The largest span of utility undergrounding in the history of San Diego, the 30th Street 20a Transmission Undergrounding moved 3.5 miles (20,304 feet) of overhead transmission line underground.
The project, which provides a safer, more reliable energy source for the people of San Diego, received a 2009 Outstanding Civil Energy Project Award from the American Society of Civil Engineers (ASCE) Region 9. The award recognizes projects that represent the greatest contribution to civil engineering progress and mankind.