There are many problems associated with faulty or deteriorated manholes. Over a period of time, manholes may develop cracks or fractures. As these defects become critical, groundwater can possibly leak into the manhole. As the groundwater leaks into the manhole, cavities will form outside of the manhole. As much as 30% of infiltrations problems can be attributed to faulty manholes. The main purpose of inspecting the manhole is to find and identify problems before they become hazardous. Manhole inspection data can also be used in conjunction with flow modeling activities. Depths from the inspections can be used to help model flows. A manhole will be evaluated for the following reasons: Structural integrity Flow modeling Infiltration/Inflow study Back