A method and apparatus for isolating a section of sewer line. In one embodiment, a chamber is provided that extends into the ground and intersects a sewer pipe. Thereafter, the fluid in the sewer pipe is exposed to an interior of the chamber and a dam is placed in the chamber to isolate an upstream portion of the chamber from a downstream portion. As fluid collects in the upstream side of the chamber, at least one pump is used to control the fluid level in the upstream portion by transferring the fluid from the chamber to a predetermined, remote location.