Percy Street goes porous


Summer has many water-related constants, among them Italian ice, swimming pools and thunderstorms. Keen on keeping residents’ attention on enjoying the first two and not dreading the third, the City’s Streets and Water departments took an early measure May 10. They unveiled the 800 block of Percy Street as the first porous green block, a title that will rely on unique asphalt to check stormwater runoff and to curtail basement flooding.

The tiny street’s occupants hosted City officials for their space’s coronation as a chief element of the Water Department’s Green Cities, Clean Waters initiative. With water balloons and containers nearby, they listened as their guests explained how the objects’ contents and any offering from the clouds will not hinder their stretch.

“Wow, what a block!” Mayor Michael A. Nutter said as he stood behind a podium in the middle of the street. “Percy Street neighbors, we destroyed your spot. The least we could do is to make something creative out of it.”

The ingenuity beneath his feet will exclude the inhabitants from having to worry when Mother Nature weeps. As a result of extensive work from January through April — at a cost of $330,000 — their block contains eight inches of porous asphalt, a material that will allow rain to seep through the pavement to soak into a nearly 30-inch layer of stone. Instead of burdening storm inlets and rivers, the drops will use the stone as a temporary storage site before becoming absorbed into the surrounding soil. The structural equal to normal asphalt, the block’s brand contains spaces to permit the suction.

According to Water Department engineering supervisor David Weld, the street can combat a two-inch storm. The soil will remove the first inch from the sewer system and detain the second amount to allow treatment plants and sewers to address it.

The earth’s involvement will represent a marked alteration to old procedures. South Philadelphia has a combined sewer system that includes the sanitary system of water from toilets and showers and the storm-water system. Massive rains tax treatment facilities and cause at least 50 annual overflows into local rivers, according to Andrew Stober, chief of staff for the Mayor’s Office of Transportation and Utilities. The new asphalt will stem aquatic pollution and will help the City to meet a mandate from the Environmental Protection Agency to reduce the combined-sewer overflows.

“We are looking to transform the health of the city’s waterways and to improve our urban landscape,” Nutter said of contributing to Green Cities, Clean Waters, a 25-year, $2 billion-project the EPA is reviewing.

Residents’ gripes about shoddy curbs and sidewalks, sinkholes and basement floods prompted the City in December to initiate infrastructure repairs. Choosing to make the block akin to many playgrounds, parking lots and basketball courts, including Herron Playground, 250 Reed St., by adjusting its composition soon followed.

“By sealing up plumbing, we thought it would be an ideal location to try to infiltrate water into the ground,” Weld said. “We figured we would reduce chances of having a sinkhole or a water trace going back into people’s basements.”

Revamping meant ripping up the pavement to line the curb with an impermeable plastic liner to prevent water from migrating back toward houses and replacing the 10-foot-sewer line, the four-foot water main and the two-and-a-half-foot gas line.

“Percy Street is a model we are hoping to replicate,” Nutter said. “We have 19,654 acres of paved streets and highways, so we have a lot of work ahead of us.”

Though summer will be the first full season to test the block with inclement weather, winter will confront it soon enough. The porous pavement’s structure will make snow less of a nuisance and will cut down on the street’s pollution, as less rock salt will be in use.

“There will also be less of an icing effect when temperatures drop,” Weld said.

Regardless of the time of year, rain will be the block’s prime visitor. The asphalt’s design will not cause puddle formation, or “ponding,” thus offering another boon to the compact space.

“Big things do come in small packages, in this case, a small street,” Water Department Commissioner Howard Neukrug said.

“We hope to have hundreds of miles more,” Streets Department commissioner Clarena Tolson added.

Sharing her sentiment, the crowd cheered and flashed eager eyes as Nutter joined her, Neukrug and Deputy Mayor of Transportation and Utilities Rina Cutler in tossing balloons onto the surface. Splashes brought more applause, and the crouching mayor felt the ground to test the immediacy. More heaves followed before Nutter emptied a jug onto a concentrated area. Another touch revealed not a trace of the liquid.

“We want to thank the Percy Street neighbors for bringing this agenda item to us,” Councilman-at-Large Jim Kenney said of their citing basement flooding as a huge hindrance to their peace of mind.

Weld nixed reports that Hawthorne’s 1300 block of Webster Street will be the next target, but mentioned South Philadelphia will likely yield the second spot. Once a season, the street will receive maintenance through vacuuming to remove any clogs items like leaves could cause.

“The true test of the street’s effectiveness will be seeing that no damage occurs to properties,” he said.

“We’ll be traipsing people through for the next couple years to show them what their street could look like if they let us play there,” Cutler said.

The hefty sum of the Percy Street project is one that resident Mike Tyler knows will come nowhere close to larger locations’ totals.

“That’s a big number,” the one-year dweller on the block said.

He took pictures of the work’s stages and concluded that although he is not well-versed in the science behind the asphalt, which he termed “high-tech gravel,” he is happy with the results.

“Our basement has stopped flooding, so I can overlook a few days of interrupted sleep for that,” he said, adding that workers constructed a rail and a ramp to facilitate his disabled sister-in-law’s travels.

Curious to see how porous pavements affect the city, Tyler has skeptical moments.

“They worked on our street, essentially shutting it down, for four months,” he said. “I just could not see this working for Broad Street, so I question the functionality of attempts to enhance other areas and the burden for taxpayers.”

Grateful for the aesthetic improvement and the reduced worry over the appearance of angry clouds, he still wishes the large initiative would start new projects instead of trying to adjust existing locales.

“I like the concept and will be checking the practicality of each move,” he said.

Contact Staff Writer Joseph Myers at or ext. 124.