Controlling Stormwater Runoff
Construction and post-construction strategies
The project’s scope is immense: When complete, SouthField, a mixed-use development in South Weymouth, MA, will be home to 2,855 residences and more than 2 million square feet of commercial space.
It’s up to Brian Brewer, project manager with Quincy, MA–based engineering firm Kimley-Horn and Associates, to prevent unfiltered stormwater from draining off the 1,400-acre construction site and into nearby waterways.
This, too, is a big job. To do it, Brewer and his crew are relying on a wide variety of stormwater-control measures—mostly biological methods of both the pre- and post-construction variety—to capture and filter any runoff from the site.
“The idea is to focus on biologically based treatment methods,” Brewer says.
That’s just another one of the pieces of this project being a sustainable design community. We try to use biological methods as much as possible. It doesn’t make sense to use these design methods everywhere, of course, but everywhere where there is a good reason to use it, we’re going to try to do it.”
SouthField has its own special stormwater challenges. The land on which the mixed-use development, a master-planned community, will sit was once the South Weymouth Naval Air Station. The station had its own set of existing stormwater control measures, a series of concrete box culverts, concrete pipes, and drainage ditches. Unfortunately, these stormwater devices are hopelessly outdated and do nothing to filter or treat stormwater.
Brewer and his fellow engineers had to work around these existing structures when creating their own stormwater management methods. The crew relied on everything from ponds to biofilters and bioswales to bring the site’s existing stormwater measures up to date.
 |
Photo: Filterra |
| Installation of an underground drainage and treatment system |
“We are working around existing systems that were, in a lot of cases, installed 60 years ago,” Brewer says. “They are not up to today’s standards of stormwater treatment. We are basically trying to accommodate the existing systems and improve them. There were no water-quality measures on the base. But water quality is a big deal now, especially since the site has a lot of wetlands that surround it.”
Brewer is far from the only engineer relying on a complete toolbox of stormwater management tools. Today, erosion control pros can choose from the traditional products—bales and silt fence, for example—to ones that are more specialized—such as underground filtration systems that come complete with their own aboveground trees and shrubs—depending on the size and scope of their jobs.
This is good news. Federal and state regulations have grown far stricter in recent years when it comes to stormwater management. Municipalities now realize how important it is to keep their waterways—the rivers, streams, lakes, and ponds that often abut construction sites—free of suspended solids. Construction crews found violating the regulations spelled out in the National Pollutant Discharge Elimination System (NPDES) requirements face both heavy fines and bad public relations.
To prevent that killer combination, engineers and contractors, such as Brewer, are not just relying on one stormwater control measure. They are using everything they have, products designed for both pre- and post-construction work phases, to prevent suspended solids, oils, and other pollutants from running off their sites.
“Contractors are more in tune with the need to control the stormwater on their sites,” says Jamie Ringenbach, president of Naperville, IL–based Inlet & Pipe Protection; a company that manufactures filters and filter baskets. “The EPA is coming out and testing rivers and lakes adjoining subdivisions. Everyone is aware of it. Contractors have update meetings on NPDES and the fines that can be levied against them. The awareness is there, and we are starting to see more enforcement forcing contractors to pay more attention to their stormwater management plans.”
 |
Photos: Inlet and Pipe Protection |
| Ponding around an inlet due to a clogged surface filter fabric under the grate |
 |
| Clogging creates a drain stop |
Brewer, along with engineers across the country, is providing examples every day of this new approach to managing stormwater runoff.
Big Doings in South Weymouth
Kimley-Horn and Associates has been working as a subcontractor on the SouthField project in South Weymouth for five years, and Brewer expects the company to remain involved with the project for at least that many more.
These days, Kimley-Horn engineers are tackling the civil engineering aspects of the project for developer LNR, designing drainage systems, landscaping, interior roads, and ponds—all the elements that will help create a final project at SouthField.
“This is an impressive development they are creating here,” Brewer says. “This is happening across the country with the military base closings that are leaving all this great land available. Developers are coming and taking something that is rundown, something that is no longer usable, and transforming it into a great community.”
Much of Kimley-Horn’s work now is focused on capturing and treating site runoff.
