Location: Willow Grove, PA
Product Used: 5’-8” SingleTrap
Total Water Stored: 54,898 CF
Number of Basins: 1
Number of pieces: 97
Owner: Abington- Jefferson Health
Consulting Engineer: Charles E. Shoemaker, Inc.
General & Installing Contractor: Haines & Kibblehouse, Inc.
Asplundh Cancer Pavilion is a new 86,000 square foot facility, constructed on the campus of the Abington Health Center in Willow Grove, PA. The facility was designed to provide a full spectrum of cancer care, including; chemotherapy, radiation therapy, oncology pharmacy, and immediately available ancillary services.
To meet local regulations, a stormwater management system had to be installed on this property to control and treat runoff. Chad W. Brensinger, P.E, LEED AP, project engineer at Charles E. Shoemaker, Inc. explains that the site is located along a tributary stream within the Pennypack Creek watershed in which the downstream areas were subjected to frequent flooding and streambank erosion. In addition to the NPDES (National Pollution Discharge Elimination System) requirements of the Pennsylvania Department of Environmental Protection, the Upper Moreland Township has adopted a strict stormwater management ordinance in order to mitigate this issue and limit future problems: “In larger storm events, flows from the 100-year storm in the proposed condition had to be limited to flows from the 50 year existing conditions,” said Brensinger.
The Charles E. Shoemaker engineering team worked with StormTrap to provide a cost-effective solution for this project. A 5’-8’’ SingleTrap retention system was installed under the main parking lot of the new Asplundh Cancer Pavilion, in addition to the supplemental rain gardens and other infiltration facilities located upstream of the StormTrap.
The modularity of the StormTrap system made the main challenges of this project, such as limited footprint and shallow bedrock, less of an issue. Other systems were also considered; however, they all would have required a larger footprint, clarified the engineer.
The StormTrap system was designed around the shallow bedrock and allowed the installation of a landscape island in the middle of the system. Although bedrock was still encountered, Brensinger explained that the flexible design allowed the project to minimize excavation and labor costs.
The system controls and treats stormwater runoff by allowing water to percolate into the native soil. Two additional StormTrap systems were also installed in an adjacent property, under the parking lot of the Thompson Lexus car dealership, considerably minimizing potential flooding and stream bank erosion issues downstream.