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Are your own foregone conclusions preventing you from using the most effective solutions to your surface-water-quality challenges? By Carol Brzozowski
Just a few years ago, the popular business press was loaded with articles telling us that if we were still doing business the same way we had been just 18 months earlier, chances were good that we were operating under obsolete and quite possibly inaccurate assumptions. Such, we were told, was the rate of change in the business world due to advances in technology. Most of us survived that era despite our insistence on sticking with our existing assumptions about the best way to get the job done, regardless of the technological changes that were popping up everywhere. Yet today we have grown comfortable with and take for granted many of those same changes. Times are different, technology has progressed, and we have changed too. The advances in understanding and dealing with our stormwater challenges have been similarly profound. Technologies and solutions that did not exist just a few years ago are proving effective in many situations where they've never appeared before. Many communities are looking at these advances and remain open to the possibility that a relatively new solution—such as a manufactured stormwater treatment system—might indeed be an improvement over a "traditional" or land-based approach and might well be just what their situation calls for. Other communities are more resistant to considering something new. Why the reluctance to consider these new approaches, and what is the cost of that reluctance? Roots of Resistance There has been what some in the industry perceive as an institutional bias against manufactured systems; many long-standing municipal codes throughout the country do not include them as options, and heavy-hitting entities like EPA and the American Society of Civil Engineers (ASCE) only recently began considering them in their third-party, independent evaluations. "It's underground, and there's that maintenance issue. Those are the two battle cries," says Michelle DeLaria, the stormwater-quality coordinator for Jefferson County in Colorado, adding, "The functional aspects of a wetland are underground, too." Others in the industry concede the challenge is rooted in a lack of education. When it comes to surface-water-quality management, are you truly exploring every option? The ever-expanding array of solutions to water quality means systems or technologies might now be in place that didn't exist just a short time ago, and assumptions or beliefs regarding their performance might not be based on today's realities. Ray Vaughan, stormwater manager for Columbia, SC, believes the resistance to underground stormwater treatment systems is indeed rooted in not knowing the different types of units in the marketplace and how they perform. "It's an education process," he says. "It's learning these devices are out there and some of them are very efficient." Columbia began using them 10 years ago as information on them became available, he says. Many communities do not recommend manufactured stormwater systems in their guidelines. One such entity is the Denver Urban Drainage and Flood Control District. Its Urban Storm Drainage Criteria Manual makes no mention of underground systems. Ben Urbonas, manager of the district's Master Planning Program, says that although the region does not ban underground facilities, there is a recommendation against them, which Urbonas attributes to water-quality issues and a stipulation that all new best management practices (BMPs) provide a water-quality capture volume. "We have a policy memorandum on our Web site saying that there are cases for small retrofit sites where having this is better than having nothing," he notes. "We suggested the local governments explore the possibility of using them under those circumstances, but in major development, there is really no good excuse for having underground systems when you can actually incorporate aboveground systems to do the same, if not a better, job. "It all boils down to what your goals are for stormwater management," he says. "If your goal is to do overall stormwater management that includes mitigating some of the effects of increased urban runoff, then you really need to start looking at some kind of capture and release systems that trickle out the water in less energy levels." The policy memorandum states that the district does not endorse, nor discourage the use of, any particular device. "Their use and approval could, in many instances, provide more water quality benefits than would be there without them," the memo states. "In addition, the evaluation should take into consideration the underground facility's stormwater quality enhancement features and the near and long-term maintenance requirements the facility will require. Finally, underground facilities should be considered for use only when 'significant' redevelopment or new development is not the dominant land use change." Rob Lambert, an engineer with SITE Engineering Concepts in Wayne, PA, says the approval process often depends on the characteristics of the particular site where a manufactured system is being considered. "I don't think there is one solution that will fit every site. That's why they hire engineers to design them. It is very site-specific," he says. That resistance is often based on a heavy reliance on the "tried and true approach," Lambert says, adding that he agrees that maintenance and a lack of data also are concerns he hears. "The tried and true systems—the way it's been done for 50 years—is the way a lot of