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42222208 Twin Falls ePulse Final Report Optimize - 2023
( MUELLER] I T 10 N The City of Twin Falls, ID C ITY O F IN FALLS O� Date: 9/12/2023 Client: City of Twin Falls, ID Utility: City of Twin Falls, ID Echo Project#: 42222208 Report Classification: Draft For more information about us or to view our full line of water products,please visit www.echologirs.com or call Echologics customer service at 1.800.423.1323. Mueller refers to one or more of Mueller Water Products,Inc.a Delaware corporation("MWP"),and its subsidiaries.MWP and each of its subsidiaries are legally separate and independent entities when providing products and services.MWP does not provide products or services to third parties.MWP and each of its subsidiaries are liable only for their own acts and omissions and not those of each other.MWP brands include Mueller®,Echologicss,Hydro Gate®,Hydro-Guard®,HYMAX®,Jones®,Krauszs,Mi.Net®,Milliken®,Pratt®, Singer®,and U.S.Pipe Valve&Hydrant. Please see muellerwp.com/brands and krauszusa.com to learn more. Copyright©2019 Echologics.All Rights Reserved.The trademarks,logos and service marks displayed in this document are the property of Mueller Water Products,Inc.,its affiliates or other third parties.Products marked with a section symbol(§)are subject to patents or patent applications.For details,visit www.mwppat.com.These products are intended for use in potable water applications.Please contact your Mueller Sales or Customer Service Representative concerning any other application(s). F 14064 3/19 Page 2 of 44 [This page left intentionally blank] IM,UELLERJ Page 3 of 44 EXECUTIVE SUMMARY Echologics, LLC (Echologics) provided acoustic condition assessment and leak detection services on critical segments of distribution water mains for the City of Twin Falls, Idaho(the City). Echologics surveyed 24,998 linear feet of cast iron and ductile iron pipe ranging in diameters from 6-inch through to 16-inch. Echologics' field personnel completed the survey in Twin Falls, ID from March 20th, 2023 to March 28th, 2023. Echologics conducted the survey using the ePulse®Discovery service. In addition to the standard ePulse results, Echologics also conducted a higher resolution condition assessment survey using the ePulse®Optimize condition assessment service.This service provided further condition assessment information on selected areas. Echologics assessed 1,094 linear feet of distribution mains using the ePulse®Optimize service. Summary of key results Leak detection: • No leaks were discovered at the time of the survey. Condition Assessment(Discovery): • 29 segments appear to be in poor condition with over 30%loss in original wall thickness. • 14 segments appear to be in moderate condition with between 10%to 30%loss in original wall thickness. • 2 segments appear to be in good condition with less than a 10%loss in original wall thickness. • 6 segments yielded no results. Condition Assessment(Optimize): • 8 sections appear to be in poor condition with over 30%loss in original wall thickness. • 1 section appeared to be in moderate condition with between 10%to 30%loss in original wall thickness. • 5 sections appear to be in good condition with less than a 10%loss in original wall thickness. • 0 segments yielded no results. Recommendations: • For the water mains in moderate condition, the City may wish to consider installing permanent monitoring systems, depending on the consequence of failure, to allow immediate notification of pressure transients and/or leaks. The installation of permanent monitoring systems may help in preventing future failures. • Echologics recommends conducting follow-up field investigations on these mains in 5 years time, in order to measure the rate of decay and update the condition of the mains. • As Echologics has only assessed a small percentage of the City's water distribution and transmission pipe network,the City may wish to consider testing more of the network.This will allow the City to identify and extend the service life of pipes reported in good condition,and allow for better prioritization of their pipe replacement program and capital budget expenditures. The City may also consider pipe rehabilitation as an option to reduce costs associated with water main replacement.Utilizing"evidence based"condition assessment data,as highlighted in this report,can be a good proactive approach to asset management that is both cost-effective and non-disruptive. [ MUELLER] Page 4 of 44 TABLE OF CONTENTS EXECUTIVESUMMARY......................................................................................................................................................................3 1.PROJECT BACKGROUND...............................................................................................................................................................5 2.RESULTS......................................................................................................................................................................................8 2.1 Leak Detection...............................................................................................................................................................................8 2.2 ePulse0 Condition Assessment....................................................................................................................................................8 2.2.1 Discussion of Results............................................................................................................................................12 2.2.2 Segments with No Results....................................................................................................................................13 2.2.3 Greater Wall Thickness Than Expected................................................................................................................13 3.CONCLUSIONS AND RECOMMENDATIONS.................................................................................................................................15 3.1 Conclusions.................................................................................................................................................................................15 3.2 Recommendations and Next Steps............................................................................................................................................15 , 4.DISCLAIMER...............................................................................................................................................................................18 APPENDIX A DETAILED RESULTS....................................................................................................................................................19 A.1 Site Details...................................................................................................................................................................................19 A.2 Leak Detection Results...............................................................................................................................................................19 A.3 Pipe Property Details...................................................................................................................................................................20 A.4 ePulse®Condition Assessment Results.....................................................................................................................................22 A.4.1 Addison Avenue West..........................................................................................................................................22 A.4.2 Addison Avenue East...........................................................................................................................................24 A.4.3 Blue Lakes Boulevard...........................................................................................................................................26 APPENDIX B INTERPRETATION OF RESULTS..................................................................................................................................34 , B.1 Echowave®Leak Detection.........................................................................................................................................................34 B.2 ePulse®Condition Assessment..................................................................................................................................................35 B.3 Limitations...................................................................................................................................................................................39 B.4 Sensitivity Analyses and