The Fabco  DownSpout™ Filter is designed to treat particulates and soluble pollutants contained in runoff water from roof tops. While most would agree that water leaving roof surfaces is much cleaner than most stormwater runoff, it is not completely free of potentially harmful contaminants.

For example:

  • Heavy metals: Water can react with the metal roofs, metal components or roof mounted equipment which then releases soluble metals, such as zinc, copper, lead and aluminum into the water stream. This release can be accelerated in areas where acid rain is prevalent.For example, studies have shown that zinc concentrations in rooftop runoff are substantially higher than those in rainwater. Elevated levels of zinc in soils may lead to phytotoxicity (the poisoning of plants), which is a concern when portions of plants will be consumed.
  • Pathogens: Birds, insects, and small mammals deposit fecal matter on rooftops and in gutters, contributing bacteria and pathogens to runoff.
  • Polycyclic aromatic hydrocarbons (PAHs), dust and particulate matter from vehicle exhaust and the burning of fossil fuels can collect on roof surfaces, producing elevated PAH levels in runoff.

The DownSpout™ filter utilizes proven StormBasin™ replaceable filter Cartridges to treat most common stormwater pollutants. Filter cartridges can be selected to treat: Sediments/debris; hydrocarbons; heavy metals; nutrients and bacteria. The High Flow DownSpout™ system is versatile and expandable beyond the standard two filter cartridge design.

System overview:

  • Large freestanding filter enclosure offers multiple installation and mounting options.
  • Constructed from high strength, exterior grade Polyethylene material (nominal ¼” wall thickness) with an aluminum internal support frame.
  • Overall dimensions: 23 ¼”W x 30 3/8L x 37 1/8” high (Std).
  • Aluminum cartridge mounting plates provide “Twist-Lok” retention and a tight seal.
  • 4” PVC inlet/Outlet pipes (Std).
  • Dual cartridge filtered flow rate can vary depending on cartridge type selected from 120 to 520 gpm.
  • Internal debris storage capacity is 11.0 ft3.
  • Built in high flow bypass is capable of passing at 848.0 gpm (1.89 cfs).
  • Internal water/debris collection tub is lined with a seamless, flexible rubber membrane to prevent long-term leakage issues due to material degradation or thermal expansion due to temperature changes.


Filter Config.

Fabco Filter Cartridge

Our filter cartridges are designed to provide effective treatment of stormwater while maintaining high flow rates throughout the life of the cartridge. Filter cartridges are available in various configurations allowing you to fine tune performance in terms of sediments and debris, heavy metals, hydrocarbons/toxic chemicals, pathogens/bacteria and nutrients. The lightweight filter cartridge comes fully assembled and snaps securely in place with a quick twist. The modular cartridge design allows quick and easy replacement while containing the spent material for safe transport and disposal.

2-Stage filtration

Each Fabco filter cartridge is composed of a standard pre-filter section, and a main filter chamber which can be configured to target specific pollutants.


The pre-filter is manufactured using FABGUARD™ antimicrobial treated open cell Polymer foam pads. The coarse open cell foam acts as a mechanical pre-filter for the cartridge restricting coarse sediments, trash and debris while allowing mostly water to flow through. Stormwater passing through the complex cellular structure contacts the antimicrobial treated internal walls substantially reducing the growth and passage of pathogens through the cartridge.

Proprietary Treatment Technologies:

Fabco offers 5 filtration configurations (Standard, HV metals, Pathogens/bacteria, HV Hydrocarbons, Nutrients) using a combination of the following treatment technologies:

  • FABMAX™:  A chemical treatment applied to our open cell polymer foam filtering media. It is hydrophobic and instantly bonds to any hydrocarbons in the water matrix.
  • FABSORB™: An oil absorbent fabric material for treating both free and emulsified oils, greases and other hydrocarbon-based compounds. This non-woven, filter  can absorb 10 to 20 times its own weight in oil, greases and hydrocarbons.
  • FABLITE™: A unique, natural mineral compound that is effective in removing heavy metals as well as low levels of dissolved pollutants like hydrocarbons and other toxic chemicals.
  • FABPHOS™: A proprietary filtering media that treats soluble, ortho-phosphates in stormwater runoff. FABPHOS also is effective in reducing nitrogen compounds thus assisting stormwater managers meet the >40% N reduction required by many states.
  • FABGUARD™: Antimicrobial Shield is a chemical technology that when applied to our foam material makes it antimicrobially active. The FABGUARD Antimicrobial Shield becomes an integral part of the material and will not wash out, or leach into the environment. Microorganisms that subsequently contact the material are neutralized.

Currently Fabco Industries offers a variety of filter cartridge types which can be used interchangeably in our StormBasin™ and StormPod™ product lines. Additionally, the compact, versatile design of the filter cartridge is easily adaptable to larger, underground, stormwater treatment vaults allowing the Fabco technology to be used in applications that require greater flow rates and larger treatment capacities.