A Clean Delaware River: Green Infrastructure Investments in Philadelphia


This blog was co-written by Liz G. Deardorff and Stacey Detwiler.


Green street in Philadelphia, PA | © Bureau of Laboratory Services, Michele Adams

A green street in Philadelphia reduces stormwater runoff which lowers the impact on combined sewer overflows in the Delaware River watershed | © Bureau of Laboratory Services, Michele Adams

The U.S. Environmental Protection Agency (EPA) has awarded almost $5 million dollars to academic research that will evaluate strategies and effectiveness of green infrastructure in Philadelphia, supporting the City’s Green City, Clean Waters plan to address combined sewer overflows in the Delaware River watershed with a focus on green infrastructure implementation for stormwater management.

Philadelphia has boldly approached its long-term plan for water management with innovative green infrastructure practices such as green streets, green roofs, rain gardens and rain barrels that help reduce the impact of stormwater, including sewage overflows, by slowing runoff and filtering pollution. The City is a national leader implementing projects, incentivizing private engagement in clean water and addressing pollution from runoff during storm events on a watershed, or sewer-shed basis. At the announcement of the EPA awards, Mayor Michael A. Nutter described the commitment to green infrastructure as one that will “…not only result in better water quality for the City, but it will also provide a multitude of benefits for Philadelphians like cleaner air, revitalized green spaces, and even new economic opportunity.” 

EPA has long promoted green infrastructure for stormwater management and in permitted approaches to control of water pollution [PDF]. And, EPA began to provide support to Philadelphia’s plan not long after Pennsylvania Department of Environmental Protection approved it in 2011. Now, EPA’s awards for academic research will ensure that the Delaware River becomes cleaner through green infrastructure implementation by the watershed’s biggest city and, in turn, knowledge gained in Philadelphia “…can be applied across the United States to create a safer and more sustainable water supply” according to EPA ’s Deputy Administrator Bob Perciasepe. This research can benefit cities and rivers across the nation, and across Pennsylvania where Pittsburgh advocates are asking EPA to ‘upgrade’ a proposed long-term plan to control sewage overflows in the Ohio River watershed by adding green infrastructure strategies.

The awards go to several universities, most located in the Philadelphia area. Projects will address:

  • Green infrastructure practices—advancing new techniques to improve infiltration and evapotranspiration of runoff, monitoring the effectiveness of different practices in the campus setting and quantifying community level benefits.
  • Policies to increase municipal adoption of green infrastructure and engage private property owners.
  • Mechanisms for funding green infrastructure—notably with private investment and for disadvantaged communities where stormwater impacts can be greatest.

The research will be conducted by institutions and researchers well respected as leaders in stormwater and green infrastructure research. Community members dependent upon clean water in greater Philadelphia and the Delaware River watershed hold these institutions’ demonstration of effective practices to a high standard emphasizing the notion that green infrastructure can be a clean water tool nationwide but must be practiced locally.

The academic research completed in Philadelphia could be replicated and tested at other institutions, providing technical support to assist communities in meeting their clean water goals. A bill introduced by Representative Donna Edwards (D-MD) and Senator Tom Udall (D-NM) would provide further support for this type of research by establishing three to five Centers of Excellence to serve as clearinghouses of information on green infrastructure. Additionally, the Innovative Stormwater Infrastructure Act (H.R. 3449, S. 1677) would promote the use of green infrastructure across EPA and would create development and implementation grants to communities. As places like Philadelphia move towards cost-effective green infrastructure solutions, this bill will provide critical tools for communities.