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Make Installation a Breeze With a Muffin Monster Manhole

The Muffin Monster® Manhole is a pre-fabricated sewer manhole with a sewage grinder which is fully assembled and ready to install. This fiberglass manhole is an excellent solution when a sewage grinder is needed but there is not enough room for conventional installations. The pre-fabricated manhole sewage grinder system is easy to install – just dig down to the sewer line, create a concrete pad for the fiberglass manhole unit to rest on and tie in the sewer lines. That’s it, you are grinding sewage and protecting pumps! Perfect for prisons, hospitals and nursing homes that need to grind up rags and trash in sewage before it enters a municipal wastewater system. It’s designed to fit almost anywhere and provide complete sewer pump protection.

The Muffin Monster Manhole is customizable to fit your exact site requirements. Options that can be specified include the exact depth required as well as the inlet and outlet pipe diameters. Additionally, you have the choice of a top cover designed as an above-ground hatch or one able to handle vehicle traffic. You can also add options to the 30K Muffin Monster included in the system such as Wipes Ready® Technology which is specifically designed to shred rags, wipes, diapers and other disposable items that commonly clog sewage pumps.

Monster Industrial Manhole site


  • Avoid municipality fines for discharging pump clogging trash in sewage
  • Stop emergency plumbing repairs
  • Pre-packaged systems avoid costly civil construction work
  • Ease of maintenance with semi-annual inspections


  • Factory-installed guide frame and access ladder make it easy to access the grinder
  • Customizable depth, sewage pipe size, and cover type
  • 30K Muffin Monster® grinder effectively grinds rags, wood, plastics, and other debris
  • Wipes Ready® Technology available which prevents materials from forming long strips and reweaving in the waste stream
  • Includes PLC to control and monitor operation of the system


  • Dimensions: 4 ft (1200 mm) diameter, ½” (12 mm) wall thickness
  • Fiberglass-reinforced polyester (FRP) construction