engineers like to see it done, whereas a manufactured system is something that is on the newer end of the spectrum," he says. Manufactured Systems Gaining Acceptance However, some government entities that initially considered only land-based options have allowed for manufactured systems in projects and are pleased with the results. Consider these case studies in Conyers, GA; Harveys Lake, PA; and Vancouver, WA. Conyers, GA "The business community had primarily experienced flooding problems," says Karl Kelley, deputy director of the Department of Public Services and Engineering for Rockdale County. He says the county and city combined grants toward the effort. "They didn't have very much knowledge about water quality. But they were interested in flooding problems, so what started out as a project that was to replace sidewalks, repave streets, and plant some trees wound up being a project that dug up about a mile of very narrow old-town city streets all the way down to the stormwater structures and replacing them all," he says. The only approved solutions at the time had been land-based options such as wetponds. However, those types of structures presented a challenge because of the proximity of the railroad bed on the lower side of the project and the need to retain as much parking space as possible. "We had to deal with the railroad company, which is sometimes intractable, and the bottom line is we had a very small area in which to work," Kelley says. "We did not have the real estate available to us in which to build a land-based detention pond, and we certainly didn't have the green space to do anything from a filtration standpoint in terms of water quality." Kelley's team considered the options as engineers and vendors of manufactured systems presented product information and even offered to take the systems out if the municipality was not satisfied. The team opted for two different types of manufactured systems. Kelley, who came from the private sector as a developer and builder, calls himself an "atypical bureaucrat." "I had a different perspective when I came to work here, and that is one of cooperation and flexibility you don't typically find in a local government bureaucrat who is afraid to stick his neck out," he says. "We were looking at other [stormwater] approaches after I came to work here six years ago, but there really wasn't anything in our code that allowed that, so every time we approved one of these things [manufactured systems], we were sticking our necks out." The Conyers project presented an opportunity to evaluate which products would be allowed for use in Rockdale County, he adds. "There were two competing devices we had a lot of contact with," he says. "We decided that as a part of our design work in this project, with their cooperation, we would design an underground tank—a series of three very long 60-inch pipes that would work as an underground storage tank. The quantity issues were the controlled output, but we would treat the water before it got into these tanks and it was coincidental that the design allowed us to do this." One device captures a bit less than half of the stormwater runoff from the entire town, and the other device captures a little more than half of it. One device is vertical; the other a horizontal vortex-based device with a chamber-based system that is heavier but considered by Kelley to be sturdier. It's also a traffic-weighted system. The horizontal device requires less effort to plant into the ground and operates based on velocity changes in water. The installation has allowed the county and city to make comparative observations about manufactured systems. "One comparison was the cost, which is of importance to everybody," says Kelley. "Then there was the construction technique that it required to get these things into the ground." Kelley's team approached the county's board of commissioners asking for funding to monitor the performance of the two devices over a period of a couple of years in order to obtain hands-on objective data. "The board agreed that if we could get these two manufacturers to put some money in for monitoring and help us monitor for a couple of years, they would fund this," he says. But after a while, the board pulled the funding. The manufacturers are doing their own monitoring, Kelley notes. Meanwhile, cities in surrounding counties that are "quickly moving up the stormwater curve" have approached Rockdale to see how the underground devices are working. The county has hosted meetings, featuring manufacturers' representatives, to help educate other local governments. "That's something we're proud of," says Kelley. "The bottom line is that these things really do work. One of the concerns these city businesses have is why are we spending all of this money on water quality? Water quality is of no concern to them. This is a 96% impervious area we're talking about. It's basically buildings, parking lots, and streets." But when business community members saw the baskets removed from the devices and noted how many floatables had been collected and how much oil was on top of them, "they were dumbfounded," Kelley points out. "Through the process of maintaining these things, we have educated these folks as to what the issues are when it comes to water quality," he says. "It's not just fecal coliform bacteria, phosphorus, and all of these runoffs from everybody's yard. It's heavy metals, oils, floatables." Harveys Lake, PA Additionally, the Pennsylvania Department of Environmental Protection (DEP) conducted a total maximum daily load (TMDL) analysis of the Harveys Lake watershed in early 2003, using the collected data. As a