basins with priority SSOs and other basins with known problems. Priority
SSOs have been identified as part of the watershed plans development.
• Phase 2 comprises all other basins with listed SSOs under the consent order with the state and
federal regulatory agencies and other basins with problems that are not as concentrated as Phase 1
basins.
• Phase 3 comprises newer basins where available data show few structural or service related
problems.
CSAP Data Collection and Management: Each of the six CSAP programs listed above includes an
assessment phase using appropriate inspection technologies such as CCTV, zoom camera, smoke & dye
testing, sonar, and visual inspection. This is followed by an action phase such as cleaning and
rehabilitation/replacement. Data for each of these programs are integrated and designed to support the
correction actions.
Collection System Inspection Approach: The primary data used by the District engineering staff for
condition assessment are obtained by CCTV and zoom camera inspections. The District operates a fleet
of five CCTV inspection vehicles (from a variety of manufacturers), which are fully equipped with
cameras, control units, rods, and other items necessary to perform CCTV inspections. This technology
enables surveying of pipes ranging from 6 to 48 in. in diameter. CCTV technology also enables District
crews to record audio information and observations while observing pipes in the field. Once the video is
captured and the data uploaded on the server, the data are converted to a condition score. The resulting
score and additional analysis determine whether the asset needs to be placed in the preventive
maintenance work program, or if it requires rehabilitation or replacement. District crews use the
SCREAM™ defect coding system developed by CH2M HILL. SCREAM™ is not a specific software
package, but a condition assessment protocol that allows inspection and testing results to be converted to
a numerical score that "ranks" each asset according to structural, O&M, and I/I concerns.
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In addition to the CCTV work performed by District crews, large diameter and some smaller diameter
sewer lines in the collection system are inspected by contractors using zoom camera screening
technology. A zoom camera is a high-powered, high-optical zoom video camera that provides a rapid
evaluation of a collection system. The results of the zoom camera screening inspection are used to
identify where cleaning or detailed CCTV inspections are needed to further assess defects. In some cases,
however, the zoom camera inspection provides sufficient condition information to move forward with
rehabilitation/replacement planning, and further CCTV inspection is not necessary.
Engineers use the zoom camera and CCTV results, combined with other information such as the sewer's
location, slope, depth and complexity of construction, to decide whether the work will be done with in-
house staffer contractors. To help expedite decision making, the District developed an automated
corrective action process that models the staffs decision logic for high priority assets. The decision
model is a SCREAM™ module that evaluates the type and grouping of defects and identifies initial
corrective action decisions. It overlays these suggested corrective actions with the asset's physical
condition information in order to produce a more definitive corrective action (e.g., repair, rehabilitation,
replacement, or further investigation). Costs are also assigned, which helps the engineering staff prepare
capital investment program (CIP), maintenance budgets, and schedules.
Data Collection and Management: gbaMS (GBA Master Series) is central to many daily functions.
Therefore, one of the goals of CSAP is to use gbaMS as the primary tool for data collection and
automation, with much of the key data integrated with the GIS. The integration of the data with the GIS
allows personnel from many different disciplines and backgrounds to view data in the same way,
facilitating a standard decision-making process.
Prior to implementation of the CSAP, field data were either collected directly within gbaMS mobile
master or were entered on hard copies in the field and then entered into gbaMS by office staff. In the
early planning stages of the CSAP, the District recognized the need to improve this data handling process
by integrating and automating the movement of field data into gbaMS. Automated future actions and
work orders would also need to be generated within gbaMS. The District selected CH2M HILL's
SCREAM™ inspection analysis methodology and SQL database integration logic because they allow the
results of single or multiple inspection technologies (e.g., smoke testing and CCTV performed on the
same asset) to be scored and compared to other assets. The SCREAM™ CCTV and manhole inspection
analysis is based on a comprehensive multi-attribute method using logarithmic functions to aggregate and
score the array of multiple defects that can occur on a single asset. For Northern Kentucky, CH2M HILL
coordinated the SCREAM™ system within the agency's existing use of the gbaMS software.
The SCREAM™ methodology and logic also allow existing CCTV and sonar pipe inspections performed
using the NASSCO's PACP CCTV codes to be mapped to the SCREAM™ codes for standardized
SCREAM™ scoring. This information can be exported to gbaMS for additional analysis and
determination of next actions. An example of how the data are linked among the various applications is
shown in Figure A-12.
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CSAP Tool
(SQL Database and procedures)
Applies Logic
Source: Image courtesy of Northern Kentucky Sanitation District No. 1.
Figure A-12. District 3's CSAP Data Flow Chart.
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Data Software/Hardware: The district uses gbaMS as its CMMS. As noted above, gbaMS is central to
the district's daily functions and the district aims to use gbaMS as the primary tool for data collection and
automation.
The District uses numerous gbaMS software products for management and maintenance of infrastructure
assets. The module-based, customizable applications promote effective data management practices.
Other gbaMS modules used include: GIS Master, Sewer Master, Work Master, and Equipment Master.
The gbaMS software generates an extensive variety of reports and can export data into spreadsheets.
Each of the gbaMS modules provides a wide range of data and work management functions that are
completely integrated to assist the district in establishing a maintenance plan, setting priorities, providing
timetables, tracking system rehabilitations, and giving direction on effectively maintaining the system. A
large number of pre-defined reports are contained within gbaMS and can be modified, or additional
reports can be created using Crystal Reports, which is a software application used to design and generate
reports. Detailed and summary reports compile the results and are accessed in three ways: through the
gbaMS application, the CSAP administrative interface, or reports created with SQL Server Reporting
Services and made available through the District's portal ftp site.
For sewer condition assessment, the district uses SCREAM™ software, which provides a standardized
defect coding system and a definitive scoring and ranking process, eliminating subjectivity by the
operator. Each defect is coded so that it has a category, type and severity associated with the code. The
scores for each pipe segment are based on a scale of 1 to 100 for structural, maintenance, and I/I
conditions. This allows for a better understanding in assigning relative risks posed by the asset and what
corrective actions are needed. The gbaMS and SCREAM™ data reside in SQL 2005 in their own
databases, which can share data with each other.
An additional database, CSAP (Figure A-13), was created and serves as a hub, pulling data from gbaMS,
SCREAM™ pipe, manhole defect coding databases, and template databases. The template databases are
used for storing and reviewing the quality of contractor data collected with NASSCO's PACP system.
The CSAP database is used for data compilation, pipe scoring based on the defects within the inspection
report, and application of the next action decision-making logic as outlined by the CSAP Process
Diagram. The predetermined procedures stored in the SQL server apply the logic and generate the next
action to take. Actions might be a list of prioritized pipes and manholes needing immediate rehabilitation
or replacement, future sonar and CCTV pipe re-inspections, future cleaning activities at differing intervals
or prioritized groups of pipes and manholes that require rehabilitation/replacement as part of a larger scale
basin-wide project. An administrative interface allows modification of CSAP logic as needed.
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Figure A-13. Example SCREAM™ scoring displayed in gbaMS.
Once the list of prioritized assets is created, the work orders are scheduled from the CSAP database logic
for future inspection and cleaning activities. The following information is taken into account in
scheduling the work:
• SCREAM™ scores.
• Number of pipes needing inspection or O&M that month.
• Location of assets (basin, street, and x/y coordinates).
• Amount of footage to be inspected per year.
• Number of crews available.
The gbaMS and GIS database(s) were analyzed for relationships and data commonalities. As a result, a
data and process flow model was developed to represent the CSAP and GIS data integration.
Based on the initial inspection results, the following actions are taken:
• Sewers with high maintenance scores in need of cleaning are cleaned and scheduled for re-
inspection in approximately six months to one year.
• Sewers in good condition with no need for cleaning or repair are scheduled for re-inspection in
one, three, or five years depending on the inspection scores for the pipes.
• Sewers with high structural scores in need of repair are brought into the
rehabilitation/replacement program to be properly addressed.
• Sewers are scheduled to be rehabilitated or replaced either immediately (collapsed pipe) or as part
of a basin-wide rehabilitation/replacement project. These sewers are also coordinated with the
District's watershed plans to ensure that watershed plan projects are properly incorporated into
the sewers' overall solution.
Utility Comments on Implementing New Databases and New Defect Coding System
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The district experienced initial challenges in implementing a new process such as the SCREAM™ codes.
Some of the field staff was initially reluctant to make the change. District management resolved this by
ensuring that the field staff clearly understood the purpose and benefits of these changes, listening to their
responses, and promptly responding to their legitimate concerns. For instance, the engineering staff made
every effort to clarify how the field data were converted into usable information to make key decisions on
spending the District's limited resources more efficiently.
The District has stressed the importance of leveraging the value of accurate and representative field data
throughout the decision-making process. For instance, the CCTV data and analysis process was reviewed
and modified to capture data to support specific district policies. An example is the terminology of
CCTV codes for the various methods by which service laterals are connected to the mainline sewer pipe.
By coding with nomenclature familiar to the field crews, the engineering staff was more assured that
CCTV reports would be reliable when deciding how to resolve service lateral issues. At the same time,
the crews became engaged in the process by recommending a number of new codes that could be used
instead of taking the time to write comments on the inspection form.
The District built automatic and manual quality control checks into the data management process to
improve data reliability. As part of the SCREAM™ data handling process, an interim database template
included queries that identified data gaps or anomalies for the field crew to resolve prior to uploading the
data. This prevented data problems from slowing subsequent engineering decisions. Also, district staff
reviews approximately 10% of a contractor's CCTV videotapes to determine whether all the defects are
being captured and captured accurately. The district developed a missed-data scoring sensitivity
calculator that will predict the impact on the asset's score if a particular defect is not included in the score.
Rules were established regarding acceptable missed data, enabling the staff to know when the data
scoring would be compromised, and how to provide feedback to the CCTV contractor to minimize future
missed data.
Collection of field data is not an activity unto itself, and the district has designed the data collection in
stages to be integrated into progress decisions. The District is already leveraging the data management
process to make more and better decisions with the same or proportionate less resources and staff.
References
Sanitation District No. 1 Capacity, Management, Operations, and Maintenance (CMOM) Self-
Assessment, March 8, 2008.
Contact: Brandon Vatter, Program Manager
Northern Kentucky Sanitation District No. 1
Fort Wright, Ky.
Phone: (859) 578-7450
E-mail: bvatter@sdl.org
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Appendix B. Defect Code Systems
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Appendix B presents a detailed discussion of PACP and SCREAM™ defect codes. The process of defect
coding summarizes observations of pipe defects from CCTV inspections in the form of pipe scores or
grades. The defect code systems record defect locations as a function of their distance from a starting
manhole, and defect codes are used to represent a variety of CCTV inspection observations.