Considerations....................................................................................................................................40 APPENDIX C DETAILED METHODOLOGY.........................................................................................................................................41 C.1 Leak Detection.............................................................................................................................................................................41 C.2 ePulse®Mean Hoop Thickness Testing.....................................................................................................................................42 APPENDIX D ABBREVIATIONS.........................................................................................................................................................43 APPENDIX E GLOSSARY OF TECHNICAL TERMS.............................................................................................................................44 [ MUELLER] Page 5 of 44 1. PROJECT BACKGROUND The City of Twin Falls,Idaho(the City)contracted Echologics as a part of their pipe condition assessment(PCA)program,to assess pipe conditions on critical segments of the City's metallic water mains. Primary objectives of the PCA program include: • Determine the condition of the tested metallic pipe • Investigate the system for the existence of any leaks • Utilize pipe condition information to assist with rehabilitation or replacement decisions by the City To help the City achieve these objectives, Echologics utilized its patented ePulse®technology to determine the current condition of the pipes in scope. In addition to condition assessment, leak detection was also performed. This report provides detailed information on how Echologics can support.the City in ensuring these objectives have been met. In addition to the standard ePulse results, Echologics also conducted a higher resolution condition assessment survey using the ePulse®Optimize condition assessment service.This service provided further condition assessment information on selected areas. Echologics assessed 1,094 linear feet of distribution mains using the ePulse®Optimize service. The project included 24,998 linear feet of distribution mains located in the City of Twin Falls,as illustrated below in Figure 1. SI. Addison Ave West , Addison Ave East a. Optimize Segment Optimize Segment 2220816003 222081BO12 Ili B�Ue fakes Blvd Optimize Segment 2220816036 .i Figure 1:System Overview and Site Locations Table 1 below shows the pipe material and installation years for each site surveyed. [ MUELLER] Page 6 of 44 Table 1 Sites Surveyed Site Distance Pipe Material Pipe Diameter Install Year Segment Number Tested(ft) 22208113003, 22208113004, Ductile Iron(DIP) 12 1962-65 22208113005, 22208113006, 22208113007 8 1940-46 22208113001, 22208113002 Addison Ave 7001 6 1940-46 22208113008 West 22208113009, 22208113010, Cast Iron (CAS) 22208113011, 4 1940-46 22208113012, 22208113013, 22208113014, 22208113015, 222081BO16 Ductile Iron(DIP) 12 1962-65 22208113017, 222081BO20 22208113021, 10 1940-46 22208113022, 222081BO23 Addison Ave 22208113018, East 7318 22208113024, Cast Iron(CAS) 22208113025, 6 1940-46 22208113026, 22208113027, 22208113028, 22208113029, 222081BO30 22208113035, 16 1962-65 22208113036, 222081BO37 22208113031, 14 1962-65 22208113032, 22208113033, 222081BO34 22208113031, 12 1962-65 22208113032, 22208113033, Blue Lakes Blvd 10679 Cast Iron (CAS) 222081BO34 22208113042, 22208113043, 22208113044, 22208113046, 8 1940-46 22208113047, 22208113048, 22208113049, 22208113050, 22208113051, 222081BO52 6 1940-46 222081BO45 Field tests began on March 20fh,2023 and required seven days to complete with a team of two members.Traffic Control support was provided by the City of Twin Falls, in addition to support installing potholes for access to the water main. Further details on potholes are provided in the project planning document. ePulse@ condition assessment combines acoustic data measured in the field with information about a pipe's construction to calculate its current average remaining wall thickness.The pipe's material,internal diameter,and modulus of elasticity are critical [ MUELLER] Page 7 of 44 variables in this calculation.ePulse®condition assessment calculates the percentage of average thickness loss by comparison of the measured thickness to the design thickness of the pipe. Echologics used the pipe properties shown in Table 2, based on install dates and pipe classes provided by Twin Falls. Information on nominal pipe specifications for ductile iron pipes were taken from AWWA C151-1955:Ductile Iron Pipe, Centrifugally Cast in Metal Molds or Sand-Lined Molds, for Water or Other Liquids. For Cast Iron pipes,Class D nominal thicknesses were taken from C100-1908:AWWA Standard Specifications For Cast Iron Water Pipes And Special Castings. It is not anticipated that any pipes in this project scope include cement mortar lining. Table 2 Pipe Properties Pipe Material Thickness Internal Nominal Thickness Class Diameter in in Ductile Iron 52 12 0.37 Cast Iron D 4 0.31 Cast Iron D 6 0.55 Cast Iron D 8 0.60 Cast Iron D 10 0.68 Cast Iron D 12 0.75 Cast Iron D 14 0.82 Cast Iron D 16 0.89 [ MUELLER] Page 8 of 44 2. RESULTS 2.1 LEAK DETECTION No leaks or points of interest were detected during the time of the survey. 2.2 EPULSE®CONDITION ASSESSMENT The ePulse®method measures the average remaining wall thickness of a segment of pipe.The technology combines acoustic data measured in the field with information about a pipe's manufacturing to calculate its current hoop thickness.The pipe's material, internal diameter,and modulus of elasticity are all critical variables in this calculation.The percentage of average wall thickness loss is calculated by comparing the measured thickness to the design thickness.The results are also presented as a qualitative category indicating the expected condition of the main.Table 3 shows these qualitative condition categories.Results marked"NR" indicate that no result was attainable on a pipe segment. Table 3:Qualitative Categories and Color Coding Change in Hoop Description Color Code Thickness Less than 100% Good Green 10%to30% Moderate Yellow Greater than 30% Poor The ePulse®condition assessment results are presented in Table 4 and 5 below. [ MUELLER] Page 9 of 44 Table 4:ePulses Pipe Condition Assessment Results Segme Pipe Internal Remaining %Change Sensor 1 Sensor 2 nt Nominal Segment Street Name Location Location Length Materia Diameter Thickness(in) Thickness from (ft) I (in) (in) Nominal 222081B001 Addison W Ave Echo-13* 24395 530 CAS 8 0.60 0.53 -11 22208113002 Addison W Ave 36034 24395 427 CAS 8 0.60 0.51 -15 22208113003 Addison W Ave 36034 24390 320 DIP 12 0.37 NR 22208113004 Addison W Ave 72-829 24390 579 DIP 12 0.37 0.37 1 22208113005 Addison W Ave 72-829 35643 464 DIP 12 0.37 0.41 10 22208113006 Addison W Ave PH1-180 35643 299 DIP 12 0.37 NR 22208113007 Addison W Ave PH-180-1 24393 325 DIP 12 0.37 NR 22208113008 Addison W Ave 28774 24393 614 CAS 6 0.55 0.35 222081B009 Addison W Ave PH-42-1 Echo-16 187 CAS 4 0.52 0.31 222081BO10 Addison W Ave Echo-17 Echo-16 444 CAS 4 0.52 0.37 -29 222081B011 Addison W Ave Echo-17 35644 664 CAS 4 0.52 0.27 jj 222081BO12 Addison W Ave Echo-19 35644 389 CAS 4 0.52 0.31 222081BO13 Addison W Ave Echo-19 Echo-19 411 CAS 4 0.52 0.46 -11 222081BO14 Addison W Ave 36035 Echo-19 524 CAS 4 0.52 0.28 222081BO15 Addison W Ave 36035 PH-6-1 405 CAS 4 0.52 0.34 222081BO16 Addison W Ave 72-726 PH-6-1 419 CAS 4 0.52 0.39 -24 222081BO17 Addison E Ave 12394 Ec1001v 719 DIP 12 0.37 NR 222081BO18 Addison E Ave Echo-Vlv- Echo-Vlv- 682 CAS 6 0.55 NR 96 100 222081BO20 Addison E Ave Echo-Vlv- Echo-Vlv- 643 DIP 12 0.37 0.27 -26 96 83 222081BO21 Addison E Ave 33710 Ech8o3-V ly- 698 CAS 10 0.68 0.49 -28 MUELLERIJ Page 10 of 44 Segme Pipe Internal Remaining %Change Sensor 1 Sensor 2 nt Nominal Segment Street Name Location Location Length Materia Diameter Thickness(in) Thickness from ft I (in) (in) Nominal 222081BO22 Addison E Ave 33710 Echo-21 671 CAS 10 0.68 0.46 -32 222081BO23 Addison E Ave Echo-Iv- Echo-21 226 CAS 10 0.68 0.38 -44 222081BO24 Addison E Ave Echo-7 Ec 78-V1v- 696 CAS 6 0.55 0.26 -52 222081BO25 Addison E Ave Echo-7 Echo-Iv- 382 CAS 6 0.55 0.27 -51 94 222081BO26 Addison E Ave 33709 Echo-12 663 CAS 6 0.55 0.34 -39 222081BO27 Addison E Ave Echo-23 Echo-Iv- 465 CAS 6 0.55 0.28 -49 94 222081BO28 Addison E Ave Echo-23 Echo-12 500 CAS 6 0.55 0.34 222081BO29 Addison E Ave 33709 EchBV o-- Iv- 508 CAS 6 0.55 0.47 -15 222081BO30 Addison E Ave Echo-24 Ech8o8-V ly- 465 CAS 6 0.55 0.47 -15 Blue Lakes Echo-Vlv- Echo-Vlv 222081B031 Blvd 73 101 308 CAS 12 0.75 NR 222081BO32 Blue Lakes Echo-25 Echo-Vlv- 398 CAS 12 0.75 0.56 -25 Blvd 101 222081BO33 Blue Lakes Echo-25 Echo-26 447 CAS 12 0.75 0.56 -26 Blvd 222081BO34 Blue Lakes Echo-27 Echo-26 416 CAS 12 0.75 0.55 -27 Blvd 222081BO35 Blue Lakes Echo-27 Echo-28 564 CAS 16 0.89 0.63 -29 Blvd 222081BO36 Blue Lakes Echo-28 Echo-Vlv- 497 CAS 16 0.89 0.51 Blvd 112 222081BO37 Blue Lakes 33695 Echo-Vlv- 666 CAS 16 0.89 0.73 -18 Blvd 112 222081BO38 Blue Lakes 33694 Echo-30 465 CAS 14 0.82 NR Blvd 222081BO39 Blue Lakes 33717 Echo-30 579 CAS 14 0.82 0.47 43 Blvd 222081BO40 Blue Lakes 33717 35231 527 CAS 14 0.82 0.37 -55 Blvd 222081BO41 Blue Lakes 33708 35231 507 CAS 14 0.82 0.33 -60 Blvd IMUELLERJ Page 11 of 44 Segme Pipe Internal Remaining %Change Sensor 1 Sensor 2 nt Nominal Segment Street Name Location Location Length Materia Diameter Thickness(in) Thickness from ft I (in) (in) Nominal 222081BO42 Blue Lakes 33707 35631 436 CAS 8 0.60 0.38 -37 Blvd 222081BO43 Blue Lakes 33700 35631 570 CAS 8 0.60 0.38 -36 Blvd 222081BO44 Blue Lakes 33700 Echo-Vlv- 452 CAS 8 0.60 0.30 -50 Blvd 110 222081BO45 Blue Lakes 33696 Echo-Vlv- 540 CAS 6 0.55 0.25 -55 Blvd 110 222081BO46 Blue Lakes 33696 Echo-Vlv- 528 CAS 8 0.60 0.33 -45 Blvd 108 Blue Lakes Echo-Vlv- Echo-Vlv 222081B047 Blvd 106 108 484 CAS 8 0.60 0.35 42 222081BO48 Blue Lakes Echo-Vlv- Echo-1 489 CAS 8 0.60 0.29 -51 Blvd 106 222081BO49 Blue Lakes Echo-31 Echo-Vlv- 505 CAS 8 0.60 0.31 -48 Blvd 104 222081BO50 Blue Lakes Echo-31 75-797 545 CAS 8 0.60 0.38 Blvd 222081BO51 Blue Lakes Echo-32 75-797 477 CAS 8 0.60 0.39 -35 Blvd 222081BO52 Blue Lakes Echo-32 Echo-Vlv Blvd 66 279 CAS 8 0.60 0.36 *Access Points noted with the Echo prefix are appurtenances without available details on provided GIS, updates to Twin Falls asset numbers may be added with further GIS information **Access Points noted with the PH prefix are potholes installed by Twin Falls for access directly to the watermain [ MUELLER] Page 12 of 44 Table 5:ePulse®Optimize Pipe Condition Assessment Results Sensor 1 Sensor 2 Pipe Remaining Segment Internal Nominal %Change Material Segment Street Name Length Diameter Thickness from Location Location (ft) (in) (in) Thickness(in) Nominal 222081B003-1 Addison W 36034 GEP-640-2 53 DIP 12 0.40 0.42 4 222081B003-2 Addison W GEP-640-2 GEP-640-3 53 DIP 12 0.40 0.43 7 222081B003-3 Addison W GEP-640-3 GEP-640-5 106 DIP 12 0.40 0.43 8 Ave 222081B003-4 Addisoen W GEP-640-5 GEP-640-6 53 DIP 12 0.40 0.41 3 Av 222081B003-5 Addisoen W GEP-640-6 24390 55 DIP 12 0.40 0.44 10 Av 222081B012-1 Addisoen W Echo-19 GEP-620-7 59 CAS 4 0.52 0.29 Av Addison W GEP-140096 222081B012-2 Ave GEP-620 7 11 220 CAS 4 0.52 0.30 Addison W GEP-140096 222081B012-3 Ave 11 35644 110 CAS 4 0.52 0.37 29 222081B036-1 Blue Lake Echo-28 GEP-1648-13 55 CAS 16 0.89 0.49 Blvd 222081B036-2 Blue Lake GEP-1648-13 GEP-1648-14 55 CAS 16 0.89 0.53 Blvd 222081B036-3 Blue Lake GEP-1648-14 GEP-1648-15 55 CAS 16 0.89 0.51 Blvd 222081B036-4 Blue Lake GEP-1648-15 GEP-1648-17 110 CAS 16 0.89 0.53 Blvd 222081B036-5 Blue Lake GEP-1648-17 GEP-1648-18 55 CAS 16 0.89 0.51 Blvd 222081B036-6 Blue Lake GEP-1648-18 GEP-147153- 55 CAS 16 0.89 0.52 Blvd 19 *Access Points noted with the Echo prefix are appurtenances without available details on provided GIS,updates to Twin Falls asset numbers may be added with further GIS information [ MUELLER] Page 13 of 44 2.2.1 DISCUSSION OF RESULTS ePulse Condition Assessment Results Breakdown 12% W27% ■Good Moderate ■ Poor No Result Figure 2:ePulse Standard Results Breakdown The results presented in Table 5 and Figure 2 show that 2 out of 51 segments tested(4%of total number of segments)appear to be in good condition with less than 10% loss in wall thickness. Echologics identified 14 segments (27% of total number of segments)to be in moderate condition with wall thickness loss of 10%to 30%from nominal.The remaining 29 segments(57%of total number of segments)appear to be in poor condition with more than 30%loss in wall thickness. Echologics could not provide a result for 6 segments. Echologics measured the presented distances on site.The following methods are used to achieve a reliable distance measurement: 1. The distance is measured multiple times with a measuring wheel 2. The distance is cross-checked with available information from GIS maps Distance accuracy is important for ePulse results and in general,a 1%error in distance measurement can result in a more than 2%error in final percentage of wall thickness lost.A discussion of the effect of distance error on the results as well as a closer look at other possible sources of error and their effect on the results can be seen in Appendix A. Detailed discussion on the results for each site and group of segments are presented in the Appendix A. 2.2.2 SEGMENTS WITH NO RESULTS Segments 222081B006,222081B007,22208113017,22208113018,222081BO31 and 222081BO38 were marked as no result("NR").These were marked as no result("NR")due to possible factors attributing to unrealistic results including positive wall thickness growth along the segment.These factors may include: 1. Inaccurate pipe material or specification. 2. Inadequate distance for accurate recording of time delay. 3. Inaccurate pipe configuration as per GIS layout Segment 22208113003 had returned a no result from standard ePulse,however was selected as an option for Optimize testing and will include detailed results in the Optimize report. 2.2.3 GREATER WALL THICKNESS THAN EXPECTED In some instances, Echologics observed acoustic wave velocities along a segment which resulted in a measured wall thickness slightly greater than the assumed nominal thickness.This can occur due to one of the following primary reasons: IMUELLERJ Page 14 of 44 1. Manufacturing tolerances or unaccounted for lining 2. Incorrect assumptions of pipe specifications 3. Incorrect distance measurements due to unknown pipe configuration. Echologics has identified 2 segments that show a measured thickness slightly greater (within 0.05 inches) than the nominal thickness.This is within typical manufacturing tolerances and/or margin of error for ePulse.These segments are expected to be in very good condition. If further information becomes available on these mains,please contact Echologics so that updates can be made to the report. 2.2.4 EPULSE®OPTIMIZE CONDITION ASSESSMENT SERVICETm A section analysis,a higher level of resolution,was tested on three selected segments,using the newly developed ePulse®Optimize Condition Assessment ServiceTM.The testing was successful in capturing higher resolution overall. All fourteen sections inspected with ePulse Optimize appear uniform with minor variation of the wall thickness along their lengths. Segment 222081B003 was able to produce usable results with the Optimize method,showing good condition for the pipe along the length tested.It is believed that the additional taps in-bracket allowed for the sections to be assessed,which originally showed No Result due to poor propagation. Segment 222081B012 presents slightly higher degradation in the sections on the western end of the segment.These two sections, representing approximately 70% of the segment, are in poor condition, showing major degradation. The eastern-most section (222081B012-3)is in moderate condition. [ MUELLER] Page 15 of 44 3. CONCLUSIONS AND RECOMMENDATIONS 3.1 CONCLUSIONS Echologics has successfully assessed pipe wall condition and leak detection of 22,562 feet of distribution water mains in Twin Falls, Idaho.The main conclusions for this project are as follows: A. The ePulse®testing method can be easily implemented within the City's water distribution network without the need for excavations,external traffic control or substantial support from Twin Falls water operators. Field-testing was completed without any interruption to service or disruptions to the City's customers. B. The ePulse®acoustic field-testing obtained results for 88%of the segments tested. Six segments tested returned "No Result(NR)". It is recommended that Twin Falls review the class and materials for all pipes tested to ensure the correct nominal thickness. If a change to the nominal thickness is required, Echologics can re-calculate the results with the updated pipe specifications. C. The ePulse®testing was able to isolate 14,483 feet of degraded pipe with high (greater than 30%)wall thickness loss. Due to the relatively high number of poor condition segments, Echologics strongly recommends the City review and compare the inputs used by Echologics to the original lay schedule and pipe specification information.Significant changes to the material or diameters presented in this report will affect Echologics' ePulse measured thickness.that Twin Falls review the material specifications of these pipes to confirm the high levels of degradation.Additionally, if the assumed nominal thickness is incorrect,the percent degradation value will also change. D. The ePulse®Optimize acoustic field-testing obtained results for all tested sections. No sections