The City of Orlando had an evaluation performed on one of their large gravity sewer mains in March, 1999 using a combination of seismic tomographic imaging (STI) to evaluate soil conditions around the gravity sewer main, and physical inspection of the pipe interior. The evaluation was intended to identify areas of impending subsidence and roadway collapses resulting from infiltration. The results of STI using the SEWREEL technique showed very loose soil conditions at a number of locations along the gravity main which for the most part could not be corroborated by the interior physical inspection.