PACP Defect Codes
The PACP code system organizes defects into five "families": continuous defects, structural, O&M,
defects related to construction features and other miscellaneous observations (NASSCO, 2001). A defect
"family" is further divided into defect groups that are assigned a combination of capital letters to form a
descriptive acronym and a grade number to indicate the severity of the defect. For example, "FL"
signifies a longitudinal fracture. The code families are further described below:
• Continuous defect coding: Continuous defect coding consists of two sub-classifications.
"Truly" continuous defects extend along the sewer for a minimum distance of 3 ft. These defects
include longitudinal fractures and cracks. "Repeated" continuous defects occur at regular
intervals along the pipe, usually at pipe joints, and include encrustation, open joints, and
circumferential fractures. Continuous defect coding can be used in conjunction with other codes.
• Structural defect coding: Structural defect coding consists of a number of classifications related
to structural degradation of the pipe: crack (C), fracture (F), broken (B), hole (H), deformed (D),
collapse (X), joint (J), surface damage (S), lining failure (LF), weld failure (WF), point repair
(PR) and brickwork (B). With each of these designations, additional letters further describe the
defect. For example: HSV indicates a hole with soil visible.
• Operational and maintenance defect coding: This family codes defects that are related to lack
of maintenance in the pipe system. The O&M defect code groups are deposits (D), roots (R),
infiltration (I), obstacles (OB) and vermin (V). Additional letters further describe the defect. For
example, VR indicates that there are vermin, specifically rats, in the pipe.
• Construction features coding: This family of codes describes defects related to construction
features located in or around the pipe system. Code groups are tap (T), intruding seal material
(IS), line (L) and access point (A). As with the other families, additional letters further define the
defect. For example, AMH indicates that there is an access point in the line that is a manhole.
• Other coding: This coding family comprises miscellaneous observations about the pipe system
that are of interest. It uses the code letter "M," plus additional letters to further define the
observation. For example, MCU designates that the camera is under water.
The PACP code system is used to describe different characteristics of each observed defect including its
classification, severity, size, proximity to joints, circumferential location (clock location), image/video
reference number, and comments. Defect codes are recorded on a standardized form; an example is
illustrated in Figure B-l. The PACP code system uses numerical grading on a scale of 1 to 5 to define the
severity of each pipe defect, with 1 representing a minimal defect and 5 representing the most severe
defect.
The PACP codes for individual defects are used to determine several overall scores for the pipe segment
(manhole-to-manhole pipe run). Structural and O&M defects are graded separately based on the risk of
further deterioration or failure. These terms for expressing pipe condition are outlined below:
B-88
-------
• Segment Grade Scores: A scoring assigned to individual pipe segments based on the number
and severity of the defects. Each segment receives five Segment Grade Scores, one for each of
the five grades. The score equals the number of defects multiplied by the grade number. For
example, a pipe segment with six Grade 5 defects has a Segment Grade 5 Score of 30 (6 defects
multiplied by a grade of 5). If a pipe segment has no defects for a particular grade, the Segment
Grade Score for that grade is 0.
• Overall Pipe Rating: The sum of five Segment Grade Scores.
• Structural Pipe Rating: The sum of five Segment Grade Scores considering only structural
defects.
• O&M Pipe Rating: The sum of five Segment Grade Scores considering only O&M defects.
• Quick Rating: A rapid method for summarizing the number and severity of the two most severe
defects in a pipe segment. The Quick Rating is a four-character score:
1. The first character is the highest severity grade occurring along the pipe length.
2. The second character is the total number of occurrences of the highest severity grade. If
the total number exceeds 9, then alphabetic characters are used as follows: 10 to 14-A,
15-19-B, 20 to 24-C and so on.
3. The third character is the next highest severity grade occurring along the pipe length.
4. The fourth character is the total number of the second highest severity grade occurrences,
which is formatted the same way as the second character.
For example, a Quick Rating of "3224" is deciphered as follows: the highest severity defect on
this pipe segment is a grade 3; the pipe segment has 2 defects with a grade 3; the next highest
severity defect is a grade 2; there are 4 defects with a grade 2. This pipe segment has no grade 4
or 5 defects.
• Overall Pipe Rating Index: An expression of the average defect severity found in the pipe
segment. The index is calculated by dividing the Overall Pipe Rating by the number of defects.
PACP provides general guidelines for assessing the Pipe Rating Index score with the following
stipulation: "The mechanisms and rates of pipeline deterioration are highly dependent on local
conditions. However the following general guidelines are provided to estimate the amount of
time before the defect causes complete line failure. These guidelines should be verified by actual
research under prevailing local conditions." (NASSCO, 2001)
• Pipe Rating Index = 5: Pipe segment has failed or will likely fail within the next 5 years.
Pipe segment requires immediate attention.
• Pipe Rating Index = 4: Pipe segment has severe defects with failure likely within the
next 5 to 10 years.
• Pipe Rating Index = 3: Pipe segment has moderate defects. Deterioration may continue,
but failure is not likely for 10 to 20 years.
• Pipe Rating Index = 2: Pipe segment has minor defects. Pipe is unlikely to fail for at
least 20 years.
• Pipe Rating Index = 1: Pipe segment has minor defects. Failure is unlikely in the
foreseeable future.
• Structural Pipe Rating Index: The average severity of structural defects in the pipe segment.
The index is calculated by dividing the Structural Pipe Rating by the number of defects.
B-89
-------
• O&M Pipe Rating Index: The average severity of O&M defects in the pipe segment. The index
is calculated by dividing the O&M Pipe Rating by the number of defects.
The Quick Rating and Ratings Index scores are the methods most commonly used to assess the general
condition of a pipe from CCTV inspection data.
Example of PACP Coding Methodology
This example uses CCTV inspection data from an 8-in. diameter VCP located in Huntsville, Ala., to
demonstrate the use of the PACP coding methodology. Figure B-l summarizes the information gathered
for each defect using the PACP defect code system. The level of detail required depends on the particular
defect code used and observations within the pipe. Distance measurements are provided for each defect
and are measured from the starting manhole. Defect codes are then provided and may include group,
descriptor, modifier, and severity codes. The start and end distances of any continuous defects are noted,
and additional information related to each defect may be provided.
B-90
-------
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-------
O&M Rating: In Figure B-l, the following defects were used to calculate the O&M Rating: the TFD
defect located at a distance of 73.4 ft, and the RFL, OBI and TFD defects located at a distance of 262.9 ft.
The two TFD defects were assigned an O&M Grade of 2, the RF defect was assigned an O&M Grade of 1
and the OBI defect was assigned an O&M Grade of 2. Therefore, the O&M Rating = (3 defects x grade
2) + (1 defect x grade 1) = 7.
Overall Rating: The Overall Rating is calculated based on the structural and O&M Ratings. Therefore,
the Overall Rating = 9 + 7 = 16.
The Quick Ratings are based on the two most severe grades and the number of defects observed in a pipe.
The three quick ratings are determined as follows:
Structural Quick Rating: In the example shown in Figure B-l, the most severe grade was a "4" and was
assigned to two defects; the second most severe grade was a "1" and was assigned to 1 defect. Therefore,
the Structural Quick Rating is "4211."
O&M Quick Rating: The most severe O&M grade was a "2" and was assigned to 3 defects; the second
most severe O&M grade was a "1" and was assigned to 1 defect. Therefore, the O&M Quick Rating is
"2311."
Overall Quick Rating: Considering both structural and O&M categories, the most severe grade used in
this pipe segment was a "4" and was assigned to 2 defects. The second most severe grade was a "2" and
was assigned to 3 defects. Therefore, the Overall Quick Rating is "4223."
The Structural, O&M and Overall Ratings Indices are calculated by dividing the Structural Rating, the
O&M Rating and Overall Rating by the number of respective defects in each category. These indices
represent the average pipe condition on a five-point scale. The indices are calculated as follows:
Structural Ratings Index = 9^-3 = 3.0.
O&M Ratings Index = 7 - 4 = 1.8.
Overall Ratings Index = 16-^7 = 2.3.
In summary, the PACP scores for the example in Figure B-l are provided below:
Structural Rating 9
Structural Quick Rating 4211
Structural Ratings Index 3.0
O&M Rating 7
O&M Quick Rating 2311
O&M Ratings Index 1.8
Overall Rating 16
Overall Quick Rating 4223
Overall Ratings Index 2.3
B-92
-------
SCREAM™ Defect Codes
The SCREAM™ defect code system has six defect categories: Access (A), Connecting Pipe (C), Fitting
(F), Joint (J), Lateral Connection (L) and Pipe (P). Categories generally reflect a location relative to when
and where along the pipe the CCTV operator is considering entering a code. The six categories are
further described below:
• Access: These codes generally describe where the inspection was launched (e.g., a manhole, a
cleanout, etc.). All access codes are in the Inventory Group and are not scored but provide
information.
• Connecting Pipe: Defects within the connecting pipe defect category are located in the interface
area of a connecting pipe with the sewer or storm sewer pipe that contains the CCTV camera and
do not represent the connecting pipe itself. Connecting pipes are sewer pipes serving a much
larger service area than laterals or pipes that service a high-flow industry and bring flow to the
sewer or storm sewer pipe. Connecting pipes (also known as "blind connections") are typically >
8 in. in diameter.
• Fitting: These codes are for factory-manufactured fittings such a 45- or 90-degree bend when the
camera is in a lateral. Fittings do not include the lateral tees or wyes, which are included under
Lateral Connection.
• Joint: These codes are for the sewer pipe, fitting or lateral junction points of two pipe segments;
a fitting and pipe or a fitting and lateral.
• Lateral Connection: These codes are for the factory-manufactured tee or wye and include field
installed cored, saddle and hammer-tap connections that connect a lateral to the pipe. A lateral
connection includes the interface area of the service lateral with the sewer pipe. Laterals bring
flow from a residence or commercial building to the pipe and are typically 4 to 6 in. in diameter.
• Pipe: These codes refer to the sewer or storm sewer pipe and the interior space within the
confines of the pipe barrel. Pipe codes are also applicable to the pipeline system components
when considering continuous type defects such as grease, sediment, lining and coating defects.
Within each of these categories, the SCREAM™ defect code system establishes four defect coding
groups: Inventory, Structural, Maintenance and I/I. Inventory codes do not influence the score.
SCREAM™ defect codes are also classified by type of defect (e.g., roots, pipe collapse, and turbulence)
and defect severity (e.g., minimum, moderate, major).
SCREAM™ Defect Scoring Approach
The SCREAM™ rating analysis system includes assigning a score to individual defects, groups of defects
(e.g., structural, maintenance, I/I) and the overall pipe condition.
