Until now, there was not a governing standard applicable to a collections system after it was placed in service. Early sewers depended upon infiltration and other forms of flushing to dilute sewage. This infiltration was originally seen as a benefit and was the primary method of “cleaning” the sewer.
Factory-manufactured joints to eliminate infiltration weren’t a requested feature of clay pipe until the 1960s. Common practice was to clean pipe only when a backup made it necessary. Cleaning methods most commonly used through the mid-20th century were either mechanical tools (some form of rodding or bucket machines) or a rudimentary flushing
