A system for comminuting solid waste material comprising: a casing defining a comminution chamber having two side walls and being open on opposite sides thereof for permitting the flow of liquid therethrough bearing solid waste material and being adapted for connection in a solid waste disposal line; a shredding device disposed within the casing and comprising parallel first and second shredding stacks that include first and second parallel shafts rotatably mounted between an upper shredding device housing and a lower shredding device housing, each of the first and second parallel shafts including a plurality of cutting elements mounted on said first shaft in interspaced relationship with a plurality of second cutting elements mounted on said second shaft, each of said cutting elements having at least one cutting tooth thereon, said cutting elements being positioned between and separated in an axial direction by spacers which are coplanar with the cutting elements of the adjacent stack such that a cutting element from one stack and a spacer from the other stack form a pair of interactive shredding members; a rotating screening drum (240, 320) disposed within the casing and rotatably mounted between an upper screening drum housing and a lower screening drum housing, the rotating screening drum configured to permit fluid to pass therethrough while capturing solids on an outer surface for delivery to shredding device, an upstream portion of the rotating screening drum disposed upstream of an upstream portion of the shredding device, characterized in that the casing further comprises an adjustment mechanism to independently adjust the position of the shredding device and the rotating screen drum (240, 320) relative to each other. a casing defining a comminution chamber having two side walls and being open on opposite sides thereof for permitting the flow of liquid therethrough bearing solid waste material and being adapted for connection in a solid waste disposal line; a shredding device disposed within the casing and comprising parallel first and second shredding stacks that include first and second parallel shafts rotatably mounted between an upper shredding device housing and a lower shredding device housing, each of the first and second parallel shafts including a plurality of cutting elements mounted on said first shaft in interspaced relationship with a plurality of second cutting elements mounted on said second shaft, each of said cutting elements having at least one cutting tooth thereon, said cutting elements being positioned between and separated in an axial direction by spacers which are coplanar with the cutting elements of the adjacent stack such that a cutting element from one stack and a spacer from the other stack form a pair of interactive shredding members; a rotating screening drum (240, 320) disposed within the casing and rotatably mounted between an upper screening drum housing and a lower screening drum housing, the rotating screening drum configured to permit fluid to pass therethrough while capturing solids on an outer surface for delivery to shredding device, an upstream portion of the rotating screening drum disposed upstream of an upstream portion of the shredding device, characterized in that the casing further comprises an adjustment mechanism to independently adjust the position of the shredding device and the rotating screen drum (240, 320) relative to each other.