The Greenfield School in Philadelphia is re-doing a playground as part of a city water department pilot project to combat stormwater overflow, which overwhelms the city’s sewage system, and can lead to water, oils, and salts to be dumped in the Delaware River. The Philadelphia Inquirer writes that in place of asphalt, the playground will “plant a wide border around the perimeter of its schoolyard, nearly equal to half the playground’s total surface. The green areas are designed to let rain percolate gently into the ground, cutting the schoolyard’s contribution to the city’s overflow problem by more than 80 percent.”
The Philadelphia Inquirer says Philadelphia’s GreenWorks plan provides a strategy for making the city more sustainable, and includes a focus on sustainable stormwater management. Among the goals outlined in the plan are converting asphalt into pervious surfaces. “The plan calls for the city to convert 3,200 acres of asphalt into fully pervious (that’s the favored term) land by 2015. It may sound like a big number, but not when you consider that 67 percent of pre-World War II Philadelphia is covered with buildings and pavement.” While there are other ways to alleviate excess stormwater (underground cisterns, or catch basins), these solutions tend to be expensive because they need to be large-scale. “Tearing up asphalt lots can be done cheaper and faster, and the new green acres have the side benefit of helping to cool the city’s air temperature.” The city’s waterworks department is targeting streets and sidewalks, too.
The Water Department will also incentivize smarter stormwater management by adding a stormwater tax. ”In 2010, the agency will charge its nonresidential customers for the runoff their sites generate. The tax will be based on the amount of impervious surface, using GIS satellite technology to determine what’s paved and what’s green. So, for instance, the owner of a fully paved, one-acre parking lot could see monthly storm-water charges rise from almost nothing today to as much as $400. Schools will be taxed like everyone else.”
In related news, Inhabitat writes that M.I.T. has created a flexible concrete that can last up to 16,000 years, which, if commercialized, would significantly cut down the 20 billion tons of concrete produced annually. “The use of new ultra high density concrete will have enormous environmental implications, given its ability to deliver lighter, stronger structures capable of lasting many civilizations, while drastically decreasing the carbon emissions sent into the atmosphere by its inferior predecessor.” Inhabitat spoke with Franz-Joself Ulm, one of the researchers on the project, who said: “The thinner the structure, the more sensitive it is to creep, so up until now, we have been unable to build large-scale lightweight, durable concrete structures. With this new understanding of concrete, we could produce filigree: light, elegant, strong structures that will require far less material.”
Inhabitat writes that the annual worldwide production of concrete contributes to 5-10 percent of CO2 emissions. “If concrete were to be produced with the same amount of initial material to be seven times normal strength, we could reduce the environmental impact by 1/7.” There is no mention whether the flexible, long-lasting concrete will be designed to be pervious as well. Read the article
[...] runoff are being implemented everywhere in Philadelphia, even in playgrounds. The post, called Unpaving Philadelphia, describes how impervious surfaces that keep water from soaking into the ground and rather push the [...]