Porous Pavement

Spongier Surfaces Reducing Stormwater Runoff

By Trey Cody

Think about the sponge on your kitchen sink.  When you hold it under the running faucet, it absorbs a surprising amount of water.  But what if the sponge was covered in plastic wrap?  The water would hit the surface and flow right off.  We can see this same concept at work in our urbanized watersheds where, in many areas, green space that once absorbed rainfall has been replaced by hard surfaces that water can’t penetrate.

There are lots of ways that cities and towns are trying to get closer to their original, spongy state.  Having a surface that is porous and permeable reduces the effects of stormwater runoff on receiving streams, like stream bank erosion and negative effects on aquatic plant and animal life.

That’s why porous paving projects are popping up all over the place.  Permeable paving refers to a different way of mixing or constructing concrete or asphalt that allows water to flow through the pavement and into the ground instead of over it.

One project can be found in our neighboring EPA Region 2’s Laboratory in Edison, New Jersey (above), where three permeable surfaces are being tested on the site of a former concrete parking lot. The performance and capabilities of these systems are being documented as part of a long term project to study the effects of paving materials such as porous asphalt, porous concrete, and interlocking concrete paver blocks. The parking lot will be monitored for its ability to accept, store, and infiltrate stormwater, water quality performance, urban heat island mitigation, maintenance effects, and parking behavior.

Closer to our regional office home, the first porous street in Philadelphia was recently unveiled.   And Washington D.C. has done a number of Green Alley Projects using permeable pavement for the street surfaces.  Have you seen other examples of pervious pavement near you?

To learn more about permeable pavement and other green infrastructure techniques, and how it benefits water quality, check out EPA’s Green Infrastructure Page.

2012 marks the 40th anniversary of the Clean Water Act, the nation’s law for protecting our most irreplaceable resource.  Throughout the year, EPA will be highlighting different aspects of the history and successes of the Clean Water Act in reducing pollution in the past 40 years.  The month of August will focus on Science and Innovation.

About the Author: Trey Cody has been an intern with EPA’s Water Protection Division since graduation from high school in 2010. He is currently attending the Pennsylvania State University.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

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Green Infrastructure Beats a Giants Parade

By Elizabeth Myer

Yesterday, while most of New York City was gathered outside of our downtown office building to observe the ticker-tape parade honoring the Giants, I, a bitter Philadelphia sports fan, was fortunate enough to spend my morning 60 blocks uptown. As part of the New York Water Environment Association’s 84th Annual Meeting, EPA held a forum to discuss green infrastructure at the Marriot Marquis in Times Square. The green infrastructure panel consisted of four experts who shared their successes and challenges regarding  their respective experiences implementing green infrastructure. 

After opening remarks by EPA Regional Administrator Judith Enck, Matt Millea, Deputy County Executive of Onondaga County, kicked off the morning with a riveting presentation that detailed Onondaga County’s “Save the Rain” initiative. Matt went into  detail about the county’s green infrastructure program, a comprehensive stormwater management plan intended to reduce pollution to Onondaga Lake and its tributaries. 

Yale graduate student Erin Gill presented yesterday on the indirect benefits of green infrastructure. (EPA photo)

Fellow panelist Suzanna Randall, a Green Infrastructure Coordinator at NYS Environmental Facilities Corporation, said it best when she reiterated Matt Millea’s offer to “steal our plans, take our ideas!” Suzanna believes that inspiring communities by demonstration, as well as sharing lessons learned, is optimal for spreading enthusiasm about green infrastructure. 

EPA’s own Mike Borst made pavement sound fascinating (yes, I can be sarcastic, but this is not one of those times) when he gave an overview of EPA’s porous pavement parking lot in Edison, NJ. The parking lot, which includes three different sizes of rain gardens to infiltrate rainfall and stormwater, is also the site of a ten year study in which data will be collected to monitor functionality and performance of the permeable surfaces and rain gardens over time, in addition to a variety of other crucial questions. I strongly encourage the permeable pavement skeptics to watch this video

If you regret not being able to attend the conference and would like access to the presentations, check out the videos for each presentation here.

Editor's Note: The opinions expressed here are those of the author. They do not reflect EPA policy, endorsement, or action, and EPA does not verify the accuracy or science of the contents of the blog.

Please share this post. However, please don't change the title or the content. If you do make changes, don't attribute the edited title or content to EPA or the author.