A Resource to Support Asset Management, Pipeline Renewal, and Replacement by Utah Water Research Laboratory, Utah State University
Deteriorating Infrastructure
Municipalities and the people they serve depend on pipe networks that provide safe drinking water. This piping is underground, out of sight, and often neglected.
Overall assessment of water infrastructure condition is not good. Using the US as an example:
- In 2009, the American Society of Civil Engineers (ASCE) issued a US report card and gave a D- to drinking water infrastructure.
- In 2017, the grade improved to a D.
- In 2021, the grade was raised to a C-, better but still not good.
- Utilities are currently losing 11% of their water to leakage.
- Pipe life estimates of 75 to 100 years contrast with an average replacement schedule of about 200 years (ASCE, 2017).
The American Water Works Association (AWWA) has also reported on water main replacements in the US. In the annual AWWA State of the Water Industry Report, renewal and replacement of aging water and wastewater infrastructure was listed as the top concern (AWWA, 2017). This has
remained a primary issue for utilities nationwide for the last five years (AWWA, 2023).
Deteriorating water mains are threats to the physical integrity of distribution systems, causing adverse effects on flow capacity, system pressure, and water quality (Grigg,
et al., 2017). In addition to maintenance requirements and economic impacts, consequences of a broken water main include local flooding, interruption of water delivery, and damage to roads and private property. These outcomes also negatively affect a utility’s customer satisfaction.
Utility data clearly indicate that the integrity of water pipelines in the US and Canada continues to deteriorate as the infrastructure ages. Among the many indicators of aging
pipes, break rates are the most significant.
Asset Management
Utilities can use asset management to facilitate water infrastructure planning and pipe replacement decision making. The goals are to control operating costs, reduce service level impacts, and minimize health risks to customers.
Water main break rates are the most important indicator for quantifying failing underground pipelines. For this reason, break rates are a critical factor in asset management
decision-making. Break rates for each utility can vary from year to year and even seasonally. Over time, however, break rates for specific pipe materials are consistent. This consistency is one reason why break-rate information is so important.
This comprehensive study of water main break rates uses input from 802 utilities to compile an accurate data set for making pipe-replacement decisions. This data set is large enough to be valid for asset management decision-making by providing information on the characteristics of aging pipe
infrastructure.
2023 Report
The water main break rates presented in this report are based on pipe characteristics and failures reported by the utilities that responded. Utilities were given the opportunity to
respond to either a basic or detailed survey which gathered information on water pipe materials, pipe diameters, pipe age, system operating characteristics, and water main failures. The report discusses the importance of water main break data in the context of asset management planning. Utah State University (USU) has published two similar studies (Folkman, 2012; 2018). This 2023 report references the previous studies to analyze changes over time.
Highlights of the study:
- Break rates of all pipe materials remain consistent when compared to previous USU studies.
- The current study received a wide distribution of responses across utility sizes.
- In the past five years, total miles of asbestos cement and cast iron pipes have been reduced, most likely being replaced with materials such as ductile iron and PVC.
- The replacement of asbestos cement and cast iron pipe is creating a shift in predominant pipe materials in several regions.
- Pipe performance is impacted by soil corrosivity.
- There is a significant correlation between water main breaks and pipe material as well as diameter.
Original Document: https://digitalcommons.usu.edu/cgi/viewcontent.cgi?article=1681&context=water_rep
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