James Madison University (JMU) serves 18,000 students on its 680-acre campus and has begun construction on University Park, the campus’ newest outdoor recreation facility. The top section of University Park will be used for recreation facilities, including tennis, sand volleyball and basketball courts as well as multipurpose fields, a disc golf course and a ropes course. The lower section of the park will contain athletic facilities, including JMU’s Division I men’s and women’s soccer, women’s lacrosse, field hockey and women’s track and field programs.
The recreation facilities will provide the JMU community with outdoor recreation spaces to meet a diverse set of needs. This environment will expand programming opportunities, support learning, promote wellness and create a sense of community among students, faculty and staff.
To accommodate this expansion, the University needed to eliminate a large sediment basin on the site that, in the past, had made construction of the new complex impossible. JMU needed an underground treatment and detention solution to control the stormwater runoff. Additionally, the Virginia Department of Conservation and Recreation (VDCR) imposed a high runoff coefficient to account for a comprehensive field underdrain system, significantly increasing the detention required.
The University worked with engineering firm Vanasse Hangen Brustlin (VHB) and chose treatment and detention solutions from Contech Engineered Solutions to address the stormwater runoff conditions that plagued the 63-acre site.
“Due to the shortage of the available surface area, combined with the high runoff coefficients enforced by the VDCR, we needed a belowground system with large storage and high filtration capacities,” said John D. Hines, P.E., Project Manager with Vanasse Hangen Brustlin.
Two CDS® hydrodynamic separation systems were installed to pre-treat the runoff. The CDS system screened, separated and trapped the debris, sediment and oil and grease from the stormwater runoff. The patented, non-blocking screen of the CDS system allowed for 100% removal of floatables and neutrally buoyant material.
Next, a CON/SPAN® detention system was installed to detain the runoff belowground. The modular 3-sided concrete structure was installed on a precast continuous foundation which ensured structural integrity, eliminated differential settlement and was watertight. Its arch shape was able to support the 15-ft.-6-in. high live loads efficiently, which also lowered material costs.
Nielsen Builders, Inc. and Partners Excavating installed 211 24-ft. span x 11-ft. rise CON/SPAN precast units manufactured by Oldcastle Precast®. The system provided a 124,000 cf temporary sediment pond during construction and a permanent 411,700 cf underground detention system after completion of construction. The CON/SPAN system design met some tough project requirements, including watertight joints to protect a soluble rock karst environment.
The final treatment stage included four 20-ft. x 8-ft. Stormwater Management StormFilter® vaults, each utilizing 47 cartridges. This passive media filtration system was installed to remove any remaining fine solids, soluble heavy metals, oil and nutrients from the runoff.
“The Contech package of watertight concrete detention chambers and StormFilter cartridges was clearly the best solution for the project,” said Hines. “We were even able to work together on a creative solution with their inhouse engineers to use the underground chambers as a sediment basin during construction.”
The installation took approximately one month and Contech provided onsite technical assistance throughout the course of the project. University Park is expected to open Summer 2012.