Maximizing the Benefits of WSSC’s Trunk Inspection Program


  • Venedra Whigham, Andrew Rossmark - WSSC
  • Russ Dalton - Hazen and Sawyer

The WSSC Trunk Inspection Program involves the inspection of trunk sewers, 15-inch in diameter or greater, and their associated manholes and feeders. Work on this project included project management, pipeline and manhole inspection, surveying and the identification of exposed assets. The assets involved in the trunk inspection program are typically located in wooded rights-of-ways and run along and/or across streams. Sewer collection systems are often far from the public eye. However, in residential and business areas, the effects of a failed sewer line can be immediately seen with service interruptions and SSO’s. This is not always the case with trunk lines within the system. The assets are typically located in difficult to access places where general monitoring can be difficult. These locations are also typically the most environmentally sensitive areas in the system, further necessitating their inspection. This presentation will focus on the methods to maximize the benefits of the program.

The presentation will include a review of the preparation required for a project of this size. Projects of this type require extensive data management. It is critical to have a well-organized data management plan in place prior to beginning field operations. The project database must be easy to update, find and access. Additionally, regardless of how the data is organized, it must be correct. In order to ensure quality data, project protocols must be in place prior to the beginning of work. Necessary protocols include detailed descriptions of expectations regarding production, quality and timeliness. Due to the remote nature of many of the assets in the program, it is critical to have well-defined procedures and goals before commencing field visits. Instances where multiple actions are required at a single asset should be identified and figured into scheduling.

This presentation will include the “hits”, and in some cases “misses”, associated with the past approach during the Trunk Inspection Program. It will include lessons learned throughout the project and as part of a retrospective review performed after the completion of the project. It will also discuss a guide to moving forward on future similar projects.

For more information, please contact the author at

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Horizons Fall 2017 (pdf)

Horizons showcases significant water, wastewater, reuse, and stormwater projects and innovations that help our clients to achieve their goals, and can help you achieve yours. Articles are written by top engineers and process group leaders, demonstrating and explaining the beneficial application of a variety of technologies and tools.

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