Manhole Inspections


Manholes are essential components of the sewer collection system and are often the only points of access into our underground infrastructure for conducting important maintenance tasks for pipes such as: cleaning, rehabilitation, and inspection. Without manholes, open-cut excavation and diversion of street traffic would be the only means of access. Therefore, manhole inspection and maintenance is one of the highest priorities in collection system management.

Manholes also offer an important opportunity for addressing the costly problem of infiltration and inflow, (I/I), which is a major cause of sewer overflows that pollute our waterways and environment. A manhole is essentially a vertical pipe that gives access to the horizontal pipes that form a collection system. An 8 foot deep manhole of typical design has about the same surface area as a 50 foot segment of 8 in. pipe. When thought of in terms of underground surface area, manholes become a major part of a collection system.

The data we gain from manholes gives us valuable insight into the overall condition of the sewer system such as: flow rates/hydraulics, presence of corrosive elements, evidence of surcharge, and overall capacity.