Collaboration in New Product Development: Including the End User in the Design

Written by Bradford Bucknum, Communications Manager, SBN.

Good design is slow. Effective collaboration takes time, too.

My colleague Sara Pevaroff Schuh, founding principal of Philadelphia-based SALT Design Studio says, “Quality fights to be a full partner at the table with quick.” She’s right. 

It may seem like an all too costly endeavor to return to the drawing board often, but the familiar cliche rings true–you either pay now or pay later. 

Rob Woodman, Senior Stormwater Engineer at ACF Environmental, witnessed the benefits of a time-intensive collaborative design process first hand when designing a new product for the Philadelphia Water Department’s (PWD) city inlets. 

PWD needed a solution. They noticed safety concerns and inefficiencies during maintenance procedures for the filter bags used in storm drain inlets. These “green” inlets are an integral component of Philadelphia’s Green City, Clean Waters program, an initiative that uses green stormwater infrastructure (GSI) to manage stormwater and reduce the volume of stormwater runoff and associated pollution entering Philadelphia’s waterways.

According to new research from the Sustainable Business Network of Greater Philadelphia (SBN), the twenty-five-year nature-based stormwater management plan is an inspiring example of the triple bottom line (people, planet, profit) in action. Their June 2019 report, “The Economic, Social, and Environmental Case for Green City, Clean Waters: An Update,” highlights a correlation between a nature-based approach to stormwater management with lower crime and health costs and billions of dollars in economic impact. 

The plan is bold, effective, and has put Philadelphia on the map as a leader in GSI, but its continued success depends on the city’s commitment to maintaining the systems and mechanisms of the plan. 

PWD’s Green Stormwater Operations Unit (GSO) is responsible for the inspection, maintenance and repair of PWD’s GSI. The Unit’s supervisor, Gerald Bright, reached out to ACF Environmental in search of a product that would improve upon the existing means of pre-treating city inlets. The existing wall-mounted units used to pretreat these inlet types lacked suitable capacity and were difficult to install and remove. 

Woodman recollected, “Maintenance staff would lay in the roadway, attempting to scoop sediment out of the filter bag by hand through narrow curb openings. The product was not working for them and there was not an existing product that would adequately fulfill their goals relating to performance and maintenance needs better than they had already installed. A solution would have to be developed specifically for them, to satisfy their requirements and not put them at risk in the field.”

The only other option to hand-scooping sediment out of the bags was to remove the 4-foot long filter bags from the inlet, but because of the design of the product and the inlet, this was nearly impossible without dumping sediment into the drains because the only opening was a 24-inch diameter manhole and the 4-foot long bag could not fit through without being tipped at a steep angle. Bright needed ACF Environmental to develop and implement a more maintenance-friendly solution.

ACF Environmental carries a variety of inlet protection products that target pollutants in various types of drains and catch basins; however, after listening to PWD’s concerns, both parties initiated a collaborative design process to create the ideal solution.

Conventionally, a company designs a product and then shops it out to a customer, but this design process was unique because ACF Environmental and PWD invited maintenance workers to join the discussions.

“Everyone had a voice at the table,” said Woodman. “By listening and including all team members in the process, we could brainstorm and develop ideas for a product that did not exist in the marketplace yet.”

New product design can be both time-consuming and challenging. It takes patience for designers to revisit the drawing board with each issue. After each round of prototyping, the ACF Environmental team met with various staff members of PWD to review the progress and determine necessary modifications. Woodman stated, “Feedback from all team members was considered a gift–whether they were a maintenance worker or the Senior Design Engineer. We discussed every piece of feedback.”

ACF Environmental completed a prototype for a new high-flow geotextile filter bag that would resolve issues with the existing filter bags, including premature failure both in place and during maintenance. The existing filter bags tore easily and maintenance workers needed to replace them every few months even though the expected lifespan was over a year. Geotextile bags would tear along the centerline seams when the weight of the accumulated sediment applied stress to the seam.

Based on a negotiation between design-driven requirements (flow rate and particle size) and maintenance-driven requirements (volume of capture and bypass capacity), they selected a woven monofilament geotextile middle filtration layer for the filtering element. They added polyethylene mesh on both sides of the woven monofilament geotextile to provide additional protection from tearing when the unit was cleaned in place with a vacuum or removed from the inlet (which often included workers dragging the sediment-laden unit to the emptying location). ACF Environmental could develop the new high-flow geotextile bag with no centerline seam and improve the bag to frame connection points.

