Any solid or viscous substances in quantities or of such size as
to be capable of causing obstruction to the flow in sewers or other
interference with the proper operation of the POTW, such as but not
limited to ashes, cinders, disposable wipes, spent lime, sand, mud,
straw, shavings, metal, glass, rags, feathers, bones, tar, plastics,
wood, unground garbage, grass clippings, whole blood, paunch manure,
hair and fleshings, entrails, grease, paper dishes, cups, milk containers,
etc., either whole or ground by garbage grinders.