For each defect type, SCREAM™ calculates a minimum or base defect score and a maximum defect
score. The base defect score represents the score of a single defect of that defect type that has the
minimum possible extent or the minimum length observed for defects of this type (e.g., < 1 ft). The
maximum defect score represents the score for defects of that defect type that have the maximum
cumulative extent over the pipe segment (e.g., multiple occurrences of the same defect or defect that
B-93
-------
extends the entire length of the pipe). The actual score assigned to a specific occurrence of a defect is
determined based on the defect's size or extent in the pipe segment (e.g., < 1 ft, occurs over 50% of pipe
length) and has a value between the minimum and maximum defect scores. If the defect affects < 1 ft of
the pipe segment (a point defect), the score would be equal to the minimum or base defect score; defects
which affect the entire pipe segment would be assigned a value close to the maximum value for that
defect type. Using this approach, the SCREAM™ scoring methodology considers the relative criticality
of specific defect types and the extent of their occurrence in the pipe segment. As a result, the occurrence
of a major defect in one limited area can be scored higher than multiple occurrences of minor defects.
For both defect coding and pipe condition scoring, a scoring scale of 1 to 100 is applied with 1
representing a very minor defect and 100 representing the most severe defect (e.g., a collapsed pipe). For
easier visual display of pipe condition, a simpler scoring scale of Grades 1 to 5 may also be used. For
example, Grade 1 may represent pipe scores of 1 to 25; Grade 2 represents pipe scores of 26 to 40; and so
forth. It is not necessary to use a linear relationship to define Grades 1 to 5 in terms of the pipe scores.
For each pipe segment, the pipe score value using the 1-to-100 scale is retained for subsequent
prioritization or corrective action decisions.
The SCREAM™ methodology includes computation of an Overall Pipe Score for the aggregated defects
found in the pipe. It also computes a separate score for the structural, maintenance and I/I groups of
defects. These scores are calculated using a multiple attribute method that involves advanced root-
square-mean mathematical principles. One key principle is to identify and build upon the highest scored
defect value found in the inspection (Kathula, 2004).
Each defect code is pre-assigned a minimum base score from 1 to 100, and the score for the defect is
increased depending on its extent along the pipe. A score of 1 represents a nearly new pipe, and a score
of 100 represents immediate urgency such as a pipe collapse. SCREAM™'s mathematical algorithm uses
a scoring system that automatically selects the highest defect score value in the pipe segment. The worst
defect score becomes the beginning point for aggregating all additional asset defect scores.
Example of SCREAM™ Coding Methodology
This example uses CCTV inspection data from an 8-in. diameter VCP located in Huntsville, Ala., to
demonstrate use of the SCREAM™ coding methodology. Figure B-2 summarizes inspection distance (ft
from manhole) and describes the type and severity of pipe defects observed. In contrast to PACP,
SCREAM™ defect codes contain all relevant information within each defect code, and no additional
supporting information is required to further describe the defect. Once the defect code is provided, the
defect category, defect family, defect type, defect severity and defect group are all known by definition.
B-94
-------
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Total Score 96.9 100-point scale
Total Grade 5 5-point scale
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with SCREAM™ defect codes or with PACP defect codes. A more significant difference between the
maintenance scores is observed. However, the total grade computed by the SCREAM™ algorithm using
either SCREAM™ defect codes or PACP defect codes is the same in both cases.
B-96
-------
Appendix C. Technology Vendors
C-97
-------
Digital Scanning
Product(s)
DigiSewer
Panoramo
Cleanflow/Fly Eye
Vendor/Address
Envirosight, LLC
lllCanfieldAve.
Randolph, NJ 07869
Rapidview-IBAK USA
1828 West Olson Road
Rochester, IN 46975
CUES Inc.
3600 Rio Vista Ave.
Orlando, FL 32805
Phone/Fax/E-mail/URL
Tel: (866) 936-8476
Fax:(973)252-1176
E-mail: through Web site
URL: http://www.envirosight.com
Tel: (800) 656-4225
Fax: (574)224-5426
E-mail: info@rapidview.com
URL: http://www.rapidview.com
Tel: (800) 327-7791
Fax:(407)425-1569
E-mail: salesinfo@cuesinc.com
URL: http://www.cuesinc.com
Zoom Cameras
Product
Vendor/Address
Phone/Fax/E-mail/URL
Aqua Zoom
AquaData, Inc.95 5th Avenue
Pincourt, Quebec
Canada J7V 5K8
Tel: (800) 567-9003
Fax:(514)425-3506
E-mail: info@aquadata.com
URL: http://www.aquadata.com
Aries HC3000 Zoom
Pole Camera
Aries Industries
550 Elizabeth St.
Waukesha,WI53186
Tel: (800)234-7205
Fax: (262) 896-7099
E-mail: through Web site
URL: http://www.ariesind.com
QuickView
Envirosight, LLC
lllCanfieldAve.
Randolph, NJ 07869
Tel: (866) 936-8476
Fax:(973)252-1176
E-mail: through Web site
URL: http://www.envirosight.com
Everest Ca-Zoom PTZ
GE Sensing & Inspection
Technologies
721 Visions Drive
Skaneateles,NY13152
Tel: (888)332-3848
Fax: (866) 899-4184
E-mail: through Web site
URL:
http: //www. geinspectiontechnologie s. com
CUES IMX Truck-
Mounted Zoom
Camera
CUES IMX Corporate Office
3600 Rio Vista Ave.
Orlando, FL 32805
Tel: (800) 327-7791
Fax:(407)425-1569
E-mail: salesinfo@cuesinc.com
URL: http://www.cuesinc.com
PortaZoom
CTZoom Technologies
2500 Boul. Des Enteprises #104
Terrebonne, Quebec
Canada J6X 4J8
Tel: (888) 965-8987
Fax: (450) 965-8987
E-mail: info@ctzoom.com
URL: http://www.ctzoom.com
Push Cameras
Product(s)
Insight Vision Push
Camera
Address
Insight Vision
600 Dekora Woods Boulevard
Phone/Fax/E-mail/URL
Tel: (800) 488-8177
Fax: (262) 268-9952
C-98
-------
Saukville, WI 53080
URL: http://insightvisioncameras.com
CrystalCam Push
Camera
Inuktun Services Ltd.
2569 Kenworth Road, Ste. C
Nanaimo, British Columbia
Canada V9T 3M4
Tel: (877) 468-5886
Fax: (250) 729-8080
E-mail: sales@inuktun.com
URL: http: //www. inuktun. com/he ad-
office.htm
Flexiprobe
Pearpoint/RADIODETECTION
154 Portland Road
Bridgton, ME 04000
Tel: (877)247-3797
Fax: (207) 647-9495
E-mail: rd.sales.us@spx.com
URL: http://www.pearpoint.com
Hydrus, Orion,
Orion L
Rapidview-IBAK USA
1828 West Olson Road
Rochester, IN 46975
Tel: (800) 656-4225
Fax: (574)224-5426
E-mail: info@rapidview.com
URL: http://www.rapidview.com
Lateral Launchers
Product(s)
LAMP
Lateral Evaluation
Television System
Lateral Inspection
System
IBAK LISY 150-M
Vendor/Address
CUES Inc.
3600 Rio Vista Ave.
Orlando, FL 32805
Aries Industries
550 Elizabeth St.
Waukesha,WI53186
RS Technical Services
1327 Clegg St.
Petaluma, CA 94954
Rapidview-IBAK USA
1828 West Olson Road
Rochester, IN 46975
Phone/Fax/E-mail/URL
Tel: (800) 327-7791
Fax:(407)425-1569
E-mail: salesinfo@cuesinc.com
URL: www.cuesinc.com
Tel: (800)234-7205
Fax: (262) 896-7099
URL: http://www.ariesind.com
Tel: (800) 767-1974
Fax: (707) 778-1974
URL: http://www.rstechserv.com
Tel: (800) 656-4225
Fax: (574)224-5426
E-mail: info@rapidview.com
URL: http://www.rapidview.com
Small Diameter Tractors
Product(s)
ELKT 100 Mini
KRA65
Mighty Mini
Transporter
Address
Pearpoint/RADIODETECTION
154 Portland Road
Bridgton, ME 04000
Rapidview-IBAK USA
1828 West Olson Road
Rochester, IN 46975
RS Technical Services
1327 Clegg St.
Petaluma, CA 94954
Phone/Fax/E-mail/URL
Tel: (877)247-3797
Fax: (207) 647-9495
E-mail: rd.sales.us@spx.com
URL: http://www.pearpoint.com
Tel: (800) 656-4225
Fax: (574)224-5426
E-mail: info@rapidview.com
URL: http://www.rapidview.com
Tel: (800) 767-1974
Fax: (707) 778-1974
URL: http://www.rstechserv.com
C-99
-------
Product(s)
ROWER 100
Versatrax 100
Xpress Silver-Bullet
Crawler
Address
Envirosight
1 1 1 Canfield Ave.
Randolph, NJ 07869
Inuktun Services Ltd.
2569 Kenworth Road, Ste. C
Nanaimo, British Columbia
Canada, V9T 3M4
Insight Vision
600 Dekora Woods Boulevard
Saukville, WI 53080
Phone/Fax/E-mail/URL
Tel: (866) 936-8476
Fax:(973)252-1176
E-mail: through Web site
URL: http://www.envirosight.com
Tel: (877) 468-5886
Fax: (250) 729-8080
E-mail: salesfoHnuktun.com
URL: http : //www . inuktun. com/he ad-
office.htm
Tel: (800) 488-8177
Fax: (262) 268-9952
URL: http://insightvisioncameras.com
Long-Range Tractors
Product
Versatrax 300 VLR
Responder
Vendor/Address
Inuktun Services Ltd.
2569 Kenworth Road, Ste. C
Nanaimo, British Columbia
Canada V9T 3M4
RedZone Robotics
91 43rd St., Ste.250
Pittsburgh, PA 15201
Phone/Fax/E-mail/URL
Tel: (877) 468-5886
Fax: (250) 729-8080
E-mail: salesfoHnuktun.com
URL: http://www.inuktun.com/head-
office.htm
Fax:(412)476-8981
E-mail: through Web site
URL: http://www.redzone.com
Condition Assessment Software
Product
Canalis™ part of
Aqua CAD® suite
CapPlan Sewer
CASS WORKS®
CityWorks
CTSpec
Vendor/Address
Aqua Data Inc.
95 5th Avenue
Pincourt, Quebec
Canada, J7V 5K8
MWH Soft
618 Michillinda Avenue,
Suite 200
Arcadia, CA 9 1007 US A
RJN Group Inc.
200 West Front Street
Wheaton,IL 60187
Azteca Systems, Inc.
11075 South State St., Ste. 24
Sandy, UT 84070 USA
CTZoom Technologies, Inc.
