journal article·2025-09Open access

Identifying Lead Water Service Lines Using Ultrasonic Stress Wave Propagation and 1D-Convolutional Neural Network

K. I. M. Iqbal, John DeVitis, Kurt Sjoblom, Charles N. Haas, Ivan Bartoli

Abstract

Abstract Water utilities across the United States face challenges in identifying lead water service lines without excavation, as existing non-destructive methods have notable limitations. This study introduces a non-invasive technology based on stress wave propagation to detect service line materials on both the public (utility) and private (customer) sides. Stress waves are generated at the curb-stop valve of the service line by striking an extension rod with an instrumented hammer, which records the input impact signal. Piezoelectric accelerometer sensors placed on the soil surface then detect the pipe’s responses (output signals). This technology was field-tested in 419 service lines across 20 cities of the US. The collected data underwent several signal processing steps for the calculation of the frequency response function (FRF). Since the data was collected from various cities and locations, there were significant variations in soil depth, soil properties, and surface conditions. These variations made it challenging to develop a physics-based algorithm that accurately differentiates lead from non-lead materials (such as copper, galvanized steel, and plastic). A 1D-Convolutional Neural Network (1D-CNN) was developed that uses combined real and imaginary FRF components as input to classify lead versus non-lead materials. The model was trained on 80% of the service line FRF data, with 10% used for validation and the remaining 10% for testing. To evaluate the model’s performance, a confusion matrix was employed to calculate accuracy, precision, recall, and F1 score using the testing data. The model achieved 80% accuracy on test data and 80.5% accuracy on 41 blind-tested service lines. These results indicate that the stress wave technology proposed in this study, combined with signal processing and 1D-CNN model, offers a promising solution for non-invasively identifying lead service lines in diverse field conditions.
Source: crossref · Quality: baseline

Research context

OpenAlex topics: Water Systems and Optimization · Water Quality Monitoring Technologies · Geophysical Methods and Applications

SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.

References (83)

