2023 TWU Asset Management Plan

WATER DISTRIBUTION SYSTEM ASSET MANAGEMENT PLAN

For the City of Tyler

Prepared by: Halff Associates, Inc.

Firm Registration No. 312

halff.com

June 2023

Table of Contents

APPENDICES

The Appendices to the Asset Management Plan are provided as an electronic deliverable. The following items are included:

A. Data Updates

B. Tyler Staff Map Markup of Chronic Problem Areas

C. LOF & COF Score Tables

D. Water Main Maps for each LOF & COF Category

E. Key Attributes of High-Risk Assets

F. Score Distribution Summaries for each LOF & COF Category

G. Replacement Costs for the High-Risk Water Main Assets

H. Risk Geodatabase

List of Abbreviations

AC asbestos cement

AMP asset management plan

CI cast iron

City City of Tyler

COF consequence of failure

GIS geographic information system

COP copper

DI ductile iron

HSPS high service pump station

LOF likelihood of failure

long-term investment program

million gallons

million gallons per day

near-term inspection program

polyvinyl chloride

concrete

risk of failure

Tyler Water Utilities Department

United States Environmental Protection Agency

water treatment plant

Executive Summary

This Asset Management Plan for the City of Tyler’s water distribution system establishes methodology to prioritize pipeline condition assessment and renewal projects to optimize the allocation of limited funds to renew the assets at the most significant risk. Part one provides an inventory of the Tyler system, estimates condition and business risk exposure for each asset, and lays the groundwork for identifying existing and developing problems in the City’s distribution system. Part two assesses risk for all distribution system assets and presents inspection and investment plans for pipeline renewal. Applying a risk-based approach allows near-term and long-term projects to be effectively identified, planned, and executed. This Asset Management Plan should be updated every 3-5 years of active condition assessment/verification as the system’s structural and operational condition is assessed per the inspection plan outlined in this report.

The Tyler system risk analysis identified 802 high-risk individual pipe segments (segments with an overall risk score greater than 1.4), equating to 64 linear miles, or approximately 10% of the system. These high-risk assets represent the pipes most likely to fail, as identified by the system condition estimate, as well as the most severe consequences should these pipes

fail. Approximately 30% of the system is designated at medium risk, while the remaining 60% is designated at low risk. The risk analysis results inform the nearterm inspection plan to specify which pipes should be inspected first. Findings from the near-term inspection plan will significantly increase the City’s knowledge of its water system asset inventory, condition, and life expectancy. The long-term investment plan provides a high-level, 30-50 year estimate of costs associated with pipe renewal in the water system. Data and actionable findings from field inspection efforts can be used to refine the results of the long-term investment plan.

The maximum pipe age in the system is greater than 100 years, and the current average age of the system is over 50 years. Figure ES.1 shows the total footage of pipe installed during each decade.

Replacement and rehabilitation costs, in 2022 dollars, were estimated for each pipe segment, with replacement representing the highest estimated cost and rehabilitation representing the lower boundary of estimated renewal costs. In 2022 dollars, the estimated cost to replace all water distribution pipelines is $485 million, and the estimated cost to rehabilitate all water distribution pipelines is $370 million. Also, in 2022 dollars, the estimated cost

Figure ES.1. Pipe Length Installed per Decade

to replace all high-risk individual pipe segments is $47 million, and the estimated cost to rehabilitate all high-risk individual pipe segments is $35 million. The average design life was based on pipe material. Figure ES.2 shows the projections for the average end-of-service year for all water main pipelines, with the associated length of pipe and replacement and rehabilitation cost per year. The cumulative replacement and rehabilitation costs estimate upper and lower bounds for the anticipated cost to renew the pipelines currently in service.

Figure ES.2 indicates that Tyler, like most utilities, is behind in replacing those water main assets that have reached the end of anticipated service life in the years leading up to 2022, approximately 2.1 million linear feet. Therefore, a significant amount of catchup in water asset rehabilitation and/or replacement

is required. The cost to replace all pipes that have reached the end of their anticipated service life by the current year is approximately $257 million.

Based on the existing pipeline inventory, the City of Tyler has some work ahead to renew its aging water distribution infrastructure. The current short-term plan of targeting pipelines with the highest risk of failure and the greatest impact on system performance is an excellent first step in addressing pipeline infrastructure renewal needs. However, over the next 50 years, this plan will not eliminate the City’s projected pipeline renewal needs. Continued investment in Tyler’s water main infrastructure will be required to avoid further degradation of the system. The long-term investment analysis reinforces the need to increase the City’s investment in its pipeline infrastructure to catch up on system renewal that is likely overdue.

Figure ES.2. Pipe Failure Projection

1. Introduction

1.1 WATER DISTRIBUTION SYSTEM

The City of Tyler Water Utilities Department (TWU) operates and maintains the City of Tyler water distribution system and facilities. TWU water system pipelines have a diameter range of 1.5 to 48 inches and a total length of almost 710 miles. The City of Tyler water system consists of two water treatment plants (WTPs), each with a high service pump station (HSPS), five booster pump stations, a ground storage volume of 8.9 million gallons (MG), an elevated storage volume of 9.0 MG, and six pressure planes within one primary pressure plane. TWU operates two WTPs that provide the entire drinking water supply to all City of Tyler (City) customers. The WTPs have a combined rated treatment capacity of 58 million gallons per day (MGD), with 28 MGD from Golden Road WTP and 30 MGD from Lake Palestine WTP. The existing rated high-service pumping capacity from the two WTPs is 88 MGD, with 38 MGD from Golden Road HSPS and 50 MGD from Lake Palestine HSPS. The stated pump capacity at Golden Road takes into consideration this facility’s existing physical and electrical limitations, which inhibits the utilization of all pump combinations. The existing average day water demand is approximately 20.3 MGD, and the existing maximum day water demand is approximately 50.7 MGD. The City of Tyler’s water distribution system is shown in Figure 1.1

TWU’s existing water distribution system serves approximately 34,040 water billing accounts for residential, commercial, and industrial customers. Each customer receives water from the distribution system through their individual water meter, which acts as the point of ownership transfer between the distribution system and the customer line. TWU maintains all water lines and connections on the distribution system side of the water meters, and the customer is responsible for any line maintenance from the water meter to the building.

The TWU water distribution system was first developed in the late 1800s and served by groundwater until 1951, when the Golden Road WTP was built. Some piping from the original distribution

system purchased by the City in 1916 is still in service today. The oldest pipes in the system are estimated to be almost 140 years old, located North of Downtown in the region bounded by Gentry Parkway and Martin Luther King Jr Boulevard. Development of the City has expanded from the Downtown area, and new development is primarily focused south of South Loop 323. The development history of the City and the associated water main age is shown in Figure 1.2

Pipe material preferences have remained fairly constant, with ductile iron pipe being the dominant pipe material installed in the Tyler system, followed by cast iron and PVC. Figure 1.3 shows the approximate distribution of water pipe materials in the Tyler system as a percentage of the total pipe length. The ‘Other’ category includes the following pipe materials: asbestos cement, copper, and concrete.