tested returned a "No Result(NR)" status. ePulse@ Optimize provided results on sections with an average length of 76 feet and a minimum length of 53 feet. 3.2 RECOMMENDATIONS AND NEXT STEPS Based on the results of the condition assessment and leak detection survey for this project,Echologics offers the following overall program recommendations and next steps: • For the water mains in moderate condition, the City may wish to consider installing permanent monitoring systems, depending on the consequence of failure, to allow immediate notification of pressure transients and/or leaks. The installation of permanent monitoring systems may help in preventing future failures. • Echologics recommends conducting field investigations on these mains in 5 years time, in order to measure the rate of decay and update the condition of the mains. • As Echologics has only assessed a small percentage of the City's water distribution and transmission pipe network,the City may wish to consider testing more of the network.This will allow the City to identify and extend the service life of pipes reported in good condition,and allow for better prioritization of their pipe replacement program and capital budget expenditures. The City may also consider pipe rehabilitation as an option to reduce costs associated with water main replacement.Utilizing"evidence based"condition assessment data,as highlighted in this report,can be a good proactive approach to asset management that is both cost-effective and non-d'isruptive. It is important to note that structural pipe condition is one of many factors in evaluating a pipe's suitability for service but should not be the only consideration used in replacement and deferral decisions.Other important factors that should be considered may include pipe-loading conditions, hydraulic capacity of the pipe, road repair/renewal schedules, consequence of pipe failure, customer complaints, rate of decay etc. When interpreting ePulse®results,asset owners should understand the following: 1. Leaks can still occur on water mains with good pipe wall condition for reasons other than pipe wall degradation, such as pressure transients,leaks at joints,leaks on service connections,winter weather(freeze/thaw),poor installation, etc. 2. If a leak is detected on these segments, a repair should be sufficient for remediation, because the majority of the remaining pipe wall is in good structural condition. 3. The need for future assessment of these pipes should take into account the consequence of failure. Depending on the consequence of failure, it may be beneficial to equip these pipelines with a continuously monitoring leak detection system.For example,a non-redundant main servicing a hospital may benefit from immediate detection of leaks as soon as they develop. With this in mind,we further recommend the following actions for the three condition categories. IMUELLERJ Page 16 of 44 Good Condition Pipe- DEFER/LOW PRIORITY If the condition assessment results classify the mains as"Good Condition",they are in good structural condition and do not need attention in the near future, (unless they are under higher than normal loading conditions). The pipes in this category have a remaining wall thickness within 10%of the nominal wall thickness. Recommendations for good condition pipe are as follows: 1. We suggest the City continue with their standard maintenance programs for these mains. 2. Common industry practice for good condition pipe is to follow-up with condition assessment testing in approximately 10 years, depending on the consequence of failure. This allows for measurement of the rate of change of condition with time. If these mains require rehabilitation for other reasons such as low pressure or poor water quality complaints,then cleaning and lining may be an option to consider. 3. Employing the use and benefits of cathodic protection to slow or even stop the"aging'process of external corrosion. Moderate Condition Pipe- MONITOR/MEDIUM PRIORITY If the condition assessment results classify the mains as"Moderate Condition",the pipes may be medium priority and should be monitored depending on pipe loading conditions.It is important to note that pipes in this category may show a reduced capacity to withstand loading conditions,especially on pipes that are approaching 30%loss in wall thickness. Depending on the criticality of the main,we recommend monitoring these pipes.The following are some of the possible mitigation methods: 1. For mains without an internal lining,cleaning and lining can often extend the life of moderate condition mains,as well as adding cathodic protection. 2. Regularly scheduled traditional leak detection surveys.These are a relatively inexpensive option capable of finding many leaks within a system. However,this method can be fairly labor intensive and may not prevent catastrophic failures on high consequence pipelines. 3. A permanent leak monitoring system that is capable of finding most leaks on a pipeline,including small leaks before they turn into catastrophic failures. 4. A follow-up condition assessment survey to measure the rate of decay and update the condition of the mains.A common practice for moderate condition pipe is to reassess these mains in 5 years,depending on the consequence of failure.An analysis of the results can be used to determine the decay rates for these mains.The established decay rate may have an impact on the remaining service life of the mains. Measuring this can allow for improved asset management. [ MUELLER] Page 17 of 44 Poor Condition Pipe-ADDRESS/HIGH PRIORITY If the condition assessment results classify the mains as "Poor Condition", the pipes are likely in need of immediate attention. Depending on pipe loading condition,these pipes are at higher risk of experiencing leaks and catastrophic failures,and they should be addressed as soon as possible. In most cases, pipe segments that fall within this category have reached,or are approaching,the end of their useful life. Actions such as structural lining,slip-lining,and/or full replacement should be investigated as a likely immediate requirement. Such actions as continuous leak monitoring,cathodic protection and/or cleaning and lining will most likely not offer tremendous value or extend the life of the water main in a cost-effective manner. Additional Considerations Each water network will have its own dominant degradation mechanism,as well as unique local considerations. We recommend that the City use the results presented in this report in combination with other data and information available from additional services.This additional asset information may include: • Soil Corrosivity.If corrosive soils are discovered and the main is in poor condition,the degradation is likely related to soil conditions. • Water Aggressiveness.Aggressive water would suggest that some of the degradation is caused from the inside,and this can be assumed to cause similar degradation rates for similar types of main. • Break History.Correlating condition assessment results with break history can help identify sections of main that are at increased risk of failure.These factors are not necessarily related,as it is possible for pipes to have high break rates for reasons other than pipe wall degradation. • Consequence of Failure. Combining condition assessment results with consequence of failure analysis is used to generate a risk assessment. Comparing the ePulse condition assessment results with these additional considerations will allow the City to direct their rehabilitation efforts in a cost-effective manner,by creating a high-level rehabilitation picture takes takes all sources of degradation into consideration. [ MUELLER] Page 18 of 44 4. DISCLAIMER All forms of non-destructive testing involve an inherent level of uncertainty.Such testing is dependent on input parameters, and outputs can be significantly affected by variation from assumed parameters. This report includes certain suggestions and recommendations made by us which are based on,among others,(i)the findings included in the report,(ii)its experience and(iii) an understanding of the client's particular requirements.We acknowledge that the client may use this report to consider potential opportunities for pipeline repairs/replacement/rehabilitation; however,we disclaim any liability that may arise in connection with decisions based on these suggestions or recommendations or their implementation. [ MUELLER] Page 19 of 44 APPENDIX DETAILED RESULTS This section provides a detailed presentation of the project scope,data collected,and results obtained during the project. A.1 SITE DETAILS This project was divided into three distinct work sites.An overview map of the sites is shown in Figure A.1-1:System Overview and Site Locations below,followed by detailed information on each of the sites. [.jH�OLQGICS