Catchbasin systems for filtering hydrocarbon spills

A water- and oil-porous sack contains a hydrophobic, compliant, oil-absorbent, copolymer material arranged in a number of bodies that (a) are generally cylindrical, (b) are porous, (c) have at least one passageway parallel to the axis of the cylinder, and (d) are dimensioned to float on water with the axis parallel to the surface of the water. The material is formed with a binder in a novel extrusion process. The inventive sack is sewn to create a number of pockets, and the seams create fold lines that permit the sack to dip below the water to allow debris to pass. The inventive sacks can be suspended below a storm drain and used in conjunction with known catchbasin inserts.