Sediment control

A sediment control roll which comprises

• 1) an elongate threshold member which is composed of a multiplicity of polymeric strands;
• each of the polymeric strands having a thickness, viewed at right angles to the plane of the threshold member, of 0.1 to 0.2 in;
• the polymeric strands being connected together at junction points and defining a multiplicity of threshold apertures through the threshold member, each of the threshold apertures having an area of 0.02 to 0.25 in2;
• and the solid surface area of the threshold member being 25 to 65% of the total area of the exposed surface of the threshold member;
• 2) an elongate outflow member which is composed of a multiplicity of polymeric strands;
• each of the polymeric strands having a thickness, viewed at right angles to the plane of the outflow member, of 0.1 to 0.2 in;
• the polymeric strands being connected together at junction points and defining a multiplicity of outflow apertures through the outflow member, each of the outflow apertures having an area of 0.02 to 0.25 in2;
• and the solid surface area of the outflow member being 25 to 65% of total area of the exposed surface of the outflow member;
• 3) an elongate outflow filter which
• (i) is supported by the outflow member,
• (ii) comprises a synthetic polymer, and
• (ii) has a mesh size of 80 to 600 micron;
• and
• 4) a location member which extends away from the threshold and outflow members;
• the sediment control roll comprising an elongate sediment collection chamber which
• (i) lies between the threshold member and the outflow member,
• (ii) has an unobstructed volume which is 50 to 98% of total volume of the sediment control roll.

A sediment control roll which comprises

• 1) an elongate threshold member having a multiplicity of threshold apertures therethrough, each of the threshold apertures having an area of 0.01 to 1.0 in2;
• 2) an elongate outflow member having a multiplicity of outflow apertures therethrough, each of the outflow apertures having an area of 0.01 to 1.0 in2;
• 3) an elongate outflow filter which
• (i) is secured to the outflow member, and
• (ii) has a multiplicity of filter apertures therethrough,
• each of the filter apertures having an area of less than 0.1 in2;
• and
• 4) a location member which extends away from the threshold and outflow members;
• the sediment control roll comprising a substantially hollow, elongate sediment collection chamber which lies between the threshold member and the outflow member;
• and the threshold member, the outflow member, and at least part of the location member being provided by a single piece of an apertured polymeric sheet having a multiplicity of apertures therethrough, each of the apertures having an area of 0.01 to 1.0 in2.