Once ACF Environmental’s manufacturing and design teams completed the bag, they brought on Fabco Industries–a Long Island, New York-based stormwater filtration and product innovation company–who specializes in metal fabrication to design to finalize the unique PWD specific aluminum frames. 

PWD was experiencing issues with their current metal frames bending or breaking during maintenance causing sediment and trash to fall into the drains. It was critical that the new frame could support the load of a full filter bag during removal. The new frame accomplished this and reduced the number of wall anchors required during installation. Each of the new frames also provided adjustability so maintenance workers could accommodate minor conflicts and drain size variations in the field.

In December 2018, ACF Environmental and PWD unveiled the new green inlet filter series, known as PWD StormSacks. PWD will install inlets throughout the City in the coming months. PWD’s maintenance staff no longer has to lay in the street because StormSacks are easy to remove and can be cleaned with a vacuum. 

Bright stated, “The new StormSack product was a marked improvement over existing products in regard to capacity, durability, and ease of maintenance. It allowed us to maintain City inlets using mechanized equipment as we do for other inlet types, which will no doubt result in an uptick in productivity for our Inlet Pretreatment Maintenance crews.”

“Using feedback from all members of the team, including feedback from key program maintenance consultants like AKRF, we developed a safer, more efficient process for inlet maintenance by producing a high-performance, long-lasting and cost-effective set of inlet filters,” said Woodman. “Collaboration is a crucial element of innovation.”

Many cities are paying attention to Philadelphia’s trailblazing Green City, Clean Waters Program, including New York City. After the installation of the PWD StormSack, the NYC DEP and their assigned consultants reached out to ACF Environmental for help in developing inlet protection devices for their right-of-way (ROW) bioswales and infiltration trench designs that meet their performance and maintenance needs.

“What we have realized through working with a series of cities now, is that every city is unique, and with that, calls for unique solutions. From a design side – we consider the obvious variables like the size of tributary areas to drains, the size of drain grates/castings, and pollutants. Sometimes the main concern is more than sediment or trash,” said Woodman. “There are other pieces to the puzzle though, which include a city’s experiences with inlet protection, their maintenance capabilities (including available equipment), desired frequency of maintenance, aesthetics, public perception, and a variety of key program personnel opinions and perspectives. A collaborative process is the only way to have a positive impact on the long-term performance, success, and cost of ownership for green infrastructure programs.”

PWD will closely monitor the enhanced performance and optimized maintenance processes their new PWD Stormsack will provide. Just as all voices were heard during the design process, ACF Environmental expects that tweaks will continue to be made as additional lessons and feedback from the field return to the team. They plan to continue to collaborate on and evolve the PWD filter bag solutions.

Referencing an earlier edition of the Green Streets, Clean Waters design manual, Howard Neukrug, the former PWD commissioner, said, “The key to the success of green streets is to develop a seamless process whereby stormwater management, street engineering, and landscape design come together to produce a functional, attractive and cost-efficient project.” 

This is clear through the design process of the new PWD StormSack. It is worth it to put in the time to protect the performance of these systems as well as the public investment in GSI, especially since the social, economic, and environmental return on investment for a nature-based approach is necessary and welcomed in Philadelphia and beyond.

When Your Needs Change, Our Team Innovates!

At Fabco, Collaboration Leads to Innovation. When people work together, they can deliver incredible results. Recently, FABCO was fortunate to be part of such an effort. 

This collaboration began in Philadelphia. As one of the oldest municipalities in the country, Philadelphia’s infrastructure has had to adapt and grow with technological development, population shifts and environmental concerns. The work requires constant vigilance. When the Philadelphia Water Department (PWD) evaluated the stormwater runoff entering into the city’s inlets, the team found the system needed upgrading. The current infrastructure included a large number of specialized filter bags called Catch Basin Inserts (CBI) to capture and treat the storm water as it entered the sub-surface conveyance system – a treatment method called Decentralized Treatment. The existing CBI filter bag designs were not able to handle new demands placed on the system. These CBI’s were difficult to maintain, in some cases requiring the staff to reach into the bags and remove sediments and collected material by hand. Worse, the overburdened frames were weak, and the bags could easily rip, spilling their contents back into the drainage system. The PWD immediately began looking for a better solution.

