The project is part of PWD’s Green City, Clean Waters program.
According to the Philadelphia Water Department, water pipes and sewers underneath many areas of the River Wards have reached the end of their useful life and will be replaced. The anticipated construction start and completion dates are still to be determined, however the PWD has identified four streets that will be impacted by construction: Gaul Street from Indiana Avenue to Clearfield Street, Weikel Street from Monmoth Street to Ann Street, Weikel Street from Ontario Streey to Tioga Street, and Witte Street from Tioga Street to Venango Street. The project is part of PWD’s Green City, Clean Waters program.
In addition to replacing pipes, the PWD plans to implement various types of green stormwater infrastructure to help soak up water to prevent it from entering the sewage system in the event of a rainstorm. The PWD defines GSI as infrastructure that “uses materials such as plants, soil, stone, and special pavement to slow, filter and soak up water during storms.”
There are four types of GSI that will be utilized by the PWD:
- Bumpouts, which are “a landscaped area that protrudes slightly into the street from the sidewalks,” said Fay Strongin, a member of the PWD’s public engagement team at last Wednesday’s PROPAC meeting. In addition to helping with stormwater, bumpouts can help with traffic calming and pedestrian safety, according to Strongin.
- Tree trenches, which are trenches filled with dirt and soil, which trees grow in. These tree trenches also absorb stormwater.
- Subsurface trenches, which are spaces that store stormwater underground. They’re often located underneath streets or sidewalks. The bed of the trench is lined with special fabric and then filled with stone or gravel and sometimes plastic storage pipes.
- Rain gardens, which are gardens planted with native plants that are both drought and water tolerant. As a result, water can flow into the garden and help hold stormwater that way.
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 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 rainstorms 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.
“That’s a problem for our water quality,” said Strongin. “It also means we can’t enjoy the rivers for recreation as much as we might be able to if we didn’t have this issue.”
For more information about PWD’s Green City, Clean Waters initiative, visit phila.gov/water.