2500 Boul. des Entreprises
#104
Terrebonne, Quebec
Canada J6X 4J8
Phone/Fax/E-mail/URL
Tel: (514) 425-1010
Toll Free: 1-800-567-9003
Fax:(514)425-3506
E-Mail: mfo(a>, aquadata.com
URL: http://www.aquadata.com
Tel: (626) 568-6868
Fax: (626) 568-6870
E-mail : sales@mwhsoft. com
Tel: (630) 682- 4700
Fax: (630) 682- 4754
E-mail: slaitas(5),rin.com
URL: http://www.rin.com/
Tel: (801) 523-2751
Fax: (801) 523-3734
URL: http://www.azteca.com/
Tel: (450) 965-8987
Toll free: 1-888-965-8987
Fax: (450) 965-6622
E-mail: info(2>ctzoom.com
URL: http://www.ctzoom.com
C-100
-------
Product
Vendor/Address
Phone/Fax/E-mail/URL
Granite XP
CUES Corporate Office
3600 Rio Vista Avenue
Orlando, Florida 32805
Tel: 800-327-7791
Fax:(407)425-1569
E-mail: salesinfo@cuesinc.com
URL: http://www.cuesinc.com/
GBA Master Series
or gbaMS
GBA Master Series, Inc.
10561 Barkley, Suite 500
Overland Park, KS 66212
Tel: (800) 492-2468 or (913) 341-3105
Fax:(913)341-3128
E-mail: info@gbams.com
URL: http://www.gbams.com/contact.htm
Hansen Asset
Management
INfOR
13560 Morris Road
Suite 4100
Alpharetta, GA 30004
Tel: (866) 244-5479
Fax:(678)319-8682
URL: www.infor365.com
InfoNet1
Wallingford Software Inc.
6015 Harris Parkway
Suite 120
Fort Worth, TX 76132
Tel: (817) 370-2425
Toll Free: 1-888-520-2224
Fax:(817)370-1981
Sales E-mail:
sales@wallingfordsoftware.com
Support E-mail:
support@wallingfordsoftware.com
URL: http://www.wallingfordsoftware.com
Maximo® Asset
Management
IBM Corporation
1 New Orchard Road
Armonk, New York 10504
Tel: (877) 426-6006
Fax:(800)314-1092
URL: http://www-
01 .ibm.com/software/tivoli/solutions/asset-
management/
SEWERview
CarteGraph
3600 Digital Drive
Dubuque, IA 52003
Tel: (563) 556-8120
Fax:(563)556-8149
E-mail: info@cartegraph.com
C-101
-------
Appendix D. Example Inspection Report - Fort Worth, Texas
D-102
-------
Example Inspection Report: Fort Worth, Texas1
Project Background
In fiscal year 2006-2007, SC03_05 Sub Drainage Basin Area was selected for cleaning and CCTV
inspection. The cleaning activities were conducted from April 2007 through July 2007. CCTV
inspection was also conducted between May 2007 and July 2007. The SC03_05 Sub Drainage Basin
Area is part of the Sycamore Creek Major Drainage Basin located in the south portion of Fort Worth. The
SC03_05 Sub Drainage Basin Area bounded on the north by MARION ST., the west by LOUSE ST., the
east by MISSISSIPPI AVE. and the south by BERRY ST. The drainage basin is comprised of
approximately 40,148 linear feet (LF) of sanitary sewer ranging in size from 6-inch to 12-inch in
diameter.
Cleaning and CCTV Inspection
A total of 39,778 LF of the collection system was cleaned representing 99% of the SC03_05 Sub
Drainage Basin Area. A total of 35,966 LF of the system was inspected representing 89.6% of the
SC03_05 Sub Drainage Basin Area. The purpose of the TV inspection was to evaluate for quality control
of the cleaning operations and pipe condition.
Analysis and Recommendation
Fifteen segments were selected for open cut and/or trenchless point repairs. Table D-1 contains four
segments identified for open-cut method. Table D-2 contains eleven segments identified for trenchless
method. Table D-3 represents a total of 6,805 LF of pipe (19 segments) identified for complete
replacement. Table D-4 represents a total of 6,935 LF (17.3%) of pipe was added to Field Operations
root control program.
A complete list of all lines within the SC03_05 Sub Drainage Basin Area along with a detailed summary
of all related activities associated with this report is given in Table D-5 and shown on the subsequent
project maps.
Should you have any questions concerning the information contained in this report, please do not hesitate
to contact me.
Kirit Patel, Graduate Engineer
Field Operations, Water Department
City Of Fort Worth
Note: This report is presented in its original form as provided by The City of Fort Worth.
D-103
-------
Table D-l. Open cut point repairs
Object ID
1143251
1 143243
1143218
483782
Lateral/
Main
L02057
L03553
L04167
M00017
USID
008+65
005+35
011+00
090+09
DSID
003+07
071+32
004+27
090+03
Pipe
Size
6
6
6
8
Pipe
Material
Vitrified
Clay
Concrete
Concrete
Concrete
Additional
Review/
Comment
Roots removed.
CANT PUSH
ROCK
ANYMORE DO
RSU.
LINE VERY
POOR
BLOCKED BY
GREASE 575
FT
NO U/S M/H; 4'
DEEP M/H D/S
CCTV review Comments
Line is in fair condition w/ some minor
cracking and root intrusion. Section of
is broken badly around taps @ 151'
US.
Fair condition pipe until CCTV
blocked (same as 2005 inspection) by
offset, bend, grade & material change
@ 114' DS (spot of previous repair).
This time debris also involved. RSU
doesn't make it out of the DSMH-
Operator says he's blocked in MH but
doesn't say by what.
Line is in fair/poor condition. Much
cracking & broken pipe, especially in
upper portion. Bad pipe @ 326' US"
being repaired. Grease @ 575' US
blocks Jeteye, survey abandoned. No
RSU attempted."
Line is in good condition. Cap on the
EOL is missing w/ a void created from
recent cleaning.
O&M
Recommendation
Root Program
None at this time
None at this time
None at this time
Structural
Recommendatio
n
Open Cut Point
Repair
Open Cut Point
Repair
Open Cut Point
Repair
Open Cut Point
Repair
D-l 04
-------
Table D-2. Trenchless point repairs
Object ID
569985
1 143247
596003
567864
569071
1 143229
584210
Lateral/
Main
L01394
L02914
L03390
L04167
L04168
L04168
L04828
USID
003+15
004+63
001+61
024+73
012+53
006+00
004+14
DSID
013+98
088+30
001+46
021+82
010+50
003+11
024+73
Pipe
Size
6
6
6
6
6
6
6
Pipe
Material
Concrete
Concrete
Concrete
Concrete
Concrete
Concrete
Concrete
Review/
Comment
LINE IS FAIR
U/SM/H
UNMAPPED
None
LINE IS FAIR
LINE IS POOR
LINE IS FAIR
LINE IS FAIR
CCTV review Comments
Line is in fair condition aside from a
large void in the pipe @ 8' US fro
DSMH (same as in 2005).
Line is in fair condition. Pipe coated
w/ a layer of glue which is heavy in
spots & threatens to clog main. Large
hole w/ void in pipe @ 203' DS
(across from tap).
Line is in fair condition w/ minor
deterioration & encrustation @ joints
noted. Holes in pipe @ 19' & 73' DS.
6" CO line slips into 8" line approx. 2'
US from DSMH. "
Line appears to be in fair condition.
Light to moderate encrustation @
joints (mostly in lower portion of
segment). Infiltration (runner) @ 116'
US. Previous repair w/ VCP/PVC @
125' US noted.
Line is in fair to poor condition. 40'
section, from approx. 115' DS to 165'
DS, is cracked & broken and in need
of repair or fortification. Remainder
of pipe is fair w/ only minor cracks
noted.
Line appears to be in fair condition w/
minor deterioration & root intrusion
noted. Pipe more notably
cracked/broken around 200' to 220'
US.
Line appears to be in fair condition
except for broken pipe @ approx. 60'
US (fairly severe).
O&M
Recommendation
None at this time
None at this time
None at this time
None at this time
None at this time
Root Program
None at this time
Structural
Recommendation
Trenchless Point
Repair
Trenchless Point
epair
Trenchless Point
Repair
Trenchless Point
Repair
Trenchless Point
D-105
-------
Object ID
1 143228
1143160
1 143226
483785
Lateral/
Main
L05012
L05248
L05740
M00017
USID
006+50
005+83
005+03
086+86
DSID
001+27
050+80
000+71
085+00
Pipe
Size
6
6
6
8
Pipe
Material
Concrete
Concrete
Concrete
Vitrified
Clay
Review/
Comment
LINE IS FAIR
LINE IS FAIR
Crew says
collapse @ 137'
DS, I disagree.
See Jeteye
footage
None
CCTV review Comments
Line appears to be in fair/poor
condition w/ some minor cracking
noted (slightly more severe around
130' US).
Line appears to be in fair condition
except for a section of broken pipe @
around 45' US.
Line is in fair condition until CCTV
encounters a heavily used tap
(laundromat & cleaners) @ 137' DS
and gets obstructed for unknown
reason (can't see for the soap suds) but
flow appears fine. RSU-Line appears
to be in fair condition except for
severely broken pipe somewhere
around the 270' US mark. Footage and
video skip around" make it hard to
pinpoint."
Fair condition glue caked" line w/
broken pipe @ 14' DS."
O&M
Recommendation
None at this time
None at this time
None at this time
None at this time
Structural
Recommendation
Trenchless Point
Repair
Trenchless Point
Trenchless Point
Trenchless Point
Repair
Table D-3. Replacements
Object ID
1143157
Lateral/
Main
L00385
USID
018+00
DSID
013+50
Pipe
Size
6
Pipe
Material
Vitrified
Clay
Review/
Comment
DSMH 6'
DEEP; VERY
POOR OLD
CLAY PIPE
CCTV review Comments
Limited quality video shows poor
condition VCP w/ much cracked &
broken pipe. Roots intrude @ many
taps, joints, & defects. Video cuts out
@ 386' US, although report says
CCTV made it to the USMH.- See
2005 video also.
O&M
Recommendation
Root Program
Structural
Recommendation
Replace
D-106
-------
Object ID
1143146
1143252
1143151
1143221
1143211
569980
Lateral/
Main
L00385
L01113R
L01328
L01381
L01381
L01381
USID
008+00
013+20
015+33
013+98
008+00
003+60
DSID
004+97
007+78
008+48
008+00
003+60
002+80
Pipe
Size
8
6
6
6
6
6
Pipe
Material
Vitrified
Clay
Vitrified
Clay
Concrete
Vitrified
Clay
Concrete
Concrete
.Aclditioniil
Review/
Comment
poor line
DORSU
BLOCK BY
ENCRUS-
TATION
CANT PASS
DSMH is 5'
deep.
45 ' SHORT OF
M/H
COMPLETE-
SEE RSU.
LINE VERY
POOR
LINE VERY
POOR
CCTV review Comments
Pipe is in fair up to 103' from U/S
MH, after that it is in poor condition
with multiple cracks, broken pipe
throughout the lower 210' of this
segment.
Poor condition line, CCTV blocked
@ 50' US by what appears to be a
large root mass growing in the flow
line, survey abandoned. RSU-Poor
condition pipe in surveyable portion.