Figure 1.3. Pipe Material – Water Mains

Figure 1.1. Water Distribution System

Figure 1 2 Water Main Age

Figure 1.2. Water Main Age

1.2 ASSET MANAGEMENT DESCRIPTION AND BENEFITS

The purpose of a municipal water utility is to provide safe and reliable drinking water to the City’s customers. The consequence of not meeting this objective includes the potential to negatively impact public health and the environment. Water systems are increasingly faced with challenges that both raise the system’s performance requirements and lower the available tools to improve and maintain the existing system. Water system challenges include:

◦ Increases in demand from population growth,

◦ Budgets limitations and opposition to water rate increases,

◦ Asset failures triggering emergency response and replacement,

◦ Decisions about time and method to fortify aging assets,

◦ Regulatory requirements are becoming increasingly more strict, and

◦ Operations and maintenance efforts to effectively protect and prolong aging infrastructure.

Asset management for water distribution systems is a transition in the infrastructure management approach from reactive methods which build then operate to failure, to proactive methods which manage the distribution system more strategically. An asset management approach prolongs asset life by prioritizing rehabilitation, repair, or replacement decisions through informed and proactive operations and maintenance practices. Through asset management, utilities maintain assets at the desired level of service at the lowest life cycle cost. This management philosophy lowers the chance of failure and employs cost-effective options to extend the remaining useful life of assets before replacement is required. Asset management focuses on system sustainability and budgeting that prioritizes critical

system performance projects. An effective asset management plan can result in the following benefits for the water utility:

◦ Improved security and safety of assets,

◦ Informed decision-making to prolong asset life,

◦ Achieve system performance demands and requirements,

◦ Develop informed costs for operational and financial planning,

◦ Determine long-term budget forecasts,

◦ Improved emergency response, and

◦ Reduced overall costs for operation and capital expenditures.

This Asset Management Plan (AMP) will outline the management paradigm coupled with business processes, practices, and tools to be applied to all infrastructure assets at all levels of the City of Tyler. With the effective application of asset management, the infrastructure inventory, condition, performance, and maintenance knowledge of each asset in the water distribution system will continuously improve over time.

1.3 USEPA 10-STEP ASSET MANAGEMENT PROCESS

The United States Environmental Protection Agency (USEPA) developed the Fundamentals of Asset Management, which established the framework for asset management policy based on this Asset Management Plan. The USEPA asset management framework is centered on five core questions:

1. What is the current state of the assets?

2. What is the required “sustainable” level of service?

3. Which assets are critical to sustained performance?

4. What are the best O&M and CIP investment strategies?

5. What is the best long-term funding strategy?

Figure 1.4. Advanced Asset Management – USEPA Ten-Step Process

These five core questions provide the framework for asset management’s best practices. The five-core questions can be addressed following the USEPA Asset Management ten-step process shown in Figure 1.4

Steps 1 through 4 address the first core question by developing the inventory of assets and then estimating each asset’s condition and remaining useful life. Each asset’s value and replacement costs can be determined with this information. Initially, the inventory will include necessary estimations, given the inherent difficulty in obtaining much of this information for buried assets. The inventory accuracy will improve as assets are rehabilitated, repaired, or replaced.

Step 5 addresses the second core question by establishing the system’s required performance level based on regulatory requirements and customer satisfaction. The level of service and system performance goals can be defined by quality, quantity, reliability, and environmental parameters.

Step 6 addresses the third core question by assigning a ranking to each asset to identify those with the highest likelihood of failure and criticality to the system’s operations. Higher failure risk can be attributed to age and other parameters that degrade the integrity of the asset. An asset’s criticality to the system can be attributed to the consequences if the asset fails, such as the cost of replacement and disruption to system operations. Steps 7 and 8 address the fourth core question by optimizing the work assigned to O&M crews and opting for rehabilitation versus replacement, where appropriate, through risk-based decision-making. These steps constitute the transition from reactive maintenance to predictive maintenance by prioritizing assets with the highest risk and consequences of failure, made available through risk analysis. Step 9 addresses the fifth core question by determining the ability to meet the system’s long-term needs with the existing financial forecast.

Identifying deficiencies in the existing funding strategy allows for alternate strategies to be considered and applied before the future system is unable to meet a performance goal. Step 10 is addressed by the completion of this AMP, but this document can and should be updated as progress is made through implementing an asset management program and new best practices are established in the future.

As asset management is implemented and evolves for the City of Tyler, it will establish a decision framework that includes planning, engineering, construction, operations, and maintenance elements. Asset management is a coordinated action plan to help the City of Tyler maintain the desired level of service that its assets can provide at the lowest life cycle cost. This AMP intends to aid in implementing an asset management program to be practiced at all levels of the City of Tyler.

1.4 ASSET MANAGEMENT REPORT ORGANIZATION

The main goal of this AMP is to provide the results of the distribution system risk analysis with a final prioritized list of water system assets to guide the City in prioritizing its distribution system assets for rehabilitation or replacement. It also includes recommendations and action plan for implementing asset management business principles and processes for the water distribution system.

This AMP summarizes the information currently available for TWU’s existing water main assets into a single, concise document and accompanies the GIS deliverables with this information specified for each asset. Figure 1.5 summarizes the organization of this report and identifies where each core question and step of the USEPA ten-step process are addressed by section of this report.

Figure 1.5. Report Organization

2. City of Tyler System Inventory

Step one requires the development of an asset inventory to summarize the location and physical attributes of all assets in the system. Per the scope of this project, an asset inventory has been developed in the form of a geospatial-aware database from the previous GIS project completed by Halff and information provided by the City.

The detailed asset inventory was developed using existing data and information obtained through Tyler’s geographic information system (GIS), geocoded work order data, the staff knowledge workshop, and staff communication and feedback. The basic steps involved in developing the asset inventory included:

1. Identifying and organizing sources of inventory data

2. Defining the unique asset identifiers

3. Developing the asset inventory using the existing unique asset identifiers

4. Identifying data gaps in attribute and location information

5. Developing the asset data through review, gapfilling, and data refinement

6. Assessing the asset data for age, useful life, and opinion of probable replacement cost

Available data that helped to characterize the assets, such as size, material type, and other attributes, were collected as the asset inventory was developed. A summary of the data and information collected for each asset is described in the following section. There were seven essential pieces of information common to all assets that were developed during the inventory process:

1. Unique Identifier – a unique label assigned to each asset based on the Tyler database standard asset labeling convention (HalffAssetID).

2. Owner – ownership data is essential to the proper selection of water mains to be evaluated as part of the AMP. Water main ownership data was refined as part of this project.

