(Boston, Massachusetts) -- Joni Mitchell vilified builders in her 1970s hit song, "Big Yellow Taxi," knocking them for paving paradise to put up parking lots. The asphalt going in at 585 Middlesex St. in Lowell probably wouldn't have changed the singer-songwriter's message, but it might have given her pause with the lyrics.
The parking lot at the new headquarters of Nobis Engineering Inc. is being installed with an environmentally friendly asphalt called porous pavement. By letting rainwater seep through to filtration beds, porous pavement is correcting a pollution problem called road runoff, which is of particular concern in the densely populated, heavily traveled Merrimack Valley.
"More and more every day, porous pavement is proving itself to be an environmentally sound method of putting down paving material," said Scott Colby, environmental and estates manager for Saugus-based Aggregate Industries Inc., the paving company doing the work for Nobis. "Using porous pavement, you can recharge ground water much better, and in the winter it doesn't freeze up like regular pavement does. The material works quite well."
The material is made by using larger-than-normal stones, called aggregate, in the asphalt mix. The aggregate creates holes in the pavement that allow water to pass through into an extra-deep bed of sand and stone that absorbs and filters the water in much the same way underlying soil in a field or forest does.
That's a crucial difference for many planners who often restrict development on open land based on how much of an area is covered by impervious surfaces such as buildings and pavement. When those areas are covered with porous pavement, road runoff is less of a concern, said John St. Pierre of the Amherst, N.H., planning and zoning department.
"Porous pavement tends to collect storm water better, so there is less runoff going into rivers and streams," he said. "It's pretty exciting technology. It has a lot of potential; it just hasn't been used a lot."
It's been gaining support, though, say Colby and several civil engineers in the area. More than 1,000 feet of roads in the Boulder Hills senior housing project in Pelham, N.H., will be covered in porous pavement, and the new Circuit City shopping plaza in Amherst is also using the material, St. Pierre said.
Supporters say porous pavement isn't just good for the environment, it can also save money on storm-water control measures foisted on construction projects by regulatory agencies alarmed by pollution from road runoff, St. Pierre said. At Boulder Hills, the use of porous pavement enabled the developer to carve additional lots where storm-water detention basins were to be installed near sensitive wetlands.
"The detention ponds didn't do much for the pollutants in the storm-water runoff; porous pavement is much better for cleaning that up," said Sean Harrington, who got the site plan approvals for Boulder Hills before selling the subdivision to another developer, who is now building it. "And we got two more units on the site because we didn't have the detention ponds. Using porous pavement just made sense from every angle. There is a lot of science coming out saying that this is the way of the future."
But the decision to go with the porous pavement is not always straightforward. Because the pavement is porous, it is more brittle than conventional asphalt, so snowplow drivers have to be careful. The holes on the asphalt also tend to trap dirt, which must be cleaned out at least once a year using a vacuum or the pavement won't remain porous.
On smaller paving jobs, where extensive storm-water controls are not needed, porous pavement tends to cost about 20 to 25 percent more than standard asphalt. Porous pavement also only works on new projects; repaving impervious asphalt does not reap the benefits of the material's ability to absorb water.
On the plus side, ice does not build up as much on the surface of porous pavement, making for better traction, and 75 percent less salt is required for de-icing, according to its proponents.
That could be a key feature for southern New Hampshire communities along Interstate 93, which is slated for expansion. Road salt contamination levels in wetlands surrounding the proposed expansion route are in violation of the federal Clean Water Act, and the government is pressuring communities near the highway to reduce salt use on driveways, side streets, and parking lots.
"We remain very concerned about the salt issue," said Tom Irwin, an attorney with the New Hampshire Conservation Law Foundation, an environmental advocacy group that successfully sued the US Department of Transportation for revisions in the environmental assessment process involved in the I-93 expansion plan. "This is an issue that doesn't get a lot of attention, but it's one of the most significant issues facing our freshwater ecosystems, and that includes our drinking water supplies."
Irwin said porous pavement represents an important technology in reducing salt use.
But it is not a panacea for salt pollution, said Concord, N.H., civil engineer Steve Whitman, who heads up an I-93 road salt reduction work group assembled by the state from local public works officials and federal, state, and local environmental specialists.
"There is a big opportunity for porous pavement along the I-93 corridor; the question is how will its use unfold," Whitman said. "For existing paved surfaces, they'd have to go through major reconstruction to use porous pavement, and with so many parking lots already in place not every community is going to embrace porous pavement with the same enthusiasm."
That's not stopping Nobis from using porous pavement at its Lowell property. The whole building is being outfitted with environmentally friendly technologies because it's good for business and it's good for the environment, said Kenneth Koornneef, vice president of the design firm.
