VILLANOVA, Pa. – Engineering professor Bridget Wadzuk and Senior Project Manager Marilou Smith from Villanova’s Facilities Management Office walk the nearly 10 acres of impervious asphalt which currently make up the University’s West Main Parking Lot—engaged in conversation about the new residence halls and landscape features that in less than three years will become a reality on that site. Their discussion centers around the cutting-edge stormwater control measures that will complement the development.
At Villanova, these conversations between Engineering faculty and University Facilities staff are the norm, not the exception. The University boasts some of the country’s leading experts in stormwater management and water resource engineering—faculty members who provide valuable input on many of the projects Villanova is doing from a facilities standpoint. Their discussions with the Facilities Management involve ideas for stormwater control measures that could be implemented as part of new construction or renovation. However, another key component of these discussions involves Facilities’ ongoing efforts to incorporate stormwater test sites into its projects for the benefit of the College of Engineering’s long-standing research in this area.
As part of Villanova’s latest development project, rainwater will be taken from the roofs of new residence halls—scheduled to open in Fall 2019—with a portion being pre-filtered and then going to underground cisterns. A significant portion will then be additionally filtered and exposed to UV light to remove biological contaminants, before it is redistributed to cooling towers as part of the required makeup water. The cooling towers are part of a chiller plant that will be used for cooling the new buildings. The remaining water will move into green infrastructure that will return rainfall runoff into the ground and atmosphere. In all, this development project will include 9 rain gardens, three infiltration trenches and two cisterns. Engineering faculty and students have already begun monitoring the entire site pre-construction and, moving forward, will be able to study the total reduction in runoff during a rain storm. The meters and Building Management Systems will enable graduate students involved in the research to record and monitor the rainwater usage within the cooling plant.
Another aspect of this campus development project involved adding two levels to a current parking garage located in the middle of Villanova’s campus—to make up for the parking lost by building on one of its main parking lots. Although there were only minimal stormwater requirements for the addition of a sidewalk at this site, Wadzuk worked with Facilities to implement stormwater control measures that vastly improved upon the prior system, including an updated Treatment Train—a series of stormwater control measures with real-time controls working in conjunction—capable of removing 1.2 inches of rain. Faculty and students monitor this test site in an effort to determine the system’s threshold and efficiency.
This partnership between the College of Engineering and Villanova Facilities Management began in 1998, when the first stormwater control measure test site was built on campus. Now, nearly 20 years later, more than a dozen test sites are actively being monitored across campus. These initiatives have decreased stormwater runoff and added significant educational value to the research being conducted in the College. Additionally, the results of this research and the knowledge it brings is being shared externally in ways that benefit society at large.
In 2002, the Villanova Urban Stormwater Partnership (VUSP) was launched under the direction of Dr. Robert Traver (Professor of Civil and Environmental Engineering and Director of the Villanova Center for the Advancement of Sustainability in Engineering)—the product of a partnership between Villanova’s College of Engineering, the Pennsylvania Department of Environmental Protection (PADEP) and private industry. With a focus on research and public education, VUSP regularly hosts groups from PennDot, township officials, municipalities and other organizations to discuss best practices. Villanova hosts 20 tours a year of its stormwater sites. This summer, Dr. Traver visited China to present on Villanova’s work and research in this area, as China has put an ambitious plan in place to address stormwater management. In August, a delegation from China visited the University’s campus to tour these sites.
This collaboration between the College of Engineering and University Facilities to leverage the campus infrastructure as a test bed for stormwater management research makes Villanova unique. Below are several highlights of the University’s stormwater control measure test sites:
Villanova University Stormwater Control Measure (SCM) National Monitoring Site
For over a decade Villanova University (VU) has made its campus available for use as a stormwater research test bed and national monitoring site. Each of these sites is a retrofit, providing benefits to our downstream neighbors, as well as acting as an educational tool for faculty-student research—as well as for the many groups visiting the sites through the Villanova Urban Stormwater Partnership (VUSP) .
Bio Infiltration Rain Garden
The bio-infiltration SCM was constructed in 2001 and its construction was funded by a PA Growing Greener Grant. The rain garden was created by retrofitting an existing traffic island on VU’s campus, and is believed to be the longest monitored green infrastructure site—with the College of Engineering having captured continuous data on this site since 2003. The facility intercepts runoff from a highly impervious student parking area and road that was previously collected by inlets and delivered through culverts to a dry detention basin. It is designed to control runoff from smaller storms through capture and infiltration of the first flush within the bowl and soil void space storage. Evapotranspiration and infiltration are responsible for capturing 100% of the volume of storm events less than a ½ inch, 97% of those between ½ and 1 inch, and half of the higher storms. Water quality studies have shown that nitrogen and other parameters such as phosphorous and metals are significantly reduced, and that subsurface groundwater mounding is limited and temporary.
