If There’s a Mysterious Gap in Your Stormwater Best Management Practices (BMPs): LOOK UP!

When we think of stormwater runoff, we most often look down. That’s where the water is, coursing over paved hardscapes and into inlets, basins and non-specific channeled conveyances. Stormwater is a surface contamination issue, first underfoot and then underground. Right?


Rooftops often represent a large percentage of an industrial site’s hardscape footprint, as much as 25% or more. They’re also collectors and incubators of a wide range of pollutants and dissolved heavy metals that can impact post-construction stormwater Best Management Practices (BMPs) and National Pollutant Discharge Elimination System (NPDES) industrial and non-industrial permit requirements. It’s not just the dissolved zinc from galvanized rooftop HVAC equipment, moss inhibitors and abrasion resistance coatings that pose a challenge. It’s also environmental deposition of dissolved copper and lead from neighboring properties or nearby roadways where copper is found in brake linings and lead is found in tire weights. When you consider the collection of organic matter, including dead birds, squirrels and insects, a rooftop is often an incubator for viruses and pathogenic bacteria that attach themselves to suspended solids resulting in toxic turbidity.

“Our downspout filtration system is just one of the creative ways we help our industrial and commercial partners meet the challenges of stormwater filtration. In fact, it’s part of a whole suite of stromwater filtration products that we’ve created, patented and are able to adapte for each customers specific needs.”

Matthew Moulton, General Manager, CleanWay Environmental Partners


CleanWay recognized the need for rooftop stormwater and downspout filtration over 20 years ago. As a result, we’ve continuously refined our downspout filtration system (also referred to as roof drain filters, gutter drain filters or rainwater filters) to meet the evolving needs of our customers. Unlike inline options, which require cutting and fitting of the existing downspout, our units are free standing, easily accessible for maintenance and cleaning and incorporate a patented water sampling port for verifiable filtration performance. Two levels of outlet openings allow the unit to be run in either a dry (where vector control is a concern) or wet configuration (to increase removal rates with additional contact time).


When you’re investigating a downspout filtration system, consider that our filtration vessel is six (6) to eight (8) times larger in volume than inline systems. Then take into account that our rigid strainer is completely covered by a site-specific absorption media envelop to maximize contact with stormwater runoff — virtually eliminating unfiltered water in high volume bypass scenarios: Here’s how it works: Our absorption media section incorporates a flexible open mesh fabric envelope with a specialized media blend suspended from the support assembly and fitted into the basin so all influent passes through both strainer and filtration media before exiting to the downstream conduit. The combination of gross solids removal via the strainer and the absorption / filtration in the media section virtually eliminates heavy metals, suspended solids, turbidity and other pollutants. Our site-specific filtration elements include:

  1. Rigid Strainer: Trash & Debris (sized to capture particles down to 3.2 mm)
  2. Geotextile Element: Sediment & TSS
  3. Adsorb-It Element: Oil & Hydrocarbons
  4. Vermiculite Media: Dissolved Zinc Only
  5. MetalZorb Media: Dissolved Heavy Metals

“We named our company advisedly; CleanWay Environmental Partners is all about the partnership between the industrial site permit holder, their engineering firm or specifier and CleanWay Environmental. We offer our clients a deep reservoir of applied technology across a wide spectrum of water treatment solutions. If you have a unique water treatment of filtration challenge, we invite your inquiry.”

Steve McInnis, President, CleanWay Environmental Partners

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Our attractive, non-obtrusive downspout filtration systems are easy to install, simply place it next to your downspout and “plug it in.” Available in standard or custom configurations, our downspout filters fit the side of any building, and can be connected on the right or left side, depending on your site configuration. Because rooftop runoff can contain many different pollutants of concern, we help you to determine the best media blend for your application. For ease of cleaning and filter replacement, the top lid can be locked in an open position so a single operator can service the unit by hand or by Vactor truck. Applications include:

  1. Industrial roofs (including permitted Industrial Users (IU), Significant Industrial Users (SIU), Categorical Industrial Users (CIU)
  2. Commercial roofs
  3. High rise buildings
  4. Parking structures
  5. Mixed use buildings

With over 25 years of experience, CleanWay Environmental Partners is dedicated to providing clients with affordable stormwater runoff solutions. Located in Portland, OR, our skilled staff is committed to serving customers nationwide with first-rate catch basin filters, downspout filtration units, premium leachate treatments, and heavy metals extraction products. Call (800) 723-1373 to request a quote and to learn more about how we can help you comply with environmental regulations.