Show source-provided references
1. Abdeljaber, O., Avci, O., Kiranyaz, S., et al.: Real-time vibration-based structural damage detection using one-dimensional convolutional neural networks. Journal of sound and vibration 388, 154–170 (2017)10.1016/j.jsv.2016.10.043 ↗
2. Abdeljaber, O., Avci, O., Kiranyaz, M.S., et al.: 1-d cnns for structural damage detection: Verification on a structural health monitoring benchmark data. Neurocomputing 275, 1308–1317 (2018)10.1016/j.neucom.2017.09.069 ↗
3. Abernethy, J., Chojnacki, A., Farahi, A., et al.: Activeremediation: The search for lead pipes in flint, michigan. In: Proceedings of the 24th ACM SIGKDD International Conference on Knowledge Discovery & Data Mining, pp 5–14 (2018)10.1145/3219819.3219896 ↗
4. Agency UEP.: Integrated science assessment for lead. office of research and development. EPA/600/R–10/075F (2013)
5. Agency UEP.: National primary drinking water regulations: Lead and copper rule revisions. Fed Regist 84(219), (2021)
6. Aminpour, P., Sjoblom, K., Bartoli, I. Identification of water pipe material based on stress wave propagation: Numerical investigations. Mater. Eval. 79(8) (2021)10.32548/2021.me-04185 ↗
7. Aristegui, C., Lowe, M.J., Cawley, P.: Guided waves in fluid-filled pipes surrounded by different fluids. Ultrasonics 39(5), 367–375 (2001)10.1016/S0041-624X(01)00064-6 ↗
8. Avci, O., Abdeljaber, O., Kiranyaz, S., et al.: Structural damage detection in real time: implementation of 1d convolutional neural networks for shm applications. In: Structural Health Monitoring & Damage Detection, Volume 7: Proceedings of the 35th IMAC, A Conference and Exposition on Structural Dynamics 2017, Springer, pp 49–54 (2017)10.1007/978-3-319-54109-9_6 ↗
9. Avci, O., Abdeljaber, O., Kiranyaz, S., et al.: Wireless and real-time structural damage detection: A novel decentralized method for wireless sensor networks. J. Sound Vib. 424, 158–172 (2018)10.1016/j.jsv.2018.03.008 ↗
10. Avci, O., Abdeljaber, O., Kiranyaz, S., et al.: A review of vibration-based damage detection in civil structures: From traditional methods to machine learning and deep learning applications. Mech. Syst. Signal Process. 147(107), 077 (2021)
11. Azimi, M., Pekcan, G.: Structural health monitoring using extremely compressed data through deep learning. Comput. Aided Civ. Infrastruct. Eng. 35(6), 597–614 (2020)10.1111/mice.12517 ↗
12. Bao, Y., Tang, Z., Li, H., et al.: Computer vision and deep learning-based data anomaly detection method for structural health monitoring. Struct. Health. Monit. 18(2), 401–421 (2019)10.1177/1475921718757405 ↗
13. Boaratti, MFG., Ting, DKS., et al.: Measurement of stress waves propagation velocities in solid media using wavelet transforms. In: International Nuclear Atlantic Conference, XIV ENFIR, Aug (2005)
14. Bukhari, Z., Ge, S., Chiavari, S., et al.: Lead service line identification techniques. Water Res. Found. Proj. (4693) (2020)
15. Chawla, N.V., Bowyer, K.W., Hall, L.O., et al.: Smote: synthetic minority over-sampling technique. J. Artif. Intell. Res. 16, 321–357 (2002)10.1613/jair.953 ↗
16. Chojnacki, A., Dai, C., Farahi, A., et al.: A data science approach to understanding residential water contamination in flint. In: Proceedings of the 23rd ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, pp 1407–1416 (2017)10.1145/3097983.3098078 ↗
17. Cornwell, D.A., Brown, R.A., Via, S.H.: National survey of lead service line occurrence. J. Am. Water Works Assoc. 108(4), E182–E191 (2016)10.5942/jawwa.2016.108.0086 ↗
18. Coşkun M, Uçar A, Yildirim Ö, et al (2017) Face recognition based on convolutional neural network. In: 2017 International Conference on Modern Electrical and Energy Systems (MEES), IEEE, pp 376–37910.1109/MEES.2017.8248937 ↗
19. Cui, R., Azuara, G., Lanza di Scalea, F., et al.: Damage imaging in skin-stringer composite aircraft panel by ultrasonic-guided waves using deep learning with convolutional neural network. Struct. Health Monit. 21(3), 1123–1138 (2022)10.1177/14759217211023934 ↗