3. Year installed and age – age is a critical factor in evaluating the current state of an asset relative to its overall life cycle.

4. Material – asset material is an indication of common deterioration or aging characteristics.

5. Useful life – average useful life data was developed based on industry standards adapted for the Tyler system by operations and maintenance staff.

6. Remaining useful life – Average useful life minus the current asset age.

7. Replacement value – Opinions of probable replacement value were estimated for each asset and included in the overall inventory.

The asset inventory created a baseline snapshot of data required to manage the Tyler water main infrastructure on an asset-centric basis. Tyler can now build on this initial inventory by expanding and improving the quality and completeness of the asset data contained in the inventory. An asset management business process will need to be established to maintain asset data and incorporate any changes or improvements made to each asset in the Tyler system.

2.1 ASSET INVENTORY DATA

Much of the inventory data was gathered from the City’s GIS. Asset inventory efforts also included the City’s geocoded work order and customer complaint data, facility age estimated from plan sets and development polygons, and pressure and flow data incorporated from the City’s hydraulic model. The asset inventory data was used during the likelihood and consequence of failure analyses. Valves were not scored uniquely as part of this analysis.

2.1.1 AGE, MATERIAL, AND SIZE DISTRIBUTION

The water distribution system contains nearly 710 miles of pipe. The system was standardized into approximately 10,581 individual segments of water main for this study. This segment count includes all pipes in the distribution system at the time of this study. A summary of the water mains based on the year of an installation is presented in Figure 1.2 and a cumulative age profile is shown in Figure 2.1

Pipe material distribution was presented previously in Figure 1.3. The size distribution of water mains in Tyler is shown in Figure 2.2.

2.1.2 WATER VALVES

The water distribution valves are integral to the City’s water distribution system. The City’s GIS database includes an inventory of all the water distribution system valves, amounting to approximately 8,060 valves. Although these water valves were not evaluated individually, critical operation valves such as pressure plane isolation valves and valves associated with pump stations, elevated storage tanks, and other water and wastewater facilities were associated with water mains as part of the Critical Operation score included in the risk analysis and prioritization.

2.1.3 DATA REVIEW AND CORRECTION

As a part of the AMP analysis, the GIS and work order data provided by the City was checked for accuracy and refined as appropriate. Details of all data updates are provided in Appendix A.

Figure 2.1. Pipe Age Profile (1885-2022)

Figure 2.2. Pipe Diameter Distribution – Water Mains

3. City of Tyler System Condition Estimate

An estimation of the condition of each asset is key to understanding the overall state of the water main system assets. The initial, top-down evaluation of asset condition reported herein applied all available data along with staff knowledge to develop an overall system condition estimation. Asset condition data were developed from available operation and maintenance data, the results of a staff knowledge workshop held on 8 April 2022 and a map markup completed by operations and maintenance staff. Through the staff knowledge workshop and map markup, operations and maintenance staff shared institutional knowledge and experience in dealing with individual assets. The condition data available for each asset were then incorporated into an overall system condition estimation.

3.1 COMPILATION OF AVAILABLE CONDITION DATA

Data was compiled from several sources to estimate system condition and performance. The data consists of information gathered from the staff knowledge workshop, historical work order data, hydraulic modeling data, and other system performance data.

3.1.1 STAFF CONDITION SCORES

Through the staff knowledge workshop and map markup, the feedback provided by Tyler staff members included the identification of specific areas in the water system with frequent issues and prioritization of the water mains from perceived pipe conditions. Tyler Staff members were provided with a map of the water distribution system pipes, which they used to identify areas with frequent issues and asked to rate the condition of the water distribution system assets. Staff members assigned condition scores using the condition descriptions listed below.

Score 1 – Good Condition: pipe is in good structural shape, with no breaks or leakage; major rehab or replacement will not be needed for at least 10 years.

Score 2 – Fair Condition: normal pipe wear but structurally sound, may have minor leakage or other problems, and will probably need work within the next 10 years.

Score 3 – Poor Condition: structural issues, leakage, or breaks are a concern, and other problems are common; they should be rehabilitated or replaced within the next 5 years.

The markup provided by Tyler staff members is included in Appendix B. The results of the staff scoring are summarized in Table 3.1 Figure 3.1 provides a map of the results for all assets.

The green, yellow, and red coding for asset condition and risk scores indicate good, fair, or poor condition. In general, the color red indicated assets of concern that may need some near-term attention.

Table 3.1 Summarized Score Staffing

Figure 3.1. Staff Opinion of Condition Scores

Figure 3 1 Staff Opinion of Condition Scores

3.1.2 STAFF CONDITION SCORES

Three criteria were used to assess the historical performance of the water distribution system:

• Number of repairs made to pipeline assets

– Maintenance work orders generally indicate maintenance repair intensity and overall performance.

• Customer water quality complaints – This includes complaints related to the visual color quality of the water as well as taste and odor problems. Historical water quality service order records for the period of January 2017 to February 2022 were requested from the City and were received as a point shapefile for estimation of pipeline performance.

• Hydraulic performance – Hydraulic model results from the City’s InfoWater model were used to identify potential areas with low water pressure.

3.1.2.1 Repair History

Water system break repair data (2016-2022) was provided as a GIS shapefile. The attributes included the date, address, and work order description. The following work order categories were used for pipeline performance history: Cave-In (Water), Dig Up Water Service, Hydro Excavate Water Main, Pothole Water Main, Valve Dig-Up, Valve Repair, Valve Replace, Water Main Repair, and Water Main Replace. The 1,993 water main work orders during this period were compiled and analyzed. A map of the work orders is illustrated in Figure 3.2.

3.1.2.2 Water Quality Complains

Water quality complaints include the visual color quality of the water as well as taste and odor problems. Water complaint data from 2017-2022 were analyzed, and a total of 2,466 custom complaints were logged during this period. A map of the customer complaints is illustrated in Figure 3.3.

3.1.2.3 Hydraulic Performance

The City has developed a hydraulic model of the water distribution system. The City’s InfoWater model for the water system was used for this analysis. The water model results (average pressure for the maximum day model run) were used to analyze the lines associated with low pressures.

The model results indicated a wide range of pressures throughout the system; however, pressures are typically maintained above 50 psi for the majority of the system. The average water pressure results are shown in Figure 3.4. Based on the maximum day model run, typical pressures in the distribution system range from 35 to 140 psi with an average of 80 psi.

3.2 CONDITION ESTIMATION –CONCLUSIONS

The initial data collection, asset inventory, and performance estimates provided the foundation for the risk analysis and prioritization of the City’s buried infrastructure. While there were some gaps in the data obtained, ample data was available to complete the risk analysis and finalize the Asset Management Plan.