This is especially important at SouthField, which is designed to function as a fully sustainable development. SouthField is located directly off a major commuter rail line. Because of its mix of housing and commercial, residents don’t have to jump into their cars to get to restaurants, shops, and entertainment.
To maintain the environmentally friendly aspects of the development, the engineers at Kimley-Horn must make sure that they capture and treat stormwater runoff in a “green” way, which is why many of the tools they’re using for the job are biologically based ones.
Kimley-Horn recently finished design work on the renovation of an existing major roadway in the SouthField project. The developer wanted the roadway widened, and also requested the installation of bike paths and sidewalks along its side. Wetlands surrounded the road on both sides.
The challenge was to install stormwater management devices along the newly improved road that were both aesthetically pleasing and functional. The developer planned for the newly widened road to serve as one of the project’s main entrances; it had to look nice.
“The developer wanted to make a splash with this roadway,” Brewer says. “It had to look attractive. At the same time, we had to be in compliance with the conservation commission. We had to come up with a way to not only widen the road, but to work in stormwater management.”
To do this, Kimley-Horn designed grass-lined bioswales that construction crews placed along the lowest spots of the widened road. Crews filled the spots with a highly permeable engineered fill and installed at the bottom of it a perforated drainage pipe surrounded by stone. The pipe was designed to discharge water into an existing inlet and into the surrounding wetlands.
 |
Photos: Inlet and Pipe Protection |
| Inlet filters can be installed under the grate. |
 |
| Inlet filters remove silt and other pollutants from water runoff. |
Stormwater then flows toward the low spots along the road, ponds up in the bioswales, and seeps through the engineered fill. It travels through the corrugated pipe and, now treated to current water-quality standards, is discharged into the surrounding wetlands.
In other locations, the developer called for attractive curbing. This meant that Kimley-Horn engineers would need a stormwater solution other than bioswales. In these locations, the engineers instead went with the underground drainage and treatment systems created by manufacturer Filterra.
These bioretention systems include underground drainage pipes and catch basins, topped with plants and shrubs. The systems are designed for urban stormwater management. All residents and business owners see are the plants. They have no idea of the stormwater filtering devices operating below the surface.
As of press time, Kimley-Horn had already installed six Filterra units at the SouthField development, and was preparing to install six more.
Kimley-Horn is also preparing to create a series of ponds on the site to handle stormwater in a natural, environmentally friendly way.
“We have the whole toolbox open right now,” Brewer says. “We are open to every tool on this project.”
A Larger Toolbox
The Filterra units are just one example of the new—and, most would say, improved—products engineers have to deal with stormwater control and treatment.
The units are examples of post-construction low-impact development devices. They are also examples of decentralized stormwater treatment. Construction crews place Filterra units strategically throughout a development or urban area. This contrasts with centralized approaches where larger stormwater-treatment devices instead must be located, sometimes unattractively, at the end of a pipe or drainage area. These products are then responsible for filtering the water from a larger drainage area, meaning more opportunity for suspended soils to slip through.
“We call our units the urban solution,” says Terry Siviter, Filterra’s general manager.
The theory behind decentralized filter systems such as Filterra’s is simple: As the units are spread throughout developments, each unit is responsible for filtering the runoff in a smaller drainage area. Each unit, then, has to catch fewer pollutants, which means more effective treatment.
The maintenance is also minimal, Siviter says. Crews need only remove mulch about two times a year and maintain each treatment unit’s landscaping.
 |
Photo: Inlet and Pipe Protection |
| Lack of maintenance and heavy rains can lead to clogged filter fabric. |
“What you have is a tree or shrub that is aesthetically pleasing,” Siviter says. “The units are easily accessed and maintained with simple landscaping tools. Wal-Mart and Target can maintain our system with their own contracted landscapers. They don’t have to deal with companies that vacuum treatment systems or use confined-space measures.”
The ease of maintenance is key, Siviter says. Too often, developers call for stormwater management devices and then forget about maintaining them. This leads to future problems.
“If you are not maintaining these units, including Filterra systems, ponds, and any other system you can think of, then we are really going backwards,” Siviter says. “A lot of these units are not being maintained. Developers might be creating hundreds of thousands of BMPs across the country that are now ineffective because no one ever maintained them. This can be a serious problem.”
