18.104.22.168 Mini Manholes
Mini manholes are generally shallower than manholes and can be used in lieu of access shafts/chambers. Maximum depth shall be 1.25 m measured from top of manhole cover lid to the invert of the sewer. They shall have an internal diameter of not less than 600mm and may be constructed from concrete, or be a manufactured unit from thermoplastics material. Technical details for concrete mini manholes shall be generally as per technical details for concrete manholes.