CCTV blocked @ 101' DS by broken
& collapsing pipe. Only able to
inspect 151' of this 542' segment.
Poor condition line w/ deterioration &
broken pipe throughout surveyed
portion. Line collapsing (as it was
back in 2005 survey) @ 142' US, now
collecting debris & clogging main
line.
Line is in fair/poor condition.
Multiple cracks & defective joints w/
root intrusion (minor/moderate)
throughout. Pipe & taps from 400' DS
on are in poor shape. Intruding tap @
554' DS blocks camera. RSU- Line is
fair to 31' US where a (12 o'clock) tap
is intruding and blocks camera.
Line is in poor condition w/ cracked,
eroded, brittle, & broken pipe & roots
intruding throughout. Jeteye blocked
by broken pipe somewhere around
465' DS. See next inspection for RSU.
RSU-More poor condition broken up
CO pipe.
Line is in poor condition w/ cracked,
eroded, brittle, & broken pipe & roots
intruding throughout. Jeteye blocked
by broken pipe somewhere around
465' DS. See next inspection for RSU.
O&M
Recommendation
None at this time
Root Program
None at this time
Root Program
Root Program
Root Program
Structural
Recommendation
Replace
Replace
Replace
Replace
Replace
Replace
D-107
-------
Object ID
569981
1 143223
1143129
1 143242
1 143246
1143213
567871
Lateral/
Main
L01381
L01389
L02506
L02612
L02759
L03674
L04167
USID
002+80
007+38
005+05
003+04
004+75
002+05
014+10
DSID
046+50
003+15
008+00
073+00
086+86
046+50
011+00
Pipe
Size
6
6
6
6
6
6
6
Pipe
Material
Concrete
Concrete
Vitrified
Clay
Concrete
Concrete
Concrete
Concrete
.Aclditioniil
Review/
Comment
LINE IS POOR
LINE IS POOR
LINE IS VERY
POOR
None
None
Need to do temp
open cut point
repair to
improve flow.
VERY POOR;
LIKE 12 FT TO
DN ST STA
CCTV review Comments
RSU-More poor condition broken up
CO pipe.
Line is in poor condition. Cracked,
broken, & deteriorated pipe w/ heavy
roots intruding throughout. Additional
cleaning or root cutting could be
detrimental and cause premature
collapse.
Line is in fair to poor condition. CO
pipe is cracked throughout w/ roots
intruding, more severely broken in
spots. 1 previous repair w/ PVC & 2
offset joints noted.
Line is fair to poor w/ moderate to
heavy cracks/broken pipe in areas.
Line is currently serviceable but could
fail at any time, especially from 275'
to 375' US. Pipe collapsing @ 450'
US.
Line is in fair/poor condition. 2 recent
repairs were done (92' and 126' US)
in order to reach EOL. Pipe is
currently serviceable, but it has many
cracks and is especially poor around
the taps.
Fair/poor condition CO line w/
several areas of broken/missing pipe.
Pipe is totally collapsed @ 441' US
(possibility of no services beyond this
point). Video skips from 325' to 416'
US.
Line is in poor condition. Multiple
cracks, voids, previous point repairs
and collapsed pipe at 101' D/D.
Replace this line - RSU done.
Line is fair from USMH to 235' DS
w/ only minor encrustation &
moderate roots inside taps. Pipe goes
O&M
Recommendation
Root Program
None at this time
None at this time
None at this time
None at this time
None at this time
Root Program
Structural
Recommendation
Replace
Replace
Replace
Replace
Replace
Replace
Replace
D-108
-------
Object ID
603291
1 143240
1143241
1143244
572405
Lateral/
Main
M00017
M00017
M00017
M00017
M00017
USID
081+88
079+46
076+23
073+00
046+50
DSID
079+46
076+23
073+00
071+32
042+65
Pipe
Size
8
8
8
8
12
Pipe
Material
Vitrified
Clay
Vitrified
Clay
Vitrified
Clay
Vitrified
Clay
HDPE
.Aclditioniil
Review/
Comment
011+00
None
THIS LINE
SHOULD NOT
BE RETVED
None
Videoed in
reverse
RECORDING
COMMING
BACK.. .due
to high flow
CCTV review Comments
poor @ 235' DS w/ moderate/major
cracking throughout remainder until
blocked by debris @ 300' DS.
Line is in fair/poor condition. Fine
roots noted in spots. Section of pipe
broken (69' to 79' DS). Pipe becomes
poor & broken starting @ 193' DS.
CCTV submerged & blocked by
unknown® 224' DS. No RSU.
Poor condition VCP line w/ cracked
& broken pipe throughout. Pipe is
severely broken and threatening total
collapse from 220' DS on to where it
IS COLLAPSING @ 262' DS, survey
abandoned.
Surveyed portion of line (60' of 322')
is in poor condition. Pipe is severely
cracked & broken throughout.
Camera remains near total
submergence for entire inspection
until being obstructed @ 60' DS.
Fair/poor condition line w/ some
cracking & broken pipe detectable
(video was shot while in reverse
due to high amount of flow, yet
camera still remains submerged for
most of the inspection.
Fair condition HDPE from DSMH to
309' US then turns to POOR
condition, replace VCP for the
remaining 62' (from USMH to 62'
DS).
O&M
Recommendation
Root Program
None at this time
None at this time
None at this time
None at this time
Structural
Recommendation
Replace
Replace
Replace
Replace
Replace
D-109
-------
Table D-4. Root abatement
Object ID
603292
1143157
1143145
1143252
1143148
1143154
1 143220
Lateral/
Main
L00385
L00385
L00385
L01113R
L01113R
L01328
L01381
USID
020+50E
018+00
000+01
013+20
007+78
003+80
021+30
DSID
018+00
013+50
008+00
007+78
004+08
001+80
013+98
Pipe
Size
6
6
8
6
6
6
6
Pipe
Material
Vitrified
Clay
Vitrified
Clay
Vitrified
Clay
Vitrified
Clay
Vitrified
Clay
Concrete
Concrete
Additional
Review/
Comment
POOR OLD
CLAYPIPE-see
also 2005
inspection
DSMH 6' DEEP;
VERY POOR
OLD CLAY PIPE
POOR
DO RSU BLOCK
BY
ENCRUSTATION
CAN'T PASS
None
DO RSU... when?
LINE IS FAIR
CCTV review Comments
Fair/poor condition VCP has much
broken pipe (at least 12 separate
spots) w/ minor/moderate roots
intruding joints & cracks throughout.
Previous repair from 75' to 95' sits
lower than rest of line.
Limited quality video shows poor
condition VCP w/ much cracked &
broken pipe. Roots intrude @ many
taps, joints, & defects. Video cuts out
@ 386' US, although report says
CCTV made it to the USMH.- See
2005 video also.
Reviewable portion of segment
(video skips from 7' US to 202' US)
is in fair condition w/ only minor
cracks noted.
Poor condition line, CCTV blocked
@ 50' US by what appears to be a
large root mass growing in the flow
line, survey abandoned. RSU-Poor
condition pipe in surveyable portion.
CCTV blocked @ 101' DS by broken
& collapsing pipe. Only able to
inspect 151' of this 542' segment.
Line appears to be in fair condition.
Much footage is either submerged or
blurry. A few cracks and some roots
in taps were noted.
Fair/poor condition CO line w/ minor
cracks & broken pipe throughout
(structurally adequate). Roots
(minor) intrude joints & defects
throughout. CCTV blocked @ 368'
US by debris in flowline.
Line appears to be in fair condition
O&M
Recommendation
Root Program
Root Program
Root Program
Root Program
Root Program
Root Program
Root Program
Structural
Recommendation
None at this time
Replace
None at this time
Replace
None at this time
None at this time
None at this time
D-110
-------
Object ID
1143221
1143211
569981
569938
1143251
Lateral/
Main
L01381
L01381
L01381
L01389
L02057
USID
013+98
008+00
002+80
007+97
008+65
DSID
008+00
002+80
046+50
007+38
003+07
Pipe
Size
6
6
6
6
6
Pipe
Material
Vitrified
Clay
Concrete
Concrete
Concrete
Vitrified
Clay
.Additional
Review/
Comment
45 ' SHORT OF
M/H
COMPLETE- SEE
RSU.
LINE VERY
POOR
LINE IS POOR
LINE IS FAIR
Roots removed.
CCTV review Comments
w/ minor to moderate roots intruding
joints & taps and some minor cracks
noted. Moderate (flow friendly)
offset joint @ 14' US (previous
repair w/VCP).
Line is in fair/poor condition.
Multiple cracks & defective joints w/
root intrusion (minor/moderate)
throughout. Pipe & taps from 400'
DS on are in poor shape. Intruding
tap @ 554' DS blocks camera. RSU-
Line is fair to 31' US where a (12
o'clock) tap is intruding and blocks
camera.
Line is in poor condition w/ cracked,
eroded, brittle, & broken pipe &
roots intruding throughout. Jeteye
blocked by broken pipe somewhere
around 465' DS. See next inspection
for RSU. RSU-More poor condition
broken up CO pipe.
Line is in poor condition. Cracked,
broken, & deteriorated pipe w/ heavy
roots intruding throughout.
Additonal cleaning or root cutting
could be detrimental and cause
premature collapse.
Line appears to be in fair condition.
Some moderate cracking w/ roots
intruding in spots.
Line is in fair condition w/ some
minor cracking and root intrusion.
Section of is broken badly around
taps® 151' US.
O&M
Recommendation
Root Program
Root Program
Root Program
Root Program
Root Program
Structural
Recommendation
Replace
Replace
Replace
None at this time
Open Cut Point
Repair
D-lll
-------
Object ID
596059
567871
569072
1 143229
594772
1143159
Lateral/
Main
L02057
L04167
L04168
L04168
L04602
L04602
USID
003+07
014+10
013+78
006+00
009+07
006+00
DSID
007+78
011+00
012+53
003+11
006+00
050+80
Pipe
Size
6
6
6
6
6
6
Pipe
Material
Vitrified
Clay
Concrete
Concrete
Concrete
Concrete
Concrete
.Additional
Review/
Comment
None
VERY POOR;
LIKE 12 FT TO
DN ST STA
011+00
LINE IS FAIR
LINE IS FAIR
BLOCKED AT
225
LINE IS FAIR
CCTV review Comments
Surveyed portion of line (181' of
307') is fair/poor w/ defective joints,
minor cracks, & roots throughout.
CCTV blocked by root mass/ grease/
grade change @ 181' DS. RSU-
CCTV blocked by same root mass @
116' US.
Line is fair from USMH to 235' DS
w/ only minor encrustation &
moderate roots inside taps. Pipe goes
poor @ 235' DS w/ moderate/major
cracking throughout remainder until
blocked by debris @ 300' DS.
