Excess nutrients carried by stormwater can cause thick, green muck that pollutes the water. Photo by Eric Vance, U.S. EPA. |
One organization focusing a lot of attention on green infrastructure for stormwater management is the Center for Sustainable Communities (CSC) at Temple University (Ambler, Pa.), which was created in 2001 and focuses on a number of "green" initiatives -- the main one of which is water.
"We have seen a lot of interest in flood control in general and stormwater management, specifically in this region," said Jeffrey Featherstone, Ph.D., director and professor, CSC, Department of Community and Regional Planning, School of Environmental Design, at Temple University. "For example, the city of Philadelphia has embarked on an ambitious green infrastructure program as a way to deal with its combined sewer overflow (CSO) problem," he said. Philadelphia is one of about 800 cities in the U.S. where sanitary sewers and storm sewers are combined.
The cost to implement a traditional graywater-type solution, which separates the sewers, or to build underground chambers is quite expensive, said Featherstone. "Philadelphia, in working with the EPA and the state Department of Environmental Protection, is proposing an alternative to the graywater solution by doing green infrastructure with the goal of capturing the first inch of runoff." The $2.5-million Philadelphia Water Department program, called "Green City, Clean Waters," carries a significantly lower price tag than the $15- to $20-million for gray infrastructure.
Philadelphia has also implemented a stormwater fee structure that accounts for commercial users, especially those with large amounts of impervious cover. "It replaces the previous approach of assessing stormwater fees based on water meter usage, which, of course, didn't make any sense," Featherstone said. "We are also working with Philadelphia on preparing watershed plans, preparing ordinances and identifying various stormwater control measures that can be implemented."
The CSC is also working with the William Penn Foundation on the Delaware Watershed Conservation Program (DWCP), a $35-million effort by the Foundation to improve water quality in the Delaware River Basin. One focus of the initiative is on the watershed that has its headwaters in the suburbs of Philadelphia and drains through the city itself. Part of the program involves constructing various stormwater control measures in the headwaters.
"We will provide oversight and expertise for dozens of restoration projects in five watersheds in the Philadelphia region," said Featherstone. "Nearly all stream segments in these watersheds have been designated as impaired by the Pennsylvania DEP -- primarily due to stormwater runoff." Proposed projects include creating infiltration systems for parking lots, restoring buffers for eroded stream banks, improving stormwater runoff management, restoring stream channels, and upgrading existing stormwater management facilities.
Green infrastructure is indeed having a positive impact. According to a March 2014 press release from the Pennsylvania DEP, efforts to reduce pollution in the state's Chesapeake Bay Watershed continue to demonstrate success. Since 1985, various efforts have helped to reduce phosphorus loadings by 25 percent, sediment by 15 percent and nitrogen by 10 percent. The press release identified a number of initiatives that have helped, one of which involves green infrastructure for stormwater runoff. In fact, the DEP issues municipal stormwater system permits that include nutrient planning requirements.
"We can't keep building bigger pipes and treatment plants," said Ron Furlan, division manager, planning and permitting, in the Bureau of Point and Non-Point Source Management, for the Pennsylvania DEP. "Green infrastructure involves rethinking what we have done in the past to manage stormwater better, with a focus on prevention rather than dealing with the onslaught afterwards. The idea is to handle the water where it comes down, not later on where it goes."
A number of projects throughout the region have supported this goal. For example, according to Furlan, the Pennsylvania Turnpike Commission has undertaken several projects to build stormwater retention structures along the road so that water doesn't end up in the creeks.