All wastes from barns, stables, animal facilities or yards for animals shall be intercepted before entering the sewer by an interceptor or catch-basin, which shall be trapped and covered with a tight iron cover, and such catch-basins, if within buildings, shall be provided with a vent not less than 3 inches (75 mm) in diameter carried through the roof. All floor drains and wash racks shall be provided with deep seal traps and heavy strainers.