The Philadelphia Water Department turned to one of Fabco’s leading stormwater innovation partners: ACF Environmental. The goal was to find a solution that could adapt and meet the performance goals within Philadelphia’s Green City, Clean Waters initiative. Project discussionswere thorough and included representatives from the PWD, ACF Environmental, The Green Stormwater Operations Unit (GSO) and, for a “feet on the street” point of view, the PWD’s maintenance team.

One of the first developments from this collaborative effort was an innovative filter bag fromACF. It featured a unique two-stage, geotextile filter bag that combined the high treatment flow rates required in the streets of Philadelphia with extreme strength for long life and effectivemaintenance. With this game changing filter bag in hand, the focus of the team shifted to the physical drain inlets where the bags would be installed. New supporting frames, hardware and mounting systems would be needed to install and hold these unique filter bags in the complex system of storm drain inlets in order to maximize effectiveness. 

With many years of first-hand experience, ACF contacted FABCO INDUSTRIES for help. As an industry leader in Catch Basin insert products and a proponent of decentralized treatment methods, Fabco saw this as an opportunity and began to conceptualize its plans.  How could a frame be constructed to support the weight of the new bags while remaining light enough to lift by maintenance crews? How would the frame be anchored for both strength and easy maintenance? How would the design deal with drain size variations? These questions led the engineers and design team at FABCO to see a product that did not yet exist. 

Guided by the work done by ACF Environmental and PWD’s long term experience as well as following the standards set by GSI and Fabco’s engineers, designers and fabricators delivered a family of three simple insert filters that met the design parameters of the project. 

In December 2018, ACF Environmental and PWD unveiled the new StormSack PWD stormwater filtration system and installed the first evaluation systems in Philadelphia. The achievement was the result of collaboration, innovation and viewing problems as opportunities. Fabco Industries is proud to have been a partner in the process. 

We invite you to read the full story of this truly inspiring group effort.

FABCO TECHNOLOGY NOW APPROVED FOR PRIVATE DEVELOPMENT IN PHILADELPHIA

Fabco Industries is proud to announce that the Philadelphia Water Department (PWD) has approved its proprietary cartridge-driven stormwater quality filtration devices for private development in the city.

After a thorough and comprehensive review process, the technicians and water quality experts at one of the oldest government-regulated water providers in the country determined that Fabco’sspecialized devices meet the PWD regulations for private development in the City of Philadelphia.  This provides owners and developers in the area the confidence of using Fabco’sproven stormwater filtration products for their projects. They can also take pride in the environmental protection afforded them by Fabco technology.

“This is a significant achievement for us,” states Warren Cohn, STORMWATER PRODUCT SPECIALIST at Fabco Industries. “Philadelphia is known for its achievements in GREEN INFRASTRUCTURE (GI). The city’s GREEN CITY, CLEAN WATERS initiative sets the standard for stormwater management nationwide. To earn PWD approval is a great honor.” 

John Markee, Fabco’s Vice President for Marketing, elaborates: “Fabco’s filter cartridges are designed to provide effective treatment of Stormwater while maintaining high flow rates throughout the life of the cartridge. Our cartridges can be used in a wide variety of configurationsthat are specifically designed for the unique challenges of each local situation.”

StormBasin: A Water Quality Insert (WQI) that can be utilized in new or retrofit construction to provide water quality treatment close to source by providing that treatment in drain precast inlets/basins.

This StormBasin, deployed close to the source treatment, is consistent with the EPA’s definition of Green Infrastructure (GI) and Low Impact Development (LID). StormBasin features easily maintained plastic basins, durable aluminum frames, covered bypass for extreme events, field adjustability and low cost of ownership.

Downspout Filter: Designed to treat particulates and soluble pollutants contained runoff from roof tops.

These units can be specifically configured for above or below grade applications. They offerflexibility to collect and treat drainage from sources other than roof top downspouts. The standard unit design includes pre-treatment, water quantity design volume and overflow drainage. These filters are easy to install and maintain at a low cost.

StormSafe Cartridge Vaults: Ideal for drainage areas that require centralized stormwatertreatment beyond simple gross pollutants and trash removal.

StormSafe Cartridge Vaults can reduce concentrations of targeted stormwater pollutants in a cost-effective manner. Standard StormSafe unit design includes pre-treatment, water quantity design volume and overflow drainage. These are easy to install and maintain, with a low cost of ownership.

Fabco is recognized as an industry leader in the design, manufacture, and application of engineered stormwater treatment systems. We practice a philosophy of continuous product innovation, research, and development.

