The Friends Center in Philadelphia encompasses 3 buildings and 2 exterior courtyards that span 1.26 acres. A new renovation project is currently underway and includes the restoration of the historic Meeting House and a four-story office building. From the outset of the planning process for the project, the Friends insisted that the renovation of the site and both buildings become models of energy conservation and environmentally sustainable design as practical and highly visible demonstrations of the Friends’ long-standing commitment to “treading lightly on the earth.” This commitment is reflected in the project’s series of stormwater management strategies.
An overarching goal of the project was to stop contributing to the degradation of the Schuylkill River watershed. Before implementation of the project, The Friends Center discharged 58,400,000 gallons of untreated stormwater runoff into the Schuylkill River on an annual basis, and was contributing to the citywide problem of Combined Sewage Overflow (CSO).
With funding from the Kresge Foundation to conduct a green planning charrette, several stormwater management strategies were identified and conceptualized. These include a vegetated roof, a rain garden in the rear courtyard, and tree trenches along the site to replenish the local aquifer through infiltration. The vegetated roof was finalized for implementation, but neither the tree trenches nor the rain garden were constructed. A rain garden in the rear courtyard would have disrupted the original outlay of the historic site, so the area was maintained as is. Other Best Management Techniques (BMPs) considered for the site included a constructed wetland and a living machine to provide natural on-site treatment for sewage and wastewater. These options would have eliminated all sanitary waste discharge from the site, but the wetland option did not prove to be space-efficient and the living machine was not cost effective since the Philadelphia sewer system could handle the sewage waste. In any case, the top priority when weighing these various options was to effectively redirect stormwater runoff from the Philadelphia sewer system.
Implemented stormwater BMPs at The Friends Center include a green roof and a stormwater collection and reuse system. The green roof was installed upon a new Energy Star roof in August 2007. Eight succulents, all “Sedum” varieties were planted on the roof in no particular order. The sedum varieties planted were: Album (Jellybean), Sexangulare (6-Sided Sedum), Spurium (Dragon’s Blood), Rupestre (Angelina), Spurium (John Creech), Lanceolatum, Stenopetalum “Rocky Mountain”, Talinum Calycinum (Fame Flower). Some of these varieties do better in the summer when they take over and flourish, and others rebound in the winter. The green roof must be weeded twice a year. The green roof on the office building retains 90% of its stormwater runoff and purifies the remaining 10% that is not absorbed by the vegetation and the soil.
The stormwater collection and reuse system collects rain from the roof of the Meeting House and stores it in six large tanks in the basement of the Meeting House. The “grey” water collected by the tanks is filtered and purified, then recycled in the office building’s restroom toilets. This will reduce the Friends Center’s potable water usage by 90%, also equating to a 90% reduction in water bills. Construction of the stormwater collection and reuse system was completed in April 2009, and is now fully operational.
Outdoor and indoor exhibits and other educational programs run by the Friends Center help publicize the necessity for progressive stormwater management techniques.
Watershed: Schuylkill River
The Friends Center is located in Center City Philadelphia at 15th and Cherry Streets, 2 blocks north from City Hall.
Mark Ueland, AIA
UJMN Architects + Designers
718 Arch Street, Suite 5N
Philadelphia, PA 19106
Phone: 215-440-0190 x104