In 2005 Katchall developed a (patented) configuration within our curb inlet filters. During the process of rotocasting the 3/8-inch thick HDPE containment structure, several angled shelving brackets are created.

When the three (3) Bio-Ramps® are inserted into the unit, they sit at opposing angles (see Figure 1), with each Bio-Ramp® forcing debris and floatables to the lowest side of the individual ramp, keeping the filtration media free of obstructions.

Additionally, each ramp includes a small high-flow bypass, should the media become obstructed by the small particulates it has removed from the stormwater discharges, water continues to flow into the next filtration media area.

This process is repeated three (3) separate times, insuring that only clean, polished water, enters the MS4.

In the unlikely event that all three Bio-Ramps® become obstructed (due to lack of maintenance), water is then allowed to flow over the top of the device and directly enter the MS4, insuring that no public safety issues ever occur.

Individual devices are joined together and can fit virtually any length (width opening) encountered.

Katchall Antimicrobial Curb Inlet Filters have been the "standard" for multiple cities and county agencies throughout California for the past 7+ years.