Patent attributes
A manhole assembly including a base, riser, and cap. The base having an upper surface forming a bench, a bottom surface, and a radially outward surface with penetrations there through; and a radial spigot in the radially outward upper edge of the base. The base having a corrosive-resistant layer covering the channels, bench, and radial spigot. Also disclosed is a riser comprised of a corrosive-resistant polymer pipe having a radially outward surface, an inner surface and a bottom surface in contact with, supported by, and sealed to the radial spigot. The cap having a radial spigot, and access hole; the radial spigot in the radially outward bottom edge of the cap resting upon and sealed to an upper edge of the riser. The radially outward surface of the cap and base are aligned with the radially outward surface of the riser.