The advent of the National Pollutant Discharge Elimination System (NPDES) Phase II has brought a new direction to stormwater management design. Volume and quality have joined peak flow as design parameters, radically changing the design approach of the stormwater profession. Design elements used to mitigate the effects of land-use change are termed best management practices (BMPs). Many BMPs utilize volume control and extended detention to replace lost recharge, reduce increased runoff caused by the loss of evapotranspiration, and reduce nonpoint-source pollutants and peak flows. Recognizing the revolutionary nature of these changes and the need to study strategies to meet these goals, Villanova University in collaboration with the Pennsylvania Department of Environmental Protection (PaDEP) created the Villanova Urban Stormwater Partnership (VUSP) in 2002.
VUSP’s mission is to advance the evolving comprehensive stormwater management field and to foster the development of public and private partnerships through research on innovative stormwater BMPs, directed studies, technology transfer, and education.
- Research and directed studies will emphasize comprehensive watershed stormwater management planning, implementation, and evaluation.
- Technology transfer will provide tools, guidance, and education for the professional.
- The partnership goal is to promote cooperation among the private, public, and academic sectors.
Sustainable design, which requires consideration of future impacts alongside present goals, is now increasingly understood as a mandate. The detrimental cumulative impact of development on the natural systems is now proven (EPA 2006). This unintended consequence of growth gives urgency to the need for new and more sophisticated design approaches–both for new works and for retrofits. Regulations based on this premise require that each project must include consideration of all those affected: distant as well as local; future as well as present; natural systems as well as human. This consideration for sustainability requires new approaches and new tools (constructed wetlands and bioinfiltration basins, for example) that have not received as much attention and study as the more familiar systems made up of inlets and pipes. Investigating the performance and proper application of these new tools and sharing the findings with the community of interest are important roles for VUSP.
Stormwater management refers to the practice of designing to prevent or mitigate damage caused by changes in the hydrologic cycle due to land practices and building. Since the Commonwealth of Pennsylvania passed its Stormwater Management Act in 1978, the main focus has been flooding based, focusing on extreme event peak flows and detention-based methodologies. Since the passage of this act, it has been found that many other issues besides flooding are linked to land changes (EPA 2006), expanding the expectations for sustainable stormwater management. Design criteria now include accelerated river channel aggregation and degradation, runoff quality, protection of base flow, aquifer recharge, and flood control. While detention as a strategy does generally reduce flood peaks, it does little to mitigate the remaining issues (Traver 1983; Emerson, Welty, and Traver 2005). To address the entire spectrum of stormwater issues on a watershed basis requires a fundamental change in design and planning philosophy. The design, performance, and maintenance of BMPs is evolving, much like the use of “best available technology” matured within the point-source design community. To further complicate the issue, stormwater is linked to other issues to include water supply, total maximum daily loads (TMDLs), stream and habitat restoration, combined sewer overflows, and flood protection.
Seeking to create a long-term research and education effort to support this change in design philosophy and to bring together government, industry, and academia, Villanova and PaDEP cofounded the Villanova Urban Stormwater Partnership. A PaDEP Growing Greener Grant was awarded in 2002, funding the initial two years of operation. A research direction board was created, which included state and regional PaDEP representatives and county and conservation district officials.
The first task of the research board was to develop the VUSP mission statement, guiding its efforts as a “technical agent of change.” In 2003, memberships were opened to industry, and currently 10 design firms have joined, contributing to the direction of the partnership through the research board and pledging over $60,000 in yearly contributions. Current public funding sources include Pennsylvania 319 and Growing Greener grants as well as EPA support. This support does not imply endorsement of these projects.