"We're trying to create a living lab for our clients so they can see products like porous pavement in a working environment," he said. "It's worth the investment."
By Tim Wacker
Globe Correspondent
SOURCE: www.boston.com
The parking lot at the new headquarters of Nobis Engineering Inc. is being installed with an environmentally friendly asphalt called porous pavement. By letting rainwater seep through to filtration beds, porous pavement is correcting a pollution problem called road runoff, which is of particular concern in the densely populated, heavily traveled Merrimack Valley.
"More and more every day, porous pavement is proving itself to be an environmentally sound method of putting down paving material," said Scott Colby, environmental and estates manager for Saugus-based Aggregate Industries Inc., the paving company doing the work for Nobis. "Using porous pavement, you can recharge ground water much better, and in the winter it doesn't freeze up like regular pavement does. The material works quite well."
The material is made by using larger-than-normal stones, called aggregate, in the asphalt mix. The aggregate creates holes in the pavement that allow water to pass through into an extra-deep bed of sand and stone that absorbs and filters the water in much the same way underlying soil in a field or forest does.
That's a crucial difference for many planners who often restrict development on open land based on how much of an area is covered by impervious surfaces such as buildings and pavement. When those areas are covered with porous pavement, road runoff is less of a concern, said John St. Pierre of the Amherst, N.H., planning and zoning department.
"Porous pavement tends to collect storm water better, so there is less runoff going into rivers and streams," he said. "It's pretty exciting technology. It has a lot of potential; it just hasn't been used a lot."
It's been gaining support, though, say Colby and several civil engineers in the area. More than 1,000 feet of roads in the Boulder Hills senior housing project in Pelham, N.H., will be covered in porous pavement, and the new Circuit City shopping plaza in Amherst is also using the material, St. Pierre said.
Supporters say porous pavement isn't just good for the environment, it can also save money on storm-water control measures foisted on construction projects by regulatory agencies alarmed by pollution from road runoff, St. Pierre said. At Boulder Hills, the use of porous pavement enabled the developer to carve additional lots where storm-water detention basins were to be installed near sensitive wetlands.
"The detention ponds didn't do much for the pollutants in the storm-water runoff; porous pavement is much better for cleaning that up," said Sean Harrington, who got the site plan approvals for Boulder Hills before selling the subdivision to another developer, who is now building it. "And we got two more units on the site because we didn't have the detention ponds. Using porous pavement just made sense from every angle. There is a lot of science coming out saying that this is the way of the future."
But the decision to go with the porous pavement is not always straightforward. Because the pavement is porous, it is more brittle than conventional asphalt, so snowplow drivers have to be careful. The holes on the asphalt also tend to trap dirt, which must be cleaned out at least once a year using a vacuum or the pavement won't remain porous.
On smaller paving jobs, where extensive storm-water controls are not needed, porous pavement tends to cost about 20 to 25 percent more than standard asphalt. Porous pavement also only works on new projects; repaving impervious asphalt does not reap the benefits of the material's ability to absorb water.
On the plus side, ice does not build up as much on the surface of porous pavement, making for better traction, and 75 percent less salt is required for de-icing, according to its proponents.
That could be a key feature for southern New Hampshire communities along Interstate 93, which is slated for expansion. Road salt contamination levels in wetlands surrounding the proposed expansion route are in violation of the federal Clean Water Act, and the government is pressuring communities near the highway to reduce salt use on driveways, side streets, and parking lots.
"We remain very concerned about the salt issue," said Tom Irwin, an attorney with the New Hampshire Conservation Law Foundation, an environmental advocacy group that successfully sued the US Department of Transportation for revisions in the environmental assessment process involved in the I-93 expansion plan. "This is an issue that doesn't get a lot of attention, but it's one of the most significant issues facing our freshwater ecosystems, and that includes our drinking water supplies."
Irwin said porous pavement represents an important technology in reducing salt use.
But it is not a panacea for salt pollution, said Concord, N.H., civil engineer Steve Whitman, who heads up an I-93 road salt reduction work group assembled by the state from local public works officials and federal, state, and local environmental specialists.
"There is a big opportunity for porous pavement along the I-93 corridor; the question is how will its use unfold," Whitman said. "For existing paved surfaces, they'd have to go through major reconstruction to use porous pavement, and with so many parking lots already in place not every community is going to embrace porous pavement with the same enthusiasm."
That's not stopping Nobis from using porous pavement at its Lowell property. The whole building is being outfitted with environmentally friendly technologies because it's good for business and it's good for the environment, said Kenneth Koornneef, vice president of the design firm.
"We're trying to create a living lab for our clients so they can see products like porous pavement in a working environment," he said. "It's worth the investment."
By Tim Wacker
Globe Correspondent
SOURCE: www.boston.com
No comments:
Post a Comment