Updates to the Tyler water system asset inventory and attribute data are provided along with the asset management plan as electronic deliverables. This data should be incorporated into the City’s asset information management systems. Validation and updating of the asset inventory data should be maintained as an asset management business process. The data can be enhanced through field inspections and other data management initiatives. The condition estimation and risk assessment will assist the City in targeting the buried assets that require additional field inspection, replacement, and rehabilitation.

Figure 3.2. Work Order History

Figure 3 2 Work Order History

Figure 3 3 Water Quality Complaints

Figure 3.3. Water Quality Complaints

Figure 3 4 Average System Pressure

Figure 3.4. Average System Pressure

4. The City of Tyler System Risk Assessment

4.1 RISK ASSESSMENT PROCESS

For most utilities, it is challenging to prioritize asset replacement or rehabilitation and set the timeline for renewal actions. A business risk assessment can help to establish renewal priorities for existing assets. The business risk assessment is a standard approach in advanced asset management to better manage an individual asset across its entire economic life. The risk assessment considers the condition of an asset in terms of how likely it is to fail, and it factors in the consequence of failure of the asset. The following section summarizes the business risk assessment conducted for the Tyler water system assets.

The business risk assessment process aims to quantify the risk of asset failure (ROF) using the equation shown in Figure 4.1.

The Likelihood of Failure (LOF) is an estimate of condition and assesses an asset’s ability to meet the intended level of service. The Consequence of Failure (COF) measures the potential impact that an asset failure may have on utility customers and the surrounding area. COF is generally related to location. It relates the impact of asset failure to repair cost, disruption to the public and economy, impairment of system operation, regulatory compliance, public health and safety, and environmental damage.

The nine-step process shown in Figure 4.2 was used to develop the business risk assessment step in the

USEPA’s ten-step asset management process. As highlighted in the tan boxes, this process offered Tyler staff several opportunities to provide input for the risk assessment and to validate results.

LOF and COF components were selected by Tyler staff to develop a custom risk matrix for the water system. Table 4.1 summarizes the water main LOF and COF risk matrix components, the associated database fields, and weighting factors. The staff selected the specific weights applied to each component in the overall risk analysis. To validate the risk scoring approach, detailed scoring tables for the water main system were developed and reviewed by Tyler staff to define the data sources and methodology. The detailed scoring tables are provided in Appendix C.

The risk scoring was conducted in a GIS environment using database tools to compute each asset’s risk score based on the Tyler risk matrix scoring tables and geospatial attributes. The risk results are presented as a composite LOF, COF, and ROF score. These are generated for each asset, and all assets are ranked by risk score.

Results from the water main system risk analysis are provided in various formats. The generic risk result matrix in Table 4.2 shows an example of the typical red, yellow, and green color coding used to communicate risk results on both charts and maps.

• Red denotes high-risk and indicates the assets assigned a top priority for further evaluation and detailed field inspection, which is recommended to

identify repairs and forecast when a comprehensive rehabilitation program may be required.

• Yellow denotes the medium-risk assets which should be inspected and evaluated within the next ten years.

• Green represents the low-risk assets that should be monitored and re-evaluated when updates are made to the renewal forecasts.

As assets age, LOF scores will typically increase as asset condition deteriorates. In contrast, COF scores do not change unless the environment surrounding the asset changes.

Preliminary risk results for water mains were reviewed with the Tyler utility staff on 8 April 2022. Based on staff feedback, adjustments were made to specific risk matrix scoring tables to better represent the water main system conditions and risk of failure. Finalized risk results were presented to the Tyler team on 23 June 2022. The final risk scores for water mains were calculated and plotted to indicate the relative state of the assets in each risk of failure category. For each LOF and COF category, a water main map is provided in Appendix D. The composite ROF score for each asset provided

the basis for prioritizing or ranking the assets for future inspection and evaluation. The final risk results were compiled and used to develop near-term inspection recommendations.

4.2 RISK RESULTS – WATER MAINS

A detailed risk analysis for the water mains was developed based on the risk matrix shown in Table 4.1. The analysis used a GIS-based risk scoring tool customized for Tyler to compute the LOF, COF, and ROF scores for each of the system’s 10,581 water main line segments. All pipe segments in the water distribution system at the time of this study were included in this analysis, regardless of diameter. All risk analysis results are unique to the Tyler system. This is due to the specific input data available for the risk

Figure 4.2. Business Risk Assessment Step Process

Table 4.2. Generic Risk Results Matrix

Water Main Risk Matrix Components and Weighting Factors

analysis, the customized risk matrix parameters, and the customized risk scoring weights. Because of the specificity inherent to the risk analysis, the Tyler risk results should not be directly compared with risk results for other cities or water utilities.

Following the Tyler staff review of the preliminary risk scoring results, adjustments and refinements were made to the scoring tables before the final calculation of risk results. Figure 4.3 shows the low, medium, and high-risk results profile for water main assets. Table 4.3 presents the risk results in terms of total linear footage in the Tyler system, and Table 4.4 presents these risk

results as a percentage of the total length of water mains.

Figure 4.4 displays the breakpoints selected for relative risk categories, as well as the overall risk results for the 10,581 line segments included in this analysis. Breakpoints were selected from inflection points in the risk analysis results output and an inspection target for all high and medium-risk assets to be inspected within a seven-year program. The line segments with risk scores less than 0.9 were placed in the low-risk category. Line segments with risk scores between 0.9 and 1.4 were placed in the medium-risk category. Line segments with overall risk scores greater than 1.4 were placed in the high-risk category. The highest ranking pipe lines should be inspected in the near term to evaluate the need for line maintenance, rehabilitation, or replacement.

The final risk results were sorted and prioritized according to ROF scores, with the highest score assigned the rank of 1. The draft risk results and ranks were reviewed with Tyler staff in a post-prioritization workshop on 23 June 2022. The high-risk water main assets are provided with key attributes in a table in Appendix E.

Table 4.1. Water Main Risk Matrix Components and Weighting Factors

Figure 4.3. Risk Profile

Figure 4.5 provides a map summary of the water main risk results, along with a supplemental risk score distribution plot. For additional details, the maps and score distribution summaries for each LOF and COF risk category are provided in Appendix F.

Table 4.3. Risk Results as Total Footage

Table 4.4. Risk Results as Percentage of Total Footage

Figure 4.4. Breakpoints of Relative Risk Categories for Water Mains

Figure 4.5. Risk Results Summary

Figure 4.5. Risk Results Summary

5. Asset Management Implementation

This initial AMP provides the basis to implement an advanced AMP for Tyler’s water main distribution system. The development of a comprehensive water main inventory provides the initial step to allow the City to track and manage individual pipeline assets by unique identification numbers. The asset inventory is housed in a GIS risk geodatabase (Risk Geodatabase, Appendix H) that will be delivered electronically to the City and provides a substantial amount of attribute data for each asset. Available physical and performance data are included in the asset inventory.

