The “green stormwater infrastructure” being added is a part of the PWD’s Green City, Clean Waters program.
The Philadelphia Water Department clarified at the Newbold Civic Association meeting Monday night that it will be adding two underground storage basins on the grounds of Guerin Recreation Center at the corner of 16th and Jackson. The “green stormwater infrastructure” being added is a part of the PWD’s Green City, Clean Waters program. The storage basins are designed to hold excess rainwater to prevent it from entering the city’s sewage system.
The key reason it’s important for Philadelphia to keep excessive amounts of stormwater from entering its sewage system is because of the city’s combined sewer system. Many more modern cities have a separate sewer system, which means there are two sets of pipes underground: one for stormwater, and another for wastewater. In these cities, the stormwater goes through the appropriate pipes, which leads back to a natural body of water, such as a river or a lake. Wastewater, which is water that comes from resident’s drains, goes through a separate set of wastewater pipes, which lead to a water treatment plant. In combined sewer systems, like the one Philadelphia has, wastewater and stormwater get mixed together. When storms happen in cities with combined sewer systems, the water level rises underground in the pipes, which have built in dams. If the water level rises over the dams, the stormwater/wastewater mix leaks into rivers, causing water pollution.
According to PWD Community Outreach Specialist Becca Fagan, the basins are designed to hold the first inch and a half of rain in the basin.
“Basically what we’re doing is we’re just digging deep holes into the ground and filling them with gravel,” she said at the meeting. “What they do is they capture the stormwater that’s running off surrounding streets around Guerin as well as the stormwater that’s on the rec center. And it catches that from going into our sewer system. And it basically prevents our sewer system from overflowing in large rainstorms like we’ve seen in the last few weeks.”
In addition, Fagan said PWD was depaving part of the concrete grounds of Guerin, which lies along 16th Street. The area will become a grassed over play area.