Rain gardens, green roof
Dills Architects has also incorporated rain gardens into the design of the transportation facility. These gardens have a dual purpose: They improve the physical appeal of the site while providing a natural filtration system. The site includes two wet ponds and seven bioretention basins.
As oil and other contaminants enter the facility, they will be washed by storm water into these gardens, which have been purposely landscaped with plants that produce microbes that consume these contaminants.
“It’s called a zero storm water site or a net-zero site,” Dills says. “You treat everything that you do onsite. This is a big deal — there’s probably only a handful in our state.”
Water runoff from the roof is collected into three onsite cisterns that can hold up to 45,000 gallons of water in total. This water is then filtered and used for secondary water uses, such as in toilets, irrigation or the facility’s bus wash.
The cisterns are designed to support the facility’s secondary water needs for up to four months in a drought period. The district projects that it will save 1 million gallons of water per year through this method.
Water is also treated by the green roof on the facility’s maintenance building. A 6-inch layer of soil and plants on the roof treat storm water in the same way as the site’s rain gardens. In addition, the green roof reduces outside noise and actively lowers the interior noise levels to well below a typical office building. These rooftop gardens cover 19,000 square feet and will help to save the district approximately 225,000 gallons of water per year.
The onsite water treatment processes, according to Dills, have effectively reduced the ecological footprint of the facility to resemble that of the farmland that existed before it.
Site’s challenges, advantages
The Pupil Transportation Maintenance Facility is located on a piece of virgin farmland adjacent to the Oceana Naval Air Station, which presented several challenges during construction. The district sought military approval when choosing the site, since it is in the station’s flight path.
The district chose not to rebuild on the site of the current facility; instead, that site is being used as a staging area for the district’s vehicles.
“When you’re building a maintenance facility for 761 school buses, not everyone wants that in their back yard,” Pace says. “Particularly in Virginia Beach, there isn’t a lot of land that size that you could build [a facility] on that was well accepted. Therefore, we had to deal with the navy and the military to get approval to put it on this site. And that was quite a challenge — to the point that we did make some concessions.”
The concessions made by the district, Pace notes, were not big ones. First, fuel tanks could not be installed on the new site. The district continues to fuel vehicles on its old site, which Pace says is perfectly convenient and has helped to keep the new site environmentally friendly.
Also, Dills Architects was required to do extensive height modeling for the site’s wind turbines, which could have potentially interfered with planes leaving or arriving at the naval station.
“The wind turbines are at their height limit for airplanes,” Dills says. “They’re 60 feet — that’s to the blade tip.”
The turbines were the first in Virginia Beach, and “when you’re the first of anything, the city officials don’t really know how to handle what you want to do,” Dills notes. “There’s a generally lengthy and tedious process that comes with that as well. They had to create a zoning ordinance for us to be able to do it.”
Pace says the district’s determination to include wind turbines in the site plan sped up the city’s process. It wasn’t until the turbines had already been installed that an ordinance was created.
“We sort of motivated them because wind-generated electricity is the talk of even our governor, who wants to put windmills out in the Atlantic,” Pace says. “So it’s getting a lot of publicity here in Virginia. Virginia Beach is ahead of the curve.”
The facility’s construction has also been environmentally friendly. The buildings themselves were created using 35 percent pre- and post-consumer recycled content, and over 75 percent of the materials were acquired from within a 500-mile radius. Over 90 percent of construction waste was recycled instead of sent to a landfill.
The transportation facility’s new location has the added benefit of more space. The district’s transportation offices were previously housed in temporary, offsite modular buildings. With the opening of the new facility, transportation services administration staff will be located in an onsite building dedicated for that purpose. The site is also host to a maintenance building, which includes repair shops, offices, tire storage and a dedicated bus wash.
The site layout has been designed to provide maximum functionality. The maintenance building is equipped with a large double loading area and a mezzanine. Maintenance crew members can easily drive vehicles through the building’s double bays to the other side and then continue on to the tire storage or the bus wash. This creates a convenient traffic flow.
“You can’t put in words what this means to my staff, to my mechanics and my bus drivers,” Pace says of the new facility. “We’ve been in some really dilapidated kinds of spaces. Having this kind of facility — a state-of-the-art facility — coupled with the fact that we’re doing the right thing by investing in the environmental components of this building, it’s just a huge morale builder.”