The initial asset condition estimate relied on staff knowledge and experience, as well as on the available performance data. LOF, COF, and ROF scores are primarily based on top-down or desktop data. Reliance on the input from the people who best know the system provides a level of assurance that these initial results can be used to target the highest priority assets for routine maintenance, inspections, and repairs.

Full implementation of a water distribution system AMP will take several years to complete. The work completed in this project should be viewed as the initial step in developing a long-term program. Asset management is typically developed through a process of continuous improvement. Based on the USEPA’s 10 steps to implement an asset management process, Table 5.1 summarizes the asset management work accomplished thus far. A summary of the next steps for asset implementation is provided in the final column of the table. Policies and business practices associated with document and information management, asset management information systems, operations and maintenance integration, and strategic decisionmaking should be developed to support continued implementation and improvement of the overall asset management process.

5.1 ASSET INFORMATION MANAGEMENT

In conjunction with the provided supplemental data for work orders and customer complaints, the Tyler GIS will be the primary information management system used to monitor the water main distribution system. The risk parameter attributes and scores, composite risk scores, replacement costs, and other data that were

developed and refined in the risk geodatabase should be incorporated or linked to Tyler’s geodatabase. A process to link the maintenance and performance data in Tyler’s work order system to the GIS should be established to maintain asset history based on each asset’s unique identification number.

5.2 ASSET MANAGEMENT BUSINESS PROCESSES

The AMP components developed in this project cover the initial phase of asset management development for Tyler’s water main system. As the AMP is implemented further, physical inspections and other condition performance measures can be used to refine the baseline data developed in the AMP and improve Tyler’s assessment of the remaining useful life and renewal options for all its water system assets.

The initial baseline data summarized in this plan can be enhanced through the development or refinement of several asset management business practices as summarized in the following:

1. Asset Inventory Updates – The updated City water system asset inventory will be maintained in the existing GIS database. Validation and updates of the asset inventory data should be an ongoing process. Field inspection data should be added to the City’s data development plans.

2. Asset Conditions and Failure Assessments – Validation and updating of asset condition data should be continued through maintenance information and field inspections. More detailed asset failure analyses can be developed for highrisk assets.

3. Performance Data Updates – The City work order system should be linked to the asset inventory geodatabase in GIS to enhance the ability to collect and evaluate performance, service, maintenance, and other asset management data. Once the City’s GIS is updated from the asset inventory and risk results geodatabase (Risk Geodatabase, Appendix H), guidance on which fields to link should be directed by the new and refined data fields listed in the tabular format for water main polylines (Appendix H).

4. Integrate Operation and Maintenance Practices

– The initial water main distribution system asset management plan focuses on asset inventories, condition estimates, and risk assessment to develop a capital renewal plan. As the program develops, operations and maintenance information should be tied to assets for updating performance and optimizing O&M costs on an asset basis. O&M costs should be combined with the capital cost projections for a total asset cost forecast.

5. Update Asset Risk Assessment – Performance data combined with inspection and rehabilitation data should be used to update LOF and COF scores and reprioritize assets based on new ROF scores. New technologies like machine learning approach allow the City to model the historical

likelihood of failure for improved insight about the Tyler water system’s failure history, trends, and patterns. This approach leverages the City’s work order data and water main failure data along with extensive asset-specific attributes to calibrate the LOF score according to the system’s observed failures and poor condition.

6. Refine Replacement Costs and Useful Life

Data – Tracking asset replacements as they occur will help update and customize the survival curve projections and actual replacement cost data. This will allow for a more refined analysis in future years.

USEPA 10-Step Advances Asset Management Process

Step 1. Develop Asset Registry

Asset Management Components Completed in Initial Development of the Tyler Asset Management Plan

Added and refined key asset attribute data.

Asset Management Steps for the Continued Development of an Asset Management Program

Transfer or link the attribute data inventories to the Tyler GIS and continue to verify, expand, update, and add inventory data. Develop a process to update system changes.

Step 2. Asset Performance Assessment

Initial condition and performance estimates were completed and documented.

Begin a more detailed condition assessment of priority assets and analyze their potential failure modes. Recommend the application of a machine learning approach to gain advanced understanding of failure modes through analysis of past work orders and break data.

Step 3. Determine Residual Life

Step 4. Determine Replacement Costs

Step 5. Set Target Levels of Service

Step 6. Conduct Risk Analysis

Asset age and survival curve data were developed to determine asset residual life.

Initial asset replacement costs were developed for all assets in the inventory, as presented in Section 6.3.

Initial asset performance data was compiled and used in the condition estimate.

Risk matrices were developed with LOF and COF components, weights, and scoring criteria. A baseline business risk assessment was performed for all assets.

Validate age and useful life data. Identify conditions that can impact the useful life of pipes.

Validate and update replacement cost data.

Develop target service levels to help measure progress toward asset management goals and objectives.

Link or incorporate the ROF data into GIS and develop a business process to update and maintain LOF, COF, and ROF data current into the system.

Step 7. Optimize O&M Investment

Step 8. Optimize Capital Investment

Step 9. Determine Funding Strategy

Developed initial capital investment strategy based on ROF prioritization of the assets, as presented in Section 6.3.

Link existing work order and maintenance data into system inventories and individual pipeline assets in the GIS inventory. Begin utilizing the unique asset ID’s as part of work order reporting, to shift from a simple addressbased WO documentation to an asset-based system.

Update the near-term capital investment program based on the results of additional field investigations.

Develop and summarize near-term capital funding requirements for Tyler. Analyze the impact of the various funding options or the services rates, tax rates, and long-term investment requirements.

Step 10. Build AMP The initial AMP was developed. Develop a process to update the AMP on a five-year cycle.

Table 5.1. Accomplishments and Next Steps for Asset Management Implementations

6. Asset Inspection and Investment Plan

Based on the information presented in previous chapters, annual recommendations have been developed to guide a near-term inspection program. The inspection program results will guide a strategic investment to support the long-term repair and rehabilitation of the City’s water distribution system, as well as to improve the integrity of key data attributes for these assets.

6.1 NEAR-TERM INSPECTION PROGRAM

The work identified in the proposed near-term inspection program (NTIP) will take place over the next seven years (2023-2029) and focus on inspecting water mains and their associated valves and fire hydrants. The recommended process for the NTIP is described below:

The total length of pipelines inspected annually was limited to a condition assessment cost of approximately $500,000 to align with the City’s annual pipeline rehabilitation and replacement budget. Limiting the annual inspection rate to this value means that all high and medium-risk assets can be inspected within a seven-year program. The highest-risk water mains (through risk rank 802) are recommended for field inspection during the first two years (2023 and 2024) of the seven-year program. An annual condition assessment budget of approximately $630,000 would allow the inspection of all high and medium-risk assets within a five-year program. However, this would require the City to increase its annual pipeline rehabilitation and replacement budget in the near term, so the current annual budget of $500,000 is used in this report.