Filterra units are attractive to many developers because they are considered a “green” approach to managing stormwater. But it can still be a challenge to convince contractors and developers to take a chance on the units, Siviter says. Many contractors prefer the more traditional methods and would rather not spend money on something they’ve not used in the past.
“It is a challenge to convince contractors to go above the bare minimum,” he notes. “We spend a lot on monitoring to prove that these units work. Contractors are doing their jobs. They want to get their permits as cheaply as possible. I don’t blame them for that. But this is changing with the NPDES Phase II requirements and the increased enforcement that comes with that.”
The NPDES Phase II requirements spell out six minimum control measures for municipalities. Developers and contractors who don’t meet the measures that apply to them are asking for fines that can sometimes be heavy.
One of the Phase II minimum control measures requires that municipalities create a program designed to educate the public about the impact of stormwater discharges on other bodies of water. This public education and outreach component must include suggestions for how members of the public can help prevent stormwater pollution.
Phase II control measures also require that permittees have a procedure for giving the public an opportunity to participate in both the development and implementation of the stormwater program.
Municipalities must develop a plan that includes devices that locate and eliminate discharges into storm sewers that come from sources other than stormwater itself. The plan must include a map of all outfalls.
A fourth requirement is that municipalities design regulatory devices and best management practices (BMPs) that reduce or prevent other pollutants associated with construction activity.
Under the NPDES Phase II regulations, municipalities must also create a program of post-construction stormwater management devices. These devices must reduce the amount of pollutants in stormwater runoff.
 |
Photos: Inlet and Pipe Protection |
| Below-grade installation of inlet filters |
 |
Finally, the requirements mandate that municipalities must create operation and maintenance programs that prevent or reduce pollutant runoff from municipal operations.
These are just the minimum requirements. Some municipalities already require more strenuous measures to control runoff.
To many manufacturers, this is a good thing. More powerful stormwater devices, they say, mean less pollution entering the country’s waterways. Now, they say, it’s just a matter of educating developers and contractors on more efficient and effective ways to control runoff.
“There is still some education going on in the field about how important it is to use products that actually do the job better,” says Alex Marks, general manager of Grafton, OH–based Filtrexx International, a manufacturer of several stormwater filtration devices.
“Most contractors do get the ‘ounce of prevention’ mantra,” Marks says. “But it often comes down to the bottom line for a lot of these guys. They are still looking at the bare minimum of what they need to do. If they can get away with just hydroseeding a slope, that’s what they’ll do. They’ll do that instead of looking at a more effective way to stabilize that slope.”
The Right Tool for the Job
Bill Becker, owner of Siltmaster based in Crystal Lake, IL, is one of the contractors who does get it. He prefers to use the right product at the beginning of a project to help prevent problems in the future.
Becker’s company is now one of the subcontractors on the expansion of Rush University Medical Center, an academic medical center in Chicago. In August 2007, he and his crewmembers installed a dozen FleXstorm inlet filters manufactured by Inlet & Pipe Protection.
Becker chose these products because they effectively filter out silt, solids, and other pollutants from water runoff. Maintenance is also low on the product.
“We use them on every residential site I’m working on now,” Becker says. “I’ve never had anyone complain about these, not once. Once I convince the contractors that these are the products they need to use, they are more than happy with them.”
Becker considers FleXstorm filter baskets as replacements for the fabric that contractors often use to protect inlets from stormwater. If a construction site is hit with heavy enough rains, the water dumped on the job site can overwhelm traditional fabrics. The water simply doesn’t pass through the fabrics quickly enough.
During especially brutal winters, such as the one that many Midwestern and Northeastern states have experienced in 2008, a construction site may see many thaws and refreezes. If it happens to rain during the thaw, and then temperatures drop 20 degrees in an hour and everything freezes again, the fabrics tend to plug up. There isn’t enough time in such instances for water to move through the fabric.
While products such as FleXstorm may cost more than some older, less effective stormwater control devices, contractors should realize that the more efficient products will save them money in the long run, Becker says.
