Screening and grinding devices are recommended for waste water and stormwater applications where course debris and high solid concentrations occur. Screen assemblies capture unwanted floatable pollutants from entering wastewater collection and treatment systems as well as stormwater sewer systems and water bodies. Grinding applications include detention and correctional institutions where vandalism is a frequent occurrence. Inmates are known to “stuff” sheets, towels, and shoes down toilets to cause flooding of the building. The macerator grinds up these solids avoiding costly flooding and maintenance.