Due to the operational challenges, logistics, and expense associated with internal inspection of active water mains and/or taking lines out of service, a twotiered approach to water main and valve inspection is recommended:

First Tier (above-ground, acoustic leak detection methods):

a. Application:

◦ To locate potential leaks and closed and/or undocumented valves.

◦ To identify areas of the water distribution system that may require internal inspection.

b. Benefits/Drawbacks:

◦ Allows the water mains and valves to remain in service during the inspection.

◦ Relatively inexpensive (allowing for basic condition assessment of more water mains and valves).

c. Additional Notes:

◦ Air and inline valves, along with fire hydrants, should be inspected and exercised, and any required maintenance should be performed. These proactive maintenance measures confirm that valves and hydrants are in good working order and can help to reduce the consequence of pipeline failure due to malfunctioning valves or gas pockets.

◦ A business process should be developed so that data collected from first-tier inspections can be used to verify, expand, update, and add inventory data. These results can be linked to the Tyler GIS or another robust system, such as Cityworks.

Second Tier (internal inspection methods)

a. Application:

◦ Includes tethered and free-swimming technologies inserted within the pipe to gather information such as pipe wall thickness, internal condition, and video footage.

◦ Recommended further investigation of pipe segments in the water distribution system that are flagged by first-tier methods for potential leaks, unacceptable pipe wall thickness, or malfunctioning valves.

b. Benefits/Drawbacks:

◦ Provides additional information for pipe segments flagged by first-tier methods but is typically more intrusive and expensive than first-tier inspection methods.

c. Additional Notes:

◦ For the NTIP, 5% of assets inspected using firsttier methods are anticipated to require second-tier inspections.

◦ Following the first full year of high-risk asset inspections (2023), all of the inspection data that has been gathered should be used to calibrate and refine the risk assessment matrix and scoring, as well as to guide the rehabilitation and replacement of water mains. The risk matrix calibration cost was not evaluated as a part of this analysis.

The NTIP for the water main system is summarized in Table 6.1 with seven years of annual assignments and a project 7-year cost totaling $3,137,000.

The water distribution system NTIP for 2023 through 2029 focuses on assessing the physical condition of the high- and medium-risk water main assets with their associated valves and hydrants, as well as the data integrity of these assets in the City’s GIS records. Through these efforts, asset defects will be identified, and funding will need to be secured to address rehabilitation and replacement needs.

In addition to identifying any required system repairs, condition assessments will provide a unique opportunity to verify and refine the integrity of primary GIS data for all water main assets. Refinement of the GIS data will translate into enhanced accuracy during each risk score and ranking update for the City’s water

main assets. The cost to verify data integrity was not evaluated as a part of this analysis.

The following is key data that should be recorded during the water main, water valve, and hydrant inspections. This data should be updated in the City’s GIS records for inclusion in the risk score calibration exercise:

Water Main Inspections

• Unique identifier of the asset

• Condition evaluation using a uniform pipeline assessment system

• Number of defects per line

• Age

• Diameter

• Material

• GIS text field for a hyperlink to detailed inspection data or video

Water Valve/Hydrant Inspections

• Unique identifier of the asset

• Unique identifier of connection pipelines

• Condition evaluation via uniform valve/hydrant assessment criteria

• Description of defects per valve/hydrant

Table 6.1. System Inspection 7-Year Plan - Water Mains and Valves

Years 1-3 of the NTIP should be viewed as a risk calibration period. The condition evaluation for assets inspected by the end of the first year should be critically evaluated against the 2022 AMP LOF score and rank. If a majority of the highest-risk assets in the system are found to be in poor condition and need rehabilitation or repair, then the City’s risk-scoring matrix may not need much refinement. However, if the highest risk assets are in mixed or better condition and appear to have substantial useful life remaining, then the LOF scoring matrix and weights should be adjusted. After appropriate adjustments are made, the risk scores and ranks should be re-evaluated before proceeding with the 2024 condition assessment activities.

An integral component of this NTIP is a timely and consistent review of the condition assessment data as they are produced to make any appropriate determinations of potential asset renewals. Actions may be categorized as follows:

• Asset in good condition – no action

• Asset shows sporadic or isolated defect(s) –consider point repair(s)

• Asset shows significant deterioration – prioritize asset for engineering review (internal or external) to determine best renewal action; determine the opinion of probable construction cost and add to CIP.

• Asset shows severe defect(s) – schedule for emergency repair.

Although it is impossible to predict the number and degree of defects to be found during the inspection program, the AMP provides some guidance regarding the possible costs. The Long-Term Investment Program, as detailed in the following section, provides a preliminary approximation of the rehabilitation costs the City will face over future years. Additionally, the opinion of probable cost prepared for each pipeline as part of the long-term analysis provides the City with an initial opinion of the cost for rehabilitation and a possible rehabilitation cost to utilize in the asset renewal, for those lines exhibiting significant defects upon inspection.

6.2 LONG-TERM INVESTMENT PROGRAM

The long-term investment program (LTIP) forecasts the pace and magnitude of long-term (30 to 50 years)

investment needed to sustain the City’s water system assets into the future. The LTIP is designed to predict the level of asset repair, rehabilitation, or replacement required to maintain standards of customer service and system performance over the coming decades. The LTIP analysis looks at cohorts or broad categories of assets with similar useful lives and degradation profiles. This high-level overview of the system is used to forecast costs based on industry replacement data that have been customized with specific institutional knowledge from within the City.

The LTIP forecast provides justification for budgetary targets relative to the City’s current investment in its assets. Given that many utilities have fallen behind with their system renewal efforts, the LTIP can provide the fiduciary motivation to maintain more informed renewal budgets over time. It can also help communicate to stakeholders the value of the existing infrastructure assets and the long-term renewal investment required to sustain those assets.

6.2.1 PIPELINE ASSET SURVIVAL TRENDS

A long-term investment analysis was conducted for the water main assets. The assets were grouped by pipe material, assuming that similar pipe materials will have comparable aging characteristics. For each pipe material group or cohort, survival function curves were developed based on industry standards and the number of years from installation to the time when:

1. 100% of the original assets would still be functional, or the number of years until the first significant asset failure.

2. 50% of the assets would still be in service without replacement or substantial rehabilitation or the average useful life of the asset group.

3. 10% of the original assets would still be in service without replacement or substantial rehabilitation, which essentially represents the maximum useful life of the asset group.

Figure 6.1 shows the survival functions developed for water main assets in the Tyler system, which consists of the following pipe materials: asbestos cement (AC), cast iron (CI), copper (COP), ductile iron (DI), polyvinyl chloride (PVC), and concrete (RCCP).

