Most residential areas have existing utilities buried in the street including water lines, sewer lines, storm drains, and natural gas lines. Some communities have underground electric utilities, and will also have telephone lines, power lines, and cable lines buried in the street and sidewalks. Of these existing utilities those that pose a high risk are high-pressure natural gas pipelines, petroleum pipelines, pressurized sewage pipelines, and high-voltage electric supply lines. EBMUD refers to these utilities as high priority utilities.
To avoid damaging existing underground utilities EBMUD requests as-built documents and system maps from all utilities and companies that operate transmission facilities within the project area; conducts site visits to observe utility markers and surface features such as manhole rims, grates, and valve pots; and contacts the Underground Service Alert to have existing utilities marked prior to excavation. EBMUD uses geophysical methods like ground penetrating radar or electromagnetic signaling when there is poor, non-existent, or conflicting utility data in congested utility locations. When the pipeline is to be installed within 5 feet of an existing high-priority utility, then EBMUD hand digs to locate the high priority utility during the design of the project.