Line appears to be in fair condition
w/ minor encrustation @ joints. Root
mass intrudes from 10 o'clock tap @
104' US (945 E Berry).
Line appears to be in fair condition
w/ minor deterioration & root
intrusion noted. Pipe more notably
cracked/broken around 200' to 220'
US.
Line appears to be in fair condition
until Jeteye gets blocked by a build-
up of unknown origin (looks like
grease) @ around 225' US. RSU-
Surveyed portion of line (116' of
302') in fair condition w/
light/moderate roots intruding taps &
joints. CCTV blocked @ 68' DS by
encrustation (concrete swag build-
up) near tap.
Line appears to be in fair/poor
condition w/ moderate cracks noted
(mostly around taps in upper 1/2 of
segment) and fine/moderate root
intrusion (mostly through joints/taps
in lower 1/2 of segment).
O&M
Recommendation
Root Program
Root Program
Root Program
Root Program
Root Program
Root Program
Structural
Recommendation
None at this time
Replace
None at this time
Trenchless Point
Repair
None at this time
None at this time
D-112
-------
Object ID
603291
Lateral/
Main
M00017
USID
081+88
DSID
079+46
Pipe
Size
8
Pipe
Material
Vitrified
Clay
Review/
Comment
None
CCTV review Comments
Line is in fair/poor condition. Fine
roots noted in spots. Section of pipe
broken (69' to 79' DS). Pipe becomes
poor & broken starting @ 193' DS.
CCTV submerged & blocked by
unknown @224'DS.
O&M
Recommendation
Root Program
Structural
Recommendation
Replace
Table D-5. Summary
Object ID
603292
1143157
1143144
Lateral/
Main
L00385
L00385
L00385
USID
020+50E
018+00
013+50
DSID
018+00
013+50
000+01
Pipe
Size
6
6
6
Pipe
Material
Vitrified
Clay
Vitrified
Clay
Vitrified
Clay
Review/
Comment
POOR OLD
CLAYPIPE-see
also 2005
inspection
DSMH 6' DEEP;
VERY POOR
OLD CLAY PIPE
Videoed upper
portion in reverse
after cleaning lens
@ DSMH.
CCTV review Comments
Fair/poor condition VCP has much
broken pipe (at least 12 separate
spots) w/ minor/moderate roots
intruding joints & cracks
throughout. Previous repair from
75' to 95' sits lower than rest of
line.
Limited quality video shows poor
condition VCP w/ much cracked &
broken pipe. Roots intrude @ many
taps, joints, & defects. Video cuts
out @ 386' US, although report
says CCTV made it to the USMH.-
See 2005 video also.
Line is in fair condition w/ several
minor/moderate cracks and 2 old
point repairs noted.
O&M
Recommendation
Root Program
Root Program
None at this time
Structural
Recommendation
None at this time
Replace
None at this time
D-113
-------
Object ID
1143146
1143155
1143156
1143145
587036
1143158
587039
587040
1143239
478443
Lateral/
Main
L00385
L00385
L00385
L00385
L00863
L00863
L00863
L00863
L00940
L00943
USID
008+00
004+85
001+80
000+01
013+19
008+54
004+35
002+50
083+40
005+94
DSID
004+97
001+80
054+86
008+00
008+54
004+35
002+50
000+01
079+46
002+90
Pipe
Size
8
8
6
8
8
8
8
8
6
8
Pipe
Material
Vitrified
Clay
Vitrified
Clay
Vitrified
Clay
Vitrified
Clay
Polyvinyl
Chloride
Polyvinyl
Chlorid
Polyvinyl
Chloride
Polyvinyl
Chloride
Concrete
Polyvinyl
Chloride
Additional
Review/
Comment
poor line
None
None
POOR
PIPE GOOD 8
PVC"
GOOD PIPE
PCV&DIP
GOOD PIPE 8'
PVC
GOOD PIPE PVC
8";No"
8 ' DEEP M/H
D/S; NO U/S
FOUND-nor does
it ping in GIS.
None
CCTV review Comments
Pipe is in fair up to 103' from U/S
MH, after that it is in poor
condition with multiple cracks,
broken pipe throughout the lower
210' of this segment.
Fair condition VCP w/ only a few
minor cracks noted. Offset joint @
314' DS (just US from DSMH
where VCP meets PVC inflow stub
portion).
Line appears to be in fair
condition. Very high flow amount
for a 6 pipe."
Reviewable portion of segment
(video skips from 7' US to 202'
US) is in fair condition w/ only
minor cracks noted.
Line is in good condition.
Line is in good condition. DIP for
1st 60' DS then PVC for the rest.
Line is in good condition. Video
skips from 54' to 65' DS and then
again from 150' to 154' DS near
where taps are located (according
to previous inspection).
Line is in good condition.
Condition unknown. Camera gets
blocked by bend in line @ 2' US.
No USMH for RSU.
Line is in good condition. Do not
rely on distances as crew forgot to
reset counter at the DSMH.
O&M
Recommendation
None at this time
None at this time
None at this time
Root Program
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
Structural
Recommendation
Replace
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
D-114
-------
Object ID
478444
1 143248
1143252
1143148
1143147
1143151
1143152
1143154
Lateral/
Main
L00943
L01113
L01113R
L01113R
L01113R
L01328
L01328
L01328
USID
002+90
022+00
013+20
007+78
004+08
015+33
008+48
003+80
DSID
085+00
005+35
007+78
004+08
004+85
008+48
003+80
001+80
Pipe
Size
8
6
6
6
8
6
6
6
Pipe
Material
Polyvmyl
Chloride
Vitrified
Clay
Vitrified
Clay
Vitrified
Clay
Vitrified
Clay
Concrete
Vitrified
Clay
Concrete
.Additional
Review/
Comment
None
LINE IS FAIR
DO RSU BLOCK
BY
ENCRUSTATION
CAN'T PASS
None
See also 2005
inspection from
USMH...it's
clearer.
DSMH is 5' deep.
1/2 VCP and 1/2
CO
DO RSU... when?
CCTV review Comments
Line is in good condition. Minor
compression deformities noted, but
none are severe.
Line appears to be in fair condition
w/ only minor cracks noted.
Poor condition line, CCTV
blocked @ 50' US by what appears
to be a large root mass growing in
the flow line, survey abandoned.
RSU-Poor condition pipe in
surveyable portion. CCTV blocked
@ 101' DS by broken & collapsing
pipe. Only able to inspect 151' of
this 542' segment.
Line appears to be in fair
condition. Much footage is either
submerged or blurry. A few cracks
and some roots in taps were noted.
Fair condition VCP aside from 2
spots w/ broken pipe (146' US @
joint of a previous repair & 363'
US). Heavy roots inside service
line @ 196' US (10 o'clock tap
serves 945 E Morningside Dr.).
Poor condition line w/
deterioration & broken pipe
throughout surveyed portion. Line
collapsing (as it was back in 2005
survey) @ 142' US, now collecting
debris & clogging main line.
Line is in fair/poor condition w/
several cracks (minor/moderate)
noted throughout (especially in CO
portions), however none are
currently severe enough to warrant
immediate repairs.
Fair/poor condition CO line w/
minor cracks & broken pipe
O&M
Recommendation
None at this time
None at this time
Root Program
Root Program
None at this time
None at this time
None at this time
Root Program
Structural
Recommendation
None at this time
None at this time
Replace
None at this time
None at this time
Replace
None at this time
None at this time
D-115
-------
Object ID
601588
601590
1 143220
1143221
Lateral/
Main
L01380
L01380
L01381
L01381
USID
009+05
005+00
021+30
013+98
DSID
005+00
001+80
013+98
008+00
Pipe
Size
8
8
6
6
Pipe
Material
Polyvinyl
Chloride
Polyvinyl
Chloride
Concrete
Vitrified
Clay
Additional
Review/
Comment
GOOD LINE...
bad inspection!
GOOD
LINE IS FAIR
45 ' SHORT OF
M/H COMPLETE-
SEE RSU.
CCTV review Comments
throughout (structurally adequate).
Roots (minor) intrude joints &
defects throughout. CCTV blocked
@ 368' US by debris in flowline.
Line is in good condition. Video
missing from 338' to 400' US.
Line is in good condition. Video
skips (US' to 122' US & 214' to
220' US).
Line appears to be in fair condition
w/ minor to moderate roots
intruding joints & taps and some
minor cracks noted. Moderate
(flow friendly) offset joint @ 14'
US (previous repair w/ VCP).
Line is in fair/poor condition.
Multiple cracks & defective joints
w/ root intrusion (minor/moderate)
throughout. Pipe & taps from 400'
DS on are in poor shape. Intruding
tap @ 554' DS blocks camera.
RSU- Line is fair to 31' US where a
(12 o'clock) tap is intruding and
blocks camera.
O&M
Recommendation
None at this time
None at this time
Root Program
Root Program
Structural
Recommendation
None at this time
None at this time
None at this time
Replace
D-116
-------
Object ID
1143211
569981
569938
1 143223
1 143224
1 143222
Lateral/
Main
L01381
L01381
L01389
L01389
L01389
L01394
USID
008+00
002+80
007+97
007+38
003+15
008+40
DSID
002+80
046+50
007+38
003+15
003+15
003+15
Pipe
Size
6
6
6
6
6
6
Pipe
Material
Concrete
Concrete
Concrete
Concrete
Concrete
Concrete
.Additional
Review/
Comment
LINE VERY
POOR
LINE IS POOR
LINE IS FAIR
LINE IS POOR
FAIR
BLOCK DEBIS
DO RSU
CCTV review Comments
Line is in poor condition w/
cracked, eroded, brittle, & broken
pipe & roots intruding throughout.
Jeteye blocked by broken pipe
somewhere around 465' DS. See
next inspection for RSU. RSU-
More poor condition broken up CO
pipe.
Line is in poor condition. Cracked,
broken, & deteriorated pipe w/
heavy roots intruding throughout.
Additional cleaning or root cutting
could be detrimental and cause
premature collapse.
Line appears to be in fair
condition. Some moderate cracking
w/ roots intruding in spots.
Line is in fair to poor condition.
CO pipe is cracked throughout w/
roots intruding, more severely
broken in spots. 1 previous repair
w/ PVC & 2 offset joints noted.
Line is in fair condition.
Surveyed portion of line (185' of
525') is in fair to poor condition w/
deterioration, cracks, & broken
pipe throughout. 2 previous repairs
noted. CCTV blocked by debris
(rocks) in flowline @ 185' DS.
RSU w/ Jeteye-Line is in fair/poor
condition. CO pipe is cracked &
broken in many places, yet still
structurally adequate. 2 previous
PVC repairs noted. Blocked @
264ish' US by rock, see RSU.