Twin Falls ePulse Overview Leqend 3 User Note Sections ddison Ave West — Grainer tliei30% 10 30% ddison Ave East Segments ..ttr a-30% 30% 0.9% Blue Lakes Blvd _- - l 1:36,OW O Notes 1.1 0 0.57 1.1 Miles This map isauser generatec ranc outputfrom an Internet mapping We arb"fo' reference ony.Data Iryersthat appear on this map mayor may not be accurate. WGS 191W_Web Mercator Mailiary_SphMe wrrem.or olherN5e reh"t ®Lalilude Geographks Group Ltd. THIS MAP IS N07 TO BE USED F00.NAVIGATION Figure A.1-1:System Overview and Site Locations A.2 LEAK DETECTION RESULTS No leaks or points of interest were detected during the time of the survey. [ MUELLER] Page 20 of 44 A.3 PIPE PROPERTY DETAILS The pipe properties used in this project are presented in Table A.3-1,which were obtained from the client through a GIs request. Nominal thicknesses were determined from pipe standards details in section 1. Table A.3-1:Pipe Properties Segment ID Street Name Install Pipe Diameter Nominal Year Material (in) Thickness(in) 222081B00l Addison W Ave 1940-46 CAS 8 0.60 22208113002 Addison W Ave 1940-46 CAS 8 0.60 2220816003 Addison W Ave 1962-65 DIP 12 0.37 22208113004 Addison W Ave 1962-65 DIP 12 0.37 2220816005 Addison W Ave 1962-65 DIP 12 0.37 22208113006 Addison W Ave 1962-65 DIP 12 0.37 2220816007 Addison W Ave 1962-65 DIP 12 0.37 22208113008 Addison W Ave 1940-46 CAS 6 0.55 22208113009 Addison W Ave 1940-46 CAS 4 0.52 222081B010 Addison W Ave 1940-46 CAS 4 0.52 222081B0ll Addison W Ave 1940-46 CAS 4 0.52 222081B012 Addison W Ave 1940-46 CAS 4 0.52 222081B013 Addison W Ave 1940-46 CAS 4 0.52 222081B014 Addison W Ave 1940-46 CAS 4 0.52 222081B015 Addison W Ave 1940-46 CAS 4 0.52 222081B016 Addison W Ave 1940-46 CAS 4 0.52 222081B017 Addison E Ave 1962-65 DIP 12 0.37 222081B018 Addison E Ave 1940-46 DIP 12 0.37 222081B020 Addison E Ave 1962-65 DIP 12 0.37 222081B021 Addison E Ave 1940-46 CAS 10 0.68 222081B022 Addison E Ave 1940-46 CAS 10 0.68 222081B023 Addison E Ave 1940-46 CAS 10 0.68 222081B024 Addison E Ave 1940-46 CAS 6 0.55 222081B025 Addison E Ave 1940-46 CAS 6 0.55 222081B026 Addison E Ave 1940-46 CAS 6 0.55 222081B027 Addison E Ave 1940-46 CAS 6 0.55 222081B028 Addison E Ave 1940-46 CAS 6 0.55 222081B029 Addison E Ave 1940-46 CAS 6 0.55 222081B030 Addison E Ave 1940-46 CAS 6 0.55 222081B031 Blue Lake Blvd 1962-65 CAS 12 0.75 222081B032 Blue Lake Blvd 1962-65 CAS 12 0.75 222081B033 Blue Lake Blvd 1962-65 CAS 12 0.75 222081B034 Blue Lake Blvd 1962-65 CAS 12 0.75 222081B035 Blue Lake Blvd 1962-65 CAS 16 0.89 MUELLER Page 21 of 44 222081BO36 Blue Lake Blvd 1962-65 CAS 16 0.89 222081BO37 Blue Lake Blvd 1962-65 CAS 16 0.89 222081BO38 Blue Lakes Blvd 1962-65 CAS 14 0.82 222081BO39 Blue Lakes Blvd 1962-65 CAS 14 0.82 222081BO40 Blue Lakes Blvd 1962-65 CAS 14 0.82 222081BO41 Blue Lakes Blvd 1962-65 CAS 14 0.82 222081BO42 Blue Lakes Blvd 1940-46 CAS 8 0.60 222081BO43 Blue Lakes Blvd 1940-46 CAS 8 0.60 222081BO44 Blue Lakes Blvd 1940-46 CAS 8 0.60 222081BO45 Blue Lakes Blvd 1940-46 CAS 6 0.55 222081BO46 Blue Lakes Blvd 1940-46 CAS 8 0.60 222081BO47 Blue Lakes Blvd 1940-46 CAS 8 0.60 222081BO48 Blue Lakes Blvd 1940-46 CAS 8 0.60 222081BO49 Blue Lakes Blvd 1940-46 CAS 8 0.60 222081BO50 Blue Lakes Blvd 1940-46 CAS 8 0.60 222081BO51 Blue Lakes Blvd 1940-46 CAS 8 0.60 222081BO52 Blue Lakes Blvd 1940-46 CAS 8 0.60 IMUELLERJ Page 22 of 44 A.4 EPULSE®CONDITION ASSESSMENT RESULTS A.4.1 ADDISON AVENUE WEST t wi 222UB1B016 2220818ppive 222081BOty —_- 20 US 30 221B011 Pt1e 0 US??2U8180.'Addis n—� 222081 B003 2220818013 —_ ♦� _ 22200— +On Aser22208fA001— 2220t US 30 222081B0p5 1 :Y IIi OxrN Figure A.4.1-1:Addison Avenue West P E t m , C G Z 222 081 8 013 I i.��Uonale. 122"lA001 2220818012 ■ US 30 us Add150n Asenul 2220818o/1 — 222081Bppy 2220818006 CM1wrnon / ; I Addhon Avenue W22 2220818010 2081 Boo] US 30 222081B008 F 93 Bus Addl-A] Ue We222081B008 I'fi L 'P I o d s -- - - - �. Ausun Av ,e u I I Figure A.4.1-2:Addison Avenue West [ MUELLER] Page 23 of 44 Table A.4.1-1:Addison Avenue West ePulse®Condition Assessment Details Sensor 1 Sensor 2 Segment Pipe Internal Nominal Remaining %Change Segment Street Name Location Location Length Material Diameter Thickness Thickness from (ft) (in) (in) (in) Nominal 222081B001 Addison W Ave Echo-13* 24395 530 CAS 8 0.60 0.53 -11 22208113002 Addison W Ave 36034 24395 427 CAS 8 0.60 0.51 -15 22208113003 Addison W Ave 36034 24390 320 DIP 12 0.37 NR 22208113004 Addison W Ave 72-829 24390 579 DIP 12 0.37 0.37 1 22208113005 Addison W Ave 72-829 35643 464 DIP 12 0.37 0.41 10 22208113006 Addison W Ave PH-180-1** 35643 299 DIP 12 0.37 NR 2220816007 Addison W Ave PH-180-1 24393 325 DIP 12 0.37 NR 2220816008 Addison W Ave 28774 24393 614 CAS 6 0.55 0.35 2220816009 Addison W Ave PH-42-1 Echo-16 187 CAS 4 0.52 0.31 222081BO10 Addison W Ave Echo-17 Echo-16 444 CAS 4 0.52 0.37 -29 222081B011 Addison W Ave Echo-17 35644 664 CAS 4 0.52 0.27 222081BO12 Addison W Ave Echo-19 35644 389 CAS 4 0.52 0.31 222081BO13 Addison W Ave Echo-19 Echo-19 411 CAS 4 0.52 0.46 -11 222081BO14 Addison W Ave 36035 Echo-19 524 CAS 4 0.52 0.28 222081BO15 Addison W Ave 36035 PH-6-1 405 CAS 4 0.52 0.34 222081BO16 Addison W Ave 72-726 PH-6-1 419 CAS 4 0.52 0.39 -24 *Access Points noted with the Echo prefix are appurtenances without available details on provided GIS, updates to Twin Falls asset numbers may be added with further GIS information **Access Points noted with the PH prefix are potholes installed by Twin Falls for access directly to the watermain [ MUELLER] Page 24 of 44 A.4.2 ADDISON AVENUE EAST amel p varE Apaitmen[s gpartments LDuval Courts / cs} 3 _ N Laurel 3 - x 519rid Avenue � _ J aurel Park P Apartments mYCourts J2220alB024 222081B025 222081B027 222081B028 _ loon Ave Eas AdJi O 222081B017 2 2220816020 22081B018 P P s i 8 e P 110,Avenue East - 3 C Figure A.4.2-1:Addison Avenue East � z 1 - - r a l P P Ip t y P em9en 222081B030 81R026 222081B029 Addison Ave Ea Wdi>on Ave East 0 222081B021 222081B022 222081B023 P p P P 11 th Avenue East - 11th Avenue East . IIII1 ■ II, � Figure A.4.2-2:Addison Avenue East Table A.4.2-1:Addison Avenue East ePulses Condition Assessment Details ( MUELLERJ Page 25 of 44 Sensor 1 Sensor 2 Segment Pipe Internal Nominal Remaining %Change Segment Street Name Location Location Length Material Diameter Thickness Thickness from (ft) (in) (in) (in) Nominal 222081BO17 Addison E Ave 12394 Echo-VI 100*v 719 DIP 12 0.37 NR 222081BO18 Addison E Ave Echo-Vlv-96 Ec1001v 682 DIP 12 0.37 NR 222081BO20 Addison E Ave Echo-Vlv-96 Echo-Vlv-83 643 DIP 12 0.37 0.27 -26 222081BO21 Addison E Ave 33710 Echo-Vlv-83 698 CAS 10 0.68 0.49 -28 222081BO22 Addison E Ave 33710 Echo-21 671 CAS 10 0.68 0.46 222081BO23 Addison E Ave Echo-Vlv-93 Echo-21 226 CAS 10 0.68 0.38 222081BO24 Addison E Ave Echo-7 Echo-Vlv-78 696 CAS 6 0.55 0.26 222081BO25 Addison E Ave Echo-7 Echo-Vlv-94 382 CAS 6 0.55 0.27 222081BO26 Addison E Ave 33709 Echo-12 663 CAS 6 0.55 0.34 222081BO27 Addison E Ave Echo-23 Echo-Vlv-94 465 CAS 6 0.55 0.28 222081BO28 Addison E Ave Echo-23 Echo-12 500 CAS 6 0.55 0.34 222081BO29 Addison E Ave 33709 Echo-Vlv-89 508 CAS 6 0.55 0.47 -15 222081BO30 Addison E Ave Echo-24 Echo-Vlv-88 465 CAS 6 0.55 0.47 -15 *Access Points noted with the Echo prefix are appurtenances without available details on provided GIS, updates to Twin Falls asset numbers may be added with further GIS information **Access Points noted with the PH prefix are potholes installed by Twin Falls for access directly to the watermain IMUELLERJ Page 26 of 44 A.4.3 BLUE LAKES BOULEVARD Bison Avenue �b Addison Ave East m 04 LO 4A 00 0 00 LP N O �G �{y N P,y 2t''VV N N 11th Avenue East LO �a m m ry / O 00 a N O ty N N r r°C N N 5 ' o A /c first ptis / urc1 of Twnnn 3 / Oth Avenue East Ii 9�h O O N Ln N N m Fdsr 00 O N N N It h`\�e M ec m each 9th Avenue East 00 N 8�h N N 00 Fys` Oco '^ Nr�o N U) m GPF m 8th Avi 00 d rP O Soh N a �L N 00 N P�GP m c Fdsr 00 O N N N Figure A.4-3-1:Blue Lakes Boulevard IMUELLERJ Page 27 of 44 '9L P7 LeF 8th Avenue East ds� D 00 7LP� m O-e 00 O N N N O co O m , 7th Avenue East _ O 1 N JII N St N I ❑ hq O 0] r 7L 00 ^ P�dS� N ~ Elizabeth BoulevardsCN y N - �� m �a 6th Avenue East c¢ M I O 0] 00 CD a0 O O N m N � N C O N N e`�ay Sth Avenue East c^ 00 m O m LO 00 O O m N 14 01 N 00 9t N P� N GP N N� FO-e ` 4 ,A 4th Avenue East Figure A.4.3-2:Blue Lakes Boulevard ( MUELLERJ Page 28 of 44 � yL e, 4th Avenue EdSt rn M O 11 m m W O ri Bickel Elementary N o School �� N r� 3rd Avenue East 3 O CO 14 O O pp m 00 00 0 r O N vDi N N 7 • N N N l US 30 ^ 2nd Avenue East Ab �� N o m o m m O 00 N O N N CV N SO wh —Kimberly Road CVri Motel e Kimberly Road Figure A.4.3-3:Blue Lakes Boulevard IMUELLERJ Page 29 of 44 Table A.4.3-1: Blue Lake Blvd ePulse®Condition Assessment Details Sensor Remainin % Segmen Pipe Internal Nominal Change Location Locatio Thickness Segment Street Name Sensor 1 2 t Length