Making an Impact: PWD's Green City, Clean Waters Plan

Many older communities in the United States—including the City of Philadelphia and others in our region—are grappling with the challenge of reducing water pollution resulting from their combined sewer systems, which mix stormwater runoff with sanitary sewage. In Philadelphia, this system reaches capacity during heavy rainfalls and discharges wastewater into area waterways, introducing contaminants into these bodies of water and compromising watershed health. Because these discharges violate the federal Clean Water Act, the City of Philadelphia entered into an agreement with the US Environmental Protection Agency to develop and implement a long-term plan to reduce the incidence of combined sewer overflows. This plan – named Green City, Clean Waters and created by the Philadelphia Water Department – emphasizes the application of green infrastructure to absorb rainfall at the source and bring the city into compliance with EPA regulations. This approach is less capital-intensive and more environmentally friendly than adding capacity to the city’s sewer network. Over the 25-year lifespan of the plan, the PWD will invest $2.4 billion—a sum far smaller than the estimated cost of upgrading and installing new pipes, tunnels,  and treatment systems—while offering incentives for property owners to pay for and build many green  infrastructure improvements.

To expand the reach of the Green City, Clean Waters plan, PWD has pursued partnerships with a number of government agencies and other organizations, including the Philadelphia City Planning Commission, the Mayor’s Office of Sustainability, the School District of Philadelphia, and the Pennsylvania Horticultural Society. These partnerships have yielded tree-planting initiatives, the replacement of impervious surfaces with pervious materials, and other efforts to help capture the first inch of rainfall at the source and reduce runoff volumes.  The Water Department has rolled out extensive educational programming for businesses and residents who wish to learn how to include green infrastructure elements on their own properties. PWD is also exploring mechanisms to incentivize real estate owners to capture rainfall on their properties.

While Philadelphia is not the first city in the United States to pursue a green infrastructure strategy for stormwater management, the scale of Green City, Clean Waters has received national attention. The Natural Resources Defense Council ranked the city atop its list of “Emerald Cities,” a designation awarded to cities with aggressive strategies for implementing green infrastructure, while former EPA Administrator Lisa Jackson cited PWD’s plan as a replicable model for helping both cities and smaller communities manage stormwater runoff.