Standard Specification for Inlet Filters with a Rigid Frame

Abstract

This specification covers the manufacturing and test requirements for geosynthetic storm sewer inlet filters used in highway drainage, roadway, residential, commercial, and industrial applications. The inlet filter is comprised of a rigid frame and a removable geosynthetic sediment bag. The sediment bag hangs suspended from the rigid frame and includes a bypass that shall allow water flow into the drainage structure if the bag is completely filled with sediment. Water flow through the bypass shall equal or exceed the design flow of the inlet required at a specified drainage location. The filter can be used with round, rectangular, gutter, rolled curb, and curb inlet types. The rigid frame shall be designed to support the design load on the frame, and must be capable of supporting the full design load without deformation when the grate is removed. The frame shall not interfere with or elevate the grate more than 1/8 in. The sediment bag shall be manufactured from a geotextile material or a composite of geotextile and geosynthetic reinforcement. When used for removal of trash or large debris only, the geosynthetic sediment bag may be constructed of open-weave geosynthetic. The requirements of this specification are intended to provide an inlet filter system to collect sediment, trash, leaves, and other storm water contaminants from surface storm water runoff at drainage inlet locations during temporary site construction.