Pound pavement

Blasted Euros give us greener parking-lot options

SN&R buys a building, wants to make it green and pays Sena: Eco-Warrior Princess to write a weekly column about it.

I am sick and tired of Europeans coming up with everything first. It’s highly annoying, how culturally advanced and avant-garde they are, as they prance around with their cool accents talking about haute couture fashion and cigarette-smoking and the Renaissance. I’m sorry, but wasn’t the whole formation of Western civilization good enough for the Europeans? No, they had to be the first to develop warm-mix asphalt, an eco-friendly pavement option for parking lots and roadways. They did so back in the late 1990s to meet stricter emissions regulations established by the Kyoto Protocol. The U.S. asphalt industry finally identified this material as a promising new technology in 2002, now performing scientific testing on demonstration sites.

If we play our cards right, SN&R just might be one of these sites.

In our quest to find the greenest pavement method for the 24,000-square-foot parking lot around the building we’re renovating on Del Paso Boulevard, we hit a wall: We have eco-friendly champagne tastes on a beer budget. So what do we do? How do we create a place where all the asphalt junkies of the world will congregate to see our parking lot and realize, “Hey, if the clowns at SN&R can go green, so can we”?

Pavement is not green. There, I said it. Every option currently available on the market wastes energy to produce. Paving the Earth inevitably pollutes waterways and displaces wildlife from native habitat. And as Alison Berry, director of the UC Davis Road Ecology Center, told SN&R: Trees and parking lots don’t do well together. Pavement dries out vegetation, and planters are often designed too small for a tree’s root volume, preventing the tree from flourishing.

Asphalt is the brownest of all paving materials. It uses petroleum (a fossil fuel) in its manufacturing process. Because it’s impermeable, it sheds rainfall and surface pollutants, including oil, antifreeze, fertilizers and viruses and bacteria from pet waste, forcing water runoff directly into nearby storm drains and then into streams and lakes.

The material also produces hydrocarbon emissions, which result from incomplete fuel combustion and from fuel evaporation, and serves as a precursor to ground-level ozone, a key component of smog. With Sacramento listed by the American Lung Association as one of the nation’s top 10 worst cities for ozone pollution, we should probably be concerned. Asphalt’s pushers attempted to rebrand the material starting in the 1970s, when the oil crisis prompted the development of new recycling methods. Rubberized asphalt made of shredded tires is one such method, but the product is expensive.

So why on (this global-warming forsaken) Earth would SN&R choose asphalt for its parking lot? Well, warm-mix asphalt is relatively eco-friendly. The material doesn’t have to be heated to 350 degrees like typical asphalt, thereby reducing emissions—the largest part of gaseous emissions comes from the heating and drying process. Warm-mix asphalt can be applied at half the temperature of normal asphalt, which reduces the toxic exposure of workers. Plus, we’d be reusing asphalt—simply pulverizing the material before lying it down again.

Next on the continuum of brown-to-green paving options: TerraPave, a natural binder comprised of aggregate and pine tree resin, a byproduct of the paper-products industry. The material doesn’t contain petroleum-based ingredients and, according to its boosters, is suitable for driveways, parking lots, decorative pathways and bike trails. The material’s gold or gray-tones reduce the heat-island effect. TerraPave is typically less expensive than concrete, but more costly than asphalt.

Much darker on the green continuum is pervious pavement, designed so storm water penetrates into the soil below where water is naturally filtered and pollutants removed. By reducing runoff, porous concrete helps property owners meet storm-water regulations, which limit the levels of pollution in our waterways, and eliminates the need for retention ponds and bioswales, creating more efficient land use. It’s the best option for trees because it allows air and water to saturate down to the roots. Expensive irrigation systems can also be downsized.

Single-sized aggregate (think gravel parking lots) without any binder is the most permeable and least expensive pervious-pavement option, but should only be used in low-traffic settings. The pavement can also be made of concrete, which is a recyclable or recycled material. Unfortunately, many areas in Sacramento aren’t conducive to pervious pavement; the ideal soil is sand, but our city has lots of clay areas, which might cause driveway or parking-lot flooding.

I’m sure I’m missing some eco-friendly pavement option here, but no worries, my friend. By the time I think of it, the Europeans will likely have come up with some new product that’ll once again put the rest of us to shame.