A sanitary manhole is a manhole that is used as an access point for maintenance and inspection of an underground sanitary sewer system. Sanitary manholes are sometimes used as vents to prevent the buildup of pressurized sewage gas. Additionally, they are used for debris removal, and application of chemicals such as degreaser and insecticide.
A sanitary manhole under construction
A channel inside a sanitary manhole
Precast concrete barrel sections before installation
Cone section (black), base section (below the cone section), and stacks of grade adjustment rings of various sizes stored at a manufacturing plant
A manhole is an opening to a confined space such as a shaft, utility vault, or large vessel. Manholes are often used as an access point for an underground public utility, allowing inspection, maintenance, and system upgrades. The majority of underground services have manholes, including water, sewers, telephone, electricity, storm drains, district heating, and gas.
PMG manholes in a city street, Perth, Western Australia
Manhole being used to access sewer
Installation of a fiber-optic manhole in Brooklyn, New York
An uncovered manhole in Beirut, Lebanon