20. Cui, Y., Jia, M., Lin, TY., et al.: Class-balanced loss based on effective number of samples. In: Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition, pp 9268–9277 (2019)10.1109/CVPR.2019.00949 ↗
21. Dang, H.V., Tatipamula, M., Nguyen, H.X.: Cloud-based digital twinning for structural health monitoring using deep learning. IEEE Trans. Ind. Inform. 18(6), 3820–3830 (2021)10.1109/TII.2021.3115119 ↗
22. DanieIs, JJ.: Fundamentals of ground penetrating radar. In: 2nd EEGS Symposium on the Application of Geophysics to Engineering and Environmental Problems, European Association of Geoscientists & Engineers, pp cp–213 (1989)
23. Das, S., Roy, K.: A state-of-the-art review on frf-based structural damage detection: development in last two decades and way forward. Int. J. Struct. Stab. Dyn. 22(02):2230,001 (2022)10.1142/S0219455422300014 ↗
24. De Marchi, L.: Sparse signal processing and deep learning for guided waves ndt and shm. In: Proceedings of Meetings on Acoustics, AIP Publishing (2019)10.1121/2.0001169 ↗
25. Deb, AK., Hasit, YJ., Grablutz, FM.: Innovative techniques for locating lead service lines. AWWA Res. Found. Am. Water Works Assoc. (1995)
26. Driss, SB., Soua, M., Kachouri, R., et al.: A comparison study between mlp and convolutional neural network models for character recognition. In: Real-Time Image and Video Processing 2017, SPIE, pp 32–42 (2017)
27. Du, J.: Understanding of object detection based on cnn family and yolo. In: Journal of Physics: Conference Series, IOP Publishing, p 012029 (2018)10.1088/1742-6596/1004/1/012029 ↗
28. Ebrahimkhanlou, A., Salamone, S.: Single-sensor acoustic emission source localization in plate-like structures using deep learning. Aerospace 5(2), 50 (2018)10.3390/aerospace5020050 ↗
29. Michigan Department of Environment GL, Energy(DEGLE).: Michigan lead and copper rules service line material notification requirements. drinking water and environmental health division (2020)
30. Eren, L.: Bearing fault detection by one-dimensional convolutional neural networks. Math. Probl. Eng. 2017(1), 8617,315 (2017)10.1155/2017/8617315 ↗
31. Eren, L., Ince, T., Kiranyaz, S.: A generic intelligent bearing fault diagnosis system using compact adaptive 1d cnn classifier. J. Signal Process. Syst. 91(2), 179–189 (2019)10.1007/s11265-018-1378-3 ↗
32. Ewald, V., Groves, RM., Benedictus, R.: Deepshm: A deep learning approach for structural health monitoring based on guided lamb wave technique. In: Sensors and Smart Structures Technologies for Civil, Mechanical, and Aerospace Systems 2019, SPIE, pp 84–99 (2019)10.1117/12.2506794 ↗
33. Goodfellow, I.: Deep learning (2016)
34. Gu, J., Wang, Z., Kuen, J., et al.: Recent advances in convolutional neural networks. Pattern Recognit. 77, 354–377 (2018)10.1016/j.patcog.2017.10.013 ↗
35. Guo, J., Liu, C., Cao, J., et al.: Damage identification of wind turbine blades with deep convolutional neural networks. Renew. Energy 174, 122–133 (2021)10.1016/j.renene.2021.04.040 ↗
36. Hao, T., Rogers, C., Metje, N., et al.: Condition assessment of the buried utility service infrastructure. Tunn. Undergr. Space Technol. 28, 331–344 (2012)10.1016/j.tust.2011.10.011 ↗
37. Helbing, G., Ritter, M.: Deep learning for fault detection in wind turbines. Renew. Sustain. Energy Rev. 98, 189–198 (2018)10.1016/j.rser.2018.09.012 ↗
38. Hu, G., Yang, Y., Yi, D., et al.: When face recognition meets with deep learning: an evaluation of convolutional neural networks for face recognition. In: Proceedings of the IEEE International Conference on Computer Vision Workshops, pp 142–150 (2015)10.1109/ICCVW.2015.58 ↗
39. Ince, T., Kiranyaz, S., Eren, L., et al.: Real-time motor fault detection by 1-d convolutional neural networks. IEEE Trans. Ind. Electron. 63(11), 7067–7075 (2016)10.1109/TIE.2016.2582729 ↗
40. Iqbal, K., Hasan, F., Sjoblom, K., et al.: Buried service line material characterization using stress wave propagation: Numerical and experimental investigations. J. Nondestruct. Eval. 43(1), 12 (2024)10.1007/s10921-023-01031-y ↗