Warren invites developers and project managers in the Philadelphia area or in any municipalitythroughout the nation to contact him regarding the use of Fabco stormwater solutions for their unique needs. He can be emailed at wcohn@fabco-industries.com or call him directly on his mobile phone at 484-689-1113.

Fabco Industries Protects NYC Drinking Water Supply By Reducing Phosphorous with StormBasin Solution.

Project Profile – Bloomer Road to U.S. 6 Stormwater Retrofit

Project Owner: East of Hudson Watershed Corporation (EOHWC)

Engineer of Record: Nathan L. Jacobson and Associates, P.C.

Contractor: Brennan Construction Company

Brewster Heights is a community that occupies approximately a half a square mile in the Town of Southeast in southern Putnam County, NY.

The East of Hudson Watershed Corporation is a local development corporation established by the municipalities in Northern Westchester, Putnam, and Dutchess Counties in the New York City Watershed. Its aim is to install stormwater retrofit projects to meet the requirements for phosphorus reduction as defined by the New York State Department of Environmental Conservation (NYSDEC). The Corporation works in conjunction with the NYSDEC and New York City Department of Environmental Protection (NYCDEP) to further Stormwater MS4 quality projects in the Croton and Kensico Reservoir Basins.

Ultimately, the driving force behind the stormwater quality improvement is protecting New York City’s filtration avoidance determination and its drinking water supply.

Fabco Industries is a NYS based manufacturer of quality stormwater treatment devices with over 5000 installations in NYS alone.

This project involved the collaboration of multiple parties over the course of the last decade.  The initial goal of the project was the stabilization of four heavily eroded channels which discharged runoff from the Brewster Heights subdivision. These channels had caused severe washout and sediment deposition onto private property and into the New York City water supply Middle Branch Reservoir. While the stabilization of the eroded channels was straightforward, identifying an appropriate water quality Best Management Practice (BMP) to implement proved challenging.  One of the last design iterations prior to approval from the NYCDEP involved the installation of two Hydrodynamic Separators (HDS), individually located at the outfall of the two channels where runoff was to be rerouted. The location of these units would have required realignment of multiple existing utilities and taken up a significant footprint within the right-of-way.

The existing phosphorus load of the drainage area tributary to the stabilized channels was calculated as 22.46 kg/yr.  The reduction credit which was attainable through installation of two HDS units would have been 2.25 kg/yr. The estimated installed cost was between $80,000 and $100,000, not taking into account the required realignment of existing utilities.

Enter Fabco Industries and the StormBasin solution. This BMP had previously been approved by the NYSDEC to provide 50% phosphorus removal at its peak treatment flow rate. It also had the advantage of offering the ability to be retrofitted into existing catch basins.



The NYSDEC’s approval was based on the comprehensive technical submittal prepared by the engineering and science consulting firm Woodard & Curran, as part of the overall East Of Hudson Coalition Stormwater Retrofit Plan. Woodard & Curran collaborated with NYDEC to consider approving additional stormwater retrofit treatment practices into the overall NYC water supply phosphorus reduction program. This allowed municipalities within the EOH watershed additional options to treat and reduce phosphorus in stormwater runoff prior to discharging into the NYC reservoirs. Based on a thorough review of the stormwater retrofits approved by NYSDEC and installed to date, Woodard & Curran strongly believed that in order for the overall phosphorus reduction program to be successful, the regulated municipalities needed cost-effective and easy-to-implement stormwater retrofit treatment solutions that also required minimal O&M. After a thorough review of various stormwater treatment retrofit practices available in the marketplace that had not yet been identified or approved by the NYSDEC as acceptable treatment practices within the EOH phosphorus reduction program, Woodard & Curran saw the promise that the STORMBASIN SOLUTION WITH FABPHOS FILTRATION MEDIA offered the municipalities.  

Steven Lauria, PE, Project Manager and Principal of Woodard & Curran, stated: “The first five years of retrofits revealed that for the program to be successful moving forward, there needed to be cost-effective and low maintenance retrofit solutions that did not require the modification of existing infrastructure or land disturbance. One of the greatest challenges of implementing retrofits on public and private property is limiting the impact to existing infrastructure, property, and current operations. The StormBasin solution met all the challenges of the retrofit model as a cost-effective and low maintenance solution. StormBasin has the potential to save the EOHC millions of dollars when compared to other NYSDEC approved retrofit practices.”