Materia Diamete Thicknes g from n (ft) I r(in) s(in) (in) Nomina I Blue Lakes Echo-Vlv- Echo- 222081B031 Blvd 73* Vlv- 308 CAS 12 0.75 NR 101 Blue Lakes Echo- 222081B032 Blvd Echo-25 Vlv- 398 CAS 12 0.75 0.56 -25 101 222081BO33 Blue Lakes Echo-25 Echo- 447 CAS 12 0.75 0.56 -26 Blvd 26 222081BO34 Blue Lakes Echo-27 Echo- 416 CAS 12 0.75 0.55 -27 Blvd 26 222081BO35 Blue Lakes Echo-27 Echo- 564 CAS 16 0.89 0.63 -29 Blvd 28 Blue Lakes Echo- 222081B036 Blvd Echo-28 Vlv- 497 CAS 16 0.89 0.51 42 112 Blue Lakes Echo- 222081B037 Blvd 33695 Vlv 666 CAS 16 0.89 0.73 18 112 222081BO38 Blue Lakes 33694 Echo- 465 CAS 14 0.82 NR Blvd 30 222081BO39 Blue Lakes 33717 Echo- 579 CAS 14 0.82 0.47 43 Blvd 30 222081BO40 Blue Lakes 33717 35231 527 CAS 14 0.82 0.37 55 Blvd 222081BO41 Blue Lakes 33708 35231 507 CAS 14 0.82 0.33 -60 Blvd 222081BO42 Blue Lakes Blvd 33707 35631 436 CAS 8 0.60 0.38 7 222081BO43 Blue Lakes 33700 35631 570 CAS 8 0.60 0.38 6 Blvd Blue Lakes Echo- 222081B044 Blvd 33700 Vlv- 452 CAS 8 0.60 0.30 0 110 Blue Lakes Echo- 222081B045 Blvd 33696 Vlv- 540 CAS 6 0.55 0.25 -55 110 Blue Lakes Echo- 222081B046 Blvd 33696 Vlv- 528 CAS 8 0.60 0.33 -45 108 Blue Lakes Echo-Vlv- Echo- 222081B047 Blvd 106 Vlv- 484 CAS 8 0.60 0.35 -42 108 222081BO48 Blue Lakes Echo-Vlv- Echo-1 489 CAS 8 0.60 0.29 -51 Blvd 106 Blue Lakes Echo 222081BO49 Blvd Echo-31 Vlv- 505 CAS 8 0.60 0.31 8 104 6, JMUELLERJ Page 30 of 44 Sensor Remainin % Segmen Pipe Internal Nominal Change Location Locatio Thickness Segment Street Name Sensor 1 2 t Length Materia Diamete Thicknes g from n (ft) I r(in) s(in) (in) Nomina I 222081BO50 Blue Lakes Echo-31 75 545 CAS 8 0.60 0.38 Blvd 797 222081BO51 Blue Lakes Echo-32 75 477 CAS 8 0.60 0.39 Blvd 797 222081BO52 Blue Lakes Echo-32 Echo 279 CAS 8 0.60 0., Blvd Vlv-66 *Access Points noted with the Echo prefix are appurtenances without available details on provided GIS, updates to Twin Falls asset numbers may be added with further GIS information **Access Points noted with the PH prefix are potholes installed by Twin Falls for access directly to the watermain [ MUELLER] Page 31 of 44 A.5 EPULSE®OPTIMIZE CONDITION ASSESSMENT RESULTS A.5.1 ADDISON AVENUE W Section Pipe Diameter Nominal Measured Deg Section# Street Name Fitting 1 Fitting 2 Length Thickness Thickness (m) Material (mm) (mm) (mm) �� 222081BO03-1 Addison W 36034 GEP-640-2 53 DIP 12 0.4 0.42 4 222081BO03-2 Addison W GEP-640-2 GEP-640-3 53 DIP 12 0.4 0.43 7 222081BO03-3 Addison W GEP-640-3 GEP-640-5 106 DIP 12 0.4 0.43 8 222081BO03-4 Addison W GEP-640-5 GEP-640-6 53 DIP 12 0.4 0.41 3 222081BO03-5 Addison W GEP-640-6 24390 55 DIP 12 0.4 0.44 10 +4ddiso - _ A,1,�e►ten us.3 Addis_.: nu West • Figure A.5.1-1:Addison Ave W(Rose St to Carney St) IM,UELLERJ Page 32 of 44 A.5.2 ADDISON AVENUE W Street Section Pipe Diameter Nominal Measured Deg Section# Name Fitting 1 Fitting 2 Length Mater ( )mm Thickness Thickness (m) ial (mm) (mm) 222081BO12-1 Addison e W Echo-19 GEP-620-7 59 CAS 4 0.52 0.29 Addison W GEP-140096 222081B012-2 Ave GEP-620 7 11 220 CAS 4 0.52 0.30 222081BO12-3 Addison W GEP- 35644 110 CAS 4 0.52 0.37 -29 Ave 140096-11 1 � Add190krf Avenue wou US30 ---- 0 —� US 93 Bus Addison Avers w est AL Figure A.5.2-1:Addison Ave W(West of Blake St) IM,UELLERJ Page 33 of 44 A.5.3 BLUE LAKE BOULEVARD Section Nominal Measured Section# Street Fitting 1 Fitting 2 Length Pipe Diameter Thickness Thickness Deg Name Blvd 13 13 (m) Material (mm) (mm) (mm) % 222081B036-1 Blue Lake Echo-28 GEP 55 CAS 16 0.89 0.49 222081B036-2 Blue Lake GEP-1648- GEP-1648- 55 CAS 16 0.89 0.53 -40 Blvd 13 14 222081B036-3 Blue Lake GEP-1648- GEP-1648- 55 CAS 16 0.89 0.51 -43 Blvd 14 15 222081B036-4 Blue Lake GEP-1648- GEP-1648- 110 CAS 16 0.89 0.53 -41 Blvd 15 17 222081B036-5 Blue Lake GEP-1648- GEP-1648- 55 CAS 16 0.89 0.51 -42 Blvd 17 18 222081B036-6 Blue Lake GEP-1648- GEP- 55 CAS 16 0.89 0.52 -42 Blvd 18 147153-19 222081B036-7 Blue Lake GEP- GEP- 55 CAS 16 0.89 0.53 -41 Blvd 147153-19 147153-20 222081B036-8 Blue Lake GEP- Echo-Vlv-112 57 CAS 16 0.89 0.49 -45 Blvd 147153-20 4 m �a ¢e 4` 9 o� 2I 3 �., �e iS1 7th Avenue Eau 4 1 1 5I € 6I 7 nay (n 9 8 •E6ra6eth Boulevard Figure A.5.2-1:Blue Lakes Blvd(Jerome St E to Elizabeth Blvd) IMUELLERJ Page 34 of 44 APPENDIX B INTERPRETATION OF RESULTS BA ECHOWAVE®LEAK DETECTION When we discover a noise on a main, it can be classified as a leak or a point of interest (P01). If further investigation reveals negative results, it is classified as no leak discovered.Within all our reports, if no mention is made of leaks on a given section, it may be assumed that the result of the test is no leak discovered. No Leak Discovered When a negative correlation is matched with poor coherence, it is concluded that no leak was detected. In effect, there is no indication of a noise source of any sort,and therefore that there is no other evidence of leakage.Where possible,leak simulations are performed to confirm the absence of leaks and to ensure equipment functionality. Point of Interest(P01) A Point of Interest(P01)designation indicates that some,but not all,of the criteria for a positive leak detection result are met.This could mean that a strong correlation is observed but coherence is poor,or that there is no confirmation of leak noise through other test methods such as ground sounding or secondary correlation tests. This does not indicate a conclusive leak; however it is recommended that the City of Twin Falls perform a secondary investigation.This will confirm the presence and location of the leak, as there is evidence of some form of noise inside the pipe. Leak Three pieces of conclusive evidence must be acquired for a Point of Interest to be classified as a Leak.This includes but is not limited to the following methods of detection: • Leak correlation • Ground sounding • Acoustic sounding of fittings • Visual observation of moving water • Confirmation of chlorine residuals in stagnant water Several criteria must be met for audio recordings in order to provide a positive leak detection result.This includes but is not limited to: • A clean distinctive correlation peak • An observable coherence level • Similar frequency spectra in each channel • A minimum amount of clipping in the time signal In some instances, more than one correlation test can be used as evidence to conclusively identify a leak. For instance, a field specialist can perform multiple correlation tests with sensors mounted to different pipe fittings. [ MUELLER] Page 35 of 44 B.2 EPULSE®CONDITION ASSESSMENT ePulse®condition assessment measures the mean hoop thickness(for asbestos cement or metallic mains)or mean hoop stiffness (for reinforced concrete).Where the original nominal thickness(or stiffness)is available,results are also presented as a percentage loss,and as a category indicating a qualitative description of the expected condition of the main. Qualitative Condition Description Categories The color-coding and descriptions in Table B.2-1:Color Coding and Hoop Thickness Loss Qualitative Descriptions are used for the results presented in all ePulse®condition assessment reports. Table B.2-1:Color Coding and Hoop Thickness Loss Qualitative Descriptions Change in Description Hoop Description Color Code Thickness Metallic Mains Less than 10% Good Green Minor levels of uniform corrosion or some localized areas with pitting corrosion. 10%to 30% Moderate Yellow Considerable levels of uniform surface or internal corrosion and/or localized areas of pittingcorrosion. Greater than Poor Significant uniform corrosion and/or numerous areas of 30% localized pitting corrosion. These descriptions are based on our experience and with validation of results through the exhumation of pipe samples tested. Following the table,more detail is provided as to the expected condition of differenttypes of main in each condition category,along with examples of validation of the ePulse®method on each type of main. Distribution of Degradation within Segments Each ePulse® result represents an average condition within a segment between two sensor attachment points. Pipe conditions may vary within a segment.The condition at any one point within the segment may not reflect the average conditions within that segment. The ePulse® method tests the mean hoop thickness of the pipe, which is not the same as the average thickness of the pipe. ePulse®measures a pipe's hoop stiffness: its resistance to axi-symmetric expansion under the tiny pressure variations caused by sound waves. Material properties are then used to calculate the hoop thickness which would provide exactly this stiffness.This is referred to as the mean hoop thickness. To obtain this same value mechanically,you would need to:divide a pipe into hoops; measure the thinnest section of structural material around the circumference of each hoop(i.e.graphite,tuberculation product,or asbestos cement with the calcium leached out would not be counted);and then average these. For example,any of the following descriptions will hold true for a pipe with a loss of 25%: 1. Circumferentially uniform loss of 25%along the entire segment. 