The long-term trends in the water main pipelines are largely governed by the type of material in the system, and the different time periods it was installed. The influence of the older AC, CI, COP, DI, and RCCP pipes, with their shorter life spans, will impact renewal rates for the next four decades. The PVC and other noncorrosive pipe materials installed from the 1970s through today are expected to last for decades with minimal renewal requirements. The following assumptions were made for assets with missing data for evaluation in the LTIP only:

• If pipe material was missing, the install date was used as a reference. The material was assumed to be DI if the installation date was before 1980 and PVC if the installation date was after 1980.

• If the pipe install date was missing, the material was used as a reference. The installation date was assumed to be 1980 if the material was DI or CI and 2000 if the material was PVC.

The distribution of water main pipes by material and the average end of service year is illustrated in Figure 6.2. The average end-of-service year is based on the current pipe age, the pipe material, and the year corresponding to 50% of the anticipated service life, according to the survival curves presented in Figure 6.1.

Figure 6.1. Survival Functions - Water Mains

Figure 6.2. Sum of Pipe Length by Material and Average End of Service Year

6.2.2 REPLACEMENT AND REHABILITATION COSTS

A general construction cost was developed for each line segment based on diameter, depth, and an assumed construction method. The open-cut construction method for a depth of up to 10 feet was selected based on the average burial depth of water mains in the City system. The replacement costs (2022 dollars) are based on recent Halff water pipeline projects. The resulting costs were converted to 2022 dollars and applied to the City system to provide an estimated replacement cost for each line segment. The estimated cost to replace pipelines for the entire water distribution system is $485 million. Appendix G provides a table of replacement costs for the highrisk water main assets in the system, accounting for approximately 10% of the estimated total pipeline replacement cost.

The estimated replacement and rehabilitation costs depend on the best available data at the time of this report and could inaccurately represent what the City has already completed in terms of renewing older assets. The estimated end of service year for each pipe is based on the best available data, which does not include georeferenced work orders for all previous pipe renewal projects completed by the City. Therefore, this

report cannot currently quantify which of the system’s assets have been renewed. However, the age and estimated remaining useful life can be validated during the NTIP and ongoing inspections, maintenance, and incorporation of repair histories. Continued and ongoing refinement of the GIS data will translate into enhanced accuracy of this long-term forecast for the City’s water main assets. For the time being, with this limitation, the total costs presented in this section should be considered the worst-case scenario as there may be fewer assets already in need of replacement.

Figure 6.3 shows the water main investment profile using 2022 replacement costs and cost-weighted age, based on the replacement cost figures for the water main assets. This figure presents the age of the system along with the annual investments that have been made since the first pipe was installed in 2022 dollars. The current cost-weighted age of the water system is 50 years. Current cost-weighted age is considered a more meaningful indicator of system condition than actual age. The primary pipe material in the water Figure 6.3 shows the water main investment profile using 2022 replacement costs and cost-weighted age , based on the replacement cost figures for the water main assets. This figure presents the age of the system along with the annual investments that have been made since the first pipe was installed in 2022 dollars.

Figure 6.3. Investment Profile

The current cost-weighted age of the water system is 50 years. Current cost-weighted age is considered a more meaningful indicator of system condition than actual age. The primary pipe material in the water system is DI, so using the survival curve functions presented in Figure 6.1, the average remaining useful life of the DI portion of the water main system piping is estimated to be 0 years.

A general rehabilitation cost was also developed for each line segment and serves as a lower bound to the estimated replacement cost. The sliplining rehabilitation method was selected based on the desire to minimize construction cost and footprint. The replacement costs (2022 dollars) are based on recent Halff water pipeline projects. The resulting costs were converted to 2022 dollars and applied to the City system to provide an estimated rehabilitation cost for each line segment. The estimated cost to rehabilitate pipelines for the entire water distribution system is $370 million.

Projections for the average end-of-service year for all water main pipelines, with the associated length of pipe and replacement and rehabilitation cost per year, are shown for the next 50 years in Figure 6.4. The solid red line represents the cumulative linear footage of waterlines installed over time, and the dashed red line is the aggregation of the individual pipe failure projection from Figures 6.1 and 6.2. The actual cost

of the pipeline renewal is expected to be bracketed by the cost of replacement (dark blue line) as an upper bound and the cost of rehabilitation (light blue line) as a lower bound. The individual pipe data presented in these figures were adjusted using the survival curves presented in Figure 6.1 to quantify the length of pipe still in service at 100%, 50%, 10%, and 0% of the anticipated service life. The anticipated end of service year is based on the current pipe age, the pipe material, and the year corresponding to the anticipated service life. Exhibit S (located in Appendix D) shows the estimated remaining service life for each pipe in the distribution system.

Figures 6.2 and 6.4 indicate that Tyler is behind in replacing those water main assets that have reached the end of anticipated service life in the years leading up to 2022, approximately 2.1 million linear feet (again, this data point does NOT reflect the amount of pipeline renewal that Tyler has been accomplishing over the years, and so it represents a worst case). Therefore, a significant amount of catch-up in water asset rehabilitation and/or replacement will be required.

6.2.3 PIPELINE ASSET FORECAST

The buried water pipeline assets represent a substantial City investment warranting a defined schedule for renewal. A typical goal for pacing water system replacement or rehabilitation is one percent of

Figure 6.4. Pipe Failure Projection

buried pipe per year. For the City, a one percent yearly replacement represents an investment of $5 million per year. At this pace, renewing the entire water distribution system would take 100 years. However, the City’s current annual pipeline rehabilitation and replacement budget of $500,000 is inordinately lower than the typical pacing goal. This renewal budget is insufficient as there are no known pipe materials that can remain in service for the time it would take to replace or rehabilitate the entire water distribution system. Figure 6.5 shows the required annual investment to support renewal programs having complete replacement schedules for a range of years.

Shifting the annual forecast data for the water main assets forward to 2023 provides the current 50-year renewal forecast, shown in Figure 6.6. The forecasts are based on estimated pipe survival curves and average asset replacement costs in today’s dollars. This long-term forecast will help the City manage the projected asset replacement costs in the future and the trends that explain variability in future needs. The LTIP forecast can help the City to establish appropriate rates to fund its ongoing investment in water infrastructure and adjust capital programs to dampen some of the peak years in the forecast. The specific line segments to be replaced should consider the prioritized risk ranking for consideration in future near-term capital improvement programs. Ongoing inspections, maintenance, and repair histories will provide better insight into the long-term performance of the various pipe materials. These data can be used to validate the assumed useful life and survival curve data and update the long-term forecast.

The largest annual rates of replacement occur in the 2000 to 2060 timeframe when the majority of the DI water mains are in the midst of a peak replacement period. From 2023 forward, the 50-year average replacement cost for the water main system is $4

Figure 6.5. Years Required for Complete System Replacement Based on Annual Expenditure

Figure 6.6. Anticipated End of Service and Replacement Cost Projections (1925 - 2072)

million per year. This 50-year cost does not account for the pipeline failure projected to have occurred before 2023, The first water main pipe (material cast iron) in the Tyler system is estimated to have failed in 1925. To establish a conservative catch-up cost, the total projected water main replacement costs from 1925 to 2022 ($257 million) were distributed over the next 30 years (2023-2063) and added to the annual projected replacement costs (Figure 6.7). The 50-year average replacement with a catch-up for the water main system is $9.2 million per year. These costs are in 2022 dollars and will need to be increased to account for inflation when budgeting for future years.