O&M
Recommendation
Root Program
Root Program
Root Program
None at this time
None at this time
None at this time
Structural
Recommendation
Replace
Replace
None at this time
Replace
None at this time
None at this time
D-117
-------
Object ID
569985
1143135
1143128
586621
572466
572467
569986
569987
569929
596115
1143130
596048
596049
Lateral/
Main
L01394
L01701
L01701
L01704R*
L01705
L01705
L01707R
L01707R
L01707R
L01743
L01743
L02057
L02057
USID
003+15
009+02
005+34
003+40
008+20
002+27
008+68
006+50
002+50
003+55
003+08
017+28E
014+50
DSID
013+98
005+34
004+85
076+23
002+27
073+00
006+50
002+50
076+23
003+08
000+01
014+50
008+47
Pipe
Size
6
6
6
8
8
8
8
8
8
6
6
6
8
Pipe
Material
Concrete
Concrete
Concrete
Polyvinyl
Chloride
Polyvinyl
Chloride
Polyvinyl
Chloride
Polyvinyl
Chloride
Polyvinyl
Chloride
Polyvinyl
Chloride
Vitrified
Clay
Concrete
Polyvinyl
Chloride
Polyvinyl
Chloride
Additional
Review/
Comment
LINE IS FAIR
LINE IS FAIR
LINE IS FAIR
None
STAT #'S DONT
MATCH
None
None
None
None
None
LINE IS FAIR
None
None
CCTV review Comments
Line is in fair condition aside from
a large void in the pipe @ 8' US fro
DSMH (same as in 2005).
Line appears to be in fair
condition, for its age.
Line appears to be in fair condition
w/ only a few minor cracks
notable. Fine roots intrude joints in
lower portion of segment (30' to 40'
of VCP from DSMH).
Line is in good condition w/some
debris present (small rocks pushed
by camera).
Line is in good condition.
Line is in good condition.
Line is in good condition.
Line is in good condition.
Line is in good condition.
Line is in fair condition. See
Jeteye inspection from lower
segment on this line. He shot thru
to this EOL and it is fair.
CO line is in fair condition w/
some minor/moderate deterioration
& cracks noted. 2 old point repairs
w/PVC also noted.
Line is in good condition.
Line is in good condition.
O&M
Recommendation
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
Structural
Recommendation
Trenchless Point
Repair
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
D-118
-------
Object ID
1143251
596059
1 143245
478892
478891
478889
478890
479319
1143129
Lateral/
Main
L02057
L02057
L02235
L02303
L02303
L02303
L02303
L02303A
L02506
USID
008+65
003+07
005+78
012+35
010+82
006+71
003+36
001+76
005+05
DSID
003+07
007+78
081+88
010+82
006+71
003+36
085+00
010+82
008+00
Pipe
Size
6
6
6
8
8
8
8
6
6
Pipe
Material
Vitrified
Clay
Vitrified
Clay
Concrete
Chloride
Chloride
Chloride
Polyvinyl
Chloride
Vitrified
Clay
Vitrified
Clay
Review/
Comment
Roots removed.
None
LINE IS FAIR
None
None
None
None
Line runs under
building (2933
Bryan). No MH @
EOL.
LINE IS VERY
POOR
CCTV review Comments
Line is in fair condition w/ some
minor cracking and root intrusion.
Section of is broken badly around
taps® 151' US.
Surveyed portion of line (181' of
307') is fair/poor w/ defective
joints, minor cracks, & roots
throughout. CCTV blocked by root
mass/grease/grade change @ 181'
DS. RSU-CCTV blocked by same
root mass @ 116' US.
Line appears to be in fair
condition. 1 previous repair noted
@ 240' US.
Line is in good condition. Other
lateral, entering same DSMH from
the west suffers infiltration.
Line is in fair condition. Tap @
344' DS has exposed gasket. Minor
offset joint® 352' DS.
Line is in good condition. Flatness
causes slight debris build-up in
flowline, not severe.
Line is in good condition.
Line is in good condition.
Line is fair to poor w/ moderate to
heavy cracks/broken pipe in areas.
Line is currently serviceable but
could fail at any time, especially
from 275' to 375' US. Pipe
collapsing @ 450' US.
O&M
Recommendation
Root Program
Root Program
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
Structural
Recommendation
Open Cut Point
Repair
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
Replace
D-119
-------
Object ID
1 143242
1 143246
479302
1155541
1 143247
479303
596013
596012
596003
Lateral/
Main
L02612
L02759
L02914
L02914
L02914
L02914A
L02981
L02981
L03390
USID
003+04
004+75
005+03
004+77
004+63
000+34
006+16
001+46
001+61
DSID
073+00
086+86
004+77
004+64
088+30
004+77
001+46
063+19
001+46
Pipe
Size
6
6
6
6
6
6
8
8
6
Pipe
Material
Concrete
Concrete
Concrete
Concrete
Concrete
Concrete
Polyvinyl
Chloride
Polyvinyl
Chloride
Concrete
Review/
Comment
None
None
NO U/S M/H @
EOL.
None
U/S M/H
UNMAPPED
NO U/S M/H
None
GOOD
None
CCTV review Comments
Line is in fair/poor condition. 2
recent repairs were done (92' and
126' US) in order to reach EOL.
Pipe is currently serviceable, but it
has many cracks and is especially
poor around the taps.
Fair/poor condition CO line w/
several areas of broken/missing
pipe. Pipe is totally collapsed @
441' US (possibility of no services
beyond this point). Video skips
from 325' to 416' US.
Line in fair condition w/minor
deterioration noted. Moderate
encrustation in top of 2nd US joint.
Line in fair condition. Large chunk
of debris pushed to DSMH.
Line is in fair condition. Pipe
coated w/ a layer of glue which is
heavy in spots & threatens to clog
main. Large hole w/ void in pipe @
203' DS (across from tap).
Condition unknown. Camera never
enters the line (just a manhole
inspect). Report claims only
encrustation.
Line is in good condition.
Line is in good condition. Video
skips from USMH to 35' DS.
Line is in fair condition w/ minor
deterioration & encrustation @
joints noted. Holes in pipe @ 19' &
73' DS. 6" CO line slips into 8" line
approx. 2' US from DSMH. "
O&M
Recommendation
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
Structural
Recommendation
Replace
Replace
None at this time
None at this time
Trenchless Point
Repair
None at this time
None at this time
None at this time
Trenchless Point
D-120
-------
Object ID
1143250
1 143243
596002
1155542
1143213
1 143227
567864
Lateral/
Main
L03553
L03553
L03553R
L03674
L03674
L04167
L04167
USID
007+19
005+35
008+47
002+60
002+05
030+47
024+73
DSID
005+35
071+32
007+19
002+05
046+50
024+73
021+82
Pipe
Size
6
6
8
6
6
6
6
Pipe
Material
Concrete
Concrete
Polyvinyl
Chloride
Concrete
Concrete
Concrete
Concrete
.Additional
Review/
Comment
None
CANT PUSH
ROCK
ANYMORE DO
RSU
BIG BEND INTO
M/HD/S
COMPLETE
CHANGED STA.
NUMBERS &
W/O#
Need to do temp
open cut point
repair to improve
flow.
LINE IS FAIR
LINE IS FAIR
CCTV review Comments
Line is in fair condition. Section of
VCP (old spot repair) from 155' to
160' US is slightly displaced,
nothing severe.
Fair condition pipe until CCTV
blocked (same as 2005 inspection)
by offset, bend, grade & material
change @ 1 14' DS (spot of
previous repair). This time debris
also involved. RSU doesn't make it
out of the DSMH-Operator says
he's blocked in MH but doesn't say
by what.
Line is in fair condition, flat in
spots. Severe bend in line leading
into DSMH causes restriction of
flow, submerging camera for the
final 10' to 15'.
Line is in fair condition. Some
deterioration but overall OK
Line is in poor condition. Multiple
cracks, voids, previous point
repairs and collapsed pipe at 101'
D/D. Replace this line - RSU done.
Line appears to be in fair
condition. 2 previous repairs w/
PVC noted @ 140' & 210' US.
Line appears to be in fair
condition. Light to moderate
encrustation @ joints (mostly in
lower portion of segment).
Infiltration (runner) @ 116' US.
Previous repair w/ VCP/PVC @
125' US noted.
O&M
Recommendation
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
Structural
Recommendation
None at this time
Open Cut Point
Repair
None at this time
None at this time
Replace
None at this time
Trenchless Point
epair
D-121
-------
Object ID
567865
1143219
567871
1143218
567877
567878
569072
569071
569070
1 143229
Lateral/
Main
L04167
L04167
L04167
L04167
L04167*
L04167*
L04168
L04168
L04168
L04168
USID
021+82
017+00
014+10
011+00
004+27
001+27
013+78
012+53
010+50
006+00
DSID
017+00
014+10
011+00
004+27
001+27
038+58
012+53
010+50
006+00
003+11
Pipe
Size
6
6
6
6
8
8
6
6
6
6
Pipe
Material
Concrete
Concrete
Concrete
Concrete
Polyvinyl
Chloride
Polyvinyl
Chloride
Concrete
Concrete
Concrete
Concrete
Additional
Review/
Comment
LINE IS FAIR
LINE IS GOOD
VERY POOR;
LIKE 12 FT TO
DN ST STA
011+00
LINE VERY
POOR BLOCKED
BY GREASE 575
FT
LINE IS GOOD
LINE IS GOOD
LINE IS FAIR
LINE IS POOR
LINE IS FAIR
LINE IS FAIR
CCTV review Comments
Line appears to be in fair
condition. Reported infiltration is
only dripper when Jeteye isn't on.
Line appears to be in fair
condition.
Line is fair from USMH to 235'
DS w/ only minor encrustation &
moderate roots inside taps. Pipe
goes poor @ 235' DS w/
moderate/major cracking
throughout remainder until blocked
by debris @ 300' DS.
Line is in fair/poor condition.
Much cracking & broken pipe,
especially in upper portion. Bad
pipe @ 326' US" being repaired.
Grease @ 575' US blocks Jeteye,
survey abandoned. No RSU
attempted."
Line is in good condition.
Line is in good condition.
Line appears to be in fair condition
w/ minor encrustation @ joints.
Root mass intrudes from 10 o'clock
tap @ 104' US (945 E Berry).
Line is in fair to poor condition.
40' section, from approx. 115' DS
to 165' DS, is cracked & broken
and in need of repair or
fortification. Remainder of pipe is
fair w/ only minor cracks noted.
Line appears to be in fair condition
w/ only a few minor cracks noted.
