After nearly two years of review, the EPA and Pennsylvania Department of Environmental Protection approved Wednesday the City of Philadelphia's 'Green City, Clean Waters' plan, a unique $2 billion proposal that could revolutionize urban stormwater management and serve as a model for other cities. Unlike traditional urban stormwater management plans, the Philadelphia plan proposes to attain water quality goals mainly by implementing green infrastructure projects, including porous asphalt, bioswales, and rooftop gardens, rather than with grey infrastructure projects, like pipelines and treatment facilities. Plus, the city framed the implementation of green infrastructure projects as a means to mitigating climate change impacts and stimulating economic development.
The plan, technically known as the Combined Sewer Overflow (CSO) Long Term Control Plan, was mandated by EPA due to adverse water quality impacts related to the city's stormwater discharges. It was submitted to the EPA and Pennsylvania DEP in September 2009 for review. The plan was the result of a reevaulation, in 2007, of the city's original plan, written in 1998.
During the review process, it was realized that water quality goals could be met more cost effectively by integrating green and grey infrastructure solutions. Additionally, implementing green infrastructure solutions could have multiple benefits, including mitigation of the heat island effect, improved air quality, increased groundwater recharge, and job creation.
To fund the plan, the city is implementing a stormwater management fee for landowners based on the amount of impervious surface they own and a drinking water rate hike of 2.5% annually for the next 20 years. The stormwater fee has been met with some backlash, with critics claiming it could hurt already struggling local businesses.
Other cities striving to meet increasingly stringent water quality requirements on shoestring budgets may follow Philadelphia's lead. But the efficacy of Philadelphia's Clean Waters, Green City, and possibly the future of green infrastructure as a city wide stormwater management solution, will be put to the test in the coming years as the plan is implemented.
Image: Philadelphia Credit: © Steven Vona.