Paving Paradise
By Veronica Burns

As 2009 draws to a close, Norfolk can acknowledge the work done by various commissions and groups throughout the year. Two documents now exist which are achievements in providing guidelines for the future of our town. The Natural Resource Inventory (NRI) and the Town Plan of Conservation and Development (POCD) should not be allowed to stagnate, but should be seen instead as active, working applications. Town plans have been known to gather dust on shelves, but let’s hope ours does not.
With that in mind, an action that once seemed a matter of routine, pouring blacktop on our driveways and parking lots, is now a matter of serious debate. It is an issue that not only involves aesthetics, but more importantly, public health and safety.
The culprit is known as impervious surfaces, those that are composed of any materials that impede natural infiltration of water into the soil.
As more development and urbanization occur, more of the natural landscape is being replaced by roads, parking lots, houses and driveways that reduce infiltration of water into the ground and accelerate runoff to ditches and streams. Water that travels too quickly to rivers and streams can pick up and carry a lot more sediment and other pollutants. It also enters in a rush, which can worsen erosion and flooding.
Aesthetically, blacktop doesn’t seem to meld well in our rural landscape. It seems too urban. It creates a barrier between person and land. Walking through the Battell-Stoeckel Estate is a case in point. It seems it would be more appealing if there were less asphalt on the ground. And come our Norfolk winter, how will that same asphalt fare? But aesthetics apart, there is also the more sinister element of pollutants.
Crude oil is the second largest component of asphalt, composing at least 5 percent and up to 7 percent of the mass of the pavement. Thus, every ton of new paving asphalt contains at least 100 pounds, and possibly 140 pounds, of crude oil. Since the oil is not sealed in, it evaporates and becomes air pollution, or it is washed off in rains and fog to become water pollution.
The NRI notes that Norfolk’s water resources “form the headwaters for two major drainage basins and four regional watersheds.” We feed water to our neighbors and our water quality is either designated A or AA, which means it is pristine. For this reason, the NRI recommends that “impermeable surfaces” be limited. “Studies show,” states the NRI, “that impermeable surfaces covering more than 12 percent of a watershed diminishes water quality.”
A recent National Public Radio piece addressed the matter of coal tar sealants, which are sometimes used to seal blacktop and prevent breakage in freeze-thaw scenarios. In Minnesota, officials had built stormwater retention ponds to prevent runoff into local rivers and streams. They then discovered high levels of polycyclic aromatic hydrocarbons, or PAHs, in the retention ponds. These potentially cancer-causing chemicals are a byproduct of coal tar sealants and some states have implemented a ban as a result.
Water quality was a critical issue for the newly-adopted POCD. “Scientific evidence indicates that two actions – vegetative buffers and a limit on impermeable surfaces – can significantly contribute to the preservation of water quality,” states the document. The POCD warned against taking our water quality for granted. Even though future development is likely to be on the low scale, Norfolk should nonetheless take all steps necessary to minimize pollution. Maybe as a step in that direction, the Norfolk Planning and Zoning Commission could incorporate an ordinance in their zoning regulations revisions, to limit the use of impervious surfaces. There are many good alternatives out there.