SAN DIEGO SEWER SYSTEM INSPECTION PROGRAM: MAKING EFFECTIVE USE OF GIS AND DIGITAL VIDEO

The City of San Diego is in the second year of an aggressive five-year program to inspect and assess the condition of 1,000 miles of its 3,000-mile sewer system. The closed-circuit television (CCTV) inspection program is a key element in the City's capital improvement program, operation and maintenance program, and comprehensive sanitary sewer overflow (SSO)- reduction strategy. This paper discusses the key challenges and benefits achieved through the development and implementation of a Geographic Information System (GIS)-based computer software system to effectively store and evaluate the vast amount of data and video collected in the inspection program.The paper first describes the basic data management challenges faced by the project team at the outset of the inspection program. These challenges included integrating inspection data from multiple CCTV contractors currently using different inspection observation codes and software systems, linking the inspection data to the City's sewer GIS database, ensuring data and video quality control, managing storage and access to the large amount of data and videos generated in the project, and creating a software system that facilitates analyzing the inspection data to generate and prioritize appropriate improvement projects.The custom solution created by the City of San Diego includes the use of compressed digital video and still image files, standards for observation codes and digital files, and integration of the inspection data in a GIS environment that also provides access to a wide variety of other GIS databases that facilitate the assessment and project development process. The solution developed by the City, as well as the “lessons learned” in the process, will be of interest to other wastewater agencies and consultants performing large-scale sewer inspection and condition assessment projects as part of their asset management and CMOM programs.