Buyers Guide 2008

The Evolving BMP

Testing the performance of stormwater treatment devices

They’re all here, spread across the 1-acre facility at the University of New Hampshire Stormwater Center: swales, ponds, sand filters, treatment wetlands, hydrodynamic separators, and a host of proprietary products all designed to keep sediment from mixing with stormwater runoff.

Every year, about 500 visitors tour this site, located in Durham, NH. When they do, they get a firsthand look at how rapidly the world of stormwater best management practices, or BMPs, has advanced. Today, highway department officials, developers, contractors, and engineers have seemingly unlimited options for preventing sediment from contaminating the water that runs off their building sites. They have what seem like hundreds of choices to rely on for meeting the stormwater BMP standards set out by state and federal regulatory agencies.

This is good news. Ever since Phase II of the National Pollutant Discharge Elimination System (NPDES) stormwater program took effect, engineers and contractors working on smaller sites have faced the prospect of heavy fines for violating the regulations set out by their local environmental agencies. The vast array of stormwater products gives these builders, planners, and engineers the best possible chance to meet these regulations and avoid fines that could impair a project.

But all this variety brings a serious problem, too: How do engineers and developers choose the right product for the right job? Who’s to say what stormwater product works best at containing or treating runoff from a 100-space parking lot surrounding a new supermarket? Who knows for certain what product best prevents the oil and gas that drains from a municipality’s vehicle repair shop from mixing with rainwater?

That’s where the Stormwater Center comes in. The facility tests stormwater products side by side, determining their strengths and weaknesses. At any time, the facility’s engineers are studying about a dozen different stormwater systems, putting them through rigorous tests to see exactly how effectively they prevent dirt and sediment from mixing with runoff.

But even here, officials with the university’s Environmental Research Group are often overwhelmed at the pace at which new stormwater products are introduced.

“It is absolutely a challenge to keep up with the way this field evolves,” says Robert Roseen, director of the Stormwater Center. “There is a phenomenal amount of growth every year. From the manufacturers’ side, it seems there is about a 20% to 40% market growth every year. There are always new products in the field. We try to act as the Consumer Reports of the stormwater industry. But it certainly is not easy keeping up with all the new products.”

Greater Demand
There’s a big reason the number of stormwater products seems to grow so quickly each year: demand. Engineers and contractors are constantly seeking out new products that help them meet BMP requirements. And they’re searching for products that not only meet the specifications drawn up by their local regulatory bodies but also are easy to use, inexpensive, and flexible.

As long as this demand remains, the companies that manufacture and develop new stormwater products are going to remain busy.

T.J. Mullen, president of Best Management Products in Middle River, MD, says the increased regulations—and the resulting drive to produce innovative new stormwater products—are good for everyone.

“They are certainly good for the industry,” Mullen says. “They’re good, too, for the environment and for everybody who lives in a community that has a discharge of stormwater that could negatively impact them. There is more need for common-sense solutions to some of the problems that stormwater brings.”

Mullen’s company produces the Snout, an oil, water, and debris separator. Contractors install the products after construction is finished to make sure that the stormwater that drains from their sites is clean. Mullen says he’s seen a greater demand for his company’s separator now that contractors face the reality of serious fines under NPDES Phase II.

“For the contractors, meeting these BMPs is now a more serious issue,” Mullen says. “They see them written into the specifications of the projects they are working on. Today, contractors are more involved with the onsite conditions. They are dealing more directly with manufacturers like us, asking for advice or giving us suggestions on the design end. That’s been a change in the last couple of years.”

Even fines, though, don’t guarantee that contractors, municipal officials, or engineers are fully aware of all the latest advancements in the stormwater industry. Just ask Robert Maestro.

Maestro is the owner of Occoquan, VA–based Hydrologic Solutions, manufacturer of the StormChamber, an open-bottomed high-density polyethylene infiltration chamber BMP. Even though his company’s product is relatively inexpensive, is easy to install, and meets BMP regulations, there are still several builders and engineers who don’t know that the StormChamber exists, Maestro says.

“We are continually amazed at how many people, engineers, still don’t know that plastic stormwater chambers exist,” he notes. “It’s amazing. We run across it frequently. A lot of the people in the industry don’t have time to go to the conferences. They don’t have time to read the journals. But it is surprising. Even with municipalities, the same is true. It becomes an educational process. That’s basically what we try to do: educate people.”

The challenge for contractors and engineers is to discover products like the StormChamber that allow them to adhere to the regulations without spending a small fortune.

Does It Work?
The first question a contractor or engineer will ask about a stormwater product is the crucial one: Will it work while at the same time meeting local BMP regulations?

Fortunately, that’s the same question that Roseen and his peers at the Stormwater Center ask.