“All it takes is one lady going out of her house for a cup of cappuccino on a Sunday morning to have to drive through a deep puddle of backed-up water for there to be big trouble,” Becker says. “That’s what contractors have to remember.”
The problem is that too many contractors are still focused on upfront costs, and are willing to overlook potential long-run cost savings, not to mention the reduction of frustration, that better-designed, more effective products bring.
“With the housing market the way it is now, all the contractors are trying to scrimp and save,” Becker says. “The big thing I always tell them is that while a product may cost $100 now, it could save you thousands down the road in having to flush out your storm sewer line or if you get contamination in your pond. The Army Corps’ fine could be tens of thousands of dollars. The price of the product is pretty irrelevant compared to what could happen down the road.”
The Holistic Approach
Alex Marks says that with the variety of advanced products available for controlling stormwater, there is no reason for engineers and developers not to take a more holistic approach to capturing and treating runoff.
Filtrexx International manufactures several types of products designed to replace traditional silt fence, straw bales, riprap, and sediment ponds; products such as Filtrexx SiltSoxx and InletSoxx, are used both pre- and post-construction. The products use mostly composted organic media, and are usually filled on site.
“We take a look at the lifecycle of a raindrop with our products,” Marks says. “We need to treat that raindrop before it becomes an issue. We look at treating all those raindrops all the way down the line. We try to back up the hill and decide where we can do the most with as little as possible.”
Contractors need to realize, he says, that while federal and local governments usually don’t require them to use a specific product or method to control stormwater, they do require them to use something that is effective.
“You will have to spend a little more upfront with our products,” Marks says. “But in the long run, you might end up saving money. Maybe the guy who has to hydroseed his site five or six times may be willing to consider a new approach.”
Doug Caldwell, president of River Valley Organics in Wrightsville, PA, is one who uses Filtrexx’s SiltSoxx as a replacement for traditional silt fence. He estimates that his company installs more than 100,000 linear feet of SiltSoxx every year on the various construction projects he’s called in on.
“It’s good business for us to install these,” Caldwell says. “It works better. Our clients, because of the increased focus on stormwater management, are looking for better products. Filtrexx fits that bill.”
Rob Carrothers, owner of Soil-Tek of Mid-America, in St. Louis, also uses SiltSoxx as a replacement for silt fence.
Carrothers likes how the product works: When a ditch gets saturated with silt-filled water, the product retains the silt and allows just the filtered water to pass through. Because the product is three-dimensional, the wind doesn’t knock it over as easily as it does silt fence. At the end of the project, Carrothers can slit the sock, incorporate the compost inside it into the soil, and plant vegetation over it.
“We use it every day,” Carrothers says. “The majority of the municipalities we work in require us to install a pretty large device to control stormwater. These work well.”
Friendly Environment, based in Shelbyville, TN, offers its own stormwater-management product, the Erosion Eel. The geotextile tube, filled with shredded rubber chips, is an extremely effective filter of polluted water, says Kevin Wolfe, principal engineer with the company.
Contractors are currently using the Erosion Eels on Department of Transportation projects in Virginia, large developments in Tennessee, and large utility projects.
The product incorporates two levels of filtration, Wolfe says. First, it slows down the flow of water as it moves through the bag. About 60 to 80% of solid materials are left behind during this process.
Whatever solids are left is filtered out as the water moves through the internal filter material.
“We are still running into some contractors who are trying to get by doing as little as they can,” Wolfe says. “But, by and large, we are coming across more and more contractors who are more environmentally conscious. A lot has to do with regulatory agencies really stepping up and becoming more aggressive with enforcement. That pressure has gotten the attention of contractors. They are looking for something that will work.”
Chris McCormick, owner of McCormick Equipment in Pleasantville, IA, the manufacturer of the Silt Fence Plow—a machine that allows contractors to install silt fence faster and more effectively—says he, too, has run into contractors who are only interested in the cheapest stormwater control measures they can find.
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But this is gradually changing, he says.
“In areas where there has been very little enforcement of regulations, yes, it can be hard to convince contractors that they need something like this,” McCormick says. “But if you’re talking with someone in an area where the EPA has given out fines, where they don’t tolerate the poorly built silt fence, then contractors are more open to the idea.”
Author's Bio: Dan Rafter is a technical writer based in Illinois.