Research and Directed Studies
Research and directed studies are focused on Villanova’s Stormwater Research and Demonstration BMP Park. As of May 2006, a stormwater wetland, a bioinfiltration traffic island, a porous concrete facility, and an infiltration trench have been built and are under study. Each of these sites is a retrofit, instrumented to facilitate study of runoff volume, peak flow, and water quality. Additionally, a recently rediscovered historic seepage pit is under study. Research is focused on the design, longevity, maintenance, and performance of the BMPs. Results are forwarded to the International Stormwater BMP Database (www.bmpdatabase.org), and the project has been incorporated within the EPA Section 319 National Nonpoint Source Monitoring Program. An equally important aspect of the BMPs is the introduction of these facilities to the public and profession so their value and functions are recognized. Educational signage has been installed to enhance the learning experience, and a Web site has been created to facilitate technology transfer.
Stormwater Wetland. An existing stormwater detention basin on Villanova University property was converted into an extended detention stormwater wetland BMP using the design concepts presented in the Pennsylvania Handbook of Best Management Practices for Developing Areas (PACD 1998). The wetland was designed to treat water quality and to reduce erosive peak flows from runoff from large parking lots, university buildings and dormitories, roadways, and train tracks. The watershed draining to the wetland is approximately 40% impervious. The project has been published in EPA 319 Success Stories Part III (EPA 2002), and the wetland is currently the subject of a base flow, microbial source tracking, and an exploratory NOAA Coastal Zone Program grant. Results show that the wetland clearly dampens peak values of all flow and quality hydrographs for all flow events, and significant removal is evident from the base flow study. The site does hold and release chlorides over the spring and summer, to the detriment of the plantings. This project was funded with a Pa319 grant in 1998.
Bioinfiltration Traffic Island. An existing traffic island was retrofitted to create a bioinfiltration BMP. The contributing drainage area is approximately 1.3 acres and is one-half paved. Through infiltration, the BMP reduces downstream stormwater volumes, streambank erosion, and the introduction of nonpoint-source pollution to the headwaters of the Darby Creek. In 2005, 41.8 out of 47.9 inches of rain were captured and not released to the surface waters. Also in 2005, only seven events overflowed the outlet weir of the BMP. What is remarkable is that the smallest overtopping event was 1.13 inches of rain, more than double the volume of surface pool when averaged over the impervious surface. An article on the modeling of this site has been accepted for publication in the Journal of the American Water Resources Association in 2006. Surface-water-quality performance for the most part mimics the volume removal. This project was funded by a Growing Greener grant in 2001.
Porous Concrete Infiltration Site. A central pedestrian area of campus was reconstructed to create a porous concrete infiltration facility. Built in 2002, the original porous concrete surface failed and was replaced in the summer of 2003. A second round of limited material problems reemerged, which were addressed through replacement, as described in an article in the July/August 2005 issue of Stormwater (“Lessons in Porous Concrete“). This site is similar to the concept to the bioinfiltration traffic island; runoff from the site and surrounding buildings (approximately 64% impervious) is captured and infiltrated, decreasing the flows and pollution to a high-priority stream segment on the state’s 303(d) list. The site has a much higher capacity than the bioinfiltration traffic island because it overlies three large rock holding beds. Only a few storm events have overflowed the outlet weir over the project’s lifetime, and a current study shows the infiltration rate is a function of soil type, soil moisture, temperature, and depth. From the water-quality perspective, the contributing runoff is remarkably clean with the exception of chlorides from snowmelt operations. It has been found that vacuum street sweeper operation is critical in maintaining the surface porosity. This project was funded with a Section 319 grant in 2002.
Infiltration Trench. This project is designed to capture the first quarter-inch from an elevated parking deck and infiltrate it through a rock bed and into the surrounding soil. The box shown in the photo contains the monitoring equipment, including a V-notch weir used to measure inflow. The trench is a 6-foot-deep rock bed under the pavers as shown. Of the demonstration sites being evaluated, it is the only site with a 100% impervious drainage area. Initial work shows that the geometry of the rock bed is key, with infiltration leaving through the sides. The trench was featured in an article in the July/August 2005 issue of Stormwater (“Constructing an Infiltration Trench Retrofit BMP,” www.stormh2o.com/sw_0507_constructing.html). This project was funded by a Section 319 grant in 2004.