2. Circumferentially uniform loss of 50%along half of the segment,but 0%loss along the other half of the segment. 3. Loss of 25%at the crown of the pipe along the entire segment, but 0%loss along any other point in the circumference along the entire segment. These descriptions hold true for asbestos cement,metallic and reinforced concrete mains. [ MUELLER] Page 36 of 44 Condition Interpretation in Metallic Mains Corrosion can occur in metallic pipes either in a localized area or in a generalized manner along the main. Examples of various levels of corrosion are presented in Figure B.2-5 below. Most of the degradation is often caused by a combination of internal corrosion, soil aggressiveness and coating defects on the surface of the main. If no coating was present upon installation,then the degradation would be due to soil aggressiveness alone. For cement mortar lined pipes, areas with higher losses may indicate the lining has been degraded to the point that the water column is now in contact with the metal, locally accelerating the degradation rate. This may also suggest that the soil loading conditions were such that the pipe experienced an over-deflection during its lifetime,causing damage to the interior lining. When considering the water aggressiveness as a mechanism for corrosion, it can be assumed that the degradation is relatively uniform across the length of the main. If pipes are unlined (bare), internal degradation may be attributed to a combination of localized pitting,and the formation of tuberculation that can also be accompanied by the formation graphitic corrosion (leaching of iron from the metal matrix). Localized corrosion is most likely due to isolated mechanisms such as direct current corrosion, or localized aggressive soil conditions.For cement lined pipes,areas with higher losses may indicate the lining has been degraded to the point that the water column is now in contact with the metal, locally accelerating the degradation rate. s 1i 6" Cl pipe with 4.2% measured loss 6" Cl pipe with 47% measured loss A j. f 6" Cl pipe with 10% measured loss 18" Cl pipe with 18.5% measured loss Figure B.2-2:Examples of Different Levels of Corrosion in Metallic Pipe IMUELLERJ Page 37 of 44 Validation As of the January 2019, a total of 173 ePulse®validation results have been provided to us by our clients or third parties. Some clients have requested confidentiality; however we are able to present the result in aggregate. ePulse Validation Results - All Materials 45.0 y= 0.916x + 0.9412 R2 = 0.9003 40.0 35.0 — 30.0 — 25.0 • — U20.0 t �+ a, • 15.0 � �''• — • • • • > • • • 10.0 5.0 •�i •�• 0.0 0 5 15 20 25 30 35 40 45 ePulse Thickness (mm) Figure B.2-3:ePulse®Validations On All Materials Two factors are worth attention in the charts. The R2 value is known as the coefficient of determination.This provides a measure of how well validation results are predicted by ePulse®results. It is the proportion of total variation of outcomes in validation results explained by the ePulse®results.An R2 of 1 indicates that the data match perfectly,while an R2 of 0 indicates that the ePulse®results cannot be used to predict the validated results at all. For non-destructive testing methods,an R2 value above 0.5 represents strong predictive power. The correlation coefficient R is the square root of the R2 value. For example, an R2 value of 0.5 means the same thing as a correlation of 0.71. The equation(y=a+(3x)indicates how well calibrated the ePulse®measurements are,on average.Values of a close to zero,and of R close to 1, indicate good calibration. For non-destructive testing methods,a R greater than 0.5 and an a less than 25%of the average value represent good calibration. Note that the variation between the ePulse®results and validation measurements is not the same thing as the error in the ePulse® results.It is actually the combination of the error in the ePulse®results and the random variation in point samples versus the true average. Comparing ePulse® results to the results of validations will over-estimate the actual error in the ePulse® results.The reason for this is thatthe ePulse®results are averages over segments of about 100 m(300")in length,whereas the validation results indicate the thickness at a one point or a small sub-segment.Each validation measurement will have a random error versus the true average over that segment.The difference between an ePulse®measurement and a validation measurement can be understood as: ePulse®-Validated=(ePulse®- True-Average)+(True-Average- Validated) [ MUELLER] Page 38 of 44 Even if the ePulse®results perfectly match the true average(ePulse®-True-Average=0),we would still expect to see a difference between validation results and ePulse®: ePulse®-Validated=(True-Average- Validated) Actual pipe conditions will vary randomly along the sample, so the difference between the true average and validation results should be a normal distribution centered around zero.If ePulse®is effectively measuring the true average,we should see the same pattern in the difference between the ePulse®and Validated results.The actual distribution is shown in Figure B.2-4,and appears to match the expected pattern. Variance - ePulse vs Validation (mm) 25 20 15 10 5 0 ■ 1 ■ I I I ■ -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 Figure B.2-4:Variance between ePulse®results and validation results There are a small number of outliers, which likely represent errors in those ePulse® measurements.The remainder of the data match the expected normal distribution. [ MUELLER] Page 39 of 44 B.3 LIMITATIONS The accuracy of the final results presented in this report can be impacted by a certain factor.The following are some of the factors that affect the accuracy of results. MODULUS OF ELASTICITY The modulus of elasticity of the pipe material is one of the factors in the calculation of the mean hoop thickness.While we have significant experience estimating the modulus of elasticity based on the material,age,and region of manufacture,we can improve the accuracy of the results by testing the actual modulus of elasticity of an exhumed sample of the pipe. If interested, please contact us for more information. PIPE SPECIFICATIONS Detailed pipe specifications were not available for all pipes surveyed.Although we have made reasonable assumptions for internal diameter, material and original hoop thickness, the results can be improved if accurate pipe specifications can be provided. If original specifications cannot be located,the City of Twin Falls may wish to exhume a pipe coupon to verify diameter,material,and thickness assumptions. STATISTICAL VARIATION The values generated by ePulse®testing are averaged for a segment of pipe which ranges in length from 150 feet to 500 feet.This averaging allows for the possibility of having small lengths within the segment which are severely degraded.This degradation will not be shown in the final result.Therefore, it is important to note that the value presented describes the general condition of the pipe and may not show future potential point failures. [ MUELLER] Page 40 of 44 B.4 SENSITIVITY ANALYSES AND CONSIDERATIONS Several variables may affect accurate analysis: • Inaccurate distance measurements • Variance in manufacturing tolerances • Variance in the modulus of elasticity of the material • Unknown pipe repairs • Inadequate correlation signals. We are constantly committed to reducing error during every step of the testing process. Distance Measurement An accurate distance measurement is crucial for an accurate assessment. In general, a 1%error in distance measurement can result to more than a 2%error in final percentage of thickness lost. For this reason, our preference is to use potholes or in-line valves,as these provide the most accurate distance measure,since it is a point-to-point measurement.As the number of bends and/or elevation changes between the sensor connection points increases, so does the potential error in the distance measurement. Pipe Manufacturing Tolerances Small differences in nominal specifications will occur between pipes due to differences in manufacturers and tolerances.These differences commonly range from between 5% and 10% depending on the manufacturer and the material. Furthermore, a contractor may have installed a pipe that exceeds the minimum specifications. Under these circumstances the measurements may show a pipe with a hoop thickness that is greater than expected. This is particularly true of older pipes as their tolerances were not adhered to as strictly. The material properties used for calculations are selected using conservative estimates.This