result of the studies, a 28.4-acre portion of residential land called Hemlock Gardens was identified as a site that generates a large nonpoint-source pollutant load of total suspended solids (TSS) and total phosphorus (TP) for the lake. To address these concerns, the Borough of Harveys Lake and the Harveys Lake Environmental Advisory Council were awarded a grant by the Pennsylvania DEP through the state's Growing Greener Program. As it was written, the grant called for a sediment basin to address stormwater issues. Princeton Hydro conducted onsite surveys and engineering analyses for a structural BMP for the Hemlock Gardens site. John Miller, senior water resource engineer for Princeton Hydro in Ringoes, NJ, took into account the lack of land availability, the presence of nearby utilities, and other factors and advised that a structural retrofit was the only feasible option. The selected BMP was a nutrient-separating baffle box in series with a water polishing unit, designed to accommodate onsite restrictions and reduce the TSS and TP loads that flow from Hemlock Gardens into a nearby tributary that in turn flows directly into Harveys Lake. The BMP was specifically designed to treat the nonpoint-source pollutant loads during one-year to 10-year storm events. It was installed in spring 2003. In August 2003, the borough, which will be responsible for the BMP maintenance, cleaned out the baffle box, removing 7.3 tons of soil, rock, and gravel. Meanwhile, Wilkes University staff and students have been collecting stormwater runoff samples as part of a BMP monitoring program. When the monitoring program is completed, the data will be used to assess the effectiveness of the manufactured BMP in reducing the TSS and TP pollutant loads entering the lake from the borough's portion of the watershed. That information, in turn, will be compared to the lake's TMDL, completed by Pennsylvania's DEP. Vancouver, WA Vancouver's approved BMP list included a host of natural treatment systems—including the biofiltration swale, wetponds, and filter strips—with the latter two requiring up to four times as much land to provide the same level of treatment. Two underground systems were on the list: a sand filter and a cartridge filter that uses a compost-based media to remove runoff pollutants. Although the sand filter was believed to offer a higher level of treatment, the issue of maintenance and installation became a concern. One of the restrictions Vancouver has for installation of stormwater treatment systems on private property is that the installed system come with a long-term maintenance program, which the sand filter system did not. Engineers opted for the cartridge filter with a compost-based media. The passive filtration system consists of an underground concrete structure that stores rechargeable media-filled filter cartridges customized to remove sediments, metals, nutrients, trash and debris, and oil and grease. The system manufacturer offered a long-term maintenance program. The system was cautiously approved for installation by the city, says Tadeusz "TZ" Zbiegien, an engineer with Mackay & Sposito in Vancouver. The city had previously allowed the product to be installed on an experimental basis, and upon receiving good reviews from the field, it gave his firm the green light to design the office building project using the product. "They looked at the swale replacement as removing public risk, because the swale was bordered by concrete retaining walls on both sides and close to the curb," Zbiegien says. "There was a potential risk that someone would fall into the ditch; we had to protect it." The success was so satisfactory that Vancouver also approved a similar installation at a music store across the street from the office building. Changing Codes Many in stormwater management are working hard to change antiquated municipal codes that do not include manufactured stormwater treatment systems as viable options. Michelle DeLaria is part of an effort to restructure the Jefferson County Storm Drainage Design and Technical Criteria Manual to include manufactured BMPs. "There were no flow-through BMPs in there, so we added that option to allow engineers to include those in their plans," she says, adding that parts of the manual had not been updated for five to 15 years. In Rockdale County, GA, the code allowed for land-based—but not manufactured—stormwater treatment systems. "The code has changed and is in the process of changing again," Kelley notes. He explains that in the late 1980s, the state mandated all communities develop a zoning map, a comprehensive land-use plan, and subdivision regulations. In 1984, Rockdale County adopted what essentially was a DeKalb County ordinance from 1966. "That's what we were operating under up until a few years ago," Kelley says. "Those kinds of codes didn't deal with water-quality issues. So we were operating under a code that was very antiquated, and when our codes changed in the mid-'90s, we got some progressive elected officials and progressive staff and we climbed the learning curve fairly quickly." The county is now in the midst of developing a stormwater utility with design and maintenance standards. "That will bring us up to where we're even with everybody else in terms of stormwater issues, where we haven't been before," Kelley notes. "We didn't allow manufactured systems in our code because our code wasn't even smart enough to know they existed. Now we do allow them." In New Berlin, WI, Eric Nitschke, a division engineer, says his city is working closely with the Wisconsin Department of Natural Resources (DNR) to ascertain what types of BMPs, including structural, are