City of Hamilton Approach to the Management of Critical Watermain Infrastructure

Managing critical water mains requires a good condition assessment program. The program will assist in a long-term asset management program by establishing a baseline for these critical assets. This program is in place to assess the 176 km (110 miles) of critical water mains. In 2006 the city started to address critical water mains. Managing these mains presents some challenges in obtaining condition ratings. Since these pipes are critical in nature and as such we have a zero tolerance for failure, it is necessary to undertake a multistaged approach to the assessment of these critical watermains. Data collected helps in identifying any preliminary deterioration factors, detailed deterioration factors, preliminary distress indicators, and detailed distress indicators. This paper will discuss the city of Hamilton's approach to the management of critical watermain infrastructure. The city has been working to determine the condition of the critical water mains by a variety of methods. Planned operations include field corrosion evaluations such as soil corrosion studies, ultrasonic inspection, corrosion pitting analyses, and corrosion rate testing of pipe coupons extracted from select locations. Other nondestructive methods include the deployment of remote field eddy current (RFEC) and/or acoustic leak detection (ALD) inspection technologies to determine pipe wall thickness or to detect the presence of active leaks and air pockets of potentially corrosive gases. This paper will describe the development of the city's approach to developing a critical water main condition assessment program; the development of a risk model, opportunistic sample procedure, leak detection, and implementing inspection technologies.