Vander Woude relates the issue as much to water conservation as to stormwater management.

“The United States has about a 3.7-billion-gallon water deficit,” he says. “Aquifer levels in certain parts of the country have dropped more than 100 feet since the 1940s. The issue is water quantity, as well as quality.”

VAST Grid Close UpClick photo to enlargeTed Corvey, paver business director for Winston-Salem, N.C.-based Pine Hall Brick Co., echoes Vander Woude.

“The idea of permeable pavers goes back about 10 years in this country, but longer in Europe,” he says. “Some 30 years ago in Europe, they started looking for ways to recharge groundwater and came up with the idea of using segmental pavements and open-graded aggregates that allow the water to flow down and infiltrate back into the soil.”

While that may not be such a stretch in a continent where sand-set cobbles were the norm for centuries, the big issue in the United States is the acceptance of segmental pavements in general – typically with higher up-front costs.

“When you’re looking at someone who wants to replace a retention pond and make the parking lot bigger, those installations are driven by economics,” says Corvey. “You’re going to see a mechanical installation to save money and you’re probably not going to see clay pavers as a result because they need to be hand-installed.”

On the other hand, one of Pine Hall Brick’s permeable products – RainPave® – is designed with the residential driveway market where impervious cover limits apply and a more-traditional material is desired specifically in mind.

Green takes on several different meaning with other pervious products entering the market. One of VAST’s goals, along recharging the aquifer, is to create products from almost 100-percent recycled materials – mainly tires and plastic.

Then, there’s the matter of plantable pavers, such as Drivable Grass®. Created by Carlsbad, Calif.-based Soil Retention Systems, it connects concrete cells in a flexible polymer grid suitable for both vehicle and pedestrian traffic.

Jim Engelke, the product’s national sales manager, says education is a big part of his job, with designers and contractors being only some of his students.

“When a client wants to use the product on a commercial project, I go ahead and meet with the fire department and explain why this is going to work,” he says. “A lot of times the agencies know what they have to conform to, but they don’t necessarily know the latest ways to achieve their ends.”

As with Pine Hall Brick, Engelke adds that often homeowners are among the most-knowledgeable and accepting of Drivable Grass.

“We probably have an equal interest at the homeowner level,” he says. “If we don’t have a regional distributor, we’ll sell a driveway’s worth of Drivable Grass and have it shipped.”