The projected annual replacement cost with the projected catch-up contribution for the water main asset categories is shown in Figure 6.7. To optimize pipe renewal project programming once pipe conditions have been verified through the NTIP, a few general guidelines should be considered:

• Assets with high-risk scores due to high LOF and COF components should be given the highest priority regardless of their estimated end-of-service life.

• Assets that have already reached the end of their estimated service life (catch-up contribution) should be given the next highest priority after all high-risk

assets.

• Medium-risk assets should be given the next priority, incorporating catch-up contributions along with the assets whose estimated end-of-service life occurs after 2022.

• Low-risk assets, assets not within the catch-up contribution, and assets whose estimated end of service life has not passed should be given the lowest priority.

The following guidelines should be considered within each programming level:

• If an asset’s risk score is high due to a high LOF component, a capital project should be considered. However, if the COF component is minimal, the renewal of this asset can be given lower priority within its programming group.

• If an asset’s risk score is high due to a high COF component, changes in operational procedures should be considered to increase redundancy to dependent customers and facilities until that asset can be replaced. Realignment of the pipe or parallel capital projects should be considered when this asset is renewed to reduce the COF component going forward.

Figure 6.7. Annual Replacement Cost with Catch-up Contribution (2023-2072)

7. Conclusions

Based on the age and material of the existing pipeline inventory, the City has some work ahead to renew its aging water distribution infrastructure. The current short-term plan of targeting pipelines with the highest risk of failure and the greatest impact on system performance is an excellent first step in addressing pipeline infrastructure renewal needs. However, over the next 50 years, this plan will not eliminate the City’s projected pipeline renewal needs. Continued investment in Tyler’s water main infrastructure will be required to avoid further degradation of the system.

The funding gap for water system infrastructure is a national issue. This analysis provides a good snapshot that reinforces the need to increase the City’s investment in its pipeline infrastructure and sustain the investment for the foreseeable future.

Implementing the NTIP will significantly increase the City’s knowledge of its infrastructure inventory, condition, and life expectancy. Actionable data and information gathered through the detailed field inspection program can be used to refine the results of the LTIP.

In conclusion, these are the recommended next steps for the successful management of water main assets:

• Asset Inventory Updates – The updated water main system asset inventory will be maintained in the existing GIS database. Validation and refinement of the asset inventory data should be an ongoing process. The field inspection data for all water mains should be added to Tyler’s data development plans.

• Asset Condition and Failure Assessments

– Validation and updating of asset condition data should be continued through maintenance information and field inspections. More detailed asset failure analyses can be developed for high-risk assets.

• Performance Data Updates – The work order system should be linked to the asset inventory geodatabase in GIS to enhance the ability to collect and evaluate performance, service, maintenance, and other asset management data. Once the City’s GIS is updated from the asset inventory and risk results geodatabase (Risk Geodatabase, Appendix H), guidance on which fields to link between the City’s GIS and work order databases should be directed by the new and refined data fields listed in tabular format for water main polylines (Appendix H).

• Integrate Operation and Maintenance Practices

– The initial water main distribution system asset management plan focuses on asset inventory, condition estimates, and risk assessment to develop capital renewal plans. As the program develops, operations and maintenance information should be tied to assets for updating performance and optimizing O&M costs on an asset basis. O&M cost should be combined with the capital cost projections for a total asset cost forecast.

• Update Asset Risk Assessment – Performance data combined with current inspection, rehabilitation, and replacement data can be used to update LOF and COF scores and reprioritize assets based on new ROF scores. It is recommended to perform this step annually.

• Build and Apply the AMP – Develop a process to update the AMP after the initial year and then on a five-year cycle. Leverage the AMP and the LTIP analysis to communicate to stakeholders the value of the existing infrastructure assets and the long-term renewal investment required to sustain those assets.

WATER DISTRIBUTION SYSTEM ASSET MANAGEMENT PLANAPPENDICES

For the City of Tyler

Firm Registration No. 312

halff.com

June 2023

Prepared by: Halff Associates, Inc.

APPENDIX A: DATA UPDATES

◦ Waterlines shapefile: Private water lines on the customer side of customer meters were removed from the shapefile and are not considered in this AMP.

◦ Pipe age assumptions: Where information was available, pipe ages were determined from record drawings/ plan sets. Remaining pipe segment ages were determined from subdivision age if the pipe segment fell within its polygon boundary or if neither previous method was possible due to unavailable data or insufficient proximity to a subdivision, the year of installation from the City GIS was used.

◦ Pipe material assumptions: Where information was available, pipe materials were determined from record drawings/plan sets. Remaining pipe segment materials for pipe segments with diameters greater than 12 inches were determined from the City GIS.

◦ Break Repair History assumptions: Of the work order logs provided by the City, only the following work order descriptions were considered in the Break Repair History score: Cave-In (Water), Dig Up Water Service, Hydro Excavate Water Main, Pothole Water Main, Valve Dig-Up, Valve Repair, Valve Replacement, Water Main Repair, and Water Main Replacement.

◦ Critical Services Score: All hospital, fire, police, and school locations provided by the City GIS were verified, and the locations for Fire Stations 1, 4, 5, and 7 were updated to reflect recent relocations. The new Fire Station 10 location was added to the shapefile. Dialysis, nursing/rehabilitation, and Assisted/Independent Living centers were added as critical service locations per City request.

◦ Critical Operations score: The Westside WWTP is not included as a critical operations location as this facility does not receive water from the Tyler water distribution system. The Water Service Center was added as a critical operations location per the City’s request.

APPENDIX B: TYLER STAFF MAP MARKUP OF CHRONIC PROBLEM AREAS

APPENDIX C: LOF and COF Score Tables

D. BREAK REPAIR SCORE:

E. PRESSURE ISSUE SCORE:

G. LOF SCORE: MIN = 1.0; MAX = 9.85

CONSEQUENCE OF FAILURE SCORES

I.

COF SCORE: Min = 1.65; Max = 9.6

APPENDIX D: WATER MAIN MAPS FOR EACH LOF AND COF CATEGORY

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX E: KEY ATTRIBUTES OF HIGH-RISK ASSETS

APPENDIX F: SCORE DISTRIBUTION SUMMARIES FOR

EACH LOF & COF CATEGORY

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN

ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX G: REPLACEMENT COSTS FOR THE HIGH-RISK WATER MAIN ASSETS

APPENDIX H: RISK GEODATABASE