going to be allowed. "Ultimately, we're trying to meet standards they set for our municipality," he says. There is a more favorable view toward manufactured BMPs in conjunction with low-impact development methods and accepted nonstructural systems, where the manufactured BMPs can pick up the slack. Wisconsin's DNR is presently doing studies on manufactured units, and engineers like Nitschke anxiously await the results. "It's great to see the third-party testing, but third-party testing doesn't give us approval on our discharge permit," he says. "The Wisconsin Pollution Discharge Elimination System permit was issued to us last year, and that's what sets the standards." With the Wisconsin DNR permitting and even studying the effectiveness of structural BMPs, that gives engineers such as Nitschke a broader range of options from which to choose. But although codes are changing, the issues of maintenance and the lack of third-party independent data remains a stumbling block for some municipal officials. The Question of Maintenance It's the maintenance issue that concerns a great number of municipal officials and engineers. "If you're talking about the political aspects of why certain towns are favoring nonstructural BMPs or saying they want to steer clear of structural BMPs, I think the concern is that if it is in the right of way that handles a public drainage, their first worry is continued maintenance," says John Miller. Miller serves on the planning board for the city in which he lives. He also chairs a stormwater committee. In that position, Miller is sensitive to the concerns of municipalities. "One of our other worries is the variety of structural products," he says. "For me as a design engineer, that's a great thing, but from a town standpoint, it's why I always bring the head of public works into our meetings and also during any time we do a review of a project. "He's going to be the one who has to be familiar with how these things operate and how they need to be maintained," Miller says. "He has to have manuals for the products, and he has to have a parts list. He needs to know if something needs to be replaced or if he has to have confined-entry-space training. Where does he take the materials that are removed? Are they considered hazardous waste, or standard? There are always issues." Since the town in which Miller lives doesn't own a vacuum truck, that equipment must be rented out and factored in as an expense, Miller says. "He [the public works manager] has to know all of those things well ahead of time so he can get the proper budget for what he needs to do," Miller adds. Zbiegien acknowledges that maintenance plays a large role in the projects he designs for municipalities. "With private projects, an agency wants to make sure there will be proper maintenance of whatever is installed," he says. "They want us to write some kind of manual into the storm report on how this should be maintained." It's viewed favorably when a maintenance agreement accompanies a manufactured system, Zbiegien says. "It's secure, it's underground, and nobody else has entry to the system," he adds. "If you have the proper agreement, the agency will like it because it's going to be maintained properly. If there is not a specific maintenance agreement, then there is the risk that it's not going to be maintained properly and it's going to be forgotten." Lambert echoes that, and says sometimes property owners don't even realize they need maintenance until they have a problem. "They put it underground and forget about it, and the only time you hear about it is when something gets washed out or the system starts to fail, gets clogged, or is not working anymore," he says. "Then you go back and see that they haven't maintained it in four years and it's full of sediment because it's stuffed." As a stormwater manager, Vaughan considers maintenance a top concern. "Of course, you have to maintain land-based options also," he says. "You're going to have maintenance issues with either one of them. These units are a lot more efficient if you do have more frequent maintenance. With the large number of units we have in the ground, we are currently developing a tracking system so we know where everything is located and are setting up a maintenance system." Calls for More Test Data Zbiegien notes that it's not only a lack of information on manufactured stormwater systems that contributes to some agencies' resistance to using them, but also a lack of third-party independent performance data. "An agency tries to be a little bit conservative about any new products on the market until some checking on the system is done in the field," he says. "It looks for information and how practically the product will present itself in the field as far as water quality or detention." He cites an example from his own experience of trying to utilize catch basins in a project for a Washington county in which cartridges would be used inside the catch basins instead of a manhole or vault. Not allowed, some county officials insisted. Zbiegien's company contacted the manufacturer, asking for a letter of recommendation for the product. His company also wrote its own letter. Both were presented to the county's upper management. "They agreed to use it and watch it to see if in the future they'd allow it in a public right of way, because this was a private project," Zbiegien says. "I think in the future, they're going to see it's doing its job, and they're probably going to open the door for the public right of way for treatment." Time seems to be the deciding factor as municipalities look to see how manufactured products "beta test" in other