Homes constructed prior to the use of city sewers often relied on cesspools, which were single-chamber dry pits intended to hold septage until it simply leached out into the surrounding ground through porous soil. After cities installed public sewer systems, these cesspools were sometimes left intact and connected to the sewer line. That can be a problem because without the multi-chamber design of a septic system, cesspools inevitably fill up eventually and fail. You won’t know whether you have one or not unless your sewer line is inspected.
The actual materials used to construct older sewer systems can also cause problems. Many homes built from the 1860s to the 1970s have sewer laterals made of pitch fiber or tar paper, called ‘black pipe’ or Orangeburg pipes. These disintegrate and collapse over time, and have been taken off the list of acceptable construction materials by most building codes. If a home has fiber piping, the lateral line definitely needs to be replaced.
These problems are all magnified when the building involved is a multi-unit building, such as an older, larger home that has been subdivided into apartments or condominiums. Even newer condos and apartments still require occasional sewer and drain line inspection to keep tree roots and other intrusions out, including unintentional piercing by other utility installations.