41. Jallouli, A.: (2020) Evaluation of lead pipe detection by electrical resistance measurement
42. Kim, YS., Kim, MK., Fu, N., et al.: Investigating the impact of data normalization methods on predicting electricity consumption in a building using different artificial neural network models. Sustainable Cities and Society p 105570 (2024)10.1016/j.scs.2024.105570 ↗
43. Kiranyaz, S., Ince, T., Gabbouj, M.: Real-time patient-specific ecg classification by 1-d convolutional neural networks. IEEE Trans. Biomed. Eng. 63(3), 664–675 (2015)10.1109/TBME.2015.2468589 ↗
44. Kiranyaz, S., Ince, T., Hamila, R., et al.: Convolutional neural networks for patient-specific ecg classification. In: 2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), IEEE, pp 2608–2611 (2015b)10.1109/EMBC.2015.7318926 ↗
45. Kiranyaz, S., Ince, T., Gabbouj, M.: Personalized monitoring and advance warning system for cardiac arrhythmias. Sci. Rep. 7(1), 9270 (2017)10.1038/s41598-017-09544-z ↗
46. Kiranyaz, S., Gastli, A., Ben-Brahim, L., et al.: Real-time fault detection and identification for mmc using 1-d convolutional neural networks. IEEE Trans. Ind. Electron. 66(11), 8760–8771 (2018)10.1109/TIE.2018.2833045 ↗
47. Krizhevsky, A., Sutskever, I., Hinton, GE.: Imagenet classification with deep convolutional neural networks. Adv. Neural Inform. Process. Syst. 25 (2012)
48. LeCun, Y., Bengio, Y., Hinton, G.: Deep learning. Nature 521(7553), 436–444 (2015)10.1038/nature14539 ↗
49. Leinov, E., Lowe, M.J., Cawley, P.: Investigation of guided wave propagation and attenuation in pipe buried in sand. J. Sound. Vib. 347, 96–114 (2015)10.1016/j.jsv.2015.02.036 ↗
50. Leinov, E., Lowe, M.J., Cawley, P.: Ultrasonic isolation of buried pipes. J. Sound Vib. 363, 225–239 (2016)10.1016/j.jsv.2015.10.018 ↗
51. LeNail, A.: Nn-svg: Publication-ready neural network architecture schematics. J. Open Source Softw. 4(33), 747 (2019)10.21105/joss.00747 ↗
52. Liggett, J., Baribeau, H., Deshommes, E., et al.: Service line material identification: Experiences from north american water systems. J. Am. Water Works Assoc. 114(1), 8–19 (2022)10.1002/awwa.1841 ↗
53. Ling, C.X., Sheng, V.S.: Cost-sensitive learning and the class imbalance problem. Encycl. Mach. Learn. 2011, 231–235 (2008)
54. Long, R., Vine, K., Lowe, M., et al.: The effect of soil properties on acoustic wave propagation in buried iron water pipes. In: AIP Conference Proceedings, American Institute of Physics, pp 1310–1317 (2002)10.1063/1.1472947 ↗
55. Long, R., Cawley, P., Lowe, M.: Acoustic wave propagation in buried iron water pipes. Proceedings of the Royal Society of London Series A: Mathematical, Physical and Engineering Sciences 459(2039), 2749–2770 (2003)10.1098/rspa.2003.1148 ↗
56. Long, R., Lowe, M., Cawley, P.: Attenuation characteristics of the fundamental modes that propagate in buried iron water pipes. Ultrasonics 41(7), 509–519 (2003)10.1016/S0041-624X(03)00166-5 ↗
57. Melville, J., Alguri, KS., Deemer, C., et al.: Structural damage detection using deep learning of ultrasonic guided waves. In: AIP Conference Proceedings, AIP Publishing (2018)10.1063/1.5031651 ↗
58. Metje, N., Atkins, P., Brennan, M., et al.: Mapping the underworld-state-of-the-art review. Tunn. Undergr. Space Technol. 22(5–6), 568–586 (2007)10.1016/j.tust.2007.04.002 ↗
59. Mohtasham Khani, M., Vahidnia, S., Ghasemzadeh, L., et al.: Deep-learning-based crack detection with applications for the structural health monitoring of gas turbines. Struct. Health Monit. 19(5), 1440–1452 (2020)10.1177/1475921719883202 ↗
60. Muggleton, J., Brennan, M., Pinnington, R.: Wavenumber prediction of waves in buried pipes for water leak detection. J. Sound Vib. 249(5), 939–954 (2002)10.1006/jsvi.2001.3881 ↗
61. Oelze, M.L., O’Brien, W.D., Darmody, R.G.: Measurement of attenuation and speed of sound in soils. Soil Sci. Soc. Am. J. 66(3), 788–796 (2002)10.2136/sssaj2002.7880 ↗
62. O’Shea, K.: An introduction to convolutional neural networks (2015). arXiv preprint arXiv:1511.08458
