Recycled Glass Paves a Path at Trailside Museum

It's no longer just an Annie Lennox hit single: Walking on broken glass is now sustainable.

A new 1,000-square-foot pathway at River Forest's Hal Tyrell Trailside Museum will be made almost entirely of crushed recycled glass. Representatives at the Forest Preserve District of Cook County say they intend for the trail to promote eco-friendly landscaping. Installation is underway.

“Here's a good use of material that could end up in a landfill,” Dave Kircher, chief landscape architect for the project, said. “The other side is, the permeable pavement.”

The new trail, composed of a porous material known as FilterPave, filters stormwater, so rain that falls onto the pavement trickles down through a mixture of specially processed glass and into the soil below. Along the way, pollutants in the water get trapped inside the pavement.

Some 90 glass bottles comprise one square foot of the pavement. The bottles can be of any color, but the Trailside path in River Forest itself will be light brown.

Kircher says the pavement's visual appeal is another of its perks: unlike concrete or asphalt, the path's light brown blends into the surrounding forest environment. And unlike woodchips, says Kircher, the trail is handicap-accessible and low-maintenance.

But FilterPave maintenance has proven to be a problem at the Morton Arboretum in suburban Lisle, according to officials there.

In 2009 the Arboretum installed a 1,000-square-foot Filterpave walkway, alongside other earth-friendly pavements such as one made of recycled granite countertops.

Officials say that over this past year, the FilterPave surface began to unravel. The other pavements stayed in tact.

Now, officials are looking into repairing or removing the recycled glass walkway.

“The verdict is still out” on what will happen with the path, said Ralph Grieco, head of facilities at the Arboretum.

Grieco noted that FilterPave's manufacturer, Wisconsin-based Presto Geosystems, has had success with the pavement elsewhere. And contractors who helped install the path there chalked up the problem to a clear topcoat, which allowed UV rays to pierce and weaken the surface.

That's been corrected with a new protective pigment, contractors said.

Recycled glass pavement need not only be used for walkways. In parking lots or driveways, FilterPave can bind to and help break down leaked car fluids, Gregory said. This process could make pollution cleanup easier.

Because the glass pavement absorbs water, it also stays cooler in the summer, reducing the "urban heat island” effect.

Would Trailside consider paving a parking lot with the recycled glass? Here, Kircher says economics come into play.

“I'm not convinced from a cost standpoint that we'd be able to repave all of our parking with this material,” he said. “But it does warrant application in other areas like our nature centers, headquarters. Situations where we're drawing a high number of visitors.”

FilterPave is made of ground post-consumer recycled glass bound together with a mostly plant-based resin. Its design can be customized to permit varying level of pedestrian and automobile traffic.

Construction of the path at the Trailside Museum was scheduled for Friday July 22 but postponed because of rainfall. It's expected to begin this week.