applications. "We try to push for the right product for our client to benefit from this, but it's a long process," says Zbiegien. "We try to be as aggressive as we can while at the same time not burning the bridges with the agencies. It's a very balanced process." Zbiegien says that in his experience, government agencies operate conservatively. "They take a cautious approach to a new product," he says. "If a product is good, there is a huge chance it will be adopted very fast." An International Stormwater Best Management Practices (BMP) Database, developed by EPA and ASCE, offers field data records on 98 BMPs at 84 test sites, selected from more than 800 studies. Those BMPs include biofilters, detention basins, filters, hydrodynamic devices, oil and water separators, porous pavement, retention ponds, and wetlands. (The database can be found at http://www.bmpdatabase.org.) Only recently did the database begin to examine manufactured stormwater treatment systems. Kelley calls the database "wonderful" as a set of BMP performance and criteria. "But only recently have they gotten into the structural devices," he notes. Some states also offer test data. The New Jersey Corporation for Advanced Technology is a public/private partnership formed by a state directive to the state's Department of Environmental Protection to "establish an energy and environmental technology verification program for the selection, promotion, and commercialization of innovative energy and environmental technologies that have significant environmental benefit for the state." Values are assigned to various treatments such as vegetative buffers, swales, and wetponds. Manufactured systems must have their performance claims validated. "A product manufacturer can say they remove 80% of total suspended solids and under what conditions, such as so many gallons per minute, so many cubic feet per second. You have certain parameters of what you claim to do and then they'll run tests and verify that," says Miller. Miller says another factor is that even after a system is verified, some products do not meet the removal requirements required by the state. "If we go to the expense of using one of these things, I want to meet the numbers," he says. "We're finding the claims are a little lower than what's required. So either you're going to have to match the structural with the nonstructural to get the total removal required, or there's going to have to be modifications made or additional products used. Many are not meeting with what New Jersey requires." Unless products go through the verification system in New Jersey, they cannot be used in the state, Miller explains. "It's really a verification system that—although I think has its flaws—also provides a method for people to have their products evaluated," he says. "I know California and Massachusetts have their own verification programs. But it's very hard to do; there are so many different pollutants we're trying to treat and so many applications of these products that to have a simple verification statement is a difficult thing." With respect to more traditional systems, Miller says he believes agencies are being a little loose with their evaluation of what they treat. "I think they're cutting that process a little more slack because in a sense, from the goal of minimizing disturbance, some of these recommended practices do some of that as well as cleaning the stormwater," he says. Lambert says in his experience, it's usually the owner who wants to go the extra mile to obtain test data. "Not only with manufactured systems, but with any pollutant removal system, a lot of it is based on percentages and a free-for-all," he says. "Because of the specific nature of each system and how they vary, that manufactured system will probably have a better shot of standardizing it than an onsite system. If you look at extended detention wetlands and what the removal rates are for nitrogen and phosphorous and heavy metals, the system is designed slightly differently and the pollutant loading level coming into it is different, so the system behaves differently. "For a manufactured system, at least you have some more definitive answers on the way it's designed and in place, but still, the water entering the system is different. It claims it has an 80% removal rate; what does that 80% really mean? "There is no good standard test data," Lambert continues. "There are agreed-upon assumptions of how much is being removed without doing a lot of testing. How much is coming off of a parking lot? How much do you measure? What are the pollutants coming off of the parking lot?" Zbiegien says when test data are involved in a design project, his firm relies on a manufacturer to present it to a municipality. "We don't have expertise in testing," he says. "We're willing to rely on a product that will be acceptable to the county." Design Preferences In design preferences, Kelley figures that some engineers are somewhat skeptical of manufactured stormwater treatment systems until they are proven. "Any time you come out with a new product that falls in the realm of the public, civil engineers have a responsibility to the public to ensure their safety and welfare in civil engineering projects," says Kelley. "Most civil engineers take that responsibility very seriously." He recognizes manufacturers of stormwater treatment systems are keeping their prices low, offering incentives to get their products in place, and working hard to get monitoring information into the hands of local governments. "Most of the time, that has to be their own monitoring information, which is always suspect," he says. "But if they could get