Sustainable Streetscape Paved With Green
The rough-and-tumble backdrop of factories and warehouses is more suggestive of urban grit than LEED Gold, making Chicago’s first sustainable streetscape, a two-mile-plus stretch along Cermak Road and Blue Island Avenue, an unlikely poster child for environmentally minded design.
“It may not seem glamorous, but engineering sustainability into basic elements such as streets and sewers can have a profound impact on our cities,” says Kevin Lentz, president of Chicago-based Knight E/A, the project’s engineer of record and mastermind of Chicago’s Green Alleys program.
Though Cermak-Blue Island doesn’t qualify for LEED certification, a rating system reserved for buildings, its team members, including the Chicago Department of Transportation (CDOT), are pursuing environmentally minded solutions with LEED-like fervor. The project, due for completion later this year, will serve as a template for similar undertakings in an effort to advance Chicago’s standing as one of the nation’s greenest cities.
Greenest Asphalt Ever
Among other technologies, the $16.6-million project incorporates warm-mix asphalt made of recycled pavement and ground tire rubber. A micro-thin topcoat of high-albedo concrete reflects radiant energy, one of the primary culprits of urban heat island effect.
“It’s the greenest asphalt ever made,” says Janet L. Attarian, project director for CDOT’s Streetscape and Sustainable Design Program.
The pavement befits a project designed to target a full array of environmental issues, from stormwater management, air quality and energy conservation to recycling, water conservation and beautification.
The project’s more prominent features include light-colored sidewalks and shade trees to further mitigate urban heat island effect, as well as pervious pavements, bioswale parkways and infiltration planters to divert, clean and reuse stormwater.
Bicycle lanes, refurbished bus stops and ADA-compliant sidewalks and ramps are aimed at reducing traffic—and emissions—while dark-sky metal halide light fixtures are intended to reduce energy consumption.
The project even incorporates recycled construction waste. New materials contain at least 10% recycled content, although many contain more.
“We talk a lot about LEED, but we are first and foremost supporters of sustainable communities,” says Doug Widener, executive director with U.S. Green Building Council Illinois. “What CDOT is doing is very cutting edge.”
Photocatalytic pavers, among the project’s more novel systems, remain white while decomposing dirt and other organic substances they encounter. To align the pavers with CDOT’s more modest budget, the project team worked with Marengo, Ill.-based supplier Paveloc to develop permeable units rather than impermeable ones, further enhancing their sustainability.
“It provided wonderful synergies,” says Attarian. “In addition to reflecting radiant energy, the pavers filter stormwater. We’re using them on the bike path.”
The system, and others like it, resulted from extensive research of green standards, including those promulgated by LEED for courtyards, sidewalks and parking lots. Team members selected criteria suitable for an urban streetscape, developed additional criteria and proceeded with design work.
The Cermak Road-Blue Island Avenue corridor was selected for several reasons, among them a dire need for remediation. CDOT also reasoned that the mix of surrounding uses, including an active railroad and school, would provide more room to flex environmental muscle than a more homogeneous location.
Design specs and contracts were minutely detailed, in some cases prescribing precise formulas for pre- and post-consumer recycled content. Not surprisingly, many materials are locally sourced.
Timing Was Everything
Funding, meantime, was cobbled from a number of sources, including the City of Chicago, the Illinois Environmental Protection Agency, the Federal Highway Administration and ComEd, a local utility.
Timing proved fortuitous. Cermak-Blue Island was one of 10 projects simultaneously bid in 2008, all of which came in lower than expected, the likely result of a faltering economy. More surprising, Cermak-Blue Island came in far lower than the others on a per-block basis. “It was nice the contracting community didn’t gouge us,” Attarian says.
Now that construction is proceeding under the direction of general contractor Pan-Oceanic of Chicago, road and landscaping crews are rolling operations at only 1,000 linear feet at a time to minimize their impact on the neighborhood.
“We’ve borrowed from LEED, and road contractors generally aren’t used to that,” says Attarian.
As they proceed, they are constructing systems to collect and purify up to 80% of the area’s average annual rainfall before it hits city sewers. In addition to slowing the flow of water, porous and landscaped surfaces remove impurities before recirculating some of it for irrigation and releasing the remainder into a combined stormwater-sewer system.
One such system, a landscaped plaza with zero-depth waterworks, was located at the neighboring Benito Juarez Community Academy. Another, a cascading stormwater planter, occupies a formerly derelict street corner.
“By detaining water, we’re taking the burden off the sewer system,” says Attarian.
It’s a marvel of engineering, says Pete Mesha, principal and group president of engineering for Darien, Ill.-based Wight and Co, which engineered the project’s landscaping and other sustainable elements. “Walking by some of these places, you’d never know they’re part of a stormwater management system,” he says.
Once construction is completed, the Chicago water-reclamation district will measure the project’s environmental impact. A community group has agreed to maintain its landscaping.
CDOT isn’t waiting to finish Cermak-Blue Island before proceeding to other sites.
“It’s taken so long to sort through all the pieces,” says Attarian. “Now that we have, it’s time to put them to use elsewhere.”