July-August 2008
Controlling Stormwater Runoff
Construction and post-construction strategies
Photo: Filterra
The project’s scope is immense: When complete, SouthField, a mixed-use development in South Weymouth, MA, will be home to 2,855 residences and more than 2 million square feet of commercial space.
It’s up to Brian Brewer, project manager with Quincy, MA–based engineering firm Kimley-Horn and Associates, to prevent unfiltered stormwater from draining off the 1,400-acre construction site and into nearby waterways.
This, too, is a big job. To do it, Brewer and his crew are relying on a wide variety of stormwater-control measures—mostly biological methods of both the pre- and post-construction variety—to capture and filter any runoff from the site.
“The idea is to focus on biologically based treatment methods,” Brewer says.
That’s just another one of the pieces of this project being a sustainable design community. We try to use biological methods as much as possible. It doesn’t make sense to use these design methods everywhere, of course, but everywhere where there is a good reason to use it, we’re going to try to do it.”
SouthField has its own special stormwater challenges. The land on which the mixed-use development, a master-planned community, will sit was once the South Weymouth Naval Air Station. The station had its own set of existing stormwater control measures, a series of concrete box culverts, concrete pipes, and drainage ditches. Unfortunately, these stormwater devices are hopelessly outdated and do nothing to filter or treat stormwater.
Brewer and his fellow engineers had to work around these existing structures when creating their own stormwater management methods. The crew relied on everything from ponds to biofilters and bioswales to bring the site’s existing stormwater measures up to date.
|
Photo: Filterra |
| Installation of an underground drainage and treatment system |
“We are working around existing systems that were, in a lot of cases, installed 60 years ago,” Brewer says. “They are not up to today’s standards of stormwater treatment. We are basically trying to accommodate the existing systems and improve them. There were no water-quality measures on the base. But water quality is a big deal now, especially since the site has a lot of wetlands that surround it.”
Brewer is far from the only engineer relying on a complete toolbox of stormwater management tools. Today, erosion control pros can choose from the traditional products—bales and silt fence, for example—to ones that are more specialized—such as underground filtration systems that come complete with their own aboveground trees and shrubs—depending on the size and scope of their jobs.
This is good news. Federal and state regulations have grown far stricter in recent years when it comes to stormwater management. Municipalities now realize how important it is to keep their waterways—the rivers, streams, lakes, and ponds that often abut construction sites—free of suspended solids. Construction crews found violating the regulations spelled out in the National Pollutant Discharge Elimination System (NPDES) requirements face both heavy fines and bad public relations.
To prevent that killer combination, engineers and contractors, such as Brewer, are not just relying on one stormwater control measure. They are using everything they have, products designed for both pre- and post-construction work phases, to prevent suspended solids, oils, and other pollutants from running off their sites.
“Contractors are more in tune with the need to control the stormwater on their sites,” says Jamie Ringenbach, president of Naperville, IL–based Inlet & Pipe Protection; a company that manufactures filters and filter baskets. “The EPA is coming out and testing rivers and lakes adjoining subdivisions. Everyone is aware of it. Contractors have update meetings on NPDES and the fines that can be levied against them. The awareness is there, and we are starting to see more enforcement forcing contractors to pay more attention to their stormwater management plans.”
|
Photos: Inlet and Pipe Protection |
| Ponding around an inlet due to a clogged surface filter fabric under the grate |
|
| Clogging creates a drain stop |
Brewer, along with engineers across the country, is providing examples every day of this new approach to managing stormwater runoff.
Big Doings in South Weymouth
Kimley-Horn and Associates has been working as a subcontractor on the SouthField project in South Weymouth for five years, and Brewer expects the company to remain involved with the project for at least that many more.
These days, Kimley-Horn engineers are tackling the civil engineering aspects of the project for developer LNR, designing drainage systems, landscaping, interior roads, and ponds—all the elements that will help create a final project at SouthField.
“This is an impressive development they are creating here,” Brewer says. “This is happening across the country with the military base closings that are leaving all this great land available. Developers are coming and taking something that is rundown, something that is no longer usable, and transforming it into a great community.”
Much of Kimley-Horn’s work now is focused on capturing and treating site runoff.