Line appears to be in fair condition
w/ minor deterioration & rooty
O&M
Recommendation
None at this time
None at this time
Root Program
None at this time
None at this time
None at this time
Root Program
None at this time
None at this time
Root Program
Structural
Recommendation
None at this time
None at this time
Replace
Open Cut Point
Repair
None at this time
None at this time
None at this time
Trenchless Point
Repair
None at this time
Trenchless Point
Repair
D-122
-------
Object ID
584201
594772
1143159
584193
584210
1143217
1 143228
1143160
567827
Lateral/
Main
L04168*
L04602
L04602
L04828
L04828
L05012
L05012
L05248
L05469
USID
003+11
009+07
006+00
004+50
004+14
010+10
006+50
005+83
015+31
DSID
004+27
006+00
050+80
004+14
024+73
006+50
001+27
050+80
014+27
Pipe
Size
8
6
6
6
6
6
6
6
6
Pipe
Material
Polyvinyl
Chloride
Concrete
Concrete
Concrete
Concrete
Concrete
Concrete
Concrete
Concrete
Review/
Comment
LINE IS GOOD
BLOCKED AT
225
LINE IS FAIR
LINE IS GOOD
LINE IS FAIR
LINE IS FAIR
LINE IS FAIR
LINE IS FAIR
LINE IS FAIR
CCTV review Comments
intrusion noted. Pipe more notably
cracked/broken around 200' to 220'
US.
Line appears to be in good
condition.
Line appears to be in fair condition
until Jeteye gets blocked by a
build-up of unknown origin (looks
like grease) @ around 225' US.
RSU-Surveyed portion of line (116'
of 302') in fair condition w/
light/moderate roots intruding taps
& joints. CCTV blocked @ 68' DS
by encrustation (concrete swag
build-up) near tap.
Line appears to be in fair/poor
condition w/ moderate cracks noted
(mostly around taps in upper 1/2 of
segment) and fine/moderate root
intrusion (mostly through
joints/taps in lower 1/2 of
segment).
Line appears to be in good
condition.
Line appears to be in fair condition
except for broken pipe @ approx.
60' US (fairly severe).
Line appears to be in fair
condition.
Line appears to be in fair/poor
condition w/ some minor cracking
noted (slightly more severe around
130' US).
Line appears to be in fair condition
except for a section of broken pipe
@ around 45' US.
Line appears to be in fair
O&M
Recommendation
None at this time
Root Program
Root Program
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
Structural
Recommendation
None at this time
None at this time
None at this time
None at this time
None at this time
Trenchless Point
Repair
None at this time
D-123
-------
Object ID
567826
1143214
1143215
1 143225
1 143226
567814
567790
1143216
1143230
Lateral/
Main
L05469
L05469
L05469
L05740
L05740
L05740
L06409
L06409
L06409
USID
014+27
012+26
006+50
008+09
005+03
000+71
016+57
012+50
006+00
DSID
012+26
006+50
045+28
005+03
000+71
021+82
012+50
006+00
040+48
Pipe
Size
6
6
6
6
6
6
6
6
6
Pipe
Material
Concrete
Concrete
Concrete
Concrete
Concrete
Concrete
Concrete
Concrete
Concrete
Review/
Comment
LINE IS
FAIR is it?
LINE IS FAIR
None
LINE IS GOOD
Crew says
collapse @ 137'
DS, I disagree. See
Jeteye footage
LINE IS FAIR
LINE IS FAIR
LINE IS FAIR
LINE IS FAIR
CCTV review Comments
condition.
Line reported to be fair by Jeteye
crew. Overall condition is
uncertain due to video being
blurred by full-on Jeteye spray for
nearly the whole segment & no
reverse footage.
Line appears to be in fair
condition.
Line appears to be in fair condition
w/ some minor cracks noted
(mostly near break-in taps and
around a few joints).
Line appears to be in fair
condition.
Line is in fair condition until
CCTV encounters a heavily used
tap (Laundromat & cleaners) @
137' DS and gets obstructed for
unknown reason (can't see for the
soap suds) but flow appears fine.
RSU-Line appears to be in fair
condition except for severely
broken pipe somewhere around the
270' US mark. Footage and video
skip around" make it hard to
pinpoint."
Line appears to be in fair
condition. Encrustation @ joints
and 1 previous repair w/ VCP
noted.
Line appears to be in fair
condition.
Line appears to be in fair condition
w/ only a few minor cracks and 1
previous repair noted.
Line appears to be in fair
O&M
Recommendation
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
Structural
Recommendation
None at this time
None at this time
None at this time
None at this time
Trenchless Point
Repair
None at this time
None at this time
None at this time
None at this time
D-124
-------
Object ID
584216
584221
483782
483783
483784
483785
Lateral/
Main
L08450*
L09113*
M00017
M00017
M00017
M00017
USID
000+58
000+74
090+09
090+03
088+30
086+86
DSID
003+11
004+14
090+03
088+30
086+86
085+00
Pipe
Size
8
6
8
8
8
8
Pipe
Material
Polyvinyl
Chloride
Vitrified
Clay
Concrete
Concrete
Vitrified
Clay
Vitrified
Clay
Additional
Review/
Comment
LINE IS GOOD
LINE IS GOOD
NO U/S M/H; 4 '
DEEP M/H D/S
None
BLKED BY
GLUE FROM U/S
PLANT; see next
inspection for RSU
None
CCTV review Comments
condition. Video is too blurry to
accurately review but Jeteye travels
MH to MH and crew reports line in
fair condition.
Line is in good condition.
Line is in good condition.
Line is in good condition. Cap on
the EOL is missing w/ a void
created from recent cleaning.
Line is in fair condition w/ slight
wear & minor crack @ 6' DS
noted.
Surveyed portion of line (34' of
139') in fair condition except for
the fact that glue from the factory
US is collecting on the walls of the
main line. CCTV blocked by glue
build up @ 34' DS. RSU- Video
skips from 2.7' to 90.3' US then
videos in reverse thru fair condition
glue caked" pipe."
Fair condition glue caked" line w/
broken pipe @ 14' DS."
O&M
Recommendation
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
Structural
Recommendation
None at this time
None at this time
Open Cut Point
Repair
None at this time
None at this time
Trenchless Point
Repair
D-125
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Object ID
603291
1 143240
1143241
1 143244
603280
589069
Lateral/
Main
M00017
M00017
M00017
M00017
M00017
M00017
USID
081+88
079+46
076+23
073+00
068+82
068+29
DSID
079+46
076+23
073+00
071+32
068+29
068+10
Pipe
Size
8
8
8
8
10
10
Pipe
Material
Vitrified
Clay
Vitrified
Clay
Vitrified
Clay
Vitrified
Clay
Concrete
Concrete
.Additional
Review/
Comment
None
THIS LINE
SHOULD NOT
BE RETVED
None
Videoed in
reverse
CAM . UNDER
WATER ALL
THE WAY/REC
COMMING
BACK , NO USE
None
CCTV review Comments
Line is in fair/poor condition. Fine
roots noted in spots. Section of
pipe broken (69' to 79' DS). Pipe
becomes poor & broken starting @
193' DS. CCTV submerged &
blocked by unknown @ 224' DS.
No RSU.
Poor condition VCP line w/
cracked & broken pipe throughout.
Pipe is severely broken and
threatening total collapse from 220'
DS on to where it IS
COLLAPSING @ 262' DS, survey
abandoned.
Surveyed portion of line (60' of
322') is in poor condition. Pipe is
severely cracked & broken
throughout. Camera remains near
total submergence for entire
inspection until being obstructed @
60' DS
Fair/poor condition line w/ some
cracking & broken pipe detectable
(video was shot while in reverse
due to high amount of flow, yet
camera still remains submerged for
most of the inspection.
Line is fair. Camera, although
submerged all the way, travels MH
toMH.
Line is in fair condition w/ a
capped hole @ 9' DS. Hole does
not threaten failure to pipe anytime
soon.
O&M
Recommendation
Root Program
None at this time
None at this time
None at this time
None at this time
None at this time
Structural
Recommendation
Replace
Replace
Replace
Replace
None at this time
None at this time
D-126
-------
Object ID
1143161
1143212
572405
572403
572402
572404
569066
569065
572401
483786
591073
Lateral/
Main
M00017
M00017
M00017
M00017
M00017
M00017
M00017
M00017
M00017
M00017R
M00017R
USID
052+83
050+80
046+50
045+28
043+64
042+65
041+99
040+48
038+58
085+00
073+75
DSID
050+80
046+50
042+65
043+64
041+99
045+28
040+48
038+58
033+74
081+88
071+06
Pipe
Size
12
12
12
10
10
10
12
12
12
10
10
Pipe
Material
HDPE
HDPE
HDPE
Vitrified
Clay
Vitrified
Clay
Vitrified
Clay
Polyvinyl
Chloride
Polyvinyl
Chloride
Vitrified
Clay
Polyvinyl
Chloride
Ductile
Iron
Additional
Review/
Comment
None
None
RECORDING
COMING
BACK.. .due to
high flow
2005 inspection
None
None
None
None
D/SM/HIN
CREEK BED
None
UNDER I -35
CCTV review Comments
Line is in fair condition w/ slightly
intruding tap @ 168' DS, no cause
for concern.
Line is in good condition w/ the
exception of a minor offset joint @
218' DS from USMH. See RSU.
Fair condition HDPE from DSMH
to 309' US then turns to POOR
condition, replace VCP for the
remaining 62' (from USMH to 62'
DS).
Line is in good condition.
Line is in fair condition. High
flow.
Line is in fair condition. High
flow.
Line is in good condition.
Line is in fair condition.
Camera totally submerged &
obscured by flow & suds. Appears
to be flowing well.
Line is in good but somewhat glue
caked" condition. Video is almost
totally from submerged viewpoint."
Line is in fair condition w/ a
moderate deterioration zone from
32' to 38' DS. Pipe here has some
wear & small holes w/ sharp edges,
none threaten the pipes current
structural capabilities.
O&M
Recommendation
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
Structural
Recommendation
None at this time
None at this time
Replace
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
D-127
-------
Object ID
603281
603282
589070
589071
589072
589073
589074
Lateral/
Main
M00017R
M00017R
M00017R
M00017R
M00017R
M00017R
M00017R
USID
071+32
071+06
068+10
065+70
063+19
058+95
054+86
DSID
073+75
068+82
065+70
063+19
058+95
054+86
052+83
Pipe
Size
10
10
10
10
10
10
10
Pipe
Material
Ductile
Iron
Ductile
Iron
Polyvinyl
Chloride
Polyvinyl
Chloride
Polyvinyl
Chloride
Polyvinyl
Chloride
Polyvinyl
Chloride
Additional
Review/
Comment
M/H071+32
=075+97 BK
None
None
None
None
None
RECORDED
COMMING
BACK
CCTV review Comments
Line is in fair condition, making a
couple of fairly dramatic bends in
the 1st 40' DS from USMH.
Line is in fair condition. High
flow.
Line is in good condition.
Line is in good condition.
Line is in good condition.
Line is in good condition. Final 50'
of video is obstructed by soap suds,
line flowing well.
Line appears to be in fair
condition. High flow results in
mostly submerged video.
O&M
Recommendation
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
Structural
Recommendation
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
None at this time
D-128
-------
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D-129
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