Treating a fraction of the drainage area, the StormBasin inserts were able to obtain a reduction of 7.43 kg/y—and at less than one third the installed cost of the HDS solution. Most impressive was that it did so with no required realignment of existing utilities!

The decentralized nature of the StormBasin solution being both “at grade” and “at source” has several advantages over a buried downstream device. StormBasin installations are easily inspected and maintained at grade and once installed can protect the downstream infrastructure.

Said Kevin Fitzpatrick, Director of Engineering for the EOHWC, “Fabco Industries and Bill Stoecker were attentive and responsive throughout the entire project to ensure we had the best solution in place to fit the Corporation needs.”

14 Fabco StormBasin Units with a total of 29 cartridge filters were installed by Fabco Industries’ team over a two-day period in November 2018. Several different styles of units were utilized to accommodate the various catch basins, frames and grates that exist in the community.

The long-term success of these installations relies on the timely approach to maintenance of the drainage area and the catch basins themselves. To this end, StormBasin units have been designed to make biannual cleaning and annual replacement of the cartridge easily done by any local workforce.

Looking to the future, StormBasin is to be implemented in several EOHWC projects. This solution should be considered in any situation where water quality improvement is needed, economics is a driver and ease of inspection and maintenance is desired.

Fabco’s FABGUARD Now Registered in California


Fabco Industries, Inc. is pleased to announce its proprietary FABGUARD anti-microbial pesticide is now registered in the state of California in addition to 17 other key stormwater markets.

In 2015, FABGUARD was granted pesticide registration with the United States Environmental Protection Agency (EPA). Since that time it has been registered for use in the following markets – Connecticut, Delaware, Florida, Massachusetts, Maine, Maryland, Michigan, New Hampshire, New Jersey, New York, Ohio, Pennsylvania, Rhode Island, South Carolina, Texas, Virginia, and Vermont.

FABGUARD media has been tested extensively under diverse laboratory and field conditions. It is an effective solution for reducing coliform bacteria in stormwater, industrial wastewater and municipal wastewater applications.

“FABGUARD is an innovative solution that complements our other filter media products and we are proud to have it registered in California – the most aggressive and demanding stormwater market in the U.S.,” said John Markee, Fabco’s Vice President of Sales and Marketing. “Its unique physical properties allow sustained high flow rates while still providing exceptional treatment of coliform bacteria. For example, when FABGUARD is applied to our Helix filters, relatively compact systems can effectively treat large volumes of water.” 

When combined with Fabco’s stormwater filtration systems, FABGUARD can be configured to reduce bacteria using centralized or decentralized treatment at varying flow rates.  FABGUARD can be applied to catch basin inserts like StormBasin and StormPod systems for retrofit applications. FABGUARD also works with end-of-pipe solutions such as the cartridge-based StormSafe and high-flow Helix vaults.

“The effectiveness of FABGUARD media is even better than anticipated,” said Markee. “FABGUARD sets a new standard for filtering coliform bacteria.”

FABGUARD filter media benefits:

·      Reduction of coliform bacteria

·      Effective treatment at high-flow rates

·      Lightweight, easy to handle and deploy

Federal – US Environmental Protection Agency Office of Pesticides Program – EPA Registration #90270-1

California – State of California Department of Pesticides Registration- Regulation License #66083, Registration Number: 90270-1-AA

 

About Fabco Industries:
Fabco Industries is a leader in stormwater management and providing stormwater solutions to engineer a better environment. The company designs and manufactures high-performance stormwater filter systems that are highly effective for various treatment applications including retrofits, new construction and green infrastructure.

Fabco’s range of cost-effective, durable products, are designed to meet increasingly stringent pollution control regulations and best management practices for municipal and commercial stormwater markets.

The Farmingdale, N.Y. based company offers sustainable, simple-to-maintain filtration solutions to meet virtually any stormwater pollution control challenge. With innovative, patented technology, a stellar reputation of proven performance, and high-quality products, Fabco is proud to provide “Evolved Stormwater Solutions.”

For more information on FABGUARD filters and the municipalities in which they are registered, please visit fabco-industries.com or contact John Markee at (631) 393-6024 ext. 114.

Fabco Trench Drain Filters – The Perfect Solution for Your Stormwater Runoff

Fabco Industries, Inc, a leader in stormwater management, provides custom evolved stormwater solutions to treat problems at the source. We design and manufacture high-performance stormwater filter systems, such as our Trench Drain Filter, for various treatment applications including retrofits, new construction, and green infrastructure.

