Asset Management and Nondestructive Evaluation of Force Mains in New York City

Wastewater infrastructure, such as sewers, force mains, etc., maintained by various municipalities across the nation are at increased risk of failure due to (i) "out of sight out of mind syndrome"-they are buried underground and not easily accessible, (ii) are generally with little or no redundancy. Force mains are typically used to carry wastewater from a low point in the collection system and discharge it into an elevated portion of the gravity sewers or to the head works of the WPCP. They rarely undergo any inspection to identify critical defects before failure because of inaccessibility and continuous operation. The paper discusses three key aspects of the asset management system for the force mains of the New York City Department of Environmental Protection; development of asset inventory database, standards for inspection ratings and technologies for internal inspection. Feasibility of a selected technology using ultrasonic scanning has been demonstrated through pilot testing on a 100 ft pipe segment.