This is especially important at SouthField, which is designed to function as a fully sustainable development. SouthField is located directly off a major commuter rail line. Because of its mix of housing and commercial, residents don’t have to jump into their cars to get to restaurants, shops, and entertainment.
To maintain the environmentally friendly aspects of the development, the engineers at Kimley-Horn must make sure that they capture and treat stormwater runoff in a “green” way, which is why many of the tools they’re using for the job are biologically based ones.
Kimley-Horn recently finished design work on the renovation of an existing major roadway in the SouthField project. The developer wanted the roadway widened, and also requested the installation of bike paths and sidewalks along its side. Wetlands surrounded the road on both sides.
The challenge was to install stormwater management devices along the newly improved road that were both aesthetically pleasing and functional. The developer planned for the newly widened road to serve as one of the project’s main entrances; it had to look nice.
“The developer wanted to make a splash with this roadway,” Brewer says. “It had to look attractive. At the same time, we had to be in compliance with the conservation commission. We had to come up with a way to not only widen the road, but to work in stormwater management.”
To do this, Kimley-Horn designed grass-lined bioswales that construction crews placed along the lowest spots of the widened road. Crews filled the spots with a highly permeable engineered fill and installed at the bottom of it a perforated drainage pipe surrounded by stone. The pipe was designed to discharge water into an existing inlet and into the surrounding wetlands.
|
Photos: Inlet and Pipe Protection |
| Inlet filters can be installed under the grate. |
|
| Inlet filters remove silt and other pollutants from water runoff. |
Stormwater then flows toward the low spots along the road, ponds up in the bioswales, and seeps through the engineered fill. It travels through the corrugated pipe and, now treated to current water-quality standards, is discharged into the surrounding wetlands.
In other locations, the developer called for attractive curbing. This meant that Kimley-Horn engineers would need a stormwater solution other than bioswales. In these locations, the engineers instead went with the underground drainage and treatment systems created by manufacturer Filterra.
These bioretention systems include underground drainage pipes and catch basins, topped with plants and shrubs. The systems are designed for urban stormwater management. All residents and business owners see are the plants. They have no idea of the stormwater filtering devices operating below the surface.
As of press time, Kimley-Horn had already installed six Filterra units at the SouthField development, and was preparing to install six more.
Kimley-Horn is also preparing to create a series of ponds on the site to handle stormwater in a natural, environmentally friendly way.
“We have the whole toolbox open right now,” Brewer says. “We are open to every tool on this project.”
A Larger Toolbox
The Filterra units are just one example of the new—and, most would say, improved—products engineers have to deal with stormwater control and treatment.
The units are examples of post-construction low-impact development devices. They are also examples of decentralized stormwater treatment. Construction crews place Filterra units strategically throughout a development or urban area. This contrasts with centralized approaches where larger stormwater-treatment devices instead must be located, sometimes unattractively, at the end of a pipe or drainage area. These products are then responsible for filtering the water from a larger drainage area, meaning more opportunity for suspended soils to slip through.
“We call our units the urban solution,” says Terry Siviter, Filterra’s general manager.
The theory behind decentralized filter systems such as Filterra’s is simple: As the units are spread throughout developments, each unit is responsible for filtering the runoff in a smaller drainage area. Each unit, then, has to catch fewer pollutants, which means more effective treatment.
The maintenance is also minimal, Siviter says. Crews need only remove mulch about two times a year and maintain each treatment unit’s landscaping.
|
Photo: Inlet and Pipe Protection |
| Lack of maintenance and heavy rains can lead to clogged filter fabric. |
“What you have is a tree or shrub that is aesthetically pleasing,” Siviter says. “The units are easily accessed and maintained with simple landscaping tools. Wal-Mart and Target can maintain our system with their own contracted landscapers. They don’t have to deal with companies that vacuum treatment systems or use confined-space measures.”
The ease of maintenance is key, Siviter says. Too often, developers call for stormwater management devices and then forget about maintaining them. This leads to future problems.
“If you are not maintaining these units, including Filterra systems, ponds, and any other system you can think of, then we are really going backwards,” Siviter says. “A lot of these units are not being maintained. Developers might be creating hundreds of thousands of BMPs across the country that are now ineffective because no one ever maintained them. This can be a serious problem.”