Fabco’s Trench Drain Filter is one of many innovative products designed for both commercial and residential use. The Trench Drain Filter is a highly effective, easy-to-install stormwater filter designed to fit a wide range of flat-bottomed, trench drain inlets. The simple design traps the common sediment, trash, and debris within the trench while allowing the pretreated runoff water to pass through the filter and exit through the storm drain system.

A trench drain is a specific type of floor drain characterized by long length and narrow width. They are optimized for rapid evacuation of surface water with the cross-section of the drain being designed for the anticipated water flow. When strategically positioned across an open area. Trench drain’s intercept excess rain water flowing across the surface to prevent accumulation and then diverts it to safer collection area. Trench drains can vary from 1 inch to 2 feet in width, with depths that can reach 2 or more feet.

Fabco’s Trench Drain Filter™ is comprised of one or more perforated metal square tubes called debris shields and a Bypass hood assembly.  The perforated debris shield also encloses are placeable oil absorbent product for treating the water.

During normal operation, surface water entering the trench drain grate falls to the bottom of the channel and flows towards the outlet pipe. To effectively treat this flow of water, the Fabco Trench Drain Filter is installed a few inches in front of the outlet pipe, positioned to intercept and treat the full flow.

If you think Febco’s Trench Drain Filter may be the perfect evolved solution for your stormwater problem, please contact us today. Click here for complete specifications and a further description of the product.

Fabco and ACF Team to Introduce FocalPoint & StormPods for Salem, MA Stormwater Projects

When the City of Salem in Massachusetts required an innovative solution to solve critical issues with their stormwater drainage, Fabco and ACF joined forces to provide a custom evolved stormwater solution to treat the problem at the two sources.

Facing a two-phase project affecting both the cities’ North and South Rivers, including the Commercial Street neighborhood, ACF and Fabco Industries combined to employ both the FocalPoint system and Fabco’s exclusive StormPods.

Considering both the environmental problems this situation posed and the level of government compliance necessary, the City of Salem needed quick and effective solutions. ACF and Fabcowere proud to assist by offering their proven innovative technology.

The Salem Sound Coastal Watch outlined the persistent problems the community faced in apresentation entitled “A 21st Century Approach to Cleaning Stormwater” at the City’s 2016 symposium “Finding Solutions to Our Coastal Challenge.

The issues included oil and hydrocarbons left on the road by vehicular traffic and parking, sediments being washed into the North River due to missing landscape timbers that once contained the islands, and sediment and dog feces washing off Commercial Street and sidewalks ending up in the North River stormwater and outfall pipes.


FocalPoint
, a scalable biofiltration system, offered a next-generation biofiltration solution for the Commercial Street and South River Projects. The system combines the efficiency of high-flow rate engineered soils with the durability and modularity of a high-pervious flat, box-shaped underdrain.

Fabco’s partner ACF, suggested the use of their patented StormPods, which are designed for stormwater hotspots such as parking lots, transportation centers, vehicle maintenance facilities, fueling locations, and industrial applications. The use of the StormPods allowed Fabco to effectively treat the major pollutants identified in surface water runoff. In both the Commercial Street and South River projects, this solution allowed the outlet screens to catch everything from oil to solids and floatables.

The Salem project showcased the capabilities of ACF and Fabco to combine environmentally effective new technology to handle unique circumstances. This example of a creative stormwater solution will have a lasting impact on the city’s drainage issues for years to come. Working collaboratively within special parameters, ACF and Fabco successfully accomplished their mission.

For further information on Fabco’s evolved stormwater solutions, please go to Fabco-Industries.com.

 

Is Rooftop Runoff Really Clean?

Technical Note #25 from Watershed Protection Techniques. 1(2): 84-85

Three recent papers investigated the quality of runoff from different roof surfaces.  Conventional wisdom holds that roof runoff is relatively clean. Its use as drinking water in rainwater cistern systems is well known. In other areas, managers maintain that cleaner roof runoff should be treated differently than runoff from dirtier parking lots and roads.  This view is supported by extensive monitoring data for several conventional pollutants such as sediment, nutrients, organic matter, and possibly bacteria.