63. Pal, J., Sikdar, S., Banerjee, S.: A deep-learning approach for health monitoring of a steel frame structure with bolted connections. Struct. Control Health Monit. 29(2),(2022)10.1002/stc.2873 ↗
64. Pathak, N.: Bridge health monitoring using cnn. In: 2020 International Conference on Convergence to Digital World-Quo Vadis (ICCDW), IEEE, pp 1–4 (2020)10.1109/ICCDW45521.2020.9318674 ↗
65. Pereira, J., Saraiva, F.: Convolutional neural network applied to detect electricity theft: A comparative study on unbalanced data handling techniques. Int. J. Electr. Power Energy Syst. 131(107), 085 (2021)
66. Program, N.T.: Ntp monograph on health effects of low-level lead. Hypertension 160, 95 (2012)
67. Rautela, M., Senthilnath, J., Moll, J., et al.: Combined two-level damage identification strategy using ultrasonic guided waves and physical knowledge assisted machine learning. Ultrasonics 115(106), 451 (2021)
68. Ren, S., He, K., Girshick, R., et al.: Faster r-cnn: Towards real-time object detection with region proposal networks. IEEE Trans. Pattern Anal. Mach. Intell. 39(6), 1137–1149 (2016)10.1109/TPAMI.2016.2577031 ↗
69. Ruiz, DV., de Bragança, CSC, Poncetti, BL., et al.: Vibration-based structural damage detection strategy using frfs and machine learning classifiers. In: Structures, Elsevier, p 105753 (2024)10.1016/j.istruc.2023.105753 ↗
70. Ruiz, D.V., de Bragança, C.S.C., Poncetti, B.L., et al.: Structural damage detection for a small population of nominally equal beams using pso-optimized convolutional neural networks. Mech. Syst. Signal Process. 225(112), 276 (2025)
71. Ruiz, JT., Pérez, JDB., Blázquez, JRB.: Arrhythmia detection using convolutional neural models. In: Distributed Computing and Artificial Intelligence, 15th International Conference 15, Springer, pp 120–127 (2019)10.1007/978-3-319-94649-8_15 ↗
72. Sampaio, R., Maia, N., Silva, J.: Damage detection using the frequency-response-function curvature method. J. Sound Vib. 226(5), 1029–1042 (1999)10.1006/jsvi.1999.2340 ↗
73. Sarkar, S., Reddy, KK., Giering, M.: Deep learning for structural health monitoring: A damage characterization application. In: Annual Conference of the PHM Society (2016)10.36001/phmconf.2016.v8i1.2544 ↗
74. Schmidhuber, J.: Deep learning in neural networks: An overview. Neural Netw. 61, 85–117 (2015)10.1016/j.neunet.2014.09.003 ↗
75. Srivastava, N., Hinton, G., Krizhevsky, A., et al.: Dropout: a simple way to prevent neural networks from overfitting. J. Mach. Learn. Res. 15(1), 1929–1958 (2014)
76. Su, N., Han, Q., Yang, Y., et al.: Analysis of longitudinal guided wave propagation in a liquid-filled pipe embedded in porous medium. Appl. Sci. 11(5), 2281 (2021)10.3390/app11052281 ↗
77. Tighe, M., Bielski, M., Wilson, M., et al.: A sensitive xrf screening method for lead in drinking water. Anal. Chem 92(7), 4949–4953 (2020)10.1021/acs.analchem.9b05058 ↗
78. Van Hulse, J., Khoshgoftaar, TM., Napolitano, A.: Experimental perspectives on learning from imbalanced data. In: Proceedings of the 24th International Conference on Machine Learning, pp 935–942 (2007)10.1145/1273496.1273614 ↗
79. Wang, C., Xin, C., Xu, Z.: A novel deep metric learning model for imbalanced fault diagnosis and toward open-set classification. Knowledge-Based Systems 220(106), 925 (2021)
80. Wang, X., Lin, M., Li, J., et al.: Ultrasonic guided wave imaging with deep learning: Applications in corrosion mapping. Mech. Syst. Signal Process. 169(108), 761 (2022)
81. Xing Z, Zhao R, Wu Y, et al (2022) Intelligent fault diagnosis of rolling bearing based on novel cnn model considering data imbalance. Appl. Intell. 52(14), 16,281–16,29310.1007/s10489-022-03196-x ↗
82. Xu, X., Cao, D., Zhou, Y., et al.: Application of neural network algorithm in fault diagnosis of mechanical intelligence. Mech. Syst. Signal Process. 141(106), 625 (2020)
83. Zhang, W., Peng, G., Li, C.: Bearings fault diagnosis based on convolutional neural networks with 2-d representation of vibration signals as input. In: MATEC web of conferences, EDP Sciences, p 13001 (2017)10.1051/matecconf/20179513001 ↗