Filterra units are attractive to many developers because they are considered a “green” approach to managing stormwater. But it can still be a challenge to convince contractors and developers to take a chance on the units, Siviter says. Many contractors prefer the more traditional methods and would rather not spend money on something they’ve not used in the past.
“It is a challenge to convince contractors to go above the bare minimum,” he notes. “We spend a lot on monitoring to prove that these units work. Contractors are doing their jobs. They want to get their permits as cheaply as possible. I don’t blame them for that. But this is changing with the NPDES Phase II requirements and the increased enforcement that comes with that.”
The NPDES Phase II requirements spell out six minimum control measures for municipalities. Developers and contractors who don’t meet the measures that apply to them are asking for fines that can sometimes be heavy.
One of the Phase II minimum control measures requires that municipalities create a program designed to educate the public about the impact of stormwater discharges on other bodies of water. This public education and outreach component must include suggestions for how members of the public can help prevent stormwater pollution.
Phase II control measures also require that permittees have a procedure for giving the public an opportunity to participate in both the development and implementation of the stormwater program.
Municipalities must develop a plan that includes devices that locate and eliminate discharges into storm sewers that come from sources other than stormwater itself. The plan must include a map of all outfalls.
A fourth requirement is that municipalities design regulatory devices and best management practices (BMPs) that reduce or prevent other pollutants associated with construction activity.
Under the NPDES Phase II regulations, municipalities must also create a program of post-construction stormwater management devices. These devices must reduce the amount of pollutants in stormwater runoff.
|
Photos: Inlet and Pipe Protection |
| Below-grade installation of inlet filters |
|
Finally, the requirements mandate that municipalities must create operation and maintenance programs that prevent or reduce pollutant runoff from municipal operations.
These are just the minimum requirements. Some municipalities already require more strenuous measures to control runoff.
To many manufacturers, this is a good thing. More powerful stormwater devices, they say, mean less pollution entering the country’s waterways. Now, they say, it’s just a matter of educating developers and contractors on more efficient and effective ways to control runoff.
“There is still some education going on in the field about how important it is to use products that actually do the job better,” says Alex Marks, general manager of Grafton, OH–based Filtrexx International, a manufacturer of several stormwater filtration devices.
“Most contractors do get the ‘ounce of prevention’ mantra,” Marks says. “But it often comes down to the bottom line for a lot of these guys. They are still looking at the bare minimum of what they need to do. If they can get away with just hydroseeding a slope, that’s what they’ll do. They’ll do that instead of looking at a more effective way to stabilize that slope.”
The Right Tool for the Job
Bill Becker, owner of Siltmaster based in Crystal Lake, IL, is one of the contractors who does get it. He prefers to use the right product at the beginning of a project to help prevent problems in the future.
Becker’s company is now one of the subcontractors on the expansion of Rush University Medical Center, an academic medical center in Chicago. In August 2007, he and his crewmembers installed a dozen FleXstorm inlet filters manufactured by Inlet & Pipe Protection.
Becker chose these products because they effectively filter out silt, solids, and other pollutants from water runoff. Maintenance is also low on the product.
“We use them on every residential site I’m working on now,” Becker says. “I’ve never had anyone complain about these, not once. Once I convince the contractors that these are the products they need to use, they are more than happy with them.”
Becker considers FleXstorm filter baskets as replacements for the fabric that contractors often use to protect inlets from stormwater. If a construction site is hit with heavy enough rains, the water dumped on the job site can overwhelm traditional fabrics. The water simply doesn’t pass through the fabrics quickly enough.
During especially brutal winters, such as the one that many Midwestern and Northeastern states have experienced in 2008, a construction site may see many thaws and refreezes. If it happens to rain during the thaw, and then temperatures drop 20 degrees in an hour and everything freezes again, the fabrics tend to plug up. There isn’t enough time in such instances for water to move through the fabric.
While products such as FleXstorm may cost more than some older, less effective stormwater control devices, contractors should realize that the more efficient products will save them money in the long run, Becker says.