However, according to recent studies, rooftop runoff is not cleaner with respect to dissolved and particulate metals such as copper, lead, and especially zinc.  Thomas and Greene (1993) sampled runoff from two kinds of roof surfaces at urban and industrial areas in Armidale, New South Wales (Australia). Good (1993) monitored runoff from five different roof surfaces in a  sawmill /wood processing plant on the coast of Washington.  Bannerman and his colleagues (1993) examined roof runoff samples from residential, commercial, and industrial sites in Wisconsin.

Monitoring results are compared in Table 1. As shown, industrial roofs had zinc levels that were two to 20 times greater than other urban source areas and often exceeded acute toxicity for aquatic life. It appears that galvanized roofing materials are a prime source of zinc in the urban landscape. Roofing materials, paints, and coatings are also suspected of being important sources of copper and lead as well. Roofs with copper flashing were found to have copper and lead concentrations up to six to eight times greater than galvanized roofs.

Good (1993) also conducted toxicity studies on roof runoff from the industrial site in Washington and found that several samples were acutely toxic to rainbow trout in bioassays. The toxicity was attributed to the rapid corrosion of galvanized metal roofs and the leaching of zinc and other contaminants. It was also thought that tar-covered roofs were a source of copper. Although  Good’s study only looked at the first flush from rooftops, there was evidence that toxicity remained high for up to three hours after the start of a storm. Taken together, the studies suggest that the perception that roof runoff is always a source of relatively clean water may not always hold true when industrial roof surfaces are considered. Galvanized roof coatings, in particular, appear to be a major source of zinc and other metals in the urban landscape.

The rooftop monitoring studies raise the intriguing possibility that the use of alternative roofing or roof coating materials could result in lower pollutant loadings. Thus, a pollution prevention approach that avoids or minimizes the use of metals in roofing materials could be an attractive solution. Further research into metal loading from urban roof surfaces will be helpful in designing these new roof surfaces.

References
Bannerman, R. 1994. “Sources of Urban Stormwater Pollutants
Defined in Wisconsin.” Tech. Note 15.
Watershed Protection Techniques. 1(1): 30-31.  1

Good, J.C. 1993. “Roof Runoff As a Diffuse Source of
Metals and Aquatic Toxicity in Stormwater.” Water
Science Technology. 28 (3-5): 317-322.  2

Thomas, P.R. and G.R. Greene. 1993. “RainWater Quality
From Different Roof Catchments.” Water Science
Technology. 28 (3-5) pp. 291-297.  3

U.S. EPA. 1983. Results of the Nationwide Urban Runoff
Program. Vol. 1, Final Report. Washington, D.C. 200
pp.  4

Clean Stormwater From the Top Down with FABCO DownSpout ™

When considering stormwater runoff from a commercial or industrial building site, water from rooftops can be overlooked or considered a relatively minor impairment to groundwater contamination. However, scientific studies have shown that rooftops in urban and industrial areas can be loaded with contaminants at far higher concentrations than anticipated. As a result, many stormwater managers are being environmentally pro-active and incorporating Fabco’s DownSpout  technology into their designs.

Runoff from roofs, although differing in concentrations from runoff generated from road surfaces or partially sealed surfaces, contains many of the same pollutants including TSS (particulates), nutrients, bacteria, hydrocarbon compounds. Also found are critically heavy metals, in particular: zinc, copper and even lead, which are released as a result of rain water reacting with the materials found in rooftop construction.

Fabco Industries, Inc. has been providing efficient and effective stormwater filter solutions for over 15 years. Our DownSpout systems remove both particulate and soluble pollutants such as heavy metals from rooftop runoff using one or more of our proprietary filter media products contained in sealed replaceable cartridges. The cartridge design has been proven through years of municipal and industrial stormwater use to provide maximum optimization for targeted pollutants while allowing fast exchange and safe disposal. The DownSpout filter can be expanded from the standard two-filter model to facilitate specialized contaminant removal or to accommodate higher flow rates. Above ground and sub-surface DownSpout designs are available.

DownSpout has been included in many new construction projects and building renovations, including libraries, municipal buildings, museums, hotels, and parking garages. It is also adaptable to existing properties such as waste transfer stations, metal fabricators/suppliers, scrap metal yards and simple metal buildings. DownSpout filters also make an excellent low-cost pre-filter for underground stormwater detention systems, keeping out grit and debris, extending their useful life and reducing costly maintenance.

Talk to us today about the benefits of protecting our water from the top down—with Fabco’s DownSpout.