By ASCE-Pittsburgh Awards Committee
The Eden Hall Campus is situated on 388 acres in Gibsonia, Pennsylvania. Originally a farm and retreat for working women of Pittsburgh, Eden Hall was gifted to Chatham University in 2009 by the Eden Hall Foundation. The 20- to 25-year development plan for the residential campus calls for it to be self-sustaining in every way; housing 1,500 students, achieving zero carbon emissions, producing more energy than it consumes, and managing all stormwater and wastewater on site.
University president Esther Barazzone proclaimed that “… Eden Hall [would] be the first community in the world built from ‘below the ground up’ for the study of sustainable living, learning, and development.”
Critical to realizing this endeavor has been the management of that which falls on the ground from above. Unique to the project was the implementation of a decentralized “treat it where it falls” approach to stormwater, preventing any singular large concentration of runoff. The stormwater management system is comprised of a series of separate rain gardens strategically placed around the site to manage small individual drainage areas. Each rain garden discharges excess water over a concrete level spreader to further mitigate concentrated runoff. Captured roof runoff is connected to a 50,000-gallon underground retention tank and later reused for landscape irrigation. Stormwater is also infiltrated into the north parking lot by using a permeable surface and underground stone infiltration beds.
Stormwater is not the only source for reuse applications. A biological wastewater treatment system is utilized for sanitary sewer waste produced by the campus. This system includes a series of primary treatment tanks at each building and secondary treatment consisting of a trickling filter, subsurface wetlands, a sand filter for polishing, and UV filter disinfection.
The primary tanks dose effluent to a trickling filter for nitrification. This effluent is then directed into two subsurface constructed wetland cells. Treated water is stored for reuse as flushing water in campus buildings. Any excess water is safely disposed of via an underground drip irrigation system. The treated water is also connected to a campus greenhouse for use in limited applications.
The overall system allows for extended contact times for the effluent at each stage of treatment. This increases the effectiveness of treatment and overall water quality. The system is designed to be expandable by simply adding additional wetland cells as needed.
The incorporation of these best-management-practice approaches has enabled Eden Hall to meet its project goal of having no point discharges from the developed site. The Eden Hall Campus masterplan allows for flexibility in design and engineering solutions so that future technologies can be integrated into the existing infrastructure. The campus acts as a living laboratory for sustainable design and operations.
Find out more about the Eden Hall Campus or to take a tour of the site.