third-party monitoring or get the local government to participate in monitoring, that's a big help. "If I know, as a local government official, that a product is on the approved Georgia Department of Transportation listing of acceptable items, then I'm going to have a much better feeling about that product if somebody wants to come and try it in my county." However, Kelley acknowledges that a government approval process can take years. He himself was part of an effort that created the Georgia Stormwater Management Manual over a three-year period in conjunction with the Atlanta Regional Commission, an intergovernmental planning agency in Atlanta. The ensuing two-volume document is approximately 1,100 pages long. Manufactured devices were included in it as an appendix. He points out the document is less than three years old. "This is the manual that almost every local government has adopted in terms of stormwater," Kelley points out. "It's a tough mountain to climb." DeLaria emphasizes that as a scientist with an ecology background, she believes in natural systems and preservation. "However, it's a fact of life in America that most of us live in urban areas, and we have to think about how do we do the best we can do when, realistically, we're not going to have the large-acre constructed wetland in the middle of New York City or Denver," she says. "So the pre-engineered, flow-through BMP people do have a point; they have a good product for some certain niche applications and I think their time is coming to where they're looked at seriously." DeLaria cites three scenarios where she believes manufactured stormwater treatment systems are ideal. "One is in urban redevelopment where a site is already developed to the maximum imperviousness," she says. "It's not really likely that any redevelopment is going to add that much more green space that is going to be functional for the purpose of having a large volume to let stormwater settle out solids." Putting in a manufactured device, she says, "is certainly better than some jurisdictions saying, 'It's underground so we don't trust it,' and not doing any treatment." A second application is in conjunction with an infiltration structure, DeLaria says. She points out that it's an expensive engineered solution to have to put an infiltration structure under a parking lot. "You're using a pre-engineered flow-through BMP to remove the sediment so the sediment doesn't slowly fill up an underground void space they don't have access to. That's another ideal solution, especially for communities concerned about groundwater loss. If they are trying to approximate postdevelopment hydrology with predevelopment hydrology and they go to an infiltration structure, these flow-through BMPs are ideal to use in conjunction with that to remove the sediment." A third consideration is mosquito habitat. "If a community is concerned with mosquito habitat and wants to get more of the structure underground and use this infiltration, they need to use a flow-through separator to get the sediment out." It's important "not to fill up an underground structure" to keep it viable. As land availability dwindles, a lack of space is driving most municipalities to consider manufactured systems where they previously did not. "If you are in a rural area and you have plenty of land, then [a manufactured system] would be more expensive than utilizing the land," says Zbiegien. "However, in an urban area where the land is very expensive and you want to utilize every square foot of it, then a manufactured system makes sense. "I would say 50% of what we design for is storm facilities underground, simply because most of our clients want the surface land reserved for other usage. It's basic economics. It's much easier for us to convince them to design an underground facility than it was before, when the land was much cheaper." Vaughan says that's also the case in Columbia, where a lack of land availability prevents some use of land-based applications. Though they are still used, Columbia also uses a lot of proprietary systems, he says. Columbia currently has 30 to 40 different manufactured devices underground, with more going in. Vaughan says that although the city has no data regarding the devices' efficiencies or effectiveness, US Geological Survey test results from the area are expected over the next couple of years. He concedes, however, that if land cost weren't the issue, Columbia would opt first for land-based systems. "It depends on what kind of pollutants we're trying to remove, but we probably would use the land-based if the cost of real estate wasn't really tremendous," he says. With an increasing number of manufactured stormwater systems coming onto the market, Zbiegien sees the competition is a positive factor for engineers. "The prices get good and you have more products to choose from," he says. "But maintenance is the key word. If someone doesn't provide maintenance, you have to look for someone who does." In the end, De Laria asserts, it's not valid to hold off in allowing the installation of an improvement because of a bias or to imply that no treatment is better than treatment with a manufactured system. "That's not where this field needs to go." The technologies are here to stay, and with time will even be taken for granted along with so many other technological advances. Remaining open to the possibilities and finding the best places to employ them is our best strategy for meeting the many stormwater treatment challenges we face. Frequent contributor Carol Brzozowski is a journalist in Coral Springs, FL. SW November/December 2004
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