“All it takes is one lady going out of her house for a cup of cappuccino on a Sunday morning to have to drive through a deep puddle of backed-up water for there to be big trouble,” Becker says. “That’s what contractors have to remember.”
The problem is that too many contractors are still focused on upfront costs, and are willing to overlook potential long-run cost savings, not to mention the reduction of frustration, that better-designed, more effective products bring.
“With the housing market the way it is now, all the contractors are trying to scrimp and save,” Becker says. “The big thing I always tell them is that while a product may cost $100 now, it could save you thousands down the road in having to flush out your storm sewer line or if you get contamination in your pond. The Army Corps’ fine could be tens of thousands of dollars. The price of the product is pretty irrelevant compared to what could happen down the road.”
The Holistic Approach
Alex Marks says that with the variety of advanced products available for controlling stormwater, there is no reason for engineers and developers not to take a more holistic approach to capturing and treating runoff.
Filtrexx International manufactures several types of products designed to replace traditional silt fence, straw bales, riprap, and sediment ponds; products such as Filtrexx SiltSoxx and InletSoxx, are used both pre- and post-construction. The products use mostly composted organic media, and are usually filled on site.
“We take a look at the lifecycle of a raindrop with our products,” Marks says. “We need to treat that raindrop before it becomes an issue. We look at treating all those raindrops all the way down the line. We try to back up the hill and decide where we can do the most with as little as possible.”
Contractors need to realize, he says, that while federal and local governments usually don’t require them to use a specific product or method to control stormwater, they do require them to use something that is effective.
“You will have to spend a little more upfront with our products,” Marks says. “But in the long run, you might end up saving money. Maybe the guy who has to hydroseed his site five or six times may be willing to consider a new approach.”
Doug Caldwell, president of River Valley Organics in Wrightsville, PA, is one who uses Filtrexx’s SiltSoxx as a replacement for traditional silt fence. He estimates that his company installs more than 100,000 linear feet of SiltSoxx every year on the various construction projects he’s called in on.
“It’s good business for us to install these,” Caldwell says. “It works better. Our clients, because of the increased focus on stormwater management, are looking for better products. Filtrexx fits that bill.”
Rob Carrothers, owner of Soil-Tek of Mid-America, in St. Louis, also uses SiltSoxx as a replacement for silt fence.
Carrothers likes how the product works: When a ditch gets saturated with silt-filled water, the product retains the silt and allows just the filtered water to pass through. Because the product is three-dimensional, the wind doesn’t knock it over as easily as it does silt fence. At the end of the project, Carrothers can slit the sock, incorporate the compost inside it into the soil, and plant vegetation over it.
“We use it every day,” Carrothers says. “The majority of the municipalities we work in require us to install a pretty large device to control stormwater. These work well.”
Friendly Environment, based in Shelbyville, TN, offers its own stormwater-management product, the Erosion Eel. The geotextile tube, filled with shredded rubber chips, is an extremely effective filter of polluted water, says Kevin Wolfe, principal engineer with the company.
Contractors are currently using the Erosion Eels on Department of Transportation projects in Virginia, large developments in Tennessee, and large utility projects.
The product incorporates two levels of filtration, Wolfe says. First, it slows down the flow of water as it moves through the bag. About 60 to 80% of solid materials are left behind during this process.
Whatever solids are left is filtered out as the water moves through the internal filter material.
“We are still running into some contractors who are trying to get by doing as little as they can,” Wolfe says. “But, by and large, we are coming across more and more contractors who are more environmentally conscious. A lot has to do with regulatory agencies really stepping up and becoming more aggressive with enforcement. That pressure has gotten the attention of contractors. They are looking for something that will work.”
Chris McCormick, owner of McCormick Equipment in Pleasantville, IA, the manufacturer of the Silt Fence Plow—a machine that allows contractors to install silt fence faster and more effectively—says he, too, has run into contractors who are only interested in the cheapest stormwater control measures they can find.
But this is gradually changing, he says.
“In areas where there has been very little enforcement of regulations, yes, it can be hard to convince contractors that they need something like this,” McCormick says. “But if you’re talking with someone in an area where the EPA has given out fines, where they don’t tolerate the poorly built silt fence, then contractors are more open to the idea.”