“Sometimes it’s hard for states to write new products into their specifications. Some states are way ahead of their time and others are not,” Roseen says. “There is a perception that every new stormwater system has to be fail-proof. But that’s a hard standard to meet. New products just don’t have that long track record yet. Many municipalities are looking for that kind of track record. They figure that they have a large capital investment in a project. They want a product that they know they won’t have to worry about for the next 20 to 30 years. The problem is, no new system can meet that standard.”

The manufacturers of stormwater products, then, rely on facilities like Roseen’s to prove to end users and municipalities that their products really do work as advertised.

Currently, the facility is testing all the major categories of stormwater measures: traditional BMPs, low-impact development (LID) techniques, and some of the more innovative proprietary BMPs. Tests are conducted at a large commuter parking lot at the University of New Hampshire, where researchers determine how well the products treat water runoff on 1 acre of impervious surface during a 1-inch rainfall event. The parking lot has a traditional stormwater management system consisting of catch basins and piping that discharges at the head of the facility. At this point, university researchers split the water flow into equal streams that are sent to each of the systems the Stormwater Center is testing.

Having each of the systems face the same storm events and contaminant loading is key, Roseen says. It’s difficult to evaluate how different products work if they’re not operating in the same conditions and facing the same challenges.

“Different types of storms and contaminant loadings present different problems,” Roseen says. “At our site, everything is normalized, the storms, the contaminant-loading duration, all of that.”

Here’s the obvious question: Which stormwater product works best?

It’s not surprising that there’s no one right answer to that question.

Stormwater products must work well in their environment. Certain products perform better, then, in hot, arid conditions while others perform more effectively in colder climates. Some systems are better at growing vegetation, a must for areas where aesthetics are important. Others don’t grow vegetation at all. This can be fine if the stormwater products are located in an area not seen by the public.

So those looking for Roseen and his team to provide them with a be-all, end-all recommendation for the perfect stormwater product are bound to be disappointed.

“Are the products getting better? That’s too big a question to generalize,” Roseen says. “There is no one silver bullet that does everything. There are variations of performance, suitability, and where you might place a product. The top-performing systems, for instance, are usually the filtration systems. But those are very large systems and are not feasible in many locations.”

The message here? Engineers, contractors, and municipal officials need to consider everything—the results from performance tests, the environment in which a product will be operating, the need to grow vegetation after construction, the cost, the ease of use—before deciding what stormwater solution will best meet a project’s BMP requirements.

“The most positive aspect of all this is that we really are struggling to keep up with inquiries from end users,” Roseen says. “I think it’s a positive that there is so much interest in our results. It does show that people are learning more about how important stormwater management is.”

Clean Runoff in Dallas
When municipal officials in Dallas asked BDS Technologies to develop a stormwater system that would provide clean runoff from the city’s service centers and auto pounds, the engineers at BDS researched several BMPs. Their final decision? The StormTrooper, a stormwater interceptor manufactured by Houston’s Park Environmental Equipment Co.

The city now relies on StormTroopers in the Dallas auto pound and in two service centers, where city mechanics work on Dallas-owned vehicles such as police cars and highway department equipment. It’s important that the stormwater solutions in these facilities work as advertised, because the vehicles stored there often leak transmission fluid and oil. Rains could easily whisk these chemicals into the city’s sewers and water supply, something no municipal official wants.

Freddie Guerra, vice president with BDS, says the decision to go with the StormTrooper was one made after his firm considered all the important elements: The product had to work well, had to be easy to maintain, and couldn’t boast a budget-busting price tag.

“This product was just the right solution for this case,” Guerra says. “Just looking at the maintenance and operational aspect of it, this was the right product. It has a separate control structure so that it’s easier to control all the debris, all the gloves, cans, and leaves. It is easier to maintain because of that aspect.”

It’s little challenge for city officials to make sure that the StormTrooper is working the way it’s supposed to. To make sure that the product is working properly, engineers need only flip off the StormTrooper’s manhole cover. This reveals a baffle between two compartments. The first compartment should always be holding the debris from the parking lots. The second should be clean. If this is the case, the machine is working properly.

The product has been working at the city auto pound for more than a year and a half, Guerra says, and at the two service centers since the fall of 2006. Dallas is now planning to have four more StormTroopers installed at four additional city-owned service centers.

“We’ve all in the industry expressed interest in installing separators like this in parking lots and facilities. They just work very well in preventing contaminants from getting in stormwater runoff,” Guerra says. “Fortunately, more municipalities are now agreeing with this. Here in Dallas, I think one driver of this acceptance is the city’s outreach programs, their stormwater management program. The other is the fact that people are so much more aware now of how runoff impacts the environment.”

Pat Schrum, director of sales and marketing with Park Environmental, can attest to this. His company introduced the StormTrooper in 2001. Since then, Park has sold about 365 units, mostly in the Houston area.