provides for a worst-case scenario analysis. Repair Clamps on Previous Leaks Acoustic waves are primarily water borne.As such, a small number of repair clamps will have an insignificant effect on the test results,since the acoustic wave will bypass the clamps. Modulus of Elasticity A change in elastic modulus of 10%will cause a change in the calculated thickness by approximately 10%.The elastic modulus is known for common materials used in the manufacturing of pressure pipe, but this value can vary among manufacturers. It is dependent on the manufacturing process and the quality of the material.The material properties used for calculations are selected using conservative estimates.This provides for a worst-case scenario analysis. Unaccounted for Replacement of Pipe Sections During Repairs Acoustic waves propagate differently depending upon the pipe material. This effect remains true for unaccounted short pipe replacements with different materials and can result in significant error. For example,a new 6 meter long(-20 feet)ductile iron repair in a 100 meter long(-328 feet)cast iron pipe section of average condition,will produce a small error of+3.5%in measured hoop thickness.However,the same repair made with PVC pipe would produce an error of-41%in measured hoop thickness. Preferably, pipe sections selected for testing should be free of repaired sections. However, if this condition does not exist, the impact of the repaired pipe section can be accounted for, provided accurate information is available for the age, location, length, material type,and class of the repair pipe section. Inadequate Correlation Signals Inadequate correlation signals can sometimes occur in the field. The following are some of the conditions that may cause an inadequate correlation: 1. The presence of plastic repairs in metallic pipes which can cause poor propagation of sound. 2. Loose or worn components in fittings used for the measurements,such as valve or hydrant stems. 3. Large air pockets in the pipe which heavily attenuate acoustic signals. 4. Heavily tuberculated pipe,particularly old cast iron or unlined ductile iron pipes,which can attenuate the acoustic signals to such an extent that a correlation is of very low quality. IM,UELLER] Page 41 of 44 APPENDIX C DETAILED METHODOLOGY C.1 LEAK DETECTION The methodology employed is known as the cross-correlation method.A correlator listens passively for noise created by a leak.If one is detected, it uses the time delay between sensors to determine the position of the leak.The following procedure was used to conduct the leak detection survey: 1. For each location surveyed,the distance between the sensors was measured. 2. Sensors were mounted either directly on the pipe or were connected to the water column with hydrophones. 3. A correlation measurement was performed without introducing noise(known as a background recording),and the signal was saved to the computer so that further analysis could be performed off-site.A preliminary analysis is performed on- site to determine if any leaks are present. [ MUELLER] Page 42 of 44 C.2 EPULSEO MEAN HOOP THICKNESS TESTING A section of pipe is the length bracketed by two contact points on the main.An out-of-bracket noise source is located outside of that segment. A known noise source may be used to determine the acoustic wave velocity in a segment of pipe. Knowing the distance between the sensors,the acoustic wave velocity(v)will be given by v=d/t, where d is the length of pipe between the sensors,and t is the time taken for the acoustic signal to propagate between the two sensors. The following procedure is followed to conduct an ePulse®data collection survey: 1. A leak detection survey is performed on the length of pipe to check for the presence of existing leaks. (Described in previous section) 2. A noise source is created "out-of-bracket". A variety of different noise sources can be used including an existing leak noise,blow-off noise,pump noise,impulse noise,running a fire hydrant,tapping on a fire hydrant,or directly on the pipe. 3. A new correlation measurement is performed and stored as a wave file for further analysis and confirmation off-site.Data is analysed further to obtain an optimum correlation,ensuring an accurate velocity measurement. Wave Velocity Equation The general form of the acoustic pipe integrity testing equation is shown below. Equation C.2-1:Wave Velocity-Thickness Model 1 V = V, X FF ) X (L,A v: measured velocity vo:propagation velocity in an infinite body of water D;:pipe internal diameter Ki:bulk modulus of the liquid E:elastic modulus of the pipe material t,: residual thickness of the pipe Bulk Modulus of Water Calibration Different water sources often produce a different bulk modulus of water. The bulk modulus essentially represents the water's inherent resistance to compression,and is impacted by factors like water temperature,dissolved salts and entrained air.Our field specialists calibrate the bulk modulus at each water company's water source.This requires performing a single test on a stretch of pipe with a known pipe condition. In practice,this generally means performing an additional test on a new section of pipe that has been installed within the past few years. [ MUELLER] Page 43 of 44 APPENDIX D ABBREVIATIONS AC Asbestos Cement: Pipe wall construction consisting of asbestos cement. BWP Bar Wrapped Pipe: Pipe wall construction comprising of a concrete core,a steel cylinder and reinforcing steel bars. Cl Cast Iron: Pipe wall construction consisting of cast iron.This includes pipes classified as pit cast iron or spun cast iron as well. CL Concrete lined: Indicates whether or not a specific pipe type has some form of concrete lining. This abbreviation will typically follow a pipe type abbreviation Ex:DICL for ductile iron concrete lined. DI Ductile Iron: Pipe wall construction consisting of ductile iron. GIS Geographic Information System:A system designed to capture,store,manipulate,analyze, manage,and present all types of spatial or geographical data. GPS Global Positioning System:a global system of satellites used to provide precise positional data and global time synchronization. IB In-Bracket. Please refer to the technical glossary. 00B Out-of-Bracket. Please refer to the technical glossary. PCCP Pre Stressed Concrete Cylinder Pipe: Pipe wall construction comprising of a concrete core,a steel cylinder and pre-stressed high tension wires. PCI Pit Cast Iron:Pipe wall construction consisting of pit cast iron. PE Poly Ethylene:Pipe wall construction consisting of poly ethylene. P01 Point of Interest. Please refer to the technical glossary. PVC Poly Vinyl Chloride:Pipe wall construction consisting of polyvinyl chloride. SCI Spun Cast Iron: Pipe wall construction consisting of spun cast iron. St Steel: Pipe wall construction consisting of steel. IMUELLERJ Page 44 of 44 APPENDIX E GLOSSARY OFTECHNICAL TERMS Acoustic Wave Also known as:wave speed,wave velocity,velocity.The speed at which a coupled-mode pressure Speed wave travels along a pipe. Blue/White Station A piece of equipment where a sensor is connected to transmit the data to a central location. Typically stations are colour coded blue or white. Coherence Measure of similar vibration frequency between two channels(Blue and White stations or a node pair). Correlation The process of comparing two acoustic signals for similarity in the time domain. Echologics technologies use correlation to judge the time delay between two signals.This allows for determination of the location of leaks along a pipeline. In-Bracket A noise source that is within the span of pipe between two Stations or Nodes. Leak Discovered A point along a pipe that is likely loosing water to the surrounding soil and environment. For a leak to be classified as discovered,a field technician must acquire at least three pieces of unique evidence that suggest existence and location. No Leak No evidence of leakage was discovered or a P01 was under investigate and it was determined that it Discovered was not a leak. Node A piece of equipment where a sensor is connected to transmit the data to a central location. Typically nodes are paired with other nodes as part of a large array installed on a pipeline or in an area. Out-of-Bracket A noise source that is outside the span of pipe between two Stations or Nodes. Point of Interest Evidence of some form of noise or energy on the pipe.There is not enough evidence to classify a point of interest as a leak. Segment A section of pipe surveyed in one measurement.The length of the segment is the distance between two sensors. Sensor A device used to measure physical or chemical properties of a system. In the context of this report this term will be typically used as a reference to a vibration sensor. Site A neighbourhood or area within which a segment of pipe exists. ( MUELLERJ