Historic Seepage Pit. Multiple seepage pits were found capturing water from the rooftop of Villanova’s Tolentine building. These pits are shown on the 1928 reconstruction plans after a fire, and they are suspected to date from the construction of the building in the 1890s. The pits were brick lined on the sides with overflow pipes leading to a grass field (note that the top is carved rock). In the 1970s during a road project, one was disconnected, and the other was connected to a sanitary outfall by accident. Core drillings were taken to enable study of the soil chemical and biological content caused by decades of infiltration, and at least one of the pits will be reconnected. This project was funded by a Section 319 grant in 2004.
Web sites featuring each of these BMPs can be found through the following link: http://www.villanova.edu/VUSP.
Technology Transfer
Technical Transfer is one of the prime missions of the VUSP and our most dramatic success to date. This element of our mission is approached through on-campus symposiums, speaking engagements, publications, tours of our BMP research and demonstration park, and the VUSP Web site. Every two years the VUSP hosts the Commonwealth of Pennsylvania Stormwater Management Symposium, a two-day event with featured speakers, paper sessions, and BMP tours. In October 2005, attendance was close to 300, including representatives from all surrounding states. Prior to the symposium, a workshop for municipal officials was held on the subject of stormwater utilities. Both of these events were broadcast live over the Internet and are available through the VUSP Web site for download or viewing. As of March 2006, more than 1,000 viewings were recorded from the Web site.
Many visitors have toured the Research and Demonstration BMP Park. At least five organizations including the American Water Resources Association, the Environmental and Water Resources Institute, and the International Erosion Control Association have held national conferences in Philadelphia and have included tours of the BMP park. Local watershed groups, Villanova classes, and other interested organizations have taken the opportunity to visit.
The VUSP Web site is a significant tool for outreach. Within the site there are links to every BMP we have built with a description, design information, streaming videos, and lessons learned. These sites are updated continuously as results from our studies continue. The Web site also includes a site for presentations and an interactive database with links to information on all aspects of stormwater BMPs.
Partnership Goal
The VUSP’s goal of promoting cooperation among private, public, and academic sectors is met through the inclusion of both public- and private-sector representatives on the research board. The board meets three times a year, and all parties represented contribute time, experience, and financial support to the direction of the partnership.
VUSP has joined with Temple University’s Center for Sustainable Communities to create the Temple–Villanova Sustainable Stormwater Initiative (T-VSSI). This partnership combines the resources from two complementary organizations to create a larger, more powerful stormwater initiative. Funded by the William Penn Foundation, the T-VSSI has created a more multidisciplinary research program, joining engineers with planners, horticulturists, geographers, ecologists, and geographic information system specialists. Temple is constructing multiple BMPs in a nearby watershed, and Villanova is supporting Temple in the design and monitoring planning. Temple will work with Villanova on its BMPs, studying plant selection for the stormwater wetland, and other “green studies.” The T-VSSI will also work together on outreach, with Temple taking the lead with a broad public program and Villanova continuing its technical outreach.
Villanova is also supporting the Berks County E&S Pilot Program. This program was initiated by Jack Deering with “Earth Management: The Team Concept” in coordination with the Berks County Conservation District. It includes construction planning and sequential phases within the E&S permit, benefiting contractors and developers as well as the community. As stated on the Pennsylvania Association of Conservation Districts website, “Benefits of this new initiative are the face-to-face meetings between the permittee, designer, earthmover, and the Conservation District. These meetings afford the District staff the opportunity to discus the importance of minimizing accelerated erosion and the impacts of poorly treated stormwater on the quality of our waterways. It also provides an opportunity to discuss the elements of an NPDES permit and the responsibilities the applicant has assumed by cutting into the earth and developing a piece of property.”
The work is just starting, and the possibilities are endless. Future sites have been identified to include a green roof and wet and dry detention ponds. The research, technical outreach, and partnerships are contributing to the changing education and perception of the profession. For more information, or if your firm wishes to be a part of our efforts, visit our website at www.villanova.eduVUSP.
The author thanks William Heasom, research fellow; Clay Emerson, Ph.D. candidate; PaDEP; and the Villanova Facilities Department; as well as all our graduate and undergraduate students.