Demand increased after the NPDES Phase II requirements went into effect, Schrum says. Schrum says company officials at Park studied the new regulations and developed a product that would meet the regulations in Houston or Harrison County, the county in which it sits.

“People are so much more aware of products like ours now,” Schrum says. “The engineers are spec’ing it on just about every project. It is not easy to change BMPs once they have been turned into the City of Houston or Harris County. But they will change them for the right products.”

Less Expensive, Easier to Use
BaySaver Technologies Inc., based in Mount Airy, MD, began in 1996 by offering a separator product to help engineers combat stormwater runoff. The company now also offers a cartridge filter product.

Rex Hansen, a company vice president, says he’s noticed a shift in recent years: Contractors are more interested in finding the right stormwater BMP than they are in throwing in any product that they can get away with.

Of course, the reason for this may not be that contractors have suddenly become more concerned with the environment and the impact of their projects. They might be more worried about violating stricter BMP regulations.

This trend, though, has encouraged positive changes in the stormwater BMP industry, Hansen says.

“The regulations are getting more stringent all over the country now,” he says. “States are asking for higher levels of performance. Those states that had virtually no treatment requirements are now creating tighter regulations. The combination of increasing regulations and the increasing performance of BMPs is a good one for the environment and for our industry.”

Companies that manufacture stormwater systems are now working to produce value-added products that offer maximum benefits to end users, Hansen says. Before, companies might have been content to offer stormwater products that were effective but were very expensive to install. Now, thanks to greater demand and improving technology, companies are developing products that are less expensive to install and operate but still provide the same or higher levels of treatment.

To do this, companies such as BaySaver talk not only with members of the engineering community but also with the contractors—the end users—themselves. This ensures that whatever new products or product enhancements BaySaver develops will meet the needs of the people who are going to be actually installing them.

“If we only sought feedback from the engineering community, we would miss out on how our products truly need to work in the actual field,” Hansen says. “It’s important to relate to the experiences that the contractors have had. We need to make sure that we create products that are going to be easy for our contractors to work with.”

What have Hansen and others at BaySaver learned from their conversations? Smaller is better. Products that are flexible, that can adapt to different situations and environments, are also much desired.

The flexibility is important. Today’s most sought-after stormwater products are flexible enough—and do enough at a low-enough cost—to meet the BMP requirements of as many states and jurisdictions as possible.

“Contractors have to worry about so many different sets of regulations,” Hansen says. “The local bodies are different state by state. Some divide their regulations by watersheds, some by counties, some by regional water-quality boards. This means you can’t take a broad-brush approach to solving a problem. You can’t just go with something that meets one requirement. You need a product that works with everyone. That could be 500 different entities or it could be 5,000.”

Some manufacturers are frustrated by the wait-and-see approach taken by many state and local regulatory boards. Too many agencies, these manufacturers say, are too cautious when it comes to writing new BMPs into their regulations.  This not only hurts those manufacturers willing to develop something new but also hurts contractors who are prevented from trying new technology that could make their jobs easier and less expensive.

Take the case of Hydroscreen, a manufacturer based in Denver. Since 1999, the company has been inventing, patenting, and selling wedge wire screen assemblies that remove leaves, sediment, and debris that flow over them. The screens are self-cleaning and so require little maintenance.

The company’s screens have played prominent roles in some high-profile projects. For example, Hydroscreen was called upon to provide some emergency services to the Princess Diana Memorial Fountain in downtown London’s Hyde Park. The fountain features water that flows into a small pool before running down both sides of an elliptical form and into a pool at the bottom. From there, the water flows by pipe to a screening vault and then into a tank where it is pumped back to the top of the fountain.

This design worked well when the fountain first opened. But then leaves began to fall and blow into it. The leaves quickly clogged the screen baskets, causing water to flood the vault and surrounding grass.

To solve the problem, municipal officials installed Coanda wedge wire screens from Hydroscreen. After installation, officials turned the fountain on and watched as the water began to circulate down the fountain, out, over, and through the screens into the holding tank. To test the screens, maintenance workers dumped eight large bags of wet leaves into the fountain. The screens captured all the leaves.

But even with such success stories, Robert Weir, owner of Hydroscreen, has found it is often a challenge to convince regulatory bodies and contractors who haven’t tried his wedge assemblies to take a chance on them.

“The fact that I’ve filtered drinking water through a screen—got it to the point where it was absolutely fine to drink—doesn’t matter to them,” Weir says. “They want to know how Pasadena uses it. Well, they don’t use it yet, but they will. The possibilities of this product are exciting.”

Weir, like others in the business of manufacturing BMPs, says he expects both contractors and regulatory agencies to be more willing to embrace alternate products in the future. For now, though, Weir will continue pushing his product’s benefits, hoping to interest as many builders and contractors as he can.