Pervious Concrete/Porous Asphalt (PCPA)
The PCPA SCM was constructed in October 2007. Its construction was funded by the USEPA (EPA) and the RMC Foundation. Additional studies have been supported by PA DEP EPA 319 funding. The site, formerly a standard asphalt paved area, is located behind Mendel Hall at VU campus. This SCM consists of an infiltration bed overlain by pervious concrete surface and an adjacent, equally sized porous asphalt surface. It captures runoff from a campus parking area, passes the flow through either the pervious concrete or porous asphalt surface course, and infiltrates it through a rock bed into the ground. The site receives continuous use by faculty and staff vehicles. The site is designed to capture and infiltrate storms of up to 5 cm of rainfall. From these events there is no runoff from the site. The base of the infiltration beds are level and range from 0.9 to 1.5 m deep and are filled with washed stone, with approximately 40% void space. In extreme events, when the capacity of the storage beds is exceeded, flows are permitted to exit the site and flow out to the original storm sewer system. A vacuum street sweeper is used two / three times of year for maintenance.
Campus Quad Pervious Pavers
An infiltration SCM utilizing permeable pavement was constructed during the retrofit of an existing paved area in the center of the campus in August 2002. The contributing watershed area is approximately 50,000 ft2 and is highly impervious, consisting of pedestrian walkways, rooftops and some grassed areas. The rooftops and some adjacent paved areas are directly connected to three separate rock storage beds (four feet deep) that are outlined by the porous surface layer. The rock beds are linked through piping systems to distribute the runoff between beds and allow for overflow during major storm events. The site was designed to capture and infiltrate the first two inches of runoff, thereby reducing downstream stormwater volumes, stream bank erosion, and non-point source pollution. Several different surfaces have overlain the site and currently it is made up of pavers that have been strategically placed as to allow infiltration of rain water between them and into the underlying rock beds.
Treatment Train (SCMs in Series)
The design and construction of the treatment train at VU’s campus took place during the Fall of 2011 and was funded through PADEP Growing Greener Grant. It includes a vegetated swale, followed by two rain gardens in series, and finally an infiltration trench. This SCM is designed to capture 1 inch storm event. The swale and rain gardens act as pretreatment to the infiltration trench so that less flow annually reaches the infiltration trench and there is a lower sediment load to preserve the infiltration capacity over a longer design life. Recent results to include data from Superstorm Sandy have demonstrated the resilience of the site and that it greatly outperforms its design expectations. The site was just retrofitted with a 51,000 gallon cistern and real-time controls to take advantage of infiltration and evapotranspiration on dry days.
Fedigan Hall Rain Gardens
The Fedigan Rain Gardens constructed in 2009 include a Bio-infiltration and Bio-retention SCM that captures runoff from the rooftop. The rain gardens were constructed as part of a joint project with the university to create a green residence hall. Some construction funding was received through the PaDEP’s Growing Greener program. Stormwater from the roof is diverted into two rain gardens in front of the building. The bio-retention site is lined to prevent percolation, with an underdrain while the bio-infiltration site has no underdrain or liner. The east rain garden (bioretention) detains the water and releases it back into the atmosphere through evapotranspiration, and slow release through the underdrain. The west rain garden (bio-infiltration) utilizes both evapotranspiration and infiltration. Research is ongoing on this site to compare the performance to other rain garden on campus.
Constructed Stormwater Wetlands
In 1998, an existing stormwater detention basin on campus was converted into an extended detention wetland SCM, and was rebuilt during 2010. Research on this SCM is currently funded by the EPA Section 319 grant. The 0.8 acre CSW treats runoff from a 41 acre watershed that includes at least 16 acres of impervious surface. The watershed includes students’ residence halls, classroom buildings, parking, roads and a railroad. The project has been published as an EPA 319 Success Stories Part III. This site was reintroduced as a 319 NPS project in May 2011. Baseflow and water quality and quantity studies are ongoing.
Construction of Villanova's Green Roof took place in 3 days in the summer of 2006. The design was a retrofit of a small portion of Villanova's Center for Engineering Education Research (CEER) roof. It serves a number of purposes, including: eliminating the first half inch of rain falling on that portion of the roof for any storm event and providing research opportunities for students and possible quantification of the environmental advantages of a green roof. The green roof is a very practical BMP in highly urbanized areas where there may not be room for an infiltration BMP in the ground. Its footprint on the landscape is no more than the building itself because it stores the water on the roof and is used by the plants or evaporates.